US2176040A - Centralized traffic controlling system for railroads - Google Patents

Description

F. w. BRIXNER ,1 ,040

CENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed Dec. 30, 1936 4 Sheets-Sheet 1 Oct. 10, 1939.

.GQZQ 120m v1 3 2 Q Y R 29$ m 1T R m 2 n w m QQ W W 3 (U l T m A hm u 3 m 3% H 3 7 AR! v 25 um 2 v Oct. 10, 1939. F. w. BRIXNER CENTRALIIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed Dec. 50, 1936 4 Sheets-Sheet 2 mcoq .6 tozn 2 S 09 mac .0 toxn 292. m io ATTORNEY Q2 5 w s a Patented Oct. 10, 1939 UNITED STATES PATENT ()FFICE OENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Application December 30, 1936, Serial No. 118,337

7 Claims.

This invention relates to centralized traffic controlling system for railroads, and it more par ticularly pertains to the communication part of such systems.

The present invention contemplates a centralized trafiic controlling system in which communication is established between a control ofiice and a large number of outlying field stations by means of a communication system of the twowire selective coded simplex type. The switches and signals at a plurality of stations located along the railroad track are controlled from the control ofiice by the coded impulses applied to the two-wire line circuit. 7

The switches and signals are under the supervision of the operator at the control ofiice so that the condition of such switches, signals and various other traffic controlling devices at the distant stations will be transmitted to the control oifice for providing the operator with the necessary information for governing train movements. In a system of this type, a series of impulses forming a particular code combination is transmitted over the line circuit for the selection of a particular field station and the transmission of controls to the selected station.

Similarly, a series of impulses forming a particular code combination is transmitted over the line circuit for the registration of a field station in the control office and the transmission of indications from the sending station. The control and'indication circuits areso interrelated in the system that controls and indications are transmitted on separate cycles of operation, in other .WOldS, the system is of the simplex type. Since the present invention is more particularly directed to outbound code transmission, that is, the trans-- mission of control codes, and since numerous forms of indication transmission may be used in the present system, the drawings and the description will be limited to the control functions of centralized trafiic controlling system.

The circuits are so organized, that, during a control cycle, the control office acts as the driver of the system, placing the proper polarity from a control office line battery on the line circuit and creating long and short energized and deenergized portions at each step of the system, as.

time they will be executed, provided the station has been selected during this cycle.

In the present system, polar impulses are used for station selection, that is, each energization of the line is positive or negative. For function control the capacity of the system is increased by making the energized periodof a step either long or short, thus giving a choice of two for each energized period and thedeenergized period for each step is made either long or short, thus giving a choice of .two more for each step. These four combinations, plus the choice of two provided by the positive or negative line energization for each step, gives a total capacity of six code combinations for each step of the system. c

The polarity of the impulses during the transmission of controls is determined in the control ofiice by reversibly connecting the line battery to the line circuit. The control ofilce acts as the driver or the impulser, and makes the impulse or energized portion of the impulses either long or short, as well as making the deenergized or time space portion of the impulses either long or short.

The above mentioned characteristic features and additional features of the present invention will be explained more in detail in the following description and various advantages of the invention will be inpart pointed out and in part apparent as the descriptionprogresses.

In describing the invention in detail reference will be made to the accompanying drawings which illustrate one method of carrying out the invention by way of example. The drawings illustrate, in a diagrammaticmanner, the apparatus and circuits employed" and for convenience in describing the invention in detail those parts having similar features and functions are designated in the various views by like letter reference characters, generally made distinctive either by reason of distinctive exponents representative of their location in the system or by reason of distinctive preceding numerals representative of the order of their operation and in which:--

Figs. 1A and 1B placed end to end in the order named and with correspondingly numered lines in alignment, illustrate in schematic form the apparatus and circuit arrangements employed at a typical control oflice embodying the present invention.

Figs. 2A and 2B placed end to end in'the order named and with correspondingly numbered lines in alignment, illustrate the'apparatus and circuit arrangment employed at a typical field station embodying the present invention.

The illustrations in the drawings are schematic 55 and abbreviated for the purpose of clearness and simplicity. In following the detailed operation of the system for the transmission of controls, Fig. 2A should be placed to the right of Fig. 1B with the line and return conductors in alignment.

The arrangement of those parts of the system which are not illustrated in the drawings and their cooperation with the illustrated portions will be set forth in the following general description. After the general description a detailed analysis of the transmission of controls from the control oflice will be given.

GENERAL DESCRIPTION The symbols and are employed to indicate the positive and negative terminals respectively of suitable batteries or other sources of direct current and the circuits with which these symbols are used always have current flowing in the same direction, that is, from to outside of the battery itself.

For convenience in describing the operation of the system the two line wires connecting the control office with the stations are identified by referring to them as the line and return conductors. These two conductors extend in series through all of the field stations and are normally connected together at the end station by means of back contact 200 of relay L0 illustrated in the upper right hand portion of Fig. 2B.

In considering the organization of the line circuit, it will be understood that additional field stations may be connected in series therewith, between the control office and the illustrated station or between the illustrated station and the end station. For convenience in describing the step-by-step operation of the system and the coding operations at the various steps, the impulse or energized periods of the line circuit will be referred to as the on periods and the space periods between impulses (deenergized periods of the line) will be referred to as the o periods.

Control oflice equipment.-The control office (Figs. 1A and 13) includes a quick acting line relay F and a quick acting line repeater relay FP, the former repeating the impulses applied to the line circuit and the latter repeating the operations of relay F during a cycle of operations. Slow acting relays SA, SB and SC are picked up in sequence at the beginning of each cycle and are dropped out in sequence at the end of each cycle. Relay SA has such slow acting characteristics that it does not drop between successive on periods during a cycle, since these on periods follow each other at a sufficiently rapid rate to intermittently energize relay SA (by the intermittent operation of relay FP), so that it does not have time to drop between periods of its energizaion. Relay SB is a direct repeater of relay SA and relay SC is a direct repeater of relay SB, consequently these two relays remain picked up as long as relay SA is picked up.

