US2344732A - Highway crossing signal system - Google Patents

Description

A. E. REID HIGHWAY CROSSING SIGNAL SYSTEM Filed May31/1940 B. onuu mtzu V0006.

INVENTOR BY A. 3.07321 H'ls ATTORNEY Patented Mar. 21, 1944 HIGHWAY CROSSING SIGNAL SYSTEM Arthur E. Reid, Gates, N. Y., assignor to General Railway Signal Company,

Rochester,

Application May 31, 1940, Serial No. 337,993

3 Claims. (Cl. MIL-130) This invention relates in general to highway crossing signal systems for intersections of highways with railways, and has more particular reference to means .for affording protection in situations where sidings enter a main track ad- ,iacent a highway crossing.

In a system of the character referred to, in connection with a main track on which traflic moves both east and west, it is desirable to give warning to highway traffic so long as a train is approaching the highway, but to discontinue the warning when the train is receding from the highway. In the event that a train should enter the main track from a siding, at the time a receding train is still on the approach section to the highway, with the usual interlocked relays employed in this type of system, no warning would be given of the train entering from the siding.

With the above and other objects in View, it is proposed, in accordance with this invention, to provide means whereby proper protection is given to highway trafiic at all dangerous times.

Further objects, purposes and characteristic features of the present invention will appear as the description progresses, reference being made to the accompanying drawing, showing solely in a, diagrammatic manner, and merely for the purpose of illustration, one form of invention which the invention can assume. In the drawing:

The'single figure of drawing is a wholly diagrammatic showing of one embodiment of the present invention. 1

, Referring now to the drawing, there is here represented a stretch of single track, constituted by track rails 4 and 5, across which passes a highway H. The main track is divided into usual insulated track sections by insulating joints 6, whereby to form an east approach section-La west approach section 2, and a central,

middle, or highway section 3.

Entering the main track is a siding constituted by track rails l and S and this siding enters the main track adjacent the highway and within the west approach section 2, and is controlled by a track switch TS.

The track switch TS is of the spring switch type, of any usual form, wherein the switch can be thrown to either its normal or its reverse position, by any desired means, although for the purpose of illustration an operating means in the form of a hand switch stand HSS has been shown. Connected in the throw rod conis arranged to operate so as to press the switch either full normal or full reverse depending upon in which position it has been placedby the hand switch stand. Any usual damping or buffer means can be employed in connection with the spring means if desired. As a result, this spring switch is biased to its operating position andcan be moved by a train trailing it to its other position.

For example, the switch is shown in its normal position, for main line traffic, but a train'passing onto the main line from the siding can move Each track section is supplied with a usual source of energy, such as a track battery TB, and a track relay TR, each identified with the section with which it is associated by an ex'- ponent corresponding to the section number. For example, track section I has track battery TB and track relay TR Usual interlocked relays XR! and XRZ are employed having the usual two separate windings and separate armatures, and with any usual interlocking means between the armatures such as M and I5. These interlocked relays function. in the usual manner, whereby, upon deenergiza-- tion of relay XRI, for example its armature drops, and makes up its back point, and moves the lock or hook member l4 counterclockwise so as to move into the path of movement of the,

hook l5 of relay XRZ. Upon the deenergizaticn of XRZ prior tov the reenergization of XRI, the armature of XR2 drops,.to move lock l5 clockwise until engaged by lock I 4, as shown, and

thus prevent the armature of relayXR2 from making up its back points. The subsequent reenergization of relay XRI' causes the armature thereof to pick up, as shown, but the lock I4 is retained in its latching position, and hence, in order to allow relay XRZ to make up its back points, it is first necessary to release the latch by energizing the winding of XRZ and then deenergizing the same. The operation of the in terlocked relays as described above is the operation which occurs as an east bound train passes along the main track. Of course, the reverse cycle of operation takes place upon a west bound nection 9 is a spring biasing means in which train passing along the main track.

These relays XRI and XRZ can be of the construction disclosed in the Field Patent 1,824,131, granted September 22, 1931.

For protection of highway traflic, signals SI and S2 are provided at opposite sides of the highway H at the intersection, and these signals are of any usual type either steady or flashing, but are shown here simply as steady light signals for the purpose of illustration. They are controlled by the interlocked relays, where'- by both signals are energized, so long as either of the interlocked relays is making up its back points.

