WO2016201404A1

WO2016201404A1 - Tapered brush assembly for self-propelled pool and tank cleaner

Info

Publication number: WO2016201404A1
Application number: PCT/US2016/037155
Authority: WO
Inventors: William Londono; Glenn WEISMANN
Original assignee: Aqua Products, Inc.
Priority date: 2015-06-12
Filing date: 2016-06-13
Publication date: 2016-12-15

Abstract

A self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool includes a housing having an upper portion disposed over a base to define an interior chamber therein. The base includes a water inlet and the upper portion has a water discharge port. Rotatabiy-mounted supports support and guide the cleaner along the pool surface, A filter assembly filters water drawn through the water inlet. A water pump draws water and debris from beneath the cleaner through the inlet. The debris is retained by the filter and the discharge port expels filtered water during a cleaning operation. A rotatable tapered brush assembly having a central portion and a tapered end portion extends in a direction substantially normal to a forward direction of movement of the cleaner. The tapered brush helps minimize drag as between the brush and pool surface when making a turn during the cleaning operation.

Description

TAPERED BRUSH ASSEMBLY FOR SELF-PROPELLED POOL AND TANK CLEANER

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application claims priority to U.S. Provisional Application number 62/174,623, filed June 12, 2015, the contents of which are incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

[0002] The present invention relates to a submersible robotic pool and tank cleaning apparatus, and more specifically to a motor driven rotatable brush assembly for stirring up and cleaning undesirable contaminants and debris from a surface of a pool or tank environment.

BACKGROUND OF THE INVENTION

[0003] Robotic pool cleaning devices are mounted on rotatable supports, such as wheels, brushes and/or tracks, and are propelled or otherwise travel along submerged surfaces of a pool, tank or the like and, through the use of suction, thereby "vacuum" the pool surfaces over which they pass. The pool cleaning devices can be propelled over the surfaces of the pool by a directional or random water jet propulsion system, or by one or more drive motors that are coupled to (e.g., to the wheel axles) and cause the rotation of the rotatable supports.

[0004] The cleaning devices that are configured with an internal filtering system have an interior chamber with one or more filters mounted therein. The internal filtering systems are effective to capture and isolate contaminants and/or debris from portions of the interior chamber where it is highly desirable that contamination not encroach. The filtered water is then discharged back into the pool or tank as a pressurized stream.

[0005] To stir up and/or remove debris from the surface beneath the cleaner, a rotatable brush can be provided which extends substantially normal to the longitudinal axis of and directional movement of the cleaner. The brush assembly can be non-powered and rotate due to the frictional forces from the surface of the pool. Alternatively, the brush assembly is powered by a water turbine or electric motor through a mechanical arrangement of belts/pulleys, tracks, gears and/or a combination thereof. The powered rotatable brush assembly can also be used to provide locomotion to the cleaner either alone or in conjunction with another power source, such as a jet drive system.

[0006] Cleaning brushes can be made of a foamed polymer or plastic sponge material, in which case they are subject to wear and tear due to their continuous rotating contact with the bottom and side wall surfaces of the pool. As a result, foamed polymer cleaning brushes must be periodically removed and replaced. Various types of brushes have been used with pool cleaning machines of the prior art. Brushes in the form of elongated cylinders produced from molded polyvinyl acetate (PVA) having a relatively fine pore size are designed to cover the entire length of the rotatable shaft in a single piece. The molded PVA is relatively rigid when dry, but becomes softer and more pliable when wet with water which facilitates fitting it to the shaft.

[0007] Other types of brushes are formed as generally rectangular elements having a flat surface on the back which can be wrapped around and tightly fitted to the rotatable shaft.

Interlocking tabs and openings at the mating ends of the flexible mat permit its secure assembly to the shaft in a generally cylindrical configuration. For example, the rotatable shaft often has indents or openings into which corresponding tabs of the mat are inserted.

[0008] US Patent No.6,564,417 to Porat provides a technique to address these drawbacks by providing a flexible web having first and second opposing edges, the first edge having at least one first element extending in the direction of the first edge, and the second edge having at least one second element extending in the direction of the second edge. The web is deformable about the rotatable shaft to bring the first and second edges into contact, with the first element being in spaced relation to the second element such that the first element is aligned with the second element. A technician provides a positive locking structure such as a pin to hold the first and second elements together in a secure, locking fit. Although the pin secures the first and second elements together, aligning and interleaving the first and second elements while inserting the pin can be time consuming.

[0009] Elements of various configurations projecting from the exterior surface of the mat contact the pool surface with a scrubbing action to loosen debris and allow it to be drawn into the pool cleaner's filter system. The flat brushes can be produced as an integrally molded element using a synthetic rubber or polymer compound. The flat brushes can also be fabricated by drawing elongated rectangular pieces of cellular foamed plastic through openings in an open- weave backing material.

[0010] While each type of cleaning brush possesses certain advantages, and is intended for use under specific conditions, these prior art brushes face a drawback in the effort associated with removing a worn brush and installing a replacement cleaning brush. In the case of the cylindrical PVA foam brush, the old element can most easily be removed by cutting it away from the shaft. However, considerable effort is required to pull and properly fit the replacement brush on the shaft.

