US2152384A

US2152384A - Railway traffic controlling apparatus

Info

Publication number: US2152384A
Application number: US254690A
Authority: US
Inventors: Lloyd V Lewis
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1928-02-16
Filing date: 1928-02-16
Publication date: 1939-03-28
Anticipated expiration: 1956-03-28

Description

March 28, 1939. 'v. LEWIS 2,152,384

RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed Feb. 16, 1928 s SheetsSheet 1 Dasha/chem;

Offi'ce l y 50.? .59 51121 I E 0W 0M I INVENTOR:

I I LJKLewM',

L k x Panel/V0.5. 48

March 28, 1939. L. v. LEWIS 2,152,384.

RAILWAY TRAFFIC CONTROLLfNG APPARATUS Original Filed Feb. 16, 1928 3 Sheets-Sheet 2 I g INVENTOR- Q7 1 A, 1/. Le MS) 111 70. a(- W 84 1.. v. LEWIS L 2,152,384

RAILWAY TRAFFIC CONTROLLING APPARATUS 5 Sheets-Sheet 3 March 28, 1939.

Original Filed Feb. 16, 1928 swam /V0.5.

' INVENTOR.

L, 2/.Le Mi 6',

Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE RAILWAY TRAFFIC CONTROLLING APPARATUS Application February 16, 1928, Serial No. 254,690 Renewed May 12, 1931 68 Claims.

My invention relates to railway traffic controlling apparatus, and particularly to apparatus for safely controlling traflic governing devices, such as railway switches and signals, from a re- 5 mote point, such for example, as a dispatchers office, and for also indicating the condition of such devices at such ofiice.

In the present application, apparatus embodying my invention is incorporated in a centralized traflic controlling system for railroads in which the indication and control functions are performed by codes, which operate selectors but this arrangement is not essential.

I will describe one form and arrangement of railway traffic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs, 1, 2 and 3, when placed end to end in the order named, comprise a diagrammatic view illustrating one form of railway traflic controlling apparatus embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring to the drawings, the apparatus comprises a control station which may be a train dispatchers office, and a plurality of field stations, here shown as five in number; stations Nos. 1 and 5 only being shown complete in the drawings. These stations are all connected together by a normally closed communication circuit comprising two line wires 53 and I4 which extends from the dispatchers office to the most remote field station, and which is supplied with energy from a single source which as illustrated comprises a line battery Q. Located at the office is a transmitting device OW for delivering control codes formed by repeatedly interrupting the line circuit including wires 13 and [4, to the various stations. 40 Located at each station is apparatus which is selectively responsive to these control codes to actuate trafific governing devices. A transmitting device is also located at each station for delivering indication codes over the same two line wires 13 and M to the office, where indication apparatus, selectively responsive to these indication codes informs the operator of the condition of the governing devices located at the several stations.

The system and apparatus herein disclosed is an improvement upon that disclosed and claimed in a copending application Serial No. 362,948, filed May 14, 1929, by Clarence S. Snavely, for Remote controlling apparatus.

The oflice is provided with a plurality of panels one for each station but only two of which are shown complete in the drawings. The office is also provided with a line relay designated by the reference character OL, a slow-acting locking relay OP controlle over a front contact of relay OL, a slow-acting relay OK controlled over a back contact of relay L, a slow acting repeating relay OJ controlled over a front contact of relay OK, a transmitting relay OT, a master relay OA, and a delivery relay OB. Each of the stations is also provided with relays similar to those just named and designated by reference characters similar to those applied to corresponding relays at the office with prefixes corresponding to the locations.

Furthermore, each panel at the ofiice and each station is provided with a series of stop relays, a series of start relays, and a series of send relays. The stop relays at each station are designated by the reference character E with a prefix corresponding to the location and a distinguishing exponent. The stop relays at the office are each designated by the reference character e with a distinguishing exponent and a prefix corresponding to the panel with which such relay is as sociated. In similar manner, the start relays at the stations are designated by the reference character G and the start relays at the oflice are designated by the reference character g, and the send relays at the stations are designated by the reference character H, while the send relays at the office are designated by the reference character h.

Each transmitting device referred to above, is designated by the reference character W with a prefix corresponding to the location, and each such device comprises a rotatable shaft 4, operatively connected with a driving motor designated by the reference character M with a prefix corresponding to the location. The shaft 4 of each device W carries a plurality of code generating devices or code wheels, each controlling a contact which is arranged to be alternately opened and closed when the shaft 4 rotates. The apparatus is arranged in such manner that the circuit including a contact controlled by one of the code wheels receives one complete code when the shaft 4 makes one complete revolution, The shaft 4 is normally locked in a predetermined position by a latch 6 which co-operates with a cam 5. Referring particularly to the device OW located at the office, this device is controlled by a motor relay OF. As shown in the drawings, relay OF is de-energized. When relay OF becomes energized, however, current flows from terminal 330 of a source of energy not shown in the drawings, through front contact 8 of relay OF wire as (at 55, and motor OM to terminal y of the same source. The latch 6 is also lifted when relay OF is energized and the motor therefore drives the shaft 4 to rotate all of the code wheels associated therewith. It should be noted that as soon as the rotation of the shaft 4 has commenced, cam 5 moves to a position in which the latch 6 holds the contacts of relay OF in their energized position. It follows that if relay OF becomes deenergized, after the device OW has started, contact 8 of the relay will be held closed mechanically by latch 6 so that the operation of the device will continue for one complete operation until the latch 6 again drops to lock the shaft 4 in its initial position. Each transmitting device W also comprises a normally closed contact II-I2 operated by a cam 9 on the shaft 4. When the shaft is rotated, cam 9 operates, just before the shaft returns to its initial position, to open contact lI-l2 and to close contact IIJ-II for a brief interval of time, The transmitting device W located at each station is controlled by an associated motor relay F in a manner similar to the control of device OW by relay OF. In addition, however, the transmitting device W located at each station is provided with a contact designated by the reference character 22 and operated by a centrifuge 23 driven from the shaft 4. When the shaft 4 is at rest, contact 22 is closed but when the shaft is being rotated by the associated motor M, the centrifuge 23 opens contact 22.

The equipment located at each station may be utilized to control traffic governing devices of any suitable form, but for purposes: of explanation, I have illustrated the apparatus embodying my invention as applied to the control of railway switches and signals associatedwith a stretch of railway track having rails l and I divided by means of insulated joints 2 to form a plurality of track sections. Section o,b is located adjacent station I and section i-j is located adjacent station 5, it being understood that each of the remaining stations control apparatus similar to that illustrated for these two stations. Referring particularly to the apparatus located at station I, the reference character 3 designates a railway switch of the usual and well known form, by means of which the rails of section ab are connected with a siding I6. A track relay designated by the reference character IR is connected across the rails adjacent the left-hand end of section ab, and a track battery I! is connected across the rails adjacent the opposite end of this section. The rails of the siding IE to the left of point b are connected with the rails of section ab in accordance with the usual practice.

Eastbound traflic over switch 3 is controlled by a signal t and westbound traffic over this switch is controlled by signals 11 and '01. The switch 3 is controlled by a motor Im which is in turn controlled by two switch relays IU and IV. The switch 3 controls a plurality of contacts in such manner that when the switch occupies its normal position, in which it is shown in the drawings, contacts I8I8 I9I9'-- and 2IJ2IJ= are closed. When the switch is reversed, however, contacts I8I8 I9I9 and 20-2I.I are closed. Furthermore, contact 2I2I is closed at all times except when the switch occupies its reverse position and contact 2 I2 I is closed at all times except when the switch occupies its normal position. The signals t u and v are controlled in part by contacts actuated by the switch 3, and in part by two signal relays IC and ID. The apparatus located at each of the remaining stations is similar to that just described in connection with station I.

Associated with each panel in the office is a track indication relay designated by the reference character X with an exponent corresponding to the panel. Each track indication relay X controls a lamp 24 in such manner that the lamp is connected with terminals as" and y" over back contact 25 of the associated relay X when this relay is deenergized. As will be described in' detail, hereinafter, each track indication relay X is de-energized when the section of track associated with the corresponding station is: occupied. When one of the lamps 24 is lighted, therefore, the operator is informed that the corresponding section of track is occupied. Furthermore, each panel is provided with two switch indication relays designated by the reference characters Y and Z with exponents corresponding to the panel. Each panel also includes movable control members or keys comprising a manually operable switch lever and a manually operable signal lever designated by the reference characters 1' and it, respectively, with exponents corresponding to the panel.

