US513938A - Balanced slide-valve - Google Patents

Description

(No ModeL) 4 AP F. KEILY. BALANCED SLIDE VALVE.

Patented Jan. 30, 1894.

I JV VEJVTOR wm mssms' flttorney UNITED STATES PATENT OFFICE.

ARTHUR F. KEILY, OF 'MACON, GEORGIA.

BALANCED SLI DE VALVE.

SPECIFICATION forming part of Letters Patent N 0. 513,938, dated January 30, 1894.

Application filed April 28, 1393. Serial No. 472,209- (No model.)

To all whom it may concern:

Be it known that I, ARTHUR F. KEILY, a citizen of the United States, and a resident of Macon, in the county of Bibb and State of Georgia, have invented certain new and useful Improvements in Balanced Slide-Valves; and I do declare the following to bea full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same,

reference being had to the accompanying.

drawings, and to letters of reference marked thereon, which form a part of this specification.

Figure 1 of the drawings is a vertical longitudinal section of valve and steam chest. Fig. 2 is a vertical transverse section taken on line a: a; Fig. 3. Fig. 3 is aperspective view of the valve. Figs. 4, 5 and 6 are views in perspective of the packing strips.

This invention has relation to certain new and useful improvements in balanced. slide valves, the object being to provide improved means for more perfectly excluding steam from the upper face of the valve, and thereby preventing to a large extent the downward pressure thereon of the steam in the chest; and the invention consists in the novel construction and combination of parts, all as hereinafter specified and pointed out in the claim.

Referring to the accompanying drawings, the letter A designates the body of the valve, which may have any suitable form of exhaust cavity therein. Upon the upper face of the valve is cast or otherwise secured a block'B, the area of the upper surface of which is somewhat less than the area of the face of the valve. Said block is cut away at its end portions to form the vertical lugs O, O, of less transverse width than the body of the block, and separated each therefrom by atransverse groove or cavity 0., having true faces or walls. Formed in the body portion B of said block or upper portion of the valve, one near each lateral edge are longitudinal grooves 19, b, having true faces or walls, and extending the entire'lengthof the said block, or upper portion of the valve.

F, F, and G, G, designate the packing strips which are placed in the grooves a, a, and b, b.

F, vF, designate the longitudinal strips, and G, G, the transverse strips. The longitudinal strips F, F, are of such length as to just fit between the inner faces of the transverse strips G, G, the latter being extended laterally beyond the strips F, F, and terminating flush with the edge of the portion B of the valve.

The strips F, F, are cut away at their lower portions, forming the chambers c, c, and the end legs or lugs f, f, upon which the strips seat when resting upon the bottom of the grooves, the end strips being similarly cut away, forming passages'g, g, at each side of the lugs C, 0, through which steam may enter underneath the strips F, F.

The outer faces of the strips G, G, are recessed at h, h, to partially receive the lugs O, G, and in a cavity '5 of said recessed portion is seated a spring H. Said spring mav be of semi-elliptical or other form, and bear against the inner faces of the lugs O, C. The outer faces of the longitudinal strips F, F, are also recessed at z', 2', to form seats for similar springs H, which bear against the outer walls of the grooves.

The upper faces of the packing strips, which should bepreferably true, are designed to bear against the cover of a steam chest, or against a balance plate K, Within said chest, in a steam tight manner, so as to exclude all steam from within the area inclosed by said strips, thus reducing the downward pressure on the valve sufficiently to balance it against the pressure of the exhaust steam at the under side. The springs H serve to press the four strips closely together at their meeting faces, so that no steam can enter at the corners. The tension of the springs is also sufficient to press the packing strips against the Valve with sufficient force to maintain them in their raised position after steam is cut off, so that the usual bottom springs may be dispensedwith, and steam be prevented from getting above the strips when it is again turned on. Said springs also serve to take up the wear of the said strip, and thereby prevent the latter from becoming loose. Strips employed without these springs soon become worn to such an extent that they become useless and have to be renewed owing to the fact that when so worn they admit steam upon all sides of them and their action is prevented. In the present device, inasmuch as close joints are maintained when the steam is cut on as well as when it is on, it is not possible for steam to get between them. With the springs, one set of strips will last until they become worn down from the top. The use of the springs also enables the strips to be fitted with less work and care, it not being necessary to fit the lateral faces with as much accuracy, inasmuch as the springs take up any play or looseness there may be. The springs further serve to prevent the strips from breaking, and pieces thereof falling into the cylinder.

Having thus described my invention, what I claim, and desire to secure by Letters latent, is-- In a balanced slide valve, the combination with the valve body, having the longitudinal grooves b, b, and the transverse grooves or seats a, of the transverse packing strips G, G seated in said grooves or seats a, a, the longitudinal packing strips F, F seated in the grooves b, b, and a spring bearing against the outer face of each of said strips F, F and G, G, and pressing them against each other and against the valve whereby a tight joint is maintained between the joints of said strips and they are held up when steam is out 01?, substantially as specified.

In testimony whereof I afiix my signature in presence of two witnesses.

A. F. KEILY.

Witnesses:

DUNCAN SMITH, L. W. HOLLINGSWORTH.

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