AU2007338916A1 - Improved water saving washing machine - Google Patents

Description

WO 2008/079070 PCT/SE2007/001102 1 Improved Water Saving Washing Machine Field of the invention [001] The present invention relates to washing machines, washing machine systems, and washing machine control methods, which assist in the saving of water. Background of the invention [002] Many countries experience water supply difficulties, such as during droughts and the like and thus there is a market for washing machines which utilise less water for washing clothes. [003] Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application. Summary of the invention [004] The present invention provides a washing machine including an outer bowl and an inner moving bowl to hold clothes to be washed, the inner bowl including at least one aperture therein to allow water to pass from the inner bowl to the outer bowl, the machine including at least one pump, and an outlet from the at least one pump which will direct water from the outer bowl to the inner bowl, the at least one pump being adapted to pump water from the outer bowl to the inner bowl so as to maintain the depth of water in the outer bowl less than the depth in the inner bowl. [005] The at least one pump can be a single pump which has two outlets, a first outlet having communicable passage to the inner bowl, and a second outlet to waste. [006] The single pump can be reversible whereby when operating in one direction pumps water to the first outlet and when operating in the other direction pumps water to the second outlet. [007] The at least one pump can be two pumps, being a first pump operating to pump water from the outer bowl to the inner bowl, and the second to pump water from the outer bowl to waste, when respectively activated to do so. [008] There can be one pump to pump water from the outer bowl to the inner bowl, with water being drained from the bowls under gravity via an outlet valve.

WO 2008/079070 PCT/SE2007/001102 2 [009] The washing machine can have its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is substantially parallel to a horizontal plane. [010] The washing machine can have its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is substantially parallel to a vertical plane. [011] The washing machine can have its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is at an angle other than 90 degrees from a horizontal or vertical plane. [012] The apertures near the top of the inner bowl can be of a greater cross sectional area than apertures located at the base of the bowl.. [013] The at least one pump can pump to the inner bowl from the outer bowl, as water is being added to the inner bowl prior to beginning a washing cycle. [014] Alternatively water can be added to fill the inner and outer bowl to a first same level, but below a desired second level in the inner bowl at which washing is to occur, whereby once the first level is achieved, the at least one pump begins pumping the water from the outer bowl to the inner bowl. [015] Some or all of the apertures can be located in a form or formation which will assist to prevent the apertures being blocked by the clothes. [016] The form or formation can be a recess, which may be conical, cylindrical, or tear drop shaped. [017] The at least one pump can be controlled by a control system so as to pump water at a rate which is dependent upon, or more particularly matched or proportional to, the rate of water entering the outer bowl from the inner bowl. [018] The at least one pump can pump water from the outer bowl to the inner bowl at a rate greater than or equal to the rate of flow of water through the apertures from the inner bowl to the outer bowl. [019] Water from said outer bowl can be returned to said inner bowl via an agitator. [020] A conduit can provide fluid passage between the outlet of the pump providing recirculation to the inlet of a valve or pump through which water will drain from said bowls. [021] A diverter valve can be used to select which outlet is pumped to.

