| WO2007069021A1 | 2007-06-21 | |||
| WO2001059236A1 | 2001-08-16 |
| CLAIMS 1. An automatic pool cleaner accessory [10] suitable for connection to a pool cleaner head [12] or for inclusion in a pool cleaner suction hose [14], the pool cleaner accessory [10] comprising - a first tubular member [16] and a second tubular member [18] arranged coaxially and being rotatable relative to each other about a substantially common axis; and a clutch mechanism [20] for controlling rotation of the tubular members relative to each other, the clutch mechanism [20] being arranged coaxially with and intermediate the first and second tubular members [16;18] and configured alternately to engage and disengage the tubular members [16;18] with each other; the clutch mechanism [20] allowing the tubular members [16;18] to rotate freely, in both directions, relative to each other about the common axis in an inoperative condition, but restricting relative rotation of the tubular members [16;18] to a substantially uni-directional rotation in an operative condition under conditions of suction or water pressure being applied. 2. An automatic pool cleaner accessory [10] according to claim 1 wherein the pool cleaner accessory [10] is integrally formed with a pool cleaner itself such that it is arranged intermediate the pool cleaner and the suction hose [14] 3. An automatic pool cleaner accessory [10] according to claim 1 wherein the first tubular member [16] is configured at least partially to penetrate into the second tubular member [18]; the first tubular member [16] comprising an outer end [22] for connection to a pool cleaner head [12] or suction hose [14]; and an inner end [24] which is received captively, but relative rotatably, within the second tubular member [18]. 4. An automatic pool cleaner accessory [10] according to claim 3 wherein the inner and outer ends [24;22] of the first tubular member [16] have substantially the same internal tube diameters [X], but the inner end [24] has an external tube diameter [Y] that is less than the external tube diameter [Z] of the outer end [22], such that a radially inwardly protruding first shoulder formation [26] is defined between the inner and outer ends [24;22] of the first tubular member [16]. 5. An automatic pool cleaner accessory [10] according to claim 4 wherein the second tubular member [18] comprises an outer end [28] for connection to a pool cleaner head [12] or suction hose [14]; and an inner skirt end [30] which is configured for receiving the inner end [24] of the first tubular member [16]; the skirt end [30] having an internal tube diameter [A] and an external tube diameter [B] which are greater than the tube diameter [C] of the outer end [28], such that a radially outwardly protruding second shoulder formation [32] is defined between the skirt end [30] and outer end [28] of the second tubular member [18]; the arrangement being such that in an assembled configuration, the inner end [24] of the first tubular member [16] penetrates at least through the skirt end [30] of the second tubular member [18] and may at least partially penetrate into the outer end [28] of the second tubular member [18]. 6. An automatic pool cleaner accessory [10] according to claim 5 wherein the clutch mechanism [20] includes a substantially cylindrical clutch body [34] having an internal wall [34.1], an external wall [34.2], a first end [34.3], and an opposing second end [34.4]; the clutch body [34] being arranged coaxially with and rotatable about the inner end [24] of the first tubular member [16] such that it is trapped between and seated against the first shoulder formation [26] of the first tubular member [16] and the second shoulder formation [32] of the second tubular member [18]; such that the clutch body [34] is being housed within and circumferentially bordered by the skirt end [30] of the second tubular member [18]. 7. An automatic pool cleaner accessory [10] according to claim 6 wherein the clutch body [34] includes a tubular clutch skirt [35], extending from a second end of the clutch body [34] and configured co-axially to penetrate at least partially into the outer end [28] of the second tubular member [18], the arrangement being such that the inner end [24] of the first tubular member [16] is held captive, but rotatable, within the clutch body [34]; the clutch body [34] is held captive, but rotatable between the inner end [24] of the first tubular member [16] and the skirt end [30] of the second tubular member [18] ; while the clutch skirt [35] of the clutch body [34] is held captive, but rotatable within the outer end [28] of the second tubular member [18]. 