US2312758A - Apparatus for control of highway crossing gate - Google Patents

Description

March 2, 1943. c. L.- GOODLIN APPARATUS FOR CONTROL OF HIGHWAY CROSSING GATE FiledJune 28, 1941 2H? fi ic am: 55* 10 0 A 5 G@ lfimh ZmZ W Q J JT a. n A ME- |-I|IIT I l. I S W 3% WW 2 M m Ti m B. 6 m w H. Aw w u u mw ymm Fla INVENTOR HIS ATTORNEY Patented Mar. 2, 1943 UNlTED STATES APPARATUS FOR CONTROL OF HIGHWAY CROSSING GATE Carl L. Goodlin, Penn Township,

Allegheny County, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application June 28, 1941, Serial No. 400,262

2 Claims. (Cl. 246-430) My invention relates to apparatus for control of highway crossing gates, and more particularly to apparatus for control of highway crossing gates that are automatically governed by trains.

An automatic highway crossing gate is ordinarily controlled by a track circuit of a track section in the approach to the intersection of the highway and railway. The gate arm is normally held at a vertical or non-obstructing position as long as the approach track section is unoccupied and is lowered to a horizontal or obstructing position across the highway in response to a train occupying the approach section, the approach section being of sufiicient length to assure that the arm reaches its lowered position not less than some predetermined period of time prior to the head end of the train entering the intersection.

To avoid lowerin the gate arm immediately in front of or on top of automobiles or other highway vehicles, a preliminary warning in the form of bells or lights or both is provided for a short period before the gate arm leaves its vertical position. When the train has passed over the intersection and is receding therefrom, the motor of the gate mechanism is energized to raise the gate arm to its vertical position, the operation of raising the gate arm requiring several seconds. It may happen that a second train is following the first train close enough to enter the approach section while the gate arm is being raised subsequent to a first train passing over the intersection and thereby cause the gate arm to be returned to its lowered position from some intermediate position with the result that highway trafiic starting to go over the track after having waited for the first train to pass is given no warning that the gate is to be lowered and it descends directly in front of or on top of the highway vehicle.

In view of such circumstances, a feature of my invention is the provision of apparatus for the control of highway crossing gates incorporating novel means wherewith the movement of a gate arm to its non-obstructing position, once started, is completed without interruption.

Another feature of my invention is the provision 7 of apparatus for the control of automatic highway crossing means wherewith the gate arm when being moved to its raised position and a second train enters the approach section, the control causes the gate arm to continue its movement to the the gate mechanism for raising the gate arm, once initiated by the main control circuit, the stick circuit control becomes efiective to continue such operation until the arm is raised to its full vertical position when the stick circuit is opened and the main control circuit is again made effective: for holding the arm at its vertical position.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims. 1

' The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention when used with an automatic highway crossing gate.

' It will be understood that my invention is not limited to apparatus for automatic control of a highway crossing gate and is useful with apparatus where the gate is entirely manually controlled or where the gate is controlled in part manually and in part by trains. This one form of apparatus will serve to illustrate the several different places where apparatus embodying the invention is useful. Q}

Referring to the drawing, the reference characters la and lb designate the track rails of a railway intersected at grade by a highway H and at which intersection two highway crossing'gates GI and G2 are located. The track rails la' and lb are formed by the usual insulated rail joints with two track sections, one on each side of the highway, a section D-E being formed on the left of the highway H as viewed in the drawing, and a section EF being formed to the right of the highway. In other words, section D-Fl is an approach section with respect to the highway in tersection when east-bound trains are considered, and section E-F is an approach section with respect to the highway intersection when westbound trains are considered.

Each track section D-E and EF is provided with a track circuit, which includes a current source such as a battery It connected across the rails at one end of the section and a winding of an interlocking relay IR connected across the rails at the other end of the section, winding! I of relay IR being included in the track circuit of section D-E and winding i2 of relay IR being included in the track circuit of section E-F. The connections of windings H and I! to the track rails are those of common practice to provide the so-called extended shunt protection as will be readily understood by an inspection of the drawing, and these connections need not be described in detail since they form no part of my invention.

The highway crossing gates GI and G2 are shown conventionally and are located one ,on. each side of the railway track and are adaptable of being operated in a manner such that their respective gate arms l3 and I4 are moved between a lowered position where the arm extends horizontally across at least a portion of crossing gate GI and G2 is similar to that shown and described in Letters Patent of the United States No. 1,138,087, granted to John P. Coleman on May 4, 1915, for Railway signals, and to which patent reference is made for a full understanding of the construction of such mechanism. In the application the gate arm is an extended form of the semaphore of the patent.

The mechanism and the control thereof for gate GI only is shown in the drawing for the sake of simplicity, since the two gates are alike and the mechanism of gate G2 and its control would be but a duplication of those for gate GI.

