US857912A - Fluid-pressure brake. - Google Patents

Description

- v PATBNTED- JUNE 25, 1907. W. V. TURNER & F. L. CLARK.

FLUID PRESSURE BRAKE. APPLICATION FILED DEC 27, 1904;

2 SHEEN-SHEET 1.

WITNESSES INVENTORS 7H5 mmms PETERS co, WASHINGTON, n c.

- PATENTED JUNE 25 1907; W; V. TURNER & F. L. CLARK.

FLUID PRESSURE BRAKE.

APPLICATION FILED 1330.27, 1904.

2 SHEETS-SHEET 2.

50/70/77 Je/w'c'e.

ITNESSES I I ajgipVEylQ'tfi/QBS 2 1 dd l/l tl l amma $34M} ment in Fluid-Pressure Brakes, of which the train pipe pressure and applying the brakes communication from the main reservoir UNITED STATES PATENT oEEIcE.

WALTER V. TURNER, oE WiHdINSBURGTAND RANcIs L. cLARK, 0E PITTSBURG, PENNSYLVANIA, ASSIGNORS TO THE WESTINGHOUSE AIR BRAKE COMPANY, oE PITTSBURG, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.

FLUID-PRESSURE BRAKE.

Specification of Letters Patent.

Patented June 25, 1907.

Application filed December 27,1904. Serial No. 238,356.

To all 1071,0121, 2125 may concern:

Be it known that we, WALTER V. TURNER and FRANoIs L. CLARK, citizens of the United States, residing, respectively, in l/Vilkinsburg and Pittsburg, both in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Improvefollowing is a specification.

This invention relates to fluid pressure brakes, and more particularly to the engineers brake valve and the feed valve de vice for regulating the supply of air from the main reservoir to the. train pipe.

In the present standard automatic air brake apparatus, as is well known, the feed valve device is connected with the engineers brake valve by certain ports which, when the brake valve is in a certain position called running position, are open for supplying air from the main reservoir through the feed valve to the train pipe, the feed valve being adjusted to close at a certain desired maxi mum degree of train pipe pressure and to open whenever the pressure falls below this standard. lVith the engineers brake valve in this position the feed valve operates to supply the leakage and to keep the train line and auxiliary reservoirs charged up to the degree of pressure which it is desired to carry in the system, but when the brake valve is turned to another position for reducing the through the feed valve is closed, so that any leakage which occurs in the train pipe while the brakes remain applied has the efl ect to further reduce the train pipe pressure and to cause further action of the triple valve to supply air from the auxiliary reservoir to the brake cylinder. By this undesirable action of the triple valve, due to train line leakage, the brake cylinder pressure is often raised much higher than was intended by the engineer in making the application, and it then frequently becomes necessary to release the brakes entirely and then re-apply with a lower degree of pressure in order to properly control the speed of the train. This depletes the pressure of the auxiliary reservoir sometimes to a dangerous degree besides wasting a large amount of compressed alr. In order 1 to prevent this objectionable action of the triple valves, it is desirable to be able to maintain the train pipe pressure substantially constant at the given degree of reduction as made at the brake valve and to compensate for the train line leakage while the engineers .brake valve is 011 lap and the brakes remain applied. Several forms of devices have been proposed for accomplishing this purpose, but the principal object of this invention is to provide a feed valve device with certain additional regulating means and connections with the engineers brake valve, whereby the same may operate to regulate the train pipe pressure to the desired degree when the brake Valve is in running position, andalso to control communication to the train line when the brake valve is on lap and to then maintain the train pipe pressure at whatever degree of reduction is made at the brake valve.

Another object of this invention is to pro vide an improved form of feed valve device of the slide valve type, in which the piston which actuates the main slide valve is operated by main reservoir pressure to open the valve while the regulating or diaphragm valve, which is subject to the train pipe'pressure, operates to open communication from the chamber on the opposite side of the piston to the atmosphere when the train pipe pressure falls below the desired maximum degree.

