Патент USA US2116177код для вставки
May 3, 1938. 2,116,177 N. p. PRESTON CENTRALIZED TRAFFIC CONTIiOLLING SYSTEM‘FOR RAILROADS ' 3 Sheets-Sheet ,F‘iled Aug. 24, 1935 E _mm. v._3 E1 11-" Q21 .Twin .HdE 1 May 3, 1938. N. D. PRESTON _ 2,116,177 CENTRALIZEOTRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed Aug.- 24, 1935 E - - ‘ s Sheets-Sheet 2 Fla-.2. . Mum INVENTOR Patented May 3, 1938 V t ‘UNITED STATES‘ PATENT OFFICE, GENTR-ALIZED' TRAFFIC. CONTROLLING SYSTEM FOR RAAILBJOAD‘S Neil D‘. Preston, Rochester, N. Y., assig-nor to General Railway Signal Company, Rochester, - N. Y. ' Application August 24, 1935, Serial No. 37,742 4 Claims. (01. 177-353) > This invention relates to centralized tra?ic confor registering the code character of the control" trol systems for railroads, and more particularly ' impulses which is reliable’ in its‘ operation but to a means for registering controls in a communi- does not require the‘ use of additional‘ decoding cation system of the multiple impulse or code means. 7 5 type. ‘ Generally speaking; and by way of explanation 5* In the multiple impulse or code type communication‘ system commonly employed in centralized tra?ic control systems for the purpose of governing the operation of switches and signals at a 10 distant ?eld station from a central control office, the controls for governing the operation of the switches and signals are transmitted by a series of time spaced plus or minus impulses, or impulses otherwise distinguishable in character by 15"variable line circuit conditions or the like. These 20 and without attempting to de?ne the nature or scope of the present invention, it is proposed to_ employ neutral stick‘ control relays directly re sponding in succession to the code character‘ of‘ the control impulses for thesuccessive' steps, these relays individually or jointly controlling, the op‘ eration of the switches and signals ;' and to con trol the stick circuits for‘each: of‘ these' neutral‘ stick control relays so as" to be temporarily‘broken‘ while‘ an energizing or pick-up circuit for such 15" distinctive control impulses are employed to condition suitable relays at the ?eld location governing the operation of power-operated track switches and‘ the indications of their associated relay is opened‘ or closed dependent upon the control impulse being transmitted,‘ said stick cir cuits maintaining the. control relay energized at other times to maintain the desired control ef signals. fective. ' In one arrangement, such as disclosed for ex- ample in- the ‘prior application of Preston and Hitchcock, Ser. No. 455,304, ?led May 24, 1930, corresponding to the British Patent ‘No. 377,971‘, the character of the control impulse for each step 25 or time interval‘5 is registered by operating a two position polarized relay to one position or the other, the armature of said relay, conveniently termed a mag-stick relay, being magnetically held in; the position to which it is set until changed by some subsequent impulse. In such an ‘arrangement, a‘ control impulse to operate the‘ mag-stick relay from its existing condition to another desired condition may not be‘ eifec5 tive,. due' to a broken wire or bad contact, or the like,>with the result that the desired control actually transmitted and received at the ?eld loca- tion- is not properly registered‘; and while the system for controlling the switches and signals 40 is‘so organized that‘ no- unsafe condition is p-roduced by such failure, trains may be signalled to advance lover‘ a wrong route not desired by the operator. , In. another arrangement for registering con45 trols, neutral decoding relays, all de-energized at the beginning of a transmitting cycle, are selectively energized in. accordance with the control code transmitted, and then the relays controlling the switches. and signals are conditioned, pro~ 50. vided‘the decoding relays have properly respondedto the control code transmitted. This arrangement requires decoding relays, usually two for each step, in addition to the switch and signal control relays. 55, One object of this invention is to provide means Other characteristic features, attributes, and“ advantages of the organization of relays and’ cir cuits'constituting the present invention will‘ be in part apparent, and in part pointed out, as the description progresses. The present invention relates‘ to only a part 25 of a complete‘ system of code communication for centralized traf?c control; and while it is con temple-ted that the invention will be usedv with the various features commonly employed‘ or suit able for such a complete communication sys tem, such as station selection, transmission of indications, and the like, in order to simplify the disclosure and explanation of the present inven tion, such features of the complete system are 35 not illustrated and will not be described, except in a general way and in so far as appears to be necessary to understand the functions and mode of operation of the parts and circuits constitut ing this particular improvement. 