US1864361A - Railway car retarder - Google Patents

Description

June 21, 1932. J. w. LIVINGSTON I 1,864,361

RAILWAY CAR RETARDER Filed June 29, 1951 7 YbSazlrce 16 ofFZuZ'd Pressure 17 54 INVENTOR: l

n r \7, W L/v/n sc Ml ATTORNEY.

Patented June 21, 1932 UNITED STATES T F F ICE JOHN W. LIVINGSTON, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR' TO THE UNION SW'ITCI-L & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A GORZPOBATION 'OF' PENNSYLVANIA Application filed .Tune 29,

- thereof in claims;

lhe accompanying drawing is av view, partly sectioned, and partly diagrammatic, illustrating one form of apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and l designate the track rails of a stretch of railwaytrack over which cars normally move in the direction indicated by the arrow under such conditions that it is desirable to control the speed of the cars. For

example, the stretch of track here shown might be in a classification yard of the hump type through which cars move under the influence or gravity. It is obvious that in service of this kind, the speed of individual cars or strings of cars will vary through wide limits, depending among other things upon the speed at which they go over the hump, the temperature, the weight of the car and contents, and the condition of the car as to whether it is a free running car or otherwise.

In order to control the speed of the cars, the stretch of track illustrated. in the drawing is provided with a car retarder which, in the form here shown, comprises two brakingbars 2 and 3, extending paral el with, and located on opposite sides of rail 1, and two similar braking bars 2 and 3 extending parallel with and located on opposite sides of rail 1 The braking bars 2, 3, 2 and 3 are operated by a fluid pressure motor M here shown as a cvlinder 4 containinga reciprocable piston 5 to which is attached a piston rod 6. The braking bars 2, 3, 2 and 3 are opera- R-AILWAY CAR RETARDER 1931. Serial No. 547,518.

tively connected with the piston rodothrough suitable linkwork including a bell crank. 7 and a lever 8 which is pivotally supportedin the traclrway at 9. When piston 5 occupies its extreme right-hand position, in-which it is illustrated in the drawing, the braking bars occupy their non-braking or ineffective positions 111 which they are out of engagement with the wheels of a passing car traversing valves V and V each comprising a valve stem 10 biased to an upper position by means of a spring 11, and each provided with a winding 12 and an armature 13. When winding 12 of valve V is deenergized, as shown in the drawing, valve stem lOkis held in its upper position by the spring, 11, and under these conditions, the right-hand end ofcylinder 4: is connected with atmosphere through pipe 14 and a port 15. l/Vhen winding;12 ofthis valve is energized, however, valve stem 10 is moved downwardly to disconnect pipe 14 from atmosphere and to connect this pipe with a suitable source of fluidpressure, usually air, through a pipe 16. Whenwinding 12 of valve V is energized,theretore, the fluid pressure supplied to the left-hand'end'ofcylinder moves piston 5 toward theright, thereby moving the braking bars to their ef; tective or braking positions W ien winding 12 of valve V is ,deenergized, valve stem 10 of this valve occupies its upper position, andthe left-hand end of cylinder 4 is then connected with atmosphere through a pipe 17 and a port 18. When wind ing 12 of valve V is energized, however, as 5 7 shown in the drawing, valve, stem 10'is moved downwardly, disconnecting pipe 17 from port 18, and connecting pipe 17 with pipe '16. It will be apparent, therefore, that'when valve V is energized,,pist'on 6 is urged toward the right, thus holding the braking bars in their ineffective or non-braking positions.

The magnet valves V and V are controlled by means of a normally energized control relay C, and by a. manually operable lever L. The lever L, in the form here shown, is capable of assuming a left-hand position a in which it is illustrated in the drawing, and a right-hand position 6, indicated by av dotted line in the drawing. Operatively connected with the lever L is a contact arm 19 which engages a fixed contact 19 or 1 b to close a contact 1919" or 1919 according as lever L occupies its a or 6 position. 7