The impulses of a cycle effect the step-bystep operation of the stepping relay bank, comprising stepping relays IV, 2V, 3V, 4V and LV and a half-step relay VP. This stepping relay bank is arranged so that a separate stepping relay is picked up during each off period and the half-step relay shifts its position, alternately picking up and dropping, during each on period.

Impulse and impulse timing relays IE, 2E and 3E are controlled by the stepping relay bank in such a way that the impulses in the line circuit are made abnormally short or normally long as determined by whether or not code sending relay PF is picked up or not respectively at each step. Relays lE, 2E and 3E also time the off periods by making them abnormally long or normally short as determined by whether or not code sending relay P13 is picked up or not respectively at each step. An off period is made abnormally long by including the drop away times of relays PT and PB, as will be more specifically pointed out in the detailed description. An on period is made abnormally short by picking up relay PF and consequently opening the line without waiting for the IE, 2E and 3E operations.

Polarity control relays PC and NC are for the purpose of applying and impulses respectively to the line circuit in accordance with selected codes. Code determining relay CD is one of a bank of such relays which are so interconnected that the momentary depression of a starting button STB picks up the associated start relay CH, which in turn picks up the associated relay CD for initiating the system and selecting the code to be applied during the resulting cycle. The interconnection of the CD and CH relays is such that the rapid successive operations of a plurality of starting buttons are stored, but only one CD relay is permitted to be picked up at any one time. Since this feature is immaterial to an understanding of the present invention it is not shown in detail, it having been completely disclosed in the prior application of N. D. Preston, et al., Ser. No. 455,304, filed May 24, 1930, corresponding to Australian Patent 1501 of 1931.

As typical of the control levers located in the control ofiice, switch machine levers ISML and ZSML are shown. These levers are for the purpose of governing track switches ITS and ZTS as the illustrated field station, which field station is assumed to be selected when relay CD of Fig. 1A is picked up, as determined by the particular connection of code jumpers l0 and II. It will be understood that additional levers for controlling the signals at the stations will be provided, but it is not believed necessary to complicate the drawings by showing this additional equipment, since the operations controlled by levers lSML and ZSML are typical of the operations controlled by additional levers.

Cycle controlling relay C is picked up to initiate a control cycle, this relay remaining up during each control cycle and, although not illustrated, it prevents a field start condition being initiated, as well as controlling the energy for the polar control selection circuits as will be pointed out in detail.

A track diagram comprising miniature track switches its and 215s, corresponding to track switches ITS and ZTS respectively at the field station, and an OS lamp OSL, are provided, but control of these miniature track switches and the OS lamp is omitted since no portion of indication transmission is included in the present disclosure.

Field station equipment.The field station (Figs. 2A and 2B) includes a quick acting line relay F of the biased to neutral polar type and it is assumed that the polar contacts of this relay are operated to the right when a impulse is applied to the line conductor and to the left (normal condition as illustrated) when a impulse is applied to the line conductor. Quick acting line repeating relay FP repeats the impulse in the line circuit irrespective of their polarities. Slow acting relays SA and SE correspond to similar relays in the control oflice and are used to define the bounds of an operating cycle, since they are picked up at the beginning of each cycle and are dropped at the end of each cycle.

A stepping relay bank, including relays 1V 2V 3V 4V and VP, is provided and which operates in synchronism with the corresponding relays of the control ofiice stepping relay bank. Executing relay EX is a last step relay corresponding to relay LV in the control office, but as will be described in detail it is for the purpose of executing stored controls.

Track switches [TS and ZTS are operated by switch machines ISM and 2SM respectively in accordance with the switch controls transmitted over the line circuit, which selectively position switch machine relays ISMR and 2SMR Suitable signals are also provided (not shown) for governing trafiic over the illustrated track section and their control is in accordance with suitable automatic signalling, in cooperation with manual signalling controlled over the communication system. Since this signal control is accomplished at the various steps of the cycle in a manner similar to that shown for controlling the switch machine operation, it is believed unnecessary to illustrate this portion of the systern.

Since indication transmission is not illustrated in the present disclosure, the usual track batteries and track relays and the usual switch machine repeating relays and the like are not shown at the illustrated field station.

Relays CF CB MF and MB illustrated in 2A are for the purpose of registering and storing the lengths of the on and off periods in accordance with the codes which determine the lengths of these periods. The detailed operation of these relays will be explained later. During the transmission of polar controls for station selection the lengths of the on and off periods during these same steps are registered by relays such as ONS and OFS until the execution period after station selection, when the code stored on these storing relays is executed to the function control relays such as ISMR and 2SMR Station identification relay S and its cooperating stick relay SOS are shown in Fig. 2A to illustrate the station selection feature, whereby controls are only transmittedto the function control relays after the station selection portion of the cycle and only at one station, which one station has its relay corresponding to S0 picked up.

OPERATION In the accompanying drawings the system is illustrated as being in its normal condition, from which it may be initiated for the transmission of controls by the operation of starting button STB (see Fig. 1A). The two-wire line circuit is normally energized with negative potential applied to the line conductor so that line relay F in the control office is picked up and the polar line relays at the stations have their polar contacts positioned to the left. The normally energized line circuit provides means whereby the system may be initiated from a field station for the transmission of indications (not shown in the present disclosure), by opening the normally energized line circuit for registering a field start in the control office by dropping normally picked up relay F, as shown, for example, in the British Patent No. 425,925 dated November 20, 1932.

A cycle of operations for the transmission of controls is started by quickly changing the negative line energization to a positive line energization, which registers in the control office and at the various field stations the condition that the following cycle is for the transmission of controls.

