US319115A - Balanced slide-valve - Google Patents

Description

2 Sheets-Sheet. l.

(No Model.)

J. D. oLDS.

BALANGED SLDE VALVE.

(No Model.) 2 Sheets- Sheet 2. J. D. OLDS.

BALANGED SLIDE VALVE.

No. 3l9,115.` Patented June 2, 1885.

zlgJj l? 1 21 1 1. Z7 i1 i f 1 m" .nimir f Miren drnrns 'Fnrnnfr @irrita JOHN D. OLDS, OF FORT IVAYNE, INDIANA.

BAL'ANCED SUBE-VALVE.

SPECIFICATION forming part of Letters Patent No. 319,115, dated June 2, 1885.

Application tiled June 13, i884.

To all whom it may concern:

Be it known that I, JOHN D. OLDs, of Fort Vayne, in the county of Allen and State of Indiana,- have invented certain new and useful Improvements in Balanced Slide-Valves; and I do hereby declare that the following specification, taken in connection with the drawings furnished and forming apart of the same, is a clear, true, and complete description of my invention.

The object of my improvements is to so far reduce the friction of aslide-valve with its seat that it can be more readily controlled by a dyi'iamometrical governor than any prior valve of this class of which I am cognizant.

My improved slide-valve belongs to that general class in which a balance-plate is employed at the inner end of a hollow piston, which occupies a cylinderin the steam-chest cover; and my invention consists of certain novel combinations of certain elements, all of which, in various forms, have heretofore been' employed.

After fully describing the mechanism illustrated in the drawings, the features deemed novel will be specified inthe several clauses of claims hereunto annexed.

Referring to the drawings, Figure Iisalongitudinal section of a steam-chest containing my improvements. Fig. 2 is a side view of the steam-chest. Figs. 3 and 4 are side and bottom views of the balance-plate piston detached. Fig. 5 is a side view of the slidevalve detached. Fig. 6 is a side view of the steam-chest with its cover detached and the balance-plate piston removed from its cylinder for disclosing the comparative areas of said cylinder and the valve-seat.

The valve-seat A, with its steam-ports a and exhaust-ports b, is as heretofore. rIhe slidevalve I3 is a plain box-valve, having, as heretofore, a iiange, c, at its back and no fianges at its'ends near its face. The valve B is moved to and fro by the valve-rod d, provided with the usual stuffing-box, and attached to the valve by way of a rectangular strap, d', which surrounds the valve. The steam-chest cover C is provided with a cylinder, e, differing from prior cylinders for balanced valves in the inatter of its proportions to the area of the steam and exhaust ports. I-Ieretofore such cylinders have had a diameter never greater than (No modcLl about equal to the distance between the outer sides or edges of the two induction-ports, and therefore a considerable proportion of such valves were unfavorabl y exposed to steampressure.

On referring to Fig. 6 it will be seen that the cylinder c has au internal diameter of such extensive proportions that it includes within its circular outline or sectional area the entire area ofthe two induction-ports a and the eX- haust-ports b. To be within one portion of my invention it is essential that said cylinder be at least large enough to thus wholly include that portion of the valve-seat which is occupied by the several ports; but it can be made still larger without departure from my invention or materially affectingthe results desired.

yThe balance-plate piston D is hollow, and has at its inner end a flange, f, which projects beyond each end of the valve-seat A, said flange serving as a guide, with which the back flange, c, of the valve is in steam-tight contact. The outside diameter of said piston D is sufficiently less than the inside diameter of the cylinder e to enable the pistou to be provided with a bull-ring, g, backed up by springs h, and the metallic packing-rings t'. 'Ihis combination of cylinder, piston, bull-ring, springs,and packing-rings', in itself considered, is substantially as heretofore employed within steam-engine cylinders; but I believe I am the first to thus organize them with a balance-plate for aslidevalve. I am aware, however, that such balance-plate pistons have been packed by means of Vsoft packing and glands, and also by metallic packing-rings; but these latter were not backed up by springs. As a result of the use of said well-known combination of bull-ring, springs, and packing-rings in this novel combination with a balance-plate piston and slidevalve, I not only obtain a good steam-tight joint, but I am enabled to properly pack a. larger piston than I find it practicable to pack either with solid packing or with such soft packing as can be used with glands, as heretofore employed. I also iind that there is less liability of undue adhesion of the piston with its cylinder than with other varieties of packing, and therefore the adjustment of the balance-plate can be effected with greater facility, as will be hereinafter further considered in connection with adjusting devices. The

