US912716A - Air-brake apparatus. - Google Patents

Description

M. Pl MURPHY. AIR BRAKE APPARATUS. APPLICATION FILED APRA, 190e.

Patented Feb. 16, 1909.

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H. M. P. MURPHY. AIR BRAKE APPARATUS.

APPLICATION FILED APHA, 1910s.

912,716. Patented Feb.16,1909.

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H. M. P. MURPHY. AIR BRAKE APPARATUS. APPLIUATION FILED APRA, 1908.

WfNEssEs A n 4A/V A2 A2 507 Q Y /VVENTOR I A//arnfy -rHe NoRms persas co Asm crc D c HOWARD M. P. MURPHY,

L. H. BOWMAN, OF MUNHALL, PENNSYLVANIA, ANI) NERY, OF PITTSBURG, PENNSYLVANIA.

OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF ONE-FOURTH TO ONE-EIGHIH TO JOSEPH M. FLAN- AIR-BRAKE APPARATUS.

Specification of Letters Patent.

Patented Feb. 16, 1909.

Application filed April 4, 1908. Serial No. 425,195.

To all whom it may concern:

Be it known that I, HOWARD M. P. MUR- PHY, a resident of Pittsburg, in the county of Allegheny and State ol' Pennsylvania, have invented certain new and useful Imrovements in Air- Brake Apparatus; and l) do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in air brake apparatus and more particularly to a triple valve mechanism, especially such as is adaptable for use on passenger trains.

One object of my present invention is to provide in a triple valve mechanism, simple and eilicient means Yfor maintaining brake cylinder pressure notwithstanding leakage which might occur on account ol imperfect joints or wearing of packings.

A further object is to so construct a triple valve mechanism that the release as well as the application of the brakes can be accurately graduated.

A further object is to provide a triple valve mechanism with simple and efficient means for venting a small amount of train ipe fluid to the brake cylinders in service applications oll the brakes and a large amount in emergency applications.

A further object is to provide in a triple valve mechanism, improved means for supplementing the volume el fluid employed in the emergency application of the brakes.

A 'further object is to so construct a triple valve mechanism that simple and ellicient means shall be provided to limit the brake cylinder pressure to a predetermined degree during the service application ol' the brakes, and to so construct the mechanism that, during the emergency application of the brakes the pressure limiting means will be eliminated from action.

With these objects in view, the invention consists in certain novel Vl'eatures ol` construction and combinations and arrangements of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings, Figure 1 f is a longitudinal sectional view ol my improved triple valve mechanism, the parts eing shown 1n their release position.

Fig. 2 is a view showing the parts in "release lap position. Fig. 3 is a view showing the parts in equalization-leed-up position. Fig. Ll is a view showing the parts in emergency position. Fig. 5 is a View showing the valve devices in quick service position. Fig. 6 is a similar View showing the full service position of the slide valves. Fig. 7 is a view showing the slide valves in equalization lap position. Fig. 8 is a plan view oi' the main slide valve seat. Fig. 9 is a top plan view of the main slide valve, and Fig. 10 is a top plan view of the graduating valve.

1 represents a casing, one head, 2, of which constitutes one end of a chamber 3. A bushing l is located within the casing and allords a valve chamber 5 which communicates at one end with the chamber 3. A piston 6 is located within the chamber 3 and is provided with a rod 7 for operating slide valves R and S in the valve chamber 5, as hereinafter described. Duets 8 -9 are provided for conducting train pi )e fluid to the chambers 3-5 and the cham er 5, together with that portion of the chamber 3 to the left of the piston will constitute what may be conveniently termed, a controlling space. At the juncture of the ducts 8 and 9 a check valve 10 is located, and is pressed upon its seat by means of a light spring 1 1, said valve being ada )ted to prevent a backward passage of vfluid from the controlling space, through the duct 9 to the train pipe. A duct 12 constitutes a continuation of the train pipe duct S and is in free communication at one end with a duct 13 which terminates in a port f in a seat T for the main slide valve S. The port f and ducts 13, 12 and 8 thus constitute a free path for iluid from the valve chamber 5 (which constitutes a.. portion of the controlling space) to the train pipe under certain conditions, but such path is closed under other conditions (as in emergency position of the mechanism) by the covering of the port f by the main slide valve S.

Auxiliary reservoir lluid is admitted to the chamber 5 (at the right hand side of the piston 6 therein) through a port 14 which receives such fluid through ports 15 in a hollow enlargement 16, from an auxiliary reservoir duct 17. When the parts are in position to e'llect a recharge of the auxiliary reservoir, the piston 6 will uncoven a duct 18 in the wall of chamber 3, so that train pipe luid can i'low from the controlling s )ace at the left of the piston through said duct 13 and thence through ports 19 in abutments 20 and finally through port 14 and the ducts 15 to the auxiliary reservoir duct.

