US2189184A - Air-brake testing apparatus - Google Patents

Description

Feb. 6, 1940. R, SIMPSON f 2,189,184

AIR -BRAKE TESTING APPARATUS Filed Malfch 19, 1938 3 Sheets-Sheet 1 Im/ENTOR. /fw )Aya/w BY @f4/Mm A TTORNEYS.

Feb. 6, 1940. R slMPSON i 2,189,184

AIAR -BRAKE TESTING APPARATUS Filed March 19, 1958 5 Sheets-Sheet 2 Feb. 6, 1940. R. SIMPSON 2,189,184

AIR-BRAKE TESTING APPARATUS Filed March 19, 1938 3 Sheets-Sheet 3 IN VEN TOR. /M' JW BY ff/M7 @MU/@22% A TTORNEYS.

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Patented Feb. je, 194e IRQBRAKE r1.7ns'151uerAeinenAtrusv` y n NRobert Simpson, Newell, Pan",` 4 n l, App1ieation-Marhi',193s,serialN0.19s,943.

My invention `relates tothe `testing yof .fluid-v aidofja pressure gauge in the testingapparatus` and a Watch-the rate of` air leakage inrthebrake system oithe train" is" checked.` If` the .leakage isf within permissive tolerance, the inspector operated zbrakes, particularly `air brakes, and more particularly the `air brakes of railroad trains. Theinvention consists in improvements in apparatus, by'fvirtue-of which theltests may befmade more readily and quickly. v The invention will be `describedas practised in testing the'ar'brakes of railroad trains..

As `those familiar vvithfthe` art know, each railroad carisequipped with brake apparatus lwhich is .adapted to be .operated Icy-air under pressure.

lmgfeneral, such lbrake `apparatus includes an V auxiliary reservoir forcompr'essed air, two .pneu- Amatic'plungers triple valves, retaining valves,

vand la brake-pipe, all lorganized and interconnected in known way to `operate-.the brakes of the car. Insert/ice, the brake-pipes of lthe cars t of ajtrain are interconnected, by means of flexiil ,therear end of the train the train-pipe is closed.

ble `coupling hoses, and (provide `a continuous air passage, knownv as the-train-pipe, that extends from one, endI of the trainto the other. `.At `the head .end ofthe :train this train-pipe communi-l cates' through Vth ,"usual` engineers brake valve The" main reservoir,l constantly .supplied` with air by a compressor inthe engine, chargesythe ,train-pipe and -auxiliaryfreservoirs and valves `of fthe `several cars with air at Anormal operating pressure-seventy pounds, pressure in the l case of freight ytrains and one hundred andten pounds in the casesof passenger trains, and when the v'train-,pipe `is charged with air at suon y.pressure,l the brakes; of `all the cars stand. in release positionsf When the ,pressure in thev train-'pipe is reduced, `the brake `apparatus ofthe several cars operate `to apply all fbrakes of the* train.

f The brakes fare, held .in `applied positions until the air pressure `in the 'train-pipeisrestored to normal valuaor `substantially so. 'I-his control of the pressuregwithin Lthe train-pipeis veffected in :known way throughmanipulation of the en- `@,'ineens brake valve.`

`Whena train Ais made up in a terminal,` and vsonietimes when aftrainout on the road is at vrestin a station, .it is required that the Abrakes offeach car shall be testedandinspected. In

making such test Ythe 'trainfpipe is connected 4 .through a testing apparatus arranged at one -end of the trainer carsto a supply of compressed and the auxiliary reservoirs andthe train- ,pipe of the kc :oupled cars are Ycharged with air `'unt-il .normal operating `pressure is established. K

