AU2010220823A1 - Reciprocating pump - Google Patents

Abstract

Disclosed herein is a fluid driven reciprocating pump. The pump comprises a reciprocating piston in a cylinder, the piston dividing the cylinder into first and second cylinder chambers. The pump also comprises first and second fluid flow pathways from a fluid inlet to the first and second cylinder chambers, respectively, and a shuttle valve switchable between first and second positions by a magnetic force. In use, fluid caused to flow into the fluid inlet flows through the first fluid flow pathway when the shuttle valve is in the first position, and through the second fluid flow pathway when the shuttle valve is in the second position. Alternating a flow of fluid through the first and second fluid flow pathways causes the piston to reciprocate in the cylinder and drive the pump. Also disclosed herein is a water powered pumping system comprising a water powered pump and an inlet that is in fluid communication with a liquid to be pumped. In use, a flow of pressurized water through the pump causes the liquid to be drawn from the inlet and pumped.

Description

WO 2010/099579 PCT/AU2010/000254 1 RECIPROCATING PUMP Technical Field The present invention relates to fluid driven reciprocating pumps and to water powered pumping systems. In one particular form, the invention relates to water operated leveraged pumps for use in households. Background Art Reciprocating pumps are typically operated using pressurized air. For example, an air operated diaphragm pump is driven by alternately supplying pressurized air to either side of a double acting diaphragm or piston, or to either of a pair of single acting diaphragms or pistons. Such an alternating supply requires the use of double acting 2 way valves to continuously "switch" the supply from one side of the piston(s) to the other, and back again, whilst simultaneously opening a connection from the opposite side of the piston(s) to the exhaust, thus affecting the continuous linear reciprocating action of these parts. In one position, one side of the piston(s) is connected to the exhaust port and the other side to the supply port, and in a second position, the connections are switched, thereby causing the piston(s) to reverse direction, and so on, so that a continuous reciprocating action is affected. Traditionally, shuttle type valves are used in such pumps. However, all double acting 2 way valves, including shuttle type double acting 2 way valves, have a "dead spot" in the middle of their action, wherein the valve is closed, and neither side of the valve is connected to either the exhaust or supply. In reciprocating pumps, a shuttle valve is typically actuated in a linear motion by means of a pushrod, by the motion of the piston. However, if a single shuttle valve was used to control the supply to the piston(s), whilst being actuated by the same piston(s), the supply would be stopped when the valve reached its "dead spot"; the linear motion of the piston would cease, the shuttle valve would stop in its dead spot, and the pump would stall. To avoid this situation, a secondary shuttle valve is traditionally employed, so that the first shuttle valve is actuated by the linear motion of the piston(s), and reverses supply to the secondary shuttle valve, which in turn reverses the supply the piston(s), causing the linear motion of the pump to be reversed, and so on, so that a continuous operation of the pump is achieved.