For reasons which will hereinafter appear, it is desirable at certain times to restrict the flow of auxiliary reservoir 'Huid from the auxiliary reservoir to the chamber 3 at the right of the piston 6 and at other times to permit free communication between the chamber 3 and the auxiliary duct. To accomplish this, a rod 21 is employed, said rod being provided with a contracted portion 22 which, when in the position shown in Fig. 1, will permit a free communication between the chamber 3 and the auxiliary reservoir duct. 1t is apparent however, that when the larger portion 23 of the rod is disposed in the port 14 and between the ports 15, the passage for auxiliary i'luid to the chamber 3 at the right of the piston will be restricted. The rod 21 passes through a gland 24 secured to the piston 6 and enters a socket 25 in the piston rod 7, the movement of said rod 21 1n one direction being limited by the engagement of a head 26 thereon with the gland 24. The rod 21 is normally pressed in this direction by a spring 27 located in the socket 25, and said rod 21 is movable in the other direction for eiliecting a slight movement of the piston by the action of the spring, by engagement with an abutment 28 afl'orded by the enlargement 16.

A duct 29 leads to the brake cylinders and communicates with a chamber 30. F rom this chamber, a duct 31 extends to the valve seat T, so as to communicate at one end with a port a therein. A check valve 32 closes the other end of the duct 31 so as to prevent a back flow of brake cylinder i'luid through the duct 31 under certain conditions. A duct 33 also communicates with the chamber 30 so as to, in effect, constitute an extension of the brake cylinder duct 29, and the said duct 33 terminatesin an elongated portion 33a under the valve seat T so as to communicate with ports e and e in the latter. Vith the parts in the position shown in Fig. 1, the brake cylinder ducts 29-33 are open to an exhaust duct 34, through the medium of certain ports and passages in the slide valve devices. This path of the brake cylinder exhaust may be traced from the duct 33, as follows: from said duct 33 through a port e in the valve seat T, thence through a port m in the main slide valve S thence through a passage or cavity g in the graduating valve R; thence through a port n in valve S and through a passage t to a port p, and thence through the exhaust port d which terminates in the exhaust duct 34.

The check valve 32 is engaged by a valve 35 which is forced thereagainst by a spring 36 which is thus adapted to hold that valve 32 on its seat. The valve 35 is adapted to control the passage of Huid from the brake cylinder ducts through a duct 37 leading to a safety or pressure reducing valve 36a, being adapted, under certain conditions, to fully close said duet 37, and under other conditions, to establish free communication between the brake cylinder ducts and the safety or reducing valve by means of ducts 35a.

The valves R and S are, as before intimated, adapted to be controlled by the movements of the piston 6, but the latter can have a movement independently-0f the valve S throughout a portion of its throw, while the graduating valve R is always movable with the piston. To provide a lost-motion connection between the main slide valve S and the piston 6, the rod 7 is provided with shoulders 33 and 39 to engage shoulders 4G and 41 respectively on the valve S, said shoulders 41 being located a distance apart which is less than the distance between the shoulders 33-39 on the piston rod 7. The graduating valve P. iits neatly in a recess 42 in rod 7 and is pressed to its seat on the main valve S by means of a spring 43, which latter also serves to hold the main valve S on its seat T.

At the leit hand end of the chamber 3, the wall of said chamber is provided with a series of O'rooves or ducts 44 and with a groove or duct 45, the latter being somewhat longer than the ducts 44 for a purpose which will hereinafter appear. 1t will be seen that w ien the piston is in a position at or near the left hand end of the chamber 3, the grooves or ducts 1445 will be uncovered so as to form ley-passes for auxiliary reservoir fluid trom the space at the right oi" the piston to the space at the left thereof and thence through ducts 44at to the valve chamber 5. When the piston reaches a position to uncover the ducts 44-45, the valve S will have been so moved as to uncover the port d in the seat T and the auxiliary reservoir air can therefore pass through the ducts 31-29 (past check valve 32) to the brake cylinders.

The main slide valve S is provided with a duct or passage Z2 having ports Zand Z at its respective ends, and these serve in certain positions of the valves (as in quick serviceH position shown in Fig. 5) to ccnneet the controlling space with the port a and hence with the brake cylinder duets. A

duct 46 communicates at one end with the chamber 3 at the auxiliary side of the piston 6 and said duct also communicates with a port t in the valve seat T. The main valve S is made with a cavity 7L into whichV fluid from the valve chamber 5 may enter through a restricted port g, so that when said cavity 7L (under certain conditions) registers with the port 70, train pipe fluid can pass from the chamber 5 (which constitutes a portion of the controlling space) to the auxiliary reservoir through the duct 46, ports 14 and 15 and duct 17. The main valve S is also provided with connected ports t' and l" and a port p connected with the port p, the functions of which will be hereinafter explained. A small groove c is provided in the upper face of' the valve seat T to receive fluidfrom the valve chamber' 5, which air is conveyed in a manner hereinafter described to the graduating valve R for balancing the latter when the port-s are in the emergency Yposition shown in Fig. 4.

