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.

Date of Patent:
Sep. 12, 1989

Filed:

Dec. 09, 1987
Applicant:
Inventors:

Kenichi Ikejiri, Saitama, JP;

Eiichiro Kawahara, Saitama, JP;

Mitsumasa Furumoto, Saitama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16D / ;
U.S. Cl.
CPC ...
60488 ; 60487 ; 184-71 ;
Abstract

A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a hydraulic motor coupled to an output shaft, a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor, a hydraulic actuator for actuating a controlled member in the closed hydraulic circuit, an auxiliary pump connectable to the closed hydraulic circuit and the hydraulic actuator, a supply oil passage for supplying oil discharged from the auxiliary pump to the hydraulic actuator, and a control valve coupled between the supply oil passage, the closed hydraulic circuit, and an oil tank. The control valve comprises a hydraulic chamber communicating with the supply oil passage, a spring, and a spool disposed between the hydraulic chamber and the spring. The spool is movable, until the pressure of oil in the hydraulic chamber and the force of the spring are balanced, successively from a first position in which the supply oil passage and the closed hydraulic circuit are disconnected and the supply oil passage and the oil tank are disconnected, to a second position in which the supply oil passage and the closed hydraulic circuit are connected, to a third position in which the supply oil passage and the oil tank are connected, in response to an increase in the pressure of oil in the hydraulic chamber.


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