US2637201A

US2637201A - Air brake testing apparatus

Info

Publication number: US2637201A
Application number: US94450A
Authority: US
Inventors: William F Meier
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1949-05-20
Filing date: 1949-05-20
Publication date: 1953-05-05
Anticipated expiration: 1970-05-05

Description

y 5, 1953 w. F. MElER 2,637,201

AIR BRAKE TESTING APPARATUS Filed May 20, 1949 2 SHEETSSHEET l l I l Lap Position INVENTOR. WILLIAM F MEIER ATTORNEY Filed May 20, 1949 M y 5, 1953 w. F. MEIER 2,637,201

AIR BRAKE TESTING APPARATUS 2 SHEETSSHEET 2 I I7 Brake Appicafion POSIIIOII JNVENTOR. WILLIAM F MEIER ATTORNEY Patented May 5, 1953 FQMirQ- Pittsburgh, Pa, assignorto Westinghouse Air Brake Company a, corporation of Pennsylvania Application May zo, 1949;-Serial No. 94,4 it chess; (or; 75

This invention relates to fluidpressure brakes and more particularlyto apparatus for testing the operability of such brakeson-a'train of coupledrailway cars prior to coupling the train to a'locomotive; v v I Before a train of coupled'railway cars are connected-to or moved by alocornotive in a railway yard or terminal the brake system on the train must be charged with fluid pressure followed by a partial service reduction in pressure in the brake pipe to cause the brake controlling valve devices on the cars of the train to operate to apply the brakes-and then move to" their lap position for isolating the reservoirs on the-cars irom'the brake pipe. With the brake pipe thus discon nected from th reservoirs onthe carsleaka-ge of fluid-under pressure fromthe brakepipe must be determined by observation of a; pressure gage connected to-the brake pipe Ifthe leakage is excessive the cause must be determined and corrected. Otherwise, or after the causeof excessive leakage is corrected, a-- full servicereduction in pressure in the-brake pipe must be efiected to effect a full service application of the brakes throughout the train-following which aminspection must be made of every car to see that the brakes thereon have applied-properly; that the travel of the brakecylinder piston on each car is correct and that'the brake rigging is notbinding or fouling. If the brakes'are appl on car properly then'the brake pipe and brake equipmenton the cars must be recharged to release the brakes on the cars following which each car in the'train must again be inspected to seethat the brakes thereon'have released asintended.

In order to test atrain as above mentioned either two men must be employed, oneto operate atrain testing device-connected to one end of the train and an inspector to walk back along the train to make the required'; inspection as to the brakes'being applied and then upon arriving at the end of the train opposite that towhich the train testing device is connectedhemust signal back to the man at the train testing device to recharge the train for releasing; the brakes, whereupon theinspector will walk back along the train to observe thebrake release on the cars, or only one man may be employed, in which case he must operate the brake-testing device to apply the'brakesthrough the train then walk back along-the train to'check onthe brake application on all cars after which he must return to operate the testing device torecharge-the train following which he will'again'havetowalk to-the opposite end of the train'to check on'the release of the brakes throughout the train and then return the testingdevice; Obviously, if one man can checkthe brakes on a train of car'sias above de scribed, it isundesirable that two men be so; ployed, but if only one man is sovemploy-ed t s undesirable that he have to-walk" the lefngtli of the-train fpur times to make. the required test (k The principal object of the inventionis ther' fore-the provision of an irnproyed testing; e whereby; one man can nake the" above test on train of cars by walking only oncefrom th'e t ing device to the opposite-end of the train arid then return. V vi i To accomplish this object the loh cj mh i ,w illl operate the improved testing device to applythe brakes through the train a-nd then walk the length of the train to clieck on the application, Upon arriving at theend of thetrain opposite the testing device he will momentarily open the usual angle cock at the endof'the last car'to initij e a wav of pressure reduction inthebrakepipe; the improved testing device beingso const' -cted as to respond to such pressure wavej to'frecha e the brake pipe and release the brakes'Iohthe the train, following which he'will return alo trainto check on the brakereleas'e on the thereby accomplishing inesame'resuu V tofore required either we" or 0 ice amount of walking in the case'o'f a sihgle'rii' I Other objects and advantages wil become" apparent from the following 'rh'oredetailed deserip: tion of the invention. I

