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. 22, 1981
Filed:
Jun. 29, 1979
Gerhard Dieterle, Gutach, DE;
Erwin Sick GmbH Optik-Elektronik, Waldkirch, DE;
Abstract
A safety circuit for a potentially dangerous machine monitored by light and which works in an operating cycle. A safety circuit is described which utilizes a series of relays each of which is switched from an energized to a de-energized condition once during each working cycle of the machine so that each of the relay contact also opens and closes during the working cycle. In this way each relay contact is tested. The relays are so interconnected that if one contact should stick it will interrupt the sequence and will ensure the potentially dangerous machine e.g. a press is rendered inactive. Circuits are given for both hand fed and automatic machines which are monitored by a light barrier or curtain. For the hand fed machine the cycle is initiated by the operator reaching through the light barrier to insert an object into the machine. For an automatically fed machine the test cycle is initiated by a switch automatically activated once per cycle.