Patent application title: SWIMMING POOL CLEANER
George Patrick Danks (Johannesburg, ZA)
IPC8 Class: AE04H416FI
Class name: Baths, closets, sinks, and spittoons pool type accessory
Publication date: 2011-07-14
Patent application number: 20110167552
A swimming pool cleaner which is located inside a passage in a body of
the cleaner, which includes a diaphragm with a first end anchored by
means of a resilient ring to the body, and a second end, into which a
pipe is inserted, which is directly engaged with the body.
1. A swimming pool cleaner which includes a body through which is formed
a passage with an inlet, an opposing outlet, and at least one stop
formation, a diaphragm, with opposed first and second open ends, which is
located in the passage, support structure at the first end of the
diaphragm, and a pipe which is engaged with the second end of the
diaphragm and which is movable from the inlet through the passage,
thereby to bring at least one limiting formation on the pipe or diaphragm
into abutment with the stop formation.
2. A pool cleaner according to claim 1 wherein the support structure is resiliently flexible, to a limited extent, in an axial direction of the passage, to compensate for a tendency of the diaphragm to vary in length between the first and second ends.
3. A pool cleaner according to claim 2 wherein the support structure is a ring which is separately formed from the diaphragm and which is engageable with the diaphragm in a first orientation in which the ring has a first resiliently flexible characteristic or in a second orientation in which the ring has a second resiliently flexible characteristic which differs from the first resiliently flexible characteristic.
4. A pool cleaner according to claim 1 which includes: (a) a plurality of the stop formations, or (b) a plurality of the limiting formations, or (c) a plurality of the stop formations and of the limiting formations.
5. A pool cleaner according to claim 1 which includes a plurality of the stop formations and the limiting formation, on the pipe or diaphragm, is resiliently deformable so that it can be moved successively to the respective stop formations.
6. A pool cleaner according to claim 5 wherein each stop formation is a shallow circular groove.
7. A pool cleaner according to claim 1 wherein the pipe and body include interengageable screw formations so that, by screwing the pipe relative to the body, an axially directed force in the diaphragm is varied.
8. A pool cleaner according to claim 1 wherein the at least one limiting formation is a groove on the diaphragm and the stop formation is a rib in the body which is engageable with the groove.
9. A pool cleaner according to claim 2, which includes: (a) a plurality of the stop formations, or (b) a plurality of the limiting formations, or (c) a plurality of the stop formations and of the limiting formations.
10. A pool cleaner according to claim 2, which includes a plurality of the stop formations and the limiting formation, on the pipe or diaphragm, is resiliently deformable so that it can be moved successively to the respective stop formations.
11. A pool cleaner according to claim 2, wherein the pipe and body include interengageable screw formations so that, by screwing the pipe relative to the body, an axially directed force in the diaphragm is varied.
BACKGROUND OF THE INVENTION
 This invention relates to a swimming pool cleaner.
 One type of cleaner includes a diaphragm which is made from a flexible material which forms a passage with opposed open ends. In use of the cleaner water is drawn through the diaphragm which is alternately collapsed and expanded. This produces a pulsating water flow in a flexible hose which is connected to the cleaner and, as a result, the cleaner is caused to move, substantially in a random manner, over a submerged surface which is to be cleaned.
 Pool cleaners of this type are exemplified in U.S. Pat. Nos. 4,642,833, 4,742,593, 4,742,833, 5,014,382, 5,315,728 and 5,450,645.
 The diaphragm is positioned inside a chamber in a body of the pool cleaner. The action of the diaphragm is dependent, inter alia, on the way in which the diaphragm is positioned inside the chamber for if the diaphragm is subjected to a high tensile force or compressive force, its length can vary and its performance can then be adversely affected.
 It is also possible for the characteristics of the material from which the diaphragm is made to vary due to a number of factors including manufacturing processes and as a result of usage. This type-of variation can manifest itself as a dimensional change which, in turn, can alter the size of a tensile or compressive force existing in the diaphragm. This alteration can affect the operation of the cleaner.
 It is desirable therefore to be able to adjust the installed condition of a diaphragm, at least to a limited extent.
SUMMARY OF INVENTION
 The invention provides a swimming pool cleaner which includes a body through which is formed a passage with an inlet, an opposing outlet, and at least one stop formation, a diaphragm, with opposed first and second open ends, which is located in the passage, support structure at the first end of the diaphragm, and a pipe which is engaged with the second end of the diaphragm and which is movable from the inlet through the passage, thereby to bring at least one limiting formation on the pipe or diaphragm into abutment with the stop formation.
 The support structure may be integral with the diaphragm, or it may be separately formed and then attached to the diaphragm. The support structure may be in the form of a ring which surrounds the diaphragm. The support structure may be resiliently deformable or flexible so that it can move, at least to a limited extent, when the length of the diaphragm tends to change due to any of a number of factors. This feature enables the effect of an axially directed force which may exist in the diaphragm to be compensated for, at least in some way, substantially automatically.
