US2176611A - Remote control system - Google Patents

Description

Oct. 17, 1939. 1 M, P|= |KAN 2,176,611

REMOTE CONTROL SYSTEM Y Filed June 28, 1938 2 Sheets-Sheet 1 N l E J Peli/ian lNIVENTOR NASE HIS ATTORNEY Oct. 17, 1939. .1. M. PELIKAN REMoTEcoNTRoL SYSTEM Filed June 28, 1938 2 Sheets-Sheet 2 .wml

[iban INVENTOR H114' TTORNEY ms MSE W Patented Oct. 17, 1939 c UNITED STATES FiiQE REMOTE CONTROL SYSTEM Application June 28, 1938, Serial No. 216,266

16 Claims.

My invention relates to remote control systems, and more particularly to remote control systems for railways.

I shall describe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

A feature of my invention is the provision of novel and improved means for continuously controlling a plurality of different mechanisms from lo a remote control point and for continuously indicating at the control point the respective positions o-f such mechanisms. Another feature of my invention is the provision in systems of this character of means for synchronously operating two pulse following relays which are located one at each of two spaced locations through the medium of a line circuit extending between the two locations and which line circuit is used to control and indicate the positions of a mechanism. An additional feature of my invention is the provision of apparatus for continuously controlling two independent mechanisms from a remote control point and for continuously indicating at such control point the respective positions z5v of such mechanisms by virtue of a single two-wire line circuit. Other features and advantages of my invention will appear as the specification progresses.

In the accompanying drawings, Fig. 1 is a diagrammatic view of one form of apparatus embodying my invention when applied to the control and indication of a railway track switch and its related signals and track circuit. Fig. 2 is a diagrammatic view of a second form of apparatus embodying my invention when applied to the control and indication of a railway track switch and vits related signals and track circuit. Fig. 3 is a chart illustrating an operating characteristic of the apparatus of Fig. 2.

It will be understood that my invention is not limited to the control and indication of railway track switches and signals, but this one use of apparatus embodying my invention will serve to illustrate the many places where it will be useful.

In the different views similar parts are designated by the same reference characters.

'Io simplify the drawings in order that they may be more readily understood, I have in many instances illustrated relay contact fingers remo-te :'10 from the relay windings which operate them. In

all such instances the reference character of the corresponding relay is placed adjacent the contact finger and the contact finger is shown in the position corresponding to the energized or deenergized condition of the relay winding.

Referring to Fig. 1, the reference characters la and lbk designate the track rails of a stretch of railway track which are formed by the usual insulated rail joints with atrack section iT having a track switch SW located therein. 'I'he track 5. section iT is provided with a track circuit com- Y prising a track battery 2 connected across the rails at one end of the section and a track relay I'I'R connected across the rails at the other end of the section. l0

'I'wo signals RA and RB govern eastbound traic over the switch SW and through the track section ET, that is, traffic moving from left to, right in Fig. l. Two other signals LA and LB govern westbound traffic over the track switch :1,5 SW and through the section l'I. I'hese signals may be of any suitable type and are shown conventionally. Other signals governing tramo appreaching the signals RA, RB, LA and LB would be provided in accordance with standard pracy20 tice, but such additional signals are not shown since they are not required to illustrate my invention.

The track switch SW is preferably operatedto its normal and reverse positions through the me- 2.75 dium of a power operated switch machine SM which may be of any standard type and is here considered as of the type including a reversible electric motor, not shown.

The switch machine SM and the signals associated with the track switch SW are controlled through the medium of apparatus located partly at a field station FS adjacent the track switch and partly at a remote oflice station DS, such as a dispatchers ofce. The two portions of the apparatus at the two respective stations FS and DS are interrelated by virtue of line circuits extending between the two stations, and which line circuits will be more fully described hereinafter. The two stations. FS and DS are equipped with `proper sources of current, a battery 3 being placed at station FS and a battery ll being placed at .office station DS. These two batteries 3 and 4 are each provided with a positive terminal B, a negative terminal N and a center terminal C 45,5 in order that current of positive or normal polarity and current of negative or reverse polarity may be supplied to the associated line circuits.

Referring rst to that portion of the apparatus located at the field station FS, a polarized switch controlling relay WR is provided for governing the operating circuits of the switch machine SM. These operating circuits are preferably those in common use and it is deemed sufficient for this application to point out that when .55

relay WR is energized by current of normal polarity closing its front neutral contact 5 and its normal polar contact 6, current is supplied from terminal B of the current source over wire 'I tothe motor of the switch machine SM and the switch machine is operated as required to move the track switch to its normal position, that is, the position sho-wn in Fig. l, the motor circuit being completed to the terminal C of the current source over wire 8. When the relay WR is energized by current of reverse polarity closing `its front neutral contact 5 and reverse polar contact 9, current is supplied over Wire I to the motor of the switch machine SM and the switch machine is operated as required to move the track switch SW to its reverse position.

The relay WR is reversibly energized through the medium of two switch control line relays NW and RW. When line relay NW is energized closing its front contacts I3 and I4, and line relay RW is released closing its back contacts I5 and. I5, the relay WR is supplied with current of normal polarity, the circuit extending from battery terminal B over back contact I5 of relay RW', front contact I3 of relay NW, winding of relay WR, front contact I4 of relay NW, back contact I5 of relay RW and to the terminal C. With line relay RW energized and line relay NW released, then current of reverse polarity is supplied to the relay WR, the circuit including terminal B, front contact Il of relay RW, back contact I8 of relay NW, winding of relay WR, back contact I9 of relay NW, front Contact 2d of relay RW and terminal C. The relay WR would alsol be governed in the usual manner by tralic conditions in the vicinity of the track switch but such traflic control is omitted since it forms no part of my present invention. The relay WR is preferably slow releasing in character.

