US171475A - Improvement in pistons or plungers for force-pumps - Google Patents

Description

G. WQGILMORE. PISTON 0R PLUNGERFOR FORCE-PUMPS. N.171.,475.

Patented Dec. 28, 1875.

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UNITED STATES VPATEET OFFICE.

GEORGE W.-GILMORE, OF WEBSTER, PENNSYLVANIA.

`IMPROVEMENT IN PISTONS R PLUNGERS FOR FORCE-PUMPS.

Specification forming part of Letters Patent N o. l7l,4715, dated December 28, 1875 application tiled April "es, 1875.

To all whom itmay concern.'

Be it known that I, GEORGE W. GILMORE, of Webster, Westmoreland county, State ot Pennsylvania, have invented an Improved Piston or Plunger'for Force-Pumps, of which the followingis a specification The object of my invention is to cause the fluid to be discharged from the pump with greater force and velocity than can be done with pistons of the ordinary construction, and this to be done by theelasticity of a body of `air in the piston acting on the column of water in the pump-barrel when the piston is driven downward.

The invention consists in making the piston with a hollow' body, having air-inlets at the top, and an opening' at the bottom, through which the air in the piston presses on the water in the barrel, when the piston is driven downward. The air-inlets and the opening y in the bottom ofthe piston are alternately closed and opened by valves, which are operated bythe recprocation of the piston, so that when the piston is lifted the air-inlets are opened, and the opening in the bottom is closed, and 4water is prevented from enteringv the chamber 5 but when the piston is forced down the air-inlets are closed, and the opening in the bottom i-s opened, which permits the air in the chamber to press upon the fluid.

Figure l is a longitudinal section of my improved piston. Fig. 2 is an end View, showing the bottom of the piston; and Fig. 3 is also an end view, showing the top of the piston separate from it.

The following is a more particular description of said drawings which are hereby made .a part of this speciication, letters ot' reference being the same in all the gures.

A is the piston, which is hollow, and forms the air-chamber F. b is the opening in the bottom of the piston, through which the air in the chamber E presses on the water in the barrel when the piston is driven downward. a, a a a are theI air-inlets. G is a valve-rod guide, formed by .a small bar crossing the openingb, and having a hole in the center g. H is also a guide-hole inthe top or head ot' vthe piston, Fig. 3. D is the valve-rod, passing through the whole llength of the airchamber F, and retained in place by the guides G, g, and H. C and G are two valves fast on the rod D, and at such points that when one is open the other will be closed. B is the piston-rod by which the piston is moved in the pump-barrel. The opening b is a hole in bottom ofthe piston about one-third less in diameter than. the air-chamber F, so as to form a valve-seat for the valve C, and the inlet is formed by several small holes surrounding the guide-hole H.

When the piston Ais drawn up in the pumpbarrel, the valve C closes the opening b, and the inlets are uncovered, and the chamber F becomesvlled with air. On the downward movement of the piston-valve G closes and C opens, and the air in the chamber E is caused to press on the top of the column of water in the barrel, and its elasticity gives greater force to the expulsion of the water from the pump than would be obtained by the pressure of the piston alone.

What I claim, and desire Letters Patent for, is-

A piston for force-pumps having4 the airchamber F, air-inlets t a, openings b, and provided with the valves C C', which alternately open and close the said openings by the reciprocation of the piston, substantially as and for the purpose hereinbetore described and set forth.

GEORGE w. GILMoEE.

Witnesses:

WM. M. GUTEEERT, JULIEN Moanow.

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