1. Field of the Invention
This invention relates to the design, construction, and use of a device for acute and chronic measurement of intracranial pressures in the human central nervous system, particularly during magnetic resonance (MR) imaging procedures, in particular during the injection or infusion of therapeutic drugs into the brain parenchyma. The present invention is an improvement over conventional methods and apparatus for measuring intracranial pressure, such as ventriculostomy with an external transducer, epidural strain gauge transducer, pressure sensitive epidural capsule, pressure sensitive subdural capsule, or subarachnoid pressure transducer.
2. Background of the Prior Art
Elevated intracranial pressure (ICP) can result from a variety of pathophysiological disturbances and frequently presents a major problem in the management of patients with head injury or other neurological disorders and diseases, including brain tumors and intracerebral hemorrhage. Although numerous autoregulatory and compensatory mechanisms protect the brain against elevations in ICP, if the ICP is increased to levels approximately equal to or greater than those of the arterial blood pressure, cerebral blood flow can be severely compromised leading to brain herniation and death.
The primary aim of ICP monitoring is to provide an early warning of a deteriorating condition so as to enable corrective therapy to be implemented. The accuracy required when measuring ICP is typically of the order of 1-2 mm Hg, but equally important is the reliability of the data. To ensure reliability, the calibration of any measuring device must be easily checked and adjusted as necessary. In addition to the steady-state accuracy of any sensing device and recording system, it is essential to have adequate dynamic response characteristics in the measuring device.
It is also essential that measurements can be made with minimum interference to the patient. To satisfy this objective, non-invasive methods of determining changes in ICP indirectly have been attempted using, for example, impedance plethysmography. Such non-invasive methods have been used successfully in neonates. However, in adults, methods which give the most accurate measurements require access into the cranial cavity and are therefore more invasive.
Invasive ICP devices have generally evolved in two basic directions. The first is based on implanting a sensor within the cranium. The second is based on mounting the sensor externally and connecting the measurement site through a fluid-filled transmission line. The three main sites for ICP Ring are the lateral ventricle, the extradural space, and the subdural or subarachmoid spaces.
U.S. Pat. No. 4,014,319 to Favre discloses an intracranial pressure transducer comprising a small sealed capsule positioned in a trephined hole in the patient""s skull, wherein a sensor diaphragm in contact with the dura mater is displaced by changes in intracranial pressure and produces an output signal proportional to the change in intracranial pressure. U.S. Pat. No. 4,026,276 to Chubbuck discloses a pressure monitoring apparatus implantable in the cranium, wherein the apparatus comprises a passive resonant circuit with inductance and capacitance capability for measuring intracranial pressure by comparison to a reference ambient pressure.
U.S. Pat. No. 4,062,354 to Taylor et al. discloses an intracranial pressure transducer system comprising a holding bracket containing sensor elements which is positioned against the dura of the brain, wherein the elements within the holding bracket transmit electromagnetic signals related to the intracranial pressure to a receiver outside the patients body.
U.S. Pat. No. 4,080,653 to Barnes et al. discloses a method and apparatus for recording intracranial pressure utilizing a transducer amplifier.
U.S. Pat. No. 4,114,603 discloses an intracranial pressure monitoring device comprising a pressure-sensitive catheter insertable between the dura mater and arachnoid membrane. U.S. Pat. No. 4,114,606 discloses a monitoring apparatus for intracranial pressure measurement, wherein electromagnetic radiation is imposed on a passive circuit implanted in the cranium, the frequency at which the radiation is absorbed reflecting intracranial pressure.
U.S. Pat. No. 4,147,161 to Ikebe et al. discloses a system for measuring or monitoring intracranial pressure which comprises a non-elastic detecting pouch inserted between the skull and the brain, wherein a pressure measuring device in the liquid in the pouch indirectly measures the intracranial pressure.
U.S. Pat. No. 4,156,422 to Hildebrandt discloses an apparatus for treating hydrocephalus comprising housing which contains subcutaneously implantable components for measuring and controlling fluid pressure, wherein a second housing outside the patient contains measuring and control components whereby an intracerebral space may be automatically drained in response to a predetermined adjustable ICP.
U.S. Pat. No. 4,210,029 to Porter discloses a differential sensor unit utilizing fiber optic light guides, wherein three light guides pass within a pneumatic line into one end of a rigid cylindrical envelope implanted in the skull. Detectors are arranged to actuate pressure display and pneumatic controls to adjust the internal pressure of the envelope to match the ICP and thereby measure the ICP. U.S. Pat. No. 4,265,252 to Chubbuck discloses an implantable transsensor device containing a passive RF resonant circuit which is responsive to changes in ICP.
U.S. Pat. No. 4,385,636 to Cosman discloses an implantable telemetric differential pressure sensing device comprising a planar closed conductive loop which moves with a flexible diaphragm, wherein the resonant frequency of the conductive loop is detected telemetrically to determine pressure in a body compartment.
U.S. Pat. No. 4,343,038 to McKean discloses a magnetic field generator and magnetic pick-up coil contained in an implanted ICP monitoring device. U.S. Pat. No. 4,354,506 to Sakaguchi et al discloses an intracranial pressure gauge which comprises a powerless resonance circuit composed of a coil and a condenser, a sensor equipped with an implantable pressure-sensitive section capable of changing the inductance or the capacitance of the condenser in response to a change in ICP. U.S. Pat. No. 4,438,773 to Letterio discloses an implantable subarachnoid bolt for use in measuring ICP. U.S. Pat. No. 4,465,075 to Swartz discloses an integrated circuit including a pressure transducer and temperature compensation circuit.
U.S. Pat. No. 4,471,786 to Inagaki discloses a telemetering intracranial pressure transducer for detecting ICP, wherein a pressure-receiving layer disposed in contact with the dura mater transmits an output signal to an telemetering transmission circuit housed entirely beneath the patients scalp.
U.S. Pat. No. 4,600,013 to Landy et al. discloses a probe for ICP measurements in the subarachnoid space, said probe comprising a threaded shaft having a lumen in contact with a pressure transducer.
U.S. Pat. No. 4,621,647 to Loveland discloses an apparatus for monitoring and regulating ICP, wherein a manometer, transducer and regulator are interconnected by tubing and stopcocks. U.S. Pat. No. 4,627,443 to Chubbuck discloses an X-ray readable implantable pressure sensor,,wherein shifting of the radiopaque means is observed to indicate the change in pressure of a body cavity.
U.S. Pat. No. 4,677,985 to Bro et al. discloses an intracranial probe to monitor both ICP and blood flow by thermal diffusion and hydrogen clearance techniques.
U.S. Pat. No. 4,703,757 to Cohen discloses an optical fiber pressure transducer, wherein variations in transversely applied pressure to an elongated flexible fiber results in proportional light refraction and corresponding output signal.
U.S. Pat. No. 4,711,246 to Alderson discloses a miniaturized pressure transducer, wherein light transmitted through a single optical fiber is reflected by a diaphragm in accordance with the pressure being measured.
U.S. Pat. No. 4,723,556 to Sussman discloses an intracranial ventricular catheter assembly, wherein a pressure sensing device is connected to the proximal catheter. U.S. Pat. No. 4,738,267 to Lazorthes discloses an implantable intracranial pressure sensor, wherein a pressure-sensitive diaphragm placed directly on the dura mater transmits the intracranial pressure through a resistive type transducer. U.S. Pat. No. 4,772,257 to Hakim et al. discloses an external programmer for magnetically-adjustable cerebrospinal fluid shunt valve.
U.S. Pat. No. 4,858,619 to Toth discloses an intracranial pressure monitoring system, wherein relief valves are combined with a pressure sensor for automatic venting of cerebrospinal fluid during elevated ICP.
U.S. Pat. No. 4,805,634 to Ullrich discloses an adapter assembly for accurately positioning a removable biosensor implanted in the cranium.
U.S. Pat. No. 4,841,986 to Marchbanks discloses a method and apparatus for measuring ICP, wherein a pressure sensor placed against the eardrum indirectly detects ICP changes based on displacement of the eardrum.
U.S. Pat. No. 4,903,707 to Knute et al. discloses a ventricular catheter assembly comprising a catheter and a bolt, wherein the catheter can be inserted to a predetermined depth into the cranium. U.S. Pat. No. 4,995,401 to Bunegin et al. discloses a device for measuring anterior fontanelle pressure, wherein ICP changes can be detected noninvasively.
U.S. Pat. No. 5,000,049 to Cooper et al. discloses an apparatus for measuring fluid pressures using a catheter device.
U.S. Pat. No. 5,005,584 to Little discloses a fiber optic transducer utilizing a flexible membrane to transduce pressure by interrupting light transmission between fiber optic paths in a catheter or guide wire carrier.
U.S. Pat. Nos. 5,074,310 and 5,117,835 to Mick disclose a method and apparatus for in non-invasively measuring changes in ICP , wherein a predetermined vibration signal is applied to one location in the skull and an output vibration signal is detected from another location in the skull reflecting ICP changes over time.
U.S. Pat. No. 5,108,364 to Takezawa et al. discloses a monitoring catheter for medical use comprised of multiple tubes equipped for fluid delivery and removal, pressure measurement, and temperature measurement. U.S. Pat. No. 5,113,868 to Wise at al. discloses a pressure sensing catheter system comprising a catheter, a pressure sensor, and a signal conduit means within the catheter for signals between an external monitor and the pressure sensor, the signal conduit including two electrical conductors which are connectable to the external monitor.
U.S. Pat. No. 5,191,898 to Millar discloses a cerebroventricular catheter means of measuring ICP and injecting or withdrawing cerebrospinal fluid, wherein a transducer positioned at the end of the cerebroventricular catheter and electrically coupled to a monitor allows for ICP monitoring.
U.S. Pat. No. 5,292,899 to Watanabe et al. discloses a method for measuring ICP by using a device comprising a reservoir implantable under the skin of a patient and into which reservoir cerebrospinal fluid can be introduced from the ventricle of the patient, a flexible dome configured to be upwardly projected from said reservoir by the pressure of the cerebrospinal fluid and flexibly deformable according to an external force, a pressing part for pressing against said dome through the skin, a pressing-part-driving means for driving said pressing part pressing the dome and a flexible membrane provided at the tip of the pressing part and having an interior filled with a fluid, the method comprising: pressing the flexible membrane of the pressing part against the dome of the reservoir through the skin by means of the pressing-part-driving means after a zero point correction of the pressure transducer is performed by communicating the interior of the flexible membrane with the atmosphere.
U.S. Pat. No. 5,325,865 to Beckman et al. discloses a catheter assembly for measuring fluid pressure in a body cavity, comprising an optical converter responsive to an electrical power source for energizing a light-emitting diode which has drift characteristics which vary in response to temperature, and a detection circuit. U.S. Pat. No. 5,230,338 to Allen et al. discloses an interactive image-guided system for displaying images corresponding to the placement of a surgical probe in the body. U.S. Pat. No. 4,173,228 to Van Steenwyk et al, and U.S. Pat. No. 5,042,486 to Pfeiler et al. disclose medical probes wherein electromagnetic signals are propagated between one antenna on the tip of the probe inserted into a body region and several antennae outside the body. The position and orientation of the probe tip are determined from the signals transmitted between said antennae.
U.S. Pat. No. 5,211,165 to Dumoulin et al., U.S. Pat. No. 5,255,680 to Darrow and Dumoulin, U.S. Pat. No. 5,307,808 to Dumoulin et al., and U.S. Pat. No. 5,318,025 to Dumoulin et al. additionally disclose a tracking system in which radiofrequency signals emitted by an invasive device, such as a catheter, are detected and used to measure the device""s position and orientation in a patient. Localization of devices in situ is achieved by transmit radiofrequency coils positioned at its distal end, which are detected by receive radiofrequency coils positioned around the imaging volume of interest. The position of the device, as determined by the tracking system, is superimposed upon independently acquired diagnostic images. U.S. Pat. No. 5,383,454 to Bucholz discloses a system for indicating a position of a tip of a probe which is positioned within an object on images of the object, wherein a computer employing translational software translate the position of the tip of said probe into a coordinate system corresponding to the coordinate system of the cross-sectional images.
Each of the above cited patents provide advantages and disadvantages for ICP monitoring. For instance, intraventricular catheters are accurate but may be difficult to position in the presence of brain swelling and shifting of tissue. Subarachnoid devices are easily placed, but may underestimate higher ICP pressures, particularly if they are not coplanar to the brain surface. Epidural devices require placement through a burr hole and can be hampered by recording artifacts, dampening, and problems with calibration.
Moreover, none of the above cited patents disclose a method or apparatus for evaluating changes in ICP resulting from the direct injection or infusion of drug agents into brain tissues. One of the significant problems with direct drug delivery to living tissue is assuring that the drug is accurately distributed to target receptor locations. The efficacious delivery of therapeutic agents for the treatment of brain tumors or neurodegenerative diseases, as two examples, requires that the agents be delivered as close to their receptors in the brain as possible, while minimizing increases in intracranial pressure during and after drug delivery. Liquid drug agents delivered into the brain through implanted catheters will disperse from the site of injection at variable rates depending on a number of factors, including the physicochemical characteristics of the drug, capillary uptake, metabolic degradation and excretion of the drug, size of the extracellular space (the volume fraction), and geometry of the brain cell microenvironment (tortuosity). The degree to which each of these factors influences the distribution of a particular drug agent may be an important determinant of the effectiveness of drug treatment of diseases of the central nervous system.
Ideally, drug material injected into the brain infiltrates the extracellular space, and the subsequent tissue distribution of the drug is governed mainly by its molecular weight, molecular radius, and the tissue matrix structure into which the material has been injected. However, injection of a solution containing a macromolecular drug agent into the intraparenchymal extracellular space of the brain may instead result in the injected drug being sequestered as a cavity or depot. If the injected drug solution forms a fluid-filled cavity in the tissue, this may lead to tissue selling, an increase in ICP and, secondarily, altered interstitial transport of the drug solute.
It is therefore apparent that increases in ICP induced by intraparenchymal injections of liquid drug agents can injure tissues directly, or indirectly by retarding the efficacious distribution of the drug due to tissue swelling and retarded interstitial solute transport. Thus, it is important to be able to monitor any local and regional increases in ICP resulting from injections of liquid drug agents directly into the brain parenchyma. The availability of an MR-visible drug delivery device which incorporates a method means for monitoring local and regional changes in ICP would make it possible to obtain near real-time information on tissue pressure changes during interventional procedures in an intra-operative MR system.
The present invention discloses a device and method for monitoring intracranial pressure (ICP) during MR image-guided neurosurgical procedures, wherein an MR-compatible microsensor pressure transducer coupled to a pressure sensing diaphragm is positioned or located on the surface of an interventional device, such as at or near either a) a distal tip of the device and b) lateral surfaces of an MR-compatible device such as an MR-compatible multi-lumen drug delivery catheter. One or preferably more than one sensing element may be present on the interventional device. The microsensor and diaphragm detect and monitor local and regional changes in ICP during and after delivery (especially immediately after delivery while changes in local concentration of the injectant or drug agents can be observed) of liquid drug agents into the brain parenchyma. In at least one method within the scope of the invention, the pressure sensor includes a pressure transducer for converting a sensed pressure into a first electrical signal which is detectable by an external monitor transmission after transmission over a signal conduit means. There may be a first switching device for selectively controlling when the first electrical signal is generated, and a device that is responsive to at least one command signal from the external monitor for controlling the delivery of drug solution in response to detected alterations in ICP. In a practice of the present invention, the ICP monitoring device may also be inserted into any convenient location such as a lateral cerebral ventricle, cerebral cistern, subarachnoid space, subdural or extradural space, or venous sinus, under MR imaging guidance, and used to record intracranial pressures over seconds, minutes, hours to days in patients undergoing diagnostic or therapeutic neurologic interventions. Continuous monitoring of the ICP in real time may also be effected in this invention.
The invention also relates to an apparatus for the determination or monitoring of intracranial pressure comprising:
an article that is insertable into the tissue or vasculature of the brain,
said article comprising a pressure sensing element, a signal transmitting connector connecting the pressure sensing element and a signal reader (meaning artificial intelligence or artificial memory such as a reader, recorder or analyzer), the signal reader being able to (read, record, or analyze) signals from said pressure sensing element to indicate hydrostatic pressure or changes in hydrostatic pressure. The pressure sensing element may, for example, comprise a solid state pressure sensing element, a curved semiconductor element, or a physical sensor, alone or combined with electronic or electrical elements, such as a diaphragm (e.g., a diaphram or flexible, compressible, deflatable, inflatable or pressure moveable layer or element that has one surface that is exposed to an environment in which the pressure sensing element is placed, such as within the fluid or tissue fluid of a patient), as where a second surface of the diaphragm defines part of an internal cavity within the pressure sensing element, and movement of said diaphragm causes changes in pressure within the internal cavity. A pressure reading device may then be present within said internal cavity and the pressure sensing element is attached to the connector by electrical attachment of the pressure reading device to the connector. The pressure-sensing device may be connected to or independent of a device for the delivery of chemical agents into the bodily fluid, and particularly into the bodily fluids of the brain. Certain semiconductor elements are known to be pressure-sensitive, and therefore semiconductor elements may be positioned on the interventional device at the tip and/or at multiple locations on the lateral surface of the interventional device and be electrically connected to an outside source to interpret the signals.
At least one method according to the present invention for sensing the intracranial pressure within a patient comprises inserting the above described apparatus into the brain of a patient, visualizing the tissue around the apparatus and visualizing the apparatus itself by magnetic resonance imaging particularly in effect by continuous or real time visualization with MRI or fluoroscopy, less preferred), and positioning the apparatus within the device under magnetic resonance imaging, and reading signals from said pressure sensing element to indicate hydrostatic pressure or changes in hydrostatic pressure within the brain during or shortly after delivery of chemical agents into the fluids and/or tissue of the brain. Upon reading changes in hydrostatic pressure of the brain that exceeds a predetermined amount, an indication of the exceeding of that predetermined amount may be provided to an operator of the apparatus, as by an alarm, special image on a video screen, or by an automatic function change directed by memory (computer) associated with the system. For example, the apparatus may also comprise at least one lumen for delivery of chemicals to the patient, and chemicals are delivered to the patient through the at least one lumen, and upon reading changes in hydrostatic pressure of the brain that exceeds a predetermined amount during delivery of chemicals to the patient from the lumen, an indication of the exceeding of that predetermined amount is provided to an operator of the apparatus. This can be effected upon the indication of the exceeding of that predetermined amount by an artificial memory, that artificial memory then signaling the apparatus to reduce the amount of chemical being delivered to the patient.
One aspect of this invention is to provide a device and method for acute measurement of ICP in the human central nervous system during magnetic resonance (MR) imaging procedures, particularly those involving direct injection or perfusion of drugs into the brain parenchyma, with the measurement and sensing being performed during those stages of the drug delivery where pressure changes may occur.
A second aspect of this invention is to provide a device and method for controlling the delivery of drug solution in response to detected alterations in ICP during magnetic resonance (MR) imaging procedures, particularly those involving direct injection of drugs into the brain parenchyma. This can be particulartly accomplished by the use of at least two pressure sensing elements, one distal and one proximal to the point of insertion of the interventional device. By having separated pressure sensing devices, a pressure gradient may be measured and/or the direction of flow and variations in flow from the point of introduction can be determined.
A third aspect of this invention is to provide a device as an alternative method for the detection and measurement of intracranial pressure, replacing devices and methods such as conventional ventriculostomy with an external transducer, an epidural strain gauge transducer, a pressure sensitive epidural capsule, a pressure sensitive subdural capsule, or a subarachnoid pressure transducer.
A fourth aspect of this invention is to provide a device and method to record intracranial pressures over extended time periods such as hours or days in patients that have been subjected to compression or shift of the cerebral ventricles resulting from severe head injury, tumor, or other causes of acute or chronic intracranial hypertension.
A fifth aspect of the invention is to provide a device and method to accurately record ICP in the lateral ventricle, epidural, subdural, and subarachmoid spaces in patients in whom these fluid-filled cavities have been compressed by trauma or medical condition, including tumors or hematoma, or may have thick or mobile walls or small volumes that cannot be reliably penetrated with standard ventricular catheters when they are attempted to be positioned under stereotaxic guidance.
A sixth aspect of this invention is to provide a device and method for safely measuring ICP with minimal risk of infection caused by meningitis or ventriculitis, minimal risk of intracranial hemorrhage from opening the dura or puncturing the ventricle, and minimal interference to the patient.
A seventh aspect of this invention is to provide a device and method for MR image-guided therapeutic drainage of cerebrospinal fluid to relieve acute rises in ICP.
An eighth aspect of this invention is to provide a device and method for injection of a small volume of MR-visible gas for MR-ventriculography while monitoring ICP.
A ninth aspect of this invention is to provide a device and method for a hydrocephalus pressure valve and self-sealing port for regulating the flow of cerebrospinal fluid through the catheter after placement of the catheter tip into the ventricle, subarachnoid, subdural, or epidural space under MR imaging guidance.
A tenth aspect of the present invention is to provide a device substantially made of MR-visible elastomeric hydrogel, polymer, thermoplastic, or similar low friction material to minimize abrasive damage to the brain during insertion.


