Patent GB-228208-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B15/02
Filed: 1923-07-25
Abstract: 228,208. British United Shoe Machinery Co., Ltd., Goulbourn, J., and Keall, F. B. July 25, 1923. Lock-stitching by shuttles; feed by needle and by devices engaging the upper surface of the work; presser-bars with periodic control.-In a machine for sewing leather articles of awkward shape, such as saddlery and pouches, in which all the surfaces of the free end of the work-arm 7 are close to the sewing point, the feed-mechanism is reversible. A work-feeding needle 8, Fig. 1, is reciprocated to enter the extreme end of a work-arm 7 to co-oparate with a shuttle 6. wholly within the arm with respect to the needle-path. The main shaft 3, Fig. 1, carries a cam-disc 13, Fig. 2, a roller 15 on which acts in a slot 16 on the needle-bar 17 to reciprocate the needle. The needle-bar 17 and a work-feeding bar 18 are slidingly held in contact in blocks 19, 21 by adjustable wedges 22. The block 19 is pivoted at' 20 while the block 21 is horizontally reciprocated to feed the work. A lever 25 pivoted at 24 to the feed-bar 18 has slotted engagement with studs on the needle-bar and a presser-bar 10 so that as the needle-bar is reciprocated the feed and presser bars are alternately raised and lowered. A lever 32 pivoted at 31 carries a roller 33 spring-pressed on to a peripheral cam on the disc 13, and is connected by links 34, 35 to a lever 36, the lower end of which is pivoted to the block 21. A three-armed lever pivoted at 37 has one arm linked to the junction of the links 34, 35. a second arm 39 which acts as a handle, and a third arm 40 which acts with a link 42 as a toggle, the position of which is regulated bv a spring-pressed manually-controlled rod 43. The pivot of the links 34, 35 is coaxial with the pivot 37 at the beginning of the feed so that' the position of the needle is always the same at this time. By altering the angularity of the toggle the length of feed can be regulated, and by throw. ing it by means of the handle 39 from one side to the other of its straightened position, the direction of feed is altered. A grooved track on the disc 13 operates a take-up 9. A rib 12 on the feed-foot 11 surrounds the needle a short distance above the work. The presser and feed bars can be manually lifted by a two-armed lever 48, 49. A link 53 connects a ball-ended crank pin 52 on the shaft 3, Fig. 1, to a lever 55 which is in turn linked to a pivoted gear segment 59 meshing with a pinion 61 on the shaft of a shuttle-driver 62. 65. The shuttle 6 rests within a race 63, 64, which is recessed to allow of the needle-feed and which ensures correct throwing of the needle-loop. The shuttle is oscillated through threequarters of a revolution. Frames; needle-guides; work-supports; thread tensioning devices.-When reverse feed is taking place, there is a tendency for extra thread to be drawn from the needle by the shuttle; to counteract this an auxiliary tension 51, Fig. 1, is provided which is normally held out of action by an arm 50 connected to the reversing arm 39. When the arm 39 is shifted t'o reverse the feed, the tension 51 comes into action. The needle which is grooved, is positioned with the eye facing the standard. An adjustable needle-guiding plate 80 is arranged on the base of the extremity of the work-arm.