US2080053A - Car retarder control apparatus and testing means therefor - Google Patents

Description

May 11, 1937. J. w. LIVINGSTON CAR RETARDER CONTROL APPARATUS AND TESTING MEANS THEREFOR Filed April 17, 1935 @10 a a 5 H Z a 2 72 2 3 K Wu b. 00 2 a 07 8 0 2 l H z m w w Wm 6 F 5, 5 2 LLW d/ 92, NJ 1 5 2 3% a 5 fill; 0 M m u vi PB INVENTOR John WLivingsLon.

Q LW HIS ATTORNEY Patented May 11, 1937 UNITED STATES PATENT OFFICE CAR .RETARDER CONTROL APPARATUS AND TESTING MEANS THEREFOR Application April 17,

3 Claims.

My invention relates to car retarder control apparatus, and to testing means therefor.

One object of my invention is the provision of improved apparatus for automatically controlling the braking action of a car retarder of the track brake type used in classification or hump yards of railroads, in accordance with the speed of cars approaching or passing through the retarder.

Another object of my invention is to provide novel means for testing the timing of the timing relays, or their equivalent, employed in control apparatus of the type embodying my invention, or in any other type of control apparatus.

I will describe one form of car retarder control apparatus, and one form of testing means, embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form of control apparatus embodying my invention and one form of testing means therefor.

Referring to the drawing, the reference characters I and l designate the track rails of a stretch of railway track 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. Forexample, the stretch'of track here shown might be in a classification yard of the hump type through which cars move under the influence of 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 conditions of the car as to Whether it is a free running car or other wise.

In order to control the speed of the cars, the stretch of track illustrated in the drawing is provided with a car retarder A which, in the 1 here shown, comprises two braking bars 2 and 3, extending parallel with, and located on opposite sides of rail I, and two similar braking bars 7: and 3 extending parallel with, and located on opposite sides of, rail i. The braking bars 2, 3, 2 and 3 are arranged to be moved toward and away from the track rail I according as a car retarder control relay C is deenergized or is energized, through the medium of oierating and control mechanism which is in dicated diagrammatically in the drawing by the rectangle OM. This operating and control mechanism forms no part of my present invention,

1935, Serial No. 16,829

except insofar as it is used in combination with the remainder of the apparatus, and this mechanism may be of any suitable type. For example, this mechanism may be similar to that shown and described in Letters Patent of the United States No. 1,958,293, granted to Herbert L. Bone and myself, on May 8, 1934.

In accordancewith my present invention I provide novel and improved means for controlling relay in such manner that this relay will at times become automatically energized when the speed of a car which is traversing the stretch of track shown in the track falls below a speed which depends upon the setting of a manually operable'speed control lever S. As here shown, these means comprise a series of relatively short insulated control sections 4, 4, 4, etc., which are formed in the rail I. These control sections will usually be of uniform lengths, and their lengths may be varied as conditions require, but the lengths of these sections will preferably be such that two wheels of a car can not occupy the same section at any one time. For example, for most conditions of operation each control section may be approximately thirty-seven inches in length.

The speed control lever S is capable of assuming a plurality of positions, indicated by dotted lines in the drawing, and designated by the reference characters 11 p and p respectively. Operatively connected with the lever S are a plurality of contact arms 5, 5, 5, etc. The contact arm 5 cooperates with three fixed contacts 5 5 ,or 5 to close a contact S -5 5-5 or li -5 according as lever S occupies its p 12 or 11 positions. Each of the other contact arms cooperates with fixed contacts 5 5 and 5 to selectively close contacts in the same manner that the arm 5 cooperates with the associated fixed contacts 5 5 and '5 respectively to selectively close the contacts 5 -5 5 5 or ti -5 Associated with each control section is a track relay designated by the reference character D with a suitable distinguishing exponent, an adjustable resistor designated by the reference .character'R with a suitable distinguishing exponent, a gaseous'discharge device having a definite potential at which it becomes conducting, said device here being shown as a neon tube and being designated by the reference character T with a suitable distinguishing exponent, three condensers each designated by the reference character F with a distinguishing exponent and subscript, and a timing relay designated by the reference character G with a suitable distinguishing exponent.

