GB114599A - Improvements in and relating to Sewing Machines. - Google Patents

Abstract

114,599. Bowen, P. A., and Little, L. A. Dec. 7, 1917. Boot - sole sewing - machines; rotary horns and related parts; lockstitching by hooks.-In a loch-stitch sewing- machme having a rotary horn, the thread-bobbin 39, Fig. 13, is held at rest in the presserfoot 41 and a looper 57 is provided to cast a loop of the thread drawn from the horn by the needle over the bobbin. The looper is mounted on a vertical shaft which makes one complete revolution for each stitch and is maintained stationary while the needle is in the work. For this purpose, the shaft carries a loose pinion to which it is connected for driving in one direction by a pawl-and-ratchet device. The pinion is actuated by a gear sector and cam on the main shaft. The looper has two fingers of which one, 59, engages the inner arm of the needle-thread loop and casts it round the bobbin, and the other, 60, at the end of each rotation, engages the outer arm of the loop and deflects it out of the path of the descending needle. To prevent over-running of the looper shaft, a stop is provided thereon in a position to engage a stop on the actuating gear sector. A loop-retainer 45 provided with a spring finger 55 is pivoted at 46, and is actuated by a pin 49 carried by a rod depending from a rocking arm which is driven by connexion with the needlebar. The retainer is adapted to take the loop of thread from the needle and hold it in position for engagement by the looper 57. The horn 3, Fig. 10, is provided with a hub 4 supported on bearings on a sleeve 11 splined to a supporting post 5. A rotatable sleeve 7 is provided with cam surfaces engaging cam surfaces on the sleeve 11 so that rotation of the former raises or lowers the horn. Means are provided for holding the sleeve 7 in adjusted position. The whirl 18. Fig. 13, has a central aperture for the passage of the needle, and an eccentric pasage-way for the thread, and is rotated by bevel-gears and flexible shaft from a shaft 25 which is in turn driven from the main shaft. The take-up for the needle-thread consists of a roller 78, Fig. 25, on a' reciprocating slide 79. The tension disk 76 is locked during the stitch-setting movement of the roller 78 by a spring-pressed rod 96 with a conical end engaging a groove in the boss of the tension-disk. The rod is withdrawn near the end of the stitch-setting movement to allow thread to be drawn off the supply by a lug 101 on the slide 79 engaging an adjustable collar 102 on the rod. Feed by devices engaging upper surface of work; presser-bars, with periodic control.-The feed-dog 103, Fig. 7, is carried by a lever 104 pivoted on a stud 105 and provided with a lug 109. An actuacting lever 106, also pivoted on the stud 105, is driven by the same cam as actuates the looperdriving sector and carries adjustable stops 110, 111 adapted to engage opposite sides of the lug 109. The presser-bar 41, Figs. 7 and 8, is pivoted to the frame at 42 and is locked when the needle is in the work by a plate 112 having a cam-edge. The plate is connected to a lever 114 pivoted on an extension 116 of the feed-actuating lever and controlled by a spring 117 and stop pin 118, thus allowing for variation in the thickness of the work. Movement of the lever 106 to give the arm 104 its work-feeding movement, operates through the lever 114 to release the locking-cam 112.