Patent GB-966606-A (GB)
Title: Button stitching machines
IPC: D05B85/00
Filed: 1961-03-21
Abstract: 966, 606. Sewing machines. AMERICAN MACHINE & FOUNDRY CO. March 21,1961 [April 7, 1960], No. 10337/61. Heading D1G. A button-sewing machine comprises a pair of opposed, alternately-operated needle bars adapted to pass a needle back and forth therebetween, a work support and a button clamp mounted on a common movable support adapted to position the button clamp with respect to the needle in accordance with a predetermined stitching and postwinding sequence, a source of supply of buttons, a button-transfer device movable between a buttonreceiving position and a button-delivery position, means for transferring a button from the source of supply to the transfer device at the receiving position, and means for transferring the button from the transfer device to the button clamp at the delivery position. The machine is generally similar to the machine described in Specifications 712,548 and 781,321 in which a button is held horizontally above the work while it is being sewn thereto by running- stitch mechanism employing a double-pointed needle, the button then being turned to the vertical position for a post-winding operation. Buttons B are stacked horizontally in a fixed vertical tubular hopper 30 from which the lowermost button is pushed, during each sewing cycle, by a swinging finger 36. The button then slides over an inclined surface 38 and rolls down a shoot 40 which is pivoted at its upper end about a vertical axis to a fixed bracket 70. The lower end of shoot 40 carries a pair of vertical fingers 71 which straddle a button-holder 72 fixed at one end of an arm 74 pivoted at its other end about a fixed vertical pin 76. The button passes through an aperature 94 in shoot 40 into the holder 72 to abut a finger 96. The latter is raised once every sewing cycle, when the button moves to abut stops 90 and is held thereagainst by a spring 92. Finger 96 is pivoted on a fixed horizontal shaft pin 100 and is rigid with an arm 110 coupled by a yieldable connection 115 to an arm 116 pivoted on a fixed horizontal pin 118. A lug 122, depending from arm 116 is engaged by a cam finger 124 on a rotary cam-shaft 126 once every sewing cycle to raise finger 96. Finger 36 is fixed to an arm 42 which is pivoted about a fixed vertical pin 44 and which is rigid with an arm 48 carrying a roller 50 biased by a spring 68 into engagement with a cam block 52 on a horizontal bar 54. The latter is pivoted at 56 to an arm 58 rigid with a rotary shaft 60, and is forked at 62 to embrace a fixed horizontal pin 64. An arm 74 is rigid with an arm 80 which carries a roller 82 biased by a spring 86 into engagement with a cam block 84 on bar 54. A button transfer device 136 comprises inclined shaft 154 which is slidably and rotatably mounted in a member 144 pivoted on aligned vertical pins 146 carried by a fixed bracket 148. A spring 166 biases member 144 into engagement with an adjustable stop 168 on bracket 148 to align hooked pins 138 on the front end of shaft 154 with the button holder 72. A bevel gear 152 rigid with shaft 154 meshes with a gear sector 150 pivoted on the lower pin 146. Sector 150 is coupled by a yielding connection 172 to a U-shaped bar 176 which is fixed to the upper end of an arm 178 rigid with shaft 60. An arm 134 rigid with shaft 60 is connected by a link 132 to the rear end 128 of a pivoted treadle 130. Depression of the front end 131 of treadle 130 will thereby move bars 54 and 176 reversibly, when cam 84 moves holder 72 towards the transfer device 136, and connection 172 turns sector 150 counter-clockwise to rotate shaft 154 via gear 152 to align pins 138 with the holes in the button in holder 72. On release of the treadle, holder 72 moves away from transfer device 136 to leave the button on pins 138. Depression of the rear end 128 of the treadle then moves bars 54 and 176 forwardly, whereby cam 52 operates the button-feeding finger 36, and connection 172 turns sector 150 clockwise to rotate shaft 154 until gear 152 engages the last tooth 153 of sector 150, when member 144 will turn with sector 150 into engagement with an adjustable stop 193 on bracket 148. Shaft 154 will then be aligned with the button clamp 194. During the final movement of member 144 the rear end of shaft 154 is engaged by an abutment 244 on bar 176, whereby the button on pins 138 is moved forwardly into the jaws of the clamp 194, a lug 156 on the rear end of shaft 154 entering a recess in member 144 to orentiate the button correctly. During a normal sewing cycle, a cam 182 on shaft 126 co-operates with a roller 184 on a spring-biased follower lever 186 pivoted on a fixed pin 188, whereby, when roller 184 moves on to a low part of cam 182, a stud 190 projecting from lever 186 engages a lug 192 on arm 178 to move bar 176 forwardly for transferring a button from the member 136 to the clamp 194. When roller 184 engages the high part of cam 182, bar 176 moves