As shown in the drawings, each section of track is unoccupied and each switch 3 occupies its normal position. Furthermore, the upper blade of each signal it indicates proceed and the remaining signals are at stop. The track indication relay X for each panel at the office is energized, so that all lamps 24 are extinguished and each switch indication relay Y is energized but each relay Z is deenergized. Each switch lever r occupies its normal position and each signal lever It occupies its left-hand position. At the office the stop relays el and e3 associated with each panel are energized, but the remaining stop relays are all de-energized and all the start relays g and send relays h are also de-energized. In similar manner at each station the stop relays: El and E3 are energized but all other stop relays are deenergized and all stop and send relays G and H are de-energized. Furthermore, at the office and at each station all transmitting relays T, master relays A, delivery relays B, and slow-acting relays J and K are de-energized. Each motor relay F is also de-energized and all transmitting devices W are at rest. At each station, relays U and C are energized but relays V and D are de-energized.

Under normal conditions, it will be seen that a closed line circuit is completed over line wires l3 and I4 which includes battery Q at the office and also includes the line relay L at the office and at each field station, so that all line relays L and all looking relays P are energized. Commencing with this normal condition of all of the apparatus, I will explain the operation of the system by first assuming that the operator wishes to change the condition of a device located at one of the stations. For purposes of explanation, I will assume that he wishes to reverse switch 3 at station I. To accomplish this result, he moves lever r of panel I in the office to its reverse position. This extinguishes lamp 26 and completes a circuit from terminal .13 over reverse contact of lever r wire 28, back contact 29 of stop relay IeZ, wire 30, winding of start relay I92, wires 3| and 32, and winding of delivery relay 013, to terminal y; Relays I92 and OB therefore become energized and the closing of front contact 39 of relay OB completes apick-up circuit for relay 0A which passes from as, over back contact 33 of relay OK, wire 34, back contact 35 of relay OJ, wire 36, back contact 1 of relay OF, wires 31 and 38, front contact 39 of relay OB, wire 40, and winding of relay 0A to terminal y Relay OA then becomes energized and is thereafter stuck up over a circuit from terminal r front contact 4| of relay OA, wires 42 and 38, front contact 39 of relay OB, Wire 40, and winding of relay 0A to terminal y Back contact 89 of relay CA is connected in parallel with front contact 90 of relay CT in the normally closed line circuit by means of which current is supplied from battery Q to the line relays L at the office and at each station, but relay OT is now ole-energized so that when relay OA becomes energized, the line circuit is opened to initiate the control code and all relays L become (la-energized. The opening of relay OL breaks the circuit for relay OP from terminal x through front contact 53 of relay OL, wires 54 and 55, and winding of relay OP to terminal y. Relay OP therefore becomes de-energized, but due to the slow acting characteristics of this relay, a time interval elapses after the opening of relay 0L and prior to the closing of back contact 51 of relay OP. At the expiration of the time interval required for relay OP to drop, back contact 5I of this relay closes, whereupon current flows from terminal at, through front contact 43 of relay OA, wire 44, back contact 51 of relay OP, wire 58, and winding of relay OF to terminal 1 The motor relay OF then becomes energized, thereby completing, at front contact 8 thereon, the circuit previously traced for motor M of the transmitting device OW. Shaft 4 therefore commences to operate and by the operation of the latch E, the rotation of this shaft continues for one complete operation, even though relay OP may be subsequently energized to interrupt the circuit just traced for relay OF.

When relay OA became energized, the closing of front contact 43 completed a circuit from terminal 112, over front contact 43 of relay OA, wires 44 and 45, contact II--I2 operated by cam 9 of device OW, wire 46, thence through a normally closed contact 41 on each of the sending relays h in series, wire 48 and thence through a back contact of each of the start relays g in series to front contact 49 of relay Ig2,

wires

50 and 5!, and winding of relay Ih2 to terminal 111. Relay Ih2 therefore picks up, thereby completing a stick circuit for this relay which passes over the path just traced to front contact 52 of relay Ih2, thence through wire 5| and winding of relay N12 to terminal y". When relay i722 becomes energized, the opening of the associated contact 41 opens the pick-up circuits for all send relays h below IhZ. Furthermore, the energization of .relay I 92 opens the circuit for all send relays h above Ih2. It will be plain therefore that only one send relay h can be energized at a time.

Since relay I712 is now energized, a circuit is completed from terminal :12, through the winding of relay OT, wire 59, front contact of relay m2, and wire 6| through the code wheel of the transmitting device OW associated with relay Ih2 to terminal 1; so that relay OT picks up to close the line circuit. This terminates the first element of the control code, which is thus a relatively long line open period. This initial element is employed as a locking element, in a manner hereinafter pointed out, to prevent interference with a control code by the stations. As the transmitting device OW operates, the code wheels rotate, and therefore, the circuit for relay OT is periodically opened and closed in accordance with a predetermined code. As a result, relay OT is periodically energized and de-energized in accordance with this code. Each time relay OT becomes energized, the closing of front contact 90 of this relay closes the line circuit including the battery Q and all of the line relays at the several stations. It follows therefore that under the conditions just described, the periodic operation of relay OT impresses upon the line wires I3 and I4 a control code which may be utilized to actuate traffic governing means at one of the stations.

Located at each of the stations is a group of selectors of any suitable type each designated by the reference character S with a distinguishing suffix and a prefix corresponding to the station. As here shown each selector comprises a winding 69 and a contact H! which is arranged to be closed for a brief interval of time when the assoclated winding is supplied with a predetermined code. Referring particularly to station I, when a control code is impressed upon line wires I3 and M by operation of transmitting relay OT at the office, relay IL at station I is periodically energized and de-energized in synchronism with relay OT. The first time the relay IL becomes de-energized, current flows from terminal 03 through back contact 53 of relay IL, wire 62, and winding of relay IK to terminal y Relay IK therefore becomes energized. Of course the circuit for relay IK is opened when relay IL next becomes energized, but due to the slow act ing characteristics of relay IK, this relay holds its front contacts closed during the brief intervals that relay IL is energized while this relay is receiving a control code. When relay IK is energized, current flows from terminal m over front contact 33 of relay IK, wire 63, and winding of relay IJ to terminal 3 so that relay IJ is also energized. It will be seen therefore that the first de-energization of relay IL in response to a code received from the office picks up both relays IK and IJ. When relay IL next becomes energized, current flows from terminal m over front contact 53 of relay IL,

wires

54 and 64, front contact of relay IJ, wire 66, back contact 6! of relay IA, wire 68, thence through windings 69 of all of the selectors IS at station I in parallel to terminal y It will be plain from the foregoing, that as a result of the intermittent operation of line relay IL, due to the reception of a control code from the office, energy is intermittently supplied to the windings 6-9 of the selectors in accordance with this code. Selector IS2 is responsive to the control code delivered to the line wires when relay Ih2 is energized as hereinbefore described. At the conclusion of the code, selector IS2 operates to close its contact I0, but theremaining selectors are unaffected. The closing of contact III of selector IS2 completes a pick-up circuit however, for switch relay IV which thereupon becomes energized and breaks the stick circuit for relay IU. When relay IU is de-energized, a stick circuit is completed for relay IV over back contact I2 of relay IU and front contact I3 of relay IV. Relay W is therefore maintained in its energized condition, even though contact ID of selector IS2 reopens.

When relay IV becomes energized, the motor im actuating switch 3 is energized. In the form here shown this motor comprises an armature BI and a field 82 and is provided with a circuit which passes from terminal x over front contact I4 of relay IR, Wires I5 and 16, front contact I8 of relay IV, wire 19, armature 8| of motor Im, wire 80, back contact 83 of relay IU, wire 84, front contact 85 of relay IV, wire 86, contact '2I--2I operated by switch 3, and field 82 of motor Im to terminal 11 As a result, the motor Im operates to move the switch 3 toward its reverse position. When the switch has attained its reverse position, contact 2I--2I opens to deenergize motor Im. It should be pointed out that the control code delivered to the line wires I3 and I4 is supplied to the selectors located at each of the stations in the same manner as has already been described in connection with station number I, but that selector ISZ is the only one which is responsive to the control code which is delivered when relay Ih2 is energized at the ofiice.

