Patent GB-991417-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B3/14
Filed: 1961-09-06
Abstract: 991,417. Sewing machines. AMERICAN MACHINE & FOUNDRY CO. Sept. 6, 1961 [Sept. 6, 1960], No. 32054/61. Heading D1G. A button sewing machine has means for supporting the fabric to which the button is to be sewn comprising a movable table member, a clamp plate mounted at the end of the member and a work supporting tongue mounted on a carriage for movement into a position adjacent the clamp plate to hold the fabric, and means for locking the carriage in that position. The sewing machine is of the running stitch type disclosed in Specification 712,548 in which buttons are attached to the fabric by a shank of thread by means of which the button is supported above the work. A movable work-table 10 has three inverted cups 12 (see Fig. 1) secured to its underside, each cup engaging and resting on a ball rotatably supported on the frame 18. The table is moved in two directions at right angles by two cams, the cam 42 (see Fig. 2) engaging a follower arm 36 attached to a rod 34 resiliently coupled at 32 with one end of a lever 30 pivoted to the frame at 28 and connected to the carriage at 22; the cam 64 operating a rod 70 attached to one arm of a bell crank lever 72 pivoted to the frame at 80 the other arm being connected to the table 10. The table 10 carries a work supporting carriage 94 and a work clamping carriage 96 (see Fig. 4) the carriages being urged away from the stitching position to the positions shown dotted by springs 106 and 160 respectively when the handle 118 is rotated manually or by a treadle (not shown) to withdraw the latch dog 116 from behind a lug 112 on the table 10. The carriage 94 carries an adjustable work supporting tongue 156 around which the work W is folded. The carriage 94 is then pushed manually to the left until it abuts the rear of the carriage 96, the carriages then moving together until the work W engaged between the tongue 156 and a clamping and tensioning plate - 164 carried on the carriage 96, is in the correct position relative to the button B. The latch dog 116 then rises behind the lug 112 to maintain the carriages in the forward position. As the carriage 94 moves forward, as described a roller thereon (not shown) rolls along the cam edge of one arm 128 of a lever pivoted to the frame 130, the other end 132 then falling from its previous, dotted, position to allow the spring 146 to pull down a lever 136 which effects the lowering of the foot 144 into engagement with the work on the tongue 156. The machine is then started, the table being moved by the cams 42, 64 so that the needle 166 passes backwards and forwards first through the work and selected holes in the button, winds several loops of thread about the thread shank thus formed, and locks the thread against unwinding. Blind stitching The table movement due to the cam 42 is limited by an adjustable stop 182 (see Fig. 2) carried by an extension 184 on the lever 26, the stop engaging a lever 186 which may be raised by a knee operated pad 194 to bring a stop on the lever into the path of the projection 184 to further limit the movement of the table and cause the needle to move through the thickness of the folded cloth and produce a blind stitch. Specifications 900,007 and 966,606 also are referred to.