Patent GB-990909-A (GB)
Title: Pneumatic work controlling devices for sewing machines
IPC: D05B65/00
Filed: 1964-02-24
Abstract: 990,909. Sewing machines. SINGER CO. Feb. 24, 1964 [Feb. 25, 1963], No. 7587/64. Heading D1G. [Also in Division B6] A work folder or guide for a sewing machine comprises means for delivering air under pressure laterally of the direction of work travel and towards a work edge-guiding surface disposed longitudinally of the direction of work travel. A guide 22, Fig. 3, for folding the edge of a collar blank 27, prior to the folded edge being secured by stitching 38, comprises an upper plate 31 fixed to an adjustably-mounted bracket 29 and formed with a folding scroll portion 32 terminating in a longitudinal edge-guiding surface 39, and a lower plate 34 which is spaced from the upper plate by a bar 33 and projects into the throat of the scroll 32. A nozzle 45, adjustably mounted on plate 31, directs air transversely of the direction of work travel for ensuring engagement of the workpiece edge with the surface 39. A nozzle 47, mounted on plate 31 behind nozzle 45, directs air in the direction of work travel to assist the passage of the workpiece. A lap seam felling guide Fig. 4, comprises a lower plate 53, having an upwardlyturned folding scroll 55 into which the edge of a lower sheet is urged by air from a nozzle 58, and an upper plate 56 having a downwardly-turned folding scroll 57 into which the edge of an upper sheet is urged by air from a nozzle 59. An edge guide, Fig. 5, comprises a lower plate 66 with an upturned edge-guiding flange 65, and an upper plate 64 spaced from plate 66. A nozzle 63 directs air towards flange 65, a nozzle 67, arranged in advance of nozzle 63, directs air away from flange 65 to prevent puckering if material thereat, and a nozzle 69, arranged behind nozzle 63, directs air downwards through a hole 70 in plate 64. Folding guide 22 is incorporated in apparatus which is arranged for automatically sewing a succession of workpieces 27, and which comprises a table 81 supporting a sewing machine 20, means 21 for feeding the workpiece to the sewing machine, and means 23 for stacking the completed workpiece. Means 21 is mounted on a bracket having a vertical plate 83, and a horizontal plate 85 fixed in adjusted angular relation to tube 81 by pin and slot connections 86, 87. A platform 90, supporting a stack of workpieces 27, is raised and lowered by an air cylinder 91 mounted on plate 83. A hinged flap 92, which rests on the topmost workpiece, is provided with nozzles 93 which direct air under flap 92 and towards its free edge, whereby, assisted by the effect of nozzles 94 and 95, the topmost workpiece adheres to the undersurface of flap 92. The latter is then turned to lay said workpiece on a feeding wheel 98 and under a raised foot 99. Flap 92 then returns to its original position, a nozzle 97 levelling the workpieces, and foot 99 descends, whereby the first workpiece is fed along a channel 82, assisted by nozzles 100, 101, into the folding guide 22. The sewn workpiece engages an abutment 117, whereby, with the assistance of nozzles 118, 119, it is correctly directed into a channel 126 leading to the stacking means 23. Severing of the thread chain is effected in channel 126 by a solenoidoperated knife 131 co-operating with an anvil 129, and movement of the workpiece in channel 126 is effected by nozzles 128. The stacking means 23 comprises a carriage 145 mounted by rollers 146 on rails 143 and movable to and away from the delivery end of channel 126 by means of an air cylinder 148. A platform 152, for receiving completed workpieces in succession, is connected by pivoted links 151 to carriage 145, and an air cylinder 154, pivoted between the latter and a link 151, governs the height of platform 152. During a sewing operation, platform 152 is adjacent channel 126, and the depending leading end of the sewn workpiece is folded by downwardly-directed air nozzles 142 over a downwardly-curved extension 157 of platform 152. When the thread chain is severed, the nozzles 142 then urge the workpiece on to the stack on platform 152, after which carriage 145 is moved outwardly. When carriage 145 is next moved inwardly, the workpieces on extension 157 engage an arm 158 for closing a switch 159, whereby air cylinder 154 is actuated to lower platform 152 sufficiently to maintain the stack thereon at a constant level. The respective operation of the feed means 21, the sewing machine and the stacking means 23 is controlled by photo-cells 110, 120 and 130 illuminated by a lamp 132. During the sewing of a workpiece, when the latter covers all the photo-cells, means 21 and 23 are inoperative. When photo-cell 110 is uncovered by the trailing end of a workpiece, means 21 is actuated to feed a fresh workpiece into the folder 22. When photo-cell 120 is similarly uncovered, the driving motor 111 of the sewing machine is de-clutched and a brake is applied to stop the machine, but, for a further period, air flows through the nozzles 45, 47 and the presser foot 25 remains lowered, to ensure formation of a thread chain during the coasting period of the machine. An upward pull is then exerted on a rod 121 connected to one end of a lever 122 pivoted on a bar 123 rigid with the presser bar 124, whereby the latter is raised and a bar 125, carried by the other end of lever 122, is lowered on to the throat plate in advance of the stitching point. When photocell 130 is uncovered, knife 131 is operated to sever the thread chain, and operation of the stacking means 23 is also initiated. Knife 131 is actuated by means of the discharge of a previously charged capacitor. Specifications 589,995 and 968,178 are referred to