The switch control line relays NW and RW are interposed in multiple in a switch control circuit local for the station FS, and which switch control circuit is at times connected with a control line wire WRL of a line circuit extending between the stations DS and FS, the other side of such line circuit being completed over a common line wire CL permanently connected with the C terminals of batteries 3 and li. The relays NW and RW are selectively responsive to current of normal and Vreverse polarity by virtue of asymmetric units 51 and 58 connected in series with the relays NW and RW, respectively. The unit 57 is disposed to pass from the line circuit only current of normal polarity to the relay NW and the unit 58 is disposed to pass only current of reverse polarity to the relay RW. The manner of supplying current of normal or reverse polarity to the line circuit at the oice station DS for governing the line relays NW and RW will be pointed out when the operation of the apparatus is described.

A switch indication relay KR is controlled according to the position of the track switch through the medium of a pole changer operatively connected with the track switch SW and the switch machine SM as indicated by a dash line. The relay KR is a polarized relay and is energized by current of normal polarity when the track switch SW occupies its normal position so that pole changing contact members ii and I2 occupy the positions illustrated by solid lines in Fig. 1. When the switch SW is moved to its reverse position, the pole changing contact members I I and I2 are moved to the positions indicated by the dotted lines and the relay KR is energized by current of reverse polarity. The indication relay KR is used to control a switch indication circuit local to the station FS and which indication circuit is at times connected with the control line wire WRL, as will later be described.

The eld station FS is provided with a signal controlling relay for each of the several signals, such signal controlling relays being each identifled by the reference character H plus a prefix corresponding to the signal it governs. The operating circuits for each signal are controlled by the associated signal controlling relay according to standard practice and these operating circuits are not shown in order to not unduly complicate the drawings since such operating circuits are well known and their specic arrangement forms no part of my present invention. It is deemed sufficient to point out that when a signal controlling relay is deenergized, the associated signal assumes a stop position, and the signal is operated to a proceed position when the relay is energized. For' example, the signal controlling relay RAI-l when deenergized causes the signal RA to assume its stop position, and when energized and picked up it causes signal RA to assume a proceed position. The several signal controlling relays are in turn selectively governed by trafc conditions, the position of the track switch and by two signal control line relays LH and RH. With the track section IT unoccupied, the track switch SW in its normal position and the line relay LH energized, a circuit can be traced from battery terminal B over front contact 2I of track relay ITR, normal polar contact 22 of relay WR, front contact 23 and normal polar contact 2&3 of relay KR, front contact 25 of line relay LH, winding of relay LAH and terminal C, and the relay LAH is energized. In the event the line relay RH is energized under the traiic conditions cited above, the-signal controlling relay RAH is energized, the circuit being the same as traced for relay LAH up to the normal polar contact 2A thence over front contact'26 of relay RH, winding of relay RAI-I and terminal C. When the track switch is moved to its reverse position and the track section IT is unoccupied and the relay LH is selected, the signal controlling relay LBH receives current over terminal B, front contact 2i of relay ITR, reverse polar contact 2l of relay WR, front contact 28 and reverse polar contact 29 of relay KR, iront Contact 30 of relay LH, winding of relay LBH and terminal C. Under this latter track condition, the relay RBH is energized when the line relay RH is selected, the circuit being the same as traced for relay LBH up to reverse polar contact 29 thence over front contact 3i of relay RH, winding of relay RBH and terminal C. These several signal controlling relays are preferably slow releasing in character. The signal controlling relays would, of course, also be governed by traiiic conditions approaching the track switch but such traffic control is omitted since it forms no part of my present invention.

The signal control line relays LH and RH are interposed in multiple in a signal control circuit local to the station FS and which signal control circuit is at times connected in a manner to later appear with a control line wire HRL. The line relays LH and RH are selectively responsive to current of normal and reverse polarity by virtue of asymmetric units 5S and 6 connected in series with the relays LH and RH, respectively. Unit 59 is disposed to pass from the line wire HRL to the relay LH only current of normal polarity and the unit Sii is disposed to pass only current of the reverse polarity to the relay RH. The line Wire I-IRL forms one side of a line circuit extending between the stations DS and FS, the other side of which line circuit is formed by the common line wire CL. The manner of supplying current' of normal or reverse polarity to the line circuit including line wire I-IRL for controlling the relays LH and RH will appear when the operation of the apparatus is described.

The field station FS is also provided with a signal repeater relay HP for indicating the positions of the signals. As here shown, the relay HP is controlled by each of the signal controlling relays RAI-I, RBH, LAH and LBH, the arrangement being such that the relay HIP is deenergized when the signal controlling relays are all deenergized and the signals at their respective stop positions, and the relay HIP is energized when any one of the signal controlling relays is picked up to effect the proceed position of the respective signal. The circuit for relay HP includes the front contacts 5l, 62, 63 and 64 of the respective signal controlling relays in multiple.

Referring to that portion of the apparatus located at the office station DS, a switch lever LI and a signal lever L2 are mounted for manual operation. The lswitch lever LI is operable to a left-hand or normal position NB and to a righthand or reverse position RD and has two circuit controlling contact members 32 and 33 connected therewith. The signal lever L2 is provided with a normal or center position CP and is operable to either a left-hand position LT or to a righthand position RT. A circuit controlling contact member 34 is connected with the signal lever L2. The switch lever LI controls through the medium of the contact members 32 and 33 a switch control circuit local to the station DS and which switch control circuit is at times connected with the line wire WRL in a manner to later appear for supplying current of normal or reverse polarity thereto. The signal lever L2 controls through the medium of the contact member 34 a signal control circuit local to the station DS and which signal control circuit is at times connected with the line wire I-IRL for supplying current thereto.

