GB1375540A - - Google Patents

Abstract

1375540 Sewing machines M SPIEGEL and M SPIEGEL 13 Oct 1971 [14 July 1970] 34211/70 Heading D1G [Also in Division F2] A machine, e.g. a sewing machine, comprises a driven element, which can be stopped in a predetermined position, driven by a motor M connected to a first input member 60 of a drive transmission by a coupling 44 releasable by means which also activate an auxiliary drive coupled to a second input member 74 of the drive transmission so as to contrive to drive the element until means 210 which indicate a predetermined position in which the element is to be stopped are detected by sensing means 208, 210 which operate to move a brake disc 218 movably connected to an output member of the drive to brake the transmission and also to disconnect the auxiliary drive. A treadle 14 is depressed to start the machine by operating coupling 44 to drive shaft 60 on which are mounted one-way bearings 66, 68 carrying a sleeve 64 on which is mounted pulley 62 which through belt 42 drives the sewing machine 10 at normal speed. When the treadle is released, coupling 44 is released and a control circuit is energised so that auxiliary drive shaft 200 driven by motor M operates through clutch 202 and speed reducer 204 to drive gear wheel 74, which is carried on a one way bearing mounted on sleeve 64, and hence pulley 42 and the machine 10 at a reduced speed of 200 r.p.m. At the same time plate 218 is attracted to plate 214 by electromagnets therein to slow down the machine. The machine then moves at reduced speed until a selected one of the two switches 206, 208 is traversed by magnet 210 when clutch 202 is disengaged and the brake 214, 218 is applied to stop the machine in the required position, i.e. needle up or needle down in the sewing machine shown. Lights 13, 15, 19 indicate the operation of various parts of the control circuit so that by using a module construction any part not operating may be readily detected and replaced. A switch bypassing the selected switch 206 or 208 may be provided which can operate coupling 202 to restart slow speed drive (indicated by light 15 going out). Instead of switches 206, 208 sensors activated by light from light emitting diodes may be used, Fig. 5 (not shown). Instead of taking the auxiliary drive from the main motor M, a second motor may be provided.