GB2346418A

GB2346418A - Pump with duckbill-type valves

Info

Publication number: GB2346418A
Application number: GB9929759A
Authority: GB
Inventors: William Alfred Ireland
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-17
Filing date: 1999-12-17
Publication date: 2000-08-09
Anticipated expiration: 2019-12-17
Also published as: GB9929759D0; GB9827674D0; GB2346418B

Abstract

A pumping device comprises a main tube 49 closed at its lower end, a hand operated piston assembly 42, 48 within the tube, a one-way inlet valve 43 in the closed lower end of the tube, and a further one-way valve 41 in a transfer passage through the piston 42. Each one-way valve 43, 41 comprises a length of rigid tube over the upper end of which is stretched one end of a tube of resiliently flexible material, the free end of each flexible tube remaining flattened and closed due to the resilience of the tube, which is normally flat in its unstressed condition. In use, the pump is lowered into a fishpond, or the like, and as the piston assembly 42, 48 is drawn upwardly, the pressure of water forces water, silt and debris through the inlet valve 43 and into the main tube. The tube is emptied by pushing the piston assembly towards the closed end again, so that the water and debris passes through the valve 41 in the piston to the upper part of the main tube, from which it may be emptied, either by inverting the tube or automatically through a side nozzle at the upper end of the tube.

Description

A PUMPING DEVICE The invention relates to a pumping device. The device is particularly suitable for use as a hand operated pump for removing silt and other debris from the bottom of a fish pond or similar body of water but is not restricted to this use.

According to the invention there is provided a pumping device comprising a chamber, means for creating a reduced pressure in the chamber, and a one-way inlet valve comprising an open-ended tube of flexible material which leads into the chamber from an external inlet aperture, means being provided for resiliently biasing the side walls of the tube together so that the end of the tube within the chamber is normally closed until a reduction in pressure in the chamber allows the external pressure of fluid material to force the side walls of the tube apart so that the material may flow through the tube and into the chamber.

The open-ended tube is preferably formed from resiliently flexible material, and the means biasing the side walls of the tube together may then be the resilience of the material itself. In this case the inlet aperture may comprise a length of rigid tube which projects into the chamber, one end ouf the tube of resiliently flexible material being stretched over the rigid tube and the free end of the flexible tube remaining flattened and closed due to the resilience Of the tube, which is normally flat in its unstressed condition.

The means for creating a reduçed pressure in the chamber preferably comprises a movable piston slidable withi the chamber, means being provided to effect sliding movement of the piston towards and away from the inlet aperture so as to vary the volume of the part of the chamber between the piston and the inlet aperture, and thereby vary the pressure within said part of the chamber. Other arrangements, for example bellows arrangements, may be provided for the creation of a reduced pressure in the chamber.

The means for effecting sliding movement of the piston may comprise a manipulating device connected to the piston and including an operating handle accessible externally of the chamber.

The chamber may include an outlet vent on the opposite side of the piston to the inlet. This vent will allow air or any other fluid material on the opposite side of the piston to escape through the outlet vent as the piston is moved away from the inlet to draw material into the chamber. The chamber may conveniently be in the form of a circular cross-section tube.

In any of the above arrangements incorporating a movable piston, the piston may include a transfer passage incorporating a further one-way valve. For example, the further one-way valve may comprise an open-ended transfer tube of flexible material which extends from the piston into the part of the chamber on the opposite side of the piston to the inlet aperture, means being provided for resiliently biasing the side walls of the tube together so that the end of the tube within said part of the chamber is normally closed until increased pressure within the part of the chamber containing the inlet aperture allows the fluid material in that part of the chamber to force the side walls of the tube apart so that material may flow through the transfer tube.

As in the case of the previously mentioned one-way valve, the open-ended transfer tube is preferably formed from resiliently flexible material, so that the means biasing the side walls of the tube together is the resilience of the material itself.

Means are preferably provided for limiting the movement of the piston towards the inlet aperture. Said limiting means may comprise an abutment, fixed in relation to the chamber, which is engageante by a part of the piston, or a part of the manipulating device connected thereto.

In one embodiment the abutment finay comprise an annular valve seat located between the piston and the inlet aperture, the piston including a valve element to close and seal the valve seat when the piston is in contact therewith. Such an arrangement will prevent undesired leakage of fluid matnat past the piston if the seal between the piston itself and the walls of the chamber is ot necessary fluid-tight, and may also help prevent larger bodies passing into the chamber through the inlet aperture as the device is initially lowered into the fluid.

