Patent Description:
This invention relates to automatic swimming pool cleaners moving on tracks.

Commonly-owned <CIT> describes components and aspects of certain automatic pool cleaners (APCs). Various embodiments of these APCs may include one or more bladed scrubbers configured to rotate about shafts oriented generally perpendicularly to a surface to be cleaned. Rotation of the scrubbers may produce downforce biasing a cleaner toward the to-be-cleaned surface. It also may create vortex action tending to induce debris-laden water to flow toward an inlet of the cleaner for filtering. Blades of the APCs may be "semi-rigid" as described in the van der Meijden patent so as to accommodate passage of large debris into the inlet with minimal or no blockage.

Disclosed in the van der Meijden patent is that exemplary APCs may utilize a fluid-powered motor of the type detailed in commonly-owned <CIT> The motor may include rotating blades or paddles configured to interact with water flowing therethrough. As disclosed in the van der Meijden application, the paddles may have distal edges which are "locally flexible to facilitate passage of debris.

Referenced in the van der Meijden application is <CIT> APCs of the Rief patent include a turbine housing defining a water-flow chamber in which a rotor is positioned. Also included are a series of vanes pivotally connected to the rotor. Water interacting with the vanes rotates the rotor in one direction (clockwise as illustrated in the Rief patent), with the vanes pivoting when encountering "debris of substantial size" to allow the debris to pass through the housing for collection.

Moreover, <CIT> discloses an automatic swimming pool cleaner according to the preamble portion of claim <NUM>, and <CIT> discloses a further automatic swimming pool cleaner.

Automatic swimming pool cleaners (APCs) are detailed herein. The APCs according to the invention are defined by the appended claims.

Avoiding clogging of APCs by large debris remains a considerable challenge to designers of these devices. Thus, although both the van der Meijden and Rief patents identify solutions to this challenge, developing additional solutions may be advantageous. The present examples seek to accomplish this in multiple innovative manners. The examples also include facilitating unclogging of APCs should clogging nevertheless occur.

<FIG> illustrates an exemplary APC <NUM> incorporating aspects of the inventions. Cleaner <NUM> may be similar to APCs shown or described in the van der Meijden patent, although such similarity is not necessary. Cleaner <NUM> may include at least body <NUM> and motive assembly <NUM>, with motive assembly <NUM> comprising (closed-loop) track <NUM> having external and internal surfaces <NUM> and <NUM>, respectively. Motive assembly <NUM> also may include pulley or drive wheel <NUM> and undriven wheels <NUM> and <NUM>. A motive assembly <NUM> typically will be present at each of the left and right sides of cleaner <NUM>.

As depicted, body <NUM> includes chamber <NUM> (see <FIG>) accessible at least via opening <NUM>. Additionally illustrated in <FIG> is cover <NUM>. Cover <NUM> preferably abuts opening <NUM> during operation of cleaner <NUM>, closing access to chamber <NUM> from above. By contrast, <FIG> shows cover <NUM> having been moved relative to opening <NUM> so as to expose chamber <NUM> from above. In this position, cover <NUM> allows access to chamber <NUM> and to fluid-powered motor <NUM> positioned at least partially therein.

Cover <NUM> may attach to body <NUM> in any appropriate manner. <FIG>, for example, illustrates cover <NUM> connecting to body <NUM> using a pin or hinges so that the cover <NUM> may pivot to and from the open position shown in <FIG>. When cover <NUM> pivots to the closed position abutting opening <NUM>, a latch, snaps, or any other suitable fasteners may be used to retain the cover <NUM> in that position during operation of APC <NUM>. Preferably (although not necessarily), a user may simply push a button to unfasten cover <NUM> from body <NUM> and thus allow cover <NUM> to pivot under manual or mechanical force. Persons skilled in the art will recognize that other methods of causing movement of cover <NUM> manually, without using tools, may be employed instead.

At least some versions of cleaner <NUM> will connect, via at least one hose, to an inlet of a pump of a water-circulation system of a swimming pool. These versions are known as "suction-side" cleaners because of their connection to a pump inlet. When the system is operating, the pump evacuates cleaner <NUM>, drawing debris-laden water from the pool through an inlet of body <NUM> into the hose for eventual travel to a filter to separate and remove debris from the water. Alternatively, versions of cleaner <NUM> may be "pressure-side" cleaners, connecting directly or indirectly to an outlet of such a pump. In these APCs, pressurized water exiting the pump is used, employing the Venturi principle, to create a low-pressure area configured to draw debris-laden water into the inlet of body <NUM>.

