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:
Sep. 22, 1981
Filed:
Sep. 28, 1979
Regie Nationale des Usines Renault, Boulogne-Billancourt, FR;
Abstract
A device controlling a multi-stage automatic transmission for an engine-driven vehicle with three forward drive ratios and change-under torque, damped by a hydrokinetic torque converter, and one reverse drive, of the type consisting of an epicyclic gear train actuated by two clutches and two brakes hydraulically controlled. A hydraulic distribution unit is monitored by two electric valves in order to feed selectively the two clutches and the two brakes on the basis of data concerning the running of the vehicle. The two electric valves are controlled in response to three different states of the two electric valves for providing selective feeds corresponding respectively to each of the three forward drive ratios and for providing an additional control of the electric valves in response to a fourth transient state for the transmission between the third and second forward drive ratios.