GB467388A - Improvements in or relating to feed mechanisms for sewing machines - Google Patents

Abstract

467,388. Sewing-machines. UNION SPECIAL MACHINE CO. Aug. 29, 1936, No. 23705. Convention date, Dec. 17, 1935. [Class 112] A feed-bar mechanism is so constructed that the feed-bar .is pivoted on an eccentric strap, to impart the rising and falling movements of the feed dog. The dog 27 is adjustably clamped to the feed bar 32 by a stud and slot 30. The underslung end 32 of the feed-bar is pivoted at 33 to the strap 34 operated by an eccentric 35 in the lower'shaft 11 to impart the rising and falling movements to the dog. The feed stroke is imparted by a rock-shaft 40 through a crank 38 and link 29. The shaft 40 is rocked by a link 52 adjustably secured for varying the feed stroke in an arcuate slot 54 of a crank arm 55. The link 52 is rocked by a strap 46 operated by an eccentric 45 on the shaft 11. The pivot 47 of the link 52 and strap 46 is also connected to a lazy arm 48 pivoted also at 49, to confine the link 52 to endwise movements. By selecting centres of curvature such as a, or b, above or below the axis of the pin 47, it is possible to determine curvatures A, B, for the slot 54 of the arm 55 such that by shifting the connections 53, the stroke of the feed dog can be increased or decreased at either end. Specification 468,109 is referred to.