In the accompanying drawings; Fig. 1 is'a d' gran inatic view, partly'irrsection aniipa'm outline, of my improved train testing dev shownin testing relation to stra n of r I 3 cars; Figs. 2 and am cro'ss-sectionalview s o'f ah operators control'd evice showflin lbiitwith a valve in different positions than in Fig. 1'; and Fig.4 isa sectional view o fa fluidwave resets; sive device shown in elevationin Fig. 1 andcoiistituting a part of the testing device.

brake pipe 5 adapted at one end of the train to be coupled to a hose coupling l of the brake testing device Ea designates the usual angle cock in the brake pipe 6 at each end of each car, all of which angle cocks in the train are adapted to be open except the one at the end opposite the end to which the testing device will be connected which latter cock will be closed during the testing of the brakes on the train except under a condition to be later described. While only six cars are shown in the drawing as comprising the train it is desired to point out that the train may be of any length.

The brake testing device, constituting the apparatus enclosed within the dot-dash line comprises an operators control device 8, a combined brake pipe charging, maintaining and reducing valve device 9, an equalizing reservoir ID, a fluid pressure wave responsive device i I, a fluid motor [2, cut-off valves I3 and I4, and a pressure gage IS,

The operators valve device 3 may, for the purpose of illustration, comprise a casing to which there are connected a pipe l6 from the hose coupling 4, a pipe ll leading to the valve device 9, and a pipe it also leading to said valve device and to the equalizing reservoir in, and which casing contains a rotary plug valve is movable to three different positions by an operating handle 20. The three different positions of the plug valve l9 and handle 25.! are shown in Figs. 1, 2 and 3 of the drawings, and may be called, respectively, lap position, brake pipe charging position, and brake application position.

The plug valve i9 is provided with a passageway 2| adapted in the lap position thereof (Fig. l) to establish a communication between the pipes I6 and i? and adapted in the brak pipe charging position (Fig. 2) to connect pipes it, I! and I8, while in the brake application position (Fig. 3) said passageway is adapted to connect pipes l6 and IT. The plug valve iii also has a cavity 22 for use only in the brake application position of said valve in which position it is adapted to connect pipe [8 to a restricted exhaust port 23 opening through the casing around said valve to atmosphere.

The combined brake pipe charging, maintaining and reducing valve device 9 comprises a casing containing a movable equalizing abutment, preferably in the form of a piston 2:1, at one side of which is a chamber 25 open to pipe i3 and thereby to the operators valve device 8 and equalizing reservoir it, while at the opposite side of said piston there is a chamber 26 which is open through a pipe 2'5 to one end of the two cut-01f valves 3 and i l. The piston 24 has a stem 28 extending into chamber 26 and connected to said stem is one arm of the bell crank 29 which is fulcrumed on a pin 30 in the casing. A brake pipe exhaust valve 3| arranged to control communication between chamber 28 and an exhaust passage 32 leading to atmosphere is provided on one end of a stem 33 extending through an opening in the other arm of bell crank 29. On the other end of stem 33 is a collar 34 arranged to be engaged by the bell crank 29 upon operation thereof by the piston 24 when moving in the direction of chamber 25 to open the exhaust valve 3|. A spring 35 acting on the collar 34 is provided for at all other times maintaining the exhaust valve 3| closed. Beneath the arm of the bell crank 29 connected to the piston stem 28 there is disposed a brake pipe pressure maintaining valve 36 which is contained in a chamber 3'! open to the pipe I]. The valve 36 has a stem 38 extending through suitable openings in the casing into operative alignment with the arm of bell crank 29 connected to piston stem 28 and which, with the piston 2! in the position in which it is shown in the drawing and with the exhaust valve 3| seated, is adapted to be engaged by said arm. Upon movement of piston 24 in the direction of chamber 25 for opening the exhaust valve 3| the bell crank 29 is adapted to move away from the maintaining valve stem 38 but upon movement of said piston in the direction of chamber 26 after closing of the exhaust valve 3| said bell crank is adapted to engage stem 38 and open the maintaining valve 35 for establishing communication between chambers 31 and 26. A spring 39 acts on the maintaining valve 38 for at other times closing it.

