AUTOMATIC POOL CLEANER COVERAGE ENHANCING ACCESSORY

FIELD OF THE INVENTION

This invention relates to an automatic swimming pool cleaner coverage enhancing accessory designed to influence the direction of movement of a swimming pool cleaner over the floor and walls of a swimming pool in order to clean same. More particularly, the invention is concerned with an accessory that tends to counter the tendency of such pool cleaners to limit themselves to general broad patterns of movement that provide a coverage that may leave out certain areas of the pool surface.

Whilst the following description will be directed primarily at swimming pool cleaners, it will be understood that the invention is intended to apply in its scope to automatic pool cleaners used to clean any other pool of liquid.

BACKGROUND TO THE INVENTION

There is a wide variety of different automatic swimming pool cleaners in use at the present time. Most of them are intended, and indeed designed, to move substantially freely and randomly over the floor and wall surface of a pool in order to cover and thus clean the entire surface area. In an effort to ensure that the entire surface area is covered there have been some designs of swimming pool cleaners in which a steering mechanism has been included with a view to modifying the uncontrolled random movement in order to make it more effective.

Nevertheless, for the most part, existing pool cleaners do not cover the entire surface area and patches, amounting quite commonly of up to about 30% of

the surface area, are not covered by the pool cleaner during its supposedly "random" movement. This is a result of the fact that repeated general patterns of movement tend to develop that do not cover to the entire surface area.

Numerous different reasons have been put forward to explain this common characteristic failure. These include the fact that many pool cleaners become trapped against some or other formation in a swimming pool; the hose characteristics vary quite significantly and indeed hose sections can take on a particular crooked configuration in consequence of temperature fluctuations and physical forces that have been applied to the individual hose sections; the effective length of the hose may be incorrect and the hose may be too long or too short; and each different design of swimming pool and the location of the point of connection of the suction hose to the filtration assembly inhibits the swimming pool cleaner to a different extent and in different ways from reaching all regions of the surface.

A common partial cure that is recommended is to take the hose out of the pool; stretch it out in a straight line; and leave it in the sun for a time sufficient to enable it to totally relieve stresses in the plastic material from which it is made. Thereafter the hose should be cooled rapidly in the straight condition. This sometimes has a beneficial effect but by no means overcomes certain limitations that are inherent in some swimming pool installations and it also does not prevent the problem from recurring.

OBJECT OF THE INVENTION

It is an object of this invention to provide an accessory that is aimed at diminishing the difficulty described above and in consequence enhancing the surface coverage achieved by many different types of automatic swimming pool cleaners.

SUMMARY OF THE INVENTION

In accordance with one aspect of this invention there is provided an automatic pool cleaner accessory for connection to, or for inclusion in, a pool cleaner suction hose or pool cleaner head, the accessory comprising a first and a second tubular member generally coaxial with each other and being relatively rotatable about a substantially common axis, the accessory being characterised in that rotation control means are included for restricting relative rotation of the first and second tubular members to substantially uni- directional rotation.

Further features of the invention provide for the first tubular member to have a part being an inner end region received coaxially and captively (but relatively rotatably) in a tubular skirt portion of the second tubular member; for the rotation control means to be a ratchet type of mechanism that preferably comprises a circumferential series of integral teeth or other stops on one tubular member, typically on the outside of the first tubular member, that cooperate with a pawl that is stationary relative to the other tubular member, typically the inner surface of the second member; for the circumferential series of integral teeth to be positioned towards one end of the part of the first tubular member that is located within the second tubular member in which case a circumferential ridge, typically composed of a series of protrusions, is provided towards the other end of said part of the first tubular member so as to axially align the said part of the first tubular member with the generally continuous cylindrical surface within the skirt of the second tubular member; and for the second tubular member to have one or more low friction rings for engagement by the inner end of the first tubular member.

