US701981A - Automatic air-brake. - Google Patents

Description

No. 70l,98l. 'Patented lune l0, I902.

v G. T. WOODS.

AUTOMATIC AIR BRAKE.

(Application filed Feb. 5, 1901. (No Model.) 3 Sheats-Sheet l.

WEI/265505: Irma/ eta! llfl a. 114M m: NuRms PETER! 00.. FNQYO'LITHO" wnsumowu. u. c.

AUTOMATIC MBv B RA'K'E- (Application filed Feb. 5, 190 1J (No Model.) 3 Shae'ts-Sheet 2.

Train 7 BRAKE CYLINDER I [29' AUXILIARY mzsgRvom MAIN RESERVOIR- THE noRms VETERS o0. PNOTO-UTHO.. WASHINGTON. n c.

7 N0. 701,,Q8l.

G. T. WOODS.

AUTOMATHI AIR BRAKE. Application filed Feb; 5, 1901.1

Patentd lune IO, 'l902.

3 Sheets-:Sheat 3k (No'ModeL) W a I.) m n H W g M A M Q m INVENTOR- WITNESSES: WW6:

THE nonms PETERS co PNo'rcsuTNO WASHINGYON, n. c.

UNITED STATES;

PATENT GRANVILLE T. WOODS, OF NEW YORK, N. Y., ASSIGNOR, BY MES NE ASSIGN- MENTS, TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

A UTOMATIC AlR-BRAKE.

SPECIFICATION formingpart of Letters Patent No. 701 ,981, dated June 10,1902.

Application filed February 5. 1901. Serial No. 46,0 80. (N model.) a

To all whom it may concern:

Be it known that I, GRANVILLE T. Woonsp a citizen of the United States, and 'a-resident of New York, in the county of New York" and State of New York, have invented certain new and useful Improvements in Automatic Air-Brakes, of which the following is'a specification. V I

My present invention relates to the pecul- 1o iar construction and arrangement of: the valves and other parts of an automatic brake mechanism which is preferably operated by compressed air. My invention has for one of its objects to I5 compel a positive action of each brake when the same is expected togoon, to stop the car, or to come off, and thereby release the car.

Railway accidents are reported frequently :0 as being due to the failure of the air=brake systems; and it is one of the objects of my present invention to avoid some of the weak points of the familiar systems in daily use. The brake system in general to which my 2 5 present improvements are shown applied is that in common use and includes; iii addition to the brake-cylinder, auxiliary reservoir, and train-pipe, the usual equipment on the locomotive-such as an air pump or compressor, 3o astorage-tank, and an engineers va'lve-all.

of which parts are familiar to persons skilled in the construction and operation of brake mechanisms. In addition to the parts named a complete automatic air-brake system .in-

5 eludes as one of its essential elements a valve mechanism located on each car and'servin g to control the ad mission and escape of air in the brake-cylinder for elfectin g the application .and release of the brakes. Such valve mech- 0 anism is popnla'rly known as triple-valve I mechanism, and the present improvements relate more particularly to the valve element or part of the brake system and introduces a peculiar mode of operation, notwithstanding V the fact that I employ the usual pressure of air when causing a gradual application of the brakes and also when a quick-action or emergency stop is being made, the gradual application being produced by energyfrom the auxiliary reservoir; but the quick and thus add greatly to the reliability of the common air-brake-equipment.

action is'caused by an initial air-supply from the train-pipe to the brake-cylinder and a final y air-supply from said auxiliary reservoir to the said brake-cylinder.

l ljtris well known to those skilled intheprofession of locomotive-running that-if an airlbrake on'on e' 'car fails to go on it not only causes the loss'of the braking effect'of that particular car-brake, 'butit'also causes the other brakes of the train to lag or gofon'slo wly, 6o

b'ecausethe air pres'sure i'n the trairi-pipe-in such cases is not reduced quickly,-;therefbeing one less brake-cylinder to take a portion of said air from said train-pipe andxither'eby accelerate the remaining-valve apparatus; :It is also well known thatif anem'ergency stop is made at a time when the brakesystem is normal the time and distance required in which to make the stop is short, w11'ile the same train will require a'lohger time anddi's- 7o tan'ce in'which to cease its motion'when the brakesystem is 's'ligh-tlyabuormal. The dif-' ference between the'short timeand distance demanded in 'the one'case and the longer time and distance required inthe other case iisi often the span between life and death.

