US245110A - Air-brake cut-off and relief valve - Google Patents

Description

(-No Model.)

G. WESTINGHOUSE Jr. & H. H. WESTINGHOUSE.

AIR BRAKE GUT-OFF AND RELIEF VALVE.

No. 245,110. r Patented Aug. 2,1881.

' enoaen WESTINGHOUSE, .13., AND H.

PATENT OFFICE.

K HERMAN WESTINGHOUSE, OF PITTS- BUItGr, PENNSYLVANIA.

AIR-BRAK E'CUT- O F Fi AND RELIEF VALVE.

SPECIFICATION forming part of Iietters I'atent No. 245,110, dated August 2, 1881.

Application filed April 21, 1881. (No model.)

To all whom it mayconcern:

Be} it known that 'we, G omen WEsTING-Q, HoUsE, Jr., and H, HERMAN WESTINGHOUSE, of Pittsburg, county of Allegheny, State of Pennsylvania, have invented ordiscovered a new and useful Improvement inAir-Brake Out- Off and Relief Val ves; andwe do'hereby declare 4 the following to be a full, clear, concise,and

exact description thereof, reference being had to the. accompanying drawings, making a part of this specification, in which-like letters indicating like partsi Figure 1 is a longitudinal sectional view of. our improved cut-ofl and relief valve. Fig. 2 is a like view detached of the diaphragm and its tubular piston. Fig. 3 is a transverse section in the plane of the line w m, Fig. 1 ,and Fig. 4is aview, in elevation, to a reduced scale, of the device of Fig. 1 in its ordinary arrangement for use between two half-con plin gs, both of whichare connected to it, one at each end. In this figure the form of coupling shown is that which forms the subject-matter of Patent No. 236,388, though other suitable form of coupling may be substituted therefor, many such being known in the art.

The construction and operation of the automatic compressed-air brake now in general use are so well known'and understood that it will be sufficient for present purposes to refer only to its general features. The compressed airis transmitted back throughout the train and charged into reservoirs, of which one is usually under each'car. When the brakes are to be applied the engineer turns a cock, so as to lower thepressure in the brake-pipe. The back pressure then from each auxiliary or car reservoir shifts a triple valve, so as to cut 011' back flow, and opens a port to the brake-cylinder. Restoration of air-pressure in the brake pipe reverses the triple valve and opens an escape-portfrom the brake-cylinder to the open air. In adapting this system to very long trains, especially freight-trains, I have found, where two or three or more ordinary or average trains are united in one, giving, say, from thirty to fifty or sixty or more cars in one train, that the reduction of pressure and the restora tion of pressurein the brake-pipe'in the'ordi'- nary use of the apparatus is necessarily somepower.

what slow, chiefly on account of the great length of thetrain, and thefactthat in ordinary braking only aslight reduction of pressure in thebrake-pipe is necessary, and that :while all cars ought to be fitted with air-brake apparatus .it is' quite suflicient for ordinary braking purposes if the brakes be applied on, say, twenty cars, more or less, at the forward end of the train. This (especially if a drivewheel brake be used) will put the train practically under the control of the engineer, so that he can make ordinary stops with ease and fa- 'cility, start again readily, and hold his train in check on ordinary down-grades. The brakepipe on the number of cars supposed is not so long but that sufficient air can be readily and quickly exhausted from and again pumped or charged into the pipe to actuate and release the brakes with such celerity and power as are essential in freight-train service. At the same time, in case of emergency, or where excessive brake-power is required,'t-he engineer ought to be able to setevery brake throughout the train with maximum quickness and power- Our present invention relates to a means for securing these desirable ends.

f At any desired point in the traiu-say fifteen or twenty cars from the forward end-,we insert in the air-conduit pipeor connection a cut-off valvular appliance of such construction that it will permit of the flow of air under pressure in one direction back through the brake-pipes so as 'to charge and keep charged the auxiliary reservoirs on all the cars of the train, but as against no more than the usual or a moderate reduction of the air-pressure forward, such as will shift the triple valves on the supposed fifteen or twenty forward cars, and apply the brakes of those cars, such device or appliance will close the air-conduit pipe and prevent the escape of air or the reduction of the pressure from the brake-pipe in the rear of it, and hence will practically cutoff in the case supposed the braking-power of the cars in its rear, while leaving the braking-power of the cars forward free to act with the desired promptness and At the same time the appliance in question is so constructed that when, in case of emergency or necessity, the englneer opens full the air-pressure reducing or escape port,

or opens it more than is common or desirable in ordinary braking, an escapeport will be opened in the appliance referred to by the backpressure, so as to permitof the escape ofair from the brake-pipe of cars in the rear, whereby the triple valve on every car will be at once shifted and the brakes applied on every car with maximum force and quickness, if desired, or with relatively less force and quickness if the reduction be less.

