US2575815A - Rail detector controller for drawbridges - Google Patents

Description

Nov. 20, 1951 cs. v. JEFFERSON RAIL. DETECTOR CONTROLLER FOR DRAWBRIDGES Filed Aug. 51, 1948 2 SHEETS-SHEET 1 IN VEN TOR.

H15 ATTORJVH Nov. 20, 1951 G. v. JEFFERSON 2,575,815

RAIL DETECTOR CONTROLLER FOR DRAWBRIDGES Filed Aug. 51, 1948 2 SHEETSSHEET 2 INVENTOR.

HIS JTWHN'EY' Patented Nov. 20, 1951 BAIL DETECTOR ooNfmopni nron DBAWBRIDG S .Glen Jefferson, Edgewood, Pa., ,assignor to Westingh mse Air Brake =1 Company, a corporacnro :Be i-ns lv Application 'Aqgust'31, 1948, Serial No. 47,101

13 :Glaims. l

-My-invention relates-tocontrol apparatus arranged for operation in response'to theposition of a movable element.

invention is disclosed herein :as applied to anelectric circuit controller operated in accordance withthepositionofthe lift rail of a railway drawbridge. Althoughcert-ain features of my inventioneareof" especial utility in connection-withsuch an arrangement, other features are of more I general utility in connection l with position responsiveeontrol apparatus.

The rail connections "between the movable span and the fixed span s on a railway drawbridge are commonly made by providing lift rails onthe end of one of each pairof adjacent span ends. Each lift rail has ,a normal or "down position in which it abuts the fixedrail on the end of the adjacent span, and in which it may safely carry railway traflic. The lift railis-movable fromits down position to an up position wherein it clears the other parts of the bridge sufliciently-to permit opening of the draw. The liftrail'is usually arranged-to have a substantial range of overtravelbeyond the up position. As long as'thelift mills in theup position or in the over-travel range, it will clear the bridge structure when the draw is opened.

The'approaches to a drawbridge areprovided with signals-to inform the operator of approaching trains whether or not it is safe to proceed -tric circuit controller in response to the posi- -tion-of a'liftrail on'a-railway 'drawbridge.

Another object is to provide improved :control apparatus-for checking boththedown and up positions of such'a lift rail.

A further object is to provide such control;

apparatus having increased sensitivity of re- :sponse to railmovement when the-rail is at or adjacent its down and up positions.

Another object of my invention is to provide control apparatus of type described including improved means for avoiding undesirableeffects due tovexpansion or. contraction of the rails.

:A further object of my invention is to provide .an improved apparatus for operating a control device in.-responseato the position of a movable member.

Another object of my invention is to provide :an'improvedm chanism for operating" the circuit controller associated with the lift rail of a. -railway'drawbridgeof the general type shown in the copending application for Letters Patent .oi .the"'U-nited States of Herbert L. Bone and *William C. McWhir-ter, Serial No. 30,535, filed *June2, 1948, for Control Apparatus.

in carrying out my invention, I mount on the ties-alongside the lift rail an electric circuit con- "troller of the tF/PBdescribed and claimed in the impending application of Herbert L. Bone and :GlenV, Jefferson, Serial No. 1955, filed January 13, 19.48. This circuit controller is provided with "anoperating crank arm having an outwardly extending projection mounted on its free end.

'Abracket is attached to the lift rail and car- --ries at its :free end another projection. inovtion :plate is mounted between the the circuit controller and the lift rail in suitable guides so thatit can move only in a vertical direction. This motion plate is provided with a horizontal slot to .receive the projection on the lift rail i-bracket andwith-a cam slotto receive the projection on the circuit controller crank arm.

.As the :lift rail rises, the projection on the 'Asthe motion plate moves vertically, the

This cam slot is contoured so as to provide an appreciable movement of -the circuit-controller crank arm when the lift rail is adjacent its down position and also when the lift --rail isadjacent its upposition. Between these two-portions of the cam slot is a vertical portion whichpermits the rail to move upwardly between'its down and up position without causmg appreciable movement of the circuit controller. I provide another vertical portion of th cam slot' beyond the portion corresponding to the-up position of the rail, so that the circuit controller is-not operated during the cvertravel of the railbeyond itsup position.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall illustrate and describe herein only one modification of m invention, and shall then point out the novel features thereof in claims.