To insure afar more positiveypowerf-ul, and

aim uch quicker'actionthan ispossibleto be ob I tained by the use of the familiar systems aforesaid, lh'ave provided a'novel construction and So arrangement of the main'or double-acting valve part; the valve of which may be of any suitable kind and combined'with the valve piston part (1 term the combination a f 'valve device) and the various ports, so thatnot; only will the valves and other parts cooperate, butthey may be incorporated with the valve mechanism of the well kk'nownfwestinghouse air-brake system or any formi'of'air-brake which will operate interchangeably with'said Westinghouse system. Furthermoraby the addition of one of my valve devices? toF-each car which is at present "supplied with the said Westinghouse system or the New 'York air-brake apparatus or some similar equip- 5 ment at system will thereby be produced which will embody the majority of the most valuable features of my present invention,

To more fully understand my invention, reference is made to the accompanying drawings, in which-- Figure 1 is a side view of the outside case of my invention. Fig. 2 illustrates a sectional view of the casing and some of the parts of Fig. 1. In Fig. 3 is shown a sectional view of some of the parts and a full side View of other parts of a modification of my invention. Fig. 4 is a side View of the valve-piston part. Fig. 5 is a face view looking from right to left of said valve-piston part. Fig. 6 is an enlarged sectional view of the valve device illustrated in Figs. 2 and 8. Fig. 7 illustrates one way of connecting up the brake-system, so that it one of the valve devices or a valve should fail to operate the other valve device will operate, so that the brake-cylinder will be certain to receive the air-pressure required for its operation. Fig. 8 is a sectional view of the valve devices and their casings when such are arranged as shown in Fig. 7.

In Fig. 1 the part indicated by numeral 1 is an air vent or box which is filled with cotton or some other suitable porous material, so that when the air is drawn through the same from the outside atmosphere, as hereiuafter set forth, the porous material then acts as a filter, serving to prevent grit or dirt from entering the valve-chamber or valvespace which is within the valve-case. Valves 2 and 3 are controlled by moving handle 4 upward or downward. The direction in which said handle is moved will of course depend upon which of the air-passages are to be opened and which are to be closed. Said handle connects with valves 2 and 3 through rod or bar 5, as shown in the drawings. 6 6 are guides for bar 5. The ends of said bar and the outer ends of said valves are provided with teeth, so as to produce What is termed a rack-and-pinion movement. 7 and 8 are the passage-ways or air-pipes controlled by valves 2 and In Figs. 2, 4, 5, 6, and S I have shown the valve device which controls the various ports. When I use the words valve device I mean the valve-piston and the main valve acting as different parts of one device, one of said parts controlling the admission of air from the auxiliary reservoir to the brake'cylinder, while the other part governs the air-admission from the train-pipe to the brake-cylinder. The valve device or, in other words, the valve-like device and the parts connected thereto are more clearly illustrated in Fig. 6, which is the preferred form, enlarged so that the parts may be more readily indicated and understood, and the same may be used as a reference to assist in the explanation of Fig.

2, the. The preferred construction of said apparatus is as follows: The main-valve part, as shown in this case, is what is technically termed a piston-valve and the piston part to which said valve is connected and by which it is moved is (in the present art) technically termed a valve-piston, each part being so named because of its peculiar construction, movements, and the work it performs. The main-valve partherein shown has three partitions E E E These are fixed upon stem 13, which in turn is firmly attached to the hub 14: of the valve-piston part. The valve-piston part of the valve device may be made in one piece, as shown in Fi 3, or it may be composed of several parts, as shown in Fig. 2. The valve-piston part has one or more ports or passages 15, leading through the web or wall 16 into piston-port 17 in the body of the said piston, thence out at the port-opening between the wall 18 and flange 19. In Figs. 2, 6, and S the said ports 15 are closed one way by check-valve 20, which is held to its seat by spring 21. In practice the space between flanges 19 and 22 is sufliciently great to normally cover port 23, which (when open or uncovered by the valve-piston part) leads from the train brakepipe through passage 11 to the brake-cylinder. The three partitions E E E of the mainvalve part are arranged in the following manner: Partitions E and E are so arranged that the restricted port 2 L is normally between them, while the restricted exhaust-port 25 is always between them. Port 26 is always between partitions E and E while port 27 is normally between partition E and wall 18. Now as the valve device moves from the extreme end of its path at the left to the other extreme end of its path to the right (as in emergency stops) then partition E moves to another position between ports 21 and 25. Partition E remains in its normal pathway between ports 25 and 26, while partition E takes up a new position between port 27 and wall 18, at which time the brakes will go on. \Vhen the engineer causes the valve device to move to take off the brakes, said partitions take up their normal positions to the left. In Fig. 3 the check valve 20 is arranged in a valve-box outside of the case A. In this arrangement valve 20 normally covers port 28. When valves 2 and 3 are open, as in Fig. 2, then passage 7 leads from the anxiliary-reservoir opening 30, around through valve 2' to opening 11, thence to the brake cylinder.

