Patent Description:
Commonly-owned <CIT>, details filtration aspects of certain APCs. Cleaners described in the Moore application may be hydraulic, pressure-side APCs, in that they may communicate with outlets ("pressure sides") of, typically, remotely located water-circulation pumps. These cleaners also may include canisters as debris filters, with the canisters being "designed so as not to be wholly internal to" bodies of the APCs "yet not materially increase hydraulic drag as" the APCs move autonomously within swimming pools. See Moore, p. <NUM>, <NUM>.

<CIT>, discloses a manually-operated (and thus not automatic) pool cleaner having a handle to allow a person to move the cleaner within a pool. The manual cleaner may include both a "mesh filter" for removing larger pieces of debris and a "filter bag" for removing finer pieces of debris. As described in the Hui application, pool water flows through the mesh filter and then through the filter bag to remove, consecutively, larger and finer debris. See Hui, p. <NUM>, ¶ <NUM>. Further examples of pool cleaners according to the prior art are disclosed in <CIT>, <CIT> and <CIT>.

Neither the Moore application nor the Hui application addresses by-passing part of a dual-stage filtration system. Neither application discusses a possibility of having a permanent by-pass, in which a portion of the pool water entering the cleaner always by-passes the small-debris filter, and neither contemplates making a small-debris filtration stage optional while retaining a large-debris filtration stage. These and other issues remain to be resolved in connection with APCs.

The present invention of an automatic swimming pool cleaner according to claim <NUM>, resolves issues such as these. In some embodiments of the innovative APCs, one (inner) filter of a dual-filtration system may be positioned, or nested, at least partially within another (outer) filter. However, openings or a gap (or both) may be present such that some water by-passes the finer outer filter yet encounters the coarser inner filter. This by-pass may function to reduce the back-pressure created by the filtration system when the outer filter is heavily loaded.

Versions of the present invention also contemplate the outer filter being optional. Accordingly, it may be removable from the inner filter, with the inner filter then standing alone. In some embodiments the inner filter may snap into the outer filter when both are to be used together, although other attachment mechanisms may be employed instead.

Filtration systems of the invention preferably are of the canister type, including mesh supported by generally rigid frames. At least part of the canister may form a top, roof, or other part of the body of the cleaner; it further may, if desired, include a transparent section allowing viewing of debris therein. Some filters additionally may contain multiple pockets so as to increase the surface area of the mesh.

The canisters may be created in at least two parts, with at least one part being movable relative to the other(s) for dumping of collected debris and cleaning. They may incorporate part of an entrance tube for debris-laden water, with the tube also serving as a handle for grasping a canister. The canister may be fitted into a cavity within the body of the cleaner and snap, or otherwise latch, in place. In at least some embodiments of the invention, the canister may be lowered linearly into the cavity for latching but, after unlatching, may be rotated out of the cavity.

Cleaners embraced within the present invention may include inlet tubes having multiple sections. A first section, for example, may be generally vertically oriented (when the cleaner is upright) and open at the bottom of the cleaner. Communicating therewith may be a second section oriented substantially vertically but curved in nature toward the nominal rear of the cleaner. In this second section may be included Venturi jets for drawing debris-laden water into the tube.

A third section of the inlet tube may be formed in the upper part of the body not only to continue the fluid-flow path, but also to isolate the debris-laden water from filtered water used to drive the cleaner. A fourth section of the tube may be positioned in a lower part of the canister and serve as the handle noted above. Finally, a fifth section of the inlet tube may extend into an upper part of the canister and, if desired, be transparent to show debris-laden water through the transparent section of the canister. Variations of this tube structure may, of course, be utilized instead.

After passing through the mesh of the canister, cleaned water may be exhausted from the cleaner in any suitable manner. Presently preferred is that the water exit the canister into the cavity of the body. Thereafter, it may be exhausted from the rear of the cleaner--through a low-restriction region similar in concept to that of the Moore application or otherwise--into the swimming pool.

APCs of the present invention may include wheels or other motive elements driven hydraulically. Pressurized water entering a cleaner from an outlet of a water-circulation pump may be jetted through nozzles within the body of the cleaner onto rotatable vanes. This internal jetting causes the vanes to rotate, in turn rotating at least one drive shaft. Rotational motion of the drive shaft is converted to movement of the motive elements in any suitable way, with a preferred mechanism including miter gears integrally formed with the shaft and configured to engage teeth of the motive elements either directly or indirectly.

