Patents Assigned to BT Industries Aktiebolag
  • Patent number: 4961316
    Abstract: 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).
    Type: Grant
    Filed: October 21, 1988
    Date of Patent: October 9, 1990
    Assignee: BT Industries Aktiebolag
    Inventors: Andrew Corke, Lennart Johansson