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:
Jun. 23, 1981
Filed:
Jul. 05, 1979
Jean Salmon, Aulnay Sous Bois, FR;
Jeumont-Schneider, Puteaux, FR;
Abstract
In a train control system wherein emitter beacons are located at predetermined points on the track near to one of the running rails, a device for detecting the position of a vehicle running on the railway track. It comprises into each beacon a radiating vertical-axis coil powered by an alternating current of a given frequency and, on board the vehicle, near to the corresponding rail, a pick-up unit including two pairs of receiver coils the axes of which are horizontal and perpendicular to the running rails. The associated circuits comprise two differential amplifiers connected to at least to two band-pass filters and a multiplier circuit in order to generate a positive signal when and only when the beacon is located between the two pairs of coils and the frequency of the beacon is the central frequency of the filters.