GB702516A - Lock-stitch sewing machine - Google Patents

Abstract

702,516. Sewing-machines. SINGER MANUFACTURING CO. June 4, 1952 [June 29, 1951], No. 14067/52. Class 112 Lock stitching. -- On a machine with a needle reciprocating in a straight line and a rotary loop-taker, the thread from the bobbin-case to the throat-plate is placed nearly vertical, to reduce friction and improve stitch-forming, by bringing the vertical plane containing the loop-taker axis forward from that containing the needle. As shown in Fig. 9, in a rotary hook machine, the axis of the loop-taker lies in a vertical plane a spaced forwardly from the parallel plane b containing the path of the needle 55, and the bobbin-case holder 35, carrying the bobbin-case 79, is shifted angularly from the normal position so that the usual gap in its bearing rib extends from a point in or somewhat to the rear of the plane b; the loop-taker rotates anticlockwise. The distance between the planes a and b is preferably approximately 4 mm., and the gap in the bobbin-case holder rib extends approximately from 15 to 58 degrees from the vertical radius of the loop-taker. The bobbin-case holderhas a needle-loop-controlling flange 86 in which is formed the notch 36 receiving the rotation-restraining finger. The tail 81 of the hook body 34 is deflected laterally, and has a needle-loop-supporting end surface at a radial distance from the loop-taker axis greater than the radius of the bobbin-case holder bearing rib. Upper and lower shafts, connecting.- Tho hook shaft is driven from the needlebar shaft, which is co-planar with the needle, through bevel gears and a vertical shaft in the standard of the machine, the latter shaft being connected to the hook shaft by hypoid gears because of the offset between the vertical planes containing the two horizontal shafts.