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:
May. 04, 2004
Filed:
May. 08, 2001
John J. Kemer, Avon Lake, OH (US);
Andrew Marsh, Elyria, OH (US);
Abstract
A braking system control requires that a first or service braking system be actuated before a second or parking braking system can be released to prevent unexpected movements. A sensor senses that the service brakes are engaged and controls a device to release the parking brakes. A latch ensures that the parking brakes remain released. For example, a piston and check valve form the sensor and latch. Service brake pressure works against the piston. Above a threshold level, service brake pressure drives the piston to open a valve that provides pressurized air to a parking brake release system. Once released, the check valve directs parking brake release pressure to the piston to keep the valve open.