US2028370A

US2028370A - Apparatus for the control of highway crossing signals

Info

Publication number: US2028370A
Application number: US683164A
Authority: US
Inventors: Arba G Williamson
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1933-08-01
Filing date: 1933-08-01
Publication date: 1936-01-21
Anticipated expiration: 1953-01-21

Description

13111.21, 1936. A QN 2,028,370

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed Aug. 1, 1953 2 Sheets-Sheet 1 400' E E l 6? H c o o 15 m 14 9/ 4 S LL NF f f48-50 61 48150 W3 C B J H B F I 8 L 10 TM l L 3 24 iii I fi 6 56 2 25 1 I Fig.1. 27 19 5 95 51 y 1. B B

' 2640' L-Xk 1 }@--1600. E 3J2 I 2 D 01 1 C2 \H c o 0 TR 9' o o C i i B s 52 NF figm IJYVENTOR Ar'ba G.Wdllam.5'017 BY WW 1115 ATTORNEY Jan. 21, 1936. A. G. WILLIAMSON APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING S IGNALS Filed Aug. 1, 1953 2 Sheets-Sheet 2 IN VEN TOR QF Arba G. l Villiamsot? 46 g- F49 BY QRW F HIS ATTORNEY Patented Jan. 21, I936 orrso STATES APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Arba G. Williamson, Carnegie, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Appiication August 1, 1933, Serial No. 683,164 14 Claims. (01. 24 -130)- My invention relates to apparatus for the control of highway crossing signals, and particularly to apparatus controlled by a train approaching a highway for starting the operation of the highway signal in accordance with the speed of the train.

I am aware that control systems have heretofore been proposed wherein apparatus controlled by a train approaching a highway intersection determines the time of starting the operation of the highway crossing signalin accordance with the speed of the train. These control systems heretofore proposed require, as faras I am aware, a measuring track circuit and a plurality of operating track circuits which a train traverses successively as it approaches the intersection. Such arrangement of track circuits is expensive to install and greatly interferes with the track circuits of the train signaling system where such is in use. A feature of my present invention is the revision of novel and improved apparatus wherewith a train approaching a highway intersection governs the ope-ration of the highway signal in accordance with the speed of a train without the necessity of such plurality of track circuits, and which apparatus is readily superposed on an existing track circuit. Other features and advantages of my invention will appear as the specification progresses.

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

In accompanying drawings, Fig. 1 is a diagrammatic view of one form of apparatus which may be employed for carrying out the embodiment of my invention, and which form is adapted to control a motor driven cam circuit controller type of time measuring device. Fig, 2 is a diagrammatic view of a second form. of apparatus embodying my invention, which form is adapted to control a time element relay type of time measuring device. Fig. 3 is a diagrammatic view of a third form of apparatus wherein the apparatus is superposed on a track circuit whose trafiic rails are intersected by a highway at a point other than at the outgoing end of the track circuit, and which apparatus also embodies my invention. Figs. 4;, 5 and 6 are views partly diagrammatical and partly sectional of a track rail contactor adaptable to be used with my invention.

In each of the several views, similar reference characters refer to similar parts.

Referring to Fig. 1, the reference characters I and E designate. the track rails of a stretch of railway over which trafiicnormally moves in the circuit. 10

At the intersection there is provided a highway crossing signal S. The signal S is indicated on the drawing by a conventional symbol commonly used :in the art to indicate a combined audible and visible signal in the form of an electric bell 15 and a pair of flashing lights. It will be understood, however, that my invention is not limited to any specific form of highway crossing signal and any of the standard signals may be used.

The immediate control of the signal S is gov- 20 erned jointly by a relay K and a flasher relay NF. The relay K is a direct current neutral relay which is slightlyslow releasing in character. The flasher relay NF may take different forms but preferably is similar to that disclosed in the 25 United States Letters Patent, Reissue No. 17,252,

to C; S. Snavely and W. B. Wells, for Electrical relays. In connection with the flasher relay'NF,

it is deemed sufficient for the present application to point out that the armature 4 is biased to a normal or central position, that is, to the position illustrated in Fig. 1, and is adapted to beattracted to the right or to the left by the energizing of

windings

1 and 9, respectively. The armature 4 makes engagement with a contact 5 when 35 it occupies its normalposition and when it is swung to the right under the influence of the winding 1. When the armature 4 swings to the left under the influence of the winding 9, it breaks engagement with the contact 5 and makes en- 40 gagement with a contact 8. Engagement of armature 4 with the contact 5 completes a shortcircuiting connection on the winding 7 and engagement of armature 4 with the contact 8 completes a short-circuiting connection on the wind- 45 ing 9 as will be readily understood by an inspection of Fig. 1. When positive current is supplied to the wire 6 in a manner to be described hereinafter, the Winding 1 Will not at firstbe energized due to the short-circuiting connection but wind- 50 ing 9 will be energized and armature 4 will be attracted away from the contact 5 and into engagement with the contact 8. Winding 9. will now be deenergized due to the short-circuiting connection and winding 1 will receive current 2 with the result that armature 4 will be attracted back to the right into engagement with the contact 5. It follows that the windings 'l and 9 will be alternately energized causing armature 4 to swing back and forth between the contacts 5 and 8. The parts are so proportioned that the armature 4 will make a complete cycle of operation substantially every two seconds.