The duct 46, which communicates with the right hand end of the chamber 3, is extended past the port of valve seat T, as shown at 46a, and at its left hand end, the duct 46 is connected, through ducts 47 in a valve .eat 48, with a chamber 49 at the left hand end of the casing. A duct 50 leading' from an emergency reservoir (not shown) also communicates with the chamber 49 and communication between the ducts 46a and 50 is normally closed by a valve 51 which is pressed to its seat by a light spring' 52. The valve 51 is provided with a rod 53 which passes snugly l.through the seat or bushing' 4S and terminates within a movable thimble 54 which is guided by a nipple 55 secured within the casing at the left hand end of the valve chamber 5. A spring 56 encircles the rod 53, bearing' at one end against the seat or bushing' 4S and at the other end against the thimble 54, and holding the latter normally in such position that its closed end will bc disposed a short distance from the end ol' rod 53, so that when the parts are moved towards the emergency position, the engagement of the rod 7 with said thimble 54 will compress the spring 56 somewhat, before causing a movement of the rod 53 to move the valve 51 from its seat. The purpose of the ducts 46 and 50 and the valve 51 is to permit a supplemental supply of fluid from a reservoir or other source separate from the auxiliary reservoir, to flow to thc brake cylinders, in the emergency application of the brakes, as will be more fully heroinafter explained.

Having now described the mechanical construction of my improvements l will proceed to explain the manner in which the same will operate under various conditions, in controlling the operation of the brakes.

The right hand side ol the piston G is in free communication with the auxiliary reservoir in the release and l'einere'ency positions of the mechanism, and in restricted communication with the auxiliary reservoir in the service positions, such restricted communication between the chamber 3 and the auxiliary reservoir being' effected by the presence of the portion 23 of the rod 21 in the port 14 and between the ports 15 which communicate with the auxiliary reservoir duct l?. By means of such restricted communication between the auxiliary reservoir and the chamber 3 at the right of the piston in conjunction with ccrtain other means which will be more fully explained hereinafter, l am enabled under certain conditions to cause thc existence in this portion of the chamber il (to the right ol the piston (S) ol' a pressure which will be somewhat lower than the auxiliary reservoir prcssurc,---the purpose ol' which will presently be made apparent.

Train pipe fluid can enter freely into the controlling` space at all times by way ol'` the ducts SWS) and check valve 1.0, and also through ducts 12 and 13 and portfwhon the valve. S docs not close said poitfwhich is the case in the service and release positions of thc valve.

Let it be assumed that after an application of the brakes the train pipe pressure is raised above that of auxiliary reservoir pressure, as a result of this, the piston 6 will be forced to the right, and move the slide valves in the same direction. During this movement of the valves, the ports r and c and the ports p and l) will first bc disconnected, and then the port p will partly register with the port d, the port m also partly registering;l with the port e. Subsequently the cavity h will register with the port l). vecausc of this sequence in the registration of the various ports, it will be seen that the. brake cylinder port c is connected with the exhaust port d, through the ports m, a and p and duct t in the main valve S, and the cavity (j in the graduating' valve R, before any fluid is permitted to vpass l'rom the train pipe to the auxiliary reservoir through the port g and cavity 7. in the main valve and `port I), duct 46 and port 14 and ducts 15 and 17. During' the movement of the piston to the right, thc rod 21 will enga-ee the abutment 28 and the spring' 27 will be compressed by the continued movement of the piston 6, and, as will be seen in Filis. 1 and 2, the contracted portion 22 ol' the rod 2l, at this time permits ol a very free passare through the port l-pl from the right hand side of the piston to thc auxiliary reservoir duct 17. As thc piston continues to move toward the 1" ht, it will uncover the large duct 18 the ight hand end of the chamber 3 (which duct r rovides for a rapid recharge of the auxiliary reservoir), and finally, the piston will meet the abutment 2O at the end of said chamber il. "he parts are now in the position shown in F 1, with train pipe fluid enterinf; the controlling' space by the port f and free to flow to thc auxiliary reservoir through the groove 1S and also through the small port (7 and cavity 7L of the main valve and port l), .in the. valve seat T and the duct 46 and port 14 and duct 15. vlt will also be observed that ports lm and c are now in. full mmmunication with each other that ports p and d are also in full communication, and that the cavity 1 ol the graduating valve freely connects ports m and n of the main valve S. (The graduating` valve h is, at this time, in its extreme right hand position with reference to the main valve). ln consequence oi the positions of the ports as above described and as shown in Fig. 1, brake cylinder fluid is free to pass to the atmosphere through trie port e in the seat T, port 'm in the main valve, cavity g in the graduating valve, port n, duct t and port p in the main valve and port d in the scat T. lf the rise of train pipe pressure be permitted to continue, the parts will remain in the positions shown in Fig. 1 until the recharge of the auxiliary reservoir has been approximately completed, that is to sayg-until the pressures acting on the two sides of the piston 6 become approximately equal.` At this time, the spring 27 will operate to return the piston and graduating valve to the positions shown in Fig. 2. The recharging ports and the exhaust ports and passages are so proportioned relatively to each other as to insure the full release of the brakes, before the auxiliary reservoir can be fully recharged. If, instead of permitting the rise of train pipe pressure to continue as above assumed, the rise of pressure should be only temporary (as would be the case when the engineer would move the brake valve handle to release" or running position for a few seconds, and then to a lap position), the pressures on the two sides of the piston would quickly equalize (through the agency of the groove 18 in the wall of chamber 3 and the port g in the valve S), and the piston would be moved to the left by the action of the spring 27 a sufficient distance to cause the cavity g of the graduating valve to move out of alinement with the ports m and nfthus closing these ports and consequently preventing the further ilow of brake cylinder luid to the atmosphere. It will be seen therefore, that by temporarily increasing the train pipe pressure periodically (at one side of the piston 6), above the auxiliary reservoir pressure (at the other side of said pis ton) the engineer is enabled to graduate the release of the brakes when desired. lt will also be observed from an inspection of Fig. 2 of the drawing, that when the piston 6 is moved by the spring 27 from its extreme right hand position, it will close or cover the large duct 18, but that the small port g will still ailord a restricted communication between the train pipe and the auxiliary reservoir. The object in thus cutting et? the large duct 18 is to prevent an excessive back How of air from the auxiliary reservoir to the train pipe when it is desired to subsequently apply the brakes.