[0011] The dismounting of the prior art flat molded brushes is likewise facilitated by cutting the neck portion of the tabs where the mating ends overlap. Installing the new brush requires some strength since the interlocking elements have limited resiliency, which characteristic is required to enhance their ability to resist disengagement once assembled in the correct interlocking position. Therefore, after the tabs and slots of the overlying ends are brought into mating alignment, it can be difficult, especially for residential pool owners, to install the new brushes. Moreover, unless the interlocking elements of these brushes are fully positioned in their precise interlocking configuration, the possibility of disengagement is appreciable, in which case the brush can become loose or detached from the rotating shaft so that it does not rotate properly, and no cleaning of the pool surface is affected.

[0012] It is also known, in the case of the molded brushes having a flat backing surface, that mildew and dirt can be formed during periods of non-use and storage between the mounting shaft and the back, thereby causing the elements to stick together and necessitating removal of the dirt, mold and mildew before a new brush can be installed.

[0013] In view of the above limitations and difficulties associated with the cleaning brushes of the prior art, it would be desirable to provide a cleaning brush for pool cleaners as original equipment or as a replacement for worn or damaged cleaning brushes that is easy to install securely and to remove. It would also be desirable to provide a cleaning brush for pool cleaners that can stir up debris along a surface of the pool for subsequent filtering by the cleaner and/or pool filtering system. It is further desirable to provide a cleaning brush for pool cleaners that can minimize drag while changing a direction of movement along the surface of the pool. It is also desirable to provide a cleaning brush for pool cleaners that can stir up debris and minimize drag while changing a direction of movement along the surface of the pool.

SUMMARY OF THE INVENTION

[0014] The above problems and disadvantages are solved and avoided by the embodiments of an apparatus and method of the present invention that are described below. In the description that follows, it will be understood that the cleaner moves on supporting wheels, brushes, rollers or tracks that are aligned with the longitudinal axis of the cleaner body when it moves in a straight line. References to the front or forward end of the cleaner will be relative to its then- direction of movement.

[0015] The present invention is directed to various embodiments of a rotatable brush assembly installed along the bottom or base of an automated pool or tank cleaner. As described in greater detail below, a pool cleaner brush includes a cylindrical roller and a resilient or semi-resilient brush covering that wraps around and completely covers the roller. The roller includes a living hinge formed between two halves of the cylindrical roller which, when folded together, forms the cylindrical roller. The brush covering wraps around the cylindrical roller.

[0016] Each opposing longitudinal edge of the brush covering includes a U-shaped flange that is oriented inwardly. Each U-shaped flange fits over a corresponding longitudinal edge of the cylindrical roller, and the brush and two halves of the roller are folded towards each other at the living hinge to form a cylindrical tube, and thereby secure the opposing longitudinal edges of the brush to the corresponding longitudinal edges of the roller. End caps are further provided at opposing ends of the cylindrical roller and at least one of which can be spring-loaded to secure (i) the brush to the roller and (ii) the roller/brush assembly to the robotic cleaner.

[0017] More specifically, each opposing end secures a corresponding end of the wrapped brush around the cylindrical roller. The end caps cover a shoulder area of the roller and a channel formed in each end cap aligns with the corresponding pair of raised edges of the shoulder of the roller. The channel edges of the end caps lock the U-shaped grooves of the brush together. [0018] In one embodiment, a rotatable brush assembly for a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprises an elongated cylindrical roller formed by a first arcuate member and a second arcuate member, each arcuate member having an inner longitudinal portion and an opposing longitudinal free end, the inner longitudinal portions being positioned adjacently and hinged together, the longitudinal free ends being positioned adjacently when the hinge is in a closed position to form the elongated cylindrical roller; a web having spaced-apart cleaning elements extends outwardly on an external surface of the web, opposing longitudinal ends that substantially conform to the opposing longitudinal free ends of the cylindrical roller, and a width dimensioned such that an inner surface of the web wraps around and directly covers an outer surface of the elongated cylindrical roller, each longitudinal end of the web terminating in a U-shaped flange which defines a channel that conforms to and interfaces with one of the longitudinal free ends of the roller; and end caps disposed over the opposing ends of the elongated cylindrical roller.

[0019] In one aspect, the arc lengths of the first and second arcuate members are equal.

Alternatively, the arc length of the first arcuate member is greater than the arc length of the second arcuate member. In another aspect, inner longitudinal portions are positioned adjacently and joined by an integral living hinge. The living hinge can extend the entire length of the adjacent inner longitudinal portions. Alternatively, the living hinge can be a plurality of living hinges that are spaced apart along the length of the inner longitudinal portions.