In some versions of the innovative drive system, multiple nozzles are arrayed about the circumference of the rotatable vanes. One presently-preferred version includes three nozzles spaced about the circumference of the vanes. This version also contains three water exits from the drive system, again spaced about the circumference of the vanes and arcuately offset from the nozzles. Water jetted by a first nozzle thus engages any particular vane through an arc and exits prior to that vane being engaged by water jetted by a second nozzle. Similarly, water jetted by the second nozzle engages the vane through an arc and exits prior to the vane being engaged by water jetted by a third nozzle.

Cleaners described herein also may include rollers, or brushes, extending from (nominally) forward sections of their bodies. Flexible blades may be spaced about the exterior of a generally cylindrical core to form the brushes, which may rotate to facilitate scrubbing of a to-be-cleaned surface. The brushes may connect directly or indirectly to the drive system of a cleaner; presently preferred is that they connect to motive elements driven by the drive system. Adjacent outer ends of the brushes may be rotating scrubbers which also function as cushioned bumpers to protect pool surfaces that otherwise might be damaged by rigid plastic portions of the cleaners.

The present innovations also contemplate use of downforce scrubbers or turbines with pressure-side cleaners. Such scrubbers are disclosed and illustrated in commonly-owned <CIT> However, in embodiments of the present cleaners, the downforce turbines may be offset (and even potentially isolated) from a water inlet and no longer materially "push" debris toward the inlet.

Consistent with some other pressure-side hydraulic cleaners, versions of the present invention may include hydraulic accessories such as either or both of at least one thrust jet to cause a bias in movement or one or more tail sweeps--i.e. hoses attached at rear regions of the cleaners and receiving pressurized water so as to cause generally serpentine (or other similar) movement thereof. This movement of the sweep tail tends to draw debris into suspension in the pool water, ultimately facilitating its being captured by the cleaner. Embodiments of the present APCs may include a mechanism for adjusting flow through the hydraulic accessories, with some versions including a slot into which a tool may be inserted to rotate a valve communicating with the hydraulic accessory.

It thus is an optional, non-exclusive object of the present invention to provide novel cleaning equipment for water-containing vessels such as swimming pools and spas.

It is also an optional, non-exclusive object of the present invention to provide APCs supplying dual filtration when desired.

It is another optional, non-exclusive object of the present invention to provide APCs including a finer filter into which a coarser filter may be fitted, with openings or gaps allowing some water to by-pass the finer filter.

It is a further optional, non-exclusive object of the present invention to provide APCs in which the finer filter is removable from the coarser filter, allowing the cleaners to operate with only the coarser filtration when desired.

It is, moreover, an optional, non-exclusive object of the present invention to provide pressure-side APCs in which the filtration is in canister, rather than bag, form.

It is an additional optional, non-exclusive object of the present invention to provide APCs whose filter canisters have multiple parts and may incorporate part of an entrance tube for debris-laden water.

It is yet another optional, non-exclusive object of the present invention to provide APCs having entrance tubes with multiple sections, one including Venturi jets, one also functioning as a handle for a canister, and one being transparent to facilitate viewing of debris entering the canister.

It is too an optional, non-exclusive object of the present invention to provide pressure-side APCs with drive systems comprising multiple nozzles arrayed about the circumference of a set of rotatable vanes.

It is also an optional, non-exclusive object of the present invention to provide APCs whose drive systems include multiple water exits, one associated with each nozzle.

It is another optional, non-exclusive object of the present invention to provide APCs having rotating downforce turbines and brushes.

It is, furthermore, an optional, non-exclusive object of the present invention to provide APCs having hydraulic accessories and mechanisms for adjusting water flow through the accessories.

Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant art with reference to the remaining text and the drawings of this application.

<FIG> depict an exemplary cleaner <NUM> consistent with the present invention. Cleaner <NUM> may be an APC capable of autonomous movement with a water-containing vessel such as a swimming pool or spa. In particular, cleaner <NUM> may be a pressure-side hydraulic APC, although some or all concepts described herein may be applicable to both suction-side hydraulic and electric (robotic) APCs as well.