In some brake systems the auxiliary reservoir is charged to the same restricted port or passage which communicates between the auxiliary reservoir J and the brake-cylinder I. In my apparatus as illustrated in Figs. 2, 3, &c., the passage 28 is for charging the auxiliary reservoir J, and said passage is arranged as a by-pass-that is, it provides a large direct passage around the restricted port (through which air is supplied from the auxiliary reservoir to the brake-cylinder) directly to the opening 30, leading to the auxiliary reservoir, thus avoiding the slow reservoir-recharging process used in said familiar systems. By the arrangement herein set forth the engineer is permitted to recharge the auxiliary reservoir while the brakes are,

of the portsand valves, andits value is great when. along heavy train is running downgrade and' the engineer desires to keep the train under control. It is well known that when the brakes are on .the airconstantly leaks'frorn-the brake-cylinder. Hence the necessity of =-recharging the auxiliary reservoir while the brakes are on.

.It will be observed that valves 2 and 3 "(shown in Fig.3 and also in the upper portjion X of Fig. 8) are set to obstruct the passages? and 8, which said'valves control, while in Fig. 2 and also the lower part Y of Fig. 8

Ilvalves 2 and 3f are set to permit an open way through said passages.

ffnever set to obstruct the air-passages except These valves are when two valve "devices and their inclosi'ng cases communicate with one brake-cylinder,

as shown in Figs.= 7 and8, one of saidvalve devices acting as a graduating main'valve,

while the othervalve device acts as an emergency-valve only,operating only when emera gency stops are'bei-ngmade. Whenever two valve devices .;are coupled up, as shown in Figs. 7 and 8-, onejof the said devices is converted into a differential piston-.-thatis to say, the valves'2 and 3, while being turned, as shwnin said figures, so as to obstruct the passages 7 and 8,1eading toor from the valve-piston part, willsimnltaneously open a passageleading from theouter end E of the main-valve part, through box or vent 1, to the outer atmosphere. Now if airunder pressure is admitted to both sides of the valve.-

I piston part the total number of pounds use-.

ful pressure upon. the said piston surface next to partition IE will be less'thanthe total numberof pounds useful pressure on the'pis-.

ton-surface next to the adjusting-stem 31,

this difference inthe useful pressures be-.

ing due to the counteracting influence of the surface of partition'E", which'is so exposed as to oppose the pressure against the pistonsurfacenext thereto. as partition E is not exposed to the air-pressure when said air-passages are obstructed the end surface thereof cannot be taken into' the calculation. The surfaces of partition E and piston-wall 18 should be so proportioned that the arrangement as a differential piston will remain quiescent unless required. to act when making an emergency stop, at. 1 which time about twenty pounds reduction is 'made in the train-pipe air-pressure, so that the preponderance .of pressure will be on theauxiliary-reservoir side of said piston part.

Then the auxiliary-reservoir air-pressure will move the said differential piston backtoward the rightuntil it reaches the extreme.

limit' of its path, as hereinafter explained, thus acting absolutely independent of any motion (or the effect of'any motion) which the associate graduating main-valve device may make. g

It will be noted that:

InFig. .7 I have shown a main air-pressure reservoir, an auxiliary reservoir, a brake-cylinder, two valve devices X and Y, an engi- 7c discharge-limit valve is to prevent the escape of more than a predetermined amount of air through the 'action of the engineers valve when an emergency stop is to be made. I It is I well understood that when an emergency stop is to be, made the engineer suddenly dis.- I charges twenty pounds (more or less) from thetrain-pipe. I When said reduction of trainpipe pressure takes place, the valve mechan: ism should act promptly, to admit air from the train-pipe and also from the auxiliary reservoir to. the brake-cylinder. Now when, an emergency stop is required the engineer has no time to gage the escaping air.. Therefore a much greater reduction of the air-pressure takes place than such cases demand, thus re- 0' ducingthe amount of compressed airwhich should have. passed from the trainrpipe into the brakecylinder instead of being discharged into the atmosphere, and thereby reducing the efficiency of the brake system and 5 'adding to the time required to eifect a stop.

