Embodiments of the subject matter disclosed herein generally relate to systems comprising turboexpanders and driven turbomachines and methods for operating the same.
Turboexpanders are widely used for industrial refrigeration, oil and gas processing and in low temperature processes. In some known applications turboexpanders are used in heat recovery cycles to drive an electric generator. US 2011/0305556 discloses a system and method for power generation including a turboexpander with at least two expansion stages for heat recovery and mechanical power generation to drive an electric generator. In this known application the turboexpander is introduced in a Rankine cycle.
EP 2400117 discloses the application of a turboexpander-compressor system according to the prior art, wherein the same fluid is processed in the turboexpander and in the compressor. FIG. 1 illustrates the turboexpander-compressor system of the prior art. The system is labeled 200. A turboexpander 210 has a turboexpander impeller 212. The turboexpander 210 receives an inlet gas flow at 214. Inside the turboexpander 210 the gas may expand and thus cause rotation of the turboexpander impeller 212. The expanded gas exits the turboexpander 210 at 216 enabled by a separator (Sep) 220. When the turboexpander-compressor system 200 functions at design conditions, a pressure p1 and a temperature T1 measured respectively by a sensor Sp1 235 and sensor ST1 236 of the inlet gas flow at 214, as well as a pressure p2 and a temperature T2 measured respectively by a sensor Sp2 237 and sensor ST2 238 of the gas flow at the exit side 216 have values close to predetermined values. However, in some situations the turboexpander-compressor system operates in off-design conditions. When off-design conditions occur, the pressure p1 of the incoming gas flow at 214 may be adjusted to become again close to the respective rated value, using, for example, a first set of moveable input guide vanes (IGV1) 218. The first set of moveable input guide vanes 218 are located at an inlet of the turboexpander 210.
In the turboexpander-compressor system 200 illustrated in FIG. 1, a compressor 224 has a compressor impeller 226. The compressor 224 receives the gas flow from the turboexpander 210 and delivers a compressed gas flow at the delivery side 228. However, between the turboexpander 210 and the compressor 224, the pressure of the gas flow may be altered due to other process components (e.g., separators, coolers, valves) and pressure losses, so that the gas flow at 216 has pressure p3 when entering the compressor 224 measured by sensor (Sp3) 239.
The mechanical work generated by the expansion of the gas in the turboexpander rotates the turboexpander impeller 212. The turboexpander impeller 212 is mounted on the same shaft 230 as the compressor impeller 226. The compressor impeller 226 therefore rotates due to the mechanical work generated during the expansion of the gas in the turboexpander 210. The rotation of the compressor impeller 226 provides energy used to compress the gas in the compressor 224. The mechanical work necessary to rotate the compressor impeller 226 affects the rotating speed u of the shaft 230 measured by speed sensor (Su) 234 and, thereby, indirectly affects the process of expanding the gas inside the turboexpander 210.
The turboexpander efficiency is related to a ratio of the rotating speed u of the shaft 230 and the enthalpy drop ΔH across the turboexpander 210. The gas expansion in the turboexpander 210 may be considered approximately an isoentropic process.
The characteristic parameters (i.e., p1, T1, p2 and T2) of the gas expansion in the turboexpander 210 and the rotating speed u of the shaft 230 may not vary independently. Therefore, in off-design conditions, in order to maximize the turboexpander efficiency, the pressure p3 of the gas flow at the inlet 216 of the compressor 224 may be controlled, for example, by a second set of moveable inlet guide vanes IGV2 232 provided at the compressor inlet. By modifying the pressure p3 of the gas flow 216 input in the compressor 224, the rotating speed u of the shaft 230 is modified and, therefore, the efficiency of the turboexpander 210 can be maximized.
A controller 240 receives information regarding the pressure p1 and the temperature T1 of the gas flow at the inlet side 214 of the turboexpander 210, the pressure p3 of the gas flow at the inlet 216 of the compressor 224, and the rotating speed u of the shaft 230, by suitable sensors. The controller 240 may send commands C1 to IGV1 218 in order to adjust the pressure p1 of the gas flow at the turboexpander inlet 214 to be within a predetermined range. Based on monitoring the acquired information, the controller 240 determines when the turboexpander-compressor system 200 functions in off-design conditions. When the controller 240 determines that the turboexpander-compressor system 200 functions in off-design conditions, the controller 240 sends commands C2 to the second set of IGV2 232 to adjust the pressure p3 of the gas input into the compressor in order to maximize a ratio R between the rotating speed u of the shaft 230 and the enthalpy drop ΔH across the turboexpander 210.
In this known embodiment, the same controller controls the moveable inlet guide vanes of the turboexpander and the moveable inlet guide vanes of the compressor to optimize the efficiency of the system, based on the assumption that the same fluid is processed in the two turbomachines.


The use of magnetic pulse compression circuits (magnetic modulators) to create high voltage, high current, short duration electrical pulses has been well described (see for example W. S. Melville, "The use of Saturable Reactors as Discharge Devices for Pulse Generators," Radio Section, Paper No. 1034, pp. 185-207, Sep. 15, 1950). Particularly, magnetic modulators have been applied advantageously to drive pulsed gas discharges for excimer lasers and other pulsed gas discharge lasers (see for example Ball et al. U.S. Pat. No. 5,177,754, Jan. 5, 1993.
Pulse propagation delay in a magnetic modulator depends upon the characteristic volt-second product(s) required to saturate the core(s) of the individual magnetic switch element(s). Since the volt-second product is nearly invariant for any individual core, operation at different voltage levels typically results in different pulse propagation or throughput delays relative to a trigger signal from master trigger (a shorter delay at higher voltages and a longer delay at lower voltages). However, in some applications, it is important to maintain a constant propagation delay, regardless of variable operating voltage levels, such that measurement events can be timed relative to a trigger signal from the master trigger. Jitter or variation in timing of the output pulse relative to the trigger signal from the master trigger can also be important in these applications. Additionally, temperature fluctuations can lead to variations in propagation delay and/or jitter in timing of pulses.
Although circuits have been used previously to control pulse propagation delay and jitter in magnetic modulators, they have typically been complex, inflexible, and/or relatively crude and inaccurate in the compensation that they allow (see for example Hill et al. "Reliable High Repetition Rate Thyratron Grid Driver Used with a Magnetic Modulator," 8th IEEE International Pulsed Power Conference, San Diego, Calif., 1991, IEEE Catalog #91CH3052-8).
A voltage timing compensation circuit in the prior art (see for example Cymer ELS5600 Data DOC. ID: ICLACY00.EPS) compensates for the delay variation at different voltages by adding a low level delay to a trigger signal from a master trigger when the magnetic modulator operates at higher voltages.
The prior art voltage timing compensation circuit operates by sampling the voltage of the initial operating stage of a magnetic modulator just prior to master trigger initiation. The sampled voltage is then digitized and used to drive a digital delay generator, which adds to the low level trigger signal a timing delay proportional to the sampled voltage. Thus according to the prior art cited above, delay compensation is linear relative to operating voltage, whereas the actual dependence of pulse propagation delay on voltage is non-linear.
Because the characteristic volt-second product of the magnetic switch element(s) is temperature dependent, some prior art implementations comprise a temperature timing compensation circuit to correct for variations in delay caused by fluctuations in operating temperature relative to a nominal design ambient temperature.
In accordance with certain prior art embodiments, this temperature timing compensation circuit comprises RC components that synthesize the approximate thermal characteristics of the system.
What is needed in the art is a simple, reliable circuit for timing compensation of a magnetic modulator that more accurately compensates for effects of voltage and/or temperature than does the prior art. Further needed in the art is a circuit for pulse timing control of a magnetic modulator in response to other independent variables, that is simple, accurate, and reliable.


1. Field of the Invention
The present invention concerns a device to reduce the electromagnetic field load caused by the presence of a medical intervention apparatus in magnetic resonance examinations.
2. Description of the Prior Art
Many medical procedures today are conducted in an interventional manner. Diagnostic or therapy methods that—in contrast to conservative procedures—conduct targeted procedures (interventions) on pathological tissue in order to positively affect the course of the illness are designated as interventional. Invasive or, respectively, minimally invasive procedures are also examples of such methods, wherein medical instruments or implants are brought to the treatment or examination location by various techniques.
Particularly in the treatment of vascular diseases, guide wires are used that are inserted by a physician into hollow vessels (lumens) of a patient. Later a catheter (for example) is inserted along this wire for diagnosis or therapy. The guide wire itself often has a diameter of less than 0.5 mm. Due to the high mechanical demands, such guide wires have been conventionally produced from metal and metal alloys. Magnetic resonance is a modality particularly suited for imaging of the human body with a high tissue contrast. It would be particularly suitable for observation of intervention apparatuses during their insertion and placement in the human body, but the electromagnetic fields in the two-digit or three-digit megahertz range that are required for imaging are problematical. Therefore, heretofore there have been high risks in the real-time tracking of guide wires and other electrically conductive intervention apparatuses given movement in the human body. This is highly risky because high-frequency currents can form on elongated electrically conductive apparatuses due to injection of the transmission fields. This leads to heating at corresponding powers and, in the disadvantageous case, to tissue burns inside the human body. The currents are even higher at such elongated intervention apparatuses if waveguide resonances occur along the entire length due to the intervention apparatus. If the lengths of the guide wires are also on the order of the wavelength of the magnetic resonance frequencies being used, the risk of endangering a patient is particularly high.
A prediction about the potential for danger by means of simulation calculations is very difficult since the actual danger is situation-dependent. The length and orientation of the intervention apparatus in the patient, the conductive paths outside the patient, and even properties of the patient, play a role. Finally, the position of the intervention apparatus in relation to the transmission antenna, and the transmission antenna type, are also very influential.
Due to the high risks from the induced radio-frequency currents, the real-time tracking of intervention apparatuses with the aid of magnetic resonance has previously been realized with the transmission power being drastically limited. Another solution is the construction of guide wires or catheters from non-conductive materials. However, all desired material properties cannot be ensured with these materials; such intervention apparatuses are additionally very expensive and complicated.