40 In the accompanying drawings, Fig. 1 illustrates diagrammatically and with‘ various conventional illustrations, one form of this invention; Fig. 2 illustrates one typical arrangement of circuits for operating the stepping relays; Fig. 3 is a dia- 46 gram or chart showing, for explanatory pur poses, the sequence of operation of certain relays particularly pertinent to an understanding of the present improvement; Fig; 4 shows how the or gani‘zation of Fig. 1 may be used in a multiple 5o control station system with station selection; and Fig. 5 shows a modi?ed organization. For the purpose of simplifying the illustration and facilitating the explanation, the various re lays and circuits have been shown diagrammati-i 55 2 2,116,177 cally and conventionally, and the symbols (+) only intermittently energized closing contact 9 and (—) are employed to indicate connections to the opposite terminals of a battery or other suitable source of current for energizing the cir cuits, instead of showing all of the wiring con nections that would be employed in practice. for each impulse to energize relay SA; a group or bank of stepping relays IV, 2V, etc., including a half-step relay VP; neutral stick control re lays WN and WR governing the operation of the switch machine, and similar relays RD and LD for governing the clearing of the associated sig nals; and a special additional relay X for govern ing the stick circuits of the control relays WN, WR, etc. 10 Any suitable arrangement of stepping relays Referring to the drawings, the central control o?ice of this system is indicated by a dotted rec tangle in the upper left-hand corner of Fig. 1. 10 The code transmitting and receiving equipment in this control office is connected to the equip ment at the various ?eld stations by three line wires, comprising a stepping and control line wire SOL, an indication line wire IL, and a common 15 return line wire CL. The stepping and control line wire SCL, together with the common return wire CL, constitute a stepping and control line circuit which is energized in the control o?ice with a series of impulses of a selected polarity for 20 operating stepping relays at the ?eld location se quentially one at a time, and conditioning con trol relays for governing the operation of switches, signals, and the like. For the purpose of explaining and understanding the present im 25 provement, it is considered unnecessary to illus trate the code transmitting equipment in the control office by which these series of impulses are applied to the stepping and control line cir cuit, ?rst in accordance with the code call for a 30 particular control station to be selected, and then in accordance with the position of switch and signal levers manually set by the operator for the purpose of controlling the operation of corresponding switch machines and signals. 35 It is contemplated that the controls for a power-operated switch or switches and associ ated signals will be transmitted as a group to each of the various control stations, one station at a time as the operator positions the switch and may be employed; and the particular stepping bank illustrated in Fig. 2, and corresponding to that disclosed in the prior application of T. J. Judge and C. S. Bushnell, Ser. No. 640,062, ?led October 28, 1932, is merely typical. Since the cir cuit organization and mode of operation of this bank of stepping relays is explained in detail in said Judge and Bushnell application, and in its speci?c form constitutes no part of the present invention, it will be su?icient to point out gen erally certain characteristic features in the oper ation of this stepping bank. During the conditioning period at the begin ning of an operating cycle, relays F and FF are ‘‘ energized, and thereafter the relay SA, where upon relay VP is picked up over a circuit that may be readily traced from (+), through front con tact Ill of relay SA, front contact II of relay FP, back contacts I2, l3 and I4 of the stepping re 30 lays 3V, 2V and I, relay VP to (—). Relay VP is maintained energized by a stick circuit through its contact I5 and back contacts of the stepping relays. When the line circuit is broken at the end of the conditioning period and relays F and 35 FP are de-energized, the ?rst stepping relay IV is energized by a circuit readily traced in Fig. 2 from (+), through a front contact I6 of relay SA, back contact I‘! of relay FP, front contact I8 I signal levers for these control stations and actu ates corresponding starting buttons, in the man ner disclosed for example in the