Thearrangement of the discharge-limit valve is as follows: Parts 35 and 36 form the two heads of a difierential piston, said heads being connected by a stem, as. shown, or head Ico 35 may be made inthe form of a plunger, if

so desired. This said piston moves within a case or cylinder in the usual way, as shown. The usual vent isindicated at 37; An, airereservoir is shown at H and a check-valve atv38. The operation-is as follows: The lever 390f the engineers valve is shown in position .toadmit air under'pressurefrom reservoir K'throu'gh i pipe 42 into the space between the valve-heads I 40 and 41, thence throughpipe 43, under pisno ton-head 36,then to the train-pipe. Meanwhile, some of the air forces its way past checkwalve '38 and accumulates in reservoir H and the tubular communications immediatelyoonnectt ed therewith. Thus there will bea' pressure 11 5 against both ends ,or heads of. saiddifferenr. tial; piston, and when the pressure in-said reservoir H is equal to that inxthe train-pipe: the check-valve'38 will be seated andthe air. in reservoir Hwill .be .entrappedor con- 12o fined. The under surface of head 36 being, greater in square inches than the upper sur-. face of head 35 permits the preponderance;

of pressure to movethe piston upward tothe. position shown in the drawings. Now if the engineer pulls lever 39- to the right until it reaches the limit of its travel by being brought 5 up against screw. 45 then air will rushout from the train-pipe and past the. outer end of head 41. As soon as the pressure in the train- 1 0 pipehas been reduced to the predetermined limit the preponderance of pressure will .then;