Then communication V.betweeny the air supply f a and the .train-.pipe is, interrupted, `ands-With the vents air from the testing apparatus `until the .pressure in the ',-trainpipe is reduced i twenty pounds,'.with the consequence that afservloe applicatio-n-oi the Abrakesis' effected. `While the brakes are thus set, the` inspector goes the length ofthe train, observingeachvbrake to seethat `it `has operated properly. "Then hereturns, to the testing apparatus at lthe head -end of thestrain` and re-establislies communication between Lthe supply ofcompressed air andthe train-pipaand recharges theI train-pipe to normal operating pressure. i This releases thepbrakes; Againlthe inspector walksv the length of the train,` looking atieachbrake to make surethatitisin proper release position. `Upon completing the test, the

inspector returns -to the head end of thetrain;` v disconnectsthe testing apparatus, and makes his report. Thus itwill be .understood that inglrnak-` y. the ftestthe inspector must travel `the length ofrthe train .four times. "The time consumed and Y the cost are great', even When` tvvo inspectors work together on the rjob, and the 1problem is becoming more acute with the @growing prac-1 vtice of operatingfreightrtrains of a `mile orfniore i in length. 3 l,

My invention consists in refinements `in :test` ing apparatus, by virtue offwhich itis `necessary vide meansin the testing apparatus iorrecharging the trainspipe and releasing 'the brakes, while the inspector, having gonethelength of the train and inspected` the brakes `in `applied vent the train-pipe and then close it again. .The `testing apparatus at the head end of the train 'operates to recharge the train-pipe injthe manner mentioned.

`In the accompanying drawings testing ap',-

'paratus embodying the invention is illustrated.

Fig. 1 is a view in side elevation ofarelatively simple form of the apparatus, with the means lfor the inspector to gowthe `length `of thetrain only once andV return. More particularly, flpropositions, still at the remote end of the train. C

for supplying compressed "air, and..a.train of cars, illustrated diagrammatically and )to-smevtllff` eriscale; Fig. II is a fragmentary view-showing .partly in side..elevation and partly. in vertical.

section a portion of the apparatus to larger scale, and illustrating a modification in detail; Fig.`III

`is a view in side elevation oi a more refined form of testing apparatus in which the invention has been embodied; and Fig. vIV is a fragmentary" the invention embodying still other kmodifica- I tions.

, fromI the air reservoir to the train-pipe.

Referring to the drawings, the brake-testing apparatus shown in Fig. I includes ina tubularbody B, constructed in this case` of standardpipe fittings, and provided at its'opposite ends with hose couplings 3 and d, by means. of which the apparatus may be connected in usual way in a line L of flow from a reservoir R of compressed air tothe train-pipe TPv of a train of cars 'I' whose brakes are to be inspected'and tested. vAn

vair compressor C maintains the supply of lcompressed air irl-reservoir R at a pressure in excess ofthe normal train-pipe pressure ('70 pounds or 110. pounds, as already mentioned), `and it will be'l understood that the reservoir and compressor may be they main reservoir and compressor of the locomotive which'jis to pull the train. Alternately, the reservoir: and compressor may, as

, here 's ljiown, consist in a permanent piece of apparatus'in the railroad yard in which trains are inade` upland inspected. Y

llIn accordanceI with the invention, the testing apparatus -includes a two-branched line of ow One branch of such line of' flow is provided in the tubular body portion to which the reference letter B is immediately applied, and in this branch two pressure gauges I, I and a manually operated valve'2 are provided, with a flow-constricting cone (or an orifice plate) included between the gauges, to 'prevent undue yviolence of flow when the valve 2 is opened and' air is charged from the reservoir --R into the train-pipe TP. The

second branch of such line of now is provided in pipe sections 5, 1, and S, connected together in the form of an inverted U, and assembled in the apparatus in such manner that the gauges I, I andthe valve 2 lie between the legs of the U. A n auxiliary valve 9 is included in this second branch, and it will be perceived that by opening such valve, communication may be established between the 'air reservoir R and the train-pipe TP, whether or'not the valve 2 is open or closed.

-Th'e invention consists in instrumentalities that are responsive to the control of the inspector, when he is at the remote end of the train, for opening the' auxiliary valve S.