8. An automatic pool cleaner accessory [10] according to claim 7 wherein the external wall [34.2] of the clutch body [34] includes a series of parallel and circumferentially spaced teeth [42] extending substantially the length of the clutch body [34] 9. An automatic pool cleaner accessory [10] according to claim 8 wherein the clutch mechanism [20] includes a first friction ring [36] intermediate the first end [34.3] of the clutch body [34] and the first shoulder formation [26] of the first tubular member [16]; and a second friction ring [38] intermediate the second end [34.4] of the clutch body [34] and the second shoulder formation [32] of the second tubular member [18]; the friction rings [36;38] being high-friction polymer rings which friction acts as a clutch when suction pulls the two tubular members [16;18] together, thus enabling frictional engagement. 10. An automatic pool cleaner accessory [10] according to claim 9 wherein the clutch mechanism [20] includes a first flat faced seal [37] arranged intermediate the second friction ring [38] and the second shoulder formation [32] of the second tubular member [18]; the first flat faced seal [37] including at least one short arm [41] extending substantially perpendicularly to the first seal [37] and facing the direction of the clutch body [34]; the arm being configured to cooperate with the clutch body [34] to constrain the first seal [37] from rotating freely relative to the clutch body [34] 11. An automatic pool cleaner accessory [10] according to claim 10 wherein the arm [41] is configured such that it is located intermediate the circumferential teeth [42] on the clutch body [34] to prevent free rotation of the first seal [37] relative to the clutch body [34] 12. An automatic pool cleaner accessory [10] according to claim 10 wherein the clutch body [34] includes at least one recess [45] within which the arm [41] is located. 13. An automatic pool cleaner accessory [10] according to claim 10 wherein the first flat faced seal [37] includes a number of short arms [41] extending from the first seal [37] 14. An automatic pool cleaner accessory [10] according to claim 10 wherein the clutch mechanism [20] also includes a second flat faced seal [39] arranged intermediate the first flat faced seal [37] and the second shoulder formation [32] of the second tubular member [18]; the second flat faced seal [39] including at least one short arm [43] extending substantially perpendicularly to the second seal [39] and facing the direction of the second tubular member [18]; the arm [43] being configured to cooperate with the second tubular member [18] to constrain the second seal [39] from rotating freely relative to the clutch body [34] 15. An automatic pool cleaner accessory [10] according to claim 14 wherein the second tubular member [18] includes at least one small recess [45] in the second shoulder formation [32] in which the short arm [43] of the second seal [39] locates to maintain the second seal [39] in position. 16. An automatic pool cleaner accessory [10] according to claim 15 wherein the second tubular member [18] includes a number of recesses [45] which are configured to cooperate with a similar number of arms [43] extending from the second seal [39]. 17. An automatic pool cleaner accessory [10] according to claim 8 wherein the clutch mechanism [20] includes at least one pawl [40] which is positioned stationary relative to the second tubular member [18], and positioned such that its free end engages the series of circumferential teeth [42] on the clutch body [34] such that the clutch body [34] can rotate in one direction only under applied suction. 18. An automatic pool cleaner accessory [10] according to claim 17 wherein the teeth [42] are directed outwards from the external wall [34.2] of the clutch body [34] towards the skirt end [30] of the second tubular member [18]; while the pawl [40] is held captive in a pawl-receiving aperture [44] within the skirt end [30] of the second tubular member [18]; the pawl [40] being inclined relative to the tangential direction towards the cylindrical clutch body [34], and being resiliently urged into engagement with the circumferential teeth [42] 19. An automatic pool cleaner accessory [10] according to claim 17 wherein the pawl [40] is held captive within the clutch body [34] and positioned such that its free end engages a series of circumferential teeth [42] extending inwardly from an interior wall of the second tubular member [18]. 20. An automatic pool cleaner accessory [10] according to claim 7 wherein the clutch mechanism [20] includes a band brake [46] consisting of a band of friction material positioned stationary relative to the second tubular member [18] and which tightens concentrically around the cylindrical clutch body [34] under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members [16;18]. 