US1302371A - Signaling system. - Google Patents

Description

W. K. HOWE.

SIGNALING SYSTEM.

APPLICATION FILED APR. 19. 1912.

Patented Apr. 29, 1919.

INVE/VTUR BY 5 o y A TH'JRIVEV I WITNESSES.

%%/MZL eoaear.

unrrnn ear clarion.

wIn'I'Hnor K. HOWE, or nocnn's'rnn, new roan, AssIeIIon TO GENERAL IIAILWAY SIGNAL coIIrANY', or eA'rns, new roan, A coaronArIoN or new roan.

SIGNALING: sYsrnr/I.

Application filedApril 19, 1912. Serial lilo. QELWQ To all whom it may concern: 7

Be it known that I, WINTHROP. K. HOWE,

, a citizen of the United States, and resident of the city of Rochester, in the county of Monroe and State of New York, have invented a new and useful Signaling System,

a of which the following is a specification.

This invention relates generally to raildications, to-wit; stop and proceed, by

the use of only two controlling electric conducting mediums between the two signals, so arranged and connected, that a break in one of the twojelectric conducting mediums, or a cross between the two electric conducting mediums, or a break and a cross to gether, will ,allow both signals to exhibit the stop indication.

A further object .of this invention is v to.

produce an arrangement and connection of single track signaling governing train movements in opposite directions, whereby, by the use of two controlling electric conducting mediums, only, between the two opposed signals, it will be possible to obtain three positive indications, of which one will be a permissive indication; and also the immunity from dangerous results flowing from crosses and breaks, as set forth above in stating. the primary object of the inven tion, together with a check, which will absolutely insure the disappearance of the permissive indication, before any opposing proceed indicatioircan be given.

A. further object of this invention is an arrangement and connection of a switch indicator, such that no, electricv conducting medium from either signal to the indicator,

other than that used to control the signals, I

is necessary. A

In short it may be said, that the main object. of applicants invention 1s the absolute permissive automatic control of two opposed signals governing a single track block, and a switch indicator in the block,

by the use of two line wires, or one line wire and aground return, safely. i

In the drawings accompanying this specification consisting of two figures,.applicant has illustrated an embodiment of his invention, to enable those skilled in the art of railway signaling to understand the construction and arrangement of the same and the principles underlying the manner of applying it to a concrete situation.

F igure l is a diagrammatic View of a railway track and signals for governing train Specification of Letters-Patent Pgflbgmtgfl App, 29, 1919,

movements over the track, to the control of which, applicants invention in a preferred form is applied; Fig. 2, is a diagram show ing the phase relations existing between 6180? tromotive forces and the currents in difi'er- 1 ent parts of the circuits shown by Fig. 1-.

In order to illustrate the application of applicants inventionfor the control of train 'movements, a portion of a single track railway is illustrated in Fig. 1, together with the necessary signals, therein shown .as light slgnals for governlng the movements of trains'o'vei' a single track block between the passing sidings at each end of the single track block.

The portion of track'illustrated is formed into electrically independent sections by means of the insulating joints 1, so that a single track block T is formed between the ,sidin s S and S and what is known as a preliminary section P, the use of which will be later explained, is formed at the right hand end of Fig. 1.

As the rails are to form part of a track. circuit, the siding S which leads from the portion of track forming the single track block, has the insulating joints I inserted inthe rails thereof, and the bond wires C connecting the rails of the siding with the rails of the single track block in the well" known and approved manner. For the same reason the rails of the siding S contain insulating joints I and bonds C connecting the rails of the siding with the rails of the preliminary section P in the well known and approved manner, it being understood that the insulating joints 1 farthest from the main line are located at what is known as the fouling point.

full speed; and the presence of a white light 1 beneath a red light, should indicate, prof ceed, expecting .to find the block occupied by a train moving in the same direction.

As the siding S leads from the single track block T, it is necessary to place an indicator J at the entrance to the siding, as

is done in all well considered signaling systems, under such conditions. The indicator should be and is in applicants embodiment,

so arranged that a clear indication must be received from the indicator before it is alon to the single track block. b e

Numeral 1 indicates an alternating current generatorfrom which the wires 2 and y 3 extend along the .whole length of the signaled portion of the single track railway.

At every signal location and at every place where it is desired to feed energy to the track rails, a transformer is installed, as 4, 5 and 6. At some locations the transformer secondary has merely two terminals, as at 4 and 5, at others, various voltages are destood that applicant considers himself in no thereof, which are cohnected to one winding rived from the secondary of the transformer by various tapsupon the secondary, as at 6, which of course is equivalent to the use of several transformers.

Transformer 5 connects by means of Wires '7 and 8 with the two track rails of the single track block T, at or approximately at,.'the

center of the block, thus in part forming, 'what is known as a centerfedmrack circuit At each end of the single tracksection. block, wires are connected to each of the ralls and are connected to one winding as 9 and 10 of a suitable relay"or' translating device, whichis shown diagrammatically as comprising a polyphasepnduction motor or similar appropriate device, 1tv being underwise limited by the particular type of translating mechanism shown. Y

The preliminary section P has-energy fed thereto at one end from transformer 6 by means of wires 11 and 12, 90, 131, 132, and 133. At the other end ofthe preliminary section wires are connected to each rail 13 of a translating device comprisingia polyphaseinduction motor. r

The motor which contains the, winding 9, also contains 'a winding 14 connected directly by means of wires 15, 89, 88', and 51 and wires 16, 82, 83 and 52 to the terminals of the secondary of transformer'4, and also contains the rotor member '17, which is actulowable for a train upon the siding to pass ated' by current flowing in the coils 9 and 14. When the coils 9 and 14 are properly energized the pivoted members 18 and 19 are caused to be in the -position as shown,

but when the windings 9 and 14 or one of and 21 and by wires 55, 56, 132, 131,- 90 and- 12 and also includes a rotor member 22, which, when the windings 10 and,20 are properly energized, causes the pivoted members 23 and 24 to be in the upper position as shown, but when either one of the windings 10 and 20 is deenergized, allows the pivoted members23 and 24 to fall.

The translating device of which winding 13 is a part,,also contains the winding 25,

which is connected by wires 57, 53, 97,49, 48,

47 and 21 and by wires58, 56, 132, 131, 90 and 12 to the secondary of the transformer 6, and the translating device also includes a rotor member 26, which, when the wind ings13 and 25 are ener ized properly, causes thepivoted member 2% to be in the upper position as shown, but when either of the windings 13 or 25 is deenergized, allows the pivoted member 27 to fall.

