US1039219A - Retarded-release valve. - Google Patents

Description

W. V. TURNER.

RBTARDBD RELEASE VALVE.

APPLICATION FILED IAN. 13, 1905. 1 ,039,2 1 9 Patented Sept. 24, 1912."

WITNESSES u opposing the to provide an improved va ve deviceoperatof all the brakes will be eected.y

UNITED STATES PATENT OFFICE.

WALTER V. TURNER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE COMPANY, 0F PITTSBURGH, PENNSYLVANIA,

A CORPORATION 0F PENNSYLVANIA.

RETARDED-RELEASE VALVE.

Application filedl January 13,

To all who/m, it may concem:

Be it-.known that I, WALTER V. TURNER, a citizen of the United States, residing in Tilkinsburg in the county of Allegheny and State of Pennsylvania, have invented a .certain new and useful Improvement in Retarded-Release'Valves, of which the following is a specification.l Y

This invention relates to automatic air brake systems, the principal object being ing u on an increase in train pipe pressure for re easing bra-kes, to retard the releaseof the brakes on the forward end of the train by temporarily closing or restrict-ing the brake cylinder exhaust port, whereby as the wave of increase `in train pipe pressure travels through the train pipe and actuates the triple valves at the rear end of the train, a. substantially simultaneous release WVith the present standard automatic air brake apparatus, as is well known, the release movement of the triple valve is produced `by an increase in train pipe pressure which accumulates rapidly at the head end of the train pipe, but requires some little time to travel to and actuate the triple valves at the rear end, especially on long trains, the result of this being that when a release is made before coming to a full stop, the head brakes are often released considerably in advance of the rear brakes thereby permitting a surgingahead of the forward end of the t-rain, while the brakes on the rear cars are still applied, which vaction is productive of violent shocks and strains andl often causes a break-in-two of the train.

In my prior application, JSer. No. 198,762, filed March 18, 1904, I have disclosed a triple valve having a retarding spring for movement of the valve from full release position, in which the brake cylinder exhaust port s fully open, to a retarded release position in which the exhaust port is restricted, and for normally returning the valve from the retarded position to full release position when the pressures substantially equalize upon opposite sides of the triple valve piston. This device is found to operatevery satisfactorily' in practice, but it is of course necessary to provide a spring of sufficient power to Specification of Letters Patent.

. pipe,

Patented sept. 24,1912.

1905. Serial N0. 240,902.

overcome the friction of the slide valve in order to return the same to full release position. On very long trains it is sometimes difticult, owing to the length of the train vto produce a sufficiently rapid increase 1n the pressure toward the rear end of the train, at the time of releasing the brakes, to cause the piston to compress the spring and move the valve far enough to restrict the exhaust port.I

According to my resent improvement, a smaller valve is usecFfor controllin the eX- haust and this is preferably in the orm of a graduating slide valve operated by the triple valve piston and mounted upon the main slide valve and having a limited relative movement for controlling exhaust ports in the main slide valve. By means of this construction a much lighter spring may also be employed, since it.need be only of sutiieient power to overcome thelfriction of the smaller valve, so that the action of the device wll be rendered more `sensitive and effeet a proportionate retard of the release even toward the rear end of long trains.

Another important feature of my present invention comprises means, operating at the time of releasing brakes, for momentarily reducing the pressure uponone side of the piston or other movable abutment operating the retarded release valve, whereby the valvev will be immediately carried to its extreme position for retarding tlierelease and then assume its proper position according to the rate of rise in train'pipe pressure corresponding to the relative location of the valve in the train from the head to the rear. While these features of my invention may be used in connection with an valve device for controlling the brake cylinder exhaust,

valve device, and this is arranged to momentarily open communication from thev triple valve chamber to the atmosphere or.

other space for the purpose of producing a momentary reduction on the auxiliary reservoir side of the triple valve piston at the time that the same moves `from service or: lap osition toward release position. The train pipe pressure then instantly moves the piston and valve to the extreme retarded release position in which the spring is compressed and communication is open for the feeding of air under pressure frein the train pipe around'the piston.

