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:
Mar. 29, 1977
Filed:
Jul. 12, 1974
Walter M Rubinstein, Oak Park, MI (US);
Other;
Abstract
A photo-electric light curtain for braking and terminating power to the ram of a press when an obstruction is detected in the curtain area uses an elongated fluorescent lamp as the light source. A number of spaced lens systems arrayed on the opposite side of the curtain area from the lamp focus on spaced points along the lamp. Fiber-optic strands connect the focal point of each of the lens systems with points arrayed about the stationary element of a circular commutator which are scanned by another fiber-optic element having one end affixed to a rotary commutator element and the other end feeding a photodetector. The output signals from the photodetector are processed to detect obstructions along the focal axis of any of the lens systems by fail-safe digital circuitry which provides an output when this blockage is detected for several cycles of the commutator. Counter circuitry, preset by manual switches, allows the system to ignore light blockages caused by permanent installations.