A PUMP

Abstract: A pump having a chamber provided with a collapsible partition. The partition is mounted for movement up and down the chamber to expel fluid from the pump. At the top of the chamber the partition collapses under its own weight and is designed to move downwards through the column of water in the pump which is to be expelled. At the bottom of the chamber the partition opens as air is admitted underneath it to trap water above it. The action of introducing the air lifts the partition to expel the water above it from the pump. At the top of the chamber, the air is released, the partition collapses and a pumping cycle is repeated.

Description: A Pump FIELD OF THE INVENTION The present invention relates to pumps. BACKGROUND OF THE INVENTION In UK Patent 2114231 there is disclosed an air pump having a chamber provided with a movable partition in sealing engagement with the chamber walls, the partition having a valve which allows the passage of liquid to be pumped entering the chamber at one end as the partition moves through the chamber towards to the other end. At a predetermined position of the partition in the chamber and prior to a lifting action the valve is closed thus trapping an amount of liquid at one * side of the partition. At this point pressurised air is introduced through a pipe to the other side of the partition to initiate a pumping action, to move the partition in the other direction and lift the trapped liquid out of the pump. SUMMARY OF THE INVENTION The present invention relates to an improvement to the above mentioned device and in particular to the movable partition with the intention of making the pump more efficient, According to the invention there is provided a pump comprising a pump chamber having inlet means for liquid to be pumped and outlet means for discharging pumped liquid, a partitioning element in the chamber having a collapsed position in which it moves from a raised position in the chamber at the end of a pumping cycle, means in the cylinder acting to cause the partitioning element to move from said collapsed position at its lowered position to partition the chamber interior and trap liquid thereabove, such that air admitted below said partition initiates a pumping action to lift the trapped liquid out of the outlet means. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by way of example with reference to the accompanying drawings wherein: Figures 1 and 2 are cross-sectional views through the pump disclosed in UK Patent 2114231 showing two res¬ pective operating positions; Figure 3 is a cross sectional view of a modified form of the pump of Figures 1 and 2. Figures 4(a),(b),(c) and (d) are schematic sectional views through the pump showing various operating positions of a modified form of movable partition for the pumps of Figures 1,2 and 3 according to an embodiment of the present invention and Figure 5(a) and (b) are top and side views respectively illustrating respectively the construction of the modified partition shown in Figure 3. BEST MODES OF CARRYING OUT THE INVENTION The pump shown in Figures 1 and 2 comprises a cylinder 1 having smooth internal sides and provided with legs 2 shown resting on a river or sea bed 3. The cylinder may also be mounted in other ways so long as water is able to enter it through a non-return valve 4 either in the bottom or sides of the cylinder 1. The cylinder 1, is provided with an internally mounted movable plate 5, which is made air and water tight around its outer edge, where it contacts the internal wall of the cylinder 1, by means of an air trapping membrane 5'. The plate 5 is provided with an opening which may be of any shape but is covered by a non-return valve 10, which opens downwardly so that when it is in the closed position, air may be trapped beneath it as will be explained. A flexible tube 6 connected to a pressurised air supply (not shown) is fed through the bottom of the cylinder 1, the end of the tube 6 being bent over to form an air trap 7, in the form of a non-return valve. The tube 6 is long enough to enable it to float upwards (by means of the trapped air) so that it is never below a distance from the water surface where the weight of the water above would put more pressure per square inch upon it than the pressure being introduced into the pipeline, Thus the air supply tube becomes self adjusting to the level of the water inside the cylinder. The depth and therefore weight of water above the movable plate 5 is controlled by a chain 8 attached to a float 9. The plate 5 sinks under its own weight through the column of water which is allowed to pass through it by means of the non-return valve 10. The valve 10 is pushed open as it passes down the water by pressure against the turned over angled edge 11. When the chain 8 between the float and the water surface and the valve 10 tightens, it closes the valve 10 which now renders the plate 5 air tight. A mercury activated switch 12 is mounted to the float 9 and is actuated when the connecting rope 8 between the float 9 and the non-return valve 10 is pulled taught. When activated the switch 12 allows pressurised air to bleed into the cylinder 1 beneath the plate 5. A wire 13 connects the switch 12 to a