A circuit controlling contact I0 is operatively connected with the armature 4 as indicated by a dotted line. The circuit controlling contact 10 normally engages with two flexible spring contacts H and I2. The arrangement is such that when armature 4 swings to the right under the influence of winding 1, the circuit controlling contact In breaks engagement with the spring 12, and when armature 4 swings to the left under the influence of winding 9, the circuit controlling contact [0 breaks engagement with the spring l I. It follows that the circuit controlling contact I0 is operated by the armature 4 to alternately break engagement with the springs I! and I2. The circuit controlling contact 10 governs the circuits for the signal lights l5 and I6 of the signal S in a manner to be pointed out hereinafter.

In order to clarify the following description, I shall assume the maximum speed for trains approaching the highway H to be 90 miles per hour and that 20 seconds operation of the signal S before a train reaches the intersection is required. A train travelling 90 miles per hour will move 2640 feet in 20 seconds. I shall further assume that the track circuit D-E is a circuit used in connection with a train signalling system and according to the usual practice is of the order of 5000 feet in length. The remaining distance of the track circuit over the 2640 feet required to assure 20 seconds operation of the signal S, I shall refer to in the following description as a distance X. For reasons to appear hereinafter, the track relay TR is preferably an interlocking relay of the well known type comprising two windings i3 and M, the winding l3 receiving current from the track circuit D-E and the winding l4 receiving current from a track circuit E-F, including the traffic rails to the right of the intersection. It will be understood, however,

that my invention is not limited to any specific layout of track circuit and may be superposed on various arrangements of track circuits, and also that the apparatus may be adjusted for different maximum speeds of trains, and different operating times of the highway crossing signal.

The relay K is normally energized over a stick circuit governed by the track relay TR. and is provided with pickup and holding circuits controlled in part by a time measuring device designated as a whole by the reference character TM. The normal stick circuit can be traced from the positive terminal B of any convenient source of current such as a battery not shown over its own front contact 62, Winding of relay K and front contact of the armature 53 of the track relay TR to the terminal C of the same source of current. Relay K may also normally receive current over a pickup circuit including the B terminal of the current source, contact 5651 to be described later, winding of relay K and the front contact of armature 53 to the opposite C terminal of the current source. The function of this pickup circuit and the manner whereby the time measuring device TM controls the pickup and holding cir cuits for relay K will be pointed out later in the description.

The time measuring device TM may take different forms and preferably includes a shaft I9 shown schematically by a dotted line, and on which are rigidly mounted two circuit controlling cams l1 and I8 and a circuit controlling contactor 23. Shaft i8 is driven in either direction by a constant speed reversible motor M through the medium of a suitable gear train indicated by the reference character GT. The cams I7 and I8 and the contactor 23 normally occupy the position illustrated in the drawings, and are arranged to be moved away from this normal position in a clockwise direction toward a reverse position by rotating the motor M in one direction, the full reverse position preferably being substantially 300 or 3 of one revolution. At the full reverse position, the contactor 23 occupies the position indicated by the dotted line and opens a motor circuit as will later appear at the contact 25 to automatically stop operation of the motor M. At

other times, shaft 19, cams l1 and I8 and the contactor 23 are restored to the normal position by rotating the motor M in the reverse direction, the contactor 23 opening the motor circuit at the contact 30 when the full normal position is reached.

The cam i8 is so positioned on the shaft it that its raised portion 55 registers with a contact spring 56 to raise that spring into engagement with a contact 51 only when the shaft is occupies its full normal position. The cam I! is so positioned on the shaft l9 that its raised portion 58 registers with a contact spring 59 to lift that spring into engagement with a contact 60 when the cam has been rotated substantially 50 clockwise from the normal position, that is, onesixth of the total movement. Once the contact 59-00 is closed, it is held closed until such time as the cam I1 is rotated back toward the normal position and the raised portion 58 moves away from beneath the spring 59.

The gear train GT of the time measuring device TM may take different forms and preferably is of the type disclosed in the United States Letters Patent, No. 1,991,756, granted February 19,

1935, to B. Lazich on Apparatus for changing speed and direction of rotation by reversing a constant speed motor, to which reference is made for a full description of this gear train. It is deemed sufiicient for the present application to point out that when motor M is rotated in the direction to drive the shaft l9 clockwise, the gear reduction of the gear train GT is so proportioned that the shaft I9 is rotated at a rate sufficient to just bring the raised portion 58 of the cam I! to the point where it registers with the spring I;

50 in the time interval required for a train travelling at the maximum speed of 90 miles per hour to pass over the distance X of the track circuit. At this speed, then, contact 59-430 will not close while the train is traversing distance X, but it will close while a train travelling at any lesser speed is traversing distance X. In other words, the gear reduction when the motor drives the shaft [9 clockwise is made such that cam ii is rotated approximately 50 in the time required by a train travelling 90 miles per hour to pass over the distance X. If the train is travelling at a lesser speed, the cam I! will be rotated some distance beyond the point where the contact 59t9 becomes closed during the time the train is pass ing over the distance X, the amount of the rotation of cam I! being increased as the speed decreases. When the motor M is rotated in the direction to drive shaft l9 counter-clockwise, the gear reduction of the gear train GT is so proporto the normal position is completed in approxi mately 120 seconds; Consequently, cam H is rotated from the point where its raised portion 55 passes from beneath the spring 59 to the full normal position in approximately '20' seconds That is to say, the gear reductionfor driving shaft l 9 clockwise is arranged in accordance with the distance X of the track circuit and the maximum speed, and the gear reduction for driving shaft l9 counter-clockwise is arranged to make the complete movement in a predetermined time interval. The function of these gear ratios will appearwhen the operation of the apparatus is described. The specific structure of this gear 'train GT, however, forms no part of'my present conventionally for the invention, and is shown sake of simplicity. 7