[0020] In yet another aspect, the first and second arcuate members include an inward shoulder portion formed at each opposing end thereof. Further, the inward shoulder portions can include an outwardly extending ridge formed proximate the longitudinal free ends of the roller and collectively define a pair of adjacent ridges on each end of the roller when the arcuate members are in abutting relation. In still another aspect, the endcaps include a circular flange having a cutout sized to conform to the pair of adjacently positioned ridges. Each endcap can be positioned about a corresponding end of the roller such that the pair of adjacent ridges extends through a corresponding cutout in the circular flange of the endcap. In another aspect, the circular flange of the endcap is positioned between the inward shoulder portion and the inner surface of the web. [0021] In one aspect, each endcap includes a mounting hub extending coaxially in a direction along the longitudinal axis of the roller for enabling installation of the brush assembly into the robotic cleaning apparatus. In another aspect, at least one of the endcap mounting hubs is resiliently mounted to facilitate mounting (installation) and removal of the brush assembly from the cleaning apparatus.

[0022] In another embodiment, a self-propelled cleaning apparatus for cleaning a submerged surface of a pool or tank comprises: a housing defining an interior chamber, a water inlet positioned over the submerged surface of the pool or tank, and an outlet for discharging filtered water; drive means for moving the cleaning apparatus over the submerged surface; filtering means mounted within the interior chamber and configured to filter water and debris entering the interior chamber via the water inlet and discharge filtered water from the interior chamber through the water discharge outlet; and at least one rotatable brush assembly comprising: an elongated cylindrical roller formed by a first arcuate member and a second arcuate member, each arcuate member having an inner longitudinal portion and an opposing longitudinal free end, the inner longitudinal portions being positional adjacently and hinged together, the longitudinal free ends being positioned adjacently when the hinge is in a closed position to form the elongated cylindrical roller; a web having spaced-apart cleaning members extending outwardly on an external surface of the web, opposing longitudinal ends that substantially conform to the opposing longitudinal free ends of the cylindrical roller, and a width dimensioned such that an inner surface of the web wraps around and directly covers an outer surface of the elongated cylindrical roller, each longitudinal end of the web terminating in a U-shaped flange which defines a channel that conforms to and interfaces with one of the longitudinal free ends of the roller; and end caps disposed over opposing ends of the elongated cylindrical roller and configured to enable rotation of the brush assembly during movement of the cleaning apparatus over the submerged surface of the pool or tank.

[0023] In one aspect, the drive means includes an electric drive motor mounted in the interior chamber and having a driveshaft, a propeller mounted on at least one end of the driveshaft, rotatable mounted supports (e.g., wheels, tracks, rollers and the like) rotatably mounted to the housing, and a drive mechanism for rotating at least a portion of the rotatable mounted supports. In another aspect, the drive means includes a water turbine mounted in the interior chamber, the discharge outlet configured for attachment to a hose to receive a pressurized stream of water from an external source to rotate the water turbine, rotatable mounted supports rotatably mounted to the housing, and a drive mechanism for rotating at least a portion of the rotatable mounted supports.

[0024] In yet another aspect, the inner longitudinal portions are positioned adjacently and are hinged together by an integral living hinge. Further, the living hinge can extend an entire length of the adjacent inner longitudinal portions. Alternatively, the living hinge can be a plurality of living hinges that are spaced apart along the length of the inner longitudinal portions.

[0025] In still another aspect, the first and second arcuate members include an inward shoulder portion formed at each opposing end thereof. In one aspect, the inward shoulder portions include an outwardly extending ridge formed proximate the longitudinal ends of the roller and collectively define a pair of adjacent ridges on each end of the roller when the arcuate members are in abutting relation.

[0026] In an aspect, the endcaps include a circular flange having cutout sized to conform to the pair of adjacently positioned ridges. Each endcap can be positioned about a corresponding end of the roller such that the pair of adjacent ridges extends through a corresponding cutout in the circular flange of the endcap. In another aspect, the circular flange of the endcap is positioned between the inward shoulder portion and the inner surface of the web. In still another aspect, each endcap includes a mounting hub extending coaxially in a direction along the longitudinal axis of the roller for enabling installation of the brush assembly into the self-propelled robotic cleaning apparatus. In still another aspect, at least one of the endcap mounting hubs is resiliently mounted to facilitate mounting and removal of the brush assembly from the cleaning apparatus.

In another embodiment, a rotatable brush assembly for a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprises an elongated cylindrical roller having a longitudinal axis; a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that one or more cleaning elements positioned at a central portion of each row has a height greater than adjacent cleaning elements in the row; and opposing ends of the brush assembly configured for attachment to the self-propelled robotic cleaning apparatus.

In one aspect, the cleaning elements that are positioned adjacent to the central portion in the row are tapered. In another aspect, the cleaning elements that are positioned adjacent to the central portion in the row define an arcuate profile. In yet another aspect the cleaning elements that are positioned adjacent to the central portion in the row define a stepped profile.

In one aspect, gaps between the outwardly extending cleaning elements in adjacent rows are offset from each other. In another aspect, gaps between the outwardly extending cleaning elements in alternate rows are aligned with each other.

In one aspect, the web is molded from a thermoplastic elastomer material exhibiting high tensile strength and resistance to abrasion. In another aspect, the rotatable brush assembly further comprises end caps provided at the opposing ends of the elongated cylindrical roller.

In one aspect, a generally central portion of the brush assembly has a diameter that is greater than a diameter proximate the ends of the brush assembly. In yet another aspect, the diameter of the brush assembly decreases from a generally central portion towards the opposing ends. In still another aspect, the diameter of the brush assembly decreases linearly from a generally central portion towards the opposing ends.

