US 7,575,202 B2
Apparatus and methods for providing relatively constant warning time at highway-rail crossings
John T. Sharkey, Elgin, Ill. (US); Richard Bamfield, Nelson (New Zealand); and Martin Paget, Anaheim Hills, Calif. (US)
Assigned to Safetran Systems Corporation, Louisville, Ky. (US)
Filed on Oct. 14, 2005, as Appl. No. 11/250,686.
Prior Publication US 2007/0084974 A1, Apr. 19, 2007
Int. Cl. B61L 29/00 (2006.01)
U.S. Cl. 246—293  [246/111; 246/125; 246/126; 246/473.1] 22 Claims
OG exemplary drawing
 
1. Apparatus for providing relatively constant warning time at a rail grade crossing for trains, said apparatus comprising:
a crossing controller for monitoring a track of the rail grade crossing;
a warning device that is actuated by the crossing controller when an approaching train is predicted by the crossing controller;
a remote controller for sensing the approach of a train, said remote controller communicating the approach of a train to said crossing controller via rail-based communications, wherein said remote controller also determines if the approaching train is a slower moving train and communicates any determination that the train is slower moving to said crossing controller via rail-based communications, and said crossing controller responds to the communication that the train is slower moving by preventing early activation of said warning device;
a first transmitter for transmitting a first communication signal via rail-based communications, said first communication signal changing when an approaching train is sensed by the remote controller,
a first receiver for receiving the first communication signal via rail-based communications, the first receiver for communicating the change in the first communication signal to the crossing controller,
said crossing controller responding to the change in the first communication signal to activate the warning device;
a second transmitter for transmitting a second communication signal via rail-based communications, said second communication signal changing when the approaching train is determined by the remote controller to be a slower moving train;
a second receiver for receiving the second communication signal via rail-based communications, the second receiver communicating the change in the second communication signal to the crossing controller; and
said crossing controller responding to the change in the second communication signal to prevent early activation of the warning device.