In either event, water drawn into body <NUM> additionally may operate fluid-powered motor <NUM>. In this respect, motor <NUM> may constitute a turbine resembling that of the Rief patent. As shown in <FIG>, motor <NUM> may include housing <NUM> defining interior vacuum chamber <NUM> and having interior chamber wall <NUM>, inlet port <NUM>, and outlet port <NUM>. Rotor <NUM> may be mounted within housing <NUM> on shaft <NUM> and configured to rotate about an axis coincident with the shaft <NUM>. Inlet port <NUM> preferably is near the inlet of body <NUM> so that water entering that inlet may pass generally unobstructed to the inlet port <NUM>. Similarly, outlet port <NUM> preferably is, or is near, an outlet of cleaner <NUM> to which a hose may be connected directly or indirectly.

Extending radially from an outer circumference of rotor <NUM> are spokes <NUM>. Seven such spokes <NUM> are illustrated as so extending in <FIG>, with spokes <NUM> being spaced uniformly along the outer circumference. More or fewer spokes <NUM> may be employed, however, and their spacing need not necessarily be uniform. Pivotally attached to each spoke <NUM> is a vane <NUM>, with vanes <NUM> beneficially pivoting about axes parallel to that about which rotor <NUM> rotates. Collectively, at least rotor <NUM>, shaft <NUM>, spokes <NUM>, and vanes <NUM> may be considered to constitute core <NUM> of motor <NUM>. In some embodiments, gears <NUM> (see <FIG>) additionally may be part of core <NUM>. Gears <NUM> may, directly or indirectly, help drive the drive wheels <NUM>.

Housing <NUM> may be formed of more than one part. <FIG> illustrates upper portion <NUM> of an exemplary housing <NUM> being attached to, or otherwise configured to move with, cover <NUM>, while lower portion <NUM> (see <FIG>) remains positioned within chamber <NUM> of body <NUM>. In this manner, the simple act of opening cover <NUM> exposes core <NUM>. This result is particularly useful when debris has impeded or obstructed operation of motor <NUM>, as exposing core <NUM> may facilitate removal of that debris.

Equally as significant, core <NUM> may be configured within chamber <NUM> so that it is manually removable as a unit for cleaning, maintenance, repair, replacement, troubleshooting, or otherwise. Hence, merely by opening cover <NUM>, core <NUM> is both exposed and available for removal from cleaner <NUM>. Especially valuable is that no tool is required for any of these actions--manual manipulation of the components is sufficient.

<FIG> illustrate and describe additional features of motor <NUM> and its interaction with, e.g., body <NUM>. <FIG> and C-F depict upper portion <NUM>, which may form an upper fluid boundary during normal operation of cleaner <NUM>. When cover <NUM> is latched, upper portion <NUM> also holds motor <NUM> in position within lower portion <NUM>, which may form a lower fluid boundary during operation of the APC <NUM>.

<FIG> and <FIG> depict seal <NUM> which may be present within interior vacuum chamber <NUM> of motor <NUM>. The existence of seal <NUM> helps bias water flow from inlet port <NUM> toward the right side of vacuum chamber <NUM> (as shown in <FIG>) and promotes efficiency of engine operation. Generally, therefore, debris-laden water flows, and rotor <NUM> rotates, generally counterclockwise in <FIG>.

Unlike conventional rigid seals, seal <NUM> is flexible in nature. In particular, seal <NUM> may flex downward in <FIG> if necessary to allow passage of debris. Thus, seal <NUM> aids motor <NUM> in avoiding seizures by allowing debris to re-circulate within vacuum chamber <NUM>.

<FIG> shows a vane <NUM> in a normal sealed position against seal <NUM>. Water pressure across the vane <NUM> helps retain this sealed relationship, and housing <NUM> may include rigid retention features <NUM> (see <FIG>) preventing seal <NUM> from extending upward in <FIG> beyond a particular point. By contrast, seal <NUM> may flex downward to accommodate extension of vane <NUM> (see <FIG>) as well as to allow passage of debris (see <FIG>). After debris passes, seal <NUM> may return to its normal position, as shown in <FIG>.

<FIG> depict structural features of a vane <NUM>. Vane <NUM> may include a proximal portion <NUM> into which an elongated hole <NUM> is formed so as to receive a connector such as pin <NUM> (see <FIG>). In this manner, vane <NUM> may connect to a corresponding spoke <NUM>. Vane <NUM> also may include a distal portion <NUM> having an edge <NUM> as well as side edges <NUM> and <NUM>. By tapering edges <NUM> and <NUM>, the likelihood that debris will be trapped between a vane <NUM> and interior chamber wall <NUM> may be reduced without increasing leakage between the vane <NUM> and the wall <NUM>.

