Patent GB-1013996-A (GB)
Title: Improvements in or relating to the hemming of sheets or the fabrication of baglike structures
IPC: D05B13/00
Filed: 1964-05-25
Abstract: 1,013,996. Sewing machines, turning inside out. G. M. PFAFF A. G. May 25, 1964 [May 31,' 1963], No. 21453/64. Headings D1G and DIX. Apparatus for hemming the opposed edges of a workpiece comprises a pair of horizontal surfaces, means for holding the end of a web of material against one of the surfaces, means disposed between the surfaces for drawing off a predetermined length of material, means for holding the opposite end of the drawn-off length against the other surface, means for cutting the web transversely adjacent said other surface to provide a  l U-shaped workpiece having legs depending from end portions overlying said surfaces, and workfeeding means for engaging said end portions to feed the workpiece in a direction parallel to the edge thereof to folding devices and a pair of sewing machines adapted to form and sew a hem along each end of said end portions. As described, the apparatus also converts the hemmed workpiece into a pillowcase by providing buttons and buttonholes at the respective hemmed end edges, by sewing together the opposed side edges, and by turning the completed workpiece inside out Work feeding. A roll 2 of fabric at a station A is engaged by a roller 3 at one end of a pivoted arm 12 biased towards roll 2 by a spring 16. A roller 11 is connected by a chain 7 to a motor 5 and is interconnected with roller 3 by gearing 10, 13 and a chain 14. A block 19, pivoted at 18, is connected by a chain 22 to a motor 23, actuation of which serves to turn block 19 through 90 degrees for positioning an initially vertical surface 20 horizontally. A block 31 is pivoted at one end of an arm 28, the other end of which is pivoted at 29 block 31, engages a chain 34 the ends of which are to the machine frame. A sprocket 33, rigid with block 31,engages a chain 34 the ends of which are anchored adjacent pivot 29. Arm 28 is connected by a link 27 to a crank disc 26 driven by a motor 25. Work-feeding means 43, carried by block 31, comprises an endless belt 55 which is driven via rollers 50 by a pinion 52, and which is normally held by spring means disengaged from an initially vertical surface 32 of block 31. Actuation of motor 25 serves to swing both arm 28 and block 31 for positioning surface 32 horizontally with pinion 52 engaging a pinion 53 driven by a motor 54. Initial operation of motor 5 serves to draw off a length of fabric from roll 2 over the vertical surfaces 20, 32. Solenoids 49 associated with the feeding means are then energized to engage belt 55 with the fabric on surface 32. Motors 23 and 25 are then actuated to position surfaces 20 and 32 horizontally, surface 32 being lower than surface 20. A motor 41 is then actuated to drive a chain 39 for lowering a sleeve 37 along a rod 38, whereby a horizontal bar 36, carried by sleeve 37, decends between the blocks 19, 31 to draw off a predetermined length of fabric from roll 2. Solenoids 49<SP>1</SP> of a work-feeding device 44 are then energized to engage a belt 55 with the fabric on surface 20, and to engage the belt-driving pinion 52<SP>1</SP> with a pinion 53<SP>1</SP> of a motor 541. Work-cutting. Block 19 carries a casing 57 containing sprockets 58, 59 interconnected by a chain 61 and driven by a motor 60. The upper run of chain 61 is fixed to a plate 62 carrying rollers 63 engaging tracks 64. The lower run of chain 61 engages a sprocket 67 carried by a shaft 66 journalled in plate 62. A shaft 69, journalled inplate 62, carried a circular cutter blade 56 and is connected by gears 67, 68 to shaft 66. Actuation of motor 60 thereby effects traversing of plate 62 and rotation of blade 56 to cut the web transversely. Work-folding. The feeding means 43, 44 transfer a severed workpiece 3<SP>1</SP> to a station B in which the out-turned ends are supported on surfaces 82, 83, and where the edges are folded upon each other prior to being sewn into hems by machines 127, 128 at a station D. Each edge-folding means comprises a stationary bar 84 at the edge of the respective surface 82, 83, and a pair of movable bars 90, 94 which co-operate with bar 84. A bar 113 rigid with bar 90 carries a rod 98 engaging a cam slot 88 formed in a fixed plate 89. Bar 113 is pivoted to links 113 and 121, the former being connected by a link 115 to one arm 116 of a bell crank lever, and the latter being pivoted to the apex of said lever together with a swinging arm 119 carrying a follower 120 co-operating with a cam 100 on a rotary shaft 102. The other arm 118 of said lever is pivoted to a