28 and 29 designate the two windings of a polyphase motor device commonly called a relay, one, 28 being energized by current flowing in a circuit to be hereinafter described, the other, 29, being energized directly from the secondary of transformer 4, by being connected thereto by wires 134, 89 and 15 and by wires 135, 84, ,83, 82 and 16.. Thetranslating device also contains a rotor member 30, which, when the windings 28 and 29 are properlyenergized, causes the pivoted member 31 to be in the upper position as shown, but when'either of the wind ings 28' or 29 is deenergized, allows the:

pivoted member 31 to fal 32 and 33 designate the two windings of a polyphase motor device, one, 32, being energized by a circuit hereinafter to be described, tlie other, 33, being energized by connection with the wires 136, 47 and 21 and the wires 137, 91, 90 and 12 leading to the secondary of the transformer 6. The motor device also includes the rotor 34, which may be caused by a proper flow of current through coil 32 to assume either one of twopositlons so that the pivoted member 35 vwill be caused to move to the left in the full line position as shown, or to the right in the dotted line position and the rotor 34 being also connected with pivoted member 36, causes it-to likewise move. at all flows through coil 32 orthrough coil 33, or if the currentis 'not of the proper If no current positions.

value or phase relation, the rotor 34 will pivoted members 35* and will move to .a position mid-way between the twoextreme 37 and '38 designate coils of what are known as stick relays and 39 and 40 designate coils of relays which will be hereinafter designated as checking relays.

The indicator. J, comprises a polyphase motor device of which one winding 41 is has attached thereto an indicator arm 44,

' connected directly to wires 7 and 8 connected to the terminals of the secondary of trans former 5, and the other winding '42, as will be hereinafter explained more at length, is connected directly in series with one of the conducting mediums-from signal A to B. The'rotor 43 of the polyphase motor device and by its movement'causes the indicator armto assume different posit 1ons,'ind1cating difl'erent condltlons as w ll be hereinafter described. The rotor'43 is also con tion asshown in Fig. 1, the following line circuit is formed: secondary of transformer '6, wires-21, 47, 48, 49 and 50, pivoted member 27, wire 60, pivoted member 23, wires 61 and 125, key 46, wires 126, armature 45,-wires'127 and 64, switch instrument M,

which connects by bridge 66 inthe'well known manner thepoint. 65 with the point 67, wire 68, pivoted member 18, wire 69, impedance 70, wire 71, winding 28, wire 72,

armature 73, which is governed by relay coil.

, 37, wire 74, conductor 75, wire- 7 6, armature 77, whichis governed relay coil 38, wires 7 8 and 79; non-inductive, resistance 80, wire 81, winding '32, wire 128 to the secondary,

be moved and held in its upper position, so

that the following circuit willbe completed:

secondary of transformer 4, wires 16, 82, 83

and 84, pivoted members 31, wires 85 'and 86 to the lamp G of the signal A, which, when lighted, causes a green light to be displayed, wires 138,139,' 87, 88, 89 and 15 to the other terminal of the secondary 4. Current flowing in the above traced path, causes a green light to be displayed at the signal A, which, as heretofore explained, indicates that a train may proceed into the single track block at full speed.

Under normal conditions the following circuit is also completed: secondary of transformer 6, wires 12, 90, 91 and 93, pivoted member 35, wires 94 and 95 to .the lamp Gr of signal B, which, when lighted causes a green light to be displayed, then by means pointed out, indicates that a train may proceed into the single track block at full speed.

It will be noticed that normally a full clear signal is exhibited at each end of the block for opposing movements, but as two trains should not enter the single track block from opposite ends at the same time, provision is made to prevent such occurrence by employing the preliminary sec-- tion P. Y

If a train approaches the single track block, moving in the direction of the arrow Y, it will first pass upon the preliminary section P and byshunting the current from the winding 13, will allow the rotor 26 to drop pivoted member 27 so that the current then flowing in the first abovetraced circuit will be displaced in phase 180 from thatcurrent which formerly flowed, so that in fflowing through the winding 28 it will in conjunction with the current flowing through winding 29, cause the rotor 30 to rotate in a dlrectlon opposite to that caused by the first above described flow, so that the pivoted member 31 will be moved downwardly both by gravity and power, thus breaking contact with wire 85 and so causing 'a break in the circuit of the lamp which causes the green light at signal A At the same time the pivoted member 31 makes connection with wire 98, so that-the current which formerly flowed to the lamp which caused the green light, would then flow by means of wire 98 to the lamp R which when lighted would cause a redlight to be exhibited at signal A, llir current returning as before by means of wires140, 139, 87, 88, 89 and 15 to the secondary of transformer 4. It will also be noticed that the reversal of the phase of the current does not cansethe extinguishment of the green light at signal B, for, a 180. change in the phase of the current flowing through winding 32, causes rotor 34 to rotate and move pivoted arm .35 to its other extreme position in contact with wife 99 which being connected to wire 94, causes the green light to remain displayed.

formed :-secondary of transformer 6, wires 12, 90, 91 and9'3, pivoted member 35, and,

As soon as a tram moving from section P wire 100 to the lamp which causes a red light to be displayed at signal B, returning by means of wires 143, 142, 96, 97, 49, 48, 47,

' and 21 to the other terminal of the secondary train enters upon the single track block,

causes a red light to be displayed atsignal B,

so that both the front and the rear of the train 'willbe protected.

As applicants circuit-s and arrangements are adapted for giving a permissive indicationto a train following another, it will next be necessary to describe how the permissive indication is obtained.

When a train moving in the direction of the arrow Y passed upon the preliminary section it caused a rotation of rotor 34, so that the pivoted members 35 and 36 assume the extreme right hand position, and by its entrance onto the single track block, caused pivoted member 24 to drop so that a circuit will then be formed as follows: secondary of transformer 6, wires 21, 47, 48 and 101, pivoted member 24,'wire 102, pivoted member 36, wire 103, 144, relay coil 38, wires 104, 91, 90 and 12 to the other terminal of the transformer 6. Current flowing in the above tracedpath causes an energization of relay coil 38 and causes armatures 77, 105 and 106 to be raised. As soon as the train considered entered upon the single track block, pivoted member 36 would, fall by gravity to an intermediate position, but, by the application of principles of construction "well understood in the art, rotor 34 which governs pivoted member 36 could and would be much slower acting than rotor 22, which governs pivoted member 24, consequently, sufficient time would elapse after pivoted member 24 touched wire 102, and before pivoted member 36 broke contact with wire 103, to energize relay coil 38 sufficiently to raise armatures 77, 105 and 106.