When it is desired to make a service application of the brakes and when the train pipe pressure is reduced at the customary rate, there will of course be a simultaneous l reduction of pressure (through the medium of portfand ducts 13, 12 and 8) in the controlling space. The piston 6 will therefore be moved to the left, from the positions shown in Figs. 1 and 2, by reason of the higher lauxiliary reservoir pressure acting a ainst the right hand side of said piston. T iis movement of the piston will first cause the graduating valve to move to its extreme left hand position with reference to the main valve S. When in this position, the cavity q Will establish full communication between the ports 7c and p and the port Z will be uncovered. The shoulder 38 will then engage the main valve S and thus cause it to be moved with the piston, to the left. The first movement of the main valve S will disconnect the cavity Zt from the port Z) and subsequently disconnect ports p/ and cZ and ports m and e. rEhe continued movement of the valve S to the left will bring port Z into alinement with the port a and subsequently cause ports 7c and e and ports p/ and ZJ to come into alinement with each other. lf the rate of train pipe pressure be such as would occur on a train or' moderate length, the valves would may be termed the quick service position of the mechanism. ln this position, the port Z will be in full communication with the brake cylinder port dy and the port Z will be fully uncovered by the graduating valve, thus permitting of a slight flow of train pipe luid from the controlling space to the brake cylinders through port Z, duct Z"- and ports Z and a. lt will also be seen that when the parts are in the positions shown in Fig. 5, luid is permitted to pass from the auxiliary reservoir through the ducts 17 and 15 and port 14 (which latter is now restricted by the large portion 23 of the rod 21) and that portion of chamber 3 at the right ci piston 6, and duct 46 and ports l), p and p, cavity q and ports Zr, 7c and e to the brake cylinder. The port 14 being properly restricted by the portion 23 of the rod 21 and the tluid from the right hand side of the piston being permitted to pass to the brake cylinder through the ducts and ports ljust mentioned, the resulting reduction of pressure at right hand side of the piston will cause the latter to stop in its quick service position, under the conditions assumed, of a moderate rate of reduction of train pipe pressure. When the pressure to the right of the piston finally becomes somewhat lower than that in the controlling space, the piston will move to the right, dragging the graduating valve with it, this movement resulting in iirst closing port Z and subsequently closing ports Zc and p. The further flow of i'luid from the train pipe and from the auxiliary reservoir to the brake cylinders will therefore be prevented. The movement of the piston and graduating valve will continue until the shoulder 39 assume the positions shown in Fig. 5, which 4again connect ports 7c ,cavity g of the graduating valve and subse- 91eme meets the main slide valve and the additional resistance thus encountered prevents the further motion of the piston. If the train pipe pressure is again reduced, the piston will again move to the left and thus and p by means of the quently uncover port l, thus permitting a further flow of fluid from the auxiliary reservoir and train pipe to the brake cylinders. If, instead of a moderate reduction of train pipe pressure, such reduction had been made at a fairly rapid rate (as would be the case on very short trains in service applications of the brakes), the valves would have assumed the position shown in Fig. 6, wherein the ports p and t and ports r and e are shown in full register', and port l is no longer connected with port c, (see Figs. 6, S and 9). Thus, a very free passage is provided for the flow of auxiliaryT reservoir fluid (from the right hand side of the piston) to the brake cylinders and the flow of train pipe fluid to the ybrake cylinders is prevented.

