US2528064A - Railway drawbridge circuit controller - Google Patents

Description

@ci EL N5@ J. W, LOGAN, .1Rj ET AL 2,528,064

RAILWAY DRAWBRIDGE CIRCUIT CONTROLLER Filed Aug. 3l, 1948 JNVENToRs Jlm TI/ogm J1. and

THEIR AT THNE Y Patented Oct. 31, 195

RAILWAY DRAWBRIDGE CIRCUIT CONTROLLER John W. Logan, Jr., Forest Hills, and Glen V. Jeierson, Edgewood, Pa., kassignors to The Union Switch and Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application August 31, 1948, Serial N o. 47,102

9- Claims. l

Our invention relates to control apparatus,

. and especially to control apparatus to be operated in response to the position o a movable member.

Our invention is illustratedherein as applied to an electric circuit controller operated in response to the position ci' the lift rail of a railway drawbridge. While certain features of our invention `are of especial utility in connection with such apparatus, other features mai7 be used in connection with control apparatus generally.

The rail connections between the movable span and the fixed spans on a/railway drawbridgeY are commonly made by providing lift rails on the end of one oi each pair of adjacent span ends. Each lift rail has a normal or down position in which it abuts the fixed rail on the end of the adjacent span, and in which it can carry railwaytraic. it is liitable from its downposition to an up position in which it clears the fixed rail and the other parts'of the bridge sufficiently to permit opening of the draw. The lift rail is usually arranged to have a substantial range of overtravel beyond the'up position. As long as the lift rail is in the up position or inthe overtravel range, it will clear the bridge structure when the draw is opened.

Signals are commonly provided to inform opera-tors o approaching trains whether or not it 'is sare to proceed across the draw.Y 1t is desirable to have these signals controlledby electrical contacts which are closed only when the lift rails .are in the down position. Other signals vmay be provided for the drawbridge operator to inform him when the rails have been lited suiiiciently so that it is safe to swing the draw open. It is desirable to have these signals controlledby contacts which are closed only when the lift rails have reached their up position or moved upwardly beyond them.

1t is therefore an object of our invention to provide improved apparatus for operating an electric circuit controller in accordance with the position of the lift rail of aA railway drawbridge.

Another object is to provide improved control apparatus of the type shown in the copending application of Herbert L. Bone and William C. McWhirtenfSerial No. 30,535, filedv June 2,`

1948, for Control Apparatus, and in the cepending application of Glen V. Jefferson, Serial No. 47,101, iiled August 31, 1948, for Control- Apparatus.

Another object is to provide improved apparatus for operating a control device in accordance with the position of a movable element.

A further object is to provide control apparatus for use in connection with the lift rail of a railway drawbridge and mounted on the ties so that its entire mechanism is above the ties.

A further object is to provide improved control apparatus ofthe type described which is moreV compact thansimilar devices vof the prior art and which is arranged to reduce friction between the several moving parts.

We accomplish the foregoing and vother objects oi our invention by attaching to the lift rail a bracket having a portion which is spaced from and parallel tothe lift rail and provided with a horizontal slot. A guide arm is pivotally mounted on the ties adjacent the lift rail for rotation about an :axis extending perpendicular to lthe lift rail. This guide arm lies between the bracket just described and a normally parallel Crank arm on an electric circuit controller ofy the type described in the copending application of Herbert L. Bone and Glen V. Jefferson, Serial No. 1,955, iiled January 13, 1948, for Control Apparatus. The guide arm carries at its end a pair of oppositely projecting pins. One of these pins extends into the horizontal slot on the bracket attached to the lift rail. The other pin extends into a cam slot formed in the crank arm of the circuit controller. The portion of the cam slot nearest the operating shaft of the circuit controller is designed to be horizontal when the lift rail is in its down position. Since the cam slot is horizontal and the initial movement of the pin is vertical, the circuit controller is very sensitive to movements of the lift rail away from its down position. This sensitivity is increased by arranging the parts so that the pin is near the axis of the controller crank arm when the lift rail is down. The outer end of this l straight portion of the cam lslot terminates in a steeply curved yportieri which is provided to cause a rapid movement of the circuit controller arm when the lift rail reaches its up position. Beyond this steeply curved portion, the cam slot has another curved portion, designed to be concentric lwith the aXis of rotation of the guide arm when thecircuit controller crank arm reaches its position corresponding to the up position'of the lift rail. This latter portion or the cam slot permits overtravel'of the lift rail without changing the position ofthe circuit'controller operating arm. l

