GB659988A - Work-feeding mechanism for sewing machines - Google Patents

Abstract

659,988. Sewing-machines. F A I RWEATHER, W. C. (Singer Manufacturing Co.). Dec. 10, 1949, No. 31777. [Class 112] A work feed mechanism comprises two feed dogs 20, 21, two feed advance and return eccentrics 30, 39 on a first shaft 11, and two feedlift cams 55, 56 on a second shaft 57 driven at a different speed to the first shaft. The dog 20 advances the work by two steps, after which the dog 21 returns the work by one step. The dog 20 is carried by a feed-bar 23 given feed movements by rockarms 25 on a rock-shaft 26 actuated by means of a pitman 29 connected to an adjustable eccentric 30 on the bed shaft 11. The dog 21 is carried by a feed-bar 32 given feed movements by a rock-arm 34 on a shaft 35 actuated by a pitman 38 from an adjustable eccentric 39 on the bed shaft. The eccentrics are set at 180 degrees to each other. Lift movement is given to the dog 21 by the engagement of a rock-arm 45 in a slot 41 in the feed bar 32. The arm 45 is carried by a shaft 47 having an arm 50 carrying a follower 52 in engagement with a one-lobed cam 56 mounted on a countershaft 57 driven by reduction gearing 60, 61 from the bed shaft at a third of the speed thereof. Lift movement is given to the dog 20 by the engagement of a rockarm 44 in a slot 40 in the feed-bar 23. The arm 44 is carried by a hollow shaft 46 rotating on the shaft 47 and having an arm 49 provided with a follower 51 in engagement with a two-lobed cam 55 on the counter-shaft.