21. An automatic pool cleaner accessory [10] according to claim 20 wherein, under conditions of applied suction, frictional engagement between the band brake [46] and a mating surface of the clutch body [34], causes the band brake [46] to tighten in response to reverse rotation, which tightening increases with increased effort. 22. An automatic pool cleaner accessory [10] according to claim 7 wherein the clutch mechanism [20] includes a rope brake [48] consisting of a rope of friction material positioned stationary relative to the second tubular member [18] and which tightens concentrically around the cylindrical clutch body [34] under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members [16;18]. 23. An automatic pool cleaner accessory [10] according to claim 22 wherein the clutch body [34] includes a circumferential groove [50] within its external wall [34.2] for accommodating and holding in position the rope brake [48], the groove [50] being V-shaped to ensure friction is maintained when reverse force is applied, and friction is released when rotated in a free running direction. 24. An automatic pool cleaner accessory [10] according to claim 5 wherein the first tubular member [16] is held captive, but rotatable, relative to the second tubular member [18] by means of an inwardly lipped ring [52] which is secured to the skirt end [30] of the second tubular member [18]. 25. An automatic pool cleaner accessory [10] according to claim 5 wherein the outer end [22] of the first tubular member [16] terminates in an integral conical spigot or socket [22.1], adapted to engage a complimentarily configured socket or spigot on a hose [14] or connector tube [13]; and the outer end [28] of the second tubular member [18] similarly terminates in an integral conical spigot or socket [28.1], adapted to engage a complimentarily configured socket or spigot on a hose [14] or connector tube [13], such that the accessory [10] can be fitted to the ends of a suction hose [14] or to a pool cleaner head [12] 26. An automatic pool cleaner accessory [10] according to claim 1 wherein the accessory [10] is suitable for use in a pressurised hose system. 27. An automatic pool cleaner accessory [10] according to anyone of claims 1 to 26 substantially as herein illustrated and exemplified. |
The invention relates to a pool cleaner accessory which is adapted for use in association with an automatic pool cleaner to enhance surface coverage of the pool cleaner.
BACKGROUND TO THE INVENTION
It will be appreciated that the prior art discloses a plurality of automatic pool cleaners that are designed to move freely and randomly over floor and wall surfaces of pools to clean said surfaces. These types of cleaners utilize the power of a pool’s pump to help remove dirt and debris from the pool surfaces. One of the main shortcomings associated with such automatic pool cleaners is that they have a tendency to limit themselves to certain broad patterns of movement that cover only certain parts of said surfaces, cleaning only patches of the floor and wall surfaces and leaving out other surface areas.
Numerous different reasons have been put forward to explain this characteristic failure. These include the fact that many pool cleaners become trapped against some or other formation within the pool; the hose characteristics vary quite significantly and hose sections can take on a particularly crooked configuration in consequence of temperature fluctuations and physical forces being 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; each different design of swimming pool and location of the point of connection of a suction hose to a filtration assembly inhibits the swimming pool cleaner to a different extent and in different ways from reaching all regions of the surface; and some pool cleaners are unable to clean the entire pool or continually miss spots due to inherit design limitations.
A common partial cure is to take the hose of the pool, stretch it out in a straight line and leave it in the sun for a period of time sufficient to enable it to 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.
One prior art solution that proposes to minimise the shortcomings discussed above is disclosed in W02007/069021 , which is registered in the name of the same applicant as in this present case. W02007/069021 provides a pool cleaner accessory for connection to a pool cleaner suction hose or a pool cleaner head and which comprises two coaxial tubular members that are rotatable relative to each other, and rotation control means in the form of a ratchet which restricts movement of one tubular member relative to the other to uni-directional rotation. Even though this accessory alleviates the problem, it also has a number of shortcomings. The applicant has found that the mechanical seal tends to leak air under rotation. In addition, uni-directional rotation may lead to a tendency for hoses to twist. The current invention aims to provide an improvement over W02007/069021.
