The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 1991
Filed:
Jan. 31, 1990
Shinya Watanabe, Hyogo, JP;
Hironori Sasaki, Kobe, JP;
Kaoru Nomichi, Ono, JP;
Yasushi Sotani, Kobe, JP;
Abstract
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.