 The cleaner may include a plurality of the stop formations or a plurality of the limiting formations or a plurality of the stop formations and of the limiting formations. By bringing a selected limiting formation into abutment with a stop formation, or a limiting formation into abutment with a selected stop formation, the position of the second end of the diaphragm, relative to the passage, can be varied. This permits at least some of the forces which might exist inside the diaphragm to be adjusted.
 In one form of the invention the pool cleaner includes a plurality of stop formations and the limiting formation, on the pipe or diaphragm, is resiliently deformable so that it can be moved successively to the respective stop formations. Each stop formation may be of any appropriate kind and, for example, may be in the nature of a shallow circular groove. The stop formation may be integrally formed with the pipe. Alternatively the stop formation may be separately formed, and may comprise a resiliently deformable component such as an O-ring or the like e.g. on an outer side of the pipe or diaphragm. An equivalent resiliently deformable component could alternatively be formed integrally with the diaphragm. Movement of the limiting formation between successive stop formations can be accomplished by exerting a tensile force on the pipe which is sufficient to cause the limiting formation to be deformed so that the limiting formation can be moved to an adjacent stop formation.
 In a different form of the invention the pipe and body include interengageable screw formations so that, by screwing the pipe relative to the body, an axially directed force in the diaphragm is varied. For example, if the pipe is screwed in one direction the diaphragm is subjected to an increasing force (tensile or compressive) while, when the pipe is screwed relative to the body in an opposing direction, the force in the diaphragm is reduced. During this type of screw movement at least one limiting formation on the pipe can be moved past at least one formation on the body with such movement only being able to take place if torque in excess of a predetermined value is applied to the pipe relative to the body. The increased level of torque causes deformation of one or both of the formations and, in this way, rotational movement is possible.
BRIEF DESCRIPTION OF THE DRAWINGS
 The invention is further described by way of examples with reference to the accompanying drawings in which:
 FIG. 1 is a side view, in section and partly exploded, of components of a swimming pool cleaner according to a first form of the invention;
 FIG. 2 is similar to FIG. 1 but illustrating the components in an assembled configuration;
 FIG. 3 shows a modification to the arrangement in FIG. 2;
 FIGS. 4 and 5 are views of a swimming pool cleaner according to a second form of the invention in different stages of assembly; and
 FIG. 6 is a cross-sectional view of the cleaner according to the second form of the invention taken on a line 6-6 in FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
 FIGS. 1 and 2 of the accompanying drawings illustrate components of a pool cleaner 10 in exploded and assembled modes respectively, in cross-section and from one side. The construction of the cleaner is not described in detail for in general terms the cleaner is constructed using principles known in the art. However those features which are necessary for an understanding of the invention are described herein.
 The cleaner includes a body 12 in which is formed a passage 14 which, at one end, has an inlet 16 and, at an opposing end, an outlet 18. A flexible diaphragm 20 is coupled to a pipe 22. The diaphragm has a first, open end 24, an opposing, second, open end 26 and a shaped, flexible wall 28 between the ends. A flow passage exists inside the diaphragm between the ends 24 and 26. In use of the diaphragm the flexible wall 28 alternately collapses and expands as water flows through the diaphragm and this produces a pulsating water flow in a flexible corrugated hose which is connected to the cleaner. This results in movement of the cleaner. This aspect is not further described for it is known in the art.
 The pipe 22, at one end, is in the form of a short spigot 32 which is flanked by an annular shoulder 34. An O-ring 36 is engaged, under tension, with an annular groove 38 on an outer side of the diaphragm. The groove is between circumferential ribs 38A and 38B. The spigot is inserted into the open end 26 of the diaphragm and, when the diaphragm is correctly engaged with the spigot, an end of the diaphragm abuts the shoulder 34. This brings the groove 38 into register with a groove 40 in the spigot 32 and, due to the tensile force which is exerted by the O-ring, the diaphragm is effectively locked to the tube.
 When the pool cleaner is assembled a leading end 44 of the pipe is passed through the inlet 16 along the passage in order to project from the outlet 18, as shown in FIG. 2.
 The body 12 has an inner tubular collar 46, close to the outlet 18, which on an inner surface is formed with a plurality of closely spaced, circular grooves or recesses 48 which are accurately dimensioned, relative to the external dimension of the O-ring 36, so that if the pipe 22 is to be moved in its axial direction sufficient force must be applied to the pipe in order for the O-ring to be compressed radially inwardly. The O-ring can thus be moved from one recess 48 to an adjacent one.