Normal condition. The line circuit is normally energized over a circuit traced from the terminal of line battery LB (Fig. 1A), back contact l2 of relay PC, front contact I3 of relay NC, return conductor l4, back contact 200 of relay LO at the end station, line conductor H4, winding of relay F line conductor H5, winding of relay F, conductor l5, back contacts 61, 66 and 65 of relays PF, PB and IE respectively, front contact 64 of relay 2E, back contact l6 of relay 3E, front contact I! of relay NC and back contact 3 of relay PC, to the terminal of battery LB. This negative line energization actuates the line relays as above described.

Relay 2E in the control office is normally energized over an obvious circuit completed at back contact IQ of relay E. Relay PT in the control ofiice is normally energized over an obvious circuit completed at back contact 28 of relay PB. Relay NC in the control office is normally energized over a circuit extending from back contact 2i of relay C, back contact 22 of relay SC and winding of relay NC, to

Relay MB at the field station is normally energized over an obvious circuit completed at back contact I09 of relay CB Relay CF at the field station is normally energized over an obvious circuit completed at back contact llll of relay FP All other neutral relays are normally deenergized and it will be understood that the mag stick relays illustrated in Fig. 2B, have their contacts illustrated in their right hand positions,

because of the construction of these relays whereby they maintain their contacts in their last operated positions after the associated relays are deenergized.

Manual start.The operation of button STB for initiating a control cycle closes an obvious circuit for picking up relay CH. Relay CH closes a stick circuit for itself extending from back contact 22 0f relay CD, front contact 23 and winding of relay CH, to Relay CD is picked up over a circuit extending from back contact 25 of relay SB, back contact 25 of relay LS, front contact 26 of relay CH and lower Winding of relay CD, to Relay CD closes a stick circuit for itself extending from back contact 2'! of relay LV, conductor 28, winding of relay LS, front contact 29 and upper winding of relay CD, to

The opening of back contact 22 of relay CD deenergizes and drops relay CH. Relay LS is picked up over the stick circuit above described for relay CD and relay LS in turn opens the pick up circuits for other CD relays at back contact 25, so that other stored office start conditions, manifested by other CH relays being picked up, are ineffective to pick up the associated CD relays during this cycle of operations.

Relay C is picked up over a circuit extending from back contact 24 of relay SB, front contact 25 of relay LS and winding of relay C, to described normally energized circuit of relay NC at back contact 2|, which releases relay NC. Relay PC is picked up over a circuit extending from front contact 2I of relay C, conductor 35, back contacts 3|, 32, 33 and 34 of relays 4V, 3V, 2V and IV respectively, conductor 35 and winding of relay PC, to

The dropping of relay NC and the picking up of relay PC reverses the connection from battery LB to the line circuit, so that this line is now energized with a positive potential by way of pole changing contacts I2, I3, IT and I8. This quick reversal of "current in the line circuit is effective to momentarily drop relay F, but this has no effect on the control ofiice circuits because the cycle demarking relays SA, SB and SC are not yet picked up so that the operation of the relay F is not repeated by the relay FP. Likewise the polar contacts of relay F are shifted to the right and its effect on the field station circuits will be later described.

Relay FP in the control ofilce is picked up over a circuit extending from front contact 35 of relay PC, conductor 36, front contact 37 of relay F and winding of relay FP, to Relay SA is picked up over a circuit extending from front contact 35 of relay PC, conductor 36, front contact 38 of relay FP, conductor 39 and winding of relay SA, to Relay SA completes a stick circuit for relay C which includes front contacts I3 and 93.

Relay SB is picked up over an obvious circuit completed at front contact 45 of relay SA and relay SC is picked up over an obvious circuit completed at front contact 24 of relay SB. The opening of back contact 22 of relay SC opens the above described normally energized circuit for relay NC, so that this circuit will not be completed at the end of the cycle until relay SC is dropped.

Referring to the field station, relays S and SOS are picked up over a circuit extending from back contact I02 of relay IV conductor I83, contact I04 of relay F in its right hand dotted position, conductor I05, back contacts I516, Ifil, I08 and I09 of relays 4V 3V 2V and IV respectively, conductor HE! and upper windings of relays SOS and S0 to Relay FP is picked up over a circuit extending from contact III of relay F in its right hand dotted position, front contact I I2 of relay S0 and winding of relay FP to Relay SA is picked up over an obvious circuit completed at front contact H3 of relay FP and relay SB is picked up over an obvious circuit completed at front contact H6 of relay SA The above operations effect the conditioning of the control office and field station circuits so that the following impulses are effective to operate the stepping relay banks in synchronism. It will be understood that the same operations as described in connection with the illustrated field station, take place at other field stations connected to the line circuit.

Line impulsing and stepping relay operations.--Although the description of the impulsing and stepping operations will be more particularly directed to Figs. 1A and IE, it will be understood that similar stepping operations take place at the field station illustrated in Figs. 2A and 2B and at other stations along the line. Contacts MI and I42 of relay FP correspond to contacts 4| and 42 of relay FP in the oifrce and the dotted line associating contacts I4I and I42 with the field station stepping relay bank indicates that this bank of stepping relays is controlled in the same manner that the stepping relay bank in the control ofiice is controlled by contacts 4! and 42. Therefore it is believed unnecessary to illustrate or describe the operation of the field station stepping relay bank in detail.

Relay VP is picked up in response to the picking up of relay SC over a circuit extending from front contact 43 of relay SC, conductor 44, front contact 4I of relay FP, back contact 45 of relay IV and winding of relay VP, to A first stick circuit for relay VP is completed which extends from on conductor 44, front contact 45 of relay VP, back contact 45 of relay IV and winding of relay VP, to

Relay IE is now picked up over a circuit extending from front contact 4? of relay SC, conductor 36, back contacts 48, 49, 50 and EI of relays 4V, 3V, 2V and IV respectively, front contact 52 of relay VP, conductor 53 and winding of relay IE, to The picking up of relay IE deenergizes relay 2E at back contact I 9 and relay 2E drops after a period of time determined by its slow acting characteristics. The dropping of relay 2E closes an obvious circuit for picking up relay 3E at back contact 54.

