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:
Jul. 03, 1984
Filed:
Nov. 19, 1981
Robert W Johnston, Auburndale, MA (US);
Black & Webster, Inc., Waltham, MA (US);
Abstract
A safety system for a power stroke machine including: a probe for sensing an obstruction in the work area; means for moving the probe between an extended position to sense obstructions in the work area and a retracted position; means for detecting the probe in the retracted position; means for detecting the probe in the extended position; start switch means for driving the means for moving, to selectively move the probe to the extended and retracted positions; a power output circuit, responsive to the start switch means and the means for detecting the probe in the extended position, for providing a power output to operate a power stroke machine when the start switch means is closed and the probe is in the extended position; a reset circuit for providing a set output in response to either the start switch means being closed or the probe being not retracted; a latching circuit responsive to the set output and the power output, for providing a latch output as long as the set output continues; and an output control circuit responsive to the latch output for transmitting the initially occurring power output and blocking subsequent power outputs until the reset circuit is cancelled in response to the start switch means being open and the probe being retracted.