In the drawings, Fig. 1 is a plan view of a fra ment of a railway drawbridge, showing the adjacent ends of a fixed rail and a lift rail, with one embodiment of my invention applied to the lift rail. Fig. 2 is an elevational view of the apparatus shown in Fig. 1 portions thereof being in section for illustrating to better advantage applicants construction. Fig. 3 is a sectional view taken along the line IIIIII of Fig. 1. Fig. 4 is a sectional view of a circuit controller which may be used in the apparatus of Figs. 1-3.

Similar reference characters refer to similar parts in each of the several views. I

Fig. 1 shows a rail connection between a movable span and a fixed span of a railway drawbridge, including a fixed rail I and a lift rail 2. The fixed rail is rigidly mounted on the ties (not shown). The lift rail rests in a rail chair 3 attached to the ties, and may be lifted from the chair by suitable driving mechanism not shown, the lift rail having fixed thereto oppositely extending guides 2a for centering the rail within the rail chair 3. Attached to the outer side of the web of lift rail 2 is a bracket 4, which carries at its outer end an outwardly projecting pin 5.

A motion plate 6 extends downwardly in a vertical slot Ia cut into the tie and is guided for vertical movement by guides I. The motion plate 6 is provided with a horizontal slot 6a which receives the pin 5 on the end of bracket 4. It may be seen that as the rail 2 is lifted, the engagement of pin 5 with slot 5a causes the motion plate 6 to follow the vertical movement of the lift rail. The horizontal slot 6a permits the rail 2 to move horizontally without affecting the position of motion plate 6. The motion of pin 5 is along an arcuate path rather than a straight vertical line, and the slot 6a accommodates the horizontal component of that motion. Horizontal movement of the rail 2 may also be occasioned, for example, by expansion and contraction of the rail due to temperature changes.

A circuit controller 8 is mounted on the ties adjacent the motion plate 6. The controller 8 has an operating shaft 9 carrying a crank arm Ill. The crank arm It carries at its end a pin I I which is received in a cam slot I2 in the motion plate 6.

The cam slot l2 has a curved portion I 2a which receives the pin II when the rail 2 is adjacent its down position, a vertical portion I2b which receives the pin II as the rail moves upwardly from its down position, another curved portion I which receives the pin II when the rail is adjacent its up position, and a vertical portion I211 which receives the pin I I when the rail moves beyond its up position.

The circuit controller 8 is shown in greater detail in Fig. 4. It includes two cams I3a and two cams I31), only one each of which appears in Fig. 4. These cams are carried by the shaft 9 and operate rocker arms I4 pivoted on a rockshaft I5 and carrying followers I ia which cooperate with the cams. One end of each rocker arm I4 is connected through a link I6 to a movable contact I'I. Each contact I! engages a stationary contact I8, and is movable away from its stationary contact I8 and into engagement with a stationary contact 20. Only one rocker arm l4 and one set of contacts [1, I8, and 2D is i1lustrat-- 4 ed in Fig. 4. It should be understood that each of the four cams I3a and I3b operates a similar rocker arm and contact set. The parts of the circuit controller are illustrated in Fig. 4 in the positions corresponding to the down position of the lift rail 2, as illustrated in Fig. 2. The contacts I'I operated by the cams I3a. are connected in the circuits of the signals which control the railway traffic moving across the drawbridge. When these contacts I! engage their associated contacts I8, the signals are controlled to permit trafiic movement over the bridge. When these contacts I! engage their associated contacts '24), the signals are controlled to prevent traffic movement over the bridge.

The contacts I! operated by the cams I3b are connected in the circuits of the signals which indicate whether or not it is safe to operate the swinging mechanism of the bridge. When these contacts II engage their associated contacts I8, these signals indicate that the lift 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 20, 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 my invention. The particular contact arrangement described herein is preferred, but other equivalent contact arrangements may be used with equal facility.

Operation The parts are shown in their positions corresponding to the down position of the lift rail 2. The dotted lines in Fig. 2 show the lift rail in its up position and the corresponding positions of some of the parts. In the down position of the lift rail, it is ready to carry traffic over the bridge. In the circuit controller, the movable contacts I! are engaging the stationary contacts I8.

