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:
Jul. 12, 1988
Filed:
Jun. 01, 1987
James K Mainquist, Mt. Clemens, MI (US);
Robert B Deady, Plymouth, MI (US);
Robert C Downs, Ortonville, MI (US);
Saturn Corporation, Troy, MI (US);
Abstract
A hydraulic transmission control uses a plurality of solenoid valves to control the engagement of friction devices during the shifting of a transmission between gear ratios. A clutch priority valve is provided to prevent the continuous simultaneous engagement of friction devices which will establish more than one ratio. Also provided is a manually controlled valve which permits the operator to determine the range in which the transmission will operate. If the clutch priority valve has been actuated, the transmission ratio can be controlled between a low ratio, for example, second gear, and a high ratio, for example, third or fourth gear, by use of the manual valve in combination with an actuator mode valve. The clutch priority valve, when actuated, is also operable to disengage a torque converter clutch.