In another embodiment, a rotatable brush assembly for a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprises: an elongated cylindrical roller having a longitudinal axis; and a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that a central portion of each row of the cleaning elements has a height greater than the height at an end portion in the row.

In one aspect, the height of each cleaning element decreases linearly from the central portion to the end portion in the row. In another aspect, the height of each cleaning element decreases along a curved pattern from the central portion to the end portion in the row. In yet another aspect, the height of each cleaning element decreases in a stepped pattern from the central portion to the end portion in the row. In still another aspect, the brush assembly further comprises end caps provided at the end portions of the elongated cylindrical roller.

In yet another embodiment, a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprises: a housing including an upper portion disposed over a lower portion to define an interior chamber therein, the lower portion including a water inlet and the upper portion having a water discharge port; rotatably-mounted supports supporting and guiding the cleaner along the pool surface; a water pump assembly for drawing water and debris through the inlet, the debris being retained by a filter and the filtered water being discharged through the water discharge port during a cleaning operation; and a brush assembly having a central portion and a tapered end portion rotatably mounted in a direction substantially normal to a forward direction of movement of the cleaner.

In one aspect, the rotatable brush assembly comprises an elongated cylindrical roller having a longitudinal axis; and a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that a central portion of each row of the cleaning elements has a height greater than the height at the end portion in the row.

In another aspect, the height of each cleaning element decreases linearly from the central portion to the end portion in the row. In yet another aspect, the height of each cleaning element decreases along a curved pattern from the central portion to the end portion in the row. In a further aspect, the height of each cleaning element decreases in a stepped pattern from the central portion to the end portion in the row. In another aspect end caps are provided at the end portions of the elongated cylindrical roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will be described in further detail below and with reference to the attached drawings in which:

[0028] FIG. 1 is a top, rear, right side perspective view of a cleaning vehicle;

[0029] FIG.2 is a perspective view of the bottom of a cleaning vehicle;

[0030] FIG. 3 is a perspective view of the interior drive train elements of the powered roller brush of a cleaning vehicle;

[0031] FIG.4 is a top, front right side perspective view of a partial cut away of a cleaning vehicle with an extended telescoping handle;

[0032] FIG. 5 is an exploded top, right side perspective view of a brush assembly illustrating the arrangement of a cylindrical roller, an outer web having outwardly extending cleaning elements on a first surface, and opposing end caps in accordance with the present invention;

[0033] FIG. 6 is a top, right side perspective view of the assembled brush assembly of FIG. 5;

[0034] FIG. 7 is a top, right side perspective view of the brush assembly of FIG. 5 including an expanded view of a living hinge formed in the brush assembly;

[0035] FIG. 8 is a left side elevational view of the brush assembly of FIG. 5;

[0036] FIG. 9 is a cross-sectional view of the brush assembly of FIG. 5 taken along lines 9 9 of FIG. 8;

[0037] FIG. 10 is a cross-sectional view of the brush assembly of FIG. 5 taken along lines

10— 10 of FIG. 9;

[0038] FIG. 11 is a cross-sectional view of the brush assembly of FIG. 5 taken along lines

11— 11 of FIG. 9;

[0039] FIG. 12 is a front elevational view of the cylindrical roller of FIG. 5 with the opposing end caps disposed thereon;

[0040] FIG. 13 is a bottom, left side perspective view of the cylindrical roller and the left end cap of FIG. 12;

[0041] FIG. 14 is a front elevational view of the left end cap of FIG. 12;

[0042] FIG. 15 is a top, front perspective view of the left end cap of FIG. 12; [0043] FIG. 16 is a bottom, right side perspective view of the cylindrical roller and the right end cap of FIG. 12;

[0044] FIG. 17 is a front elevational view of the right end cap of FIG. 12;

[0045] FIG. 18 is a top, front perspective view of the right end cap of FIG. 12;

[0046] FIG. 19 is an exploded top, front perspective view of the right end cap of FIG. 16 illustrating a spring-loaded retractable mounting hub;

[0047] FIG.20 is an exploded front elevational view of the cylindrical roller and end caps of FIG. 12;

[0048] FIG.21 is a perspective view illustrating the outer web being positioned over the cylindrical roller of FIG. 5;

[0049] FIG.22 is a top, left side perspective view of a tapered brush assembly suitable for use with the cleaner of FIG. 1 ;

[0050] FIG.23 is a front elevational view of the tapered brush assembly of FIG.22 including left and right end caps;

[0051] FIG. 24 is a front elevational view of the right end cap of the tapered brush assembly of FIG.23;

[0052] FIG.25 is a cross-sectional view of the brush assembly of FIG.22 taken along lines 25—25 of FIG.24;

[0053] FIG.26 is a top, right-side perspective view of a length of a web material used in the brush assembly of FIG. 22;

[0054] FIG. 27 is a top plan view of the web of FIG.26;

[0055] FIG.28 is an enlarged top plan view of the web taken along Detail A of FIG. 27; and

[0056] FIG.29 is a front elevation view of the web of FIG.26.

