US1855135A - Test rack - Google Patents

Description

April 19, 1932. w. F. MEIER TEST RACK Filed Feb. 15, 195o E mE C mw. mm mn? ERPNL MEAUEv E LRR Patented pr. 19, 1932 UNITED STATES PATENT o1-*Fica Y WILLIAM' EAVMEEB', OF NILKINSBURQ PENNSYLVANIA, ASSIGNOR TO THE W'ESTING- HOUSE AIR BRAKE COMPANY, 'OF WILMER-DING, PENNSYLVANIA, A CORPORATION 0F PENNSYLVANIA TEST RACK Y Application filed February 15, 1930. Serial No. 428,655.

This invention relates to testing devices of the type employed to check the operation of fluid pressure brakes.

When railroad cars are in the shop for repairs, or prior to coupling a locomotive to a train of coupled cars for movingthe train in service, it is customary to test the operation of th-e brake controlling devices on said cars. For this purpose, a portable testing apparatus is provided which is adapted to be connected to the brake pipe at one end of a train of coupled cars and is operative to vary the pressure in said brake pipe for causing the operation of the valve devices on the cars in the train. If any of the valve devices are thereby found to be unsatisfactory for service operation, they may be removed or replaced.

The principal object of my invention is to provide an improved testing apparatus of the above character.

In the accompanying drawings: Fig. 1 is a diagrammatic view, partly in section, of an improved fluid pressure brake testing apparatus embodying my invention; and Fig. 2 is a diagrammatic development view of the brake valve device shown in F ig. 1.

As shown in the drawings, the testing apparatus comprises a ,brake valve device 1, a cont-rol valve device 2, a release check valve device 3, an application check valve Adevice 4, a diaphragm cock 5, a diaphragm cock 6, a three-way plug valve device 7, a duplex pressure gauge 8, a main or supply reservoir 9, a control valve reservoir 10, and an equalizing reservoir 11.

The brake valve device 1 is of the usual well known construction comprising a casing having a chamber 12 containing a rotary valve 13 adapted to be operated by a handle 14.`

In said casing is disposed the usual brake pipe discharge valve mechanism comprising an equalizing piston 15 having at one side a chamber 16 connected to the equalizing reservoir 11 through a passage and pipe 17, and

a brale'. pipe discharge valve 18'contained in a chamber 19 at the opposite side of the equalizing piston 15 and adapted to be operated thereby. Preferably associated with the brake valve device 1 is a feed valve device Y2O which is of thek usual `well known constructioniand isk adapted to reduce the pressure of fluid supplied thereto from anyV suitable source, such as the supply reservoir4 9, to a pressure such as is employed in a brake pipe' 21 for operating the brakes on ya train,y as will be evident from thefollowing more detailed description of the operation of my invention.

The-control valve devi-ce 2 comprises a casing containing a diaphragm 22, and a valve 23 contained .in a chamber 24. Follower plates 25 and 26` are clamped to the opposite sides of said diaphragm by a cap screw 29,

extending through the follower plate 25 and vdiaphragm 22, and having yscrew-threaded engagement in the follower plate 26. The valve 23 has a stern 27 engaging the follower plate 26 so that deflection of the diaphragm 22 in a downwardly direction'will unseat said valve againstxthe pressureofa spring. 28. A chamber 30 formed at oneside of diaphragm 22 is connected through a-.passage 31 to a pipe 32, which is connected tothe control lvalve reservoir 10, and a chamber 33 at the opposite side of said diaphragm isconnected to brake pipe 21 throughports 34 anda passage 35.

The release check valve device 3 comprises l a casing having* a chamber 36; containing a 'poppet valver37` and a spring 38 engaging said poppet valve for urging, same into lengagement with a seatrib 39 vformed inthe The chamber` 36y is connected by a casing. passage 40 to the control valve reservoir pipe 32 and a chamber 41 formed in the casing at the lowerside of said poppet valve is connected by a passage to brake pipe 21.