Generally, an iron and steel plant produces slabs according to the customer requirements on steel products, such as specification, steel grade, chemical composition, hardness and so on. During the steel production process, first of all, a production schedule is made for steelmaking and continuous casting according to the production order. After slabs are produced, they are subjected to further treatments such as hot-rolling, cold-rolling and so on according to the customer requirements on the products. Finally, finished products are produced to be delivered to the customers. However, the following several reasons cause a low slab utilization, leading to a lot of irrational slab-order matching relationships: 1) In the current iron and steel market, orders tend to require a large variety and a small volume production, which is contradictory to batch production mode of iron and steel industry, for example, a converter or an electric furnace can handle 300 or 250 tons of molten steel in a batch, such that the amount of slabs in accordance with the order may be more than that required by the order; 2) when allocating the open-order slabs to orders, the matching relationship between the open-order slabs and the orders may be sub-optimal due to lack of working experiences and complete information; 3) the generation of unqualified products in post operations may cause that the amount of the products remaining for the order, to which the unqualified products belong, is less than that required by the order. Then, some more slabs need to be allocated to this order.
In prior literatures, most of the domestic and foreign studies on the slab matching problem aim at open-order slabs, which is about the matching of the surplus inventory, while the present invention tries to re-optimize the matching relationship in consideration of the original slab-order matching relationship and the load balance of all equipment units, so as to improve the slab-order matching relationship, decrease the slab cutting loss, reduce the redundant slabs weight of each order, and improve the integrity of an order, thus improving slab utilization, ensuring to deliver an urgent order on time, and improving the customer satisfaction.