Still further features of the invention provide for each free end of the accessory to carry a spigot or socket formation for connection to a socket or

spigot end of a conventional length of suction hose or, alternatively, to a plain end of a conventional length of suction hose; for the axis of each spigot or socket formation to be generally coincident with that of the associated tubular members or, alternatively, for the axis of a spigot or socket to be inclined to the axis of the associated tubular member with the angle of inclination being of the order of 5 to 45 degrees and preferably between 10 and 25 degrees; for the spigot or socket associated with the first tubular member to be integral therewith whereas the spigot or socket associated with the second tubular member may either be integral therewith or integral with a third tubular member that is also rotatable relative to the second tubular member either unidirectionally or bidirectionally; and for the said part of the first tubular member that is received in the tubular skirt portion of the second tubular member to be held captively within the second tubular member by a ring secured to the open end of the tubular skirt and having an inwardly directed lip cooperating with the circumferential series of teeth.

In use the accessory provided by this invention is, at least in instances in which the axes of the terminal spigots and / or sockets are coincident with the axis of the tubular members, preferably used in combination with a connector tube for installation in a suction hose assembly substantially as described in my published international patent application number WO/2002/050391 the disclosure of which is included herein by reference.

Whether or not a connector tube of the type described in my said patent application is employed, some arrangement providing a change of direction or a lateral offset of the inlet and outlet is necessary in order to achieve a satisfactory direction influencing effect.

Preferably, the accessory of the invention is operatively included in a suction hose assembly at or towards the end of the suction hose nearest the suction head.

The connector tube, where same is present, is preferably installed between the suction head and the accessory of the invention with the first terminal portion thereof being connected to the connector tube and the second terminal portion thereof being connected to the suction hose.

In order that the invention may be more fully understood one embodiment and two variations thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a plan view of a swimming pool employing an automatic pool cleaner fitted with the accessory of the invention;

Figure 2 is an elevation of one embodiment of accessory according to the invention;

Figure 3 is a sectional elevation thereof;

Figure 4 is an exploded elevation thereof;

Figure 5 is a cross-section taken along line V-V in Figure 3;

Figure 6 is the same as Figure 5 but showing the pawl in a disengaged position during rotation of the first tubular member relative to the second tubular member;

Figure 7 is a sectional elevation showing one variation of the accessory illustrated in Figures 1 to 6;

Figure 8 is a sectional elevation showing a second variation of the accessory illustrated in Figures 1 to 6;

Figure 9 is a sectional elevation showing a first variation of a second embodiment of the invention;

Figure 10 is a sectional elevation showing a second variation of the second embodiment of the invention;

Figure 11 is a sectional elevation showing a third variation of the second embodiment of the invention;

Figure 12 is a sectional elevation showing a fourth variation of the second embodiment of the invention; and,

Figure 13 is a perspective illustration of a further assembly including the accessory of the invention.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

The accessory of this invention is intended to be applied to any automatic swimming pool cleaner such as is illustrated in Figure 1 and wherein an automatic pool cleaner suction head (1) is connected to the suction side of a filtration pump (not shown), usually at an inlet in a weir (2) positioned at the side of a swimming pool (3), by way of a suction hose that is generally indicated by numeral (4). The suction hose is often made up of a series of contiguous lengths (5) of suction hose whereof each length has a spigot connector at one end and a socket connector at the opposite end. This arrangement enables a series of lengths to be connected together to provide a hose of the required overall length.

The accessory of the invention, generally indicated by numeral (6), may be applied to such an installation by installing it between the spigot or socket of one length of suction hose (5c) and the suction head (1) or the socket or spigot on the next contiguous length of suction hose. This is preferably effected at a position nearest the suction head (1) and, in the illustrated situation, is between a connector tube (7) of the type indicated above connected directly to the suction head and the suction hose (5c) nearest the suction head.

It is to be noted that the accessory of the invention can in fact be located anywhere in the length of the suction hose even up to the two lengths (5a) and (5b) of suction hose nearest the weir. The selection of the position may depend on the fact that, as a general rule, the suction nearer the weir end of the suction hose is higher than the suction at the suction head and accordingly there is greater resistance to rotation nearer the weir.

