US810514A - Fluid-pressure brake. - Google Patents

Description

No. 810,514.. PATENTED JAN. 23, 1906. W. V. TURNER & J. S. GUSTER.

FLUID PRESSURE BRAKE.

APPLICATION FILED Amm?, 1904.

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INVENTORS WITNESSES No. 810,514. PATBNTED JAN. 23, 1906. W. V. TURNER & J. S. GUSTBR. FLUID PRESSURE BRAKE.

APPLIOATION FILED APB..27. 1904.

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No. 810,514. yPA'IEN'IED JAN. 23, 1906.

w. V. TURNER a; J. s. GUSTER.

FLUID PRESSURE BRAKE. APPLIOATION FILED APR.2'1. 1904.

3 SHEETS-SHEET 3.

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/ @t www( WALTER V. TURNER, OF WILKINSBURG, AND

BURG, PENNSYLVANIA, ASSIGN ORS TO THE WESTINGHOUSE AIR BRAKE -OOMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENN- SYLVAN IA.

FLUID-PRESSURE BFIAKE.I

Specicaton of Letters Patent.

Patented .18.11.23, 190e.

Application tiled April 27, 1904. Serial No. 205,116.

To all whom it may con/cern,.-

Be it known that we, WALTER V. TURNER,

vresiding at Wilkinsburg, and JOHN S. CUsTER,

residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, citizens of the United States, have invented a certain new and useful Improvement in Fluid-Pressure Brakes, of which the following is a speciprincipal object to length of travel of the brake-piston.

With the present standard air-brake apparatus, as is well known, the degree oi' pressure which will be supplied from the auxiliary reservoir to the brake-cylinder corresponding to any given amount o reduction in train-pipe pressure depends upon the relative capacities or volumes of the auxiliary reservoir and the brake-cylinder; but since the capacity of the brake-cylinder varies according to the travel of its piston a certain length of travel, such as eight inches, has been assumed as standard and the capacity of the auxiliary reservoir made to correspond thereto. Now if the travel of the brake-piston on each car of the train remained constant at this amount-say eight inches-#then the pressure in all the brake-cylinders-would be substantially the same at each application o'i the brakes; but it is found in actual practice that owing to various conditions-such as wear of brakeshoes, stretching of brake-riggingy l'ooseness of joints, and careless adjustment-the travel on different oarsvaries anywhere from four or six inches up to the tullstroke of the piston, or twelve inches, and this of course produces corresponding variations in the brakecylinder pressure from practically zero up to what mightbe an excessive degree o1 pressure sufiicient to cause a sliding of the wheels of the car. Various slack-adjusting devices for automatically keepin the length-of piston travel constant have eenproposed, and some of thesel have -been found to operate quite successfully; but these devices have' not as yet been generally applied in freight service, to which our invention is -particularly applicable.

This feature of our invention comprises a compartment or chamber of a certain redetermined capacity to give the desire pressure corresponding with that of the brakecylinder at a standard length ot piston travel, and combined with this chamber are valve devices operating in response to variations in train-pipe pressure for controlling the supply of air to this chamber at the desired degree of brake-cylinder pressure and means controlled by the pressure in said chamber for re ulating thepressure admitted to the brakecyglinder to the same degree. The air for char ing this chamber may be taken from the auXi iary reservoir, train-pipe, sup lemental reservoir, or other source, and the rake-cylinder may also be supplied from any of these sources or from a combination of any of them'.

Another object of our invention is the provision of improved means for maintaining the train-pipe pressure constant While the brakes remain applied and the engineers brakevalve is in lap position.

In the accompanying drawings, Figure 1 is a diagrammatic view of a standard air-brake equipment with our improvements applied thereto; Fig. 2, a sectional view showing a standard engineers brake-valve with ourlmproved means for seatn the equalizing-piston; Fig. 3a sectional view of the valve device for maintaining the train-pi e pressure; Fig. 4, a sectional view of a trip e-valve device and regulating-valve device constructed in accordance with one form of our improvements, the parts being indicated in release position; Figs. 5 and 6, similar sections of the triple-valve device, showing the parts in service and lap positions, respectively; Fig. 7, a plan view of the valve-seat; Fig. 8, a face view of the main slide-valve; Fig. 9, a face View of the graduating slide-valve; Fig. 10, a diagrammatic view of a car equipment, showing a-modified form of ourimprovement, including a supplemental reservoir; Fig'. 11, ya sectional view of a' triple-valve device and regulating-valve device constructed according to this modification.; Figs. 12 and 13, similar sections of the triple-valve device, showing the parts in service andlap positions, respectively; Fig. 14, a plan view of the slidevalve seat; Fig.4 15, a face view of the'main slide-valve, and Fig. 16 a face viewA of the graduating slide-valve.