The track relays D D D etc., are similar relays, and, as here shown, each of these relays is provided with a back contact 6 and with a front contact 7. Each track relay D is connected in a track circuit which includes the associated control section 4, the rail 1 and a suitable source of current here shown as a battery E. It will be apparent, therefore, that when none of the sections 4 is occupied, as is the case when no car is traversing the stretch of track shown in the drawing, all of the track relays D will be deenergized, but that, when a car is traversing the stretch of track shown in the drawing, each time a car wheel moves onto one of the sections 4, the associated track relay D will become energized. It will also be apparent that the length of time a track relay remains energized after it becomes energized will depend upon the time required for the car which caused it to become energized to traverse a distance which is equal to the length of the associated control section, and hence upon the speed of the car.

The timing relays G G G, etc, are likewise similar relays, and as here shown, these relays are made slow acting for reasons which will appear hereinafter. Each relay G is controlled by the associated track relay D through the medium of a control circuit which includes the associated neon tube T. These control circuits are similar, and it is believed, therefore, that a description of one will suffice for all. Referring particularly to relay G, the control circuit for this relay passes from terminal B of a suitable source of current not shown in the drawing through line wire 8, front contact 1 of track relay D resistor R neon tube T winding of relay G and line wire 9 to the other terminal X of the source. This control circuit is provided with a plurality of branch paths which may be selectively connected in multiple with neon tube T by moving the speed control lever S to different positions, and each of which includes a different one of the condensers F r, F z and F x, and a different one of the contacts 5 5 5 5 and 5 of lever S. The condensers 5 1, 5% and 5 3 have diiferent capacities for reasons which will be made clear presently.

With the control system for relay G arranged in the manner just described it will be seen that when no car is traversing the stretch of track shown in the drawing, so that track relay D is deenergized, the control circuit for relay G will be interrupted at front contact I of relay D, and under these conditions relay G will be deenergized, and its front contact 10 will be open. When, however, a car is traversing the stretch of track shown in the drawing, each time a car wheel moves onto the control section 4 and causes track relay D to become energized, the control circuit for timing relay G will then become closed, and will subsequently remain closed for a time interval which depends upon the speed of the car. Assuming that lever S occupies its 11 position in which it is shown in the drawing so that condenser F l is connected in multiple with tube T each time relay D picks up and completes the control circuit for relay G condenser F l will start to charge at a relatively slow rate which depends upon the adjustment of resistor R As the condenser F r charges, the voltage across its terminals will increase and, if the speed of the car which caused track relay 13 to pick up is sufficiently slow so that this relay subsequently remains picked up long enough to permit the voltage across the terminals of condensers F l to build up to that at which tube T becomes conducting, relay G will pick up and will close its front contact ID. If, however, the speed of the car which caused relay D to pick up is not sufficiently slow to cause this relay to remain picked up long enough to permit condenser F l to charge to the potential at which tube T becomes conducting, relay G will not pick up its armature, and its front contact II] will remain open. The time required for the voltage across condenser F 1 to build up to that at which tube T becomes conducting depends not only upon the resistance of the resistor R but also upon the capacity of the condenser F r, and it will be apparent, therefore, that by choosing the proper capacity for condenser F 1, and by properly adjusting the resistance of the resistor R the car speed below which it is desired that relay G should pick up may be varied as conditions require. It will also be apparent that, since the condensers F 1, F 2 and F 3 have different capacities, the car speed at which relay Ci will pick up its armature and close its front contact may be varied by moving speed control lever S to its diiferent positions. For purposes of illustration, I will assume that the parts are so proportioned that relay G will pick up its armature and close its front contact ID for all car speeds below three, four or five and onehalf miles per hour, respectively, according as the lever S occupies its 12 p or p positions.