WO 2010/099579 PCT/AU2010/000254 2 It can be seen from the above description that the valving of reciprocating pumps is a complicated process, requiring 2 shuttle valves, and the necessary pushrods, dynamic seals, static seals, housings and connections. Many of these elements are prone to wear, particularly the dynamic seals which, when worn, begin to leak. Furthermore, the operation of 2 shuttle valves requires the use of more energy due to friction losses. Furthermore the operation of the primary shuttle valve via a pushrod, requires a further dynamic seal in the form of a rod seal, which causes further problems of friction and wear. The present invention seeks to provide a simpler alternating valving system, requiring fewer parts and seals. Due to expanding urban populations, and in some areas a decrease in water supplies, possibly as a result of climate change, there is currently much concern about efficient water use in the home. Recently, efforts have been made to recycle water from showers, baths, and kitchen sinks (known as grey water) and also to store rainwater in tanks for use in non-drinking applications. Whilst new dwellings can have such systems installed in their original design, the retro-fitting of existing dwellings is a considerable problem. Freestanding houses with easy access to under floor plumbing can be relatively easily converted for grey water recycling or rainwater use, however many houses, and almost all flats are impossible to retro fit using existing rain and grey water plumbing techniques. Furthermore, in houses with grey or rainwater tanks fitted, electric pumps are often used to pump the water to where it is required, which necessitates the installation of wiring, and introduces the cost and inherent reliability problems of electric water pumps, and the use of electrical energy. Disclosure of Invention In a first aspect, the present invention provides a fluid driven reciprocating pump. The pump comprises a reciprocating piston in a cylinder, the piston dividing the cylinder into first and second cylinder chambers. The pump also comprises first and second fluid flow pathways from a fluid inlet to the first and second cylinder chambers, respectively, and a shuttle valve switchable between first and second positions by a magnetic force. In use, fluid caused to flow into the fluid inlet flows through the first fluid flow pathway when the shuttle valve is in WO 2010/099579 PCT/AU2010/000254 3 the first position, and through the second fluid flow pathway when the shuttle valve is in the second position. Alternating a flow of fluid through the first and second fluid flow pathways causes the piston to reciprocate in the cylinder and drive the pump. As will be appreciated, the present invention employs the use of magnetic force to overcome the problem of the "dead spot" in shuttle valves described above, and to eliminate the necessity to use pushrods. This can provide a number of advantages, as will be described below. As used herein, the term "piston" is to be understood to encompass other components which perform a similar function, such as diaphragms. In some embodiments, the shuttle valve comprises one or more magnets. The shuttle valve may, for example, be elongate and comprise two magnets located near to opposite ends of the shuttle valve. In some embodiments, the reciprocating piston may also comprise one or more magnets. In some embodiments, the magnet(s) may be integrally formed with or positioned adjacent to the piston. In other embodiments, the magnet(s) may be integrally formed with or positioned adjacent to the rod attached to the piston. Alternatively, the piston magnet(s) may be otherwise associated with the piston, for example, attached to the piston by a rod or other form of linkage. Furthermore magnet(s) may be positioned within the piston in such a manner as to induce magnetic force equally in two or more directions, thus reducing sideways load, and associated uneven wear on the piston. In some embodiments, movement of the reciprocating piston in the cylinder causes the shuttle valve to switch positions (e.g. because of the interactions between magnet(s) in the piston and/or shuttle valve). As will be appreciated, by placing one or more magnet or magnetic objects in the driving piston(s) of the pump, and a second magnet or pair of magnets or magnetic objects in the shuttle valve, and placing the shuttle valve close enough to the piston or diaphragm to allow the magnets to exert magnetic force on each other, the operation of the shuttle valve can be WO 2010/099579 PCT/AU2010/000254 4 effected without the use of a pushrod. Furthermore, because magnetic attraction between two objects increases with their proximity to each other, it has been found that a magnetically actuated shuttle valve will complete its "switching" action without stopping in its "dead spot", thereby negating the need for a secondary shuttle valve. In some embodiments, the shuttle valve comprises conduits through which a fluid caused to flow through the first and second fluid flow pathways can flow. The conduits are brought into fluid communication with the respective fluid flow pathway by movement of the shuttle valve. Typically, the fluid that drives the pump is water (e.g. mains pressure water), but other fluids such as compressed air could readily be used. In some embodiments, it is envisaged that a combination of fluids could even be used to drive the pump. Typically, the reciprocating piston would be coupled to a second reciprocating piston in a second cylinder. In such embodiments, driving the reciprocating piston in the first cylinder causes the piston (or diaphragm) in the second cylinder to pump a liquid (e.g. rainwater or grey water from a receptacle, or underground water). In some embodiments, the second reciprocating piston in the second cylinder pumps a greater volume of the liquid than the volume of the fluid used to drive the reciprocating piston. That is, the pump is a leveraged pump. In a second aspect, the present invention provides a water powered pumping system comprising a water powered pump and an inlet that is in fluid communication with a liquid to be pumped. In use, a flow of pressurized water through the pump causes the liquid to be drawn from the inlet and pumped. Not only can the system of the present invention be used to pump a liquid such as rainwater or grey water for numerous applications, the system is powered only by a flow of pressurized water. As one skilled in the art will appreciate, using pressurized water instead of other means (e.g. electricity or compressed air) for pumping rainwater etc. can provide numerous advantages. For example, electric pumps generally utilize an electric motor, gearbox and WO 2010/099579 PCT/AU2010/000254 5 crank or cam arrangement in order to pump a fluid. Such pumps may be unreliable and require periodic maintenance, and are not ideal for use in water applications because of the necessity of electrical wiring, low voltage transformers etc. Compressed air pumps are generally more reliable and longer lasting than electric pumps because they have fewer parts, and do not necessarily require an electrical supply to be in close proximity to the water. However, such pumps are not particularly suitable for domestic use because they require large amounts of compressed air to operate. In some embodiments, the water powered pump may be a water powered leveraged reciprocating pump, which comprises a first reciprocating piston in a first cylinder and a second reciprocating piston in a second cylinder. The first reciprocating piston is drivable by a flow of pressurized water into the first cylinder, and the second reciprocating piston and cylinder are operable to pump a greater volume of the liquid than the volume of the pressurized water used to drive the first reciprocating piston (in a leveraged pump, the first piston and cylinder are usually smaller than the second piston and cylinder). The first and second pistons are coupled such that driving of the first piston causes operation of the second piston. Advantageously, a water powered leveraged pump can utilize the stored energy of small amounts of pressurized water (e.g. mains-water) to pump large volumes of a liquid (e.g. rain water). In such embodiments, the first cylinder may define two chambers separated by the first reciprocating piston, the chambers being adapted to alternately receive and expel the flow of pressurized water and thus drive the first reciprocating piston. The second cylinder may define two chambers separated by the second reciprocating piston, the chambers being adapted to alternately draw the liquid from the inlet and pump the liquid. In some embodiments, the second reciprocating piston may be a diaphragm. Pumps having diaphragms are widely used to pump water that my contain foreign objects such as hair, grit etc due to their low number of wearing parts such as pistons, piston rings, impellers etc, as well as their absence of rotating parts, e.g. impellers, which might become entangled with hair etc.

