US23629A - Valve-gear fob - Google Patents

Description

UNIE STATES PATENT OFFIOE.

ELIJAH WARE, OF SOUTH BOSTON, MASSACHUSETTS.

VALVE-GEAR FOR STEAM-ENGINES.

Specication of Letters Patent No. 23,629, dated April 12, 1859.

To all whom it may concern:

Be it known that I, ELIJAH VARE, of South Boston, in the county of Suffolk and State of Massachusetts, have invented a new and Improved Valve-Gear for Locomotive and other Steam Engines; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing, forming part of this specification, said drawing representing a side view of my improved valve-gear as adapted to the locomotive-engine.

This invention consists in a novel means of connecting the eccentric rod with the valve rock-shaft, or its equivalent, for the purpose of enabling the stroke of the valve to be varied to vary the point of cutting off the steam from the cylinder of an engine.

It also consists in a novel combination of mechanism through whose agency the operation of the slide or other valve or system of valves' employed in a steam engine, is effected by means of a single eccentric, which, without ever being shifted upon the shaft, is made to work the valves for running the engine in either direction, and to vary the movement of the valve for'cutting off the steam at different points in the stroke of the engine.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A, is the driving axle or crank-shaft of the engine.

B, is the crank, and C, is the valve eccentric which is keyed firmly to -the shaft and whose position may coincide with or be directly opposite to that of the crank, according to the nature of the valve connections, but whic'h is represented in the lirst named position.

F, is the valve seat, and E, the valve, which is of the short D kind and made with a lap and which is connected with the arm a, of the rock shaft Gr, which works in fixed bearings on the frame of the engine, and which derives its rocking movement from an eccentric through the agency of the mechanism which constitutes my invention.

H, is the eccentric rod connecting the eccentric C, with a three-armed lever I, which works on a fixed fulcrum pin l), secured in the framing of the engine, and which is connected by a rod J, with the arm c, of the valve rock-shaft G, to operate the valve by the revolution of the eccentric. The lever I, contains two arc-formed slots d, and e, the formerwhich extends nearly the whole length of one armto receive a pin f, secured to the eccentric rod H, and the latter which extends nearly the whole length of two arms-to receive a pin g, secured to the rod J. The arc of the slot d, is described with a radius equal to the distance of the pin j", from the center of the eccentric O, and the arc of the slot e, with a radius equal to the working length of the rod J, and the two arcs and fulcrum pin Z), are severally so arranged permanently in relation to each other that in the movements of the lever the said arc CZ, deviates as little as possible from a position concentric to the center of the eccentric, and the said arc e, deviates as little as possible from a position concentric to the pin h, which attaches the rod J, to the arm o, of the valve rockshaft. The slots d, and e, are to permit the changing of the positions of the pins f, and g, relatively to the fulcrum b, to vary the stroke of the valve and the point of cut on and for reversing the engine, and for these purposes the means of shifting the said pins in the said slots are as follows.

The pin f, is also received within a slot z', in a lever K, which is tted to swing loosely on the shaft or crank axle A, and which is connected by a rod L, with what I term a secondary lever O, attached by a fulcrum pin j, to the arm N, of a lever M N, which works on a fixed fulcrum ,70, secured in the frame of the engine, and the pin g, is connected by a rod P, with t-he arm M, of the said lever M N. The slot i, is of a length to permit the stroke of the eccentric rod. The arm N, is connected by a rod m, with a hand lever Q, which works on a fixed fulcrum n, and which is conveniently situated to be operated by the engineer, and which is fitted with a catch or bolt which is capable of entering either one of two series of notches 79, p, in a stationary arc R, and thereby locking the lever Q, in various positions. The secondary lever O, has attached to it a pinion u, which is concentric with its fulcrum 7c, and this pinion gears with a toothed are S, attached rigidly to a lever T, which is arranged to move on the same fulcrum 7e, as the lever M N. This lever T, is connected by a rod U, with a hand lever V, which is arranged to work on the same fulcrum n., as the hand lever Q. This lever V, has atthe valve, and consequently the point of cut off, depends upon the relative distances of the pins f, and g, from the fulcrum Z). When the pin g, is below' the fulcrum as represented, the valve will be so operated that the direction of the revolution of the crank will be as indicated by the arrow shown near it in the drawing. To place the said pin g, above the fulcrum to reverse it, the

lever Q, is moved to the opposite end of the arc piece g, of the lever, and the pin s, secured in the notch r, and in this movementthe pin t, is shifted from one of the notches p, p, to one of those, p1, p1, near the other end of the crank R. The leverQ, in this movement acts through the rod m, lever M N, and rod P, to raise the pin g, and the movement of the pinion u, along with the lever M, with its teeth in gear with the arc S, causes the said pinion to make half a revolution on the fulcrum pin j, and shift the secondary lever O, to the position indicated in red color in the drawing and thus by its action through the rod L, on the lever K, to shift the pin y", and eccentric rod H, toward the fulcrum b. The reason for having the pin f, to shift along with the pin g, in this movement is not that it is so necessary for the reversal alone, but that the reversal and change of stroke could not both be effected by the mere shifting of the pins f, and g, or either of them, without it'. The portion of the slot e, below the fulcrum requires to be much longer than the portion above, as when the pin g, is in the lower part, the pin f, is nearer the fulcrum Z).

To vary the length of stroke of the valve, and thus vary to some extent the cut off point, the lever Q, is shifted to change the pin from one to another of the notches p, p, or p1, 201, but never moved past the middle of the arc from one notch p, to one p1, or vice versa, and this movement, by changingA the relative distances of the pins f, and g, from the fulcrum b, effects a variation in the length of stroke of the valve without eii'ecting any change in the position relatively to the piston, at which the valve commences to open the ports and admit steam.

It may be observed in the drawings that theV fulcrums la, and I), are both secured in a kneed frame VV which is arranged to vibrate at its knee upon a fixed pin w, secured in the main frame of the engine and which is connected with the shaft or driving axle A, in such a manner as to cause it to vibrate with the said shaft or axle, as the latter is, or may be caused to move up and down by the passage of the locomotive over the track. This frame lV, will be dispensed with in a stationary engine and the fulcrums 7G, and b, will be attached to the main framing.

In adapting the improvement to stationary engines the levers Q, and V, and all their connections with the pins f, and `g, may be dispensed with and the said pins lboth connected with the governor for the purpose of governing the speed of the engine by varying the stroke of the slide valve.

The same valve gear either with or without the combination of reversing levers Q, V, may be adapted to puppet valve engines by substituting for the arm a, of the valve rock-shaft G, two toes, as shown in the drawing in blue outline.

lVhat I claim as my invention and desire to secure by Letters Patent isl. Combining the eccentric rod with the valve rockshaft G, or its equivalent by means of the lever I, with its two arc-formed slots cl, e, and the movable pins 7", g, the whole applied and operating substantially as and for the purpose herein specified.

2. And I also claim the combination with the double slotted lever I, and its movable pins f, g, of the levers Q., V, rods m, U, levers M N, and T, secondary lever O, pinion u, toothed arc S, and rods L, P, the whole applied and operating substantially as and for the purpose herein described.

. ELIJAH VARE. lVitnesses NIARTHA A. WARE, EMLINE SIMPSON.

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