The time measuring device TM also includes a direct current neutral relay L which is adapted to control the motor M in the following manner. When relay L is energized, an operating circuit is completed from the B terminal of the source of current over front contact 24, armature 25 of motor M, contact 23-26, front contact 21, and field wind-ing 28 to the opposite terminal C of the current source. The flow of current through the armature 25 is in adirection to cause the motor M to rotate in the direction that'drives the shaft l9 clockwise. When relay L is deenergized, an operating circuit is completed from the B terminal of the current source over back contact 29, contact 23-40 when shaft l9 has'been moved away from its normal position, armature 25, back contact 3!, and the field winding 28 to the opposite battery terminal C. The fiow of current through the armature 25 is reverse to that previously mentioned and the motor M rotates in a direction to rotate the shaft 19 counterclockwise. It is clear from the foregoing that energizing the relay L results in the circuit controlling'cams l7 and I 8 being rotated in the clockwise direction from the normal position toward the reverse position, and deenergizing the relay L reverses the movement and the cams I! and I? are rotated toward the normal position,- the movement being stoppedwhen the full reverse and the full normal positions are reached by the circuit controller 23. 1 r a 7 Cl and C2 are track rail contactors which are operated from an engaging to a non-engaging position by the leading wheel of a train, and which are automatically restored to theengaging position when the train has vacated the track circuit. Referring to Figs. 4, 5 and 6, the casting is adapted to be attached to the web of the traflic rail in anyconvenient manner. 2! is a rocker arm pivoted by a pin 22 having bearo ings in the casting 20 and an outer plate 99.

The left-hand end of the rocker arm 2! is formed with an engaging surface 3 which is raised adjacent the rail head to a position to be engaged by the flange of a car wheel as it moves along the rail. An eyebolt 32 is pinned to a jaw 33 at the left-hand end of the rocker arm 2I'by a ,pin 34. A trunnion block 35 is carried by trunnion pins 3% journaled in the casting'w and in the outer plate 99. The eyebolt 32 extends through the trunnion block 3'5 and a spring 31 under compression is carried betweenthe block 35 and a shoulder 33 of the eyebolt 32. It follows that when the rocker arm 2| is depressed to ,aipoint where the pin 34 passes below the center line of the bearing pins 36,'the spring- 37 will force the left-hand end of the rocker arm 21 Sen further downward until a stop 39 is reached. In the depressed position, the contactsurface 3 is below engagement. with the flange of the car wheels, that is to say, only the leading wheel of a train operates the rocker arm 2|.

A magnetic plunger 40 is pinned to the righthandend of the rocker arm 21 by. a pin H,

and isaclapted to be drawn downward when a solenoid magnet 42 is energized It is clear, therefore, that energizing the magnet 42 subse quently to a car wheel depressing the rocker arm'Zl in the manner pointed out above, draws the plunger 40 downwardand raises the lefthand end of the rocker arm 2i. When the pin 3 passes above the center line of the bearing pins '35, the toggle spring 31 will force the arm 2| still'further upward to the engaging position, the movement being limited by a stop 43.

-At the right-hand end of the rocker arm 2! is pinned a controller rod 44 of suitable material and into which are secured pins 65 and 56, the

pins

45 and 66 carrying rollers 9'! and 98, respectively. It follows that the controller rod- 44 is raised to an upper position when the rocker arm 2i is depressed and is lowered to a down position when the rocker arm 2! is restored to its engaging position. The rollers 91 and 98 engage two contact springs 4'! and 48, respectively, the arrangement being such that with rod M in its down position, the spring 41 breaks engagement with a mating spring 49 to open the con tact therethrough, and the spring d8 makes enspring 50. Although a specific form of track rail contactor is here disclosed, it will be understood that I do not wish to limit myself to any specific structure of contactor, and the form here shown will serve to illustrate a contactor adaptable to my invention.

Referring again to Fig. 1, the track rail contactor Ci is preferably located 2640 feet to the left of the highway H, and the track rail c0ntactor C2 is preferably located at substantially 400 feet t'othe left of the highway. The function of the'position of these track rail contactors will appear as the operation of the apparatus is described. 7

In describing the operation of the apparatus of Fig. l, I shall assume that the apparatus occupies the position shown. in the drawings and that a train travelling in the normal direction of traific approaches the intersection. As the leading Wheels of the train enter the track circuit D-E, the winding l3 of the trackrelay TR will be deenergized and the armatures 5|, 52, 53 and E i controlled thereby will be released to their full down positions. Current will now flow from the positive terminal B of the current source through the winding of the relay L, back contact of armature 52 of'the track relay TR, line wire Bl, normally closedcontact 48-59 of the track rail contactor Cl and thence to the C terminal of the current source, and relay L will be picked up. With relay L picked up, motor M will be operated in a direction to rotate shaft I 9, and the cams it and I8 clockwise away from the normal position. The stick circuit by which the relay K is normally held energized and which includes the front contact of armature 53 of the track relay TR will now be open,.and that relay will be released unless some other means is provided for supplying its winding with current. The picking up of the relay L completes a holding circuit for the relay K by which current will flow from the B terminal of the current source over the front contact 52 of relay K, winding of that relay, front contact 63 of relay L, back contact of armature 52 of relay TR, line wire 6|, and the normally closed contact 48-50 of the contactor CI to the opposite C terminal of the current source. Consequently, the relay K will be retained energized after the train enters the track circuit D-E, providing the relay L is picked up to start operation of the timing device TM, and the contactor CI has not yet opened contact 48-50.