WO 2008/079070 PCT/SE2007/001102 3 [022] A diverter valve can be controlled by the control system to open so as to drain water which is in the outer bowl. [023] The pump and the at least one aperture can have capacities whereby the outer bowl can be substantially evacuated. [024] The inner bowl remains full enough to wash clothes while the outer bowl is substantially evacuated. [025] The present invention further provides a control system for a washing machine as described above, the control system can activate the at least one pump to pump water to the inner bowl from the outer bowl, as water is being added to the inner bowl prior to beginning a washing cycle. [026] The at least one pump can be caused to be activated for the filling and washing cycle. [027] The at least one pump can be caused to be activated for a rinsing cycle. [028] The present invention also provides a control for a washing machine as described above, the control system can activate the at least one pump after water is added to fill the inner and outer bowl to a first same level, but below a desired second level in the inner bowl at which washing is to occur, whereby once the first level is achieved, the at least one pump begins pumping the water from the outer bowl to the inner bowl to achieve the desired second level. [029] The at least one pump can be caused to be activated during the filling and washing cycle. [030] The at least one pump can be caused to be activated before or during a rinsing cycle. [031] The control system can control the at least one pump so as to pump water at a rate which is dependent upon, or more particularly matched or proportional to, the rate of water entering the outer bowl from the inner bowl. [032] The control system can control the at least one pump to pump water from the outer bowl to the inner bowl at a rate greater than or equal to the rate of flow of water through the apertures from the inner bowl to the outer bowl. [033] The present invention further provides a method of controlling a recirculation pump in a clothes washing machine, the washing machine including means to activate and deactivate said pump according to a filling, washing, or rinsing cycle, the method including the WO 2008/079070 PCT/SE2007/001102 4 step of intermittently deactivating the pump for a period of time during one or more of the cycles. [034] The period of time is between 3 and 15 seconds and is most preferably 5. [035] The period of time of deactivation is controlled to occur at a set time interval. [036] The set time interval can be between 60 and 120 seconds, and is most preferably 100 seconds. [037] The present invention further provides a method of operating a washing machine, the washing machine including an outer bowl and an inner moving bowl to hold clothes to be washed, the inner bowl including at least one aperture therein to allow water to pass from the inner bowl to the outer bowl, the machine including at least one pump which inlets water from the outer bowl, the method being characterised by directing outflow from the at least one pump to the inner bowl, so as to maintain the depth of water in the outer bowl less than the depth in the inner bowl. Brief description of the drawings [038] An embodiment or embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [039] Figure 1 is a diagrammatic cross section through a vertical axis washing machine; [040] Figure 2 is a cross section of one of the extraction holes through the inner bowl of the machine of figure 1; [041] Figure 3 is an elevation of the extraction hole of figure 2; [042] Figure 4 is a cross section through an alternative hole and recess to that of figure 2 and 3; [043] Figure 5 is an elevation of the hole and recess of figure 4 [044] Figure 6 is a recirculation pump system where a single reversible pump is used; [045] Figure 7 is a recirculation pump system where a single pump is used with a diverter valve to select either a recirculation outlet or a waste outlet; [046] Figure 8 illustrates a horizontal axis washing machine; [047] Figure 9 illustrates a vertical axis washing machine where recirculation water is returned to the inner bowl via the agitator; WO 2008/079070 PCT/SE2007/001102 5 [048] .Figure 10 illustrates a diagrammatic cross section through a vertical axis machine similar to figure 1, with a conduit from the outlet of the recirculation pump to the inlet to the drain pump; [049] Figure 11 illustrates a diagrammatic cross section through a horizontal axis machine similar to figure 8, with a conduit from the outlet of the recirculation pump to the inlet to the drain pump; [050] Figure 12 illustrates a diagrammatic cross section through a vertical axis machine similar to that of figure 10, which has a valve substituted for the drain pump; and [051] Figure 13 illustrates a diagrammatic cross section through a horizontal axis machine similar to that of figure 11, which has a valve substituted for the drain pump. Detailed description of the embodiment or embodiments [052] Illustrated in figure 1, a clothes washing machine 10 has an inner spin bowl or wash bowl 12 to hold the clothes load and water is introduced directly into the wash bowl 12 by a water outlet (not illustrated) to feed water for washing directly into the wash bowl 12. [053] In the centre of the wash bowl 12 is an impeller or agitator 20 which moves to create a washing action. If desired the agitator 20 (or impeller if used- an "agitator" generally has a column which extends above the water level while an "impeller" generally is of lesser height and is below the water level) can also be fixed with the wash bowl 12 or made as one part, in which case the bowl/agitator assembly will move as one by the motor and gear box assembly 22 to create a wash action. [054] The wash bowl 12 is perforated with a series of apertures being two rows of upper circumferential spin extraction holes 30, two rows of lower circumferential spin extraction holes 32 and base extraction holes 36, so that when in the spin cycle water to be extracted can centrifuge into the outer bowl 14, so as to be pumped therefrom to waste by the pump 24. [055] The outer bowl 14 is a water tight bowl in which the wash bowl 12 is located. The outer bowl 14 is assembled in the washer and is mounted on a suspension system which includes springs and or dampers 53 as illustrated in figure 1, as is known in the art. [056] When the wash bowl 12 is filled with water, the spin extraction holes 30, 32 and 36 allow a common water-level inside and outside the wash bowl, that is the inner bowl 12 and outer bowl 14 have a common or the same water level. As the number of apertures is reduced by comparison to prior art washing machines, the control system of the washing machine 10 can be WO 2008/079070 PCT/SE2007/001102 6 set to make a time allowance so that the common water level can stabilize in the respective bowls. This time allowance can be made to occur once during a fill cycle or more than once if desired. [057] While in a practical sense the water in the space between the wash bowl 12 and outer bowl 14 tends to be "unused", there needs to be a clearance between the inner bowl 12 and outer bowl 14 so as to: (a) accumulate water from the wash bowl 12 and (b) to provide a falling path for the water being extracted during the spin cycle. If this space is made too small it causes water and detergent to foam. This can disadvantageously create a viscous coupling which causes over loading of the spin drive system. If the space is made too large, then this results in a greater amount of "unused" or wasted water. Thus, such a space is needed but results in wasted water. [058] The wash bowl 12 has a base which has eight holes 36 equi-spaced around its circumference, with each hole having a cross sectional area of 5.85 square millimeters making a total surface area of 46.8 square millimeters, as well as another four small final drain holes in the bottom plate adding a further 12 square millimeters. [059] In the vertical wall 40 of the wash or inner bowl 12 there are a total of twenty holes: ten upper circumferential holes 30 of 5.85 millimeters each, making 58.5 square millimeters; and ten lower circumferential holes 32 of 5.85 millimeters each, also making 58.5 millimeters, and thus a total of 117 square millimeters in the circumferential wall of the inner bowl 12, and making a total of approx 176 square millimeters of holes in the inner bowl 12. [060] While eight holes 36 and twenty holes 30 and 32, is a preference with the primary objective of the number and size of holes being selected so as to balance the competing requirements of the size, volumetric rate, type and cost of pump used, versus the rate of flow out of the inner bowl 12 into the outer bowl 14 and the need to obtain effective water transference from the inner bowl to the outer bowl when in a spin cycle. [061] The base of the outer bowl 14 has a catchment 38 at the entry point to the pump 16 so as to get a maximum depth of water above the pump entry. The catchment 38 drains to or leads to the inlet to recirculation pump 16. The catchment 38 preferably has three vertically oriented vanes (not illustrated) to impart a straight or vertical flow to the water entering the pump 16, so as to counteract a natural whirlpool effect that occurs when water is drained through a vertical drain. By counteracting the natural whirlpool effect, water will flow directly to the pump 16 which in operation is expected to not run dry. However even if air starts to enter the pump 16, the pump 16 will lose flow and because of this loss of flow, the pump will tend to gather more water and thus re prime.

