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:
Aug. 09, 1977
Filed:
Aug. 05, 1976
Richard H Noens, Arlington Heights, IL (US);
Vapor Corporation, Chicago, IL (US);
Abstract
A locomotive is fitted with a transmit and a receive coil. Resonant circuits are packaged within a housing that is secured at a preselected point along a railroad track to serve as a position marker. When the locomotive passes the marker, a signal is coupled from the transmit coil in the locomotive to the marker resonant circuit and back to the receiver coil in the locomotive. Discrimination circuitry is connected to the receive coil for ensuring that the received signal has a minimum amplitude and a particular phase relationship with the signal in the transmit coil. Further, the received signal must maintain these amplitude and phase relationships for a preselected count. Upon proper discrimination, a 'mark' signal is generated to an event recorder on board the locomotive.