Motor M operated in response to the picking up of relay L causes the cams I1 and IE to be rotated in the clockwise direction until the train advances to the point where its leading wheel depresses the contactor Cl and opens the contact 48-59 which is included in the energizing circuit for relay L, and also in the holding circuit for relay K. Relay L will now be deenergized and the motor M will be reversed in its operation with the result that the cams i1 and I8 will be rotated counter-clockwise from the position to which they had advanced back to the normal position. As stated above, the holding circuit for the relay K is also opened at the contact 48-59 of the contactor CI, but that relay may now be supplied with current over another holding circuit extending from the B terminal of the current source over front contact 52, winding of the relay, contact 59-69 providing the cam IT has been rotated clockwise far enough to bring its raised portion 58 under the spring 59, back contact 64 of the relay L, normally closed contact 48-50 of the contactor C2, and thence to the C terminal of the current source.

As set forth hereinbefore, the gear reduction through which the motor M operates the shaft I9 in a clockwise direction is so proportioned with respect to the distance X of the track circuit D-E that in the event the train is travelling at the maximum speed of miles per hour, the cam H will not have been rotated to the point where its raised portion 58 will lift the spring 59 into engagement with the contact 60. Hence, it is clear that in the event the train approaching the intersection is travelling at the maximum speed of 90 miles per hour, the last traced holding circuit for the relay K, and which includes the contact 59-60, will not be closed and relay K will be released to start operation of the highway crossing signal S. Relay K, upon releasing, closes a back contact 93 and current will flow from the B terminal of the current source over the back contact of armature 54 of the track relay TR, back contact 93 of the relay K, wire 6, windings and 9 of the flasher relay NF, and to the C terminal of the current source, and relay NF will be operated in the manner described hereinbefore. Current will also flow over this same circuit up to the wire 6 and thence over the springs H and i2 alternately to the lamps l5 and 15 of the signal S and thence to the C battery terminal, to flash these lamps in step with the operation of the flasher relay NF. Furthermore, current will pass from the wire 6 through the winding of the bell 94 of the signal S, and thence to the C terminal of the current source to sound the bell. The result would be that the signal S will be operated from the time the leading wheel of the train engages the contactor Cl and a full 20 seconds operation before the train travelling 90 miles per hour reaches the highway will be assured.

A train travelling 30 miles per hour over the distance X of the track circuit D-E will take an interval three times as long as the train travelling 90 miles per hour and will consume a time interval great enough so that the cam l1 will be rotated substantially 150 away from the normal position, the contact 59-60 being closed during the last of that movement. When the leading wheel of this train engages the contactor Cl and causes reverse operation of the motor M of the timing device TM, the holding circuit for the relay K including the contact 59-60 will be closed and that relay will be retained energized. If the full 300 movement from reverse to normal requires seconds, it

will require substantially 60 seconds of operation of the motor M in the reverse direction to rotate the cam I1 from the position back to its normal position. Hence, contacts 59-80 will be held closed during the first 40 seconds of that 60 second period with the result that the relay K will not be released and the signal S will not be operated until this train has advanced for 40 seconds to the right of contactor Cl. A train travelling 30 miles per hour will require 60 secends in travelling 2640 feet, and hence it follows that 20 seconds operation of the signal S will be obtained before this train travelling 30 miles per hour reaches the highway H.

The time measuring device TM will function in a similar manner for trains of other speeds with the result that substantially 20 seconds operation is assured for the signal S regardless of the speed of the train. In any event, a train advancing to the track rail contactor C2 will operate that contactor and open its normally closed contact 48-50. The holding circuit for the relay K which includes the contact 59-60 of cam I! also includes the contact 48-50 of the contactor C2, and hence positive operation of the signal S when a train reaches the contactor C2 is assured. That is to say, the distance from the contactor C2 to the highway H forms a positive operating section.

Track rail contactors Cl and C2 when depressed each closes the respective contact 41-49, and, consequently, when the rear of the train vacates the track section D-E, and the winding [3 of the track relay TR is reenergized, current will flow from the B terminal of the current source over front contact of the armature 5| of relay TR, wire 65, magnet 42 of the contactor C2, the associated contact 41-49 and to the opposite terminal C of the current source, and magnet 42 of contactor C2 will be energized. Magnet 42 when energized restores the contactor C2 to its engaging position and the associated contact 41-49 will be opened in the manner described hereinbefore. Current will also flow over this same circuit up to the wire 65 and thence over wire 66, magnet 42 of the contactor Cl and its associated contact 41-49 to the opposite terminal C of the current source, and the contactor Cl will be restored to its engaging position in the same manner just described for contactor C2.

After the train has vacated the track circuit D-E and winding l3 of relay TR is reenergized and the time measuring device TM has been operated back to its full normal position, current will flow over the pickup circuit including the B terminal of the current source, contact 56-51 of the cam 18, winding of the relay K, front contact of armature 53 of relay TR and to the opposite terminal C of the current source, and relay K will be picked up to stop operation of the flasher relay NF and of the signal S. It is to be noted that in the event a second and following train should enter the track circuit DE before the first train clears the highway H, the contactors CI and C2 both will remain inthe non-engaging position and the relay K will remain deenergized with the result that operation of the signal S will be continued until the following train has cleared the highway H.