WO 2008/079070 PCT/SE2007/001102 7 [062] The vanes (not illustrated) are a preference and it is envisaged that embodiments can be made without such vanes., or that possibly a larger number of vanes than three may be used. [063] If insufficient water were present, the pump 16 would begin cavitating and whilst this would generally not harm the pump 16 or its agitator, a disadvantage would be that there can be more noise. A water level sensing system in the outer bowl 14 can be used by the control system to switch off the pump 16 in these circumstances where the water level in the outer bowl is continuously too low, and to re-activate the pump 16 when a desired level is achieved in the outer bowl. [064] Leading from the outlet of the pump 16 is a recirculation conduit 18 which empties water pumped therein to the inner bowl 12 via the outlet or nozzle 28. [065] In operation the pump 16 will generally have a minimum flow rate which is greater than the flow rate of water passing through the holes 30, 32 and 36, when there is water in the inner bowl 12 above the upper holes 30. By this means the pump 16 will always be able to keep the space between the inner and outer bowls evacuated when the water level in the inner bowl is at its highest. [066] Alternatively the control system of the pump 16 in sensing the water level in the outer bowl 14, can adjust or vary the pump flow rate dependent upon, or more particularly to match or be in proportion with, the rate of flow of water from the inner bowl 12 to the outer, thereby reducing the water level in the outer bowl 14 to a desired level. Thus during the operation of the pump 16, the pump 16 will reduce the water level during which time it will be pumping at a greater rate than the rate of flow from the inner bowl to the outer bowl. However to maintain the depth desired, it may be that the pump 16 will be controlled to pump at a lesser rate than that of water entering the outer bowl 14 from inner bowl 12. While in most cycles this desired level will be empty or near empty, it may BE that the desired level will be different to these, so as to for example keep a minimum or maximum level of water above the pump 16 to prevent noise which may occur due to cavitation. [067] The wash or inner bowl 12, by virtue of having a restricted number of extraction holes in the side-wall and the base and the pump 16 recirculating the water from the space between the wash bowl 12 and the outer bowl 14 back into the wash bowl 12, will receive recirculated water via nozzle 28.