be against the small head 35of said differen-i tial piston,.and therefore said pistonwill be forced down to its seat. In other words, the pressure of the said entrapped air is not reduced by the reduction of the train-pipe pressure. Therefore when the train-pipe pressure is'reduced to a point where its total nu mber of pounds pressure against head 36 is below the total number of pounds pressure exerted against head 35 by the entrapped air then the said piston will be forced down to its seat, and thereby limiting the reduction of the train-pipe pressure by closing or obstructing the train-pipe at the appropriate moment, thus permitting the air to be trans ferred while at its highest permissible pressure from the train-pipe to the brake-cylinder. When the train-pipe is to be recharged, lever 39 is moved to the position shown in the drawings. Then air will pass from the reservoir K, as hereinbefore set forth, until it reaches passage 44, through which the air has access to the under side of piston-head 36, which will then be forced upward until it reaches the position shown in the drawings. Air will in the meantime recharge the trainpipeand the auxiliary reservoirs. It will be noted that the discharge of air is automatically limited or stopped independently of the engineers valve. When connecting up a single valve device to a car, connections are made between the train-pipe and valve-case A, as follows: A branch pipe leads from said trainpipe and connects with said case at point 10. Another connecting-pipe is placed between the brake-cylinder and said case at point 11, while a third pipe connection is supplied between the auxiliary reservoir and said case at point 30. The train-pipe has the usual conneetions from car to car, &c. When a single valve device is used, the operation is as follows: To charge the auxiliary reservoir and prepare the brakes for action, air at about seventy pounds pressure is permitted to flow from the main reservoir K through the train-pipe and its connections into opening 10, (of valvecase A,) thence through chamber B, passages 50, ports 15, around check-valve 20, through piston-port 17 port 28, passage 30, to the auxiliary reservoir. Aportion of the air passes along through passage 7, valve 2, to the outer side of partition E. In the meantime the valve device has been forced to the extreme left of case A. Thus the brake-cylinder is cut 01f from the train-pipe and the auxiliary reservoir, and the exhaust-passage is open between the brake-cylinder and the atmosphere. When it is desired to apply the brake gradually, the handle 39 of the engineers valve will be moved for a moment to such a position that communication between the main reservoir K on the engine and the trainpipe will be closed and an escape-passage is open between the train-pipe and the atmosphere. Thereby the air-pressure in the trainpipe will be reduced about five pounds. This reduction of pressure on the train-pipe side of the valve-piston part disturbs the balance previously existing on the opposite sides thereof, resulting in establishing a preponderance of air-pressure on the auxiliary-reservoir side, and the air delivered from the auxiliary reservoir through passage 30 and acting upon the valve-piston part causes the valve device to move toward the right. This movement will'continue until partition E has passed to the right ofport 24, thus allowing auxiliaryreservoir air to flow through passages 30 and 7, valve 2, to port 24, thence through passage 8 and valve 3, passage 11, to brake-cylinder, where it acts uponthe piston thereof to cause the brakes to go on. When by reason of the flow of air intothe brake-cylinder the pressure in the valve-chamber ahd auxiliary reservoir has been reduced to or below that of the train-pipe, a slight return or leftward movement of the valve device will be prod uced,(by the combined action of the trainpipe pressure and the adjusting-stem 31), sufficient to cause the partition E to rest upon and close port 24, and thus close communication between the valve-chamber and the brake-cylinder and confine the air admitted within the latter. In case it is desired to gradually increase the air-pressure in the brake cylinder the above operation is repeated. To permit the air in the brake-cylinder to escape and let elf or release the brakes, the air-pressure in the train-pipe is restored or increased by a proper and well known movement of the engineers valve. The increase of pressure in the train-pipe causes the valve device to move leftward to the limit of its path, when it will occupy the position shown in Fig. 2, 850., thereby placing restricted port 24 in communication with exhaust-port 25 and allowing the brake-cylinder air to escape. It should be understood that in practice I cause the passage which directly connects with exhaust-port 25 to be much more restricted than any of the other said passages, thereby causing the exhaust from the brake-cylinder to be very gradual. At the same time the restoration of the pressure in the train-pipe will unseat check-valve 20, (after the piston-port 17 registers with port 28,) and air from the train-pipe will flow into the auxiliary reservoir, recharging it for future use. The pressure in the auxiliary reservoir will then equal that in the train-pipe, when the check-valve 20 will be seated by its spring 21. When it becomes necessary to recharge the auxiliary reservoir while the brakes are on, the engineer moves his valve suddenly and connects the main reservoir K to the train-pipe. This causes the valve devices to move quickly to the full limit of their paths toward the left, thus placing the auxiliary reservoir in communication (through large passages) with the fully-charged train-pipe, thus causing the auxiliary reservoir to be charged in an instant. The passage from the brake cylinder through the exhaust (said passage being open while said recharging was being accomplished) is quite small or restricted at the ports. Therefore the air which is confined in said brake-cylinder will have escaped but slightly before said auxiliary reservoir was fully chargedland the engineer dischargedsome airv from the train-pipe as when first applyingthe brakes; Thus-it will be. noted that the brake-cylinder was permitted to receivea second supplyof air-pressure before the first s'upplywas exhausted.

' When itbecomes necessary ordesirable to apply the brakesquickly and with full power for an emergencyzstop, the e'ngineers valve Willbe moved to close .the communication between the main reservoir Ktand thetrainpipe and open the latter .to the atmosphere andiproduce a sudden reduction of pressure of about twenty pounds in the train-pipe. The effect of this sudden diminution of pressure in the train-pipe vis. immediatelywmanitest at the v-discharge limit ,valve (which acts instantly) and the nearest valve device or that on the first canciausinglthe valve device to be movedbythehigher pressure of auxiliary-reservoir airquic'kly toward the right to the endof its path. .Then port 23'r egisters with the piston-port'ilfof the valve-piston part, and thereby placingthe auxiliary res'er Voirand the train-pipe inlcommunication with the brake-cylinder and closing the exhaust-port, The followingpassages are now open: A pathway leads. from opening through pa'ssa'gei'i, valve '2, port 24, passage Q 8,'Valv e 3 to opening 11, thence to the brakecylinder. Another communication s, from opening 3,0throughv ports 27 and 26' to open- 'ing ,11, thence to thellbrake-cylinder. Yet another airpathwayis from openingv 10 through chamberB, opening 50, ports '15,