With relay Cr controlled in the manner thus far described, it will be apparent that if relay D becomes energized for a time interval which is less than that required to render the associated tube 'I' conducting, when this relay subsequently becomes deenergized, the condenser F which was previously connected in multiple with the tube T will be partly charged, so that when relay D again becomes energized the condenser will not require as long a time to charge up to the potential at which tube '1 becomes conduct ing, as it would have required if the condenser had been fully discharged when relay D became deenergized. This is undesirable, and in order to prevent this from happening, each condenser F is provided with a discharge circuit which includes back contact 6 of the track relay D and the associated contact of lever S. It will be apparent, therefore, that whenever track relay D is deenergized, the condenser which is then connected in multiple with tube 'I will be short circuited, so that when relay D subsequently picks up, the condenser will be fully discharged.

As was previously pointed out, the control circuits for each of the remaining relays G are similar to those for relay G and the condensers which are associated with these control circuits are provided with discharge circuits which are similar to those provided for the condensers which are associated with the control circuit for relay G It follows, therefore, that each of the rel ys G will operate in a manner similar to relay G The timing relays (3.- control relay 0 by virtue of a plurality of parallel pick-up circuits, each of which includes suitable source of current, here shown as a battery H, a manually operable switch and the front contact in of a different one of the timing relays G. It will be seen, therefore, that when all of the timing relays are deenergized, relay C will also be deenergized, but that, when any one of the timing relays becomes energized and closes its front contact l0, relay C will become energized.

As shown in the drawing, all parts are in the positions which they normally occupy when it is desired to retard a car which is approaching the retarder from the left, to the slowest speed for which the apparatus is designed. That is to say, all relays are in their deenergized positions, speed control lever S occupies its p position, and the braking bars occupy their braking positions. With the parts in the positions just described, I will assume that a car which is traveling at a higher rate of speed than that for which the speed control lever S is set enters the retarder. As the car moves through the retarder, each time a car wheel moves onto one of the control sections 4, the associated track relay D will become energized, and will complete the control circuit for the associated timing relay G, but as long as the speed of the car is above that corresponding to the p position of the lever S, none of the timing relays G will pick up and close its front contact [0. Relay C will therefore remain deenergized, and the car retarder will therefore continue to slow down the car. As soon, however, as the car speed has been slowed down by the car retarder to a speed which is equal to, or less than the speed corresponding to the 17 position of the lever S, and a wheel of the car traverses one of the control sections 4, the associated timing relay G will close its front contact 10, and relay C will then become energized. When relay C becomes energized, the braking bars will be moved to their non-braking positions by the operating mechanism OM, and it will be apparent, therefore, that no further retardation of the car will take place unless relay C again becomes deenergized while a car is still within the limits of the retarder. The timing relays G are made sufficiently slow acting so that when one of these relays picks up its armature and closes its front contact II], it will subsequently retain its front contact closed until a car moving at control speed has traversed a distance equal to the length of one of the control sections, and it will be seen, therefore, that when relay C once becomes energized, it will subsequently remain energized until the car has passed out of the retarder unless the car speed again increases to a speed which is greater than that corresponding to the p position of the speed control lever S. Assuming that the car does this, then as soon thereafter as the timing relay G which last became energized has remained energizedfor a time interval of sufficient duration to cause it to release its armature and open its front contact l0, relay C will become deenergized and will subsequently remain deenergized because under these conditions none of the other timing relays will pick up its armature and close its front contact lfl. As soon as relay C becomes deenergized, the braking bars of the car retarder A will again move to their braking positions.

If while a car is passing through the retarder, lever S occupies its position or 32 position instead of its p position, the operation of the apparatus will be similar to that just described with the exception that the timing relays G will then pick up their armatures and close their front contacts ID at the car speed corresponding to the position which the lever then occupies, as will readily be understood from an inspection of the drawing and from the foregoing description.

One advantage of a speed control system embodying my invention is that changes in ambient temperature have substantially no effect on the operation of the system.

