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:
Sep. 24, 1996
Filed:
Jan. 26, 1994
Terry E Nels, Beavercreek, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A volute spring that is particularly adapted to be incorporated in a damper assembly to absorb or neutralize the transient torsional spikes normally occurring at the crankshaft of a vehicle. A volute spring having the improved frictional hysteresis characteristic provided by the present invention utilizes the conventional plurality of telescopically adjacent coils, and each coil has oppositely directed surfaces which present opposed surfaces on the telescopically adjacent coils. At least one of the opposed engaging surfaces has a configuration that obviates the formation of a hydrodynamic oil film. One configuration that obviates the formation of a hydrodynamic oil film comprises a plurality of intersecting grooves recessed into at least one surface of the metallic strip from which the volute spring is wound. The intersecting grooves define a plurality of polygonal lands which cumulatively provide at least one of the engaging surfaces on the adjacent coils of the volute spring. Another configuration that obviates the formation of a hydrodynamic oil film utilizes a porous surface such as may be provided by conventional paper and resin clutch wear materials. The clutch wear material is bonded to at least one of the opposed surfaces of the metallic strip from which the volute spring is wound.