Patent GB-697211-A (GB)
Title: Control system for regulating the speed of vehicles
IPC: B61L3/22
Filed: 1952-01-31
Abstract: 697,211. Automatic speed control. VEHICULES GUIDES SUR PNEUMATIQUES SOC. AR.L. Jan. 31, 1952. [March 7, 1951], No. 2596/52. Class 38 (iv). The speed of a train along a route is kept to a predetermined programme by controlling the acceleration and braking of the train according to whether the time taken to pass through predetermined sections is more or less than an ideal time. The timing apparatus on the train determines a certain ideal time so that the required ideal speed is determined by the length of the route sections. Route sections.-The route sections are defined by cables placed in two staggered lines alternately on each side of the route, and energized by alternating current. Each section may be energized from a separate transformer, Fig. 1 (not shown), or the sections may be connected in series and the interconnecting or return cables kept remote from the route, Figs. 2, 3, 4 (not shown). Timing.-The time for which the train is in a section is detected by relays G, D energized from magnetic pick-ups 5a, 5b carried on either side of the train to be influenced by the cable sections. The detector relays control slow release repeaters A1, B1, whereby there is an overlap in the operation of the repeater relays as the train passes from one section to the next, to start a timing chain of slow release relays A2-A11. The timing chain relays pick up successively to energize a proving relay A12 (which holds over All when energized), and the timing periods are defined by the drop-out of relays in the chain, the ideal time being between the drop out of a A5 and A6. Speed control, Fig. 5.-Relays DV1 ... 3 and AV1 ... 2 provide three degrees of braking control and two degrees of acceleration respectively. Each operation has a time differential between starting and stopping, e.g. relays DV3A.B are released and energized by relays A2 and A6 respectively. The brakes are applied by the de-energization of the control relays. For example with the train running too fast, and assuming third degree braking is operating the brake line 29 is energized over contacts 27, 28 of relays DV3A, DV3B down (see bottom of Fig. 5). If when the train enters a section energizing relay B it has slowed down sufficiently for third degree braking to be cancelled, relay A6 will drop while A1 is still up to make a circuit over contacts 12, 18 (the proving relay) and 14 to energize the DV3A which makes a holding circuit for itself over contact 18 and disconnects the brake circuit at contact 28. As B1 will also be up it energizes DV3B over 19, 20, 23 and 24, and DV3B picks up and completes its holding circuit over 25. Thereafter the two relays DV3A.B alternately energizes one another over contacts 17, 24 to keep the braking circuit 29 de-energized, unless the train should increase speed so that the time taken to pass through a section is less than the ideal time then, detector repeater relay A1 or B1 will have released before timing relay #2 drops. When this occurs, the maintaining circuit for the control relay DV3A or B will not be completed and the control relay will drop out and make the braking circuit 29 over contacts 27, 28. The other degrees of braking and acceleration are similarly controlled by other timing relays, e.g. second degree braking is controlled by relays DV2 being energized over the contacts of timing relays A8 and A3.