1 IMPROVEMENTS IN OR IN RELATION TO POOL CLEANERS FIELD This disclosure relates to pool cleaners and particularly to pool cleaners of the self propelled type. 5 BACKGROUND Self propelled pool cleaners have various mechanisms used for propulsion, some involving pulsating water flow, two examples are described below. Some pool cleaners that employ self propulsion mechanisms have a 10 valve arrangement that intermittently opens and closes and this provides the propulsive force that propels the pool cleaner across the pool bottom and up and around wall surfaces. One arrangement employs a flexible diaphragm. The diaphragm has a flow through passage with a normally narrow throat. The throat is biased to a normally narrow position by the form of its construction but 15 can be pulled open when a negative pressure is applied thus opening the passage. The throat is located inside a chamber and due to the construction of the chamber as pump pressure is applied to the cleaner outlet, pressure drops around the diaphragm and since the throat is flexible and can expand, thethroat widens and in turn produces a pulse of flow. The pulse gives rise to a 20 corresponding change in pressure as the throat widens, the pressure equalizes which allows the throat to return to normal but as soon as it does the pressure drops and the process repeats at a frequency of about 60 cycles per minute. In another arrangement a hammer mechanism oscillates back and forth opening and closing the flow and this propels the pool cleaner.
2 Cleaners of this type have a generally circular skirt which travels over the pool bottom and wall surface to clean the surface. The skirts have a varying configuration from radially pleated to flat skirts. Some skirts include projecting fingers, castellated periphery and radial slits. The skirts may include 5 circumferentially spaced radially extending slots or grooves, or pleats. The skirt remains in close contact with the surface being cleaned as the cleaner moves with a pulsing action across the pool surface. These cleaners typically include the skirt in a horizontal plane, a main body inclined to the vertical at about 45 degrees and a bumper wheel located at the top of the main body 10 which serves to deflect the top portion of the cleaner and keep the cleaner in operative alignment when close to walls, steps and other obstacles around the pool. It is usual for the pool cleaners of this type to have the ability to climb pool walls and the like and in a climbing action, once the skirt comes away from 15 the wall, the pool cleaner usually free falls back to the bottom of the pool to re commence its cleaning action. In some cleaners, it is usual to employ a float and opposed counter weight so that when the cleaner is in free falltowards the bottom, the float serves to right the cleaner so that it lands "catlike" with the skirt facing downwards and engaging the bottom of the pool. 20 US Patent 4,742,593 describes a pool cleaner of the type employing a flexible diaphragm as described above. WO 2004/007872 describes a pool cleaner with round skirt and a float carried at an aft portion for acting in conjunction with a weight in allowing the cleaner to fall to an upright position when dropping from the side wall of a 3 swimming pool. The float is a sphere or ball and is in a fixed central position. The float and weight are just above and just below a horizontal line extending front to back. The float is on the end of an arm toward the rear of the cleaner and the weight toward the front located at the end of a projecting spur. This 5 arrangement means that as the front is being pulled down by the weight the rear is being pulled up by the float so as the cleaner falls the front of the skirt is the first part to touch the pool bottom in the usual way but the spur weight is prone to damage and wear. US Patent 6,119,293 describes a similar cleaner in as far as the relative positions of the float and weight, in this case the float is at 10 the end of a central stem fitted at the very rear and bottom of the cleaner body and behind the water inlet in the centre of the skirt. The stem is either flexible or swivels about on a ball in a D-shaped cut out within side lobes. A weight is located in front of the cleaner and the effect of the float and weight is to steer the cleaner away from the water surface. In this patent there are various options 15 and extra additions including extra weights around the base that are said to further assist in the cleaner adopting the desired attitude. In addition the cleaner in US 6,119,293 is basically a float on a stick attached to a ball jointwhich is non-adjustable. The float and stick arrangement will wear the body at the ball joint and the whole cleaner must be replaced. The single arm applies torque at 20 only one point which is not near its centre of mass. WO 2006/109118 describes a pool cleaner with a float suspended on a pair of slotted arms which move freely on bilateral pins. The slots are much larger than the pins so that the float arms not only move in and out but there is enough play between the slots and the pins that the float has limited sideways 4 movement. In Figure 3 of this specification the position of the float arms are illustrated for the situation where the cleaner is travelling along a wall. Specifically, since the pivot pins are fixed on the sides of the cleaner the upper arm nearest the wall shortens relative to its pin and the lower arm furtherest 5 from the wall lengthens relative to its pin effectively jamming the float in an inclined attitude with two points of contact for each arm, one with the pin and the other with the body of the cleaner. Thus the turning moment applied is proportional to the length of the lower arm and its contact point with the body. In the description this is position is said to aid the cleaner climbing the wall. 10 There is no mention of the float serving any other purpose. WO 2008/037024 uses a pivoting float to keep the cleaner correctly oriented. The float is a cylindrical float having its long axis extending across the cleaner and being supported at each end by arms which pivot about a pivotaxis parallel to the cylinder axis. A counterweight is opposite the float and the float is 15 said to stabilise the cleaner body as it sinks and keep it upright. The pivot axis of the float is directly over the weight so that the float can swing front to back across the weight. A cleaner marketed under the brand name KreepyKrauly is similar to this having a float assembly where two floats are joined by U-shaped joiners and the floats can pivot fore and aft and the float and counterweight are 20 mounted on a rotating collar so that the float and counter weight rotate in concert with the collar. US Patent 7,434,285 describes a pool cleaner with a fixed float for automatic uprighting. The pool cleaner has an opening for flow of water into the pool cleaner and the float is located directly and vertically above the opening.