Also illustrated in <FIG> are components of cleaner <NUM> including body <NUM>, motive elements <NUM>, brushes <NUM>, and sweep tail <NUM>. In use, body <NUM> normally will travel in direction A along a to-be-cleaned surface of a pool or spa when in the upright position depicted. Body <NUM> thus nominally may comprise front <NUM>, rear <NUM>, left side <NUM>, right side <NUM>, top <NUM>, and bottom <NUM> (see <FIG>). Inlet <NUM> is configured to receive pressurized water (as from an outlet of a pump); as depicted, it extends upward from top <NUM> in the region of front <NUM>, although persons skilled in the art will recognize that the inlet <NUM> may be positioned elsewhere in connection with cleaner <NUM>. Body <NUM> optionally may include handle <NUM> as well.

Motive elements <NUM> preferably comprise wheels 18A-D, with two such wheels 18A-B positioned on left side <NUM> and two more wheels 18C-D positioned on right side <NUM>. Wheels 18A and 18C preferably are driven, although in some embodiments wheels 18B and 18D may be driven as well. Alternatively, tracks (or combinations of tracks and wheels) may be employed as some or all motive elements <NUM>.

Brushes <NUM> may extend nominally forward of body <NUM> in the region of front <NUM> and bottom <NUM>. They hence may function as the leading edge of cleaner <NUM> when the cleaner <NUM> is travelling in direction A. Sweep tail <NUM>, by contrast, may extend nominally rearward of body <NUM> in the region of rear <NUM>, functioning as the trailing portion of cleaner <NUM>.

<FIG> show filter assembly or canister <NUM> and its constituent parts. In most cases canister <NUM> may comprise first and second filters <NUM> and <NUM>, respectively, each preferably including mesh <NUM> supported by a molded plastic frame <NUM>. Each of filters <NUM> and <NUM> effectively forms a basket into which debris may be deposited. First filter <NUM> may be referred to as a "coarser" filter, advantageously utilizing mesh (made of flexible plastic or other material) whose openings approximate six hundred (<NUM>) microns. Second filter <NUM> may be a "finer" filter with mesh openings of approximately two hundred (<NUM>) microns. Other size meshes may be used instead as appropriate or desired, however, as neither filter <NUM> or <NUM> is restricted to including any particular mesh <NUM>.

Each of filters <NUM> and <NUM> beneficially may (but need not necessarily) be divided into at least two "pockets" <NUM> for receiving debris. Dividing filters <NUM> and <NUM> in this manner increases the amount of mesh used and thus the overall surface area available for filtering debris. First filter <NUM> additionally may include fourth section <NUM> of inlet tube <NUM> (see <FIG>), with the fourth section <NUM> available as a handle for grasping the first filter <NUM>.

As shown especially in <FIG>, first filter <NUM> may fit into second filter <NUM>, with the pockets <NUM> of each filter aligned. Generally, therefore, fluid entering first filter <NUM> will exit its pockets <NUM> and flow into corresponding pockets <NUM> of second filter <NUM>. However, some versions of filters <NUM> and <NUM> intentionally may be designed so that not all fluid entering first filter <NUM> will flow through mesh <NUM> of second filter <NUM>. Instead, second filter <NUM> may contain one or more openings <NUM> in its frame <NUM> allowing water to exit the second filter <NUM> without passing through its mesh <NUM>, effectively by-passing filtration otherwise provided by the second filter <NUM>. If present, one or more openings <NUM> may function similarly. Size and number of the openings <NUM> or <NUM> may vary as desired to balance effectiveness of cleaner <NUM> when second filter <NUM> is heavily loaded versus when it is not heavily loaded.

When present, therefore, first filter <NUM> and second filter <NUM> may provide dual-stage filtration of debris-laden water of a swimming pool or spa. The coarser first filter <NUM> will remove larger debris from the water, while the finer second filter <NUM> will remove smaller debris. As noted above, some debris-laden water preferably will enter first filter <NUM> but exit it in a manner by-passing mesh <NUM> of second filter <NUM> (hence being subject only to one-stage filtering). Conceivably, however, this by-pass could be omitted from some versions of canister <NUM>.

