Patent GB-571845-A (GB)
Title: Improvements relating to railway traffic controlling apparatus
IPC: B61L5/06
Filed: 1941-02-03
Abstract: 571,845. Railway traffic-control apparatus. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Feb. 3, 1941, No. 13S3. Convention date; May 11, 1940. [Class 105] In a system for the control of switches and signals at a field station FS from a control office DS by current transmitted over a line circuit a polarized line relay at the office and a line relay at the station are normally connected in series in the line circuit, which is supplied with indicating current of one or other polarity depending on the setting of the controlled station apparatus, the release of these line relays consequent on opening the line circuit at either end being arranged to disconnect these relays and complete circuits for the transmission of control current of desired polarity. As described the desired control operation is initiated at the office by a manually operated contact lever, the control and indication operations then following automatically. Control and indication currents are respectively supplied by batteries 7, 8 at office and station, their mid-points C being connected by a common return CL so that the required polarity of current may be obtained by completing circuit from positive pole B1 (normal polarity) or negative pole N1 (reverse polarity). The duration of control current, and the performance of operations in proper sequence, such as ensuring that battery 7 is disconnected and the receiving circuits are prepared before battery 8 is connected to line to supply indication current, is controlled by the use of slowacting relays. The drawing .shows a lay-out comprising a track IT with an insulated detector track section TS including the turn-out rails of a track switch SW leading to a second track 2T. Signals R2A, R2B on a single mast govern right-bound. traffic, and signals L2A, L2B govern left-hand traffic. Section TS is provided with a track relay TR energized by a track battery 3 in the usual way. Switch SW is operated by a switch machine SM of usual type which operates the switch to normal position shown when energized over wire 5 and to reverse position when energized over wire 6. Operation of the switch is accompanied by corresponding operation of contacts 18,21,44, 58, which occupy their full-line positions when the switch is at normal, and their dotted line positions when the switch is reverse. Machine SM is controlled by a polarized relay WR of the kind in which the polar contacts remain in the position to which last moved until the relay is energized by current of other polarity. Relay WR is energized by control current from the office and moves its contacts to normal position shown, closing normal contacts 9, 45 with normal control current, and to reverse position closing contacts 11, 60 with reverse control current. Control current need persist only long enough to operate the relay contacts to selected positions The circuit of switch machine SM is thus closed from battery terminal B1 over contact 10 of relav TR and normal contact 9 to wire 5 or reverse contact 11 to wire 6. The signals are operated by corresponding 'individual relays R2AH, R2BH, L2AH, L2BH, under control of switch contacts and contacts of a polarized signal control relay SR similar to relay WR and selectively energized by control current from the office. Neutral contact 15 closes with control current of either polarity whilst the polarized armature closes normal contacts 73, 16 with normal control current and reverse contacts 83, 20 with reverse control current. When a signal relay is de-energized the corresponding signal is operated to " stop " position, and when energized, to " proceed " position. Thus with relay R2AH de-energized a circuit is closed from battery terminal B1 over back contact 13 of relay R2AH to the signal operating means to indicate " stop," whilst with relay R2AH. energized the circuit is over front contact 14 to effect " proceed " indication. Similar circuits are controlled by the other signal relays. Control by relay SR is as follows. When relay SR is energized by normal control current a circuit is completed from terminal B1 of battery 8 over front contact 17 of relay TR, neutral front contact 15 and normal contact 16 of relay SR to contact 18, and thence, with switch SW in normal position and contact 18 in full-line position, to relay R2AH, or, with switch SW in reverse position and contact 18 in dotted line position, to relay R2BH,and in both cases over traffic-controlled contact 19 to battery terminal C. With relay SR energized by " reverse " control current a circuit is completed from terminal B over contacts 17, 15 as before, but now over reverse contact 20 to contact 21, and thence, with switch SW normal and contact 21 in full line position, to relay L2AH, or, with switch SW reversed and contact 21 in dotted line position, to relay L2BH, and in both cases over traffic-controlled contact 2 to terminal C. Connection of relav WR to line