Patent GB-1229809-A (GB)
IPC: B65G57/00
Filed: 1968-04-01
Abstract: 1,229,809. Loading pallets. SCOTTISH AGRICULTURAL INDUSTRIES Ltd. 20 March, 1969 [1 April, 1968], No. 15540/68. Heading B8C. In a pallet loading device, packages or containers e.g. filled polythene sacks for stacking on the pallet, are conveyed by an air operated conveyer 9 and feed belt 10 on to a loading table 1 provided with a smooth perforated surface e.g. of stainless steel or polytetrafluroethylene, through which air under pressure is supplied to facilitate manual arrangement thereon of the pallet load into a layer which, by pneumatically actuated sections 5, is then transferred on to a stripping table 2 (which is similarly perforated and supplied with pressure air) and simultaneously transversely compacted in formation, against a vertically and horizontally adjustable guide 8, by a pneumatically actuated section 6. The layer is then restrained by a vertically and horizontally adjustable stripping plate 7, as the stripping table 2 is horizontally retracted e.g. pneumatically or by a linear electric motor, and after retraction of sections 5 and 6, the layer drops on to a pallet 12, supported on a vertically reciprocable device 3, which is then automatically lowered until the layer clears an ultrasonic or photo-electric sensing device, the sequence of operations then being repeated, after closing of table 2, for successive layers on the pallet 12, the alignment of each layer preferably being regularized by rollers extending adjacent the pallet and parallel to the abutting edges of tables 1 and 2. The stripping plate 7 may also be reciprocable towards the table 1 to assist layer transfer to the pallet 12. The pallet 12 with the desired number of layers thereon is lowered by the device 3 on to a pallet conveying system 4, comprising a pair of chains, which is then automatically actuated simultaneously to replace the loaded pallet 12 by an unloaded pallet 12, whereby the device 3 is automatically actuated to raise it to the layer receiving position. The edge of the stripping table 2 adjacent the abutting edge of the loading table 1 may be complementary thereto, and slope downwardly theretowards to facilitate load transfer to the pallet. It is stated that the loading table 1 may be omitted, with the function thereof performed by the stripping table 2. Alternatively the table 1 may also be retractable to perform the loading function, whilst the table 2 retracts to discharge the layer on to the pallet 12. The tables 1 and 2 are supplied with compressed air by a blower 13 and pipes 14, and the conveyer 9 by a blower 15 and pipes 16. With filled sacks of a high length breadth ratio, overhead arms or jets of air may be provided which function to prevent misalignment by urging the sacks outwardly against the operation of sections 6. The layer may alternatively be transferred from table 1 to table 2 by a pusher bar (not shown) carried by an endless chain device, the action whereof is stopped by a limit switch and, when the layer on the pallet clears the sensing device therefore, is automatically restarted to traverse the pusher beneath the table 1 to return to the position for transferring a further layer therefrom. The layer on the pallet 12 may also be downwardly compacted by a downwardly acting plate (not shown) whilst the table 2 is retracted. Alternatively the device 3 may be upwardly displaceable to compact the pallet layer against the underside of the table 2, which may be perforated for the downward discharge of compressed air. The operation of all the loading device elements may be controlled in sequence by switching means. The device 3 is hydraulically actuated and may also be horizontally displaceable to successively receive adjacent layers thereon, and the vertical displacement may be controlled by a single solenoid operated hydraulic valve. However, the slower fall of the pallet under the lighter weight of the first and second layers may be increased by utilizing three hydraulic valves which, by selector relays, are all actuated during the fall of the pallet bearing the first layer, and two and then one whereof are actuated respectively during the fall of the second and successive layers. Safety plates 20 are provided between the chains of conveyer 4, which is halted on displacement thereof.