1. Field of the Invention
The present invention relates to an actuator and a blade drive device for a camera.
2. Description of the Related Art
Conventionally, there has been known an actuator used for driving a shutter blade employed in a camera, and composed of a rotor, a stator, a coil for exciting the stator, and an outputting member for transmitting the rotational movement of the rotor to the shutter blade. Japanese Unexamined Patent Application Publication No. 2004-309531 discloses a device in which a rotor and a drive pin, serving as an outputting member, are integrally formed.
However, in the case where the rotor and the drive pin are integrally formed, it is difficult to change the positional relationships between the rotor and the drive pin whereas it is effective for downsizing. Therefore, it is difficult to change an angular position of the drive pin relative to the rotor according to a design variation.


The present invention relates to amplifiers and more particular to amplifiers employing shunt feedback.
The traditional series shunt feedback architecture illustrated in FIG. 1 has been widely hailed as the preferred architecture for Low Noise Amplifiers (LNAs) requiring a well defined input impedance. However combining series shunt feedback with Gilbert""s current steering techniques for providing an Automatic Gain Control (AGC) function presents certain difficulties.
The following equations describe how the input impedance Rin of the traditional series shunt feedback amplifier is set by a negative feedback amplifier:
Rf=Rs*(1+A)
Rin=Rf/(1+A)
where Rf is the effective feedback impedance, Rs is the source impedance, and |A| is the magnitude of the gain of the amplifier. It will be appreciated that as long as Rf remains constant, then so does the input impedance Rin. However, if the amplifier has a varying gain, then the input impedance Rin will also change.
A potential solution to this problem is offered by the architecture of FIG. 2, where the input impedance of an amplifier arrangement is set by an input stage comprising an amplifier which has a fixed gain. The output of the input stage feeds a variable gain amplifier stage. This solution is not optimal however, since the input stage has a fixed gain and the input signal to the variable gain amplifier stage is therefore higher than the input signal to the amplifier arrangement as a whole. This creates a problem in signal handling requirements and may result in a power in-efficient solution.
In view of the disadvantages noted above, existing amplifier arrangements may not meet the strict requirements of modem electronic systems, such as interactive cable television equipment, in which a range of high performance RF products are required ranging from mixer oscillator circuits to LNAs with AGC and loop through circuits.
It is an object of the present invention to provide an amplifier arrangement having a stable input impedance. It is a further object of the present invention to provide a low noise amplifier which is power efficient. These and other objects are achieved at least in part by an amplifier arrangement in which the amplifier stages thereof are operated in current mode.
According to a first aspect of the present invention there is provided an AC voltage amplifier arrangement comprising:
an input stage having an input, an amplifier connected in series shunt feedback mode, and an output; and
a second stage having an input coupled to the output of said input stage, and an output,
wherein said input and second stages are arranged to operate in current mode.
Preferably, said second stage is a variable gain amplification stage.
Preferably, the voltage amplifier arrangement is arranged to amplify radio frequency voltage signals.
Preferably, said amplifier of the input stage is a transconductance amplifier. More preferably, the transconductance amplifier comprises a bipolar junction transistor configured as a common emitter stage, or a differential pair of bipolar junction transistors configured as common emitter stages.
Preferably, the arrangement comprises a unity gain buffer amplifier coupled in the series shunt feedback loop of the input stage.
Preferably, said second stage comprises a current steering arrangement arranged in use to steer a proportion of the current, provided to the input of the second stage, to an output load, whereby an output voltage is developed across said load and is available at said output of the second stage. The current steering arrangement may be a Gilbert steering stage. More preferably, said current steering arrangement comprises a pair of bipolar junction transistors having their emitters coupled together and to said output of the input stage. The current steering arrangement may comprise two pairs of bipolar junction transistors in a differential arrangement, coupled respectively to differential outputs of the input stage.
The second stage may be arranged to be controlled by an Automatic Gain Control (AGC) signal in order to maintain the output of the stage at a desired level. More preferably, where the stage comprises a pair (or pairs) of bipolar junction transistors, said AGC signal is applied to the bases of the transistors.
The second stage may comprise a mixer or a buffer.
According to a second aspect of the present invention there is provided a method of amplifying an AC voltage signal, the method comprising:
converting the voltage signal into a current signal;
amplifying said current signal to a desired level; and
converting the amplified current signal into an amplified voltage signal.
Preferably, the amplification factor by which the current signal is amplified is less than one.
Preferably, amplification of the current signal comprises splitting the current signal into at least two parts, with one of said parts being converted into the amplified voltage signal.


In automatic transmissions of modern motor vehicles, the transmission control modules are in many cases arranged within the automatic transmission. In order to electrically conductively connect these transmission control modules to electrical connection lines for voltage supply, to signal lines and to bus lines, electrical lines are guided from the transmission control module to an electrical plug-type connector, which is arranged in a through-hole in a transmission housing surrounding the automatic transmission. The transmission housing delimits an interior space filled with automatic transmission oil from an exterior space surrounding the automatic transmission. The electrical plug-type connector can be electrically contacted from the exterior space by means of an electrical mating plug-type connector. The electrical plug-type connector arranged in the through-hole is formed in such a way that no fluid can pass from the interior space to the exterior space. In this case, the plug housing is sealed on its outer wall with respect to the transmission housing, generally by means of an elastomer ring seal. Electrical plug-type contacts are generally arranged in the plug housing of the electrical plug-type connector and protrude from the exterior space into the interior space. These plug-type contacts are sealed with respect to the plug housing fabricated from plastic. This can be achieved for example in that the plug-type contacts have specifically shaped surface profiles, such as a fir-tree profile, in the region with which the plug-type contacts are connected to the plug housing. It is also known to form the seal using O-rings, which are fitted to each plug-type contact. Furthermore, seals by casting, for example with polyurethane, epoxy resin, silicones or similar materials, are known.
It has been found however that, after a few temperature changes within the automatic transmission, wherein the temperature fluctuations may be between −40° C. and +150° C., the adhesion or press-fit between the plug-type contact and the plug housing can loosen. Casting compounds are also susceptible to crack formations or are not sufficiently resistant to automatic transmission oils. This leads to leaks in so far as fluid can now pass from the interior space along the plug-type contacts through the plug housing into the exterior space.