U.S. Pat. No. 4,155,441 to Albrecht et al. discloses a conveyor system for separating columns of articles into spaced groups, each group containing a predetermined number of articles. The columns of articles are fed onto a conveyor having an extendable noser arrangement at the output end that is positioned over the input end of a second conveyor. The noser arrangement is extended to prevent the flow of articles from the first conveyor to the second, faster conveyor, thereby providing a space on the second conveyor between successive groups or articles. During extension of the noser arrangement, no articles are transferred since the noser arrangement extends the conveyor at the same rate that the articles are carried toward the end of the conveyor. A photoelectric device counts the articles as they are transferred and actuates the noser extending mechanism. U.S. Pat. No. 4,155,441 does not disclose changes in the noser arrangement due to the detection of an unevenly spaced article. In addition, this patent does not disclose continuous correcting of unevenly spaced articles during transfer to a second conveyor belt.
Devices for shingling articles are known. For example, FIG. 1A shows a side view of a typical shingle stacking conveyor arrangement. The speed of the first belt (V1) is faster than the speed of the second belt (V2). This causes the articles on the second belt to be spaced closer together and to overlap or shingle. FIG. 1A shows an article that is ahead of where it would be if it were evenly spaced, causing it to arrive early at the second conveyor. FIG. 1B shows an article that is behind the position it would occupy if it were evenly spaced, causing it to arrive late at the second conveyor.
The effect of uneven article spacing on the first conveyor is to cause an uneven article spacing on the second conveyor, which results in an uneven shingle pattern (i.e., the articles are shingled at different angles). If the product arrives sufficiently ahead or behind of an evenly-spaced position, then the shingle pattern can be lost altogether, resulting in articles being piled on top of each other in a random manner, as shown in FIG. 1C.
Randomly spaced or randomly stacked products is not just a matter of aesthetics. Unevenly distributed product does not go through conveyor systems to wrapping systems well. Any disruption in the pattern of products only gets worse as it makes its way to wrapping. Loss of product overlap, buckled product, and product jams all occur with regularity. When the disordered product arrives at the wrappers, it is prone to jam in chutes, feed mechanisms, infeed track, and the like. As a result, serious product breakage and wrapper downtime occurs. The present invention provides an apparatus that can take a single row of unevenly spaced articles on a first conveyor and ensures that the articles are more evenly spaced or more evenly stacked on a second conveyor.


The present invention relates to electrostatic filters in general, and more particularly to improvements in so-called high tension (ionic bombardment) filters. Still more particularly, the invention relates to improvements in a method and apparatus for automatically regulating the operation of high tension filters by regulating the potential which is applied to such filters.
In presently known high tension filters, the potential which is applied thereto is increased to reach the breakdown value and is thereupon reduced to a variable extent and for a variable interval of time to a value below the preceding breakdown value. Such operation is followed by a renewed increase of potential to the breakdown value. This is deemed to be advisable and advantageous because the electrical filter output can be regulated in a more satisfactory way to follow the varying breakdown resistance of the gaseous carrier medium for solid impurities which require segregation from the carrier medium.
The operating potential of a high tension filter is invariably limited by spark discharge between the corona discharge electrode and the collecting electrode of the filter. As a rule, the filter potential is selected in such a way that some arcing in the filter will take place because the rate of separation (i.e., the separation efficiency) is then at a maximum value. On the other hand, the frequency of arcing should not be too high.
The aforediscussed prior filtering methods and apparatus exhibit the drawback that each arcing leads to a total collapse of the electric field and, by using modern operational switches (thyristors), each arcing is followed by a complete shutdown of the supply of potential for a period of a few half waves in order to avoid the initiation of an immediately ensuing follow-up arcing. This entails the development of breakdown times during which the charging does not take place in an optimum way and to an interruption of field forces which are required for separation.


1. Field of the Invention
The present invention relates to a fluid control system, and in particular to a fluid flow control valve. In one application, the fluid flow control valve can check the free flow of water from a broken or damaged riser of an overhead irrigation system.
2. Description of Related Art
Overhead irrigation systems often incorporate water spray devices (e.g., sprinkler heads) mounted on risers. A riser supports a sprinkler some distance above the ground, e.g., one to three feet high. At this elevated position, the sprinkler has an enlarged spray pattern and irrigates a larger area than if the sprinkler were positioned closer to the ground. Riser mounted sprinklers also accommodate crops of varying heights.
Risers are pipes or conduits, typically made of plastic such as polyvinylchloride ("PVC"), copper or galvanized steel. In many irrigation systems, the riser extends upward from a fitting of the irrigation system, such as from a "T" or an elbow juncture, located under ground. In such an arrangement, water flows from a subterranean irrigation pipe through the riser to the sprinkler.
While the use of a riser-mounted sprinkler head enlarges the area irrigated by the sprinkler, the riser is susceptible to mechanical damage because it extends above ground in an exposed position. No external structure typically braces or buttresses the riser. Plastic or metal risers are thus easily broken (e.g., severed) or otherwise damaged (e.g., theft, vandalism, etc.), resulting most often in an open, free-flowing outlet.
When a riser is broken or the sprinkler is removed, water cannot be properly distributed through the sprinkler head. The rate of water flow increases without the restricting back pressure provided by the sprinkler, such that a large stream of water projects above the broken riser. The resulting water geyser impacts against a relatively small ground surface. Serious flooding and erosion consequently results in a small area, while the remainder of the area normally irrigated by the sprinkler goes unwatered. A significant amount of water is wasted as the result of the unrestricted flow through the broken riser, and substantial soil erosion can occur.
In addition, the water fountain gushing from the broken riser also can pose a serious highway problem if the water sprays onto highway lanes, or if the resulting water and soil run-off flows onto the highway. Numerous automobile accidents occur each year due to broken irrigation system risers.
While valves exist in the prior art for control of fluid flow in general, many such valves are inappropriate for restricting the flow of irrigation water through broken risers. Additionally, high volume farm irrigation systems introduce special needs for flow control. Prior valves are overly complicated and expensive for application to farm irrigation systems, which utilize hundreds of riser-mounted sprinklers. Some devices which have been implemented for stanching the unrestricted flow of irrigation water have proven unreliable, often failing to stop or even slow the rate of water flow when a riser breaks or other failure occurs. Other prior devices are too sensitive, shutting down water flow to undamaged risers.
In addition, when prior devices do function to stop the flow of water through a broken riser, the broken sprinkler often remains undetected for days, leaving the area surrounding the broken sprinkler unwatered. This danger is especially true of farm irrigation, where a single broken riser in a large field with many sprinklers could easily escape notice for many days, damaging crops in the vicinity.
Further deficiencies in prior devices include an inability of these devices to cope with transient flow conditions. For instance, the prior devices may prematurely shut off the valve in response to the combination of air and water in the system that often occurs when the system is first turned on. In addition, prior devices often include improperly restrained components which vibrate and wear under normal flow conditions.
Prior devices also have close fitting parts which are subject to corrosion. As a result, the small space between the parts cannot be maintained as corrosion, scale, debris, etc., often fill the space between the closely fit parts, and the device is likely to malfunction. For example, in a prior valve, a disc or poppet is shaped and sized to have a close fit with the valve seat in order to arrest fluid flow under abnormal flow conditions. Upon corrosion, however, the disc or poppet will not properly seal the valve seat, thereby allowing fluid flow within the valve. Under some conditions, such corrosion, scale formation, or like collected debris will prevent the valve disc or poppet from moving at all.
A need therefore exists for a simple, inexpensive yet reliable irrigation control valve which allows water to flow to an operational sprinkler, but restricts the water flow through a broken riser. Ideally, such a valve should allow detection of the broken riser, even when the flow is essentially shut off.