The picking up of relay 3E marks the end of the conditioning period and the beginning of the first off period, by deenergizing the line circuit at open back contact It. The deenergization of the line effects the dropping of relays F and F and because of open front contact 3! of relay F and open polar contact III of relay F relays PP and FP are dropped.

A second stick circuit is now closed for relay VP extending from front contact 43 of relay SC, conductor 44, back contact 4| of relay FP, front contact 55 and winding of relay VP, to Relay IV is now picked up over a circuit extending from on conductor 44, back contact 42 of relay FP, front contact 56 of relay VP, back contacts and 58 of relays 4V and 2V respectively and winding of relay IV, to Relay IV closes an obvious stick circuit for itself at its front contact 59. During the following operation, when relays 2V, 3V, 4V and LV are picked up in sequence, similar stick circuits are closed at their front contacts 63, GI, 62 and 63 respectively.

The picking up of relay IV deenergizes relay IE because the above described energizing circuit for this relay is now open at back contact 5I. The dropping of relay IE effects the picking up of relay 2E because of closed back contact I9 and the picking up of relay 2E effects the dropping of relay 3E because of open back contact 54.

This marks the end of the first off period and the beginning of the first on period by again energizing the line circuit at back contact I5 of relay 3E, completed through front contact 54 of relay 2E and. back contacts 65, 65 and 6'! of relays IE, PB and PF respectively. The energization of the line circuit effects the picking up of relays F, F, FP and FP over the previously described circuits. Relay VP is now dropped because its first stick circuit is open at back contact 45 of relay IV and its second stick circuit is open at back contact 4| of relay PP. The dropping of relay VP again completes the pick up circuit for relay IE, previously described but now extending through back contact 52 of relay VP and front contact 5I of relay IV. The picking up of relay IE and the consequent opening of its back contact I9 drops relay 2E and the closure of its back contact 54 picks up relay 3E.

This marks the end of the first on period and the beginning of the second off period by deenergizing the line circuit at open back contact l6. Relays F, FP, F and FP are released as before and relay 2V is picked up over a circuit extending from on conductor 44, back contact 42 of relay FP, back contact 56 of relay VP, back contact 68 of relay 3V, front contact 69 of relay IV and winding of relay 2V to The picking up of relay 2V deenergizes relay |E by opening the circuit at back contact 50. The dropping of relay |E again picks up relay 2E by way of back contact l9 and the picking up of relay 2E deenergizes relay 3E because of open back contact 54'.

This marks the end of the second off period and the beginning of the second on period by again energizing the line, which again picks up relays F, FP, F and PP. Relay VP is now picked up over a circuit extending from on conductor 44, front contact 4| of relay FP, back contact 10 of relay 3V, front contact ll of relay 2V and winding of relay VP, to Relay VP again closes its first stick circuit as previously described and relay |E is picked up by means of the circuit completed at front contact 52 of relay VP and front contact 55 of relay 2V. Relay 2E is now released because of openback contact l9 and relay SE is picked up because of closed back contact 54.

This marks the end of the second on period and the beginning of the third off period by again deenergizing the line circuit, which in turn drops. relays F, FP, F and PP. The second stick circuit for relay VP is again completed and relay 3V is picked up over a circuit extending from on conductor 44, back contact 42 of relay FP, front contact 55 of relay VP, back contact 5! of relay 4V, front contact 53 of relay 2V and winding of relay 3V, to Relay |E is now released because of open back contact 49 of relay 3V, relay 2E is now picked up because of closed back contact H] of relay IE and relay 3E is now dropped because of open back contact 54 of relay 2E.

This marks the end of the third off period and the beginning of the third on period by again energizing the line circuit, which in turn picks up relays F, FP, F and FF. Relay VP is again released because its first stick circuit is open at back contact if! of relay 3V, and its second stick circuit is open at back contact 4| of relay FP. Relay |E is again picked up because its circuit is now complete at back contact 52 of relay VP and front contact 49 of relay 3V. Relay 2151 is released and relay 3E is picked up because of open back contact 9 and closed back contact 54- respectively.

This marks the end of the third on period and the beginning of the fourth o-fi period by again deenergizing the line circuit, which in turn drops relays F, FP, F and FP Relay 4V is now picked up over a circuit extending from on conductor 44, back contact 42 of relay FP, back contact 55 of relay VP, front contact 68 of relay 3V and winding of relay 4V, to Relay IE is now released because of open back contact 48 of relay 4V, relay 2E is picked up because of closed back contact N of relay E and relay 3E is released because of open back contact 54 of relay 2E.

This marks the end of the fourth off period and the beginning of the fourth on period by again energizing the line circuit, which is effective to pick up relays F, FP, F and FE", Relay VP is now picked up over a circuit extending from on conductor 44, front contact 4| of relay FP, front contact 12 of relay 4V and winding of relay VP to The first stick circuit for relay. VP is again closed and relay IE is picked up because its circuit is completed at front contact 52 of relay VP and front contact 48 of relay 4V. Relay 2E is released because of open back contact I9 and relay SE is picked up because of closed back contact 54.

This marks the end of the fourth on period and the beginning of the clearing out off period by deenergizing the line circuit, which in turn drops relays F, FP, F and PP. Relay LV is now picked up over a circuit extending from on conductor 44, back contact 42 of relay FTP,

front contact 56 of relay VP, front contact 51 of relay 4V and winding of relay LV, to The picking up of relay LV effects the release of relays CD and LS because of open back contact 21 of relay LV.

The circuit for relay IE is not controlled by relay LV, as it was with the previous stepping relays, therefore relay IE is not dropped during this off period to cause the picking up of relay 2E and the dropping of relay 3E for again energizing the line. This makes the clearing out off period extremely long and, because relay FP remains down, the energizing circuit for relay SA is held open for an extremely long period at open front contact 38, which allows relay SA to drop. The dropping of relay SA and the consequent opening of its front contact 4|] releases relay SB and the opening of its front contact 24 releases relay SC. Relay SC removes energy from the stick circuits of the stepping and half-step relays at open front contact 43, so that these relays are released.