A normal switch indication line relay NWK and a reverse switch indication line relay RWK are associated with the switch lever LI for controlling a normal switch indication lamp and a reverse switch indication lamp 46, respectively. When line relay N'WK is picked up closing front Contact 4l, a simple circuit is completed for illuminating the lamp 45, and when line relay RWK is picked up closing front contact 48, a circuit is completed for illuminating the lamp 46. The relays NWK and RWK are interposed in multiple in a switch indication circuit local to the station DS and which circuit is at times connected with the line wire WRL. The line relays NWK and RWK are made selectively responsive to current of normal and reverse polarity through the medium of asymmetric units 49 and 50, the unit 49 being connected in series with the relay NWK and disposed to pass only current of normal polarity to that relay, and the unit 50 being connected in series with the relay RWK and disposed to pass only current of reverse polarity to that relay. In Fig. l, the line relays NWK and RWK are preferably slow releasing in character.

Two signal indication line relays TK and HTK are associated with the signal lever L2 for governing indication lamps OS and 5|, the arrangement being such that when relay TK is picked up closing front contact 52 the lamp OS is illuminated, and when relay HTK is picked up closing front contacts 53 and 54, both lamps OS and 5I are illuminated. The line relays TK andHTK are connected in multiple in a signal indication circuit local to the station DS and which indication circuit is at times connected with the line wire HRL in a manner to later appear. The relays TK and HTK are made selectively responsive to current of normal and reverse polarity by asymmetric units 55 and 56, unit 55 being connected in series with relay TK and disposed to pass only current of reverse polarity and the unit 56 being connected in series with the relay HTK and ldisposed to pass only current of normal polarity. The relays TK and HTK are preferably slow releasing in character.

Two pulse following relays are provided one at each station DS and FS for operating the two respective portions of the apparatus in synchronism, and which pulse following relays are themselves operated in step with each other through the medium of other relays controlled in part by the line circiut including line wires WRL and CL. As here shown, a pulse following relay DZ is located at station DS and a pulse following relay FZ is located at station FS. As here shown, these two pulse following relays are of the two winding polar type. Looking at relay DZ, when its left-hand winding 35 is energized in a manner to shortly appear, the polar armature 36 is operated to the left-hand position closing normal polar contact 36-31, and when the right-hand winding 33 is energized the polar armature 36 is operated to the right-hand position closing reverse polar contact 35-35- the left-hand winding 46 of relay FZ is energized the polar armature 4I is operated to the left-hand position closing normal polar contact 4 l-42, and when the right-hand winding 43 is energized the polar armature 4l is operated to the right-hand position closing reverse polar contact 4I-44. These polar relays DZ and FZ are preferably constructed with like operating characteristics and are of the type in which the polar armature remains in the position to which it was last moved when the relay is deenergized.

A control relay DC and an indication relay DN are associated with the polar relay DZ and in like manner a control relay FC and an indication relay FN are associated with the polar relay FZ. The control relays DC and FC as well as the indication relays DN and FN are preferably quick acting neutral relays and are operated by the polar relays for alternately connecting the associated line circuits with the local control and indication circuits at the same oice in step with the operation of the polar relay. In other words, the polar relays divide time into consecutive operating cycles, each cycle of which is subdivided into two substantially equal intervals. During the rst interval of each cycle the local control circuits at the respective stations are connected with their respective line circuits, and during the second interval of each cycle the local indication circuits at the respective stations are connected with their respective line circuits.

W'hen the polar relays DZ and FZ are energized at normal polarity closing the respective normal polar contacts 36-3'l and 4l-42 the respective control relays DC and FC are energized over simple circuits easily traced and these control relays are at once picked up. When the polar DZ, and FZ are energized at reverse polarity closing reverse polar contacts 36-39 and 4I-44,

In like fashion, when the respective indication relays DN and FN are l .energized and: at once picked up. The control relays DC and FC are immediately released when the. polar relays are operated to their reverse 'positions, and the indication relays DN and FN are, immediately released when the polar relays are operated to their normal positions.

In describing the operation of the apparatus of Y Fig. 1,1 shall assume that at the start the switch lever Li is at its normal position NB, signal lever L2 at its center position CP, the track section iT -is unoccupied, the track switch SW is at its normal position causing indication relay KR to be energized at normal polarity, the signals are all at stop so that the relay HP is deenergized, and the polar relays DZ and FZ have just been operated to their respective normal positions` to initiate an operating cycle. The indication relays DN and FN are now deenergized and released while the control relays DC and FCare energized and picked up. With the control relays DC and FC picked up, the line wire WRL is `transferred to the switch control circuits and'a'switch control impulse of current iiows fromterminal B of battery 'l over contact member 32 oflever Li,winding of a line relay T, to be referred to later, front contact 55 of relay DC,

Vline wire WRL,front contact 66 of relay FC,

asymmetric unit 5l, winding of relay NW, terminal C at station FS, common line wire CL and to C terminal of battery d, and the line relays T and NW are serially energized and simultaneously picked up. The relay NW on picking up closes front contacts i3 and i4 causes current of normal polarity to be supplied to the switch controlling relay WR to govern the normal position of the switch. The closing of front contact its of line relay T and of front contact 6l of line relay NW energizes the right-hand windings 33 and 153 of the polar relays DZ and FZ, respectively, and the polar relays are operated in stepy with each other to their right-hand posi- `tions closing the respective reverse polar contacts 'Ihe first interval of the operating cycle is now completed and the second interval is initiated.