application of of relay VP, and back contact I9 of relay 2V, said 40 station selection, arrangement and grouping of switch and signal controls, and other features characteristic of a complete system, incorporating in Fig. 1, after relay VP is initially energized during the ?rst energization of the line circuit in the conditioning period, a stepping relay picks up during each succeeding ole-energization or “off” period, and the relay VP shifts, i. e., changes ?rst stepping relay IV, when energized, being maintained energized through its own front con Preston and Hitchcock, Ser. No. 455,304, May 24, tact 20 and a stick bus 2| and front contact I6 1930 or T. J. Judge and C. S. Bushnell, Ser. No. of relay SA until the end of the operating cycle. While relay FF is de-energized, relay VP is held 640,062, ?led October 28, 1932. These applica tions correspond respectively to British Patent up by a stick circuit through back contact II of No. 377,971 and U. S. Patent No. 2,082,544. It is relay FP and front contact 22 of relay VP. When the line circuit is again energized, relay VP drops, I also contemplated that the controls for a plural ity of switches or for various routes may be trans~ relay IV being now up. During the next de-en ergization of the line circuit, the next stepping 50 mitted, either simultaneously during the same operating cycle, or successively on different oper relay 2V is energized through back contact I8 of ating cycles, as best adapted to the particularv relay VP, back contact 23 of‘ 3V, and front contact track layout. For the purpose of explaining the 24 of IV; and during the next following energiza nature of the present invention, the various Ways tion of the line circuit, relay VP again picks up to of communicating controls to several control sta prepare the energizing circuit for the next step tions for various track layouts may be disregard ping relay 3V. The same operation is repeated ed, and it is sufficient to consider this invention for as many steps as desired. as applied to a single switch and its associated Thus, in accordance with the particular ar signals at one ?eld location. rangement of stepping relays assumed for the 00 Disregarding the transmission of indications, speci?c embodiment of the invention illustrated (50 the present improvement, and considering this improvement as embodied in its simplest form, the ?eld station equipment as shown in Fig. 1 comprises a three-position biased to neutral polar line relay F in the stepping and control line SCL; a neutral repeater line relay FP energized each time the line relay F is energized by closure of contact 8, irrespective of the polarity of such energization; a slow-release relay SA picked up at the beginning of each operating cycle and maintained picked up during such cycle even though the line relay F and its repeater FP‘ are from its energized or de-energized condition as the case may be, during each of the succeeding energization or “on” periods. This operation of the stepping relays IV, 2V, and 3V establishes sequentially local channel cir cuits for energizing the control relays WN, WR, RD and LD in accordance with the polarity of energization of the line relay F, during the next “on" period following the “off” period during 75 2,116,177 which the corresponding stepping relay ‘was en-= ergized.) - l , y , energizing circuit controlled by relay VP and the stepping relays l V, 2V, etcsare provided. (Remem beri-ngthat during the energization of the line. circuit for, conditioning relays WN or'WR, relay Referring to the control relay WN as ‘typical, this relay is energized through its upper winding 3 during the first stepping period when the line, V]? is .de-energized, it can be seen that an ener relay Fis energized with a particular ‘polarity and. gizing circuit for relay X is established ‘from (4-), relay IV is energized, thisvpolarity in the case of‘ through black contacts 40, ‘4 I of the stepping relays the relay ‘WN being assumed to ‘be plus to .set the 3V and 2V, front contact 42 of‘ relay IV, back‘ polar contact vof relay ‘F to the right; This ener contact 43 of relay VP,'.and relay X to (—). This energization of :relay X supplies current‘to the to gizingcircuit may be traced from (+-) , polar ‘con tact .25 of relay Fwto the right, back contacts 26 stick bus 32', and holds up relayWN or ‘WR, ‘as 10; and 21 “of stepping relays -3V and 2V, front con the case may ‘be, during the time the energizing tact, 28 of relay 1 V, through the upper winding circuit for one or the other of these ‘relays is" of relay WN to (—). ‘ broken at the polar contact 25 of the line relay Each control relay ‘has a plurality of stick-cir F‘until line relay repeater FP closes its back 15. 