It should be understood that the present invention is not limited to use with swimming pool cleaners, but indeed can be applied equally to automatic pool cleaners used to clean any other pool of liquid.
SUMMARY OF THE INVENTION According to the invention there is provided an automatic pool cleaner accessory suitable for connection to a pool cleaner head or for inclusion in a pool cleaner suction hose, the pool cleaner accessory comprising - a first and a second tubular member arranged coaxially and being rotatable relative to each other about a substantially common axis; and a clutch mechanism for controlling rotation of the tubular members relative to each other, the clutch mechanism being arranged coaxially with and intermediate the first and second tubular members and configured alternately to engage and disengage the tubular members with each other; the clutch mechanism allowing the tubular members to rotate freely, in both directions, relative to each other about the common axis in an inoperative condition, but restricting relative rotation of the tubular members to a substantially uni-directional rotation in an operative condition under conditions of suction or water pressure being applied. The pool cleaner accessory may integrally be formed with the pool cleaner itself such that it is arranged intermediate the pool cleaner and the suction hose.
The first tubular member may be configured at least partially to penetrate into the second tubular member. The first tubular member comprises an outer end for connection to a pool cleaner head or suction hose; and an inner end which is received captively, but relative rotatably, within the second tubular member. The inner and outer ends of the first tubular member have substantially the same internal tube diameters, but the inner end has an external tube diameter that is less than that of the outer end, such that a radially inwardly protruding first shoulder formation is defined between the inner and outer ends of the first tubular member.
The second tubular member comprises an outer end for connection to a pool cleaner head or suction hose; and an inner skirt end which is configured for receiving the inner end of the first tubular member; the skirt end having an internal tube diameter and an external tube diameter which are greater than those of the outer end, such that a radially outwardly protruding second shoulder formation is defined between the skirt end and outer end of the second tubular member. In an assembled configuration, the inner end of the first tubular member penetrates at least through the skirt end of the second tubular member and may at least partially penetrate into the outer end of the second tubular member.
The clutch mechanism includes a substantially cylindrical clutch body having an internal wall, an external wall, a first end, and an opposing second end. The clutch body is arranged coaxially with and rotatable about the inner end of the first tubular member such that it is trapped between and seated against the first shoulder formation of the first tubular member and the second shoulder formation of the second tubular member. The clutch body is housed within and circumferentially bordered by the skirt end of the second tubular member.
In one embodiment of the invention, the clutch body may include a tubular clutch skirt, extending from a second end of the clutch body and configured co-axially to penetrate at least partially into the outer end of the second tubular member, the arrangement being such that the inner end of the first tubular member is held captive, but rotatable, within the clutch body; the clutch body is held captive, but rotatable between the inner end of the first tubular member and the skirt end of the second tubular member; while the clutch skirt of the clutch body is held captive, but rotatable within the outer end of the second tubular member. The external wall of the clutch body may include a series of parallel and circumferentially spaced teeth extending substantially the length of the clutch body.
The clutch mechanism may include a first friction ring intermediate the first end of the clutch body and the first shoulder formation of the first tubular member; and a second friction ring intermediate the second end of the clutch body and the second shoulder formation of the second tubular member. The friction rings may be high-friction polymer rings which friction acts as a clutch when suction pulls the two tubular members together, thus enabling frictional engagement. The clutch mechanism may include a first flat faced seal arranged intermediate the second friction ring and the second shoulder formation of the second tubular member. The first flat faced seal may include at least one short arm extending substantially perpendicularly to the first seal and facing the direction of the clutch body, the arm being configured to cooperate with the clutch body to constrain the first seal from rotating freely relative to the clutch body. In one embodiment of the invention, the arm may be configured such that it is located intermediate the circumferential teeth on the clutch body to prevent free rotation of the first seal relative to the clutch body. In an alternative embodiment of the invention, the clutch body may include at least one recess in which the arm may be located. The first flat faced seal may include a number of short arms extending from the first seal.