The present invention relates to metal coordination complexes having constrained geometry. The invention also relates to certain novel addition polymerization catalysts comprising such metal complexes having constrained geometry. Furthermore, the invention relates to methods for the polymerization of addition polymerizable monomers and to the resulting polymers.
Because of the unique exposure of the active metal site of the metal coordination complexes having constrained geometry, catalysts resulting therefrom have unique properties. Under certain conditions, the catalysts of the invention are capable of preparing novel olefin polymers having previously unknown properties due to their unique facile abilities to polymerize xcex1-olefins, diolefins, hindered vinylidene aliphatic monomers, vinylidene aromatic monomers and mixtures thereof.
Numerous metal coordination complexes are known in the art including such complexes involving monocyclopentadienyl groups and substituted monocyclopentadienyl groups. The present metal coordination complexes differ from those previously known in the art due to the fact that the metal is bound to a delocalized substituted xcfx80-bonded moiety in a manner so as to induce a constrained geometry about the metal. Preferably the metal is bound to a cyclopentadienyl, substituted cyclopentadienyl or similar group by both a xcex75-bond and a bridging linkage including other ligands of the metal. The complexes also preferably include metals having useful catalytic properties.
Also previously known in the art are transition metal coordination complexes known as tucked complexes. Such complexes are described in Organometallics 6, 232-241 (1987).
In U.S. Ser. No. 8,800, filed Jan. 30, 1987 (published in equivalent form as EP 277,004) there are disclosed certain bis(cyclopentadienyl) metal compounds formed by reacting a bis(cyclopentadienyl) metal complex with salts of Bronsted acids containing a noncoordinating compatible anion. The reference discloses the fact that such complexes are usefully employed as catalysts in the polymerization of olefins. For the teachings contained therein U.S. Ser. No. 8,800 and EP 277,004 are herein incorporated in their entirety by reference thereto.
Previous attempts to prepare copolymers of vinylidene aromatic monomers and xcex1-olefins, in particular copolymers of styrene and ethylene, have either failed to obtain substantial incorporation of the vinylidene aromatic monomer or else have achieved polymers of low molecular weight. In Polymer Bulletin, 20, 237-241 (1988) there is disclosed a random copolymer of styrene and ethylene containing 1 mole percent styrene incorporated therein. The reported polymer yield was 8.3xc3x9710xe2x88x924 grams of polymer per micromole titanium employed.
It has now been discovered that previously known addition polymerization catalysts are incapable of high activity and polymerization of numerous monomers because they lack constrained geometry.
It would be desirable if there were provided novel complexes of groups 3 (other than scandium), 4-10 and the lanthamides having constrained geometry.
Additionally it would be desirable if there were provided novel catalysts for addition polymerizations comprising novel complexes of groups 3 (other than scandium), 4-10 and the lanthamides having constrained geometry.
Furthermore, it would desirable if there were provided a process for the preparation of polymers of addition polymerizable monomers using novel catalysts comprising complexes of groups 3 (other than scandium), 4-10 and the lanthamides having constrained geometry.
Finally, it would be desirable if there were provided novel polymers of addition polymerizable monomers that may be prepared by an addition polymerization process using catalysts comprising novel complexes of groups 3 (other than scandium), 4-10 and the lanthamides having constrained geometry.
In one aspect the present invention relates to a metal coordination complex having constrained geometry. More particularly it relates to such coordination complexes that are usefully employed in combination with activating cocatalyst compounds or mixtures of compounds to form a catalytic system usefully employed in the polymerization of addition polymerizable monomers, especially ethylenically unsaturated monomers.
In another aspect the present invention relates to a process for preparing certain components of the above metal coordination complexes having constrained geometry and to the precursor compounds necessary therefor.
In yet another aspect the present invention relates to a process for preparing addition polymers, especially homopolymers and copolymers of olefins, diolefins, hindered aliphatic vinyl monomers, vinylidene aromatic monomers and mixtures of the foregoing and to the resulting polymer products.
According to the present invention there is provided a metal coordination complex comprising a metal of group 3 (other than scandium), 4-10 or the lanthamide series of the periodic table of the elements and a delocalized _-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry about the metal atom such that the angle at the metal between the centroid of the delocalized, substituted xcfx80-bonded moiety and the center of at least one remaining substituent is less than such angle in a similar complex containing a similar xcfx80-bonded moiety lacking in such constrain-inducing substituent, and provided further that for such complexes comprising more than one delocalized, substituted xcfx80-bonded moiety, only one thereof for each metal atom of the complex is a cyclic, delocalized, substituted xcfx80-bonded moiety.
In addition there is provided a metal coordination complex corresponding to the formula:
wherein:
M is a metal of group 3 (other than scandium), 4-10, or the lanthamide series of the periodic table of the elements;
Cp* is a cyclopentadienyl or substituted cyclopentadienyl group bound in an xcex75 bonding mode to M;
Z is a moiety comprising boron, or a member of group 14 of the periodic table of the elements, and optionally sulfur or oxygen, said moiety having up to 20 non-hydrogen atoms, and optionally Cp* and Z together form a fused ring system;
X independently each occurrence is an anionic ligand group or neutral Lewis base ligand group having up to 30 non-hydrogen atoms;
n is 0, 1, 2, 3, or 4 depending on the valence of M; and
Y is an anionic or nonanionic ligand group bonded to Z and M comprising nitrogen, phosphorus, oxygen or sulfur and having up to 20 non-hydrogen atoms, optionally Y and Z together form a fused ring system.
There is also provided according to the present invention a process for preparing a metal coordination complex corresponding to the foregoing formula I comprising the steps of:
A) contacting a metal compound of the formula MXn+2 or a coordinated adduct thereof with a dianionic salt compound corresponding to the formula:
(L+x)y(Cp*-Z-Y)xe2x88x922xe2x80x83xe2x80x83(II)
or
((LXxe2x80x3)+x)y(Cp*-Z-Y)xe2x88x922xe2x80x83xe2x80x83(III)
wherein:
L is a metal of group 1 or 2 of the periodic table of the elements,
Xxe2x80x3 is fluoro, chloro, bromo, or iodo,
x and y are either 1 or 2 and the product of x and y equals 2, and
M, X, Cp, R, and Y are as previously defined; and
B) recovering the resulting product.
Further there is provided a process for preparing a metal coordination complex corresponding to the foregoing formula I comprising the steps of:
A) contacting a metal compound of the formula MXn+1 or a coordinated adduct thereof with a dianionic salt compound corresponding to the formulas II or III;
B) oxidizing the metal to a higher oxidation state by contacting the reaction product of step A) with a noninterfering oxidizing agent; and
C) recovering the resulting product.
There is also provided a catalyst useful in addition polymerizations comprising the following components:
a) a metal coordination complex comprising a metal of group 3 (other than scandium), 4-10 or the lanthamide series of the periodic table of the elements and a delocalized xcfx80-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry about the metal atom such that the angle at the metal between the centroid of the delocalized, substituted xcfx80-bonded moiety and the center of at least one remaining substituent is less than such angle in a similar complex containing a similar xcfx80-bonded moiety lacking in such constrain-inducing substituent, and provided further that for such complexes comprising more than one delocalized, substituted xcfx80-bonded moiety, only one thereof for each metal atom of the complex is a cyclic, delocalized, substituted xcfx80-bonded moiety; and
b) an activating cocatalyst.
In a further embodiment of the present invention there is provided a catalyst useful in addition polymerizations comprising the following components:
a) a metal coordination complex corresponding to the formula I, and
b) an activating cocatalyst.
Even further according to the present invention there is provided a polymerization process comprising contacting one or more addition polymerizable monomers under addition polymerization conditions with a catalyst comprising:
a) a metal coordination complex comprising a metal of group 3 (other than scandium), 4-10 or the lanthamide series of the periodic table of the elements and a delocalized xcfx80-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry about the metal atom such that the angle at the metal between the centroid of the delocalized, substituted xcfx80-bonded moiety and the center of at least one remaining substituent is less than such angle in a similar complex containing a similar xcfx80-bonded moiety lacking in such constrain-inducing substituent, and provided further that for such complexes comprising more than one delocalized, substituted xcfx80-bonded moiety, only one thereof for each metal atom of the complex is a cyclic, delocalized, substituted xcfx80-bonded moiety; and
b) an activating cocatalyst.
Further according to the present invention there is provided an addition polymerization process comprising the steps of;
A) contacting a mixture comprising one or more addition polymerizable monomers under polymerization conditions in the presence of a catalyst comprising a metal coordination complex corresponding to the formula I and an activating cocatalyst; and
B) recovering the resulting polymer.
Further still according to the present invention there is provided a polymer comprising in interpolymerized form one or more addition polymerizable monomers prepared by contacting an addition polymerizable monomer or mixture thereof under addition polymerization conditions with a catalyst comprising:
a) a metal coordination complex comprising a metal of group 3 (other than scandium), 4-10 or the lanthamide series of the periodic table of the elements and a delocalized xcfx80-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry about the metal atom such that the angle at, the metal between the centroid of the delocalized, substituted xcfx80-bonded moiety and the center of at least one remaining substituent is less than such angle in a similar complex containing a similar xcfx80-bonded moiety lacking in such constrain-inducing substituent, and provided further that for such complexes comprising more than one delocalized, substituted xcfx80-bonded moiety, only one thereof for each metal atom of the complex is a cyclic, delocalized, substituted xcfx80-bonded moiety; and
b) an activating cocatalyst.
In a still further embodiment of the present invention there is provided a polymer comprising in polymerized form one or more addition polymerizable monomers prepared by contacting an addition polymerizable monomer or mixture thereof under addition polymerization conditions with a catalyst comprising the following components:
a) a metal coordination complex corresponding to the formula I and an activating cocatalyst.
In still further embodiments there are provided ElPE polymers which are highly elastic, interpolymers of ethylene and one or more olefins other than ethylene.
In addition there are provided pseudo-random interpolymers of an xcex1-olefin, particularly ethylene and a vinylidene aromatic monomer, a hindered aliphatic vinylidene monomer, or a mixture thereof.
The complexes of the invention are usefully employed as catalysts for addition polymerization processes to prepare polymers that are useful as molded articles, films for packaging applications, and foams for cushioning applications; and in the modification of synthetic and naturally occuring resins. The complexes may also be used as catalysts for hydrogenations, catalytic cracking processes, and in other industrial applications.