Other objects jand characteristic features of our invention will become apparent as the description proceeds.

We shall illustrate and describe herein one embodiment of our invention, and shall'then point out the novel features thereof Vin claims.,

In the accompanying drawings, Fig. 1 is a plan View of a fragment of a railway drawbridge, showing the adjacent ends of a nxed rail and a lift rail, with our invention appliedto the lift rail.

Fig. 2 is an elevational View of the rails and circuit controller structure shown in Fig. 1, with certain `parts broken away to permit betterv illusl is shown in its down position in Fig. 1 and in full lines in Fig. 2. It is shown in its up position in dotted lines in Fig. 2. When the lift rail is down, it is received in a rail chair 3, Spacer pads 4 are attached to the web of the rail I and are contoured to guide the lift rail l in its movement into the rail chair 3. Bolts 5 hold the ends of a generally U-shaped bracket i on the rail I. The center portion of bracket 5 is oiset and parallel to the rail I, and is provided with a horizontal slot 6a.

Attached to the ties alongside the lift rail l is a mounting plate Bolted on the plate TI is a circuit controller generally indicated at A, which may be of the type shown in the copending Bone and Jefferson application previously referred to.

One end of the plate 'i is offset upwardly, as at la (Fig. 2). A sleeve 8 is welded or otherwise suitably attached to the oiset portion 1a of the `plate "I, and serves as a journal for a shaft 9 which carries a guide arm I. The free end of guide arm I supports oppositely disposed pins Illa and Ib carrying rollers Ic and iid, respectively. The pin Ia is received in and cooperates ywith the slot Ba in the bracket attached to lift rail I. One end of slot 6a. is enlarged to receive roller Illc during assembly.

The circuit controller A is provided with an operating shaft II on which is mounted a crank arm I2. The crank arm i2 is provided with a cam slot I'2a-I2b-I2c which cooperates with and receives the pin {Si} on the guide arm i0.

The portion I2a of the cam slot nearest the shaft II of the circuit controller 8 is straight and is designed to be horizontal when the lift rail I is in its down position.

The shaft 9 which carries the guide arm i0 is rigidly mounted at a xed distance from the axis of crank arm I2. The guide arm I is made almost as long as that iiXed distance so that pin 10b is near the axis of crank arm I2 when the lift rail is adjacent its down position. Also, the ypath of motion of pin Ib is at such times substantially at right angles tothe portion of cam slot I2C which it engages. construction produces a relatively large movement of the crank arm I2 for a given movement of the lift rail, and thereby makes the controller very sensitive when it is checking the down position of the lift rail. This sensitivity is highly desirable, since it is essential, for reasons of safety, that the lift rail be completely down in its traine-carrying position whenever the circuit controller position indicates that it is down. This is the most critical position of the lift rail, and hence the sensitivity of .the circuit controller must be maximum at this position, as it is in the construction shown.

As the lift rail moves upwardly, the bracket 6 carries pin Ilia upwardly with it, thereby rotating the guide arm Iii on its shaft 9, and carrying pin Iilb and the crank arm I2 upwardly also. During this movement, the guide arm Hl rotates counterclockwise and the crank arm I2 rotates clockwise. Pin Ib moves toward the outer end of the cam slot.

