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:
May. 03, 1977
Filed:
Jun. 27, 1975
John Joseph Erickson, Kingston, NY (US);
Harold Lester Leland, Hyde Park, NY (US);
Einar Skau Mathisen, Poughkeepsie, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An article handler or positioner includes an X-Y table driven by reversible stepping motors. Zero position sensors function to provide an output signal when the X-Y table moves into a zero or home or reference position. The sensors are electro-optical devices having two beams of light one of which is gradually interrupted while the other one is gradually uninterrupted as the table moves into the zero position. Photo detectors provide output signals one of which increases and the other of which decreases as the table moves into the zero position and, at the point of crossover of the respective output signals, another output signal is generated indicating the home position is reached. This signal is then used to inhibit further operation of the driving motors.