W1 provided for switch-machine control and indication currents is governed by a line relay 6R and slow-release, slow pick-up relay 5R. These relays also control connection of battery 8 to line. Delay period of relay 5R ensures that office circuits are correct before connecting battery 8 to line. Connection of relay SR to line W2 provided for signal control and indication currents is governed bv line relay 68 and slow-release relay 5S which also control connection of battery 8 to line. When relay 6S releases, back contact 63 connects relay SR to line W2 to receive control current. At the office station a switch-control lever Ll can occupy a normal position N as shown, in which lever contacts 22, 24 are closed, or a reverse position R in which contacts 23, 25 are closed. Trackoccupation indication lamp OS, normal and reverse switch indication lamps NL, RL are provided adjacent to lever L1, their circuits being controlled by a polarized line relay 1R. As shown, neutral contact 31 directly closes circuit of lamp OS, and in series with normal contact 32 closes circuit of lamp NL, these lamps being lit to indicate respectively that track section TS is unoccupied and switch SW is in normal position. When relay 1R is energized by reverse indication current contact 31 closes circuit of lamp OS and contact 34 completes circuit of lamp RL. Connection of relay 1R to line is governed by contacts of a relay 3R and slow-release repeater relay 4R which also control connection of battery 7 to line for transmission of control current. Relay 3R is controlled by a polarized lever-controlled relay 2B having normal upper winding 63 and lower reverse winding 53. As shown, winding 62 has been energized from pole BI of battery 7 over lever contact 24 and back contact 52 of relay 4R, relay 3R is being energized over contact 24 and normal contact 42, repeater relay 4R is being energized from pole B1 of battery 7 over front contact 43, and contact 62 has lifted to break the circuit of winding 62, contact 42 remaining in normal position. Relay 1B is connected to line W1 in series with line relay 6R at the field station and both relays are being energized by normal indication current from battery 8, the circuit being from pole B1 over contacts 44, 45, winding of relay 6R, back contact 46 of relay 5R front contact 41 of relay 6R, contact 47 of track relay TB.Iuie W1, contacts 48, 49, winding of relay 1R, and common return CL to mid-point G of battery 8. Occupation of the track wpulfl break this circuit at contact 47, relay 1B would de-energize and opening of contact 31 would extinguish lamp OS to indicate occupation. A lever L2 for signal operation normally occupies mid-position N in which lever contact 30 is closed, but may be moved to left position LT, closing lever contacts 27, 29, or to right position BT dosing lever contacts 26, 28. Adjacent signal indication lamps LS, RS are controlled by a polarized line relay IS and are respectively lit when the relay is normally and reversely energized. Connections of relay 1S and battery 7 to line W2 are controlled by relays 3S, 4S, which are themselves controlled by lever contacts. At times, relay 1S is connected over line W2 in series with line relay 6S but as shown this circuit is broken at lever contacts 26, 27 and at back contact 77 of relay 4S, relay 4S being energized over lever contact 30. Starting. with the apparatus in the condition shown and, already described, the Specification traces the following operations. Assuming lever L2 moved to the right to reverse switch SW, lever contact 24 opens and releases relay 3R which de-energizes relay 4R to release slowly. Release of relay SB breaks the line circuit at contact 49 and releases relays 1B, 6R. With relay 3R released and until relay 4R releases reverse control current flows from battery 7 over lever contact 23, back contacts 50, 51, line W1, front contact 47 of relay TR, back contact 40 of relay 6R to relay WR which reverses, followed by reversal of switch SW. Release of relay 4R terminates the control current and closes circuit from battery 7 through winding 53 of relay 2B over back contact 52 and lever contact 25. Relay 2R reverses and re-energizes relay 3R over contacts 25, 54. In consequence relay 4R is re-energized and relay 1R is again connected to line W1. The release of relay 6R meanwhile energizes relay 5R over contact 55 and subsequent closure of contact 57 prepares a local circuit from battery 8 for relay 6R which picks up when the circuit is completed by operation of contact 58 to reverse position when switch SW has reversed. Pick-up of relay 6R de-energizes relay 5R and prepares a reverse current circuit from battery 8 which is completed when relay 5R releases to transfer relay 6R from the local pick-up circuit to the line circuit so that relays 1R, 6R are energized in series, by reverse indication current and lamps OS, RL are lit to indicate completion of the switch reversal process. Assuming lever L1 to be moved to normal position to restore switch SW to normal, relay. 3R is relea