15 cuits for maintaining it energized, if energized, contact 33. Relay X is v‘not energized vuntil relay underldifferent conditions. One ‘of these stick VP has‘operated following energization of relay circuits through the slower winding includes a PP, ‘and during this time relay‘WN or WR-pre back contact of the ‘corresponding stepping Irelay, viously energized will have time'to releaseTits this stick circuit in the case‘cf relay ‘WNFbeing armature. In this connection, it may be' stated 'readily traced from-(~14), through back contact that the purpose of using the relay X,‘ rather than‘ 30 of relay 1 V, front contact 31 of‘relay WN,‘ and energizing the ‘stick bus 32 directly through the‘ lower winding of relay WN to (—). contacts of relay VP and the stepping relays is to All of the control relays also have stickcircuits provide an‘ additional relay operating time dur 25, through their upper windings connected toia ‘stick ingwhich the control relay, such as WN may re-‘ 25, bus 32 ‘which is energized through back contacts lease its armature; and in this respect, the use'of 33 and 34 of relays ‘FF and SA and front contact 35 of relay X in multiple. ‘ " Each control relay,‘except the‘ 1one ‘controlled 30. on the last step,‘ has a stick circuit through its lower winding including a front contact of the stepping relay next succeeding thestepping relay controlling the energization of such control relay. In the case ‘of control relay WN, this supple; 35.; mental stick‘circuit may Ibe‘traced from (+), through front contact 36 of stepping relay 2V, front ‘contact ‘31 of relay WN, and lower winding of relay WN to (~-). ‘ ' ‘ Considering now the sequence of operation,‘ and ' referring to-Fig. 3 ‘for explanatory purposes,as— 40 ‘ sume that the last switch control code was plus such a'relay X is optional. “ ‘ Following the energization period during which‘ the control relay WN or WR is conditioned, in accordance with the polarity of such energization, 30:, as just described, the opening of ‘the line circ‘uit and de-energization of relays‘ F and FF ‘cause energization of the next steppingrelay ‘2V, which closes through its front contact .36 the supple‘ mental stick circuit‘to hold ‘up WN or‘ WR until the end of the cycle. Relay 2V also opens‘ at its back contact 4| the energizing circuit 'for relay X and causes this relay to release its armature preparatory to‘ the control of another control relay, such as RD, ‘during the next succeeding 40. energization period. t ‘ to energize relay WN ‘and cause the switch‘ ma chine to assume its normalp-osition, and suppose steps as desired; and in the same manner as‘ that the operator sets the‘ switch‘lever to the‘ reverse position ‘and initiates‘ the ‘operation of described a ‘pair of control ‘relays, such‘as WN or WR, may be selectivelyconditioned on each lays F, FP, SA, and VP are energized, and-when, relays F ‘and FF are ‘dc-energized, following this tion of the steppingand control line circuit. In conditioning period, the first. stepping relay IV ‘This breaks the ‘stick circuit for control relay RD is energized by a positive impulse on the second step, and the signal control relay‘ " relays WN and WR through the back contact '30 LD by a positive impulse on the third step. a This isno ‘the system. During'the conditioning period,‘re is energized. of relay 1V; 'but relay is de-energized at this time ‘and the ‘stick ‘bus 32 is energized through back contact 33 of relay FP to maintain relay WN 55; energized by its stick circuit through its upper " winding. When the line circuit is again ‘closed and energized ‘with a minus polarity correspond ing to the switch lever in the re‘ver‘se position as assumed, the energizing vcircuit for ‘relay WN is contact 25. of the line not closed, sincethe polar or’ relay F moves to the left; but a similarL‘pick-up circuit for ‘energizing the-relay WR is established. When the line relay repeater relay FP picks .up and opens ‘its back contact’ 33, the stick bus 32 , is de-energized andtthe relay WN releases its ‘ armature.‘ ' ' It can be seen that ‘when the ‘lirie‘cir‘cuit is opened, after transmission, of‘this control impulse, the line relay F assumes its de-energized condi 7,10 tion and opens the energizing or pick-up circuit ‘This'same operation is repeated for as‘ many step in accordance with the polarity'of energize the particular arrangement illustrated, the signal arrangement is ‘merely illustrative of how a single relay may be energized or not on a particular's‘tep depending upon the polarity of ‘the control ‘im pulse.