Patent GB-361413-A (GB)
Title: Improvements in electrical control systems for railway traffic controlling apparatus
IPC: B61L7/08
Filed: 1930-08-21
Abstract: 361,413. Electric signalling systems. WESTINGHOUSE BRAKE & SAXBY SIGNAL CO., Ltd., 82, York Road, King's Cross, London.-(Assignees of Miller, A. B. ; 259, Maple Avenue, Edgwood Borough, Pennsylvania, U.S.A.) Aug. 21, 1930, No. 25007. Convention date, Oct. 9, 1929. [Class 105.] In an electrical system for the control of railway signals, &c. at distant stations, and for indicating at the control office the condition of the apparatus at the stations, by code currents, different code characters are obtained by current impulses in one or any combination of a number of line circuits, and decoding relays at each station respond to different sequences of operation of line relays controlled by the code currents in the various line circuits. Fig. 1 shows the apparatus at the control office, which has a control panel such as BB and indicators 121, 122, 139, 140, 126 for each distant station, and Fig. 2 shows the apparatus at the station controlled by panel BB at the control office. The apparatus at the station comprises a pair of points, eastbound signals W<1>, W<2>, and westbound signals W<3>, W<4>; a track circuit controlling a relay v is provided. Two line wires 1,. 2 with a common return 3 are used, the circuits being normally closed and the line relays AR<1>, AR<2> at the office and BR<1>, BR<2> at the station energized by batteries 4 A, 4 B. The control panel BB has a lever BE<1> for the points and BE<2> for the signals at the distant station ; each lever, during its stroke, moves a pivoted arm 18 by means of a cam, to open a contact 19 and move an arm 20 away from a contact 22 into engagement with a contact 21; at the end of the stroke of the lever, the arm 18 returns to its original position and recloses contact 19, but the arm 20 is held over by a latch 23. The latch 23 is released by an arm 24 when a relay BW is energized, but the arm 20 then remains held over by 24 until BW is de-energized. The code impulses are delivered to the lines by transmitting relays AT<1>, AT<2>, AT3, which open line 1, line 2 and both lines respectively ; these relays are controlled by the levers such as BE<1>, BE<2> on the various control panels and by a stepping contactor P A, which always has one contact closed and which is moved to the next contact each time a relay F A is deenergized. Transmission of code from control office. A starting relay L<A> is normally energized in a circuit containing the contacts 22 of all the control panels BB ... When lever BE<1> or BE<2> is moved, the circuit for relay L A is broken at contact 22 of panel BB, and AS is energized over back contact 48 of L<A>. AS closes a stick circuit for itself at 51, and opens lines 1, 2 at 49, 50 ; the line relays at the distant stations are therefore de-energized, but local circuits for AR<1>, AR<2> are completed from battery 4 A over front contacts 49, 50 of AS. AS also energizes a relay M A and transmitting relay AT3 over its front contact 42. M A closes a stick circuit through its front contact 53, and completes a circuit for transmitting relay AT<3> over contact 53. AT<3> opens the circuits of AR<1>, AR<2>, which deenergize Q A by opening their front contacts 58, 59, 60. The closing of back contact 46 of Q A energizes two slow-release relays H A, K A. K A opens the stick circuit of AS and closes a slow release circuit for AS through a resistance. When AS releases; the code relay BW of panel BB is energized in a circuit passing through back contact 42 of AS, contacts 44a of J<A> and 21; 19 of panel BB, and the winding of a resetting relay a. BW closes contacts 66 and moves the arm 24 into contact with 20, thus energizing the right-hand winding of J A by connecting it in parallel with a resistance in the circuit for BW; contact 44a of J A therefore opens, breaking the circuits of the code relays of all the other control panels, but BW remains energized over contact 24 ; contact 44b of J A closes and energizes a relay b, which completes a circuit for F A over contact 56. F A de-energizes AT<3>, which energizes AR<1>, AR<2> if the line circuits are closed at all the other stations. Q A is therefore energized, and this breaks the circuits of H A, K A; these two relays, however, are slow-dropping, and do not act until the completion of the code. F A energizes D A, which opens the circuit for F<A>; the contactor P A is thus stepped clockwise on to the second contact and AT<2> is energized to open line 2 and give the first element of the control code. When F A opens its front contact, D A is de-energized, and this re-energizes F A to cut off current from the contact, thus de-energizing AT<2> and restoring the line to complete the first code element. F A again energizes D A, which de-energizes F A to step P A on to the third contact and energizes AT<3> to open both lines 1, 2 for the second code element. P A thus steps on to successive contacts, giving a code element at