SWIMMING POOL CLEANING SYSTEM AND APPARATUS

Abstract: System for automatically cleaning a swimming pool. Water jets (3) above and below the designed water level (2) of the pool are placed at one end thereof so as to inject water into the surface layer and cause a general movement across the entire pool surface toward the opposite end of the pool. In the opposite end of the pool is placed a throat leading (6) into a strainer box (7) so that a continuous free water surface exists between the pool and the strainer box. At the entrance to the throat (6) is a weir (4) having a lip (5) extending outwardly and downwardly into the pool water so that the moving surface layer of water experiences a shallowing as it enters the throat (6). This shallowing of the water induces an acceleration which helps to ensure that all matter floating on, or held in suspension in, the moving upper surface layer travels down the throat (6) into the strainer box. In order to clean out any debris which may have sunk into the pool side wall jets (42) close to the bottom of the pool are also included. These stir up the sub surface water of the pool producing turbulence right throughout its volume sufficient to gradually bring any debris up to the moving surface layer. Once within the moving surface layer such debris will ultimately be taken down the throat (6) into the strainer box (7). Water from the strainer box can be pumped through a suitable filter (10) and returned to the pool through the various jets described above.

Description: SWIMMING POOL CLEANING SYSTEM AND APPARATUS This invention relates to the cleaning of swimming pools, and is principally designed for use in relation to swimming pools installed adjacent private homes although larger pools, such as Council and Olympic type pools are also susceptible to treatment and installation according to this invention. BACKGROUND ART Most existing pool cleaning systems consist of either submerged mobile units connected to the filter pump suction and/or discharge and rely on water flow into the unit to remove sediment from the pool floor, or a series of hoses supplied from the filtra¬ tion pump discharge which move about in the water with the object of either sweeping sediment towards a bottom outlet in the pool or attempting to maintain sediment in suspension for progressive removal into the normal filtration system. The most obvious deficiency in such systems is their inability to quickly remove floating and semi-floating matter, in particular leaves, loose grass and pieces of bark, which are not only themselves the cause of much of the contamination of the pool by dust but more importantly must be largely removed manually. Less common in modern pools is a system which by allowing a small overflow from the pool surface aims to cause leaves to float into a recepta¬ cle from which they are then removed by hand. Such a system has proved in practical application to be of very limited use mainly because any air movement in a direction other than towards the leaf receptacles results in floating matter drifting to other parts of the pool and finally becoming saturated and sinking to the bottom. The sediment problem remains and conse¬ quently continuous manual cleaning of the pool is necessary. In addition such leaves as do reach the receptacles tend to float or be washed back into the pool as soon as the filtration pump is shut down. These systems are as a result not often seen in present day pools. It is an object of this invention to amelio¬ rate disadvantages of conventional pool cleaning systems. DISCLOSURE OF THE INVENTION This invention is based on the observation that when leaves fall or are blown into a swimming pool they will float for some time before becoming saturated and sinking. The time involved will vary from leaf to leaf, dependent upon species, age, dust load and other factors. This invention is principally concerned with providing a system which has the capacity to remove from a pool leaves and other floating debris before they with their associated dust particles or the like can sink to the pool floor. The invention, in a preferred form, also provides means for lifting leaves and other debris including fine material from the pool floor to be removed by the principal system of this invention. Accordingly this invention, in one broad form, comprises in a swimming pool with a designed operating water level, means adapted to induce surface water movement in a general direction from one end of said pool to an opposite end, a strainer box external of and proximate the pool boundary at said opposite end, a throat communicating between said strainer box and said pool providing a common free water surface when said pool is filled to said designed water level, and a weir at the pool end of said throat, said weir including a transversely horizontal protrusion ex¬ tending outwardly and downwardly into the volume to be occupied by pool water, the highest transverse line of said protrusion being slightly lower than said designed water level so as to provide a gradual shallowing of pool water in the vicinity of said OMPI - throat so that surface water is accelerated as it is induced by said means to pass over said weir. In a preferred form the strainer box will incorporate a filter element arranged so that with the system running normally some eighty to one hundred percent of the water will be filtered. The man skilled in the art will appreciate that appropriate surface water movement can be pro¬ vided by use of one or more water jets or throwers adapted to spray water onto the pool surface and/or inject it at a suitable point or points just below the surface level. Such surface water movement will ensure that floating matter will be carried to the end of the pool where the weir is located before such matter becomes saturated and sinks. This manner of cleaning the surface of the pool is substantially different from the well known "sweeping" method in which a spray from for example a hand held hose is used to move floating objects to one portion of the pool for easy removal therefrom. By moving a whole surface layer not only floating matter but matter in suspension within