GB217821A - Improvements in loop stitching machines - Google Patents

Abstract

217,821. Armstrong, J. J. V., (Union Special Machine Co.). Oct. 15, 1923. Loop-stitching.-In a double-loop sewing-machine having reversible feed a loop-positioning finger is provided to hold the looper-thread for the passage of the needle. A threaded looper 11 pivoted at 13 is oscillated by a link 15 and is given the usual needle-avoiding movements. A hooked-finger 46 is adjustably fixed in a carrier 52 which is pivoted diagonally to the looper on a spindle 55, Fig. 6. Arms 61, 62, pivoted at right angles to the under-shaft 16 on the support 52, embrace a cam 59 on the shaft 16. Fig. 10 shows the position of the stitch-forming devices when the needle 9 is descending, the feed being normal; the previous stitch s is so placed that the finger 46 is really unnecessary. Fig. 11 shows a similar portion with the feed reversed, the previous stitch being shown at s<1>; the necessity for the finger 46 is clearly shown here. Feed by dogs.-A feed-bar 19, Fig. 2, is pivoted on a spindle 20 journaled in an arm 21 which is fixed to a rocker-shaft 35. The bar 19 is given its vertical movements by an eccentric on the shaft 16. A slotted arm 29 pivoted on a fixed shaft 26 is connected at one end to a crank 24 on the shaft 16. A link 36, one end of which is connected to an arm 34 on the shaft 35, is slidingly connected at the other end to the arm 29. A link 43 connects the link 36 to a treadle-actuated bell-crank lever 42, 40 which is loosely mounted on the shaft 35. A spring 44 acts on an extension 45 of the lever 40, 42 so as to hold the link 36 normally at the right-hand end of the arm 29. When the link 36 is shifted from one side to the other of the pivot 26 the direction of feed is reversed. An adjustable stop 39 is provided for varying the length of stitch when reversed.