WO 2008/079070 PCT/SE2007/001102 8 [068] The holes 30 and 32 in the wash bowl 12 are each formed in a small indent or recess 42 as illustrated in figure 2, so as to give a space between the clothes and the hole. This helps keep the clothes from blocking the holes, and as spin occurs, provides a space for water to accumulate at the hole. The shape of the recess 42 as illustrated in figures 2 and 3 is conical or tapered and is overall of a circular configuration. If desired a more complex shape such as the tear drop or water droplet shape illustrated in figures 4 and 5 can be utilised. The tear drop or water droplet shaped recess 42 will be particularly useful for purchasers to be able to identify that the washing machine they are looking at has this water saving feature, The apertures or holes 30 and 32 in the side wall being in a form or recess 42 assists to keep clothes from blocking the apertures or holes 30 and 32 in the spin extraction process and allow water movement from inner bowl to outer bowl (and vica versa) when filling, draining and measurement stages are in progress [069] The holes 36 in the base of the inner bowl however are not in a formation or recess like recess 42 so that the clothes wipe the holes or apertures 36 during the wash cycle to stop blockage of these holes or apertures 36. [070] In operation the pump 16 can have its flow rate controlled to maintain a set water level in the outer bowl 14 at all times, once the filling of the machine 10 begins. [071] Alternatively, the pump 16 can be activated once the water level in the inner bowl 12 has achieved a predetermined depth. That predetermined depth can occur at point in the filling program, where the water achieves a desired percentage of the final depth required. In this case the water from the space between the inner bowl 12 and outer bowl 14, will augment the water in the inner bowl 12 to bring the water level to the desired depth for the washing program. [072] In summary the pump 16 pumps the water from the bottom of the outer bowl 14 back into the wash bowl 12 generally as fast as it escapes through the spin extraction holes 30, 32 and 36, during the washing and rinsing cycle. [073] The most preferred method of operation is, to begin a wash program so that the water fill process for the wash bowl 12 begins in the normal manner and the pump 16 for recirculating the water is off. The water level is sensed in the outer bowl 14, and when the water level reaches a predetermined level in the outer bowl 14, the water fill program ceases and the recirculation pump 16 starts up. As the water level is pumped down in the space between the bowls 12 and 14, the water level in the wash bowl 12 rises to a predetermined level suitable for the wash process.