swinging arm 122. A bar 111, rigid with bar 94, carries a rod 99 engaging a cam slot 87 formed in plate 89. Bar 111 has associated therewith members 104, 106, 107, 108, 109, 110, 112 similar to the respective members 119, 118, 116, 122, 115, 114, 121, member 104 carrying a follower 103 co-operating with a cam 101 on shaft 102. The arrangement is such that bar 94 moves inwardly first, when a tongue 95 thereon holes the workpiece against bar 84 while a second tongue 93 folds the workpiece under a tongue 85 on bar 84. Bar 90 then moves inwardly, when a tongue 92 thereon folds the edge of the workpiece over tongue 85. Work-feeding-hemming, button and buttonhole stitching. Work-feeding means 125,126 and 133, 134 similar to the means 43, 44 but without the solenoids, then feed the workpiece past the machines 127, 128 at station C to a station D comprising six buttonhole sewing machines 140 and three button sewing machines 141. The latter are adapted to be shifted by a buttonhole spacing after sewing on the first three buttons. The work is next fed, by means associated with the machines 140, 141 and by means 184, 185 similar to the means 43, 44, to a station E. The U-shaped workpiece then extends between interconnected plates 162, 163, the out-turned ends being held on respective hinged flaps 170, 171 by the feeding means 184, 185, plate 163 carrying a bracket 165 pivoted on a fixed shaft 164. Suction is then applied via nozzles 188 to hold the workpiece to the plates 162, 163, and the means 184, 185 are disengaged from the flaps 170, 171. Journalled on shaft 164 are sprockets 166, 172, 173 rigid with bracket 165. Sprocket 166 is connected by a chain 169 to a motor 167. Sprocket 172 is connected by a chain 174 to a sprocket 176 rigid with flap 170. Sprocket 173 is connected by a chain 175 and gears 178, 181 to a gear 182 rigid with flap 171. The arrangement is such that when motor 167 is actuated,after release of suction from the nozzles 188 on plate 163,the plates 162, 163 turn counterclockwise till a roller 195 carried thereby engages a roller 194 connected by a chain 192 to a motor 190, flap 171 turns through 90 degrees into alignment with plate 163, and flap 170 turns through 270 degrees to lie parallel to plate 162 thereby folding the workpiece and engaged thereon upon the end previously engaging flap 171. After release of the suction from the nozzles 188 on plate 162, motor 190 is actuated to feed the workpiece past a pair of machines 200, 201 for sewing together the respective edges of the workpiece. Feeding of the sewn workpiece over a surface 218 is effected by belts 210 to convey the workpiece to a station G at which the workpiece is turned inside out. Turning inside out. The button-carrying fold at the open end of the completed pillowcase is turned inside out by means 216, 217. Each of the latter comprises a scissors-like structure pivoted on a fixed pin 219 and having opposed legs 226, 227 and 228, 229. A disc 233, pivoted on pin 219, is connected by a chain 221 to a motor 222. A spring 230, connected between legs 228, 229, biases leg 228 against a fixed pin 231 and leg 229 against a pin 232 depending from disc 233 and so positioned as to separate the free ends of legs 226, 227. A suction tube 238 raises the button-carrying fold to permit the entry therein of leg 226 at the end of the feeding movement. Motor 222 is then actuated to rotate pin 232 counter-clockwise, whereby the ends of legs 226, 227 first close to grip the end of said fold, and then rotate through 180 degrees to turn the fold inside out. A lever 235, pivoted on surface 218, is then actuated by a pneumatic jack 237 to engage leg 229 and thereby separate the ends of legs 226, 227. The pillowcase is then fed by the belts 210 to engage the surface of a drum 240 rigid with a fixed shaft 241, the pillowcase being held to said surface by suction nozzles 242, and feeding continuing until the open end of the pillowcase is positioned under, and held open by a suction tube 253. During said feeding the buttoncarrying fold is flattened by a fixed bar 239. At each end of drum 240, and adjacent the surface thereof, is an arcuate bar 243 carried by a radial arm 244 which is journalled on shaft 241 and is connected by a chain 246 to a motor. Similar armate bars 248 are carried by a similar arcuate arm 249 connected by a chain 251 to a motor. On actuation of the motor to rotate arm 244 clockwise, the bars 243 enter the open end of the pillowcase and engage the closed end internally. Arm 249 is then rotated clockwise, whereby the bars 248 engage the closed end of the pillowcase externally, and on continued rotation turn the pillowcase inside out.