The appliance or device referred to has a case, A A, made in two parts bolted together, and which clamp between their meeting surfaces the outer edge of a flexible diaphragm, a, made preferably of india-rnbber. This diaphragm is open at the center, as shown, and rests or laps onto the end of a hollow piston, to, to the radial flange of which it is secured by a clamping-rin g, a and screws a The tubular sides of the piston a have holes or ports 8, in any desired number.

Passing lengthwise through the opening or bore of the hollow piston is a valve-stem, v, which carries a valve, a, which seats like a flat-faced poppet-valve on the inner edge of the diaphragm a, and a cylindrical head, d, on the end of the stem closes and keeps closed the otherwise open end of the hollow piston. The hollow piston has, however, a shortrange of possible motion away from the valve '0 and into the annular recess d made around the base of the cylindrical head d, and in this recess one end of a spring, 0, is inserted, the other end of which bears with a moderate pressure against the adjacent or under face of the piston-flange, so as to hold the valveseat of the valve 0 up against said valve. From the plane of the seating-face of the valve 1: guiding-wings e extend down to the head (I. The valve o is clamped down against the ends of these wings by a screw-nut, '0 and the end of the valve-stem is guided by being passed through an eye in a spider'fraine, a.

Between the spider-frame and the top or back of the valve '0, I arrange a spring, 0, the resiliency of which is intended to be equal to or a little in excess of the amount of the reduction of air-pressure intended to be effected in the brake-pipe at the forward end of the train in doing ordinary or average braking. For example, if such reduction of air-pressure is to equal or not exceed, say, fifteen pounds per square inch, then the spring 0 should exert a force approximately equal to or greater than fifteen pounds multiplied by the number of square inches in the diaphragm a and its movable attachments, against which air-pressure acts effectively to compress the spring a.

The head (1 has a hole bored in its end in the axial line thereof, in which we insert and loosely secure by a pin, 0 the stem 0' of a poppet-valve, c. This valve seats (when seated) on a bush, 0 which latter is slipped tightly in a seat or socket made in a bridge-piece, B, which latter extends across the hollow of the half-case A, but so as to leave ports 1) past the outside of the bridge-piece, and also make ports I) from the tubular openings of the bush 6 to the external atmosphere. A winged stem on the under side of the valve 0 plays in the bore of the bush 0, the better to guide the valve. In each end of the case thus made we screw a half-coupling, H, Fig.4, which may be of any suitable construction; but, as shown, we prefer to use the well-known VVestin ghouse clutch-couplin g. The appliance or device thus constructed is to be arranged between and connected with the two half-couplings, which otherwise would connect the brake-pipes of any two cars, and at such point in the length of the train as will give forward thereof a brake power sufficient for ordinary purposes, but not too long for ready application 5 but the place in the train where it is inserted or inter-coupled is not material, and is to be left to the choice orjudgment of the trainman or employ to whom the matter may be intrusted.

In a train of, say, from thirty to fifty cars, more or less, the device may be arranged about midway of the train, and on longer trains a convenient or advantageous point for inserting it would be anywhere along from fifteen to twenty-five cars from the forward end of the train. The train and pipes being coupled up, the engineer turns on air-pressure to charge the brake-reservoirs. The operation forward of this device will be as is usual in the automatic brake. At the device, air-pressure, entering at the forward end, P, (which end must always be forward or toward the charging end of the train,) will act on that side of the diaphragm a so as to compress the spring a, slide the piston a down on the wings 02 of the stem 7] and on the cylinder or plug d, and leave an open annular port beneath the valve 0, so that the air-pressure may be transmitted or pass onward through the ports 8 and charge the reservoirs on cars in the rear.

When the engineer wishes to apply the brakes in ordinary braking he lowers the airpressure in the usual way, so as to operate the brakes in the usual way forward of the device thus interooupled. Ordinarily this can be done so as to apply the brakes with sufficient power for ordinary purposes by a reduction of airpressure of not to exceed ten or fifteen pounds per square inch, more or less.

As the spring 0 is adjusted, as above ex plained, to resist a back or compressive force corresponding in amount to such reduction, such back-pressure, acting on the right-hand side of diaphragm a, will perform no effect except to force the inner edge of the diaphragm over against the under or seating face of the valve 1;, and thereby close the charging-port. The inner part of the rubber diaphragm furnishes a seat to the valve, so as to make a tight joint. The devices will then be in the relative position shown in Fig. 1, and the valve 0, which governs the escape-ports b, will be seated, the effective back-pressure not being sufiicient to unseat it; but when in case of emergency or danger, or when for any reason more than the usual or a moderate braking-power is desired,

the engineer opens his cock, soias to lower the and head d, carrying the valve 0, will be shifted.

to the left a greater or less distance, according to the amount of the supposed reduction, and the unseatin g of the valve 0 opens the escape from the rear brake through the ports I). The pressure being thus reduced in the rear brakepipe, the back-pressure of the air in the auxiliary reservoirs connected therewith will shift the corresponding triple valves and the brakes will be applied throughout the train.