The clutch mechanism may also include a second flat faced seal arranged intermediate the first flat faced seal and the second shoulder formation of the second tubular member. The second flat faced seal may include at least one short arm extending substantially perpendicularly to the second seal and facing the direction of the second tubular member, the arm being configured to cooperate with the second tubular member to constrain the second seal from rotating freely relative to the clutch body. In particular, the second tubular member may include at least one small recess in the second shoulder formation in which the short arm of the second seal locates to maintain the second seal in position. It will be appreciated that the second tubular member may include a number of these recesses which are configured to cooperate with a similar number of arms extending from the second seal. In a first embodiment of the invention, the clutch mechanism includes a pawl which is positioned stationary relative to the second tubular member, and positioned such that its free end engages the series of circumferential teeth on the clutch body such that the clutch body can rotate in one direction only under applied suction. In a preferred embodiment of the invention, the teeth are directed outwards from the external wall of the clutch body towards the skirt end of the second tubular member. The pawl is held captive in a pawl-receiving aperture within the skirt end of the second tubular member, is inclined relative to the tangential direction towards the cylindrical clutch body, and is resiliently urged into engagement with the circumferential teeth. It will be appreciated that in an alternative embodiment, the pawl could be held captive within the clutch body and positioned such that its free end engages a series of circumferential teeth extending inwardly from an interior wall of the second tubular member. It will also be appreciated that the clutch mechanism may include a number of pawls.
In a second embodiment of the invention, the clutch mechanism includes a band brake consisting of a band of friction material positioned stationary relative to the second tubular member and which tightens concentrically around the cylindrical clutch body under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members. More specifically, under conditions of applied suction, frictional engagement between the band and a mating surface of the clutch body, causes the band to tighten in response to reverse rotation, which tightening increases with increased effort. In a third embodiment of the invention, the clutch mechanism includes a rope brake consisting of a rope of friction material positioned stationary relative to the second tubular member and which tightens concentrically around the cylindrical clutch body under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members. In this embodiment of the invention, the clutch body includes a circumferential groove within its external wall for accommodating and holding in position the rope brake. The groove may be V-shaped to ensure friction is maintained when reverse force is applied, and friction is released when rotated in a free running direction.
The first tubular member is held captive, but rotatable, relative to the second tubular member by means of an inwardly lipped ring which is secured to the skirt end of the second tubular member.
The outer end of the first tubular member may terminate in an integral conical spigot or socket, adapted to engage a complimentarily configured socket or spigot on a hose length or connector tube; and the outer end of the second tubular member similarly may terminate in an integral conical spigot or socket, adapted to engage a complimentarily configured socket or spigot on a hose length or connector tube, such that the accessory can be fitted to the ends of suction hoses or to a pool cleaner head.