According to anothery feature of my invention, the valve device is provided with means: for closing or restricting the com,- munication from the auxiliary reservoir to the valve chamber in theretarded release position and for opening this communication as-the valve returns toits normal full release posit-ionA under the act-ion of theY spring as the pressure equalizes upon the pisto y 1n the accompanying drawing: Figure 1 is a sectional view showing my invention applied to a triple valve device, the section being taken on the line w-y of Fig.V 6, with the valve in normal full release position;

Fig. 2 a similar sectional view, taken onv the line yi/ of Fig. 6, and showing the valvel in service application position; Fig. 3 a similar sectional view, takensubstantially onl the line -a of Fig. 6, and showing the valve in position for 'venting the valve chamber to the atmosphere while moving to the retarded release posit-ion; Fig. 4

a similar sectionalview,onjthe line fia-y' of Fig. 6, showing'the parts in retarded release position; Fig. 5 a plan yview of the main slide valve seat; Fig. 6 a face view of the main slide valve; Fig. 7 a face View of the smallv graduating slide' valve; and Fig. 8, a similar view with t-he small extension cavity omitted. l y

According to the construction shown, the casing is provided with the usual piston chamber 1 and valve chamber 2, containing the `movable abutment or Vpiston 3, stem 4, main slide valve 5, and small graduating slide valve 6, the casing having the usual connection 7 to the train pipe which com` municates with the piston chamber 1. The end lof the valve chamber 'is'closed by. a cap 11, in which is located a resistance spring 9 and stop 10 `for engaging the end of the piston stem 4 when the piston movesfrom its normal release position farther inward voir port 12, and port 22 for venting airv from the valve chamber in a certain position of thevalve. in the small auxiliary or graduating valve 6 is formed a cavity 23 which may have a small extension 24, and this valve is preferably mounted to move with the piston stem upon the main slide valve and has'a certain lindependent movement relative thereto. A. ixed stop 26 limits the inward travel of. the main slide lvalve and defines its release position in which'the ports -19 and 20 register respec-l tively with the brake cylinder port 14 and Y exhaust portI 16. y When the system is charged up to the `normal standard pressure the parts or the around the piston 3 through the feed groove 8 to the valve chamber 2 and to the auxiliary reservoir through ports 21 and 12.," At the same time the brake cylinder is open to the atmosphere through ports 14, 19, cavity 23 and ports 20 and 16. When a service application of the brakes is made by reducing the train pipe pressure in the usualway, the pist-on with the small graduating valve first -moves outward until the headl of the piston.. stem engages the main slide valve,- during which f inoveifnent"l the` graduating valve uncovers the service port 18 and closes the xhaust ports 19 and 20 and the vent lport`22 inthe main slide valve.' 'The piston `continues its outward movement carrying along the main slide valve to-service position, in which it engages vthe usual graduat-V ing stem, as indicated in Fig. 2. During this movement of the main slide valve, the large port 12A is uncovered and the vent port 22 passes over theexhaust port 17, but yno air can escape, as the graduating valve 6N covers the port 22. 1n service'position, the

service Aport 18 registers with the brake cylinder port '14,. and air under pressure from the auxiliary reservoir ows to the brake cylinder, charging the same in the usual way. Ast-he auxiliary reservoir pressure falls to or slightly below that of the train pipe the piston moves the graduating valve to lap position in the ordinary manner, closing the service port 18 andthe port 21, uncovering vent port 22, and connecting ports19 and 20 through the cavity 23 and the restricted extension 24. When the train pipe pressure is increased for releasing the brakes, the piston starts to move the parts inward in this relative position, the first Apart of the movement serving to close the auxiliary reservoir portl 12 and to register 'the vent port 22 with exhaust port 17, as indicated in Fig. 3. 1n this position the piston stein engages the yielding stop l0, and as the air in the valve chamber vents to the atmosphere throughports 22 and 17 a very decided 'reduction in pressure isprof duced upon the auxiliary reservoir "sid-cof the piston, whereupon the train' pipe pressure acts to immediately force the piston to the extreme inward retarded release position, as shown in Fig. 4, compressing the resistance spring 9 of the yielding stop v10 until the main slide valve strikes the fixed stop 26. 1n this position the brake cylinder iso exhaust is closed when the 4small extension cavity of the graduating slide valve is omitted, as shown in Fig. 8, or restricted to the extent of the small extension cavity Q4 in the graduating slide valve as shown in Fig. 7, and the feed groove 8 opens communication from the train pipe to the valve chamber. The pressure then begins to equalize around the piston and the gradu ating valve will be held in a position in which the exhaust is closed or more or less restricted for a short period of time, depending upon the rate of increase in the train pipe pressure corresponding to the position of the triple valve in the train from the front to the rea-r end. When the engineers brake valve is thrown to release position for supplying air 'from the main reservoir to the train pipe in releasing brakes, the pressure builds up very rapidly at the head end of the train line, but as the Wave of increased pressure flows toward the rear, it is retarded by frictional resistance along the pipe until at the rear end of long trains the rate of increase is greatly diminished and an appreciable period of time is required to effect the release movement of the rear triple valves. During this interval the exhaust upon the forward cars is held closed or more or less restricted by the more rapid rate of increase in train pipe pressure in order to prevent the earlier complete re-l lease of those brakes and to secure a substantially simultaneous release throughout the train.