The fluid pressure wave responsive device [I may be of any suitable structure adapted to respond to a wave of reduction in pressure of fluid in brak pipe 5, initiated in a manner to be later described, for supplying fiuid under pressure to actuate the motor I2, but, for the purpose of illustration, may be of the type disclosed in United States Patent No. 2,028,605 issued to E. E. Hewitt on January 21, 1936 and may therefore comprise a casing containing two, coaxially aligned, flexible diaphragms 4| and 42 which are spaced apart and clamped around their edges in the casing. Between the two diaphragms 4| and 42 there is provided in the casing a chamber 43. At the opposite side of diaphragm 4| there is a chamber 34 which is in constant communication with a pipe 45 leading to the end of cut-off valve i3 opposite that to which pipe 2'! is connected. At the opposite side of diaphragm 42 there is a fluid pressure operating chamber 46. Extending into chamber 33 formed between the two diaphragms is a casing rib 41 in which there is provided a passageway 48 extending to the outside of the casing where it is connected to a pipe 4-9 leading to the fluid motor I2. The rib 4'! extends to the center of diaphragms 4| and 42 and there is open through a restricted port Ell to the interior of annular valve seat 5| formed coaxially with and facing diaphragm 4|.

The central portion of diaphragm 4| is clamped between two followers 52 and 53 while the central portion of diaphragm 42 is clamped between

followers

54 and 55, the followers 53 and 54 being disposed in chamber 43 and connected together by spacers 56 engaging same and cap screws 51 extending through the followers 52 and 55 and having screw-threaded engagement with said spacers whereby said followers are rigidly secured to opposite sides of the respective diaphragms and the diaphragm; are secured together for movement in unison. The follower 52 has a boss 58 extending into chamber 44 to provide within said boss a chamber 59 open through a central aperture in the diaphragm 4| and an aligned opening in the follower 53 to chamber 43 and also open through a port 60 to chamber 4-2. A check valve 6! loosely mounted in chamber 59 is provided for engagement with the valve seat 5|, a spring 62 in the boss 58 acting on said valve for urging it into such engagement. The follower 53 is provided with one or more fingers 63 extending into its axial opening for engaging the check valve SI for moving it out of contact with the seat 5| upon deflection of diaphragm 4| in an upward direction. Depending from the diaphragm follower55 is a stem 66 the lower end of which is slidably mounted in a suitable bore in the casing. In the upper end of stem 64 there is a chamber 65 open through aport $6 tochamber 45 and containing a valve 61 arranged to cooperate with a seat for controlling communication between said chambers and the chamber 43 by way of a passageway through which extends a tapered stem 68 of said valve which stem upon deflection of the diaphragm 42 in an upward direction is adaptedto engage the casing rib '4"! for opening said valve. The chamber it is also constantly open to chamber 43 through chamber'65 and a port 69 in the follower 55. A bias spring 19 contained in chamber a l acts to bias the diaphragrns and associated parts in the direction of chamber 66.

The fluid motor I2 comprises a casing containing a piston III at one sideof which is a pressure chamber?! open to pipe is. At the opposite side .of piston I is a non-pressure chamber 32. through which there extends a piston rod 53 projecting from said piston and disposed for movement in the plane of movement in handle 20 of the operators valve device 8. A spring M in chamber acts on piston I0 forurging it to the position in which it is shown in the drawing when chamber II is void of fluid under pressure. Upon. supply of fluid under pressure to chamber H such pres sure acting on piston Iii is. adapted to move said piston and-rod 13 against the spring I4. A restricted port 15 opens pressure chamber 'H to atmosphere for releasing fluid under pressure from said chamber. The motor I2 is so arranged with respect to the operator's valve device 8 that when the piston Hi is in the position in. which it is shown in the drawing the end of rod 13 will be withdrawn to a position. out of the path of movement of the operators control lever 26 to permit free movement of said leverto any one of its three different positions, but upon supply of fluid under pressure to chamber Al to actuate piston Hi the rod 1-3 will be operated against the handles H at right angles to the pipe connections between the valves and the respective pipes that the communications through the valves will. be closed while with the handles pointed in the direction of such connections such communications will be open. ItJwill be seen that the cutoff valve I3 is arranged to control communication between pipe 2'1 and pipe 45, while the cutoff valve I4 is arranged to control communication between pipe 21 and the hosecoupling'l.

