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. 03, 1991
Filed:
Dec. 27, 1989
John H Auer, Jr, Fairport, NY (US);
Klaus H Frielinghaus, Rochester, NY (US);
General Signal Corporation, Stamford, CT (US);
Abstract
A technique for measuring the insulation resistance of an insulated rail joint in the presence of leakage ground resistance (ballast resistance), as well as other track run-around paths, without the use of calibrated meters, such technique characterized by the use of a bridge circuit which includes a leg having the insulated joint therein whose resistance is being measured, the other three legs including a resistor of fixed known value and two variable resistors respectively, such that when the variable resistors are varied to obtain simultaneously both (a) the null of the rail, or ballast, current, and (b) ballast in the bridge circuit, the resistance value of the insulated joint is determined.