US1302984A - Triple valve - Google Patents

Description

J. R. SNYDER.

TRHLEA VANI/E.lv 41,302,984-APPLICATION FILED JUNE R ,Pa-te-nted 6, FIG.1

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JACOB RIJ'SH SNYDER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PERCY E.

DONNER, 0F PITTSBUR GH, PENNSYLVANIA.

Application led .Tune 10, 1914, Serial No. $44,275. Renewed February To all whom t may concern l 1 Be it known that I, JACOB RUSH SNYDER, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania., have invented a new and useful Improvement in Triple Valves, of which thek following is a specification, p

This invention relates to triple and control valves for air brake systems. n

The object of the invention is to provide 4means in conjunctionwith triple-and control valves whereby upon service reductions in train pipe pressure the valve is prevented from accidentallyn going to quick action or emergency position. y

W'ith' present forms of quick action triple and control valves for freight and passenger cars and locomotive service, it frequently 19 happens that the main piston fails to move to service application position upon initial service reductions of train pipe pressure. This is due to a variety of causes, such as insufficient or imperfect lubrication, improperly :fitted packing rings, binding of packing rings and pistons, dirt in the valve, and numerous other causes. As a resultof kthe failure of the triple valve to move upon initial reduction of train `pipe pressure, substantially the full auxiliary reservoir pressure is retained on the auxiliary side of the main piston. Consequently, whenthe valve moves under the second or third reduction of train pipe pressure, this excess pressure on the auxiliary reservoir side moves the piston over so violently that the standard graduating spring does not stop the valve in service position, as a consequence ofy which anundesired quick action or emergency application `is `brought labout. means the pulling out of draw barsforsome other serious injury tothe train.

The object of the present invention is to provide a1 `triple or type where train pipe pressure is vented to the brake cylinder in quick actions, .with means whereby the undesired quickk action on service reductions of train `pipe pressure cannot occur, no matter how much the triple valve piston may stick. f

The invention comprises the construction and arrangement scribed and claimed. v

In the accompanying drawings Figure 1 is a longitudinal section through a portion of Specification of Letters Patent.

VThis invariably i control valve ofthe i of parts hereinafter de? Patented May 6, 1919. 17, 1919. serial No. 277,651.

a `triple valve with the improvements applied thereto showing' the same .in normal `or running position, and Fig. 2 1s a longitudinal vertical section through the same parts, but taken Von a different plane from that of Fig. 1, and also showing the parts in normal or running position.

'The improvementsof this application, are applicabile to that type of triple valve in which the main piston in en ergency position kunseats a valve for admitting pressure from the train pipe to the brake cylinder, and more particularly a triple valve in which the emergency valve is actuated by the graduating stem, such as shown in m applications Serial N o. 727,542, led Oct. 24, 192114? and Serial No. 818,571, led Feb. 13,

Only a portion otthe triple valve is shown, as it is not importantI just how the ports inthe main valve seat are arranged. In the drawings, 1 indicates a portion of the main casing in which is the usual bushing 2 inclosing a chamber 3 which is open to the train pipe through the train pipe passage l and inwhich chamber works the main piston 5. This piston operates slide valves of any preferred` type and under variations of train pipe pressure efi'ects'the usual functions of applying and releasing the brakes. In thephead 6 is slidably mounted the lgraduating stem 7', which is acted against by the graduating spring 8, and which serves in the outward piston 5 under gradual or service reductions 'of train pipe pressure to arrest said piston 5 in service application position` as will be understood. Surrounding the graduating stem 7 is a bushing'lO in which is a cavity lli communicating with the passage-l2 leading` to the brake cylinder.

provided with ka collar 16, which sleeve and collar are so located with reference to each other that the stem is free to move outwardly under service .reductions without contacting with sleeve 15, but upon emergency reductions of train pipe pressure the full'outward travel of the main piston moves the graduating stem 7 outwardly so far that collar 16 engages sleeve 15 and unseats the valve 14.

movement of the main :tion .of service train pipe lowing arrangement is provided. The valve :514 is carried-by la piston The'chamber 17finthe outer :portion of the head 6 is open to train pipe pressurethrough port 18 and passage l19 so that the unseating of thel valve 14 permits train pipe pressure to flow through the cavity 11 and passage 12 to the brake cylinder, thereby securing the local venting of the train pipe necessary for..quick or emergency action. The vvalve. 'so 'far described may be in all particulars the :same VAasx; hat described and illustrated in my applications. above referred to, but

the main lslide y,valves `(not herein illustinted) .may u In. orderito prevent the undesired be or any other suitable type. quick lactionci the triple valve iii case the piston Vshould stick during the initial'service reduc- ;tions .of train p ipe pressure and move outa later reducwardly with great Jforce under the folpressure,