Referring now more particularly to Figures 2 to 6, one embodiment of accessory according to the invention comprises first and second substantially coaxial tubular plastics members indicated by numerals (8) and (9) respectively. The first tubular member (8) has a major part (11) received in an enlarged skirt (12) of the second tubular member (9). The said major part (11) of the first tubular member has, on its outer surface, a circumferentially extending series of longitudinally extending integral teeth (13) towards the entry end (14) of the skirt. The teeth are directed outwards towards the inner surface of the skirt that has at least one pivotally movable pawl (15) held in a suitable formation for restraining it angularly relative to the skirt.

The pawl is generally flat and inclined relative to the tangential direction towards the first tubular member such that the operative end edge (16) of the pawl cooperates with a tooth of the series to prevent rotation of the first tubular member in one direction (herein termed the reverse direction) but to

allow relative rotation in the other direction (herein termed the forward direction). The pawl is resiliently urged into engagement with the circumferentially extending series of teeth by a leaf spring (17). Figure 5 illustrates the pawl in an engaged position with a tooth and Figure 6 illustrates the pawl in a retracted position allowing a tooth to pass it in the forward direction. It will be understood that by varying the pitch of the teeth and the space between them, a limited amount of rotation in the reverse direction may be permitted.

The first tubular member is held captive but rotatable relative to the second tubular member by means of an inwardly lipped ring or nut (18) secured to the entry end of the skirt. The arrangement is such that the inwardly directed lip cooperates with the teeth to hold the first tubular member captive.

The second tubular member has a shoulder (19) at the inner end of the enlarged skirt (12) and the shoulder supports one or more low friction rings (20) that the inner end of the first tubular member operatively engages in order to facilitate relative rotation of the two tubular members when suction is applied to the interior of the assembly. The low friction rings may be of acetyl or HDPE (high density polyethylene), for example. It should also be noted that in the event that either one or both of the tubular members themselves are made out of low friction material, the rings may not be required.

As an alternative to the inner end of the first tubular member engaging the shoulder itself, it may have a shoulder that engages the shoulder or low friction ring with a short tubular section extending a short distance beyond the shoulder in the second tubular member. This may assist in maintaining the alignment of the two tubular members and in resisting ingress of debris into the bearing surfaces or in modifying suction differential. Alternatively,

the short tubular section may form part of the second tubular member and extend into the first tubular member.

In order to maintain axial alignment of the first and second tubular members, the first tubular member may alternatively, or in addition, have a second circumferential series of protrusions (21) towards its end that engages the low friction ring so as to align the first tubular member within the skirt.

Alternatively, one continuous set of protrusions may be provided extending along a major portion of the length of the first tubular member that is located within the skirt.

The first tubular member (8) has at its free outer end an integral conical spigot (22) (or socket) complementary to a socket (or spigot) on a hose length or connector tube and the end of the second tubular member may similarly be formed into another complementary spigot (23) (or socket) so that the accessory can be fitted to the ends of suction hose lengths.

The arrangement is such that the one tubular member can rotate substantially freely relative to the other tubular member in the forward direction, but not in the reverse direction. It has been found, in use, that when a suitable lateral offset is applied, as provided by use of the above- mentioned connector tube, an appreciable amount of relative rotation is generated during the normal movement of an automatic pool cleaner in a swimming pool. The result is a periodic change in the relative angular positions of the two tubular members of the accessory in conjunction with a suitable connecting tube and this causes the swimming pool cleaner to adopt differing general patterns of movement with a consequent enhancement of the overall coverage of the swimming pool surface being achieved over a period of time.

It is to be noted that it is preferred that a series of angularly spaced inlets (24) in the form small holes be provided through the shoulder (19) to communicate with the outer zone of the shoulder beyond the outer periphery of the low friction ring (20) so that water is drawn into the space between the skirt and adjacent surface of the first tubular member with a view to flushing any grit or debris away, or more properly preventing entry of dirt, into this volume for the purpose of protecting the contact surfaces of the low friction ring. This is shown clearly in Figure 3.

