US284472A - Cut-off valve - Google Patents

Description

(No Model.) 3

B. F. OLMSTED.

GUT-OFF ALVE. V NQ. 284,472. Patented Sept. 4,1883.

WITNESSES; I INVENTOR Q BY ATTORNEY ject is to cut off steam at different travels of the main piston in the cylinder, according to UNITE STATES PATENT 'QFFICE.

BENJAMIN F. OLMSTED, on GRAND RAPIDS, MICHIGAN. I

CUT-OFF VALVE.

SPEGIFTCATION forming part of Letterslatent No, 284,472, dated September 4, 1883. 7

Application filed June 15,1883. (No model.)

an d'useful Automatic Out-Off Valve for Steam- Engines, of which the followingis a specification.

My invention relates to improvements in cut-off valves for steam-engines; and theobthe different labors on the engine on each halfstroke, respectively. I attain this object by invention (with such other parts of an engine 1 pressure from the governor.

as are attached to the part by me invented) on line 3 3 of Fig. 2. Fig. 2 is also a vertical sectional view ofthe same on line as x of Fig. 1.

Similar letters refer to similar parts throughout the several views. 1,

In the drawings, L is the oompressionrod, operated by the governor, which governor is not shown in the drawings, as it is no part of my invention. I

R is a spring designed to counteract the U is apiston, so placed that it is depressed by the action of the rod L, and depresses the parallel planes T T, which planes are placed above the roller A A and in contact with it, as shown in Fig. 2, and the roller A A, with the blades B, j ournaled thereto, is also depressed, through the piston U and planes T T, by the action of the rod L. The journals are shown by a a a, there-being two or more of these journals.

H is a cut-off valve, so constructed that it receives the sliding blade B and swings on journals or pivots, and springs c c c are placed in openings in the valve H, beneath the edge of the blade, so as to press outwardly on the presses outwardly on the blade the tendency of the spring is to continuallypress the roller toward the upper part of the smaller arc M at all times.

n 01. n are vents in valve H to allow the steam to enter and surround the blade and hold it in equilibrium.

D is an ordinary D-valve. S and S are steam-ports which receive the steam from the steam'passages F F and convey it to the cylinder, thereby creating a ourrent of steam alternately through the passages F and F, which steam-current acts alternately first on one side of valve H and then upon the other. J J are steamvents for the purpose of equalizing the steam-pressure under the valve H, al lowing the spring to bring the valve to its nor= mal position when the pressure is equalized.

E is an exhaust for main D-valve. Q is a grip-collar on the, main valve-stem P. V, G is the governor steam-chest, restingon the top D of the main steam-chest. u u u u are vent-holes extending through piston U and the base of the governor steam-chest, in order to equalize the steam-pressure in the governor steam-chest G, as also over and around the governor piston. The counter spring R is regulated by the nut Z, so that its counteracting stress on rod L maybe increasedor decreased at pleasure.

K K are journals 011 which the valve H turns or swings. The socket M may or may not be the arc of a circle, and the same is true of arcs V V; but the arcs are so placed that as the roller passes from the arc M to are V it passes over an angle or obstacle.

The operation of my invention is as follows:

When the engine is set in motion, as the speed increases, the governor rod L depresses the piston U, planes T T, and roller A until the steam, entering the cylinder through port S,

passage F; and," as the main D-valve reverses its motion, the steam, prior to the opening of port S, passes by means of vent J into passage F, when the spring instantly brings H to its normal position, (shown in Fig. 1,) and when port S is opened a reverse current is created and valve H is carried to the reverse 7. seat on Ffl and the operation is thus continuedand the steam is alternately cut off from passages F and F. If the engine is running rapidly, the depression of the planes T T is such that roller A cannot pass into socket M but a short distance, and the valve passes to its seat much more quickly and readily than it will do with a slower motion, as the angle or obstacle between arc M and are V but slightly retards the roller, and a strong current will force the valve to its seat much more quickly than a weak or slow current, so that the cut off may be at any part of the stroke, and the engine is perfectly regulated and the steam most economically used.

I am aware that automatic cut-off valves are not new, and that there are many in use, and I do not broadly claim to have invented the same; but I am not aware that an oscillating valve adjusted by means of sliding blades and. springs, so as to regulate the resistance .by Letters Patent, is

1. In an automatic out 01f valve, the oscillating valve H, in combination with the sliding blade B, spring 0 c a, roller A, and arcs M and V, all constructed substantially as described.

2. The combination of the spring B, piston U, rod L, planes T T, roller A, arcs M and V, blade B, and valve H, all constructed and operated substantially as described.

3. In an automatic. cut-off valve, the oscillating valve H, in combination with the steampassages F and F and vents J J, as described.

4.. In an automatic cut-off valve,'the oscillating valve H, in combination with the blade B, spring 0 c c, and vents a a a, for the purpose described.

5. The following parts in combination, viz: rod L, spring R, piston U, provided with vents u u u u, planes T T, roller A, arcs M V V, blade 45 B, valve H, provided with vent n and journals K K, steam-passages F and F, main D- valve D, and vents J J, all constructed as described.

BENJAMIN F. QLMSTED.

Witnesses:

FRED W. SrEvENs, EDWARD TAGGART.

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