US124817A - Improvement in steam-engine valves - Google Patents

Description

VA w. HARRIS. Improvement in Steam Engine-Valves. No. 124,817. I Patented Marchl9,1872.

NITED S'rA'rEs rrrcn.

ABRAHAM w. HARRIs, or PROVIDENCE, RHoDE isnAnn.

IMPROVEMENT IN STEAM-ENGINE VALVES.

Specification forming part of Letters Patent No. 124,817, dated March 19, 1872.

- inal vertical section, showing valve about to open. Fig. 3 is a horizontal section of Fig. 2 on line AB. Fig. 4 is a vertical section through lower box. Fig. 5 is vertical section through lower box, showing valve open. Fig. 6 is a horizontal section of Fig. 5 on line B C. Fig. 7 is a bottom view of upper valve, showing slot. Fig. 8 is a bottom view of lower valve, showing slot. Fig. 9 is a long vertical section through cylinder, &c., of engine, showing valves in position.

The object of my invention is to so construct the valves and their seats that the ridges usually formed upon their wearing-surfacesby the constant action of the former will. be entirely avoided; and consists in the recessing of the steam and exhaust valves and their seats, in the manner hereinafter described.

To illustrate my invention I will take the construction of the induction and eduction valves of the Corliss engine and their seats.

These valves are four in number, the two at the top of the cylinder being the steam-valves, and

serving both as induction and cut-off valves,

connect them with the wrist-plate, motion being imparted to the wrist-plate by the eccen-.

trio. I It is well understood that the constant forward and backward motion of the valves upon their seats will in a short time, by wearing away that portion of the seats over which they actually pass, leave at the points where their movements cease a ridge upon the seat, as well as upon the valve at a point in its wearing-surface near the opening edge of the port.

These ridges make it necessary to turn off the valves and bore out the seats whenever it is desired to alter the connections-such alterations involving much delay and expenseotherwise the valves will be thrown up by these ridges and separated from their seats, thus allowing the steam to blow under, the efl'ect of which it is not necessary for me to describe.

My invention, which is particularly adapted to what is known as the Corliss engine, and in connection with which 1 will now proceed to describe it,is intended to provide against the possibility of wearing ridges upon the valves or seats, and, consequently, the unsatisfactory results arising therefrom.

In the drawing, Figures 1, 2, 3, and 7, which represent the steam or induction valves, A is the valve-box, B the valve, C the valve-seat, and D the port. The valve B is constructed with a recess, E, running the entire length of the port, and-the valve-seat C with two recesses, F and F, both running its entire length.

The operation of this portion of my invention is as follows: Commencing with the valve B closed, as shown in Fig. 1, it will be seen that, as it moves toward the position indicated by the dotted lines and opens the port, it will, before reaching its extreme throw in that direction, run off its seat a portion of its width and overlap the recess F; and again, upon resuming its former position, it will run off and also. overlap a portion of the recess F; at the same time the recess E of the valve will overlap the opening edge of the port D.

In Figs. 4., 5, 6, and 8, which represent the exhaust or eduction valves, G is the valve, H the seat, and I and J the ports. The valve G is provided with a recess, K, and the valveseat with two recesses, L and M.

The operation of this portion of my invention is as follows: Commencing with the valve closed, as shown in Fig. 4, it will be seen that the recess K in the valve Gr overlaps the opening edge of the port I; and when the valve has attained its extreme throw in the opposite direction, as shown in Fig. 5, it will be found that the valve has run off its seat and slightly overlaps the recess L and again, upon its resuming its former position, as shown in Fig. 4, it will run off and overlap a portion of the recess M.

Thus, by recessing the valves and seats, as herein described, so that the valves at their extreme throw each way will run off their seats, the formation of ridges is eflectually prevented.

What I claim as my invention and desire to secure by Letters Patent, is-

I claim as my invention the Within-described recesses in the valves and valve-seats of steamengines, which conjointly operate with each other substantially as and for the purpose set forth.

ABRAHAM W. HARRIS.

Witnesses:

WALTER B. VINCENT, JOHN D. W. TAYLOR.

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