Patent Application
20070144602
This invention relates generally to automatic pool cleaners which use a power conduit for supplying energy to enable a cleaner to travel through a water pool for cleaning the water surface and/or the wall surface of a containment wall containing the water pool. More particularly, the present invention is directed to an improved conduit configured to couple a power source (e.g., positive pressure fluid and/or negative pressure fluid and/or electric) to a cleaner for supplying energy for propulsion and/or cleaning.
Automatic cleaners configured to travel through a water pool for cleaning the pool water surface and/or containment wall surface are well known in the art. Such cleaners include units which operate (1) solely at the wall surface (which shall be understood to include side and floor portions), (2) solely at the water surface, or (3) selectively at the wall surface and water surface (e.g., U.S. Pat. Nos. 5,985,156; 6,039,886; 6,090,219).
Such automatic pool cleaners are generally powered by energy delivered to the cleaner via a flexible elongate conduit, e.g., a pressure hose, a suction hose, an electric wire, etc. The delivered energy functions to propel the cleaner, typically along a substantially random travel path, while pulling the conduit behind it. Regardless of the energy form used, the flexible conduit can on occasion physically interfere with and hinder the cleaner's ability to freely travel through the pool. To avoid such interference, cleaner systems are generally configured to maintain the conduit out of the normal travel path of the cleaner. For example, a conduit used with a wall surface cleaner is generally configured (i.e., effective specific gravity <1.0) to float near the water surface to avoid the cleaner having to climb over the conduit. Water surface cleaners generally use a conduit configured (i.e., effective specific gravity >1.0) to sink to the wall surface, i.e., pool floor, to avoid obstructing the cleaner. Cleaners configured to selectively travel at the water surface and wall surface preferably use a conduit configured to situate the major length of the conduit at a level between the pool water surface and containment wall surface to avoid obstructing the cleaner's movement along its travel path. The desired specific gravity for the conduit can be achieved by an appropriate choice of conduit materials and/or a proper utilization and placement of positive and/or negative buoyancy members (e.g., floats and/or weights) along the conduit length.
Typical prior art conduit assemblies are comprised of one or more elongate flexible sections which form a continuous path extending from a power source, generally via a stationary fitting mounted adjacent to the containment wall, to the cleaner. The conduit should be of sufficient length (typically, 15-45 feet) to enable the cleaner to travel to any point in the pool. A typical conduit for use with a positive pressure fluid power source comprises a hose of axially flexible material having an inner diameter of about ⅜″-1″. A typical conduit for use with a negative pressure (i.e., suction) fluid source comprises an axially flexible hose having an inner diameter of about 1-2″. The smaller diameter pressure hose is typically formed of soft wall material which is able to maintain easy axial flexibility in the pool environment (wet with large temperature excursions) over an extended period of time. The larger diameter suction hose is typically formed of a corrugated wall material which affords axial flexibility.
Typical prior art conduit assemblies include one or more swivels located between the power source and the cleaner to enable the conduit and/or conduit sections to swivel axially to minimize the tendency of the conduit to form persistent coils which can hinder the cleaner's freedom of movement.
Despite the aforementioned efforts to prevent the cleaner from engaging the conduit and efforts to facilitate conduit axial flexibility and axial swivelability, in practice, a typical conduit over an extended period of operation may develop persistent coils and/or knots which can hinder the cleaner's ability to freely and fully travel throughout the pool.
Applicant's PCT Application PCT/US2003/032639 discloses an improved power conduit for use with automatic pool cleaners particularly configured to avoid the formation of persistent coils and/or knots. Whereas prior art conduits are characterized by the use of elongate hoses which exhibit substantially uniform axial flexibility along substantially their entire length, embodiments described in said PCT Application 032639 are configured to restrict axial flexibility to designated locations spaced along the conduit length. Such embodiments are characterized by the use of at least one axially stiff elongate section in combination with axially flexible and axially swivelable means. The axially flexible and axially swivelable means can be implemented in a variety of ways. For example, the desired axially flexible and swivelable behavior can be afforded by an integrated universal joint, e.g., ball, or by separate devices such as a soft hose or a hinge affording axial flexibility and a sleeve swivel affording axial swivelability.
