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:
Dec. 23, 1986
Filed:
Nov. 19, 1984
Bruce M Hatton, Carol Stream, IL (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A housing (A) which is connected with an internal combustion engine to be vibrated therewith. A diaphragm (B) is mounted in an interior chamber of the housing to undergo vibration therewith. The diaphragm is constructed to have a natural resonant frequency which substantially matches the knock frequency of the engine model for which the knock sensor is designed. The diaphragm is mounted to the housing by a central portion (20) such that an edge portion (24) undergoes maximum resonant displacement. To facilitate the passage of air from one side of the diaphragm to the other during near resonant displacement, a plurality of apertures (26) are provided through the diaphragm edge portion. In this manner, viscous drag is reduced which increases the magnitude of the resonant displacement and decreases the bandwidth or range of frequencies over which the diaphragm undergoes significant displacement. A piezoelectric element (30) is connected with the diaphragm to provide an electrical output signal which varies with the diaphragm displacement.