Patent GB-1013998-A (GB)
Title: Improvements in or relating to multiple automatic sewing apparatus
IPC: D05B3/06
Filed: 1964-08-04
Abstract: 1,013,998. Sewing machines. G. M. PFAFF A. G. Aug. 4, 1964 [Sept.21, 1963], No. 30591/64. Heading D1G. Sewing apparatus comprises a plurality of sewing units each of which has adjusting means for varying the stitch width and stitch position, a common work-displacing means for said units, and a stitch pattern control means operably connected to said adjusting and work-displacing means. The apparatus is adapted to sew a plurality of buttonholes simultaneously, either parallel to or at right angles to the edge of a workpiece. A frame 1 Fig. 1 has side walls 2, 3 a base 4 and a vertical longitudinal wall 5 formed with horizontal ribs 6 to which the casings 15 of a plurality of sewing units are secured. A motor 12 drives a shaft 11 coupled by a chain 9 to a longitudinal shaft 7. Each casing 15 journals a vertical shaft 21 Fig. 2, coupled by gearing to shaft 7. A vertical shaft 140, Fig. 8, journalled in casing 15, is coupled by gearing to shaft 21 and carries in looptaker 145. A disc 25, fixed to shaft 21, has an inwardlyinclined bore 26 journalling in pin 27 fixed to an arm 28 pivoted at 30 to a lever 29 pivoted on casing 15 and connected by a link 31 to a needle bar 33 which carries a needle 32 and is slidable in a frame 35 pivoted at 38, at its upper end, to casing 15. A lever 41, pivoted at 40 to frame 35, is formed with a channel 42 embracing a cam 43 rigid with a gear 44 journalled on a shaft 46 fixed in casing 15. Gear 44 is driven by a gear 52 on shaft 21. A block 54, Fig. 4,pivoted on lever 41, is embraced by a channel member 56 carried by a pin 57 pivoted intermediately in a bar 59. The lower end of bar 59 is pivoted on a pin 58 fixed in casing 15, and the upper ends connected by a link 249 to a crank 248 on a shaft 246 pivoted in frame 1. Rotation of shaft 246 thereby serves to shift the stitch position. Pin 57 is connected by a link 61 to a bar 63 which is pivoted to one arm of a bell crank lever 65 pivoted on pin 58. The other arm of lever 65 is connected by a link 237 to a crank 236 on a shaft 234 pivoted in frame 1. Rotation of shaft 234 thereby serves to vary the stitch width. A crank 245 on shaft 246 is adjustably connected by a link 239 to a slidable bar 224 carrying a follower roller 225 biased by a spring 250 to cooperate with a cam 219 on a control disc 121 journalled on a shaft 124 fixed in frame 1 and coupled by gearing, via a shaft 209, to shaft 7. A crank 232 on shaft 234 is adjustably connected by a link 230 to a lever 226 coupled to slidable bars 222, 223 carrying follower rollers 225 biased by a spring 238 to co-operate with cams 216, 217, 218 on control disc 121. Shaft 21 is coupled by gears 68, 69 to a shaft 70 journalled in casing 15 and carrying a crank pin 72 journalling one end of a needle thread takeup lever 73 connected intermediately to a swing- ing arm 74. A shaft 188, journalled in casing 15, carries at opposite ends cranks 189 and 190. In the position of frame 35 for straight stitching, the upper end of bar 63 co-operates with crank 189 to engage crank 190 with the tension-releasing pin of the needle thread tensioner. The upper end of shaft 140 carries an eccentric 141 embraced by a member 142 formed with a slot 144 embracing a leg 143 pivoted on casing 15. The bobbin case in looptaker 145 comprises a lower member 147 having an extension 148 engaging member 142. The upper member 150 of the bobbin case has a split depending pin 151 which engages an aperture in member 147 and serves to journal the bobbin 149. The looptaker is covered by a pivoted and upwardly spring biased worksupporting plate 166. A pin 157 axially slidable in shaft 140, is spring-biased downwardly to engage a crank 163 on a shaft 162 pivoted in frame 1 and provided with a handle 161. Actuation of the latter thereby raises rods 157 to engage the pins 151, whereby the upper members 150 are expelled from the looptakers, expansion of the pins 151 on release from members 147 serving to grip and thereby expel the bobbins also. Gear 44 meshes with a gear 78 Fig. 6 rigid with an eccentric 77 coupled by a pitman 79 to a crank 80 on a shaft 81 journalled in casing 15 and carrying a double crank 82, 83. A block 85, slidably mounted in crank 83, carries a pin 84 connected by a link 126 to one arm of a bell crank lever 129 pivoted on casing 15, the other arm carrying a buttonhole-cutting knife blade 131. Block 85 is embraced by a slot 86 in an arm 87 rigid with a shaft 88 which is pivoted in casing 15 and is biased by a spring 133 to position pin 84 normally in alignment with shaft 81, whereby lever 129 remains stationary on oscillation of shaft 81. Shafts 89, 90, journalled in frame 1, are coupled by a magnetic clutch 95, shaft 89 being coupled by a link 94 to 110,112 to a shaft 111 slidable in frame 