The control relays DC and FC are now deenergized and released, and the indication relays .DN and FN are energized and picked up simultaneously. With the indication relays DN and FN picked up, the line wire WRL is transferred to the local indication circuits and a switch indication impulse of current of normal polarity ilows from terminal B of battery 3 at the eld. station over normal polar contact 58 and front contact lili of relay KR, front contact 'lll of relay FN, line wire WRL, front contact ll of relay DN, asymmetric unit e9, winding of indication aso 'line relay NWK, terminal C at station DS, line wire CL and terminal C of battery 3. Relay NWK is energized and picked up closing front contact el so that the lamp i5 is illuminated to indicate the normal position of the track switch SW.

The indication relays DN and FN on picking up closing the respective front contacts l2 and 'i3 complete the circuits for the respective lefthand windings 35 and 4&3 of the polar relays and the vpolar relays are operated to their normal positions in step with each other. The indication relays DN and FN are now deenergized and immediately released while the control relays DC and FC are again energized and picked up simultaneously. That is to say, the first operating cycle new completed and a second operating cycle is initiated.

"It should be noted that when the control relays DC and FC are picked up during the first interval of the operating cycle to close the respective front contacts 79 and St, the line wire HRL is transferred to the signal control circuits at the stations DS and FS but no signal control current ows since the lever L2 is at its center position CP. During the second interval of the operating cycle and the indication relays DN and FN are picked up closing the respective front contacts l and 56, the line wire HRL is transferred to the signal indication circuits at the two stations and a signal indication impulse of current iiows from terminal C of battery 3 over the common line wire CL to terminal C at station DS, winding of relay TK, asymmetric unit 55, front contact 'l5 of relay DN, line Wire HRL, front contacts 76 and 17 of relays FN and ITR, respectively, back contact 18 of relay HP and to the terminal N of battery 3, and the indication line relay TK is energized and picked up closing front Contact 52 so that the lamp CS is illuminated to indicate the stop position of the signals and the unoccupied condition of the track sectionr IT.

It is to be seen, therefore, that the operating cycle described v-above willbe periodically repeated, during the rst interval of each cycle .the line wire WRL being transferred to the switch control circuits at the two stations and the line wire HRL being transferred to the signal control circuits at the two stations. During the second interval of each cycle, the line wire WRL is transferred to the switch indication circuits at the two stations `and the line wire HRL is transferred to the signal indication circuits at the two stations. Furthermore, operation of the line relays .T and NW and the indication relays DN and FN is effective to cause the two polar relays DZ and FZ to be operated instep with each other.

,In the event the switch lever Li is moved to its reverse position RD, the operation of the apparatus is the same except for the polarity of the switch control current supplied to the line wire the reverse polar contact It of relay KR. Under these circumstances, the switch indication line relay RWK is selected and picks up closing front contact i8 to cause the reverse switch indication lamp l5 to be illuminated. It is to be noted that windingll of relay FZ is, when lever L! is at its RD position, controlled over front contact 82 of relay RW and the relays DZ and FZ are operated in step with each other by means of line relays T and RW and the indication relays DN and FN. It is also to be noted that since the indication line relays NWK and RWK are slow releasing in character they remain picked up from one indication impulse to the next and the switch indication lamp 5 or G5, as the case may be, is steadily illuminated. Also the switch controlling relay WR remains picked up from one switch control impulse to the next by virtue of its slow release characteristic. In like manner, the lamp OS is steadily illuminated due to the relay TK remaining picked up from one signal indication impulse to the next because of its slow release characteristic.

Assuming the signal lever L2 is moved to its left-hand position LT while the switch lever Ll is at its normal position, a signal control impulse of current is supplied to the line circuit includ- "battery 4 over contact member 34, front contact i This circuit extends from terminal B of battery 3 impulse supplied to the line circuit including line 4@ RA is operated to its proceed position. In the 5 The signal repeater relay HP is now over front contact tion and the signal lever L2 19 of relay DC, line wire HRL, front contact 8@ of control relay FC, asymmetric unit 59, winding of relay LH, terminal C at station FS, line wire CL and terminal C of battery 4. With the signal -control line relay IH picked up closing front contact 25, the signal controlling relay LAH is selected in the manner described hereinbefore and the signal LA is operated to a'proceed position. energized 63 of relay LAI-I so that the signal indication impulse of current supplied to the line wire HRL during the second interval of each operating cycle is of normal polarity and the signal indication line relay I-ITK is energized.

over front contact 8i of relay HP, front contacts 'l1 and 16 of relays lTR and FN, respectively, line wire HRL, front contact 15 o-f relay DN, asymmetric unit 56, winding lof relay HTK, terminal C at station DS, line wire CL and the terminal C of battery 3. With relay HTK picked up closing front contacts 53 and 54, the lamps OS and I are illuminated to indicate the proceed position of signal LA and the unoccupied condition ci the track section IT.

In the event the signal lever L2 is moved to its right-hand position RT so that the contact member 34 completes the signal control circuit to the terminal N of battery 4, the signal control wire HRL is of reverse polarity and the signal control line relay RH is selected closing its front contact 26 with the result that the signal controlling relay RAH is energized and the signal event the switch lever Ll is moved to its reverse position RD to bring about a movement of the track switch to its reverse position, the operation of the apparatus is th-e same when the signal lever L2 is moved to its left-hand position LT as previously described except for the fact that the signal controlling relay LBH is selected and the signal LB is operated toa proceed position. Again, if the switch lever LI is at its reverse posiis moved to its righthand position RT, the operation is the same as described above except for the fact that the signal controlling relay RBH is energized and the signal RB is operated to a proceed position. It

'v should be noted that when the section IT is occupied and the track relay ITR is released opening front contact ll, the signal indication impulse is stopped so that both lamps OS and 5i are dark.