Just before the conclusion of the control code, cam 9 of transmitting device OW moves contact I9 into engagement with contact II. As a result, current flows from terminal cc, over front con tact 43 of relay A, wires 44 and 45, contact II-IO operated by cam 9, wire 9|, front contact 92 of relay IhZ, wire 93, winding of stop relay IeZ to terminal y. Relay Ie2 therefore becomes energized to interrupt the circuit for start relay IgZ. Relay 62 is stuck up over its own contact and a reverse contact of lever r At the same time, contact III2 is opened by cam 9 so that the stick circuit for relay Ih2 is interrupted and this relay becomes de-energized. If no other lever at the office has been operated to energize the start relay, all of the parallel circuits for relay OB are now open, so that this relay becomes de-energized, breaking the stick circuit for relay OA and causing the latter relay to become de-energized. This de-energizes the circuit for motor relay OF so that when the shaft 4 has completed its rotation, latch 6 engages the cam to lock the shaft in its initial position. Furthermore, the closing of back contact 89 of relay 0A again closes the line circuit, energizing relay OL, causing relay OP to pick up, and restoring the apparatus to its original condition.

In similar fashion, at the station, when the line circuit is continuously closed, relay IL is continuously energized. Under these conditions, relays IK and IJ both become die-energized so that the apparatus at the station is also restored to its initial condition. The operation of the apparatus in moving the switch from the reverse to the normal position, will be understood Without further explanation, lever 1' being moved to the left-hand position to pick up selector I SI at station I for this purpose. It should be understood that the operation of the apparatus located at each of the remaining stations is similar to the operation of the apparatus located at station I.

I will now assume that prior to the completion of the code delivered by send relay IhZ, another start relay g at the oifice was energized, as by movement of lever to its middle position to set all the signals at station I at stop. Under these conditions, current from terminal x flows through lever k in its middle position, wire 94, back contact 55 of relay Ie4, wire 95, winding of relay igt, wire 32, and winding of relay OB to terminal y It will be plain, therefore, that with lever k in its middle position, relay Ig4 is energized in series with relay OB, so that when stop relay !e2 becomes energized to open the circuit first traced for relay OB in series with relay Igi, relay OB remains energized by virtue of current supplied thereto in series with relay I-g l. Relay OB therefore holds closed the stick circuit for relay CA and this relay in turn holds closed the circuit for motor relay OF. Under these conditions, the

transmitting device OW does not stop at the conclusion of the first rotation but continues to operate for a second rotation during which the code wheel associated with relay Ih I operates to supply a control code to the line wires I3 and I4 in the same manner as has already been described in connection with the supply of a control code to these line wires by the code wheel associated with the sending relay Ih2. when start relay Ig2 associated therewith is energized. When relay I h t is energized to deliver a control code to the line wires, contact 1'0 of selector IS4 at station I is closed for a brief interval, but none of the other selectors is affected. The closing of contact III of selector I S4 connects terminal r with a common terminal of relays IC and ID. The free terminals of these relays are at times also connected with terminal :0 and it follows that when contact 19 of selector IS4 is closed, both terminals of relays I C and ID are at the same potential so that these relays become de-energized. If contact Ii! of selector IS3 is closed, relay IC becomes energized and is thereafter stuck up over back contact 91 of relay ID and front contact 98 of relay IC, winding of relay IC, wire 99, and resistor I99 to terminal 1 In similar manner if contact I9 of selector IS5 is closed, relay ID is picked up, and this relay is subsequently stuck up by current which flows from terminal 1*, over back contact 98 of relay IC, front contact 9'! of relay ID, winding of relay ID, wire 99, and resistor I98 to terminal 11 Selector IS3 may be closed by moving lever 70 on panel number I at the ofiice to the left-hand position, whereupon the energization of relay Ih3 delivers a control code to the line wires, which actuatesselector 583. Furthermore, selector IS5 may be actuated to pick up relay ID by moving lever k of panel number I at the office to the right-hand position, whereupon a sending relay Ih5 is actuated to deliver a control code to the wires to operate selector IS5.

As has already been explained, either of the signal relays IC or ID may be de-energized by actuating selector IS4 by placing lever k in panel number I in the middle position. If relay IC is energized, when switch 3 at station I occupies its normal position, as shown in the drawings, current flows from terminal x over front contact I4 of relay IR, wires I5, I6 and 11, front contact I82 of relay IC, wire I 03, back contact I04 of relay ID, wire I95, contact I9I9 operated by switch 3, wire I96, and operating mechanism of the upper blade of signal to terminal y Under these conditions, the upper blade of signal 25 indicates proceed. If switch 3 is reversed, when relay IC is energized current flows over the circuit just traced as far as wire I 05, thence through contact I9I9 wire I01, and operating mechanism of the lower blade of signal t to terminal g thereby causing the lower blade of signal t to indicate proceed. If, however, relay ID is energized, signal u or signal '0 may be cleared, depending upon the condition of switch 3. The circuit for signal 11 may be traced from terminal r over front contact I4 of relay IR, wires 55, 16, H and I08, front contact I09 of relay ID, wire II B, back contact III of relay EC, wire 1 I2, contact I8---I8 operated by switch 3, wire I 93, and operating mechanism of signal b to terminal 31 If switch 3 is reversed, however, current flows over the circuit just traced as far as wire II2, thence over contact I8I8 wire II 4,

and operating mechanism of signal u to terminal 11 Although I have referred particularly to the apparatus located at station I, it should be understood that the apparatus at the remaining stations operates in similar manner, the selectors S at the several stations being separately responsive to the control codes delivered to the line wires when the code Wheels associated with the corresponding panels at the oflice are utilized to supply the codes.

In addition to the transmission of control codes from the office to the several stations, the apparatus is arranged to transmit indication codes from the several stations to the office. In explaining this feature of the apparatus, I will assume that a train enters section (1-5 at station I, thereby de-energizing track relay IR. The closing of back contact I I5 of this relay picks up relay IG2 and IB in series, over back contact I I6 of stop relay IE2, the circuit being clear from the drawings without tracing it in detail. When relay I B becomes energized, the closing of front contacts II! and I30 thereon completes pick-up circuit'for relays IA and IT. The pick up circuit for relay IA may be traced from terminal 92 over front contact 53 of relay IL,

wires

54 and 64, back contact 65 of relay IJ, wire II 8, back contact I of motor relay IF, Wire II9, front contact II'I of relay B, wire I20, winding of relay IA, wire I2I, and front contact I22 of relay IP, to terminal 1 It will be plain that this circuit is closed only if the line circuit is completed so that relay IL is energized, and if relay IP is also energized. The circuit for relay IT may be traced from terminal x relay IT, wire I29, front contact I30 of relay IB, contact 22, which is closed when motor I M is at rest, to terminal 11 When relay IA becomes energized, the normal line circuit through its back contact I 32 is interrupted, and the line beyond station I is shunted by a connection from that portion of line wire I4 at the right of the station to line wire I3, over front contact I32 of relay IA, so that the portion of the line circuit to the right of station I is short-circuited. At the same time, the portion of line wire I4 to the left of station I and including relay IL is connected with line wire I3 through a resistance I33 over front contacts I32 and I34 of relays IA and IT. The resistance I33 is proportioned to compensate for that portion of the line which has been shunted by closing of front contact I32 of relay IA. When relay IA becomes energized, a stick circuit is closed for this relay from terminal :0 over front contact I23 of relay IA, wire I24, front contact II! of relay IB, wire I20, winding of relay IA, wire IZI, and front contact I22 of relay IP to terminal 11 After relay IA has once been energized, therefore, over back contact I of relay IF, the relay is subsequently held closed as long as relays IB and IP are picked up even though motor relay IF subsequently becomes energized. When front contact I25 of relay IA closes, current flows from terminal 33 over front contact I25 of relay IA, wires I26 and I21, and Winding of relay IE to terminal y It should also be noted that the closing of front contact I25 connects terminal through contact III2 operated by cam 9 of transmitting device IW, with wire I3I and thence through the normally closed contacts of send relays H and back contacts of start relays G to front contact I35 of relay IG2, now energized, thereby picking up relay I H2 and preventing the energization of any other H relay. The energization of relay IF sets the transmitting device IW into operation,

so that contact 22 opens, thereby de-energizing relay IT, so that the line circuit is opened to initiate the indication code. Relay III2 is now energized, however, so that the code Wheel associated with this send relay is included in the circuit for relay IT over front contact I36 of relay IH2. It follows that as the transmitting device IW operates, relay IT is again energized by a circuit through the code wheel. The opening of the contact 22 therefore deenergizes relay IT to open the line circuit for only a very brief time interval which is terminated as soon as the code wheel has commenced its operation. During the subsequent rotation of the code wheel, relay IT is periodically energized in accordance with the indication code determined by the code wheel associated with relay I H2. Each time relay IT becomes energized, the line circuit is closed to energize relay IL and also to energize relay OL at the office. Each time front contact 53 of relay IL opens, relay IP is de-energized, but this relay is slow acting and holds its front contact I22 closed for the duration of each of the line open intervals between impulses in the indication code delivered to the line, so that relay IA remains energized.