As the pin IUb moves toward the outer end of the cam slot, the increment of motion of the cranky arm I2 for each increment of motion of the guide arm Ii' becomes progressively less, until, when pin I 0b nears the end of the straight portion I2a of the cam slot, the crank arm is almost tangential to the arc of travel of pin IUI), and hence is substantially at rest. This construction allows the lift rail to move through a This' relatively long distance between its down and up positions without much movement of the controller crank arm.

When the lift rail I reaches its up position, the pin IIlb reaches the end of the straight portion |211 of the cam slot and moves into the steeply curved portion I2b, which causes a substantial counterclockwise movement of crank arm I2. This up position of the lift rail I is the position at which it sufficiently clears the fixed rail and the other parts of the drawbridge to permit opening of the swing span of the draw. The steeply curved portion I2?) of the cam slot insures operation of the controller when the lift rail reaches its up position, and may be contoured as required to make the circuit controller sufficiently sensitive to movements of the lift rail adjacent its up position. This position of the lift rail is not nearly as critical from the safety standpoint as the down position, and hence the sensitivity of the circuit controller need not be as great.

The mechanism for operating the lift rail usually includes provision for overtravel of the lift rail beyond its up position. The portion I2C of the cam slot is provided to accommodate this movement. Portion I2c is arcuate and is arranged to be concentric with the guide arm Il) when the lift rail is in its up position. rTherefore, as soon as the lift rail reaches its up position, the pin ISD enters the arcuate portion I2b of the cam slot. As long as the pin IDb remains in the arcuate portion I2b, its continued upward movement rotates guide arm I, but causes no rotation of the crank arm I2 or of the circuit controller shaft II.

The horizontal slot 6a in the bracket 6 permits expansion and contraction of the lift rail I without causing operation of the circuit controller, and also accommodates lateral movement of pin Ia due to its circular path of movement.

The circuit controller A includes two cams I3@ I and two cams I3b, only one each of which appears in Fig. 3. These cams are carried by the shaft II and operate rocker arms lli pivoted on a rockshaft I5 and carrying followers Illa which cooperate with the cams. One end of each rocker arm lil is connected through a link I6 to a movable contact Il. Each contact Il engages a stationary contact I8, and is movable away from its contact I3 and into engagement with a stationary Contact 2U.

The contacts Il operated by the cams i3d are connected in the circuits of the signals which control the railway traido moving across the drawbridge. vWhen these contacts Il engage their associated contacts i8, the signals are controlled to permit trac movement over the bridge. When these contacts il engage their associated contacts 2d, the signals are controlled to prevent trailic movement over the bridge.

The contacts I'I operated by the cams I3?) are connected in the circuits of the signals which indicate to the swing bridge operator whether or not it is safe to operate the swinging mechanism. When these contacts I'I engage their associated contacts I8, these signals indicate that the liit rail is in a position where it will not clear the other parts of the bridge structure if the swing span is moved. When these contacts I? engage their associated contacts 2d, the signals indicate that the lift rail has reached its up position and that it is safe to move the swing span.

Any suitable signal controlling circuits may be used in connection with our invention. The particular contact arrangement described herein Operation The parts of the circuit controller are illustrated in Fig. 3 in their positions corresponding to the down position of the lift rail 2, which is shown in full lines in Fig. 2. When the lift rail begins to move upwardly from that position, the arm i2 moves rapidly because the projection Ich engages slot IZ-a near the axis of rotation of crank arm I2 and is moving at right angles to the slot. The consequent rotation of cams 13a moves their contacts Il quickly away from their contacts i8 .and into engagement with contacts 20. As the rail continues to move upwardly, the rate of movement of cam I3 is slowed as compared to the rate of movement of the rail, because the pin lb moves outwardly along the slot [2a. The parts are so proportioned that the cams |32) do not move their contacts Il' away from their contacts i8 and into engagement with their contacts 2@ until the rail reaches its up position and pin Mib entersthe steeply curved portion I2b of the cam slot.