that layer will be moved to the desired end of the pool. Further, in the preferred embodiment of this invention wherein some sub-surface turbulence is caused in order to stir up sunken debris, such debris generally finds its way to the moving surface layer and is thus transported to the far end of the pool for removal therefrom. The above surface water jets or throwers in fact only supplement the sub surface water jets in ' creating surface layer movement. The above water jets, however, have the advantage in that they tend to aerate the water of the pool which increases the ability of the pool water to hold matter in suspension within the surface layer while it is transported to the strainer box. Further, aeration tends to inhibit growth of algae, and helps prevent discolouration at the water line. Preferably the weir is positioned proximate the pool side wall so as to be slightly below the designed surface level of the pool. The width will depend upon such parameters as pool size and required water throughput of the strainer system. Usually a width of less than one metre will be required. The water level height above the weir is important. The system provides a surface water flow to float debris over the weir rather than splashing it over as with conventional scumgutters. Also the water surface is continuous from the pool into the strainer box, so that floating debris is not trapped anywhere before it reaches the strainer. The shallowing of water depth is important as it accelerates the water as it enters the throat. Floating objects, and even more so objects in suspension, are less likely to sink in the accelerated water. Thus the debris, once it reaches -BURfi OMP the weir is sure to be swept down the throat into the strainer. Best results from a system and apparatus according to this invention are arrived at if the level of the pool water is maintained at a predeter¬ mined constant height and it is thus preferred that apparatus be provided to achieve this end. One embodiment of such apparatus comprises two elements the first can be in the form of an inverted U-tube fitted at the appropriate height relative to the desired pool water surface level and arranged so that excess water is directed to waste. The second element can be arranged so that any loss of water from the pool is automatically made up, and can comprise a device in the nature of a float valve and cistern or other means such as a probe controlled valve or a pilot operated valve. Excess water in the pool can result from rain or from manual topping up of the water level. It is further preferred that the strainer tank be arranged so that all matter therein can be removed simply for disposal. Further the strainer tank is preferably fitted at such a level that it contains a free surface at the same level as that of the pool water and therefore does not require a watertight cover or lid, and facilitates removal of rubbish and servicing of the filter element. If desired, and dependent upon pool size and shape, one or more jets or hose outlets may be arranged on or adjacent the pool floor in such a manner as to, at selected intervals, stir into sus¬ pension sediment deposited on the pool floor, this sediment then being removed over said weir(s) by the movement of surface water. BRIEF DESCRIPTION OF THE DRAWINGS By way of example only one embodiment of a system according to this invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic section of a swimming pool together with associated apparatus for practice of the system of this invention; Fig. 2 is a detailed section of the strainer box of Fig. 1; Fig. 3 is a detailed section of the pool water surface level control device of Fig. 1; Fig. 4 is a diagrammatic section of a swimming pool including a second embodiment of the invention; Fig. 5 is a plan view of the pool of Fig. 4; Fig. 6 is a detailed section view of a portion of the pool of Figs. 4 and 5; Fig. 7 shows in detail a part of the portion of the pool shown in Fig. 6. BEST MODE OF CARRYING OUT THE INVENTION In the drawings, pool 1 is filled with water to surface line 2. Water throwers (or sprayers) 3 are provided at one end of pool 1 just above and/or below pool surface level line 2 to inject water causing a movement of said pool surface water towards the opposite end of pool 1 wherein is accommodated weir 4 comprising lip 5 which is shaped and located so as to occasion an increase in the flow rate of surface water in the vicinity of weir 4. As this water exits pool 1 it cascades into pipe 6 and thence into strainer box 7, the water level 16 of strainer box 7 being the same as that of pool 1 so that lid 15 of strainer box 7 need not be of any specially fitted manufacture. It will be appreciated that leaves and other detritus located at or adjacent surface 2 of the pool water will be conducted in the fast moving surface water into strainer box 7. Box 7 is provided with a coarse strainer 13 which will arrest leaves, bark and similarly sized material, and a fine strainer, e.g., 20-200 mesh, 14 which will arrest finer material. Water passing through strainers 13 and 14 will be returned via pipe 8 to the conventional pool pump 9 and filter 10. In a further embodiment of this invention use of a simple filter element in the tank 7 will eliminate use of a separate conventional filter 10, and permit quick and easy removal for periodic cleaning. Water is returned to pool 1 from pump 9 and filter 10 via pipe 11 and water throwers 3. Pool 1 is also provided with water level maintenance device 17 which comprises an overflow device in the form of an inverted U-tube 18 arranged so that excess pool water will exit to waste thereby. In an alternative arrangement the overflow device can be incorporated in an automatic topping up device as described above. In the event that some detritus sinks to or towards the pool floor, submerged jets or hose connec¬ tions 12 are provided therein. When water is forced to" enter the pool through these jets or hose connec¬ tions detritus in the pool other than on the water surface is stirred into suspension to be conducted from the pool over weir 4 by operation of sprayers 3. Figs. 4 and 5 show diagrammatically the