WO 2010/099579 PCT/AU2010/000254 6 Typically, the pressurized water is mains pressure water. Mains pressure water is in plentiful supply in households, and has a pressure sufficient for most domestic pumping applications. As noted above, the liquid may, for example, be rainwater, grey water or underground water. The liquid may, for example, be pumped to a toilet cistern, a washing machine, a garden, an air conditioner and/or a household tap. In some embodiments, the pressurized water used to power the pump is also pumped with the liquid, so that no water is wasted in the system. In some embodiments, the water powered pump of the second aspect comprises the fluid driven reciprocating pump of the first aspect. Brief Description of the Drawings Preferred embodiments of the present invention will now be described, by way of example only, with respect to the accompanying Figures, in which: Figure 1 is a diagram of a fluid driven reciprocating pump with a magnetically operated shuttle valve in accordance with an embodiment of the pump of the invention; Figure 2 is a diagram of the pump of Figure 1, in a different part of its cycle; Figure 3 is a diagram of a leveraged water-powered pump for use in embodiments of the system of the present invention; Figures 4 and 4A are diagrams showing exploded views of parts of the leveraged water powered pump of Figure 3. Figures 5 and 5A are diagrams of an embodiment of a water powered pumping system fitted in a toilet cistern; WO 2010/099579 PCT/AU2010/000254 7 Figure 6 is a diagram of a water recovery device suitable for installation in a shower drain; and Figure 7 is a cross section of the device shown in Figure 6, installed in a typical shower drain. Best Mode for Carrying Out the Invention In its broadest aspects, the invention disclosed herein relates to a fluid driven reciprocating pump, and to a water powered pumping system, optionally using the fluid driven reciprocating pump. The fluid driven reciprocating pump comprises a reciprocating piston in a cylinder, the piston dividing the cylinder into first and second cylinder chambers, first and second fluid flow pathways from a fluid inlet to the first and second cylinder chambers, respectively, and a shuttle valve switchable between first and second positions by a magnetic force. In use, fluid (e.g. mains pressure water or air) caused to flow into the fluid inlet flows through the first fluid flow pathway when the shuttle valve is in the first position, and through the second fluid flow pathway when the shuttle valve is in the second position. Alternating a flow of fluid through the first and second fluid flow pathways causes the piston to reciprocate in the cylinder and drive the pump. The water powered pumping system comprises a water powered pump (e.g. the fluid driven reciprocating pump described above) and an inlet that is in fluid communication with a liquid to be pumped (e.g. rainwater, grey water or underground water). In use, a flow of pressurized water (e.g. mains pressure water) through the pump causes the liquid to be drawn from the inlet and pumped. Also disclosed herein is a shuttle valve adapted to be located in a shuttle valve chamber. The shuttle valve comprises at least one magnet, and can be moved from a first position to a second position in the shuttle valve chamber using a magnetic force. Embodiments of the fluid driven reciprocating pump and water powered pumping system of the present invention will be described in further detail below.

