Patent GB-1169838-A (GB)
Title: Improvements in Conveying Apparatus for Feeding Work Pieces to be Sewn
IPC: D05B35/10
Filed: 1968-06-13
Abstract: 1,169,838. Endless conveyers. UNION SPECIAL MACHINE CO. 13 June, 1968 [14 June, 1967], No. 28058/68. Heading B8A. [Also in Division D1] Work-feeding means for a sewing machine comprise a lower conveyer having an upper run for supporting and moving workpieces thereon, upper clamping means having a lower surface contiguous with said lower conveyer and movable therewith for clamping said workpieces between the lower conveyer and upper clamping means, and means for moving said support means with and opposite the movement of said lower conveyer. Endless driven belts 20 for conveying workpieces past a sewing machine 11 are supported on roller assemblies 14, (15). The workpieces are engaged between the upper runs of belts 20 and the lower run of a belt 36 supported on rollers (37), 38 freely journalled in a frame 41. The latter is slidably mounted on rods (49) carried by a beam 50 rigid with bars 51, 52 pivoted on a fixed rod 55. Extensions 53, 54 of bars 51, 52 are acted upon by adjustable springs 57, 58 for partly counterbalancing frame 41. An air cylinder 63, carried by beam 50, has a piston-rod 64 coupled by a bracket 65 to frame 41. A worksupporting platform 70, slidable on fixed rods 80, 81, is secured to a horizontal flange 72 of a bracket 71, a vertical flange 73 of which is secured by bolt and spacer means 74, 75 to frame 41. The edge of a workpiece to be sewn is guided under roller 38 by means 90 having a lower work-supporting plate 91 rigid with bracket 71 and an upper work-engaging plate 92 slidable on pins 94 upstanding from plate 91. Plate 92 is rigid with the piston-rod 97 of an air cylinder 96, energization of which thereby serves to compress the workpiece edge between plates 91 and 92. Initially, piston-rod 64 is retracted to position frame 41 and platform 70 closest to machine 11. The leading portion of a workpiece is then engaged with the belts 20, the edge to be sewn passing through guide 90 and under roller 38. The operator's hands interrupt a light beam between a lamp 156 and a photocell 157, mounted on platform 70, for de-energizing a coil (154) to open contacts (144), (145). The presence of the workpiece in guide 90 influences a lamp 158 and photo-cell 160, mounted on bracket 71, to energize a coil (155) for closing contacts (147), (148) in series with contacts (144), (145) and with a solenoid (142) controlling the operation of cylinder 63. Coil (155) also closes contacts (177), (178) in series with a normally-open switch 182 associated with a solenoid (170) controlling the operation of cylinder 96. The operator then momentarily closes switch 182 to energize solenoid (170) and to establish a holding circuit therefor, for lowering plate 92. Depression of a treadle then closes a switch for energizing the solenoid effecting drive of machine 11 and belts 20. When the operator releases the workpiece, the beam of light between lamp 156 and photo-cell 157 is re-established for energizing coil (154) to close contacts (144), (145). Solenoid 142 is thereby energized to actuate cylinder 63 for extending piston 64 and moving frame 41 and platform 70 rightwards, when a fresh workpiece may be arranged on the latter. Passage of the leading edge of the workpiece under a lamp 124 and photo-cell 125, mounted on beam 50 in advance of machine 11, serves to establish a holding circuit for the drive-controlling solenoid, and the treadle may be released. Associated with photo-cell 125 is a delay circuit for maintaining the drive during the normal interval between successive workpieces. When the trailing end of a workpiece leaves guide 90, photo-cell 160 de-energizes coil (155), whereby frame 41 and platform 70 move leftwards, the supply of air to cylinder 63 being so regulated that piston rod 64 and the belts 20 move leftwards at the same speed. The fresh workpiece may then be passed through guide 90, cylinder 96 being respectively de-energized and energized as the operator's hands break and restore the light beam between lamp 156 and photo-cell 157.