Patent GB-1006962-A (GB)
Title: Fabric positioning and sewing apparatus
IPC: D05B23/00
Filed: 1964-02-14
Abstract: 1,006,962. Sewing machines. MASTER SEW CONTROL CORPORATION. Feb. 14,1964 [March 15,1963], No. 6306/64. Heading D1G. A rectangle of cloth is placed on a conveyer belt, and is then so positioned that an edge thereof extends over an edge of the conveyer belt, the latter feeding the cloth through a hemming machine, the cloth being simultaneously held down upon the conveyer belt, to form a line of duplicater marked stitching parallel to the edge of the belt, and the stitch chain is severed as the hemmed edge leaves the machine. As described, the rectangular piece of cloth is cut from a roll of cloth the two sides of which are initially hemmed, and the other two sides of the piece are hemmed in succession, to form a handkerchief, while the piece travels on the conveyer belt. An endless conveyer belt 15 is arranged with its upper run supported on a table 18. Rectangles of cloth having two opposite sides initially hemmed are laid on belt 15 with the unhemmed edges parallel to the edges of the latter. An edgepositioning means 25 moves a workpiece laterally till its right hand edge overlaps the edge of belt 15 by a predetermined amount. Said edge of the workpiece is then trimmed by cutting means 280, and is next hemmed by a sewing machine 200 while being simultaneously held down by means 175, the stitch chain finally being severed by means 325, and any tail at the end of the hem being removed by cutting means 350. The left hand edge is then similarly hemmed while the workpiece travels on the belt. Edge-positioning means 25, Figs. 1 and 3, comprises a carriage 26 movable on tracks 70 in the direction of belt movement. A pusher bar 27, adapted to move the work transversely, has work-engaging feet 30, and is rigid at its respective ends with rods 28, 29, the upper ends of which carry rollers 127 movable on the ends of levers 31, 32 pivoted at 33, 34 to carriage 26. The other ends of levers 31, 32 are rigid with a bar 37 carrying a collar 40 spring-biased into engagement with a cam surface 42 formed in a fixed plate 41 parallel to the line of belt movement. The arrangement is such that when roller 40 is at the ends of cam surface 42, bar 27 is raised from belt 15, and when carriage 26 is moved in the direction of work feed roller 40 travels in engagement with cam surface 42 to lower bar 27 into engagement with belt 15, while when carriage 26 is moved in the direction opposite to work feed roller 40 remains latched in the depressed position out of engagement with surface 42 and bar 27 is raised from belt 15. A pin 147 projecting from carriage 26 engages the upper end of a channel bar 140 pivoted at its lower end on a fixed pin 141. A pin 145 on bar 140 is biased by a spring 150 against a cam 143 on a shaft 144, rotation of which thereby serves to reciprocate carriage 26 on the tracks 70. Rods 28, 29 are resiliently coupled via springs 92 to respective hollow cylinders 84 slidable in cylinders 81 fixed to carriage 26. A rack 83 rigid with cylinder 82 engages a gear 126 which is journalled on carriage 26 and the rotation of which is controlled by an electro-magnetic brake 125. A plunger 98, slidable into cylinder 84 against the bias of a spring contained therein, carries at its outer end a roller 106 engaged with a fixed cam channel 107. The leading edge of carriage 26 carries a photo-cell 130 positioned above a black line provided on belt 15. Photocells 137 and 138 are arranged on carriage 26 adjacent the path of movement of the front and rear ends respectively of bar 27, and are positioned above a black line provided on table 18 adjacent the edge of belt 15. The arrangement is such that when a workpiece is carried by belt 15 beneath photo-cell 130, the additional light reflected on to the latter serves to energize a onerevolution clutch to drive shaft 144. Carriage 26 thereby moves in the direction of work feed, and bar 27, engaging the workpiece, is moved by plungers 98, controlled by cams 107, towards the edge of belt 15. When the leading part of the workpiece covers the stationary black line, the additional light reflected on photo-cell 137 serves to actuate the associated brake 125 to prevent further movement of the associated cylinder 84. Photo-cell 138 is similarly influenced by the trailing end of the workpiece, whereby the edge of the workpiece overlaps belt 15 in alignment with the stationary black line. Carriage 26 then returns to its initial position with bar 27 raised from belt 15. A compressed air duct 160 on carriage 26 has nozzles 161,162 directed downwardly at the leading and trailing edges of the latter. The edge of the workpiece overlying table 18 is then trimmed by a rotary knife 281 of the cutting means 280, the trimmings being removed via a suction duct 290. The means 175 for holding down the workpiece, while the latter is being hemmed by machine 200, comprises a structure 190, Fig. 4, carrying idler rollers 177,178,179. A bar 185, pivoted at 186 to structure 190, is rigid with a rod 182 carrying idler rollers 183,184. An endless belt 176 is trained on rollers 177,178,179 and 183,184,and its lower run engages belt 15. A chamber 220, carried by structure 190, is closed on its top and sides, while its perforated bottom surface engages the lower run of belt 176. Compressed air supplied to chamber 220 via a pipe 225 thereby biases belt 176 against belt 15. A comb 181, rigid with rod 182, contacts belt 176 and is earthed to discharge static electricity therefrom. To disengage belt 176 from belt 15, suction is applied to chamber 220 via a pipe 226, and structure 190 is then lifted and swung rearwardly by co-operation of pins 201 thereon with slots 200 in fixed members 197. Machine 200 is provided with a hemming presser foot 250, Fig. 13, having an aperture 251 for the needle 252. The presser foot is formed with a slot 259 to provide an inner branch 254 formed with an upwardly-bent end 255, and an outer branch 258. An edge-folding scroll 260 is provided at the inner end of slot 259. An elongated feed dog 261 co-operates with branch 254. The drive to machine 200 is momentarily speeded up when a workpiece enters the machine, in order to tension the workpiece. For this purpose a pivoted yoke 460, Fig. 12, carries a shaft 465 journalling three bevelled pulleys 462, 463, 464. An endless driving belt 471 is disposed between pulleys 463, 464, and an endless driven belt 472 is disposed between pulleys 462, 463. A follower roller 469, carried at one end of a linkage 467, 468 the other end of which is connected to yoke 460, is spring- biased against a rotary cam 470. A workpiece on approaching presser foot 250 passes under a photocell 275 to energize a one-revolution clutch 480 for driving cam 470. Yoke 460 is thereby swung momentarily to the left, whereby belt 471 is depressed between the pulleys 463, 464, and belt 472 rises between the pulleys 462, 463 to increase the speed of sewing machine 200. The workpiece on leaving machine 200, Fig. 1, passes under presser rollers 301, 302, 303, 304, 305 carried by a fixed bar 307, and under an endless belt 313 carried by rollers 311, 312 supported by bar 307. Belt 313 engages the newly-hemmed edge, and while the latter is so engaged the thread chain is severed by means 325, and any tail T on the hem is severed by means 350. Severing means 325, Fig. 14, comprises two sets 326, 327 of intermeshing and oscillating cutter blades which are positioned below an opening 328 in table 18. Compressed air is blown downwardly on to the cutter blades from a nozzle 332, and the severed chain is removed by a suction duct 350. Severing means 350, Fig. 16, comprises a knife blade 351 carried at one end of a lever 352, the other end of which is connected to the armature 355 of a solenoid 354. The latter is energized, to actuate knife 351, when a photo-cell 360 detects the presence of a workpiece beneath it.