For indicating whether a vehicle can pass through a bridge, a radio transmitter is positioned adjacent the bridge to generate radio signals which are encoded with information as to the height of the bridge as presented to vehicles. A vehicle is provided with a radio receiver capable of receiving and decoding the signals from the transmitter, and comparing the height information so derived with pre-encoded information as to the height of the vehicle. A warning signal is produced in the event that the comparison indicates a danger that the vehicle cannot safely pass under the bridge. The technique is also applicable to railway crossings where a transmitter is positioned at the crossing to generate ratio signals indicative of approach of a train so that the receiver on the vehicle may provide a warning of such approach of a train on decoding the radio signals.
申请公布号
US4621252(A)
申请公布日期
1986.11.04
申请号
US19840652972
申请日期
1984.09.21
申请人
JOHNS, DAVID G.;DONLON, KIERAN J.;BRAUN, MANFRED E.
发明人
JOHNS, DAVID G.;DONLON, KIERAN J.;BRAUN, MANFRED E.