JOHN S. OUSTER, OF PITTS- i Our improvements are illustrated as apreservoir, the triple-valve device being" provided with additional ports and assages for performing both functions, as s own more particularly in the figures on Sheet 2 of the drawings, which will now be more fully described.

The chamber 43 of the'brake-cylinder-regulating. device 9 is made of a predetermined capacity, such that the relation between the capacity of the train-pipe of the car and this chamber and the connecting-port is substantially the same as that between the auxiliary reservoir, the brake-cylinder, and the serviceort. A valve 46 controls the su ply of -air om pipe 10 and chamber 47 to chamber 45 and pipe 11, leading to the brake-cylinder 8, the valve being operated by the diaphragm 44, which is subject to the opposing fluidpressures of the regulating-chamber 43 and the brake-cylinder.

The valve-seat of the tri le-valve device 6 is provided with the following ports 30, leadin to the brake-cylinder; 40, leading to the ex aust; 31, connected to the train-pipe by passage 34; 32, connected to pipe 10, and 33, connected by pipe 12 with the regulatingchamber 43. On the valve-seat is mounted the main slide-valve 28, carrying the gradued to be connected by cavity 39 in small graduating-valve 29 when in service position,

as shownin Fig. 5. In release position of the valve the ports 33 30, and 40 communicate with the exhaust-cavity 36, so that the brake-cylinder and the chamber 43 are open to the atmosphere, while the auxiliary reservoir is charged from the train-pipe in the usual way. When a reduction in train-pipe pressure is made for a service application of the brakes, the triple piston and valve move back under the preponderating auxiliaryreservoir pressure to. service fposition, as shown in Fig. 5, in which the service-port 41 is open through the mam slide-valve and reg- 6 5 isters with the brake-cylinder port 30 there- The main valve is4 by establishing communication from the auxiliary reservoir to the brake-cylinder. In this position the train-pipe is also put into communication with the pipe 10 through ports 34 31, cavity 35, and port 32, while at the same time the train-pipe communicates with the regulating-chamber`43 through ports 38, cavity 39, ports 37 and 33, and pipe 12. Air then flows from the train-pipe to the regulating-chamber 43 and serves as a local venting of the train-pipe to quicken the action of the triple valves in service applications. At the same time thel brake-cylinder is being charged from the auxiliary reservoir through the service-port, and as soon as the auxiliaryreservoir pressureis thereby reduced to or slightly below that of the train-pipe the pis t0n and graduating-valve move to lap posi- 'standard piston travel, and the service-port,

so that the degree of air-pressure admitted to -chamber 43 corresponds substantially with that desired in the brake-cylinder for any Given reduction in train-pipe pressure. Now 1f the travel of the brake-piston is accurately adjusted at standard-say eight inches-then the pressure admitted from the auxiliary reservoir to the brake-cylinder will be substantially equal to that which obtains in the regulating-chamber and the regulating-valve will remain closed; but if the brake -piston has a greater travel, which is usually the case, it wil be readily seen that owing to the greater volume the brake-c linder pressure will be less than desired and ess than that of the regulating-reservoir. Consequently the diaphragm 44 will be depressed, thereby opening valve 46 and supplying additional air to the brake-cylinder until the pressure therein is equal to that contained in the regulating-chamber,I and it will be noted that the triple piston and graduating-valve do not move to lap position until this operation is completed. As thisaction takes place on each and all cars of the train equipped with this improvement, itwill be seen that the brake-cylinder pressure will be substantially uniform throughout the train, thereby securing an efficient and uniform braking power. As the graduating-valve moves to lap position the service-port 41 is closed and communication between ports 38 and 37 cut off,

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thereby sealing up the air under pressure in i the regulating-chamber 43. The train-pipe is still connected with pipe 10, however, through cavity 35 in the main slide-valve, so

'that should there be any leakage from the valve and diaphragm. In order to maintain the brake-cylinder pressure from the trainpipe'in this mannerfit is necessary to also provide means for maintaining the train-pipe pressure while the brakes are applied and the engineers brake-valve is in lap position, and for this purpose the valve device 20 is provided on the locomotive. (See Figs. 1 and 3.) This device comprises a diaphragm 24, subject tothe opposing pressures of the trainpipe by pipe connection 22 and the equalizing-reservoir by pipe connection 23, and operates a valve 25 for controlling the supply of air from the main reservoir and pipe 21 to the pipe 22 and the train-pipe. It will now be evidentthat by means YVof this device the train-plpe pressure will be maintained from the main reservoir substantially equal to that of the equalizing-reservoir, While the brakes remain applied and the engineers brake-valve is in lap position.