Thepressure gauge I5 is of the duplex type having one pressure element (not shown) connected by a pipe I! to a pipe 18 connecting the cut-off valve I4 to the hosecoupling I, and hav-' ing other pressure element (not shown) connected by a pipe 19 to the equalizing reservoir 9 whereby said gauge will register the pressures in both the brake pipe Brand saidreservoir.

Operation In operation, let it"be assumed that the train of cars 5 has been coupled upon whichiit isdesired to test the brakes, that all angle cocks 6a in the" train are open except the one" at" one end 6 of thetrain and thatthe reservoir Zis supplied with fluid under pressure for such testing purposes. The operators test device -I will thenbe connected'at coupling 1 to brake-pipes at the opposite end of the train-5 and at coupling 4 to the reservoir pipe 3. The cut-oil valve I4 in the testing device will be opened and the cut-off valve I3 closed.

Now to test the brakes on the train the operators control device 8 willbe moved to the brake pipe charging position (in Fig. 2) in which fluid under pressure from reservoir 2 will be supplied from pipe 15 to pipe H and thence to the maintainingvalve chamber -31 in the valve devices and alsoirompipe I6 to pipe I8 and thence to the equalizing reservoir I!) and equalizing piston 'chamber25 in thedevice- 9.

The pressure of fluid thus provided in piston chamber 25 will move piston 24 in a downward direction'for thereby actuating the bell crank 29 to open the maintaining valve 36 while allowing the brake pipe discharge valve 3| to remain closed. Upon openingthe maintaining valve 36 fluid supplied from the reservoir 2 to "the maintaining valve chamber 37 willflow into chamber 26 and thence through pipe 21, the open cut-oil valve I4 and out through pipe I8 and the'hose coupling 1 to the brake'pipe 6 extending through the train whereby said brake'pipe and 'thebrake equipments on the several cars of the train will become charged with fluid at thepressure' in said reservoir, it being noted that the angle cock 6a at the end of the train opposite that to'which'the testing device I is connected is closed at this time to permit such charging. When the pressure of fluid thus obtained in 'the'brak'e pipe 6 and in chamber 25 at one side of" piston 24 in theval ve device 9 becomes substantially equal to that in the equalizing reservoir I0 and in chamber 25st the opposite side of said piston, spring 39 acting on the maintaining valve 36 will actuate the bell crank 29 and said piston to a'position in which the maintaining valve will be closed and the brake pipe discharge valve 3| will also be still closed.

After the brake pipe 6 and brake equipments on the cars of'the train have thus become charged to the pressure in the main reservoir-'2, the brake inspector will operate the operator's control handle 20 to move the plug valve I9 to its brake application position inwhieh it is shown in Fig. 3 of the drawing. In the br'akeapplication position the reservoir 2' will remain connected to the maintaining valve c'hamber' s'l, while the equalizing piston chamber 25 and reservoir iii will be disconnected from reservoir 2 and opened through cavity 22 in thezplug valve ISito the restricted exhaust passage 23 for venting fluid under pressure from said equalizing piston chamber 25 and equalizing reservoir Hi. 'Thepressure of fluid in chamber 25 andreservoir I6 will thus 'be reduced to a degree such as or 5'5pounds, assuming that the brake pipe 6 was initially charged to for example '70 pounds, and when the pressure 1n said chamber and reservoir becomes so reduced the handle 20 will be operated to turn the plug valve !9'to lapposition, in which it is shown in Fig. l in'the drawing, fordisconnecting pipe I8 from the atmospheric exhaust passage'23 to thereby terminate the reduction in pressure in chamber '25 and equalizing reservoir 9.