After the train pipe pressure has been reduced sufficiently to cause a complete equalization of the pressures in the auxiliary reservoir and brake cylinder, a further reduction oftrain pipe pressure will obviously cause the piston to move to the left beyond its service position. This movement will continue until the middle slide valve has been moved lar enough to close the ort f and thus prevent a further reduction o' pressure in the controlling space, even though the train pipe pressure may be reduced to a very low degree. Durin@r the movement ol' the va ve to the left ports t" and e and p and t were first disconnected; then port a was uncovered by the main valve, (the check valve 32 preventing a flow of fluid from the brake cylinders to the controlling space at this time) and subsequently the port frias closed. The parts will finally assume the positions shown in Fig. 7, which may be termed the equalization lap and maintaining position of the mechanism. ln this position, the le'l't handend of the piston rod will just meet the sprin abutment 54 'which continually tends to ho d the piston in this position. rThere will then be no communication between the auxiliary reservoir and the controlling space, nor between the auxiliary reservoir and the brake cylinder. lf now, the brake cylinder pressure drops slightly (because of leakage) below that in the controlling space, fluid will pass through the port c to supply this loss. ll' the train pipe pressure is maintained nearly equal to that in the controlling space, fluid will flow from the train pipe to the controlling space and thence through port a to the brake cylinder. Thus it will be seen that under the conditions above stated, brake cylinder pressure may be maintained through the medium of the train pipe without in any piston and the main way interfering with the action of the valve in releasing the brakes, because at this time, the auxiliary reservoir is cut olf completely from the controlling space and from the brake cylinder. lf, however, the train pi e pressure were considerably below that in tlie controlling space and the brake cylinder pressure had fallen slightly (through leakage), the resulting reduction of pressure in the controlling space (effected tlnough the ort a) would cause the auxiliary reservoir pressure to force the piston 6, to the left, compressing the spring 56 until the piston moved far enough to uncover the groove 45 and thus permit a flow ol' auxiliary reservoir liuid to the controlling space to supply the brake cylinders through the port c. The position assumed by the various parts under these conditions are fully illustrated in Fig. 3. This movement of the piston to the left under the conditions above stated, will be stopped when the piston rod causes the thimble 54 to meet the end of the rod 53, as the high pressure of the i'luid in the emergency reservoir acting on the top of the valve 5l (the under side ol' which latter is exposed to auxiliary reservoir pressure) will add so much resistance t0 the movement that by reason of the approximate equalization of pressures on the two sides of the piston because of the flow of fluid around the piston, the further Inovement of the latter will be impossible. This position of the mechanism, as illustrated in Fig. 3, may be called the equalization feed up position, for reasons which are obvious from the foregoin(T description. Zhen the brake cylinder leakage has been supplied as above described, the spring 56 will act te rcturn the piston so as to cover, or close, the groove 45.

'When it is desired to make an emergency application of the brakes, the train pipe pressure will be reduced in the usual way, that is to say, a quick, heavy reduction is made. This will cause the piston to move suddenly to the left, carrying the slide valves with it, and the reduction of train pipe pressure will be so rapid that wh en the service positions of the valves are reached, the resulting reduction of pressure at the right hand side of tle piston will be insuflicient to cause said piston and the valves to stop. Up to this time, the fluid in the controlling space has been at the same pressure as that in the train pipe because the port f has been wide open,-but new, the valve S having passed beyond its service positions, the port c will be o ened and subsequently, the port f will be c osed. As the pressure in the brake cylinder is very low at this time equal to atmos heric pressure) the pressure in the control ing space will immediately drop somewhat below that in the train pipe, thus causing a greater force than before to effect the travel of the piston to the left and (it being approximately Y piston 6.

also causing train pipe fluid to flow into the controlling space (by way of the ducts 8kg) and thence through port c to the brake cylinder. As soon as the piston passes its "equalization feed upH position, the end of the piston rod 7 having forced the thimble 54 against the end of the rod 53, causes the latter to unseat the valve 51 and thus admit emergency reservoir fluid (entering by way of the duct 50) to the duct 46a, from wlii it will flow, by way of the duct 46 to the chamber 3 at the right of, i. e., behind, the Before this occurs, however, he restricting rod 2l had been withdrawn from the auxiliary reservoir port i4, and subsequently the piston will uncover the ducts 44 at the left hand end of the chamber 3. A flow of auxiliary fluid and also of emergency reservoir fluid can now take place through the duct 44a to the controlling space. Finally, the piston 6 will reach the left andv end of the chamber 3 and its further movements to the left will be stopped by the end by the bushing 4. The parts will now assume the positions` shown in lfig. 4, with the port f closed completely and he port a wide o en. It will be seen that a large passage is t us afforded for the flow of train pipe liuid to the brake cylinder, and that at the same time, fluid from the auxiliary and emergency reservoirs is permitted to pass to the brake cylinders. At this time, the pressure on the top of the main valve is suilicient to lold it on its seat, even though a higher re sure is exerted on that portion of its fwer face which covers the port t a much larger portion of its lower surface exposed to atmospheric pressure through tite port d.