5 While these pools cleaners all work well they all operate randomly and while it is desirable to clean the pool wall most sediment accumulates on the pool bottom so the length of time that a cleaner is travelling on the pool wall means there is less time spent cleaning the pool bottom. 5 Therefore it is an object of the present disclosure to provide a pool cleaner which has a greater residence time on the pool bottom. US Patent 6,119,293 operates similar to the presently disclosed pool cleaner in so far as the float is able to move both sideways and fore and aft by reason of the ball joint andscalloped guide. The geometry of relative positions of the float and 10 weight and the independent fore and aft pivot and sideways movement of the disclosed pool cleaners may provide an improved response time and faster self righting which makes a pool cleaner with the present improvements more efficient. In the present disclosure when the cleaner is oriented on a wall and climbing the applied torque to force the cleaner back down the wall is optimized 15 so that total residence time on the pool bottom is increased. It is therefore a further object of the present disclosure to provide a pool cleaner with fore and aft and sideways float movement that in some embodiments may improve applied torque and therefore response time and overall efficiency. 20 OUTLINE OF THE DISCLOSURE In view of the above objects of the pool cleaners actual orientation during cleaner operation is a significant and controlling consideration indefining the invention, consequently the following statements describes broad aspects of the disclosure both in terms of structure and orientation during operation.
6 In one aspect there is disclosed a self-propelled pool cleaner having; an inclined body having a longitudinal axis, a lower suction end, an upper outlet end connectable to a suction hose, an upper side and a lower side, the body being forwardly inclined relative to the direction of travel across a submerged 5 surface; a counter weight mounted to the lower side of the body; a float assembly including a float suspended from the upper side of the body and at least one pivot arm having a distal end attached to the float; a float mounting mechanism including a pivot pin extending transversely 10 from the body to which the proximal end of the at least one rigid pivot arm is pivotally mounted to allow pivotal movement of the float towards and away from the lower suction end of the body; a guideway defining a circular arc having an axis that is co-axial with the longitudinal axis of the body land that is located on the upper side of the body at 15 a position that is vertically opposite to at least part of the counterweight the counterweight ; the pivot pin of the float mounting mechanism is mounted to the guideway for movement within the guideway to allow side to side movement of the attached float is that is constrained to movement through an arc co-axial 20 with the longitudinal axis of the body; wherein the pivotal movement of the float towards and away from the lower end of the body and the side to side pivotal movement are independent and are the only degrees of freedom in which the float is permitted to move. In another aspect, there is disclosed a self propelled pool cleaner of the 7 pulsating flow type having a generally flat skirt, a hollow body having a lower aft end and an upper fore end, an inlet near the aft end of the body, the inlet being bounded by the skirt, an outlet near the fore end of the body and connectable to a hose, the body housing a valve and flow passage communicating between 5 the inlet and outlet, the body having an upper side and a lower side and having its aft end coupled to the skirt and the body being inclined to the skirt, a pivoting float assembly, the float assembly having a float suspended from theupper side of the body, a float mounting mechanism positioned on the upper side of the body, the mounting mechanism permitting fore and aft movement of the float 10 assembly as well as side to side movement of the float assembly, a counterweight opposite the float wherein: the mounting mechanism has a transversely extending guideway constraining the side to side movement of the float along the guideway independently of the fore and aft float movement; 15 the float being moveable relative to the counterweight; bilateral float stops limiting sideways travel of the float; such that when the skirt is travelling along a pool wall the float travels toward its zenith and an uppermost stop is engaged before the float reaches its zenith, the float applying an upward moment to the body whereafter the float 20 moves aft turning the pool cleaner down the wall. In another aspect there is provided in a self propelled pool cleaner of the pulsating flow type having a generally flat skirt, a hollow body having a lower aft end and an upper fore end, an inlet near the aft end of the body, the inlet being bounded by the skirt, an outlet near the fore end of the body and connectableto 8 a hose, the body housing a valve and flow passage communicating