control box (not shown). As the pressure of the air below the plate builds up it starts to lift the plate with a column of water 14 now trapped above it as shown in Figure 2, which then over flows from the top of the cylinder 1, with the pump activating air 15 being trapped between the lift plate and the incoming water. During lift the valve 10 is naturally held closed by the pressure of the air 15 beneath, while the rope 8 becomes slack, allowing the switch 12 to switch off the air supply from the tube 6. The lifting plate 5 will continue to be forced upwards by the re-expansion of the air already trapped and by the water level inside the cylinder below the lifting plate 5 reaching the outside water level as the column of water 14 continues to rise and over flow. The pump as described above has general applicability but would be particularly suitable for operating in desert regions. In such situations, a more constantly natural available air supply would be preferable and a means for providing this is possible by the pump construction shown in Figure 3. This arrangement is operable entirely by solar power. It comprises a cooling chamber 18 installed beneath the gound level such that the floor of the chamber 18 is at the water table level as shown. The cooling chamber 18 has a shaft 19 extending above the ground such that air can enter the shaft through an opening 20. The floor of the chamber 18 is constructed of a suitable material which will absorb water or draw it up by capilliary action so that heat from the sun will cause evaporation and thereby a cooling effect to cool the air within the chamber 18. Thus in desert climates the chamber 18 would serve a dual purpose for storage. The interior of the chamber 18 is in communication through a non-return valve 21 with a bellow 22 situated at the base of a chamber 23 having insulated sides 24, the chamber 23 together with the bellows structure 22 being disposed below ground level. The chamber 23 has a domed glass roof 24 at or above ground level to encourage maximum heating from the sun. The bellows structure 22 is normally held in an expanded condition as shown by means of a counterweight (not shown), so that an upper wall 25 of the bellows structure 22 extends in an upward direction between the walls 26 of the chamber 23. The base of the chamber 23 is provided with a non¬ return valve 27 for admitting cooled air into the chamber 23 from the chamber 18. Located adjacent the chamber 23 is an air pump 28 of: the type as described with reference to Figures 1 and 2.. The. air pump 28 is installed in the ground as shown with the lower portion beneath the water table level so that water to be lifted by the pump can collect at the base of the pump cylinder, and has an upper portion above ground level. A pipe 29 communicate * 5 ~ the interior" o ~ t the bellows structure 22 with the bottom of the cylinder of the air pump 25 through non-return valve 33. The domed roof 24 of the chamber 23 is provided with a non-return valve 30. The valve 30 is controlled by a float arm 31 which closes the valve 30 when a water storage tank 32 for collecting pumped water from the chamber of the air pump 28, is empty. The operation of the solar powered air pump as described with reference to Figure 3 is as follows. The pump cycle will commence when all the chambers are filled with cooled air, that is chamber 18, chamber 23 and the bellows structure 22, and the partition 34 within the air pump 28 is resting at the bottom of the cylinder of the pump 28 beneath the water level therein. In this position the non-return valve 30 is closed so that trapped air in the chamber 23 is heated by the sun causing expansion of the air. This expansion operates the bellows structure 22 to compress the air inside, until the pressure build-up therein is greater than that below the water level under the partition in the cylinder of the pump 28. The pressurised air thus passes into the cylinder of the pump 28 beneath the lifting partition 34 therein through the pipe 29 and non-return valve 33. This causes the pump to operate and water is lifted to the top of the cylinder which in turn fills the overflow tank 32. As the tank 32 is filled the float arm 31 is lifted so opening non-return valve 30 and allowing the hot air therein to escape to atmosphere to be replaced by cooled air from the chamber 18 through valve 27. The process continues so long as the air in the chamber 23 can be heated. In this connection, for agricultural use at least, it would not matter if there was a break in supply due to lack of sunshine. The amount of water lifted by the solar powered air pump would of course be controlled by the pressure of air obtainable to lift a certain column of water. For example air heated by 40° centigrade from a particular starting temperature expands to 2 p.s.i. This should easily be attainable in most middle east countries and would mean that a 4 foot column of water could be lifted each pump cycle. The lifting partition in the pump depicted in Figure 3 is similar to the partition 5 in the Figure 1 and 2 embodiment, less the non-return valve 10 and being wholly self-actuating. To improve the efficiency of the pump of Figure 3, the improved partition