GB2158162A

GB2158162A - Hand plunger pump

Info

Publication number: GB2158162A
Application number: GB08411549A
Authority: GB
Inventors: Gerrit Hendrik Heetbrink; Dijk Berend Jan Van
Original assignee: Wavin BV
Current assignee: Wavin BV
Priority date: 1984-05-04
Filing date: 1984-05-04
Publication date: 1985-11-06
Also published as: GB8411549D0; GB2158162B

Abstract

A hand plunger pump having a plunger reciprocating in a pump cylinder and, thereabove, a drop pipe 6 with a pump rod 7 therein, said pump rod being in the form of a hollow tube having an outside diameter equal to or larger than half the inside diameter of the drop pipe, said inside diameter being equal to the diameter of the pump cylinder. The drop pipe is built up from sections which are interchangeable with each other by means of connectors 14a, 14b. <IMAGE>

Description

SPECIFICATION A hand plunger pump This invention relates to a hand plunger pump having a plunger reciprocating in a pump cylinder and, thereabove, a drop pipe with a pump rod therein. These pumps are generally known and are used in a well at population centres where there is no water main.

Pumps intended for this purpose have to satisfy stringent requirements due to their very intensive use and the limited possibilities for maintenance and repairs. The number of moving parts should be restricted to the minimum, since each articulation, e.g. for a handle lever, results in the possibility of additional wear. This means that the minimum force that should be applied for pumping even from relatively considerable depths. The flow of liquid to be delivered should be as uniform as possible. In view of the possibility of corrosion, non-corrodable materials should preferably be used for these pumps. Plastics are accordingly extremely suitable for this purpose.

The known hand plunger pumps use a metal pump rod having a relatively small diameter with respect to the diameter of the pump cylinder and the drop pipe. This means that during pumping the stream of liquid emerging from the pump is subject to considerable pulsation as the pump rod moves up and down. Resulting in, as the pump rod rises, a relatively heavy column of liquid is lifted, particularly in the case of deep pumps, and this requires considerable force.

The object of this invention is to provide a hand pump without these disadvantages and which therefore requires no extra handle levers, even when the pump is to operate at considerable depths.

According to the invention this is achieved with a hand plunger pump of the type described hereinbefore, wherein the pump rod in the drop pipe is constructed in the form of a hollow tube and has a outside diameter larger than half the inside diameter of the drop pipe.

Preferably is the outside diameter d, of the pump rod equal to the equation d1 = (d2/2)} wherein d2 represents the inside diameter of the drop pipe.

The advantage of this is that the pump rod not only has great rigidity, but also acquires a certain floatability in the column of liquid in the drop pipe. Consequently, the reciprocation can be so balanced that the same force can be applied in both directions. For considerable depths it is even possible to provide a certain quantity of ballast in the pump rod in order to adapt the difference in the forces during the upward and downward movements.

Another advantage of the invention is that due to the relatively considerable diameter of the pump rod the liquid rises in the drop pipe during the down-going movement as a result of the differential effect beneath and above the plunger, and the pulsating action of the pump is dramatically reduced or completely eliminated.

Advantageously, in a hand plunger pump according to the invention, the inside diameter of the drop pipe is equal to the inside diameter of the pump cylinder. The pump cylinder can be part of the drop pipe if the outside diameter of the drop pipe is equal to the outside diameter of the pump cylinder.

In one practical embodiment, at least the drop pipe is made up of interconnectable sections, using separable connectors. The advantage of this is not only that the pump can readily be adapted to the depth of a well, but also, in the event of pump cylinder wear, the pump cylinder can readily be reversed or replaced by an upper section of the drop pipe so that the pump can readily be maintained on the spot without purchasing new parts which are usually difficult to obtain, and the pump has a long life as a result.

In the hand plunger pump according to the invention, use is made of two valve systems constructed as ball check valves, one of which is in the form of a fixed suction check valve and one in the form of a plunger discharge check valve. According to the invention, the valve housings with the ball cage, seat, and means for receiving sealing means for the two valve systems are of identical construction and a single moulding serves for each valve system. Each valve housing is provided with one or more circumferential grooves to receive fixing and/or sealing means.

The invention will now be explained in detail with reference to the accompanying drawings wherein: Figure 1 is an axial section through the top part of a hand pump according to the invention.