between the inlet and outlet, the body having an upper side and a lower side and having its aft end coupled to the skirt and the body being inclined to the skirt, a pivoting float assembly, the float assembly having a float suspended from the upper 5 side of the body, a float mounting mechanism positioned on the upperside of the body, the mounting mechanism permitting fore and aft movement of the float assembly as well as side to side movement of the float assembly, a counterweight mounted opposite the float mounting, wherein the hollow body has a central axis; 10 the counterweight extends axially and is confined to a region adjacent the inlet and just below the central axis; the mounting mechanism is located adjacent the inlet and being directly above the counterweight in opposed relation; the float being moveable relative to the counterweight; 15 the mounting mechanism having bilateral float stops limiting sideways travel of the float such that when the skirt is travelling along a pool wall the float travels toward its zenith and the uppermost stop is engaged before the float reaches its zenith, as the cleaner begins to travel horizontally the body is urged to rotate about its central axis by the counterweight applying a downward 20 rotational force on one side of the central axis while the float applies an upward rotational force on the opposite side of the central axis, the upward rotational force being applied to the body in the vicinity of the counterweight. Preferably, the counterweight is formed integrally with the body and is located just in front of the inlet.
9 In one preferred embodiment there is provided a self propelled pool cleaner of the pulsating flow type having a generally flat skirt, a hollow body having a lower aft end and an upper fore end, an inlet near the aft end of the body and connectable to a hose, the inlet being bounded by the skirt, an outlet 5 near the fore end of the body, the body housing a valve and flow passage communicating between the inlet and outlet, the body having an upper sideand a lower side and having its aft end coupled to the skirt and the body being inclined to the skirt, a pivoting float assembly, the float assembly having a float suspended from the upper side of the body, a float mounting mechanism 10 positioned on the upper side of the body, the mounting mechanism permitting fore and aft pivoting movement of the float assembly as well as side to side movement of the float assembly relative to an opposing counterweight, the mounting mechanism having a transversely extending fore and aft float movement pivot axis, the fore and aft float movement pivot axis beingmoveable 15 side to side as the float travels side to side, bilateral float stops to limit sideways travel of the float such that when the skirt is travelling along a pool wall the float travels toward its zenith and the uppermost stop is engaged before the float reaches its zenith, the float applying an upward moment to the body to relieve the skirt wherein the float pivots aft driving the pool cleaner down the wall. In 20 this embodiment the counterweight and the float mounting mechanism are located just in front of the inlet. Preferably, the float is mounted with a first pivot mounting and the first pivot mounting is itself mounted with a guide moveable in a guide-way. Typically, the guide-way is an arcuate guide-way and preferably the guide-way 10 is a circumferentially extending guide-way extending around an upper most part of the body opposite the counter weight. The guide-way may be circular and be connected to a non-circular main body. Preferably, the float is a pivoting float and the mounting mechanism has 5 a transversely extending fore and aft float movement pivot axis, the fore and aft float movement pivot axis being moveable side to side as the float travels side to side, the float being suspended on a transverse pivot pin having a length about as wide as the body adjacent to the pivot pin. Preferably, the pool cleaner has a generally horizontal skirt and a body 10 inclined to the vertical coupled to the skirt, a deflector wheel in a plane substantially at right angles to the body and having a lower edge of the deflector wheel adjacent the peripheral edge of the skirt, the spacing between the peripheral edge of the skirt adjacent to the lower edge of the deflectorwheel being so chosen and arranged to prevent pool surfaces entering thespace 15 between the lower edge of the deflector wheel and the nearest adjacent edge of the skirt and impinging against the body of the pool cleaner. Preferably, the pool cleaner has an inner tube with an inner tube support for a pool cleaner employing inner and outer tubes held within a two part main outer body, the inner tube having a diaphragm mounted in line with the inner 20 tube forming an inner tube and diaphragm assembly, the outer tube forming a pressure chamber around the diaphragm, the inner tube support comprising a plug in diaphragm holder surrounding the inner tube and holding the inner tube in axial alignment, the tube support having flow though passage