US Patent 7409828 Control device

Control device 1 having a changeover valve 5, a pump 4 delivering operating medium, in particular a motor-operated pump or a hand pump, connection devices for connecting the control device 1 to at least two tools, in particular a first lifting cylinder 2 and a second lifting cylinder 3 or the like, the changeover valve 5 being operable in particular by hand; whereina) the changeover valve 5, when the operator lets go of it, can be brought automatically into a basic position in which no pressure build-up in the region of the tools is possible,b) a control valve 7 is provided between the changeover valve 5 and the tools, andc) the control valve 7 can likewise be operated by hand by an operator.