Patent ID: 6145792
Filing Date: 2000-11-14
Classification: B61L

Abstract:
A warning system for warning an operator of a train that the train is approaching personnel in proximity to railroad tracks, the system comprising:a transmitter disposed adjacent the personnel in proximity to the railroad tracks for transmitting a radio frequency (RF) warning signal with a given power output along a wireless RF transmission path, wherein the given power output of the RF warning signal is dependent upon the speed of the train, wherein the RF warning signal is indicative of the presence of personnel in proximity to the railroad tracks;a receiver disposed on the train for receiving the RF warning signal along the wireless RF transmission path, wherein the receiver disposed on the train receives the RF warning signal a predetermined amount of time prior to the train reaching the personnel, the predetermined amount of time being dependent upon the given power output of the RF warning signal, whereupon receiving the RF warning signal the receiver generates an alarm to notify the train operator of the presence of the personnel in proximity to the railroad tracks;a transmitter disposed on the train for transmitting an RF confirmation signal upon receipt of the RF warning signal by the receiver disposed on the train; anda receiver disposed adjacent the personnel in proximity to the railroad tracks for receiving the RF confirmation signal, whereupon receiving the RF confirmation signal the receiver disposed adjacent the personnel in proximity to the railroad tracks generates an alarm to notify the personnel that the train operator is aware of the presence of the personnel in proximity to the railroad tracks.