GB610365A - Looper-actuating mechanism for sewing machines - Google Patents

Abstract

610,365. Sewing-machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.). April 1, 1946, No. 9968. [Class 112] A threaded chain-stitch looper is carried by a shaft which oscillates in bearings carried eccentrically in rotating bushings, so that the shaft moves bodily in an orbit as well as oscillating. The looper carries a needle guide, and co-operates with takeup and loop-spreading means. The mechanism is particularly adapted for multi-needle machines, and parts of such machines providing for adjustment of the needles and variation in their numbers are described. Stitch-forming devices.-The looper L, Fig. 6, has a stem s secured adjustably in a carrier 26 which is mounted, detachably between two shaft sections 36, 37, Fig. 1, oscillatably carried in eccentric bores in bushings formed by the hubs of gears 51, 52 and supported in bearings in the machine frame; the gears 51, 52 are eccentric and mesh with corresponding gears on the under-shaft 27 of the machine, so that the looper carrier 26 moves bodily, with varying speed, in a circular orbit. The carrier is oscillated by an eccentric on the shaft 27, of which the strap 58 has a transverse bore receiving a pin 60 fixed to the shaft section 37. The loop-taking movement of the looper, produced by this mechanism is substantially straight, slightly downward, and decelerating towards its end, and the loop-shedding movement is arcuate, rising close to the workplate to minimise the take-up action required, and accelerating. The take-up action is obtained by leading the thread through an eye 42 in the lower end of the looper stem between eyes in fixed members 45, 46. A loop-spreader 65 carried by a sliding member 67, which is reciprocated by a cam 73 fixed to the gear 51, holds the looper thread loop open for the needle. The looper carries a hook-shaped needle-guide 66. Multiple - needle machines.-When the mechanism is used in a machine for sewing several separate seams simultaneously, the looper-carrier 26 is adapted to receive several loopers, as shown in Fig. 1, and the members 45, 46, 67 are similarly adapted for use with several threads; all of these parts are detachable, for replacement by others with provision for loopers of different spacing or number. The needles N are secured in blocks 25 which are adjustable laterally on a pair of bars 24 carried by twin needle-bars 22 driven in the usual manner. Two presser-feet are provided. Specification 534,438 is referred to.