Relay IE is also released because of open front contact 41 of relay SC, relay PC being down at this time with its front contact 35 open. The dropping of relay IE picks up relay 2E because of closed back contact I9 and the picking up of relay 2E drops relay 3E because of open back contact, 54.

This marks the end of the clearing out off period and the beginning of the normal on period by again normally energizing the line. This energization is negative because relay C was dropped during the clearing out off period, by the opening of its stick circuit at front contact 13 of relay SA andthe dropping of relay C effected the release of relay PC or NO (which ever was picked up by the last code), by the opening of front contact 2|. Relay NC is picked up when relay SC drops to close its back contact 22, which again completes the normal energizing circuit for relay NC. This negative energization of the line again picks up relay F and positions the polar contacts of relay F to the left, which is the normal condition of the system.

As above mentioned, the field station steps through the cycle in a manner similar to that described for the oifice. Relay EX however, is picked up during the clearing out off period at the same time that relay LV picks up and by means of a similar circuit. Relay 5A is dropped during the clearing out period because of open front contact 3 of relay PP and relay SE is dropped because of open front contact N6 of relay SA The stepping and half-step relays are deenergized in a manner similar to the deenergization of these relays in the control ofiice. Assuming that the station illustrated is the one selected during this cycle, relay S0 will remain picked up throughout the cycle until the clearing out period'when it will be released by deenergizing its stick circuit at open front contact ll! of relay SE The SOS relay will be selectively operated and the SO relay will be maintained operated in a manner which will be described in connection with station selection.

Polarity selection of control impulsea-It has been described how the normal negative energization of the line circuit is changed to a positive energization for conditioning the office and field station circuits in response to the initiation of a control cycle.

It will now be assumed that the system steps through the cycle as previously described and an explanation will be given of how the polarity of each control impulse is determined.

Code jumper No. II in its illustrated position makes the first impulse (first on period) positive. This is because relay PC is energized during the preceding (first) olf period when relay iV picks up. In other words, the switching of contact 30, of relay IV from its back to its front point switches the on conductor 30 from conductor 35, by way of conductor 14, front contact 15 of relay CD, jumper l l, PC bus and winding of relay PC, to With relay PC up and relay NC down, the line is energized with a positive impulse by way of pole changing contacts l2, 23, If and I8 and over the circuit including the line and return conductors as previously described.

In the event that jumper l is connected in its alternate dotted line position, then relay NC would be picked up and relay PC would be down, which would result in applying a negative impulse to the line circuit.

When relay 2V is picked up during the second off period, the polarity of the second impulse is determined by the connection of code jumper l6 and as illustrated in Fig. 1A, relay NC will be picked up over a circuit extending from front contact 2! of relay C, conductor 30, back contacts 3| and 32 of relays 4V and 3V respectively, front contact 33 of relay 2V, conductor 16, front contact ll of relay CD, jumper Ill, NC bus and winding of relay NC, to

In the event that jumper H3 is in its alternate dotted line position, then relay PC would be picked up during the second off period for making the second impulse positive instead of negative. Although only two code jumpers are shown, it is believed that the typical example illustrated and described is suificient to indicate how the selection may be made on additional steps of the cycle, for rendering the impulses in the line circuit positive or negative, as determined by the code jumper connections selected by the particular CD relay which is picked up. These polar impulses are determined for the third and fourth steps (when these steps are used for applying polar impulses to the line), by selections No. 3 and No. 4 made at front contacts 32 and 3! of relays 3V and 6V respectively.

It will also be understood that, in the event of the station selection impulses being controlled on the first two steps of the cycle as indicated in the drawings, function control impulses on additional steps of the cycle can be made positive or negative, by extending the No. 3, No. 4 and the like channel circuits through front contacts of relay CD to control levers, which determine the polarity of these impulses in their normal and reverse positions, in the same way that they are determined by the two connections of the code jumpers. In the present disclosure, however, it is assumed that station selection is effected by the polarity of the first two control impulses.

From the above it will be apparent that different polar code combinations, comprising a choice of two per step may be used for selecting field stations and for controlling devices at the selected station.

Timing of control impuZses.The timing of the control impulses applied to the line circuit is illustrated as being determined by the positions of levers ISML and ZSML of Fig. LA, but it will be apparent from the previous description, as Well as the description which follows, that the timing of the impulses may be effective to provide station selection codes, since a choice of two is provided for each on period and another choice of two for each off period.

In the previous description of the stepping operations it was assumed that each off period was normally short. This because relay PB or Fig. 1A remains down, so that the line is closed to mark the end of each off period by the dropping of relay 3E and the consequent closing of its back contact i6. With levers iSML and 2SML in their illustrated positions no energy is applied to the channel circuits to which they are connected for picking up relay PB, thus the off periods coded by these two levers are normally short.

To illustrate how an off period may be abnormally long it will be assumed that lever ISML is in its reverse position. When relay iV picks up during the first off period a circuit is closed for picking up relay PB which extends from lever iSlVlL in its left hand dotted position, front contact 18 of relay CD, conductor 15', front contact 86 of relay lV, back contact 8! of relay 2V, front contact 82 of relay VP, back contact 83 of relay FP, conductor 54%, front contact 85 of relay PT and winding of relay PB, to The picking up of relay PB opens the line at another point, that is, back contact 85 of this relay so that the closure of back contact i6 is ineffective to energize the line, since front contact 9 of relay F is open at this time.

Relay PB remains picked up and the line remains open until slow acting relay PT drops and, by opening the circuit of relay PB at front contact 35, relay PB drops and closes up the line. Due to the time interval introduced by the release time of relays PT and PB, the off period is made abnormally long.

It will be observed that the dropping of relay PB again picks up relay PT because of closed back contact 28 and that the closure of front contact 85 again picks up relay PB. This line is not opened by the opening of back contact 56 this time, because relay F is up which closes a bridge path around contact 66 at front contact 9.