1. Field of Invention
This invention relates to golf and more specifically, to three-dimensional (3-D) mapping, photogrammetry, and light detection and ranging (LIDAR) techniques used to produce the software and data required for implementation into a series of golf course navigation software and physical hardware devices that use satellite navigation and geospatial database systems for assisting golf players, fans, and viewers in course navigation, visualization, management, and administration.
2. Description of Related Art
Golf is a game of accuracy, precision and distance. Without an expert caddie along, there's a lot of analysis and sometimes guesswork involved in determining shot distance to the hole, and various course targets such as greens or landing areas with water hazards in play. A golfer's club selection directly depends on the perceived distance of the desired shot.
Global Navigation Satellite Systems (GNSS) is a standard generic term for satellite navigation systems that provide autonomous geo-spatial positioning with global coverage. GNSS allows small electronic receivers to determine their location (longitude, latitude, and altitude) to within several meters using time signals transmitted along a line-of-sight by radio from satellites. Receivers calculate the precise time as well as position, which can be used as a reference for distance measurements. Within the United States, the NAVSTAR global positioning system (GPS) is the only fully operational GNSS. GPS is currently the world's most utilized satellite navigation system. GPS technology has made its way into devices designed to be used as a navigation aid by a player on a golf course. The primary goal of a golf course navigation system is to provide players with distances to all kind of features on the course and especially to the green they are targeting. Beyond basic distance-to-the-hole data, many standard, golf GPS devices tell you the length of your last shot; distance to, and location of targets and hazards; and distance to the front, middle, and back of the green.
Conventional golf GPS devices suffer from a number of drawbacks. First, the geospatial data used (satellite imagery and differential GPS collection systems) in the production in commercially available golf GPS devices, such as those produced by GPS Industries, Sky Golf's Sky Caddie, and Callaway's uPro is very low resolution and is no better than five (5) to thirty (30) yards or meters. This degree of error is critical as a player's full shot distance typically varies by 10 yards or more for each golf club. For example, a player may hit an 8-iron 150 yards and a 7-iron 160 yards. If the golf GPS device indicates that the remaining distance to a pin is 150 yards when it is really 160 yards, then a player hitting an 8-iron instead of a 7-iron will come up well short—an unnecessary error that may result in the player's ball coming to rest in a hazard rather than on the green. This type of inherent error is not well suited for a game considered by many to be a game of inches.
The accuracy of conventional GPS devices is further complicated as some courses are better fit to use the capabilities of GPS than others. For example, in order to obtain a location reading, the GPS receiver must have a non-obstructed view of the sky. Accordingly, courses with lots of trees and other types of natural obstructions are less suitable for golf GPS devices. Objects such a mountains or buildings between the satellite and the receiver can produce significant error, sometimes up to 30 meters.
The graphics displayed on conventional GPS devices are rudimentary at best. Some devices are very basic as they merely display distance data without illustrating respective hole layout, e.g., a superimposed graphic displaying the overall geometry of the fairway, green, and related hazards. Other devices may show a hole's layout, but only through an artist's rendering in two-dimensions using computer generated imagery (CGI). These CGI renderings are then referenced geospatially with latitude and longitude values. For example, the artist will attribute the CGI created bunker with a lat/long value. When this data is loaded to a device with a GPS receiver, the GPS receiver will try to record a true location relating it to the pre-rendered imagery. Recently, airborne imagery of an “oblique” hole layout has been implemented in a golf GPS device provided by Callaway. However, this oblique imagery and perspective view was acquired by Pictometry's Oblique camera system and is not considered a mapping or calibrated camera system usable for mapping or civil engineering. Moreover, all of the images used in these systems are acquired using non-stereo specifications and are considered only two-dimensional in nature, i.e., the hole layout is only displayed as a flat two-dimensional image. No stereo compiled topographic or 3-D terrain data (x,y,z) are provided with respect to changes in topographic elevation, height, and related information such as slope. For a game that depends on where and the way a golf ball lands and bounces, conventional golf GPS systems are woefully inadequate. For example, any device that does not calculate the change in hypotenuse or change in elevation (topography) between point A and point B, is programmatically assuming that a golf course is flat and that a constant horizontal grid of X and Y values are sufficient. In fact, this is not the case as golf courses are not flat and a “true” golf course navigation device must calculate for the change in hypotenuse or change in elevation, topography or slope with respect to a calculated distance between point A and point B.


This invention relates broadly to the chemical modification of wool by reacting it simultaneously with a halogenated acid anhydride and an isocyanate. In particular, the invention concerns and has as its prime object the provision of processes wherein the reaction of wool with the above reagents is conducted in the presence of cresol, whereby to facilitate and promote the reaction. The unqualified term "cresol" used herein includes o-cresol, m-cresol, p-cresol, or any mixture of these isomers. Further objects and advantages of the invention will be apparent from the following description wherein parts and percentages are by weight, unless otherwise specified.
Although wool is a very useful fiber, it is often desirable to improve its properties for particular applications by chemically modifying it. Previously, wool has been shrinkproofed with isocyanates, but the product is not flameproof. Furthermore, wool has been flameproofed with halogenated acid anhydrides, but the product does not meet consumer requirements for shrinkproofing.
Wool which is both shrinkproof and flameproof has also been prepared. However, a two-step process is required-- the wool is first shrinkproofed and then flameproofed. The two-step process has the disadvantage of being less efficient and economical than a one-step process.


In the field of magnetic recording using a head and a medium, further performance improvement of thin film magnetic heads and magnetic recording media is in demand in association with the high recording density of magnetic disc devices. As a thin film magnetic head, at present, a composite type thin film magnetic head made of a structure where a magnetoresistant (MR) element for reading and an electromagnetic transducer element for writing are laminated is widely used.
The magnetic recording medium is a discontinuous medium in which magnetic grains are aggregated, and each magnetic grain has a single magnetic domain structure. In the magnetic recording medium, one recording bit is configured by a plurality of magnetic grains. Consequently, in order to enhance the recording density, asperities at the border between adjacent recording bits need to be reduced by decreasing the size of the magnetic grains. However, if the magnetic grains are reduced in size, there is the problem that the thermal stability of magnetization of the magnetic grains is reduced in association with a decrease in the volume of the magnetic grain.
As a countermeasure against this problem, an increase of magneto anisotropy energy Ku of magnetic grains may be considered; however, the increase of Ku results in an increase in an anisotropy field (coercive force) of a magnetic recording medium. On the other hand, the upper limit of the recording magnetic field intensity of the thin film magnetic head is substantially determined by saturation magnetic flux density of a soft magnetic material configuring a magnetic core within the head. Consequently, if the anisotropy field of the magnetic recording medium exceeds the acceptable value determined by the upper limit of the recording magnetic field intensity, it becomes impossible to write to the magnetic recording medium. Currently, as a method to solve such a thermal stability problem, a so-called thermally assisted magnetic recording method is proposed in which a recording magnetic field is applied to record information under a state where the anisotropy field is reduced by heating the magnetic recording medium while a magnetic recording medium made from a magnetic material with large Ku is used.
In this thermally assisted magnetic recording method, a method using a near-field light probe, or so-called plasmon-generator, comprising a metal piece that generates NF light from plasmon excited by laser light is generally known, and as a magnetic head including such a plasmon-generator, a magnetic head including a magnetic pole, a waveguide and a plasmon-generator facing the waveguide is proposed.
In a thermally-assisted magnetic recording head, light propagated through the waveguide is coupled with a plasmon-generator in a surface plasmon mode, and excites the surface plasmon. Propagation of such surface plasmon in the plasmon-generator causes the generation of near-field light at the near-field light generating portion positioned at the end portion of the plasmon-generator at the medium opposed surface side. Then, a magnetic recording medium is heated by irradiating the magnetic recording medium with the near-field light generated at the near-field light generating portion of the plasmon-generator, and information is recorded by applying a magnetic field under a state where the anisotropy field of the magnetic recording field is decreased.
In a thermally-assisted magnetic disk device including such a thermally-assisted magnetic recording head, the distance between the thermally-assisted magnetic recording head and the magnetic recording medium, i.e., the flying height of the thermally-assisted magnetic recording head relative to the magnetic recording medium, is an important parameter to satisfy demands, such as reduction of the bit error rate (BER) or high recording density.
Recently, in order to respond to demands, such as high recording density, a technology is proposed in which a medium opposed surface of the thermally-assisted magnetic recording head toward the magnetic recording medium side is protruded by heat-expanding the surface due to the heat generation of a heater and the like, and the flying height of the thermally-assisted magnetic recording head relative to the magnetic recording medium is reduced (see for example, JP 2010-79978). In the patent literature (JP 2010-79978), it is disclosed that the protrusion amount of the medium opposed surface is controlled by controlling the power supply to the heater, and the optimum flying height (the target flying height) can be realized. However, in a thermally-assisted magnetic disk device, in addition to the protrusion of the medium opposed surface due to supply of power to the heater and the application of writing current, since the medium opposed surface also protrudes due to the generation of near-field light, it is actually difficult to reduce the target flying height to approximately several nm (approximately 2 nm).
In the technology disclosed in the patent literature, the supply of power to the heater that can accomplish the target flying height can be set by a touch down test of the thermally-assisted magnetic recording head. In other words, the medium opposed surface gradually protrudes while the supply of power to the heater is increased, contact (touch down) between the thermally-assisted magnetic recording head and the magnetic recording medium is detected, and the supply of power to the heater that can accomplish the target flying height is determined.
In the meantime, in a thermally-assisted magnetic recording head, when a signal is recorded, the near-field light generated at the plasmon-generator is irradiated to the magnetic recording medium. In association with the generation of the near-field light, the vicinity of the medium opposed surface of the thermally-assisted magnetic recording head is heated, and the medium opposed surface protrudes toward the magnetic recording medium side. Therefore, taking into consideration the protrusion of the medium opposed surface of the thermally-assisted magnetic recording head due to the near-field light, it is necessary to set a supply of power to the heater that can accomplish the target flying height.