Now, as will be recalled, during the service application of the brakes, the iluid from the auxiliary reservoir passed to the brake cylinder through the port e and the small amount of uid flowing through the ports Z and Z and port a from the train pipe (in the quick service position of the mechanism) was so slight that it passed freely by the cylindrical portion 321 of the check valve 32 and theree fore caused the latter to rise only a very slight distance from its seat. Consequently, during the service application of the brakes, the valve 35 remained approximately in the position shown in Figs. l, 2 and 3, and therefore maintained, at such time, a free communication between the bralie cylinder and the pressure reducing valve through the ducts in the emergei'icy7 application of the bralres however, the entire volume of air flowing to the brake cylinders must pass through the port a, and the cylindrical portion 32a of the valve 32 so restricts the duct 31 that when there is a heavy flow of uid through the latter', the valve 32 will be forced down far enough to permit the cylindrical portion 32a to pass beyond the lower l i l clavie end of the duct 31 (thus freely opening the latter) and consequently forcinCr the valve 35 far enough toward itsseat to completely close the ducts 35a in the valve 35. in this way, the pressure reducing valve will be practically cut off from the brake cylinder ducts until the pressure in the bralre cylin` der becomes slightly higher than that for which the reducing valve is set. rllhen the lower pressure on the under side of the valve 35 will permit the higher pressure on its upper side toy force it tightly on its seat, thus completely cutting olf the reducing valve until the brake cylinder pressure is subsequently released. rlhe spring 36 will then return the valves 35 and 32 to their normal positions, as shown in Figs. l, 2 and 3. By this means a much higher brake cylinder' pressure can be obtained in an emergency application of the bralres than in the ordinary service operation, not only because of the fact that the pressure reducing valve is out off from the bralre cylinder, but also because a large volume of fluid enters the brake cylinder from the train pipe and also from the emergency reservoir, as well as from the auxiliary reservoir. The heavy flow of fluid from the train pipe to the bralre cylinder at this time will, of course, insure the transmission of the rapid reduction of train pi )e pressure throughout the train, and, when tue pressure in the controlling space tends to become higher than that in the train pipe, the check valve l0 will be closed by its spring. il bach flow of fluid to the train pipe will thus be prevented, the port f being closed at this time as previously explained. lllhen the pressures in the controlling space and in the chamber 3 at the right of the piston (or, in other words, the brale cylinder pressure and that of the auxiliary and einere gency reservoirs) become nearly equalized, the piston will be moved by the spring 56 a sufficient distance to the right to close the grooves or ducts 44`45 and thus shut off all communication between the controlling space and the auxiliary reservoir. rllhis will insure the prompt and positive release of the bralies when the train pipe pressure is subsequently built up for that purpose. rlhe port p registers with the groove c in the emergency position of the main valve (as shown in l? ig. 4) in order to ermit fluid from the controlling space to 'iow through ports p and p into cavity g of the graduating valve, and the ports communicating with it, to insure the balancing of said valve for the purpose of eliminating all undue resistance to the returning of the piston by the spring 56. The lost motion between the main valve and the piston rod is suflicient to permit the return of the piston by the sprinfr 56 without the necessity of moving the main valve from its emergency position (F ig. 4),

time) will cause the piston to again move to 2. ln a triple valve mechanism, the comand it Will be observed that an excessive l over-travel of the main valve will be prevented by the engagement of the projecting left hand end of the valve with the end Wall of the valve chamber 5.

It is apparent that when the parts are in their emergency position, any leakage in the brake cylinder, causing a loss el" pressure in the latter and in the controlling' space, (these being connected by the port a at this the left and thus permit iluid to ilow from the auxiliary reservoir to supply the leakage in the same manner as after a full service applieation,-or if the train pipe pressure is maintained at some de'linite degree equal to or lower than that obtained in the controlling space after an emergency application, it is also obvious that the brake cylinder pressure may be maintained at this time in the same Way as after a full servie application of the brakes, and as previously explained in this description.

It Will be seen from an inspection of Fig. l that when an emergency reservoir is connected to the duet 50, said reservoir will be charged (when the pressure in it is below the normal value) with compressed air simultaneously with the recharge of the auxiliary reservoir; i'luid from the chamber 3 (at the right of the piston 6) passing through ducts L.i6-46 and 47, and unseating valve 5l, the air Will low through the chamber 9 and duct 50 to the emergency reservoir.

Having Jr'ully described my invention, what I eil-aim as new and desire to secure by Letters-Patent, is,-

l. In a triple valve mechanism, the coni- ,bination with a casing and brake cylinder and exhaust ports therein, ol` a main valve, a graduating valve, means for operating said valves, said main valve having ports to register with the brake cylinder and exhaust ports when the mechanism is in release position, the graduating valve having a passage to connect said ports of the main valve, and spring-actuated means tending to operate the graduating valve to close said ports when the main valve is in the release position.

bination with a casing and brale cylinder and exhaust ports therein, oi a main valve, a graduating valve, a piston for controlling the movements of said valves, said main valve having ports to register with the brake cylinder and exhaust ports when the mechanism is in release position, the graduatingv valve having a passage to connect said ports of the main valve, a movable rod carried by the piston, an abutment to be engaged by said rod, and a spring exerting a pressure longitudinally against said rod and tending to move the piston in a direction to cause the graduating valve to close said ports when the main valve is in release position.