Such instrumentalities include yielding means thattend to turnthe valveg from closed to open position, and means for normally holding the valve, against the urging of said yielding means, in closed positionv until the air pressure in the trainepipe is intentionally reduced to a value below that which effects a service application oi the brakes being inspected. In the apparatus of Fig.' I, suohyielding means consist in a spring I II,

tending to swing the operating handle I I of the l valve 9 counterclockwise from the horizontal position illustrated, in which the valve is closed,

1nto a vertical position, in which the valve isopen;

and the'means for holding the valve in closed p osition consist in a trip-arm I3 which is: pivoted at its'lowerY end to a rigid bar I2 that spans the pipes' and 3. f'Ihe upper, distal end of the trip-- arm lis adaptedto engage the outer end of the handle IIl from beneath and hold the valve against the tension of spring I in closed position. A plunger rod I5 in a cylinder I6 is movable in response to an intentional reduction in pressure in the train-pipe, to swing the trip-arm from engagement .with the handle II and permit the spring ID to open the valve.A Further detail in the structure and operation of the apparatus will be considered in the ensuing description of a brake inspection. i

' Preparatory to 'making lan inspection, .the upper hooked end of the spring Inis disengaged from the pin 3| that secures it to the operating handle II of valve 9, and both valve 9 and valve 2 are closed. The testing apparatus is then connected in line L between the reservoir R and the train-pipe TP. When this has been done, the 'valve 2 is opened and air is fed from the reservoir R into the train-pipe, until the gauges I, I indicate that the pressure in the train-pipe and brake system of the train has reached normal operating value, 70 pounds in the case of the-illustrated freight train. Such charging of the system operates to release the brakes. of the train.

The pressure existing inthe train-pipe and line L is eiective through branch pipe 3 and pipe fittings I'I upon the left-hand face of a piston I8 (Fig. 1I) which is secured within cylinder I6 to the end of plunger rod I5. Between the piston and the head I9 of the cylinder a compression y springiopposes movement of the piston and rod under" the influence of such 'air pressure. While air is being initially charged into the system, the rising pressure gradually shifts the inder head I9, and arrests the movement of the piston; in such positionof the piston the spring is fully energized. As already mentioned, the charging oi' the sytem is continued until the pressure reaches the' value of 70 'pounds and the valve 2 hasbeenclosed. The plunger rod I5, pros jecting from cylinder. I6, 'extends with sliding fit through the'trip-arm I3, and at its outer end carries a block-2|. When the partshave come to rest, under'the conditions described, the trip arm I3 is' set bene'aththe` valve handle II, and the spring IB is expanded and its free end hooked upon the pin 3| on the handle. The positions of the parts at this stage of the operation are shown in Fig. I,'it being noted that the block- 2I lies at an interval tothe right of the triparm. All is in readiness to proceed with the test. The inspector opens a normally closed angle-cock 22 and releases air from the charged system, until the gauges show a 15 pound drop in pressure; that is, until the pressure in the train-pipe is reduced to 55 pounds in this case. The anglecock is then closed and the gauges are watched for one minute, to note the pressure loss in the system. If the loss exceeds seven pounds in such interval of time, the inspector cannot approve the train for road service, but must nd the source, or sources, of leakage and make necessary repairs. If the loss is less than this critical limit, a limit xed by law, the inspector goes forward with the test. (It may bev remarked that some railroads have voluntarily set lve pounds per minute` as the limit of leakage which will be permitted.)

The angle-cock 22 is again'opened andthe pressure is permitted -to fall -to a value of 50 pounds, at which pressure the brake apparatus of the several cars of the train operate to eiect fully compressed. This fall inpressure in the' train-pipe relieves the pneumatic pressure onthe piston i8 in the testing apparatus at the head end of the train, with the consequence and eiliect that the spring 2t expands and shifts the pistonl i8 and rod i5 to the left'. The block 2| on the shift ing rod l5 moves. into contact with the sideof y the trip-arm i3, and swingssuch arm in'counterclockwise` direction. The distal end of the triparm is thus disengagedirorn the valve-operating handle Il (cf. broken-line position" in Fig. II) l,

and the handle, under the stress of spring ll,

swings downward and opens the valve 9. Thereupon, branch line l, l, il of iiow opened and communication is established between the supply R of compressed air and the train'pipe, and the train-pipeis recharged to the pressure of the air supply, which is equal to, or in excess of, the 'pressure (70 pounds) necessary to effect Vthe release of the brakes. When the Vbrakes of the train have thus been released, the inspector returns along the lengthof the train and checks each brake, making note of any that have not operated properly. Upon reaching the head end of the train, with the inspection completed, the testing appa' ratus is disconnected andthe customary report made to the yardmaster or other supervisor.`

