Bt Industries Ab

Bt Industries Aktiebolag

Lennart Johansson

Andrew Corke

A hydraulic lifting arrangement for a lift assembly on a materials-handling vehicle includes a working piston-cylinder device (17) for raising and lowering the lift assembly, a reversible pump assembly (40) for operating the piston-cylinder device, and an electric motor for driving the pump assembly. The piston-cylinder device (17) is a double-acting device and has two working chambers (28,29), which are connected to the pump assembly by connecting pipes (46,47). The pump assembly comprises a first and a second hydraulic pump (41,42) having fixed displacements. The pumps are so arranged in the system that together they supply hydraulic medium to and receive hydraulic medium from solely the first chamber (28) whereas only the pump motor (41) supplies and receives hydraulic medium to and from the second chamber (29). The relationship between the displacement of the first pump (41) and the sum of the displacements of both pumps (41,42) corresponds essentially to the relationship between the respective active piston areas in the second and the first chambers. Conveniently, a pressure-gas chamber (26) is arranged in the piston-cylinder device for biassing the piston (19) so as to enable the dead weight of the lift assembly and a given part of the load to be counter-balanced.

Controlled electric pump drive for hydraulic lifting arrangement with

A handling apparatus for handling boxes stored in shelving compartments of storage shelving systems comprises a main body structure (11) which is adapted to be carried by a lifting device (12) and which is adjustable positionally thereby to a given level to be in registration with a respective shelf compartment (35). The body structure incorporates a plate-like support table (17) for supporting boxes (23), and a box dogging device (20) for dogging the boxes between the support table and respective shelf compartments. The box dogging device includes a vacuum device (21) which includes a plurality of suction cups (22) and which is movable along both the body structure and the support table. The dogging device and the support table are connected together so that the support table will move together with the dogging device during the initial and the final part of the movement of the dogging device. The suction cups engage an end or side wall of respective boxes, which boxes may be of various different shapes and sizes.

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Mjolby, Sweden

Lennart Johansson