As indicated above, the effect may be favourably enhanced utilizing a connector tube as described in my international patent application referred to above.

Clearly, many variations may be made to the embodiment of the invention described above without departing from the scope hereof. In particular, the mechanism utilized for the rotation control means can be varied widely although a simple resiliently biased pawl is envisaged to be the most cost- effective. Also the low friction rings can be replaced by any other low friction device that will allow relative rotation of the first and second tubular members even under suction when the two members are urged firmly towards each other. The friction desired may be varied by choice of such devices or their material of manufacture.

Still further, a combination effect may also be achieved by means of the variations to the embodiment of the invention described above that are illustrated in Figure 7 and 8.

In the case of the variation illustrated in Figure 7, the spigot (25) that is formed integral with the first tubular member has its axis (26) angularly offset relative to the axis (27) of the major part (8) and skirt (12). The angular offset could, for example, be of the order of 5 to 45 degrees and generally

between about 10 and 30 degrees.

As illustrated in Figure 8, both the spigot (28) of the first tubular member and that (29) of the second tubular member could be angularly offset as indicated.

In all of the embodiments of the invention described above, the spigot (or socket) associated with the first tubular member is integral with it as is the spigot or socket associated with the second tubular member.

However, in a second embodiment of the invention whereof different variations are illustrated in Figures 9 to 12, the spigot (or socket) associated with the second tubular member is formed integral with a third tubular member that is itself rotatable relative to the second tubular member in a manner similar to that in which the first tubular member is thus rotatable.

In the variation of the second embodiment of the invention that is illustrated in Figure 9, the spigot (30) (or socket) associated with the first tubular member (31) is integral therewith. However, the spigot (32) (or socket) associated with the second tubular member (33) is integral with a third tubular member (34) that is also rotatable relative to the second tubular member unidirectionally in a manner identical to that of the first tubular member. In this variation, the second tubular member that has two skirts (35, 36) that in each case receives in relatively rotatable manner a part of the first and third tubular members, as the case may be. The two skirts have their axes inclined to each other at an angle of, in this instance, about 20 degrees and the spigot (30) of the first tubular member (31) has its axis inclined an angle of about 15 degrees to the axis of the skirt and part of the first tubular member that extends into the skirt. On the other hand, the spigot (32) associated with the third tubular member (34) is coaxial therewith.

In this instance, the rotation of the first tubular member is unidirectional by virtue of a ratchet mechanism (37) whilst the rotation of the third tubular member is bidirectional without such a ratchet mechanism.

In the second variation illustrated in Figure 10 the arrangement is similar except that the spigot (38) on the third tubular member (39) is also inclined at an angle, in this instance, of about 15 degrees to the axis of the skirt and part of the tubular member in therein. Also, in this instance, arresting mechanism (40) is included to render the rotation of the third tubular member unidirectional relative to the second tubular member. The direction of rotation of each of the first and third tubular members relative to the second tubular member may be the same or opposite.

In the third variation illustrated in Figure 11 , the arrangement is similar to that described with reference to Figure 9 except that the second tubular member (41) is straight.

In the fourth variation that is illustrated in Figure 12, the arrangement is similar to that described with reference to Figure 10 except, once more, that the second tubular member (42) is straight.

As a further alternative, and as shown in Figure 13, a connector tube may have an inlet and an outlet indicated by numeral (43) that have their axes extending in the same general direction but not necessarily, and preferably not exactly parallel, with the inlet and outlet being laterally offset by way of an inclined central region (44).

In any of the above arrangements the accessory of this invention may be built into the suction head of a swimming pool cleaner and, by the same token, a connector tube of any of the types indicated above could also be permanently attached to the swimming pool cleaner suction head so that a

suction hose can simply be attached to it and the combination is described by this invention achieved.

Numerous variations may be made to the embodiments of the invention described above without departing from the scope hereof. In particular, the direction of rotation can be varied as may be required and, indeed, two or more unidirectional accessories according to the invention having opposite directions of rotation could be included in an assembly.