 The diaphragm has support structure in the form of a ring 54 which is integrally formed with the diaphragm, or which is attached to the diaphragm, adjacent the first end 24. The ring 54 abuts a shoulder 56 in the body. The ring is resiliently deformable or flexible, to a slight extent, in an axial direction i.e. towards or away from the inlet 24. This is a useful feature for although the ring anchors the diaphragm at the end 24 to the body 12, it does so in a way which allows a degree of axial movement of the diaphragm to take place relative to the body of the cleaner. It has been found that if the length of the diaphragm tends to vary due, for example, to extended usage of the cleaner, that the capability of the ring to move in one direction or the other can compensate, substantially automatically, for such tendency. This characteristic enables the diaphragm, in many instances, to continue functioning satisfactorily without a manual adjustment of the compressive or tensile force in the diaphragm being required.
 It is possible to configure the cross-sectional shape of the ring 54 to achieve different effects. For example FIG. 1A illustrates a cross-section of a ring 54A which is rectangular with opposed surfaces X and Y respectively which are identical. If the ring is separately formed from the diaphragm then the orientation of the ring relative to the diaphragm is not relevant. There is no difference in the effect of the ring on the diaphragm if the surface X faces towards the inlet 24 or if the surface Y faces towards the inlet 24.
 On the other hand FIG. 1B illustrates a ring 54B, in cross-section, which has a planar surface P and a channel-shaped surface Q. The capability of the ring 54B to flex varies significantly if the surface P abuts the shoulder 56 or if the surface Q abuts the shoulder 56. This characteristic can also be used (by manually changing the orientation of the ring) to adjust the tensile or compressive force in the diaphragm to take account of variations arising from usage or other factors.
 In a modified form of the invention the diaphragm is integrally formed with a projection or projections which are resiliently deformable, as is the case with the O-ring, thereby to be engaged with successive recesses 48 and so adjust the force in the diaphragm. The use of an O-ring is then optional for, when the projection, e.g. one of the ribs 38A and 38B on the diaphragm, is engaged with the recess 48 in the body the diaphragm at that location is urged inwardly and is thereby automatically secured to the pipe.
 A similar effect can be achieved if the body is formed with an inwardly projecting rib 58 as is shown in FIG. 3. The rib is shaped and positioned to engage directly with the groove 38. The O-ring 36 is not used. When the pipe 22 is moved to its chosen position the rib 58 slips into the groove 38 and locks that end of the diaphragm securely to the body of the pool cleaner and to the pipe. The opposing end is connected to the body by means of the support structure 54, i.e. the ring, in the manner which has been described.
 FIGS. 4 and 5 illustrate a pool cleaner 10A according to a second form of the invention which has a number of similarities to the cleaner 10. Components in the cleaner 10A which are the same as components in the cleaner 10 carry like reference numerals and are not further described herein.
 The body 12 of the cleaner 10A has an inner tubular collar 60 with an inner thread 62 and a plurality of equally spaced, axially extending, elongate ribs 64, each of which acts as a stop formation, see FIG. 6.
 The pipe carries a thread 66 which is screwed into the thread 62. The pipe, adjacent the thread, also carries a number of spaced protrusions 70, each of which acts as a limiting formation. Referring to FIG. 6 it can be seen that the maximum diametrical dimension 72 of the pipe, between an opposed pair of the protrusions 70, is slightly greater than a minimum diametrical dimension 74 inside the tubular formation i.e. between a diametrically opposed pair of the ribs 64. It is therefore only possible for the pipe to be rotated inside the body, when the threads 62 and 66 are engaged with each other, if restraining forces exerted by abutting ribs 64 and protrusions 70 are overcome. Rotation of the pipe relative to the body thus takes place in a succession of steps as successive ribs are brought into contact with successive protrusions 70.
 The attachment of the diaphragm to the pipe 22 is such that the pipe is free to rotate inside the diaphragm without the pipe becoming detached from the diaphragm. Consequently rotation of the pipe causes the prevailing force in the diaphragm, whether compressive or tensile, to be varied in a plurality of increments. On the other hand, due to the restraining effect of the interengaged ribs and protrusions, it is not possible for the pipe to move with a threaded action relative to the body without human intervention.
 The force which prevails in the diaphragm, in an axial sense, whether compressive or tensile, is thus adjustable in various ways. The position at which the end 26 is fixed to the body 12 is manually variable. A manual adjustment of the force is done in small incremental steps when the pipe is axially moved (FIGS. 1 and 2) and when the pipe is rotated (FIGS. 4 and 5). Fine adjustment takes place automatically through the action of the supporting structure i.e. the ring 54 which can flex slightly, in an axial direction, due to the natural resilience of the material from which the ring is. made. The degree of flexing is determined by the magnitude of the axially directed force which prevails in the diaphragm at the time and thus, at least, to a limited extent, an automatic compensation is made to cater for a change in the force in the diaphragm. The degree of flexing available from the ring can be altered by changing the orientation of the ring or the nature or material of the ring.
Patent applications in class Accessory
Patent applications in all subclasses Accessory