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:
Feb. 23, 1988
Filed:
Apr. 29, 1987
Yuchi P Peng, Noblesville, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A knock sensor includes a circular mounting surface with a flat, self-resonant vibration element and piezoelectric disk coaxially mounted thereon. The vibration element comprises a central circular portion and a pair of outer semicircular portions of larger radius, the outer semicircular portions being shifted in opposite direction along their common border from the axis by an equal distances and each being divided into an equal number of sectors by radial slots centered on the axis and extending outward from the first radius with equal angles therebetween to from diametrically opposed pairs of similarly shaped and sized vibrating sectors. The pairs of sectors have resonant frequencies together forming a sensor passband wider than the individual passbands of the pairs taken separately. In addition, differences in resonant frequency between members of a pair due to misalignment of the axes of the vibration element and mounting surface do not significantly affect the sensor passband.