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:
Jan. 24, 1995
Filed:
Mar. 08, 1993
Thomas T Tibbles, Livonia, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A continuously variable transmission control system having adjustable driving and driven sheave assemblies (124,126) connected drivably by a torque transfer belt or chain (144), each sheave assembly having a fluid pressure operated servo with a pressure chamber, distribution of control pressure to one servo (150,158,162) effecting a transmission ratio adjustment, control of pressure distribution to the other servo (202,210) resulting in a clamping force, a ratio control valve (246) for controlling distribution of pressure to the ratio controlling servo to effect upshifts and downshifts, provision being made for stabilizing the ratio control valve by providing for flow entry to the ratio control valve that is unrestricted, flow distribution to the ratio controlling servo having a controlled restriction whereby stability of the ratio control valve is achieved, fluid displaced from the ratio controlling servo being adapted to circulate through the ratio control valve to the inlet side (372) of the control system pump (70,72).