The application checlr valve device 4 comprises a casing having a chamber 42 containing a poppet valve 43 and a spring 44 engaging said poppet valve for urging same into engagement with a seat frib45 formed in the casing. The chamber 42 is connected by a passage 46 to a pipe Vv47 and a chamber 48p formed in the casing at the lower Side of the poppet valve 43 is connected-by a passage 49 to the control valve reservoir pipe 32. i

The diaphragm cock 5 comprises a casing formed of a body section 51 and a cover sec-` tion 52. AfleXible diaphragm 53 is clamped adjacent its periphery between the body section and cover section of said casing. A follower plate 54 is disposed on one side of said diaphragm. One end of a screw 55, having screw-threaded engagement in the cover portion 52 of the casing, engages sai-d follower and the other 'end is provided with an operating handle 56. Turning of the screw 55 by handle 56 provides relative movement between thev screw and casing to move the diaphragm 53 into engagement with a seat 57 provided in the body section of the casing.

Y The diaphragm cock 6 is of the same 'construction as diaphragm cock 5 and comprises a Casing formed ofl a body section 58 and a cover section 59. A flexible diaphragm 60 is clampedV adjacent its periphery between said two casing sections and is adapted to be moved by turning a handle 63 on a screw 61,

rhaving screw-threaded engagement inthe cover portion of the casing, said screw acting upon -a follower plate 62 engaging the diaphragm. In closed position of the cock, the diaphragm is adapted to engage a seat 64.

The three way plug valve device 7 comprises a casing containing a rotatable plug valve 65 adapted yto be operated by a handle 66. c

The duplex pressure gauge 8 is of the usual well known construction, having Va graduated dial 67, and pointers 68 and 69 which Vare adapted to be rotated around said dial. The gauge is'connected to the supply reservoir 9 through pipe 70, passage 71 in the brake valve device, pipe 72, couplings 73, a liexible hose 74, a-plug valve 75 and a pipe 76, and one of the gauge pointers, for instance pointer 69, isfadapted to registerl the pressure offluid supplied from saidY supply reservoir to the brake valve device. VThe gauge is also connected through pipe 77 to the three-way plugvalve device7 and the other gauge pointer 68 is therefore adapted to register either the pressure of fluid in brake pipe 21 or in equalizing reservoir 11, according to the position of said three-way plug valve device 7, as will be evident from the following more detailed description of the operation of my invention. As shown in the drawings, the brake pipe connection 21 of the testing apparatus is adapted to be connected to the brake pipe 78 on a car at one end of a train of coupledV cars by means of a pair of couplings 79 and a flexible; hose 80, and isA well understood that by varying the pressure in the brake pipe 7 8, the

brake controlling devices on the cars in the train, lwhich are adapted to operate in response to variations'in brake pipe pressure,

ywill be operated and while being operated may be inspected.

In operation, the brake vvalve kdevice 1 Ais initially placed in ruiming position, the srew 55 of diaphragm cock 5 is turned so Vas tpermit diaphragm 53 to deliect away from the control valve reservoir pipe 32 yto pipe 47,v through the choke fitting 81, and the plug Avalve 65 of the three-way plug valve device 7 is turned to the position shown in the-drawings, in which the equalizing reservoir 11 is connected to the pressure gauge 8 by kway of pipe 17, port 82 in plug valve 65 and pipe 77.

The brake pipe connection 21 of the testing apparatus is connected to the brake pipe 78 of the train by means of the couplings V79 and flexible hose 80, and the iluid pressure supply pipe 72 of the testing apparatus is connected to the fluid pressure supply reservoir 9 by means of the couplings 73,-. flexible hose 74, plug valve and pipe 76, the plug valve 75 being normally opened.