Whenjthe pressure-of fiuid 'inequalizing piston chamber 25 and equalizing reservoir It is reduced as just described to auegree below the pressure of fluid in chamberze-actingron'the opposite side of piston 24, the latter pressure will actuate said .piston in the direction of chamber 25 and thereby operate the bell crank 29 to open the brake pipe discharge valve 3|, whereupon fluid under pressure will be vented from the brake pipe 6 past said valve to passage 32 and thence to atmosphere. Fluid will thus be released from the equalizing piston chamber 26 and the brake pipe 6 until the pressure of such fluid becomes reduced to substantially that acting in piston chamber 25 whereupon spring 35 will actuate the bell crank 29 and piston 24 to permit closure of the exhaust valve 3| for thereby limiting the reduction in pressure in brake pipe 6 to substantially the same degree as that acting in chamber 25 and in the equalizing reservoir l0. As well-known when less than a full service reduction in pressure is thus efiected in brake pipe 6 in a train the brake controlling valve devices on the cars of the train will operate to apply the brakes to a degree corresponding to such reduction and then move to their lap position in which the brake pipe on the cars is isolated from other parts of the brake equipment on the cars. With the brake pipe on the cars thus isolated the cut-oir valve M will be closed to disconnect the testing apparatus from the brake pipe and by observation of the pressure gauge l4 for a certain period of time the leakage .of fluid under pressure from the brake pipe on the train will be determined.

If the leakage of fluid under pressure from the brake pipe exceeds a certain permissible amount, such as seven pounds per minute, the cut-off valve l4 will be reopened to reconnect the brake pipe 6 to pipe 21 and chamber 26 below the equalizing piston 24. With the operators valve device 8 still in lap position, as shown in Fig. 1, the pressure of fluid in equalizing piston chamber 25 and in equalizing reservoir I is bottled up so that as the pressure in chamber 26 at the opposite side of said piston reduces with brake pipe pressure, due to leakage, the pressure in chamber 25 will actuate said piston to operate the bell-crank 29 to open the maintaining valve 36, whereupon fluid under pressure from the reservoir 2 supplied to pipe I? will flow to chamber 26 and thence to the brake pipe 6 on the train to build the latter pressure up to that in chamber 25 and equalizing reservoir |0. As the pressure of fluid in the brake pipe 6 is thus increased the piston 24 will be moved in the direction of chamber 25 until the maintaining valve 36 obtains a position for supplying fluid to the brake pipe at a rate just suflicient to maintain the pressure therein against the leakage and equal to the pressure in the equalizing reservoir l0. With the pressure of fluid in' the brake pipe thus maintained against leakage the cause of excessive brake pipe leakage will be determined and corrected.

If the brake pipe leakage is within the permissible degree, or after it has been reduced to such a degree, the operators control device 8 will again be moved to the brake application position (Fig. 3) for effecting a further reduction in pressure in the equalizing reservoir l6 and equalizing piston chamber 25 to a full service degree. The equalizing piston 24 will then respond to effect a corresponding further reduction in pressure in the brake pipe 6 and through subsequent operation of the maintaining valve 36 maintain the be effected whereupon the inspector will walk from the brake testing device I along the train to the rear end thereof for inspecting the brake equipments on the different cars to determine if they have operated as intended.

After a full service application of brakes has been effected on the train, and before the inspector leaves the brake testing device I to walk back along the train to note if the brake equipments on the car have operated as intended, he will open the cut-off valve I3 of the testing device whereupon fluid under pressure from pipe 21 will flow to pipe 45 and thence into chamber 44 of the fluid pressure wave responsive device When fluid under pressure is thus supplied to chamber 44 it will fiow through port 60 in the diaphragm follower boss 58 into chamber 59 and thence around the check valve 6| to chamber 43 and from the latter chamber through port 69 to chamber 46 and charge these three chambers with fluid at the pressure acting in pipe 21 and the brake pipe 6, it being noted that such pressure will be maintained at the same degree as acting in the equalizing piston chamber 25 and equalizing reservoir II) with the operators control device 8 in lap position (Fig. 1) due to operation of the maintaining valve 36 as hereinbefore described. With the pressures equal in

chambers

44, 43 and 46 of the wave responsive device H the bias spring 19 will maintain the diaphragms 4| and 42 and'associated parts in the position in which they are shown in the drawing and spring 62 will hold the check valve 6| seated closing communication between chamber 43 and passage 48 leading to pipe 49.