1. Shaft 111 is coupled by a linkage 113 to 117 to a swinging arm 118 carrying a follower roller 120 co-operating with a cam 123 Fig. 5, on the control disc 121. A cam slot 251 Fig. 5, in control disc 121 cooperates with a follower roller 252 on a crank 253 carried by a shaft 255 also carrying a crank 256 adjustably connected by linkage 258, 260 to a shaft 264 which is slidable and rotatable in frame 1 and is connected by arms 270 to a shaft 271. Brackets 275 on the latter carry work-feeding feet 272 Fig. 10. A crank 295, splined to shaft 264, is connected to the plumper 293 of a solenoid 292 and is biased by a spring 293 to engage the feet 272 with the work-supporting plate 165. A shaft 277 Fig. 5, is slidable and rotatable in legs 278 carried by pins 279 which are slidable in frame 1 at right angles to shaft 277. The latter is connected by arms 280, slotted at 282 to embrace shaft 271, to a shaft 281 carrying brackets 283 supporting needle thread cutters 284, Fig. 10. Each of the latter comprises a fixed blade 288 and a blade 287 which is pivoted at 286 and carries a pin 289 disposed in a channel 290 carried by a bracket 291 fixed to shaft 271. An arm 300,rigid with shaft 277, is coupled by a pin 302 to a bar 303 which is coupled by a pin and slot connection to the plunger 304 of a solenoid 305. A spring 314 normally biases bar 303 to its right hand end position, when a follower roller 318, carried by a pin 316 depending from shaft 277, engages the right hand end of a cam surface 320 in a fired plate 319, under the influence of a spring 322, to bias shaft 277 outwardly from frame 1. A vertical shaft 180 Fig. 8 pivoted in casing 15, carries at its upper end a blade 181 adapted to co-operate with a stationary blade 183 for severing the bobbin thread. The lower end of shaft 180 carries a crank 185 having a slotted end 186 embracing a pin 338 on a shaft 336 slidable in frame 1 and coupled by a linkage 333, 334, 337 to the plunger 332 of a solenoid 330, a spring 339 serving to bias blade 181 to the inoperative position. At the commencement of the operating cycle, frame 35 is in the straight-stitching position, solenoid 292 is energized to raise the feeding feet 272, a cam 347 on a disc 344 rigid with the control disc 121 actuates a switch 348 to d-energize the clutches 95, and a cam 352 on disc 344 actuates a switch 355 to de-energize solenoid 305 and to energize solenoid 330. Operation is initiated by actuating a switch 343 to de-energize solenoid 292 for lowering the presser feet, and to energize motor 12 for driving shaft 7. Initial locking stitches are sewn with zero thread tension until cam 216 actuates bar 222 and cam 251 moves shaft 264 leftwards to commence the sewing of the first side of the buttonhole. Switches 348 and 355 are then released, whereby the clutches 95 are energized, solenoid 330 is de-energized, and solenoid 305 is energized to move bar 303 and shaft 277 leftwards whereby roller 318 co-operates with surface 320 to move shaft 277 inwardly, whereby pin 289 cooperates with channel 290 to open the blades 287, 288, and a tooth 328 rigid with pin 316 finally engages a spring-biased block 325, anchored in a slot 323 formed in plate 319, to retain shaft 277 in its leftmost and innermost position. When disc 121 has rotated nearly 180 degrees, cam 217 actuates bar 223 and cam 219 actuates bar 224 for sewing the first bearing stitches until cam 251 has commenced to move shaft 264 rightwards and cam 217 leaves bar 223. Sewing of the second side of the buttonhole then proceeds with cams 216 and 219 actuating bars 222 and 224 respectively. Near the end of said second side, cam 123 actuates roller 120, whereby arm 87 is actuated to shift block 85 along crank 83 and thereby pin 84 out of alignment with shaft 81, whereby oscillation is imported to the buttonhole-cutting blade 131. Breakage of needle thread results in de-energizing of clutch 95 and consequently no actuation of blade 131. Cam 218 then actuates bar 223 for sewing of the short barring stitches, and cam 123 is then disengaged from roller 120 to stop the actuation of blade 131. After disc 121 has completed one revaluation, a cam 351 on disc 344 stops motor 12, and cam 352 actuates switch 355, whereby solenoid 305 is de-energized and spring 314 shifts shaft 277 rightwards, when tooth 328 on leaving block 325 allows spring 322 to shift shaft 277 outwards for closing blades 287, 288 to sever the needle threads, while solenoid 330 is energized for actuating blades 181 to sever the bobbin threads. Sever 334, associated with solenoid 330, also actuates a switch 360 for energizing solenoid 292 to raise the work-feeding feet. The arrangement is also such that the casings 15 may be turned through 90 degrees and movement may then be imparted to the work-feeding feet in the transverse direction, to enable the buttonholes to be sewn at right angles to the edges of the workpiece.