Winding 12 of valve V is provided with a circuit which passes from a suitable source of current, here shown as a battery 20, through wire 21, winding 12 of valve V wire 22', contact 1919 of lever L, wire 23, front contact 24-2 of relay C, and wire 25 back to battery 20. Winding 12 of valve V is also provided with a circuit which is similar to the circuit just traced with the exception that this circuit includes a wire 26 and back contact 24.2t of relay C, instead of contact 1919 of lever L, wire 23, and front contact 2l24 of relay C. It will be apparent, therefore, that winding 12 of valve V will become energized when relay C is energized and leverL occupies its a position, or when relay C is deenergized.

lVinding 12 of valve V is provided with a circuit which passes from battery 20 through wire 21, winding 12 of valve V wire 27, contact 1919 of lever L, wire 23, front contact 24-24 of relay C, and wire 25 back to battery 20. It will be apparent, therefore, that winding 12 of valve V will be energized when and only when lever L occupies its 1) position and relay C is energized.

It follows from the foregoing that when relay C is energized, the braking bars will occupy their braking or non-braking positions according as lever L occupies its a or 1) position, but that, when relay C is deenergized, the braking bars Wlll occupy their non-braking positions regardless of the position of lever L. I

The apparatus includes a series of treadles 28, 28*, 28, 28, 28 and 28, which as here shown, are located adjacent the rail 1 in positions where they will be successively engaged and depressed by the flanges of the wheels of a car proceeding along the track. These treadles may be of the usual spring biased type and each returns to its normal position after being depressed by a car wheel. Each of the treadles 28, 28*, 28, 28 28 and 28 controls a'normally open contact, designated by the reference character 29 with an exponent corresponding to the exponent for the reference character of the associated treadle, and arranged in such manner that this contact will become closed during the entire time that the associated treadle is depressed. Each of the treadles 28", 28, 28 28 and 28 also controls a second normally open contact, designated by the reference character 30 with a suitable distinguishing exponent, and arranged in such manner that this contact will become closed momentarily when the associated treadle is being depressed, but that, this contact will be opened when the associated treadle has reached its fully depressed position, and it will remain open as the treadle returns to its raised or normal position. Furthermore, each of the treadles 28, 28 28 and 28 controls a normally closed contact designated by the reference character 31 with a suitable distinguishing exponent, and so arranged that this contact will become opened as soon as the associated trea dle becomes depressed and will remain open until the associated treadle returns to its normal position. The spacing between the adjacent ends of adjacent treadles is such that when any treadle has been depressed by a car wheel, it will be held in its depressed position by the car wheel until the car wheel has depressed the treadle next in advance, after which it will immediately return to its normal position. It will be seen, therefore, that when any one of the treadles 28 28 or 28 is depressed, the associated contact 31 will remain open until after the contact 31 for the treadle next in advance becomes opened.

The contacts 30 and 31 jointly control a selective relay A, and the contacts 29 control a slowpick-up relay S, in a manner which will become apparent as the description proceeds.

The selective relay A may be of any suitable type having contact which will become closed when and only when the relay has been consecutively energized a predetermined number of times in such manner that the length of the time interval which elapses between successive energizations is less than a predetermined value. One form of relay which will operate in the manner described is disclosed and claimed in my copending application for Letters Patent of the United States, Serial No. 512,925, filed February 2, 1931, for Electrical Relays. In the particular embodiment of my invention illustrated in the drawing, the parts are so proportioned, and relay A is so designed that this relay will close its contact 33 when and only when its winding has been consecutively energized three times in such manner that the time interval which elapses between successive energizations is less than the time interval which elapses between the closing of any two adjacent contacts 30 when the associated treadles are successively depressed by a wheel of a car which is travelling at the speed at which it is desired to have the car leave the braking apparatus, which speed I will term control speed.

The slow pick-up relay S is so designed that this relay will not open its back contact 32 until its winding has been energized for a timeinterval which is slightly longer than the time interval required for a car which is travelling at control speed to move from the position where a wheel of the car first depresses the treadle 28 to the position where such wheel first depresses the treadle 28 The relays Sand A jointly control relay C by Virtue of acircuit which includes a suitable source of current here shown as a battery B, and'back contact 32 of relay S and contact 33 of relay A connected in parallel. It will be apparent, therefore, that relay 0 will be energized when either back contact 32 of relay S or contact 33 of relay A is closed, butthat relay C will become deenerg'ized when both of these contacts are open. Under normal conditions, that is to say, when no car is occupying the stretch of track shown in the drawing, relay S is deenergized, and it follows, therefore, hat relay C is nor mally energized.