If after inspection the inspector has found that the brake equipments on all cars of the train have operated to apply the brakes as intended, then upon arriving at the end of the train opposite the brake testing device he will momentarily open and then reclose the angle cock 6a at the end of the last car and thereby create a wave of reduction in pressure in the brake pipe 6. This wave of reduction will travel very rapidly throughout the length of the train and become effective in diaphragm chamber 44 of the wave responsive device H at the brake testing device I and reduce the pressure in said chamber to a degree below that acting in

chambers

43 and 46, as a result of which, the higher pressure of fluid in the latter chambers will deflect the diaphragms 4|, 42 upward. As the diaphragm 4| is thus deflected upward the follower 53 connected thereto will lift the check valve 6| off of its seat 5| to permit fluid under pressure to flow from chambers 44 and 43 to passage 46 and thence to chamber 1| in the fluid motor |2. At the same time fluid under pressure will also flow from chamber 46 through port 69 to chamber 43 and the valve 61 will be opened to accentuate such flow from chamber 46, the fluid thus supplied from chamber 46 to chamber 43 also flowing to chamber H in the fluid motor |2. The port 60 through the boss 58 of the follower 52 has such flow capacity with respect to the capacity of port 50 and valve 61 for reducing the pressure in chamber 46 that the pressure in the latter chamber will reduce faster than that in chamber 44 so as to destroy the difierential in pressures in chambers 44 and 46 whereupon the spring 19 will deflect the diaphragms 4| and 42 back to their normal position to permit closing of valve 6| by ,spring 62 for terminating supply of fluid under pressure to chamber H in the motor |2.

The fluid under pressure supplied, as just described, tochamber H in the motor l2 will however be sufiicient to actuate pistonagainst spring 14 to move rod 13 against handle 20 of the operators valve device 3, which handle is at this tion to brake pipe charging position in which it ,is shown in Fig. 2 of the drawing. After the handle 20 is thus moved by fluid motor [2 to its brake pipe charging position the fluid under pressure will be released from chamber H in said motor by way of the leakage port 15 to permit spring 14 to actuate piston T0 to retract the rod 13 to its normal position in which it is shown in the drawing.

When the handle and thereby the rotary valve I9 of the operators control device 8 are thus moved to their brake pipe charging position by operation of motor l2 in response to a wave of reduction effected in the pressure of fluid in the brake pipe by the inspector operating the angle cock to at the opposite end of the train, fluid under pressure will be supplied to the brake pipe 6 throughout the train in the same manner as above described for recharging said brake pipe to normal pressure and for in turn operating the brake equipments on the cars throughout the train to their brake release position for eftesting a release of the brakes on the cars. After the brakes on the car of the train most remote from the brake testing device I have thus reof the brake testing device I, as above described,

and have been found to operate as intended, the brake testing device atcoupling 4 and I will be disconnectedfrom the main reservoir 2 and from the train brake pipe 6, respectively, the train now being ready for connection to and movement by a locomotive with the assurance that the brakes will operate as intended.

With the operators control device 8 in lap position (Fig. 1) after having effected a full service application of the brakes just prior to the inspecter walking from the testing device back along the train to the rear end, it Will be noted that the maintaining valve will operate during this period to maintain the pressure of fluid in the pipe it throughout the train against leakage at the same pressure as acting in equalicing reservoir Hi. This is very necessary, for otherwise, with permissible leakage of fluid under pressure. from the brake pipe the pressure of such fluid, particularly on a long train, would be substantially fully dissipated before the inspector reached the oppositeend of the train, so that he, would be unable to create a wave of reduction in pressure in the brake pipe for operating the wave responsive device I! atthe testing deviceby momentarily opening of the angle cock ta at the rear end of the train.

Summary It will now be seen that a brake testing device been provided which requires the service of only one man to check the brake eouipment'on a 1O plication of brakes and subsequently a release of such a brake application.

Having now described the invention what I claim as new and desire to secure by Letters Patent, is:

1. A device for testing the air brake equipment on the coupled cars of a train through the medium of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressure, a brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a first position for operating said valve means to supply fluid under pressure from said supply conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from said brake pipe conduit and to a third position for holding constant reduced pressure or" fluid in said brake pipe conduit, a motor piston operable by fluid under pressure to move said handle to its first position, and means subject to pressure of fluid in said brake pipe conduit and an opposing pressure operative in response to a wave of reduction in pressure in said brake pipe conduit relative to said opposing pressure to supply fluid under pressure to said motor for actuating said piston and operative upon substantial equalization of pressure in said brake pipe and said opposing pressure to cut off supply of fluid under pressure to said motor, and means for releasing fluid under pressure from said motor with supply of fluid under pressure thereto out off.

