| 摘要 |
<p>1,033,571. Sewing-machines. GENERAL AUTOMATED MACHINERY CORPORATION. March 13,1963 [Aug. 31, 1962], No. 10006/63. Heading D1C. A sewing machine has control means which on contact between the work and a work guide actuates a presser foot to engage the work and a clutch to engage a motor with the machine, and which on breaking of the contact actuates the presser foot to move it from the work disengages the clutch and operates a thread cutter. The control means described comprises a pneumatic system. When work is applied to a combined work guide and air valve 52 leakage of air therefrom is stopped, causing pressure to build up in device 49 and close switch 58. This energizes the solenoid 53 of a four port valve and allows air under pressure to flow from line 25 to lines 34, 35, lines 45, 47 being connected to exhaust. The piston operated thread cutter 39 is opened and presser foot 20 forced down to engage the work, while clutch brake 4 is operated to drive the machine. Removal of the work at the end of the operation allows air to leak from the guide 52 opening valve 53, stop the machine, raise the foot and cut the thread. The work guide and switch may comprise a roller 123 (Fig. 12 not shown) which when engaged by the work covers an oriface 118 in its hollow axle to restrict airflow therethrough. An alternative form (Fig. 8 not shown) includes a curved, plate 113 which swings about its pivot 115 to restrict an air passage opening in its body 52. The clutch brake unit 4 is that described in Specification 938,536.</p> |