When the feature of venting air from the auxiliary reservoir side of the piston is employcd,it will be noted that each triple valve piston as it moves to release will ybe carried to its` extreme inner retarded release position, but at the rear end of the train the pressure Will immediately substantially equalize on opposite sides of the piston owing to the slow rate .of increase intrain pipe pressure, whereupon the resistance spring operates to return thel piston and graduating valve to f| ll release position'. By means of this feature it is not necessary to depend entirely upon the rate of increase in train pipe pressure over that of the auxiliary reservoir for e'ecting the compression of the resistance spring and the movement of the piston to its retarded release position, and the spring may then be of such strength as to readily return the valve to full release position when the desired relation between the pressures upon opposite sides of the piston is attained. It is not necessary to the practical operation of my invention that the valve chamber should be cut off from the auxiliary reservoir when the valve moves to retarded release position, although such is the preferred construction, since the vent port 22 may then be very v small, as it is only the pressure in the valve chamber that is reduced which causes prompt movement of the piston to its inner position. With this construction the grad uating valve then covers the portl 21, con- Y trolling communication with the auxiliary reservoir, so that as the train pipe pressurey is increased air fiows throughthe feed groove and raises the pressure in the valve chamher. Atthe head end of the train therapid increase in train pipe pressure will hold the piston and valve atits inner position with port 21 closed and the exhaust port closed or restricted until the pressure in t-he valve chamber has risen with that of the train pipe to near the equalization point, whereupon the spring operates to return the graduating valve toward normalreleasc position. But as soon as the port 2l is opened thev ow of vair from the valve chamber into the auxiliary reservoir, which is at a lower pressure, checks'the movement of thepiston and valve and the train' pipe pressure acting on the piston will hold the valve at this intermediate position until the auxiliary reservoir pressure rises to nearly that of 'the train pipe, When the spring acts to return the graduating valve and piston to full release position. The restricted portion of the exhaust'cavity may beso formed as to restrict the exhaust port either more or less as desired, at this intermediate position of the valve,and the extent to which the release is retarded upon the forward portion of the train may thereby beadjusted to suit different conditions. At the rear 'of the train, Where the increase in train pipepressure is slow, the valve will not pause materially at the intermediate position, but will be immediately. returned bythe spring to its normal full release position, since the pressure in -the valve chamber and the auxiliary reservoir will increase at substantially the same rate as the train pipe. At other portions of the train -the release will be retarded in proportion to the variation in, train pipe pressure from the frontY to the rear and ma)r be effected'substantially at the same time throughout the train, or, if desired, may be made to occur from the rear toward the forward end. Another advantage of controlling the auxiliary reservoir,port in the main u slide valve with the graduating valve isthat in normal release position the auxiliary reservolr 1s not cut off from the valve chamber and there 1s no danger `of failure to move the triple piston by a reduction in train pipe pressure. In emergency applications the piston operates under a sudden reduction in train pipe pressure to move the main slide valve out to emergency,position, in which the graduating spring is compressed and the auxiliary reservoir pressure equalizes into the brake cylinder through the ports 25 and 14 in the usual way.

y While I have described in detail one form laov of valve device, it is to. be understood that my invention is not limited to this construction but may be. lapplied to any valve device controlling a brake cylinder exhaust. 1t will also be evident that my invention may be employed either with or without the feature of-venting air from one side of the movable abutment in operating the valve, and that as applied to al triple valve device the valve chamber may or may not be cut 0E from the auxiliaryreservoir in' retarded release position.

Having now described my invention, what I claim as new and desire to secure by Letters/Patent is z- 1. A valve device for controlling-a brake cylinder exhaust, comprising a main valve having an exhaust port, or ports, a sec' ondary valve having a movement relative to 'the main valve for controlling said exhaust port, or ports, a ymovable'abutmentoperated by train pipe pressure to move said secondary valve to restrict said exhaust, and yielding resistance means for opposing the movement of said secondary valve to its restricted position.

2. In a `fluid pressure bra-ke, the combination wit-h a main valve having a brakecylinder exhaust port, a secondary valve having a normal full release position in which saidI port is fullyv open, and a retarded release position in which said port .is restricted, of a movable abutment operated by train pipe pressure :tor moving said secondary valve to its retarded release position, and

yielding resistance meansfor returning the same to full release positlon.