We will now describe more particularly one form of valve mechanism embodying ourimprovements, reference being had to the accompanying drawings, in which Figure 1 is a partial horizontal section and lan view of the engineers brake valve with reed valve device attached, the top of-the brake valve casing and rotary valve being removed to show the Valve seat; Fig. 2 a face view of the rotary valve; Fig. 3 an end elevation and partial section of the feed valve device taken substantially on the line f-f of Fig. 4 Fig. 4 a broken sectional View of the feed valve device and a portion of the engineers brake valve taken substantially on the different planes indicated by the lines c-c and a-a of Fig. 1 and de of Fig. 3, in order to show the relati Ve position of the va rious ports and passages Fig. 5 a similar broken sectional view taken substantially on the lines bb of Fig. 1 and dd of Fig. 3; Fig. 6 a diagram of the engineers brake valve showing the relative position of the ports in the valve seat and in the rotary valve in running position; Figs. 7 and 8 similar diagrams showing the valve in service and lap positions respectively; and Fig. 9 an elevation of the engineers brake valve and attached feed valve device complete, and showing connections to the main reservoir, equalizing reservoir and the controlling reservoir.

The engineers brake valve 1, as shown, is of the rotary type and is provided with the usual connections to the train pipe 2, equalizing reservoir 3, and main reservoir pipe 4 leading to main reservoir 5.

The improved feed valve device 6 is preferably oi the slide valve type and is adapted to be bolted against the bodyoi the engineers brake valve with which it is connected by certain ports and passages leading to the seat of the rotary valve. According to the preferred construction the feed valve device comprises a main valve chamber 7 and piston chamber 8 containing slide valve 9 and piston 10, the valve and piston being subject to main reservoir pressure, which is admitted to said valve chamber and controlling the port 11 leading to the train pipe space 12 which communicates through passages 13 and 14 in the engineers brake valve with the train pipe. The piston is so fitted to the chamber as to permit air under pressure from the main reservoir to equalize around the piston when the chamber on the opposite side is closed and a light spring 15 is employed for them normally moving the piston and slide valve to close the feed port 11.

A regulating valve 16 operated by dia phragm 17 subject to the opposing pressures of the train pipe in chamber 18 and an adjustable load device, such as spring 19, is used for governing the action of the main valve 9 by controlling the release of air from the piston chamber through ports 20, 21 and 22 'to the atmosphere. A maintaining valve 25 is preferably employed iorfalso governing the pressure in the piston chamber 8 and is operated by a diaphragm 27 which is subject to the opposing pressures of the train pipe in chamber 26 on one side and of a controlling chamber 28 on the other side, the chamber 26 communicating with the train pipe space 12 through port 31 and the controlling c iamber 28 being in open communication through ports 30 and 42 and pipe 43 with controlling reservoir 44, which forms merely an enlargement of said chamber for giving the desired volume. According to the construction shown the valve 25 serves to control the release of air from the rear of piston chamber 8 through port 32 to the chamber 26 and port 31 to the train pipe. Light springs, 29 and closes the port 21,

53, may, if desired, be employed for assisting the action of the valve 25.

The ports 20, 23 and 30 lead to the seat of the rotary valve, which is also provided with port 24 leading to the main slide valve chamber 7, port 32 commimicating with the train pipe, exhaust port 45 leading to the atmosphere, preliminary discharge port 46 connected with the chamber 34 above the piston 35 of the train pipe discharge valve, which chamber communicates through pipe 36 wit-h the equalizing reservoir 3 according to the usual standard construction, equalizing port 33 and port 31 communicating with the equalizing chamber 34, and groove 47 communicating with exhaust port 45. For cooperating with these ports in the valve seat the rotary valve is provided with a through port 41, a large cavity 38 having openings 48, 51, and 50 in the face of the valve, and small cavities 39, 37, 49, and 52.