means communicating with the pressure chamber, the support comprising a wall 11 projecting across from an inner wall of the main body to the inner tube to hold the inner tube in fixed spaced relation to the inner wall of the main body, the flow though passage means comprises circumferentially spaced openings, the wall projecting across has an inner ring which fits into a circular channel in a 5 collar in the diaphragm and the body is separable into two axially extending housing parts joined together at or adjacent the diaphragm holder. Preferably, the float mounting mechanism is axially adjustable. Typically, the float mounting mechanism includes a C-shaped clip on guideway and the body has axially spaced latches so that the body can clip into the floatmounting 10 mechanism with a hand insertable snap action. Typically, the housing parts are oval in cross-section where they join so that they separate when twisted. BRIEF DESCRIPTION OF THE DRAWINGS In order that the present disclosure may be more readily understood and 15 be put into practical effect, reference will now be made to theaccompanying drawings and wherein: Figures 1 and 2 illustrate embodiments wherein longer and shorter body portions are utilised, where in Figure 1 a bumper strap is used and Figure 2 a shorter body is used to eliminate the need for a bumper strap; 20 Figure 3 illustrates use of a two direction pivoting float; Figure 4 is a cross sectional view of a typical pool cleaner according to the one aspect of the disclosure; Figure 5 is the section of Figure 4 with the skirt and bumper wheel omitted; 12 Figure 6 is an embodiment showing a longitudinal cross section illustrating the inner tube support and the diaphragm in position; Figure 7 is a section through 7-7 of Figure 6; Figures 8 and 9 illustrate the multi-directional pivoting action of the float; 5 Figure 10 illustrates a preferred guide and guide-way for the float; Figure 11 illustrates the guide-way in greater detail; Figure 12 is a drawing illustrating a typical trajectory of a pool cleaner according to the disclosure compared with a similar pool cleaner but without the specific float and counterweight relationship peculiar to the present disclosure; 10 Figures 13 to 15 illustrate how the body separates into two parts; and Figure 16A - 16F illustrate how a diaphragm is replaced. METHOD OF PERFORMANCE Referring to the drawings and initially to Figures 1 and 2 there is illustrated respective pool cleaners 10 and 11 with the pool cleaner 10 having a 15 body portion 12 and the pool cleaner 11 having a body portion 13 which is as shown shorter in length than the body portion 12 of the pool cleaner 10. As illustrated, the two pool cleaners shown are navigating across a series of steps 14 and 15 respectively. The body portion 12 of the pool cleaner 10 is prone to engage a step as shown and the arrows 16 and 17 show the effect of 20 theoscillating action of an internal diaphragm or hammer arrangement usual in these types of cleaners. The pool cleaner 10 has become stuck on the step and will simply vibrate up and down and remain in that position by reason of the step engaging against the body and the bumper wheel 18 being caught on the horizontal section 19 of the step above. In order to overcome this problem, 13 shown in phantom is the use of a bumper strap 20. Bumper straps is of the type illustrated in Figure 1 and are commonly used in order to prevent the problem illustrated in Figure 1. Figure 2 illustrates an alternative to this whereby the shorter body and 5 the relative disposition of the extremity of the bumper wheel 21 and the peripheral edge 22 of the skirt 23 is such that it is much shorter than the height 24 of a step and in this case about 180mm. Thus it is not possible for the step corner 25 to pass between the bumper wheel 21 and the skirt periphery 22 at their nearest points. 10 In both cases the cleaners are equipped with a float 26 which is located opposite a counter weight 27 with the float 26 being mounted on a pivot arm 28 so that the float may pivot in the direction of arrow 29 about a pivot pin 30. The counterweight is close in to the central axis and formed integral with the body so that there is little if any prospect of wear. The float is suspended a relatively 15 long distance from the central axis so that it provides a rotary moment to the body while the counterweight also provides a rotary movement and both these are in the same vicinity so that rotary torque is optimised for better steering without twisting as in some of the prior art models. The pivot pin 30 is adapted to travel in a guide-way about an arc having 20 a pivot axis co-axial or thereabouts with the central axis 31 of the body 12 and body 13 respectively. The guide way can be made integral with the body or may be a detachable and adjustable part as will be described below. The function and operation of this shall become clearer in the description to follow. The cleaner 11 is shown in perspective view in Figure 3, it being appreciated 14 that the only substantial difference between the cleaner 11 and