GB309771A - Stop motion devices for power-driven machines - Google Patents

Abstract

309,771. Fair-weather, W., (Singer Manufacturing Co.). May 30, 1928. Buttonhole sewing-machines; stopping gear.- A stop-motion device for a machine comprises a wheel geared to the driving shaft and normally running idly at a speed less than that of the shaft, and stopped at a certain point of the machine cycle by a spring plunger, to stop the rotation of the driving shaft. The invention is illustrated as applied to a buttonhole sewing-machine. At a given point in the machine cycle, e.g. when each buttonhole is completed, a lug 49 on the cycle cam 50 trips an adjustable stop 48 on a lever 43 to withdraw a pin from a notch 44 in an arm 45 pivoted at 46 to the stop,-lever 47, 38. This lever then swings from the inoperative position, shown in dotted lines in Fig. 1, to the operative position, shown in full lines, when a spring plunger 41 carried by it comes into the-path of a cam 24 on the member 23 carried within the gear 21 which meshes with the pinion 13 on the driving shaft 9. The plunger rides up the cam 24 and engages the recess 25, bringing the gears 21, 13 to rest. The stopping shock is absorbed by the buffering springs 31 in the usual way. The gears are in the ratio 2 : 1 so that the stopping gear 21 rotates at half the speed of the driving shaft. The stop-lever 38 carries an arm 39 provided with a belt-shift 40 which transfers the belt from the fixed pulley 10 to the loose pulley 11 at the time of stopping the machine. The work clamp 50<1> is operated from the driving shaft 9 through gears 73, 72, 71, 70 and shaft 64 and gears 65, 66, 67 in the usual way. The cutter 6<1> is operated from the stop-lever 38 by a bar 52, fixed to the plunger 41 by a screw 51, carrying a roller 53 engaging a notch in the lever 55. This lever is connected to the cutter by links 57, 58, 59. The link 57 has pivoted thereto a latch 61 with a shoulder 62 engaging under the pin 63 on the lever 58. The cutter is prevented from actuation by the stopping device by moving the latch from under the pin 63.