The circuit controller 8 isv provided with a torsion spring which biases the shaft 'Il toward an intermediate position. 'I'his springs loads the crank arm l2, and thereby the guide arm i0 and so yieldably holds the pins lila and llb and rollers Hic and iiid against the upper sides of their respective slots. This prevents rattling oi the pins in their slots due to vibration, and materially reduces the wear which otherwise might take place between the various moving parts.

The details of construction of the circuit controller A are set forth only briey herein. For a more complete description, reference is made to the copending Bone and Jefferson application, Serial No. 1,955, previously mentioned.

It should be noted that all the parts of the control apparatus shown are mounted on the ties and do not lrequire the cutting vof any tie for the installation on an existing drawbridge.

Although we have herein shown and described only one embodiment of our 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 our invention.

Having thus described our invention, what we claim is:

l. Control apparatus to beoperated in accordance with `the position ofthe lift rail of a railway drawbridge, comprising an electric circuit controller, a rst member connected to the lift rail for concurrent movement therewith, a second member connected to the circuit controller for concurrent movement therewith, a

third member supported at one end on a xed pivot and positioned between said vfirst and second members, a rst connection between said third and first members which moves the third member as the rst member moves vertically but which permits independent horizontal movement of the first member relative to said third member, and a second connection between the third and second members which causes the second member to move and operate the circuit controller as said third member moves.

2. Control apparatus to be operated in accordance with the position of the lift rail of a railway drawbridge, comprising an electric circuit controller, a rst member connected to the lift rail for concurrent movement therewith, a second member connected to the circuit controller for concurrent movement therewith, a third member guided for movement along a xed path vand positioned between said first and second members, said third member having projections extending from its opposite sides to engage said first and second members, said first member having a horizontal slot which receives one of said projections and cooperates therewith to move the third member as the first member moves vertically but which permits independent horizontal movement of the first member relative to said `third member, said second member having a cam slot which receives the other projection land cooperates therewith to move and operate the circuit controller as said third member moves.

3. Control apparatus to be operated in accordance with the position of the lift rail of a railway drawbridge, comprising an electric circuit controller, a first member connected tothe lift rail for concurrent movement therewith, a .second member connected to the circuit controller for concurrent movement therewith, a third member supported at one end on a fixed pivot and positioned between said rst and second members, said third member having projections extending from its opposite sides to engageV said rst and second members, said first member having a horizontal slot which receives horizontal movement of the first member relative to said third member, said second member having a cam slot which receives the other projection and cooperates therewith to move and operate the circuit controller as said third member moves.

4. Control apparatus to be operated in accordance with the position of the lift rail of a railway drawbridge, said lift rail being movable between a down position wherein it can carry railway trafflc and an up position wherein it clears the other parts of the bridge sufficiently to permit opening of the draw, comprising an electric circuit controller, a first member connected to the lift rail for concurrent movement therewith, a second member connected to the circuit controller for concurrent movement therewith,vancl a third member extending betweenthe rst and second members, said second and third members being pivoted for rotation about spaced parallel axes, said third member having projections extending oppositely from its free end to engage said iirst and second members, said rst member having a horizontal slot which receives one of said projections and cooperates therewith to move the third member as the rst member moves vertically and to permit independent horizontal movement of the rst member relative to said third member, said second memberl having a cam slot Awhich receives the other projection and cooperates therewith to move and operate the circuit controller as said third member moves, said second and third members lying'substantially parallel to each other when the lift rail is in its down position so that said other projection engages said cam slot near the axis of rotation of said second member and causes a substantial movement of lthe circuit controller in response to a small movement of the lift rail from its down position. n

