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:
Mar. 29, 1988
Filed:
Mar. 17, 1986
Eric G Smith, Burlington, CA;
Chuck Crawford, Stoney Creek, CA;
WABCO Ltd., Stoney Creek, CA;
Abstract
A hydraulic brake actuator including a hydraulic parking brake that can be applied by mechanically locking up either a normal service brake application or a hand pump operated brake application. The lock-up mechanism includes a friction collar that surrounds the piston push rod and a hand pump actuated locking member that surrounds the friction collar. The friction collar and locking member have complementary conical surfaces that are engageable when hydraulic hand pump pressure is applied to a piston face of the locking member to wedge the friction member into pressure engagement with the piston push rod, as a means of locking up the push rod to obtain a parking brake. The locking member also includes a plurality of spring-like fingers that project axially from the periphery of the locking member and are provided with latching tabs adapted to enter a recess in the body to prevent return-movement of the locking member when the hydraulic hand pump operation is terminated. A plug member is provided to prevent the tabs from being disengaged from the recess. This provides a means for releasing the locking mechanism by either manually or hydraulically withdrawing the plug member, thereby allowing the hand brake to be released by separation of the conical surfaces of the locking member relative to the friction collar.