21, which works in the chamber 17 and whose outer face is constantly open to the train' pipe pressure in said chamber' 17', while its inner face is in part normally open to atmospheric pressure in the cavity 11 (due to the brake cylinders beiiigreleased) and in part-to a pressure ber' 22 and normally equal to train -pipe pressure, to-wit, in the annular chamber 22 which is connected to chamber 17 by means of a suitable equalizing passage, shown as an opening 2 3 through the piston 21. and is controlled by a check valve 21 opening toward the annular chainheld to its seat by a vlight springl 25.V An additional equaliziiig v passage-is also provided between chambers 17 and 22, and is shown as a small port 26 through the check valve 24, but may be -a lport or passage located at any other posi- Y for onlythat portion of its area represented bythe annular space Y22, the central portion ofthe pistonbeing srbject tofatmospheric pressure. The piston is furthermoreheld against the seat on bushing 10 a graduating spring 8 acting through the' graduating stem and holding collar16 against the outer face ofthe piston. In normal or running position the pressures vin chambers 17 and 22Jare equal to Ieach other and to the train pipe pressure. f f v Upon service reductions .of train pipe pressure the piston 5 moves outwardly, and such outward movement ordinarily is arrested by the graduating-spring 8, which ordinarily brings the piston to rest in service position before the collar 16 contacts with the sleeve 15. Should, however, the piston stick during initial service .reductions of train pipe pressure, and move under a subsequent service reduction of train pipe pressure (and with a `greater force), it will nevertheless be' arrested as Y soon as the. collar 16 vcontacts withithe sleeve 15, being then resisted not only by the greater resistance of spring 8 (which has ecome considerably compressed), but also by the di'ferentialpiston 21, the differential of which will be made suiiicient to overcome any excess pressure likely to occur on theauXiliary reservoir side of the main piston. Consequently, the device shown will to a large extent prevent the undesired quick action of the vtriple valve, as above described. A service reduction of pressure necessarily reduces the pressure in chamber 17 but the pressure in cha nber 22`will always equalize therewith through the equalizing port 26, whichis large enough to permit such equalization as rapidly ductions. This equalization takes place each time the train pipe pressure is reduced for service application, and entirely irrespective of vwhether the main piston has moved or not. Consequently, the piston 21 is always a differential one in service reductions;

Then however, the train pipe pressure is suddenly reduced, such as by an .emergency application, or `by a burst vhose, the reduction in chamber 17 is so rapid that the small port 26 is not suiiicient to equalize chamber 22 with chamber 17. Consequently, thediferential value of the piston 21 is destroyed, so that the sudden outward movement of the main piston 5 will,- when the collar 16 contacts with the sleeve 15, move the piston 21 outwardly, thereby unseating valve 1li. This permits the pressure in chamber 22 to t once escape to the brake cylinder, there- Y pressure on the inner face of piston 21. In order to prevent the valve 111 from again immediately seating under the pressure in chamber 17, the check valve 24 is provided, which is merely held to its seat by the light spring 25, so that as soon as the pressure in chamber 22 is reduced, this check valve opens and admits air in a relatively large volume to chamber 22. The vpassage controlled bythe check valve 24 is larger vthan the port 18 connecting chamber 17 with the train pipe and yconsequently the pressure from chamber 17 will equalize into chamber 22 and prevent the piston from again seating valve 24, and, indeed, the piston will continue to move outwardly until it unthence to the brake cylinder thus providing as required in service realmost instantly entirely reducing the iso` for the necessary local venting of the train pipe to secure the quick action of the brakes throughout the train.

The invention described is applicable to any form of triple valvein which the outward movement of the main piston unseats the emergency valve, and the actuation of the. supplementary devices is dependent upon the differential eiiect of the supplementary piston, which differential eEect Y must be suiiiciently great to assist the graduating spring in preventing the main piston from moving outwardly sufficiently to unseat the train pipe vent valve under any such differential pressure as the main piston may be subject to in service reductions of train pipe pressure when the main valve sticks.

