GB1179561A - Box Unstacking Machine - Google Patents

Abstract

1,179,561. Stacking and unstacking machines. N. T. TAMPLIN. 24 May, 1967 [24 Feb., 1966], No. 8178/66. Heading B8C. A machine for stacking and unstacking boxes trays &c. 71 and of the kind in which an elevator platform raises or lowers each box between a pair of catches which support the lowermost box of the stack includes a trip mechanism spring-biasing the catches to the inner box engaging or outer disengaging position according to whether it is set for stacking or unstacking. In unstacking, the elevator, on moving downwards, operates the trip to engage the catches beneath the last but one box so that the boxes are unstacked from below. In stacking, the catches remain inwardly biased and are moved apart by the box being lifted to the stack base. The elevator is operated by a scissor mechanism (30-35), Fig. I (not shown), including a ram (37). The trip mechanism includes an over-centre device comprising a rod 51 pivoted at 53 to a lug 54 on a rod 43 carrying a spring 58 and slider 55. A lever 56 is pivoted to the slider and to the machine frame at 57. Stops 59 limit the travel of the lever 56. When in the unstacking position shown, the spring 58 biases the rod 43 to the left to retract the catches but the lever 56 may be swung manually to rest against the other stop 59 when the catches are biased to the closed position for stacking. A spring-backed cam member 66 pivoted on the elevator engages a roller 65 on the lug 54 to move the bar 43 to the right to engage the catches beneath a box. When stacking, the catches 42 are pressed open by a box lifted between them but down again beneath the box so allowing a stack to form. An alternative trip device. Fig. 5, for unstacking, has a lever 75 operated by a rod 76 on the elevator to move the catches 42 as before. For stacking, the trip is made inoperative and spring means (not shown) biases the catches to the inner position. The machine may be made automatic and a device to count the number of boxes in a stack to stop stacking at the required number included.