Fail-safe safety system to detect and annunciate fractured running rails in electrically propelled transit systems

Abstract

The present invention relates to a fail-safe safety system to detect and annunciate fractured running rails in electrically propelled transit systems using catenaries or third rail power contactors without the need to induce block by block communication signals currently required by existing systems for detecting occupancy and broken running rails. In addition, unlike existing systems, the present invention is fail-safe, fault tolerant, and self annunciating in that if any component, or connection, of the system fail, or is out of tolerance, it is immediately communicated to a central location. Further, also unlike existing systems, the present invention does not require, or interfere with, automatic train controls because it uses the propulsion power bus, itself fail-safe, as an independent means of communication without additional wiring.

Description

CROSS-REFERENCE TO RELATED APPLICATIONSReferences Cited[0001]U.S. Patent Documents6,972,687December, 2005Marshall, et al.340 / 686.16,655,639December, 2003Grappone.246 / 1205,680,054October, 1997Gauthier.324 / 7134,886,226December, 1989Frielinghaus246 / 1214,728,063March, 1988Petit, et al.246 / 34R4,306,694December, 1981Kuhn246 / 1254,117,529September, 1978Stark, Ehrlich361 / 182BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a fail-safe safety system to detect and annunciate fractured running rails in electrically propelled transit systems without the need to induce block by block communication signals, using block transmitters and receivers, currently required by existing systems for detecting occupancy, transmitting speed commands, and detecting broken running rails. Additionally, unlike existing systems, the present invention can detect running rail fractures that are not completely broken and bidirectionally communicate control operating param...

AI Technical Summary

Benefits of technology

[0012]Accordingly the major factors associated with the detection and annunciation of fractured rails, already briefly recited, the present invention provides a simple means for the long-felt need to detect and annunciate fractures in running rails of CBTC systems in a fail-safe manner. The core of the invention is detecting an unbalance in propulsion currents in the ground returns provided by the two running rails with, or without, automatic train controls, and communicate this imbalance in a fail-safe manner to a central location—indicating a fracture. The invention measures and compares electrical propulsion currents in existing running rail returns and communicates this information, in a fail-safe manner, over existing propulsion power lines using commercially available power line communications (PLC) equipment to a central controller location.

Problems solved by technology

It has been, and still is, an ongoing problem detecting, and annunciating, a fractured running rail with CBTC systems because in these systems there are no, as in fixed block systems, individual block signaling currents that detect and annunciate a broken running rail.

Further exasperating the problem is the present lack of communication lines from wayside to communicate fractured running rail information to a central location that can control train movement.

These leading areas of concern, coupled with projected costs and time to implement a solution, have caused transit agencies to avoid upgrading their fixed block systems to CBTC that can, and would, substantially increase passenger throughput and reduce commute times.

Virtually all of these induce signals into the running rails, can only detect completely broken rails, and use a unidirectional hard wired, or radio frequency, communications link that only transmits information and is, more importantly, not fail-safe.

Images