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. 15, 1992
Filed:
Sep. 20, 1990
Eugene P Finger, Brewster, NY (US);
Bernard W Jalbert, Richboro, PA (US);
Thomas A Penkalski, Broad View Heights, OH (US);
Yale Materials Handling Corporation, Flemington, NJ (US);
Abstract
A proximity switch including an inductor having an actuator rod movable in proximity thereto to affect the inductance thereof. An electrical pulse of relatively short duration is applied to the inductor and the current from the inductor is measured at a selected time interval after the initiation of the pulse. When a selected value of the current is exceeded, the switch is triggered. A plurality of inductors may be sequentially interrogated by one electronic circuit, thus requiring low power and affording smooth operation. Calibration of the trigger point is accomplished electronically after mechanical installation, thus inherently compensating for mechanical tolerances and proximity effects.