Starting with the parts in the positions shown, let it be assumed that the lift rail 2 is moved toward its up position, which is illustrated in dotted lines in Fig. 2. As the rail 2 moves upwardly, engagement of pin 5 with slot to carries the motion plate B-upwardly. The pin I I on crank arm I0 engages curved portion I2a of the cam slot I2 in the motionplate 6. As the motion plate 6 starts upwardly, pin II is moved to the right in the cam slot portion I2a, thereby rotating the crank arm It counterclockwise. As the crank arm Ill and shaft 9 starts to move counterclockwise from the position shown, the two cams I3a operate their associated rocker arms I4 to move their respective contacts I1 away from their contacts I8 and into engagement with their contacts 20. No further movement of these contacts I'l takes place.

When the lift rail reaches its up position, wherein the rail is sufficiently clear of the other parts of the bridge to permit opening of the draw, then the pin I i moves into the curved portion I 20 of the cam slot. As the pin I I moves through the portion I20 of the cam slot, crank arm IE5 is rotated additionally counterclockwise. The corresponding counterclockwise rotation of shaft 9 operates the cams I3?) to move their contacts I1 out of engagement with their contacts I8 and into engagement with their respective contact 23. As previously mentioned, this contact movement completes a signal circuit for indicating to the bridge operator that it is safe to proceed with the opening of the draw.

After this operation of the circuit controller 8 by the crank arm i0 is completed, the lift rail 2 may continue to move upward in accordance with the overtravel provision of its driving mechanism. During this phase of its movement, the pin ii rides in the vertical portion l2d of the cam slot l2, and therefore does not cause any additional operation of the circuit controller 8.

During the downward movement of the lift rail, the operation of the circuit controller is just the reverse of that previously described for the upward movement. The cams l3b are operated to move their contacts I? away from their contacts 20 and into engagement with the contacts i8 as the pin passes through the curved portion I20 of the cam slot. The contacts ll operated by cams [3a are moved away from their contacts 20 and restored to engagement with their contacts l8 when the lift rail 2 reaches its down position and the pin I! moves through the curved portion l2a of the cam slot.

Although I have herein shown and described only one modification of control 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. Apparatus for operating a circuit controller in accordance with the position of the lift rail of a railway drawbridge, comprising a projection on the lift rail, a lever arm operatively connected to the circuit controller and having a follower projecting therefrom, and a motion plate guided for vertical movement and having a horizontal slot to receive said projection so that it follows vertical movements of the lift rail but is not affected by horizontal movements of the rail, said motion plate having a cam slot to receive said follower, said cam slot being contoured to rotate the lever arm and operate the circuit controller as the motion plate moves vertically.

2. Apparatus for operating a circuit controller 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 other parts of the bridge sufficiently to permit opening of the draw, comprising a projection on the lift rail, a lever arm operatively connected to iii the circuit controller and having a follower projecting therefrom, and a motion plate guided for vertical movement and having a horizontal slot to receive said projection so that it follows vertical movements of the lift rail but is not affected by horizonal movements of the rail, said motion plate having a cam slot to receive said follower, said cam slot being contoured to rotate the lever arm and operate the circuit controller from a first circuit-controlling position to a second circuitcontrolling position as the lift rail moves upwardly from its down position, to hold the lever arm substantially stationary thereafter during continued upward movement of the lift rail until the rail approaches its up position, to rotate the lever arm and operate the circuit controller from its second circuit-controlling position to a third circuit-controlling position as the rail moves to its up position, and to hold the lever arm substantially stationary thereafter during overtravel of the lift rail beyond its up position.

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 to the lift rail for con urrent movement therewith, said first member having a first projection thereon, a second member connected to the circuit controller for concurrent movement therewith and having a second projection thereon, and a third member guided for movement along a fixed path, said third member having a horizontal slot which receives said first projection and causes the third member to move along said fixed path as the first member moves vertically but permits independent horizontal movement of the first member, said third member also having a cam slot which receives said second projection and causes the second member to move and operate the circuit controller as said third member moves along said path.

GLEN V. JEFFERSON.

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

UNITED STATES PATENTS Number Name Date 258,601 Putnam May 30, 1882 1,362,205 Waldron et al Dec. 14, 1920 2,528,064 Logan, Jr., et al Oct. 31, 1950

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