Fluid under pressure is supplied to reservoir 9 in the usual well known manner and flows from said reservoir through pipe 76,

plug valve 75,' flexible hose 74, couplings 73 Vand pipe 72 to the brake valve device 1 and from thence through passage 7l to the pressure gauge 8 and to the rotary valve chamber 12 of the brake valve device. The pointer 69 on the gauge 8 is thereby operated by the fluid under pressure supplied through 'pipe 70 to register the supply reservoir pressure.

lVith the brake valve device in the running position, as shown in the drawings, fluid at supply reservoir pressure flows from the rotary valve chamber 12 through port 83 in the rotary valve 13 and passage 84 to the feed valve device 20. The feed valve device Y then'operates in the .usual manner tov reduce the supply reservoir pressure to the pressure which is normally carried in the brake pipe and supplyiluid at the reduced pressure to passage 85 through which it flows to equalizing piston chamber 19, and through port 86 in the rotary valve 13 to passage 17 leading to the equalizing piston chamber 16 and Y through pipe 17 to the equalizing reservoir From the equalizing piston chamber 19. fluid runder pressure flows through passage and pipe 47 to the application check valve chamber 42, to valve chamber 24 of the control valve device 2, through choke fitting 81 to the diaphragm cock 6, and to the dia-V phragm cock 5.

The diaphragm 53 of cock 5 is initially dey flected away from the seat 57, so that fluid under pressure flows from pipe 47 to brake pipe connection 21 and from thence through couplings 79 andV flexible hose 80 to the brake pipe 78, thereby charging said brake pipe. When thus charging the brake pipe, after a certain pressure is obtained therein, the brake pipe may be inspected for leakage such as at joints and at connections to the brake pipe.V

15am-,lee

tthe same time asthe-bral-{eipipe-78 is;k

chamher 33 and also from pipe 21 to chamber- 41 of the releasecheck valvedevice 3. The.

pressure of iiuid in valveichamber, 41 moves the valve 37 vupvvardly againstl the pressure of` spring 39 and fiuidA under, pressure-then ioivs from chamber` 41y to chamber 36 and from thence through passage 40 4andil pipe 32- tothe control valve reservoir 10 and `from pipe 32 through passage 3,1 to., diaphragm chamber 30.

Ther pressure of` spring 38, in therelease check valvevdevice 3ds such as to cause substantially no reductioirin the pressure supplied to control reservoir 10 and diaphragm chamber 30 of the-control valve device. Thus the fluid pressures acting on the opposite sites of the control valve diaphragm 22 become substantially equal, so*` that the diaphragm 22 is in ast-ate or"l equilibrium which permits spring 28 to hold the valve 23 seated, As the testing apparatus and brake pipe 78 are thus charged, the pressure in the cqualizing. iistonchamber 16, which is connected to the equalizing reservoir 11, and in the equalizingpiston chamber 19 builds up substantially the same rate andthe equal.

izing piston lholds the brake pipe discharge valve 18 seated inthe usual Well known manner. i y

The equalizing reservoir 11 being initially connected to the pressure gauge8 through pipe 17, port 82 inthe three-Way plug valve.

65 and pipe 77, the pressure-obtained in sai-d reservoir is registered by pointer 68on said gauge.

After the brake pipe 7`8,the controlvalve reservoir 10 and equalizing reservoir 11 are thus charged-With iiuidat the pressurenOr.- inaily carried inthe brake pipe, as governed by tle adjustment of the feed valve device 20, the brake pipepressure may be reduced any predetermined amount to apply the brake.v on the train, and thepressure in the bral-:e pipe then maintained at the reduced pressure in order to offset leakage from the brake pipe, as Will now be explained To effect a reduction in brake. pipe' pressure, the rotary valve 13 of the brakevalve device 1 is turned to service position byy operating the handle 14. In service-position of Y-he rotary valve 13, passage 17 is connected to an atmospheric port 87 which permits fluid under pressure to fiovv fromvthe equaliz'ing reservoirll and equalizingpiston chamber 16 to the atmosphere and reduce the' pressure acting on the upper-side of the equalizing piston 15, such a reduction beingregisteredby pointer 68 on the pressure gauge Which` 1s,

connected to the' equalilzing reservoir.