5. Control apparatus to be operated in'accordance with the position of the lift rail of a railway drawbridge, said lift rail being movable between a down position wherein it can carry railn way traiiic and an up position wherein it clears the other parts of the bridge suiiciently to permit opening of the draw, comprisiing an electric circuit controller, a rst member connected to the lift rail for concurrent movement therewith,

a second member connected to the circuit controller for concurrent movement therewith, and a third member extending between the rst and second members, said second and third members being pivoted for rotation about spaced parallel axes, said third member having projections extending oppositelyfrom its free end to engage said rst and second members, said rst member having a horizontal slot which receives one of said projections and cooperates therewith to move the third member as the first member moves vertically and to permit independent horizontal movement of the first membei` relative to said third member, said second member having a cam slot which receives the other projection and cooperates therewith to move and operate the circuit controller as said third member moves, said second and third members lying substantially parallel to each other when the lift rail is in its down position so that said other projection engages said cam slot near the axis oi rotation of said second member and causes a substantial movement of the circuit controller in response to a small movement of the lift rail from its down position, said cani slot having a portion contoured to provide a substantial movement of the circuit controller as the lift rail reaches its up position.

6. Control apparatus to be operated in accordance with the position of the lift rail of a railway drawbridge, said lift rail being movable between a down position wherein it can carry railway traffic and an up position wherein it clears the other parts of the bridge suiiciently to permit opening of the draw, comprising an electric circuit controller, a rst member connected to the lift rail for concurrent movement therewith, a second member `connected to the circuit controller for concurrent movement therewith, and a third member extending between the rst and second members, said second and third members being pivoted for rotation about spaced parallel axes, said thirdy member having projections extending oppositely from its free end to engage said first and second members, said rst member having a horizontal slot which receives one of said projections and cooperates therewith to move the third member as the rst member moves vertically and to permit independent horizontal movement of the first member relative to said third member, said second member having a cam slot which receives the other projection and cooperates therewith to move and operate the circuit controller as said third member moves, said second and third members lyingsubstantially parallel to each other when the lift rail is in its down position so that said other projection engages said cam slot near the axis of rotation of said second member and causes a substantial movement of the circuit controller in response to a small movementV of the lift rail fromv its down position, said camV slot having a portion contoured to provide a substantial movement of the circuit controller as the lift rail reaches its up position and an adjacent portion concentric with the axis of the third member when the lift rail is in its up position. to provide substantially no movementV of the circuit controller during overtravel ofthe lift rail beyond its up position.

7. Control apparatus to be operated in accordance 4with the position of the lift rail of a railway drawbridge, comprising an electric circuit controller, a first member connected to the lift rail for concurrent movement therewith, a second member connected to the circuit controller for concurrent movement therewith, a third member guided for movement along a xed path and positioned between said iirst and second members, said third member having a projection extending toward said first member, said rst member having a horizontal slot which receives said projection and cooperates therewith to move the third members as the rst member moves vertically but which permits independent horizontal movement of the rst member relative to said third member, and a connection between the third and second members which causes the second member to move and operate the circuit controller as said third member moves.

8. Control apparatus, comprising an element movable along a predetermined path but subject to lateral deviations therefrom, a control device to be operated in accordance with the position of said element along said path, a rst member connected to the movable element for concurrent movement therewith, a second member connected to the control device for concurrent movement therewith, a third member supported at one end on a fixed pivot and positioned between said rst and second members, said third member having projections extending from its opposite ksides to engage said first and second members, said first member having a slot extending laterally with respect to the path of movement oi said element, said slot receiving one cf said projections and cooperating there-- with to move the third member as the element moves along its path while permitting independent lateral movement of the element relative to said third member, said second member having a cam slot which receives the other projection and cooperates therewith to move and operate the control device as said third member moves.

9. Control apparatus to be operated in accordance with the position of the lift rail of a railway drawloridge, comprising an electric circuit controller mounted on and above the ties alongside the lift rail, a first member connected to the lift rail for concurrent movement therewith, a second member connected to the circuit con troller for concurrent movement therewith, a

' third member mounted on and above the ties be- JOHN W. LOGAN, JR. GLEN V. JEFFERSON.

REFERENCES CITED The following references are of record in the le of this patent: Y

UNITED STATES PATENTS Number Name Date 2,083,288 Bone June 8, 1937

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