Hydraulic lift apparatus for a battery driven lift truck

A hydraulic lift apparatus for a battery driven lift truck including:

• a hydraulic lift cylinder,
• a hydraulic pump, which operates as a pump in a load raising mode, so as to feed pressure fluid to said lift cylinder, and which operates as a motor in a load lowering mode and is driven by the pressure fluid displaced by the lift cylinder,
• a direct current machine coupled to the hydraulic pump, so as to operate as an electric motor in the load raising mode and to operate as a generator in the load lowering mode,
• a useful brake circuit energized by said direct current machine in the load lowering mode,
• a valve assembly disposed in a pressure fluid path between said lift cylinder and said hydraulic pump,
• control means for controlling the valve assembly and including speed regulating means for varying speed of said direct current machine, and
• at least one secondary hydraulic consumer adapted to be connected to a hydraulic pressure source via the valve assembly, characterized in that a lowering branch (28) is provided between said valve assembly (18) and a connection between a check valve (16) and an inlet of said hydraulic pump (12), that the secondary hydraulic consumer (22) receives fluid from said hydraulic pump (12) via said valve assembly (18), that the direct current machine is an externally excited direct current machine (10) having its speed controlled by said speed regulating means in response to operation of said valve assembly (18), and that a hydraulic pressure limiter (30) is disposed in said lowering branch (28), a decrease of total hydraulic pressure being experienced at said pressure limiter under certain operational conditions, such that the hydraulic pressure limiter (30) performs a load holding function.