GB1489460A - Sewing machines - Google Patents

Abstract

1489460 Sewing machines UNION SPECIAL CORP 22 Mav 1975 [27 Sept 1974] 22203/75 Heading D1G A sewing machine, e.g. group stitch machine for sewing on buttons, having a main drive shaft 18 drivably connectable through a clutch to driving pulley 42 is provided with a stop motion mechanism comprising a lever 41 for actuating the clutch and a lever 37 for lockingly engaging a disc 43 to stop shaft 18, these levers being rocked in unison e.g. through a shaft 34 by a rock lever 47 carrying a cam follower 48 riding on a cam 49 which is rotated by a shaft 51 driven from the shaft 18 through reduction gearing, the profile of cam 49 having two steps 65, 64 so that when follower 48 drops on to step 65 the levers rock sufficiently for lever 41 to disengage the clutch and the shaft 18 continues to coast and slow down until the follower drops onto step 64 and lever 37 locks the shaft. The coasting interval may be I to 1¢ revolutions of the drive shaft and is adjustable by a second cam 50 displaceable relative to cam 49 to vary the effective length of step 65. As shown cam 49 has two sets of steps, one of which is selectively rendered inoperative by a horse-shoe shaped member 58 according as to whether an 8- or 16-stitch cycle is required. A chain operated by a foot treadle rocks the levers to allow the machine to start. A buttonclamping mechanism 31 is pivotally raised by a lever 25, link 21, rock member 20 and eccentric 19 on shaft 18 at the end of each cycle, rocking of lever 47 bringing the link 21 and member 20 into engagement through a linkage 35, 36.