Referring to Fig. 2, the track layout and signals as well as the immediate control thereof are the same as in Fig. l, the switch machine SM being governed by the switch controlling relay WR and the signals RA, RB, LA and LB being governed by the signal controlling relays RAH, RBH, LAH and LBH, respectively. Also, the switch controlling relay WR is governed by the twoy switch control line relays NW and RW, and the signal controlling relays are governed by the two signal co-ntrol line relays LH and RH in the same manner as in Fig. 1. The signal repeater relay HP of Fig. 2 is likewise controlled in the same manner as in Fig. 1. At the office station DS, the switch lever Ll, signal lever L2 and the associated indication line relays and lamps are the same as in Fig. 1 except for the fact that the switch indication line relays NWK and RWK are of the quick acting type. In Fig. 2, the switch SW and the associated signals and track circuits are continuously controlled and continuously indicated over a single two-wire line circuit including a control line wire WHL and the common return wire CL.v

In the form of the invention disclosed in Fig. 2, time is divided into consecutive operating cycles of substantially equal duration the same as in Fig. l, but in Fig. 2 each operating cycle is subdivided into four substantially equal intervals whereas in Fig. l each cycle is divided into two substantially equal intervals. 'Ihis operating characteristic of the apparatus of Fig. 2 is illustrated in the chart of Fig, 3. Looking at Fig. 3, an operating cycle is illustrated, the cycle being shown by dotted lines as subdivided into four substantially equal intervals. The iirst interval of the cycle is for the transmission of a switch control impulse which impulse is illustrated by an arrow placed in the rst interval of the cycle, the direction of the arrow indicating that the impulse is transmitted from the oilice station to the iield station. The second interval of the cycle is for the transmission of a switch indication impulse which is illustrated by an arrow placed in the second interval space of the cycle, the direction of the arrow indicating that the impulse is transmitted from the field station to the office station. Th-e third and fourth intervals of the cycle are for the transmission of signal control and signal indication impulses, respectively, and these impulses are illustrated by arrows placed in the third and fourth spaces of the cycle, the direction of the arrows indicating the direction of the transmission of the impulses with respect to the ofce and iield stations. The cons-ecutive operating cycles are each subdivided in the manner illustrated in Fig. 3.

The operating cycles described above for the apparatus of Fig. 2 is accomplished by four pulse following relays, two at each station, together with associated control and indication relays. The pulse following relays are preferably of the polar type, the same as in Fig. 1, relays DY and DZ being located at the cnice station- DS and relays FY and FZ being located at the eld station FS; This combination of relays transfers synchronously at the two stations the line circuit consecutively to four diiierent and distinct station circuits, namely, switch control, switch indication, signal control and signal indication. Thus, for example, if each operating cycle is one second long, each of the above mentioned four circuits receives a current impulse every second, the duration of each impulse being approximately one-fourth of a second. Furthermore, the pair of polar relays at the office station are made to operate in step with the pair of polar relays at the field station through the medium of the control and indication relays together with line relays controlled by this same line circuit, the line relay T being located at station DS and a line relay FT being located at station FS.

The polar relays DY and FY select between switch and signal functions by controlling, when operated to their left-hand positions, two switch relays DSW and FSW, respectively, and by controlling when operated to their right-hand positions, two signal relays DSG and FSG, respectively. The polar relays DZ and FZ select between the control and indication functions by l. controlling, when operated to their left-hand positions, the control relays DC and FC, respectively, and by controlling, when operated to their right-hand positions, the two indication relays DN and FN, respectively, the same asin Fig. 1.

In describing the operationv of the apparatus of Fig. 2, I shall assume that at the start the switch lever Ll is positioned at its normal position NB, the track switch is at itsv normal position, the track section iT is unoccupied, the signals are all at stop, the signal lever L2 has just been moved to its left-hand position LT to govern the signal LA, and the relays have just operated to the positions illustrated in Fig. 2 to start an operating cycle. The switch relay DSW and the control relay DC at the oflice station are energized and picked up over the normal polar contacts 8,3-34 and 36-3'! of the polar relays DY and DZ, respectively. The switch relay FSW and control relay FC at the iield station are also energized and picked up, their circuits being completed at the normal polar contacts -86 and ll-42 of the relays FY and FZ, respectively. The line circuit is now transferred to the switch control circuits and a switch control impulse of current ows from terminal B of the oflice station battery i over contact member 32 of lever Ll, winding of line relay T, front contact t5 of relay DC, front contact 8l of switch relay DSW, line wire WHL, front contacts 88 and 66 of relays FSW and FC, respectively, asymmetric unit 51, winding oi switch control line relay NW, terminal C at the eld station, line wire CL and to the terminal C of battery 4. The line relays T and NW are now picked up in series. Relay NW on picking up closing front contacts I3 and I4 controls the relay WR the same as in Fig. 1. Relays T and NW on picking up closing front contacts mi] and 6l, respectively, cause the polar relays DZ and FZ to be operated to their right-hand positions, terminating the first interval of the operating cycle and initiating the second interval.

The control relays DC and FC as well as the line relays T and 'NW are now deenergized and released while the indication relays DN and FN are picked up and the line circuit is transferred to the switch indication circuits so that a switch indication "current impulse flows from terminal B'of battery 3"over normal polar Contact E8 and front contact Stof relay KR, winding of line relay FT, front contacts 'It and 83 of relays FN and FSV/,"respectively, line wire WHL, front contacts't'l and li 'oi relays DSW and DN, respectively, asymmetric unit 139, winding of relay NWK, terminal C of station DS, line wire CL and terminal C of rbattery t. The line relay FT at station FS and the indication line relay NWK at the office station DS are energized in series and picked up simultaneously. The closing of front contact lil'oi relay NWK causes the lamp 45 to be momentarily illuminated to indicate the normal position of the switch SW. The closing of front contact 89 vof relay NWK and front contact 9@ of relay FT energizes the right-hand windings of the polar relays DY and FY, respectively, and these two polar relays are operated to their respective right-hand positions. At the saine time, the closing of front contact l2 of relay DN andfront contact i3 of relay FN energizes the left-hand windings of relays DZ and FZ, respectively, and these polar relays are operated to their left-hand positions. The second interval o f the operating cycle is now terminated and the third interval is initiated, the polar relays DY and FY. being at their right-hand positions and the polar relays DZ and FZ being at their left-hand positions.