In explaining the operation of the apparatusesa whole, I will assume that the braking ba-rs'have been moved to their braking positions-by moving lever L from its a to its b position, and that a car which is approaching the'stretch of track shown in the drawing in the direction of the arrow, at a speed which is greater than control speed, traverses the stretch of track shown in the drawing. l/Vhen the first wheel of the car depressestreadle 28*, contact 29 will become closed and will complete a circuit for relay S including this contact and a suitable source of current here shown as a battery D. Relay S will therefore become energized, but due to the slow pick-up characteristics of this relay previously pointed out, it will not immediately open its back contact 32. Before the car wheel departs entirely from the treadle 28 it will depress treadle 28. thereby closing contact 29. This will establish a second circuit for relay S which circuit will be apparent from the drawing. As a result, when the car wheel leaves the treadle 28 and contact 29 opens, relays will remain energized. The depression of the treadle28 will also momentarily close contact 30 which will establish a circuit for relay A passing from battery D through contact 30 contacts 31, 31 31 and 31 in series, andthe winding of relay A back to battery D. Relay A will therefore become momentarily energized, but contact 33 will continue to remain open. When the forward wheel next depresses treadle 28, contact 31 will become opened, and contacts 29 and 30 will become closed. The opening of contact 31 will interruptthe circuit previously traced for relay A including this contact, thus insuring that relayA will not become energized due to another wheel of the car depressing the treadle 28 while the forward wheel is stillengaging the treadle 28. The closing of contact 29 will complete a third circuit for relay S which circuit will also be appar'- ent from the drawing, while the closingiof contact 30 will complete a second circuit for relay A, this second circuit passing from battery D through contact 30, contacts 31, 31 and 31 in series, and the winding of relay A back to battery D. Due to this second cir-' cuit for relay A, relay A will become momentarily energized a second time. When the forward wheel next engages treadle 28 the subsequent opening of contact 31 will open the circuit last traced for relay A, and theclosing of contact 30 will complete a third circuit for relay A, while the closing of contact 29 will complete a fourth circuit for relay S. Both this third circuit for relay A and this fourth circuit for relay S willbe apparent from an inspection of the drawing without describing them in detail. Due to this fourth circuit for relay S, relay S will continue to remain energized, and due to this third circuit for relay A, relay A will become energized a third time. Since the car is travelling at a speed which is greater than control speed when relay A becomes energized the third time, it will close its contact 33, thus closing the circuit for relay C at this contact. As a result, when relay S closes its armature, thus opening its back contact 32, relay C will remain energized, and the braking bars will therefore continue to remain in their braking positions under these conditions. When the forward wheel of the car next depresses treadle 28, the circuit last traced for relay A will become opened at contact 31 and a fourth circuit for relay A will momentarily become closed at Contact 30, this latter circuit passing from battery D through contact 30 contact 31 and thewinding of relay A back to battery D. Furthermore, when treadle 28 becomes depressed, a fifth circuit for relay S will become closed at contact 29 so that relay S will still remain energized and will continue to hold its back contact 32 open. Due to the closing of this fourth circuit for relay A, relay A will again become energized. If, when this happens, the car is still travelling at a speed which is greater than control speed, relay A will maintain its contact 33 closed, and relay C will therefore remain energized so that the braking bars will continue to retard the car. If, 7

however, the speed of the-car has decreased toa speed which is less than control speed before this fourth circuit for relay A becomes closed, then by the time this fourth circuit becomes closed, contact 33 of relay A will have opened. Under this condition, the

closing of this fourth circuit will start the operation of relay A over again. Assuming that contact 33 of relay A has opened due to the speed of the car having decreased to a speed which is less than control speed before the fourth circuit for relay A becomes closed, Q

then both. circuits for relay C will beopen,

and relay C will therefore become deenergized. As a result, valve V will become dcenergized, and valve V will become energized. The braking bars will therefore move to their non-braking positions, thus preventing further retardation of the car as long as relay C remains deenergized, lVhen the lirst wheel of the car neXt depresses treadle 28 the fourth circuit for relay A will become opened at contact 31 and a fifth circuit for this relay will become closed at contact 30, while a sixth circuit for relay S will become closed at contact 29. Both of these latter circuits will be apparent from an inspection of the drawing. The closing of the sixth cir-' cuit for relay S will continue to maintain relay S in its energized condition, while the closing of the fifth circuit for relay A will again energize this latter relay.

