US2048328A - Retaining valve device - Google Patents

Description

Patented July 21, 1936 UNITED:

PATENT OFFICE- 2,048,32 1 RE'rnIN G VALVE DEVICE Clyde 0. Farmer, Pittsburgh, Pa., assignor to The Westinghouse [Air Brake Company, Wilmerding, Pa.,' a, corporation of Pennsylvania Application August 17, 1932, Serial No. 629,117 4 Claims. (cum- 9 This invention relates to retaining valvedevices of the type employed ,on railway cars for retaining fluid under pressure in the brake cylinders'when, in gra'de service; the brake equipment '5 on a train is being recharged with fluid under pressure. U 3 I r The retaining valve devices now in common use n cars employedineithr freighter passenger service are adapted, when turned upto their-pres- 10 sure retaining positiong to retaina predetermined fluid pressure in the brakefcyliridersformain taining'the brakes appliedwhile the-brake'equip ment is being; recharged'with' fluid under pres l Preparatory to"descending a -grade, it lsthe usual practice to bring the train: to a'stop and to then turn the retaining valvedevice s-to their pressure retaining position. Att hef bbttom--"of the grade the train isjagain brought- -to a stop "20 and the retaining'valves'turn'ad to their normal to the atmosphere-as is well knot/n. g I In passengenfimail, expressand'like servica it maynot'be desirable to bring'thetrainto a stop position," in which the brakefcylinders are open 25 preparatory to descending a gradeand'when such is the casefthe retaining valve fdevices' 'must be "turned to their pressure retaining position, while the train is in motion; Since: in these c asses-of service, it is objecticnableto have the' trainmen "3'0 .pass'throughsome of the cars of the trainQ'oriIy those retaining "valve devices "which' areacces- 'sible' to the trainmen will be turned to their pressure retaining position and f n ay result in 'only aiew of the retaining valve devices being 35 turned to their pressureretainingposition; This Fisfof course, objectionab1ein that it causes-excessive wear of the brake shoes and wheels of the cars on'which'the retaining-valvedevices are in their pressure retainingposition and is 40 further objectionable in that it resultsin excessive air consumption due to the-brakecylinders,

-on the'cars-where the retaining valve devices device for fluid pressure brakes whichjmay be turned up, i. e., turned to pressure retaining position, preparatory-to a train entering a grade territory and which may be left turned up until after the train is out of the territory, even 5 though the territory may have level stretches and ascending grades which the train must traverse, and even though the train should be stopped at or between stations, thus eliminating the before mentioned difiiculties' which are experienced with the ordinary retaining valve device.

To attain this object I provide a retaining valve device which, when turned to pressure retaining position, will function in substantially the same manner'as the ordinary retaining valve device to vent fluid under pressure fromthe brake cylinder until the brake cylinder pressure has been reduced to a predetermined degree, and

will then function to continue the venting of fluid from the brake cylinder to insure the'complete release of the brakes. This final venting of fluid from the brake cylinder is at a. slow rate through a restricted passage formedin either the retaining valve or in the valve casing and is for the purpose of insuring the brakes remaining applied for a predetermined period of time after the retaining valve has been moved to its pressure retaining position. 1

Other objects and advantages will" appear in the following more detailed description of the invention.

fIn the accompanying drawing; Fig. 1 is a central sectional View of a pressure retaining valve device embodying my invention; the device beingshown in its normal or turned down position; Fig. 2 is a similar sectional view showing the device turned up, i. e., turned to its pressure retaining position; Fig. 3 is a fragmentary sectional view of 'the device taken onthe line 3-3 of Fig. 1 and Fig. 4 is a fragmentary sectional 40 view-pf a pressure retaining valve device embodying another form of my invention, the device being shown in its pressure retaining position.

As shown in the drawing, the pressure retaining valve device may comprise the usual casing l having mounted therein a plug valve 2 which is ad'aptedto be rotated through the medium of the usual handle 3. With the handle 3 in its normal positionas shown in Fig. 1, a portd in the plug valve 2 connects abrake cylinder exhaust passage 5 to a passage 6, which is open to the atmosphere and with the handle turned-up as shown inFig. 2-, the port! connects the brake cylinder-massage" 5 to an exhaust passage 1 in anecasmgr A hollow cap 8 is provided which has screwthreaded connection with the casing I, said cap and casing defining a chamber II] which is open 7 to the atmosphere through the usual small exhaust port ll. Contained in this chamber is a retaining valve I2 which is operative to control a, communication from the passage 1 to the chamber Ill. This valve is normally maintained seated on the seat I 3, provided on aseat" member 'seat member l4, the spaces l9 between t e flat sides of the stem and the circular wall permitting the flow of fluid from the passage I to the enam- 7 ber lllwhen the valve l3 isunseated.

' bein l e restricted v passage ;2 U extends centrally through the valve l2 and stem l 'L-andat all times establishes communicationirom the passage] to thechamber I- 0. .{I'he restriction-islocated atthe outlet end of the; passage and is of considerably ess. len t t the rem i in re e r h passageg By thus making themain portion of {the passageof greaterdiameter than therestrictedwpqrtion, he. poss y of the est i dgpo tion becomingjclogged with dirt brother matter s-.re. iuee e;a' m im m- .h or

.ilu onerat qn, when the ha d e, 3 f th e a ninavalre-d i nrpressure et in ng pos t on, a OWIl1i l Fiaflu d unde rp e e from the brakecylinder flowsto the'under side of thee-val ew z-br w yq pa a Pa t4 nt p u Jvepas a e 1 and spaces I9 b t -the Ye YeLstem a nte io c rc ar a o the valve ea m rnberil- Fluid u d r r s t u en ;e r m t e brake cy inder c u e e v e t e :un's e ed a ai st the,.oppq n ip es ur e the spr ng; I 5 h. 1 o enin qv men l-ef e valve .cted. bro h r v ve eneae e the i e e d o ge to me be li h eh s u ym m e ;the n he st nm mb rpl e serves uidee ereth ee of thespr n 5- ,7 .r a