2. A device for testing the air brake equipment on the coupled cars of a train through the medium of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressures, brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a first position for operating said valve means to supply fluid under pressure from said supply conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from said brake pipe conduit and to a third position for holding constant reduced pressure of fluid in said brake pipe conduit, pressure responsive means subject to pressure of fluid in said brake pipe conduit and an opposin pressure operative um of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressure, a brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a first position for operating said valve meansto supply fluid under pressure from said supply conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from said brake pipe conduit and to a third position for holdingconstant reduced pressure of fluid in said brake pipe conduit, pressure responsive means subject to pressure of fluid in said brake pipe conduit and a substantially equal opposing pressure and operative upon a reduction in pressure of fluid in said brake pipe conduit relative to said opposing pressure to move said handle to its first position, and means for selectively opening and closing communication between said brake pipe conduit and said valve means and pressure responsive means.

4. A device for testing the air brake equipment on the coupled cars of a train through the medium of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressure, a brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a first position for operating said valve means to supply fluid under pressure from said supp y conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from said brake pipe conduit and to a third position for holding constant reduced pressure of fluid in said brake pipe conduit, a motor operable by fluid under pressure to move said handle to its said first position, and pressure wave responsive means comprising a movable abutment subject to opposing pressures in said brake pipe conduit and in a chamber and responsive to a wave of reduction in pressure in said brake pipe conduit to open communication from said brake pipe conduit to said motor for supplying fluid under pressure to said motor, and restricting means for equalizing pressure of fluid in said brake pipe conduit and in said chamber.

5. A device for testing the air brake equipment on the coupled cars of a train through the medium of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressure, a brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a first position for operating said valve means to supply fluid under pressure from said supply conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from said brake pipe conduit and to a third pos tion for holding constant reduced pres ure in said brake pipe conduit, a motor operable b fluid under pressure to move said handle to its said first position, and pressure wave responsive means comprising a movable abutment subiect to opposing pressure in said brake pipe conduit and in a chamber responsive to a wave of reduction in pressure in said brake pipe conduit to open communication from said chamber to said motor for supplying fluid under pressure from said chamber to said motor, and a restricted communication connecting said brake pipe conduit and chamber for equalizing pressures of fluid therein.

6. A device for testing the air brake equipment on the coupled cars of a train through the medium of the brake pipe extending through the train, comprising in combination, a fluid pressure supply conduit adapted to be connected to a source of fluid under pressure, a brake pipe conduit for connection with said brake pipe at one end of said train, valve means including an operators control handle movable manually to a flrst position for operating saidvalve means to supply fluid under pressure from said supply conduit to said brake pipe conduit, to a second position for releasing fluid under pressure from aid brake pipe conduit and to a third position for holding constant reduced pressure of fluid in said brake pipe conduit, a motor operable by fluid under pressure to move said handle to its said first position and pressure wave responsive means comprising a movable abutment subject to opposing pressures of fluid in said brake pipe conduit and in a chamber and responsive to a wave of reduction in pressure in said brake pipe conduit to open communication from said chamber and brake pipe conduit to said motor for supplying fluid under pressure to actuate said motor, and a restricted communication connecting said brake pipe conduit and chamber for equalizing pressures of fluid therein.

7. A device for selectively opening and closing communication between a source of fluid under pressure and a brake pipe of a train and between said brake pipe and atmosphere for testing the air brakes on the train comprising in combination, a fluid pressure supply conduit adapted to be connected to said source of fluid under pressure, a brake pipe conduit adapted to be connected to said brake pipe, a brake pipe charging and maintaining valve controlling a communication between said supply conduit and said brake pipe conduit, a brake pipe discharge valve controlling a communication between said brake pipe conduit and atmosphere, an equalizing reservoir adapted to be charged with fluid under pressure, an equalizing piston subject opposingly to pressures of fluid in said equalizing reservoir and in said brake pipe conduit, means connecting said charging and discharge valves to said piston, said piston being operative upon a preponderance in pressure of fluid in said reservoir over that in said brake pipe to open said maintaining valve and upon a preponderance in pressure of fluid in said brake pipe conduit over that in said reservoir to open said brake pipe discharge valve and operative upon substantial equalization of said opposing fluid pressures to effect closing of both said maintaining valve and said brake pipe discharge valve, an operators control device comprising valve means and a handle for moving said valve means to one position for opening said equalizing reservoir to said source of fluid under pressure, to a second position for opening said equalizing reservoir to atmosphere and a third position for bottling up the fluid under pressure in said reservoir, and a manually operative valve for selectively opening and closing the communication through said brake pipe conduit.