Contemplated by many embodiments of the invention is that canister <NUM> always will include the "coarser" first filter <NUM> (in which fourth section <NUM> of inlet tube <NUM> is present). Second filter <NUM> need not necessarily be used as part of canister <NUM>, however, when its "finer" filtration is unneeded or undesired. Thus, even after first filter <NUM> is fitted into second filter <NUM> (as shown in <FIG>), it may be separated therefrom (as shown in <FIG>) both in the event second filter <NUM> is not to be deployed further or if the second filter <NUM> needs to be cleaned of fine debris.

Either first filter <NUM> (when used alone) or the combined first and second filters <NUM> and <NUM> (when used together) form lower part <NUM> of canister <NUM>. The canister <NUM> also includes upper part <NUM> which may be connected to lower part <NUM>. Upper part <NUM> may incorporate fifth section <NUM> of inlet tube <NUM>, which section <NUM> is configured to align in fluid communication with fourth section <NUM> when canister <NUM> is closed as shown in <FIG>. Some or all of upper part <NUM> may be transparent (clear) to permit viewing of at least some debris captured by canister <NUM>.

In use, canister <NUM> may be fitted into cavity <NUM> of body <NUM> (see <FIG>). As so fitted, aligned fourth and fifth sections <NUM> and <NUM> also are aligned, and communicate, with third section <NUM> of inlet tube <NUM>. Canister <NUM> additionally is isolated from inlet <NUM> (which receives filtered, pressurized water for the drive system) so as to avoid material contamination of the pressurized drive water by the debris-laden water passing through the canister <NUM>.

The sectional views of <FIG> provide additional illustration of, e.g., inlet tube <NUM>. Beyond third section <NUM>, fourth section <NUM>, and fifth section <NUM> discussed above, inlet tube <NUM> may include first section <NUM> and second section <NUM>. When cleaner <NUM> is in use, these (first through fifth) sections are connected together in order to function as a unitary structure to communicate debris-laden pool water from cleaning inlet <NUM> to filters of canister <NUM> for filtering.

First section <NUM> preferably is positioned closer to front <NUM> than to rear <NUM> and laterally in a central part of body <NUM>. First section <NUM> also may be positioned nominally forward of downforce turbines <NUM> and connect to second section <NUM>. It further may be molded as part of body <NUM> or a separate component connected thereto.

Water entering first section <NUM> travels nominally upward into second section <NUM>. Like first section <NUM>, second section <NUM> is generally vertically oriented. Second section <NUM>, however, may be curved if desired so as to slant toward rear <NUM>, where canister <NUM> is housed in cavity <NUM>. Second section <NUM> also may include one or more Venturi nozzles or jets <NUM> (one of which is visible in <FIG> through a cut-away portion of the second section <NUM>) designed to receive pressurized water via inlet <NUM> and jet it upward further into tube <NUM>, thereby facilitating debris-laden water being drawn into first section <NUM>.

Third section <NUM> may be formed as part of body <NUM> if desired. As noted above, fourth section <NUM> may be part of first filter <NUM> and upper part <NUM> may include fifth section <NUM>. Although sectioning inlet tube <NUM> in this manner has multiple benefits, inlet tube <NUM> need not necessarily be sectioned or, if sectioned, need not necessarily be sectioned in the manner described herein.

Arrow sequence B (<FIG>) generally depicts flow of debris-laden water through cleaner <NUM>. This water is evacuated from a pool into cleaning inlet <NUM>. It then may travel through inlet tube <NUM>, emptying within first filter <NUM>. As the debris-laden water passes through first filter <NUM>, larger debris is stopped by the coarser mesh and retained within its pockets <NUM>. Assuming second filter <NUM> is present, much of the water exiting first filter <NUM> will pass into the second filter <NUM>, whose finer mesh will stop smaller debris. Thereafter this twice-filtered water will enter cavity <NUM> and then exhaust mostly at rear <NUM> through, preferably, openings of low-restriction region <NUM>.

Some water exiting first filter <NUM> may by-pass second filter <NUM>, however, and instead immediately enter cavity <NUM> for exhausting through region <NUM>. Hence, this latter portion of water is only filtered once, by the coarser mesh of filter <NUM> before intermingling with the remaining twice-filtered water in cavity <NUM>. Always maintaining this by-pass may reduce back-pressure created by the filtration system of canister <NUM> when second filter <NUM> is heavily loaded and thus enhance operation of cleaner <NUM> overall.

