US172064A - Improvement in air-brake valves - Google Patents

Description

G..WESTING'H0USE.J1-.

yAIR-151mm VALVE. No.172.,064. Patented Jan.11,1a7ve.

l VE lill?.

NFTERS, FMOTOLITHOGRAFNER. WASHINGTON. D. (.V

PATENT Orrcnu GEORGE v,VVES'IINGHOUSE, AJR., vlPIT'ISBURG, PENNSYLVANIA.

IMPRQVEMENT lN AIR-BRAKE VALVES.

Specication forming part of -Letters Patent No. 172,064, dated January 11, 1876; application filed December 18, 1875.

To alt whom it may concern Be it known. that I, GEORGE WEs'rING- HOUSE, Jr., of Pittsburg, county of Allegheny, State of Pennsylvania, have invented or discovered a new and useful Improvement in Air-Brake Valves; and I do hereby declare the following to be a full, clear, concise, and exact description thereof, reference being had tothe accompanying drawing, making a part of this specitication, in which-like letters indicating like parts- Figure l is a longitudinal sectional view of my improved valve; and Fig. 2 is a transverse sectional view through the line a: 00 Fig. 1.

My present invention relates to an improvement in the valve device patented to me October 5, 1875,7by Patent No. 168,359. It is intended for the same purpose as therein set forth, performsthe same function, and includes only such changes in construction and operation as hereinafter set forth.

The valve-case D is the same, inclosng a like piston-chamber, a, valve-chamber, al, and communicating passage a? also the screwcap D', with its air grooves and ports,` and tubular extension d, and stem-guide d1; also the stem el, with its collar and spring; also the piston G, with its stem g, valve H, cock B', and the passages and ports which lead from and to such valve and cock, and from and to an auxiliary reservoir, brake-cylinder, and brake-pipe.

All these devices, having by the prior patent become a part of the prior state of the art, need. not here be more fully described.

My present improvement dispenses with the side port s in the `valve-case, and provides for an air-portlherein alsolettered s) directly through the piston G, with one or more lateral ports, s', open 54 thence into the passage a2. The end of the port s next thc chamber a is made large enough for the insertion of a stem, c, of a somewhat less diameter, such 'stem c being connected by an enlargement,

c', to the end of the stern d4. The smallest part c of this compound stem is of the diameter of the smaller part of the port s, (or preferably a little less,) so that as the pistonG makes a downstroke, c will enter the` smaller part of s, and clean out any dust, dirt, or other obstruction which may have lodged therein.

The enlargement c of the compound stem is .ofsuch length, size, and position relative to the piston G and the adjacent end of the port s that when the devices are in the position shown, (the brakes then being off and the train in' running condition,) such end of s will be open for the free passage of air from the brake-pipe to the auxiliary reservoir; but with a diminution of air-pressure in the chamber a the back pressure of air from the auxiliary reservoir will shift the piston G, so that the port s, slipping onto the enlarged part c',

will be closed thereby, andthe escape of air cut off in advance of the opening of the communication from the auxiliary reservoir to the brakecylinder; and that this may be done without having to overcome any resistance from the slide-valve H, I make the distance between the collars c e a little greater then the length of the valve, as shown.

Hence the port s will be closed before the valve H begins to move for applying the stem, with the operation and result stated in the patent above cited.

It is not necessaryvthat the ports should be of a reduced size at any point, but I prefer to make it as small as practicable for supplying the amount of compressed air desired,

in order that there may be as small an escape as possible when the back pressure on the piston G is brought into effective operation.

I claim herein as my inventionl. The sliding piston G, having an air-port, s, closed and opened by sliding onto and oli' of a stem, c', and in combination therewith, substantially as set forth.

2. The sliding piston G, having an air-port,

s, in combination with the compound stem c In testimony whereof I have hereunto'set and c d, substantiallyas set forth. myh'an'd.

3. The slide-valve H, made shorter than the distance between its end bearings, iu com GEORGE WESTINGHOUSE, JR. bination with the port s' and stem c', relative- 1y arranged with reference to the operation Witnesses:

of the valve H, While the port s is closed,` lsubv JAMES M. CHRISTY, stantially as set forth. GEORGE H. CHRISTY.

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