WO 2008/079070 PCT/SE2007/001102 9 [074] If desired a water level sensing method can be provided in the wash bowl 12, such as by laser, infra red, ultra sonic or other means. An alternative depth measurement can be achieved by volumetric measurement of water on entry or volumetric measurement of the water being recirculated. If these systems are provided then the recirculation pump 16 could run at all times during the fill process and the washing cycle. [075] The filling for the rinse cycle can be performed by the same water management process as the wash cycle so as to achieve what is normally called a deep rinse. Alternatively the rinse can be done by spraying fresh water onto the clothes and spinning at various speeds to extract detergent with a minimum amount of water. The recirculation process could be reactivated during some of the spray rinse process to enhance rinse performance. [076] There is provided a clearance space 49 beneath a balance ring 50 at the top of the inner bowl so that in the spin cycle any excess water, that cannot flow quickly enough from the extraction holes 30, 32 or 36, can exit through the clearance space 49 into the outer bowl. [077] In the system of figure 1, the pump 16 for recirculation is a separate pump to the drain pump 24. The pump 16 can be attached to or remote from the outer bowl 14. [078] Alternatively the recirculating pump 16 can be provided as a shared function with the drain pump 24, as is illustrated in figure 6, whereby one pump 1624 is utilised and by reversing its direction will either drain to waste 26 or recirculate via conduit 18. [079] Another alternative is as illustrated in figure 7, whereby a single pump 1624 is used with a diverter valve 1625 to control which outlet 18 or 26 is selected. [080] No matter what the load size of clothes to be washed, the system described above will save, on each wash cycle, the amount of water which would otherwise be present between the inner bowl 12 and outer bowl 14. [081] In the wash cycle the water amount can be set, dependent upon or almost proportional to the clothes load, and there is only a small additional fixed amount of water in the remainder of the system such as the hoses, pumps AND outer bowl. [082] Illustrated in figure 9 is vertical axis washing machine 210, which is similar to that of figure 1, and like parts have been like numbered. The washing machine 210 differs from the machine 10, by the presence of an agitator or agitator 20 which has a fluid passage 60 vertically through it. The passage 60 has a series of holes or outlets 56 in its side along the height of the agitator, and holes 58 in the base thereof, so water ejected into the agitator 20 from the nozzle 28 will flow to the inner bowl 12.

WO 2008/079070 PCT/SE2007/001102 10 [083] The top of the agitator 20 has an inlet 54 to receive water ejected from the nozzle 28, which receives water pumped from the re-circulation pump 16. The washer 210 also differs from the washer 10 in that the nozzle 28 has its outlet near the centre of the inner bowl 12, not at the circumference like in figure 1. This is achieved by a conduit extension 52 which can be located in or attached to the lid (not illustrated) of the washing machine, or otherwise arranged and mounted to achieve this result. The arrangement of figure 9 is particularly advantageous to assist in minimising the formation of foam. [084] The system described above, if present in a top loader vertical axis washing machine, has the ability to make the water performance of such a vertical axis machine equal to or better than many front loader horizontal axis machines. [085] However, by applying the above system to front loader horizontal axis washing machines such as washer 110, as is illustrated in figure 8, benefits can also be achieved for front loader horizontal axis washing machines as well. In the system of figure 8, like parts with those of figure 1 have been like numbered. [086] While horizontal and vertical axis washing machines are the more common in the current market place, the present invention can be readily applied to washing machines which have their agitator, their inner bowl or their outer bowl rotation or longitudinal axis at an angle to a vertical or horizontal plane. [087] If desired, for vertical axis washing machines, the extraction holes 30, 32, and 36 in the inner bowl 12 of figure 1 or figure 8 can be arranged in a pattern to assist the extraction, for example holes at the upper end of the bowl can be larger than at the base, so that a similar flow rate through different height or depth of holes is achieved. [088] In the system described above, on the inner bowl 12 of figure 1, there are two levels of holes on the vertical wall and holes in the base. However, the most preferred arrangement has five levels of extraction holes in the vertical wall 40 of inner bowl 12 (in addition to holes in the base), with the first being approximately 90 mm above the base of the inner bowl 12, and four others above the first level at 60mm spacings. [089] The nozzle or outlet 28 can include a servo means to change said outlet from an unrestricted outlet to an outlet that can achieve a spray pattern. This will provide an unrestricted outlet path during washing cycle and a desired spray pattern during rinsing cycle. If desired this can be achieve by an outlet which is bifurcated, with the selection of the two passages being WO 2008/079070 PCT/SE2007/001102 11 controlled by a diverter valve to direct water to a spray nozzle or an unrestricted outlet depending upon the cycle being conducted. [090] Another control feature which is preferably used with the above system, is that the pump which is used for recirculation (whether in a one or two pump system) is controlled to switch off or deactivated for between 3 to 15 seconds (but most preferably for a minimum of 5 seconds) in every 30 seconds to 200 seconds (but most preferably approximately 100 seconds) that the recirculation pump is on. This intermittent or periodic switching off creates a reverse flow in the- recirculation pump and dislodges lint and other items, and helps this unwanted material to pass through the pump thereby avoiding blockage and stalling of the recirculation pump. [091] If desired, the water level sensing system can sense, when the water level in the outer bowl rises above a predetermined level, when the recirculation pump is running. This rise in depth will indicate that the recirculation pump is not working effectively. If this occurs the control system, whether or not 30 to 200 seconds has elapsed since the last deactivation, can shut down the recirculation pump for between 3 to 15 seconds, so as to attempt to clear the blockage, if one exists. This can be repeated several times, and if after a predetermined number of times, the blockage is still present, the control system can relay a message back to the user that the recirculation system needs attention by a serviceman. [092] The above embodiments describe the inner bowl 12 as having a series of apertures, which are generally round or other shaped holes at selected locations. As an alternative, the aperture can be a single axially extending slot in the vertical wall 40 of the inner bowl 12, from the top to the bottom of the inner bowl (which may also vary in width from the top to the bottom of the inner bowl), or one or more circumferentially slots. Such an embodiment may require additional reinforcement so that the inner bowl 12 can withstand the hoop stresses developed during the spin cycle. [093] When the machines described above are not in use for some time, residual water, if too much, may cause a problem of odour, or may become mixed with the water used in the next wash load. [094] Thus, to prevent a recirculation pump 16, its entry port and the output delivery tube 18 from retaining an amount of water after the completion of a wash program, a modification to the washers of figures 1 and 8 is described and illustrated with respect to figures 10 and 11 respectively.

