Patent GB-781736-A (GB)
Title: Improvements in or relating to article-stacking apparatus
IPC: B65G57/00
Filed: 1955-07-12
Abstract: 781,736. Stacking articles on pallets. GREER CO., J. W. July 12, 1955 [July 22, 1954], No. 20144/55. Class 94(1). In a machine for stacking cartons on pallets, the cartons pass down an inclined rollerway A, Fig. 1, on to a table B and are arranged in rows by the operator. Successive rows are then pushed on to an inclined rollerway C to form a layer, the leading row being arrested by a stop roller 20, and the latter is then depressed manually to allow the layer to pass on to a roller carriage 60, Figs. 2 and 6, which is suspended by links 62 from rollers running in tracks on an elevator frame 30 which is guided for vertical movement in a frame comprising uprights 24 and cross members 26. The carriage is reciprocable horizontally on the frame 30 by a reversible electric motor 80 operating through chain and sprocket gearing, and the frame 30 is suspended by chains passing over sprockets 40 and 41 which are driven through chain and sprocket gearing by a reversible electric motor 50. The pallets are stacked in a framework F, Fig. 1, and are released in succession on to an inclined rollerway-261 which feeds them on to a,pivoted rollerway 264 located at the stacking station E. The rollerway 264 is normally maintained in a horizontal position by a releasable support and is fitted with a pallet stop 267, Fig. 2. The carriage 60 is locked in the loading position by a releasable latch and is provided with a pivoted gate 90, which retains the layer of cartons, and a feeler 282, Fig. 1, which when engaged by the leading row operates a switch 281 in the control circuits of the motors 50 and 80. This causes the frame 30 to descend to a level determined by a limit switch 180, energises a solenoid to release the latch locking the carriage 60 and energises the motor 80 to. cause the carriage to move to the right so that the layer is positioned over the pallet. The gate 90 is then lowered by linkage operated by a fixed abutment and on the return movement of the carriage arms 111, Fig. 6, carrying a roller 110 are lowered to strip the layer from the carriage so that it falls on to the pallet. The reversal of the motor 80 to cause return movement of the carriage is effected by a limit switch 161, Fig. 2, operated by an abutment on the carriage. This return movement is arrested by a further limit switch; and the carriage also operates a switch in the control circuit of motor 50 whereby the frame 30 is returned to the level of the conveyer C. The sequence of operations is repeated when the next layer of cartons is fed on to the carriage 60, but the level at which the frame 30 is positioned during the unloading of the layer is now determined by switches 175, 176 on the circuit of motor 50 which are controlled by the engagement of a roller 170 by the first layers. This roller is carried by an arm 171 pivoted at 173 to an arm 174 pivoted at 172, anticlockwise movement of both arms about, the pivot 172 operating the switch 175 and clockwise movement of the arm 171 about the pivot 173 operating the switch 176. The roller 170 is moved to the right by the first layer when the carriage 60 moves to the right and so operates the switch 175 that the frame 30 is elevated after the next layer has been fed on to the carriage. When the roller clears the first layer it returns to its original position, thus operating the switch 175 to cause lowering of the frame until the roller engages the top of the layer and the arm 171 is swung about the pivot 173 to operate the switch 176 and stop the motor, The frame is thus positioned correctly for the unloading of the next layer and the sequence of operations is repeated as further layers are fed on to the carriage and the frame is positioned at successively higher levels so that a stack is built up on the pallet. The switch 161 operates a counting mechanism whereby after a predetermined number of layers have been stacked the frame 30 is elevated to the top of the machine and operates trip mechanism 275 coupled to the pallet stop 267 and the releasable support of the rollerway 264. The stop is thus retracted and the rollerway lowered about its pivot to eject the loaded pallet from the machine. Mechanism is also operated to release the nest pallet from the stack in the framework F.