WO 2010/099579 PCT/AU2010/000254 8 In one form, the fluid driven reciprocating pump comprises a reciprocating piston comprising a piston magnet, the piston being located in a cylinder which comprises first and second chambers separated by the piston. The apparatus also comprises a fluid inlet for directing a fluid into a shuttle valve chamber; and an elongate shuttle valve comprising shuttle magnets located near to opposite ends of the shuttle valve. The shuttle valve is located in the shuttle valve chamber and is moveable between first and second positions by a magnetic force between the piston magnet and the first or second shuttle magnet. The first and second positions define respective first and second fluid flow pathways through the apparatus. In use, fluid flowing through the first or second fluid flow pathway drives the piston in one direction until the proximity of the piston magnet to one of the shuttle magnets causes the shuttle valve to change positions and the fluid to flow through the other fluid flow pathway such that the piston is driven in the opposite direction. Referring now to Figure 1, shown is a pump housing (1), divided into 2 chambers (2 and 3) by a diaphragm (4). The diaphragm is connected to a reciprocating piston (5) which is located in a cylinder (6) by a pushrod (7). A piston magnet (8) is mounted within the piston (5). A shuttle (9), in which is mounted two shuttle magnets (10 and 11), is positioned within a shuttle chamber (12). The shuttle chamber (12) is positioned immediately adjacent to the cylinder (6), so that the shuttle magnets (10 and 11) and the piston magnet (8) can exert significant magnetic force on each other. The cylinder and the shuttle chamber are connected with each other by 2 ports (13 and 14). Within the shuttle (9) is an exhaust channel (15) which connects in a slideable manner with the exhaust port (16). Figure 1 shows that when pressurized water is passed through an inlet (17) into the shuttle chamber (12), it is directed, according to the position of the shuttle, through one of the 2 ports (e.g., 13) into the cylinder, exerting pressure on the piston. As this is occurring, the opposite port (e.g., 14) allows the water on the other side of the piston to flow through the exhaust channel (15) within the shuttle and out of the exhaust port (16), causing the piston to move. It can be seen in Figure 2 that when the piston (5) approaches the opposite end of the cylinder (6), the piston magnet (8) and the shuttle magnet (11) become increasingly closer to each other, thereby exerting an increasing magnetic force on each other. When the magnetic force WO 2010/099579 PCT/AU2010/000254 9 reaches a sufficient strength, the shuttle (9) slides to its second position, which reverses the flow of water through the cylinder ports (13, 14), causing the piston (5) to reverse its movement, and so on, so that the continuous reciprocating action of the piston is continued. The continuous reciprocating action of the piston (5) using pressurized water causes the diaphragm (4) to also reciprocate in the pump housing (1), which in turn pumps a fluid through pump housing (1). Typically, the diaphragm (4) would be used to pump fluids, rather than other, similar, components (e.g. a piston). Diaphragm pumps are widely used to pump water that my contain foreign objects such as hair, grit etc due to their low number of wearing parts such as pistons, piston rings, impellers etc, as well as their absence of rotating parts, e.g. impellers, which might become entangled with hair etc. However, diaphragms become increasingly inefficient as the output pressure of the pump increases, therefore a piston may be more suitable when water is required to be pumped to pressures above 20 kpa. The pump may be powered by pressurized water, e.g., water supplied from a pressurized water supply typically available in dwellings in developed countries (mains water). In some embodiments, the pump is a "leveraged" pump, i.e., it uses a small volume of water at a high pressure, to pump a larger volume of water at a low pressure. More specifically, it can use a small volume of mains water to move a large volume of rainwater or recycled water at a low pressure. This is achieved by the coupling of a small diameter, master cylinder, powered by mains water, to a larger diameter diaphragm, used to pump the rainwater or recycled water, as described above. For example, in a specific embodiment, the pump is a mains water powered leveraged pump having a reciprocating diaphragm with a surface area of 22.7 cmA2 in a diaphragm housing. Said diaphragm is driven by way of a connecting rod to a master cylinder with a reciprocating piston with a surface area of 2.27 cmA2. Said master cylinder is placed in a cylinder block adjacent to the diaphragm housing. In another embodiment (not shown) magnet(s) may be positioned within the piston in such a manner as to induce magnetic force equally in two or more directions, thus reducing sideways load, and associated uneven wear on the piston. In such an embodiment, if magnet(s) are connected to the shuttle valve, they could be placed on two or more sides of the cylinder. In this way, driving the piston within the cylinder will cause movement of the shuttle valve with negligible sideways load on the piston.

