This invention relates to a well pump and in particular it relates to a pump of the type which is positioned in a well at the end of a string of delivery pipes which convey liquid pumped from the 5. well to an elevated position, in which the pump is actuated by a plunger rod passing up the string of pipes.

It is customary in pumps of this kind to have a barrel which has in it a piston reciprocated by the

10. plunger rod actuated from a windmill or other driving means and to have in the base of the barrel a foot valve which allows liquid to enter the barrel at the appropriate time, and to have within the piston a valve which allows liquid to move upwardly through

15. the piston but not down, so that as the piston is reciprocated, liquid is lifted by the piston on the upstroke with the piston valve closed and the foot valve open, but on the downstroke the piston moves freely through the liquid with the piston valve open

20. and the foot valve closed so that the space above the piston is then filled with liquid for the next lift.

According to an earlier invention of mine, the pumping was achieved by a balance system using fluids to actuate the piston in the pump cylinder, 25. but the present invention is directed to a mechanic¬ ally actuated pump of the general type described earlier herein.

The object of the present invention is to pro¬ vide certain improvements to pumps of this type, the object being achieved according to this invention by utilizing a barrel in which a piston is recipro- 5. cated by means of a plunger rod, but the piston itself is not provided with valve means but has buckets arranged to prevent the passage of liquid or fluids past the piston, the valve mechanism being situated in an extension at the top of the barrel 10. in which the piston moves, the valves being situated in this extension.

The invention thus comprises a submersible well pump of the barrel and piston type characterised by a valve chamber formed coextensively with the 15. barrel and containing at least an inlet valve and an outlet valve arranged to admit fluid to one end of the barrel on a first stroke of the piston and to discharge the fluid from the same end of the barrel on a second opposite stroke of the piston.

20. In its preferred form the invention comprises a pump having a barrel adapted to be supported by a delivery type and adapted to be submerged in the fluid to be pumped and comprising a barrel having a piston within it adapted to be coupled by a plunger

25. rod to a reciprocating mechanism and including inlet and outlet flow control valves, characterised in that the flow control valves are positioned in an

extension of the barrel coextensive with the barrel and arranged on a first stroke in one direction to cause a flow of fluid into the barrel through the inlet valve to the retreating side of the piston and, j. at a second stroke in the opposite direction to discharge the fluid from the barrel through the outlet valve to the delivery pipe.

The invention also has reference to a double- acting pump.

10. To enable the invention to be fully understood embodiments thereof will now be described with refer¬ ence to the accompanying drawings in which:

FIG. 1 is a longitudinal sectional view of 15. first embodiment of the invention,

FIG. 2 is an enlarged longitudinal sectional view of the valve extension,

FIGS. 3, 4, 5 and 6 are components of the valve 20. mechanism, and

FIG. 7 is a longitudinal sectional view of a second embodiment showing a double-acting arrangement.

Describing first the form illustrated in FIGS. 25. 1 to 6 inclusive, the extension 1 screws to the top of a barrel 2 to be coextensive therewith and

this extension 1 has in it intake ports 3 which terminate in which I term a garter-type reed valve 4, that is a valve which is expanded in a chamber 5 in the extension to engage the inner face of the

5. extension over the intake ports 3. This prevents outflow of fluid but allows fluid flow into the chamber 5 when the reed valve 4 contracts into the chamber 5 due to fluid being drawn into the hollow by the piston 6. The fluid flows through the intake

10. pert 3 and around the reed valve 4 into the chamber 5 and thence into the barrel 2 of the pump. This reed valve 4 is the fluid inlet valve to the barrel 2.

By this arrangement the pump barrel 2 is filled from the top end when the piston 6 is on the down- 15. stroke, the piston aiding inflow of the liquid to the barrel 2 as it is downwardly displaced.

Within the extension 1, situated in the chamber 5 surrounding the plunger rod 7 is a non-return disc valve 8 having rod seal 9, which valve is adapted to 20. seat downwardly onto a webbed valve seat 10 also surrounding the plunger rod 7. This is the outlet valve from the barrel 2.

The arrangement of this non-return valve 8 is such that on the upstroke of the piston 6, when 25. the reed valve 4 is forced outwardly to close off the intake ports 3, liquid flows upward through the ported valve seat 10 and past the non-return

valve 8 which it lifts to allow free flow past it and up the delivery pipe 11 which in turn is secured to the top of the extension 1.

This non-return valve 8 frictionally engages _, the plunger rod 7 through the rod seal 9 so that when the plunger rod 7 moves downwardly it moves with it until the ported valve seat 10 is engaged to. seal downward flow, and at that stage the delivery pipe 11 holds the liquid within it as it cannot 10. return to the barrel 2.