The first time relay OL at the oflice becomes de-energized in response to an indication code, the closing of back contact 53 of this relay completes a circuit for relay OK, which thereupon closes its front contact 33 to energize relay OJ. Relays OK and OJ, due to their slow releasing characteristics, are subsequently held energized during the periodic energization of relay OL, corresponding to the code received from station I. Each time relay OL becomes energized, current flows from terminal as", over front contact 53 of relay OL, wires 54 and I31, back contact I38 of relay OA, wire I33, front contact I 43 of relay OJ, and thence to wire I4I which is connected with the windings 69 of all of the selectors N at the ofilce. Each of the panels is provided with a set of these selectors N which are similar to selectors S at the stations and are selectively responsive to the indication codes received from the stations. Selector IN2 is responsive to the code delivered to the line when sending relay lI-IZ at station I is energized, so this selector now closes its contact If! for a brief interval. When contact 'IU of selector INZ becomes closed terminal 33 is connected with the right-hand terminal of relay x and since the potential of the two terminals of this relay are then equal, the relay becomes de-energized and remains de-energized after contact I3 of selector INZ opens. With relay 3: de-energized, the lamp 24 is lighted to indicate to the operator that a train occupies section 41-41 at station I.

When the transmitting device IW has completed one rotation, contact III--II closes and contact III2 opens. Stop relay IE2 then picks up, and assuming that no other relay G at station I is energized, the energization of stop relay IE2 breaks the circuit for relay IB at back contact H5 of relay IE2. The relay IE2 is subsequently held closed by its stick circuit over back that the apparatus isnow restored to its normal condition.

If the line relay remains open during transmission of' the code, as would be the case, for ex ample, if the line circuit were opened due to a line break, relay IP opens its front dontact. When this happens, relay IA, of course, becomes de-energized. This opens the circuit for the send relaythen energized and immediately discontinues the supply of code to the line circuit. Contact 8 of relay IF-is now held closed mechanically however, and the transmitter is restored to its initial position so that when the line break is repaired, the transmitter starts from the proper position to deliver aperfect code to the line circuit.

If'track relay IR now becomes energized, the closing of front contact I I5 of this relay picks up relays IG;I and: IB, whereupon the operation of the apparatus located at station I is similar. to that already described in connection with the de-energization of relay IR, with the exception that whenrelay I-I-II becomes energized the code wheel associated with this relay determines the code delivered to the office. The indication code transmitted under these conditions, picks upselector INI atthe ofiice and when contact 'Illizof this selector closes, current is supplied to-relay 1: and this relay is subsequently stuck up over itsown front contact 25, thereby-extinguishing the lamp 2 4: to indicate tothe operator that the train has passed out of section a-b at station I.

Furthermore, thecontacts 2Il----2ll and 2IJ--2Il operated by switch 3: at station I control send relays IH3 and IE4, respectively, so that indication: codesgoverned by the code wheels associated with these relays can be delivered to the office to actuate selectors IN3 and IN4, respectively. As-shown in the drawings, relayY is energized by-current which flows from terminal x over a normal contact of lever r back contact Mil of relay 2 a front. contact I4I of relay Y and through, the winding of relay Y to terminal y". Under these conditions, current also flows over a frontcontact IA], of relay Y to an indicator lamp 26. When lamp 26 is lighted, therefore, theoperator is informed that the switch occupies itsnormal position. If the operator moves lever T to. its reverse position, thereby transmitting the control code to actuate motor Im at station I to reverse switch 3, contact 2020 at station I will be closed, whereupon the apparatus at station I will be actuated totransmit to the office an indication code which picks up selector IN4. It should be noted as soon as the lever r was moved away from its normal position the stick circuit for relay Y was opened and lamp 26 was extinguished. When contact III of selector IN4 closes, a pick up circuit is closed for-relay Z and this relay is subsequently stuck up over its own front contact I48, back contact I II of relay Y and the reverse contact of lever r Under these conditions, current is supplied to lamp 2'! to indicate that switch 3 at station I occupies its reverse position.

Attention should be drawn to the fact that the switch indication lamps 26 and 21 can be lighted only when the position of the switch corresponds tothe position of the control lever at the ofiice.

The apparatus located at each station is arranged to permit the storing of indications in the, same manner as has already been described in connection with the apparatus at the office, That is to say, if relay IB at station I has been picked up in series with relay IGZ, to deliver tothe oflice the indication code corresponding to the send-.

ing. relay IE2, and if prior to thecompletion of this code another start relay G. is energized, as for example, start relay IG I, the transmitting device IW does not stop at the end of its first rotation but continues for a second rotation or for successive rotations until the codes corresponding to all start relays GI which are energized are delivered in succession to the ofilce;

It will be apparent from the above description that the start relays G at each station are deenergized by picking up the associated stop relay E and in similar manner the start relays gat the office are de-energized by picking up the associated stop relay e. Each stop relay e re mains energized, after it has once been picked up, until the device which controls it is moved to a different position. For example, as shown in the drawings, the stop relays el and e3 asso ciated with each panel at the ofiice are energized as a result of the fact that the control codes last transmitted from each of these panels were the codes corresponding to the normal position of lever r and the left-hand position of lever 70.

In similarmanner, the stop relays IEI and IE3.

at station I are energized: as a result of the fact that the energization oftrack relay IR- and'the movement of theswitch 3 to its normalposition initiatedthe transmission of the indication: codes which were last transmittedbydevice IW; As soon as one of the levers associated-with-a panel in the oifice is movedfromthe position in whichit is illustrated in the drawings, the corresponding stop relay will become de-energized; audit the lever is quickly returned toits original position, the control code corresponding to that position may be delivered to the stations without first sending another code. At the stations, it is, of course, impossible-'to'repeatan indicationcode until the indication code-corresponding to the opposite position of the related function has been delivered to the ofiice. For-example, after track relay IR has'been: energized to pick up selector INI- at the office, stop relay IEI isenergizedand relay IGI- cannot again be energized until stop relay IEI is de-energized-by deenergization of relay- IR.

It will be observed fromthe: drawings that the selectors N at-the ofiice can be actuated only when relay OJ is energized and whenrelay-OA is de-energized. But when: a control code is being delivered from the oflice to the stations, relay 0A is energized so that'under these-conditions all of the selectors at the office are deenergized. Furthermore, the selectors S at each stationare disconnected when the corresponding relay A is energized but this relay must be energized when an indication code is being delivered from such station to the office. With this arrangement it will be seen that all selectors located at the ofiice and at' each station are disconnected when a code is being delivered to, the line from that location. One advantage of this feature is that it results in economy of codes necessary to operate the system. That is to say, selectors associated with panel number I can be operated upon codes which are the same, except for the character of the initial locking element which distinguishes a control code from an indication code, as the codes which operate the selectors located at station I without interference between the two sets of selectors because when selectors N associated with the office are connected with the line wires to receive indication codes from the code wheels atstation I, selectors S at this station are always disconnected from the line wires.

It has already been pointed out that after one of the transmitting devices W has been set into operation, the motor will continue to operate to rotate the shaft until the wheels have been restored to their initial positions, irrespective of changes in the circuits which first set the device into operation, It is therefore assured that the devices W will always come to rest in their initial position.