It should be pointed out before proceeding further with the description that, as long as the forward wheel of the car is engaging any of the treadles of the series, the operation of any of the other treadles by any of the other wheels of the car will have no effect on the apparatus because, under these conditions, relay S will already be energized, and the opening of the contact 31 which is controlled by the treadle which the forward wheel is engaging will prevent relay A from becoming energized as a result of the closing of any of the contacts 30 in rear of this treadle. As soon, however, as the forward wheel departs from the last treadle of the series, the second wheel will become eii'ective for controlling the operation of the relays A and S. Similarly, the third and fourth wheels will become the governing wheels when the preceding wheels leave the series.

lVhen the first wheel leaves the series the next energization of relay A will come at a shorter interval of time than normal for the speed at which the car is moving because the distance from the second wheel to the next treadle to be depressed will be less than the distance between the treadles. This one energization, however, will not cause improper operation of the apparatus because it requires three successive energizations at the required time intervals to cause relay A to close its contact 33.

' If, at any time after relay A has opened its contact 33 due to the speed of the car having decreased below control speed,the car speeds up to a speed which is above control speed, as might happen when the retarder is located on a grade, then as soon as the car has moved through a sufiicient distance for the forward one of the wheels which is operating the treadles to successively operate three treadles, relay A will again close its contact As a result, relay C will again become energized thus causing the braking bars to again more to their braking positions. The braking bars will then subsequently remain in their braking positions as long as the speed of the car remains above control speed. .VVhen the last .wheel of the car has departed from the series, relays A and S will both become deenergized, and the parts will then be restored to the positions corresponding to the position of lever L.

If when the braking bars are in their braking positions, a car which is travelling in the direction of the arrow at a speedwhich is less than control speed enters the stretch of track shown in the drawing, the operation of the apparatus will be similar to that just described with the exception that under these conditions relay S will pick up before the forward wheel of the car reaches treadle 28 and contact 33 of relay A will remain open long as the speed of the car remains below control speed. As a result, the braking bars will move to their non-braking positions before the car reaches theretarder, and will subsequently remain in their non-braking positions as the car moves through the retarder, unless the car subsequently speeds up to a speed which is greater than control speed.

If several cars coupled together traverse the stretch of track shown in the drawing, the operation of the apparatus will be substantially the same as when a single car is traversing the stretch, it being remembered that the forward wheel which is operating the treadles will always be the governing wheel.

It should be pointed out that while in describing my invention, 1 have shown the relays S and A controlled by only six treadles, in actual practice, these relays may be controlled by any other suitable number of treadles. Furthermore, the pick-up timeof relay S and the number of successive energizations of relay A necessary to cause this latter relay to close its contact may be varied to suit the conditions.

Under some conditions, it isdesirable that the operator should retain complete manual control of the retarder. In order to permit the operator to do this, I have provided a manually operable switch 34. which is connected in parallel with back contact 32 of relay A. It will be seen that when the switch 34 is closed, relay C will remain energized even though back contact 32 of relay S and contact 33 of relay A are both open, and it follows, therefore, that when switch 34 is closed, the car operated apparatus will be ineffective to release the retarder, and that the braking bars will occupy their braking or non-braking positions according as lever L occupies its a or 5 position.

One advantage of car retarder controlling apparatus embodying my invention is that all cars will leave the retarder at substantially the same speed thus greatly simplifying yard operation, Another advantage of car retarder controlling apparatus e nbodying my invention is that a close approach to continuous control of a car may be obtained by employing a large number of very short treadles to control the relays S and A.

Still another advantage of car retarder controlling apparatus embodying my invention is that a relatively small number of parts are required, and maintenance is therefore reduced to a minimum.