Employed in the system for the purpose of warning of a move from the siding into the main track while a receding train is still occupying the siding approach section is a stick relay SR which has connected across its winding a rectifier 25 7 whereby to make it somewhat slow to release while having quick pick-up characteristics.

Having described the apparatus employed in the system, an understanding of the operation of the system will be best obtained by considering various train movements.

As shown in the drawing a train or car I6 is shown passing eastward and in the west approach section 2, and the various parts of the system are shown in the positions and conditions they have assumed, due to this movement,

When train l6 entered approach section I, track relay TR released to deenergize interlocked relay XRI and thereby energize the highway sig nals SI and S2 through contact finger 261 and back point of relay XRI, and a remaining circuit obvious from the drawing. As the train entered highway section 3, relay TR. released to maintain the signal energized until the rear end of the train had passed out of highway section 3 whereupon interlocked relay XRI picked up through a circuit including contact finger III and front point of relay TR and contact finger l8 and front point of relay TR whereby to deenergize the signals, as should be the case since the receding train does not endanger highway traiiic.

It can be seen that interlocked relay XRZ, having an energizing circuit including contact finger l9 and front point of relay TR and contact finger l1 and front point of relay 'I'R was deenergized upon the train entering section 3 at which time relay XRI was deenergized. Hence, even though relay XRI subsequently became reenergized, the armature of relay XRZ was latched up as shown in the drawing, and though it is deenergized, due to the presence of the train in section 2, it cannot make up its back point, and hence cannot energize the highway signals.

Assume now that a train 20 on the. siding enters the main track in section 2, while train I still occupies section 2, and hence still maintains relay XR2 latched up. Unless means he provided for releasing this latch, the train entering from the siding can approach and pass over the highway without having, given any warning to highway traffic. v

As set forth above, after one of the interlocking relays is latched up, and the other relay has become reenergized, in order to release the latch it is merely necessary to momentarily energize the latched up relay, in the case in point, relay XRZ, whereby to permit the latching means, as M, of the other interlocked relay, to swing in a clockwise direction and out of the way.

Upon train 20 passing onto the main track, the

spring switch is trailed and is moved over to its full reverse position, thereby closing track switch operated contact l2 to thus complete a circuit for energizing the interlocked relay XR2, which circuit includes contact finger l1 and front point of relay TR contact finger l9 and back point of relay TR switch operated contact l2 in its closed position, and contact finger 2| and back point of the stick relay SR,

Upon relay XR2 picking up, it closes a circuit for picking up stick relay SR which pick-up circuit includes contact finger I1 and front point, contact finger l9 and back point, contact finger 22 and front point of relay XRZ, and the winding of relay SR.

The picking up of relay SR opens the energizing circuit for relay XRZ at contact 2| whereby relay XRZ releases. The releasing of relay XRZ breaks the pick-up circuit for relay SR, but this relay remains up through a stick circuit which includes contact finger l1 and front point, contact finger l9 and back point, and its own contact fin er 23 and front point.

With the release of the latching and the deenergization of interlocked relay XRZ, the signals at the highway crossing are energized through contact finger 24 and back point of relay XRZ, whereby to give adequate warning to highway traffic of the approach of the train 20 which is entering the main track from the siding and approaching the highway.

It is obvious that an east bound train instead of proceeding as is train l6, past the siding, might enter the siding, in which case the track switch would be moved by hand to its reverse position to permit the train to enter th siding. Unless provision be made against it, this movement of the switch would cause a display of the highway warning signals, and thus warn of a danger which would not exist because'the train is receding from the highway and thus would cause unnecessary delay and confusion.

Assume now, with the system all restored to normal, and no trains present on the track, that an east bound train passes over the highway and onto the siding. As the train passes through sections I and 3, the warning signals are given as described above, until the rear end of the train passes out of section 3, whereupon the signals become deenergized. It is also to be assumed that the track switch TS is thrown by hand to reverse position while the train is still occupying section 3. Accordingly, a circuit is completed for picking up stick relay SR which circuit includes. contact finger l1 and back point of relay TR and the switch operated contact IS in its closed position.

