US273597A - Valve-gear for steam-engines - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1. G. T. PILLINGS.

VALVE GEAR FOR STEAM ENGINES. No. 273,597. Patented Mar. 6,1883.

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VALVE GEAR FOR STEAM ENGINES.

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'NITE STATES GEORGE T. PILLINGS, OF BALTIMORE, MARYLAND.

VALVE-GEAR-FOR STEAM=ENGINES.

.SQPIECII. ICA'IIO.T. J' forming part of Letters Patent No. 273,597, dated March 6, 1883,

Application filed December 11, 1882. (No model.)

To all whom tt may concern Be it known that I, GEORGE T. FILLING-S, of the city of Baltimore and State of Maryland, have invented certain Improvements in Valve- Gear for Steam-Engines, of which the following is a specification.

This invention relates to means for controlling the steam cutting-off point or regulating the distance traveled by the cylinder-piston before expansion of steam within the cylinder takes place from the engine-governor; and it consists, briefly stated, in connecting some portion of the governor mechanism which is alterable in position by an increase or decrease in velocity of the governor-balls to ablock in apivoted link, which is applied to the steamvalve stem through the agency of suitable devices, as hereinafter fully described.

In the further description of my said invention which follows, reference is made to the accompanying drawings, forming a part hereof, and in which FigureI is a front view of a direct-acting high-pressure steam-engine embodying my invention, and Fig. II a rear view of the same. Fig. III is a sectional plan of the improved engine; and Figs. 1V to XX, inclusive, are details of the engine on an enlarged scale.

Similar letters of reference indicate similar parts in all the views.

A is the cylinder, 13 the steam-piston, and G the piston-rod, ot the engine. The cylinder is secured to a suitable frame, D, carrying the shaft-bearing box E. The piston-rod has the usual cross-head, F, and connecting-rod G, which latter device forms the means of communication between the said cross-head and the crank-pin a of the crank-wheel H. The cylinder is of the four-ported description-that is to say, the steam and exhaust ports are each provided with an independent valve.

The steam-valves, which are represented by b. and the exhaust-valves by c, consist of flat plates, as shown in Figs.X, XI, XII, and XIII.

I is an eccentric keyed to the main shaft K, and d the eccentric-strap. This eccentricstrap is connected to a rocker, e, which in turn is attached by means of a rod, f, to the adjustable block 9 of the link L. The link L is pivoted at its lowerend to the engine-frame. M is an arm, which, in the present case, forms a part of the link L, and consequently has a movement in common with that device. The arm M is slotted and provided with two pins, h, which are adjustable in its slot. (See Fig. XIX.) It is not necessary to theproper working of the link and slotted arm that they should be made in a single piece, as their operation would be the same if they were keyed to a shaft. 7

N N are pivoted bars, to which the steamvalve stems z t are connected, (see Fig. XIX.) and'these bars are provided with springs k, which effect the closing of the said valves. The adjustable pins h aresituated between the bars N N, and in the movement of the eccentric and its attendant mechanism efi'ectthe alternate opening of the two steam-valves. The plus it are made movable for the purpose of allowing the proper adjustment of the steamvalves.

By referring to Fig. II it will be seen that the rodf, at a point near to the block 9, is connected by a link,m, to a vertically-moving part of the engine-governor, the height of which depends upon the rapidity of motion of the governor-balls.

The governor proper is of ordinary construe tion and requires no description herein, as it forms no part ofmy invention.

The exhaust-valves are actuated from the eccentric I through the medium of a system of rods and other devices, as shown in the drawings; but my invention does not extend to the exhaust-valve mechanism; consequently it is not specifically described.

As the link-block g is connected to the governor, it will be understood that any variation in the speed of theengine changes the position of the said block in its link and lengthens or shortens the stroke of the steam-valves and changes their steam cutting-oft point.

Supposing the engine to be running and an increased load is placed thereon, a slight diminution in speed takes place, and the vertically-moving part of the governor, in view of thereduced centrifugal force of the balls, is consequently depressed. The sliding block g is therefore lowered in its link, and as its 1011- gitudinal motion is constant, and is then applied nearer to the fulcra of the bars N N, their motion, and that of the steam-valves, is

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increased. An increased stroke of the steamvalves causes the steam to follow further, which accelerates the speed of the piston until it is checked by the extension of the governor-balls, as Will he readily understood.

In some cases I prefer tooperate the exhaustvalves through the agency of a second eccentric; but in this invention such change need not be considered.

I claim as my invention- I 1. In a steam-engine. the steam eccentricrod connected to a sliding block within a pivoted vibratory link, and to some adjustable portion 2. In asteam-engine, the steam eccentric rod connected to a sliding block within a pivoted vibratory link, and to some adjustable portion of the governor, an arm adapted to have a movement in common with the said link, a pair of projecting pins secured adjustably Within a slot in the said arm, apairot' pivoted barsprovided with devices to connect them with the stems of the steam-valves, whereby, in the vibratory movement of the arm and pins, the said bars are alternately actuated in one direction, and spring mechanism to efi'ect the motion of the said bars in an opposite direction, substantially as and for the purpose specified.

GEORG T. PILLINGS.

Witnesses;

EDWARD J. Dress, JOHN WILLIAMS.

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