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:
Jul. 04, 2000
Filed:
Apr. 22, 1998
John Benjamin Hageman, Vandalia, OH (US);
Ernst Severin Baumgartner, Dayton, OH (US);
Donald Edward Schenk, Vandalia, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A brake apply system includes a modulator that has a first bore carrying a power driven dual-effect piston. The piston has a base piston surface and an augmentation piston surface. A wheel brake is hydraulically connected to the modulator through an open fluid communication route that is provided between the wheel brake and the base piston surface. A selectively open fluid communication route is provided between the wheel brake and the augmentation piston surface with a check valve mechanism positioned in the selectively open fluid communication route. An augmentation chamber is defined adjacent the augmentation surface of the dual-effect piston. The modulator includes a second bore carrying a valve mechanism that provides an open flow path between the augmentation chamber and a reservoir when pressure at the wheel brake is relatively high and that significantly restricts the flow path when the wheel brake pressure is relatively low. Through this mechanism the augmentation surface is added to the base piston surface for a dual-effect pressure generation area that increases the initial pressurization rate of the brake apply system. Advantageously, the faster the apply rate of the braking system, the greater the augmentation pressure and displacement that is available.