Conceivably, though, such a by-pass might be disadvantageous in certain circumstances, so the present invention may encompass apparatus in which no by-pass exists. Nevertheless, continuously diverting a portion of water around second filter <NUM> is preferred. Also preferred is that the by-pass be sufficiently large as to allow a significant flow of water through the cleaner <NUM> yet sufficiently small as to maintain a pressure differential across the mesh of second filter <NUM> to force through the finer mesh screen water that has entered the second filter <NUM>, even in the presence of the by-pass and to maintain fine debris stuck to the fine mesh though water may be flowing past it.

<FIG>, <FIG>, and <FIG> illustrate portions of drive system <NUM> of cleaner <NUM>. Drive system <NUM> may include hydraulic engine <NUM> comprising manifold 130A, housing 130B-C, hydraulic turbine <NUM>, and drive shaft <NUM>. Drive system <NUM> additionally may include components such as nozzles 142A-C (which may be present in manifold 130A), corresponding openings 144A-C in housing 130B-C, and miter gear <NUM>.

As housed in housing 130B-C, turbine <NUM> may comprise a structure configured to rotate in response to water impinging on its vanes <NUM>. Rotation of turbine <NUM> in turn produces rotation of drive shaft <NUM> (which typically is aligned with the axis about which turbine <NUM> rotates) and of miter gear <NUM> attached to, or integrally formed with, shaft <NUM>. Directly or indirectly, this rotation is utilized to drive some or all of motive elements <NUM>.

Unlike many hydraulic turbines, in which only a single fluid entrance path exists, turbine <NUM> of the present invention may include multiple such paths. For example, <FIG> illustrates three distinct entrances for water into housing 130B-C, one associated with each of nozzles 142A, 142B, and 142C. Thus, in this example, water jetted from nozzles 142A-C may impinge upon multiple vanes <NUM> simultaneously. <FIG> also illustrates that nozzles 142A-C may be spaced about the circumference of turbine <NUM>, with the spacing being either uniform or non-uniform. Of course, persons skilled in the art will recognize that more or fewer nozzles may be utilized instead of the three depicted in the figure.

Associated with each of nozzles 142A-C is an opening 144A-C. When considering the flow of water within housing 130B-C, the water may encounter each opening 144A-C prior to encountering water entering from the next adjacent nozzle 142A-C. Stated differently, water entering housing 130B-C via nozzle 142A encounters opening 144A prior to encountering nozzle 142B; water entering housing 130B-C via nozzle 142B encounters opening 144B prior to encountering nozzle 142C; and water entering housing 130B-C via nozzle 142C encounters opening 144C prior to encountering nozzle 142A. In this manner, most of the water entering housing 130B-C from a particular nozzle exits the housing 130B-C rather than collide with water entering housing 130B-C from the next circumferentially-adjacent nozzle. The result is an efficient use of the pressurized fluid received from inlet <NUM> to produce driving force.

<FIG> detail aspects of adjustment mechanism <NUM> associated with hydraulic accessories such as sweep tail <NUM> and thrust jet 26B. Mechanism <NUM> advantageously includes valve <NUM> having stem <NUM> positioned at or near rear <NUM> and capable of being accessed externally of body <NUM> and rotated as, for example, by a tool such as a screw driver. Rotating stem <NUM> changes the size of the passage through which pressurized water (from conduit <NUM>) flows to sweep tail <NUM> or thrust jet 26B, hence changing the flow rate to the tail <NUM> or jet 26B. <FIG> and <FIG> also illustrate that sweep tail <NUM> or thrust jet 26B may be attached to body <NUM> by pushing a proximal end of the accessory over a barb and clamping it to the body <NUM> using a threaded nut <NUM>. Other attachment means may be employed instead, however.

