| 摘要 |
1,237,299. Driver display unit. BRITISH RAILWAYS BOARD. 15 April, 1970 [17 April, 1969], No. 19704/69. Heading B7N. A visual display unit for a train driver's cab comprises a schematic representation of the route 11 which is moved downwardly past line 12 representing the head of the train in synchronism with the train movement and an indication 14 of the maximum safe speed which is varied in dependence on the signal aspect. The route display is provided on an area 1 of a film of plastics material mounted on reels 15, 16 and driven past a viewing window by motor 17. The motor is controlled by a logic unit 18 which receives signals from an odometer or the like driven from a train axle; the unit also receives signals from, e.g., permanent magnets mounted on the track which are compared with signals received via line 22 from marker points on a magnetic strip 24 alongside the display 1 to provide a film position correcting signal controlling motor 17. The magnetic strip also has four tracks each having recorded along its length the safe maximum speed for a respective signal aspect. The outputs from the four tracks are applied to selection unit 30 and in dependence on signal aspect, as signalled to the train from conductor loops adjacent the track, the relevant maximum safe speed is selected and displayed. Instead of a record of the safe speed the data strip 24 can carry information relating to the track gradient, speed restrictions &c. from which a small computer on the train can calculate, taking into account the class of train, e.g. passenger, fast goods &c., the maximum safe speed. The system can also be used to display in window 36 the number of minutes the train is behind schedule and also to display the maximum speed as a profile or graph. |