3. ln a triple valve mechanism, the cembination with a casing and brake :ylinder and exhaust ports therein, ol" a main valve, a grar'luating valve, a piston for controlling said valves, said main valve having ports to register with the brake cylinder and exhaust ports when th'e mechanism in in release position, the graduating valve having a passage to connect said ports of the main valve, spring actuated means tending to operate the graduating valve to close said ports when the main valve is in the "re/lease position, means for admitting train pipe Vlluid at one side ol said piston, means for connecting the chamber at the other side of said piston with an auxiliary reservoir and means controlled by the piston to eiieet communication between the spaces at respective sides of the piston..

e. ln a triple valve mechanism, the combination with a casing and brake cylinder and exhaust ports therein, of a main valve, a graduating valve, a piston connected with said valves, means for admitting train pipe "luid to one side of said piston, an auxiliary reservoir duct communicating with the space at the other side ol said piston, said main valve having ports to register with the brake cylinder and exhaust ports when the mechanism is in release position, the graduating valve having a passage to connect said ports of the main valve, spring actuated means tending to operate the graduating valve to close said ports when the main valve is in the v release position, and means controlled b v the piston and said spring actuated means l'or controlling coniiininication between the spaces at the respective sides ol said piston.

ln a triple valve mechanism, the combination with a casing having brake cylinder and exhaust ports, of a main valve, a graduating valve, a piston connected with said valves, means for admittingl train pipe 'fluid at one side of said piston, an auxiliary reservoir duct communicating with the space at the other side of the piston, said main valve having ports to register with the brake cylinder and exhaust ports when the mechanism is in release position, the graduating valve having a passage to connect said ports of the main valve, a spring pressed rod carried by the piston, an abutment Jfor said rod whereby said springpressed rod Will tend to operate the graduating valve to close said ports when the main valve is in the release position, a duet controlled by said piston to control communication between the spaces at respective sides of said piston, said spring pressed rod being adapted to enter the port of the auxiliary reservoir duct to restrict said port and having a contracted said auxiliary reservoir port.

6. .ln a triple valve mechanism, the combination with a casing, valve devices, a piston connected with said valve devices, an auxiliary reservoir duct communicating with the space at one side of said piston, means for admitting train pipe iriuid to the space at the other side of said piston, and a brake cylinder duct, of means for establishing free communication between the space at the auxiliary reservoir side of the piston and the auxiliary reservoir duct when the mechanism is in release position and for restricting such communication when the mechanism is in service position.

7. ln a triple valve mechanism, the con.- bination with a casing, valve devices, a piston connected with said valve devices, an auxiliary port communicating with the space at one side of said piston, means for admitting train ipe fluid to the space at the other side cip said piston, and a bral cylinder duct, of a rod carried by the piston and entering the auxiliary port to restrict communication between the auxiliary reservoir side of the piston and the auxiliary reservoir when the mechanism is in service7 position, said rod having a contracted portion for permitting such communication to be free when the mechanism is in releaseI position.

8. ln a triple valve mechanism, the combination with a casing, valve devices for controlling the application and release of the brakes, means for controlling said valve devices, a brake cylinder duct, and a reducing valve connection communicating with said brake cylinder duct, o' a valve interposed between said brake cylinder duct and reducing valve connection, and means controlled by said valve devices for controllin the movements of the valve which is interposed between the brake cylinder duct and the reducing valve connection.

9. In a triple valve mechanism, the combination with a casing, valve devices for controlling the application and release ol" the brakes, means for controlling said valve devices, a brake cylinder duct, and a reducing valve connection communicating with said brake cylinder duct, of a valve interposed between said brake cylinder duct and reducing valve connection, and means Jfor subjecting said valve on one side to bral:

cylinder pressure and means controlled by said valve devices for subjecting the other side of said valve to a dillerent pressure.

10. ln a triple valve mechanism, the combination with a casing, valve devices therein for controlling the application and release of the brakes, and a piston for controlling said valve devices, oi' two brake cylinder eiavlc portion to unrestrict l ducts, one of said ducts adapted to freely communicate with the brale cylinder, a checlr valve in the other brake eylin der duct, a reducing valve connection communicating with one of said bralre cylinder ducts, and a valve controlled by said checlr valve for closing communication between said brake cylinder duct and the reducing valve connection when the meclianism is in the emergencyH position.

11. ln a triple valve mecl'ianism, the combination with a casing, a brake cylinder duct, and valve devices for controlling the passage orp luid to said duct, of a check valve for closing said duct, a reducing valve connection communicati g with the bralre cylinder duct, and 1r Ls controlled l y said checl; valve for closirk communication be tween the brake cylinder' duct and the reducing valve connection when said duct is open to a full flow oi' air to the brake cylin ders in emergency application of the brakes.

12. ln a triple valve mechanism, the combination with a casing, a brake cylinder duct, and valve devices for controlling the passage of iiuid to said duct, of a valve for closing said duct, a passage for 'fluid past the valve when the latter is partially open, a reducing valve connection and means for closing communication between the brake cylinder duct and the reducing valve connection when the iirst mentioned valve is fully opened for the emergency application oi the brakes.

13. ln a triple valve mechanism, the combination with casing, two brake cylinder ducts and valve devices for controlling the passage ol liuid to said ducts, of a check valve lor closing one of said ducts and having a passage for a limited llow 0i l'iuid past said valve when the latter is partially open, a reducing valve connection communicating with said brake cylinder ducts, and a valve controlled by the checl valve to close such communication with the reducing valve connection, when said check valve is fully opened in the emergency application of the brakes.

