Patent GB-898180-A (GB)
Title: Sewing machines
IPC: D05B33/00
Filed: 1960-08-04
Abstract: 898,180. Sewing-machines. SINGER MANUFACTURING CO. Aug. 4, 1960 [Aug. 5, 1959], No. 27034/60. Class 112 A sewing unit for automatically producing a plurality of separate stitching operations on a garment or other fabric article comprises a sewing-machine 11 and work indexing means comprising an endless conveyer adapted to be driven in step in one direction and carrying a work gripping clamp. The button sewing- machine 11 has a button holding clamp 15 and a button loading device 20 driven by a motor 22 which drives a shaft 21 through one revolution, in two separate increments, for each button loading operation. The first increment loads a button into the button clamp, closes the clamp and actuates the sewing-machine starting lever 13. When the button has been sewn the machine stop mechanism in releasing the lever 13 starts the second increment of movement of the shaft 21 to pick up another button from the feed shoot, open the button clamp, and pulse a microswitch MS-1 to initiate the work indexing mechanism described below. The endless conveyer comprises a pair of link belts 35 extending across the front of the sewing- machine between sprockets 32, and provided with guide rails 36, (see Fig. 6). Clamps 37 are secured to the belts 35 and have jaws 72, 74, which latter is biased into a closed work gripping position by a spring 75. Levers 80 movable about pivots 81 by solenoids S3, S4, (see also Fig. 2) engage extensions 76 on those clamps 37 disposed opposite them to open the clamps when the solenoids are energized. Stop blocks 86 are secured to each leading work clamp 37L to perform two functions, one to underly the guide rails 36 to hold the clamps and belts thereto, and the other to engage a withdrawable stop lug 85 on the armature of a solenoid S5 to define a starting position. The conveyer movement is derived from a continuously running motor 44 (see Fig. 3) which drives the sewing-machine by a belt 45, and a speed reducer 46 by a belt 47. The reducer 46 is connected by a belt 48 to a clutch sprocket wheel 50 on a shaft 51, and by a further belt 49 to a clutch sprocket wheel 52 on the drive shaft 40. The sprocket wheel 50 is associated with a one revolution clutch controlled by a solenoid, and the wheel 52 with an electric clutch 61. Operation. When a work panel is located in the open work gripping clamps the foot switch 90 is released to de-energize solenoids S3, S4 and close the clamps. Closure of the cycle start switch 180 operates the button loader which loads a button, starts the sewing-machine to sew on the button, stops the machine, opens the button clamp and pulses the microswitch MS-1 to energize the solenoid of the one revolution clutch, when cam 54 on shaft 51 executes one revolution and its follower 55 moves to rock a ratchet device 58 to turn the shaft 40. Shaft 40 is connected by belt 41 to the conveyer, which is thus indexed and moves the work panel the distance between button positions. At the completion of its revolution the shaft 51 actuates a further microswitch to restart the button loader, so that buttons are successively sewn on to the panel at spaced positions. After the correct number of buttons, as determined by a counting clutch, have been sewn on, the clutch 61 on the shaft 40 is energized and the conveyer moves on, being driven by belt 49, until a further pair of clamps are in position to receive a panel. The completed panel now hangs from its clamps, under the conveyer and the operation of the foot switch 90 opens the clamp and actuates a solenoid operated rod 114, (see Fig. 3), which swings across to fold the completed panel over the work holder 110.