WO 2008/079070 PCT/SE2007/001102 12 [095] As illustrated in figures 10 and 11 are a vertical axis washer 310 and a horizontal axis washer 410 respectively which are similar to the washers 10 and 110, described in figures 1 and 8, and like parts have been like numbered. [096] The washers 310 and 410 each have a small diameter connection tube or conduit 60, of the order of 8 to 10 mm in diameter, which connects between the outlet of the pump 16, at the base of the recirculation conduit 18 and the inlet of drain pump 24. When water is to be removed from the wash bowl 12 by the drain pump 24, the conduit 60 will also allow evacuation of most of the residual water from the recirculation pump 16, its entry port, and recirculation tube 18. [097] During the wash program when the recirculation pump 16 is running, so as to minimise water in the space between the bowl 12 and 14, there will be a small amount of flow through the connection tube or conduit 60 to the inlet of pump 24 and back to the base of the outer bowl 14. This is will not adversely influence the operation of the recirculation system, as this amount of water can be taken into account by the selected flow rate required of recirculation pump 16. [098] Illustrated in figures 12 and 13 are washers 510 and 610 similar to those of figures 10 and 11 respectively. Accordingly like parts have been like numbered. [099] The washing machines 510 and 610 do not have a drain pump 24, and water is held in the bowl system by a valve 62 having an outlet 64 which drains to a floor or a waste conduit (not illustrated). In the washers 510 and 610 the conduit 60 also connects to the base of the recirculation conduit 18 so that when valve 62 is opened, as the valve 62 is below the base of the conduit 18, water will flow out of the outlet 64, draining the bowls 12, 14 and the conduit 18. [0100] With respect to the systems illustrated in figures 6, as the pump 1624 is reversible, this problem of stagnant water will not occur, as most water left in the recirculation conduit 18 will be pumped out with the water from the bowls 12 and 14. [0101] In regards to the system of figure 7 where a diverter valve 1625 is used, when the bowls 12 and 14 are to be drained, the control sequence of the diverter valve can first close off the conduit 18 and then drain the bowls. Then when completed, the diverter valve 1625 is opened to allow water in the conduit 18 to drain back to the pump 1624 or to the drain conduit 26, whereby the mount of water in the conduit 18 will be diminished. [0102] In the above described embodiments the holes 30 and 32 are in 4 rows where there are two rows grouped closely at the top and two rows grouped closely at the bottom.