A train moving against the normal direction of traffic will deenergize the winding M of the relay TR previous to the shunting of the winding 83. The interlocking feature usually provided between the 'armatures controlled by the winding M and the armatures controlled by the winding 83 will prevent the full release of the armatures controlled by the winding l3 and the relay NF and signal S will not be operated by this train moving against traffic. The leading wheel of the train moving against traffic will cause operation of the contactors C2 and Cl and once depressed these contactors will remain in the non-engaging position inasmuch as the front contact of armature 5! of the track relay TR will be open, but

when the rear of the train vacates the track circuit DE, the winding l3 will be reenergized, and contactors Cl and C2 will be automatically restored to their engaging positions.

Referring now to Fig. 2, the traflic rails l and 1 are intersected by a highway H and are provided with a track circuit D--E the same is in Fig. 1. Relay K and the flasher relay NF jointly control the operation of signal S in the same manner as in Fig. 1. Relay K is also provided with pickup and stick circuits similar to those of Fig. 1 as will shortly appear.

In this form of my invention, the time measuring device TMI is of the time element relay type which may take different forms but a preferred form is that fully disclosed in the Letters Patent of the United States, No. 1,966,965, granted July 17, 1934, to B. Lazich and H. E. Ashworth, for Electrical relays. present application to say that with. the operating winding El of device TM! energized, an armature 58 is oscillated back and forth at a predetermined rate to actuate a pawl 69 and drive a ratchet m in the clockwise direction. Ratchet '50 operates a segment H through a planetary gear. With a clutch winding 12 energized, oscillations of armature 68 are stopped and a clutch Z3 is actuated by an armature M as indicated by a dotted line to engage and hold stationary the segment H. Circuit controlling contacts 15, it and '8!) are operatively connected with the segment H as indicated by a dotted line, and hence are operated from a normal position illustrated by the full lines in the drawings to a reverse position illustrated by the dotted lines, the movement of circuit controlling contacts l5, l6 and all being completed in a predetermined time interval. For reasons to appear hereinafter, the parts are so proportioned that the contacts l5, l6 and 80' are operated from the normal position to the full reverse position in the time interval required for a train travelling, sa for example, 55 miles per hour to pass over the distance X of the track circuit DE. lhe clutch winding 12, when deenergized, permits the segment H to fall back under the force of gravity to its normal position operating the controller contacts l5, l6 and 89 back to the fullnormal position. A check con- It is deemed sufficient for the tact 8I-82 is provided to check the normal position of segment H, the contact spring 8| being lifted into engagement with the contact spring 82 through the medium of a member 83 attached to the segment 1!, and the arrangement being such that the contact ill-82 is closed only when the segment H is in its full normal position as illustrated in the drawings.

Circuit controlling contact 15 makes engagement with a contact segment ll from its full normal position until just before the full reverse position is reached. Circuit controlling contacts !6 and 80 make engagement with contacts l8 and 84, respectively, only inthe full reverse position.

Track rail contactors Cl and C2 of Fig. 2 are similar in all respects to the corresponding contactors of Fig. l, and contactor Cl is located 2640 feet from the intersection. In this form of my invention, the contactor C2 is preferably located at a point which I shall assume to be 1600 feet from the highway. It will be understood, of course, that the contactors Cl and C2 may be set down along the traffic rails at other distances from the intersection should it seem desirable to do so.

I shall now describe-the operation of the apparatus of Fig. 2. A train approaching the intersection in the normal direction of traffic and. entering the track circuit DE will shunt the winding l3 of the track relay TR and the associated armatures will be released to their full down positions. Current will now flow from. the B terminal of the current source through the operating winding 6'! of the time measuring device TMI, back contact of armature 52 of the track relay TR, line wire 19, and the normally closed contact 48--5l| of the contactor CI to the opposite terminal C of the current source, and the time measuring device TMI will be set into operation. The normal stick circuit for the relay K will be opened at the front contact of armature 5 50f relay TR as the train enters the track section DE, but said relay K will now be supplied with current over a holding circuit that includes its own front contact 62, winding of relay K, contact 15--11, back contact of armature 52 of relay TR, wire 19, and the normally closed contact 485l of the track relay contactor CI to the C battery terminal. When the train has advanced to the location of the contactor Cl, its leading wheel will depress the contactor to its non-engaging position to open the contact 485l'! and current will be removed from the operating winding 61 of the time measuring device TMI, and also from the winding of the relay .K. In the event the train is travelling at a speed above 55 miles per hour and the segment H has not been advanced far enough to bring the

circuit controlling contacts

15, 16 and 8!! to their reverse positions before the operating winding 61 is deenergized, the segment 1! immediately falls back to its normal position. Relay K will now be without current and its back contact 93 will be closed to cause operation of the flasher relay NF and, in turn, operation of the signal S in the same manner as described in connection with the apparatus of Fig. 1. In the event the speed of the train is below 55 miles per hour and the segment H has been operated to bring the circuit controlling contacts I5, 16 and 8!] to the full reverse position before the track rail contactor Cl is actuated by the leading wheel of the train, current will flow from the B terminal of the current source through the clutch winding 12, contact -84, and contact 48-40 of the contactor C2 to the opposite terminal C of the current source, and the segment 1| will be held in the full reverse position. Relay K will now receive current over another holding circuit that includes its own front contact 62, winding of this relay, contact 'IB'I8 of the time measuring device TMI, and the contact 48-50 of the contactor C2 to the 0 battery terminal. Under this condition, operation of the track rail contactor CI will not result in starting the operation of the signal S.

