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. 17, 1979
Filed:
Dec. 27, 1977
Charles E Buck, Anderson, IN (US);
James M Johnson, Anderson, IN (US);
Paul A Joseph, Anderson, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A sensor for engine vibrations at a predetermined frequency characteristic of detonation comprises a housing adapted at one axial end for attachment to an internal combustion engine, a magnetostrictive element axially compressed in said housing with a source of permanent magnetic flux and a pickup coil on a spool around the magnetostrictive element. The spool engages the magnetostrictive element in a force fit characterized by a predetermined push-out force. The sensor housing comprises a first resonant assembly having a first resonant frequency slightly higher than the predetermined frequency. The spool and coil are coupled to the magnetostrictive element by the force fit to comprise a second resonant assembly having a second resonant frequency slightly lower than the predetermined frequency. The overall output characteristic of the sensor thus has a single resonant peak at substantially the predetermined frequency.