The raising of armature 105 allows the following circuit to be completed: secondary of transformer 6, wires 12 and 107, armature 105, wire 108, lamp W which when lighted causes the signal B to exhibit a white light, and wires 145, 96, 97, 49, 48, 47 and 21 to the other terminal of the secondary of transformer. 6. Current flowing in the above traced path causes the lamp to be lighted and a white light to be exhibited at signal B, so that with a train in the single track block, moving in the direction of the arrow Y a red light over a white light is exhibited by signal B, indicating to a following train, that it may proceed into the block expecting to find. a train therein moving in the same direction as itself.

lVhen relay coil 38 was energized, and

nausea armature 105 raised, armature 106 was'also raised, so that a circuit was formed as folwires 104, 91, -and 12 to the other terminal of the secondary of transformer 6. Current flowing in the above traced path would ener gize the relay coil 38 and keep it energized, even though pivoted member 24 were raised from in contact with wire 102, so that, although when the train passes beyond the connections of the secondary oftransformer 5 to the rails of-the single track block, the coil 10 may be again energized and the rotor at 22 may raise the pivoted member 24, nevertheless, relay coil 38 will remain energized as long as the train is in the single track block, so that armature will remain in the upperposition and the white light will be exposed at signal B and also the armature 77;wi1l be held in anupper position until the train passes entirely from theblock; When the train heretofore considered, moving in the direction of the arrow Y apno preaches closely to or passes the connections j of the transformer-5 to the rails of the single track block, the winding 9 will be deenergizedand the rotor 17 will then allow pivoted members 18 and 19 to fall, so that the line circuit will be broken between wire 68 and pivoted member 18, thus retaining the same condition of affairs caused by the pre 'j vious break between pivoted member 233ml wire 60. v 1

As relay coil 37 performs a function'similar to relay coil 38, it seems best to at this time point out that the train-heretofore considered moving in the direction of the arrow coil 37 and would not cause the stick circuit "to be formed. This is due to the fact that at the time the train moves out of the single track block, the pivoted member 31 is in its lower position, so that no current can flow 110 in that circuit, which it is necessary to have formed in order to get a preliminary energization of the relay, which circuit is as follows: secondary of transformer 4, wires 16,

82, 83, and 84, pivoted'meinber 31,' wires 85 and 113, pivoted member 19, wires 114 and 115, relay coil 37 and wires 1 16 and 15, to the other terminal of the secondary of the trans former 4. As the above tracedcircuit was broken at the pivoted member 31, when the train left the block, no. preliminary energization of relay 37 was caused, so that" the stick circuit could not be formed, therefore the white light at signal A would not be displayed.

When the .train entirely leaves the single track block, all parts should then return to the normal position and they do for the following reasons: the windings 9 and 10 connected with the track become energized and v130 aoasrr cause the rotors 17 and 22 to turn and move the pivoted members 18 and 19 and 23 and 24 into their upper positions. The movement of pivoted members 18 and 23 into their upper position, and the fact that pivoted member 27 moved to its upper position, when the train left thepreliminary section P, enables current to again flow in the line circuit, but as armature 77 is raised, on account of the fact that relay 38 is energized, the current which flows in the line must pass through relay coil 40-instead of passing by wire 76, armature 77 and wire 78 around relay 40, consequently, while the current is flowingin coil'40 the current does not have the proper phase relation to the current flowing in windings 29 and 33 to cause rotors and 34 to revolve but relaycoil 40 is energized and causes armature 111 to be raised, but when armature 111 is raised the stick circuitthrough relay coil 38 is broken,

consequently, armature 77 drops and shunts relaycoil 40, then as relay coil40 is shunted,

the circuit. formed will be the line circuit heretofore traced, in which the current flowingwi'll cause rotors 30 and 34 to turn,

. and so cause pivoted member 31 to be raised and pivoted members '35 and 36 to be moved to their extreme left hand position, so that the net result will be, that the red and white lights at signal B are extinguished and thegreen lights at signals A and B will be exhibited.

If a train approaches the single track block moving in the direction of the arrow X, if no train is present either upon the single track block or upon the preliminary] section P, then a green light will be exhibited to the train, which will permit the train 'to' pass upon the single track block. As soon as the train enters upon the single track block, winding 9 will be deenergized to cause the pivoted member.18 to drop, consequently, the line circuit will be broken so that wind ing 28 will be deenergized, pivoted member 31 will fall to its lower position, thereby breaking the circuit of the green lamp at signal A and causing the circuit for the red lamp to be closed, and as windings 28 and 29 are so proportioned by means well known to those'skilled in the art, so that rotor 30 will be extremely slow acting,"the pivoted member 19 will contact with wire 114 before pivoted member 31 contacts with wire 98, so that a preliminary energizing circuit through relay coil 37 will be formed as follows: terminal of secondary of transformer 4, wires 16, 82, 83 and 84, pivoted member 31, wires 85 and 113, pivoted member 19, wires-114 and 115, relay coil 37 and wires 116. and 15 to the other terminal of the secondary of the transformer 4. Current would flow in the above traced path for only an instant, as pivoted member 31 would soon break contact with-wire 30 after the train entered the single track block but during the instant that the current does flow, relay coil 37 would be sufficiently energized to attract its armatures 122, 123 and 73. The movement upwardly of armature 123 would allow a stick circuit to be formed as follows: terminal of secondary of transformer 4, wires 16 and 120, armature 117, wire 118, armature 123, wires 119 and 115, relay coil 37 and wires 116 and 15 to the other terminal of the secondary of transformer 4. Current flowing in the above traced path would continue the energization of relay-coil '37 even after the train heretofore considered passes beyond the connections to the rail of the terminals of the secondary of trans former 5, which allows an energization of winding 9 and a consequent turning of rotor 17 and a raising of pivoted member 19. Armature 122 would be raised simultaneously with armature 123 and would close a circuit as follows: secondary of'transformer light behind the train, and by reason of the I, dropping of pivoted member 18, the line circuit would be broken and consequently wind' ing32 would be denergized and rotor 34 would assume the neutral or middle position, thereby causing pivoted members 35 and 36 to assume the neutral or middle position, so

*that the red light at signal 18 would be exhibited by reason of pivoted member 35 contacting with wire 100, so that the train would be protected by a permissive signal in its rear and by a stop and stay signal ahead.