' Fluid from the brake cylfnder flowspast-the 91 1 v ve-J2. nd th ou h he Pas a e 9..t9; Leh mber; lltahdi mthen flows to e t sphere by way of the port I I. I w rhe underet dth c W hie .w lp wil iiil :ir mth 'brake c i er m eet bet et e l fthe same; rate as that provided iorinthe usual eta nin ra e e Now when the bra]; cylinder pressurejhas' been el uees t su h a. degr e that it c nlonger holdth'eyalVe i2 unseatedgthe s prihgflli acts'to seat the Vall/- Wit h ire 'v Q QLWQQ or exhaus r m bra e ylin 2 th Ichamber i0 is byway ofthe'restricted passage 20 in thevalve. If a subsequentapplica'tion of the b rakes isnot-effected within a predetermined period Fortun the r e cylinder willbeb inneemqep e ee Q fluid under P es e-H Th jfiow of fluidirom the brake cylinder to theiatm rhere byway ere tfie w s?" a ,port l l is preferably at such a slow rate as to preventthe complete release of thebrakes during fthe p eriod of timenormally required to recharge th brak e ui men L In f l qd'fi d f ie ii v inv nti n s iillll ft d 1 1 whi h a restr ted passa zl em- 1 is constantly open to the valve chamber l0.

' vid d in the eae heg hr ll h Wh eh;t .p a

. seats and will also insure the complete release of 'the brakes when said predetermined period of time has "elapsed.

My improved retaining valve device is particuflar lyadaptedror 'use on cars to be employed in "passeng'l'erandlikeservice, but it is to be understobdthat I'odntem'plate its use on cars to be em- .Vployed in freight service.

While two illustrative embodiments of the inventionhave been described in detail, it is not my intention to limit its scope to these embodiments orE-otherwise than bythe "terms of the appended claims. H H o. ---I-Iavi n g= now described rny invention, -what I claim asinewjand desire to secure by Letters Patent, is:

' -1.;-iA wbrakeicylinder pressure retaining valve device comprising a casing having an exhaust portend :a exh ust-pa s hrou h wh ch-fluid is adapted to be vented from the brake cylinder when; the device is in brake cylinder pressure-retainina p sition, said exhaust port being-rstricted t provide fora'retardedflowoflfluid fromthe' brake cylinder while the brake cylinder pressure is -being reduced to that whichit is usual to-r tain,--a valve ,in said'c asing controlling communi- =et na r m:theexh u t-haae e to t eXhefiT-et Po t. sa d va v b n ere veb eiheutt ilow of iiuid from the bralge cylindertozopensaid eem henieet en an e eretir whe the k eywl pde ere s r h te r e d e' he retained pressure to close; said communication, and a restricted passage byi-pas'singf said" valve having a smaller flow area thanith'atbf the .ieet ietedeee let er "t iu t r it d the State of how of fluid from the brake Tcyliiidr'whn the valve closedj and to insure theconiplete venting of b from-thebrake'cylindr. f

V I 2, "a brake tunner Iprssure retaining" valve ideyi'oekcomprisihg a casing'having'an eihaiist 0 port nd an e haustpassag'thraugifwmehfiuid isfadapte'd to be engearrom' 'the'brakecyliiidr wh n the device is brakeeynnaertpressurereg pdsition, said "'irhaust part beir'ig reed te;.-= 2 7 fsie. ut i r ar e of fliiid l lq xt e a ieey iede whi etfie'b' cilifiiier press isbeing reduced to that which'it is usual to reta1n, a valve in said casing controlling communication from the exhaust passage to the e):- eust ee -treaii val be p et r l y -1 haust fio w of lipid from the brake cylinder to open "said communication and --operative when the brake'cylinderfpressure has been reduced to the is adapted to be vented from the brake cylinder when the device is in brake cylinder pressure retaining position, said exhaust port being restricted to provide for a retarded flow of fluid from the brake cylinder while the brake cylinder pressure is being reduced to that which it is usual to retain, a valve in said casing controlling communication from the exhaust passage to the exhaust port, said valve being operative by the exhaust flow of fluid from the brake cylinder to open said communication and operative when the brake cylinder pressure has been reduced to the usual retained pressure to close said communication, and a by-pass port extending through said valve connecting said exhaust passage with said exhaust port, the by-pass port, for the greater portion of its length, having a relatively large flow area and, for the remainder of its length, having a flow area less than the flow area of the restricted exhaust port for further reducing the rate of flow of fluid from the brake cylinder when the valve is closed and to insure the complete venting of fluid from the brake cylinder. 7

4. In combination with the brake cylinder exhaust pipe of a fluid pressure brake equipment, a pressure retaining valve device having a valve normally establishing a communication through which fluid under pressure is adapted to be completely vented from the brake cylinder at the usual release rate and manually operative to a position 'for closing said communication and for establishing another communication through which fluid under pressure is adapted to be completely vented from the brake cylinder, and means for varying the rate of flow of fluid through the last mentioned communication, said'means comprising a choked exhaust port to provide for a retarded flow of fluid from the brake cylinder, a valve interposed in the last mentioned communication and operative by fluid under pressure vented from the brake cylinder to permit the free flow of fluid under pressure from the brake cylinder exhaust CLYDE C. FARMER.

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