,'I'hus, it will be perceived that my apparatus makes for substantial savings in time and labor; it eliminates the` need of two men to do the Vjob, and does not require signaling betweenthe head end and rear of the train.

It may be remarked that, if the train being inspected is a long train,y there is a possibility that the leakage of pressure from the system` may, while the` attendantis making his Ainspection with the brakes applied, cause the pressure inthe train-pipe to fall 'below "the l'brake-applying pressure of 50 pounds, in such manner that the trip-arm i3 ywill be thrown and the valve 9 opened before the end of the train is reached. In order to prevent such an occurrence; the main valveV 2 may be allowed to stand in slightly open position, to permit the reservoir to supply air to the system in quantity equal `to `thatlost by leakage.

Another feature of .adjustment fis to be noted.r

The block 2l is'adjustable axially of the piston l yrod 15,150 the end that the valve-releasing move ment ofthe trip-arm may be accurately responsive to desired` critical value of pressure relief in the train-pipe. Conveniently, the rod and the block `are threaded, whereby the block may be rotated to effect such adjustment.

'I'he spring ld andr the plunger l5 are err-fy emplary only ci the means for achieving the ends in view. In modification,y the operating handle of the valve 9 may be counter-weighted, asshown at lbin Fig. IL'and needless to say the designer may operate to opcnthe valve."

Thus, the pressure in the train-pipe may be maintained at brale-applying value, untilv handle,A so that the counter-weight` (or spring) In `I "igs.-III and IV, a refined andlrrnorecom# pact "embodiment of the invention is illustrated.

AIn this rened structure, as in the-structure first described, couplings 3a `and la are provided for connecting vthe apparatus in the line of flow between the air reservoir and the train-pipe. Be-

tween the couplings 3a and 4a, the line of flow through the apparatus includes two branches, one branch through the bodyof a valve 9a, and the other through interconnected pipe `sections 6a, la, and lla.` The apparatusincludes a gauge la arranged to indicate pressure in the line of flow, on each side of the valve 9a. It will be understood that, save for `the connections 6a, la, 8a and certain additional 4parts presently to be described, the structure illustrated in Figs.

III and IV is a piece of apparatus well known to the art. l

A manually operated valve 2a controls llow in` one branch of the double line of flow, and valve Se. controls iiow in the other. Theyoperating handle Ha of the Valve 9a is provided with a lug Hb, and the distal end of a pivotally supported trip-arm i3d, which is backed by a leafmay provide other known sorts ofmotorsto eiieot the desired release of thezvalve-operating,

spring leb, is adapted to engage the lug I l b and Y lock the handle ila, against the'tensionof a spring Sila, with the valve in closed position. Within a vertical cylinder I 6a, a compression spring 2da exerts a thrust upon the upper face of a piston 53a, tending to shift the piston downward; a plunger rod 15a, securedto the piston kand projecting from the upper end of the cylinsur der, `extends with sliding t through the triparm i3d, and above such trip-arm carries a block 25a; thelower end of the cylinder lGacommunicates with the line `of flow on the trainpipe side (theright-hand side) of the valve 2a, and air at train-pipe pressure, acting on the bottom of the piston i3d, opposes the thrust of the spring above. v