each according to the connections of contacts 66 on the control panel with the wires to the transmitting relays. The first four elements of the code are used to select the distant station corresponding to the control panel on which a lever has been operated, the fifth gives a point-control impulse through contact 14 of lever BE<1> and the sixth (and last) a signal-control impulse through lever BE<2>. When the contactor P A closes its last contact, a relay V A is energized; this deenergizes the right-hand winding of J A, and also relays BW, b, a, and energizes the left-hand winding of J A to close contact 44a. When BW is deenergized, contacts 66, 24 open, and 24 allows arm 20 to return into contact with 22. When b is de-energized, the circuit for F A is opened at contact 56, so that F A is not energized when D <A> is deenergized by the opening of the front contact of F <A>. The contactor thus pauses on the last contact, and relay H <A> releases, since the lines are both closed and Q <A> is energized for an appreciable period; F A is thus energized, opening the circuit of V and energizing D <A>, which de-energizes F A to step the contactor on so that its first contact is closed again. D A is de-energized at the front contact of F <A>, L A is energized at the back contact of V <A> and M A is deenergized by L A. K A now opens its front contact, and the apparatus is then in its normal position. If a lever such as CE<1> has been moved during this cycle of operations, L A will not be energized when V A is de-energized, M A will remain energized, and code relay CW will be energized to send the code corresponding to the operation of the lever. If, however, the lever originally moved, or the other lever on the same panel, is moved during the cycle, contact 19 is broken for a moment, and BW and a are de-energized; contacts 66 open to prevent any further code impulses from passing to the lines during the remainder of the cycle of operation of the contactor, and AT<3> is energized through the back contact of a to de-energize AR<1>, AR<2>, which therefore de-energize Q A to maintain the circuits for H A, K <A> until the end of the cycle. Reception of code at station. When relay AT3 at the control office is energized, consequent upon the movement of one of the levers, both line circuits are opened, and the line relays BR<1>, BR2 are deenergized. Q B is therefore de-energized and H <B>, K <B> energized. At the end of this initial impulse BR<1>, BR<2>, Q B are energized again, and then the line relays respond to the six code impulses. Decoding relays BN<1>, BN<2>, each having a holding circuit and three stepping circuits, close their contacts only if the stepping circuits receive current impulses in a predetermined sequence and their holding circuits are closed between the impulses in the stepping circuits ; the three different stepping circuits are established when BR<1>, BR<2> and both BR<1> and BR2 are de-energized respectively. The first four impulses of all codes from panel BB are the same. If lever BE<1> is normal, the filth impulse de-energizes BR<1>, and decoding relay BN<1> is energized, thus energizing the left-hand windings of relays BY3, BY<1> to establish a circuit through the contact of BY<1> for relay p<2>, which closes the normal operating circuit for the point motor g ; if lever BE<1> is reversed, however, BN<2> is energized by the fifth impulse of the code, and the right-hand winding of BY<1> is energized to close the circuit for the reverseoperating point relay p<1>. The sixth and final element of the code is determined by the signal lever BE<2>. When this lever is in either extreme position, the last code element opens one or other of the lines, according to the lever position, and thus energizes the corresponding winding of BY<2> to close the circuit for the signal relay q<1> (for eastbound signals) or q<2> (for west-bound signals) ; the right-hand winding of BY3 is also energized to close the circuit to the contact of BY<2>; the particular signal to be operated is selected by a relay k, which is controlled by contacts actuated by the points. When the signal lever BE<2> is in its normal or midposition, the sixth impulse of the code opens both lines, so that only the left-hand winding of BY<2> is energized, thus cutting off power from the signal relays so that all signals return to or remain at "danger." The power circuits for points and signals are taken through front contacts of the track-circuit relay v. Indication. Three indication code delivery units G<1>, G<2>, G3, which may be similar to those described in Specification 306,147, [Class 105, Railway signals &c.], are provided at the station. Each unit consists of a storing magnet r, the armature of which is held, when attracted, by a latch, and a delivery magnet d having an armature which operates a trigger 142 to release the latch ; the trigger holds the armature of the storing magnet until the delivery magnet is de-energized. A stepping contactor P B, moving anticlockwise, and other relays similar to th