The switch relays DSW and FSW as well as the indication relays DN and FN are now deenergized and released while the signal relays DSG and FSG as well as the control relays DC and FC are picked up toV transfer the line circuit to the signal control circuits. A signal control impulse of current now flows from terminal B of battery i over contact member 34' of lever L2 at its LT position, front contacts 9| and 92 of relays DC and DSG, respectively, line Wire WHL, front contacts S3 and 80 of relays FSG and FC, respectively, asymmetric unit 59,'winding of relay LH, terminal C at station FS, line wire CL and to terminal C of battery Il.V The signal control line relay LH on picking up selects the signal controlling relay LAH in the same manner as described in Fig. l with the result that the signal LA is operated to a proceed position and the signal repeater relay HP is energized and picked up to indicate the proceed position of the signal. The closing of front contact 94 of signal Vrelay DSG and front contact 95 of signal relay FSG, respectively, energizes the right-hand windings of the polar relays DZ and FZ, and these relays are operated to their right-hand positions to` terminate the third interval of the operating cycle and initiate the fourth interval of the cycle.

The control relays DC and FC are now released while the indication relays DN and FN are picked up to transfer the line circuit to the signal indication circuits. A signal indication impulse of current flows from terminal B of battery 3 over iront contacts 8l, l?, i6 and 93 of relays HP, lTR, FN and FSG, respectively, line wire WHL, front contacts 92 and l5 lof relays DSG and DN, respectively, asymmetric unit 56, winding of relay HTK, terminal C at station DS, line wire CL and terminal C of battery 3. The picking up of the signal indication line relay HTK closing iro-nt contacts and 54 causes the lamps OS and 5l to b e illuminated to indicate the proceed` position of the signal LA and the unoccupied condition of the track section iT. The closing of front contacts 96 and 9i of relays DSG and DN, respectively, energizes the left-hand winding of relay DY, and the closing of the front contacts 9B and t of relays FSG and FN, respectively, energizes the left-hand winding of relay FY with the result that these two pollar relays are operated to their respective left-hand positions. Also, the closing of the front contact 72 of relay DN and the iront contact 'i3 of relay FN causes the polar relays DZ and FZ to be operated to their respective left-hand positions. The fourth interval of the operating cycle is now completed and the relays are in the positions from which they started so that a second operating cycle is initiated.

it is to be seen, therefore, that during the operating cycle the switch SW is controlled according to the position of the switch lever LI, the position of the switch'is indicated by the illumination of the lamp t5, the signal LA is controlled according to the position of the signal lever L2 and the position of the signal LA as well as the occupancy of the track section IT are indicated by the lamps OS and 5l. Since the operating cycle will be repeated over and over again, it follows that the switch SW and the signal LA are continuously controlled and continuously indicating through the medium of the single twowire line circuit. Also, the polar relays at the two stations are operated in synchronism by Virtue of this same two-wire line circuit extending between the two stations.

From an analysis of Fig. 2, it is readily seen that the apparatus will operate in a similar fashion for other positions of the switch lever LI and signal lever L2 and a description of the vToperation is not necessary.

It is to be observed that in Fig. 2 the switch indication lamps 55 and @E are ashed in step with the operation of the switch indication line relays NWK and RWK. If it is desirable to have the switch indication lamps illuminated continuously, then slow acting repeater relays would be controlled by the relays NWK and RWK and such repeater relays made to govern the indication lamps l5 and 46.

It is also to be observed that should the operating cycle of the apparatus of either Fig. l or Fig. 2 be interrupted at any point due to a loss of power or other conditions, the polar relays and the relays associated therewith will at once start their operation when the power is restored or such other condition is removed.

Although I have herein shown an-d described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope oi my invention.

Having thus described my invention, what I claim is:

1. In a remote control system, a two-wire line circuit extending between two remotely spaced locations, two polar relays one at each location, means partly at each location and controlled by said line circuit to alternately and periodically energize said relays at normal and reverse polarity in step with each other, controlling apparatus at one location having different positions for governing corresponding positions of controlled apparatus at the other location, indicating means at said other location governed by the different positions of said controlled apparatus for controlling dierent indicators at said one location, means governed by said relays when energized at normal polarity to connect said controlling apparatus and said controlled apparatus to said line circuit, and means governed by said relays when energized at reverse polarity to connect said indicating means and said indicators to said line circuit.

2. In a remote control system, a two-wire line circuit'extending between two remotely spaced locations, two polar relays one at each location, a control relay and an indication relay associated with each of said polar relays, said control relays each energized over a normal polar contact of the associated polar relay and said indication relays each energized over a reverse polar contact of the associated polar relay, two line relays one at each location and each line relay having its winding interposed in said line circuit over a iront contact of the control relay at the same location, means governed by each indication relay when energized to operate the associated polar relay to its normal position, means governed by each line relay when energized to operate the polar relay at the same location to its reverse position, and apparatus partly at each location governed by said polar relays.