[0057] To facilitate an understanding of the invention, identical reference numerals have been used, when appropriate, to designate the same or similar elements that are common to the figures. Further, unless stated otherwise, the features shown in the figures are not drawn to scale, but are shown for illustrative purposes only. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] For purposes of providing a better understanding the invention, terms connoting direction and positioning of components are defined as follows:

The terms "cleaning apparatus", "cleaning vehicle" and "pool cleaner"' as used herein are interchangeable and defined as a self-propelled vehicle that is submersible in water and operable to move and filter debris located along a surface of the pool.

longitudinal axis of the cleaner is defined as a single, fixed axis extending centrally through the cleaner parallel to a pool surface beneath the cleaner and in the general direction of movement;

movement of the cleaner in a forward direction is the direction that the cleaner is generally being propelled or driven along its cleaning path;

movement of the cleaner in a reverse direction is a direction that is generally opposite to the previous forward direction along the cleaning path;

the front of the cleaner is defined as the portion of the cleaner generally extending perpendicular to the longitudinal axis in the forward direction of movement as the cleaner travels along its cleaning path;

"base" or "base plate" is broadly interpreted as one or more components forming or otherwise defining an underside or bottom portion of the housing and which is positioned substantially parallel to the surface of the pool or tank which is being cleaned; and

"top", "bottom", "upper" and "lower" are adjectives that denote different cleaner components, as well as define the relative positioning of such components with respect to a central vertical axis extending centrally through the housing cover and base of the cleaner.

[0059] Referring to FIGS. 1-4, there is shown one embodiment of a cleaning vehicle 10 having an electro-mechanically powered roller brush 100. The cleaning vehicle 10 includes a housing 11 having a base 13 or bottom portion and a housing cover 15 which together define an interior chamber 12. In one embodiment, the housing cover 12 is removably fastened over the base 13 to define an interior chamber 12. The housing cover 12 and base 13 are removably fastened with one or more fasteners, such as a clasp, latch, spring clip, bolt or other well-known and conventional fastener. A gasket or other seal (not shown) can be inserted between the base 13 and cover 12 to prevent water flowing therebetween into and out of the interior chamber 12. The housing cover 12 and base 13 are preferably made of a plastic-like material, such as polyvinylchloride (PVC), polypropylene, among other well-known thermoplastic materials, aluminum and/or alloys thereof, and/or combinations thereof, and/or other water impermeable materials.

[0060] The roller brush 100 is suspended transversely with respect to the longitudinal axis of the cleaner 10 proximately between a pair of front wheels 30 and/or back wheels 40 and at a height such that cleaning elements 122 extending from the roller brush 100 contact the surface on which the wheels 30 and 40 travel. In one embodiment, the distal ends of cleaning

elements 122 just make contact with the surface on which the wheels 30 and 40 travel, to stir up debris from the surface and minimize the load on the motor, as will be discussed below in further detail. Alternatively, the cleaning elements 122 can have a length sufficient to provide additional frictional forces with the surface beneath the cleaner and thereby contribute to the movement of the cleaner 10 along the surface as the power driven roller brush 100 is rotated by the electric motor 80 and drive belt system 21 (FIG. 3).

[0061] Rotationally-mounted supports 18 are coupled to the housing 11 for moving the cleaner 10 over the submerged surface of a pool or tank. As shown in FIGS. 1 and 4, the rotationally- mounted supports 18 are wheels 30 and 40 mounted on axles 32. Alternatively, the rotationally- mounted supports 18 can be or include one or more tracks, rollers, casters, among other well- known rotationally-mounted supports. As shown in FIG. 3, the cleaner 10 is propelled by one or more drive motors 80 which engage and rotate one or more of the wheels 18 through a mechanical transmission system 86.

[0062] In one embodiment the cleaning vehicle 10 may be placed in and removed from its use environment by a handle 50 (e.g., a telescoping handle). The cleaner's internal electric motor 80 (shown in FIG. 3) receives power from a power cable 60 which connects to a remote power source (not shown). The vehicle is propelled by the expulsion of the liquid from one of its outlet ports 70. The vehicle 10 functions to clean the surfaces of a large liquid reservoir, such as a swimming pool, which are covered by the liquid stored in the reservoir. [0063] Referring to FIG.4, a telescoping handle 50 makes it easier to place the pool cleaning vehicle 10 into and withdraw it from the reservoir in which it is to operate. The handle comprises two side arms 52 and a cross arm 54, which can be readily grasped. The side arms 52 are accommodated in receiver shafts 56 which have ends 58. The shafts 56 are long enough that the handle 50 may be fully retracted so that it is flush with the vehicle as can be seen in FIG. 1. The side arms 52 and the shafts 56 interact such that the handle 50 can support the free air weight of the vehicle 10. This is accomplished by providing one or the other or both with locking mechanisms to limit the travel of the side arms 52 out of the shafts 56.

