GB461832A - Improvements relating to overseam sewing machines - Google Patents

Abstract

461,832. Sewing-machines. SMITH, H. Nov. 15, 1935, No. 31674. [Class 112] In an overseam sewing-machine of the kind described in Specification 6557/92, [Class 112], as modified for producing an overedge seam on the three threads, the counterweight at the right-hand end of the main shaft of the above machine is replaced either by the eccentric mechanism 42 for actuating a second looper 31 for the third thread, or by the take-up mechanism 60, 61, the mechanism 42 in the latter case taking the place of the take-up mechanism on the shaft 3. The take-up and eccentric mechanisms are operated in phase with each other and their joint masses are arranged to serve as a counterweight in place of that dispensed with. The looper 31 is actuated by the eccentric 42 through a lever 39, provided with an axial adjustable hub, and the first looper 19 is actuated as in the original machine by a rock shaft 24 driven by an eccentric on the main shaft 3. The upper crank 21 of the looper 19 is longer and the lower crank 22 shorter than the corresponding crank of the original machine. The two looper threads 67, 68 have a single take-up 64 provided with two eyes and arranged to be oscillated by the eccentric mechanism 60, 61, between two fixed guides each provided with two eyes 69, 70, the range of movement being such that the thread 68 experiences a single take-up per cycle while the other thread 67 experiences a double take-up per cycle. The take-up of the needle thread 82 comprises a rocking lever 71 actuated by an eccentric 72 on the shaft 3, and carrying a guide 76 with an elongated eye 77 which moves to and fro past a round eye 79 in an adjustable plate 78 and past an elongated eye 84 in a guide plate 83, so that the needle thread is given a double take-up per cycle with a dwell provided by the elongated eyes. The needle arm is rocked as in the original machine by an eccentric on the shaft 3, the arm being connected to the eccentric rod by a pivot comprising an adjustable eccentric sleeve. The needle plate 18 is provided with a long beak or chaining finger.