GB1507213A - Needle bar release device - Google Patents

Abstract

1507213 Disconnecting sewing needle drive SINGER CO 22 May 1975 [13 Sept 1974] 22322/75 Heading DIG A sewing machine, which is provided with a drive disconnectable from a needle bar 14 mounted for reciprocation in a frame 10 by electrical actuating means, comprises coupling means 32, 40 forming a detachable connection between the needle bar 14, 26 and the drive means 18, a coupling release member 52 normally disposed (as shown) in a position where coupling is maintained and pivotable to a second position by the electrical means 96 to a position where the members 18 and 26 are uncoupled. The drive means 18 comprises a block 20 slidable on needle bar 14 to which is secured a block 28 having pivoted thereto interengaging levers 32, 40 of which the latter has a lug (48 Fig. 2 not shown) normally urged by spring 50 to engage below block 18 to couple the drive to the needle bar. The release member 50 has a slot 54 and a notch 74 having cam edges 56, 58 and 76, 78 respectively, engaging respective posts 60, 80, a spring 86 normally biassing the release member downwards when upper cam edges 56, 76 position the member 52 away from a trigger extension 36 on lever 32 pivoted to block 28. Operation of solenoid 96 causes linkage 124, 122, 116 to pivot release member 66 anti-clockwise about post 60 to engage extension 36 and rotate lever 32 anti-clockwise about pivot 34, lever ends 38, 46 abutting to pivot lever 40 against spring 50 and uncouple driving block 20 from block 28, when spring 49 raises the needle bar to an inoperative position. De-energisation of the solenoid allows spring 50 to act through levers 40, 32 and trigger extension 36 to move 66 back to its inoperative position, the extension (48) on lever 40 re-engaging below block 20 when the latter next rises to its upper position. The coupling may also be disengaged manually by raising the release member 52 by a lower flange 94, the camming action of the edges 58, 78 on the respective posts 60, 80 moving member 52 laterally to engage trigger extension 36 and release the drive coupling as before.