Patent GB-210606-A (GB)
Title: Improvements in or relating to work feeding and incising mechanism for sewing machines
IPC: D05B15/04
Filed: 1923-01-09
Abstract: 210,606. Reed, J. H., and Little Co., A. E. Jan. 9,1923. Boot-sole sewing-machines, lockstitching by shuttle; channelling; perforating devices.-A work-feeding and incising tool is given a positive fourmotion feed, the operating mechanism therefore being controlled by the presser foot or other work-engaging member, so that the tool incises the work to a definite depth irrespective of the work-thickness. The tool cuts a stitch receiving channel in the line of the seam and a transverse notch. A straight flattened barbed needle is reciprocated through a lever 21, Fig. 1, and a link 20 from a cam 23 on the main shaft 24. The shuttle is of the discoidal type' and is mounted in a race 27 with its front face slightly inclined to the needle-path. The shuttle is oscillated through a, pinion 30 on a shaft 29, by a rack 31 on a lever 32 pivoted to the frame and actuated by a cam 33 on the shaft 24. Presser-bars with periodic control; presser feet; rotary horns. - The presser-foot 34, Fig. 3, partly surrounds the feed-point and the needle path, and has adjustably attached to its underside a sole edge-guide 49. The presser bar 35, Fig. 3, is pressed upon the work by a torsion-spring 36 fixed to the frame..4 slide 43 on the bar 35 carries a pivoted dog 44, which engages with a bell-crank lever 45 pivoted to the frame and actuated by the cam 23. When the dog 44 is raised it grips and raises the bar 35. As the dog 44 is released by the lever 45, it in turn releases the presser-bar which is depressed on to the work, the slide 43 being independently depressed by a spring 46 to an extent limited by an adjusting-screw 47, Fig. 1, thereon. As the stroke of the lever 45 is con. stant, the stroke of the, slide 43 and therefore of the presser-bar is constant. for each adjustment of the screw 47 irrespective of the work-thickness. The presser-foot may be lifted by a treadleoperated lever 48. Feed by devices engaging upper surface of work; channelling; perfnrating devices. -- The feeding and incising tool 42, Fig. 6, has a. cutting or indenting edge 54 as long as the longest stitch required for making the stitch-channel, and a transverse incising edge 53 which may be oblique to the line of feed. The tool 42 is fixed to an arm 52 of a vertical slide 58, Figs. 3 and 6, mounted in a horizontal slide 59, Figs. 3 and 5, which is mounted in a bracket 60 on the frame. Mounted in a vertical groove 61, Fig. 5, in the slide 59 is a block 62 to which is pivoted a slide 63 adjustably fixed to an arm 64 of a sleeve 66 loosely mounted on a shaft 67, Fig. 1. Abutment screws 69 in a pair of lugs 68 on the sleeve 66 engage a lug 70 on a second sleeve 71 loosely mounted on the shaft 67. An arm 72 on the sleeve 71 engages with a cam 73 on the main shaft 24. Oscillation of the arm 72 transmits positive feeding movements to the tool 42, the length of feed being adjusted by altering the relative position of the slide 63 and the arm 64. The point of engagement of the tool 42 with the work is varied, irrespective of the length of stitch, by adjustment of the screws 69. The slide 58 is reciprocated to incise or penetrate the work by means of a bell-crank lever 74, Fig. 6, pivoted to the presser bar. A block 76 on one arm of the lever 74 engages a horizontal slot .77 in the slide 58, while the other arm of the lever is linked to a slide 79 laterally movable in the presser-bar. A block 82 pivoted to an arm 83 of a sleeve 85 fixed to the shaft 67, slides in a vertical groove in the slide 79. Also fixed to the shaft 67, Figs. 1 and 6, is a sleeve 87 having a pair of lugs 88, 89 between which engages a lug 90 on a sleeve 91 loosely mounted on the shaft. An arm 92 of the sleeve 91 engages with a cam 93 on the main-shaft 24. The lug 88 carries an abutment screw 94, while the lug 89 carries a hollow threaded sleeve 95 in which is mounted a plunger 97, adjustably pressed by a spring 96. Clockwise movement of the lug 90 similarly oscillates the lugs 88, 89 and the arm 83 and a consequent movement of the feed-point towards the work until it encounters resistance sufficient to compress the spring 96 whereupon the feed-point is positively actuated to penetrate the work- When the presser-bar is raised to allow the feed to take place, the spring 96 keeps the feed-point in engagement with the work. The feed-point is positively raised by the engagement of the lug 90 with the abutment-screw 94. Specifications 202,223 and 210,605 are referred to.