When this train travelling less than 55 miles per hour reaches the location of the contactor C2, and operates that contactor to open the associated contact 4B-50, current will be removed from the clutch winding I2 of the time measuring device TMI and also from the winding of the relay K. Relay K will now be without current and the signal S will be set into operation. When a train has passed beyond the highway H and vacated the track circuit DE of Fig. 2, current will be supplied to the operating magnet 42 of each of the track rail contactors CI and C2 over the front contact of armature 5| of the track relay TR, and these contactors will be restored to their normal engaging positions in the same manner as described in Fig. 1. As the train vacates the track circuit DE, the relay K will be supplied with current over a pickup circuit which includes the B terminal of the current source, check contact 8I82, winding of that relay, and the front contact of armature 53. of the relay TR to the opposite terminal C of the current source. Consequently, relay K will be picked up and operation of the signal S stopped when the rear of the train has passed beyond the highway H providing the time measuring device has also assumed its normal position.

It follows that for trains having speeds above 55 miles per hour, the signal S will be set into operation when the train reaches the location of the more remote track rail contactor CI, and. which is located far enough from the highway so that at least 20 seconds operation of the signal before the train reaches the highway is assured even for the maximum speed of miles per hour. For trains travelling at a speed less than 55 miles per hour, the operation of the signal S is delayed until the train reaches the: location of the second track rail contactor C2, and which location is a sufficient distance from the highway that at least 20 seconds operation of the signal before these trains reach the highway is assured.

In Fig. 3, the traffic rails I and I are intersected by the highway H at a point some distance from the outgoing end of the track circuit DE. At the intersection, there is provided in the rail I an insulated rail joint 35 around which is connected the winding of a relay R so that the Winding of this relay is serially connected into the track circuit. The relay R is so proportioned and adjusted that the energization resulting from the normal track circuit current is sufficient to lift the armature of that relay out of engagement with the back contacts and into engagement with the front contacts. The track rail contactors CI and C2 and the time measuring device TMI are preferably similar to the corresponding devices of Fig. 2, and the contactors CI and C2 are located withrespect to the highway H as in Fig. 2. The highway crossing signal SI of Fig. 3 is shown as an audible signal in the form of an electric bell, the operating circuit of which is controlled by an interlocking relay KI.

The circuits and the operation of the apparatus of Fig. 3 can best be described simultaneously. Normally the apparatus occupies the position illustrated in the drawings and both

windings

36 and 81 of the relay KI are supplied with current and the signal SI is silent, the winding 36 being controlled over a stick circuit including its own front contact 89 and the front contact 90 of relay R, and winding 81 being controlled over front contact 94 of relay TRI. normal direction of traflic and approaching the intersection will shunt the track circuit D-E and both relays R and TRI will be deenergized. Current will now flow from the B terminal of the current source over back contact 88 of relay R, operating winding 61 of the time measuring device TMI and the normally closed contact 48-50 of the contactor CI to the opposite battery terminal C, and the device TMI will be set into operation. The winding 86 of the relay KI, which normally received current over the stick circuit including front contact 90 of relay R will, upon the deenergizing of the relay R, receive current over a holding circuit extending from the B terminal of the current source, front contact 89, winding 86, back contact 9| of the relay R, contact I5-TI of the time measuring device TN, and the contact 48-5Il of the contactor CI to the C battery terminal. Thus it follows that winding 86 remains energized and the signal SI remains silent after the train enters the track circuit. It will be noted that winding 81 of .relay KI will now receive current over the back contact 95 of relay R and its own front contact 95. In the event the train is travelling at a speed above a predetermined I value, say 55 miles per hour, it will pass over the portion X of the track circuit DE, and its leading wheel will actuate the track rail contactor CI before the time measuring device TMI has been 'operated long enough to close the contacts 'IE'I8 and 8fi84, and hence operation of the device TMI will be stopped and the winding 86 of the relay KI will be deenergized. The full-down contact 92 of the relay KI will now be closed and current will be supplied to the operating circuit easily traced for the signal Si, and the signal set into operation. In the event the train is travelling' at a speed less than 55 miles per hour the device TMI will be operated to close its contacts 16-18 and 8084 before the contactor CI is actuated, and the clutch winding I2 of the device TMI will receive current over the back contact 88 of relay R, contact til-84 of device TMI and the normally closed contact 48-59 of the track rail contactor C2; and the time measuring device will 1;; be held in its reverse position. The winding 86 of the relay KI will now receive current over its own front contact 89, winding 86, back contact 9! of relay R, contact It-18 of device TME and the contact 48-5t of the contactor C2, and hence, the signal SI will remain silent. When the train moves on closer to the intersection and actuates the contactor C2, the opening of its contact 48-58 will deprive both the clutch winding I2 of the device TMI and the winding 86 of the relay KI of I A train travelling in the ing 86 of relay KI and front contact 90 of the relay R to the opposite battery terminal C, and winding 85 will be energized to open the back contact 92, and the operation of the signal SI will be stopped. When the trainvacates the track circuit D-E and the relay TRI is reenergized, the track rail contactors CI and C2 will each be restored to its normal engaging position over the circuit including the front contact 93 of the relay TRI, the manner of restoring these contactors being similar to that already described in connection with Figs. 1 and 2.

