GB419726A - Improvements in or relating to sewing machines - Google Patents

Abstract

419,726. Boot-sole sewing-machines. UNITED SHOE MACHINERY CORPORATION, 140, Federal Street, Boston, U.S.A.- (Assignees of Haas, O. R. ; Beverly, Massachusetts, U.S.A.) March 18, 1933, No. 8252. Convention date, March 19, 1932. [Class 112.] An outsole sewing-machine of the general type described in Specification 289,142, [Class 112], has means for severing the needle and bobbin threads on the same side of the work, means for bringing the stitch-forming devices to rest on the completion of the sewing with the awl in position to enter the work, means for preventing the looper from threading the needle on stopping the machine, a manner of operating the looper to support the needle when the needle is in the work during feeding, a thread measurer, take-up and a channelling device. Starting and stopping gear.-The power driver 18 has a conical clutching surface 34 for engaging a correspondingly shaped surface 36 on a driven member 38 carried by a sleeve 40 freely slidable and rotatable on the shaft 30 and having a helical gear 42 for driving a sewing camshaft 166 and the pattern camshaft of the machine. The clutch surfaces are held in engagement by a strong spring. The outside surface of the driven clutch member is also conical in shape and is engaged by an annular braking member 46 on the frame. A cam groove in the sleeve 40 engages the lock bolt 50 for disengaging the clutch members and operating the brake. Feed by awl.-The feed is practically continuous. To this end, the work support and presser foot are mounted on a laterally sliding carriage or feed slide 668. The needle and feed awl are mounted on the same carriage, but at certain times, are moved in the line of feed independently of the carriage. The back movement of the feed carriage takes place while the needle is in the work. Feeding movements of the carriage are imparted by the gudgeon 1008, links 1016 cam-operated lever 1020, guide block 1024 and bolt 1022. The forward end of the feed carriage 668 supports a threaded bearing 1042 carrying the needle and awl segments rotatably mounted on the stud 1044. The stud is oscillated by a segment 1050, to produce lateral feeding movement of the needle and awl independent of the carriage. The needle and awl are actuated by segments carried on levers provided with arms engaging suitably shaped cams on the shaft 166. In order to relieve the strain on the needle during feeding, the looper 550 lays a loop of thread in the barb of the needle and pulls in the direction of feed to counteract the drag of the work. Stitching.-The stitch-forming devices comprise a needle 540, awl 642, work support 544, tresser 546, shuttle 548 and looper 550. The devices are timed so that the awl enters the work after the needle has withdrawn its loop and before the loop has been drawn to set the stitch. The stop mechanism is arranged to arrest the machine at that point of the cycle where, during the normal operation, the needle is out of the work with a loop of thread in its hook and mechanism is provided to prevent the placing of the loop in the hook at the final work piercing stroke. This mislooping of the needle is accomplished by a change in the path of the looper 550 during the last cycle of the stitch-forming devices. Thread - cutting mechanisms.-The thread cutter mechanism comprises a knife edged member 660 carried by a bent arm 662 mounted on a horizontal screw 664 having its end threaded into the forward end of the presser 546. The presser foot 546 is pivoted on a screw 666 carried by the feed carriage. Oscillation of a gear segment 680 imparts movement to the arm 674 and through the link 672, moves the cutting knife 660 into contact with the upper tread surface of the sole of a shoe 686. The knife edge is arranged to pass obliquely beneath the lower work engaging face of the presser foot and enter the substance of the shoe sole to sever the threads. The eccentric for operating the thread cutter is driven from the main driver through a suitable train of gears. Channelling.-A fudge knife 1082 is projected upwardly through the work table and is operated in timed relation with the stitch forming elements.