Patent GB-704524-A (GB)
Title: Button sewing machine
IPC: D05B3/14
Filed: 1952-10-30
Abstract: 704,524. Sewing - machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.). Oct. 30, 1952, No. 27291/52. Class112 A cyclically-operating sewing-machine including a work clamp, for example, for attaching buttons or other articles to a work-piece, complemental driving members are provided on the needlebar actuating shaft and a clamp - opening rock - shaft, these driving members being relatively moved into operative relation at the end of the cycle to cause the opening of the clamp. Button-attaching machines; needles, driving and vibrating laterally; stopping. In a machine for attaching flat buttons, having a main shaft 27 which drives a patterncam shaft 42 through worm gear 43, a rotary chain-stitch looper shaft 22 through spur gears 38, and a needle-bar rock-shaft 31 through an eccentric 28 and pitman 29, the needle-bar 18 is mounted for reciprocation in a gate 19 which is pivoted on a hollow shaft 20 and which has an arm 57 whereby it is oscillated from a cam 45 through a follower lever 48 and adjustably connected link 55; the needle-bar is actuated by an arm 34 on the rock-shaft 31 carrying a pivoted block 35 which engages a channel in a block 37 clamped on the needle-bar. The looper-shaft 22, which has a universal joint 40, is carried in a bracket 23 slidably guided beneath the top plate of the machine bed 11 so that it can be oscillated about the joint 40 to keep the looper under the needle; this oscillation is produced by a lever 73 pivoted on a screw 25 (which also serves to guide the bracket 23) and connected to the bracket at 75, the lever being actuated by an arm 71 on the lower end of a shaft 50 of which the upper end carries an arm 70 connected by a link 69 to 'the needle-bar gate arm 57. Stopping devices comprising a positive stop-arm 79 and a belt-shifter 80 are carried by a rod slidable parallel to the shaft 27 and moved to the left against a spring by treadle or like means to be engaged by a latch which holds it in the running position; the latch is disengaged, about half a revolution of the shaft 27 before the end of the stitching cycle, by a projection 90 on the hub of a cam 106 on the shaft 42. The button-clamp arm 99 is pivoted at 97 to a work-plate 93 which is shifted longitudinally, to allow stitching through the second pair of holes of a four-hole button, by mechanism including an arm 110 actuated by the cam 106; if it is only required to sew two-hole buttons the clamp arm may be pivoted to lugs 105 on the standard of the machine. The clamp arm is lifted by a hinged link 132 connected to an arm 128 on a rockshaft 122 in the machine arm. and is guided, to prevent movement laterally of the machine, by members 104 receiving between them the lower end of a rod 103 which slides in the hollow shaft 20 carrying the needle bar gate and which is pressed down by a spring, adjustable by a screw 102, to hold the clamp arm on the work. The shaft 122 has an arm 123 for actuation by treadle or like means, and may also be actuated automatically by an arm 150 on the needle-bax shaft 31 engaging the arm 128 on the shaft 122; the shaft 122 is normally held by a spring 151 in such a longitudinal position that the arms 150, 128 do not come into contact, but is moved to the left against this spring through a stiffer spring 160, by an arm 158 on a shaft 157 which is actuated through an arm 156 by a cam member 153, adjustably fixed to the cam 45, at the beginning of the last upstroke of the needle in a stitching cycle, so that the clamp arm is lifted through the arms 150, 128 as the machine stops. This automatic clamp-lifting may be prevented by pushing in a plunger 163 which has its inner end resting in a bore in the end of the shaft 122; the plunger is retained in its inner position by a partial turn, and in that position abuts the end of the bore in the shaft to prevent movement of the latter to bring the arm 128 into line with the arm 150. Frames. The machine is pivotally mounted in a base 10 by trunnions such as 16. The right-hand side of the arm and standard is closed by a cover-plate with a projecting portion which accommodates the cam 45 and arm 48 and has a hinged top to allow access to the adjustment means of the link 55. Threads, controlling otherwise than in stitch-forming; thread-end holders. The clamp lifting rock-shaft 122 carries a pulloff arm 143 co-operating with a fixed thread-guide 147 between the tension devices 145 and the usual thread-nipper 144 to draw off thread for the initial stitch of a new cycle. A finger 137 of spring wire, normally lying to the right of the needle, is moved across beneath the needle as the clamp is lifted, by means of a rod 135 connected to the arm 128 and an arm 136 on a rock-shaft 139 carrying the finger 137, to draw the needle thread through the work after it has been broken beneath the work by the lifting of the clamp-arm; when the clamp is closed again the finger 137 returns, carrying the end of the needle thread clear of the needle path for the first stitch.