WO 2010/099579 PCT/AU2010/000254 10 Mains water is typically supplied to domestic buildings at pressures between 300- 800 kpa. Therefore, the master cylinder, when supplied with mains water at, say, 300 kpa, will (not allowing for losses) exert a force of 30 N per square centimeter area of the piston. Therefore it can be seen that, not accounting for losses, 1 liter of mains water has sufficient potential energy to lift 30 liters of grey water 1m i.e., a ratio of 1:30. In a real world situation, losses must be accounted for due mainly to the friction of water in the necessary pipes and hoses, and it has been found that a pump with a ratio of 1:10 (i.e., that lifts 10 liters of grey water per liter of mains water) is more suitable to the task at hand. However, depending on variations in mains water supply pressure, and the desired end use of the pumped water, a higher or lower ratio may be more appropriate. Therefore it can be seen that savings of 90% or more of mains water are possible. In some embodiments, the fluid driven reciprocating pump of the first aspect of the invention (e.g., in the form of the specific embodiment depicted in Figures 1 and 2) is used in the water powered pumping system of the second aspect of the present invention. However, in alternate embodiments of the second aspect, other types of water powered pumps may be used. For example, in a specific embodiment of a leverage pump for use in the system of the present invention, the leverage pump may have a double acting diaphragm with a surface area of 22.7 cmA2 in a diaphragm housing. Said diaphragm is driven by way of a connecting rod to a master cylinder with a double acting piston with a surface area of 2.27 cmA2. Said master cylinder is placed in a cylinder block adjacent to the diaphragm housing. Said cylinder block also contains a two way shuttle valve, which is actuated by mains water pressure from each end, and which connects, by way of tubing or hosing either integral with, or external to the cylinder block, to both ends of the master cylinder. The cylinder block may also include a pilot valve, positioned at one end of the master cylinder, and actuated by the opposite end of the connecting rod to the diaphragm and connected by way of tubing or hosing either integral with or external to the cylinder block. A specific embodiment of a leveraged water-powered pump for use in the system of the second aspect is shown in Figure 3. As discussed above, a leveraged pump is a pump that can use small amounts of water at high pressure to pump larger amounts of water at lower pressure. Figure 3 is a drawing illustrating how such a pump would work. The pump shown WO 2010/099579 PCT/AU2010/000254 :11 in Figure 3 consists of a cylinder block (101) adjacent to a pump housing (102). The cylinder block (101) contains a master cylinder (103) and double acting master piston (104), which is driven by water from a shuttle type distributor, consisting of the distributor cylinder (105) and a distributor shuttle (106). This distributor assembly is actuated by a shuttle type pilot valve, consisting of the pilot housing (107) and a pilot shuttle (108). This pilot valve is actuated by the master piston (104) by way of a pushrod (109), one end of which slides inside the pilot shuttle (108). The other end of the pushrod (109) actuates the diaphragm assembly (110) inside the pump housing (102). The diaphragm assembly divides the internal space of the pump housing into two chambers (112 and 112A), which are fitted with check type inlet valves (113 and 1 13A) and an outlet valves (114 and 1 14A). High pressure water enters the cylinder block by way of an inlet (111), and is directed through either of apertures (190) or (191), depending on the orientation of the distributor shuttle (106) within the distributor cylinder (107), to either end of the master cylinder (103), causing the master piston (104) to move within the master cylinder (103), which in turn causes the diaphragm assembly (110) to move within the pump housing (102). This movement of the diaphragm assembly (110) causes low pressure water to be drawn into either chamber 112 or 112A, through its inlet valve 113 or 114, and simultaneously ejected from the other chamber through its outlet valve 113A or 1 14A. When the master piston (104) reaches the end of its stroke within the master cylinder (103), the pushrod (109) moves the pilot shuttle (108) to the opposite end of the pilot housing (107), which directs high pressure water entering the pilot cylinder through aperture (115) to one end of the distributor cylinder (105) through aperture (192) or (193), and simultaneously directs water from the opposite end of the distributor cylinder (105), through aperture (192) or (193) to the pilot outlet (116). This action causes the distributor shuttle (106) to move to the other end of the distributor cylinder (105), which causes the high pressure water entering through the inlet (111) to be redirected through aperture (190) or (191)'to the other end of the master cylinder (103), and the water from the opposite end of the master cylinder to be directed through aperture (190) or (191) to the distributor outlet (117). Thus the process is repeated in the opposite direction and so on.

WO 2010/099579 PCT/AU2010/000254 12 It can be seen that the total volume of high pressure water used per stroke is the total of the displacement of one side of the master cylinder, and the displacement of one side of the distributor cylinder, whereas the volume of low pressure water pumped per stroke is the displacement of the movement of the diaphragm within a chamber of the pump housing. The ratio of these two volumes is the ratio between the volume of water used and the volume of water pumped. Figures 4 and 4A show two perspective views of the same plan for a specific embodiment of a water powered pump. They show a cylinder block comprising 3 main parts: the main block (120) the seal plate (121) and the plumbing block (123). The main block contains a master cylinder (125) a distributor cylinder (126) a distributor shuttle housing (127) a pilot housing (128) mains water inlet (131). Mounting holes (129) show where the diaphragm pump housing is mounted. The seal plate (121) presses firmly against the main block (120) and provides a surface upon which the distributor shuttle (not shown) and the pilot shuttle (not shown) slide. The plumbing block (123) which includes an array of grooving (130) seals against the seal plate by way of the grooving gasket (124). The recycled water to be pumped using the system of the invention may be sourced from a receptacle located in a drain of a shower, a sink or a bath, or a receptacle adapted to receive rainwater from a rain catching surface (e.g., a rainwater tank). Grey water that is about to run down the drain of a shower or bathtub is at ambient pressure, but if it is to be recycled for use in, for example, a toilet cistern, it must be lifted approximately 1m into the cistern. Assuming the pump is placed in the cistern, this requires a partial vacuum of 10 kpa to be created by the diaphragm (not allowing for losses), requiring a force of 1 N per square centimeter area of the diaphragm. The grey water intake may, for example, be a receptacle locatable in a drain of a shower, a sink or a bath, or a receptacle adapted to receive rainwater from a rain catching surface. The grey water intake may comprise a float which, upon receipt of grey water into the receptacle, floats and actuates a valve which causes pressurised water to flow through the pump. Once actuated, grey water can be pumped from the receptacle to a grey water storage vessel (e.g., a toilet cistern).