The preferred conduit embodiment disclosed in said PCT Application 032639 is comprised of two or more elongate axially stiff members arranged in series with an axially flexible and axially swivelable means. Axial flexibility is preferably provided by a flexible elongate member and axial swivelability by a sleeve swivel. Multiple elongate stiff members and flexible members are arranged in series to form a length sufficient to extend between a stationary power source fitting and a cleaner configured to travel throughout a water pool. In a preferred implementation for use with a positive pressure power source (e.g., water pump), each stiff elongate member comprises a substantially rigid tube defining a central lumen for carrying a fluid (e.g., water) under positive pressure and each flexible elongate member comprises a soft hose which also defines a central lumen for carrying the positive pressure fluid. The preferred implementation is comprised of alternating rigid tubes and soft hoses connected between a stationary power source fitting and a cleaner. The lengths of the rigid tubes are preferably considerably greater than the lengths of the soft hoses between adjacent rigid tubes. For example, a typical embodiment uses rigid tubes having a length of about four feet, connecting soft hoses having a length of about 1½ feet, and longer proximal and distal soft hose lengths respectively coupled to the power source fitting and to the cleaner.
The present invention is directed to a pool cleaner power conduit and more particularly to an enhanced axially flexible means for coupling together adjacent ends of first and second stiff members to form the conduit.
A coupling means in accordance with the present invention is configured to not only permit adjacent stiff members to variably angulate relative to one another, i.e., assume a wide range of axially nonaligned orientations, but also to resiliently bias the stiff members into substantially axial alignment. The resilient biasing incorporated in the coupling means acts in a direction to straighten out the conduit thereby further reducing any tendency to coil and/or knot.
In a first preferred embodiment, the axially flexible coupler comprises an axially flexible tube having an associated coil spring acting to bias the tub to a straight orientation. A net lateral force applied to one end of the coupler acts to axially deflect or bend the coupler. However, when the lateral force is removed, the coupler's resilient bias restores the tube to a substantially straight orientation and axially aligns the stiff members coupled thereto.
In an alternative embodiment, the axially flexible coupler comprises first and second tubular members which respectively have cooperating ball and socket surfaces. The ball and socket surfaces permit relative movement between the tubular members allowing them to assume a wide variety of axially nonaligned orientations. The first and second tubular members are configured to be respectively connected to first and second stiff members. A spring coupled to at least one of the tubular members resiliently biases the tubular members and stiff members into axial alignment.
In a still further embodiment, the axially flexible coupler can comprise a short length of hose material which can readily axially bend but has sufficient memory to resiliently bias the hose length and stiff members connected thereto to a substantially axially aligned orientation.
Many automatic pool cleaners are described in the literature which include a cleaner body for traveling through a pool for cleaning a pool's water surface 14 and/or wall surface 16.
Various types of power sources 24 have been used in the prior art for powering pool cleaners. For example, power source 24 can supply a positive pressure fluid (typically water) to cleaner 22 via conduit 28. Alternatively, power source 24 can apply a negative pressure (i.e., suction) to cleaner 22 via conduit 28. Still further, power source 24 can supply an electric voltage to cleaner 22 via conduit 28, configured as an electric wire.
Swivel couplings are intended to allow conduit sections to swivel axially relative to one another and to the stationary fitting 31 and cleaner 22 to prevent the formation of coils in the conduit. That is, as the cleaner travels along its generally random path, the conduit 28 is subjected to various forces e.g., axial twisting forces, which, if not relieved by relative axial swiveling will act to coil the conduit. Normally, the cleaner propulsion force pulling axially on the conduit is adequate to produce sufficient swiveling at the swivel couplings to straighten the conduit and avoid significant coiling. However, over extended periods of operation, it is not unusual for coils to form in prior art conduits which are not readily removed by the axial pulling force provided by the cleaner. The formation of persistent coils in the conduit hinders the cleaner's ability to freely and fully travel throughout the pool. Similarly, the formation of knots in the conduit, attributable to the cleaner passing over and then under the conduit will also hinder the cleaner's ability to freely and fully travel throughout the pool.
Aforementioned PCT Application PCT/US2003/032639 is directed primarily to an enhanced conduit assembly particularly configured to avoid the formation of persistent coils and knots to thereby facilitate the cleaner traveling unhindered throughout the pool. Embodiments disclosed therein are compatible with cleaners configured to operate (1) solely at the wall surface, (2) solely at the water surface, and (3) selectively at the water surface and wall surface and also with a variety of power sources including positive pressure fluid, negative pressure fluid, and electric.
