Patent GB-420838-A (GB)
Title: Improvements relating to apparatus for the remote control of railway points, signalsand the like
IPC: B61L7/08
Filed: 1933-06-10
Abstract: 420,838. Railway signals. TOMLINSON, A. V., 65, Victoria Street, London.-(Compagnie Generale de Signalisation; 23, Rue d'Athenes, Paris) June 10, 1933, No. 16671. [Class 105] The invention relates to the control of signals and points at a moderately remote distance with cabin indications of the settings and of the entrance of trains into track sections by polarized currents transmitted over combined control and indication lines which are transferred from the indication condition to the control condition when a change of setting is to be effected. According to the invention the supply of current at one end of the line is prevented until the supply at the other end has been disconnected. This is achieved by relays OS, 1S, the relay OS not being energized to apply control current until all the indication relays have dropped, while the relay 1S which is situated at the remote point and applies indication current when de-energized is not de-energized until the relay OS has dropped. Cross protection relays are provided. Figs. 2-4, show the circuit arrangements for a layout corresponding to the miniature track diagram shown in Fig. 1. The lever 30 controls the points while the lever 8 clears the signal L when moved to the left and clears signal R1 or R2, according as the points are at normal or reverse, when moved to the right. When any change of setting is to be effected the levers 8, 30 are appropriately set and the starting button S is pressed. This picks up a relay ST which then sticks over its own front contact 149 and back contact 147 of the relay OS. The closure of contact 152 of the relay ST completes a circuit for the relay 1S at the remote situation, the circuit being from battery 1B1 over relay 1S, starting line 101, contact 152, to lead 114 and common return line 105. The relay 1S lifts its contacts 1SW, 1SH, 1SA to transfer each of the combined control and indication lines 102, 103, 104 to the lead 163 going to the common return line 105 so that all the cabin indication relays WKR, HKR, AKP are now without current. The relay OS is now energized over front contact 150 of the relay ST and back contacts 156 and 159 of the indication relays WKR and HKR. Relay OS thus closes its front contacts OSW, OSS to apply to lines 102, 103 polarity as determined by contacts 31, 32 and 164, 165 of the points and signal levers 30, 8 and thereby to energize polarized points and signal control relays WS, HS, at the remote situation. The lifting of contact 147 of the relay OS opens the stick circuit of the relay ST which in due course, being slow acting, drops its contacts 149 .... 152 ; contact 150 opens the circuit to the relay OS which in turn drops its contacts 148 OSW, OSS, OSA, the first of which 148 opens the starting line 101 so causing the relay IS to be de-energized and the others connect up the lines 102, 103, 104 to the common return line 105 through the indication relays WKR, HKR, AKP. The dropped contacts 1SW, 1SH, 1SA of the relay 1S connect the lines 102, 103, 104 to positive, negative, or zero potential in accordance with the setting of the points or signals or the entrance of trains into the track sections. In the condition shown the points have previously been set at normal so that pointsrepeater-relay contacts 106, 107 are up and contacts 108, 109 down. Accordingly positive potential is applied from battery 1B1 to line 102 over contact 106, through a cross-protection relay PW, a time element contact 113 and a fouling-section track-relay front contact 110 ; thus the cabin indication relay WKR is energized in the normal direction and actuates a " points normal " indicator such as a lamp 35. The signals being at danger contacts 168, 169, 121 and 168<a>, 170, 122 of two repeater relays (not shown) are all up. Accordingly line 103 is at zero potential over contacts 168, 168<a> and lead 163 going to the common return line 105 ; thus the cabin indicator relay HKR is de-energized and actuates a " signals at danger " indicator 14. To set points to reverse the cabin lever 30 is moved to close contact 32 whereby negative potential is applied from battery OB2 to the line 102 when the push S has been operated. At the remote situation the relay WS is negatively energized and so energizes a relay RWS to effect the movement of the points to reverse. When the movement is completed and the relays ST, OS, 1S have dropped to return the lines 102, 103, 104 to the indication state, negative potential is applied to line 102 from battery 1B2 over front contact 108 of a points-at-reverse repeater relay and through cross-protection relay PW and contacts 113, 110 so that the cabin relay WKR is reversely energized and so actuates the indicator 36. To clear the signal L the cabin lever 8 is moved to the left so closing contact 165 whereby positive potential from battery OB1 is applied to line 103 when the push S has been operated to effect the change over of the line to its control state ; this energizes relay HS in the normal direction which in turn energizes signal control relay RGS. When the line 103 returns to its indication state, negative potential is applied thereto from battery 1B2, over back contact 121 of a "signal L at danger" repeater relay (not shown), front contact 170 of a " signals R1R2 at danger " repeater relay, and through a cross-protection relay PS ; the cabin relay HKR is thus reversely energized and actuates indicator 16. The line 104 is only used for indicating the entry of a train into approach sections 3, 4. The track relays of these sections have slow-dropping repeater relays RP3, RP4 so that a train entering, say, section 3 causes the track relay and the repeater relay of such section briefly to be out of correspondence so that the track relay contact 127 is down but repeater relay contact 135 is still up and thus negative potential from battery 1B2 is briefly applied to line 104 so reversely energizing relay AKP which picks up a relay AKL which sticks up over contact 143 and actuates an indicator APL over contact 141. The indication can be cancelled by a button BPL which breaks the stick circuit. If the sections 3, 4 are both simultaneously entered both the track relays drop at once, and it is necessary to give the precedence to one approach indication in order that the relay AKP may be properly actuated by spacing the two brief indication currents. To this end the repeater relay RP4 is held by a stick circuit, Fig. 4, including a back contact 131 of track relay of section 3 and a front contact 134 of repeater relay RP3. The action is that first the indication of section 3 is given by negative potential applied to the line 104 by battery 1B2 over back contact 127 and front contact 135 during the time that the track and repeater relays of section 3 are briefly out of correspondence. When these two relays for section 3 have both dropped, the back contacts 128, 136 thereof apply positive potential to line 104 by battery 1B1 over back contact 125 of track relay for section 4 and front contact 139 of repeater relay RP4 which up to this time has been held by its stick circuit which is now opened by the dropping of contact 134 of relay RP3. The second indication current is transmitted during the brief time required by the slow relay RP4 to drop and energizes the cabin relay AKP in the normal direction to pick up relay AKR whereby an indicator APR is actuated. Any abnormal currents arising from crossing of wires will either actuate the cross protection relays PW, PS at the remote situation to prevent the apparatus being operated or will actuate indicators CMW, CMS at the cabin to denote the faulty line. A modification is described in which a single line when in the control state is used to clear a signal L or R and when in the indication state to indicate train entrances into two track sections. Specifications 392,157 and 406,995 are referred to.