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cylinder e has a cover, 7c, securely bolted in place and provided with a central aperture, 7c. Vhen the valve-chest is on the side of a cylinder,it is provided with an oil-cup on its upper side,which will deliver alubricant upon the valve adjacent to its contact with the balance-plate piston; but when said chest is on top of a cylinder the oil-cup is located in said aperture k, so that in either case all steampressure which may occur within the cylinder and piston can be relieved by way of said aperture. @ther arrangements for oiling can be provided Without in any manner affecting my invention. The cylinder-cover k is bored and tapped at four equidistant points over the corners of the steam-ports for the reception of four adjusting-screws, Z, which at their inner ends abut against the surface of the outer end of the piston,or in suitable seats formed therein. At two opposite points, substantially over the center ofthe exhaust-port b, the cylinder-cover is bored to receive the two lifting-screws m, which, at their inner ends, occupy tapped holes in the piston, and having shoulders which abut against the surface of the cover said screws can be relied upon for lifting vor moving the piston away from the valve. Each of these screws Z and 'm is preferably ofthe thumb or hand screw varieties, (although ordinary heads can be employed,`) so that they may be conveniently manipulated from time to time. It will be seen that the adjusting-screws Zenable the loose adjustment of the guiding-angef into proper relations with the iiange c on the back of the valve, while the lifting-screws m are free, and that the Ylatter can then be relied upon for sustaining the weight of the piston, or, in other words, for wholly relieving the valve from pressure on its seat. The use of the two lifting-screws thus located enables both sides of the guidingiiange f to be separately controlled and maintained in exact parallelism with the back of Vthe valve. It isnot broadly new to thus provide for forcing a balance-plate piston toward a valve, nor for lifting it from the valve; but heretofore the periphery of the upper end of the piston has been threaded and provided with a lifting-nut bearing upon the steamvchest cover, and four adj listing-screws similar to mine passed through the cover and engaged with yielding surfaces on top of the guiding-flange of the balance-plate piston. As compared with said prior construction, l

am enabled to better pack my piston in its cylinder, and to independently adjust each end of the guiding-ilange; and in this connection I can make it readily obvious wherein my ring-packing backed up by springs enables adjustments of the piston more readily than gland-packing. Gland-packing must be set up tightly to secure a tight joint, and there-- fore the piston is strictly limited to a longitudinal movement, whereas the ring-packing as employed by me enables the piston to be slightly canted or tipped `in either direction without impairing the steam-tight joint between the rings and the walls of the cylinder, and, moreover, while the gland-packing is liable to be unduly adhesive, the springbacked metallic packing always permits a free adjustment.

Having thusdescribed my invention, I claim as new and desire to secure by Letters Patentv l. The combination, with a steam-chest, a single slide-valve., its seat, and ports, of a balance-plate provided with a hollow cylindrical piston, and opposite thevalve-seat, in the cover of the steam-chest, a pistou-cylinder;

which includes within. its sectional area that portion of the valve-seat which is occupied by the induction and exhaust ports, and also the main portion of said seat, substantially as described, and for the purpose-specitied.

2. The combination ofthe balance-plate piston provided with valve-guiding flange, the steam-chest, its cover, and cylinder, the four adjusting-screws, and the two lifting-screws, located at opposite sides of the piston, snbstantially as described.

3. The combination of the steam-chest cover and its cylinder, the balance-plate piston, the bull-ring, its springs, and the metallic packing-rings, substantially as described, whereby said piston, without impairing the packed joint between it and its cylinder, can be canted or tipped, as set forth.

4. The combination of the slide-valve, its seat, the steanrchest having the large cylinder in its cover opposite the valve-seat, as described, the balance-plate piston, its valve- Aguiding flange, its packing-rings, andthe adjusting and lifting screws, substantially as described.

JOHN D. OLDS.

W'itnesses:

PHILIP F. LARNER, HOWELL BAn'rLn.

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