US1963746A - Railway signaling - Google Patents

Description

June 19, 1934. R. R. KEMMERER RAILWAY SIGNALING Filed 001;. 17, 1951 R Y E e HQ "QM m \h kw R XQ X Patented June 19, 1934 RAILWAY SIGNALING Ralph R. Kemmerer, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a, corporation of Pennsylvania Application October 17,

Claims.

My present invention-relates to a railway block .signal and automatic stop control particularly suitable for monorail installations, and comprises circuits adapted to operate signals or the like at 5 theentrance to each block and to control the position of a tripping device in accordance with traffic conditions. The invention includes means for providing in monorail installations the equivalentof the 'usual continuous track circuits, and means responsive thereto for indicating the condition of the track ahead, and for normally causingoperationofa tripping device at the entrance to ablock when that block or the first part of the succeeding block is occupied while suppressing the operation of the tripping mechanism under oertain conditions to permit a following car or train to enter an occupied block.

For a better understanding of the invention, reference may be had to the accompanying drawing in which is diagrammatically illustrated, a train signaling and control system for monorail installations embodying the invention.

In the drawing, the running rail of a monorail system is indicated at Z, and an auxiliary rail or trolley at X. Rail X, which is so positioned as to be engaged by any suitable contactor carried by a car travelling on the running rail Z, serves, together with track relays, to complete the track circuits for each block 2T, 4'1 and GT of the rail Z. In the particular embodiment of the invention illustrated, rail Z is not subdivided and hence is common to all track circuits, while rail X is subdivided into two insulated sections per block. each of which is connected to rail Z through the secondary of a transformer l. Alternating current is supplied to the primary of each transformer 1 from any suitable source the terminals of which are indicated by BX and CX. The track circuits thus formed, divide each block into two sections designated in the drawing by the subscripts 1- and 2.

At the entrance to each block is arr automatic tripping mechanism for cooperation with stopping mechanism carried by the car; mechanisms 4V and 6V at the entrance to track sections 4T and GT respectively being indicated diagrammatically on the drawing. The construction of these mechanisms is immaterial to the present invention. Any mechanism of the type which is biased into tripping position and which, when current is supplied to the winding thereof, is held in inoperative position, would be suitable. At the and T6 at 4 and 6 respectively. Signals 4 and 1931, Serial No. 569,462

6 are controlled by the home and distant relays associated with blocks 4T and ST respectively. In the embodiment illustrated these signals are assumed to be of the colored light type in which green indicates clear, yellow caution, and red 6 danger but, as will be apparent as the description proceeds, the signals could be of the semaphore type with or without the addition of lights; the controlling circuits being equally suitable for any type of three indication signal.

As the circuits for mechanisms 4V and 6V and for the signals 4 and 6 are controlled by the track and home relays, the circuits for these relays will now be described.

Track relay 4T1R associated with track section 4T1 has its control element connected across the rail X and auxiliary rail'or trolley Z so as to be energized by the track current when block 4T1 is unoccupied. One side of the local element of relay 4T1R is connected to one terminal CX of a 7 source ofalternating electromotive force, and the other side through a stick circuit including itsiown top contact is connected to the other terminal BX of the source. The pick-up circuit for relay 4T1R is from source BX through a back contact of track relay 4T2R associated with block portion 4T2, and a pair of contacts 8 which are carried by tripping mechanism 4V and are closed only when the mechanism is in tripping position. The circuits for track relay 6T1R are similar to those of track relays 4T1 and hence need no separate description.

For convenience contacts 8 have been shown dissociated from the mechanism 4V but it will be understood that in practice, these contacts will be so positioned as to be closed when the tripping arm of the mechanism is moved into position to engage the train carried automatic stop.

The circuits for the home relay 4HR for signal 4 are as follows: Source CX is connected to one side of the winding, and the other side is connected over its own top contact and top contacts of relays 4T1R, 6T1Rand 4T2R to BX. The top contact of relay 4BR, in this circuit is bridged by a pair of contacts 9 which, like contacts 8, are carried by automatic tripping mechanism 4V although for convenience are shown dissociated therefrom. Like contacts 8, contacts 9 are closed when the mechanism is'in tripping position.' 7

Thus, when a car enters track section 4T1, relay 4T1R will drop its armatures opening the circuit for relay 4HR which can not again be energized until relay 4T1R has been energized and until the car has proceeded through track section 4T2 and the circuit of relay 4T2R has again been closed. Even then relay 4HR will not be energized unless the automatic mechanism 4V has gone to stopping position and closed contacts 9. When this occurs relay 4HR, will pick up and the stick circuit over its own top contact will be closed to shunt contacts 9.

Relay 4T2R has its control element connected across the rails X and Z at track section 4T2. One side of its local element is connected toone side CX of a source of alternating voltage and the other side connected to BX through a stick circuit including its own armature and top contact. A pick-up circuit is provided for this relay through a back contact of relay 6T1R. Thus, after a car has entered track section 4T2, relay'4T2R can not be reenergized until after I'BIZJYGTIR has dropped its armature. V

For convenience in illustrating the circuits of the stopping mechanism 4V, the winding 4VW thereof has been shown dissociated from the mechanism. It will be understood that when current flows through the winding 4VW the mechanism 4V will be held in inoperative or normal position and that when the circuit of winding 4VW is open the mechanism moves into operative or stopping position.