8. A device for selectively opening and closing communication between a source of fluid under pressure and a brake pipe of a train and between said brake pipe and atmosphere for testing the air brakes on the train comprising in combination, a fluid pressure supply conduit adapted to be connected to said source of fluid under pressure, a brake pipe conduit adapted to be connected to said brake pipe, a brake pipe charging and maintaining valve controlling a communication between said supply conduit and said brake pipe conduit, a brake pipe discharge valve controlling a communication between said brake pipe conduit and atmosphere, an equalizing reservoir adapted to be charged with fluid under pressure, an equalizing piston subject opposingly to pressures of fluid in said equalizing reservoir and in said brake pipe conduit, mean connecting said charging and discharge valves to said piston, said piston being operative upon a preponderance in pressure of fluid in said reservoir over that in said brake pipe to open said maintaining valve and upon a preponderance in pressure of fluid in said brake pipe conduit over that in said reservoir to open said brake pipe discharge valve and operative upon substantial equalization of said opposing fluid pressures to effect closing of both said maintaining valve and said brake pipe discharge valve, an operator's control device comprising valve means and a handle for moving said valve means to one position for opening said equalizing reservoir to said source of fluid under pressure, to a second position for opening said equalizing reservoir to atmosphere and a third position for bottling up the fluid under pressure in said reservoir, actuating means for moving said handle to its said first position, a movable abutment subject to pressure of fluid in said brake pipe and an opposing substantially equal pressure and operative upon a wave of pressure reduction in said brake pipe conduit to effect operation of said actuating means, and manually operable valve means for selectively opening and closing communication between said wave responsive means and through said brake pipe conduit.

9. In train air brake testing apparatus including a source of fluid under pressure, conduit means for conveying fluid under pressure from said source to the brake pipe of the train of coupled cars the brakes of which are to be inspected and tested, a valve in said conduit means having an open position and a closed position, actuating means responsive to a variation in pressure of fluid for shifting said valve from said closed position to said open position, valve means for effecting said variation in pressure in said actuating means and pressure sensitive means subject to pressure of fiuid in said brake pipe and an opposing pressure and operative by said opposing pressure upon a wave of pressure reduction in the connection of said conduit means with said brake pipe to effect operation of said valve means whereby an attendant at the end of said train remote from said apparatus may initiate a wave of pressure reduction in said brake pipe to effect movement of said valve to said open position for charging said brake pipe with fluid under pressure from said source.

10. In train air brake testing apparatus including a source of fluid under pressure, conduit means for conveying fluid under pressure from said source to the brake pipe of a train of coupled cars the brakes of which are to be inspected and tested, a valve in said conduit, means operable manually for moving said valve to an open position for supplying fluid under pressure from said source to said brake pipe, to a brake application position for releasing fluid under pressure from said brake pipe, and to a lap position for closing communication between the conduit connection with said brake pipe and both said source and atmosphere, power means for shifting said valve to said open position, control means for effecting operation of said power means, and pressure sensitive means subject to pressure of fluid in said brake pipe and an opposing pressure and operative by said opposing pressure upon a wave of pressure reduction in said conduit connection with said brake pipe to effect operation of said control means whereby an attendant at the end of said train remote from said apparatus may initiate a wave or" pressure reduction in said brake pipe and effect movement of said valve to said open position for charging said brake pipe with fluid under pressure from said source.

WILLIAM F. MEIER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,855,135 Meier Apr. 19, 1932 2,028,605 Hewitt Jan. 21, 1936 2,189,184 Simpson Feb. 6, 1940