US2213377A - Apparatus for the control of highway crossing signals - Google Patents

Description

Sept. 3, 1940. c. w. BELL 2,213,377

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed Jan. 51, 1939 INVENTOR Chanles W Z3611- HIS ATTORNEY Patented Sept. 3, 1940 UNITED STATES PATENT APPARATUS FOR THE CONTROL OF HIGH- WAY CROSSING SIGNALS Charles W. Bell, Forest Hills, Pa, assignor to The Union Switch & Signal Company, Swissvale, Pa, a corporation of Pennsylvania,

Application January 31, 1939, Serial No.- 253,831

4 Claims. (01. 246-130) My invention relates to apparatus for the con- WI and a second winding W2, and may take any trol of highway crossing signals, and has for an one of the well-known forms of interlocking object the provision of novel and improved means relays characterized by the fact that the first to provide directional control of ahighway crosswinding only of the two windings to be suc- 5 ing signal for a track over which trains move cessively deenergized is permitted to open or close 5 in each direction, where conditions are such that its front or back control contacts, the second the control track sections for the signal cannot winding of the interlocking relay to be sucextend through the highway but are separated cessively deenergized being released to an interfrom each other at the crossing by a section of locked position wherein its front and back contrack longer than a single car or light engine. trol contacts are latched up and are held re 10' Other objects and advantages of my invention spectively closed or open. will appear as the specification progresses. The immediate operating circuit for signal S I shall describe one form of apparatus empasses from one terminal B of a suitable source bodying my invention, and shall then point out of current, such as a battery not shown, through the novel features thereof in claims. back contact l of winding Wl or back contact 5 15 The accompanying drawing is a diagrammatic of winding W2, and the winding of signal S to view of a preferred form of apparatus embodythe other terminal C of the source of current. ing my invention. The reference character TER designates a time Referring to the drawing, the reference charelement device for at times controlling winding 20. acters l and la. designate the track rails of a W! or W2 of relay 2%. The device TEE. may

stretch of railway track over which traffic moves take any one of many forms well known to the in both directions, and which is intersected at art, and as here shown is a thermal relay prograde by a highway I-I. Located adjacent the vided with a normally open contact 6, which intersection is a highway crossing signal, desigcontact is closed in a predetermined time inter- 25 nated by the reference character S. Signal S val after relay TEE is energized. Relay HER 80 may take any one of several forms, and as here is provided with three energizing circuits, a first shown is an audible signal in the form of an circuit of which passes from terminal B through electric bell. back contact l of winding W l or back contact 8 The track rails I and la are divided by means of winding W2, front contact 9 of relay 2TB,

of the usual insulated track joints 2 into the front contact iii of relay lTR, and the winding 3'5 track sections D-E and FG, which sections of relay TER to terminal 0; a second path of extend in opposite directions from the interwhich passes from terminal B through back consection. The sections D-E and FG are protact ll of winding Wl, back contact 52 of relay vided with track circuits comprising in each in- 2TB, front contact l3 of relay iTR, and the stance a suitable source of current, such as winding of relay TER to terminal C; and a third track battery 3, connected across the rails at path of which passes from terminal B through one end of the section, and a track relay, desigback contact it of winding W2, front contact is hated by the reference character lTR or 2TB, of relay 2TB, back contact to of relay lTR, and connected across the track rails at the other end. th winding of relay TER to terminal (3.

40 The section EF, which iS intermediate the The apparatus embodying my invention is in Sections and and Which contailfls h its normal condition when no trains are operathighwa'y is not provided Wlth track clrcult ing on the track rails l and la intermediate the it being assumed that at the points D and Gr. In this normal condition of n 1terect1n render .esmbhfshment. of aitrmk the apparatus, as shown in the drawing, relays circuit for that section impossible or inadvisable. 6TB, 2TH and windings W5 and W2 of KR are The section EFI shall assume to be longer than d and Tel m1 Si 1 a d the length of a single car or light engine operatg l c l D ing on the tracks l and lot, while the sections envrglzed Wmdmg 9 energized over a stick circuit which may be D--E and FG I shall assume to be sufiiciently 1 50 long enough to provide an adequate Warning traced from terminal B through front contact i'i period to highway users f the approach of a of winding Wi, front contact iii of relay lTR and train t t intersection, the winding Wi of relay XR. to terminal C.

