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. 10, 1976
Filed:
Oct. 21, 1974
Gerhard Will, Beutelsbach, DT;
Robert Bosch G.m.b.H., Gerlingen-Schillerhohe, DT;
Abstract
To permit continued operation of an electronically controlled gear change transmission in case of failure of electronic control signals, at least one three-way check valve is included in the system to connect, in one mode of operation, the normal output control signals from a hydraulic control valve system to engage an operating element (such as a control clutch, control band, or the like in the automatic transmission) and, when in another position, connect hydraulic pressure to effect connection of drive power to the first gear, or reverse (as selected by a control selector) and in the absence of electrical command signals from the electronic control unit. By use of a second three-way check valve, simple interlocks to prevent shifting into reverse when the vehicle is moving forward in excess of a given speed, and to permit holding of an engaged gear in case of malfunction, can be provided.