In the previous description the on periods were normally long because relay PF was not picked up, thus the end of each on period was not marked until relay 3E picked up, which, because of the time interval introduced by the slow dropping of relay 2E during each on period, results in these on periods being normally long.

To illustrate how an on period is made abnormally short, it will be assumed that lever ESML is in its reverse position. With relay lV picked up, a circuit is closed for picking up relay PF during the first on period, when relay VP drops, which circuit extends from contact of lever ZSML in its reverse position, front contact 85 of relay CD, conductor Si, front contact 83 of relay lV, back contact 89 of relay 2V, back contact 9!] of relay VP, front contact of relay FP, conductor 92 and winding of relay PF, to

The picking up of relay PF, immediately after the shifting of the VP relay, opens up the line circuit at back contact 61 without waiting for relay IE to pick up, relay 2E to drop and relay 3E to pick up for opening the line as previously described. This quick opening of the line circuit terminates the on period very shortly after the shift of the VP relay, which makes the on period comparatively short.

From the above examples it is believed apparent that any of the four off and on periods of the previously described cycle can be made short or long for coding the control impulses, either for station selection 'or for the transmission of controls to the selected station, as determined by the separate channel circuit selections made as illustrated in Fig. 1B, having the legends 01f controls short or long and on controls short or long applied thereto.

Station selection and transmission of controlsr-It was previously described how relays and S08 were picked up at the start of the cycle. With the first impulse as determined by jumper II and the second impulse as determined by jumper Ill, relay F is positioned to the right during the first on period and to the left during the second on period. The picking up of relay SB during the conditioning on period establishes a stick circuit for relay SO8 extending from front contact III of relay SE front contact H8 of relay FP front contact I IQ and lower winding of relay SOS to A stick circuit is also closed for relay S0 extending from front contact III of relay SB front contact I29 of relay SO8 front contact I EI and lower winding of relay S0 to The dropping of relay FP during the first off period drops relay $08 by opening the above described stick circuit at front contact I I8. At the same time that this stick circuit is opened, and before relay SOS drops, another stick circuit is closed for relay S0 extending from front contact III of relay SE back contact II 8 of relay FP front contact I2I and lower winding of relay S0 to During the first on period the actuation of the polar contacts of relay F to the right completes a pick up circuitfor relay SOS extending from front contact I22 of relay S0 contact IE4 of relay F in its right hand dotted position, conductor I05, back contacts I86, I67 and I08 of relays 4V 3V and 2V respectively, front contact I09 of relay IV code jumper I23 in its full line position, conductor H0 and upper windings of relays SOS and $0 to It will be observed that this pick up circuit for relay SOS is dependent on relay SO being picked up, this because relay IV has its back contact I92 open.

It will also be observed that this pick up circuit for relay SOS comprises an energizing and holding circuit for. relay S0 before relay FP drops and breaks the stick circuit for relay SO3 at front contact II8. Therefore, if the code jumper I23 is in its alternate dotted line position, relay SOS cannot be picked up and the stick circuit for relay S0 by way of front contact I28 of relay SOS is incomplete, so that the continued energization of relay S0 is made dependent on this selecting circuit including jumper I23. If this selecting circuit is incomplete and relay SOS is not picked up, then when relay FP opens its back contact H8 the stick circuit including this back contact for relay S0 is broken and this latter relay is dropped out.

In the example assumed, jumper I23 in' its full line position maintains relay S0 picked up and allows relay SO3 to'be picked up, after which the stick circuit for relay S0 is completed through front contacts I20 and I2I and the stick circuit for relay SOS is completed through front contacts H8 and II 9. This illustrates how the selection is made during the first on period and it will now be pointed out how relay S0 continues to be energized in response to the negative code applied to the line circuit during the second on? period.

. During the second off period, relay S0 is stuck up because of the closure of back contact N8 of relay F12 and relay SOS is dropped out because of open front contact H8. Relay 2V is picked up during the second off period and with relay F actuated to the left the above described circuit through the upper windings of the S08 and S0 relays is complete and may be traced from front contact I22 of relay S0 contact I94 of relay F in its left hand position, conductor I24, back contacts I 25 and I25 of relays dV and 3V respectively, front contact I21 of relay 2V jumper I28 in its full line position and conductor III! to the upper windings of the SO and SOS relays. Relay SOS is picked up and stuck up and relay S0 is stuck up as previously described. 'It will be obvious that, with jumper I28 in its alternate dotted line position, a positive impulse is required for the second on period to complete the above described circuit.

With the station selection made on the first two steps, then a permanent stick circuit (complete throughout thecycle) is completed during the next off period when relay 3V picks up, which stick circuit extends from front contact .I II of relay SB conductor I29, front contact I38 of relay 3V back contact IBI of relay EX conductor I32, front contact I IN and lower windingof relay S0 to Since the polar impulses of the first two steps are used for station selection, it becomes necessary to store the code comprising the short and long .off and on periods of these two steps, so that these codes may be executed to the function control relays after the station is selected and only at the selected station.

Lever ISML in its normal position determines that the first off period will be normally short as previously described. This means that relay FP at the station will be picked up for again energizing relay CB at front contact I95, before this relay had time to drop after its deenergization at open front contact Iill. It will be obvious of course that relay CB is picked up dur ing each on period and is only dropped out during the succeeding off period when this off period is abnormally long.