The reference character XR designates an Winding W2 is normally energized over a stick interlocking relay for controlling the operation circuit which may be traced from terminal B of signal S. Relay XR comprises a first winding through front contact it of winding W2, front contact 20 of relay 2TB, and winding W2 of relay XR to terminal C.

In describing the operation of the apparatus embodying my invention, I shall assume that an eastbound train, that is, a train operating from left to right in the drawing, enters section DE so that relay ITR is shunted and releases. When this happens, front contact I8 of relay ITR is opened to open the stick circuit just traced for winding WI, with the result that winding WI releases to close its back contact 4 and thereby complete the operating circuit for signal S, 50 that signal S becomes energized to display its warning indication to highway users of the approach of the train to the intersection. Front contact II of winding WI is also opened when winding W I releases, so that the stick circuit for winding WI is opened at that point. Back contacts I and II of winding WI are also closed, to prepare respectively the first and second energizing circuits for relay TER.

In the event that the train is long enough to bridge both sections DE and F-G, the entrance of the train on section F-G and consequent shunting of relay 2TB results in relay 2TB releasing. When this happens, front contact 2!) of relay 2TB is opened to open the stick circuit previously traced for winding W2 with the result that winding W2 is deenergized and releases its armature to its interlocked position, wherein front contact I9 of winding W2 remains closed and back contacts 5, 8 and IA of winding W2 are prevented from closing.

When the train vacates section DE, relay ITR picks up to close its front contacts I8 and I3, the closing of front contact I8 of relay ITR preparing the stick circuit for winding WI, while the closing of front contact I3 completes the second energizing circuit for relay TER, which circuit, as pointed out hereinbefore, includes back contact II of winding WI, back contact I2 of relay 2TB, and front contact I3 of relay ITR. Relay 'I'ER at the end of its predetermined time interval of energization closes contact 6 to establish a pick-up circuit for winding WI, which circuit may be traced from terminal B through front contact I9 of winding W2, contact 6 of relay TER, front contact I8 of relay ITR, and the winding W! of relay XR to terminal C. Winding WI picks up over its pick-up circuit to open back contacts 4 and II, the opening of back contact 4 interrupting the operating circuit for signal S, and the opening of back contact II opening the second energizing circuit for relay TER. The picking up of winding WI of relay XR also closes front contact I! to complete its previously traced stick circuit, with the result that winding WI is held energized over that circuit when contact 6 of relay 'IER is opened upon the deenergization of that relay. It is to be noted that since winding W2 is released to its interlocked position prior to winding WI picking up, directional control of the signal S is established whereby the operation of the signal is not eifected by a train operating through a control section in receding from the intersection.

When the train vacates section FG, relay 2TB, picks up to close front contact 28 and thereby complete the stick circuit for winding W2, with the result that Winding W2 picks up so that the apparatus is restored to its normal condition.

In the event that the eastbound train operating over tracks I and Ia is short so that it does not bridge sections D-E and F-G, then the train will vacate section DE and relay ITR will pick up, prior to the train entering section F-G. When the train vacates section DE and relay ITR picks up, the first energizing circuit for relay TER is completed, which circuit includes back contact I of winding WI, front contact 9 of relay 2TB and front contact II] of relay ITR, Relay TER becomes energized, but since relay TER does not close its contact 6 until the expiration of its predetermined time interval, the train will ordinarily enter section F-G to efiect the deenergization of relay 2TB and of winding W2 to its interlocked position, prior to contact 6 of relay TER closing.

The release of relay 2TB, when the train enters section F--G, and the consequent release of winding W2 of relay XR to its interlocked position, results in the opening of the first energizing circuit for relay TER, but relay TER is held energized over its previously traced second energizing circuit. The operation of the apparatus with the short train on section F-G is now substantially similar to the operation for the long train on section F-G. That is to say, relay TER. is energized and closes its contact 6 at the expiration of its predetermined time interval, whereupon winding WI picks up to complete its own stick circuit, which holds winding WI energized when relay TER opens its contact 6. When section F-G is vacated, relay 2TB, and winding W2 pick up to restore the apparatus to the normal position.

The operation of the apparatus embodying my invention for both a long and short westbound train is substantially similar to the operation just described for a long and a short eastbound train, and it is thought that this latter operation for the Westbound train will be readily apparent from the foregoing description for the operation of the eastbound train together with an inspection of the drawing without further detailed explanation.