When the train now being; considered advances in the direction of thearrow K beyond the connections of the secondary of transformer 5 with the rails of. the single track block, the winding 10"would be deenergized and pivoted member 23 would fall, so that the denergization of winding 32 and 28-would be continued.

Whenthe' train which has just been considered passes upon the preliminary section the winding 13 would be deenergized and rotor 26 would causepivoted member 27 to contact with wire 129 so that current would be sent through the line circuit, as wire 129 .is connected through wires 131, 90 and 12 with secondary of transformer 6 and as armature 73 is in the upper position by reason of the energization of relay cpil 37, it would have to pass through relay coil 39 and thus energize it, thus causing relay armature117 to be raised, thereby breaking the circuit through relay coil- 37 and causing a deener'gization of relay coil 37, and consequently, causing armatures 122 and 123 to drop and break. the circuit for the lamp,

which causedth'e White light to be exhibited at signal A and also causing armature 73 to fall, so as to make contact with wire 74, so as to shunt relay 39, which would allow armature 117 ,to again drop Assoon as armature 73 has dropped and shunted relay coil 39, current would flow through the line circuit and through windings 28 and 32, but the phase ofthe current would be displaced 180 from that normallyflowing when no train is present upon any part of the track, consequently,-rotors 30 and 34 would be so rotated that pivoted member 31 would contact with wire 98 and pivoted member 35- would cdnt'act with wire 99 'and pivoted member 36 with wire 103, so that a 7 red light would be exhibited at signal A, and

a green light at signal B.

The relays of which coils :39 and 40 form apart, are-called checking relays and are so .designed that when current flows through these coils the windings 28 and 32 will not be so'energized as to cause a rotation of rotors 30 and 34. By so doing it is absolutely certain that the permissive lights W and W at the two signals will be extinguished before a full clear signal can be given for an oppos ing movement. -Thus, if the train entered the single track block moving in the direc-' tion of the arrow Y and then left the single track block at. the end at which signalA is located, it would be necessary to first break the stick circuit through relay 38 by raising armature 111 and thereby dropping armature 77 before the current flowing through the line circuit would be able to so energize winding 28 as to cause it to move rotor 30, so as to move pivoted member 31 into contact with wire 85 and so light the green light,

that is, the white light at one end of the single track block must be extinguished be-. fore the green light can be exhibited at the other end.

The method of checking the extinguishment of the white light by a train moving in the direction of the arrow Y, also holds true in regard to the extinguishment of the white light by a train moving in the direction of the arrow X.

4 If a train is upon the siding S and desires to move upon the rails of the single track block, assurance should first be given that no train will pass upon the single track block from either end. This assurance is given by means of the indicator J. When a train desires to pass from the siding S to the main line, push button 46 is first operated which breaks the shunt circuit around winding 42, which 15 composed of wire 125,

push key 46,, wire 126, armature 45 and wire 127. Normally the-shunt circuit just traced is formed around winding 42, so that the current which flows in the line circuit does not flow through winding 42 to any extent, at least not enough to cause'a rotation of key 46 were operated,

rotor 43, but if push key 46' is operated, the shunt circuit is broken, then all of the current in the line circuit flowsthrough winding 42, which causes such a change in the phase of the current that no effective torque is produced upon rotors 30 and 34, consequently, the red lamps at both ends of the single track block are lighted and as local winding 41 is energized directly from the secondary of the transformerfi, the rotor 43 moves in the direction of the arrow 6, but, local winding 41 and line winding 42 are so proportioned that rotor 43 moves eX- tremely slowly, so thata-con'siderable interval of time elapses after push key 46 is operated before the arm 44 assumes the full vertical position, consequently, it it is de- -sired to move a train from the siding S rection of the arrow X about to pass upon at the time the push the single track line itwould have ample time to do so, or wouldbe stopped by the red light, and if it had passed upon the single track block it would have prevented the clearing of the indicator, and if a train had been approaching, moving in the direction of the arrow Y at the time the push key 46 were operated, it would have had ample opportunity to pass upon the single track block before the blade 44 assumed the full vertical position or would have been stopped by the red light, and if it had passed upon the single track block it would have prevented the clearingof the indicator, but if" no train from either direction passed upon the single track block, the blade 44' wouldassume the full vertical position and immediately the switch were thrown, the switch instrument M would be operated and bridge 66 would break contact between points 65 and 67, so that the line circuit from wire 64' to 68 would be broken, consequently, winding 28 and 32 would be .denergized,

and pivoted member 31 would remain upon wire 98 and continue a red light at signal A, and pivoted member 35 would continue in the neutral position in contact with wire 100 and continue a red light at signal B,

.Under such conditions, with a red light guarding the entrance to both ends of the block, there would be no danger caused by a train-moving from the siding S on the single track block '1. As soon as the train did move upon the single track block T, winding 9 would be deenergized and pivoted member 18 dropped, thereby breaking the line circuit and keeping it" broken, although the switch were afterward closed and switch instrument M operated so as to I close the line circuit between wlres 64 and 68. As'soon as the train passed beyond the the time needed to clear the indicator.

When the switch instrument M is operated the line circuit is broken, the winding 42 deie'nergized and armature 45 .falls back to complete the shunt circuit partially completed by the return of push key 46 to normal position.

If a cross should occur between wire 61 and conductor 75 current could flow in the following path: terminal of secondary of transformer 6, wires 21, 47, 48, 49 and 50, pivoted member 27, wire'60,pivoted member 23, and wire 61, by means of the cross to. conductor 75, wire 76, armature 77, wires 7S and 79, non-inductive resistance 80, wire S1, winding 32 and wire 128 to another terminal of a secondary of transformer 6. In order to prevent current that flows in the above traced path from so operating rotor 34, that pivoted member will be moved to the extreme left hand position, a non-inductive resistance 80'has been inserted in the circuit of winding 32 which limits the flow of current and causes the phase'of the current to'so. closely approach that of the local winding 33 that. rotation of rotor 34 is not caused and gravity is not prevented from operating pivoted members 35 and 36.