If the train has, say, from sixty to eighty cars, two or more such cut-off appliances may be employed at properintervals along the train, the spring 0 being so set in each case that any reduction of air-pressure forward in excess of a predeterminedamount shall result in the compression of the spring and the unseating of the valve 0. v

Various modifications may be made in the appliance described, such as may be suggested by or copied from various triple-valve patents heretofore granted to George Westinghouse, Jr., and in fact the device in question has many of the features'of construction and operation of a triple valve, the principal distinctive features being in the addition of the spring 0 and in the arrangement of the chargin g and exit ports P P in line with each other on opposite sides of the diaphragm, instead of at right angles, as has heretofore been usual in triple valves, as an auxiliary reservoir attachment; and it may also be modified so as to embrace the valvular structure shown and described in United States Patent to George Westinghouse, J r., No. 21.7 ,838, of July 22, 1879, or other suitable known forms of reliefvalve, so called, such as may at pleasure be insertible and removable from a line of brakepipe at a point intermediate between its ends, and such as will automatically, under the action of fluid-pressure, perform the functions set forth substantially in the manner described.

We are aware that relief-valves, so called, adapted to open an air-escape port at each brake-cylinder on the release of air-pressure in a compressed-air-brake mechanism, as distinguished from an automatic-brake mechanism, is not new; but we are not aware of any prior construction of valvular apparatus in which both the cut-off and relief or escape functions are unitedly employed, so that at one degree of reduction of pressure the cut-off function will be brought into play, and at another degree of reduction of pressure an escapeport will be opened to the external. air. And it is also true that other forms or construction of couplings, such as may be used in the brake apparatus with which the valve in question is to be used, may be attached at or connected with the ports P P, instead of those shown, without any substantial departure from the scope of the present invention; or, instead of using a brake-coupling proper, other suitable form of readily attachable and detachable coupling may be employed. It should be stated, however, that the cylindrical head at performs no function of importance, and that that device is so made simply as a matter of convenience. The wings 12 might be extended entirely down the stem, with radial ribs by which to furnish bearings for the end of the spring 0, and bearings so made are included herein as the equivalents of the annular recess d; also, in such case the open end of the piston would be the equivalent of the ports 8.

We claim herein as our invention 1. An air-brake cut-off and relief valve adapted to be at pleasure inserted in and removed from a line of train-brake pipe at any desired point between its ends, and automatically operative under the action of the fluidpressure in the charging of the reservoirs in cutting off the escape-port at one degree of back pressure and opening it at another de- 2. An air-brake cut-off and relief valve automatically operative under the action of the fluid-pressure, substantially in the manner set forth, in combination with a brake-pipe coupling secured to or connected with each end thereof, whereby to be readily connected with and disconnected from the ordinary brake-pipe couplings (ofcorresponding kind) as employed on the cars of the train. a

3. in an air-brake cut-ofi' and relief valve of the class described, the arrangement of the ports P P or coupling ends substantially inline with each other.

4. The valve-caseAA, having ported bridge B and valve-seat thereon, in combination with a valve, e, spring a, and suitable interposed mechanism whereby the valve will be held to its seat as against a moderate reduction of fluid-pressure, but will be lifted from its seat and open an escape-port in case of a greater reduction of air-pressure in the brake-pipes, substantially as and for the purposes set forth.

5. In a valve-case, A A, a ported bridge, B, having a valve-seat and a valve, 6, thereon, in combination with spring 0, stem 4;, having a valve, '12, and end bearings for the spring 0, diaphragm a, and hollow ported piston a, substantially as and for the purposes set forth.

6. In a valve-case, A A, a diaphragm, a, and hollow ported piston a, in combination, by spring 0, with valve 12 and annular recess 01, as a meansfor actuating the valve of an escape port, substantially as set forth.

7. The method of actuating brakes in long trains by interposing at one or more suitable points in the length of the brake-pipe thereof a corresponding number of automatically-acting cut-off and relief valves, substantially as set forth, and adapted to cut off or out of ac gree ofback-pressure, substantially as setforth. 5

tion the rear section or sections of brake appa- In testimony whereof we have hereunto set ratus, as against a. moderate reduction of airour hands.

pressure in the section forward, and also adapt- GEORGE WESTINGHOUSE, JR. ed, on a greater reduction of pressure forward H. HERMAN WESTINGHOUSE.

rear section, and thereby bring the brake apparatus of the rear section into operation.

R. H. WHITTLEsEY,

to open a relief-valve on the brake-pipe of the Witnesses:

1 GEORGE H. GHRIs'rY.

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