The operation of our improvement is as follows :When the engineers brake valve is set in running position, as indicated in Fig. 6, air under pressure from the main reservoir flows through the port 41 in the rotary valve, and port 24 to the main valve chamber 7 of the feed valve device and there acting upon the piston 10 moves the same over to its extreme position, compressing spring 15 and opening wide the feed port 11. The spring 19 of the regulating valve having been adjusted for the desired maximum degree of train pipe pressure, say pounds per square inch, will hold the valve 16 wide open since the air pressure in chamber 18 on the diaphragm 17 is much below the maximum pressure, so that the air which leaks around the piston 10 to chamber 8 is released to the atmosphere through port 23, cavity 39 in the rotary valve, ports 20, 21 and 22, whereby the pressure in the valve chamber acting on the piston 10 holds the feed port 11 open to charge the train line. In this position of the rotary valve the openings 51 and 50 of large cavity 38 register with the train pipe port 32 and equalizing port 33, while ports 20 and 23 are connected by cavity 39, and ports 30 and 31 by cavity 37. Air under pressure then flows through passages 12, 13 and 14 to the train pipe 2 and also through ports 32 and 33 to the equalizing reservoir and chamber 34, and through ports 31, 37 and 30 to the controlling reservoir and chamber, charging all to the maximum degree of train pipe pressure. As the pressure in the train pipe and consequently in the chamber 18 on dia phragm 17 rises to this desired maximum the spring 19 is compressed and the valve 16 thereby preventing further escape of air from chamber 8, whereupon the pressure immediately equalizes on opposite sides of piston 10 and the spring 15 moves the piston and valve 9 to close the feed port and prevent overcharging the train pipe. I11 the meantime, the pressures upon opposite sides of the maintaining diaphragm 27 remain equal and the valve 25 remains closed so that it does not affect the pressure in the piston chamber 8 at this time. If then the train pipe pressure reduces on account of leakage the spring 19 acts to open the valve 16 suficiently to permit a lowering of the pressure in pistonchamber 8, whereupon the higher pressure of the valve cham ber again moves the piston and valve to open the feed port 11 and supply the train line. By means of this feature of venting air through the regulating valve from the piston chamber to the atmosphere a more positive reduction is produced than in the case'where this valve vents into the train pipe, and consequently a more positive and quicker action of the feed valve results. It will now be ap parent that this feature of our invention may, if desired, be applied to feed valves of the standard type and having the usual function, without the addition of the improved maintaining valve feature.

When the engineers brake valve is turned to service position, Fig. 7, the groove 52 connects the preliminary discharge port 46 with the exhaust port and the pressure in the chamber 34 and equalizing reservoir reduces in the usual way, thereby causing the upward movement of the equalizing piston 35 and the opening of the train pipe discharge valve in the ordinary manner. In this position of the rotary valve it will be noticed that the supply of air through port 24 to the feed valve is cut off, and that the controlling res- 'ervoir is in communication with the equalizing reservoir and chamber 34 through port 30, cavity 49 and port 31, whereby the pressure in the controlling reservoir is reduced to exactly the same degree as the equalizing reservoir. When the desired reduction has been made the brake valve is turned back to lap position, see Fig. 8, in which the preliminary discharge port 46 is closed. The train pipe pressure continues to fall through the train pipe discharge valve until this is closed by the equalizing piston 35 in the usual manner when the train pipe pressure has reduced to equal that of the equalizing reservoir. In this position of the rotary valve it will be observed that the through port 41 partially registers with port 24 for supplying air from the main reservoir to the feed valve chamber, while all the other ports in the rotary valve seat are closed. By this means the regulating valve is entirely out out and the air under pressure in the control ling reservoir is tightly sealed up against all leakage at the desired degree to which the train pipe pressure is reduced in making the- As long as the,

application of the brakes. brakes are held applied with the brake valve in this position the pressure in the controlling reservoir and chamber 28 on diaphragm 27 remains constant, while the pressure in chamber 26 on the opposite side of the diaphragm, varies with the train pipe pressure. Should the train pipe pressure diminish on account of leakage, the greater pressure of the controlling reservoir acting on the dia phragm causes the same to open the maintaining valve 25 and thereby vent air under pressure from the piston chamber 8 through the port 32 to chamber 26 port 31 and passage 12 to the train pipe. This reduction of pressure on the piston 10 causes the opening of the feed port 11 in the same manner as be fore described.

l/Vhen the pressure in the train line rises to substantially equal that of the controlling reservoir, the diaphragm 27 permits the valve 25 to close, whereupon the pressure equalizes around the main piston 1.0 and the spring 15 moves the piston and slide valve to close the feed port. In this manner the maintaining valve acts in the place of the regulating valve to control the pressure upon the main slide valve piston when the brake valve is on lap and maintains the degree of train pipe pressure substantially constant and equal to that scaled up in the controlling reservoir.

The braking pressure may be increased as desired by making further reductions in train pipe pressure in the usual way, or may be held applied for any length of time without danger of further and undesirable action of the triple valves due to leaks in the train pipe.

The brakes may be released by turning the brake valve to running position or further to release position, in which the ports 41 and 48 both register with port 24 and port 51 with ports 32 and 33, while port 50 connects with port 30 leading to the controlling reservoir. Air from the main reservoir then flows through the large cavity 38 in the rotary valve directly to the train pipe, equalizing reservoir and controlling reservoir, these two reservoirs instantly equalizing with the train pipe when the brake valve is returned to run ning position.