, piston-port l7, and port I23ut o .openingfll,

thence to thebrake-cylinder. The auxiliary reservoir and the train-pipe being thus brought suddenly into communication with thebrfake-cylinder passageswill cause checkyalve '20 tolbeLimmediately u'nsea'ted and train-pipe air will pass along said path between opening 0am openinglli, thence directly. into the brake-cylinder, Ithus effecting the quick initial application of'Ythe brakes fu'ithe'r' reduction f Pressure in the train-pipe that will'be sufi icient to accelerate th'eaction of the valve fmecha nisinson .the cars follow'ing. The valve -lpiston part will in the meantime beheld to itsoutward position (toward the right) .bythe relatively higher air-pressurefroinfthe auxiliary reservoir, which is delivered through large passage '30,whilethe'transmission ofthe auxiliary-reservoir air from passage 3 0 ito the brake-cylinder is retarded by havingto pass through the restricted port 2%. JAfter'th'e air-pressures in the train-pipeand the brake ecylin'der have equalized auxiliary-reservoir air will continue to flow from the auxiliaryreservoir into the brake-cylinder untilithere is an equalization of air-pressureinboth said ausiliaryireservoir and brake-cylinder. Ilhen adj ustingstem 31, together with the train pipe pressure, will I move the valve device toward the leftiuntil partition E covers port 24. It will be seen that tion by the auxiliaryueservoir pressure, the return movement beingproduced by the trainpipe pressure or adjusting stem 31, or both combined, as hereinbefore set forth; It willbe noted that by restricting the How of auxiliaryreservoirair a considerable volumeof train pipe airis allowedto flow freely intothe brakecylinder, notwithstanding the admission to theZbrake-cylinder at the same time of a small volumeof the auxiliaryqeservoir air under a higher pressure. An appreciable period of time is required to raiselthe pressure in the brake-cylinder to thatin the auxiliary reservoir, and itzis during this intervaliand before the pressure inthebrake-cyh ,inder'is raised to that inthe train-pipe that .the air in the latteris free toenter the brakeeylinder. To release the brakes, a sufiicient amountofair is admitted from the train-reservoir K to the train-pipe to overcome the resistanceof the auxiliary-reservoir pressure and friction. of the valve'mechanism and move the valve device-tothe en d of itsstroke,

(toward. the left, as shown ,in' '2, &c.,)

and thereb y establish "a co nmunication between the brake-cylinder and the atmosphere by way of the exhaustpassage 25.v It will be noted.that ports'26and. 27 are brought into use. only'when fan emergency action of the Valve device takes place. In making a gradual stop the valve device is not movedi ar enough to the ii 7 to. communicate with eachother.

' In Fig. 8 I haveillu'strated an arrangement in whic htwo valve devices (such as shown in Fig. 2) are so coupled up that both parts X' and Yare per nanently and independently connected to the train-pipe, the; brake-cy1- the valve-piston part is movedin one direev 1 I00. ght to allow'ports'26 and 27 inder, and the auxiliary reservoir; but the valve devices of each part X and Y control 7 the various port's atthe appropriate'tim and IIO the action of one of said wvalve devices will always be absolutely independent of the con- V dition or action ofthe other valvedevice. In

other Words, the valves 2a'nd 3 (part X) being set t'oobstruct the air- passages 7 ,8,which said valves cohtroLandvalves 2' 3 (part Y) permitting the passage ways, which I they control, to

vice of, pa'rtY will act in tliemanner hereinbefore set forth, describingtheoperation'of asingle valve'device. 'In making either a gradual stop: Oranemergency stop the engineers valve is manipulated in" exactly the same manner as when controlling the Westinghouse system, w rming thesame manner jinwhich my .present'single' valve device is controlled, In making the. gradual stop the,

valve device in part 1Y4 controls "the ,airfpr essureIn'ecessarytofmake the}. stop and acts as previously set forth herein. In the' meantime the valve device igpartg; win remain quiescent. for thereasonsralreadyi'set forthghereinl be open, then. the valvedevice of part X must 'act as a differential valve device, as, pre