[0064] The vehicle 10 is submerged in the stored liquid (water) and is then propelled by taking in liquid through its inlet ports 72 formed in the base 13 or bottom of the housing 11 (visible in FIG.2) and expelling it out one of its outlet ports 70 (visible in FIGS. 1 and 4). The inlet ports 72 are illustratively formed through the base 13 and outlets 70 are formed in the housing cover 15. The water movement is effected by electric motor 80 (visible in FIGS. 3 and 4) by turning its propellers 82 and 84 at opposing ends of the motor drive shaft 81. The direction in which the vehicle 10 is propelled is determined by the direction of rotation of the electric motor 80 which is in turn is controlled by signals received from the power supply via floating cable 60. Preferably, tlie polarity of the motor 80 is reversed to effect a change in rotation of the motor drive shaft 81, transmission assembly 86, and propellers 82 and 84. The propellers 82 and 84 are driven by the motor 80 to expel liquid out of either the outlet port 70 above the front wheels 30 (visible in FIG. 1 ) or the outlet port 70 (visible in FIG.4) above the back pair of wheels 40. In accordance with the well-known physics concept of action and reaction, the vehicle 10 will be propelled in a direction opposite to that in which the liquid is expelled.

[0065] More specifically, the expelled water is in the form of a water jet that is discharged through one of the outlets 70, which has a resultant force vector preferably directed towards the pool surface beneath the cleaner. Preferably and as shown in the FIG. 1 , the outlets 70 are aligned generally along the longitudinal axis of the cleaner and angled acutely with respect to the surface beneath the cleaner such that the resultant force vector from the water jet has a horizontal component and a vertical component and which propels the cleaner in a forward direction and maintains the cleaner along the surface being cleaned. Preferably, the resultant force vector is directed directly beneath the vehicle 10 proximate to and rearward of an axis of the front wheels 30 which is generally transverse to the longitudinal axis of the cleaner. However, the acute angles of the water jet and corresponding resultant force vector are not considered limiting.

[0066] Referring again to FIG.4, the design of the vehicle with longitudinal filters 90 readily accommodates the shafts 56 which are sized to receive a corresponding side arm 52 of the handle 50. The vehicle 10 serves its cleaning function by drawing fluid containing dirt and debris into its inlet ports 72 and subjecting this fluid to a filtering action before expelling it out of its outlet ports 70. The positioning of the electric motor 80 and its propellers 82 and 84 longitudinally above the centerline of the vehicle allows the placement of the filters 90 parallel to this centerline and in one embodiment filters 90 are angled to accommodate the shafts 56. The configuration of the filter assembly and it's positioning within the interior chamber 12 or on the housing is not considered limiting. For example, the filter assembly can be formed by one or more shells or buckets comprising a frame and a mesh and/or web covering, one or more pleated filter cartridges, a semi-deformable wire or plastic mesh structure, a filter bag, among other well- known filter assemblies. Moreover, the filter can be disposed about the outlet 70 to provide filtering of debris entrained with the water through the inlet 72 of the cleaner 10.

[0067] During operation, each motor-driven propeller 82, 84 functions as a water pump to create a low pressure environment in the interior chamber 12, which causes water and debris from the pool or tank to be drawn through the at least one water inlet 72 into the interior chamber 12, flow through the filter assembly 90, and the filtered water is discharged through the water discharge outlet 70. The expelled filtered water forms the water jet as described above. The debris and/or other contaminants are separated from the intake water and isolated within the interior chamber 12 by the filter assembly 90.

[0068] As can be seen in FIG. 3, the electric motor 80 is also used to power the roller brush 100. The electric motor 80 is equipped with a transmission assembly, e.g., gear

box 86, which translates the rotation of the electric motor 80 by ninety degrees or some other angle and also reduces the number of rotations in some fixed ratio such as 1 :30 or any other ratio. A common way to effect these changes is with a combination of a worm gear with a spur gear. However other types of mechanical connections may be used. The gear box has a takeoff spindle 88 which carries a first pulley 89 which transmits rotational force to a gear train or drive belt system 21. The drive belt 21 in turn transmits this force to a second pulley 22 on a drive transfer shaft 23. This drive transfer shaft 23 is supported by an elongated bushing 24. This drive transfer shaft 23 carries another pulley 25 at its other end which transmits force to a second drive belt 26. The second drive belt 26 is looped over a fourth pulley 27 which is free to rotate. The drive belt 26 frictionally engages the axle 28 of the roller brush 100. This facilitates slippage between the roller brush 100 and ultimately the electric motor 80, should the roller brush encounter some type of obstacle like a large piece of debris on the surface being cleaned. This avoids the vehicle 10 becoming stalled by such obstacles and allows the vehicle 10 to pass over them. Where a gear train is used in place of a drive belts, a clutch may be positioned between the motor and the roller brush 100. The clutch will allow the motor continue to rotate the propellers if the roller brush is obstructed from rotating by debris within the pool.

[0069] The roller brush 100 and the front wheels 30 are both mounted to the vehicle 10 via suspension brackets 34. This arrangement allows the front wheels 30 to be mounted without a transverse axle, thereby facilitating the mounting of the roller brush 100 between the front wheels 30. The suction created through the inlet ports 72 by the action of the

propellers 82 and 84 holds the vehicle to non-horizontal and even vertical side walls so long as these side walls are submerged in liquid, while the expulsion of liquid from an outlet port 70 propels the vehicle up the side wall.