3. In a remote control system, a line circuit comprising a control line wire and a common return wire extending between two remote stations, two pulse following relays one at each station and each operative to a normal and a reverse position, a control relay an-d an indication relay governed by each of said pulse following relays, said control relays each energized over a normal position contact of the associated pulse following relay and said indication relays each energized over a reverse position contact of the associated pulse following relay, means governed by each indication relay when energized to operate the associated pulse following relay to its normal position, means governed by said line circuit and elective -only when said control relays are both energized to operate each pulse following relay to its reverse position, control apparatus partly at each station and connected with said line circuit over iront contacts of said control relays, and indication apparatus partly at each station connected with said line circuit over front contacts of said indication relays.

4. In a remote control system, a rst line circuit extending between two remote stations and comprising a first control line wire and a coinrnon return wire, a second line circuit extending between said stations and comprising a second control line wire and said common return wire, two pulse following relays one at each station and each operative to a normal and a reverse position, a control relay and an indication relay governed by each of said pulse following relays, said control relays each energized over a normal position contact of the associated pulse following relay and said indication relays each energized over a reverse position Contact of the associated pulse following relay, a rst control apparatus partly at each station connected with said first control line wire over front contacts of said control relays, a first indication apparatus partly at each station connected with said first control line wire over iront contacts of said indication relays, a second control apparatus partly at .each station connected with said second control line wire over other front contacts of said control relays, a second indication apparatus partly at each station connected with said second control line wire over other front contacts of said indication relays, means governed by each indication relay when energized to operate the associated pulse following relay to its normal position, and means governed jointly by said control relays and said first line circuit to operate the pulse following relays to their reverse positions.

5. In a remote control system, a first line circuit extending between two rernote stations and comprising a iirst control line wire and common return wire, a second line circuit extending between said stations and comprising a second control line wire and said common return wire, two pulse following relays one at each station and each operative to a normal and a reverse position, a control relay and an indication relay governed by each of said pulse following relays, said control relays each energized over a normal position contact of the associated pulse following relay and said indication relays each energized over a reverse position contact of the associated pulse following relay, two line relays one at each station and each having its winding interposed in said first line circuit over a front contact of the control relay at the same station, means governed by each indication relay when energized to operate the associated pulse following relay to its normal position, means governed by each of said line relays when energized to operate the apparatus located partly at each station'governed by said rst line circuit and alternately operated to a control and an indication condition by said control and indication relays, and a vsecond control and indication apparatus located partly at each station governed by said second line circuit kand alternately operatedto a control 1m and an indication condition by said control and indication relays. v

6. In a remote control system, two independent line circuits extending between two remotely spaced loca-ions, two polar relays one at each 1M location, means partly at each location and governed by a selectedone of said line circuits to alternately 4energize said relays at normal and reverse polarity in step with each other, a first apparatus including a control unit at one location and a controlled means at the otherY location, a second apparatusV including another control unit at said one location and another controlled means at said other location, a rst circuit means governed by said relays to continugously control and indi-cate over said one line circuit the position of the controlled means of said nrst apparatus according to the position of the associated control unit, and other circuit means governed by said relays to continuously control 30;; and indicate over the other line circuit the position of the controlled means of said second apparatus according to the position of the associated control unit.

'7. In a remote control system, a two-wire line 35,3 circuit extending between an office station and a field station and at times serially including the windings of two line relays one at each of said stations, two polar relays one at each of said stations, synchronizing means controlled in part by said line relays and operative to reversibly energize said polar relays in step with each other to form consecutive operating cycles each cycle of which is divided into two substantially equal intervals, means controlled by said polar relays and made operative during the rst interval of each cycle to transmit from the oce station to the held station over said line circuit a control impulse of current for energizing said line relays and for governing a eld station mechanism in response to a given position of an office station unit, and other means controlled by said polar relays and made operative during the second interval of each cycle to transmit from the eld station to the oiice station an indication impulse of current for governing an office station indicator in response to a given position of said field station mechanism.

8. In a remote control system, a two-wire line circuit extending between an ofce station and a o()` field station and at times serially including the windings of two line relays one at each station, two pulse following relays one at each station and each operable to a normal and a reverse position, synchronizing means controlled in part by said line relays to periodically operate said puise following relays to their respective positions in step with each other to form operating cycles each of which has a first and a second interval that are repeated in each cycle in the order named, means controlled by said pulse following relays and made operative during the first interval of each cycle to transmit from the office station to the iield station over said line circuit a control impulse of current for energizing said line relays and for governing a iield station mechpulse following relay at the same'station to `its reverseposition, a rst'control andtindication.

anism in response toa given position of an oce station unit, and other means controlled by said pulse following relays and made operative during the second interval of each cycle to transmit from the field station to the oiiice station over said line circuit an indication impulse of current for governing an oice station indicator in response to a` given position of said field station mechanism.

9. In a remote control system, a two-wire line circuit extending between an ofce station and a field station, a pair of polar relays at each of said stations, synchronizing means controlled by said line circuit for energizing each pair of polar relays in a selected sequence to form at both stations consecutive operating cycles which are in phase and eachcycle of which is divided into four substantially equal intervals, means governed by each pair of polar relays to transfer said line circuit to1 a diierent circuit local to the associated station during each interval of each cycle to effect four diiferent control conditions between said stations each of which conditions is repeated each cycle.

