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:
May. 23, 1989
Filed:
Nov. 17, 1987
Ernst-August Honig, Wolfsburg, DE;
Volkswagen AG, Wolfsburg, DE;
Abstract
A hydraulic control system for controlling application of a pressure medium in a hydraulically actuable shift member intended for an automatic automotive transmission, the control system including a throttle disposed in a pressure application line leading to the shift member, and a control valve controlling an unthrottled communication between a pressure medium supply line and the shift member, bypassing the throttle, as a function of the application pressure prevailing ahead of the shift member, in such manner that the communication is opened at the beginning of the application of pressure to the shift member and interrupted when a preassigned application pressure is reached. In addition, a device is provided for at least temporary maintenance of an engagement pressure lying below the full application pressure and remaining substantially at a constant level the control valve is to be configured to operate this device only upon interruption of the unthrottled communication between the pressure medium supply line and the shift member to ensure that the device for maintaining the engagement pressure will not become operative too early.