The circuits for the winding 4VW of mechanism 4V are as follows:

CX is connected to one side of the winding 4VW, and the other side is connected through a top contact of relay 4T1R and a top contact of :relay 4'I-IR to BX. When relay 4T1R is deenergized due to a train entering track section 4T1 and the stopping mechanism 4V is in its inoperative position with contacts 8 open, the circuitior winding 4VW is closed through a back contact of relay4T1R,'a pair'of contacts 10 carried by mechanism 4V and so positioned'as to be closed when the mechanism is in its inoperative position, and top contacts of relays 6T1R and 4T2R. This circuit is for the purpose of holding mechanism 4V in its inoperative position until all cars of the train have passed over it. Still another circuit for winding 4VW is provided through the back contact of relay 4T1R and a back contact of relay 2T2R. This last circuit permitsa following train to enter the occupied block without being stopped by the automatic mechanism. 7

,7 If -a train enters track section 4T1 from section 2T2-and-there is no train in'blockfiT, the'entrance of the train into block 4T1 shunts the control element of relay 4T1R causing it to drop its armature and open the circuit for' relay 4I-IR. The opening of the top contacts of track relay 4T1R does not cause the stopping-mechanism'4V to go to tripping position because the circuit for winding 4VW is still closed through contacts 10, -(mechanism- 4V being in inoperative position) and the top contacts of relays '6T1R and 4T2R. As the train enters track section 4T2, however, this latter circuit fOI the winding 4VW is openedat the top-contact of relay'4T2R'with the result that mechanism 4V will go to stopping position. This closes the circuit for relay 4T1-R which relay will then stay picked up through its-stick circuit, the control element thereof being'no longer shunted by the car. The automatic-mechanism 4V, however, will stay in tripping position because the circuit for winding 4VW is 'held open at the top contact of relay 4I-IR. Iffhowever, when the train entered track-section 4T2 a following car was in track section 2T2 then the automatic mechanismwould not go to tripping position 'for there would be a circuit for its windings through the "back locating the stopping mechanism 4V a given dis- ;tance ahead of the insulated joint separating sections 2T2 and 4T1, so that if the train is moving at less than a given speed when it enters section 4T1, the circuit for 4V through a back contact or 4T'1R and a back contact of 2T2R will be closed before the tripping device on the train reaches.

mechanism 4V, and the train can then proceed Without an automatic brake application.

The circuit for relay 4DR is from source BX over a top contact of relay 6BR, contacts 11 which are carried 'by mechanism 6V and are closed when the mechanism is in inoperative position, top contact of relay 4HR andthewinding of relay 4DR to CX.

Relays 4l-IR and 4DR and mechanism 4V control the light signals G, Y and R for signal 4. The circuit for the green or clear light G is from battery B over a pair of contacts 12 carried by mechanism 4V and closed when the mechanism is in inoperative position, and over top contacts of relays 4HR and 4DH. As relay 4DR will be deenergized over the top contacts of relay 6HR' if there is a car in block GT or in the first portion of the succeeding block andrelay 4I-IR will be 'deenergized if there is a car in block 4T or in block sec- F tion'6'I'1, it follows that the lighting of clear light G for signal 4 indicates that there are at least two and a half clear blocks ahead of signal 4. It also indicates that mechanisms 4V and 6V are each in inoperative position as the circuit for relay I:

4DR, is over contacts 11 of mechanism 6V and that of the green light G is over contacts 12 of mechanism 4V. The circuit for caution light Y for signal 4"is over'contacts 12, top contact of relay 4HR and back contacts of relay 4DR. Thus, if ii the yellow light Y is lighted at signal 4 an indication is given that there is a train in the latter portion of block GT or in the first portion of the succeeding block or that, for some other reason, mechanism 6V is in stopping position. One circuit for danger light R for signal 4 is over contacts 12 and back'contact of relay 4I-IR. Another circuit for this light is over a pair-of contacts l3 carried by -mechanism 4V and closed when the mechanism is in stopping position. Thus, thedisplay of a red light at signal 4 indicates either a train in blck 4T or in block section 6T1 or mechanism 4V is in tripping position. It will be noted that the circuits for light R aresuch that a-following train receives a stop signal even when mechanism 4V is held in inoperative position by the special circuits described for winding 4VW.

The preferred embodiment of the invent-ion'has now been described. It will be apparent that the new circuits provide a complete system or 1:

control for block signals and for the track elements of automatic stopping devices for a monorail installation and that the system so provided is responsive to traffic conditions and is substantially self-checking to prevent false clear indica- .4::

tions. Moreover the system is comparatively simple and lends -itself readily to expansion or contraction should it be desired to'change-either the number of clear blocks indicated "by a particular.

signal or the number of signal indications to be displayed. Although the invention is particularly applicable to monorail installation, and has so been described, obviously the novel features thereof might be advantageously employed on ordinary two rail trackways handling trafiic in one direction only.