At each of the stations and at the ofiice the pick up circuit for the associated relay A is carried over a back contact of the motor relay F. It is therefore impossible to energize a relay A until the corresponding motor relay is de-energized, as will be the case only when the transmitting device is at rest. With these arrangements, since the relay A must be energized before codes can be transmitted, it is impossible to start the sending of a code from a location unless all of the code wheels at that location occupy their initial positions.

It will be remembered that when the office starts to send a control code, the line is opened for a relatively long time interval, and that all line relays L become de-energized as soon as relay OA picks up, and do not become re-energized until after the time interval required to release relay OP, start the transmitting device OW, and energize relay OT to begin the first line closed impulse of the code. At each of the stations, the de-energization of the line relay L at that station picks up the associated relays K and J in cascade, so that the pick-up circuit for relay A at such station is opened at the beginning of the control code at front contact 53 of relay L, and is then held open for the duration of the code at back contact 65 of the associated relay J. Since no station can commence to send, until the associated relay A is energized, it follows that no station can send an indication code while a control code is being delivered to the line wires from the oflice.

Furthermore, when any field station is sending, the relays J at all remaining stations will be energized to prevent such other stations from sending indication codes until the first station has completed its codes. If two stations start to send simultaneously, front contact I32 of relay A at the station nearest the office sectionalizes the line circuit as already described and so causes the line relays at more remote stations to release and to remain deenergized for the duration of the indication code. The locking relay P at each more remote station will therefore release, opening its contact I22 in the stick circuit for the associated relay A to release relay A if energized, thereby preventing such remote stations from sending until the normal line is again closed at all stations.

When a code originates at a station, the line is opened only for a brief interval as explained hereinbefore, and if a station and the office start to send at the same time, the initial long line open period during which the line is held open at the office allows the locking relay P at each station to release to open the stick circuit for the associated relay A. It follows that any station relay A that is energized will be released during the initial locking element of a control code, so that the office takes command of the line for sending its codes before any station can send.

Finally, the office can start to send only when the line is closed and no code is being received.

Thus if an indication code is being received from a station, the release of relay OL at the beginning of the code energizes relay OK to open back contact 33 in the pickup circuit for relay OA, and then relay OJ picks up, opening contact 35 to hold the pickup circuit for relay OA open for the duration of the code. Under these conditions, even though one or more of the start relays g and the delivery relay OB become energized, relay OA can not pick up to start sending control codes until the indication. codes have been received and the line is again steadily closed for a time sufficient to pick up relay 0L and to allow relays OK and OJ to release. It will be apparent from the foregoing that the line circuits are so arranged that it is impossible for two stations to send codes at the same time and it is therefore impossible for codes to be confused by simultaneous operation of more than one of the transmitting devices W.

Although I have herein shown and described only one form of railway traffic controlling 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 of my invention.

Having thus described my invention, what I claim is:

1. Railway trafiic controlling apparatus comprising an office and a remote station, a line relay at the ofllce, a normally closed line circuitineluding said line relay and extending to said station, a slow releasing relay arranged to be energized when said line relay is de-energized, a manually operable lever, means controlled by said lever and effective when said slow releasing relay is released to initiate the delivery of a control code to said circuit, means for completing the delivery of said control code after said slow releasing relay becomes energized, means at said station selectively responsive to said control code, means also at the station for at times periodically opening and closing said circuit in accordance with an indication code, and a selector at the oifice selectively responsive to said indication code and controlled by said line relay when and only when said slow releasing relay is energized.

2. Railway traffic controlling apparatus comprising an office and a station, a line relay at said station, a normally closed line circuit including said line relay and extending to said office, a slow releasing locking relay controlled by a front contact of said line relay, means responsive to traffic conditions adjacent said station and operating when said locking relay is picked up to periodically interrupt said circuit in accordance with an indication code, means located at the ofiice and responsive to said periodic interruptions of said circuit in accordance with said indication code, means also located at the ofiice for at. times opening said circuit for a time interval greater than the release time of said locking relay, and for subsequently delivering a control code to said circuit, and a selector at said station controlled by said line relay and selectively responsive to said control code.

3. A centralized trafiic controlling system for railroads comprising a line circuit, a movable member, a start relay, a stop relay, a send relay, means effective upon operation of said member to energize said start relay provided said step relay is de-energized, means for energizing said send relay when said start relay is energized,

transmitting means for delivering a distinctive code to said line circuit when said start and send relays are both energized, means for energizing said stop relay at the conclusion of said code, and means for subsequently maintaining said stop relay in its energized condition until said member is again operated.

4. A centralized trafiic controlling system for railroads comprising a line circuit, a movable member, a start relay, a stop relay, a send relay, means eifective upon operation of said member to energize said start relay provided said stop relay is de-energized, means for energizing said send relay when said start relay is energized provided said line circuit is clear, transmitting means for delivering a distinctive code to said line circuit when said start and send relays are both energized, and means for energizing said stop relay at the conclusion of said code.

5. A centralized traffic controlling system for railroads comprising a line circuit, a movable member, a start relay and a delivery relay arranged to be energized when said member is operated, means eiiective when said delivery relay is energized to include a transmitting contact in said line circuit provided the line circuit is clear, a'send relay arranged to be energized when said start relay is energized provided said transmitting contact is included in the line circuit, means effective when said send relay is energized tooperate said transmitting contact to'deliver a distinctive code to-said line circuit, and means for deenergizing said start and delivery relays at the conclusion of said code.

6. A centralized traffic controlling system for railroads comprising a line circuit, a plurality of code wheels each having a contact operated in accordance with a distinctive code when the wheel is rotated, a plurality of start relays one for each said wheel, means for selectively energizing said start relays, means set into operation when any start relay is energized for operating all of said code wheels, a plurality of send relays one for each said start relay, means for energizing in a definite sequence all send relays havingthe associated start relays energized, and means operating'when any send relay is energized to supply said line circuit with a distinctive code under the control of the contact operated I by the associated code wheel.

7. In combination with a line circuit, a plurality or" manually operable levers; a start relay, 2. send relay and a stop relay for each position of each such lever; means for energizing each such start relay when the associated lever is moved to the position corresponding to such start relay provided the corresponding stop relay is de-energized, a circuit for each send relay including a front contact of the associated start relay, means operating when any send relay is energized to deliver a distinctive code to said line circuit, means for energizing each stop relay momentarily at the conclusion of the corresponding code, and means for subsequently holding such stop relay energized until the associated lever is moved away from the corresponding position.

8. In combination with a line circuit, a plurality of manually operable levers, a plurality of code wheels each having a contact operated in accordance with a distinctive code when the wheel is rotated, means set into operation upon a movement of any of said levers for driving all said code wheels, and means for delivering to said line wires a distinctive code under the control of a selected one of said code wheels depending upon the new position of the operated lever.

9. In combination, a movable lever, a line circuit, means responsive to a movement of said lever for delivering a control code to said line circuit, a device controlled in accordance with said control code, means responsive to the condition of said device for delivering an. indication code to said line circuit, a relay selectively controlled in accordance with said indication code, and indication means controlled jointly by said lever and said relay.

10. In combination with an office and a plurality of stations, a plurality of line relays one at the olfice and one at each said station, a single source of energy, a line circuit including said source and all said line relays, means at the ofiice for delivering codes to said line circuit, sectionalizing means at each station for at times closing the portion of said circuit between such station and the oflice through a resistance to compensate for the portion of the line circuit then eliminated, means at each station efiective when the associated sectionalizing means is effective to deliver codes to that portion of the line circuit between such station and the ofiice, and code receiving means controlled by each line relay.

11. In combination with an ofiice and a plurality of stations, a single source of energy located at said ofiice, a plurality of line relays one at said ofiice and one at each station, a line circuit including said source and all said line relays in series, a transmitting contact at each station, means at each station for at times closing the portion'of said line circuit between such station and the oflice through the associated line relay and transmitting contact and a resistance to compensate for the portion of the line circuit then eliminated, means controlled by the line relay at such station for subsequently operating the corresponding transmitting contact to deliver a code to the portion of the line circuit between such station and the office, and code receiving means at the oflice controlled by the line relay there located.

