Patent GB-924898-A (GB)
Title: An improved sheet separating and forwarding machine
Inventor: FAWDRY CHARLES FREDERICK
IPC: B65H3/52
Filed: 1960-03-16
Abstract: 924,898. Feeding sheets. H. T. BACKHOUSE. March 16, 1960, No. 9329/60. Class 100 (1). Apparatus for separating sheets &c. from a stack which is supported on edge at a small angle to the vertical, comprises jogging- mechanism to give the stack up and down movement to relieve the pressure between the sheets, means for gripping in turn each sheet at the underface of the stack to separate and forward the sheet substantially in its own plane, and rejecting means for preventing the separation of two sheets at a time consisting of a roller or pusher which is arranged to engage the additional sheet by a sheet-engaging surface which moves oppositely to the forwarding direction of the sheet. The jogging mechanism operates during operation of the rejecting means. Pile tables; sheet-separators.-As described, the apparatus is for use with paper sack bodies thickened along their side edges by folded gussets. The stack of sacks 26 is supported on edge, between side guides 230, on a shelf 25 carried by - a table 21 which is inclined about 17¢ degrees to the vertical. The shelf is adjustable up and down the table by chain-and-sprocket means to suit the length of sack. The table 21 is supported at its upper end to the main frame by links 22 and a system of recoil springs 23, and at its lower end by a mechanical high-frequency jogging mechanism, whereby the table is jogged in its own plane to facilitate separation of sacks. The front sack 26 is gripped by a suction gripper 41 mounted adjustably in a channel within the table 21, and the channel and gripper are reciprocated in the plane of the table by cam-and-lever mechanism so that the sack is fed in two stages; over a fixed table 60, Fig. 14, first beneath a sack-rejecting roller 120 which rotates clockwise, and, after a dwell, into the bite of forwarding rollers 64, 65. The suction gripper 41 comprises a body casting to which is secured a face-plate 168, Fig. 5, which is perforated and in communication with a source of suction. Six cylinders 170, each connected to a source of suction, are mounted in the gripper casting, and in each cylinder there is a piston provided with a sucker mouth 175. When suction is applied, each mouth 175 projects beyond the plate 168 into contact with a sack 26; suction then builds up between the piston and bottom of the cylinder which draws the piston into the cylinder and causes the sack to be drawn firmly against the plate 168. Suction is now applied to the plate 168 to grip the sack, and the gripper assembly is moved upwardly to separate the sack and feed it between the feed rollers 64, 65. The table 21 is jogged vertically just before and during the upward movement of the gripper. Means for preventing more than one sack being separated comprises an oscillating frame including a drop roller 85 and the rejecting roller 120. When the roller 85 contacts the roller 64, the roller 120 is separated from the table 60 by a distance just over the thickness of a single sack 26, and thus pushes back a second sack if two are separated together. Where sacks are separated from the stack in overlapping relationship, the first sack is already between the rollers 64, 85, so that the rejecting roller 120 allows two sacks to pass thereunder. Sheet-forwarders.-Each sack 26, fed upwardly by the suction gripper 41 in two stages, is gripped by the feed rollers 64, 65 and fed between endless tapes 131 and a drum 130, and transferred by the drum between endless tapes 135 and a second drum 134 which deliver it to a conveyer 144. The tapes 131, 135 are wide and engage the edges of the sack as it passes around the drums, and a central narrow endless tape136 engages the sack body as it passes around the drum 130. Further narrow tapes 137 assist the transfer of the sack from drum 130 to drum 134. As described, the sacks are fed in overlapping relationship. The machine is driven from a shaft 150 through a series of lay shafts, gears, and chain-and-sprocket means, and there is a change-speed gear between the lay shafts 50 and 145 enabling three speeds to be selected for the feed rollers 64, 65, the reject roller 120, and the drums 130, 134 to accommodate sacks 26 of different lengths.