Quick action of the brakes may be produced by turning the brake valve to emergency position, in which the port 48 registers with. train pipe port 32 and port 51 with exhaust port 45, thereby opening a direct discharge from the train pipe through cavity 38 to the atmosphere in the usual way. In this position the groove 52 also connects the pre liminary discharge port 46 with the groove 47 and the exhaust port 45, and cavity 39 may connect ports 30 and 31 so that air will be discharged from the equalizing reservoir and the controlling reservoir at the same time that it is being discharged from the train pipe.

l/Vhile we have described our improvements in connection with an engineers brake valve of the rotary type, it will be evident that the invention is not limited thereto but may also be employed with various other styles of brake valves.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is 1. In a fluid pressure brake, the combination with an engineers brake valve, of a feed valve device for normally regulating the train pipe pressure and having additional means for maintaining the train pipe pressure substantially constant at any given degree of reduction from normal when the brake valve is in lap position.

2. In a fluid pressure brake, the combination with an engineers brake valve, of a valve device governed by train pipe pressure for normally regulating the same, means for supplying air to said valve device when the brake valve is in lap position, and a main taining valve mechanism for controlling the action of said valve device when the brake valve/is in lap position.

3. A feed valve device for fluid pressure brakes comprising a main valve for controlling communication from the main reservoir to the train pipe in both the running and lap positions of the brake valve, a regulating valve subject to the train pipe pressure for normally governing the action of the main valve, and a maintaining valve mechanism for also governing the action of the main valve.

4. A feed valve device for fluid pressure brakes comprising a main valve for controlling communication from the main reservoir to the train pipe in both the running and lap positions of the brake valve, a movtble abutment for actuating said valve, a regulating valve subject to the train pipe pressure for normally controlling the pressure on said abutment, and a maintaining valve for also controlling the pressure upon said abutment.

5. In a fluid pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve for controlling communication from the main reservoir to the train pipe in both the running and lap positions of the brake valve, a movable abutment for operating said valve, a regulating valve governed by the train pipe pressure for controlling the pressure upon the abutment, and a maintaining valve operated by the train pipe pressure when the engineers brake valve is in lap position for also controlling the pressure upon said abutment.

6. In a fluid pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a valve device comprising a main valve for controlling communication from the main reservoir to the train pipe in both the running and lap positions of the brake valve, a movable abutment for operating said valve, a maintaining valve for controlling the pressure upon said abutment and operated by the opposing pressures of the train pipe and a controlling chamber or reservoir, and means operated by the movement of the brake valve in applying the brakes for reducing the pressure in the controlling chamber to that of the train pipe and then tightly closing said chamber.

7. In a fluid. pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve with piston for controlling communication from the main reservoir to the train pipe in both the running and lap positions of the brake valve, a regulating valve governed by train pipe pressure for normally controlling the pressure upon one side of the piston, and a maintaining valve operated by the opposing pressures of a con trolling chamber and the train pipe for also controlling the pressure upon the piston of the main valve:

8. In a fluid pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve with piston for controlling communication from the main reser voir to the train pipe, a regulating valve governed by train pipe pressure for normally controlling the pressure upon one side of the piston, a controlling reservoir or chamber, a maintaining valve operated by the'opposing pressures of the train pipe and said chamber for also controlling the pressure upon one side of the main valve piston, and means operated by the movement of the brake valve in applying the brakes for cutting out the regulating valve.

9. In a fluid pressure brake, the combina tion with a mam reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve with piston for controlling communication i'rom the main reservoir to the train pipe, a regulating valve governed by train pipe pressure for normally controlling the pressure upon one side of the piston, a controlling reservoir or chamber, a maintaining valve operated by the opposing pressures of the train pipe and said chamber for also controlling the pressure upon one side of the main valve piston, means operated by the movement of the brake valve in applying the brakes for reducing the pressure in said control reservoir to the desired degree of train pipe pressure and then closing communication to or from said control reservoir.