viously set forthhe'rein', while the valve d'e-" 12o \Vhen an emergency stop is to be made, air is discharged from the train-pipe, thereby reducing the pressure about twenty pounds. The preponderance of air-pressu re will then be on the auxiliary-reservoir side of both of said valve devices. Therefore they will immediately move toward the right to the ends of their paths. This will open five paths through which the air-pressure will travel to reach the brake-cylinder. The said paths are as f 01- lows: The train pipe discharges into the brake-cylinder th rough ports 15 in both valve devices, and thence through ports 23 to the brake-cylinder. Another path leads from openings 30 (in both valve cases) through ports 27 and 26 (part X) to the brake-cylinder, and a fifth path leads from opening 30 (part Y) through passage 7, valve 2, around to port 24, thence through valve 3 to the brake-cylinder. To release the brakes, airis admitted as previously described, and the valve devices will move to their normal position to the left, at which time the air confined in the brakecylinder escapes through one outlet onlyviz., through passage 8, valve 3', restricted port 24, and exhaust-port 25. The partition E in part X is exposed to the atmosphere through vent 1. It will be observed from the foregoing description that if one of the valve devices failed to perform its work the other device would act promptly. This is because the train-pipe pressure and the auxiliary-reservoir pressure act upon the pistons of said valve devices simultaneously, independently,

and differentially. From the explanation herein set forth it will be noted that I may use one of said parts (X or Y) for gradual stops, while the other part may be used for quickaction or emergency stops only. Either part X or Y (when arranged as illustrated in Figs. 7 and 8) maybe transformed at will by means of handle 4 from a graduation valve device to an emergency valve device, and vice versa.

I do not limit my invention to any particular kind or shape of valve.

I am aware that it has been proposed to control the director emergency communication between the train-pipe and the brake-cylinder by means of a supplemental valve and piston which is unconnected with the mainvalve piston, but upon the movement of which said supplemental piston (to obtain motion) must depend for a supply of air-pressure, and such construction, which involves an operation and arrangement different from that of my invention, I therefore hereby disclaim.

What I claim is-- 1. In an air-brake system, the combination of a train-pipe having a direct communication a with two adjacent piston or valve chambers,

a communication between an auxiliary reservoir and a brake-cylinder, a communication between the train-pipe and the brake-cylinder, a restricted exhaust-passage between the brake-cylinder and the atmosphere, a valve device in one of said chambers and adapted to control said exhaust and also admit airfrom the auxiliary reservoir to said brakecylinder when such valve device is in its normal condition, and a normally inert valve device in the remaining or second of said chambers and adapted to admit air-pressure sufficient to apply the brakes independently of the condition of the first -mentioned valve device in an emergency application, the said restricted exhaust being adapted to restrict the'escape of air from the brake-cylinder if the first-mentioned valve device should fail to close the exhaust when an emergency-brake application is made.

2. In an air-brake system, the combination of a passage from the train-pipe, a passage from the brake-cylinder which is smaller or more restricted than said train-pipe passage, and a valve device, consisting of a valve connected with a ported piston, coacting with both of said passages and controlling communicatioh between said train-pipe passage and the auxiliary reservoir and also between said brake-cylinder and the exhaust whereby when it is desired to release the brakes, the trainpipe air will have a passage through said ported piston and thence through a large passage-way to the auxiliary reservoir, the brakecylinder air will have a passage-way through a valve-controllod restricted passage to the atmosphere.

3. A valve apparatus for automatic airbrakes, having in combination two ports or passages communicating with the brake-cylinder, one of said passages being small and from the auxiliary reservoir and the other a large passage from the train-pipe, so that the flow of auxiliary-reservoir air is restricted as compared with the flow of train-pipe air when both are flowing to the brake-cylinder during an emergency brake action, a ported piston actuated in both directions by air-pressure, a stem having one end suit-ably connected with said piston, and a suitable valve operated by said stem to open and close the passage from the auxiliary reservoir whilesaid piston controls the valved passage from the train-pipe to the brake-cylinder and opens the same for emergency stops only.

4. I11 an air-brake system, the combination of a passage from the train-pipe, a passage from the auxiliary reservoir which is smaller or more restricted than said trainpipe passage, and a valve device consisting of a valve which is mechanically connected to and moved in both directions by a ported piston, the said valve device coacttng with both of said passages and controlling communication between them and the brake-cylinder whereby, when an emergency application I of the brakes is desired the train-pipe air and the auxiliary-reservoir air, the former at a lower pressure than the latter, will both have passages open to the brake-cylinder as follows: said train-pipe air-passage being through said piston and thence through a by-path in the valve-case, the said auxiliary-reservoir air-passage being through another pathin the valve-case and controlled by said valve.