With the exception Iof an improvement hereinafter described the engineers brakevalve, as shown in Fig. 2, may be of the standard Westinghouse type havingrotary valve 13, train-pipe passage 14, equaliZing-piston 15, and stem 19 for operating the train-pipedischarge valve. In the standard' construction the valve carried by the stem 19 is of the pup et type, and there is no means for positive y preventing a slight leakage around the packing-ring of the sliding equaliZing-piston. When used with the train-pipe maintainingvalve device 20, connected to the e ua'lizingreservoir, as shown in'Fig. 1, it Wi l be seen that it becomes necessary to prevent the possibility of any leakage from said reservoir around the equalizing-piston `to the trainpipe when the brake-valve is in lap position and the train-pipe-discharge valve closed, in order that the pressure on the diaphragm 24 shall remain constant, and according to this feature of our invention means, such as a gasket 16, is provided against which the piston 15 may tightly seat when the discharge-valve is closed, and thereby positively prevent any leakage from the egualiging-reservoir. In order to insure the seating ofthe piston upon the gasket, the train-pipe-discharge valve operated by stem 19 is preferably made in the form of. a slide-valve 17, controlling the port 18, and means, such as a'light spring 54, may also be used, if desired.

A modified form of apparatus for'regulating the brake-cylinder pressure is shown in Figs. 10 to 16 of the drawings, in which Ia supplemental reservoir 50 is employed. According to this construction the triple-valve device 6 is provided with an additional port 52, connected by pipe 5l with the supplemental reservoir, and the main slide-valve has an additional cavity 53 for establishing communication from the supplemental reservoir to the pipe 10, leading to theregulatingvalve when the triple valve is in service posishown in Fig. 12, in which the auxiliary res.

ervoir communicates with the brake-cylinder and the train-pipe communicates with chamber 43, as before described, and the supplemental reservoir communicates with the regulating-valve and pipe 10 through ports 52 and 32 and cavity 53 in th main slidevalve. Air then flows from the train-pipe to chamber 43 and from the auxiliary reservoir to the brake-cylinder, as before described, any additional air required by the brake-cylder due to excessive piston travel being supplied from the supplemental through the regulating-valve for bringing the brake-cylinder pressure up to substantially equal that of the regulating-chamber. The triple valve then moves to lap position, as shown in Fig. 13, and any further leakage from the brake-cylinder will be supplied from the supplemental reservoir through the cavity 53 in the main slide-valve, pipe 10, and the regulating-valve 47, as will be readily understood. The brakes may be released in the usual manner by increasing the train-pipe pressure.

While this improvement is shown as applied to a triple-valve device of the plain reservoir IOO type, in which the port 42 is adapted to register with brake-cylinder port 30 in emergency applications, it will be evident the same may so be used in connection with a so-called quick-action triple-valve device, in which an emergency-valve is used for suddenly venting the train-pipe in emergency applications. From the foregoing description it will now be apparent that by means of our improvements we secure not only the advantages usually derived from a local venting of the train-pipe in service applications of the brakes, but also the additional and important result ofa constant and uniform braking-pressure in all the cylinders, whereby each car is made to perform its share of the work in braking regardless lof the length of travel of its brake-piston.

The feature of this invention relating to the maintaining of the'train-pipe pressure while the brakes are applied, as shown more particularly in Figs. 2 and 3 of the drawings, comprises la very simple and efficient mechanism for accomplishing this result and may pendently of any means for regulating the brake-cylinder pressure. With the present standard apparatus, as is well known, there IIO IZO

be applied to an air-brake apparatus indevalve is no means for compensating for train-pipe leakage when the brake-valve is in lap position., Consequently after the brakes are applied the train-pipe leakage further reduces the pressure, which causes further graduating movements of the triple valves, thereby applying the brakes harder than was intended and often necessitating a release and reapplication, which Wastes a large amount of compressed air. By means of this feature of our invention any leakage from the trainpi e While the brake-valve is in lap position Wi l be replenished from the main reservoir through valve device 20, which is governed by the pressure in the equalizing-reservoir, and the train-pipe pressure Will be maintained constant at the given degree of reduction,

thereby preventing any undesired further increase in the brake-cvlinder pressure.

