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. 05, 1978
Filed:
Apr. 09, 1976
Ralph A Gordon, Centerville, OH (US);
Thomas P Mathues, Miamisburg, OH (US);
Donald L Parker, Middletown, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A vehicle brake booster and master cylinder assembly has a vacuum suspended booster section and a hydraulic booster section in series, and a master cylinder unit in series with the booster sections. During normal operation the vehicle operator obtains boosted brake actuating pressures from the master cylinder by operation of the hydraulic booster section throughout the normal stroke of both booster sections without operating the vacuum booster section. If additional brake actuating pressure is required after the hydraulic booster has reached its run-out condition, the master cylinder is actuated normally through mechanical force transmitting elements which are parts of the booster sections. If there is no hydraulic pressure available for hydraulic booster operation, the control valves of the booster sections move from the first range of operation which normally controls the hydraulic booster section to a second range of operation which actuates the vacuum booster section. If additional master cylinder output pressure is required when the vacuum booster section has reached its run-out condition, the master cylinder is actuated manually as before. A hydraulic pressure actuated blocking mechanism prevents control valve movement to actuate the vacuum booster section when the hydraulic booster section is normally operating.