GB153522A - Improvements in feeding mechanisms for sewing machines - Google Patents

Abstract

153,522. Thompson, W. P., (Union Special Machine Co.). March 12, 1920. Sewing-machines; feed 5y dogs; frames.-Work is fed by means of main feed-dogs 17 and auxiliary dogs 15 beneath a verticaly reciprocating needle across a cylindrical work-supporting arm 1 enclosing the feed and hopper mechanism in a plane at right-angles to the axis of the arm. Means are provided for giving the auxiliary dogs a differential feed movement relative to that of the main dogs. The dogs are carried on feed-bars 16, 13, which are raised and lowered toward and from the work by a rock-shaft 3 oscillated through a link 11 and eccentric 12 by the main shaft 2, and having arms 4, 5 carrying pins 6, 8 on which are mounted the feed-bars. The main feed-bar 16 is oscillated about the pins 6, 8 from an adjustable crank comprising a pin mounted in a block slidable by a screw 20 in a diametrical slot in a disk 18 on the end of the shaft 2. On this pin is mounted a roller which is encircled by a strap 23 connected to a pin 24 mounted in a sleeve 25 carried by an arm 26 projecting from the feed-bar 16. The feed-bar 13 is secured by a screw 14 to the pin 8 which is rocked, to give the feed-bar its feeding mcvements, by an arm 28 secured on the pin by a screw 36 and connected by a link 29, Fig. 4, to a bell-crank lever 30 journaled on a shaft 31. The other arm 32 of this lever has a slot 33 in which engages a pin 34 on an arm 35 connected to the pin 24, whereby adjustment of the pin 34 in the slot 33 varies the motion imparted to the auxiliary feed-bar 13 and dogs 15 relatively to that of the main feedbar 16 and dogs 17.