Microarray technology has been widely used for genomics and proteomics research as well as for drug screening. Currently, the spot size in most microarrays is larger than one micron. The use of nanometric biomolecular arrays, with smaller spot sizes, will enable high-throughput screening of biomolecules—eventually at the single molecule level. Also, nanometric arrays permitting precise control over the position and orientation of individual molecules will become a powerful tool for studying multi-valent and/or multi-component molecular interactions in biological systems. Toward these ends, protein arrays with feature sizes smaller than 100 nm have been fabricated, mostly using dip-pen nanolithography and nanografting. See Lee et al., Science 2002, vol. 295, p. 1702; Wilson et al., Proc. Natl. Acadi Sci. USA 2001, vol. 98, p. 13660; Liu et al., Proc. Natl. Acad. Sci. USA 2002, vol. 99, p. 5165; Pavlovic et al., Nano Lett. 2003, vol. 3, p. 779; and Krämer et al., Chem. Rev. 2003, vol. 103, p. 4367.
Biological microelectromechanical systems (bioMEMS) are of tremendous interest for their potential applications in microscale, high throughput biosensing and medical devices (Shawgo et al., J. Curr. Opin. Solid State Mater. Sci. 2002, v. 6, p. 329). Using silicon as a substrate for the preparation of such devices is particularly attractive, since the extensive micro-fabrication techniques developed by the microelectronic industries can be used to fabricate and integrate various micro-components into the devices. For reducing biofouling, considerable research has been directed to the modification of substrate surfaces with stable and ultrathin films of poly(ethylene glycol) (PEG) or oligo(ethylene glycol) (OEG) (Prime et al., Science 1991, vol. 252, p. 1164). Since many of the ultimate applications for bio-devices require moderate-term (e.g., a few hours to several days) exposure to biological media (e.g., buffer of pH 7.4 at 37° C.), stability of the bio-compatible coatings on the devices under these conditions is highly desirable. All of the OEG/PEG-terminated films on silicon substrates reported by others are bound onto the silicon surfaces via Si—O bonds that are prone to hydrolysis (Calistri-Yeh et al., Langmuir 1996, v. 12, p. 2747), thereby limiting their stability under physiological conditions (Sharma et al., Langmuir 2004, v. 20, p. 348).
As described in commonly assigned, co-pending U.S. patent application Ser. No. 10/742,047, olig(ethylene glycol) (OEG) terminated alkenes were grafted onto hydrogen-terminated silicon surfaces through hydrosilylation (as developed by Linford and Chidsey, see Linford et al., J. Am. Chem. Soc. 1993, v. 115, p. 12631; Buriak, Chem. Rev. 2002, v. 102, p. 1271) forming robust Si—C bonds with the silicon surfaces. It was shown that the alkyl monolayers grown by this method were stable in boiling organic solvents, water, and acids, as well as slightly basic solutions (Linford et al., J. Am. Chem. Soc. 1995, v. 117, p. 3145). A method describing the modification of hydrogen-terminated silicon surfaces, including a silicon atomic force microscopy (AFM) cantilever tip, with OEG-terminated alkenes via either thermally- or photo-induced hydrosilylation is also found in commonly assigned, co-pending U.S. patent application Ser. No. 10/742,047. See also Yam et al., J. Am. Chem. Soc. 2003, v. 125, p. 7498; Yam et al., Chem. Commun., 2004, p. 2510). The efficiency with which such OEG-terminated films resist protein adsorption depends on many factors including the number of ethylene glycol (EG) units and the packing density of the films that is determined by the underlying substrate surface and the deposition methods. For example, OEG-terminated thiolate self-assembled monolayers (SAMs) on gold (111) surfaces are protein resistant, but those on silver (111) surfaces are not (Herrwerth et al., J. Am. Chem. Soc. 2003, vol. 125, p. 9359). The latter was attributed to the high packing density and structural ordering of the SAMs. Research has demonstrated that films grown on Si (111) surfaces had a density similar to that of the corresponding thiolate SAMs on gold (111) surfaces, and similarly reduced the adsorption of fibrinogen to 1% monolayer or less (Cai et al., to be submitted).
As a result of the foregoing, a nanometric biomolecular array comprising a stable, patternable monolayer surface, and an efficient method of making such an array, would be very beneficial.


The present invention relates to a presentation device for carrying out a product presentation. The present invention also relates to a method for presenting the product at a presentation location at which the customer is present.
Before a customer purchases a particular product, for example, a motor vehicle, he/she would generally like to obtain an impression of the article to be purchased. For this purpose, the customer may visit the vendor's premises. However, in markets covering a wide area, for example, in rural areas, the business premises of the commercial establishment and the domicile of the customer, for example, his/her place of residence, may be separated by great distances. This makes it unappealing for the customer to visit the business premises. Internet commerce allows customers to obtain an impression of the goods for sale conveniently from home. However, this impression is generally not highly realistic, and the photographs of the products depicted on the Internet pages often do not address the particular questions that a customer may have. For example, it is not possible to estimate how large a particular object is, based on a photograph of the product. For example, if the customer is interested in a motor vehicle and would like to know how spacious the rear seat is, he/she is not able to assess this based on the photographs.
DE 10 2005 048 926 A1 describes a method for simulating the appearance of items of furniture at their place of destination. In this method, a customer at a home computer is able to create virtual models of both the items of furniture and the place of destination. The customer generates the model of the place of destination based on two-dimensional images, for example, photos of his/her living room. The virtual models of the item of furniture and the place of destination may then be combined with the aid of the computer.
US 2010/0289817 A1 also describes a method for illustrating a virtual object in real surroundings. In this method as well, the real surroundings are imaged by photographs, and a virtual model of the surroundings is formed from the photographs. The virtual objects may then be inserted into the model, overlaps of real objects imaged in the photographs with the virtual object being taken into account, so that the virtual object in the model may also be situated behind the real objects.
DE 102 30 911 A1 describes a sales portal for the Internet, via which a customer may obtain product data which describe the product three-dimensionally, so that the user is able to superimpose images of the product into his/her field of vision by so-called augmented-reality glasses, thereby obtaining the impression that the product is in front of the user in his/her familiar living environment. However, to generate the three-dimensional virtual objects, the user needs a relatively high-powered computer as well as the expensive augmented-reality data glasses. Therefore, this purchasing portal is usable only by people who have both hardware components, the high-powered personal computer and the expensive data glasses.


There are many characteristics of tissue products such as bath and facial tissue that must be considered in producing a final product having desirable attributes for the product's intended purpose. Improved softness of the product has long been one major objective, particularly for the success of premium products. In general, the components of “softness” include stiffness and bulk (density), with lower stiffness and higher bulk (lower density) generally improving perceived softness. While enhanced softness is generally desirable for all types of tissue products, it has been especially challenging to achieve.
The throughdrying process is well known in the art and is used extensively in the manufacture of all types of tissue products having desirable softness characteristics. Throughdrying provides a relatively noncompressive method of removing water from a web by passing hot air through the web until it is dry. More specifically, a wet-laid web is transferred from the forming fabric to a coarse, highly permeable throughdrying fabric and retained on the throughdrying fabric until dry. The web is typically conveyed on the fabric through passage of one or more throughair dryers (“TAD”) where the web is dried to its final dryness state. The resulting dried web is typically softer and bulkier than a conventionally dried uncreped sheet because fewer bonds are formed in the web and the web is less compressed. Such throughdrying processes are described in detail, for example, in U.S. Pat. Nos. 6,149,767 and 6,331,230 B1.
However, from a manufacturing perspective, the throughdrying process is relatively energy intensive and therefore expensive compared to conventional wet pressing processes. The energy consumption issue is compounded by the fact that a significant amount of heat is vented to atmosphere during the process and, thus, wasted.
The present invention relates to an improvement in throughdrying processes that will significantly enhance the energy efficiency of such processes.