Shown in <FIG> is that edge <NUM> may comprise leading portion <NUM> and lagging portion <NUM>. Preferably, leading portion <NUM> is configured so as to be perpendicular to the direction of motion of its vane <NUM>, while lagging portion <NUM> has an angled surface. The perpendicular nature of leading portion <NUM> facilitates its moving debris while not channeling the debris toward any gap between components. The angled surface of lagging portion <NUM>, by contrast, aids debris located between components to move out of any such gap.

<FIG> illustrate pin <NUM>. As especially visible in <FIG>, pin <NUM> may comprise a generally-straight first section <NUM> and a generally-curved second section <NUM>. First section <NUM> is sized and shaped so as to be received by hole <NUM> of a vane <NUM> and forms an axis about which vane <NUM> can pivot. Second section <NUM> bears against surface protrusion <NUM> of rotor <NUM> (see, e.g., <FIG> and <FIG>), being retained in that position by rise <NUM> of rotor <NUM>. Thus, to attach a vane <NUM>, one may insert first section <NUM> into hole <NUM>, deform second section <NUM> so that it may pass over rise <NUM>, and then allow second section <NUM> to relax so that it bears against surface protrusion <NUM>.

No adhesive hence need be used to retain pin <NUM> in appropriate position. Likewise, no other component of cleaner <NUM> need be deformed to allow placement of the pin <NUM>. Accordingly, in use, pin <NUM> may function as a pivot axis for a corresponding vane <NUM> while restricting any translation of the vane <NUM>. Moreover, the attachment process is reversible if necessary at least in part by re-deforming pin <NUM> and passing it back over rise <NUM>.

<FIG> conceptually detail additional features of vanes <NUM>. Whenever an APC includes gaps (around hinges between components, for example), debris may settle in or be forced into the gaps and potentially impede proper exercise of hinges or other moveable components. Historically, gaps sizes have been fixed prior to manufacturing production components: if made too large, more debris may settle in them; if made smaller, increased fabrication precision, leading to increased manufacturing costs, may occur.

Accordingly, the present example seeks to provide dynamic gap sizing that may both increase and decrease during operation of cleaner <NUM>. <FIG> illustrate this concept, with <FIG> showing vane <NUM> in a sealed position with respect to spoke <NUM>. <FIG> illustrate vane <NUM> separating slightly from spoke <NUM>, allowing release of accumulated debris. <FIG> depict vane <NUM> returning to its sealed position relative to spoke <NUM>. Similar functionality is illustrated in <FIG>. <FIG>, finally, illustrates core <NUM> with vanes <NUM> in various positions.

<FIG> illustrates an exemplary APC <NUM> incorporating aspects of the inventions. Cleaner <NUM> may be similar to APC <NUM> shown in the previous figures, although such similarity is not necessary. Cleaner <NUM> may include at least body <NUM> and motive assembly <NUM>, with motive assembly <NUM> comprising (closed-loop) track <NUM> having external and internal surfaces <NUM> and <NUM>, respectively. Motive assembly <NUM> also may include pulley or drive wheel <NUM> and undriven wheels <NUM> and <NUM>. Drive wheel <NUM> may include an oversized outer flange <NUM> that helps retain track <NUM> in position and prevent it from slipping laterally off the motive assembly <NUM>. More specifically, outer flange <NUM> may be configured so it extends beyond external surface <NUM> of track <NUM> to serve as a stop against which track <NUM> can abut, restricting lateral movement of track <NUM>. A motive assembly <NUM> typically will be present at each of the left and right sides of cleaner <NUM>.

As shown in <FIG>, track <NUM> includes tread <NUM> on external surface <NUM> and teeth <NUM> on internal surface <NUM>. The pattern of tread <NUM> is such that tread <NUM> is in-line with each tooth <NUM>. In this way, an axis <NUM> of each tooth <NUM> intersects at least a portion of tread <NUM>. This tooth <NUM> to tread <NUM> alignment leaves thin sections <NUM> (corresponding to gaps between the teeth <NUM> and gaps between the tread <NUM>), allowing track <NUM> to remain flexible. Moreover, as shown in <FIG>, track <NUM> includes bridges <NUM> that link the tread <NUM>. These bridges <NUM> help prevent track <NUM> from stretching. Moreover, the vertical position of each bridge <NUM> alternates between each tread <NUM>, such that adjacent bridges <NUM> are vertically offset from one another. Offsetting bridges <NUM> further helps track <NUM> remain flexible.