A dangerous condition might arise if cur-- rent flowing in-sucha path could cause a green light to be exhibited at signal B, for,

if a green light were exhibited at signal B byv reason of a cross, as described, a train might enter the single track block moving in the direction of the arrow X, and although it would cause pivoted member 18 to drop and so break the line circuit, it would not cause a red light to be exhibited at signal B, so that a condition would exist,

which would allow a train moving in the' direction of the arrow Y to enter the single track blockwhile a train was in the single track block, moving in the direction of the arrow X. i

The resistance 80 heretofore described prevents a false clear signal due to a cross being given at one end of the block wlhile the block is occupied by a train moving against the signal, but the insertion of the resistance 80 causes such a displacement of the phase of the normal current flowing therethrough that good operation of rotors 30 and 34, cannot be obtained, consequently, impedance is inserted in series with the line circuit with which resistance'80 is also series,cso as to correct the phase of the current, so that a good torque will be produced upon rotors 30 and 34 by the normal flow of current in the line circuit.

The relation of the phase of the current to the; electro-motive force may be readily understood by refere1 ce to Fig. 2, in which the length of al lines except O- G represent values of impedance and in which the line OG represents the electro-niotive force; OK represents by its length the impedance of a local winding as 29 or 33, and by its angular distance from OG, the phase displacement of a current which might fiow' therein. K--H represents the effect of .ohmic, resistance 130 in displacing the phase of the current in the locals 29 and 33. The resultant phase displacement is represented by line 0 H. The displacement of thephase of the current caused by winding 28 and 32 is'represented by O L. If nothing else were in the circuit except windings 28 and 32 a good phase displacement would be obtained between windings 28 and 29 and and 33, soas to obtain good torque upon the rotors 30 and 34, but in order to prevent a false clear signal by a'cross between wire 61 and conductor 75, the non-inductive resistance has been inserted, the efi'ect of which may be represented by the lineLN and as the line wire connecting the two statiohs has some ohmic resistance, its effect may be represented by, the line N-U, so that the 'combined eifect'of the ohmic resistance 80 and the ohmic resistances of the line is to bring the phase of the current flowing in the line wire and the windings 28 and 32 to a dis placement represented by the line O-U, but

as under such conditions the phase of the current flowing inlocals 29 and 33 would not be displaced sufiicie'ntly from the phase of the current flowing inwindings-28 and 32, the highly reactive impedance70 has been inserted in series with the line wire and its effect may be represented by. th

line ll-J and the resulting phase otthe current by the line OV, which gives a dis placement of the current in the windings 28- and 32 sufficiently removed from the phase of the current in windings 29 and 33 as to cause a proper torque to be exerted uponv rotors 30 and 34 when current flows in the line wire. i

As heretofore explained, when the relays 39 and 40 are not shunted, the current flowing in windings 28 and 32 should .not be such as to cause a rotation of'rotors 30and 34 and this result is obtained'by making the .relay coils 39 and 40 each of suchan impedance as will cause a phase displace ment represented by the line V-Z, sothat the phase of the current when flowing; through the line circuit including ohmic resistance 80 and impedance and 'resistance' 70 and a checking relay, as 39 or 40, would a be represented by the line O Z, which it will be seen exactly coincides with the line representing the phase of the current flowing in the windings 29 and 33, and as the phase of the current in both the winding 28 and 29 and 32 and 33 is the same, no torque would be produced uponrotors 30 and 34.

No account has been taken in the vector diagram of the efiect of conductor 75 and this, because in the great majority of cases conductor 75 will be the ordinary ground return. But if a wire were substituted therefor, its effect upon displacing the phase of the current would be no greater than the effect of the other linewire of which 61 and 68 form a part and wouldnot have such an effect as to prevent an effective torque from being produced under normal conditions upon rotors and-34..

Although applicant has herein illustrated and described his invention as applied to a particular type of signal and to a particular situation, it is to be understood that the em- 25 bodiment herein shown and described is merely illustrative,.;and that divers changes and arrangements obvious to those skilled in the art may be made, without departing from the underlying principle characteristic 3 0 of 'applicants invention.-

Having thus described one particular physical embodiment of my invention and explained the principle thereof, what I claim .as new and desire to secure by Letters Pat- 35 net, is:' p

1. In a signaling system, a block, a signal for'governing entrance into the block from one end, a signal for governing entrance into the block fromthe other end, controlling 40 devices, for the signals in a series circuit, a

constantly acting source of alternating current energy connected in series in the circuit, means to change the phase of the current in the circuit 180 for changing the aspect only of one of the signals. I

2. In a signaling system, a block, signals governing entrance into the block from either end, two conductors, signal controlling devicesat either end of the block for controlling said signals in series with said conductors, a constantly actingsource of energy in series with said conductors, and means to reverse the phase of the current in said conductors for changing the aspect of 55' one of saidsignals.

,3. In a signaling system for railways, in combination: a block; a signal governing the'entrance to each end of, said block and having a proceed aspect, a stop aspectand means associated with each of said relays and controlled thereby for rendering said circuit inefi'ective to operate the other relay.

4. In a signaling system, a block, aswitch within the block, signals governing entrance into the block from either end, 'a single signal control wire from one end of the block to the other, and a switch vindicator controlled by said single wire. 1 V

5. In a signaling system: a block; a source 7 5 of alternating current; signals governing entrance into the block from either end; translating devices, one .for controlling each of said signals; each of said translating devices having two windings; one of'said wind- 8 ings in each of said translating devices being permanently energized from the said source;

a series circuit including the other of said windingsand the sourceof energy; means inserted'in said circuit for rendering one of said translating devices torqueless when the energy from the source is shunted around the winding of-the other translating device in the series circuit. i

6. In a signaling system: a track circuit 0 block; signals, one governing the entrance into the block from either end; translatingdevices, one for controlling each of said signals; each of said translating deviceshaving two windings; one of said windings in each s r of said translating devices being permanently energized; a series circuit including the other of saidwindings and a source of energy; translating devices, each includingcircuit controllers, one of the circuit controllers of each of the second mentioned translating devices normally included in said series circuit; translating devices, each shunting one of said circuit controllers and including a circuit-controller; means governed by the track circuit of the block and including one of the first mentioned translating devices for energizing the second mentioned translating devices and opening'those circuit controllers of the second mentioned translating devices which are included in said series circuit; means for maintaining energized each of the second mentioned translating devices including a circuit controller of the corresponding third mentioned translating devicea'nd a circuit controller of the corresponding second men-tioned translating device, whereby current flowing in the series circuit must" pass through the third mentioned translating devices; said 1% third mentioned translating devices being of such impedance that the first mentioned translating devices will be rendered torqueless when the current flowing in the series circuit flows through the third mentioned 1% translating devices.

