US168251A - Improvement in valves for pumping-englnes - Google Patents

Description

' 'U-NITEDSTATES'- PATENT 'OFFER WILLIAM H. ARRISON, OF BETHLEHEM, PENNSYLVANIA.

IMPROVEMENT |N vALi/Es FoR PuMPlNe-ENGINES.

Specification forming part of Letters Patent No. l 68,25 l, dated September 28, 1875; application led v November 3, 1874. l

To all mwho it may concern Be it known that I, WILLIAM HENRY HAR- RISON, of Bethlehem Northampton county, Pennsylvania, haveinvented certain Improvements in Pumping-Engines, lof which the following is a specification:

The main object of my invention is to prea vent the detrimental' ,shocks which occur in y vertical section of sufficient of a direct-acting steam-pump to illustrate my improvement; Fig. 2, part of Fig. l, showing the valves in a different position; and Fig. 3 an enlarged view ofthe main valve and its connections.

A is the steam-cylinder, thefpiston of which is connected to 4that of the pump-barrel by the piston-rod D, as in ordinary direct-action steam-pumps. The face for the main valve has the usual steam-ports a a', and exhaustpirts b b', adapted to a valve madeiin two parts, Gr G', connected together by a rod, e, on which is apiston, f, adapted to a small cylinder, h, the latter forming part 'of a vertical partition, which separates the lower steamchest into two compartments, J and J'. This lower steam-chest is separated from the upper, to which steam is admitted through a pipe, a, by a horizontal partition, fi, which forms the seat for the controlling valve M, the said l partition having a port, m, communicating with the compartment J, and a port, m',

communicating with theV compartment J', of

the lower steam-chest, as will be rendered ap parent hereafter.

In Fig. l the piston of the engine is approaching the termination of its stroke in the direction of the arrow, the steam-port a' being full open, but the port m' in the partition i is very nearly closed by the controlling-valve M, which is in the act of moving in the same direction as the piston; hence but little steam can gain access to the compartment J', and thence to the cylinder A, and therefore the movement of the piston mustdecrease in speed as it nears the termination of its stroke. The momentjthe regulating-valve closes the port m', as shown in Fig. 2, the port m being slightly open, the pressure of steam in the compartment J will necessarily exceed that in the compartment J', and the main valve, owing to the ,excess of pressure on the front side of the small piston f, will be suddenly moved to the posi- Ation shown in Fig. 2, thereby closing the steamport a', and exposing the entire steam-port a, so that the rear end of the cylinder A will be open to the exhaust, and the front end to the steam; but it will be noticed, on referring to Fig. 2, that the regulating-valve has exposed but very little of the port m in the partition i;- -hence the supply of steam to force the piston back will be very limited in the rst instance, and its movement will consequently be slow, as it commences its return stroke, the controlling-valve, however, exposing more of the port m, as this return stroke is continued, until a full supply of steam is afforded to the piston. Thelatter, therefore., increases in speed until it approaches the rear end of its stroke, when the movement of the piston decreases, owing to the partial throttling of the port m by the controlling-valve, and this port remains lclosed until the piston has again 'commenced its forward movement.

It will now be seen that the piston, on apl preaching and commencing to return from the limits of its strokes, must be so gentle in its movements that the shocks common to engines of this class, and due to the sudden reversing of the piston, are obviated.

In order to relieve the two-part main valve from sudden and detrimental shocks I arrange on each side ofthe piston f of the small cylinder h a cone, x, of such dimensions, in relation to an opening in each side of the said small cylinder, that the said opening cannot, zunder any' circumstances, be entirely closed', but when the small piston is suddenly moved towardone end of the cylinder h the cone will contract the opening at that end so much that the piston will operate against a cushion of steam, which cannot escape through the contracted opening as fast as .the live steam, acting on the opposite side of the pistonmoves the latter.

I wish it to be understood that I do not claim, broadly, thecombination in direct-aetion pumping-engine, of a main valve operated solely by the pressure vof steam with a supplementary valve operated by the engine '5 but `I claim as my inventiony 1. The combination, in a direct-action pump ing-engine, of the regulatingyalve K, operated by and moving simultaneously and in unison. with the engine, the main valve operated byl the pressure of steam, the partition in the chest of the main valve, and a .partition having ports adapted to the regulating-valve, substantially as described, so that the admission of steam to the chest of the main valve shall be graduated by the regulating-valve, in the manner set forth, as .the piston is concluding and commencing each stroke, for the purpose specified.

2. The combination of the small cylinder h, its piston f, connected to the two parts ofthe main valve, and the cones x x, adapted to openings in the cylinder-heads, all as set forth. In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM H. HARRISON.v

Witnesses HUBERT HowsoN, HARRY SMITH.

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