It is obvious that in a speed control system of the type described, and in all other control systems where timing relays or other equivalent are employed, it is desirable to be able to readily test when the relays are adjusted to operate in the proper time intervals in order to facilitate adjusting the relays and to check the operation of the system. To permit this to be done, I provide a test device J which I will now describe. The test device J in the form here shown comprises a contact drum K which is driven at a constant speed by a motor M, the brushes of which are connected with terminal posts l5 and I6 by means of wires l1 and 18, respectively. Mounted on the contact drum K are a plurality of contact segments I9, 20, 2|, 22, 23 and 24 which cooperate respectively with fixed contact hereinafter, the contacts l9 -I9-l9 and 20-- 20-23 are adapted to function only when it is desired to test whether the relays G are operating their contacts at the expiration of the proper time interval after the associated track relays pick up when lever S occupies its p position, and the parts are so proportioned that the contact l9 -lll9 will be closed during each revolution of the contact drum K for a time interval which is equal to the time interval during which one of the car wheels of a car which 3 is traveiing at the control speed corresponding to the 10 position of lever S occupies one of the control sections t, and that, the contact 29- 2c28 will become closed during each revolution of the contact drum K at the same time that the contact l9 -l9l9 becomes closed, and will subsequently remain closed for a time interval which is just a little less than the minimum permissible time interval allowed for one of the relays G to pick up its armature and close its front contact Ill following the energization of the associated track relay D when lever S occupies its 29 position. In a similar manner, the contacts ZI -Jl- ZI and 22 -2222 are adapted to function for testing the timing of the relays G when lever S occupies its 19 position, and the parts are so proportioned that contact 2 l -2 1-21 will become closed during each revolution of the contact drum K for a time interval which is equal to the time interval that a car 1,

wheel traveling at the control speed corresponding to the p position of the lever S would occupy one of the sections 4, and that contact 22 -22- 22 will become closed during each revolution of the contact drum K at the same time that the contact ZI -Z i-2 i becomes closed and will remain closed for a time interval which is just a little less than the minimum permissible time interval for one of the relays G to operate its contact after the associated track relay picks cupy one of the sections 4, and that contact 24 2424 will become closed during each revolution of the contact drum K at the same time that the contact 23 -2323 becomes closed and will subsequently remain closed for a time interval which is just a little less than the minimum permissible time interval for one of the relays to close its front contact In after the associated track relay D picks up when lever S occupies its p position.

The test device J also comprises a speed selector lever S for selecting which of the pairs of contacts l |9|9 -20-20 2l 2! 21 22 -22-2 23 -23 23 24 24---24 will function at any one time, a relay selector lever N for selecting which relay G will be tested at any one time, a push button P which must be depressed to test a relay, and tWo indication lights L and L for indicating when the relay which is being tested is operating within the proper time limits.

The speed selector lever S comprises a contact arm which is capable of assuming three positions indicated by dotted lines in the drawing, and designated by the reference characters 3 s and 8 respectively. When the contact arm 25 occupies its 5 position, it engages a fixed contact member 25 to close a contact 25- 25 when the arm 25 occupies its 8 position, it engages a fixed contact member 25 to close a contact 2525 and when the arm 25 occupies its 8 position, it engages a contact member 25 to close a contact 25-25 The contact arm 25 is connected with the terminal post I 6 through the push button P, wires 26 and 21, and lamp L and also with a terminal post 0 through the push button P and a wire 29. The contact members 25 25 and 25 are respectively connected by means of wires 38, 3'! and 38 with the contact members 59 2i=-, 2| 22 and 23 24 as will be apparent from an inspection of the drawing.

The fixed contact members I9 2 l and 23 are all connected together and are connected with a terminal post i by means of a wire 35. The fixed contact members 20 22 and 24 are also all connected together and are connected with terminal post 16 through wire 32, lamp L and Terminal post i5 is connected with a ial post 0 by means of a wire 34.

The relay selector switch N comprises an arm w ich may be selectively moved into engageth a plurality of fixed contacts a, b, 0, etc., .ny such fixed contacts being provided as there are relays G to be tested. The arm 39 of the switch N is connected by means of a wire 25 with the wires 26 and 21, while the fixed contact members a, b, 0, etc., are connected by means of suitable wires with terminal posts t i etc., respectively.