A train moving again-st the normal direction of traific and entering the track circuit DE will shunt the track relay TRI, but the relay R will remain energized until the head end of the train has advancedto the left of the insulated rail joint 85. Under this condition, the winding 8'! of the relay KI will be deprived of current inasmuch as both'the front contact 94 of relay TRI and the back contact 95 of relay R are open at the same time. Winding 81 once deenergized, it will not be reenergized until the train has Vacated the circuit 'DE and the track relay TRI is picked up. Winding 81 being deenergized previous to the deenergizing of winding 86, the interlocking feature between the armatures of these windings will prevent the full-down contact 92 from becoming closed and the signal SI will not be operated by the train moving against traffic. It is to be seen from the foregoing description that the signal SI is set into operation at the location of the more remote contactor CI ior trains travelling above 55 miles per hour, and that its operation is delayed until the train reaches the nearer contactor C2 when the speed of the train is below 55 miles per hour. Operation of thesignal SI is stopped as soon as the rear of the train passes the highway, and is not operated by a train moving against traffic. The track rail contactors CI and C2 are restored to their normal engaging positions automatically in response to a train vacating the track circuit travelling in either direction. The normal position of the contactors and also the normal position of the time measuring device TM l is checked. Although a time element relay type of time measuring device is disclosed for the apparatus of Fig. 3, it is clear that a time measuring device of the type disclosed in Fig. 1 may be employed should it seem desirable to do so.

Apparatus such as here disclosed governs the operation of a highway crossing signal in accordance with'the speed of a train approaching the intersection, and is adaptable to be superimposed upon an existing track circuit irrespective of the point at which the highway intersects the trafiic rails without subdivision of the track circuit.

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

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a track rail contactor located at a fixed point which a train passes in approaching the highway and which contactor includes a member adapted to be depressed from an engaging position to a non engaging position by a wheel of the train, means for retaining said member in'the non-engaging position, operating means controlled by said member when depressed for setting said signal into operation, time measuring means, means controlled by the train moving over a given distance in approaching said track rail contactor for operating said. time measuring means, means controlled by said time measuring means for delaying the operating means from setting said signal into operation in accordance with the measured time, and means controlled by the train moving away from the intersection for restoring the member of said contactor to the engaging position.

2. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a track rail contactor located a given distance from the intersection and including a member adapted to be depressed from an engaging position to a nonengaging position by a wheel of the train, means for retaining said member in the non-engaging position, operating means controlled by said member when depressed for setting said signal into operation, speed measuring means controlled by the train approaching said track rail contactor for determining the speed of the train, means controlled by said speed measuring means for at times delaying the operating means from setting said signal into operation, and means controlled by the train moving away from said intersection for restoring said member of the track rail contactor toits engaging position.

3. In combination, a stretch of railway track intersected'by a highway, a highway crossing signal located at the intersection, a track rail contactor located. a given distance from the intersection and including a member adapted to be actuated from a first positionto a second position by a wheel of a train, means for retaining saidmember in said second position, operating means controlled by said member in said second position for setting said signal into operation, speed measuring means controlled by'the train approaching said track rail contactor for deterrmining the speed of the train, means controlled by the speed measuring means for delaying the operating means from setting said signal into operation in accordance with the measured speed, and means controlled by the train moving away from said intersection for restoring said member of the track rail contactor to said first position.

4. In combination, a stretch of railway track over which trafiic normally moves in a given direction and which is intersected by a highway, a highway crossing signal located at the intersection, a track circuit including the track rails of the stretch, a track rail contactor located adjacent one of said rails at a fixed point in advance of the entrance of said track circuit and which includes a member adapted to be actuated from a first position to a second position by the leading wheel of a train and having means for retaining said member in said second position, a time measuring device, means controlled by said track circuit effective to render said time measuring device active in response to a-train entering the track circuit, and operating means controlled jointly by ,said member and said time measuring device to highway crossing signal, located at the intersection, a track circuit including the track rails .of the stretch, a track rail contactor including a member positioned adjacent, one of said rails to' be engaged by a car wheel moving along the rail and actuated to a non-engaging position and having means for retaining said member in the nonengaging position, said contactor located in advance of the entrance of the track circuit and at a given distance from the intersection, a time measuring device including a motor element and a circuit controlling element actuated by said motor element, means controlled by the track circuit to set said motor element into operation in response to a train entering the track circuit, operating means controlled jointly by said member and said circuit controlling element for setting said signal into operation, and means controlled by the track circuit for restoring said member to its engaging position in response to the train clearing said track circuit.

6. In combination, a stretch of railway track over which trailic normally moves in a given direction and which is intersected by a highway, a highway crossing signal located at the intersection, a track circuit including the track rails of the stretch, a track rail contactor including a member positioned adjacent one of said rails to be engaged by a car wheel moving along the rail and actuated to a non-engaging position and having means for retaining said member in the non-engaging position, said contactor located in advance of the entrance of the track circuit and at a given distance from the intersection, a time measuring device including a circuit controlling element having a normal position and a motor element adapted to move said circuit controller element away from said normal position at a predetermined rate, means controlled by the track circuit to set said motor element into operation in response to a train entering the track circuit, means controlled by said member when actuated to govern said motor element and effective to arrest the movement of the circuit controlling element away from the normal position, operating means controlled by said member when actuated to start operation of the signal, means controlled by said circuit controlling element effective to delay the operating means in starting operation of the signal in accordance with the distance the circuit controlling element is moved away from the normal position, and means controlled by said track circuit effective to restore said member to its engaging position in response to the train vacating the track circuit.

'7. In combination, a stretch of railway track over which traffic normally moves in a given direction and which is intersected by a highway, a highway crossing signal located at the intersection, a track circuit including the track rails of the stretch, a track rail contactor including a member adjacent one of said rails in a position to be engaged by a car wheel moving along the rail and actuated to a non-engaging position, said contactor located in advance of the entrance of said track circuit and at a given distance from the intersection, a circuit controller operated by said member and including a contact normally closed, operating means controlled by the track circuit for setting said signal into operation in response to a train entering the track circuit, circuit means including said normally closed contact for rendering said operating means ineffective to set said signal into operation whereby operation of said signal is delayed until said member is actuated by the leading wheel of the train, means for retaining said member in the non-engaging position, and means controlled by said track circuit for restoring said member to its engaging position in response to the train vacating the track circuit.