[0070] Referring to FIGS. 5-21 , an illustrative roller brush 100 is now described. Referring now to FIGS. 5-10 and 21, the roller brush 100 comprises a cylindrical roller 102, a web 110 and a pair of opposing end caps 138. Referring to FIGS. 5 and 21 , the roller 102 is formed by a first arcuate member 104 and a second arcuate member 106, each arcuate member having an inner longitudinal portion 103, 105 and an opposing free longitudinal end 107, 109, the inner longitudinal portions 103, 105 being positioned adjacently and hinged 110 together, the longitudinal free ends 107, 109 being positioned adjacently when the hinge 110 is in a closed position to form the elongated cylindrical roller 102.

[0071] In one embodiment, the arc lengths of the first and second arcuate members 104 and 105 are equal. Alternatively, the arc length of one of the portions, e.g., the first arcuate member 104 is greater than the arc length of the other (e.g., second 106) arcuate member. In either embodiment, the two portions 104 and 106 collectively form a cylindrical roller 102.

[0072] Preferably, the inner longitudinal portions 103 and 105 are hinged together by a living hinge 110 which extends the entire length along the inner longitudinal portions 103 and 105. Alternatively, the living hinge 110 can be formed as spaced-apart segments along the inner longitudinal portions 103 and 105.

[0073] The roller 102 is preferably fabricated from polypropylene. Alternatively, the roller 102 can be fabricated from acrylonitrile butadiene styrene (ABS) or polyvinylchloride (PVC), among other well-known rigid or semi-rigid materials.

[0074] Referring to FIGS. 5, 9, 11, 12 and 19, the first and second arcuate members 104 and 106 include an inward shoulder portion 112 formed at each opposing end thereof. The inward shoulder portions 112 include an outwardly extending ridge 114 formed proximate the longitudinal free ends 107, 109 of the roller and collectively define a pair of adjacent ridges 114 on each end of the roller when the hinge 110 is closed.

[0075] Referring to FIGS. 10 and 21 , the web 120 includes a flat or substantially flat inner surface 121, and an outer surface 123 having spaced-apart and outwardly extending protrusions which serve as cleaning elements 122. The web 120 is preferably fabricated from a thermal plastic elastomer (TPE). Alternatively, the web 120 can be fabricated from silicone, or vinyl, among other well-known flexible and/or deformable materials.

[0076] The web 120 is substantially rectangular in shape and has opposing longitudinal ends 124 that substantially conform to the opposing longitudinal free ends 107 and 109 of the cylindrical roller 100, and a width 126 dimensioned such that an inner surface 121 of the web 120 wraps around and directly covers an outer surface 101 of the elongated cylindrical roller 100. Each longitudinal end 124 of the web 120 terminates in a U-shaped flange 128, which defines a channel 129 that conforms to and interfaces with one of the longitudinal free ends 107, 109 of the roller 102.

[0077] Referring to FIG. 21 , inner surface 121 of the web 120 is positioned adjacent to the outer surface 101 of the roller 102. Specifically, the longitudinal free end 107 of the first portion 104 of the roller 102 is slidably inserted into the channel 129i of the longitudinal end 128i. Similarly, the longitudinal free end 109 of the second portion 106 of the roller 102 is slidably inserted into the channel 129₂ of the longitudinal end 128_?.. The longitudinal free ends 107 and 109 are rotated about the living hinge 110 adjacently together to thereby tightly wrap the inner surface 121 of the web 120 around the cylindrical roller 102. The width 126 of the web 120 is configured to conform to the outer circumference of the cylindrical roller 102 to minimize slack therebetween. Moreover, the longitudinal ends 128 of the web 120 are locked about the longitudinal free ends 107, 109 of the roller 102.

[0078] As discussed above, the cleaning elements 122 can be a length suitable to stir up debris without or with minimal or negligible contribution towards the movement of the cleaner along the pool surface. Alternatively, the cleaning elements 122 can have an extended length suitable to contribute to or cause in its entirety the movement of the cleaner 10 over the surface of the pool.

[0079] As shown in FIGS. 5-11 , the cleaning elements can be a plurality of cleaning elements which extend as rows continuously and equidistantly apart along the entire length of the roller. In one embodiment, eighteen cleaning element 122 extend radially outward equidistantly apart, where each one is tapered on opposing sides at an angle of 3.5 degrees and extends a length of 0.45 mm. As shown in FIGS. 1 -4, each of the rows of cleaning elements can be segmented to and extend equidistantly apart along the entire length of the roller. A person of ordinary skill in the art will appreciate that the shape and the dimensions of cleaning elements 122 discussed herein are not considered limiting as other configurations can be implemented.

[0080] Referring now to FIGS. 5-19, opposing end caps 138 are disposed over opposing ends 130 of the elongated cylindrical roller 102. The opposing ends 130 are formed by each adjacent pair of inward shoulder portions 112 of each of the first and second portions 104 and 106 of the roller 102. Referring to FIGS. 13-17, the end caps 138 comprise a circular-shaped wall 140 having an exterior surface 141 and opposing interior surface 144. Each end cap 138 further includes a circular flange 142 extending in a direction that is normal from the interior surface 144 and having a cutout 143 sized to conform to a corresponding pair of adjacently positioned ridges 114. [0081] The end caps 138 are preferably fabricated from polycarbonate. Alternatively, the end caps 138 can be fabricated from ABS or nylon, among other well-known suitable materials.