Optical gratings are well known in the art and are used to disperse optical spectra spatially. Such gratings are commonly used in optical spectrometers to analyze the spectral composition of an optical beam. There is always a tradeoff between the length of an optical spectrometer and its resolution. Thus, if a higher wavelength resolution is required, the length required is also longer. Consider an example of a typical 1-meter long grating spectrometer in the market, which has a typical wavelength resolution of about ΔλSM=0.1 nm at a center operating wavelength λSM=1000 nm or ΔλSM/λSM=10−4. The dimensionless quantity for the length of the spectrometer LSM is LSM/λSM and LSM/λSM=106 in this example. The dimensionless product of the relative resolution ΔλSM/λSM and the relative physical size LSM/λSM of the spectrometer is dependent on the design of the spectrometer.
Resolution Vs Size/Area Factor
More precisely, consider a curved grating spectrometer device 1000 shown in FIG. 1 with a curved grating CG 1010 and a wave or beam propagating region between the input slit SLI1 1201 and the grating or the grating and the output slit SLO1 1401 called grating-propagating region GPR 1020. If the spectrometer has a width WSM 1002 and a length LSM 1003, then the dimensionless product of interest is:RSSM=(ΔλSM/λSM)*[(WSM/λSM)*(LSM/λSM)]0.5,  (1)where “*” denotes numerical multiplication. This factor (RSSM) is referred to here as the “resolution vs size” factor of the spectrometer. The square of RSSM factor is called “resolution vs area” factor:RASM=(RSSM)2.  (2)The factors RASM and RSSM basically measure the compactness of a spectrometer for a given spectral resolution power. In this example, if WSM=LSM=1 m, then RSSM=100 and RASM=104. The smaller the RSSM and RASM value, the more compact is the spectrometer.
Only a few conventional spectrometers have RASM factor less than about 100 (or RSSM<10). This is primarily because of the various limitations in the prior arts (as will be described below). In many photonic integrated circuit, electronic-photonic integrated circuit, and fiber-optic applications, RASM factors of smaller than about RASM=1 down to RASM=0.01 are desirable. These cannot be achieved via the methods in the prior arts.
Furthermore, for many applications in photonic integrated circuits, electronic-photonic integrated circuits, and fiber-optics, the background extinction of the spectral power outside the wavelength range that is supposed to be detected is important, which measures the relative optical power from outside the detection wavelength range that is scattered into the output slit or photodetector of the spectrometer.
Spectral Output Power Efficiency
A parameter that measures such unwanted background scattering is the “adjacent-channel power extinction ratio”. As shown by FIGS. 1 and 1B, assuming the input light at an input slit labeled as slit “SLI1” 1201 for which “I1” labels “input” “1” has an optical spectrum with optical power spectral density PSI1(λ) 1131 at wavelength λ. Let λI1-O1 1321 be the center spectral wavelength that goes from the spectrometer's input slit SLI1 to the spectrometer's output slit labeled as output slit “SLO1” 1401. Let the optical power spectrum entering or being detected at output slit SLO1 1401 be PSI1-O1(λ) 1331. PSI1-O1(λ) 1331 is then given in terms of the spectral density of the input beam PSI1(λ) by:PSI1-O1(λ)=ηeffI1-O1(λ)*PSI1(λ).  (3)The factor ηeffI1-O1(λM) is the efficiency of passing or detecting the power of the input beam from input slit SLI1 at the output slit SLO1 at wavelength λM, assuming that the input beam is basically a monochromatic light source at λM (e.g. a narrow-bandwidth laser light). The factor ηeffI1-O1(λM) is called the “spectral power output efficiency”.
As shown in FIG. 1B, the power at input slit SL 1201 over a small spectral bandwidth Δλ centered at wavelength λA (small comparing to the spectral bandwidth of PSI1-O1(λ) at λA or more precisely, small enough so that PSI1-O1(λ) at λA does not change much over the wavelength bandwidth Δλ), denoted as PI1(λA; Δλ) 1131DL, is given by:PI1(λA;Δλ)=PSI1(λA)*Δλ.  (4A)Let the total optical power entering or being detected at output slit SLO1 1401 over a small spectral bandwidth Δλ centered at wavelength λA for the beam from input slit SLI1 be PI1-O1(λA; Δλ) 1331DL. PI1-O1(λA; Δλ) is then given by PSI1-O1(λA)*Δλ=ηeffI1-O1(λ)*PSI1(λ)Δλ according to Eq. (3). It is also given by ηeffI1-O1(λA)*(λA; Δλ). PI1-O1(λA; Δλ) is thus related to the spectral density of the input beam PSI1(λA) by:PI1-O1(λA;Δλ)=PSI1-O1(λA)*Δλ=ηeffI1-O1(λA)*PSI1(λA)*Δλ.  (4B)In the situation that Δλ is large, Eqs. (4A) and (4B) should be more precisely converted to an integration of PSI1-O1(λ) with respect to wavelength λ over wavelength bandwidth Δλ centered at wavelength λ=λA given by:
                                                                                P                              I                                                                                1                                                                (                                                λ                  A                                ;                Δλ                            )                                =                                    ∫                                                λ                  A                                -                                  Δλ                  2                                                                              λ                  A                                +                                  Δλ                  2                                                                                PS                                      I                                        1                                                                                (                  λ                  )                                                                                d                                                                                λ                                                          (                  5                    A                )                                                      P                                          I                                1                            -                              O                                1                                                                    (                                          λ                A                            ;              Δλ                        )                          =                                            ∫                                                λ                  A                                -                                  Δλ                  2                                                                              λ                  A                                +                                  Δλ                  2                                                                                PS                                                            I                                            1                                        -                                          O                                            1                                                                                (                  λ                  )                                                                                ⅆ                λ                                              =                                    ∫                                                λ                  A                                -                                  Δλ                  2                                                                              λ                  A                                +                                  Δλ                  2                                                                                η                                                            effI                                            1                                        -                                          O                                            1                                                                                (                  λ                  )                                            *                                                PS                                      I                                        1                                                                                (                  λ                  )                                                                                d                                                                                λ                                                          (                  5                    B                )            Total Power and Power Spectrum
To define the “adjacent-channel power extinction ratio”, let the spectral resolution bandwidth for a beam at wavelength λI1-O1 1321 from input slit SLI1 1201 to output slit SLO1 1401 be ΔλRes-I1-O1 1381Res, as shown in FIG. 1B. Assuming the input power spectrum at an input slit of the spectrometer PSI1(λ) 1131 is approximately a constant for the wavelength λ around λ=λI1-O1 1321. Let the optical power from the input slit SLI1 1201 entering or being detected at an output slit of the spectrometer SLO1 1401 over the spectral bandwidth given by the spectral resolution bandwidth ΔλRes-I1-O1 1381Res be PI1-O1(λI1-O1; ΔλRes-I1-O1), where:
                                          P                                          I                                1                            -                              O                                1                                              =                                                    P                                                      I                                        1                                    -                                      O                                        1                                                                                (                                                      λ                                                                  I                                                1                                            -                                              O                                                1                                                                              ;                                      Δλ                                          Res                      -                                              I                                                1                                            -                                              O                                                1                                                                                )                                      =                                          ∫                                                      λ                                                                  I                                                1                                            -                                              O                                                1                                                                              -                                                            Δλ                                              Res                        -                                                  I                                                    1                                                -                                                  O                                                    1                                                                                2                                                                                λ                                                                  I                                                1                                            -                                              O                                                1                                                                              +                                                            Δλ                                              Res                        -                                                  I                                                    1                                                -                                                  O                                                    1                                                                                2                                                                                η                                                                  effI                                                1                                            -                                              O                                                1                                                                                (                    λ                    )                                                  *                                                      PS                                          I                                            1                                                                                (                    λ                    )                                                                                d                                                                                λ                                                    ,                            (                  6                    A                )            Then at an adjacent wavelength that is separated from λI1-O1 1321 by “one spectral resolution bandwidth” ΔλRes-I1-O1 1381Res away, the power detected over the same spectral resolution bandwidth ΔλRes-I1-O1 1381Res given by:
                                                        P                              I1                -                                  O                                    1                                                                                (                                                                    λ                                                                  I                                                1                                            -                                              O                                                1                                                                              +                                      Δλ                                          Res                      -                                              I                                                1                                            -                                              O                                                1                                                                                ;                                  Δλ                                      Res                    -                                          I                                            1                                        -                                          O                                            1                                                                                )                                =                                    ∫                                                λ                                                            I                                            1                                        -                                          O                                            1                                                                      +                                  Δλ                                      Res                    -                                          I                                            1                                        -                                          O                                            1                                                                      -                                                      Δλ                                          Res                      -                                              I                                                1                                            -                                              O                                                1                                                                              2                                                                              λ                                                            I                                            1                                        -                                          O                                            1                                                                      +                                  Δλ                                      Res                    -                                          I                                            1                                        -                                          O                                            1                                                                      +                                                      ΔλΔλ                                          Res                      -                                              I                                                1                                            -                                              O                                                1                                                                              2                                                                                η                                                            effI                                            1                                        -                                          O                                            1                                                                                (                  λ                  )                                            *                                                PS                                      I                                        1                                                                                (                  λ                  )                                                                                d                                                                                λ                                      ,                            (                  6                    B                )            should ideally be zero at the output slit (as the spectral power output efficiency ηeffI1-O1(λ) shall be approximately zero when λ=λI1-O1+ΔλRes-I1-O1 is not at the supposed output detection/passing wavelength λI1-O1 1321 of output slot SLO1 and is at one resolution bandwidth ΔλRes-I1-O1 1381Res away from λI1-O1 1321).Adjacent-Channel Extinction Ratio
The ratio of the power at λI1-O1 1321 and the power at λI1-O1+ΔλRes-I1-O1 given by:ηace(λI1-O1)=PI1-O1(λI1-O1;ΔλRes-I1-O1)/PI1-O1(λI1-O1+ΔλRes-I1-O1;ΔλRes-I1-O1),  (7)is called the “adjacent-channel power extinction ratio” or “adjacent-wavelength power extinction ratio” or “adjacent wavelength-channel extinction ratio”, or “adjacent channel extinction ratio” for the beam from input slit SLI1 1201 to output slit SLO1 1401. It is also related to what is known to those skilled in the art as “adjacent-channel crosstalk rejection” or “adjacent-channel crosstalk extinction”. These terminologies will thus be used interchangeably below.Adjacent Channel Extinction Ratio of a Spectrometer
Let ηace(λSM) denotes the adjacent channel extinction ratio for the spectrometer at its center operating wavelength λSM. It is called the “adjacent channel extinction ratio of a spectrometer”. This adjacent-channel extinction ratio ηace(λSM) is typically higher than about 100, especially when the size of the spectrometer is small (i.e. when the RASM factor is smaller than about 104). For many applications in photonic integrated circuits, electronic-photonic integrated circuits, and fiber-optics, ηace(λSM) higher than about 100, and RASM factor smaller than about 104 are desirable but they are largely not reachable via the methods in the prior arts.
Furthermore, for many applications in photonic integrated circuits, electronic-photonic integrated circuits, and fiber-optics, it is desirable that at the wavelength range of interest, the efficiency of passing or detecting the input spectral power be efficient, which is given by the spectral power output efficiency factor ηeffI1-O1(λI1-O1) defined above.
Spectral Power Output Efficiency of a Spectrometer
Let ηeff(λSM) denote the spectral power output efficiency ηeffI1-O1(λI1-O1) when the output slit wavelength λI1-O1 1321 is at the center operating wavelength λSM of the spectrometer. In an ideal situation, ηeff(λSM) shall be equal to unity (i.e. the number “1” so that the output power is equal to the input power or it has 100% passing or detection efficiency) or at least near unity. In many applications ηace(λSM) higher than about 100 with RASM factor smaller than about 104 and ηeff(λSM) higher than about 0.5 or having a higher than 50% passing/detection efficiency is desirable. In some other applications, ηace(λSM) higher than about 100 with RASM factor smaller than about 104, and ηeff(λSM) higher than about 0.1 (i.e. having a higher than 10% passing/detection efficiency) are desirable. These capabilities are desirable for the spectrometer but they are largely not reachable via the methods in the prior arts.
Conventional Rowland Gratings and their General Limitations
Although a small input slit width is required to achieve high spectral resolution for a spectrometer, a smaller input slit width WI1 1291W (see FIG. 1A), however, leads to a larger beam divergence full angle θdvdf-BI1-IP % 1141 (see FIG. 2) from the input slit defined as the beam angular span that encompasses IP %=95% of the beam energy. It can be shown that the conventional Rowland design in the prior art works reasonably well only up to (θdvdf-BI1-95%)/2<4° (for a grating in air for which the beam propagation region has a refractive index of ngr=1). More specifically, θdvdf-BI1-95% is the full divergence angle of the input beam due to spatial diffraction that we refer to as the “divergence-diffraction” (dvdf) angle. The 95% refers to the angle being defined by 95% of the beam power to be within the divergence angle. Note that the 4° is half the divergence angle of θdvdf-BI1-95%. If the grating cannot intercept or refocus a large percentage of the beam power well, then it will result in an unnecessarily large beam spot size at the output slit, and hence a worse wavelength resolution at the output slit.
Let the input beam be a monochromatic beam with wavelength λI1-O1 1321 (see FIG. 2) and the focal spot size for this beam at the output slit SLO1 1401 be WBI1-O1-IP % 1381W (see FIG. 2). When θdvdf-BI1-95%/2>4°, the Rowland design could not give a sharp enough focus at the output slit SLO1 1401, thereby limiting the resolution of the spectrometer.
A half-diffraction angle of θdvdf-BI1-95%/2=4° corresponds to a slit width of about 25 microns (for an input beam wavelength around λI1-O1=1000 nm and n=1). In the current art, it is typically difficult to make slit width smaller than about 25 microns, and Rowland design is adequate for most present spectrometers with slit widths larger than about 25 microns (for a grating in air for which the beam propagation region has a refractive index of ngr=1).
Slit size (n = 3.4)θD(>95% energy)10μm 6°6μm10°2μm24°1μm46°0.5μm70°0.3μm90°
Focusing Aberration Limitation:
In the case of the Rowland design, when (θdvdf-BI1-95%)/2>4 Degree(s) (DEG), serious aberration in the refocusing beam will occur to limit wavelength resolution (θdvdf-BI1-95% 1141 is the full divergence angle of the input beam due to spatial diffraction that we refer to as the “divergence-diffraction” (dvdf) angle. The 95% refers to the angle being defined by 95% of the beam power to be within the divergence angle). This is shown in FIG. 4, illustrating the ray tracing for the typical Roland-Echelle design at 4, 8, and 16 DEG diffraction. The ray tracing will allow us to see potential focusing distortion or aberration at the exit slit. In the figure, we show the focusing behavior for two sets of rays with wavelengths separated by 0.4 nm. Let the “half angle” θdiv=(θdvdf-BI1-95%)/2. From the figure, we see that their focused spots are clearly separated when θdiv=4 DEG. However, when θdiv=8 DEG, the focused spots began to smear out. FIG. 4A shows the cases of θdiv=16 DEG, and θdiv=50 DEG, for which the focused spots smear out even more. Thus, there is substantial distortion for the focusing rays when θdiv>4 DEG. Further simulations based on numerical solutions to Maxwell's wave equations using finite-difference time-domain (FDTD) method also show similar onset of focused spot size distortion at θdiv>4 DEG. In short, the current designs are close to their resolution-area (RASM) limits at θdiv of about 4 DEG and cannot be made substantially more compact without losing wavelength resolution.


