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:
Feb. 26, 1985
Filed:
Dec. 01, 1982
Ernst-August Honig, Wolfsburg, DE;
Volkswagenwerk Aktiengesellschaft, Wolfsburg, DE;
Abstract
A control device for effecting variable hydraulic fluid delivery to a gearshift element of an automatic transmission and controlling actuation of the gearshift element. Such a control device includes a delivery line for supplying a pressurized fluid to the gearshift element, a throttle in the delivery line, a bypass line for bypassing the throttle and supplying the pressurized fluid to the gearshift element, and a valve arranged in the bypass line that has a piston that is moveable between an open position, which permits flow through the bypass line, and a closed position, which prevents flow. Pressure downstream of the throttle acts on the valve and urges the piston into the open position; a vehicle speed-dependent pressure acts on the valve and urges the piston into the closed position. The piston can be biased, for example, with a spring, such that the piston remains in the open position up to a predetermined vehicle speed. The vehicle speed-dependent pressure can act on an end face of the piston that has two surfaces, which are arranged in step form; this pressure acts on only one surface when the piston is in the open position and acts on both surfaces when the piston is in the closed position.