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:
Apr. 10, 1979
Filed:
May. 31, 1977
Malvin L Schubert, Kettering, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A booster having a vacuum powered booster section and a hydraulic powered booster section which are normally actuated together to supply boosted force to a master cylinder. When the air valve of the vacuum booster section is operated to cause atmospheric air to enter the variable pressure chamber of the vacuum booster, it also engages and moves the hydraulic booster control valve to restrict hydraulic fluid flow therethrough, causing the hydraulic booster section control valve to be actuated to create a hydraulic pressure differential across the power wall of the hydraulic booster section. Both booster sections deliver boosted force through the output member of the hydraulic booster section to the master cylinder. Either booster section is operable when for any reason there is no power available for actuation of the other booster section. The hydraulic booster section has an integral reaction piston within its control valve, permitting simple reaction system changes depending upon the calibration required for each different vehicle. The hydraulic booster section control valve is almost completely balanced, lowering the force required to push the hydraulic control valve member to the hydraulic control valve seat.