The non-return valve rod seal 9 is pressed against the plunger rod so that when this non-return valve 8 is seated on the ported valve seat 10, no fluid can flow past the non-return valve 8.

^I S- Situated above the non-return valve 8 is a ported rod guide 12 through the ports 13 of which the liquid flows into the delivery pipe, but this rod guide 12 correctly guides the plunger rod to retain its axial position in relation to the chamber 5 in

20* the extension 1.

Assembly of the valves in the extension 1 is by inserting the ported valve seat 10 upwards into the chamber 5 from the barrel end and holding it against a step 14 in the chamber 5 in the exten- 25- sion 1 by means of a flow-through holding member 15 which comprises a spider 16 with a hollow stem

17 which encircles the plunger rod 7, and retaining this by a threaded ferrule 18 which is part of or engages the barrel 2.

In this way a cage is formed, consisting of 5. a spider 16 and the ported valve seat 10, in which the reed valve 4 is axially confined. The reed valve 4 is however able to flex to allow fluid to be drawn inward to the chamber 5 by action of the piston 6 or by fluid pressure.

10. The non-return valve 8 is confined in a flow- through cage formed by the webbed valve seat 10 and the ported rod guide 12, and the ported rod guide is inserted from above and is held against the stop 14 by a socket 19 which engages the deliv-

15. ery pipe 11.

The piston 6 is provided with a pair of buckets

20 and 21 which are positioned to prevent flow past the piston 6 during its lifting stroke. The lower bucket 21 can however be reversed if greater 20. suction is required on the down-stroke of the piston

6 to draw fluid through the ports 3 and past the reed valve 4.

The above described embodiment results in a single acting pump which delivers liquid on the 25. upstroke but draws liquid into the barrel on the downstroke.

According to a modification of the invention as shown in FIG. 7, in which similar reference numerals for components similar to those referred to with reference to the first described embodiments 5- are used.

This is generally similar in construction to the form first described but has a foot valve 22 positioned in the barrel 2 so that on the upstroke of the piston 6, fluid can be drawn into the lower

10 part of the barrel 2. A port 23 in the lower part of the barrel 2 is connected to a port 24 in the upper part of the extension 1 above the ported rod guide 12 by a transfer pipe 25, which allows fluid on the downstroke of the piston 6, when the foot

15. valve 22 and the non-return valve 8 are closed, to flow upwardly through the transfer pipe 25 into the delivery pipe 11 so that, on the downstroke, the fluid below the piston 6 is displaced into the transfer pipe 25 and hence into the delivery pipe 11

20. which takes the fluid to the surface.

The port 24, which communicates with the trans¬ fer pipe 25, is in turn provided with a second non-return valve 26, which is in the form of another garter-type reed valve at the upper part of the 25. extension 1, although a flap valve could be used. This garter-type reed valve 26 is positioned in the upper part of the chamber 5 above a ported disc 27 to normally close the port 24 when the

reed valve 26 is pressed against the wall of the chamber in which it is housed to prevent back flow down the transfer pipe 25 from the delivery pipe 11 which leads to the surface.

5. The second reed valve 26 can be inserted from above and held in a cage formed between a spider 27 and a ported disc 28 which is engaged by the socket 19, the spider having a hollow stem 29 pro¬ jecting upwards to space the ported disc 28 at

10. the correct distance from the spider 27.

From the foregoing it will be realised that a simple and effective pump is provided which can be readily assembled and which comprises a barrel as a lower integer of the pump with an extension 15. at the top which carries all the valve means except¬ ing the foot valve in the case where the pump is to be double acting.

It will also be appreciated that a pump is formed having an extension 1 on one side of the

20. barrel 2 which is coextensive with the barrel 2 and houses at least an inlet valve 4 and an outlet valve 8 in flow-through cages in the chamber 5 formed in the extension 1, and that the pump can readily be converted to be double acting by simply adding a

25. foot valve 22 and a second inlet valve 26.

The valves 4 and 8 and 26 can be located by means other than the flow-through cages, but the form illustrated allows the valves to be located by

positioning at least one from each end of the chamber and locking the structure together by end mei.ir.ei-s such as the barrel 2 and the socket 19.

To enable the string of delivery pipes and 5. pump to be withdrawn readily for servicing or the like a small valve may be included at the top of the pump which is normally closed, but can be opened by pull on a line leading to the surface to allow the water from the delivery pipe to flow out of 10. the pipe to thereby lighten the load when with¬ drawing the pipe, but such a release is not illus¬ trated but can be readily applied by persons versed in the art.