Saw blades beveling is an advantageous capability to be included with power saw assemblies, such as table saw assemblies which include a saw assembly comprising a saw blade, extending through a planar surface (table), coupled with a motor by a mounting assembly. Beveling assemblies, provide the operator of a table saw with the ability to adjust the angular presentation of the saw blade relative to the planar surface of the table. Unfortunately, many beveling assemblies included with table saw assemblies, and the like, are limited in the capabilities they may provide to the operator.
A typical limitation of many beveling assemblies is the enablement of beveling in a single tilt orientation. For instance, a beveling assembly may provide the operator with the ability to adjust the angular presentation of the saw blade relative to the planar surface of the table in a right tilt orientation or a left tilt orientation. Other beveling assemblies have limited beveling capabilities resulting from unwanted contact between the component features of the saw assembly or beveling assembly and other structural impediments of the table saw assembly, such as the unwanted contact between the motor, which drives the saw blade of the table saw assembly, and the underside of the planar surface of the table or structural support features of the table saw assembly. Additionally, unwanted contact may result from contact between the mounting assembly of the saw blade and the table. For instance, when the blade is beveled, the mounting assembly may contact the underside of the table because of the mounting assembly's proximate location to the table.
Unfortunately, attempts to resolve these problems have resulted in assemblies which may require a user to accept limited capabilities. For example, unwanted contact is decreased, but only by limiting the depth of cut capabilities of the saw blade of the table saw assembly. Therefore, it would be desirable to provide a table saw assembly which enables the saw blade with bi-directional beveling capabilities (right and left tilt orientation) without reducing the capabilities of the saw blade due to factors, such as unwanted structural impedance.
Additional limitations may be a result of design limitations. For instance, the assembly, which couples the saw blade with the motor of the table saw, typically, statically fixes the position of the motor relative to the saw blade. Such a situation may result in decreased performance of the saw assembly during beveling due to changes in tolerances resulting from changes in the positions of these features due to beveling.
Therefore, it would be desirable to provide a beveling assembly which increased the ability of the component features of the table saw assembly to remain near optimal tolerances during the beveling of the saw blade. Another design limitation is the typical arbor assembly is enabled as a single axle, which may be limited to coupling with the saw blade to impart angular momentum on a single end of the axle. This may result in the beveling assembly enabled with the single axle arbor assembly limiting its capabilities to a single tilt orientation, as described previously. Still further, this may result in increased time spent attempting to properly re-align the single axle arbor assembly when transitioning between beveling in a first tilt orientation to beveling in a second tilt orientation, such as from right to left. This may significantly decrease productivity accomplished through use of the table saw employing such a single axle arbor assembly. Further, due to such drastic re-positioning required by the single axle arbor assembly there may be an increase in tolerance misalignments resulting in increases in non-production time spent by the power tool. Therefore, it would be desirable to provide an arbor assembly which decreased time spent re-aligning the arbor assembly and increased the ease of employing the saw blade on the arbor assembly for beveling in both tilt orientations.
Further, it is common practice in the field of power tools, particularly arbor assemblies for table saws, to take steps to “true” the assembly after it has been assembled. This truing may assist in increasing the productivity and life span of the power tool by assisting in reducing wear to the component features of the power tool. Steps, such as machining the flange may true the arbor assembly and may decrease the amount of “wobble” introduced into the saw blade during operation of the table saw. Unfortunately, after the truing of the arbor assembly is complete the parts of the arbor assembly, such as the bearing for example, may wear out due to use, requiring replacement. It is known to allow for the operator to disassemble the arbor assembly in order to replace the bearing. This often requires removal of the flange in order to access the bearing. It is typically the case that when the operator re-assembles the arbor assembly the flange and possibly other component features are no longer in the trued position, as originally provided by the manufacturer. Thus, “wobble” may be introduced into the spinning blade of the table saw. Therefore, it would be further desirable to provide an arbor assembly which assists the operator in maintaining its trued position even after replacement of component features of the arbor assembly.
Therefore, it would be further desirable to provide an arbor assembly which assists the operator in maintaining its trued position even after replacement of component features of the arbor assembly.