WO 2008/079070 PCT/SE2007/001102 13 However, other arrangements can be utilised such as the 4 or 5 rows spread substantially evenly or substantially equi spaced from the upper region or top of the inner bowl 12 to its bottom. [0103] In the above description and claims the word "water" is used and is to be taken to include not just clean water but also liquor, which may be made up of solutions of dirt and surfactants and other substances with water which liquor may be produced by the washing process. [0104] The above embodiments and the invention allow designers and manufacturers of washing machines to reduce the effects of viscous coupling which may occur during the spin cycle (during which time the recirculation system is not operating) by providing a larger space between the inner and outer bowls. [0105] Where ever it is used, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of'. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear. [0106] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention. [0107] While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

Claims (36)

1. A washing machine including an outer bowl and an inner moving bowl to hold clothes to be washed, said inner bowl including at least one aperture therein to allow water to pass from said inner bowl to said outer bowl, said machine including at least one pump, and an outlet from said at least one pump which will direct water from said outer bowl to said inner bowl, said at least one pump being adapted to pump water from said outer bowl to said inner bowl so as to maintain the depth of water in said outer bowl less than the depth in said inner bowl.

2. A washing machine as claimed in claim 1, wherein said at least one pump is a single pump which has two outlets, a first outlet having communicable passage to the inner bowl, and a second outlet to waste.

3. A washing machine as claimed in claim 1, wherein a single pump is provided which is reversible whereby when operating in one direction pumps water to said first outlet and when operating in the other direction pumps water to said second outlet.

4. A washing machine as claimed in claim 1, wherein there are two pumps, being a first pump operating to pump water from said outer bowl to said inner bowl, and the second to pump water from said outer bowl to waste, when respectively activated to do so.

5. A washing machine as claimed in claim 1 wherein there is one pump to pump water from said outer bowl to said inner bowl, with water being drained from said bowls under gravity via an outlet valve.

6. A washing machine as claimed in any one of claims 1 to 5, wherein the machine has its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is substantially parallel to a horizontal plane.

7. A washing machine as claimed in any one of claims 1 to 6, wherein the machine has its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is substantially parallel to a vertical plane.

8. A washing machine as claimed in any one of claims 1 to 7, wherein the machine has its agitator or impeller or inner bowl or outer bowl arranged so that the rotation axis or longitudinal axis is at an angle other than 90 degrees from a horizontal or vertical plane.

9. A washing machine as claimed in any one of the preceding claim, wherein said at least one aperture near the top of said inner bowl is or are of a greater cross sectional area than said at least one aperture located at the base of said bowl. WO 2008/079070 PCT/SE2007/001102 15

10. A washing machine as claimed in any one of the previous claims wherein a controller controls said at least one pump so as to activate said at least one pump to pump water to said inner bowl from said outer bowl, as water is being added to said inner bowl, prior to beginning a washing cycle.

11. A washing machine as claimed in any one of claims 1 to 9, wherein a controller causes water to be added to fill said inner and outer bowl to a common first level, but below a desired second level in said inner bowl at which washing is to occur, whereby once said first level is achieved, said controller activates said at least one pump to pump said water from said outer bowl to said inner bowl to achieve said desired second level.

12. A washing machine as claimed in any one of the preceding claims wherein said at least one aperture is or are located in a form or formation which is adapted to prevent said apertures being blocked by said clothes.

13. A washing machine as claimed in any one of the preceding claims wherein said at least one pump is controlled by a control system so as to pump water at a rate which will substantially evacuate said outer bowl, with respect to the rate of water entering said outer bowl from said inner bowl.