In any of the arrangements according to the invention the device preferably includes external spacer means, adjacent thé inlet aperture, to space the inlet aperture from an adjacent surface when the device is, in use, the spacer means being adapted to permit the flow of fluid material past the spacer means and into the inlet aperture. For example, the spacer means may comprise 4 skirt at least partly surrounding the inlet aperture, the skirt being formed with a plurality of apertures or cut-outs to permit the flow of fluid material through the skirt to the inlet aperture when the skirt is in engagement with a surface.

The following is a more detailed description of various embodiments of the invention, reference being made to the accmpanying drawings in which : Figure 1 is a diagrammatic verti, cal section through one form of pumping device according to the invention, Figure 2 is a similar section through a modified version of the device, Figure 3 is a diagrammatic vertical section through a further form of pumping device, and Figure 4 shows, on a smaller scale, an optional modification for any of the devices.

Referring to the arrangement shown in Figure 1 : the main body of the pump comprises a tube 10 which may conveniently be formed from PVC or other plastics material. Removably fitted at the upper end of the tube 10 is a cover/spout assembly 11, the lower end of which is stepped so as to be a friction fit in the upper end of the tube 10, a sealing ring 12 being provided to form a seal between the two parts.

The upper end of the assembly 11 is formed with a central hole 13 through which passes the plunger 14 of the pump, a T-shaped handle 15 being secured to the upper end of the plunger. A spout 16 extends laterally from the assembly 11.

Mounted on the lower end of the plunger 14 is a piston assembly 17 comprising a felt disc 18 sandwiched between an upper rigid washer 19 and a lower valve disc 20 formed from rubber, neoprene or other suitably resilient material The piston assembly is secured to the bottom of the plunger 14 by a screw 21, a further rigid washer 22 being located between the head of the screw and the valve disc 20.

The valve disc 20 cooperates with an annular seat 23 formed at the upper end of a tubular insert 24 which is a snug fit within the lower end of the tube 10. The lower ends of the tube 10 and insert 24 fit into the upper half of a tubular bottom member 25.

Extending partly across the bottom member 25 is an annular web 26 from the inner periphery of which extends upwardly a valve tube 27 which is integral with the web.

A short length of rubber or plastics tubing 28 is stretched over the valve tube 27 as shown. The tubing 28 is of the kind which is flattened in its unstressed state so that the two sides of the tubing come together, under the natural resilience of the tubing, a short way above the valve tube 27, as indicated at 29.

Cut-outs 30 are formed around the lower part of the wall of the bottom member 25.

In operation the plunger 14 is first pushed downwardly into the position shown in the drawing in which the valve disc 20 bears against the annular valve seat 23. The pump is then introduced vertically into the pond or other body of water until the bottom member 25 rests on the bottom of the pond Closing off the upper end of the tubular insert 24 by the piston assembly 17 ensures that, as the pump is introduced into the pond, water or small fish are not swept into the bqdy of the pump.

Once the pump has been introduced into the pond, the T-shaped handle 15 is raised, withdrawing the piston assembly 17 upwardly along the length of the tube 10. This reduces the pressure within the tube 10 belpw the piston assembly 17 so that material, such as silt, gravel, pond weed etc., is drawn Upwardly through the valve tube 27, forcing apart the sides of the tubing 28 so that the material enters the tube 10 below the piston assembly 17.

The pump is then lifted out of the, water and the valve provided by the tubing 28 closes tightly under the pressure of the water and debris within the tube 10 so that the material within the tube cannot escape as it i lifted out of the water. The tubing 28 can cling around material, such as pond weed, which might have been only partly drawn into the tube 10 so as still to provide an effective seal.

Once the pump has been removed om the pond, the cover/spout assembly is removed, with the plunger 14 and piston assembly 17, so that the debris from the bottom of the pond can be tipped out of the pump and, disposed of The purpose of the spout 16 is to act as an air vent as the plunger is raised and also to permit any water or material above the piston assembly 17 to be discharged from the pump as the plunger 14 is raised in operation.

The use of a felt disc 18 for the piston is preferred since a more solid disc may jam against the walls of the tube 10 as a result of gravel or other debris finding its way around the periphery of the piston. However, other suitable forms of piston may be employed, such as a dished neoprene or other plastics washer secured to the lower end of the plunger 14 above the washer 22.

The pump can be of any convenient length, for example it might be one or two metres long.

Although the pump is particularly suitable for cleaning the bottoms of fish ponds and the like, it will be appreciated that it may be used in any circumstance where debris requires to be removed from beneath a body of water, for example it might be used for removing silt from a trap in an underground drain system.

In the modified arrangement shown in Figure 2 the tubular insert 24 and valve seat 23 of the Figure 1 arrangement are omitted. Instead, the handle 33 on the upper end of the plunger 34, to which the piston 31 is connected, is engageable, when in its lowermost position, within the sloping side walls of an upwardly divergent collar 35 which is secured to the upper end of the tube 32. The length of the plunger 34 is such that when the handle 33 is fully engaged within the collar 35 the lower surface of the piston 31 is a short distance above the upper edge of the rubber or plastics tubing 36 which constitutes the non-return inlet valve of the device.