Figure 2 is an axial section through the bottom part thereof.

Figure 3 is an axial section to an enlarged scale at a connector with a suction valve mounted therein; and Figure 4 is a perspective view of a valve system according to the invention.

In Fig. 1, a pump stand 1 provided with a spout 2 is fixed in a concrete base 5 by means of a metal socket 3 provided with anchors 4. The top end of a drop pipe 6 leads into the pump stand 1. The pump rod 7 in the form of a hollow tube extends at the top through a cap 8 mounted on the stand 1. Cap 8 is preferably made of a plastics having a low coefficient of friction. The cap 8 is fixed in the pump stand 1 by means of bolts 9 or cams 1 2. A metal insert 10 of a metal handle 11 is fitted in the top end of the pump rod 7, which is in the form of a hollow tube. The pump stand 1 together with the insert 10 and handle 11, is made of metal in order to prevent damage due to improper use as far as possible.The hand plunger pump comprises a plunger 1 3 reciprocating in a pump cylinder 6a (Fig. 2) and thereabove a drop pipe 6 with a pump rod 7 therein. The pump rod 7 in the drop pipe 6 is in the form of a hollow tube and has an outside diameter larger than half the inside diameter of the drop pipe 6. The inside diameter of the drop pipe 6 is equal to the inside diameter of the pump cylinder 6a.

Since the outside diameter of the drop pipe 6 is equal to the outside diameter of the pump cylinder 6a, this pump cylinder may be a part of the drop pipe. The hand plunger pump also conventionally has a suction pipe 6b having the same inside and outside diameters as the pump cylinder 6a. As will be seen from the drawing (Figs. 2 and 3), at least the drop pipe 6 is made up of interconnectable sections using separable connectors. Each connector comprises a part 1 4a having an internal screwthread and a part 1 4b having an external screwthread fitting therein. Each part 1 4a and 1 4b has on the inside a socket member 15a, 15b and a collar member 16a, 16b respectively.The inside diameter of the collar member 16a. 1 6b is equal to the inside diameter of the drop pipe 6 and the pump cylinder 6, and the inside diameter of the socket member 1 5a, 1 sub is equal to the outside diameter of the drop pipe and the pump cylinder 6, 6a respectively to the extent such that fixing by gluing is possible. All the pump components, such as the drop pipe 6, the pump cylinder 6a and the suction pipe 6b can in this way be assembled by means of the same connector. The connector is also usable for fixing the suction valve as will be explained hereinafter.

The hand plunger pump is provided with two valve systems in the form of ball check valves, one being constructed as a fixed suction valve 1 3a and another as a plunger discharge valve 1 3. According to the invention, the two valves are constructed in the same configuration, in that the valve housings 1 7 with the ball cage 18, seat 1 9 for a ball 20, and means for receiving sealing means for the two valve systems 1 3 and 1 3a are of identical construction and a single moulding serves for each valve system. The moulding is shown clearly in Fig. 4. The means for receiv ing the sealing means are such that each valve housing 1 7 has one or more circumferential grooves to receive fixing and/or sealing means.For the valve system 1 3a, these seal ing means consist of half rings 21 which fit in a circumferential groove 22. These half rings 21 thus form parts of a discoid ring which fit against a collar member 1 6a and between the two parts 1 4a and 1 4b of the connector and extend into the connector passage, which parts of the discoid ring 21 fit into the circumferential groove 22 of the valve housing 1 7.

The sealing means fitting into one or more circumferential grooves of the valve housing 1 7 are formed from one or more pieces of packing cord 23 curved into the form of a ring and provided with a lubricant. An extra wide groove 24 in the valve body 1 7 serves to receive these pieces of packing cord 23 having their splits situated over 180 to one another. When the valve body 1 7 serves as a suction valve 13a, the rings 21 are fitted whereas the pieces of packing cord 23 can be left out. A liquid tight seal can be obtained with these rings 21 by means of an O-ring 25 (Fig. 3). When the valve housing 1 7 is used as a plunger 13, the half rings are omitted and the pieces of packing cord 23 are used to provide a seal with respect to the pump cylinder 6a.When used as a plunger, the valve body 1 7 should be secured to the pump rod 7, and to this end the ball cage 1 8 of the valve body 1 7 is provided at its free end with a socket member 26 to receive the end of the pump rod 7 constructed as a hollow tube.