Reducing the pressure ofE fluid inequalizring pistonL chamber- 1,6,Y permits thefhi'gherA pressure. of fluid in the equalizingV piston, chamber 19t-to move the equalizing piston 15j Y upwardly and unseat the brake. 'pipedis,.

charge valve 18, which connects pipe' 47to the atmosphere through an exhaust pasf sage 88. t i

Withv the diaphragm 53 of coclr` 5 away from its seat 57f1uid-under pressure is permitted to iowfrom the brake pipe 78 through ieXible hose 80, couplings 7 9, and brake pipe connection 2 1 to pipe 47. and -from thence to the atmosphere past the unseated` dischargeV valve 18 and through the exhaust passage 88,

thereby reducing the pressure of 'fluid in said;

brake pipe.

21 through ports 34 andzpassage 35, the pressure in said chamber. reduceswith brake pipe pressure. As the pressure in pipel 47 is` re duced, the pressure of iiuid inthe applica;

Since diaphragm chamber 33 oi'i the control-valve device isconnected-to pipetion check valve chamber 48 inoves'the check" valve 43 yupwardly avvay from seat 45, Which permits Huid underpressure to iioW from the; control valve reservoir 10 and the control valvediaphragm chamberSO through pipe 32, passage 49, past the application check valve 43 to chamber 42, and from thence through passage 46 to pipe 47 Which'is connected to the atmosphere past the-unseated 1 discharge valve 18 and through atmospheric exhaust passage 88.

The spring 44 in the application check` valvedevice 4- is. provided to urge the check.

valve 43 intoengagement with seat 45 but is of such value as to permit substantially the same. degree of reduction to occur` in chamber 48 as occurs in chamber. 42 when thc pressure is reduced in pipe 47 in the mannerV liust described.

It Will thus be noted that When the pressure of fluid in thcbralre pipe 78 is reduced, the pressure of fluid is reduced on the oppor site sides of the control valve diaphragm 22',v thereby maintaining said diaphragm in equilibrium, and a-lso the pressureof fluidin the control valve reservoir 10 is reduced, the degree of reduction in the reservoir 10 beingv substantially equal to the degree of brake pipe. reduction.

When the desired degree of reduction. isl

eifected in equalizing reservoir pressure,'as

indicated by pointer 68 on the pressure gauge 8, the rotary valve 13 of the brake valve device 1 is turned to lap position in Which passage 17 is lapped so as to prevent further reduction in pressure in the equalizing piston chamber 16 and equalizing reservoir- 1 1. Then when thebrake pipe pressure acting in equalizing piston chamber 19 becomes re-` duced, by flow to the atmosphere past the unseated discharge valve 18, to a degree slight-r ly less than the reduced pressure in equalizing piston chamber 16, the equalizing piston` 15 isoperated by the higher pressure in cham,-

ber 16to seat the brakepipe discharge valveY isc 18 yso as tb prevent furtherreduction in bra-ke pipe pressure and in the pressure in the control valve reservoir 10.

After a certain reduction in brake pipe Y pressure'is effect-ed, if it is desired to maintain I the brake valve device V1. The rotary valve 13 of the brake valve device is then turned to release position in which passageA 85 is connected through said rotary valve to thevalve chamber 12, which permits 'Huid at supply reservoir pressure toflow fromV said chamber through passage 85 to passage and pipe lr-7 leading to diaphragm cock 5, which is now closed, to the valve chamber 2e of the con Vtrol valve device and to check valve chamber ll2 of the application check valve device 1.

