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:
Dec. 28, 1982
Filed:
May. 12, 1981
Frederick J Adams, Clevedon, GB;
Cam Gears Limited, Hitchin, GB;
Abstract
A power assisted vehicle steering system has a pressure biased piston and cylinder (1) actuation of which effects in the power assistance. The piston (2) has axially opposed faces (5, 7) with different effective pressurized areas of which the face (5) with the smaller area communicates with a first chamber (6) and the face (7) with the larger effective area communicates with a second chamber (8). A valve (10) which is axially adjustable (but may be rotary) in response to a steering manoeuvre controls flow of pressure fluid from the pump (9) to the piston and cylinder (1) for providing power assistance. The valve (10) derives fluid pressure from the pump (9) through a restrictor (26) (which may be adjustable) and has a neutral condition in which the first and second chambers (6, 8) and the pump output communicate with the reservoir (23) by way of control ports (18, 19, 20) in the valve, the second chamber (8) communicates with the pump by way of the restrictor (26) and the control port (19) and the first chamber (6) communicates with the pump upstream of the restrictor (26) and the control port (19). The restrictor (26) is arranged so that with the valve (10) in its neutral condition the fluid pressure in the second chamber (8) provides an axial force on the piston face (7) which balances the opposing axial force on the smaller piston face (5).