overall arrangement of a second embodiment of the invention. Surface and sub surface jets 23 provide the means to induce water surface movement along the length of pool 1. Bottom jets 42 create turbulence within the entire water volume of pool 1 thus stirring up any debris which may have sunk to the pool floor. This stirred up debris will finally reach the surface layer which is moving toward the pool end opposite jets 23. At this end of the pool is weir 24 providing clear liquid communication to strainer tank 27. As clearly seen in Fig. 6 the water level 36 within strainer tank 27 is continuous with the designed water level 2 of pool 1. Thus there is no overhead obstruction to floating debris which is brought in with the moving surface layer of water from pool 1. At the entrance to weir 24 is a protruding lip 25 which extends inwardly and downwardly within the water of pool 1. Lip 25 is more fully shown in Fig. 7 where it can be seen to extend across the complete opening of weir 24. The profile of lip 25 is such that water approaching weir 24 gradually accelerates due to the shallowing of the surface water in this region. It has been found that a depth of 16 mm below the designed water level 2 is optimal for a weir 24 incorporating lip 25 as shown. INDUSTRIAL APPLICABILITY It is contemplated that the system of this invention when used in conjunction with a conventional or special filter mentioned above will clean the average pool on the basis of a one to three hour operation each morning and each evening. If desired, operation of the system can be implemented to cater for unusual conditions such as abnormal winds causing deposition of leaves and other debris on the pool surface. On the other hand, the embodiment of this invention whether used in conjunction with a conven¬ tional filter or not will require a sufficient daily operation to turn over pool water say one and a half times daily for cleansing purposes, especially when an automatic chlorination system is used. Not only does the system greatly simplify the disposal of rubbish from the pool by collecting it at a single point but the rapid elimination of leaves also results in a significant reduction in the amount of dust trapped in the pool. This combined with agitation of the pool water to keep sediment in suspension simplifies removal of what remains through the normal filtration system, and greatly reduces the need for manual "vacuuming". It is considered also that spraying water onto the pool surface combined with the general agitation will enhance aeration and thus assist in maintaining a healthy water condition which will tend to retard or inhibit algae growth. Further such aeration will reduce the tendency to discolouration at the water line. 'BU EA OMP

Claims: 1. In a swimming pool with a designed operating water level, means adapted to induce surface water movement in a general direction from one end of said pool to an opposite end, a strainer box external of and proximate the pool boundary at said opposite end, a throat communicating between said strainer box and said pool providing a common free water surface when said pool is filled to said designed water level, and a weir at the pool end of said throat, said weir including a transversely horizontal protrusion ex¬ tending outwardly and downwardly into the volume to be occupied by pool water, the highest transverse line of said protrusion being slightly lower than said designed water level so as to provide a gradual shallowing of pool water in the vicinity of said throat so that surface water is accelerated as it is induced by said means to pass over said weir. 2. Apparatus as defined in claim 1 wherein said surface water movement inducement means consists of one or more water jets or throwers disposed above the surface level of water in said pool adapted to spray water under pressure on to the surface of said pool water. BU EA 3. Apparatus as defined in claim 1 wherein sai surface water movement inducement means consists of one or more water jets or throwers located below the surface of said pool water adapted to inject pressur¬ ized water to said pool surface. 4. Apparatus as defined in claim 1 wherein said surface water movement inducement means consists of one or more water jets or throwers disposed above the surface level of water in said pool adapted to spray water under pressure on to the surface of said pool water and one or more water jets or throwers located below the surface of said pool water adapted to inject pressurized water to said pool surface. 5. Apparatus as defined in claim 1 wherein said strainer box incorporates a filter element adapted to filter from eighty to one hundred percent of the pool water during an operation period of 1 to 3 hours of said apparatus. 6. Apparatus as defined in claim 1 wherein said strainer box contains a plurality of graded coarse and fine strainers adapted to arrest solid matter carried into said strainer box. 7. Apparatus as defined in claim 4 further comprising a plurality of jets or hose means arranged on or adjacent the pool floor so as, when actuated, to stir into suspension sediment deposited on the pool floor, said sediment then being transported to and removed over said weir by movement of said surface water. 8. The swimming pool of claim 1 further in¬ cluding means to maintain pool water level at said design level. 9. A swimming pool as defined in claim 8 wherein said pool water level maintaining means comprises a first element adapted to direct excess water to waste and a second element adapted to auto¬ matically add water to replace water loss from said pool. 10. A swimming pool as defined in claim 9 wherein said first element is an inverted U-tube fixed adjacent said pool and wherein said second element is a float valve and cistern. 11. A swimming pool as defined in claim 9 wherein said first element is an inverted U-tube fixed adjacent said pool and said second element is a valve which is either float operated or probe controlled.

Inventors: CANT PETER R, CANT, PETER, R.
Applicants: UNITED MIDWEST INTERNATIONAL C, UNITED MIDWEST INTERNATIONAL CORPORATION
Application year: 1984
Main classification: E04H3
IPC codes: E04H4