USRE9972E - Balanced valve - Google Patents

Description

NITED STATES PATENT OFFICE.

v MGWILLIAM F. MARGACH, OF MEADVILLE, PENNSYLVANIA.

BALANCED VALVE.

SPECIFICATION forming part of Ressued Letters Patent No. 9,972, dated December 13, 1881.

Original No. 218,()40, dated July 29, 1879. Application for reissne filed October 15, [581.

To all whom it may concm:

Be it known that I, MGWILLIAM F. MAR.- GAGH, of Meadville, in the county of Crawford and Stateof Pennsylvania, have invented a new and Inprovcd Balanced V'alve, 'of which the following is a specification.

This invention relates to improvements in balancing the slide-valves ot' steam-engines by the pressure of a plate affixed to the upper side of the valve against the top plate of the stean-chest' Heretofore this has been accomplished by forcin g the balancing-plate against the top of the steain-ch est by means of springs; but this n'eihod is objectionable on two accounts: first, the pressure exerted by the springs is continuous, and the balance-plate is kept in contact with the top of the steam-chest at all times, and'thus when running without steam there is unnecessary friction above and below; secondly, when running downgrade with the stean shut off a valvc constructed in this manner creates avacuum in the cylinder, the same as au ordinary slide-valve, with the result of drawing cinders, ashes, 860., through the exhaust into the cylinder and causing a rapid cuttin g and wearing therecf.

The object of my .inventidn is to adapt the balancing device to be relieved from contact with the top of the steam-chest as soon as the stean is shut off, and to prevent the formation of a vacuum in the cylinder.

It consists, first, of a disk placed on top of the slide-valve, and encircling this disk with a ring, which, by the pressure of the ste'am underneath it, is forced up against the under side of the top of the steam-chest, so as to shut ofi` from the pressure of the stean the area on the upper side of the valve inclosed by it, but which is adapted to fall back from contact with the top as soon as the steam is shut ofi'.

It consists, secondly, in providin g aholein the top of the valve, at the center of the disk, leading through to the eXhaust-opening, through which, when the steam is shut'ofi', the stean i and air in the cylinder are given way from end to end of the cylinder and the formation of a Vacuun prevented.

In the accompanying drawings, Figure l is a top plan or View of a valve provided with my improvement, with a part of the balancing device in section on line a: 50 of Fig. 2; and

Fg. 2 is a longitndinal section of the same ou line y y of Fig. 1.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, A is the sleauichest, and B is the slide-valve.

G is a disk with a central neck, a, having a hole, b, through it. The said neck is passed through a hole in the top of the valve nidway of its length, giving thus a free passage-way between the eXhaust-opening c in the valve and the stean-chest. The neck a also serves as a dowel for holding the disk -on the valve, further security being given by the screws d d d d, passed down through the disk into the valve. The disk is provided With a crownflange, e, and in its periphery is a groove,f, in which is placed spring stean packing g.

D is the ring for closing the passage-way between the exhaustopening and the steamchest, and which I call the floating ring. It is placed over the periphery ot' the disk,and a steaIn-tight joint is formed between it and the periphery of the disk by the expansion of the springpacking g. The under edge of ring D is beveled ironi the outer periphery downward and inward, so as to leave but a narrow hearing-ed gc for resting on the top ol' the valve,

and thus furni'sh a better surface for the action of the steam. When no stean is ente'ing ,the steam-chest the floating ring rests on top of the valve, so that a space offrom one-sixteenth to one-quarter of an inch is left between it and the top plate of the steam-chest; but when the engine is running under steam the pressure of the steam on the under side ot' the ring forces it up in contact with the top'plate of the steam-chest, and thus the steam is shut olf from the surface of the disk, and to the extent of its area the valve is entirely relieved from the pressure of the steam downward on its seat, wherebya practical balancing of the valve is obtained. When steain is shut ofi` in running downgrade and into stations, the ring falls back on the valve and thus friction between it and the top plate of the steam-chest is avoided, and thereis no downward pressure' on the valvc-seat'.

Another advantage obtained by this con struction is that when the engine is running downgrade without steam a vacuun is pre IOO vented from formin g in the cylinder, as the passage-way through the valve and over the disk to the steam-ports pernits the steam and air remaining in the cylinder at every stroke of the piston to pass from endto end back and forth, preventing a vacuum at either end, and thereby preventing the drawing of ashes, cinders, dust, &e.,from the smoke-box into the cylinder. Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. In a baiauce-valve, a disk and a ring encirciing the disk, and so constructed that the pressure of the steam nnderneath it will force it against the under side of the top of the steam-chest, and will fall back from contact with; the top when the pressure is removed,

substantially as set forth. 4

- 2. In a balance-valve, the combination, with a disk attached to the top of a slide-vaive, as described, of a ring encircling said disk, and so constructed that the pressure of the steam underneath it will force the ring against the under side of the top of the steam-chest, and will permit it to fail back from contact with the top when the pressure is removed, substantially as set fo-th.

3. `In a halance-valve, a disk attached to the top of a slide-valve, said disk and valve provided with eXhaust-opening, whereby a passage for the steam and air is provided when the steam is shut off through the valve from one end of the cyiiuder to the other, substantially as and for the purposes shown.

4. In a balance-vaive, a ring encircling the disk of the valve, and so constructed that the pressure of the steam underneath it will force itagainst the under side of the top of the steamchest and will fall back from contact with the top when the pressure is removed, and providedwith an exhaust-opening, by means of which a -pressure upon the valve may be removed, substantially' as and for the purposes shown.

5.' In a baiance-valve, the combination of a disk attached to the top of 'a slide-valve, with a ring encrcling the said disk, and so constructed that the pressure of the stean underneath it will force it against the under side of 'the top of the steam-chest, and will fall back from contact with the top when the pressure is removed, said disk and ring being each por- Vided with an exhaust-opening, by means of which a pressure upon the valve may be removed, substantialiy as and for the purposes' shown.

6. As an improvement in balaneed valves for steam-engines, the disk G, with holiow neck a, fitted into the exhaust-opening in the valve, and provided with steam-packing g in its periphery,in combination with an encircling-ring adapted to rest on the valve when the engine is running downgrade without steam,but when under steam-pressure it is forced up against the top piate of the steam-chest, and thus shuts off the area of the disk from the pressure of the steam and relieves the pressure on the valve, suhstantialiy as described.

7. In combination with a balance-vaive provided with a circular top or disk, the iatter encircied byaring and provided with steam-paoking and also with an eXhaust-opening for the passage of air or steam, the ring, whereby the pressure of stean forces the ring against the steam-chest cover, thus shntting off the press- .ure from the area of the circle iuclosed by the ring, substantially as and for the purposes shown.

r 8. In a balance-valve having a circular top 'or disk provided with an encircling-ring adapted to revolve freely about the top, and a groove adapted to receive stean-packing, wherehy the steam is preve'ted 'from passing between the circular vaive-top and encirclin g-rin g, said circular vaive-top being further provided with an opening sufficientiy large to permit the passage of the Volume of exhaust by way of the chestcover at wiii, substantialiy as and for the purppses shown. v

9. In a ba1ance-va1ve,a disk attached to the slide-valve by means of a central hollow neck passing through t'he disk, and by screws or equivalent means, suhstantially as set forth.

'In testimony whereot' I aflix my signature in the presence of two subscrihing witnesses.

MGWHJLIAM FRED. MARGACH. In presence 0f- MILTON H. MGNAIR, v L. J. RoBERTs.

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