rearwardly until a roller 185 on arm 178 engages a high part of a cam 183 or shaft 126. Sector 150 will then be halted in the position shown in Fig. 1 with gear 152 still engaging the last tooth 153 of sector 150. When roller 185 moves on to the low part of cam 183, bar 178 will move rearwardly till lug 192 re-engages stud 190 for transferring a button from the holder 72 to the member 136. The button clamp 194 comprises a pair of opposed jaws 196, 198 slidably mounted in a head 200 adjustably fixed to a shaft 208 journalled in a bearing 204 carried by the work-supporting table 206. An L-shaped lever 216 is pivoted at 214 to head 200 and carries pins 218, 220 engaged in notches 222, 224 formed in jaws 198 and 196 respectively. A spring-biased plunger 226 engages lever 216 to urge the jaws together. A gear 210 fixed to the end of shaft 218, is partially enclosed by a shield 212 also fixed to shaft 208. The jaws are disposed vertically for button reception and post winding, and are turned to the horizontal position by shaft 208 for the sewing-on operation. The tail of lever 216 is engaged by the hooked front end 230 of a lever 232 pivoted on a fixed pin 234. An arm 242 rigid with shaft 60, carries a pawl 238 which, when the rear end 128 of treadle 130 is depressed, engages a cam 236 on the rear end of lever 232 to swing the latter against the bias of a spring 246. End 230 thereby swings lever 216 to open the jaws 196, 198 for receiving the button transferred thereto by the device 138, the jaws snapping shut when pawl 238 moves clear of cam 236. During a sewing cycle gear 210 is driven by a gear sector formed on an arm 250 to rotate shaft 208. Arm 250 is pivoted at 252 to a bracket 254 rigid with bearing 204, and is connected by a link 258 to a lever 260. The later is pivoted on a fixed pin 262 and is supported by a spring post 270. A follower roller 266 on lever 260 co-operates with a cam 268 on shaft 126 to turn the button clamp to the horizontal position. A pin 272 projecting from bearing 204 engages the end of a groove 274 in shield 212 to position the clamp in the vertical position. To prevent depression of end 128 during sewing, an arm 276 rigid with shaft 60 carries a roller 278 which can enter a notch 280 in a disc rigid with shaft 126, on depression of end 128, only when the machine is stationary. During the post-winding operation, the needle thread is alternately pressed against opposite sides of the post by spaced fingers 302, 304 on a reciprocating bar 300. The thread is clamped by a pair of grippers 356 adjacent the lower needle bar B2 as the latter rises with the needle N, and the thread between clamp 356 and the finger 302 which is pressing the thread against the post, is then pulled by the hooked end 354 of a reciprocating bar 353. Bar 300 is connected to one arm of a bell crank lever 310 pivoted at 313 to a bracket 322 rigid with the work supporting table 206. The other arm of lever 310 is connected by a link 316 to a lever 318 pivoted at 320 to the machine frame. A lever 328, also pivoted at 320, has one arm coupled by a yieldable spring connection 346-to lever 318, and its other end carries a roller 336 biased by a spring 330 into engagement with a cam 340, rotation of which thereby serves to reciprocate bar 300. Bar 353 is slidable in a fixed bearings 358 and 368. A lever 378, pivoted to a fixed pin 380, carries at one end a roller 376 which co-operates with a rotary cam 374, whereby the other end of lever 328 engages a pin 382 on bar 353 to move the latter towards the needle against the bias of a spring 370. A lever 384 pivoted to a fixed bracket 386, has pivoted to its upper end a horizontally slidable bar 388 which is formed with a notch through which bar 353 reciprocates during post winding. A roller 396 on lever 384 is biased by a spring 385 into engagement with a cam 394 on shaft 126, the arrangement being such that for the button-sewing operation an abutment on bar 388 is shifted into alignment with bar 353 to stop the thread-engaging movement of the latter. Simultaneously, a horizontally slidable bar 400 pivoted to the lower end of lever 384, is moved to engage a lug 406 thereon with a recess 404 in lever 318 to stop the reciprocation of rod 300, the yieldable connection 346 permitting lever 328 to oscillate relatively to lever 318. Thread tensioning. In the raised position of the lower needle bar B2, a conical portion 410 thereon bears against a correspondingly tapered recess in a resiliently-biased bar 408 to tension the thread passing between said portion and recess. Bar 408 is clamped to a block 412 pivoted about a horizontal axis to the machine frame. An adjustable stop screw 424 abuts the end of bar 408 adjacent block 412 to limit the downward movement of the other side thread-engaging end. An adjustable stop screw 426 abuts a leaf spring 420 fixed to block 412 for resiliently opposing upward movement of said thread-engaging end. Specifications 543,805 and 900,007 also are referred to.