US313868A - Valve-movement for direct-acting engines - Google Patents

Description

(No Model.)

W. D. HOOKER.

` VALVE MOVEMENT FOR DIRECT ACTING ENGINES. No. 313,868.

Patented Mar. 17, 1885.

Unirse Smarts artnr Orgien..

VILLIAM DAVIS HOOKER, OF ST. LOUIS. MlSSOURl.

VALVE-MOVEMENT FOR DIRECT-'ACTlNL-l ENGINES.

fearing part of Letters Patent No. 313,863, date-d March 17,1885.

Application tiled Ja:.u ry IS, 18:4. (No ino le-l.)

To all whom it may concern: y

Be it known that I, WILLIAM Davis HOOKER., a citizen of the United States, residing at St. Louis, in the State ot' Missouri, haveinventd certain new and useful Improvements in Valve- Movements for Direct-Aeting Engines; and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in valve-movements for directacting engines. An essential feature of the mechanism which I employ in the present invention is found in a patent granted to me for improvements in Hand Lever Attachments for Steam- Pumps,77 dated January 3, 1882, No. 251,715, in which a right-angle oscillating shaft or bearing and a reciprocating arm or lever are shown.

The invention herein set forth and claimed contemplates improvements whose'object may be briefly stated as follows: first, to provide, in connection with the right-angle oscillating shaft and its reciprocating arm. above mentioned, a simple, durable, and efficient valvemovement for working the valve or valves of a direct-acting engine in such a manner as to cause the reversal of said valve or valves, and thereby render the reciprocating movement of the engine continuous as long as steam is supplied to drive it; second, to produce a short movement of thc valve as compared with the movement of the main piston ofthe engine, and to make this movement adjustable so as to vary the movement ofthe steam-valve as desired; third, to provide a means whereby the main piston shall be caused to slow down gradually at the termination ot' its stroke, thereby preventing it from striking the cylinder-heads, and also causing the pump-valve to beat quietly, producing a more steady pressure in the pump; fourth, by the reaction of the means for slowing down the main piston at the end of its stroke to give a quicker start to iton its return-stroke; and, fifth, to compel the main valve to stop at the right point and not overrun its proper stroke. To attainthese objects I construct a valve-movement mechanism in connection with the rightangle' oscillating shaft and reciprocating arm, which I have adopted from my previous patent, hereinbefore mentioned, substantially in the manner about to be described.

Referring to the accompanying drawings, which illustrate what I consider the best means for carrying the invention into practice, Figure 1 is a side elevation of the device; Fig. 2, a transverse vertical section. Fig. 3 is a modilied form ofthe arm L; Fig. 4, a detail ofthe dog.

Similar letters of reference indicate corresponding parts in theiiigures.

A is aportion ofthe steam-cylinder; A', the valve-chamber mounted thereon. B is a por tion ofthe pump. The cylinder and pump are connected by the yoke O. Through the stuft'- ing-boXes ofthe yoke slides the piston-rod D. To one end of this rod is fastened the steampiston, and to the other end is fastened the pump plunger or piston in theinanner usually followed in steam-pumps of this construction.

On the pistonrod D, midway between the two pistons, is secured the hub E, to which is pivoted the driving-arm F. rlhe arm or rod F passes loosely through a hub, G', which is formed at a right angle, and integral with or rigidly secured to the oscillating pin or shaft G. 'lhis latter is supported in a bearing, H, mounted on and fastened to the yoke G, or any part ofthe machine most convenient.

On the right-angle oscillating pin Gis loosely fitted the valve arm J, the opposite end of which is pivoted to the valveestem K of the engine. At the side ofthe valve-arm J, and rigidly attached to the pin G, is the arm L, which has dogs m m fitted to it. rllhe dogs lie on opposite sides of the arm J, and may be adjusted so as to lie nearer to or farther away from each other. For this purpose slots Z are cut in the arm L, and the dogs are provided with nuts, as shown, to set them in any relative position. The arm J above the pin G is provided with an extension or projection, s, and the support H has stops p p on either side of the part s to limit its movement.

rlhe drivingarm F extends some little distance above the hub G', and is provided with a coiled spring, a, and an adjustable collar, O, with a set-screw, o. The spring a bears against the hub G' and collar O, and is atlj usted by the latter.

The slots Z in the arm L may be inclineds, a shown in Fig. 1, or horizontal, as shown in ICO Fig. 3, in which latter case set-screws will be necessary to hold the dogs m, in place. The dog m is provided with a rubber cushion, m', to strike on the arm J.

The parts thus constructed and combined operate as follows: When the piston-rod D is moved in either direction, the arm F is carried to an inclined position, and causes the rightangle pin Gto be partially turned. The arm L, rigidly secured to the pin G, is moved with it, and the dogsmm, coming alternatelyin contact with the valve-arm J, (which is loose upon the pin G,) push said arm in one direction or the other, thereby causing the reversal of the engine. During the movement of the piston toward the end ofa stroke the arm F will be drawn out and the spring n compressed, by means of which the engine will be slowed down at the end of the stroke and the piston prevented from striking the ends of the cylinder, and the pump-valves will be seated quietly. On the engine being reversed and commencing the return-stroke the recoil of the compressed spring n will give back the power stored in it, and the engine will respond by starting back quickly. All slamming and jars are prevented, and the parts ofthe engine and pump are saved from much Wear and breakage, while a decided increase in point of speed in starting on the return-stroke is insured.

`The construction by which the valve is moved by the operation of the dogs m on the rigid arm L upon the swinging valve-arm J produces ashort movement of the valve, compared with the movement which the main piston has, and this movement may be made greater or less by setting the dogs closer together or farther apart.

'A positive stop is given to the valve-arm J by vthe contact of the projection s with the stopspp on either side, and the valve is prevented from overrunning its stroke and compelled to stop at the right point.

Modifications within wide limits may be made in the form and manner of connecting the parts without departing from the spirit 0r sacrificing the advantages of my invention.

Having thus described my invention, what Idesire to claim and secure by Letters Patent is- 1. The right-angle oscillating shaft G and driving-arm F, pivoted to the pistonrod and passing through said shaft, in combination with lthe valve-arm J, fitted loosely to the oscillating shaft G and pivoted to the valvestem, and the arm L, having the dogs m m, fastened to and moving with the oscillating shaft, as described, and for the purpose set forth.

2. The combination, with the right-angle oscillating shaft or pin G and driving-arm F, ofthe valve-arm J, swinging on the oscillating shaft and provided with the extension or projection s, the arm L, rigidly secured to the shaft G, and provided with the dogs m m, and the stopsp @for contact with the projection s, to limit the stroke of the valve,l as set forth.

3. The combination, with the driving-arm F and oscillating shaft G, through which the l driving-arm loosely passes, of the spring n, exerting its force to retard and accelerate the movement of the steam-pump at the end and beginning of the strokes, respectively, substantially as set forth.

4. The combination of the oscillating pin or shaft G and means for operating it, with the swinging valve-arm J and rigid arm L, having the adjustable dogs m, for contact with the valve-arm, as set forth.

In testimony whereof l afx my signature in presence of two witnesses.

WILLIAM DAVIS HOOKER.

Witnesses:

FRANK M. EsTns, L. FRANK OTToFY.

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