Mating fasteners that include two opposed fastener members are popular in a variety of applications. The particular type of mating fastener with which the present invention is concerned includes two opposed fastener members, each including a surface having a plurality of arranged headed stems projecting therefrom. Such fasteners are particularly useful in an environment where it is desirable to interengage the fastener using a relatively small amount of force, while requiring a larger force to separate the fastener members.
A conventional molded polymeric fastener is shown in FIG. 1. Included are opposed fastener members 10 and 12, including bases 14 and 16, respectively. Each base includes a plurality of arranged stems 18 orthogonally projecting therefrom, and each terminating in a head 20 at the respective distal ends of stems 18. The heads have generally arcuate surfaces 22 opposite the respective bases 14 and 16, which surfaces are adapted for sliding contact with the encountered arcuate surfaces 22 of heads 20 when the fastener members are first brought together. Heads 20 also each include a generally planar latching surface 24 extending radially outwardly of the stem, which is adapted to engage a latching surface of an opposed head, as shown in FIG. 2.
FIG. 1 shows fastener members 10 and 12 prepared for engagement, with the heads of one fastener member positioned generally between the heads of the other fastener member. To engage the fastener, fastener members 10 and 12 are urged toward each other with the respective bases generally parallel, causing heads 20 to contact and to deflect the attached stems laterally. The lateral deflection of the stems allows the heads of one fastener member to pass the heads of the opposed fastener member to engage the fastener members in the manner illustrated in FIG. 2.
In the past, fasteners of the type discussed above were generally formed by passing a backing layer having a multiplicity of projecting stems beneath a heat source, which heat source tends to melt the stems to form heads atop each of the stems. Such a process is known in the art, as illustrated by U.S. Pat. No. 4,290,832 (Kalleberg), entitled "Method for Making Fasteners." The '832 patent discloses a multi-step process for producing a fastener member having a backing layer, a plurality of monofilament stems projecting normally from the backing layer, and a head atop each stem.
The process, illustrated schematically in FIG. 3, includes moving two backing layers 50 and 52 in parallel paths while feeding monofilament 54 between the layers, and pressing the monofilaments using applicators 56 and 58, so that the monofilaments extend normally between the layers. The monofilaments are severed halfway between the backing layers by blade 60, which produces dual, opposed backing layers each having a plurality of monofilaments extending from each backing. The newly severed terminal ends of the monofilaments are then heated by heat sources 62 and 64 to a temperature sufficient to form a head atop each of the stems. After the heads have solidified, the two fastener members 66 and 68 are wound onto separate rollers 70 and 72, respectively, for dispensation and use.
While having their own utility, the fasteners formed by the process described above tend to exhibit inconsistently shaped heads, which can potentially affect release performance. For example, a generally spherical head having an arcuate latching surface may be unintentionally formed by such a process. An arcuate latching surface tends to disengage more easily than a planar latching surface extending radially from the stem, and could lower the force required to disengage the fastener. Alternatively, the heads could be irregularly formed due to the inconsistent application of heat, differences in production speed, and the like. Such irregularities could prompt inconsistent release characteristics, which may be undesirable under some circumstances.
Furthermore, for certain applications it may be preferable to provide heads that are generally conical, spherical, or some other such desired shape in order to obtain certain engagement and release characteristics. For example, U.S. Pat. No. 4,454,183 (Wollman) discloses a three lobed head structure formed by the application of heat to a triangular monofilament stem. However, as discussed above, heads formed by the application of heat to a monofilament stem tend not to be consistently formed. Furthermore, the number of different head structures is generally limited by the size and shape of the stems from which they are formed.
Another approach to forming heads atop stems in a desired shape is disclosed in Japanese patent publication no. 1-238805 (Anzai). The method disclosed in the '805 publication involves forming individual rows of stems by injection molding. Each individual row of stems, which stems may include spherical, conical, or other shaped heads, is typically formed in a mold that is split along the longitudinal axis of the stem. After the molten material has been injected and solidified, the halves of the mold may be separated, and the individual row of stems removed.
In order to form a fastener from the individual rows of stems, several such rows must be aligned and connected together. The individual rows may be connected by means of adhesive, thermal bonding, high frequency bonding, and the like. Although this method of forming a fastener may represent an improvement over the prior art in terms of head formation, it involves a greater investment of time and equipment to connect the individual rows together to form the fastener, and is therefore more expensive and undesirable.
Finally, it is often desirable to form a secondary fastening portion on one surface of the fastener, typically the back surface, in order to enable the fastener to be easily attached to a surface, body, or the like. At present, the secondary fastening portion is typically attached to the back of the fastener member by welding (either solvent, heat, or ultrasonic welding), which requires a manufacturing step separate from the formation of the fastener portion. The second manufacturing step increases the cost of the article, and is therefore undesirable.
It is therefore desirable to provide a method of making a unitary fastener member having rows and columns of stems having consistently identical head structures of a desired shape, to provide a method of making a unitary fastener having head structures of different desired shapes, and to provide a fastener member having an integral secondary fastening portion that is formed concurrently with the fastener member.


Proximity detection devices are used in a wide variety of applications for determining the relative nearness or separation of an object or person relative to another object or person. An application of such devices that has recently acquired considerable public interest involves using such devices to allow a responsible individual, such as parent or guardian, to monitor the whereabouts of another person in the custody of the responsible individual. One example of a monitoring system that is intended to equip a responsible individual with the ability to monitor the whereabouts of another person, such as a child, is described in the U.S. Pat. No. 4,598,272, to Cox, the disclosure of which is incorporated herein.
In accordance with the system described in the Cox patent, proximity monitoring is performed by equipping each of a parent and a child with a respective radio transmitter-radio receiver pair. The radio transmitter carried by the child is operative to broadcast or radiate a high frequency RF electromagnetic wave to which the receiver in the unit carried by the parent is tuned. Should the level of the received RF signal monitored by the parent's radio receiver drop below a prescribed threshold, indicating that the child has moved to location beyond a prescribed distance from the parent, an alarm signal is generated by the parent's device. In response to the alarm signal, the parent may then active his or her own radio transmitter, which broadcasts a radio wave that has substantial signal strength, so that it will be detected by the child's unit. When the child's unit detects the RF signal transmitted by the parent's unit, it outputs an audible alarm signal that is loud enough to be heard by the parent, thereby enabling the parent to locate the child.
Now although the signal strength-monitoring--alarm--response radio wave communication scheme employed in the system described in the Cox patent facilitates alerting a parent/guardian of the separation of a child, patient, etc. beyond a prescribed distance, it has been found that the use of a high frequency radio wave as the signalling mechanism has a number of inherent problems that limit its performance, and thereby prevent its practical application to a wide variety of signalling environments.
More particularly, a fundamental shortcoming of a high frequency radio wave (e.g. one on the order of 300+ MHz) is the fact that radio waves are subject to multipath propagation, which can be especially severe in the interior of a building. Secondly, colinearity between the direction of polarization of the broadcast RF signal and the receiver antenna is required for ensuring optimum signal reception. A further problem is the effect of the dielectric distortion effect of the human body (a substantial salt water mass) on the signal, which can typically causing a fluctuation in signal amplitude on the order of 10-15 dB. Moreover, since the signal strength of a radiated electromagnetic wave is inversely proportional to the square of the distance from the emitter, the setting of a signal strength threshold to trigger an alarm yields very imprecise results, especially when considering the other effects described above.