‘ 1 ‘ ' ‘ ‘~ ‘I ‘ Y The circuits governed by control relays, such as WN and WE, are preferably organized inac cordance with this invention, ‘so that a'relay of each pair-for opposite or conflicting conditions must be energized whilethe other is de-energizedi 60 in order to produce a controlling conditioiiithere being no control exercised if ‘both of these relays are either energized or ?le-energized. For eX-' ample, in‘ the particular arrangement illustrated, the'i‘switch machineSM is'assumed to ‘be con str‘uctedto respond to‘ the polarity of energiza ti‘on of’ its ‘control Wires ‘N and B, ‘being pro’ vided‘with‘a polarized master relay :as disclosed,‘ for'example, in the ‘patent to W. K. Howe, No. 1,975,135, granted October 2, 1934. , to maintain energized the control relay that was‘ With such an arrangement, if the control relay 70‘ WNis ‘energized and the other controlrelay WR.‘ is de-energized, the control circuit for the'switchl machine is energized with‘ one polarity‘ior-the energized by the control impulse, relay Xrandits normalposition through contacts 46 and “of “ for relays WN or WR, as the ‘case may be, ‘before the line "repeater relay F‘P closes its back‘ con~ tact to energize the stick bus ‘32; and in order 4 2,116,177 these relays, and if relay WR is energized while relay WN is de-energized, the switch machine control circuit is energized with the opposite polarity for the reverse position; but if both re lays WN and WR are either energized or de-ener gized, the switch machine control circuit is not energized and the switch machine remains in its existing condition. The signal clearing circuits are similarly con trolled by contacts on the control relays RD and 10 LD; and these signal clearing circuits are also controlled by the switch control relays WN and WR in opposite conditions, so that no signal ‘clearing circuit is established, if both relays WN 15 and WR, or both relays RD and LD, are either energized or tie-energized. For example, taking the signal clearing circuit for signal IA as typi cal, this circuit may be traced from (+), through back contact 48 of relay LD, front contact 49 of 20 relay RD, front contact 50 of relay WN, back contact 5| of relay WR, and thence through con tacts (not shown) of a suitable point detector or switch position relay closed only if the switch points are over and locked ‘m the corresponding 25 normal position, with such other control of the clearing of the signal in accordance with traffic conditions, as may be desirable in accordance with the common, practice in signalling systems of this character, such control of the signals in 30? accordance with the positions of the switch point and the like being omitted. In the particular arrangement shown, the pick up and stick circuits for the signal control relays LD and RD include a front contact 52 of the de tector track relay T, in multiple with a back con tact 53 of the slow-release repeater TP of this track relay, in the manner characteristic of the disclosure in other prior applications, such as R. F. Wells, Ser. No. 634,370, ?led September 22, I932, so that the passage of a train de-energizes the relay LD or RD to cause the signals to assume the stop condition and remain at stop until cleared by some subsequent code, while permit ting energization of these relays by a signal clear ing code while the detector track circuit is occu 45 pied. Either signal control relay LD or RD, if energized to clear a signal, may be de-energized by the operator by sending a control code having an impulse on the respective steps controlling re lays RD and LD of a polarity which does not close 50 the energizing circuits for these relays. From the foregoing it can be seen that, in ac cordance with this invention, the control relays governing the switch machines and signals at a ?eld location are directly responsive to the char acter of the successive code impulses, and are se lectively energized or de-energized successively as the impulses of the control code are transmitted, so that no additional decoding relays are required to register the control code step by step as trans 60 mitted prior to the conditioning of the switch and signal control relays. Even though the control relays are thus directly controlled, each control relay is positively rendered dependent upon the character of the corresponding control impulse, 65 because it is a neutral relay and assumes its de energized condition when its stick circuits are broken, unless an energizing or pick-up circuit is established. If such energizing or maintaining circuit for any control relay is not established on 70 account of broken wires or bad contacts, such ling condition of the ?eld equipment, rather than some controlling condition different from that transmitted. Also, in accordance with this improvement, the pick-up or sustaining circuit for each control re lay is established before its stick circuits are broken, so that a control relay does not release its armature even temporarily if the same control code is repeated. This feature is desirable, par ticularly in connection with the signal control re 10 lays RD and LD, because a