US380661A - Steam-valve - Google Patents

Description

5Sheets-Sheet 1. D H RICE STEAM VALVE.

(No Model.)

Patented Apr. 3, 1888.

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5 Sheets-Sheet 2.

(No Model.)

D. H. RICE.

STEAM VALVE.

No. 380,661. Patented Apr. 3, l 8.

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(No Model.) 5 Sheets-Sheet '3.

1). RICE. STEAM VALVE.

No. 380,661. Patented Apr. 3, 18.88.-

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(No Model.) 5 Sheets-Sheet 4.

' D. H. RICE.

STEAM VALVE. I No. 380,661. Patented Apr. 3, 1888.

Wiinmms (No Model.) 5 Sheets-Sheet 5.

D. H. RICE. STEAM VALVE.

Nb. 380,661. Patnted Apr. 3, 1888.

UNITED STATES PATENT OEFicE.

DAVID HALL RICE, OF BROOKLINE, ASSIGNOR TO JAMES FERGUSON, OF BRIDGEWATER, MASSACHUSETTS.

'STEAlVhVALVE.

SPECIFICATION forming part of Letters Patent No. 380,661, dated April 3, 1888.

Applicaton filed December 12, 1887. Serial No. 257,590. (No model.)

To all whom it may concern.-

Be it known that I, DAVID HALL RICE, of Brookline, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Steam-Valves, of which the following is a specification.

My invention relates to steam-valves for 10- comotive and other engines; and it consists in certain new and useful constructions and combinations of the various parts thereof, substantially as hereinafter described and claimed.

My invention relates to balanced valves for steam-engines, and is illustrated as being applied to the type shown and described in the Letters Patent N 0. 385,571, granted to James Ferguson February 9, 1886, although it may be applied to other types.

In the drawings, Figure l is atop plan view of a steam-chest with the top removed, showing the valve and its cylinder with my improvement applied thereto. Fig. 2 is a transverse vertical section of the same on the dotted line X X. Fig. 3 is alongitudinal vertical section of the same on the dotted line WV W. Fig. 4 is a top plan view of the valve-cylinder, with a modification of my relief-valve shown in Fig. 1. Fig. 5 is a transverse vertical sec tion of the same upon the line Z Z, Fig. 4. Fig. 6 is a longitudinal vertical section of the same. Fig. 7 is a longitudinal vertical section like Fig. 3, with a modified form of constructing and applying my improvement.

In balanced valves of the type shown, when the steam is shut off and the locomotive is allowed to run downhill by the force of gravity, the wheels drive the steam-pistons, and these act as air-pumps, throwing out the contents of the steam-chest into the exhaust and creating a partial vacuum in the steam-chest, steamports, and engine-cylinder. This vacuum continually drags back upon the piston and prevents the engine from running downhill, or with the steam shut off, at the requiredspeed. In order to overcome this difficulty, reliefvalves have been applied in various places between the exhaustchamber and ports of the valve to connect the latter with the steamchest; but as all these relief-valves were necessarily so made as to close themselves when steam was let into the chest from the boiler they relieved the vacuum, when steam was D is the steam-chest secured to the top of the cylinder.

Bis the valve-cylinder, in which the balanced valve V moves to and fro. This cylinder B is connected to the engine=cylinder O by steam-ports c c, and has the eXhaustc-hamber E and exit-pipe e for the escape of the exhaust-steam. The steam-ports c c extend entirely around the valve V, and upon the upper side of the latter they have passages c 0 cut entirely through the valve-cylinder B into them. The top of thecylinder is made flat on its upper side and has a raised lip, 0, around each aperture 0 into the port 0. Over each opening a avalve, o, is fitted steam-tight upon its lip c. These valves "0 o are connected to each other and to a central plunger, A, by a cross-bar, a. The central plunger, A, fits snugly into a corresponding aperture cut through the top of the valve-cylinder B into the exhaust-chamber E, but so as to move up and down therein, thus raising the valves v o"- from their seats or closing them down.

The central plunger, A, is so made as to have the aperture in which it moves up and down of greater superficial area than that of either aperture covered by valves 1) and to be substantially steam-tight therein, and the limit of its upward movement is such thatit cannot rise out of that aperture, but only moves upward therein the distance required to lift valves 12' '0 off their seats and relieve the piston P.

To limit the motion of the plunger A and valves 12 '0', cars 5 5 are formed upon the outer sides of the valves 1; c and screw-bolts 6 6 are passed loosely through vertical holes in the same and screwed firmly into valve-cylinder B. The heads of these bolts arrest the IOD upward movement of the valves '0 o and plunger A. Around these bolts light springs s 8 may be placed, if desired, to assist in raising the valves from their seats when the steam.

is shut off. The steam-pipe d admits steam to the chest D.

The operation of theinvention is as follows: Suppose steam to be on. The parts will be in the position shown in Figs. 1, 2, and 3, because the pressure of the steam in chest D upon plunger A over the exhaust holds the valves 0 u down upon their sea s 0 c. As soon as steam is shut off, (by a suitable cock attached to inlet d,) the pressureis removed from plunger A and it will be raised by the action of the piston P, assisted by the springs s s, and lift the valves 0 off their seats, relieving the piston and preventing their chattering. When steam is again let into the chest D, its pressure upon plunger A will move it downward and close the valves o 1), because the area of the plunger-opening is larger than that of opening 0 and the steam rushing into the latter will not overcome the force exercised by it upon the plunger.