the cleaner 10 as illustrated in Figure 1 is the length of the body with the internal structure and other parts of the cleaner being the same and these will be discussed in the description which follows. One important consequence of the shortening of the 5 body is that the float is prevented from laying flat against the body by the bumper wheel. This means that when the cleaner is travelling up a wall the float rides against the bumper wheel so as the cleaner begins to move to the horizontal the float is already substantially in position to turn the pool cleaner down. Again this further increases response time which increases residence 10 time on the pool bottom. As can be seen in Figure 3, the arm 28 is fitted to a clip on guide-way 32 which has tangs which clip into slots 33 on opposite sides of the body 13. The operation and pivoting action of the guide-way and float relative to the body 13 will be described in greater detail in relation to Figures 8 to 11. 15 In Figure 3, the outer body 13 has a flange 34 which takes a removable foot 35 to adapt the flange to hold the skirt 23. Referring now to Figures 4 and 5, Figures 4 and 5 illustrate the assembly of the body 13 with the interior part whereby a diaphragm of known construction 36 is located inside the body 13. The diaphragm is in communication with an 20 inner tube 37 connected to the upper end 38 of the diaphragm so arranged that parallel flow paths are created from the inlet 39between the inner tube 37 and the outer tube 40 to a hose, not shown, connected to the outer tube 40. The outer tube has a tapered end 41. A pressure differential causes the diaphragm 36 to expand and contract between the position shown and the expanded 15 position shown in phantom at 42 thus causing an intermittent pulsing action which propels the pool cleaner along the surface of the pool being cleaned. Pool cleaners of this type are self propelled along the bottom of the pool and up the side walls of the pool until such time as the suction holding the skirt in place 5 against the surface weakens or becomes dislodged by obstacles such as pool lights so that it is released from the surface and the pool cleaner falls by gravity back to the bottom of the pool. Cleaners of this type have been prone to fall to the bottom in a non operative position and it has been known to utilise floats but these floats have 10 not utilised the dual directional pivoting action illustrated which dual directional pivoting action is in the vicinity of the counter weight 27 and is guided in its sideways movement. This speeds up the righting of the pool cleaner so that it rights itself quicker than is the case in the prior art. In the illustrated embodiment, the pivot arms 28 have ends located in a circular guide-way 43 15 and the body 13 in this embodiment is circular as well as is the guide-way 43 and the guide 44. Further features illustrated in Figures 4 and 5 include the section of the foot 35, the foot 35 being of known configuration and having a channel 45 adapted to receive the skirt within the channel 45 in operative position as 20 illustrated in Figure 4. In the illustrated embodiment, the outer tube 40 is secured to the outer body 13 using a hand nut 46 which screws on to a threaded clamping arrangement at 47. The outer tube includes a flange 48 which abuts against a washer 49 and the outer tube 40 includes an extension 50 extending into the 16 body 13 so that the outer tube 40 may rotate within the body 13. The extension 50 is selected in length to minimise rocking action of the tube 40 and thereby inhibit wear in the region of its connection within the body 13 since the outer tube permits rotation of the hose relative to the cleaner and is to 5 minimise hose twisting. The bumper wheel 21 is held in position by reason of the inner surface 51 of the hand nut 46 butting against the bumper wheel at 52 and the shoulder 53 on the other side of the hand wheel of the body 13. Referring now to Figures 6 and 7, the connection of the diaphragm 36 in 10 place is illustrated and the inner tube 37 is fitted in the flexible end 54. The outer end 55 has flexible ribs 56, 57, 58 and 59 which clip in to corresponding channels as illustrated. The inner end 54 has a channel 60 which by reason of the flexibility of the rubber material from which the diaphragm is made the diaphragm locates with the channel 60 in the position illustrated relative to a 15 circular retainer ring 61. The retainer ring or support which can more clearly be seen in Figure 7 has flow through apertures 62, 63, 64 and 65 for water flow between the inner and outer tubes. Referring now to Figures 8 to 10 an alternative arrangement mounting of the float 26 is illustrated when compared to the arrangement of Figures 5 and 20 6. The arrangement of Figures 8 to 11 corresponds to the arrangement illustrated in Figures 1 to 3 whereby the body 13 has slots 33 diametrically opposed on the body 13 and these receive tangs 66 and 67 which dependfrom a circular body 68. The body 68 carries a circular guide-way 69 with a guide 70 travelling between 17 opposite