As depicted, for example in <FIG>, body <NUM> includes chamber <NUM> accessible at least via opening <NUM>. Additionally illustrated in <FIG> is cover <NUM>. Cover <NUM> preferably abuts opening <NUM> during operation of cleaner <NUM>, closing access to chamber <NUM> from above. By contrast, <FIG> shows cover <NUM> having been moved relative to opening <NUM> into an open position so as to expose chamber <NUM> from above. In this position, cover <NUM> allows access to chamber <NUM> and to fluid-powered motor <NUM> positioned at least partially therein.

As with cover <NUM>, cover <NUM> may attach to body <NUM> in any appropriate manner, including those described with respect to the cleaner <NUM> of <FIG>. Cleaner <NUM> also includes a handle <NUM>, which can help facilitate carrying and manually moving cleaner <NUM>. Cleaner <NUM> further includes scrub brushes <NUM> for scrubbing the bottom of the swimming pool or other liquid-containing body. Any number of scrub brushes <NUM> may be included and they make take any suitable form.

Like cleaner <NUM>, cleaner <NUM> may be configured as a suction-side cleaner or a pressure-side cleaner. In either case, water drawn into body <NUM> additionally may operate fluid-powered motor <NUM>. As shown in <FIG>, motor <NUM> may include housing <NUM> defining interior vacuum chamber <NUM> and having interior chamber wall <NUM>, inlet port <NUM>, and outlet port <NUM>. Rotor <NUM> may be mounted within housing <NUM> on shaft <NUM> and configured to rotate about an axis coincident with the shaft <NUM>. Inlet port <NUM> preferably is near the inlet of body <NUM> so that water entering that inlet may pass generally unobstructed to the inlet port <NUM>. Similarly, outlet port <NUM> preferably is, or is near, an outlet of cleaner <NUM> to which a hose may be connected directly or indirectly.

Extending radially from an outer circumference of rotor <NUM> are spokes <NUM>. Seven such spokes <NUM> are illustrated as so extending in <FIG>, with spokes <NUM> being spaced uniformly along the outer circumference. More or fewer spokes <NUM> may be employed, however, and their spacing need not necessarily be uniform. Pivotally attached to each spoke <NUM> is a vane <NUM>, with vanes <NUM> pivoting about axes parallel to that about which rotor <NUM> rotates. Collectively, at least rotor <NUM>, shaft <NUM>, spokes <NUM>, and vanes <NUM> may be considered to constitute core <NUM> (see <FIG> and <FIG>) of motor <NUM>. In some embodiments, gears <NUM> (see <FIG>) additionally may be part of core <NUM>. Gears <NUM> may, directly or indirectly, help drive the drive wheels <NUM>.

Like housing <NUM>, housing <NUM> may be formed of more than one part if desired, although it need not be. Also like core <NUM>, core <NUM> may be configured within chamber <NUM> so that it is manually removable as a unit, as shown in <FIG>, for cleaning, maintenance, repair, replacement, troubleshooting, or otherwise. Hence, merely by opening cover <NUM>, core <NUM> can be removed without obstruction from cleaner <NUM> without requiring use of a tool, as shown in <FIG>.

As shown in <FIG>, some or all of vanes <NUM> of core <NUM> may include a domed portion <NUM> so a face of vane <NUM> is convex. In some cases, domed portion <NUM> extends from a distal end to a proximal end of each vane <NUM> to substantially cover face of vane <NUM>. As the motor <NUM> turns (for example, in a counterclockwise direction relative to <FIG>), debris that does not exit through outlet port <NUM> may nest in cavity <NUM> (see <FIG>) created between housing <NUM> and domed portion <NUM> of vane <NUM>. This cavity <NUM> allows the debris to circulate through the motor <NUM> again without causing the motor <NUM> to stall. As shown in <FIG>, cleaner <NUM> may not have a seal such as seal <NUM> described with respect to cleaner <NUM>.

Claim 1:
An automatic swimming pool cleaner (<NUM>) comprising a motive assembly (<NUM>), the motive assembly comprising a drive wheel (<NUM>) and a track (<NUM>), the track comprising an external surface (<NUM>) and an internal surface (<NUM>), wherein:
the external surface of the track comprises tread (<NUM>), and
the internal surface of the track comprises teeth (<NUM>),
characterized in that an axis (<NUM>) of each tooth of the teeth intersects at least a portion of the tread.