In Figs. 4, 5, and 6 is shown a modification in which the plunger A is attached to the cross-bar a by a pin, of, passing through bar a, and provided with a spring, 7, between its head and the bar, and the plunger has a horizontal flange, 8, projecting outwardly around its upper edge and resting upon a seat upon cylinder B when the plunger is pressed down. This arrangement allows the valves 12 o to be seated independently of the plunger A and the latter to be supported independently on flange 8 by its subsequent downward movement. The flange can be ground to form a steam-tight joint.

If the plunger A is made to fitsnugly enough in the aperture in the top of the steam-chest in which it works up and down, or if the holes in the ears 5 5 are made to fit the bolts 6 6 snugly enough to prevent the plunger and valves from dropping down by gravity, the springs s 8 may be omitted, as the pressure of the steam when on will cause the valves o o" to be closed, and the vacuum in the steamchest will cause them to be opened when the steam is off.

It will be observed that the valves 12 v, although referred to separately, really constitute one piece of metal or valve covering two openings into the valve-cylinder B.

In Fig. 7 another method of applying the relief-valve is shown. In this construction the plunger A is made to enter the discharge end of the steam-pipe d, being fitted to an en: largement, d of the latter, and the relief-valve a, corresponding to o a in the other construction, fits directly over a passage through cylinder B into the exhaust and is connected to the plunger by a short spindle, a. This spindle moves freely through a guide-hole in the yoke b, which is bolted to the top of cylinder B. The plunger A and relief-valve n are so arranged that when the plunger is forced out of the into the chest the valve will enter a tubular extension, n around the valve-seat n and the pressure of the steam upon the top of the valve will continue to withdraw the plunger A from the pipe d as the valve is forced downward upon its seat. thus affording the necessary clearance of the plunger from the steam inlet into the chest. A valve, d, in steam-pipe (2 serves to let on and shut off the steam. The stem a may be made to fit snugly enough 1n the yoke 12 to cause the valvea and plunger to remain up when raised, or the spiral spring a may be placed around the stem between the plunger and yoke b to assist in raising the valve, ifdesired. In any event, when the steam is shut off the valve will be in the posltlon shown in Fig. 7, and the letting on ofthe steam automatically closes the valve by its pressure upon the plunger, as in the former construction. Althoughthislatter construction (shown in Fig. 7) is effective, yet I prefer to have the relief-valve open into the steam-ports c c, because the lead of the balanced valve V closes these ports alternately to the exhaust-chamber E, and consequently to the action of the valve 11., for a short space during each stroke, while the valve can never close the relief-passages c c from the ports. There is also an advantage inhaving the relief-passages c 0 always open when the steam is shut off, because if allowed to close by gravity there is a period 1n each stroke of the piston when a partial vacuum 1s formed in each port 0, which is wholly overcome by the relief-valve v standing open. The part termed the plunger A will be observed to be, in fact, such a plate or surface attached to the valve as shall, when presented to the pressure of the infiowing steam into the chest D, move the valve downward upon its seat from the open position in which it is held or sustained while the steam is shut off, and thus allow the steam-pressure to hold the valve shut. This surface or plate attached to the valve may be presented in various ways besides those I have illustrated to the steam-pressure to accomplish this result without departing from the spirit of my invention.

With either construction shown, however, the relief-valve only moves when steam is shut off or let on, and the wear of the valve and its consequent liability to get out of order are in a great measure overcome, and the exhaustchamber Eis connected with the steam-chest D.

What I claim as new and of my invention 1s- 1. The combination of the steam-chest D,the valve-cylinder B, the valve V, the steam-ports c c, the exhaust-chamber E, and a relief-valve connecting the exhaust chamber with the steam-chest, arranged to remain open while the steam is shut off from the chest, and having a plunger or plate connected therewith and adapted to be acted on by the steam-pressure when steam is let on and to close the reliefvalve, substantially as described.

2. The combination of the steam-chest D, the

valve-cylinder B, the valve V, the steam-ports c c, the exhaust-chamber E, and a relief-valve connecting the exhaust chamber with the steam-chest, arranged to remain open while the steam is shut off from the chest, and having a plunger or plate connected therewith by a yielding connection and adapted to be acted on by the steam-pressure when it is let on and to close the relief-valve, substantially as described.

3. The combination of the steam-chest D,the valve-cylinder B, the valve V, the steam-ports c c, the exhaust-chamber E, and a relief-valve connecting the ports 0 c separately with the steam-chest, arranged to remain open while the steam is shut off from the chest, and having a plunger or plate connected therewith and adapted to be acted on by the steam-pressure when steam is let on and to close the re lief-valve, substantially as described.

4. The combination of the steam-chest D, the valve-cylinder B, the valve V, the steam-ports c c, the exhaust-chamber E, and a relief-valve connecting the ports a c separately with the steam-chest, arranged to remain open while the steam is shut off from the chest, and having a plunger or plate connected therewith by a yielding connection and adapted to be acted on by the steam-pressure when it is let on and to close the reliefvalve, substantially as described.

5. The combination of the steam-chest D,the

.in exhaust-chamber E and connected to said relief-valves by yielding fastenings, substantially as described.

DAVID HALL RICE.

Witnesses:

WILLIAM P. BLAKE, N. P. OCKINGTON.

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