Although I have herein shown and described only one form of retarder controlling apparatus embodying my invention, it is understood that various changes and mod1iications 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, means located along said stretch for controlling the speed of cars traversing the stretch, a relay having a contact which becomes closed when and only when the relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, means effective when a car is traversing said stretch for energizing said relay at least said predetermined number of tlmes in such manner that the time interval which elapses between successive energizations depends upon the speed of the car, and means controlled by said contact for controlling said first mentioned means.

2. In combination, a stretch of railway track, a braking bar located along saidstretch for controlling the speed of cars traversing the stretch, a relay having a contact which becomes closed when and only when the' relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, means effective when a car is traversing said stretch for energizing said relay at least said predetermined number of times in such manner that the time interval which elapses between successive energizations depends upon the speed of the car, and means controlled by said contact for controlling said braking bar.

3. In combination, a stretch of railway track, a braking bar located in the trackway adjacent a track rail, a winding, means controlled by said winding for moving said braking bar into position to engage a partof a car to retard the speed of the car, a relay having a contact which becomes closed when and only when the relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, means efiective when a car is traversing said stretch for energizing said relay at least said predeter mined number of times inIsuc'h'mannerthat the time interval whichelaps'es between successive energizations depends upon the speed of the car, and means controlled in partby said contact for eontrolling'said winding.

4. In combination, a stretch 'ofjr'ailway track, means located along said stretch for controlling the speed of cars traversing the stretch, a relay having a contactwhichbecomes closed when and only when the relay times momentarily energizing said relay,

and means controlled by said contact for controlling said first mentioned means.

5. In combination, a stretch of railway track, a braking bar located in the traokway, a first relay, means controlled, bysaid first relay for controlling said braking bar, a slow pick-up relay, a selective relay having a contact which becomes closed vwhen and only when said selective relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, means" for energizing said slow pick-up relay when a car enters said stretch and for subsequently maintaining said slow pick-up relay in its energizedcondition until the car'leav'esthe stretch, means effective While a car is traversing said stretch for successively energizing said selective relay at least said predetermined number of times in such manner that the time which elapses between successive energizations depends upon the speed of the car, and means controlled by said slow pick-up relay and by the contact of said selective relay for controlling said first relay.

6. In combination, a stretch of railway track, a braking bar located in the trackway, a first relay, means for moving said braking bar to a braking or non-braking position according as said first relay is energized or deenergized, a slow pick-up relay, a selective relay having a contact which becomes closed when and only when said selective relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, means for energizing said slow pickup relay when a car enters said stretch and for subsequently maintaining said slow pick-up relay in its energized condition until the car leaves the stretch, means effective while a car is traversing said stretch for successively energizing said selective relay at least said predetermined number of times in such manner that the time which elaps'es between successive energization depends upon the speed of the car, and means controlled by a back contact of said slow pick-up relay and by the contact of said selective relay for controlling said first relay.

7. In combination, a stretch of railway 10 track, a braking bar located in the trackway adjacent one of the track rails of said stretch, a first relay, pressure responsive means for moving said braking bar into position to engage a part of a car, means for supplying pressure to said pressure responsive means when said first relay is energized; a series of treadles located in the trackway adjacent one of the track rails of the stretch in a position to be successively engaged and depressed by the wheels of a car traversing said stretch, each of said treadlesbeing provided with afirst normally open contact which is closed during the entire time the treadle is depressed, with a second normally open contact which becomes momentarily closed when the treadle is depressed, and with a normally closed contact which becomes opened as soon as the treadle is depressed; a slow pick-up relay, a'plurality of circuits for said slow pick-up relay each controlled by the first normally open contact for a different one of said treadles, a Selective relay having a contact which becomes closed when and only when the relay is successively energized a predetermined number of times in such manner that the time interval which elapses between successive energizations is less than a predetermined value, a plurality of circuits for said selective relay each including the second normally open contact of a dillerent one of said treadles and the normally closed contacts connected in series for all of the treadles in advance of the treadle which controls such one contact, and a circuit for said first relay controlled by a back contact of said slow pick-up relay and by the contact of said selective relay.

Intestimony whereof I aflix my signature.

JOHN W. LIVINGSTON.

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