7. In a signaling systemza source of al ternating current; a block; signals, one\governing the entrance to the block at each end; translating devices, one for controlling each sistance included in said circuit near one end of the block; a non-inductive resistance and I signal, each translating device including two windings, one each of which is permanently connected to the source of alternating current; two conductors between the ends of the block; a single series circuit including said two conductors and the other windings of the translating devices; an inductive rea source of alternating current included in the circuit near the other end of the block, whereby a cross between the. said two conductors intermediate theends of the block will prevent the operation of either of the translating devices by the alternating-current.

8. In a signaling System: a block; signals, one governing the entrance to the block at each end; a means responsive to-phase relations of alternating currents for controlling each of said signals: a single series circuit controlling said means; a source of alternating current in said circuit, a non-inductive resistance in said circuit and an inductive resistance, in said circuit, the resistances being such that the alternating currentwill not operate one of said means whenthe in ductive resistance is shunted.

9. In a signaling system: a block; signals, one governing the entrance to each end of the block, said signals adapted to asssume a stop aspect; a track switch intermediate the ends ofthe block for allowing the entrance of a train to the block; a signallocated in proximityto the switch; means for'causing .said signal to start to change its indication and to simultaneously cause each of the sig-' nals at the ends of the block to assume the stop aspect, and to further cause said signal at the switch to complete its change of indication.

i 10. In asignaling system for railways, in combination: signals having aiproceed as-' pect, a stop aspect and a permissive aspect and protecting the entrance to each end of said block; means for controlling each of said signals; a circuit including in series said means; and means associated with eachv signal for preventing said controlllng means I of the other signal from operating to cause that signal to assume a proceed aspect, said last-mentioned means being set into operation when the corresponding first-mentioned controlling means is operated to cause the signal controlled thereby to assume a permissive aspect, whereby a proceed aspectof either signal can not be given until the per missive aspect of the other signal has dis:

combination: a block; a signal governing the entrance to each end of said-block; means for controlling said signals; a series circuit including said signal controlling means; a source of current included in sa d serles cirsource of current for preventing the operation otthat signal controlling means by said source of current; and means associated with the signal controlling means at the other end 01' said block for nullifying the efiect of said last-mentioned means at the first mentioned end of said block.

12. Ina signaling system for railways, in combination: a signal; means for modifying the appearance of said signal and thereby cause it to assume a permissive aspect; an energizing circuit for said means; a maintaining circuit for said means including cooperating contacts closed by said means when it is energized; a relay having cooperating contacts operated thereby which are included in said maintaining circuit and which are opened when said relay is enermeans is energized; and signal'controlling devices included in said signaling circuit and operated by alternating current, said devices being responsive to variations in the lag of current flowlng 1n sald s1gnal1ng circuit, the lag of current flowing in said signaling circuit whenever said relay is included therein being such that said signaling controlling devices are not operated.

13. In a signaling system for railways, in combination a stretch of track divided into two adjacent electrically isolated track circuited sections, each'having a track relay; a circuit; a source of current; a translating device included in said circuit and responsive to the interruption of the flow of current from said source and the reversal of the connection between said circuit and said source; a circuit controller operated by the track relay of one of said sections for reversing the connection between said source of current and said circuit; a second circuit its Ill]

controller operated by the track relay of controlled jointly by said translating device and by said second circuit controller, said energizing circuit being closed at said translating device when said circuit is connected to said source of current by said first circuit controller in the position which it assumes when its track relay is denergized;'and a signaling circuit controlled by said relay.

14. In a railway signaling system, in com- 'bination: two adjacent track sections each having a track relay, a line relay. controlled by the track relays ofboth track sections,

said line'relay being slow acting to open its front contacts after an interval of delay following its. deenergization, an auxiliary relay, an energizing circuit for said auxiliary relay including a front contact of the line relay'and a back contact of the track relay of one of said track sections, the opening of the front contact of the line relay being delayedby the slow action of the line relay long enough after. the closing of the back contact of the track relay to permit energization of the auxiliary relay, and a circuit for signaling controlled by said auxiliary relay.

15. lln a railway signaling syStem in combination: two ad acent electrically independent track circuit sections, each having a track relay; a signal governing trafic' from one section to the other in one direction and having a stop aspect, a proceed aspect and a permissive aspect; a relay for controlling said signal; a controlling circuit for said relay; a source of current for supplying power for operating said relay; said relay being responsive to the difi'erent character of current produced by reversing the connection between said source audits controlling circuit as well as to the interruption of current in its controlling circuit, said relay being operated when its controlling circuit is connected in either way to saidv source ofcurrent to cause said signal to assume its proceed aspect, said relay being operated when its controlling circuit is deenergized to cause said signal to assumeits stop aspect; a circuit controller operated by the track relay of the section over which a train passes before it reaches said signal and arranged to reverse the connection between said controlling circuit of said relay and said source of current; another circuit con troller operated by the track relay of the section protected by said signal 'andar ranged to interrupt said controlling circuit of said relay; and means for causing said signal to assume its permissive aspect which is controlled jointly by said relay and the track relay of the block protected by said signal, and which is operated when said track relays of said sections are operated in a predetermined sequence by a train passing over said sections in the direction of traffic governed by said signal.

16. In a railway signaling system, in combination: two adjacent track circuit sections, each having a track relay; a signal for governing traffic from one section to the other section in one d1r ect1on and having a stop,

aspect, a proceed aspect and a permissive aspect; a source of current; a three-position alternating current relay for controllingsaid signal, said relay having two windings, one of which is permanently connected to said source of current; a controlling circuit for the other winding of said relay; a circuit controller operated by the track relay of the section preceding said signal over which a train passes before reaching said aspect when said translating device is en ergized and said relay is in its deenergized position; and an energizing circuit for said' translating'j device, said energizing circuit being controlled jointly by the track'relay of the section protected by. said signal and by said relay, said energizing circuit being closed when said track relay is de'nergized and said relay assumes an operated position correspondin to the deenergized condition of the track relay of the section preceding said signal.

