  The filamentary infrared dark cloud L1287 is actively forming a dense cluster
of low-mass YSOs at its inner $\sim$0.1 pc region. To help understand the
origin of this low-mass YSO cluster, the present work aims at resolving the gas
structures and kinematics. We have performed $\sim$1$"$ angular resolution
($\sim$930 AU) SMA observations at $\sim$1.3 mm. From a $\sim$2$"$ resolution
1.3 mm continuum image we identified six dense cores, namely SMA1-6 with masses
in the range of $\sim0.4-4$ M$_\odot$. From a $\sim$1$"$ resolution 1.3 mm
continuum image, we find a high fragmentation level, with 14 compact millimeter
sources within 0.1 pc (two of them associated with the known accretion outburst
YSOs RNO 1C and RNO 1B). The dense gas tracer DCN (3--2) traces well the dust
continuum emission and shows a clear velocity gradient along the NW-SE
direction centered at SMA3. There is another velocity gradient with opposite
direction around the most luminous YSO IRAS 00338+6312. The fragmentation
within 0.1 pc in L1287 is very high compared to other regions at the same
spatial scales. The incoherent motions of dense gas flows are sometimes
interpreted by being influenced by (proto)stellar feedback (e.g., outflows),
which is not yet ruled out in this particular target source. The directions of
the velocity gradients traced by DCN are approximately perpendicular to those
of the dominant CO outflow(s). Therefore, we alternatively hypothesize that the
velocity gradients revealed by DCN trace the convergence from the $\gtrsim$0.1
pc scales infalling motion towards the rotational motions around the more
compact ($\sim0.02$ pc) sources. This global molecular gas converging flow may
feed the formation of the dense low-mass YSO cluster. IRAS 00338+6312 is the
most likely powering source of the dominant CO outflow. A compact blue-shifted
outflow from RNO 1C is also identified.