The invention relates generally to mops, and more particularly to mops in which a connector is used to connect mop fibers to a handle.
U.S. Pat. No. 1,924,978 discloses an early version of a cleaning product with a separate connector used to secure a "dusting element" to a handle. In that device, the connector (head H) is illustrated as being attached to the handle ferrule 5 that is anchored to the handle by a pin 6 or the like. The connector includes two deformable arms 2 that are used to hold the dusting element. The dusting element includes an internal casing or envelope 7 with a central opening 8, through which the arms can pass when squeezed together. After the arms are inserted into the casing or envelope, they can be released to hold the dusting element in place. Unfortunately, the device appears to require an internal casing or envelope, which could be unduly expensive for use with a mop.
U.S. Pat. No. 2,299,480 shows a more conventional method for attaching mop fibers to a handle. The illustrated mop head includes a U-shaped wire loop 11 that has pointed ends 13 that can be used to pierce a cylindrical ferrule 12. The completed head can be attached to a handle by a driving a nail through a hole 14 in the ferrule.
U.S. Pat. No. 4,135,272 discloses a more modem implementation of the idea. That discloses a plastic connector 12 having an aperture 27 and slot 29 used for securing fibers to the head. A separate strap 34 having a head 35 is first passed through the aperture 27, then under the mop fibers, then up through the slot 29. The head holds one end of the strap in the aperture 27, while projecting teeth 38 hold the other end in the slot 29. The connector includes an upper cylindrical portion 14 that permits it to be threaded onto a handle 18.
U.S. Pat. No. 4,377,879 discloses a one-piece mop connector comprising a tongue 16 that can be used to hold mop fibers. The tongue can be locked in place by a series of grips 18 that can engage locking members 22 molded onto the sides of the connector. The connector is secured to a handle through the seating of an interior retaining projection 28 in a groove 30 on the end of the handle. This semi-permanent connection of the connector to the handle is not particularly desirable.
In apparent recognition of the need for improving the security of the connection of a connector to a handle, while permitting easy replacement or exchange of a mop head, U.S. Pat. No. 5,375,286 discloses a resilient bayonet-type mounting system for cleaning implements. The disclosed mop head apparently traps mop fibers between distinct upper and lower elements 9 and 10 that are secured together by ultrasonic welding.
A simpler and more convenient connector for attaching mop fibers to a mop handle would be desirable.


1. Field of the Invention
The invention relates to rifle actions in general and bolt actions in particular.
2. Prior Art
In a bolt action rifle, the barrel is typically threaded into the receiver. The barrel includes the chamber, which is that portion of the barrel that holds the round immediately prior to firing. The rough dimensions of the chamber are formed prior to the barrel being threaded into the receiver. However, the final dimensions of the chamber are formed by hand in order to ensure that the headspace is proper.
Headspace is the distance from the face of the bolt to whatever surface in the chamber stops the round from advancing into the barrel. In a rimless cartridge, such as the .308, the headspace is the distance from the bolt face to the shoulder in the chamber. Stated more broadly, in a rimless cartridge, the headspace is a function of the distance from the face of the bolt to the chamber and of the chamber dimensions. Headspace in a rimless cartridge is illustrated in FIG. 1 as dimension X.
The acceptable tolerance for headspace in rifles is relatively narrow. In a .308, the acceptable headspace range is 1.6300 to 1.6340 inches. Thus, only 4 thousandths of an inch separate too little headspace from too much.
Very bad things can happen if the headspace is not within specification for the rifle. When the round is fired, the chamber is supposed to hold the casing in place so that the expanding (i.e., exploding) gases can be used to drive the bullet down the barrel. However, if there is too much headspace, those same gases can drive the casing back toward the bolt. This can result in failure of the casing, damage to the bolt, and in some cases, even catastrophic failure of the rifle. Excessive headspace can also result in the round advancing into the chamber so that the firing pin in the bolt cannot adequately impact the primer, with the result that the round fails to go off. Similarly, excessive headspace can allow the spent shell casing to slide forward into the chamber so that it cannot be extracted, which can preclude the rifle from being reloaded—an annoyance in the best of circumstances and a potentially deadly occurrence to the shooter in certain conditions, such as self-defense applications and dangerous game hunting.
Insufficient headspace can be a serious problem as well. If the bolt is closed on a round in a rifle with insufficient headspace, the bolt may be exerting tension on the casing in the chamber. This can lead to casing failure, resulting in the emission of the hot expanding powder gases into the chamber. This can result in catastrophic failure of the rifle and/or emission of hot gases directly into the face of the shooter. It can also result in a portion of a failed casing not extracting from the chamber.
Because of the close tolerances required of headspace and the significant risks associated with the operation of a rifle whose headspace is out of specification, the chambering of a rifle is typically finished by hand. First, the rifle will be rough chambered. Then, the gunsmith installing the barrel must manually ream the chamber, very slowly. He turns the reamer, measures the headspace, and then turns the reamer some more, until the headspace measurement is correct. This is a very time consuming process, and it is a substantial factor in the cost of rifle manufacturing as well as after market barrel replacement.
In view of the foregoing, a bolt action rifle meeting the following objectives is desired.


Medical devices may be used during internal operations on a patient. During these operations, bodily fluids, such as blood, and/or tissue may come into contact with the medical device. Once blood and/or tissue come into contact with the medical device, the device may lose its sterility and may be contaminated. In general, medical devices may be constructed with little consideration for the potential of disassembly since the medical devices may be designed to be disposed of once contaminated after a single use. In some instances where portions may be made to be removable, they may generally consist of disposable parts for the device that detach to be thrown away before a new disposable part is used for a new patient. For some medical instruments lacking disposable parts, they may generally either be only used once or may need to be entirely resterilized before reuse.
With the advancement of the electronics industry, medical devices may be adapted to contain most, if not all, of the required components within the medical device. More specifically, some medical devices may be adapted to use an internal or attachable power source instead of requiring the device to be plugged into an external source by a cable. Merely exemplary devices that may be adapted to include a portable power source are disclosed in U.S. Pat. No. 6,500,176 entitled “Electrosurgical Systems and Techniques for Sealing Tissue,” issued Dec. 31, 2002, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,416,101 entitled “Motor-Driven Surgical Cutting and Fastening Instrument with Loading Force Feedback,” issued Aug. 26, 2008, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,738,971 entitled “Post-Sterilization Programming of Surgical Instruments,” issued Jun. 15, 2010, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2006/0079874 entitled “Tissue Pad for Use with an Ultrasonic Surgical Instrument,” published Apr. 13, 2006, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2007/0191713 entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug. 16, 2007, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2007/0282333 entitled “Ultrasonic Waveguide and Blade,” published Dec. 6, 2007, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2008/0200940 entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug. 21, 2008, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2009/0209990 entitled “Motorized Surgical Cutting and Fastening Instrument Having Handle Based Power Source,” published Aug. 20, 2009, issued as U.S. Pat. No. 8,657,174 on Feb. 25, 2014, the disclosure of which is incorporated by reference herein; and U.S. Pub. No. 2010/0069940 entitled “Ultrasonic Device for Fingertip Control,” published Mar. 18, 2010, the disclosure of which is incorporated by reference herein. Similarly, various ways in which medical devices may be adapted to include a portable power source are disclosed in U.S. Provisional Application Ser. No. 61/410,603, filed Nov. 5, 2010, entitled “Energy-Based Surgical Instruments,” the disclosure of which is incorporated by reference herein.
Electrically powered medical devices such as those referred to herein may require the use of high value or environmentally restricted disposable components to operate. The ability to reuse or reprocess these components over multiple uses may increase the value of the initial purchase by possibly spreading the cost of those components over the multiple uses. It may also be desirable in some settings to allow portable electronic components such as batteries to be recharged and/or be otherwise reprocessed between uses in sterile medical devices, without such electronic components having to be resterilized between uses in sterile medical devices, and without such devices contaminating sterile medical devices during re-use of the non-sterile electronic components. In addition or in the alternative, reclamation and reuse of the components may avoid or mitigate any environmental issues that may otherwise be associated with the disposal of the components after a single use. One potential approach may include reusing clean electrical components within multiple medical devices.
While several systems and methods have been made and used for component acceptance and release features for medical devices, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present technology, and together with the description serve to explain the principles of the technology; it being understood, however, that this technology is not limited to the precise arrangements shown.


