US113428A - Improvement in valves and valve-gears - Google Patents

Description

ETERS. FNOTQLITHOGRAPHER, WASHINGTON D C NUNITED 'IArns {AHI'N wILLIAM Z. HAroHnn, or PLYMOUTH, PENNSYLVANIA, AssIeNon To HIMsnLr AND WILLIAM L. LANGE, on sAMn rLAcn.

IMPROVEMENT IN VALVES AND VALVE-GEARS.

Specification forming part of Letters Patent N0. 1&3A2S, dated April 4, 1871.

have invented an Improved Valve and Valve- Motion for Steam-Engines, of which the following is a specification:

Nature uml Object of' the Intention.

My invention consists of the combination, with a steam-cylinder and piston, of a valve operated, substantially in the manner described hereafter partly by the positive motion of the piston and partly by the direct action of the steam also, of the combination, described hereafter, of a grooved cylindrical valve with certain steam and exhaust ports.

The object of my invention is to obtain such a rapid reciprocating motion of the piston without the aid of the usual eccentric or crank for operating the valve that the engine may be applied directly to the operating of pumps, blowing-cylinders, and especially to rock or coal drills.

Description of thc Accompanying Drawing.

Figure 1 represents a longitudinal section of cylinder and valve-chest with my improved valve-motion; Fig. 2, a transverse section of the same on the line l 2, Fig. l; Fig. 3, a transverse section on the line 3 4, Fig. l; and Fig. 4, a sectional plan view of the valve-chest on the line 5 `(j, Fig. 1.

General Description. A represents a steam-cylinder, and B its piston, the rods a a of the latter projecting tained in an elongated slot in the spindle E of l the valve, and which can be either adjustable or not, the distance between the peripheries of the two rollers being greater than the width of the arm, for a purpose rendered apparent hereafter. Y

Fis a cylindrical valve, arranged to slide in a cylindrical chamber formed in the valvechest G, in which, above the valve, is alongitudinal passage, m, steam from the generator being admitted to this passage, which communicates.through ports 7L h with the in.- terior of the valve-chest at one end of the same, and `through ports h1 h1 with the opposite end of the said valvechest. It will be observed, on reference to Figs. 3 and 4, that these steam-ports h h and hl lil communicate at points directly opposite to each other with the interior of the valve-chest, so that, the pressure of steam from the ports being equal on both sides of thevalvc, the latter will be equally balanced, and will work Inuch more freely than if the steam were admitted at one point Only. Portions only of the steam-ports g and g are opposite to theV ports h h and hl.

h1, as will be observed on reference to Figs. 1 and 4.

The exhaust-ports p p communicate, during a portion of the stroke of the valve, with annular grooves w fw cut in the said valve, the steam escaping through a suitable opening or openings in the side of the steam-chest.

The operation ofthe valve is as follows: When the piston has very nearly reached the limit of its stroke in the directionof the arrow the arm h3 strikes the roller t" of the valvespindle, and so moves the valve as to cover theeXhaust-port p and steam-ports h1 h, halfopen the steam-port q, and very slightly open the steam-ports It h and exhaust-port p. This partial movement of the valve is all the duty which the arm h has to perform, the further movement of the valve being accomplished by the pressure of steam against the rear end, w, of the valve, which causes the latter to move suddenly, and t-hus flirt-her` and fully opens the steam-ports L h and brings the annular groove w opposite the exhaustport p', thereby insuring a free escape of the exhaust-steam at the front end of the cylinder through the passages t p w', while a full volume of live steam is introduced at the rear end of the same through the passages q t.

The result of the above movement of the valve is the instant reversal of the piston, and as the latter reaches the limit of its forward movement the arm h3 strikes the rollerz' of the 2 nadas valve-spindle, and thereby slightly moves the valve, so as to close the steam-ports h 71 partly close the port q, and slightly open the exhaustport p and steam-ports h1 h1, the completion of the valve movement being effected by the pressure of steam against its end y, and the movement of the piston being again reversed.

To increase or diminish the stroke of the valveitis onlynecessary to lengthen or shorten the operating-arm h3 by a proper vertical adjustment of the pin c, or to adjustthe rollers c' t" from or toward each other. (See Fig. l.)

It will be thus seen that the necessary movement of the valve to cause a reciprocating movement of the piston is accomplished partly by a positive motion derived from the pistonrod andpartly by the pressure of steam against the valve itself.

Although the movements of the valve are sudden, it is relieved at every stroke from jars or shocks by a cushion of steam between the end of the chamber of the valve-chest and the end of the valve opposite to that on which the live steam is acting.

Although the above-described valve-motion is applicable to pumping-engines and blowingengines, it has been more especially designed for rock or coal drills, inwhich the drillingtool is secured directly to the piston-rod.

Y It Will be seen that as the direct or live steam from the boiler passes to the ends of the valve F, the latter will not be balanced under any circumstances, so that the steam can act with its full force upon the valve, the rapid positive movement of which is thus insured.

Claims.

1. The combination, with a steam cylinder and piston, of a valve, F, and devices, substantially as described, whereby the valve is operated partly by a positive movementl derived from the piston and partly by the action of steam passing directly from the boiler.

2. rlhe ports q q', p p', and h h1, arrangedin respect to the grooves in the valve F, as described.

3. The ports h h h1 h1, arranged in relation to the valve F, covering said ports, and communicatin g with the interiorof the valve-chest, substantially as described.

4. The arrangement of the ports h h1 in respectl to the ports q q and to the valve F, as and for the purpose specified.

In testimony whereof I have signed my name to this specication in the presence of two subscribing witnesses.

WILLIAM Z. HATCHER.

Witnesses:

HARRY SMITH, WM. A. STEEL.

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