It may be noted that the principles of operation of the subject invention could also be adapted for application in a pressurised hose system. SPECIFIC EMBODIMENT OF THE INVENTION
Without wishing to be bound by it, the invention will now further be described and exemplified with reference to the accompanying drawings in which -
FIGURE 1 is an exploded perspective view of a pool cleaner accessory according to a first embodiment of the invention;
FIGURE 2 is an assembled perspective view of the pool cleaner accessory of Figure 1 ;
FIGURE 3 is an exploded sectional side elevation of the pool cleaner accessory of Figure 1 ;
FIGURE 4 is an exploded side elevation of the pool cleaner accessory of Figure 1 ; FIGURE 5 is an assembled sectional side elevation of the pool cleaner accessory of Figure 2;
FIGURE 6 is an assembled side elevation of the pool cleaner accessory of Figure
2;
FIGURE 7 is a sectional plan view from above of the pool cleaner accessory of Figure 1 ;
FIGURE 8 is an exploded perspective view of a pool cleaner accessory according to a second embodiment of the invention;
FIGURE 9 is an assembled perspective view of the pool cleaner accessory of Figure 8;
FIGURE 10 is an exploded sectional side elevation of the pool cleaner accessory of Figure 8; FIGURE 11 is an exploded side elevation of the pool cleaner accessory of Figure 8; FIGURE 12 is an exploded perspective view of a pool cleaner accessory according to a third embodiment of the invention;
FIGURE 13 is an assembled perspective view of the pool cleaner accessory of Figure 12;
FIGURE 14 is an exploded perspective view of a pool cleaner accessory according to a fourth embodiment of the invention, which is similar to the embodiment illustrated in Figure 1 , but where the clutch body does not include a clutch skirt;
FIGURE 15 is an exploded sectional side elevation of the pool cleaner accessory of Figure 14;
FIGURE 16 illustrates the pool cleaner accessory of the invention and suggests a way in which the accessory of the invention and a pool cleaner could be integrated into a single unit; and
FIGURE 17 illustrates positioning of the pool cleaner accessory between a pool cleaner head and a suction hose.
An automatic pool cleaner accessory according to the invention is generally designated by reference numeral [10]. The pool cleaner accessory [10] is adapted for connection to a pool cleaner head [12] and/or for inclusion in a pool cleaner suction hose [14] The pool cleaner accessory [10] comprises a first tubular member [16] and a second tubular member [18], which are arranged coaxially, and which are rotatable relative to each other about a substantially common axis. The pool cleaner accessory [10] further comprises a clutch mechanism [20] for controlling rotation of the tubular members [16; 18] relative to each other, the clutch mechanism [20] being arranged coaxially with and intermediate the first and second tubular members [16; 18], and configured alternately to engage and disengage the tubular members with each other. The clutch mechanism [20] is characterised therein that it allows the tubular members [16; 18] to rotate freely, in both directions, relative to each other about the common axis in an inoperative condition, when no suction is applied, but restricts relative rotation of the tubular members [16; 18] to a substantially uni-directional rotation when in an operative condition, that is under conditions of suction or water pressure being applied.
The first tubular member [16] is configured at least partially to penetrate into the second tubular member [18]. The first tubular member [16] comprises an outer end [22] for connection to a pool cleaner head [12] or suction hose [14]. The first tubular member also may be connected to a connector tube [13] (refer Figure 17), such as the one which is disclosed in W02002/50391 by the same applicant. Connector tube [13], which incorporates at least one bend of suitable angle, assists in effective steering of the pool cleaner in a variety of directions, which in turn causes a variety of cleaning routes. W02007/069021 discloses a number of ways in which such an angled connector tube may be incorporated into and combined with a pool cleaner accessory and likewise into the pool cleaner head. The first tubular member [16] further comprises an inner end [24] which is received captively, but relative rotatably, within the second tubular member [18]. The inner and outer ends [24; 22] have a relatively constant internal tube diameter [X], but the inner end [24] has an external tube diameter [Y] that is less than the external tube diameter [Z] of the outer end [22], such that a radially inwardly protruding first shoulder formation [26] is defined between the inner and outer ends [24; 22] of the first tubular member [16].