' 'The picking up of relay CB during the previous on period opens the pick up circuit of relay MB at back contact I00, but relay MB is stuck up over a circuit including front contacts I 33 and I34 of relays FP and MB respectively. During the short 0 period, both the pick up and stick circuits of relay M13 remain open at contacts I 33 and IIII] so that this relay drops and, since relay CB does not drop out, relay MB remains down. Then during the succeeding on period the condition of relay M28 is transferred by completing a circuit for the lower winding of relay OF'S which may be traced from front contact I 35 of relay Sl3 front contact I36 of relay S0 front contact I31 of relay F1 back contact I38 of relay MB conductor I39, back contacts I 43, I44 and I45 of relays 4V 3V and 2V respectively, front contact I46 of relay IV and lower winding of relay CF8 to Since relay OFS is of the mag stick type the energization of its lower winding positions its polar contacts to the right and they stay there until the end of the cycle. During the executing period switch control relay ISMR is energized to position its polar contacts to the right by means of a circuit extending from back contact I4! of relay SA front contact I48 of relay 8B front contact 49 of relay S0 conductor I50, front contact I55 of relay EX contact I5I of relay OFS in its right hand position and upper winding of relay ISMR to Polar contact I52 of relay ISMR. in its right hand position, controls the operation of switch machine ISM to its normal position.

In the event that lever ISML is in its reverse position, then the first off period would be abnormally long allowing relay CB to drop out during this off period for picking up relay MB by Way of back contact I50, after the stick circuit of relay MB is broken at front contact I33 of relay FP During the next succeeding on period the stick circuit for relay MB is completed at front contact I33 before relay CB is again picked up. This condition is transferred during the above mentioned succeeding on period by completing a circuit extending from at front contact I35 of relay SB and extending through front contact I38 of relay MB conductor I53, back contacts I54, I55 and I56 of relays 4V 3V and 2V respectively, front contact I5'I of relay W and upper winding of relay OFS to The energization of the upper winding of this relay positions its polar contacts to the left for energizing the lower winding of relay ISMR. during the executing period, which positions its polar contacts to the left for operating switch machine ISM to its reverse position.

With lever 2SML in its normal position the first on period is normally long as already described. Because relay FP remains picked up with its back contact IBI open for a comparatively long interval, relay CF, drops and closes a circuit for picking up relay MF extending from back contact I58 of relay CF and winding of relay ME to During the next succeeding off period the dropping of relay FP completes a stick circuit for relay ME by way of front contact I59 of relay MF before its pick up circuit is opened by the picking up of relay CF This condition is transferred during the above mentioned succeeding off period by energizing the upper winding of relay ONS over a circuit extending from front contact I35 of relay SE front contact I36 of relay S0 back contact I31 of relay FP front contact I60 of relay MF conductor IBi, back contacts I62, I63 and I64 of relays 5V 3V and 2V respectively, front contact I65 of relay IV and upper winding of relay ONS to Polar contact I66 of relay ONS is positioned to the right and an executing circuit is closed at the end of the cycle for energizing the lower Winding of relay ZSMR by way of contact I66 in its right hand position. Polar contact I61 of relay ZSMR controls the operation of switch machine ZSM to its normal position.

With lever ZSML in its reverse position, the first on" period is made abnormally short and relay C? does not have time to drop before relay FP closes its back contact IIJI and reenergizes this relay. Relay MP is released (if up) by the opening of its stick circuit at back contact I33 and is not again picked up because its pick up circuit is open at back contact I58. During the succeeding off period the lower winding of relay CNS is energized over a circuit extending through back contact I60 of relay MF conductor I68, back contacts I69, I10 and [ll of relays 5V 3V and 2V respectively, front contact I12 of relay IV and lower winding of relay ONS to Relay ONS operates its polar contacts to the left and during the execution period a circuit is completed through contact I66 in its left hand dotted position for energizing the upper winding of relay 2SMR which positions polar contact I51 to the left for operating switch machine 2SM to its reverse position.

It is believed that the above examples are sufficient to indicate how the various code combinations are provided at any number of steps, as determined by the capacity of the system to which the present invention is applied. It will be understood that, when a station is dropped out during the station selection portion of a cycle by the dropping of its associated SO relay, stepping does not take place at such station because the associated FP relay has its circuit maintained open at a front contact such as front contact H2 of relay S0 It will furthermore be observed that relay FF is not energized during the normal condition of the system, because contact III of relay F in its left hand position leads to open contact I13 of relay SE but during the cycle front contact H3 is closed, so that relay FF is operated irrespective of the position of polar contact ill of relay F as long as front contact H2 remains closed.

Having thus described one specific embodiment of a centralized traffic controlling system, it is desired to be understood that the particular arrangements illustrated and suggested are only typical of applicants invention and are not intended to indicate the exact circuit design and specific arrangement of parts necessary to carry out the features of the invention. This particular form has been chosen to facilitate in the disclosure rather than to limit the number of forms which the invention may assume and it is furthermore to be understood that various modifications may be made in order to meet the various problems encountered in practice, the system may be varied in the number of field stations and the amount of apparatus at each field station may be varied to suit local conditions, and any desired organization for the registration of a field station in the control office and the transmission of indications therefrom may be provided, all without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:

1. In a remote control system; a line circuit; a source of current connected to said line circuit; a polar line relay included in said line circuit; an impulse relay controlled by said line relay; means for at times opening and closing said line circuit and reversibly connecting said source of current thereto for producing a series of time spaced polar impulses having polar characters in accordance with different codes, said line relay being intermittently operated by said time spaced impulses dependent upon their polarity and said impulse relay being operated irrespective of their polarity; means for prolonging selected ones of said impulses and time spaces of said series; two slow release relays each having a release time less than said prolonged impulses and time spaces and greater than impulses and Iii) time spaces not prolonged; a pick up circuit for a first one of said slow release relays controlled by a back contact of said impulse relay; a pick up circuit for a, second one of said slow release relays controlled by a front contact of said impulse relay; a plurality of devices; a first register means selectively controlled 'by the polarity of said series of time spaced impulses so as to be rendered active only in response to a particular one of said difierent codes; a second register means selectively positioned by said first slow relay during said impulses of said seriesinaccordance with lengths of such impulses; a third register means selectively positioned by said second slow relay during time spaces between impulses of said series in accordance with the length of such spaces; and means for selectively controlling said plurality of devices at the end of said time spaced impulses in accordance with said second and said third register means only if said first register means is rendered active.