10. In a fluid pressure brake, the combination with a main reservoir and train pipe, of a feed valve device comprising a main valve and piston for controlling communication from the main reservoir to the train pipe, a

regulating valve governed by the train pipe pressure for controlling the pressure upon one side of the main valve piston, a controlling reservoir, and a maintaining valve operated by the opposing pressures of the said reservoir and the train pipe for also controlling the pressure upon one side of the main valve piston, an engineers brake valve having an equalizing reservoir, ports for connecting the two reservoirs in service application position and means for closing communication to or from the control reservoir, and for cutting out the regulating valve when the brake valve is in lap position.

11. A feed valve device for fluid pressure brakes comprising a main valve for controlling communication from the main reservoir to the train pipe, a movable abutment subject to main reservoir pressure for actuating said valve, and a regulating valve operated by train pipe pressure for governing the release of air from one side of said abutment to the atmosphere.

12. A feed valve device for fluid pressure brakes comprising a main valve for controlling communication from the main reservoir to the train pipe, a piston exposed on one side to main reservoir pressure for operating said valve, means for equalizing the pressure around said piston, a regulating valve controlling communication from the piston chamber to the atmosphere, and a diaphragm subject to the opposing pressures of the train pipe, and an adjustable load device for operating said regulating valve.

13. A feed valve device for fluid pressure brakes comprising a main valve for controlling communication from the main reservoir to the train pipe, a movable abutment subject to main'reservoir pressure for actuating said valve, and a regulating valve operated by train pipe pressure for governing the release of air from one side of said abutment to-the atmosphere, and a maintaining valve operated by train pipe pressure for controlling communication from the-same side of said abutment to the train pipe.

14. In a fluid pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a valve device comprising a main valve with piston for operating the same for controlling communication from the main reservoir to the train pipe, a maintaining valve operated by the train pipe pressure and an opposing fluid pressure for governing the pressure upon said piston, a regulating valve operated by train ipe pressure for controlling a port leading ii om one side of said piston, and means operated by the engineers brake valve for opening and closing said port.

15. In a fluid pressure brake, the combination with a main reservoir, en "ineers brake valve, and train pipe, of a fee valve device comprising a main valve and its actuating piston, a regulating valve operated by train pipe pressure for governing the pressure acting upon said piston, a maintaining valve 0perated by the opposing pressures of the train pipe and a fluid. pressure chamber for also governing the pressure acting on said piston, said brake valvehaving ports for opening communication from the main reservoir through the feed valve in running and lap positions, ports for reducing the pressure of said fluid pressure chamber to the desired degree of train pipe pressure in service application position, and means for closing said chamber and for cutting out the regulating valve in lap position.

16. In a fluid pressure brake, the combination with a main reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve for controlling the supply of air to the train pipe in two difl'erent positions ofthe brake valve, a regulating valve device subject to train pipe pressure for normally governing the action of the main valve when the brake valve is in one.

position, and a maintaining valve mechanism for governing the action of the main valve when the brake valve is in the other position.

17. In a fluid pressure brake, the combina- I tion with a mam reservoir, engineers brake valve, and train pipe, of a feed valve device comprising a main valve for controlling the supply of air to the train pipe in two different positions of the brake valve, a movable abutment'for operating said main valve, a regulating valve device subject to the train pipe pressure for controlling the pressure upon the abutment when the brake valve is in one position, and a maintaining valve mechanism operated by the train pipe pressure when the brake valve is in the other position for also controlling'the pressure upon said abutment.

18. In a fluid'pressure brake, the combination with a main reservoir, a train pipe, and an engineers brake valve having an equalizing reservoir, of a main feed valve for controlling the supply of air to the train pipe, a regulating valve device subject to train pipe pressure for governing the action of the main valve, a control chamber or reservoir, a maintaining valve mechanism governed by the control reservoir pressure for also controlling the action of the main feed valve, and means acting at one time to open communication between the equalizing reservoir and the control reservoir, and at another time to close said communication.

19. In a fluid pressure brake, the combination with a main reservoir, en ineers brake valve, and train pipe, of a fee valve device comprising a main valve for controlling the supply of airto the train pipe in two positions of the brake valve, a regulating valve device subject to the train pipe pressure for IIO normally governing the action of the main In testimony whereof We have hereunto valve when the brake valve is in one posiset our hands.

tion, a maintaining valve mechanism for WVALTER V. TURNER. also governing the action of the main valve, FRANCIS L. CLARK. and means for cutting out communication l/Vitnesses:

through the regulating valve when the brake R. F. EMERY,

valve is moved to the other position. J. B. MACDONALD.

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