It is well known to establish a vehicle occupant classification such as, for example, by measuring the weight of an occupant. Vehicle occupant classification information identifies the type of occupant seated within a vehicle and generally includes the following three categories: adult, child, or none. This information may be useful, for example, in determining whether or not to deploy an airbag. As an example, it may be desirable to deploy an airbag under certain circumstances if the vehicle occupant in a particular seat is an adult, but the airbag may not be deployed if the vehicle occupant is a child or if the particular seat is empty.


This application is a continuation of pending U.S. patent application Ser. No. 13/184,619, filed on Jul. 18, 2011 and entitled “Methods And Apparatus For Vacuum Ultraviolet (VUV) Or Shorter Wavelength Circular Dichroism Spectroscopy” which claims priority to Provisional Patent Application No. 61/400,153 filed Jul. 22, 2010; the disclosures of which are expressly incorporated herein by reference.
The present disclosure relates to the field of polarization spectroscopy. More specifically, it provides a means by which circular dichroism (CD) measurements may be performed in the vacuum ultraviolet (VUV). In one embodiment a highly efficient laboratory-scale VUV CD spectrometer is provided. As used herein, vacuum ultraviolet (VUV) light includes, generally, wavelengths of light that are about 190 nm and less wavelengths.
When light passes through a solution of optically active (e.g. chiral) molecules, left- and right-circularly polarized components traverse the solution with different speeds and are absorbed by the solution to different extents. The differing propagation speeds lead to the effect of optical rotation (OR), which can be probed by measuring the rotation of the polarization plane via optical rotatory dispersion (ORD). Near absorption bands, circular dichroism (CD) spectroscopy measures the differential absorption of left- and right-circularly polarized light by the substance. Both methods have been successfully used to characterize properties of solutions containing optically active molecules. In addition to being sensitive to inherent chirality, ORD and CD are also sensitive to different conformations of complex molecules. As a result, one of the most prolific applications of CD spectroscopy has been the study of the secondary structure of soluble proteins.
Optical rotation and circular dichroism have the same underlying cause, and are related to each other via Kramers-Kronig integration. Defining circular birefringence (CB) as twice the optical rotation, a complex general circular retardation can be defined by:C=CB−iCD,  Eqn. 1where CB and CD are functions of wavelength. The form of Eqn. 1 and the Kramers-Kronig relationship it obeys are familiar from the (isotropic) optical dispersion of materials, n−ik, where n is the material's refractive index and k is the extinction coefficient. That n and k obey the Kramers-Kronig relation implies that the wavelength dependence of the index of refraction is determined by the material's absorption, and vice versa. Similarly, that CB and CD are related via Kramers-Kronig integration implies that complete knowledge of one over all wavelengths or energies determines the other.
Practical experiments, however, occur over finite wavelength ranges and ORD and CD spectroscopy have different advantages, depending on the wavelength range explored. While the ORD spectrum can be determined far from the absorption bands responsible for its effect, the CD spectrum directly probes the bands, and as such, is considered more sensitive and spectrally “compact”. In ORD spectroscopy the information associated with a given absorption band is typically spread out over a large energy range. As a result, the ORD spectrum in a given wavelength range contains overlapping contributions from multiple absorption bands. In contrast, with CD spectroscopy the information due to a single absorption band is localized within a smaller energy range, resulting in much less overlap between measured features. If the absorption region is accessible experimentally, CD spectroscopy is typically the preferred technique since it more directly probes the underlying “cause” of the optical activity of the substance being measured.
In the case of soluble proteins, the secondary structure of the molecules results in the optical activity of the solution, and different types of secondary structure, such as alpha-helix, beta sheet, polyproline-II helix, etc. give rise to distinct features in CD spectra. The electronic bands responsible for protein CD largely reside in the ultraviolet. The alpha-helical structures generally involve bands centered at ˜222, 208, 192, 175, 160, and 140 nm. Meanwhile, beta sheet structures have weaker bands at ˜215, 198, 175, and 168 nm. Variations in beta sheet geometry result in further modifications to CD spectra. The polyprolene-II helix has observed bands near 226 nm and 206 nm, and gives rise to spectra similar to those of proteins previously characterized as “un-ordered”. In all cases, other bands may exist but have yet to be observed and/or identified.
The ultraviolet wavelength region may be considered as consisting of two distinct segments: the near-UV region from ˜190-400 nm, and the “far-UV” or vacuum ultraviolet (VUV) region below 190 nm. Conventional CD spectrometers are limited in operation down to about 190 nm. The primary motivation to extend CD studies into the VUV lies in the existence of additional absorption bands present at shorter wavelengths. As a consequence of these supplementary features, VUV CD spectra inherently posses increased information content relative to their longer wavelength counterparts. While traditional CD instruments are often limited to determining the amount of alpha-helix structure present in a solution, VUV CD systems are capable of extracting numerous secondary component fractions. In addition, these powerful systems can also provide insight into conformational changes, such as fold state, independent of secondary structure. It is important to note that this information enhancement is not simply due to a “more data is better” argument; the improved capabilities are a direct consequence of the additional absorption bands present in the VUV.
Optical studies in the VUV are difficult to conduct due to the intrinsic absorption of most materials in this region. This phenomenon precludes the simple extension of, or modification to, traditional longer wavelength optical instrumentation to facilitate operation at these energies. To achieve efficient optical performance in the VUV, an instrument must be explicitly designed to do so. Specifically, conventional optical systems are designed to operate in atmospheric conditions and typically lack, among other things, the controlled environment required for operation at these shorter wavelengths. VUV radiation is strongly absorbed by both oxygen and moisture; hence, these species must be maintained at sufficiently low levels in order to permit transmission of VUV photons through instrument optical paths. Attempts to reach shorter wavelengths by simply purging with non-absorbing gases generally yield poor results. Furthermore, transmissive optical components that are otherwise suitable for near-UV or visible wavelength operation, routinely absorb strongly in the VUV. Consequently, reflective elements must instead be employed, greatly restricting design options. As a result, it is comparatively difficult to achieve high optical throughput in VUV optical instrumentation.
With the exception of early work by Johnson (Johnson W. C. (1971). “A circular dichroism spectrometer for the vacuum ultraviolet”. Rev. Sci. Instrum. 42(9): 1283-1286), progress towards development of a dedicated, highly efficient VUV-CD instrument has been limited. Today's commercial bench top systems are designed to operate at near-UV and longer wavelengths. Several of these systems offer simplistic purge functionality in an effort to extend capabilities into the VUV. Practically however, poor data quality restricts these instruments to operation at wavelengths above approximately 185 nm.
The most capable VUV CD systems in existence are those integrated into synchrotron radiation (SR) beam lines. The advent of such instruments in the 1980's and 1990's brought about tremendous enhancements in both CD data quality and information content. These improvements however, were largely the result of the remarkable intensity of SR sources, rather than fundamental advancements in instrument designs. As a consequence of these developments, interest in VUV-CD spectroscopy has grown considerably, resulting in the commissioning of several new beam lines and the identification of a myriad of applications for this technology. SR-CD systems are powerful, but the disadvantages are obvious: synchrotron facilities are huge and enormously expensive, making accessibility a severe limitation.
It follows that there would be great benefit in the development of a highly efficient, high throughput laboratory-scale VUV CD spectrometer, which does not require synchrotron radiation. Such an instrument would render high-throughput structural investigations of proteins widely available, thus creating new opportunities to accelerate discoveries in structural proteomics.


The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Riding mowers typically include some form of steering device. These steering devices can include hydraulic cylinders and electric rotary motors for wheel turning operation. However, these steering devices can include complicated geometry including a large number of parts. Further, use of hydraulic cylinder devices can result in oil spillage, which can damage turf.


The present invention is generally related to radiotelephones, and more particularly to a cellular portable telephone which accommodates a power source change and corresponding operating mode change during a radiotelephone call.
Cellular portable telephones currently have batteries with capacity for one-half hour of continuous operation. As a result most users typically carry one or more spare batteries so that they can switch to another battery when the portable telephone indicates that the battery voltage is low. However, when the battery is removed during a cellular telephone call, the call is terminated and the user must redial the call. Interruption of the power source and termination of a cellular telephone call in process also occurs when the user plugs the cellular portable telephone into a vehicle's battery by way of a vehicular adaptor installed therein, such as a battery eliminator connected to the vehicle's cigarette lighter. For the foregoing reasons, there is a need for a cellular portable telephone which accommodates a power source change and corresponding operating mode change during a cellular telephone call.


