Patent GB-362847-A (GB)
Title: Improvements in train dispatching systems
IPC: B61L7/08
Filed: 1930-08-06
Abstract: 362,847. Electric systems for operating railway signals. GENERAL RAILWAY SIGNAL CO., Rochester, New York, U.S.A.-(Assignees of Leake, R. C.; 45, Gardiner Avenue, and Phinney, R. M.; 236, Ravenwood Avenue, both in Rochester, New York, U.S.A.) Aug. 6, 1930, No. 23581. Convention date, Aug. 14, 1929. [Class 105.] In a system for the distant control of railway signals, points, &c. and for giving an indication at the control office-of the condition of the track or the apparatus, using a minimum of line wires, a chain of relays is provided at the control office and a similar chain at the location of the apparatus controlled; the relays of any one chain operate in succession, the cycle of operation being initiated by the movement of any control lever or by any change in the condition of track or' apparatus, and each relay is only energized after the previous relay in the chain has been de-energized and before its contact has opened, so that any stray current delaying the action of one of the relays till the contact of the previous relay has opened will stop the operation altogether; the system is thus designed to cease operation rather than operate incorrectly. These successively operating or "stepping" relays are connected in .two groups, each containing alternate relays, and a polarized line relay completes the circuit of one or other of the groups according to its position. Each of the stepping relays operates in synchronism with the corresponding relay in the other chain, and the contacts of each pair of corresponding relays form part of the circuit for a particular controlling or indicating function ; a particular circuit is only completed, however, after a polarized master relay, which controls the application of current to the line, has operated in response to the energization of the stepping relay concerned and before the polarized line relay controlling the stepping relays of the control office chain has followed the master relay, so that.each circuit is only closed for a very short time, and two circuits cannot possibly overlap and cause incorrect operation. The system is arranged so that if the condition of the track or apparatus changes during a cycle of operation of the stepping relays the indication of the change is delayed until the relays have all come to rest, when a new cycle of operation is commenced for the indicating function. The system is shown applied to a passing station PS, Fig. 1B, the complete equipment for the eastern end only being shown. The points are operated by a machine SM2 controlled by relay SMR, which is energized from lever SML at the control office, Fig. 1A. Signals ME, MW for the main track and DE, DW for the siding are controlled by relay SR, the signal to be operated being selected by relays DR and SMR; the relays SR, DR are controlled by signal lever SL. A track circuit, operating a track relay 2T, is provided at the points. The station is reproduced in miniature at ps in the control office, and indicators IW, IE are provided for the track circuits at the west and east ends of the station respectively ; the system shown gives no indication other than for the track circuits. The apparatus at the control office is shown in Fig. 1A and that at the station in Fig. 1B; the two sets of apparatus are connected by two line wires 18, 19, which carry current for the stepping control relays LR1, LR2 and for control and indicating functions or "messages" respectively, and a common return C. 1A .. 1C are the stepping relays at the control office, which pick up successively in response to repeated reversals of a polar biased-to-neutral line relay LR<0>, provided that a slow-dropping relay K<0> has dropped at least momentarily before operation of LR<0>; K<0>, being slow-dropping, does not drop during reversals of LR<0>, but only when LR<0> assumes its neutral position. A1 .. A4 are the stepping relays at the west end of the station, operating in synchronism with 1A .. 4A respectively under the action of relay LR1 (similar to LR<0>), and B1 .. B4 at the east end, controlled by relay LR2, similarly correspond to 1B .. 4B at the control office. Each stepping relay at the crmtrol office operates a master relay MR to reverse the current in the stepping wire 18 and thus to operate the relays LR<0>, LR1 ... In the normal position of the apparatus, with no train in the area controlled, the track relays 1T, 2T, and therefore relays PR1, PR2, are energized; all the other relays are de-energized, but MR remains in its left-hand position from previous operation. Stepping operation. When contact 26 on lever SML, or the corresponding contact on any other lever, is closed momentarily relays SR1, SR2 are energized from the battery 20. SR1 is held through its own contact 30 and contact 32 of relay 1C, and SR2 is held through its own contact 37, and contacts 40 of relay CR and 39 of relay K<0> in parallel, and also through the stick circuit of SR1. Relay CR is energized through contacts 42 of SR2 and 44 of K<0>, and this energizes W. W energizes the lower winding of MR, through its contact 50 and back contacts 53 .. 