14. A washing machine as claimed in any one of claims 1 to 9, wherein said at least one pump will pump water from said outer bowl to said inner bowl at a rate greater than or equal to the rate of flow of water through said apertures from said inner bowl to said outer bowl.

15. A washing machine as claimed in any one of claims 1 to 14 wherein said water from said outer bowl is returned to said inner bowl via an agitator.

16. A washing machine as claimed in any one of the preceding claims wherein a conduit provides fluid passage between the outlet of the pump providing recirculation to the inlet of a valve or pump through which water will drain from said bowls.

17. A washing machine as claimed in claim 2, wherein a diverter valve is used to select which outlet is pumped to.

18. A washing machine as claimed in claim 17, wherein said diverter valve is controlled by said control system to open so as to drain water which is in said outer bowl.

19. A washing machine as claimed in any one of the preceding claims wherein said pump, said at least one aperture have capacities whereby said outer bowl is substantially evacuated. WO 2008/079070 PCT/SE2007/001102 16

20. A washing machine as claimed in claim 19, wherein said inner bowl remains full enough to wash clothes while said outer bowl is substantially evacuated.

21. A control system for a washing machine as claimed in any one of claims 1 to 20, wherein said control system activates said at least one pump to pump water to said inner bowl from said outer bowl, as water is being added to said inner bowl prior to beginning a washing cycle.

22. A control system as claimed in claim 21, wherein said at least one pump is caused to be activated for the filling and washing cycle.

23. A control system as claimed in claim 22, wherein said at least one pump is caused to be activated for a rinsing cycle.

24. A control system for a washing machine as claimed in any one of claims 1 to 20, said control system activates said at least one pump after water is added to fill said inner and outer bowl to a first same level, but below a desired second level in said inner bowl at which washing is to occur, whereby once said first level is achieved, said at least one pump begins pumping said water from said outer bowl to said inner bowl to achieve said desired second level.

25. A control system as claimed in claim 24, wherein said at least one pump is caused to be activated during the filling and washing cycle.

26. A control system as claimed in claim 25, wherein said at least one pump is caused to be activated before or during a rinsing cycle.

27. A control system as claimed in any one of claims 21 to 26, wherein said control system controls said at least one pump so as to pump water at a rate which will substantially evacuate said outer bowl, with respect to the rate of water entering said outer bowl from said inner bowl.

28. A control system as claimed in any one of claims 21 to 27, wherein said control system controls said at least one pump to pump water from said outer bowl to said inner bowl at a rate greater than or equal to the rate of flow of water through said apertures from said inner bowl to said outer bowl.

29. A method of controlling a recirculation pump in a clothes washing machine, said method including means to activate and deactivate said pump according to a filling, washing, or rinsing cycle, said method also including the step of intermittently deactivating said pump for a period of time during one or more of said cycles. WO 2008/079070 PCT/SE2007/001102 17

30. A method as claimed in claim 29 wherein said period of time is between 3 and 15 seconds and is most preferably 5 seconds.

31. A method as claimed in claim 30 wherein said period of time of deactivation is controlled to occur at a set time interval.

32. A method as claimed in claim 31 wherein said set time interval is between 30 and 200 seconds, and is most preferably 100 seconds.

33. A method of operating a washing machine, said washing machine including an outer bowl and an inner moving bowl to hold clothes to be washed, said inner bowl including at least one aperture therein to allow water to pass from said inner bowl to said outer bowl, said machine including at least one pump which inlets water from said outer bowl, said method being characterised by directing outflow from said at least one pump to said inner bowl, so as to maintain the depth of water in said outer bowl less than the depth in said inner bowl.

34. A washing machine operating by the method of claim 33, or having a control system as claimed in any one of claims 21 to 28, which utilises a method as claimed in any one of claims 27 to 30.

35. A washing machine being substantially as herein described with reference to the accompanying figures.

36. A control system or method of operating a washing machine , being substantially as herein described with reference to the accompanying figures.