The present invention relates to a screen for treating fibrous suspensions, such as pulps, of the wood processing industry. Especially it relates to the construction of a rotor element for the screen.
Pressure screens are essential devices in the production of pulp and paper. They remove from the pulp suspension mainly impurities, over-sized pieces of wood and fiber bundles as well as other undesired substances. The screen can also fractionate fibers according to their length for improving the properties of the pulp. The precise function of the screen is dependent on the location in the process where it is used. In the screening process the water suspension of the pulp fibers is typically pumped into a cylindrical chamber, wherein the suspension is brought to contact with the screen surface and a rotor moving at high velocity. The rotational velocity of the rotor pushes the fibrous material into movement, whereby part of it is passed as accept through apertures in the screen surface. The high-speed rotor applies positive and negative impact pulses to the suspension. The positive impact pulses push the fibers through the apertures in the screen and may fractionate the fibers. The negative impact pulses provide for a regular flush-back of the apertures in the screen surface so that the fibers do not plug the apertures.
The pulp suspension consists of millions of elastic fibers that easily attach to each other forming so-called fiber flocks. Even at a low consistency such as 0.01% the fibers form unstable flocs. In a typical screening consistency, 1-3% the fibers form stable flocks and fiber networks hamper the screening. The fibers and undesired solid matter are periodically removed from the net in order to enable the screening the remaining fibers from the flocks and fiber networks into reject and accept fibers. When the pulp consistency increases, the force required for decomposing the fiber network increases intensively and finally a process limit is reached, where the apertures in the screen surface or the reject line is clogged. A large number of various rotor solutions has been developed with the aim of ensuring a continuous screening operation.
In principle, the rotors can be divided into two basic groups, open and closed rotors. Both are being used and their purpose is, as known, to keep the screening surface clean, i.e. to prevent the formation of a fiber mat on the screening surface. The first group is characterized in that the interior of the screen drum is provided with a rotary shaft or a rotor, whereto blades are attached by means of arms. An example of this kind is the rotor solution according to U.S. Pat. No. 4,193,865, where the rotor is arranged rotatably inside a cylindrical stationary screen drum, said rotor comprising blades located in the vicinity of the screen drum surface, which blades in the construction according to said patent form an angle with the drum axis i.e. the blades extend obliquely from one end of the screen drum to another. When moving, the blades impact pressure pulses on the screen surface, which pulses open the surface apertures. There are also solutions, in which the blades have been located on both sides of the screen drum. In that case, the suspension to be treated is fed to the inside or to the outside of the drum and the accept is, respectively, discharged from the outside or inside of the drum.
In stationary rotors the rotor is an essentially closed cylindrical piece, the surface of which is provided with pulsation members, for instance almost hemispherical protrusions, so-called bulges. In this kind of an apparatus the pulp is fed into a treatment space located between the rotor cylinder and the screen drum outside thereof, whereby the purpose of the rotor protrusions, e.g., the bulges, is both to press the pulp against the screen drum and by means of its trailing edge to withdraw the fiber mat off the screen drum apertures. The bulges can be replaced by other kinds of protrusions.
A solution widely used in the market is a represented by a method according to FI patent 77279 (U.S. Pat. No. 5,000,842) and the solution developed for the implementation thereof. The method according to said patent is characterized in that the fiber suspension is subjected to axial forces with varying intensity and effective direction, the direction and intensity of which are determined based on the mutual axial positioning of the point of application and the countersurface of the screen drum and by means of which the axial velocity profile of the fiber suspension is changed while maintaining the flow direction continuously towards the discharge end. Preferably the surface of the rotor is divided into four zones: feed, feed and mixing, mixing, and efficient mixing. The rotor surface is typically provided with 10-40 protrusions, the shape of which varies according to the zone i.e. the axial part of the rotor that they are located on. The protrusions on the housing surface of the rotor are mainly formed of front surfaces facing the flow, preferably surfaces parallel to the housing surface and back surfaces that descend towards the housing surface of the rotor. The housing surface of the rotor is provided with protrusions of several different forms, which have been arranged onto the rotor housing so that two or more circumferential zones are formed separated from each other in the axial direction of the rotor, such as e.g. 4 zones. At least part of the front surfaces of the protrusions forms an angle with the axial direction. The front surface of the protrusions can be divided into two parts that form with the axial direction angles of different size. The variation interval of the angles is −45°-+45° compared to the axial direction. However, the functioning principle of the protrusions is the same as in other corresponding devices. The abrupt front surface imparts a strong pressure shock to the fiber mat on the screen drum, whereby the accept is pressed through the apertures of the drum. The sloping back surface of the protrusion withdraws some water back to the screening zone and thus releases from the grooves and apertures major particles and fiber flocks thus cleaning the screen drum.
U.S. Pat. No. 5,192,438 describes a rotor which provides high intensity axial shear stress in addition to high positive pulses and negative pulses. The rotor has a contoured surface including a plurality of protrusions. A protrusion has a front plane, an upper plane, an inclined plane and edge surfaces, which may converge. The trailing surface of the protrusion is abrupt.
So, in prior known solutions the functional prerequisite of pressure screens starts from the presumption that the rotor element is to develop an adequate pressure impulse on the interface to make the fiber particles flow through the screening surface and that the rotor element is to create by its trailing edge a negative pressure impulse to generate a turbulence that cleans the apertures clogged by the previous positive impulse. It has also been generally presented in the field that a negative impulse withdraws liquid back towards the feeding space preventing excess thickening of the fiber suspension in the feeding space and in its part cleaning the apertures of the screening surface. For enabling to create these conditions, the rotor must have an adequate rotational speed, which is, however, limited by energy consumption and mechanical durability of the screen, a typical speed for a rotor described in FI-patent 77279 (U.S. Pat. No. 5,000,842) is 24 m/s.
In the present industrially used pressure screen applications the rotor solutions have enabled to reach the maximum feed consistency level of pulp. The consistency level is almost the same for different rotor types, for instance for softwood (SW)-pulp approximately 2-3%. Thus, there is a need in the field to develop a screen rotor that will allow higher feed consistencies.


The various embodiments described herein provide a system and method for dynamically rendering a 3D representation of data in a dimension different than an initial 2D base layer representing related space and aerospace datasets, although the techniques described herein will find broader occasions in a variety of data representation situations.
In an embodiment, the user selects desired parameters from a datastore to be displayed in the 2D base layer. The user also selects one or more parameters to be represented in a third dimension from a datastore. The system has an inventory of display techniques through which certain data may be displayed.
The system also comprises rules for the display of specific data. For example, and without limitation, certain data may be appropriately displayed in one format but is not susceptible to being displayed in a second format. The processor and server have rules associated with the data type to allow the processor to present the user options for display of a specific data based upon the techniques by which that data may be displayed. Thus the user is presented only with choices for display that are relevant to the data type.
Based on the type of data selected by the user, the processor determines which of a plurality of predetermined display formats would be appropriate and presents the options to the user. The user selects the desired display format from the list of choices and the processor generates the image.
The various display formats are selected from the set comprising 2D surface morphing, 2D plane rotation, 2D to 3D continuous morphing, 3D to 2D continuous morphing, and 2D/3D combined data representation. This list is by way of illustration only and is not meant as a limitation.


The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example, lactate, cholesterol and bilirubin should be monitored in certain individuals. In particular, determining glucose in body fluids is important to diabetic individuals who must frequently check the glucose level in their body fluids to regulate the glucose intake in their diets. While the remainder of the disclosure herein will be directed towards determining glucose, it is to be understood that the methods of this invention may be used for determining other analytes on selection of an appropriate enzyme.
The results of such tests can be used to determine what, if any, insulin or other medication needs to be administered. In one type of blood glucose testing system, sensors are used to test a fluid such as a sample of blood.
A sensor contains biosensing or reagent material that will react with blood glucose. The testing end of the sensor is adapted to be placed into the fluid being tested, for example, blood that has accumulated on a person's finger after the finger has been pricked. The fluid is drawn into a capillary channel that extends in the sensor from the testing end to the reagent material by capillary action so that a sufficient amount of fluid to be tested is drawn into the sensor. The fluid then chemically reacts with the reagent material in the sensor resulting in an electrical signal indicative of the glucose level in the fluid being tested is supplied to contact areas located near the rear or contact end of the sensor.
Such a sensor is often sensitive to the effects of ambient humidity. One way to reduce or eliminate the effects of ambient humidity is to individually package each of the sensors with desiccant. Such a method has a drawback of requiring the unpacking of a strip before each use. Thus, it would be desirable to have a cartridge that would contain a plurality of test sensors that would not require unpacking each strip before using. Also, for the convenience and case of use, it would also be desirable to have a simple mechanism to feed the test sensors one at a time for testing by the user. This provides ease of use to normal users and is especially important for those users who may have some physical limitations.


1. Field of the Invention
This invention relates to a power semiconductor component having at least three layers, including first and second layers extending up to a first surface which has sectionalized contact planes resulting in a step-like structure for contacting the first and second layers, and to a process for its manufacture.
2. Description of the Prior Art
Such a component as noted above is known, for example, from German Offenlegungsschrift No. 2,719,219. The semiconductor device described therein has four layers in a pnpn arrangement. The n-doped cathode layer 8 is subdivided into several sections, in order to allow contacting in two planes (FIG. 1). It has a surface doping of 5.times.10.sup.20 atoms cm.sup.3 and is 10 .mu.m thick. The p-base layer 6, located underneath, has a surface doping of 2.times.10.sup.18 atoms/cm.sup.3 and is 53 .mu.m thick. The width of the cathode sections is at least 320 .mu.m. The maximum reverse voltage of the pn junction between the cathode layer 8 and the p base 6 is 10 volt. The semiconductor device described is designed for a total current capacity of 400 A.
A process for manufacturing the abovementioned semiconductor device is also indicated (FIG. 6). For this purpose, boron or gallium is first diffused into both sides of an n-doped silicon substrate 42. The doping of the n substrate is about 10.sup.13 -10.sup.16 atoms/cm.sup.3. The p layers which have been diffused in, the p base layer 46 and the anode 44 have a surface doping of about 2.times.10.sup.18 atoms/cm.sup.3. To form the cathode layer 48, phosphorus is diffused into the p base layer 46. This n layer 48 is photolithographically subdivided into several sections. Aluminium layers are then applied to the anode layer 44, to the cathode sections 48 and to the subdivided p base layers 46.
The known semiconductor device can be switched off by applying a negative current pulse to the p base layer 6 (gate). The power required for this purpose and supplied from the outside is considerable. The load current is constricted towards the middle of a cathode section by this current pulse and a part of the load current is thus drawn away to the gate. The current density of the remaining load current then becomes very high. If the switching-off step proceeds too slowly--for example in the case of unduly high switching-off amplification--or not homogeneously over the entire area of the semiconductor device, the latter is locally overloaded thermally and hence destroyed. The switching-off current via the gate produces a lateral voltage drop which should be smaller than the breakdown voltage of the pn junction between the cathode and the p base layer. However, the maximum reverse voltage of this pn junction is so low that an avalanche breakdown of this junction can occur during the switching-off step. The manufacturing process described is admittedly adequate for the structure having the dimensions of the known semiconductor device, but finer structures can hardly be produced satisfactorily this way.
German Offenlegungsschrift No. 2,855,546 describes a field-controlled thyristor which has characteristics similar to those of a p-i-n diode. This thyristor consists of a thin, heavily p-doped anode zone 15, a thick, lightly n-doped semiconductor substrate 11, several deep p-doped grid zones 12 and thin, heavily n-doped cathode zones 14 arranged in between (FIG. 3). The grid zones 12 consist of channels having a width of about 12 .mu.m and a depth of 15 to 40 .mu.m. To produce these grid zones 12, channels are etched into a <110>-oriented silicon substrate with a mixture of potassium hydroxide and isopropanol in a ratio of about 3:1 (FIG. 1). For this purpose, a mask 13 of silicon dioxide is first formed. The channels are then epitactically refilled with heavily p-doped silicon. A thin layer of poly-silicon then additionally forms on the silicon oxide layer which is removed by etching. A mask of silicon oxide is then formed for the cathode zones 14 which are produced by diffusion of phosphorus. Finally, the grid zones 12 and the cathode zones 14 are provided with metallizations, silicon dioxide being left in between for electrical insulation.
The silicon with <110>-orientation, required for the process described, cannot be drawn without dislocations. For this reason, the silicon wafers can be obtained only in an elliptical form and must be sand-blasted to give a round form for further processing. The base material for the component described is therefore much more expensive than that for conventional components.