Looking at the gate GI mechanism, a motor MI, a slot magnet SM and a circuit controller CI are among the essential elements of the mechanism. Motor MI comprises an armature I5 and a field winding I6 and is operatively connected by suitable drive mechanism (not shown) to the gate arm I3. Gate arm I3 is biased by gravity to its lowered or obstructing position,

and the motor MI when energized and eifective- 1y coupled to the drive mechanism, is operative to raise the arm I3 against thebiasing force to its raised or non-obstructingposition, the full movement of the arm being approximately 90 degrees. In the following description, the lowered or obstructing position of the gate arm will be considered as the 0 degree position, and the raised position of the arm will be considered as the 90 degree position.

Slot magnet SM includes a high resistance or holding winding I1 and a low resistance or pick-up winding I8. The slot magnet SM governs the operation of motor MI for driving the gate arm, the arrangement being such that when both windings I1 and I8 are energized, the motor circuit is closed whereby the motor is operated to raise the arm, winding I8 serving as an aid to winding I1 in closing the motor circuit. When the raised position of the arm 7 is effected, winding I8 is deenergized along with the motor and the arm is held at the raised position by energization of winding I1 only. The slot magnet armature has mounted thereon contacts by which the motor operating circuit and other circuits later to be described are controlled.

. Circuit controller CI is operatively connected to the mechanism for opening and closing circuit controlling contacts of which only the two contacts 2 and 8 are shown in the drawing. Contacts 2 and 8 are shown conventionally and each is closed except at the full raised or 90 degree position of the gate arm. That is to say, each contact 2 and 8 is closed between the 0 and 89 degree movement of the gate arm as indicated on the drawing.

The control means includes a control relay XR and the interlocking relay IR. Relay XR is slow releasing in character and is normally ener gized over a circuit including terminal B of any convenient source of current such as a battery not shown, front flagman contacts I9 and 20 of windings II and I2, respectively, of relay IR,

winding of relay XR and terminal C- of the samesource of current. That is to say,'relay XR is energized and picked up when the track sections D-E and EF are unoccupied and also when ,either section is occupied by a train receding from the highway and the other section is unoccupied. Relay XR in turn governs control circuits for the windings I1 and I8 of slot magnet SM. The control circuit for winding I1 includes terminal B, front contact 2I of relay XR, Wire 22, winding I1, wire 42 and terminal C. The control circuit for winding I8 can be traced from terminal B over front contact 2I of relay XR, Wires 22 and 23, contact 2 of circuit controller CI when closed, wire 24, winding I8 and wire 42 to terminal C.

As here shown, a motor operating circuit extends from terminal B over contact 8 of circuit controller CI and closed at the 0 to 89 degree position of the gate arm, wire 25, front contacts 26 and 21 in multiple of winding I1, wire 28, motor armature I5, motor field winding I8, and wire 42 to terminal C. It is to be noted that motor M I is provided with a low resistance circuit which causes the motor to act as a generator and cushion the movement of the gate arm I3 when moved to its lowered position by the biasing element. Such low resistance circuit can be traced from the right-hand terminal of motor armature I5 over wire 28, back contacts 29 and 30 in multiple of winding I1, wire 3I, a resistor 32, motor field winding I8 and to the left-hand terminal of motor armature I5.

According to my invention, I provide winding I1 with a special stick circuit and winding I8 with a special control circuit. The stick circuit for winding I1 includes terminal B, contact 8 of controller CI, wire 25, front contact 33 of winding I1, winding I1 and wire 42 to terminal C. The special control circuit for winding I8 is the same as the stick circuit for winding I1 up to and including front contact 33 and hence over wire 23, contact 2 of controller CI, wire 24, winding I8 and wire 42 to terminal C.

In accordance with standard practice, the interlocking relay IR also controls a warning signal circuit by which warning bells 0r warning lamps, or both, are operated, such circuit being closed over a full down contact 34 of winding II of relay IR or a full down contact 35 of winding I2. The remaining portion of such warning circuit is not shown since it forms no part of my invention, and that portion shown on the drawing is suflicient for a full understanding of the invention.