In chamber 42, fluid at main reservoir pres-V sure aids spring 11i in effectively seating the check valve 43, so that fluid under pressure in the control reservoir is bottled upV and will remain constant at the pressure to which Vit was reduced, corresponding to the degree of reduction effected in brake pipe pressure, and since diaphragm chamber of the'control valve device is connected through parsage 31 and pipe 32 to the control valve reservoir 10, the pressure in said chamber, acting on the diaphragm 22, will alsoV remain constant.

-. With the testing apparatus in the condition just described, if there is leakage from the l brake pipe 78, the reduction in brake pipe pressure caused by mitted through the flexible hose 80, couplings u79, pipe 21, passage 35 and ports in the.

control valve device to chamber 33 below the diaphragm 22. r1`his reduction in pressure in chamber 33 permits the bottled up or constant control valve reservoir pressure in chamber 30, acting' on diaphragm 22, to deiect said diaphragm against the reduced pressure in chamber 33V and thereby act through stem 27 to unseat the valve 23 against the spring 28. 1V ith the valve 33 unseated, fluid atsupply reservoir pressure is permitted to flow from the valve chamber 2li past valve 23 to passage 35 and from thence through pipe 21, couplings 7 9 and flexible hose 8O toY brake pipe 78 to lcompensate for the leakage of fluid under pressure from said brake pipe.

In the operation `of the control valve device as just described, the deflection of dia phragm 22 gradually7 unseats the valve 23 until said valve is open suiliciently. to permit a rate of flow of fluid under pressure to brake pipe 78 just equal to the rate at which the such leakage is tra-ns#V fluid pressure is ventedl from thebrake pipe by leakage, and when such a position of the p 30 at the upper side of said diaphragm. Thel movement of said diaphragm to further unseat the valve 23 then ceases. viVVith the brake ,pipe pressure thus maintainedvagainst leak- Y age, the degree of brake pipe reduction re` mains constant, so that the operator may inspect the brake devices on the train in their applied position.

To recharge the brake pipe 78 in order to release the brakes, therotary kvalve 13 of the 4brake valve device is turned to running position, in which position port 83 in *saidy rotary valve registers with passage 84C and per mits fluid at supply reservoir pressure to flowV from' valve chamber12 to the feed valve device 20. The' feed valve device is thereby i operated in the usual manner to reduce supply reservoir pressure to the pressure nor-V mally carried 1n the brake pipe and supply fluid at such reduced pressure to passage 85,

sage 17 thereby permitting fluid at feed valve pressure to flow from passage 85 through port 86 .and passage 17 to the equalizing piston chamber 16 and equalizing reservoir 11. The fluid pressuresthus build up in equalizing piston chambers 16 and 19 at thel same time, and since the pressure of fluid supplied to both of said chambers is the same, the equalizing piston 15 operates in the Vusual well known manner tohold the brake pipe discharge valve 18 seated.

The screw of diaphragm cock 5 is turned so as to permit diaphragm` 53 to deflect'away from seat 57, which permits fluid at feed valve pressure t0 flow from pipe 47 to pipe 21 and from thence through couplings 79 and flexible hoseL to brake pipe 78, thereby charging the brake pipe.

Fluid at feed valve pressure supplied to pipe 21 also flows through passage 50, in the release check valve device, to chamber 41. rEhe valve 37 is unseated against spring 39 by the pressure of fluid in chamber 4:1, and fluid underl pressure then flows from said chamber past the check valve 37' to chamber 36 andfrom thence through passa'ge 40 and pipe 32 to the control valve reservoir 10 and from pipe 32 through passage 31 to diaphragm chamber 30 of the control valve device, thereby charging said reservoir and chamber with fluidY at feed valve pressure,

such as' supplied to brake pipe78. At the same time, fluid at feed valvev pressure flows .from pipe 21 through passage 35 and ports 311 to diaphragm chamber 33-of the control sof valve`4 device. The control valve diaphragm chambers 30 and 33 are thus both charged with fluid at feed valve pressure, and theA diaphragm is thereby placed in a state of equilibrium which permits the spring 28 to seat the valve 23.