temporary de-ener gization of one of these relays upon a repetition of the same signal clearing code might give a stop indication to confuse the engineer of an ap proaching train, particularly if color light signals 15 are used. In the organization of Fig. 1, just described, it is assumed that the desired controls are trans mitted on each operating cycle for governing the control relays WN, WR, RD and LD illustrated, but in applying this invention to a multiple sta tion system of the so-called duplex type, such as disclosed for example, in the application of Preston and Hitchcock, Ser. No. 455,304, ?led May 24, 1930, there are conditions under which the 25 ?eld station apparatus, including the stepping re lays, operates at a time when the proper controls for covering the control relays WN, WR, etc. are not applied to the stepping and control line cir cuit. Under such circumstances, it is necessary 30 to provide means for holding the control relays WN, WR, etc. in their existing condition, except when controls are being transmitted to the par ticular control station in question; and such an arrangement is illustrated in Fig. 4. Referring to Fig. 4, it is contemplated that a relay or relays, such as the relay S0, is energized when controls are being transmitted to the par ticular control station for governing the control relays WN, WR, etc. The speci?c type of station selecting or identi?cation means is not material to the present invention; and the station selecting relay S0‘ for out-bound controls shown in Fig. 4, which is assumed to be governed in the manner disclosed in the above mentioned Preston and 45 Hitchcock application, Ser. No. 455,304, is merely typical. Assuming such a suitable station selecting or identifying relay SO as shown in Fig. 4, the stick bus 32 for the control relay WN, WR, etc. is energized through a back contact 55 of this re lay SO, and is connected to the bus wire 321 extending to the contacts 33, 34 and 35 of the relays FP, SA, and X. Also, the energizing 'cir cuits for the control relays WN, WR, etc. through the polar contact 25 of the line relay F includes 55 the'front contact 55 of the relay SO. During the station selecting steps, during which the con— tinued energization of relay S0 is determined, control relay WN or WR, as the case may be, is maintained energized by its stick circuit through the back contact of the stepping relay aV, corresponding to stepping relay IV of Fig. 1. Control relays RD and LD, and such others as may be employed, are similarly maintained energized by the stick circuits through the back 55 contacts of the corresponding stepping relays bV, cV, and the like. If the control station in ques tion is not called to receive new controls, relay S0 is de-energized when the stepping relays aV, bV, etc. are operated, and the control relays WN 70 control relay assumes its de-energized or non and WR are maintained in their existing con controlling condition, rather than remaining in the condition where last put. Consequently, cir dition by their stick circuits energized from the stick bus 32, and no current is supplied to their 75 cuitfailures produce an inactive or non-control energizing circuits since the front contact 550i 15 When the station is called to establishing an energizing circuit for relay WR, receive new controls, however, relay SO‘is ener g‘ized at the time the stepping relay (W and the others for the ‘control steps are energized; and relay S0 is open. and at the same time interrupting the supply of current to the stick bus 13. Relay WN then under these conditions current is supplied to the polar ‘ contact 25 of the line relay F, and the ener gization‘of the stick bus 32 is controlled by relays FP, SA, and X, so that the control relays WN, WR, etc. are set‘or conditioned in accordance with the control code in the same manner al ready described. Fig. 5 illustrates a modi?cation in which the line relay F1 and the stepping relays aV, bV, etc. are equipped‘ with, special make-before-break or continuity contacts in such away as to simpli fy the circuit organization as illustrated in Fig. 1. The"arniature 60 of the line relay F1, pivoted at‘ its center, and biased by a spring 6| to the its de-energized position, after the transmission of the control impulse in question, its contact 10 ?nger 64 energizes the stick bus 14 and the stick circuit for relay WR now up, before the energiz ing circuit for relay WR is broken, clue to the make-before-‘break construction of the‘contacts associated with said contact ?nger 64. During 15 this de-energ'ization period, the next stepping re lay bV is energized, and in this modi?cation the stick circuit for the next preceding step relay aV includes a back contact 15 of the stepping re rocked and/moves a contact driver 62 to the right nately shifted‘ from‘the position shown to a dotted line position by the driver 62 as the line relay is energized with current of opposite polarity, and open and close contacts suitably constructed, as lay bV, so that stepping relay av drops and closes the stick circuit for relay WR at its back contact 73, this stick circuit being closed prior to the interruption of ‘the ‘stick circuit to the stick bus 74, due to the make-bBfore-break construction of ‘these front and back contacts. ‘This same plan of operation takes place for as many ‘steps as indicated diagrammatically, to be make-before ‘desired. break. Other contact ?ngers 65 supply current to the line relay repeater FP whenever the‘ line a relay F1‘ is energized with current of either polar ity. ‘The control relays WN, WR, and ‘such others as vrnay be used, have pick-up or energiz ing circuits through their lower windings, which are supplied with current through the contact as ?ngers 6'3 and 64, with relay SO energized and its front contact 66 closed, when the polar line re lay‘ F1 is “energized, in substantially the same'way as shown in Fig. 1. The energizing circuit‘ for ' The modi?cation of Fig. 5 employs make-be fore-break contacts on they polar line relay and on the stepping‘ relays, so as to obtain‘the de sired overlapping ‘or continuity of the pick-up and stickci‘rcuits for the control relays, rather than dependent upon the sequence of relay op~ eration as in the arrangement of Fig. 1. This modi?cation of Fig. 5 has the various character , istic features and advantages already explained for the arrangement shown in Fig. l, the ‘control relays being set or conditioned, if‘ at all, in ac WN, for example, may be traced from (-1-) , front co‘rclan‘ce“ with'the control impulse actually‘r'ee 63 in the energized dotted position, wire 69, back ceive‘d,rwithout relying upon the integrity of any “a circuit, so that broken wires and‘bad contacts to contact ‘65 of relay SO, wire 61, contact ?nger ' contacts ‘Ill and ‘II, of stepping relays 0V and 12V, front contact‘ 12 of stepping relay aV, lower winding of relay WN to- (—-). 45 upper winding being broken at the contact 64 of line‘ relay F1, and the energizing circuit through its lower winding being opened at the contact 63 of said line‘ relay. When line relay Fl assumes intermediate de-energized position‘ shown, is ‘or left, dependent upon the polarity of energiza tion. Spring contact ?ngers 63, 64 are alter a ‘releases its‘ armature, its stick circuit through its The two control relays for each step, such as WN and WR, have stick circuits including a back contact, as 13, of the corresponding stepping relay; and this contact of the stepping relay has a make-before-break front contact connected to a stick bus 14. When the station is not being called and relay S0 is de-energized, this stick bus 74 is permanently energized through the back contact 66 of the relay SO. When the station is being called, this stick bus is energized through 55 the front contact 66 of relay SO, wire 61, contact ?nger B3 of relay F1 in the de-energized position, wire 68, and contact ?nger B4 in the de-energized position. Considering the operation of this modi?cation shown in Fig. 5, assume that relay WN is ener gized, and that an impulse of opposite polarity is transmitted to the particular station in question on step aV for the purpose of de-energizing relay WN and energizing relay WR. During the 65 de-energization period of the line circuit next preceding the control impulse in question, the stepping relay aV is energized, breaking at its back contact 13 the stick circuit for WN, but simultaneously connecting this stick circuit to the 70 stick bus 14, which at this time is energized through contacts of the line relay F1 and front contact 66 of relay SO. When the impulse of the selected polarity in question is applied to the line circuit and line relay F1 is energized, its contact 75 ?nger 64 moves to the left in the case assumed, produce ‘a' non-controlling condition, rather than a controlling condition inconsistent with the con trol received. In this connection, it may be pointed out that in both of the arrangements 45 of Figs. 1 and 5, if the line relay during a given stepping interval should, for any reason, due to line surges or the like, shift its contacts quickly from one position to the other and simulate the condition of con?icting controls, the simulta 50 neous energization of the pair of control relays for that step, such as relays WN and WR by such improper double controls, if this should occur, is a non-controlling condition. Various adaptations, and modi?cations may 55 be made in the particular arrangement of de vices and circuits shown and described as ex~ emplifying the invention, without departing from the fundamental functions and advantages of the