As in the previously described arrangement, the lower end of the tube 32 is closed by an annular member 37 which is formed with a rigid valve tube 38 over which the flexible tubing 36 is stretched. The downwardly projecting skirt 39 of the member 37 is frusto-conical and is formed with cut-ots 40, as before, so that fluid material can enter the skirt 39 and flow through the inlet valve into the pumping device.

The pump of Figure 2 is used irE essentially the same manner as the pump shown in Figure 1. However, in this case the tube 32 is open at the top and it is not therefore necessary to remove an upper assembly of the kind indicated at 11 in Figure 1, in order to empty the pump. It is merely necessary to pull the plunger 34 and piston 31 out of the upper end of the tube 32 and invert the tube to tip out the silt and liquid and other debris which has beerj drawn into the tube through the one-way valve 36.

Figure 3 shows a modified version) of the pump of Figure 2. In the modified arrangement a one-way valve 41 is provided in the piston 42 in addition to the one-way valve 43 associated with the inlet 44.

The one-way valve 41 is similar iq construction to the valve 43. The piston 42 is provided with a transfer passage 45 etending through it, the upper part of the transfer passage 45 being provided by a short rigid tube 46 which projects upwardly from the piston 42. A normally flattened. length of rubber or plastics tubing 47 is stretched over the rigid tube 46. The plunger 48 of the piston assembly is cranked so as to clear the valve assembly 41.

The valve assembly 41 provides, two functions. As the piston is initially urged downwardly to its lowermost position, the valve 41 allows air in the lower part of the tube 49 to pass upwardly through the tijansfer passage 45 to the upper side of the piston 42. This makes it easier to push the plunger down since it avoids the build-up of pressure below the piston 42. Otherwise, ih the previously described arrangements, air has to escape upwardly around the periphery of the piston and the arrangement of Figure 3 therefore allows a more fluid-tight fit between the piston and the surrounding tube.

After the plunger has been lifted to draw a body of water and debris through the lower inlet valve 43 and into the lower part of the tube 49, the plunger itself may be used to remove the material from the pump avoiding the necessity of withdrawing the plunger from the tube and tipping the material out. Thus, when the lower part of the tube is full of fluid and debris, the plunger may be pushed downwards again so that the fluid and debris passes upwardly through the transfer passage 45 and valve assembly 41 to the upper side of the piston 42. When the plunger is raised again, the valve assembly 41 automatically closes and the fluid and debris which is above the piston 42 is then ejected from the open upper end of the tube 49.

The construction shown in Figure 3 may be modified to provide constant flow of water from a reservoir by continuous operation of the pump. In order to achieve this a side nozzle may be mounted on the upper part of the tube 49 as shown diagrammatically in Figure 4. A horizontally and downwardly curved spout 50 is provided on a collar 51 which surrounds the tube 49, fluid tight seals 52 being provided on the collar. The collar 51 may be rotated on the tube 49 to bring the nozzle 50 into or out of register with an aperture 53 formed in the side wall of the tube 49.

As described in relation to Figure 3, fluid which is transferred to the upper side of the piston 42 is raised to the upper part of the tube 49, as indicated at 54 in Figure 4, and it may then flow out of the nozzle 50 if the nozzle is in register with the aperture 53 in the main tube. As the plunger is pushed down again more fluid will be transferred through the valve 41 to the upper side of the piston, so that a head of fluid will be continuously maintained above the piston, providing for a constant flow of fluid out of the nozzle 50.

It will be appreciated that tis arrangement is mainly suitable for circumstances where the fluid being pumpe < ) does not contain a high proportion of silt and other solid debris since this might otherwise block the nozzle 50. When the continuous pumping operation is not required and the pump is to be operated in the previously described manner to remove debris from a pond or the like, the collar 51 may be rotated on the tube 49 to bring tbe nozzle 50 out of register with the side aperture 53.

Using the arrangement of Figure 4, the pumping device may thus be used as an effective water pump, for example it nay be used to empty a pond by attaching a hosepipe to the nozzle 50.

Also, the pumping device may bS used as a fixed decorative garden pump.

In this case the lower end of the pump is mounted on a sunken water reservoir tank and an operating lever handle is connected to the upper end of the plunger so that water may be pumped up from the reservoir by operating the lever. Water delivered from the nozzle is arranged to flow back into the sunken reservoir for re-use. In this case the tube and nozzle etc. may be configure to give the appearance of a traditional village hand pump.