17. lln a signaling system for railways, in combination: a block; a track switch between the ends of said block; a signal for governing trailic through said block and having a stop' aspect and a proceed aspect; a controlling circuit for said signal; a switch indicator having a stop position and a proceed position; means for moving said switch indicatorfrom its stop positionto its proceed position; means controlled by the controlling circuit of said signal for preventing the operation of said means; means for setting said indicator moving means into operation and for simultaneously controlling said signal circuit to cause said signal to assume its stop position; and. means for last-mentioned means has been set into operation before'said indicator assumes its proceed position.

18. In a signaling system for railways, in combination: a block; a track switch be tween the ends of said block; a signal for governing traffic through said block and having a stop aspect; a controlling circuit for said signal; a switch indicator having a stop position and a proceed position;

means for slowly moving said switch indicator from its stop position to its proceed position, whereby a certain time elapses after said means hasbeen set into operation before said indicator assumes its proceed position; means for setting. said means into operation and for simultaneously controlling said signal controlling circuit to cause said signal to assume its stop aspect; and means controlled by said signal controlling circuit for preventing the operation of said indiator moving means.

19. In a signaling system combination: a block; a track switch between the ends of said-block; a signal for for railways, in

recast/i protecting the entrance to each end of said block; relays forcontrolling said signal; a source of current; a controlling circuit for said relays; means for reversing the connection between said source of current and said controlling circuit, said relays being re sponsive to the diflere'nt character of current caused by the difierent connections between said: source of current andsaid controlling circuit; a switch indicator at said switch having a proceed position'and" a stop posi tion; and electrically operated means for operating said indicator, said means being included in said controlling circuit and being" responsive to the different characters of current flowing in said circuit, said means being arranged so it will not operate to move said indicator to its proceed position while said controlling circuit is in a conditon to cause either of said signals to assume its stop aspect.

20. In asignaling system for railways, in-

' combination: a block; a signal protecting the entrance to each end of said block; alternating current relays for controlling said sig nals and each having two Wind1ngs, said .relays being operated when alternating currents havinga predetermined phase relation flow through its respective windings a series circuit including said relays; a track switch between the ends of said block; a switch'indicator electrically operated meansfor moving said switch indicator, said means having two windings and being operated when alternating currents having predetermined phase relationsilow through its respective windings, one of said windings'ofsaid means heing included in said circuit; a normally closed shunt around said Winding of said means which is included in said circuit; and

manually operable means for interrupting said shunt, the phase relation between cur-- rents flowing in therespective windings of,

said relays necessary for the operation thereof being destroyed when said winding of said means is included in said circuit.

In a signaling system for railways, in

' combination: a block; al'track switch between the ends of said block; a; signal' for protecting the entrance to each end of said block and having a stop aspectaa controlling circuit for said signals; aswitch; indicator for said track switch; means for operating said switch indicator; aiid means for 'governing said controlling circuit to cause said aspects when signals to assume their stop said means is set nto operation.

22. 1n a signaling system-for railways, in combination: a track circuited block; a preliminary track circuited section at one end of said block; a signal for protecting the entrance-to each end of said block; polarized relays for controllingsaid signals; a nor- 'mally energized series circuit including said relays; a source of current and means con- Y combination: a block; Y entrance to each end of said block and havtrolled by the track circuit of said preliminary section for changing the polarity of the connection between and said circuit.

23. In a signaling system for railways, in

combination: a track circuited block; a preliminary track circuited section at one end of-said block; a signal forprotecting the entrance to said block at each end and having a stop aspect, a proceed aspect and a permissive aspect; polarized relays for controlling said signals; a controlling circuit for said relays arranged to be opened and closed by the track circuited sections of said block;

means governed by the track circuit of said preliminary section for reversing the polarity of said controlling circuit, said relays causing said signals to assume a stop aspect .when deenergized, the relay at the end of the block opposite to said preliminary section: being operated by a reversal of polarity of said circuit to cause its corresponding signal to assume a stop aspect, the relay at the end of the block adjacent tosaid preliminary section being operated by a reversal of polarity of said circuit to cause its corresponding signal to assume a proceed assaid source of current i pect; means operated by a movement of a tra n from said preliminary section onto said block for causing the ad acent signal to assume a permissive aspect; and means operated by the movement of a train into said block at its other end for causing the adja cent signal to assume its permissive aspect.

24. In a signalingsysteni for railways, in a signal governing the cuit for said relays; a source of current; and

means for reversing the connection between said source of current and said controlling circuit and thereby cause the polarity of said controlling circuit to be reversed.

25. In a signaling system for railways, in

combination: a track circuited block; a preliminary trackcircuited section adjacent to one end of sand block; signals for governing the entrance to each end of said block and having a stop aspect and a proceed aspect; polarized relays for controlling said signals; a controlling-circuit for said relays; each of said relays being electrically connected to its corresponding signal to cause said signal to assume a proceed aspect when thepolarity of said controlling circuit is normal, the relay for controlling the signal adjacent to said preliminary section being controlled by either polarity of said circuit to cause its corresponding signal to assume a proceed aspect, the relay at the other end of said block being operated by the polarity of said circuit opposite to its normal polarity to cause its corresponding signal to assume a stop aspect; and means controlled by the track circuit of said preliminary section for reversing the polarity of said controlling circuit.

26. In a signaling system for railways, in combination: a relay; an energized circuit for said relay; a maintaining circuit for said relay including cooperating contacts operated by said relay which are closed when said relay is energized; a signaling circuit; anotherrelay included in said signaling circuit; a normally closed shunt for said an other relay which is controlled by said firstmentioned relay and which is opened when said first-mentioned relay is energized; and a circuit controller operated by said another relay and opened when said relay is energized, said circuit controller being included in said maintaining circuit of said first-men tioned relay. a