If it is desired to hasten the rate of recharge of brake pipe 78, the rotary valve 13 of brake valve device 1 is turned to release position in which a direct connection is effected from the supply reservoir passage 71 to passage 85. In this manner, the supply reservoir pressure, which is greater than the pressure supplied by feed valve device 20, is permitted to flow directly to the brake pipe 7 8 through passage 85, passage and pipe 47, pipe 2l, couplings 79 and flexible hose 80, and at the same time to the control valve reservoir 10 and control valve diaphragm chambers 30 and 33. When the brake pipe pressure isthus rapidly increased to a certain degree, then the rotary valve 13 of the brake valve device is turned to running position in which the charging of the brake pipe and testing apparatus continues, but the pressure of the fluid is governed by the adjustment of the feed valve device 20, in the manner bereinbefore described.

If instead of recharging the brake pipe 78 in the manner hereinbefore described, it is desired to incr-ease the brake pipe pressure at a slow gradual rate, the rotary valve 13 of the brake valve device is turned to running position and the screw of diaphragm cock 5 is turned to deflect the diaphragm 53 into engagement with seat 57 so as to prevent flow of fluid at feed valve pressure to the brake pipe 78 in the manner hereinbefore described. The screw 61 of diaphragm cock 6 is turned to permit diaphragm 60 to deflect away from seat 64 so as to establish communication between pipe 47 and control valve reservoir pipe 32.

Fluid at feed valve pressure supplied through the brake valve device to pipe 47 flows to valve chamber 24 of the control valve device and through the choke fitting 81 and diaphragm cock 6 to pipe 32, which is connected through passage 31 to diaphragm chamber 30 of the control valve device and which is also connected to the control reservoir 10. The pressure of fluid in said chamber and reservoir is thus gradually increased at a rate governed by the flow area of choke fitting 81. This gradual increase in pressure in diaphragm chamber 30 over the brake pipe pressure in chamber 33 deflects the diaphragm 22 downwardly, unseating the valve 23 which permits fluid at feed valve pressure to fiow from chamber 24 past said valve, through passage 35, pipe 21, couplings 79 and flexible hose 8O to brake pipe 78. From passage 35, fluid under pressure also flows through ports 34 to diaphragm chamber 33 s to oppose the pressure in diaphragm chamber 30.Y The pressuresk on the opposite sides When'V effecting agradual recharge of thel brake pipe, the plug valve 65 of the three-way plug valve device is turned clockwise 90 so as to connect gauge pipe 7 7 to a pipe 90 from the brake pipe connection 21. By so doing,l

the rate and degree of gradual rise in brake pipe pressure is direct-lyV indicated to the operator by the" movement of the pointer 68. At any time when it is desired Wto note the pressure in the brake pipe, the three-way plug valve device may be so operated.

. It will be noted 4fromfthe above description of the operation of the improved testing apparatus, that the'cont'rol reservoir 10 is supplied with fluid under pressure from pipe 21 at the Sametime as fluid under pressure is supplied through said pipe to bralrepipe` 78 in normally charging the lbrake pipe, and when a brake pipe reduction is made, fluid under pressureis permitted to flow from the control reservoir'lOto pipe 47 from which it is' vented' by operation of the brake valve device 11, in the 'manner hereinbefore described. However, in order to bottle up the Y pressure in the control reservoir '10 when the brake pipev` pressure, is being' maintained against l'eakagejin the manner ,also hereinbefore described, the check valve device 3`is provided to preventflow' from' theI control reservoirf`t0the1brake lpipe through pipe 21, and vthe check valve device 4 is provided to prevent| flow 'of fluidil at higherv pressure from pipe47 tosaid-reservoir, the higher pressure being supplied-to saidpipe'and ,controll valve chamber 24 lof the control valve device when the braleval'vedeviceis'in release position. Sometrainsare provided'with more than one pipe line extending from oneend to the otherend, such as, for instance,iasignal'p1pe. In the drawings, my improvedtestingapparatus is preferably shown connected'to a brake pipe, but I do not desire'to thus' limit its application, since iti may equallyy well be' employed in testing the condition ofl anytram 1 e. Y p iN/bile one illustrative embodiment of the inventionhas been described in detail, it is not my intention todimit its scope to vthat embodiment or otherwise than by the terms of thev appended claims.