It should be noted that, with track relay TR deenergized, the circuit for energizing the interlocked relay XRZ to release its latching, is not completed by movement of the track switch since this circuit included a front point of relay TR Thus, the movement of the switch under the circumstances outlined cannot eifect an unlocking of the interlocked relay XR2, and thus the,

stick relay in picked up position and prevent the energization of interlocked relay XRZ by maintaining the energizing circuit for it open at contact finger 2!, of the stick relay. Thus, the operation of the switch to permit th east bound train to enter the siding is prevented from causing an unlatching of the interlocked relay XRE, and a resulting unnecessary and confusing highway warning.

It is obvious that, should there be a siding entering the main track in approach section I, track switch operated contacts and a stick relay and associated circuits could be employed in connection with interlocked relay XRI to protect against unnecessary and undesired highway Warning in connection with this siding in the same manner as described above.

The above rather detailed description of one form which this invention can assume, has been given solely by way of example, and is not intended in any manner whatsoever in a limiting r sense. The present application contemplates covering all the various modifications and variations of structure and arrangement as may occur from time to time as desirable insofar as they are not specifically excluded from the scope of this application by the appended claims.

Having described my invention, I now claim:

1. In a signal system for highway-railway crossings, a highway crossing a stretch of main line track, a highway signal at the crossing, a passing siding, a track switch connecting the passing siding to the main line adjacent the highway, an approach track section at each side of the highway, a middle track section interconnecting the approach sections, the approach section at the siding side including the track switch, two interlocked relays, associated, respectively, with the two approach sections, circuit means for displaying the signal and effective when either relay makes up its back point, an energizing circuit for each relay closed only when its approach sectionv and the middle section is unoccupied, the relays being so interlocked that if one be deenergized, while the other is in deenergized position, the armature of the one is latched up so as to prevent its making up its back point until after said other is reenergized and then said one is reenergized, a stick relay, a second energizing circuit for the interlocked relay associated with the passing siding approach section and including a back point of the stick relay, a contact closed upon positioning of the track switch away from its full normal position and a contact closed only if the passing siding approach section be occupied, and a pick-up circuit for the stick relay including a front point of said passing siding approach section interlocked relay, and the contact closed only if said passing siding approach section be occupied.

2. In a signal system for highway-railway crossings, a highway crossing a stretch of main line track, a highway signal at the crossing, a passing siding, a track switch connecting the passing siding to the main line track adjacent the highway, an approach track section at each side of the highway, the on at the siding side including, at an intermediate point, the track switch, a middle section of track interconnecting the approach sections, two interlocked relays, associated, respectively, with the two approach sections, circuit means for displaying the signal and effective when either relay makes up its back point, an energizing circuit for each relay closed only when its approach section, and the middle section, is unoccupied, the relays being so interlooked that if one be deenergized, while the other is in deenergized position, the armature of the one is latched against making up its back point until after said other is reenergized and then said one is reenergized, a stick relay, a second energizing circuit for the interlocked relay associated with the passing sidin approach section and including a back point of the stick relay, a contact closed upon positioning the track switch away from its full normal position, a contact closed only if the passing siding approach section be occupied and a contact closed only if the middle section be unoccupied, a pick-up circuit for the stick relay including a front point of said passing siding approach section interlocked relay, and the contact closed only if said passing siding approach section be occupied, and the contact closed only if the middle section be unoccupied, and a stick circuit for the stick relay including a contact finger and front point of the stick relay constituting a shunt across the front point of said passing siding approach section interlocked relay.

3. In a highway crossing signal system, in combination, a stretch of main track crossin a highway, a highway signal at the crossing, an approach section of track at each side of the highway and each terminating short of the highway, a common highway section of track including the highway and interconnecting the adjacent ends of the approach sections, a normally open signal energizing circuit for each direction of trafiic, a control means for each energizing circuit and responsive to track occupancy to close its circuit and energize the signal so long as its approach section or the commonhighway section is occupied, a passing siding, atrailable spring track switch, operable to assume either normal or reverse positions and spring biased to its then operated position connecting the siding with an intermediate point of one of the approach sections, interlockin means between the two control means, and normally preventing the occupancy of the approach siding section, by a vehicle receding from the crossing after having occupied the highway section, from energizing the signal, additiona1 circuit means effective, when closed and then opened, to make the interlocking means ineffective, means closing the additional circuit means when the track switch is trailed away from its full normal position and the siding approach section is occupied and the highway section is unoccupied and means reopening said additional circuit after said additional circuit has been closed.

ARTHUR E. REID.

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