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:
Jan. 05, 1993
Filed:
Jul. 05, 1991
David B Rich, Indianapolis, IN (US);
Dan W Chilcott, Greentown, IN (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
An impact detector includes a center chip of micromachined silicon, a top cap, and a back plate, with the center chip being sandwiched between the top cap and the back plate. The center chip is micromachined to provide a seismic mass, a perimeter ring, and a plurality of beams interconnecting the perimeter ring and the seismic mass. The center chip and back plate mount aligned switch contacts which close to each other when the seismic mass moves from its static or nondisplaced position to its operative or displaced position. An electrostatic attractive force is generated between the seismic mass and the back plate. This electrostatic attractive force is less than the tensile force applied to the seismic mass by the beams so that the seismic mass remains in its static or nondisplaced position unless the impact detector is subjected to an impulsive force of sufficient magnitude and duration such that the inertial reaction force of the seismic mass when coupled with the electrostatic attractive force is greater than the tensile force so that the seismic mass moves to the operative displaced position. In the operative displaced position, the electrostatic attractive force latches the switch contacts to each other until the electrostatic attractive force is reduced and the tensile force can then return the seismic mass to its static or nondisplaced position.