ends of the guide-way. It will be appreciated that the body 13 need not be of circular cross section in this arrangement since the guide-way clips to it and is independent of it as is the guide. Thus from the perspective of aesthetics an oval body may be 5 used without affecting the operation of the pivoting action of the float as illustrated. An oval body also facilitates construction of the body from two parts that may be easily separated by hand for replacement of the diaphragm. The float 26 is connected to the guide by two pivot arms 71 and 72 which have openings at their ends so that they slide into position and are retained in place 10 by snap in retainers 73 and 74 (not shown in Figures 10 and 11). The guide 70 has a circular shoulder 75 and at opposite ends of the guide has projections 76 and 77 such that the rail 78 of the guide-way is retained between the surface 75 and the inner surfaces 78 and 79 of the projections 76 and 77 with the rail against the surface 80. A corresponding structure is on the opposite side of the 15 guide and this retains the rail 81 so that the guide slides around a circular path defined by the rails 78 and 81. The guide 70 includes internal bores 82 and 83 at opposite ends and these are blind bores with an internal rib 84 so that stubs projecting from retainers 73 and 74 may snap fit into the bores 82 and 83 to retain the arms 71 and 72 in place and permit the pivoting action of the float 26 20 as illustrated in Figure 8 and Figure 9. Referring to Figure 12 there is illustrated a typical comparative trajectory of the disclosed pool cleaner showing the trajectory of a poolcleaner with a lower response time in broken line. Both pool cleaners enter the turn at the same trajectory but a pool cleaner as presently disclosed turns sooner.
18 In pool cleaners of the present kind equipped with a diaphragm, the diaphragm goes through a very large number of repetitions of expansions and contractions so its life is limited and it can split and must be replaced. The present pool cleaner is made to facilitate ease of diaphragm replacement and 5 this is depicted in drawings Figures 13-15 and 16A-16F. Referring to Figures 13-15 a pool cleaner 11 with it outer tube, nut and bumper wheel removed exposing the thread 85 and the top end of inner tube 86. The body 87 in this case is made from an upper part 88 and a lower part 89. The lower part 89 has a circular recess 90. An annular spacer 91 fits into the 10 recess 90. A flexible diaphragm 92 has an upper collar 93 which includes an outer circular groove 94. The annular spacer 91 has an inner ring 95 which fits snugly into the groove 94 so that the annular spacer may operate as a diaphragm holder, the holder being a plug in part that fits into the cleaner body. The inner tube 86 then fits inside the collar and is retained in the collar. The 15 body is non-circular in cross section in the region of the spacer and is held together by axial protrusions on the inside of the part 88 locating in shallow axial recesses on the overlapping outside of the part 89. In order to separate the parts it is simply back and further twisting action while pulling and they easily separate as shown in Figures 13 and 15. 20 Once the parts 88 and 89 have been separated the part 88 may be removed as shown in Figure 16A. The tube 86 is then removed as shown in Figure 16B exposing the collar 93 of the damaged diaphragm. The damaged diaphragm may be manually manipulated and pulled out through the skirt end 95 and then with the inner tube reversed and fed through the inner ring 95 of 19 the spacer 91 exposing the top end 96 of the inner tube 86 as shown in Figure 16C. The collar of the diaphragm is then squeezed as shown in Figure 16D and fitted into the end 96 so that the tube 86 may be used to drawer the diaphragm into the part 89 and thereby manually manipulate the collar of the 5 diaphragm into the position illustrated in Figure 14. This involves the top end of the tube 86 being removed after drawing the diaphragm though and this is shown at Figure 16E. The tube 86 is then reversed and its opposite grooved end 97 is then inserted back into the collar being the reverse of Figure 16B and then the reverse of Figure 16A sees the two parts put back together. The 10 bumper wheel and outer tube are then put back in place and the nut is screwed onto thread 85. Whilst the above has been given by way of illustrative example, many variations and modifications thereto will be apparent to those skilled in the art without depending from the broad ambit and scope of the invention as set out in 15 the appended claims. For example the counterweight weighs approximately 375 gms and the float is mounted at the end of arms measuring 13cm and the float is oval in cross-section having a length of 9 cm and elliptical axes of 8cm and 4cm. The float is filled a material having a Specific Gravity less than 1 so that even if the float becomes cracked the cleaner will still work properly. Of 20 course all these dimensions could vary considerably while still being within the ambit of the invention.