GB377673A - Improvements in or relating to train control systems - Google Patents

Abstract

377,673. Train control and cab signalling apparatus. ASSOCIATED TELEPHONE & TELEGRAPH CO., 1033, West Van Buren Street, and HUDD, A. E., 947, West Van Buren Street, Chicago, U.S.A. April 22, 1931, Nos. 17810 and 17811/32. Divided on 377,702. [Class 105.] In a train control and cab signalling system a manual re-setting device for the restoration of the receiver device which is operated directly from the track to initiate a braking action is rendered ineffective by a speed-controlled device unless the train speed is below a certain limit. Figs. 1 and 2 (17810/32) show a centrifugal valve device mounted on the wheel axle and comprising a chamber 30 with a port 14 closed by a pivoted weight 11 which at a predetermined train speed moves outwards against the action of a spring 9 to open the port 14 and thereby to vent the piping 32, 34 so that depression of a re-setting plunger 13 will be ineffective to set up air pressure for the actuation of a diaphragm by which an armature 33 of a magnetic receiver relay 18 is normally restored. The armature restoration may be effected by a lug on a spindle rocked by the action of the diaphragm. Fig. 10 (17811/32) shows the centrifugal valve device S applied to the control of a valve 107 which remains open after the operation and subsequent immediate restoration of a magnetic receiver relay R by appropriate track magnets. The open valve 107 gives a partial braking and a sustained operation of the horn 104 both of which can be cancelled, if the train speed is below the required limit, by operating the plunger 120 to actuate the diaphragm 105 and so to re-close the valve 107. The valve 107 is opened by the spindle 112 of a main train pipe venting valve 113 which is opened when the magnetic receiver relay R is operated but which is closed when the relay R is restored, as at a caution signal. At a danger signal the relay R is not restored so that the main valve 113 remains open to give a full brake application and due to the large opening of valve 113 the pressure in the piping 114 immediately reaches atmospheric so that the horn 104 is only sounded momentarily. The track magnets comprise permanent and electromagnets arranged as described in Specification 377,702. Specifications 351,039, 351,071, 351,072, and 353,502 are referred to.