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:
Nov. 17, 1987
Filed:
Jul. 30, 1985
Jidosha Kiki Co., Ltd., Tokyo, JP;
Abstract
A liquid pressure booster as may be used in a brake booster or clutch booster produces an oil pressure of a level which corresponds to the magnitude of an input applied to an input shaft. The oil pressure acts upon a power piston, which then produces an amplified output in response to a small input. The oil pressure is also returned to act upon the input shaft so as to provide a reaction to the input. The invention provides a step in at least one of the input shaft and the power piston so that the combination of the step and the housing defines a pressure chamber having a pressure responsive surface at the step. A flow path switching valve selectively establishes a communication of the pressure chamber with either the power chamber or a reservoir. When the switching valve is operated, the pressure responsive area of the input shaft which is acted upon by the oil pressure can be changed, thereby changing the magnitude of the reaction transmitted to a driver. The pressure responsive area of the power piston which is acted upon by the oil pressure may be changed, thereby changing the magnitude of an output. The booster ratio of liquid pressure booster may be changed according to the preference of a driver or the conditions under which the braking action is applied.