59 of relays 1A .. 3B to keep contacts 64 and 65 to the left ; W also energizes the line relay LR<0> to the left by current through contact 64 of MR in its left-hand position and contact 67 of W. LR<0> in its left-hand position picks up 1A and K‹ through its contact 68 and the back contact 70 of K<0>; 1A picks up more quickly than K‹, and establishes a stick circuit for these two relays through its contact 82 and contact 68 of LR<0> before contact 70 opens ; also, the circuit for the lower winding of MR is broken at contact 53 of 1A. Operation of K<0> breaks the circuit of CR at contact 44, but completes a stick circuit for W through contacts 101 of 1C, 103 of K<0> and 105 of W. When CR drops, the upper coil of MR is energized through contact 85 of CR, front contact 53 of 1A and contact 50 of W, and its contacts move to the right, thus reversing the current in the line wire 18 and moving LR<0> to the right. LR<0> in its right-hand position de-energizes 1A, but before the contacts of the latter open 2A is energized through contacts 90 of 1A and 68 of LR<0> and closes its stick contact 99. K‹ is now energized in series with 2A, having been momentarily de-energized during the operation of LR<0> without dropping its armature. When 1A drops, contact 53 breaks the circuit for the upper winding' of MR and makes that for the lower winding, thus energizing MR to move to the left, which causes LR<0> also to move to the left, energizing 3A and de-energizing 2A. This operation continues, each stepping relay reversing the contacts of MR and LR<0> and thus de-energizing itself and energizing the succeeding relay in the chain. When 1C is energized, the stick circuit of W is broken at contact 101, and this breaks the circuit of LR<0> at 67 ; LR<0> therefore goes to neutral'; 1C also breaks the stick circuit of SR1 at contact 32. LR<0> in the neutral position de-energizes K‹, which presently drops and closes the circuit for CR at contact 44. CR energizes W, and a second stepping cycle commences. When K‹ picks up this time, SR2 drops, its three circuits now being broken at contacts 30 of SRI, 40 of CR and 39 of K‹ respectively (in the first cycle it remained energized through the stick circuit of SR1). At the end of the second cycle the operation stops, since the circuit of CR is now broken at contact 42 of SR2. Relays LR1, LR2 and K1, K2 operate in synchronism with LR<0> and K<0> respectively, and the stepping relays A1 .. A4 and Bl .. B4 operate in synchronism with the corresponding relays 1A .. 4A and 1B .. 4B at the control office. Message circuit operation. To operate the points at the east end of the station, lever SML is moved; contact 26 is momentarily closed during the movement, and the stepping cycle is commenced. When relay 3B is energized and MR has moved to the right in response, but before LR<0> has moved to the right, the circuit for relay SMR is closed through contact 175 of lever SML, front contact 177 of 3B, back contacts 178 .. 183 of relays 2B .. 1A, contact 69 of LR<0> in the left-hand position, contact 65 of MR in its right-hand position, front contact 187 of K<0>, line wire 19, front contact 189 of K2, back contacts of B1, B2 and front contact of B3. To operate one of the signals, lever SL is moved (to the right for ME or DE, to the left for MW or DW), starting the stepping cycle in the same way as SML did; when 1B and B1 are energized, a circuit from contact 248 of lever SL to relay SR is completed, and when 2B and B2 pick up relay DR is energized from contact 251 of lever SL. All messages pass through the contacts 69 of LR<0> and 65 of MR in opposite positions, before LR<0> has time to respond to the operation of MR, so that the circuits are only closed for a very short time. If the track-circuit at the eastern points is occupied, relay 2T will drop, picking up relay QR2 through back contact 200 of 2T and front contact of PR2 before PR2 responds to the opening of front contact 200 of 2T. If the apparatus is at rest, relay SR2 is energized, to start a stepping cycle, through the second contact of QR2, back contact 189 of K2, line wire 19, and back contact 187 of K<0>. If, however, a cycle of operation is already going on, K2 is energized, and in this case QR2 is held up through its own contact 212 and a contact of K2 until the cycle is completed and K2 drops, when SR2 is energized as before to start a new cycle. In either case QR2 drops immediately after energizing SR2. During the cycle thus started, when stepping relays B4 and 4B are. energized a circuit is completed from battery 225 through the,contact of 2T to indicator relay IR2 which controls the indicator IE. When the track-circuit is cleared, 2T picks up and energizes QR2 momentarily, through the back contact of PR2, before the latter picks up, to start a stepping cycle, immediately or after a cycle in process