Theprocedurein making a test is the same as that already described, and it remains only to say that a relief valve 22a. (or other suitable means) is provided on the train-pipe side of the valve 2a, so that in the initial stages of the test the charged system may be vented to the `open atmosphere, to reduce the train-pipe pressure from brake-releasing to` brake-applying value. When the inspector has gone the length of the train withl the brakes applied, he momentarily vents the train-pipe, with the consequence and eilect that the spring 25a expands, the plunger rod |5a descends, the trip-arm` 63a swings downward, the handle lla rotates under the stress of spring Staand opens valve 9a, and air at supply pressure' is `charged into the brake system of` the train. 'The brakes of the train are thus released and the inspector moves forward from the remote l end of the train and completes his inspectionf Turning to Fig. V,;still anotherembodiment of the invention is shown, but it willA beunderstcod that the general procedure of ymaking a brake test is no different with the structure of Fig. V than withv the structures oi Figs. I to IV; In F'gV the coupling fic serves to connect the apparatus to the line leading Ato the supply of compressed air, and coupling 3c (fragmentarily illustrated) serves to make connection tothetline leading to the plunger assembly manually operated valve 2c) forms one branch, and pipe 50 (controlled by a'slide-valve 9c) provides the other.. And, as in the structures described, a gauge Ic and a manually operated relief cock 22o are arranged on the train-pipe side of the valve 2c.

The slide valve llc is by a rod 9d connected to a. plunger rod 55e; the plunger rod I5c carries two pistons-a piston I8c of relatively small diameter in a cylinder IGC, and a piston Id of relatively large diameter in a cylinder 16d. Between cylinderslc and Iid, a tubular housing I6e incloses the plunger rod IEC; rwithin housing IBea ring 30 is arranged; the plunger rod extends with sliding fit through this ring, and between the ring and the piston Idd a helical compression spring 2Ilc is organized, as shown. The ring 39 carries on each of its two diametrically opposite sides a pin 3l, and each pin 3l extends radially outward through a slot 32- A sec-y formed in the side wall of housing I 6e. ond ring, a ring 33, is by a screw 34 secured externally upon the housing IIe, and the righthand edge of this ring 33 provides an abutment against which the projecting ends of the pins 3l bear. secured against axial displacement in right-toleft direction,A and the compressed kspring 20c, held captive between the ring 3G and the plunger I8d, tends to move the plunger assembly I5c,

I8c, IIld to the right and shift the slide-valvev 9c into open position. The position of the internal ring 3l] may be adjusted axially of the plunger assembly, to regulate the magnitude of spring pressure on the piston iSd, and such adjustment is effected by varying the otherwise xed position of the external ring 33 axially of the housing Iie. Y When the apparatus is in service, the piston Ic is, manifestly, subject on its left-hand face to air at supply pressure, and piston ld is subject on its right-hand face to air at train-pipe pressure. When the brakes are set in applied positions, both the manually operated valve 2c and the slide-valve 9c are closed, and the pressure of the air on the left face of piston Ille and the thrust of spring 20c of the left face of piston ltd are opposed and equalized by the pressure of air on theright-hand face of piston I8d. When the inspector has checked over the applied brakes. and momentarily vents the trainpipe at the remote end of the train, the pressure of air on the right-hand side of plunger 18d drops; the equilibrium of the iorces acting on I5c, Ic, Id is destroyed, and the plunger assembly shifts in leftto-right direction, sliding the valve @c into open position, withthe consequence that air flows from the supply, through pipes 5b and 5I, into the train-pipe. Thus, the train-pipe is recharged and th-e brakes shifted into release positions while the inspector is at the remote end of the train. From this point on, the test is completed in the usual-way. v

It will be perceived that in each of the structures described means are provided for shifting from closed to open position a valve (9, 9a or 9c) in one of two lines of iiow. Inthe structure of Fig. I suchvmeans consist in the spring I9, in that of Fig. III in the spring Illa, and in that of FigV in the spring 20c and the piston ISC which is subject to air at supply pressure. in each of the structures, I provide means subject to train-pipe pressure for holding the valve, against theA urging `of such shifting means, in

Thus, the ring 30 within the housing is And` closed position. In the structures of Figs. I to IV, the valve-holding means consist in atrip-arm I3 or Ita, together with a plunger l5 or I5a, subject to spring pressure in one direction of movement and train-pipe pressure in the opposite direction, for throwing the trip-arm into release position when the train-pipe pressure is reduced below a critical value. And in the structure of Fig. V the means for holding the valve 9c in closed position consists simply in the piston Id which, subject to the train-pipe pressure on its right-hand face, masters the forces tending to shift the Valve into open position, until the train-pipe pressure is reduced below the` critical value.