Having now described our invention, what We claim as new, and desire to secure by Letters Patent, is l 1. In a fluid-pressure brake, the combination with a train-pipe, auxiliary reservoir and brake-cylinder7 of a regulatin -chamber, a valve device for controlling t e supply of fluid to said regulating-chamber, and means operated b the pressure in said chamber for supplying uid directly to the brake-cylinder. 2. In a fluid-pressure brake, the combina- 'tion with a train-pipe, auxiliary reservoir and brake-cylinder, of a regulating-chamber, a valve device operating in response to variations in train-pipe pressure for controlling the supply of fluid to `said regulating-chamber, and means operated by the pressure in said chamber for regulating the brake-cylinder pressure.

3. In a fluid-pressure brake, -the -combina-l tion with a train-pipe,auxiliary;reservoir and brake-cylinder, of' al regulatingehamber, a

valve evice operated Yiby .ajr'eduction -in train-pipe pressure for supplying fluid from the auxlliary reservoir to the brake-cylinder and for controllingthe supply to said regulating-chamber, and'means operated by the pressure in said chamber for'regulating the brake-cylinder pressure. c

4. In a fluid-pressure brake, the combination With a train-pipe, auxiliary reservoir and brake-c linder, of a regulating-chamber, a evice operated by a reduction in train-pipe pressure for sup lying fluid from the auxiliary reservoir to t e brake-cylinder and for controlling the supplyl to said regulatin -chamben and a valve device governed by tle pressure of said regulating-chamber for also supplying fluid to the brake-cylinder.

`5.- In a fluid-pressure brake, the combination with a train-pipe, auxiliary reservoir and brake-cylinder, of a regulating-chamber, a valve device operating in response to variations inl train-pipe pressure for supplying fluid from the auxiliary reservoir to the brake-cylinder and from the train-pipe to the regulating-chamber, and means operated by the pressure in said chamber for regulating the brake-cylinder pressure. p 6. In a fluid-pressure brake, the combination With a train-pipe, auxiliary reservoir and brake-cylinder, of a regulating-chamber, a valve device operating in response to variations in trainN-pipe pressure for supplying fluid' from the auxiliary reservoir to the brake-cylinder and from the train-pipe to the regulating-chamber, and means operated by the pressure in said chamber for also supplying fluid from the train-pipe to the brakecylinder.l

7. In a fluid-pressure brake, the combination with a train-pipe, auxiliary reservoir and brake-cylinder, of a regulating-chamber of predetermined capacity independent of the brake-cylinder, a valve device operating in response to variations in train-pipe pressure for vcontrollin the supply of fluid to said regulating-cham er, and means operated by the pressure in said chamber for supplying fluid to the brake-cylinder.

, 8. In a fluid-pressure-brake, the combination with a, train-pipe, auxiliary reservolr and brake-cylinder, of a regulating-chamber of predetermined capacity independent of the brake-cylinder, a valve device operating in response to variations in train-pipe pressure for controlling the supply of fluid from the auxiliary reservoir to the brake-cylinder and from the train-pipe to the regula'tin -chamber, and a valve device governed by t e pressure of said chamber for supplying fluid to 'the brake-cylinder.

9. In a fluid-pressure tion with a train-pipe, auxiliary reservoir and brake-cylinder, of a regulating-chamber, and a triple-valve device comprising a piston subject to the opposing pressures of the trainpipe and auxiliary reservoir, a main slidevalve having orts for establishing communication from tlie train-pipe to the regulatin chamber, andra graduating-valve for contro ling the ports in the main slide-valve.

10. In a fluid-pressure brake, the combination with a brake-valve having an equalizing-l .opposing pressures of the e ualizing-reservo1r and train-pipe for control ing the supply of fluid to the train-pipe.

12. In a fluid-pressure brake, the combination with a brake-valve having an equalizingbrake, the combina- IOO :310,514l l I 5 reservoir7 a sliding piston operated by the In testimony whereof We have hereunto opposing pressures of the equalizing-reserset our hands. Voir and train-pipe, a slide-Valve operated by said piston for Controlling a train-ppe-dis- WALTER V. TURNER. A

charge port, a seat adapted to be engaged by JOHN S' CUSTER' said piston, and Ineens governed by the pres- Witnesses: sure in the equalzng-reservoir for supplying B F. EMERY,

Huid to the train-pipe. JAS. B. MACDONALD.

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