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:
Dec. 22, 1987
Filed:
Jun. 05, 1987
John S Hoelzer, Wauwatosa, WI (US);
Richard J Graefe, Milwaukee, WI (US);
James T Libert, Waukesha, WI (US);
Square D Company, Palatine, IL (US);
Abstract
A machine tool timing relay has immunity from electrical noise on a control signal, and has an oscillator capable of generating pulses having a predetermined frequency, a means for adjusting the predetermined frequency over a continuous range of frequencies, a counter capable of counting the pulses and capable of generating an output signal after a predetermined number of the pulses are counted, means responsive to a start signal for initiating the counter to count the pulses, an optical isolator circuit responsive to the control signal for generating a light, detecting the light, and generating the start signal in response to detecting the light in order to isolate the counter from electrical noise mixed with the control signal, an electrical contact, and an output circuit responsive to the output signal for operating the electrical contact when the counter generates the output signal so that the contact is operated after the counter counts a predetermined number of the pulses. The contact is controlled after an interval of time required for the oscillator to generate the predetermined number of pulses. An electromechanical relay serves as the contact.