8. In combination, a stretch of railway track intersected by a highway, at highway crossing signal locatedat the intersection, a first and a second track rail contactor each including a member positioned adjacent a traiiic rail to be engaged by a car wheel moving along the rail and actuated to a non-engaging position and each having an element adapted to retain the member in the non-engaging position, said contactors located along the stretch and arranged to be successively passed by a train approaching the intersection, a time measuring device including a circuit controlling element, means controlled by a train approaching the more remote contactor for actuating said time measuring device, operating means controlled by the member of the more remote contactor when actuated for setting said signal into operation, circuit means including the circuit controlling element of the time measuring means eiiective to delay at times the operating means in setting said signal into operation, means controlled by the member of the contactor nearer the highway when actuated for rendering said circuit means ineffective, and means controlled by the train effective to restore the member of said contactors to their engaging positions when the rear of the train clears the highway.

9. In combination, a stretch of railway track intersected by a highway, a highway crossing signaliccated at the intersection, a first and a second traclc rail contactor each including a member positioned adjacent a traffic rail to be engaged by a car wheel moving along the rail and actuto a non-engaging position and each having an element adapted to retain the member in the non-engaging position, said contactors located along the stretch and arranged to be successively passed by a train approaching the intersection, a time measuring device including a magnet and a contact adapted to be closed a predetermined time after said magnet is energized, means controlled by a train approaching the more remote contactor for energizing said magnet, means controlled by said member of the more remote contactor when actuated to deenergize said magnet, operating means controlled by said member of the more remote contactor when actuated for setting said signal into operation, circuit means including the contact of the time measuring device and effective when said contact is closed to render the operating means inefiective to set the signal into operation, means controlled by the member of the contactor nearer the highway when actuated to remove the control of said circuit means over the operating means, and means controlled by the train to restore the members of said contactors to their engaging positions rendered eiiective when the rear of the train clears the highway.

10. In combination, a stretch of railway track intersected by a highway, a highway crossing si nal located at the intersection, a track rail contactor including a member positioned adjacent a trafiic rail to be engaged by a car wheel moving along the rail and actuated to a non-engaging position and having an element adapted to retain said member in the non-engaging position, said contactor located a given distance from the intersection, a time measuring device including a member movable in opposite directions from and toward an initial position by a reversible motor, a contact actuated by said member during a predetermined portion of its movement, means controlled by a train for operating said motor in a, direction to move themember away from the initial position during the time the train is travelling a fixed distance in approaching said contactor, means controlled by said member of the contactor when actuated for reversing the operation of the motor, operating means controlled by said member of the contactor when actuated for setting said signal into operation, circuit means including said contact effective when said contact is closed to render the operating means ineffective to operate the signal, and means controlled by the train to restore the member of said contactor to its engaging position rendered effective after the rear of the train clears the highway- 11. In combination, a stretch of railway track over which traffic normally moves in a given direction, a track circuit including the track rails of said stretch and arranged with the source of current at the entrance of said circuit, a highway intersecting the stretch at an intermediate point of the track circuit, a highway crossing signal located at theintersection, an insulated rail joint located in one rail at the intersection, a relay having its winding connected around said insulated joint, a track rail contactor located along the stretch a given distance from the intersection and including a member adapted to be actuated by a car wheel moving along the rail, operating means controlled by said member when actuated for setting'said signal into operation, and circuit means including a front contact of said relay for rendering said operating means ineffective whereby operation of said signal is stopped as the rear of a train clears the highway.

12. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a track circuit including the track rails of the stretch, a train actuated device attached to at least one rail at a fixed point in advance of the entrance of said track circuit and including an element responsive to the front end of a train passing said point, a time measuring device, means controlled by said track circuit effective to render said time measuring device active in response to a train entering the track circuit, operating means controlled by said elementfor setting said signal into operation in response to a train passing said point, and means controlled by said time measuring means for at times delaying the operating means in setting said signal into operation.

13. In combination, a stretch of railway track intersected by a highway, at highway crossing signal located at the intersection, a track circuit including the track rails of the stretch, a train actuated device adjacent the track rails at a fixed point in advance of the entrance of said track circuit and including an element responsive to the front end of a train passing said point,

a time measuring device, means controlled by said track circuit efiective to render said time measuring device active in response to a train entering said track circuit, operating means controlled by said element for setting said signal into operation in response to a train passing said point, and means controlled by said time measuring device for at times delaying the operating means in setting said signal into operation.

14. In combination, a stretch of railway track over which traffic normally moves in a given direction, a track circuit including the track rails of said stretch and arranged with the source of current at the entrance of said circuit, a highway intersecting the stretch at an intermediate point of the track circuit, a highwaycrossing signal located at the intersection, an insulated rail joint located in one rail at the intersection, a track relay having its winding connected around said insulated joint, a train actuated device located adjacent the track rails at a fixed point in advance of the entrance of the section and including an element responsive to the front end of a train passing said fixed point, a control relay, means controlled by said relay when deenergized to set said signal into operation, a first energizing circuit for said control relay including afront contact of said track relay, and a second energizing circuit for said control relay including the element of said train actuated device.

ARBA G. WILLIAMSON.