A conduit assembly in accordance with said PCT Application, is comprised of one or more elongate axially stiff, e.g., rigid, sections connected in series with axially flexible and axially swivelable mechanisms, between a stationary power source fitting and a cleaner. Such a conduit assembly 50 is illustrated in
Note in
Optionally, the conduit assembly 50 can incorporate one or more propulsion devices 67 along its length for producing a thrust to reduce the drag of the conduit assembly on the cleaner 60. For example, the propulsion device 67 shown in
Attention is now directed to
The aforementioned elements are connected in series to form a conduit length appropriate to the size of the pool to be cleaned to enable the cleaner to travel to any point in the pool. Typical embodiments of the invention will have conduit lengths within a range of about 15-45 feet and will include stiff members having lengths greater than 1½ feet.
The distal end of coupling tube 94 is provided with a pair of radial pins 102, 104 adapted to be received within slots 106, 108 formed in the flared end 88 of rigid tube 86, to form a “bayonet” connection. A sealing washer 110 is preferably captured between the distal end of tube 94 and the flared interior surface of tube 86 to prevent leakage.
The distal end 90 of rigid tube 86 is slotted at 122, 124 for receiving in a “bayonet” connection pins 126, 127 extending radially from the tubular end 128 of swivel coupling 82. The tubular end 128 is dimensioned to be snugly accommodated in flared end 90 of rigid tube 86 and to capture a sealing washer 132 there between.
The swivel coupling 82 is comprised of an outer housing 136 axially aligned with an inner body 138. Bearings 140 contained between the housing 136 and body 138 permit the housing and body to swivel axially relative to one another. The outer housing 136 is preferably formed integral with the aforementioned tubular end 128. The inner body 138 is preferably formed integral with a tubular end 142 having a circumferential groove formed therein for clamping to the proximal end of axially flexible member 78 using damping band 144. Additional sealing material 146 is disposed between housing 136 and body 138 to prevent leakage.
In the operation of the pool cleaning system depicted in
When a net lateral force FL is applied to one end of the coupler 200, e.g., as a consequence of a force Fc applied to stiff member 202, the coupler 200 will bend, or axially deflect, as represented in
Attention is now directed to
A spring 250, e.g., a coil spring, is mounted around tubular member 238 retained between flange 252 on tubular member 238 and flange 254 on tubular member 240. The spring 250 is configured with memory to form a tight coil so that when it is stretched, or deflected, as depicted in
In operation, as the cleaner travels along a substantially random path through the pool, it pulls the conduit and continually reorients the stiff members relative to one another. This action produces a dynamic display of randomly oriented essentially straight line segments (i.e., the stiff elongate members) which is visually interesting and pleasing. The visual aspects of the display can be enhanced by illuminating the sections, e.g., by providing an illumination source on each stiff section. Such sources can comprise an electrically energizable element such as a bulb, LED, etc., or a light energizable surface such as photoluminesent material mounted on the stiff section exterior surface which absorbs light energy during daylight and glows after dark.
It is pointed out that embodiments of the present invention are compatible with the teachings of applicant's U.S. application Ser. No. 10/133,088 which describes attaching buoyancy (positive or negative) members to the conduit for situating the conduit at a level between the pool water surface and wall surface to avoid obstructing the cleaner's travel.
Although applicants have disclosed a limited number of embodiments herein, it should be understood that many other variations can be used within the scope of the invention. For example, alternative mechanism can be used to introduce axial flexibility and resilient biasing. Similarly, although the illustrated embodiments have introduced axial swivelability by incorporating swivel couplings distributed along the length of the embodiment, swivelability can be introduced at the power source end and/or the cleaner end, e.g., a swivel coupling can be integrated into the stationary fitting proximate to the wall surface and/or integrated into the cleaner assembly. Moreover, although the illustrated embodiments use separate elements to introduce axial flexibility (i.e., elongate flexible members) and axial swivelability (i.e., swivel couplings), it is recognized that these degrees of freedom can be integrated in appropriate alternative mechanisms, e.g. ball joint.
Accordingly, from the foregoing, it should be understood that applicants have described an automatic pool cleaning system characterized by a conduit for transferring energy from a power source to a pool cleaner where the conduit includes at least one axially stiff elongate member and resiliently biased axially flexible and/or axially swivelable means for minimizing the formation of persistent coils and/or knots in the conduit.