The following is claimed:

1. An automatic block signaling system for railroads comprising in combination, two rails, two track relays per block each having its control element connected across said rails, one of said rails being subdivided into two sections per block, means for impressing an alternating electromotive force between each section of the subdivided rail and said other rail to provide track current for the control elements of said relays, a stick circuit for the local element of each track relay including its own top contact, a pick-up circuit for the local element of each track relay controlled over a back contact of the track relay of the next succeeding section of the rails whereby a track relay which has dropped its armature due to shunting of the control element thereof can not again raise its armature until the control element of the next track relay has been shunted, home and distant relays for each block controlled by top contacts of said track relays, automatic tripping devices, one located at the entrance to each block and each carrying a pair of contacts adapted to be closed only when the device is in tripping position, the said pick-up circuit for the local element of the track relay for the first section of each block including the pair of contacts of the tripping device for said block, each tripping device having a control winding which when energized maintains the device in inoperative position, and a circuit for which is controlled over a top contact of the home relay for the associated block and a top contact of the track relay for the first section of such associated block.

2. An automatic block signal and train stop control for unidirectional traiiic comprising in combination two rails, two track relays for each block each having its control element connected across said rails, a pick-up circuit for the local elements of each track relay controlled over a back contact of the next succeeding track relay, home and distant relays controlled by said track relays, tripping devices of the type which are normally biased into operative position but which when current is supplied to a winding thereof are held in inoperative position, circuits for the windings of said devices closed over top contacts of said track and home relays under clear or caution conditions, signals for each block controlled by the said home and distant relays thereof and means, including additional circuits for the windings of said devices, for maintaining the windings of said devices energized under certain conditions when the first mentioned circuits thereof are opened to permit a following train to enter an occupied block.

3, The combination according to claim 2 wherein the pick-up circuit for the track relay associated with the first portion of each block includes a pair of contacts which are carried by the device associated with that block and are closed when said device is in tripping position and the said additional circuit for the device of any one block is controlled over back contacts of the track relay associated with the first portion of that block and of the track relay associated with the last portion or" the preceding block whereby one train following within a block of another train may enter a block of which the latter portion is occupied without interference from the tripping device associated with that block.

4. In an automatic block signal and train stop system for monorail installations, the combination including a running rail and an auxiliary rail sub-divided into two portions per block, track relays having their control elements connected across said rails for completion of two continuous track circuits per block, and a tripping device for each block of the type normally biased to tripping position but held in inoperative position when the circuit for a winding thereof is closed, the winding of said device being normally energized over a top contact of the track relay associated with the first portion of the block with,

which the device is associated, and two additional circuits for the winding of said device each connected to the back contact of the track relay associated with the first portion of the block with which the device is associated, one of said additional circuits being controlled over top contacts of the two next succeeding track relays and including a pair of contacts which are carried by said device and which are closed when the device is in inoperative position, and the other of said additional circuits being controlled over a back contact of the next preceding track relay, whereby shunting of the control element of a track relay associated with the first portion of a block does not necessarily cause the tripping device at that block to go to tripping position and shunting of the control element of the track relay associated with the last portion of a block does not cause the device associated with that block to go to tripping position if the control element of the track relay associated with the last portion of the preceding block has already been shunted.

5. An automatic block signal and train stop control system including in combination two rails subdivided by continuous track circuits into two portions per block, a track relay for each block portion having its control element connected across said rails for completion of the track circuit thereof, each of said track relays having a stick circuit for the local element thereof and a pick-up circuit controlled over back contacts of the next receding track relay, a home relay for each block controlled over its own top contact and over top contacts of both track relays for that block and of the track relay associated with the first portion of the next block, a distant relay for each block controlled over top contacts of the home relay for the next block, a signal at the entrance of each block controlled to three positions by said home and distant relays, a tripping type normally biased into tripping position but held inoperative when current is supplied to a winding thereof, a normal circuit for the winding of each device controlled over a top contact of device adjacent the entrance to each block of the the track relay associated with the first portion of the block in which the device is located and over a top contact of the home relay for that block; a holding circuit for the winding of each device controlled over a back contact of the track relay associated with thefirst portion of the block in which the device is located and top contacts of the two next succeeding relays and a permissive circuit for the winding of each device controlled over back contacts of the track relay associated with the first portion of the block in which the device is located and of the track relay associated with the last portion of the preceding block, each of said devices carrying two pairs of contacts each of which are closed when the device is in trip-,

-ping-positioinoneiof saidpairs-of contacts being in the pick-up'circuit cf the track relay associated with-the first-portion of the block "in which the 7 device is locatecLthe other of said pairs ofcontacts being in the circuit'of the home relay and in parallelwith the portion thereof which includes the top contact of that re1ay,'each of said devices carrying two other pairs'of contacts each of which the circuit of the distant" relay associated with the block preceding that inwhich the device is located.

RALPH R. KEMMERER.

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