The second tubular member [18] comprises an outer end [28] for connection to a pool cleaner head [12] or suction hose [14] or to a suitably formed connector tube [13], as disclosed in W02002/50391 ; and an inner skirt end [30] which is configured for receiving the inner end [24] of the first tubular member [16]. The skirt end [30] has an internal tube diameter [A], and an external tube diameter [B], which is greater than the tube diameter [C] of the outer end [28], such that a radially outwardly protruding second shoulder formation [32] is defined between the skirt end [30] and outer end [28] of the second tubular member [18]. In an assembled configuration, the inner end [24] of the first tubular member [16] penetrates through the skirt end [30] and at least partially into the outer end [28] of the second tubular member [18]. The clutch mechanism [20] includes a substantially cylindrical clutch body [34] having an internal wall [34.1], an external wall [34.2], a first end [34.3], and an opposing second end [34.4] The clutch body [34] is arranged coaxially with and rotatable about the inner end [24] of the first tubular member [16], such that it is trapped between the first shoulder formation [26] of the first tubular member [16] and the second shoulder formation [32] of the second tubular member [18]. The clutch body [34] is housed within and circumferentially bordered by the skirt end [30] of the second tubular member [18].
In Figures 1 to 13, the clutch body [34] includes a tubular clutch skirt [35], extending from the second end [34.4] of the clutch body [34] and configured co-axially to penetrate at least partially into the outer end [28] of the second tubular member [18], the arrangement being such that the inner end [24] of the first tubular member [16] is held captive, but rotatable, within the clutch body [34]; the clutch body [34] is held captive, but rotatable between the inner end [24] of the first tubular member [16] and the skirt end [30] of the second tubular member [18]; while the clutch skirt [35] of the clutch body [34] is held captive, but rotatable within the outer end [28] of the second tubular member [18].
The clutch mechanism [20] includes a first friction ring, such as an O-ring [36], intermediate the first end [34.3] of the clutch body [34] and the first shoulder formation [26] of the first tubular member [16]; and a second friction ring, such as an O-ring [38], intermediate the second end [34.4] of the clutch body [34] and the second shoulder formation [32] of the second tubular member [18]. The O-rings [36; 38] are high-friction polymer rings.
The clutch mechanism [20] also includes a first flat faced seal [37], typically a low- friction, flat-faced washer, arranged intermediate the second friction ring [38] and the second shoulder formation [32] of the second tubular member [18]. The first flat faced seal [37] includes at least one short arm [41] extending substantially perpendicularly to the first seal [37] and facing the direction of the clutch body [34]; the arm [41] being configured to cooperate with the clutch body [34] to constrain the first seal [37] from rotating freely relative to the clutch body [34] In one embodiment of the invention, such as is illustrated in Figures 1 and 14, the arm [41] is configured such that it is located intermediate the circumferential teeth [42] on the clutch body [34] to prevent free rotation of the first seal [37] relative to the clutch body [34] In an alternative embodiment of the invention, the clutch body [34] includes at least one recess (not shown) in which the arm [41] is located.
The clutch mechanism [20] also includes a second flat faced seal [39] arranged intermediate the first flat faced seal [37] and the second shoulder formation [32] of the second tubular member [18]. The second flat faced seal [39] includes at least one short arm [43] extending substantially perpendicularly to the second seal [39] and facing the direction of the second tubular member [18], the arm [43] being configured to cooperate with the second tubular member [18] to constrain the second seal [39] from rotating freely relative to the clutch body. To this end, the second tubular member [18] includes at least one small recess [45] in the second shoulder formation [32] in which the short arm [43] of the second seal [39] locates to maintain the second seal [39] in position. A further friction ring (not shown) may be included between the second seal [39] and the second shoulder formation [32]
The purpose of the friction ring [38] is to provide both a seal and a resilient cushion between clutch body [34] and the flat faced mechanical seal washer [37] This design provides a solution over the seal leakage problem referred to in the prior art. Not only is there now a seal [38] at the back of the flat faced washers [37, 39], which prevents the possibility of leakage behind the flat washers [37, 39], but also a front face of the flat washers [37, 39] can flex slightly by being supported against the cushioning friction ring [38], thus assisting alignment and good contact between the two faces of the mechanical seal, i.e. the flat faced washers [37, 39] and the second shoulder formation [32] of the second tubular member [18]. Therefore, under conditions of applied suction there is frictional engagement between the first tubular member [16] and the clutch body [34] only. Between the clutch body [34] and the second tubular member [18] the O-ring [38] serves a different purpose and does not inhibit rotation. In a situation of applied suction, rotation between the first tubular member [16] and the second tubular member [18] can still occur, but only uni-directionally as controlled by the clutch mechanism [34]
In a first embodiment of the invention, the clutch mechanism [20] includes a pawl [40] which is positioned stationary relative to either the first or second tubular members [16; 18], and positioned such that its free end engages a series of circumferential teeth [42] on the clutch body [34] such that the clutch body [34] can rotate in one direction only under applied suction. In the illustrated embodiment of the invention, the teeth [42] are directed outwards from the external wall [34.2] of the clutch body [34] towards the skirt end [30] of the second tubular member [18]. The pawl [40] is held captive in a pawl-receiving aperture [44] within the skirt end [30] of the second tubular member [18], is inclined relative to the tangential direction towards the cylindrical clutch body
[34], and is resiliently urged into engagement with the circumferential teeth [42] (refer Figure 7).
