Evenson, Wands, Edwards, Lenahan & McKeown
Elevator valve apparatus
 An elevator valve apparatus for controlling the hydraulic supply flow to the hydraulic actuator and the hydraulic discharge flow from the actuator, comprises a solenoid proportional control valve device for ascending, a solenoid proportional control valve device for descending, and a valve control unit for controlling both of the control valve devices with a predetermined acceleration characteristic and a predetermined deceleration characteristic by an open loop control system. Furthermore, if preferable, the valve control unit carries out oil temperature compensating control, pressure compensating control, pre-start pressure raising compensation control, and feedback control of the supply flow in the low speed ascending. 
Kawasaki Jukogyo Kabushiki Kaisha
B B
B66B B62B
inventional inventional
Kaoru Yasushi Hironori Shinya
Nomichi Sotani Sasaki Watanabe