WO 2010/099579 PCT/AU2010/000254 13 The water powered pumping system of the invention may, for example, be used to pump grey water or rainwater from a source to a storage vessel, such as a toilet cistern, washing machine, etc. If the storage vessel is a toilet cistern, then the cistern could be adapted to store a quantity of grey water. In such embodiments, the cistern may comprise a high level float valve operable to stop the flow of grey water into the cistern when the level of water in the cistern reaches a high level. In some embodiments, the high level float valve may stop the flow of grey water into the cistern by stopping the flow of pressurised water through the pump. The cistern may also comprise a low level float valve operable to cause mains water to flow into the cistern if the level of water in the cistern drops below a low level. Such a cistern may be designed to store sufficient water for a plurality of flushes before the level of water in the cistern drops below the low level. In such a case, the cistern further comprises a flush mechanism adapted to dispense a portion of the stored water each time a user flushes the toilet. Such a flush mechanism may comprise a substantially vertical flushing rod having an end which defines a cover for a flushing aperture and being operable between flushing aperture open and flushing aperture closed positions; a float that can float on the surface of water in the cistern and which is slideably engageable to the flushing rod; and an actuating mechanism, operable to lift the flushing rod a set distance and then engage the float. In use, following actuation by a user, the float holds the flushing rod in a raised position, and the flushing aperture in an open position such that water flows through the flushing aperture until the flushing rod returns to the flushing aperture closed position once the level of water in the cistern has dropped by the set distance and the portion of stored water has been dispensed. However, it is necessary that the float does not engage the flushing rod when the flushing aperture is closed, so that the float can float on the surface of water in the cistern while grey water is pumped into the cistern without causing the flushing aperture to open. Typically, the actuating mechanism is operable to selectively lift the flushing rod by a first set distance or a second set distance, whereby different portions of stored water are dispensable (i.e. a "half flush" or "full flush" of the type commonly found in existing cisterns).

