Patent GB-934463-A (GB)
Title: Apparatus for transferring glass sheets
IPC: B65G49/06
Filed: 1961-09-08
Abstract: 934,463. Feeding sheets. PITTSBURGH PLATE GLASS CO. Sept. 8, 1961 [Sept. 13, 1960], No. 32290/61. Class 100 (1). Sheets G of glass in a stack S supported on edge at 21 on a turn-table support 11 are separated and conveyed to a horizontal position above a conveyer 12 by suckers 22 on a frame 19, 20 which is pivotally mounted on a horizontally-slidable carriage 17, the latter being power-driven, the frame 19, 20 being power-driven to tilted positions, and the part 20 of the frame carrying the suckers also being power-driven to tilt that part relative to the part 20 when the suckers engage a sheet in the stack so that the sheet is moved upwardly and horizontally during the removal thereof from the stack. Pile tables.-The turn-table 11 includes two opposed and inclined sides 93 with horizontal wooden cross-pieces 94, bottom ledges 21, and vertical side plates to support two opposed stacks S of glass sheets. When one stack is exhausted, the turn-table is driven through 180 degrees by a motor 89 and gearing to bring the other stack into operative position. A feeler arm of a switch LS16 is engaged by the stack S, and when the last sheet has been removed the switch is opened to stop the forward movement of the sheet-removing carriage 17 until the motor 89 has been operated to bring the other stacks into position. The motor 89 is stopped when a dog 92 trips a limit switch LS11. The motor can, however, be operated at any time before the last sheet has been removed from a stack to prevent stoppage of the carriage 17. Sheet-separators and forwarders.-The frame 20 carries three rows, each having four suction cups 22, each connected to a hose 73, and each hose is connected to a solenoid-operated 3-way valve in supply lines coupled, respectively, to a suction and a compressed-air source. Each cup 22 is urged away from the frame 20 by a spring, and when the cups engage a sheet in the stack and are forced towards the frame, a limit switch LS2 is opened by one cup to stop further forward movement of the carriage 17 and frame. The frame 20 is connected at its ends to the frame 19 by means which permit it to be tilted relatively to the frame 19, so that when a sheet is being taken from the stack S, the bottom part of the frame 20 moves farther away from the turn-table 11 than the upper part of that frame. This tilting is caused by the automatic operation of air cylinders 64 on the carriage acting on a cam and slot connection between the frames 19, 20. The frame 19 has an upper extension keyed to a horizontal pivot shaft 47 to which is also keyed two levers 46 connected to piston-rods 44 in a pair of air cylinders 43 on the carriage 17. When compressed-air is supplied to the cylinders 43 during the forward movement of the carriage 17 and frames 19, 20, the rods 44 are retracted to rock the shaft 47, and this causes the frames 19, 20 to pivot about the axis of the shaft to the phantom line position adjacent the stack S. The carriage 17 includes rollers 15, 16 guided to roll along a horizontal track, the shaft 36 of rollers 16 being driven by a chain and sprockets from a motor 18 on the carriage. Gears secured to the shaft 36 mesh with racks 33, whereby the motor drives the carriage along the horizontal track. In addition to the switches LS2 and LS16, there are switches LS1 to LS15 in the electric circuit most of which are operated by the moving frames 19, 20 or by cam means on rockable levers thereon to condition the machine for automatic operation. The switches LS9 and LS10 are associated with the conveyer 12 which receives each glass sheet G from the suckers 22. When a sheet drops on the conveyer, a further sheet cannot be deposited thereon by the suckers until the first sheet is clear of both switches LS9, LS10. The motor 18 is reversible and operates at two speeds in either direction, the lower speeds being used automatically when the carriage 17 is close to the stack S in the forward direction, and close to the conveyer 12 in the return direction. U.S.A. Specification 2,049,850 is referred to.