US1512452A - Throttle valve - Google Patents

Description

' A. \N. BRUCE THROTTLE VALVE Filed March 28. 1923 WITNESSS Patented Oct. 21, 1924.

ALFIRED W. BRUCE, OF NEW YORK, N. Y.

THROTTLE VALVE.

Application filed- March 28, 1923.

TojaZZ whom it may concern:

Be it known that I, ALFRED WV, BRUCE, of New York, in the county and State of New York, have invented a certain new and useful Improvement in Throttle Valves, of which im rovement the following is aspecific'ation, v

My invention relates to throttle valves of the single poppet type, and its object is to provide a throttle valve of such type which will be simple, and ,compact in construction, and inex ensive in cost of maintenance, and in, the operation ofwhich all the advantages of a single seated valve will be fully attained,

The improvement claimed is hereinafter fully set forth. g

In the accompanying drawing: Figure 1 is a vertical central section through a throttle valve embodying my invention, ,in operative position in a steam boiler; Fig. 2,

a horizontal section through the same, on the line a 0; of Fig. 1; and, Fig. 3, a vertical central section, on an enlarged scale, through the valve, detached.

In the practice of my invention, referring descriptively to the specific embodiment thereof which is herein exemplified, I provide an open topped throttle box or chest, 1, which is preferably, as shown, formed integral with a stand pipe, 2, and is suitably supported in, or adjacent to, a steam boiler, being, in this instance, shown as located in the steam dome, A, of a locomotive boiler. Communication between the steam space of the boiler and the stand pipe and connected dry pipe, is controlled by a single sea-ted throttle valve, 3, of the lift or poppet type, connected, with the capacity of a limited degree of relative movement, as hereinafter explained, to a stem, 5, by the longitudinal movement of which it is brought against, or moved away from, an inclined seat, 1*, in the lower portion of the throttle box, 1, to prevent the admission of, or to admit, as the case may be, steam from the boiler to the dry pipe. A cross head, 6, is secured to the valve stem, at its end further from the valve, for connection to an actuating mechanism for moving the valve stem and connected valve. Such mechanism, of various types, is well known in practice, and as it does not form part of my present invention, it is not, in detail, herein set forth.

A balancing sleeve, 3*, which is open, at its end further from the valve, is formed Serial No. 628,258.

integral therewith, and extends therefrom into a superimposed balancing chamber, 4, formed integral with, or secured to, the inside of the throttle box. The balancing chamber is closed by a removable cap plate, 4*, having a properly packed stufling box, 49, through which the valve stem, 5, passes. The sleeve, 3 may either be fitted sufliciently freely in the balancing chamber to allow a limited degree of leakage of steam. into the chamber, or a small part, 3 may be formed in its wall for the same purpose. The'se exp'edients are equivalents, and either of them will perform the essential function of effectin positive. and continuous steam admission to the balancing chamber.

A central passage, 3", surrounding the valve stem, 5, and of greater diameter than said stem, is formed in the throttle valve, 3, and is normally closed by a pilot valve, 8, fixed on the valve stem. Said stem carries, adjacent to its lower end, a washer, 5 the position of which is adjustable by a. nut, 5 engaging a screw thread on the stem. The metal of the valve which surrounds the bottom of the central passage, 3', is radially recessed or channeled by grooves, 3 as more clearly shown in Fig. 3, to permit the free flow of steam from the passage, 3, when the washer, 5 bears against the bottom of the throttle valve.

In operation, the throttle valve, 3, being normally seated, it is subjected to downward pressure and held to its seat, by the boiler steam which surrounds its sleeve, 3 and, by positive and uninterrupted steam admission around said sleeve, or through the port, 3, fills the superposed balancing chamber, 4t, and exerts downward pressure on the throttle valve, 3. When it is desired to admit steam to the stand pipe, 2, and connected dry pipe, 2 the valve stem, 5, is raised by the actuating mechanism, its preliminary movement unseating the pilot valve, 8, and bringing the washer, 5 to a bearing against the bottom of the throttle valve. The transverse area of the space around the valve stem in the passage, 3*, of the throttle valve is materially greater than that of the leakage space allowed around the sleeve, 3*, in the b-alancing chamber, or of the leakage port, 3, if one is provided, and the steam. in the balancing chamber, 4, is, therefore, immediately exhausted therefrom into the stand pipe and dry pipe. The throttle valve, 3, is thereby relieved from the downward pressure which held it; to its seat, and, by the continued upward movement of the valve stem, 5, which is transmitted to it by the bearing of the washer, 5*, on its bottom, it may be unseated to any desired degree. There being a continuous coincident release of pressure n the balancing chamber during the period thatithe throttle valve is unseated, no r'e sista-nce is opposed to its upward movement.

The throttle valve is seated by the down ward movement of the stem, 5, in bringing the pilot valve, 8, to its seat, and after being seated, is held to its seat by the uninterrupted admission of steam into the balancing chamber.

I claim as my invention and desire to secure by Letters Patent:

1}. The combination of a throttle box,

continuousl 0 en to steam sup lv' a single seated throttle valve, controlling communication between said throttle box and an avenue of steam delivery; a superposed balancing chamber, open to said throttle valve; means for effecting positive and uninterrupted admission of steam to said chamber to exert downward pressure on the throttle valve, when seated; and means for exhaust ing steam from said chamber, to release downward pressure on said valve in effecting its unseating movement.

2. The combination of a throttle box,

avenue of steam delivery; a superposed balancing chamber; a sleeve, fixed to the throttle valve; means for effecting positive and uninterrupted admission of steam to the balancing chamber; and means for exhausting steam from said chamber, to release downward pressure on the throttle valve in effecting its unseating movement.

3. The combination of a throttle box, con tinuously open to steam supply; a steam delivery pipe; a single seated throttle valve, controlling communication between said throttle box and said pipe; a superimposed closed topped balancing chamber, fixed in the throttle box; a sleeve, fixed to the throttle valve and fitting in the balancing chamber, said sleeve having a continuously open steam supply port; a stem, connected with the capacity of limited degree of relative movement, to the throttle valve; and a pilot valve, fixed on said stem, and controlling an exhaust port in the throttle valve. of greater capacity than the supply port of the sleeve.

ALFRED W. BRUCE.

Witnesses J. RoWDnN BELL, FRED. A. WADSVVORTH.

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