Yet additionally, cleaner <NUM> may include features facilitating its assembly (and disassembly). In particular, each of top cover <NUM>, front grille <NUM>, and chassis <NUM> may comprise, among other things, parts of body <NUM> of cleaner <NUM>. Consistent with <FIG>, front grille <NUM> and adjustment mechanism <NUM> may be trapped between chassis <NUM> and top cover <NUM> for assembly, hence not requiring any fasteners to fix the positions of the grille <NUM> and mechanism <NUM>. Similarly, no fasteners need be removed from grille <NUM> and mechanism <NUM> when front grille <NUM> is detached from chassis <NUM>.

Illustrated in <FIG> are aspects of interface or connector <NUM> available for use in connection with cleaner <NUM>. Connector <NUM> is designed as a "quick-connect" device and may connect inlet <NUM> of body <NUM> to a water hose without using any tools. As shown especially in <FIG>, first end <NUM> of connector <NUM> may be frictionally pushed onto inlet <NUM> so that post <NUM> of inlet <NUM> is fitted within track <NUM> of connector <NUM>. Connector <NUM> then may be rotated so that post <NUM> moves within track <NUM> past detent <NUM> (<FIG>), thus maintaining engagement of the connector <NUM> and inlet <NUM> even if pressurized water is not flowing through the hose to the connector <NUM>.

During operation of cleaner <NUM>, internal pressurization of connector <NUM> and inlet <NUM> move the connector <NUM> so that post <NUM> nestles into pocket <NUM> of track <NUM>, as depicted in <FIG>. Additionally shown in the cross-sectional view of <FIG> is that connector <NUM> may include second end <NUM> configured to swivel (and to do so independent of rotation or other movement of first end <NUM>). Allowing end <NUM> to swivel reduces the likelihood that the hose to which it connects will entangle as cleaner <NUM> moves within a swimming pool.

As noted earlier, canister <NUM> may be lowered linearly into cavity <NUM> for latching but, after unlatching, may be rotated out of the cavity <NUM>. <FIG> illustrate such linear and rotational motions. Shown in <FIG> is that canister <NUM> may contain portions of both (nominally) forward latch <NUM> and (nominally) rear latch <NUM> as well as release button <NUM>. To remove canister <NUM> from cavity <NUM>, one may depress button <NUM> so as to unlatch forward latch <NUM>. Thereafter, canister <NUM> may be rotated, as depicted by arrow C of <FIG>, until neither forward latch <NUM> nor rear latch <NUM> remains engaged (see also <FIG>). Canister <NUM> then may be withdrawn from cavity <NUM> as shown in <FIG>. Canister <NUM> may be returned to body <NUM> by lowering the canister <NUM> linearly into the cavity <NUM> (see <FIG>). Doing so causes latches <NUM> and <NUM> to spring out of the way and then return to their locking positions (see <FIG>).

<FIG> illustrate aspects of idler assembly <NUM> which may be included as another part of drive system <NUM> of cleaner <NUM>. As shown in <FIG>, assembly <NUM> may include a first gear <NUM> driven by a gear of hydraulic engine <NUM>. Assembly <NUM> also may include at least one idler gear <NUM> configured to transfer torque from, e.g., wheel 18A to wheel 18C or from wheel 18B to wheel 18D. Idler gear <NUM> may be mounted on a free-spinning bearing and rotate independently of the remainder of assembly <NUM>. Also depicted in <FIG> is a miter gear <NUM> which may be used to drive at least one downforce turbine <NUM>.

Text appearing in drawings of the Provisional Application includes:.

The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope of the invention as defined by the appended claims.

Claim 1:
An automatic swimming pool cleaner (<NUM>) comprising:
a. a body (<NUM>) comprising an inlet (<NUM>) for debris-laden water of a pool, and an outlet for filtered water;
b. at least one motive element (<NUM>) for moving the body (<NUM>) along a surface of the pool; and
c. a filter assembly (<NUM>) (i) configured to receive debris-laden water of the pool and exhaust filtered water, and (ii) including a first filter (<NUM>) comprising a mesh (<NUM>) having openings of a first size and,
characterized in that the filter assembly (<NUM>) includes:
- a second filter (<NUM>) comprising a mesh (<NUM>) having openings of a second size smaller than the first size, and
- one or more openings (<NUM>, <NUM>) defining a by-pass in which some water exiting the first filter (<NUM>) bypasses the mesh (<NUM>) of the second filter (<NUM>) while flowing to the outlet.