2. In a remote control system, control office and a field station connected by a single line circuit, transmitting means ,in said office for transmitting a series of time spaced positive and negative impulses over said line circuit, said impulses and said time spaces of said series all being selectively varied in length in accordance with controls to be transmitted and the polarity of the same impulses of said series being selected in accordance with a predetermined code pattern, step-by-step means at said station for operating through a cycle of operation in response to said impulses, means at said station for registering the length of the impulse and the length of the time space for each step, selecting means at said station distinctively conditioned only providing the polarity of said impulses for several steps conforms to a particular code pattern, a plurality of electro-responsive devices at said station, and means for controlling said electro-responsive devices at the end of an operating cycle in accordance with the registered lengths of said impulses and time spaces only providing said selecting means has been distinctively conditioned, whereby the reception of controls and distinctive conditioning in accordance with a code can be simultaneously accomplished.

3. In a remote control system, a control mice and a plurality of field stations connected by a single line circuit, means at said office for transmitting a series of time spaced positive or negative impulses over said line circuit, means at said office for varying the lengths of said impulses and the time spaces between such impulses in accordance with the controls to be transmitted to a particular station, said means also acting to determine the positive or negative polarity of the impulses in accordance with a code pattern assigned to that station, means at each of said stations for registering the lengths of the impulses and the lengths of the time spaces between said impulses, selecting means at each of said stations distinctively conditioned only provided said impulses conform in polarity to the code pattern assigned to that station, a plurality of electroresponsive means at each station, and means at each station for controlling said electro-responsive means at that station in accordance with the registered lengths of the impulses and time spaces at the end of said series of impulses only provided the selecting means at that station has been distinctively conditioned during such series of impulses by their positive and negative characteristics conforming to the code call for that station.

4. In a remote control system; a control office and a plurality of field stations connected by a line circuit; transmitting means at said control ofiice for transmitting different series of time spaced current impulses of selected polarities over said line circuit, the polarities of any given series being dependent upon the particular station to be selected for the reception of controls during that series of impulses; means at said control omce acting on said transmitting means during any given series for varying the lengths of said impulses and the time spaces between such impulses or" that given series in accordance with the controls for the field station to be selected for that series; storing means at each of said field stations for receiving and distinctively registering, only when rendered effective, the lengths of the impulses and the lengths of the time spaces between the impulses of any series; station selecting means at each of said field stations responsive only to the polarity of the impulses of a particular one of said different series for rendering erfective said storing means at that station; a plurality of power-operated devices at each of said field stations; and means at each of said field stations dependent upon the response of said station selecting means at that station to its particular one of said different series for distinctively operating the power-operated devices at that station in accordance with the lengths of the impulses and the lengths of the time spaces for that series as registered in said storing means.

5. In a remote control system; a control ofiice and a field station connected by a line circuit; transmitting means at said control office for transmitting a plurality of time spaced current impulses over said line circuit; means at said office for acting on said transmitting means to vary the polarity of said plurality of impulses, the lengths of said plurality of impulses, and the time spaces between said plurality of impulses; receiving means at said station responsive to said plurality of impulses on said line circuit and acting to store the lengths of said impulses and the time spaces between such impulses when such receiving means is rendered effective; selecting means controlled by the polarity of said plurality of impulses for rendering said receiving means effective; a plurality of devices at the field station; and means acting only after all of said plurality of impulses have been received and their polar characteristics have controlled said selecting means for distinctively and simultaneously controlling said devices. in accordance with the lengths of said plurality of impulses and the lengths of said time spaces between such impulses as stored in said receiving means.

6. In a remote control system; a control office and a plurality of field stations connected by a single line circuit; a source of direct current energy in said control ofiice; transmitting means at said control office alone for timing and impressing series of time spaced impulses of selected polarities on said line circuit from said source of energy; means at the control oflice acting on said transmitting means to determine the relative short and long lengths of said impulses and the relative short and long lengths of the spaces between such impulses of any given series in ac cordanoe with the controls to be transmitted to the particular station selected for that series, said means also acting to determine the positive and negative polarities of said impulses in accordance with the code assigned to that particular station; station selecting means at each of said field stations rendered active at the beginning of every series but maintained active during any given series only if the polarities of the impulses of that series conform to the code assigned that field station; storing means at each field station for registering the lengths of the impulses and the lengths of the spaces between said impulses of any given series only so long as said station selecting means is active during said series; a plurality of devices at each of said field stations; and means at each of said field stations for controlling said devices at that station in accordance with the condition of said storing means at the end of any given series only if said station selecting means has been maintained active throughout said series.

'7. In a remote control system; a control oifice and a plurality of field stations connected by a single line circuit; a plurality of devices at each of the several field stations, a plurality of control levers in the control oifice for each of said field stations; transmitting means at said control office alone for timing and impressing series of time spaced impulses of selected polarities on said line circuit from said source of energy; a plurality of code determining relays in the control oifice respectively associated with the several field stations and effective, when rendered active, to cause said transmitting means during a particular series of impulses to be controlled in accordance with the control levers for that associated field station to determine the relative short and long lengths of said impulses and the relative short and long lengths of the spaces between such impulses of any given series for the particular station with which such levers are associated, said code determining relay for any particular station also acting to determine the positive and negative polarities of said impulses for the series in accordance with the code assigned to that particular station; means associated with said code determining relays for allowing only one of the several code determining relays to be active during the same series of time spaced impulses; station selecting means at each of said field stations rendered active at the beginning of every series of impulses but maintained active during any particular series only if the polarities of the impulses of that series conform to the code assigned to its field station; storing means at each field station for registering the lengths of the impulses of any series and the lengths of the spaces between the impulses of any series only so long as said station selecting means is active during said series; and means at each of said field stations for controlling said devices at that station in accordance with the condition of said storing means at the end of any given series providing said station selecting means has been maintained active throughout the series by reason of the polarity of the impulses of such series conforming to the code call of that station.

FREDERICK W. BRIXNER.

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