It is to be noted that relay TER functions to restore winding WI or W2 to its normal condition when a train enters the control section to initiate the operation of signal S, but which train reverses its direction and vacates that section without proceeding across the intersection. That is to say, since relay TER is energized over its first energizing circuit when winding WI or W2 is released and both track relays I'I'It and 2TH are picked up, it follows that when an eastbound train, for example, reverses direction in section DE and vacates that section after having initiated the operation of signal S, then relay 'IER is energized and completes at the end of its predetermined time interval the pick-up circuit for winding WI whereupon winding WI is restored to its normal condition and the operation of signal S is terminated.

It should further be noted that although the control track sections cannot be extended to the intersection, the intersection is protected for a predetermined time interval after the train vacates the control section on the approach side of the intersection, and that directional control of the signal is established.

Although I have herein shown and described only one form 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 divided into a first section and a second section separated from each other by an intermediate section, a signal, a first relay operable by a car entering said first section, a second relay operable by a car entering said second section, operating means controlled by each of said first and second relays for operating said signal for railway traffic approaching the intermediate section in either of said first and second sections, a timing device effective when operated to control said operating means to terminate operation of said signal, and circuit means controlled by said operating means and including a back contact of the track relay associated with the section on the receding side of the intermediate section for operating said time element device whenever the section in approach of the intersection is vacated provided the other section is occupied, the characteristics of said timing device being such as to maintain operation of said signal by said operating means during the time interval required for a car to traverse said intermediate section.

2. In combination, a stretch of railway track divided into two outer sections separated from each other by an intermediate section intersected by a highway, a highway crossing signal positioned at such intersection, a first track relay for said first section, a second track relay for said second section, operating means governed by said track relays for operating the signal when a train approaches the intersection, a time element device having a contact closed at the expiration of a predetermined time interval after energization thereof, circuit means for energizing said time element device governed by said track relays and by said operating means and effective when both said first and said second sections are unoccupied, other circuit means for energizing said time element device governed by said operating means and including a front contact of the track relay associated with the section on the approach side of the intersection and a back contact of the track relay associated with the section on the receding side of the intersection, and means controlled by said contact of said time element device for terminating operation of said signal by said operating means whereby to insure the operation of said signal for said predetermined time interval after said approach section is vacated, said predetermined time interval being selected to provide operation of said signal for the time interval required by a car moving at a normal rate of speed to traverse said intermediate section.

3. In combination, a stretch ofrailway track divided into two outer sections separated from each other by an intermediate section intersected by a highway, a highway crossing signal positioned at such intersection, two track relays one for each of said two outer sections, an interlocking relay having two windings one for each of said two track relays, operating circuit means for operating said signal governed by each of the two windings of said interlocking relay, stick circuit means for normally energizing each winding of said interlocking relay governed by its associated track relay, a time element device having a contact closed in a predetermined period contacts of said two track relays arranged in such manner that said timing device is energized whenever either section on the approach side of the intersection is vacated regardless of traffic conditions in the other section on the receding side of the intersection, whereby energization of the winding of said interlocking relay associated with the track relay of said approach section is avoided'for said predetermined time interval to insure operation of said signal for the time interval required by a car moving at a normal rate of speed to traverse said intermediate section.

4. In combination, a stretch of railway track divided into two outer sections separated from each other by an intermediate section intersected by a highway, a highway crossing signal located at such intersection, two track relays one for each of said two outer sections, an interlockingv relay having two windings one for each of said two track relays, a stick circuit controlled by each track relay for normally energizing the associated winding of said interlocking relay, means controlled by each of said two windings of the interlocking relay for operating said signal, a time element device having a contact operated from a normal to an operated position after a predetermined time interval of energization of such device, three alternate ,circuit pathsfor energizing said time element device one path of which includes a back contact of either of the two windings of said interlocking relay and a front contact of each of said two track relays, each of the other two circuit paths of which includes a full-released back contact of one or the other winding of said interlocking relay and a front contact of the track relay associated with such full-released winding as well as a back contact of the other track relay, and means controlled by each of said two track relays and by said contact of said time element device for establishing a pick-up circuit for the winding of said interlocking relay associated with the one of said two track sections occupied by a train in approaching the intersection, whereby to insure the operation of said signal for the time interval required by a car moving at a normal speed to traverse said intermediate section.

CHARLES W. BELLG

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