construction shown in Figures 4 and 5 may be employed. In this modification the internal walls of the pump cylinder 28 are provided with grooves 35 lying at each end of. a diameter of the cylinder 28. Guide arms 36 at the respective ends of a support bar 37 engage the grooves 28 and the arms 36 may be fitted with wheels (not shown) to assist movement up and down the walls of the cylinder 1. The pump partition is formed by a pair of plates 38 and 39 hinge mounted to the bar 37, one of the plates 38 having an additional extension 40 which, when the partition is in the fully open and horizontal position, overlaps the other plate 39, thereby to cover the hinged area between the plates 38 and 39 to effect a seal. When the trapped air is released from under the plates 38 and 39 as they reach the top of their lift and the partition passes the outlet to the storage tank 32 see Figure 4(a), the two halves 38 and 39 collapse as shown in Figure 4(b). The weight then causes the plates 38 and 39 to fall, edges downwards, through the water column in the cylinder 28 with much reduced water resistance in contrast to the flat plate 34 of Figure 3, and 5 of Figures 1 and 2. When the leading edges 41 of the plates 38 and 39 reach the bottom of the cylinder 28 see Figure 4(c), they are opened up by means of a pointed projection 42 formed on the bottom wall of the cylinder 28, and due to the weight and momentum of the falling plate 38 and 39 they are caused to open fully ready for the next cycle see Figure 4(d) . The plates 38 and 39 are shown as having angled leading edges 43 and trailing depressions 44 see Figure 5(a) and (b). The angled edges 43 will act to keep the plates closed as they move downwardly through the water column, and the depressions 43 to trap the first injection of air as at 45 in Figure 4(d) when the plates 38 and 39 are in their lower most open position, to ensure that they come into positive sealing engagement with the sides of the cylinder to trap the continuing flow of air and thus lift the plates 38 and 39 and the water column to effect removal of water from the cylinder. A further advantage gained by using the hinged plates 38 and 39 as above discussed, is that they may be made over-sized in relation to the diameter of the pump cylinder 1. Thus when provided with edges for example a flexible rubberised membrane (not shown), to always expand under pressure from below to ensure an air tight seal, but will not slow down the action of the plate as it moves through the water column to initiate a pumping action. Although described with reference to the pump arrange¬ ment of Figure 3, nevertheless the modified partition is equally useful in the Figure 1 and 2 pump embodiments wherein the rope 8 would then be coupled to the bar support 37.

Claims: CLAIMS 1. A pump comprising a pump chamber having inlet means for liquid to be pumped and outlet means for discharging pumped liquid, a partitioning element in the chamber having a collapsed position in which it moves from a raised position in the chamber at the end of a pumping cycle through fluid to be pumped in the chamber ingressing said inlet means to a lowered position at the start of a pumping cycle, means in the cylinder acting to cause the partitioning element to move from said collapsed position at its lowered position to partition the chamber interior and trap liquid thereabove, such that air admitted below said partition initiates a pumpirfg action to lift the trapped liquid out of the outlet means. 2. A pump as claimed in claim 1 wherein said partition is composed of a pair of plates pivotally mounted to a support bar movable up and down the internal walls of the chamber. 3. A pump as claimed in claim 2 wherein one of the plates has an extension which rests on the other plate in the position where the plates partition the chamber. 4. A pump as claimed in claim 3 wherein the plates are at least part hemispherical or domed in section to provide angled leading edges which assist movement of the plates in the collapsed position to said lowered position therein. 5. A pump as claimed in claim 4 wherein said at least part hemispherical or domed plates provide trapping means for collecting air below said plates in said lowered position whereby to constrain said plates to move to partition the chamber for a subsequent pumping cycle. 6. A pump as claimed in claim 5 wherein the bottom wall has a centrally located projection which acts to separate the plates upon reaching said lower most position and allow air to collect therebeneath in said trapping means. 7. A pump as claimed in any preceding claim wherein air is admitted to said chamber by air bellows operated by solar means. 8. A pump as claimed in claim 7 wherein said pump chamber and air bellows are located underground, a first underground chamber in communication with ambient surroundings, a second chamber exposed to the sun and housing said bellows whereby the bellows are operated by expansion of the air in the second chamber by solar means to feed air to the pump from said first chamber.

Inventors: KNOWLES ALBERT HENRY, KNOWLES, ALBERT, HENRY
Applicants: SAVE THE CHILDREN
Application year: 1986
Main classification: F03B17
IPC codes: F03B17, F03G6, F04B9