For reasons which will become apparent as the description proceeds it is desirable that the indication lamps L and L should become illumiated immediately upon their energization, and ese lamps are therefore preferably of the glow tube type, although any other form of lamp which will operate without time lag may be employed.

The timing device J is intended to be portable,

while in the drawing, it is illustrated dia- -..matically, it will be understood that in actual practice this device will be built into as small a housing as can conveniently be done, the various terminal posts, lights and switches will be mounted on a suitable top plate where they are readily accessible.

In utilizing the device J, if it is desirable to be able to test the complete system, the various terminal posts will be connected with the system by means of wires in the manner indicated by the clash lines in the drawing. That is to say, the terminal post t will be connected by means of a wire 40 with the side of the battery E which is connected to rail I, while the terminal posts t t t t t and i will be connected by means of wires 4|, 42, 43, 44, and 46, respectively, with one terminal of the relays D D D, D, D and D respectively, in such manner that if a. connection is made within the device J between the post t and any of the other posts t, a circuit will be completed for the relay whose terminal is connected with such terminal post. The terminal posts 0 and c are connected with each of the parallel circuits for relay C by means of wires 4'! and 48, respectively, in such manner that the closing of the front contact [0 of any one of these relays will complete a circuit from terminal post 0 through wire 41, the closed contact l0, and wire 48 to the other terminal post 0 The terminal posts 15 and 16 are connected respectively with the terminals B and X of the source.

In explaining the operation of the device J, I will assume that the speed control lever S occupies its 50 position and that it is desired to test the timing of the control relay G under these i conditions. To do this, the operator will first open switch Q to prevent relay C from operating the car retarder. He will then turn the speed selector lever S to its .9 position and the arm 30 of the relay selector N to the position in which it engages the fixed contact member a, whereupon he will depress the push button P. When the push button P is depressed, each time contact l9*l9l9 of the device J closes, a circuit for relay D will be closed which circuit may be traced from battery E through the winding of relay D wire 4!, terminal post i, contact member a of relay selector N, arm 30 of relay selector N, wires 3| and 26, push button P, contact 2525 of speed selector lever S wire 36, contact l9 |9|9 wire 35, and udre 40 back to the other terminal of battery E. Relay D will therefore become energized during each revolution of the contact drum K for the same time interval that this relay would become energized if a.

wheel of a car traveling at the control speed corresponding to the p position of the lever S traversed the control section 4, and each time relay D becomes energized it will complete the previously described control circu t for relay G. If relay G is adjusted to close its front contact at the expiration of the proper time interval, each time relay D becomes energized front contact I0 of relay G will become closed just after contact 2S 2020 of device J has opened, and under these conditions, lamp L will remain deenergized, but lamp L will become energized by virtue of a circuit which passes from terminal B through lamp L wires 27, 26 and 29, terminal post 0 wire 48, front contact ID of relay G wire 41, terminal post 0 and wire 34 to terminal X. If, however, relay G is adjusted to close its front contact ID in too short an interval of time, each time relay D becomes energized contact ID of relay G will become closed while contact 2G -2'3-2S of device J is still closed, and under these conditions, lamp L will become lighted by virtue of the circuit just traced, and lamp L will also become lighted by virtue of a circuit which passes from terminal B through wire 33,

lamp L wire 32, contact 20-20 wire 36, contact 25 of switch S push button P, wire 29, terminal post 0 wire 48, contact 10 of relay G wire 41, terminal post c and wire 34 to terminal X. If relay G is adjusted to close its contact at the expiration of too long a time interval,

relay D will not remain energized long enough to permit contact H] of relay G8 to close at all, and under these conditions, neither of the lights L nor L will become lighted. It will be seen, therefore, that if relay G is properly timed, lamp L will become lighted each time relay D becomes energized, but lamp L will remain continuously dark, and the operator will therefore be able to readily adjust the timing of this relay to the proper value by means of the resistance R if this relay is not already operating within the proper time interval.