In the arrangements of Figures 1 and 2, where a one-way valve is not provided in the piston itself, downward movement of the piston is permitted by the upward escape of air and perhaps some fluid around the periphery of the piston. This requires that the piston is not a particularly tight fit within the outer tube so that a perfect seal is not provided when the pump is in static mode. However, in practice, these versions of the pump will work effectively to draw up large volumes of water, partly because silt entrained in the water assists in formed a seal around the piston.

This may allow the arrangements of Figures 1 and 2 also to be used to provide a continuing flow of water, as described in relation to Figure 3.

In all of the above described arrangements the lower member on which the flexible inlet one-way valve is mounted is preferably readily detachable from the lower end of the main tube so that the flexible member may easily be replaced if required.

For example, as shown in Figure 3, the lower member may be connected to the lower end of the tube by screws 55 or some other form of releasable catch may be provided.

The flexible tube which forms the one-way inlet valve is preferably vertically orientated as shown in the drawings, but other arrangements are possible. For example, the flexible tube may be stretched over a rigid tube which extends inward laterally from an inlet aperture in the side wall of the main tube of the pump.

Claims

1. A pumping device comprising a chamber, means for creating a reduced pressure in the chamber, and a one-way inlet valve comprising an open-ended tube of flexible material which leads into the chamber from an external inlet aperture, means being provided for resiliently biasing the side walls of the tube together so that the end of the tube within the chamber is normally closed until a reduction in pressure in the chamber allows the external pressure of flpid material to force the side walls of the tube apart so that the material may flow through the tube and into the chamber.

2. A pumping device according to Claim 1, wherein the open-ended tube is formed from resiliently flexible material, ajnd the means biasing the side walls of the tube together is then the resilience of the material itself.

3. A pumping device accordin, to Claim 2, wherein the inlet aperture comprises a length of rigid tube which projects into the chamber, one end of the tube of resiliently flexible material being stretched over the rigid tube and the free end of the flexible tube remaining flattened and closed due to the resilience of the tube, which is normally flat in its unstressed condition.

4. A pumping device according tb any of Claims 1 to 3, wherein the means for creating a reduced pressure in the chamber comprises a movable piston slidable within the chamber, means being provided to effect sliding movement of the piston towards and away from the inlet aperture st as to vary the volume of the part of the chamber between the piston and the inlet aperture, and thereby vary the pressure within said part of the chamber.

5. A pumping device according to Claim 4, wherein the means for effecting sliding movement of the piston comprises a manipulating device connected to the piston and including an operating handle accessible externally of the chamber.

6. A pumping device according to Claim 4 or Claim 5, wherein the chamber includes an outlet vent on the opposite side of the piston to the inlet.

7. A pumping device according to any of Claims 4 to 6, wherein the chamber is in the form of a circular cross-section tube.

8. A pumping device according to any of Claims 4 to 7, wherein the piston includes a transfer passage incorporating a further one-way valve.

9. A pumping device according to Claim 8, wherein the further one-way valve comprises an open-ended transfer tube of flexible material which extends from the piston into the part of the chamber on the opposite side of the piston to the inlet aperture, means being provided for resiliently biasing the side walls of the tube together so that the end of the tube within said part of the chamber is normally closed until increased pressure within the part of the chamber containing the inlet aperture allows the fluid material in that part of the chamber to force the side walls of the tube apart so that material may flow through the transfer tube.

10. A pumping device according to Claim 9, wherein the open-ended transfer tube is formed from resiliently flexible material, so that the means biasing the side walls of the tube together is the resilience of the material itself.

11. A pumping device according to any of Claims 4 to 10, wherein means are provided for limiting the movement of, the piston towards the inlet aperture.

12. A pumping device according to Claim 11, wherein said limiting means comprises an abutment, fixed in relation to the chamber, which is engageable by a part of the piston, or a part of the manipulating device connected thereto.

13. A pumping device according to Claim 12, wherein the abutment comprises an annular valve seat located between the piston and the inlet aperture, the piston including a valve element to close and seal the valve seat when the piston is in contact therewith.

14. A pumping device according to any of the preceding claims, wherein the device includes external spacer means, adjacent the inlet aperture, to space the inlet aperture from an adjacent surface when thç device is in use, the spacer means being adapted to permit the flow of fluid material past the spacer means and into the inlet aperture.

15. A pumping device according to Claim 14, wherein the spacer means comprises a skirt at least partly surrounding the inlet aperture, the skirt being formed with a plurality of apertures or cut-outs to permit the flow of fluid material through the skirt to the inlet aperture when the skirt is in engagement with a surface.

16. A pumping device substantially as hereinbefore described with reference to any of Figures 1 to 4 of the accompanying drawings.