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N.PETERS. PHOTO-LITHOGRAPHER, WASHINGTON, D. C.

United States Patent Office.

LEVIS H. DAVIS, OF WEST CHESTER, PENNSYLVANIA.

IMPROVEMENT IN PUMPS.

Specification forming part of Letters Patent No. 38,291, dated April 28, 1863.

To all whom it may concern:

Be it known that I, Levis H. Davis, of West Chester, Chester county, Pennsylvania, have invented an Improvement in Pumps; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

My invention consists of certain improvements, fully described hereinafter, in the barrels and valve-chests and packing of doubleacting pumps, whereby the advantages of economy and simplicity as regards construction are attained.

In order to enable others skilled in this class of mechanism to make and use my invention, I will now proceed to describe its construction and operation.

On reference to the accompanying drawings, which form a part of this specification, Figure 1 is a side view, partly in section, of my improved pump ; Fig. 2, a sectional plan ; and Fig. 3, an exterior view of part of the pump.

Similar letters refer to similar parts throughout the several views.

A represents the barrel of the pump, a the rear cover, and b the front cover of the barrel, B being the valve-chest, 0 the piston, and D the piston-rod, the latter being connected by suitable links, E, to the operating handle, F. A shoulder, x, is’formed in the barrel midway, or thereabout, between the opposite ends of the same, the barrel being of increased bore from this shoulder to the cover, for the admission of the hollow cylinder G, between the inner end of which and the shoulder x intervenes the annular packing-piece H, of gumelastic or other suitable material.

Into the cover b, which is secured to the front end of the barrel, screws the gland or follower d of a stuffing-box, and into the same opening of the cover a projection on the cylinder G fits loosely, suitable packing intervening between this projection and the end of the follower d, so that on screwing the latter into the cover b the packing for the piston-rod and the packing H of the piston are tightened simultaneously, the latter packing dividing the interior of the barrel into two chambers, I and J.

The valve-chest B, which may be secured to or form part of the barrel of the pump, has two chambers, K and K', separated from each other by a partition, e, each chamber containing a ball, n, of gum-elastic or other suitable material, and above these chambers a third, L, is formed in the portion M of the valvechest. This chamber L also contains a ballval ve, which is permitted to move to and fro longitudinally, but which is prevented from escaping vertically from the chamber by the strip p, placed across the opening g, which forms a communication between the said chamber L and the air-vessel N, the latter being secured to the top of the valve-chest and being furnished with a suitable discharge-pipe, P.

The valve-chamber K communicates with the rear chamber of the barrel through a passage, t, Fig. 2, and with the chamber L through the opening u, the chamber JK7 communicating through a passage, t¹, cut in the cylinder G, with the front chamber of the barrel, the chamber E? also communicating through an opening, u', with the chamber L, and both chambers Kand K7 communicating, the former through the opening v, the latter through the opening ν', with the suction pipe Q. The open ings u and u' and v and ν' are circular, and are beveled at their edges, so that the latter may form appropriate seats for the ball-valves. Supposing the piston C to be moving in the direction of the arrow and to be about completing its inward movement, the water in the chamber J of the barrel will be in the act of passing from that chamber through the passage t into the chamber K, and thence (the valve of the latter chamber being closed) through the opening u into the chamber L, and thence through the opening q into the airchamber N. In the meantime the water will be passing through the suction-pipe Q, thence through the opening ν' into the chamber K?, and thence into the front chamber, I, of the barrel. The direction taken by the water on the reverse motion of the piston will be readily understood, as will also the fact that a continuous stream of water must flow from the discharge-pipe P on imparting a reciprocatingmotion to the piston through the medium of the lever F. It will be seen that as the piston reciprocates the valve m will move backward and forward in the chamber L, first closing the opening u and then the opening u'. It will also be seen that the general arrangement of chambers and valves is of the most simple

38,291 character, and that access can readily be liad to the interior of the valve-chest.

One of the main objects of my invention' has been to dispense as far as possible with the turning, boring, and fitting which add so much to the expense of ordinary double-a cting pumps. No boring of the barrel A is necessary, as the piston is never in contact withit, the barrel, as well as the cylinder G, consisting of crude but properly cleansed castings. The only portion of the pump on which it is necessary to expend any very careful or expensive work being the piston C and its rod D, which it would be well to turn truly, and even these parts may be made sufficiently exact without resorting to turnings As to the valve-chests and valve-seats, sufficient exactitude can be obtained by careful molding and casting without resorting to boring or turning.