US315485A - Joseph banks davies - Google Patents

Description

2 sheets-s'neet 1.

(No Model.)

y J. D. DAVIES.

PUMP..

No. 315,485. Patented Apr. 14, 41885 WIT/VESSES me Model.) 2 sheetsTsneen 2.

' J. D. DAVIES.

. PUMP. N0. 315,485.

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WIM/8858 UNITED STAT-IISN JOSEPH BANKS DAvInS, or NATCHEZ, MISSISSIPPI.

PATENT FPICE.

PUMP. f

SPECIFICATION forming part of Letters Patent No. 315,485, dated April 14, 1885. V'

Application mea May 1`, 1884. (No moda.)

To all whom it may concern:

Be it known that I, JOSEPH DANKS DAvII-Is, of Natchez, in the county of Adams and State of Mississippi, haveinvented certain new and useful Improvements in Pumps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such `as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in pumps, the object of the same being to provide a pump which shall be differential-viz., one in which the amount of work accomplished shall be proportional to the pressure or head, thus enabling the engine to drive it'against any load, a further object being to prevent shocks from taking place in the pump from sudden changes of pressure either on the in-4 let or exit side of the piston.

` With these ends in view my invention consists in certain features of construction and combinations of parts, as will be fully described, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in vertical longitudinal section through the pump and cushion-cylinder. Figs. 2 and 3 are views showing springs employed in place of the fluid or air cushion cylinder. Fig. Ltis a view in vertical section of the pump, showing two cushion-cylinders connected thereto. Fig. 5 is a view on the line x .fr of Fig. 4.-; and Fig. 6 is a view on the line y y of Fig. 5, the pipe O, which is omitted in Fig. 5, being shown. t

a represents apump-cylinder tted as usual with a piston or plunger, B,which is attached to an operating-rod, A.' c is another vcylinder of any approvedfsize, situated conveniently in close proximity to and parallel'with the cylinder a. The cylinders a and a communicate with each other at both ends. The cylinder a is provided with a piston, B. A third cylinder, a2, is preferably situated longitudinally opposite the cylinder a, and rigidly secured thereto by means of bolts n or other suitable means. The cylinder a is provided with a-piston, BZ, the latter being connected with the piston B by a connecting-rod, b, passing through the adjacent ends of the cylinders a' and a2, which ends of the .cylinders are held a sufficient distance apart to admit the proper stuffing-boxes. The cylinder a is the cylinder a.

provided with the exit-valves c c, and the cylinder a withthe inletvalves d d. rlhe cylinder a2, which may be conveniently termed the cushion-cylinder, is p rovided with the inlet-valves e e' and with the safety-valves F y, F. f The cylinder a is further provided with the feed-pipes H H', one of which may conveniently feed liquid and the other gas or 6o steam.

The operation of the pump is as follows: Supposethevalvcs c c d d e e F F to be closed, the cylinders a apfull of water, and the cylindergiglled with air, gas, steam, liquid, or a mixture of liquid and air or gas. Let

' the three pist'ons be in the position shown in Fig. l. Suppose, now, power to be applied to the rod A, forcing the piston B in the direction Shown by the arrow. The piston B 7o will be thereby forced inthe opposite direction, and will carry with it the piston B2 in The air not being able to escape from a2 until the pressure is sufficiently great to lift/the safety-valve, the piston `B2 75 will accumulatepressure before it and tend to produce 'a vacuum behind it until the said piston nearly or quite comes "to a standstill, when the pressure beforethe piston B in a will'become sufcientlystrong to lift the exit- 8o valve c and'deliver water therefrom. AtA this same moment there is produced a suffI- p cient vacuum behind the piston B `to open the inlet-valve d', 'which now admits water.

B now starts on its return. force of the gas or air,com`pressed by the previous motion of the piston B2 will now be given back to the piston B. As the piston B'z moves in the return motion, the air in the c linder a2 is again com ressed beforeit and 9a Y s P a partial rvacuum formed behind it until it again comesvto a standstill. J ust before it` comes to a rest, the pressure in the cylinder a becomes sufciently great to open the valve c',

and water is delivered at the same moment 95"" the valve d is opened by the partial vacuum formed, and water enters the pump.` `Vhen the piston B2 arrives atmid-stroke, it is in equilibrium as far as the pressure in the cylinder ai is concerned, `but will continue to loo move on account of its own momentum and the pressure on the piston B until the com" pressed air before it causes it to stop.

The dropping of the valves c c may take .The expansive f place as soon as the pistons B and B2 stop, or as soon as the return motion of the piston B releases the pressure and allows the air in a2 to regain its equilibrium.

t' represents an air-chamber in connection with the cylinder c. It is provided with a cut-off valve, K, to shut the air in the chamber oft` from the cylinder a whenever desired. It is found advantageous to do this when starting the pump. The air-chamber i may or may not be used in connection with the cylinder, or there may be two air-chambers, one at each end of the cylinder.

