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. 30, 2002
Filed:
Feb. 28, 2000
Edward Harry Warwick, Englewood, OH (US);
David F. Nelson, Springfield, OH (US);
Delpi Technologies, Inc., Troy, MI (US);
Abstract
A retraction device for a disc brake caliper is provided having brake pads actuated by hydraulic fluid. The device includes a housing having a bore that defines an axis. A piston is disposed within the bore and is movable along the axis between applied and retracted positions. The piston includes an apply end adapted to coact with the brake pads in the applied position and a hydraulic end opposite the apply end. A hydraulic chamber is defined by the bore and the hydraulic end and contains hydraulic fluid for generating a brake pressure to achieve the applied position. An annular groove is formed in the bore adjacent to the piston, and the annular groove includes a forward angled surface. A resilient seal is disposed within the annular groove for retracting the piston from the applied position to the retracted position. The resilient seal has a first side adjacent the forward angled surface and a second side opposite the first side. A pressure mechanism is arranged adjacent to the second side and is in communication with the hydraulic chamber for generating a retaining pressure to retain the resilient seal against the forward angled surface in response to the brake pressure. The pressure mechanism releases the retaining pressure to permit the resilient seal to retract the piston when below the brake pressure.