In a Huid pressure brake, the combina tion with a valve for controlling the brake cylinder exhaust,` and a movable abutment for operating said valve, olf means operating atthe time of releasing brakes for reducing u the pressure upon one side of said abutment to move said valve to restrict the exhaust port, and yielding resistance means for opposing this movement.

4f. A retarded release valve device for fluid pressure brakes, comprising a movable abutment -and valve for controlling the brake cylinder exhaust, means operating upon an increase in trainpipe pressure for causing a sudden variation of pressure upon one side of said abutment to move said valve to restrict the exhaust, and yielding resistance means for returning said valve to full release position.

5. A retarded release valve deviceA comprising a valve for controlling the brake cylinder exhaust and having a normal full 'release position and a retarded release position, a movable abutment subject to train pipe pressure for operating said valve, means operating upon an increase in train pipe pressure for venting air from one side of Said' abutment and moving said valve to retarded release position, and yieldingresistance means for returning the valve tov full release position. v

6. A triple valve device y comprising a main valve having Ja brake cylinder exhaust port, -fa secondary or vgraduating valve for ytion and a further inwardmovement for.

restricting said exhaust, a movable -abutment operated by an increase in train pipe pressure for moving said graduating valve to its restricted position, and yielding re'- sistance means-for returning same to its full release position.

8. yA triple valve device comprising a movhble abutment and valvel for controlling the brake cylinderexhaust, means operating at the time of releasing the brakesfor venting air from the auxiliary reservoirside of said abutmentto move the valve to restrict the exhaust, and yielding resistance means for returning the valve/to full release position. s j

49. A\`triple valve device comprising a main valve having a brake cylinder exhaust port, a` graduating valve .controlling said exhaust? and havmga normal release position and a further inward movement for restricting said' exhaust, a movable abutment operatedV by an increase intrain pipe pressure for moving said, graduating valve to its restricted position, a fixed stop for limiting the inward movement of the main slide valve, and a yielding resistance means for returning jthe graduating valve to its normal release position.

10. A triple valve device comprising a movable abutment and valve for controlling the brake cylinder exhaust and having a normal full release'position and a further .inward movement to a retarded. release position in which the exhaust is restricted, means operating upon the movement of the valve to release position forl reducing the pressure on the lauxiliary reservoir side of said abutment and means for-normally re-A turning said valve to its full release posin tion.

`111. A triple valve device, comprising a valve and a movable abutment subject to the opposing pressures ofthe train pipe and the auxiliary reservoir ier' operating said valve to control the' brake cylinder exhaust, means operated by anvmcrease in train pipe pressure when the brakes are applied,;tor Y venting airl from the auxiliary reservoir side i of said abutment and moving said valve to restrict said exhaust, and means for normally opening said exhaust port.

12. A triple valve device comprising a main valve having a brake cylinder exhaust port and a vent port, a graduating valve for controlling said ports, a piston subject to train pipe pressure for operating' said valves and having an inner retarded release position in which the exhaust port is restricted, andyielding resistance vmeans for returnin said piston and graduating valve to normal full release position.

13. In a fluid pressure brake, the combination with the train ipe, auxiliary reservoir, and brake cylin er, of a triple valve device having means operating under an increase in train ipe pressure for restricting the brake cylin er exhaust and closing communication ,from the auxiliary reservoir to the valve chamber, and means for normally opening said communication and said exhaust. V

14. In a fluid pressure brake, the combination with the train pipe, auxiliary reservoir, and brake cylinder, of a triple valve device having a piston and valve operating upon an increase in .train pipe pressure 'to close communication from the auxiliary reservoir to the valve chamber, to vent air from the valve chamber, and to restrict the brake cylinder exhaust, and yielding resistance means for normally opening the exhaust, and communication between the valve chamber and the auxiliary reservoir.

15. In a fluid pressure brake, the combination with the train pipe, auxiliary reservoir, and brake cylinder, of a triple valve device comprising a main valve having` a brake cylinder exhaust port and a vent port for the valve chamber, and a graduating valve and piston having a movementrelative to the main valve for controlling the said ports.

16. In a fluid pressure brake, the combination with the train pipe, auxiliary, reservoir, and brake cylinder, of a triple valve device comprising a main valve having a brake cylinder exhaust port, a port for controlling connnunication bet-Ween the valvel chamber and the auxiliary reservoir, and a vent port for the valve chamber, and a graduating valve and piston having a movement relative to the main valve for controllingsaid ports.