10. In a remote control system, a two-Wire line circuit extending between an ofi-ice station and a field station, a pair of polar relays at each of said stations, synchronizing means controlled by said line circuit for energizing each pair of polar relays in a selected sequence to form consecutive operating cycles which are in phase and each cycle of which is divided into four substantially equal intervals, a first controlled mechanism at the eld station governed by a first controlling unit at the oice station in response to current transmitted over said line circuit during the first interval of each cycle, a first indication mechanism at the oice station governed by said first controlled mechanism in response to current transmitted over said line circuit during the second interval of each cycle, a seco-nd controlled mechanism at the eld station governed by a second controlling unit at the oiice station in response to current transmitted over said circuit during the third interval of each cycle, and a second indication mechanism at the office station governed by'said second controlled mechanism in response to current transmitted over said line circuit during the fourth interval of each cycle.

l1. In a remote control system, a two-wire line circuit extending between an ofce station and a eld station, a group of line relays at each of said stations, apair of polar relays at each of said stations, means controlled by each group of line relays for operating the pair of polar relays at the same station in a selected sequence to form consecutive operating cycles each cycle of which is divided into four substantially equal intervals, means governed by each pair of polar relays to transfer said line circuit to a different local circuit during each interval of each cycle for energizing during each of said intervals selected relays of they associated group of line relays for synchronizing the operation of the two pairs of polar relays, and control and indication apparatus partly at each station governed by said line circuit;

12. In a remote control system, a two-wire line circuit extending between an oice station and a eld station, an electroresponsive means at each station operative to four distinctive positions, means including line relays located partly at each of said stations and controlled by said line circuit to periodically operate the two electroresponsive means to their respective four positions in agreement with each other, four local circuits at each of said stations a selected one of which is assigned to each of the four positions of the associated electroresponsive means, means governed by each electroresponsive means to consecutively transfer the line circuit to the local circuits at the same station, and control and indication apparatus partly at each station interrelated in its operation by said line circuit through the medium of said local circuits.

13. In a remote control system, a controlled means and an indication means at one location, said controlled means operable to a rst or a second position when respectively energized at normal or reverse polarity and said indication means operative to supply current of normal or reverse polarity in response to the iirst or second position of the controlled means respectively, a controlling unit and an indicating unit at a second location, said controlling unit operative to supply current of normal or reverse polarity when moved to a rst or a second position respectively and said indicating unit operable to display a rst or a second signal when respectively energized at normal or reverse polarity, a two-wire line circuit extending between said locations, two polar relays one at each location, circuit means governed by said relays when energized at normal polarity to connect said controlling unit and said controlled means to said line circuit to operate the controlled means according to the position of the controlling unit, other circuit means governed by said relays when energized at reverse polarity to connect said indication means and said indicating unit to said line circuit to display a signal according to the position of said controlled means, and synchronizing means controlled by said line circuit to alternately energize said polar relays at normal and reverse polarity in step with each other.

14. In a remote control system, a controlled means and an indication means at one location, said controlled means operable to a rst or a second position when respectively energized at normal or reverse polarity and said indication means operative to supply current of normal or reverse polarity in response to the first or second position of the controlled means respectively, a controlling unit and an indicating unit at a second location, said controlling unit operative to supply current of normal or reverse polarity when moved to a first or a second position respectively and said indicating unit operable to display a first or a second signal when respectively energized at normal or reverse polarity, a two-wire line circuit extending between said locations, two polar relays one at each location, circuit means governed by said relays when energized at normal polarity to connect said controlling unit and said controlled means to said line circuit to operate the controlled means according to the position of the controlling unit, other circuit means governed by said relays when energized at reverse polarity to connect said indication means and said indicating unit to said line circuit to display a signal according to the position of said controlled means, a control and an indication relay associated with each polar relay and selectively energized according to the position of the associated polar relay, and means governed by said control and indication relays jointly with said line circuit to operate the polar relays in step with each other.

15. In a remo-te control system for railways, a track switch, a pair of switch control line relays located at the switch and selectively responsive to current of normal or reverse polarity to govern the position of the switch, indication circuit means' governed by the position of the switch to supply current of normal or reverse polarity, a remote switch lever operable to a normal or a reverse position, control circuit means governed by the position of the lever to supply current of normal or reverse polarity, a pair of switch indication line relays adjacent the lever and selectively responsive to current of normal or reverse polarity, a two-wire line circuit extending between the switch and said lever, two polar relays one at the switch and one at the lever, means governed by the normal position of said polar relays to connect said control circuit means and said switch control line: relays to said line circuit, means governed by the reverse position of said polar relays to connect said indication circuit means and said switch indication line relays to said line circuit, and means governed by said switch control and switch indication line relays to alternately operate the polar relays to their normal and reverse positions in step with each other to continuously control and indicate the position of the switch over said line circuit.

16. In a remote control system for railways, a track switch having associated therewith a track circuit and two signals for governing traffic over the switch, a pair of switch control line relays selectively responsive to current of normal or reverse polarity to govern the position of the switch, switch indication circuit means governed by the position of the switch to supply current of normal or reverse polarity, a pair of signal control line relays selectively responsive to current of normal or reverse polarity to selectively govern said signals, signal indication circuit means governed by said signals to supply current of normal or reverse polarity and by said track circuit to sto-p the supply of such current, a switch lever and a signal lever remote from the switch and each lever operable to a iirst and a second position, switch control circuit means governed by said switch lever to supply current of normal or reverse polarity, signal control circuit means governed by said signal leve-r to supply current of normal or reverse polarity, a pair of switch indication line relays selectively responsive to current of normal or reverse polarity, a pair of signal indication line relays selectively responsive to current of normal or reverse polarity, a two-wire line circuit extending between said levers and said switch, a pair of polar relays adjacent said levers and a pair of polar relays adjacent said switch, and each pair of polar relays operable to four different positions; means governed by said polar relays to connect at a first one of said positions the switch control circuit means and theswitch control line relays to said line circuit, to connect at a second position the switch indication circuit me-ans and the switch indication line relays to the line circuit, to connect at a third position the signal control circuit means and the signal control line relays to the line circuit and to connect at a fourth position the signal indication circuit means and the signal indication line relays to the line circuit; and means governed in part by said line circuit to operate both pairs of polar relays consecutively to their four positions in step with each other to continuously control and indicate the positions of the track switch and signals and occupancy of the track circuit over said line circuit.

JOI-IN M. PELIKAN.

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