invention; and means for receiving or reg 60 istering controls in a centralized traf?c control system, in accordance with this invention, may be employed in conjunction with various other features of a complete system. What I claim is:— 1. In a remote control system of the multiple impulse or code type, an organization for regis tering controls transmitted to govern the oper ation of movable devices comprising, line wires for transmitting a series of code conditions each controllable in character, step-by-step means op erable to take one step for each code condition, a pair of neutral control relays associated with a particular step and each having energizing cir~ cuits, means for selectively energizing the en 6 2,116,177 ergizing circuit for one or the other of said con trol relays on said particular step dependent upon the character of the code condition for that step, ?rst and second stick circuits for each of said control relays, means for opening said ?rst stick circuits only while said step-by-step means is operated for said particular step, and means for energizing said second stick circuits while said step-by-step means is thus operated for said 10 particular step except for a time while one of said energizing circuits is closed. ' 2. In a remote control system of the charac ter described, line wires energized distinctively to provide code impulses of different characters, a series of stepping relays, means for sequen tially energizing said stepping relays one at a time for successive energizations of said line wires irrespective of the character of the im pulses, a pair of neutral control relays associ 20 ated with a particular step, means for energiz ing said control relays selectively in accordance with the character of the code impulse being transmitted, means for maintaining said control relays energized at all other times except while 25 they are being thus conditioned in accordance with the character of the code impulse then be ing transmitted, and circuits governing the op eration of a movable device closed only if said control relays are in opposite conditions of ener 30 gization and de-energization. 3. In a remote control system; a stepping and control line circuit selectively energized with a series of positive and/or negative impulses; a polar line relay included in said line circuit; a 35 neutral line repeating relay energized each time said polar line relay is energized irrespective of the character of the impulse; a series of step ping relays, means for energizing said stepping relays sequentially, one each time said line re peater relay is deenergized; a pair of control relays for each step; an energizing circuit for each control relay including a front contact of the corresponding stepping relay and a partic ular polar contact of said polar line relay so that one or the other of a pair of control relays is en ergized, while their stepping relay is picked up, dependent upon the polarity of the impulse then energizing said polar line relay; stick circuit means for maintaining said control relays ener gized, if picked up, at all times except a portion of that time while they are being conditioned in accordance with the polarity of the impulse transmitted while their respective stepping re .10 lays are picked up; electro-responsive means for each pair of control relays; and circuit means governing the operation of each electro-respon sive device closed only if its said pair of control relays are in opposite conditions of energization 15 and d'eenergization. 4. In a communication system of the remote control type; a line circuit having different se ries of time spaced characteristic impulses trans mitted thereover; a line relay included in said 2,0 line circuit; step-by-step means controlled by said line relay to take one step for each of said impulses; a pair of control relays associated with a particular step; ?rst and second stick circuits for each of said control relays; means controlled 25 by said step-by-step means for opening said ?rst stick circuits during said particular step and at other times closing such stick circuits; means ef fective while an impulse is being transmitted during said particular step for momentarily 30 opening said second stick circuits; station iden tifying means rendered effective. only during par ticular ‘ones of said di?erent series of impulses; means controlled by the character of the im' pulse during said particular step, only if said 35 station identifying means is rendered effective,for selectively energizing one or the other of said control relays during the time that both said ?rst and second stick circuits are opened; and means controlled by said station identifying 40 means, while rendered ineffective, for maintain- ‘ ing said second stick circuits closed. NEIL D. PRESTON.