14. In a triple valve mechanism, the combination with a casing, two brake cylinder ducts, and valve devices for controlling the passage of fluid to said ducts, of a check valve closing one of said ducts, a reducing valve connection having a port communicating with said brake cylinder ducts, a valve entering said port and having grooves, and a spring holding said valve normally onen and pressing the same against said checli valve, whereby, when the checlr valve is opened in the emergency application of the brakes, it will operate to close the valve in the port of the reducing valve connection.

15. in a triple valve mechanism, the combination with a casing provided with means of communication with a brake cylinder', a piston, and valve devices controlled by said piston for applying and releasing the brakes, the space at one side of said piston constituting a controlling space, of means of conmunication for fluid from an emergency reservoir to the space at the other side of the piston, means for introducing auxiliary reservoir fluid at the same side of the piston with emergency reservoir fluid, a normally closed valve in said means of communication for emergency reservoir fluid, means actuated by the piston for opening said valve, and means controlled by the piston and said firstmentioned valve devices to control the passave of fluid to the brake cylinder when the valve controlling the passage of fluid from the emergency reservoir is open.

16. In a triple valve mechanism, the combination with a casing provided with means of communieationwith the brake cylinders, a piston in said casing, valve devices connected With said piston for controlling the application and release of the brakes, the space at one side of said piston constituting a controlling space, means of communication for fluid from an emergency reservoir with the space at the other side of the piston and means for introducing auxiliary reservoir fluid at the same side of the piston, of a valve in said means of communication for emergency reservoir fluid, a spring normally maintaining said valve closed, means controlled by the piston for opening said valve in the emergency application of the brakes, ducts controlled by said piston for opening communication between respective sides of the piston in emergency application of the brakes, and a spring abutment tending to operate the piston to close all of said ducts.

17. In a triple valve mechanism, the combination with a casing provided with means of communication With the brake cylinders, a piston in said casing, valve devices connected With said piston for controlling the application and release of the brakes, the space at one side of said piston constituting a controlling space, means of communication for fluid from an emergency reservoir with the space at the other side of the piston, and means for introducing auxiliary reservoir fluid at the same side of the piston, of a valve in said means of communication for emergency reservoir fluid, a spring normally maintaining said valve closed, means controlled by the piston for opening said valve in the emergency application of the brakes, ducts controlled b T said piston for opening communication betvveen respective sides ofthe iston in the emergency application of the rakes, one of said ducts being longer than the others, and a tpring abutment tending to operate the piston to close all of said ducts.

18. ln a triple valve mechanism, the combination with a casing having means of communication with a brake cylinder, a piston, valve devices controlled by said piston to control the application and release of the brakes, the space at one side of said piston constituting a controlling space, means of communication for an en'iergency reservoir with the space at the other side of said piston, means for introducing auxiliary reservoir 'Huid at the same side of the piston, and a series of ducts controlled by the piston for admitting fluid from said last-mentioned space to the controlling space, one of said ducts being longer than the others, of a valve in the means of communication between the emergency reservoir and thc space at one side of said piston, a rod projecting from said valve, a longitudinally movable spring abutment normally terminating beyond the free end of said valve rod, and a piston rod connected with the piston and said first mentioned valve devices and adapted to engage said spring abutment and open the emergency valve after moving said spring abutment a limited distance and after opening said longer duct.

19. ln a triple valve mechanism, the combination with a casing having means of communication with a brake cylinder, a piston, the space at one side of said piston constituting a controlling space, means of communication with the other side of the piston for fluid from an emergency reservoir, means for admitting auxiliary reservoir fluid to the same side of the piston, of valve devices comprising a main valve and a graduating valve for applying and releasing the brakes, a piston rod projecting from said piston and having lost-motion connection with the main valve and a direct connection with the graduating valve, duets controlled by the piston for controlling communication between the space at one side of the piston with the controlling space at the other side thereof, one of' said ducts being longer than the other, a valve in the means of communication for fluid from the emergency reservoir, a rod projecting from said valve to be engaged by the piston rod to open said valve, and a spring tending to move the piston independently of the main valve to close said ducts.

20. ln a triple valve mechanism, the combination with a casing provided with means of communication with a brake cylinder, a piston, and valve devices controlled by said piston for applying and releasing the brakes, the space at one side of said piston constituting a controlling space, of means of communication for fluid from an emergency reservoir to the controlling space, means for introducing auxiliary reservoir fluid at the other side of the piston, a normally closed valve in said means of communication for emergency reservoir fluid, means actuated by the piston Y for Opening said Valve, and means controlled spec'caton in the presence of tWo subscrib by the piston and said rst-mentioned Valve ing Witnesses.

devices to control the passage offluid tothe 1 D 5 brake cylinder when Ishe Valve controlling v 50x/JARD M' MURPHY' 5 J@he passage of fluid from the emergency res- Vitnesses:

ervoir is open. A. N. MITCHELL,

In testimony whereof, I have signed this R. S. FERGUSON.

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