In a second embodiment of the invention, as illustrated in Figures 8 - 11 , the clutch mechanism [20] includes a band brake [46] consisting of a band of friction material positioned stationary relative to the second tubular member [18] and which tightens concentrically around the cylindrical clutch body [34] under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members [16; 18] In a third embodiment of the invention, as illustrated in Figures 12 - 13, the clutch mechanism [20] includes a rope brake [48] consisting of a rope of friction material positioned stationary relative to the second tubular member [18] and which tightens concentrically around the cylindrical clutch body [34] under applied suction, thereby forcing uni-directional relative rotation between the first and second tubular members [16; 18]. In this embodiment of the invention, the clutch body [34] includes a circumferential groove [50] within its external wall [34.2] for accommodating and holding in position the rope brake [48]. The groove [50] is V-shaped to ensure friction is maintained when reverse force is applied, and friction is released when rotated in a free running direction.
It will be appreciated that other clutch arrangements may be possible without derogating from the operational principles described herein. So, for example, the invention may include a sprag clutch; or a clutch where the teeth are located radially on a face, such as at the end of the clutch body.
The first tubular member [16] is held captive, but rotatable, relative to the second tubular member [18] by means of an inwardly lipped ring [52], which is secured to the skirt end [30] of the second tubular member [18].
The outer end [22] of the first tubular member [16] terminates in an integral conical spigot [22.1], adapted to engage a complimentarily configured socket on a hose [14] or connector tube [13]; and the outer end [28] of the second tubular member [18] similarly terminates in an integral conical spigot [28.1], adapted to engage a complimentarily configured socket on a hose [14] or connector tube [13], such that the accessory [10] can be fitted to the ends of a suction hose [14] or to a pool cleaner head [12]. The connector tube [13], which is described in W02002/50391 , has two bends forming a compound angle. However, a connector tube [13] with a single bend will also induce a steering effect, albeit perhaps to a lesser degree. W02002/50391 illustrates a variety of ways in which swivels and bends might be configured. Referring to Figure 17, when assembled, the accessory [10] must be fitted to a hose [14], causing rotation of everything which lies between the accessory [10] and a pool cleaner head [12]. Hence, the connector tube [13] performs a steering function as it rotates.
The arrangement is such that the one tubular member [16/18] can rotate substantially freely relative to the other tubular member [18/16] in both forward and reverse directions in the absence of suction being applied. However, under conditions of applied suction, the clutch mechanism [20] is actuated, allowing relative free rotation of the one tubular member [16/18] relative to the other tubular member [18/16] in the forward direction, but not in the reverse direction. It should be noted that the direction of free rotation may be either clockwise or counter-clockwise, depending upon the way which the pawl is facing. This would normally be as-assembled in a factory, but it does not rule out the possibility of a user being able to select this.
It will be appreciated that other embodiments of the invention are possible without departing from the spirit or scope of the invention as set defined in the claims.