If under the conditions just described it had been desired to test any of the other relays G instead of relay G, for example, the operator would have proceeded in the manner just described with the exception that instead of moving the arm of the selector lever N to the position in which the contact arm 30 engages the fixed contact member a, he would have moved the arm 30 of the relay selector N to the position in which it engages the proper fixed contact member.

If it is desired to test the operation of the timing relays when the speed control lever S occupies its p position or its p position instead of its p position, the operation of the test device will be similar to that just described with the exception that under these conditions the operator will move the speed selector lever S to its 5 or its s position instead of its 3 position.

As was previously pointed out, the device J is shown in the drawing connected with the speed control apparatus in the manner in which it would be connected for a permanent set-up. Under some conditions, however, it may be desirable to utilize the device J as a portable instrument and to test the timing of only one of the timing relays G. To do this the terminal post i and any one of the other terminal posts t would be connected by means of wires with the relay which it is desired to test in the manner shown in the drawing, and the terminal posts 0 and 0 would be connected with the circuits for relay C in the manner shown in the drawing. The operation of the test device under these conditions would be similar to that just described and it is believed that this operation will be readily understood from the foregoing and from an inspection of the drawing without further description.

One advantage of a test device embodying my invention is that the device may be manufactured so as to be very compact and will therefore be readily portable.

Another advantage of a test device embodying my invention is that the device is very simple to use.

Although I have herein shown and described only one form of car retarder control apparatus embodying my invention, and one form of test device therefor, it is understod 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, a car retarder associated with said stretch, a plurality of relays which are successively operated by the wheels of a car passing through said retarder for time intervals which depend upon the speed of the car, a plurality of contacts,

means controlled by each of said relays for operating a different one of said contacts at the saidicontactscomprising a contact drum driven at a constant speed, a first contact which becomes closed for a predetermined time during each revolution of said contact drum, a second contact which becomes closed during each revolution of said contact drum and which remains closed for a time interval which is just a little less than the time interval that said first contact becomes closed, two indication lights, a circuit for one of said lights including said plurality of contacts connected in parallel, a circuit for the other light including the second contact of said device connected in series with said plurality of contacts connected in parallel, a relay selector switch including a plurality of contacts, and a test circuit for each of said relays including said first contact of said test device and a different contact of said selector switch.

2. In combination, a stretch of railway track, a car retarder associated with said stretch, a plurality of relays which are successively operated by the wheels of a car passing through said retarder for time intervals which depend upon the speed of the car, a plurality of contacts, a speed control lever having a plurality of positions each corresponding to a different carspeed,means controlled by each of said relays for operating an associated one of said contacts at the expiration of different time intervals after said relay becomes energized depending upon the position of said speed control lever, and means controlled by said contacts for controlling the braking action of said car retarder, the combination with the aforementioned instrumentalities of a test device comprising a pair of contacts for each position of said speed control lever so controlled that the one contact of each pair will cyclically become closed for a time interval which is equal to the time interval that one of said track relays remains operated when it is operated by a car traveling at the control speed corresponding to the lever position for which said contact is provided and that the other contact of each pair will become closed each time the associated contact becomes closed and will subsequently remain closed for a time interval which is just a little less than the time interval that the associated contact becomes closed, a speed selector lever having a plurality of contacts, one corresponding to each position of said Speed control lever, a relay selector having a plurality of contacts one for each of said track relays, two indicator lamps, a push button, a circuit for one of said lamps including a source of current and said plurality of contacts connected in parallel, a plurality of circuits for the other lamp each including said push button, a different one of the contacts of said speed selector lever, said other contact of a different one of said pair of contacts, and said plurality of contacts connected in parallel; and a plurality of test circuits for each relay each including a corresponding contact of said relay selector, said push button, a differmultaneously with said first contact and which subsequently remains closed for a time interval which is slightly shorter than the time interval that said first contact remains closed, a circuit for said first relay controlled by said first contact, two indication lamps, a circuit for one of said indication lamps controlled by a contact of said timing relay, and a circuit for the other lamp controlled by a contact of said timing relay and said second contact connected in series. 10

JOHN W. LIVINGSTON.

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