Preferably, the hollow pump rod is provided with a plug or a diaphragm 27 to seal off the passage from the hollow pump rod to the interior of the ball cage. The pump rod 7 can thus be filled with ballast if necessary at a given well depth or pump cylinder diameter.

Accordingly there is no column of water to be lifted inside the pump rod when the plunger 1 3 rises. The suction pipe can be open at its bottom end, as shown by reference 28, or be closed, in which case the bottom end of the suction pipe 6b is provided with a lid 29. In the latter case the bottom end of the suction pipe serves as a sand trap. However, openings 28a should be formed in the suction pipe to admit liquid to the interior of the suction pipe. The entire pump is conventionally mounted inside a filter pipe 30 which over part of its length is provided with slots 31 extending in the longitudinal direction of the pipe. This entire system is in turn conventionally placed in a gravel bed of a well. For the sake of clarity, however, the gravel bed is not shown in the drawing. At the top the filter tube 30 adjoins the metal socket 3 as shown in Fig. 1. Sealing means 31 are provided at the top end of the filter tube 30 and the bottom end of the pump stand 1.

Claims

1. A hand plunger pump having a plunger reciprocating in a pump cylinder and, therea bove, a drop pipe with a pump rod therein, wherein the pump rod in the drop pipe is constructed in the form of a hollow tube and has an outside diameter equal to or larger than half the inside diameter of the drop pipe.

2. A hand plunger pump as claimed in claim 1, wherein the outside diameter d1 of the pump rod is equal to the equation d1 = (d2/2)i wherein d2 represents the inside diameter of the drop pipe.

3. A hand plunger pump as claimed in claim 1 or 2, wherein the inside-and outside diameter of the drop pipe is equal to the inside-and outside diameter respectively of the pump cylinder.

4. A hand plunger pump as claimed in claim 1-3, wherein the pump cylinder is part of the drop pipe.

5. A hand plunger pump as claimed in claim 1-3, wherein a suction pipe has the same inside and outside diameter as that of the pump cylinder.

6. A hand plunger pump as claimed in any one or several of claims 1-5, wherein at least the drop pipe is made up of interconnectable sections, using separable connectors.

7. A hand plunger pump as claimed in claim 1, wherein a stopper of diaphragm is provided at the bottom end of the hollow pump rod to seal off the passage from the hollow pump rod to the inside of the ball cage.

8. A connector for use in a hand plunger pump as claimed in claim 5, the connector having a part with an internal screwthread and a part with an external screwthread fitting therein, and each part internally has a socket member and a collar member, wherein the inside diameter of the collar member is equal to the inside diameter of the drop pipe and the pump cylinder and the inside diameter of the socket member is equal to the outside diameter of the drop pipe and the pump cylinder to an extent such that fixing by gluing is possible.

9. A hand plunger pump as claimed in any one or several of claims 1-6, provided with two valve systems constructed as ball check valves, one of which is in the form of a fixed suction check valve and one in the form of a plunger discharge check valve, wherein the valve housings with the ball cage, seat, and means for receiving sealing means for the two valve systems are of identical construction and a single moulding serves for each valve system.

10. A hand plunger pump as claimed in claim 9, wherein each valve housing is provided with one or more circumferential grooves to receive fixing and/or sealing means.

11. A hand plunger pump as claimed in any one or several of claims 1-10, wherein parts of a discoid ring fit against a collar member and between the two parts of the connector and extend into the connector passage, which parts of the discoid ring fit in a circumferential groove of a valve housing.

1 2. A hand plunger pump as claimed in claim 10, wherein the sealing means fitting in one or more circumferential grooves of the valve housing are formed from one or more pieces of packing cord curved into annular shape and provided with a lubricant.

1 3. A hand plunger pump as claimed in any one or several of claims 1-1 2, wherein the ball cage of the valve body is provided with a socket member at its free end to receive the end of the pump rod constructed in the form of a hollow tube.

14. A hand plunger pump as claimed in any one or several of claims 1 to 6, wherein a meal bar or tube connected to a handle is provided in the top end of the hollow pump rod.

1 5. A hand plunger pump as claimed in claim 1, wherein the interior of the hollow pump rod is provided with ballast.