5. A valve mechanism for automatic airbrakes having in combination, apass'age leading to the brake-cylinder from the train-pipe, a passage leading to the brake-cylinder from the auxiliary-reservoir, which is smaller or more restricted than said train-pipe passage,

.a ported piston actuated in one direction, by

pressure from the train-pipe to close said trainpipe passage, and actuated in the opposite direction by pressure from the auxiliary reservoir to open said train-pipe passage, a stem having one end suitably connected with said piston, and a valve suitably connected with said stem and moved thereby to controlsaid passage between the auxiliary reservoir and the brake-cylinder, while said piston controls the passage betweensaid train-pipe and the brake-cylinder and opens said passage for emergency stops only. 7

6. In an automatic air-brake system, the combination, with the train-pipe, an auxiliary reservoir, and a valve device, of a second valve device which is adapted to act absolutely independent of the action or inaction of the first-mentioned valve device and only when emergency brake applications are made, both of said valve devices being adapted to admit air 'from the auxiliary reservoir to brake-cylinder, and a passage from said trainpipe to said brake-cylinder, and controlled by said second valve device.

7. In an air-brake system, the combination of a train-pipe, two valve devices communieating therewith, the piston parts of both of said devices being constantly under the trainpipe air-pressure and each of said devices being adapted to operate absolutely independent of either the action or inaction of -the other and each of such devices being adapted tocontrol a passage leading from the auxiliary reservoir to the brake-cylinder.

S. In an air-brake mechanism, the combinaticn of a train-pipe having a connection to a valve-device chamber or casing, a communication between said chamber or casing and an auxiliary reservoir, a comm unication between said chamber or casing and a brake-cylinder, and a normally inert differential piston-valve device located within said chamber or casing and adapted to act when making emergency stops only, and establish a check-valved communication between said train-pipe and saidbrake-cylinder, the piston of said valve device being actuated by auxiliary-reservoir air-pressure in one direction to open or establish the latter communication, and moved by train-pipe air-pressure to cutoff or close said communication, during such movements said device operating free from any other valve dovice.

9. .In an air-brake system, the combination of a train-pipe,an auxiliary reservoir, a brakecylinder, two valve devices adapted to act absolutely independent of each other, air

communication between said train-pipe and the auxiliary reservoir, air communication between said. train-pipe and said brake-cylinder, air communication between said aux iliary reservoir and said brake-cylinder and .a restricted air-passage between said brakecylinder and the atmosphere, each of said valve devices being adapted to infi uence the air movement from said auxiliaryreservoir to said brake-cylinder, one of said'valve devices operating only during emergency applications of the brakes.

10. In an air-brakesystelmthe combination of a valve device, substantially'as described, having a ported piston mechanically connected with a valve, a chamber or case for-said piston, a chamber for said valve, a passage from the train-pipe to said piston-chamber, a

passage from said piston-chamber to the auxiliary reservoir, a passage from said piston-' chamber to the brake-cylinder, arestricted passage from said auxiliary reservoir tov the brake-cylinder, and a restricted passage from said brake-cylinder to the exhaust-opening, the said piston when at oneend of its cylininder forms a part of a communication be tween said train-pipe and said auxiliary reservoir, said Valve in the meantime forming a part of a communication between said brakecylinder and said exhaust-openin g, but when said piston is at the other end of its cylinder it becomes a part of a communication between said train-pipe and said brake-cylinder, said communication being open for emergency stops only, and said valve, in themeantiine, opening a communication between the auxiliary reservoir and said brake-cylinder.

11. In an air-brake mechanism, the com'bination of a train-pipe having a tubular connection to two adjacent valve-device chambe'rs or casings, a tubularconnection from each of said chambers or casings to'a brakecylinder, a tubular connection fromeach of said chambers or casings to an auxiliary reservoir, a passage from the brakecylinder to the atmosphere, a graduating-valve device located within one of said chambers orcasings, and a normally inert diderential piston- -valve device located within the other chamber or casing, the latter VaIVG'dGVlCQ being ,adapted to operate when making emergency stops only, and control the communication between said train-pipe and said brake-cylinder, each piston of said valve devices be" ing actuated by auxiliary-reservoir air-pressure in one direction to open or establish said communications and moved by train-pipe airpressure in the opposite direction to close or cut off said communications, in operation saidlvalve devices acting absolutelyindependent of each other.

Signed at New York, in the county of New York and State of New York, this 17th day of January, A. D. 1898. v Y

' GRANVILLE. T. WOODS. Witnesses: l 4

E. RILEY, ORY CANE.

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