VHaving now described myinvention, what I claim as new and desire to'secure by Letters Patent, is: Y

1. The combination with a train` pipe, Vof a testing apparatus comprising a brake valve device for varying the pressure-fof liuid in Y governed bythe pressure of fluid in said res- Y Vsaid trainl pipe, a reservoir charged With fluid Vunder pressure, a control valve 'device ervoirv for supplying fluid under pressure to said train pipe and valve means for preventing flow of fluid from said reservoir to said train pipe and operating automatically to permit flow of fluid from the train pipe to said reservoir. v, Y.

e 2. The combination With a train pipe, of a testing apparatus comprising a brake valve device for varying the pressure of fluid in said train pipe, a reservoir charged with fluid under pressure, a control valve device governed bythe pressure of fluid in said reservoir for supplying fluid under pressure to 'said train pipe., a pipe through Which fluid under pressure is supplied to said reservoir and through Which fluid is vented from said reservoir, and valve means for preventing the Lflow of fluidV fromisaid pipe to said reservoir and operating automatically to permit the ventingof fluid from said reservoir to said pipe;

3. The combination with al train pipe, of a testing apparatus comprising a brake valve 'device for supplying fluid under pressure to said train pipe and for venting fluid under pressure from said train pipe, a cock having an Open position for permitting fluid under pressure to flow from said brake' valve device to said train pipe, a reservoir charged with fluid under pressure, and a control valve device governed b v the pressureor` fluid in ysaid reservoir and in said train pipe for controlling the supply of fluid under pressure from 'said brake valve device to said train pipe when said cock is in closed position, said reservoir having an inlet connection from the `train pipe side of said cock and an outlet connection to the brake valve' side of said cock for permitting the pressure of fluid in said reservoir to vary lWith variations in brake pipe pressure when said cock is in open position, a check valve device interposedin the' closedto supply fluid under pressure from said brake' valve device to said'train pipe,

and a check valve device for preventing flowfor venting fluid under pressure from sa-id'-,V

train pipe, a reservoir having a connection to said train pipe through Which fluid under pressure is supplied for charging said reservoir, a check valve interposed in said connection, said reservoir having another cony nection to said brake valve device through which fluid is vented from said reservoir, a

check valve interposed in said other reservoir connection, a cock interposed between the first mentioned check valve and said brake valve' device for closing communication from said brake valve device to said train pipe, and a control valve device governedby the ypressure of fluid in said reservoir for controlling the supply of fluid under pressure from said brake valve device to said train pipe when said cock is in closed position.

In testimony whereof I have hereunto set my hand this 12th day of February, 1930. v WILLIAM F. MEIER.`

inlet connection forl preventing the flowk of Y fluid from said reservoir to said train pipe when the train pipepressure is reduced and said cock is in closed position, and a check valve device interposed in said outlet connection to prevent flow of fluid from said brake valve device to said reservoir. e

4. The combination with a train pipe and a source of fluid under pressure of a reservoir, a testing apparatus comprising a brake valve device for supplying fluidv under pressure from said source to said train pipe and to said reservoir, a cock for closing 'communication from said brake valve device to said train pipe, a checkV valve Vdevice for preventing flow of fluid from said reservoir to said train pipe When` said cock is closed and the train pipe pressure is reduced, a control valve device governed by the pressure of fluid in said reservoir and operative 'when said cock is

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