12 In combination, an office and a plurality of stations, a plurality of line relays one at the ofiice and one at each station, a single source of energy, a normally closed line circuit including said source and all said line relays in series, seetionalizing means at each station for at times closing the portion of the line circuit between such station and the ofiice through the associated line relay and for short circuiting the line circuit portion extending to all stations more remote from said ofiice, transmitting means at each station controlled by the associated sectionalizing means and line relay for delivering codes to the portion of the line circuit between such station and the ofiice and code receiving means at the ofiice controlled by the line relay there located.

13. In combination with a line circuit, a transmitter relay for controlling said line circuit, a code wheel, a motor for driving said code wheel, means effective if and only if said motor is at rest for causing a preliminary operation of said transmitter relay, means responsive to said preliminary operation of said transmitter relay to operate said motor, and means for subsequently controlling said transmitter relay by said code wheel to deliver a code to said line circuit.

14. In combination with a normally closed line circuit including a source of energy and a line relay, time measuring means arranged to be operated if said line relay remains deenergized for more than a definite time interval, a movable device, a stop relay normally agreeing in position with said device, transmitting means set into operation upon a disagreement between said device and said stop relay to periodically open said line circuit to produce a complete code, and means controlled by said time measuring means and effective upon the completion of said code to move said stop relay into agreement with said device.

15. In combination with an ofiice and a plurality of stations, a plurality of line relays one at the oifice and one at each station, a normally closed line circuit including a source and all said line relays in series, transmitting means at the oifice and at each station for delivering codes to at least a portion of said line circuit, and code receiving means at the oilice and at each station arranged to be controlled by the associated line relay and means for modifying the control of each receiving means by the associated line relay when the corresponding transmitting means is delivering a code to the line circuit.

16. In combination with a normally closed line circuit including a source of energy and a line relay, time measuring means arranged to be operated if said line relay remains deenergized for more than a definite time interval, a start relay, transmitting means actuated when said start relay is operated to periodically open said line circuit to produce a complete code, means for operating said start relay, means controlled by said time measuring means for maintaining said transmitting means in operation until said code is completed, and means controlled by the last named means effective upon the completion of said code to restore said start relay to its original condition.

17. Remote controlling apparatus comprising a normally closed line circuit extending from an office to a plurality of remote stations and including in series a line relay at each station, means for supplying current to said line circuit, a delay relay for each remote station arranged to be energized when the corresponding line relay is deenergized, a code transmitting contact at each station, means for each station effective only if the associated line relay is energized and the associated delay relay is deenergized for at times closing the portion of said line circuit between said station and the office through the associated transmitting contact and for disconnecting said current supplying means from the line circuit portion extending to all stations more remotefrom the ofiice, means for subsequently operating said transmitting contact to deliver a code to the line circuit portion extending to the ofiice provided such portion is closed, and means operating upon the completion of such code to restore the normal line circuit.

18. Remote controlling apparatus comprising a normally closed line circuit extending from a control station to a plurality of remote stations and including in series a line relay at each station, means for supplying current to said line circuit, storing contacts at each remote station, means operating when a storing contact is closed at any remote station to deliver a code to the portion of the line circuit between such remote station and the control station and including the line relay at such control station, means effective when any station is delivering a code to the line circuit to disconnect said current supplying means from all stations more remote from the control station, and means for preventing the delivery of code from each remote station until the associated line relay is energized and the line circuit between such station and the control station is closed.

19. In combination, a normally closed line circuit, a plurality of transmitting stations each comprising a circuit controller for sending a signal over said circuit by successive brief interruptions of the circuit, a slow releasing relay at each station for preventing operation of the circuit controller at such station While the armature of the relay is released, the time required for said relay torelease being greater than the interval between interruptions in the signals, a line relay at each station included in said line circuit and having a front contact, and a circuit for each slow releasing relay including the front contact of the line relay at the same station.

20. In combination with a line circuit, a code transmitter for repeatedly interrupting said line circuit, a line relay in said line circuit, a first slow release relay controlled by a front contact of said line relay, a second slow release relay controlled by a back contact of said line relay, means for starting said transmitter effective only when said first slow release relay is energized and the second slow release relay is deenergized. 21. In combination with a line circuit, a code transmitter for repeatedly interrupting said line circuit, a line relay in said line circuit, a first slow release relay controlled by a front contact of said line relay, a second slow release relay controlled by aback contact of said line relay, means requiring one of said slow release relays to be energized f or starting said transmitter, and means requiring the other relay to be energized to complete the operation of said transmitter.

22. Means for transmitting code over a line circuit to a. remote station comprising a transmitter for interrupting said line circuit, a line relay in said line circuit at said transmitter station, a first slow release relay energized during each code operation of said line relay, a second slow release relay controlled by a front contact of said first slow release relay, and means for starting said transmitter effective only if both of said slow release relays are deenergized.

23. In combination with a line circuit including a source of energy and a line relay, transmitting means for periodically opening said line circuit to produce a code, apparatus for setting said transmitting means into operation, a slow acting relay controlled by said line relay for maintaining said transmitting means in operation to complete said code, and a. stop relay controlled by said slow acting relay for stopping said transmitting means upon the completion of said code.

24. In combination with a line circuit including a source of energy and a line relay, time measuring means arranged to be operated if said line relay remains deenergized for more than a definite time interval, transmitting means arranged when operated to periodically open said line circuit to produce a complete code, and means controlled by said time measuring means and eiTective upon the completion of said code to discontinue the operation of said transmitting means.

25. In combination with a line circuit including a source of energy and a line relay, time measuring means arranged to be operated if said line relay remains deenergized for more than a definite time interval, a start relay, transmitting means actuated when said start relay is operated to periodically open said line circuit to produce a complete code, means for Operating said start relay, and means controlled by said time measuring means and effective upon the completion of said code to restore said start relay to its'original condition.

26. In combination, a plurality of receiving stations connected by a line circuit supplied with codes, a line relay at each station in said line circuit, receiving means at each station selectively responsive to a selected sequence of operations of the line relay at the corresponding station in response to a particular code, and means at each station responsive to a first operation of said line relay to place said receiving means under the control of said line relay, said last-named means being responsive to a cessation of the operation of said line relay to remove said receiving means from the control of said line relay.

27. In combination with a line circuit including a source of energy and a line relay, transmitting means for periodically opening and closing said line circuit to produce a code, receiving means selectively responsive to said code, means responsive to the first operation of the line relay to place the receiving means under the control of said line relay, and means effective if the line relay is energized for more than a definite time interval to remove the receiving means from control by said line relay.

28. In combination with a line circuit including a source of energy and a line relay, means for controlling said line circuit to produce a code, time measuring means arranged to be operated if said line relay remains deenergized for more than a definite time interval, receiving means, and means controlled by said time measuring means for placing said receiving means under the control of said line relay.

29. In a centralized traffic controlling system for railways, means for selectively transmitting a plurality of code signals over a line circuit comprising a series of manually operable keys, one for each code to be transmitted, a starting relay for each key, means for starting transmission of a code when any starting relay is actuated and the line is clear, means controlled by each starting relay when actuated for selecting a particular code for transmission so arranged that the codes corresponding to a plurality of starting relays actuated simultaneously are transmitted consecutively in predetermined order, a circuit for actuating each starting relay when the corresponding key is operated, and means for releasing each starting relay at the completion of the transmission of the code determined by such starting relay.

30. A centralized trafiic controlling system for railroads comprising in combination, a line circuit, means for transmitting code signals to said line circuit; a plurality of individual transmitting units each comprising a movable member and normally deenergized start, send, and stoprelays; means effective upon operation of any said member to energize the corresponding start relay, means effective when any start relay is energized to energize the corresponding send relay and to start said transmitter provided said line relay and said transmitter are at rest, means controlled by each said send relay for selecting a particular code for transmission, means for energizing said stop relay at the end of such code, means controlled by said stop relay for releasing said start and send relays and to thereby stop said transmitter, and holding means efiective to maintain said stop relay energized until said movable member moves to a new position.

31. In combination with a line circuit, a starting circuit'including a start relay, control means having at least two positions and effective in one position to close said starting circuit, means efiective when said starting relay is energized to transmit a code to said line circuit, means effective momentarily at the conclusion of said code for opening said starting circuit, and means controlled by said control means for subsequently holding said starting circuit open as long as said control means occupies said one position.