Normally, that is, when both section D-E' and E-F are unoccupied, the interlocking relay IR is picked up causing control relay XR to be in turn picked up and the warning circuit to be opened. Control relay XR when picked up closes the circuit for winding I1 and that winding is energized to hold the gate GI at its raised position, it being assumed that the gate arm has been raised in a manner to shortly appear. Assuming an eastbound train approaches the intersection to enter track section D-E, winding II of interlocking relay IR is deenergized to open its front contact I9 and to close its back contact 34. The closing of back contact 34 completes the warning signal circuit causing the bells and lamps controlled by that circuit to be immediately operated as a Warning'indication to highway users that a train is approaching and that the gate GI is about to be lowered. The opening of front contact I9 of Winding, II deenergizes control relay XR and that relay is released at the end of its slow release period to open the circuit for winding II of the slot magnet, with the result that the gate mechanism is released and gate arm 13 is moved to its lowered position by the biasing element of the mechanism. As stated hereinbefore, the approach section DE is made of suflicient length to assure that the gate arm I3 is moved to its lowered position before the head end of the train enters the intersection. When the head end of this eastbound train clear the intersection to enter the section E-F, the winding I2 of relay IR is shunted and its contacts released to the interlocked position of the relay. When the rear of the train vacates the section DE, winding 1 I of relay IR is reenergized and picked up to close the circuit for control relay XR and in turn close the circuit for windings l1 and I8, the energizing of both winding l1 and I8 being effective to close the motor circuit and cause operation of the motor for driving the gate arm 13. That is, with both windings l1 and I8 energized to close front contacts 26 and 21, the motor operating circuit is closed and the motor is operated to move the gate arm. At the 90 degree position, contacts 2 and 8 of controller Cl are opened to open the motor operating circuit and also the circuit for winding [8. It is to be noted that when windings l1 and I8 become energized to close front contact 33, the stick circuit for winding l1 and the special control circuit for winding I 8 are closed and consequently if a second eastbound train should now enter the approach section D-E shunting winding Ii of relay IR and bringing about the release of control relay XR to open the main control circuit for windings l1 and I8, winding I! is retained energized over its stick circuit and winding [8 is retained energized over its special control circuit governed by winding l1 and the operation of raising the gate arm I3 is continued. When the 90 degree position of the gate arm is reached, however, contacts 2 and 8 of controller Cl are opened with the result that the stick circuit for winding [1 and the special control circuit for winding 18 are opened. It follows, therefore, that when the 90 degree or full vertical position of the gate arm is reached, it is immediately lowered to its lowered position by the biasing element of the mechanism in the event the control relay XR is released due to a second eastbound train in the approach section D-E. However, the gate arm i3 is not returned from any intermediate position to its lowered position due to the second eastbound train entering the approach section, and hence it is not lowered immediately in front of or on top of any highway vehicle that may have started to pass Over the intersection subsequent to the first train clearing the intersection. When winding II of relay IR is released in response to the second eastbound train entering the approach section DE, the warning signal circuit is reclosed and these devices operated as a warning indication to the highway users that a train is approaching the intersection and that the gates are about to be lowered.

Operation of the apparatus in response to a westbound train is substantially the same as that described in connection with an eastbound train and a description of the operation of the apparatus for a westbound train is readily apparent from an inspection of the drawing taken in connection with the description of the operation of the apparatus for an eastbound train.

Although the main control relay XR for gate GI is here shown as governed by track circuits, it is apparent that relay XR and in turn gate GI may be governed by a manually operable switch if desired.

Although I have herein shown and described but one form of apparatus for control of highway crossing gates 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 highway crossing gate located at an intersection of a highway and a railway and biased to an obstructing position and operable to a non-obstructing position; a gate mechanism including a motor, a slot magnet and a circuit controller; said motor operable to move the gate to its non-obstructing position, said slot magnet operable to hold the gate at its non-obstructing position and provided with a holding and a pick-up winding and circuit controlling contacts, a normally energized control relay governed by railway trafiic and deenergized in response to a train approaching the intersection, a first control circuit including a front contact of said relay to energize said holding winding, a second control circuit including said front contact of the control relay and a contact of said circuit controller closed except at the non-obstructing position to energize said pick-up winding, an operating circuit including a contact of said controller closed except at the non-obstructing position and a front Contact of said slot magnet for operating said motor, and stick circuit means including said last mentioned controller contact and a front contact of said slot magnet to energize both said holding and pick-up windings to continue the movement of said gate to its nonobstructing position once such movement is started and a train approaches the intersection to deenergize said control relay.

2. In combination, a highway crossing gate located at an intersection of a highway and a railway and biased to an obstructing position and operable to a non-obstructing position; a mechanism for said gate and including .a motor for operating the gate to its non-obstructing position, a slot magnet for controlling said motor and for holding the gate at its non-obstructing position and a circuit controller; said slot magnet comprising a holding and a pick-up winding and circuit contacts which become closed when both of said windings are energized and are retained closed when said holding winding alone is energized, a control relay, a first circuit including a contact of said relay to energize Said holding winding, a second circuit including said relay contact and a contact of said circuit controller opened only at the non-obstructing position of the gate to energize said pick-up winding, an operating circuit including a contact of said circuit controller opened only at the non-obstructing position of the gate and a front contact of said slot magnet for operating said motor, and a stick circuit including the last mentioned controller contact and a front contact of said slot magnet to energize said holding winding to continue operation of the gate to its non-obstructing position independent of said control relay.

CARL L. GOODLIN.

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