17. A triple valve device, comprising a piston subject to variations in train pipe pressure, a Valve operated bysaid piston for controlling the supply ot' fluid to and its release from the brake cylinder, and means for venting fluid from one side of said piston to cause the valve to move to release position.

18. In a triple valve, the combination of a main valve having a brake-releasing passage therethrough, a secondary valve conton is'in a trolling said release passage, a piston operatively engaging both said valves whereby said release passage is open when said pisosition intermediate its two extreme positions, and meansl tending to move I said piston and secondary valve from an extreme position to said intermediate position, i

19. In a tri le valve for air brakes, the combination o a main valve through which exhaust from the brake cylinder passes to release the brakes, a secondary valve controlling said exhaust, a valve-operating piston operatively connected to said main and secondary valves, said piston and secondary valve each having a full or unrestricted release position'an a restricted release position, and a spring acting on said piston and tending to throw it to the full or unrestricted release position.

20. In a triple valve for air brakes, the combination of a main valve through which exhaust -from the brake cylinder passes to release the brakes, a secondaryl valvecontrolling said exhaust, a valve-operating piston operatively connected to said main and secondary valves, said iston and secondary valve each havin a ful or unrestricted release position an a restricted release position, and means acting on said piston and tending to throw it to the full or unrestricted release position.

21. A triple valve device, comprising a piston, a main slide valve controlling a brake cylinder exhaust, an auxiliary valve operated by the piston to have a small movementrelative to the main slide valve, and a yielding means for moving lthe auxiliar valve relative to the main slide valve to e fcct a free opening of the brake cylinder exhaust. i

22. A triple valve device, comprising a main valve, an auxiliary valve having a lsmall independent movement relative to the main valve, and a piston for actuating said valves, and having means operating under aninc'rease of train pipe pressure at the forward part of the train to retard the release from the brake cylinder, and a spring for causing a movement of the auxiliary valve relatlve to the main valve to effect the tree opening of the brake cylinder exhaust.

23. A triple valve device, comprising a main slide valve controlling a brake cylinder exhaust, a graduating valve having a. small independent movement relative to the main valve, a piston for actuating said valves, and having means operating under an increase ot' train pipe pressure at the forward partl of the train for restricting the brake cylinder exhaust, and ayiclding resistance spring for moving the graduatin valve relative to the main slide valve to e feet a free opening of the brake cylinder exliaust.

2 4. A triple -valve Adevice comprising a in aln slide valve, an auxiliary valve and piston having a normal release position in which the brake cylinder exhaust is lfully open, and a further inward movement relative to the main valve to a retarded release position in which the exhaust from the brake cylinder is restricted, and means for return i ing said auxiliary valve to its normal position. v

25. VA triple valve device, comprising a main slide valve, an auxiliary slide Valve and piston having a slight movement relative to the main valve and a normal release position in which there is a free exhaust p from the brake cylinder, and a further in- Ward retarded release position, and a yielding resistance spring for returning the auxiliary valve and piston relative to the main valve from said inward position to normal release position.

' 26. In a fluid pressure brake system, the combination of a triple valve having a iston, ar main valve With lost motion an a secondary valve operated by said piston,l and a passage for releasing'brakes controlled by both saidvalves, which may be restricted 'While the piston is moved to one limit of its traverse by increasing `train pipe pressure and then opened when the secondary valve makes a partial movement in the opposite direction.

27. In a fluid pressure brake system, the

combination of a triple valve havingapiston, a main valve with lost motion and a secondary valve operated by said piston, a passage for releasing-brakesso controlledv by both valves that the passage may be re'- stricted While the piston Ais' actuated by admit-ting train pipe pressure and opened when the piston and secondary valve make a partial movement in the opposite direction, and means for causing said partial movement.

28. In a fluid pressure brake system, the combination, With a, triple valve having a piston'capableof occupying three positions, one of Which is intermediate the other two, amain and a secondary valve operated thereby, a passage controlled by both valves for releasing brakes, which is open while the piston occupies its intermediate position and a spring orymoving the pistonl and secondary valve from one extreme to said intermediate position. v

29. In a fluid pressure brake syst-em, the combination, with a triple valve having a piston, a main valve, and a secondary valve operatedthereby, of a passage through the main valve and controlled by the secondary valve for releasing brakes, `which is opened While saidpiston occupies an intermediate position between two outer`positions and meansfor moving saidipiston from one of my hand.

WALTER V. TURNER. Witnesses:

R. F. EMERY,

J. B. MAoDoNaLD. v

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