WO 2010/099579 PCT/AU2010/000254 14 The grey water may, in some embodiments, be pumped from a receptacle located in a drain of a shower, a sink or a bath, or a receptacle adapted to receive rainwater from a rain catching surface. Alternatively, the system may be used to pump rainwater (e.g., from a rainwater tank) or ground water. Figure 5 shows an embodiment of a water powered pumping system in the form of a grey water recycling system suitable for installation in a typical domestic bathroom. The cistern (140) is larger than typical cisterns i.e., 20-30 liters capacity. It includes in its construction, a translucent vertical strip (141) which allows the user to visually inspect the water level in the cistern. Also shown is a shower water recovery assembly (146), which is connected to the cistern by 3 flexible hoses: a grey water hose (147), preferably with an internal diameter of 19mm, a mains water pressure supply hose (148), preferably of an internal diameter of 4.5 mm, and a mains water pressure return hose (149) preferably of an internal diameter of 4.5mm. In this embodiment, the two mains water pressure hoses are mounted on the exterior of the grey water hose, however, they could also be mounted inside the grey water hose, thus providing a neater appearance (not shown). Figure 5A is a cut-away view of the cistern (140) showing the internal features. Mounted inside the cistern is a pump (142) which may be the leveraged water powered pump described above and depicted in Figure 3, or which may be a water driven reciprocating pump in accordance with the first aspect of the invention (e.g., as depicted in Figures 1 and 2). Also mounted within the cistern (140) is a high level float valve (143) adjusted so that it closes when the water level reaches a certain maximum level, and a low level float valve (144) adjusted so that it is opened when the water level falls below a certain minimum level. Also within the cistern is a variable level flush mechanism (145), actuated by one or more buttons (150) protruding through the cistern lid (151). Filtration and other water treatment devices (not shown) may also be housed within the cistern, if necessary. In some embodiments, the system of the invention may also comprise a grey water collecting receptacle. The grey water collecting receptacle may include a chamber with an inlet for receiving gray water, a grey water outlet, and an actuator for actuating a grey water pump. In use, a flow of grey water into the chamber actuates the actuator and causes the grey water WO 2010/099579 PCT/AU2010/000254 15 pump to pump grey water from the grey water outlet. The grey water collecting receptacle may, for example, be adapted for insertion into a drain of a shower, a sink or a bath or adapted to receive rainwater from a rain catching surface. The actuator may comprise a float inside the chamber. Typically, the float is operable to open a valve to cause pressurised water to flow through a water powered pump and pump grey water from the grey water outlet. Typically the grey water collecting receptacle further comprises an overflow for enabling excess grey water to flow through the receptacle. Figure 6 is a perspective view of a water recovery receptacle in the form of a shower water recovery device. It consists of a cup (160) having a plurality of raised holes (161) around its rim, a snorkel (162) connected to the grey water hose (not shown), a float (163), and valve (164) connected to the 2 mains water pressure hoses (not shown). Figure 7 is a cross sectional view of a shower water recovery device installed in a typical shower drain. The arrows (170) indicate the path of grey water running from the shower pan into the cup (160), wherein, once a certain water level is reached, the float (173) is caused to move upwards thereby actuating the valve (164) by bearing on the valve button (165). It also may be seen that the snorkel (162) is positioned within the cup in such a position that, when suction is applied through the grey water hose, water is drawn from the bottom of the cup, as indicated by the arrows (171). Arrows (172) indicate how, if water reaches a certain level in the shower pan, it will flow through the raised holes (161) and then into the shower drain itself. In practice, when a person uses the shower, the grey water flows across the shower pan and into the shower water recovery device, filling the cup (160) and raising the float (161), causing the valve (164) to allow water pressure from the mains water pressure supply hose (148) into the mains water pressure return hose (149). This pressure in the mains water pressure return hose then activates the pump (142), as shown in Figure 5A, which draws grey water from the cup (160) via the grey water hose (147) and the snorkel (162), and expels it into the cistern. As the person continues to use the shower, grey water continues to flow into the cup, ensuring that the valve continues to stay open and the pump continues to draw water into the cistern. In the event that the volume of grey water flowing from the shower exceeds WO 2010/099579 PCT/AU2010/000254 16 the maximum pumping capacity of the pump, or in the event that the pump is not running, the grey water level rises to the level of the drain holes (161) and thus bypasses the cup, and drains directly into the shower drain. When the water in the cistern (140) reaches a desired level, the high level float valve (143) stops the supply of mains pressure water to the mains pressure supply hose (148) thus preventing the pump from pumping further grey water into the cistern. During this process, the mains water used to drive pump (142) also flows into the cistern (140) as it is expelled from the pump. Thus, no water is wasted during operation of the system. In one embodiment, when a person wishes to flush the toilet, a variable level flush mechanism is actuated by pressing buttons (150) which, when pressed, lift a substantially vertical flushing rod (181), which has an end which defines a cover for a flushing aperture (182), and which is slideably engageable to a float (180). Following actuation by a user, the float holds the flushing rod in a raised position, and the flushing aperture in an open position such that water flows through the flushing aperture until the flushing rod returns to the flushing aperture closed position once the level of water in the cistern has dropped by the set distance and the portion of stored water has been dispensed. Typically, the actuating mechanism is operable to selectively lift the flushing rod by a first set distance or a second set distance, whereby different portions of stored water are dispensable (i.e. a "half flush" or "full flush" of the type commonly found in existing cisterns). Assuming that the water level in the cistern is at maximum, when the water level in the cistern falls, the high level float valve (143) will open, thus supplying mains water pressure to the mains pressure supply hose (148), which ensures that when the shower is used, grey water from the shower will be pumped into the cistern as described above. However, if the user continues to flush the toilet without using the shower, the water level in the cistern will fall to such a level that the low level float valve (144) will open, thus causing mains water to flow directly into the cistern and ensuring that it contains adequate water for further flushing. In the event that the shower continues not to be used, or if grey water ceases to be pumped into the cistern for any reason, the low level float valve will continue to maintain adequate water for flushing, and the cistern will operate in the same way as a conventional cistern.