WhatI claim is l. In a triple or control valve mechanism, the combination of a main movable abutment 'actuated by variations of train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brake cylinder, and brake cylinder and atmosphere, anda supplementary abutment subject on one side to train pipe pressure, on

a portion of its opposite side to an equal trapped pressure and on a portion of said side to a lesser pressure, said supplementary abutment controlling a train pipe vent valve, and a check valve controlling a communication between the two faces of said supplementary abutment and seating toward the train pipe side thereof.

2. In a triple or control valve mechanism, the combination of the main movable abutment actuated by variations of .train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brake cylinder, and brake cylinder and atmosphere, a train pipe vent valve arranged to be opened by the movement of the main piston under emergency reductions of train pipe pressure, a supplementary movable abutment acting against such train pipe vent valve and subject on one face to train pipe pressure, on a portion of its opposite face to an equal trapped pressure, and on a portion of said side to a lesser pressure, and a restricted equalizing port connecting the faces of said vent valve.

l"3. In a triple or control valve mechanism, the combination of the main movable abutment actuated by variations of train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brake cylinder, and brake cylinder and atmosphere, a train pipe vent valve arranged to be opened upon movement of the movable abutment under emergency reductions of train pipe pressure, a supplementary movable abutment acting Vment actuated by variations the combination of against said emergency valve and open on one face to train pipe pressure and on a portion of its opposite face to an equal trapped pressure, a check valve controlling communication between the two faces of said movable abutment and seating toward the train pipe side thereof, and a restricted equalizing passage between the two faces of said movable abutment.

4. In a triple or control valve mechanism, thev combination of the main movable abutof'train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliarv reservoir and brake cylinder, and brake cylinder and atmosphere, a supplementary abutment subject on its opposite faces to varying pressures and a check valve controlling communication between the two faces of said supplementary abutment and seating toward the train pipe side thereof.

5. In a triple or control valve mechanism,

the main movable abutment actuated by variations of train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir-and brake cylinder, and brake cylinder and atmosphere, and a supplementary abutment subject on one side to train pipe pressure and on a portion of its opposite side to an equal trapped pressure, said supplementary abutment controlling a train pipe vent valve, and a check valve controlling a communication between the two faces of said supplementary abutment andseating toward the train pipe side thereof.

6. In a triple or control valve mechanism, the combination of the main movable abutment actuated by variations of train pipe pressure and eifecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brake cylinder, and brake cylinder and atmosphere, a graduating stem and a graduating spring arranged to cont-rol the movement of said movable abutment, a train pipe vent valve slidable on said graduating stem and arranged to be opened by the movement of said graduating stem outwardly under emergency application movements of the movable abutment, and a diiferential piston mechanism operable only upon emergency reductions of train pipe pressure and arranged to prevent the unseating of said vent valve under service reductions of train pipe pressure.

7. In a triple or control valve mechanism, the combination of the main movable abutment actuated by variations of train pipe pressure and effecting the usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brake cylinder, and brake cylinder and atmosphere, a graduating stem and a graduating' spring arranged to control the movement of said mov able abutment, a train pipe vent valve slidable on said graduating stem and arrange to be opened by the movemen-t of said gradportion of its. inner face to an equal trapped pressure, and an equalizing connection between the two acesoi said abutment arranged to permit equalization under service reductions of. train pipe pressure but prevent equalization upon emergency reductions of train pipe pressure.

8. In a triple or control valve mechanism, the combination of themain movable abutvment actuated by variations of train pipe 20` pressure and effecting he usual combinations between the train pipe and auxiliary reservoir, auxiliary reservoir and brakeY cylinder, and brake cylinder and atmosphere, a graduating stem and a graduating` spring arranged to control the movement of said Copies of this patent may be obtained Ior veleents eaeh, .by `adclressingthe youter face to train pressure,

ranged to be opened by. the movement o-said graduating; stem outwardly under emergency application movements of the movable abutment, a supplementary movable abutment acting 4onsaid vent valve and subject on its pipe pressure and on a portion of its inner faceto. an equal trapped pressure, an equalizing connectionbetween the two faces of saidabutment arranged to permit equalization upon service reductions of train pipe pressure but prevent equalizartion upon emergency reductions of train pipe and a passage between the two faces of saidmovable abutment controlled bya eheck valve seating toward the train pipe side thereof. l

In testimony whereof` Iliave hereunto set my hand.

JACOB y'ansia sNYDnn.

Vitnesses;

ELBERT L. HYDE, GLENN H. LERESGHE.

Commissioner of Patents,

Washington, 1). 0.

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