GB834641A - Apparatus for initiating an operation on a vehicle after completion of a predetermined distance - Google Patents

Abstract

834,641. Train control and cab-signalling by track apparatus. SOC. TECHNIQUE POUR L'INDUSTRIE NOUVELLE S.A. STIN. June 17, 1958 [June 18, 1957], No. 19298/58. Class 105. Apparatus for initiating on a vehicle an operation such as the application of the brakes, on completion of a predetermined distance travelled thereby from a datum position as when a train passes over a track magnet 13 associated with a signal 15 to prepare circuits on the train for, e.g. applying the brakes 16 in the event that a second signal is not received e.g. from an electromagnet 14 energized when the associated signal 15 is at clear aspect, to cancel the effect of the track magnet and prevent the application of the brakes; comprises on the vehicle a counter to count electrical impulses derived from the rotation of a track wheel or axle of the vehicle and means for initiating the said operation when the number of impulses counted represents a predetermined distance. As the pick-up coil 12 on the train passes over the track magnet 13, the train receiving equipment 11 receives an impulse to start a counter 02, e.g. of the binary type employing transistors and when this has counted a predetermined number of impulses representing at least the distance L and fed thereto from a balanced A.C. bridge 03 one arm of which includes an inductance variable cyclically by the rotation of the track wheel 31 and fed from an oscillator circuit 04 preferably employing transistors and energized from a source 05, a signal is fed from the counter to the equipment 11 to initiate the operation of the brakes 16 unless in the mean time a signal has been received by the equipment 11 from the pick-up 12 passing over the magnet 14, indicating that the train may proceed.