27. In a signaling system for railways, in combination: a block; a signal at the entrance to each end of said block and comprising three different colored lamps; a source of current; a relay associated with each signal for selectively controlling the connection between said source and two of said lamps of that signal; and means'controlled by each of said relays 'for controlling the connection between said source and the third lamp of the corresponding signal)" 28. In a signaling system for railways, in combination: a track circuited block having a track relay; a track circuited preliminary section adjacent to one end of said block and having a track relay; a signal for protecting each end of said block and having a stop aspect, a proceed aspect and a permissive aspect; a polarized relay for controlling each signal; the relay for controlling the signal adjacent to said preliminary section being arranged to cause the signal controlled thereby to assume its proceed aspect when said relay is energized by current of either polarity and to cause said signal to assume a stop aspect when said relay is deenergized,

the relay for controlling the signal at the other end of said block being arranged to cause the signal controlled thereby to assume its proceed aspect when said relay is energized by current of one polarity and to cause said signal to assume a stop aspect when said relay is deenergized or is energized by current of the opposite polarity; a series section and arranged to reverse the conneci tion between said source of current and said controlling circuit, said circuit controller normally maintaining the polarity of said controlling circuit' such that said relays cause the respective signals controlled thereby to assume their proceed aspects; means associated with the signal atthe end of the block adjacent to said preliminary section for causlng said slgnal to assume its *permissive aspect; an energizmg circuit for said means controlled jointlyby the track relay of the block and the polarized relay at that end of the block, said energizing circuit being closed when said track relay is deenergized and said polarized relay is energized by current of av polarity opposite to its normal polarity; means associated with the signal at the end of the block opposite to said preliminary section for causing that signal to assume its permissive aspect; an en-' ergizing circuit for said last mentioned means controlled jointly by the track relay of the block and the polarized relay at that end of the block, said energizing circuit being closed when said track relay is deenergized and said polarized relay is-energized by current of a normal polarity; a maintaining circuit for each of said means including cooperating contacts operated by the respective means which are'closed when said means is energized; a circuit controller included in each of said maintaining circuits; and means included in said controlling circuit for said tioned circuit controllers when current flows in said controlling circuit.

29. In a signaling system for railways, in combination: a block divided into track circuit sections, a signal for protecting the en trance to each end of said block and having polarized relays for opening said last-mena stop aspect, a proceed aspect and a permis sive aspect; a translating device associated thereby for changing the proceed aspect of that signal into a permissive aspect.

30'. In a signaling system for railways, in

- combination: a block; a signal for protecting the entrance to each, end of said block and having a: proceed aspect, a stop aspect eoaerr combination: a blockga track switch beincluding a winding; and means for in tween the ends of said block; a signal a controlling circuit for said signal aswitch indicator having a stop position and a proceed position; means for operating said switch indicator to its proceed position and eluding said winding in the controlling circuit for said signal to set said switch indicator into operation, said winding of said last-mentioned means when included in said controlling circuit'for' said signal modifying the electric characteristics thereof without interrupting its continuity and thereby producing a'controlling effect on said signal.

32. In a signalingsystem for railways, in combination: a block; a track switch between the. ends of said block; a signal for governing traflic through said block, a co trolling circuit for said signal; a switch indicator having a proceed aspectand a sto aspect; means for causing said switch indicator to assume its proceed aspect after a predetermined lapse of time after its initial operation; and means for simultaneously controlling said controlling circuit for said signal and setting said last-mentioned means into operation.

3.3. In a: signaling system for railways,in

combination: two track circuit sections; a translating device controlled by 7 said track circuit sections; a circuit controller actuated by said translating device,-said circuit controller beingclosed when one of said track circuit sections is occupied and being opened after a short lapse of timewhen the other track circuit section is occupied; a device adapted to be governed electrically; a circuit for'governing said device controlled jointly by said circuit controller and said other track circuit section; and means forsignaling governed by said device.

34. In a signaling svstem for railways, in combination; two track circuit sections; a polarized relay; a controlling circuit for said relay; means governed by one of said track circuitsections for reversing the polarity of said circuit; means governed by the other track circuit section for interrupting said circuit; a circuit controller gov- -erned by said relay, said circuit controller being closed when the polarity of said controlling circuit is reversed and being opened after a short lapse-of time when said-controlling circuit is interrupted; and means for signaling controlled jointly by said circuit controller and one of said track circuit sections.

7 35. In a: signaling system for railways, in combination: two track circuit sections; a

translating device controlled by said track tive; means controlled by said first-meutioned circuit for governing said last-mentioned circuit; and means for signaling governed by said device.

; 36. In a signaling system for railways, in combination: a ,block divided into track cir cuit sections; a signal for protecting each end of said block and having :1; proceed aspect; a circuit; means associated with each signal and responsive to a predetermined electrical characteristic of said circuit for causing said signal to assume its proceed aspect; a stick relay associated with each signal and governed by said circuit and one of said track circuit sections adjacent to that signal; and meansren'dered efiective,wl1en either of said stick relays is ener ized for making the electrical cl1aracteristicsof said circuit different from the predetermined electrical characteristic necessary for the operation of said first-mentioned means.

37 I11 a signaling system for railways, in combination: a trackway divided into track circuit sections each having a track relay; a line relay controlled by the track relays of a plurality of said track circuit sections; a stick relay; an energizing circuit for said stick relay including a back contact of a.

particular track relay and a contact circuit for said stick relay including a contact operated thereby; means controlled by said line circuit for governing said holding circuit; and a, circuit for signaling controlled by said stick relay.

39. In a signaling system for railways, in combination: a stretch of track divided into track circuit sections each having a track relay; a line relay controlled by the track relays of the stretch and having a front contact;' a stick relay; an energizing circuit for said stick relay lncluding sald front track circuit sections each having a track relay; a line relay having a front contact; a line circuit for controlling said line relay governed by the track relays of said stretch; a stick relay; an energizing circuit for said stick relay including a back contact of a particular track relay at one end of the stretch and said front contact of the line relay, said front contact of the line relay remaining closed until aftensaid back contact has closed; a holding circuit for said stick relay including a contact operated thereby; means controlled by said line circuit for keeping said holding circuit closed after said stick relay has been initially entact of the second relay naoaa'ri ergized so long as the line circuit is open; and a circuit for signaling controlled by said stick relay.

41. In a signaling system for railways, in combination: a relay having a front and aback contact; means for controlling said relay; a second relay controlled by the front contact of the first relay; a third relay; a circuit forthe third relay ,including theback contact of the first relayand a front conand a circuit for signaling controlled by the third relay.

42. In a signaling system for railways, in

combination: two adjacent track sections each having a track relay, a slow acting line relay having a front contact, a line circuit for said line relay controlledby the track relays ofboth of said track sections, a stick relay, an energizing circuit for said stick relay including a back contact ofone of said track relays and a front contact of said line relay, a stick circuit for said stick relay including a contact operated thereby, means controlled by said line circuit for maintaining said stick circuit closed so long as the line circuit is open, and a circuit for signaling controlled by said stick relay.

WINTHROP K. HOWE. Witnesses v LILLIAN L. PHILLIPS, MARY G. DALBEY.

Images