WO 2010/099579 PCT/AU2010/000254 17 As will be appreciated, the water powered pumping system has other applications in addition to those described in detail above. For example, the water may be pumped to a washing machine, an air conditioner or a household tap. The water may also be pumped to a garden in order to water the garden. The pump may also be used to pump treated sewerage onto a garden. Advantageously, in some embodiments, the pressurized water used to power the pump is also pumped with the fluid, thus forming an effectively "closed" system, in which no water is wasted. As a person skilled in the art will appreciate, the present invention has been described above with respect to specific embodiments. However, the invention is not limited to such embodiments. For example, in alternate embodiments falling within the broad scope of the invention, an alternative to a linear shuttle valve may be used, e.g., a double acting 2-way valve in the form of a rotating element within a enclosure, so that when the rotating element is rotated the flow of water through the cylinder ports is reversed as described above. In such an embodiment, magnet(s) may be encapsulated within or otherwise attached to the rotating element so that a magnetic force may cause the rotating element to rotate in said enclosure thereby causing the flow of water through the cylinder ports to be reversed as described above. In other embodiments, the pump of the invention may be used as a dosing or metering device, or a proportional pumping device, wherein one fluid is used to pump a second fluid, so that the two fluids are supplied in a predetermined ratio.

Claims (20)

1. A fluid driven reciprocating pump comprising: a reciprocating piston in a cylinder, the piston dividing the cylinder into first and second cylinder chambers; first and second fluid flow pathways from a fluid inlet to the first and second cylinder chambers, respectively; and a shuttle valve switchable between first and second positions by a magnetic force; whereby fluid caused to flow into the fluid inlet flows through the first fluid flow pathway when the shuttle valve is in the first position, and through the second fluid flow pathway when the shuttle valve is in the second position; and whereby alternating a flow of fluid through the first and second fluid flow pathways causes the piston to reciprocate in the cylinder and drive the pump.

2. The pump of claim 1, wherein the shuttle valve comprises one or more magnets.

3. The pump of claim 1 or 2, wherein the shuttle valve is elongate and comprises two magnets located near to opposite ends of the shuttle valve.

4. The pump of any one of claims 1 to 3, wherein the reciprocating piston comprises one or more magnets.

5. The pump of any one of claims I to 4, wherein movement of the reciprocating piston in the cylinder causes the shuttle valve to switch positions.

6. The pump of any one of claims 1 to 5, wherein the shuttle valve comprises conduits through which a fluid is caused to flow through the first and second fluid flow pathways can flow, the conduits being brought into fluid communication with the respective fluid flow pathway by movement of the shuttle valve.

7. The pump of any one of claims 1 to 6, wherein the fluid is mains pressure water. WO 2010/099579 PCT/AU2010/000254 19

8. The pump of any one of claims 1 to 7, wherein the reciprocating piston is coupled to a second reciprocating piston in a second cylinder.

9. The pump of claim 8, wherein the second reciprocating piston is a diaphragm, and reciprocation of the reciprocating piston causes the diaphragm in the second cylinder to pump a liquid.

10. The pump of claim 9, wherein the second reciprocating piston in the second cylinder pumps a greater volume of the liquid than the volume of the fluid used to drive the reciprocating piston.

11. The pump of claim 9 or 10, wherein the liquid is rainwater, grey water or underground water.

12. A water powered pumping system comprising: a water powered pump; an inlet that is in fluid communication with a liquid to be pumped; whereby a flow of pressurised water through the pump causes the liquid to be drawn from the inlet and pumped.

13. The system of claim 12, wherein the water powered pump is a water powered reciprocating pump which comprises: a first reciprocating piston in a first cylinder, the first reciprocating piston being drivable by a flow of pressurized water into the first cylinder; a second reciprocating piston in a second cylinder, the second reciprocating piston and cylinder being operable to pump a greater volume of the liquid than the volume of the pressurized water used to drive the first reciprocating piston; the first and second pistons being coupled such that driving of the first piston causes operation of the second piston.

14. The system of claim 13, wherein the first cylinder defines two chambers separated by the first reciprocating piston, the chambers being adapted to alternately receive and expel the flow of pressurized water and thus drive the first reciprocating piston; and wherein the WO 2010/099579 PCT/AU2010/000254 20 second cylinder defines two chambers separated by the second reciprocating piston, the chambers being adapted to alternately draw the liquid from the inlet and pump the liquid.

15. The system of claim 13 or 14, wherein the second reciprocating piston is a diaphragm.

16. The system of any one of claims 12 to 15, wherein the pressurized water is mains pressure water.

17. The system of any one of claims 12 to 16, wherein the liquid is rainwater, grey water or underground water.

18. The system of any one of claims 12 to 17, wherein the liquid is pumped to one or more of a toilet cistern, a washing machine, a garden, an air conditioner or a household tap.

19. The system of claim 18, wherein the pressurised water used to power the pump is also pumped with the liquid.

20. The system of any one of claims 12 to 19, wherein the water powered pump comprises the fluid driven reciprocating pump of any one of claims 1 to 11.