This invention relates to an arrangement for coupling undeveloped films to a leader.
When developing undeveloped films (hereinafter simply referred to as "films") in an automatic film developing machine of a type that utilizes leaders to guide films, the front ends of films F are connected to a leader L after pulling them out of patrones P as shown in FIG. 27. The films F are sent to the film developing unit, led by the leader.
The leader L is formed of a flexible synthetic resin sheet. Along its longitudinal center are formed a plurality of holes a arranged at equal intervals and adapted to engage a feed sprocket provided in the film developing unit.
Such an automatic film developing machine is ordinarily provided with a film guide. If films are detached from the film guide while being fed, their surfaces may be damaged due to contact with the film guide. Thus, it is necessary to couple films reliably to the leader with high positional accuracy.
If a film F should come off the leader L while developing, it will be stuck in the treating solution. It is extremely troublesome to take out such a stuck film. If taken out carelessly, the film F may be exposed to light. Thus, films F have to be rigidly coupled to leaders L.
For this purpose, films F were heretofore connected to a leader F by means of splicing tapes T as shown in FIG. 27.
In order to connect films to a leader using splicing tapes T with high positional accuracy, the leader has to be placed on a special-purpose workbench. It is necessary to keep oil and dust from the adhesive surface of the splicing tapes T. Thus, a taping job tends to be very troublesome. In order to prevent films F from coming off the leader while being fed, it is necessary to use splicing tapes with high bond strength. It is difficult to peel off such tapes after developing films F. Such tapes are not recyclable and thus are uneconomical.


1. Field of the Invention
This invention lies in the field of sulfur removal and recovery, and particularly in the treatment of sour gases and other gases in the chemical process industry that contain hydrogen sulfide.
2. Description of the Prior Art
Much of the natural gas produced in the United States has a hydrogen sulfide content exceeding 4 parts per million and is therefore classified as xe2x80x9csour.xe2x80x9d Since hydrogen sulfide is an environmental hazard, sour natural gas is considered unacceptable for transport or use. Hydrogen sulfide levels are also a problem in the fabrication of fuels derived from petroleum, coal and lignite, whose sulfur content is converted to hydrogen sulfide during the conversion of these materials to gasoline, jet fuels, refinery gas, coal gas, blue-water gas and the like. In addition to the environmental hazard, hydrogen sulfide represents a loss of the sulfur value of the raw material, which if recovered as elemental sulfur would be of significant use to the chemical industry.
The traditional method for converting hydrogen sulfide in natural gases and in gaseous plant effluents is the Claus process, in which part of the hydrogen sulfide is burned in air to form sulfur dioxide and water:
2H2S+3O2xe2x86x922SO2+2H2Oxe2x80x83xe2x80x83(A)
and the sulfur dioxide thus produced is reacted with further hydrogen sulfide to form sulfur and additional water:                                           2                                      xe2x80x83                                                  H              2                                    S                    +                      SO            2                          ->                                            3              x                                                  S              x                                +                      2                                      xe2x80x83                                                  H              2                                    O                                              (        B        )
The symbol xe2x80x9cxxe2x80x9d in Reaction B is used to denote that the elemental sulfur exists in a mixture of molecular species varying in the number of sulfur atoms per molecule.
The furnace (Reaction A) in the Claus process is operated with a fuel-rich mixture, converting only one-third of the H2S to SO2. The fuel-rich atmosphere results in the partial conversion of hydrocarbons that are present in the H2S feed to such compounds as COS and CS2, which lessen the yield of elemental sulfur and are themselves hazardous. The fuel-rich atmosphere also promotes the breakdown of aromatics to soot. For high sulfur recovery, precise control of the overall stoichiometry is needed, and this is made especially difficult when considerable amounts of CO2 and other inerts are present.
Part of Reaction B occurs in the furnace and the rest is conducted in a heterogeneous system in which the reaction mixture is gas-phase and contacts a solid activated alumina catalyst of a sort well known to those skilled in the art of the Claus process. With continued use, the alumina catalyst fouls and becomes otherwise deactivated over time. This requires plant shutdown, loss of process time, and the cost of regeneration or replacement of the catalyst, together with the associated labor costs.
A further disadvantage of Reaction B is that it is equilibrium-limited at temperatures above the dewpoint of sulfur, and despite being performed in two to four stages, the reaction leaves 2% to 5% of the H2S and SO2 unreacted. Each stage requires a separate condenser to remove the elemental sulfur, and these condensers require a large heat-exchange area and reheating of the gas leaving each but the last condenser. Furthermore, the steam generated by each condenser is low in pressure, limiting its usefulness. Additional costs are entailed in treating the tail gas in which the sulfur content must be reduced by ten to twenty times.
It has now been discovered that virtually complete conversion of hydrogen sulfide in natural gas or other gas mixtures to elemental sulfur and water can be achieved with the use of a single-stage reaction between hydrogen sulfide and sulfur dioxide, in a manner producing no reaction products other than elemental sulfur and water. The reaction
2H2S+SO2xe2x86x923S+2H2Oxe2x80x83xe2x80x83(I)
is conducted with excess H2S in the liquid phase in the presence of a homogeneous liquid-phase Claus catalyst, at a temperature above the melting point of sulfur but low enough to keep the reaction in the liquid phase, and upstream of the furnace where unreacted H2S is combusted to produce the SO2 that is consumed in reaction (I). The H2S that is combusted in the furnace is the excess H2S that passes unreacted through the liquid-phase reaction, optionally supplemented by H2S from an H2S-containing stream that bypasses the reaction (I) reactor. The SO2 in the furnace combustion gas is recycled to the reaction (I) reactor either as a gas or dissolved in a solvent, and in any case serves as the entire SO2 feed to the reaction.
In basic terms, the invention as shown in FIG. 1 proceeds as follows:
(a) In a first stage 1, an H2S-containing mixture is passed through a continuous-flow catalytic reactor where the mixture contacts SO2 in accordance with the reaction
2H2S+SO2xe2x86x923S+2H2Oxe2x80x83xe2x80x83(I)
using approximately 10% to 50% excess H2S. The H2S enters the reactor either as a gas or dissolved in an organic solvent; in most cases the H2S will enter as a gas. The SO2 likewise enters the reactor either as a gas or dissolved in an organic solvent. Regardless of the phases of the streams entering the reactor, both reactants dissolve in an organic liquid solvent flowing through the reactor, the solvent entering either with one of the two incoming reactant streams with the H2S or the SO2 dissolved in the solvent, or as a circulating stream recycled from the reactor exit. The reaction causes a major fraction of the SO2, preferably substantially all of it, to react. The term xe2x80x9ca major fractionxe2x80x9d is used herein to indicate at least half, and preferably 80-90% or more. The organic liquid solvent also contains a dissolved catalyst that promotes reaction (I). The reaction produces elemental sulfur, which is recovered from the product mixture by phase separation. The reaction is conducted at a temperature above the melting point of sulfur and below the boiling point of the solvent, preferably below the temperature at which sulfur polymerizes.
(b) In a second stage, 2, H2S, including H2S that passed unreacted through the first stage, is combusted with oxygen according to the reaction
xe2x80x832H2S+3O2xe2x86x922SO2+2H2Oxe2x80x83xe2x80x83(II)
to convert the H2S to SO2. Hydrocarbons that may accompany the H2S are combusted to CO2 and H2O whereas organic sulfur compounds that may be present additionally yield SO2.
(c) In a third stage, 3, the SO2 produced in the second stage is recovered by absorption and returned to the reactor (the first stage). The SO2 in the third stage may be recovered in the solvent used in the first stage, 1, with the first stage catalyst dissolved in the solvent. The solution containing both the SO2 and the catalyst can then be recycled in its entirety to the continuous-flow reactor (the first stage) as the SO2 feed to the reactor. Alternatively, the solvent used to recover the SO2 in the third stage, 3, may be kept separate from the solvent in the reactor of the first stage, 1, with the SO2 being stripped from it and sent to the first stage, 1, as a gas. The third stage absorption leaves a tail gas that is substantially free of H2S and SO2.
Various additional process stages upstream, intermediate and downstream of these three stages are included in any of various arrangements in preferred embodiments of the invention to enhance the flow and transfer of streams, to separate phases and control concentrations and flow rates, to separate the water formed in Reactions I and II, and to control other process parameters such as temperature and pressure. These and. other characteristics, features and advantages of the invention will be better understood from the description that follows.


1. Technical Field
The present disclosure generally relates to optical transceivers, and more particularly to a packaging method of an optical transceiver.
2. Description of Related Art
Optical communications has become increasingly popular and is widely used in information transmission. Generally, optical transceivers are used in optical communication devices to perform a conversion between electrical signals and optical signals. An optical transceiver comprises a plurality of laser components and a plurality of lenses. Definition of position between the laser components and the lenses affects performance of transmitting information of the optical transceiver. Therefore, how to make an exact definition of position between the laser components and the lenses is an important problem in study.
Therefore, a need exists in the industry to overcome the described limitations and reduce the size of the electronic device.