This invention is directed to a new and improved toy device for launching a compressible foam ball.
In the past, many different toy constructions for launching balls were proposed e.g. see U.S. Pat. Nos. 1,171,197; 2,725,869; 2,853,991; 3,120,387; 3,236,521; 3,301,246; 3,744,472 and 3,765,396.
The present invention is an improvement over such prior art based on its simple construction as well as the manner in which it functions to propell a soft compressible closed cell foam ball from the forward section of the lanucher.


1. Field of the Invention
The invention relates to semiconductor wafer processing equipment and, more particularly, the invention relates to a method and apparatus for selectively marking a semiconductor wafer with identifiable markings.
2. Description of the Background Art
Identifying defects on the surface of a wafer, such as particulate contaminants and other surface irregularities, is extremely important to integrated circuit manufacturing processes. To eliminate defect sources, defects are identified and analyzed to determine the source of the defect. Thereafter, corrective action can be taken to reduce or eliminate the defect source.
Typically, the defect identification process is accomplished in two steps. First, a laser scanner device scans a wafer with a laser and analyses the backscatter of the laser to locate defects on the surface of the wafer. One such laser scanner device is a Tencor SurfScan 6200, manufactured by Tencor Instruments. Second, each defect located by the scanner is analyzed to identify the root cause of the defect. The most commonly employed analysis tool is a high magnification imaging system such as a scanning electron microscope (SEM). An SEM is used to identify the defect and/or the source of the defect by inspecting the defect at high magnification. Additionally, the SEM may be accompanied by instrumentation for performing chemical analysis of the defect. Such instrumentation includes an energy dispersive x-ray (EDX) detector. Other tools may include instrumentation for performing an Auger analysis, an atomic force microscope (AFM), a tunneling electron microscope (TEM), an optical spectrometer and the like.
Since the SEM as well as other analysis tools use a high magnification (on the order of 200 to 2000 times), rapidly positioning the SEM at the defect location can be time consuming. Although the laser device provides defect coordinates that are accurate to approximately 300 microns, a substantial amount of time can be spent manually searching, for example, a 300 by 300 micron region with the SEM for a defect having dimensions of a few tenths of micron.
Additionally, when using a SEM (or other optical analysis tool) to analyze a "bare" wafer, i.e., a wafer having no surface features, the SEM has difficulty focusing on the wafer surface. Without an accurate focus, finding a small defect on the surface is nearly impossible.
Furthermore, some defects are identified by laser scanning, but cannot be seen with a SEM. As such, the SEM operator may search for a defect for a long period of time until realizing the defect cannot be seen with the SEM.
Some defect analysis tools, e.g., an atomic force microscope (AFM), are not readily useful when a large search area is used. Generally, the field of view for an AFM is approximately 10 .mu.m.sup.2, and the search area is as large as 300 .mu.m.sup.2. Unfortunately, an AFM requires approximately five minutes to obtain a 10 .mu.m.sup.2 image. As such, 900 images are required to cover a 300 .mu.m.sup.2 search area, requiring 4500 minutes to complete the search.
Therefore, a need exists in the art for a method and apparatus that selectively marks a wafer proximate a defect such that the defect can be rapidly identified and examined with a SEM or other defect analysis system.


1. Field of the Invention
This invention relates to a terpolymer with a high refractive index and the plastic lenses made of the terpolymer.
2. Description of the Prior Art
Recently lenses of organic glass have been widely used instead of lenses of inorganic glass, because organic glass is superior to inorganic glass in its lightness, safety due to its high impact resistance, workability, dyeability, etc. For example, lenses made of diethylene glycol bisallyl carbonate (hereinafter referred to CR39) have already been used widely. But, lenses of CR39 have such a disadvantage that the lenses must be thicker than those of inorganic glass, because of their relatively low refractive index such as 1.499. There is known a method for overcoming the disadvantage comprising copolymerizing CR39 with benzyl methacrylate so as to increase the refractive index. However, lenses obtained by the copolymerization are inferior to lenses of CR39 in their superficial hardness, so that the lenses must be more carefully handled.
We have now found that copolymerization of ternary monomers consisting of CR39, benzyl methacrylate, and triallylisocyanurate enables to produce lens with a high refractive index and a high superficial hardness.
An object of this invention is to provide a plastic lens with a high refractive index and a high superficial hardness.


In computer graphics, three-dimensional (3D) modeling involves generation of a representation of a 3D surface of an object. The representation may be referred to as a 3D object data model, and can be rendered or displayed as a two-dimensional image via 3D rendering or displayed as a 3D image. 3D object data models represent a 3D object using a collection of points in 3D space, connected by various geometric entities such as triangles, lines, curved surfaces, etc. Various techniques exist for generating 3D object data models utilizing point clouds and geometric shapes, for examples.
Being a collection of data, 3D models can be created by hand, algorithmically, or objects can be scanned, for example. As an example, an artist may manually generate a 3D image of an object that can be used as the 3D model. As another example, a given object may be scanned from a number of different angles, and the scanned images can be combined to generate the 3D image of the object. As still another example, an image of an object may be used to generate a point cloud that can be algorithmically processed to generate the 3D image.
3D object data models may include solid models that define a volume of the object, or may include shell or boundary models that represent a surface (e.g. the boundary) of the object. Because an appearance of an object depends largely on an exterior of the object, boundary representations are common in computer graphics.
3D models are used in a wide variety of fields, and may be displayed using a number of different types of interfaces. Example interfaces may provide functionality to enable interaction between a user and the 3D models.


The present invention is directed to the field of serving food portions, and is more specifically directed to a device for inserting a filling into a taco shell or the like. Taco shells, as found in restaurants or as packaged for sales to consumers in food stores, have a substantially uniform shape and size. However, the shape, which in profile is substantially semi-circular, does not lend itself easily to filling with presently available devices. For example, a teaspoon, tablespoon, or large serving spoon can be used to deposit the filling in the taco shell, but this generally results in the entire portion of the filling being deposited in the center, and none in the sides. If a spoon is used, additional portions of filling can be inserted on either side, but because of the semi-circular shape, the filling will tend to fall out at the sides. Likewise, if the spoon is used to more evenly distribute the filling across the bottom of the taco shell, there will be too much filling at the sides, which will tend to fall out, and not enough filling at the center.
There are many specialized devices for serving specific kinds of food, but I have found that none of these are suitable for filling taco shells. For example, a number of different devices are known for serving a portion of food such as ice cream or hamburger meat. A common type of device for serving ice cream includes a scoop, a handle extending rearwardly from the scoop, and a plunger with an ejector bar mounted for reciprocating motion in the handle. The shape of the scoop is dependent upon the shape of the ice cream portion which is desired. Thus, the scoop is often triangular, to produce a portion which will fit into an ice cream cone or a tall ice cream dish. In such devices, the end of the scoop which is inserted into the ice cream forms the point of the triangle, to make introduction of the scoop into the hard ice cream easier. Such devices are characterized by U.S. Pat. Nos. 1,688,595 and 1,798,490 to Parr and 2,178,648 to Rothenbush. In other devices, the scoop is rectangular in shape, to form a rectangular brick for filling an ice cream sandwich. Such devices are characterized by U.S. Pat. Nos. 1,352,755 to Levy and 1,529,782 to Gerstein. Although all of these devices are excellent for their stated purpose, that is, serving portions of ice cream, the sizes and shapes of the various scoops prevent turning them to use in filling a taco shell.
Somewhat analogously, devices have been provided for slicing an opening in a sandwich bun and inserting into the opening the filling, for example a hamburger or a hot dog. Again, the shape of the scoop is dependent upon the shape of the sandwich bun, and the front is provided with a pointed blade for cutting the opening in the sandwich. Such a device is characterized by U.S. Pat. No. 2,784,682 to Clevenger. The size and shape of this type of device also renders it unsuitable for use in filling a taco shell.
In summary, no simple device exists which in shape and size is adapted to fill a taco shell with an amount of filling which corresponds to the shape of the taco shell. It is the solution of these problems to which the present invention is directed.