32. A code transmitter for selectively transmitting a plurality of codes over a line circuit, comprising a series of starting relays one for each code to be transmitted, a series of sending relays one for each starting relay, means for independ ently actuating said starting relays; means for energizing each sending relay when the corresponding starting relay is actuated, provided no succeeding starting relays, and no preceding sending relays of the series have been actuated; and means effective when a sending relay becomes energized to transmit a selected code to said line circuit.

33. In a centralized trafiic controlling system for railroads comprising an office and a station located at spaced points and connected by a line circuit, a plurality of movable devices at one said point, a series of starting mechanisms each having normal and reverse contacts and each controlled by a particular one-of said devices, a series of sending relays one for each said starting mechanism, a circuit for each sen-ding relay including a reverse contact of the associated starting mechanism and a back contact of each succeeding sending relay in said series, a master relay, means for operating said master relay when any starting mechanism is moved to its reverse position, trans,- mitting means effective when said master relay is operated to deliver to the line circuit a distinctive code the character of which depends upon the particular sending relay then energized, and receiving means at the other said point selectively responsive to said code.

34. In a centralized traflic controlling system for railroads comprising an oflice and a station located at spaced points and connected by a line circuit, a plurality of movable devices at one said point, a series of starting mechanism each having normal and reverse contacts and each controlled by a particular one of said'devices, a series of sending relays one for each said starting mechanism, a circuit for each sending relay including a reverse contact of the associated starting mechanism, a normal contact of each preceding starting mechanism, and a back Contact of each succeeding sending relay, a mast-er relay, means for operating said master relay when any starting mechanism is moved to its reverse position, transmitting means efiective when said master relay is operated to deliver to the line circuit a distinc tive code the character of which depends upon the particular sending relay then energized, and

. receiving means at the other said point selectively mechanism, a circuit for each sending relay including a reverse contact of the associated starting mechanism, a normal contact of each preceding starting mechanism, and a back contact of every sending relay in said series, a master relay, means for operating said master relay when any starting mechanism is moved to its reverse position, transmitting means efiective when said master relay is operated to deliver to the line circuit a distinctive code the character of which depends upon the particular sending relay then energized, and'receiving means at the other said point selectively responsive to said code.

36. In a centralized traffic controlling system for railroads comprising an ofiice and a station located at spaced points and connected by a line circuit, a plurality of movable devices at one said point, a series of starting mechanisms each having normal and reverse contacts and each controlled by a particular one of said devices, a series of sending relays one for each said starting mechanism, a pick-up circuit for each sending relay including a reverse contact of the associated starting mechanism, a holding circuit for each sending relay including its own front contact, a master relay, means for operating said master relay when any starting mechanism is moved to its reverse position, transmitting means effective when said master relay is operated to deliver to the line circuit a distinctive code the character of which depends upon the particular sending relay then energized, and receiving means at the other said point selectively responsive to said code.

3'7. In a centralized trafilc controlling system for railroads comprising an oflice and a station located at spaced points and connected by a line circuit, a plurality of movable devices at one said point, a series of starting mechanisms each having normal and reverse contacts and each controlled by a particular one of said devices, a series of sending relays one for each said starting mechanism, a pick-up circuit for each sending relay including a reverse contact of the associated starting mechanism, holding means for subsequently maintaining said sending relay in its energized condition, a master relay, means for operating said master relay when any starting mechanism is moved to its reverse position, transmitting means efiective when said master relay is operated to deliver to the line circuit a distinctive code the character of which depends upon the particular sending relay then energized, means efiective upon the conclusion of such code to disable the holding means for the sending relay then energized, and receiving means at the other said point selectively responsive to said code.

38. In combination, a control lever, a line circuit, and a movable device, means for delivering a control code to said line circuit to actuate said device to a position determined by the position of said lever, indication means associated with said lever, means controlled by said device when actuated for delivering an indication code to said line circuit, means responsive to the delivery of a control code to said line circuit to deenergize said indication means, and means responsive to said indication code to reenergize said indication means to indicate the position of said device.

39. In combination, a railway switch, a line circuit, a control lever for the remote control of said switch, means associated with said lever for indicating the position of the switch, means controlled by said lever for transmitting a control code signal over said line circuit to operate said switch and for simultaneously deenergizing said indication means, means actuated by said control code for moving said switch, means responsive to the completion of the movement of said switch for transmitting an indication code signal over said line circuit, and means controlled by said indication code for energizing said indication means to indicate the position of said switch.

40. In combination with a line circuit, a movable device having at least two positions, two starting circuits arranged to be closed when the device is moved to said two positions respectively, code transmitting means, starting means in said starting circuits energized by the closing of either such circuit to operate the transmitting means to deliver a distinctive code to the line circuit, means effective momentarily at the conclusion of a code to deenergize said starting means, and means controlled by said device for subsequently holding said starting means deenergized as long as the device remains in the position it then occupies.

41. Field station apparatus for a remote control system comprising a line circuit and having means for delivering codes to said line circuit having initial locking elements of selected characters, comprising transmitting means at said station for at times delivering to said line circuit codes all having initial locking elements of the same one of said characters, a master relay arranged to be energized during operation of said transmitting means, means for releasing said master.relay rendered effective upon the delivery to said line circuit of an initial locking element which is not of said one character, and receiving means at said station effective when said master relay is denergized to respond selectively to codes having locking elements not of said one character.

42. In combination with a line circuit, a code sending relay, transmitting means eifective when said relay is energized to alternately open and close said line circuit for brief time intervals to produce a code, means for energizing said code sending relay, a slow release relay, means for energizing said slow release relay each time said line circuit is closed during a code, and means controlled by a front contact of said slow releasing relay for maintaining said code sending relay in its energized condition.

43. In combination with a line circuit including a source of energy, a contact and a line relay, transmitting means for controlling said contact to produce a series of alternate periods of open and closed circuit in said line circuit, and a slow acting relay controlled by said line relay and operating if the line relay fails to pick up when said contact is closed to discontinue operation of said transmitting means.

44. In combination with a line circuit including a source of energy and a line relay, a slow release relay, means energizing said slow release relay when said line relay is released, transmitting means for controlling the line circuit to produce a series of alternate periods of open and closed circuit therein, and means requiring said slow release relay to be released to start operation of said transmitting means.

45. In combination with a line circuit including a source of energy and a line relay, a slow release relay, means energizing said slow release relay when said line relay is picked up, and transmitting means effective only when said slow release relay is picked up to control the line circuit to produce a series of alternate periods of open and closed circuit therein.

46. In combination with a line circuit including a source of energy and a line relay, transmitting means for controlling the line circuit to produce a series of alternate periods of open and closed circuit therein, means for discontinuing the control of said line circuit by said transmitting means if said line relay fails to pick up when the line circuit is closed, and means for stopping said transmitter at the conclusion of said series.

47. In combination, a line circuit connecting a plurality of receiving stations, a line relay in said circuit at each station, means for controlling said line circuit to produce a series of alternate periods of open and closed circuit therein, receiving apparatus at each station controlled selectively by the associated line relay, and means at each station responsive to a first operation of the associated line relay for placing the receiving apparatus at that station under the control of the corresponding line relay and responsive to a cessation of the operation of said line relay to remove the receiving apparatus from the control of the line relay.

48. In combination, a line circuit connecting a plurality of receiving stations, a, line relay in said circuit at each station, a transmitter for controlling said line circuit to cause repeated operation of all said line relays, receiving apparatus at each station controlled selectively by the associated line relay, and means at each station responsive to a first operation of the associated line relay for placing the receiving apparatus at that station under the control of the corresponding line relay and responsive to a cessation of the operation of said line relay to remove the receiving apparatus from the control of the line relay.

49. In combination, a line circuit connecting a plurality of receiving stations, aline relay in said circuit at each station, a transmitter for controlling said line circuit to cause repeated operation of all said line relays, receiving apparatus at each station controlled selectively by the associated line relay, aslow acting relay at each station controlled by the associated line relay, and means at each station controlled by the associated slow acting relay and responsive to a first operation of the associated line relay for placing the receiving apparatus at that sta-- tion under the control of the corresponding line relay and responsive to a cessation of the operation of said line relay to remove the receiving apparatus from the control of the line relay.

50. In combination, a line circuit connecting a plurality of receiving stations, a line relay in said circuit at each station, a transmitter for controlling said line circuit to cause repeated operation of all said'line relays, receiving apparatus at each station controlled selectively by the associated line relay, a slow acting relay at each station controlled by the associated line relay and arranged to be picked up in response to a first operation of the line relay but to be released upon the cessation of said repeated op eration of the line relay, and means at each station controlled by the associated slow acting relay for placing the receiving apparatus at that station under the control of the associated line relay.