When the valves 9 and 9a of the structures of Figs. I to IV are released and shiftedinto open position, they stand in open position, regardless of train-pipe pressure, until they are manually reclosed. When the valve 9c of Fig. V is opened and recharging of the train-pipe begins, the risf ing pressure on the right-hand side of the piston iSd tends immediately to reclose the valve 9c. To the end that the valve, once opened, shall remain open until it is manually reclosed, I provide a spring-backed latch that bears upon the plunger rod I5c; oneA or more notches 36V are formed in the plunger rod, and when in service the plunger assembly travels to the right and opens the valve 9c, notches 36 come to a position beneath the latch. The inner tip of the latch enters one of the notches and locks the parts against return movement, with the Valve 9c in open position. When desired the latch may be manually withdrawn, and the valve 9c returned to closed position. In order to prevent undue violence in the operation of the plunger, an orifice-plate 5d is arranged in the line of flow between cylinder 56d and the air supply.

I claim as my invention:

1. In air-brake testing apparatus including a supply of compressed air,`an air line adapted to establish communication from said supply to the train-pipe of a line of coupled cars whose brakes are to be inspected and tested, and a valve arranged in said air line; the herein described refinements in such apparatus which include Valve-controlling mechanism including means for sluiting said valve from closed to open position, means for securing said valve in closed position when air pressure in said train-pipe is above a critical value, and means adapted upon reductionof train-pipe pressure to a point below critical value to render said valve-securing means ineffective, whereby an attendant at the end of said line of cars remote from said apparatus may momentarily vent said train-pipe and effect th-e immediate opening of said valve and the recharging of the train-pipe to a pressure vabove said critical Value.

2. The structure of', claim 1, in which said valve-shifting means comprise a spring tending to shift said valve from closed to open position,

land a spring exerting tension on said piston in opposition to train-pipe pressure.

3. In air-brake testing apparatus including a supply of compressed air, an air line adapted to establish communication from said supply to the train-pipe of aline of coupled carswhose brakes are to be inspected and tested, a valve arranged in said air line, and means for shifting said valve from closed. position to open position; theherein described refinements in such apparatus which include a device that, subject to train-pipe pressure', is adapted to retain said valve in closed position when train-pipe pressure is above a critical value, and means adapted, upon the reductionof train-,pipe pressure to a point below critical value, to shift said device into valve-releasing position, with the effect: that the valve, responding to the', valve-shifting means mentioned above, is moved into open position, whereby an `attendantl at the end of the line of cars remote from vsaid apparatus may momentarily Vent said train-pipe and eiect the immediate opening of said valve and the recharging of the train-pipe to a pressure `above critical value. Y

4. In air-brake testing apparatus including a supply offco-mpressed air, an air line including two branches adapted to establish communication from saidsupplyto the 'train-pipe of a line of .coupled cars Whose brakes arey to be inspected l and tested, a manually operated valve in one of said branches, a valve in the other of said branches, and means for shifting saidflast valve value.

from' a position in which communication between air supply and train-pipe is interrupted to a position in which such communication is established; the herein described `renements in such apparatus which include a device that, subject `to train-pipe pressure, is adapted to retain said valve-releasingposition, with the effect that the last valve, responding to the Valve-shifting `means mentioned above, moves into open position, whereby an attendant at the end of the line of cars remote `from said apparatus may momentarily vent said train-pipe and eiect the immediate opening of said valve and the recharg-` ing of the train-pipe to a pressure abovecritical 5. 'I'he `structure of claim -4, in which said device-shifting member consists in a piston subject to train-pipe pressure on one side, and a spring exerting tension on said piston in opposition to train-pipe pressure.

ROBERT SIMPSON. Y

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