GB485733A - Sprocket-driven belt - Google Patents

Abstract

485,733. Positive - driving belts ; sprockets. FAIRWEATHER, W. C. (Singer Manufacturing Co.) Dec. 1, 1937, No. 33177. [Class 80 (i)] A sprocket-driven belt, particularly for use in a sewing machine, comprises crossbars 8, 10, Fig. 3, connected together in alternation in an endless circuit by an interwoven winding of flexible non-metallic strip material 12, preferably a textile cord, in a single length which passes sinuously over and under in contact relation with successive cross-bars. Alternate bars have projections or studs 9 adapted to engage the toothed flanges 4, Fig. 2, of the sprocket wheel 1 the bearing surface 5 of which is grooved at 6, adjacent the flanges, to accommodate flanges 7, 11 on the cross-bars. The number of cross-bars is odd so that successive courses of the cord will pass alternately over and under any given bar. Preferably the cords at the inner face of the belt rest on the surface 5, Fig. 2, to ensure quiet running. To deal with the beginning and finishing ends of the cords, a special tubular cross-bar 14, Fig. 7, is provided. This has cord-end admission slots 15 cut in its flanges. The beginning end a and finishing end b of the cord 12 pass through the slots 15 to the inside of the member 14 where they may be held by a plug 16. In a modification, the bars instead of being cylindrical are of flattened cross-section between the flanges, the non-studded bars being of flattened tubular section produced from sheet metal blanks. The belt may be readily manufactured by providing a disc 22, Fig. 15, having a circular series of holes 23 to receive a stud 9 of a crossbar 8, and intervening pins 24 to enter a hole 101 in the non-studded bars 10.