51. In combination, a movable lever, a' line circuit, means responsive to a movement of said lever for delivering'a control code to said line circuit, a device controlled in accordance with said control code, means responsive to the condition of said device for delivering an indication code to said line circuit, a relay having a pickupcircuit controlled selectively in accordance with said indication code, a stick circuit for said indication relay controlled by said lever, and indication means controlled by said relay.

52. In combination, a movable lever, a line circuit, means responsive to a movement of said lever for delivering a control code to said line circuit, a device controlled in accordance with said control code, means responsive to the coin dition of said device for delivering an indication code to said line circuit, an indication relay, means responsive to said indication code for briefly energizing said indication relay, a stick circuit for said relay, and an indicator controlled jointly by said relay and by saidlever.

53. In combination with a movable device having two positions, a lever capable of assuming two positions, two indication relays one for each position of said device, a code system set into operation by a movement of the lever fromone position to another to position the device in agreement with said lever and effective upon a movement of said device to either position to briefly energize the corresponding indication relay, and a stick circuit for each indication relay including a back contact of the other indication relay and a contact controlled by said lever.

54. In combination with a line circuit, a man ually operable key, a start relay, means for energizing the start relay when said key is operated, a send relay having a circuitincluding a front contact of said start relay, a .code transmitter effective when said send relayis energized to deliver a distinctive code to said line wires, and a stop relay picked up at the conclusion of said code to deenergize said start relay to prevent further supply of code to, said line wires from said transmitter.

55. In combination with a line circuit, a manually operable key, a start relay, means forenergizing the start relay when said key is operated, a send relay having a circuit including a front contact of said start relay, a code transmitter effective when said send relay is energized to deliver a distinctive code to said line Wires, and

a stop relay picked up at the conclusion of said code to deenergizev said send relay to prevent further supply of code to said line wires from said transmitter. V

56. In combination with a line circuit, a plurality of manually operable contacts, a series of start relays one for each said contact, means for energizing each said start relay when the corresponding contact is closed, a series of send relays one for each said start relay, means effective when any of said start relays is energized to energize the corresponding send relay provided no preceding start relay is energized, transmitting means including a code wheel for each send relay eifective when the corresponding send relay is energized to deliver a complete code to said line wires, and means effective upon the completion of any such code to deenergize .the corresponding start relay, whereby the operation of a plurality of said contacts Will cause the corresponding codes to be delivered one at a time in a predetermined sequence.

57. In combination with a line circuit, a plurality of manually operable contacts, a series or" start relays one for each said contact, means for energizing each said start relay When'the corresponding contact is closed, a series of send relays one for each said start relay, means'eiiective when any start relays are energized to energize the first send relay in said series having its start relay energized, transmitting means including a code wheel for each send relay effective when the corresponding send relay is energized to deliver a complete code to said line wires, and means efiective upon the completion of any such code to deenergize the corresponding start relay to permit the energization of the next send relay in said series having its start relay energized.

58. In a centralized traffic control system for railroads, a line circuit, a section of railway track, a first relay having a pickup circuit closed when said track circuit is occupied, means controlled by said first relay for transmitting over said line circuit a track occupied indication when said first relay is energized and a track clear indicationwhen said first relay is deenergized, a second relay, a holding circuit for said first relay controlled by said second relay, and means controlled by said transmitting means to actuate said second relay to open said holding circuit.

59. In a centralized traflic control system for railroads, a line circuit, a section of railway track, a first relay having a pickup circuit closed when said track circuit is occupied, means controlled by said first relay for transmitting over said line circuit a track occupied indication when said first relay is energized and a track clear indication when said first relay is deenergized, a stick relay controlled by said transmitting means, and a stick circuit for said first relay controlled by said stick relay.

60. In a centralized traflic controlling system for railroads and comprising an office and a station, the combination with a transmitter at said station for transmitting indications to said oflice, of a relay which if energized causes the transmission of an indication of one character and if deenergized causes the transmission of an indication of a different character, means at said station for selectively controlling said relay, and means effective when said relay is energized for preventing deenergization thereof until an indication of said one character has been transmitted.

61. In a centralized traflic controlling system for railroads and comprising an oflice and a station, the combination with a transmitter at said station for transmitting indications to said office, of a relay which if energized causes the transmission of an indication of one character and if deenergized causes the transmission of an indication of a different character, a. holding circuit for said relay including a front contact of said relay, a pickup circuit for said relay controlled by traffic conditions adjacent said station, and means for preparing said holding circuit when an indication of said difierent character is transmitted and for opening said holding circuit when an indication of said one character is transmitted.

62. In a centralized traffic controlling system for railroads and comprising an ofiice and a station, the combination with a transmitter at said station for transmitting indications to said office, of a relay which if energized causes the transmission of an indication of one character and if deenergized causes the transmission of an indication of a different character, a track section at said station provided with a track relay, a pickup circuit for said relay controlled by said track relay and closed when said section is occupied, and a holding circuit for said first relay including its own front contact and a contact controlled by said transmitter.

63. In a remote control system comprising an office and a plurality of stations connected by a line circuit, a single source of energy included in said line circuit at said ofilce, a plurality of line relays one at the office and one at each station and all connected in series in said line circuit, means at the ofiice for delivering control codes to said line circuit, means at each station controlled by the associated line relay and selectively responsive to said control codes, means at each station for shunting said line circuit through the associated line relay andsubsequently transmitting an indication code to the portion of the line circuit between such station and the office, and means at the office controlled by the associated line relay and selectively responsive to said indication code.

64. In combination, an office and a station, a normally energized track relay which when released manifests the presence of a train in a track section adjacent said station, apparatus at said station for transmitting a code to the office indicating when the track relay is released, a starting relay, means effective when said starting relay becomes energized for initiating the operation of said apparatus, a stick relay which becomes energized upon the completion of said code, means energizing said starting relay when said track relay releases, said means maintaining said starting relay energized only until said stick relay becomes energized, and means effective when said stick relay becomes energized for holding said relay energized until the track relay again picks up.

65. In a centralized traffic controlling system for railroads, a control office, a field station, a ransmitting means at the control ofiice and at the field station for delivering a series of code elements, meansat the control office for selecting one character and means at the field station for selecting a different character for the first element of a series of code elements, means for determining whether the succeeding elements of a series are to be transmitted by the transmitting means at the control office or by the transmitting means at the field station, and means selectively controlled by the first element of each series for imparting selected charactersv to the succeeding elements of such series of elements.

66. In a centralized traffic controlling system for railroads, a control office, a plurality of field stations, a transmitting means at the control office and at each field station for delivering a series of code elements, means at the control ofidce for selecting one character and means at each field station for selecting a difierent character for the first element of a series of code elements, means for determining whether the succeeding elements of a series are to be transmitted by the transmitting means at the control ofiice or by the transmitting means at such field station, means at the control office for imparting selected characters to the succeeding elements of the series when the transmitting means at the control o-fiice is delivering the succeeding elements to thereby designate the field station at which the series of code elements is to become effective, and means at each field station for imparting selected characters to the succeeding elements of a series when the transmitting means at such field station is delivering the succeeding elements to thereby designate the field station at which the series of code elements is originating.

. 67. In a system of the type in which any one of a large number of trafiic controlling devices at a way station of a railway system may be controlled from a central ofiice through a normally at rest selector system, of a first relay which must be energized to permit operation of said selector system and which is de-energized at the end of an operating cycle of such selector system, a plurality of stick relays each of which if energized closes contacts to transmit a particular code through the medium of said selector system, levers for energizing said stick relays, and a front the transmission of a code to thereby prevent its 10 mutilation.

i V. LEWIS.

Patent No. 2,152,58L

CERTIFICATE OF CORRECTION.

March 28; 1939. LLOYD v. LEWIS. It is hereby certified that error appears in the printed specification of the above numbered patent reciuiring correction as follows: Page 9, second 7 column, line 55, claim 21, for "energized" read deenergized; page 10, second column, line 51, claim 5b.; for the word "mechanism" read mechanisms; and

that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 50th dayof May, A. D. i9 9.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.