There may be cut-oft` valves also, arranged between the cylinders a and a to throw the latter out of communication with the former Whenever desired.

As before stated, the pipes H H may lead gas and liquid, respectively. Now, it is obvious that the more liquid in combination with the gas the less will be the movement of piston B2, the pressure from piston B remaining constant. Again,the curve of force transmitted may be varied by either of the following methods-viz., first, by increasing the pressure; secondly, by changing the relative sizes of the cylinders a a2; and, thirdly, by the amount of clearance in a2. These several changes give results represented by different portions of the hyperbolic curve of expansion of gases. It will be seen,therefore, that different pressures required to pump against cause different sweeps of piston B', thereby causing the amount of delivery to be in proportion to the pressure.

In place of the expansion of gases a spring may be used in the cylinder a2, as shown in Figs. 2 and 3. Vith straight connections the effect will now be invariable; but if a'volute or elliptic spring, S, be used, as represented, and the center connection,B2,be made so that it can move more or less before catching the spring S,the differential will be modified.

In Figs. 4, 5, and 6 the cushion-cylinder is made in two parts, f f, pivoted to a suitable frame by its hollow trunnions o. Each cylinder f is provided with a piston and pistonrod, the outer ends of which latter are connected by the iianged collar t to the rod b. The hollow trunnions of both of these pistons are connected tothe steam, air, or water supply pipe O, provided, preferably, at a point outside of both hollow trunnions with a checkvalve, o', adapted to prevent the escape or backliow of the gas or water. The ports o2 of the hollow trunnions terminate at or near the inner or adjacent ends of the cylinders f, so as to admit the actuating-fluid in front of both pistons. When the pistons are in equilibrium, as shown in Figs. 4 and 5, the pistons of the cylinders f rest at the limit of their outward movement. As soon, however, as Vthe pressure in the cylinder c is sufficient to move the piston B in either direction, both cylinders turn on their trunnions,and thepistons thereof are drawn toward the inner or adjacent ends of their respective cylinders and form the cushions.

It is evident that numerous slight changes in the construction and relative arrangement of the several parts might be. resorted to without departing from the spirit of my invention, and hence I would have it understood that I do not conline myself to the exact construction shown and described, but consider myself at liberty to make such changes as fairly fall within the spirit and scope of my invention.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a pump, the combination,with a main cylinder having outlet-valves and a piston,V

and an auxiliary cylinder provided with a piston and supply-valves in communication with the main cylinder, of a cushion-cylinder connected with the piston in said auxiliary cylinder by a piston-connecting rod, substantially as set forth.

2. In a pump, the combination,with a main cylinder having outlet-valves and operatingpiston, and an auxiliary cylinder in communication with the main cylinder and provided with a piston and supply-valves, of a cushioncylinder having its axial line on the prolongation of the axial line of the said auxiliary cylinder, said cushion-cylinder being connected with the auxiliary cylinder by an independent pistonconnecting rod, substantially as set forth.

3. In a pump, the combination,with a main cylinder having outlet-valves and an operating-piston, and an auxiliary cylinder provided with supply-valves and a piston in communication with the main cylinder, of a cushioncylinder provided with valves for admitting air, gas, or liquid, and a rod connecting the piston in the auxiliary cylinder with a piston in the cushion-cylinder, substantially as set forth. y Y

4. In a pump, the combination,with a main cylinder having outlet-valves and an operating-piston, and an auxiliary cylinderI having supply-Valves in communication with the main cylinder, of a cushion-cylinder provided with check-valves for alternately admitting and preventing the escape of air, gas, or liquid, and further provided with safety-valves and a rod connecting a piston in the auxiliary cylinder with a piston in the cushioncylinder, substantially asset forth.

5. In a pump, the combination,with a main and auxiliary cylinder having their axial lines parallel and communicating directly with each other, the main cylinder being provided with a piston and two delivery-valves, and the auxiliary cylinder with two supply-valves, of a cushion-cylinder situated longitudinally opposite the auxiliary cylinder, and a rod connecting a piston in the auxiliary cylinder with a piston in the cushion-cylinder, substantially as set forth.

6. In a pump, the combination,with a main IOO IIO

315,485 K V l if fr cylinder provided with suitable supply and specification inthe presence of two snbserilo` delivery valves and operating-piston, of one ing Witnesses. l

or more air-chambers communicating with the 4 main cylinder, and devices for shutting off the JOSEPH BANKS DAVIEST 5 air-chambers from the cylinder at pleasure, Witnesses: substantially as set forth. W. B. PRINCE,

In testimony whereof I have signed this WALTER MCCREA.

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