[0082] Each end cap 138 is positioned about a corresponding end of the roller 102 such that the pair of adjacent ridges 114 extends through a corresponding cutout 143 in tine circular flange 142 of the end cap 138, as shown in FIGS. 11 , 12, 15 and 19. In this manner, the web is wrapped about the outer surface 101 of the roller 102 and the circular flange 142 of each end cap 138 is positioned and trictionally retained between the inward shoulder portion 112 and the inner surface 121 of the web 120. Accordingly, the keying arrangement of the cutouts 143 with the adjacent ridges 114 collectively lock the adjacent first and second portions 104 and 106 together in a closed position to form the cylindrical roller 102, and the U or C-shaped flanges 128 retain the ends of the web along the adjacent longitudinal free ends 107 and 109 of the roller 102.

[0083] Referring to FIGS. 5 and 9, each end cap 138 includes a central mounting hub (e.g., pin) 146 extending coaxially in a direction along the longitudinal axis 116 (FIG. 5) of the roller 102 for enabling installation of the brush assembly 100 onto the self-propelled robotic cleaning apparatus 10. In one embodiment, the mounting hubs are molded integrally with the end caps 138 and are fixed along the central longitudinal axis 145. The mounting hubs 146 are configured to permit rotation of and removably securing the roller brush assembly 100 to the cleaner 10.

[0084] Referring to FIGS. 11-19, at least one of the endcap mounting hubs 146 can be a spring-loaded pin to further enable installation and removal of the brush assembly from the cleaning apparatus 10. Referring to FIGS. 18 and 19, the spring-loaded pin 146 includes a rear portion 149 that is slidably engagable with a cylindrical rear housing 148 which is fastenable to the interior wall 141 of the end cap 138. The rear housing 148 is tubular in shape having closed rear end 152 and a channel 150 having a length and circumference that is greater than the length and circumference of the rear portion 149 of the mounting hub 146. A coil spring 147 is positioned in the channel 150 with one end abutting the closed rear end 152 of the channel 150, and the opposing end adjacent the rear portion 149 of the mounting hub 146. The rear portion 149 is inserted over the free end of the coil spring and into the channel, and the rear housing, spring and pin 146 are collectively fastened to the interior wall 141 of the end cap 138 by aligning and inserting the mounting hub 146 through an orifice 145, and fastening the open end of the rear housing to the interior wall 144 using one or more fasteners, such as detents 151, threaded fasteners, adhesives and/or the like.

[0085] In this manner, the mounting hub 146 extends outwardly in a direction that is normal from the exterior wall 141 and is retained by the interior wall 144 and rear housing 148. The coil spring 147 has a length sufficient to normally maintain the mounting hub 146 in a position extending through the orifice 145 of the end cap 138. When an external force is applied longitudinally along the mounting hub 146 towards the rear housing 148, the mounting hub 146 slides in the channel 150 towards the closed rear end 152, thereby compressing the spring 147. The mounting hub can be slidably moved so that the tip is flush with the exterior wall 141 to thereby readily enable installation into and removal from the cleaner 10. When the external force is removed from the mounting hub 146, the spring returns to its normal uncompressed state and slides the mounting hub 146 along the channel 150 in the opposite direction back to the normally extended position.

[0086] Referring now to FIGS.22-26, a second illustrative embodiment of the brush assembly is shown. The brush assembly 100 includes a cylindrical roller 102, web of material 120 and end caps 138, and the assembly thereof is similar to that described above with reference to FIGS. 5- 21.

[0087] The web of material 120 which circumscribes the cylindrical roller 102 can be cut from a larger sheet or from a roll, and has a plurality of cleaning elements or fins 122 that extend radially outward along the length of the roller 102. The cleaning elements are arranged in rows 125 which extend along the length, i.e., the longitudinal axis of the roller 100. The cleaning elements 122 are segmented along each row 125 and have substantially uniform lengths and extend lengthwise along the rows, as shown in the figures. Alternatively, the lengths of the segments 122 can be varied to produce a different visual and/or functional effect. The segments 122 are spaced equidistantly apart so that gaps 127 are formed between the lengths, as illustratively shown in FIGS. 1 -3 and 23. As best shown in FIGS. 22 and 23, the alignment of the segments 122 is offset as between adjacent rows, such that the gaps 127 between the cleaning element segments 122 of adjacent rows are also non-aligned. Preferably, the segments 122 and gaps 127 in alternate rows 125 are aligned about the circumference of the brush 100, i.e., segments 122 in every other row are aligned. Other special arrangements can be employed and are within the scope of the invention.

[0088] Referring now to FIGS. 26-29, in one illustrative embodiment, the length of the brush is approximately 9.5 inches and the diameter of the brush 100 as measured about the cylindrical roller 102 is approximately 2 inches. Each segment 122 has a width of approximately 0.7 inches a thickness of approximately 0.06 (1/16) inch, and the width of the gaps 127 between the laterally adjacent fin segments are approximately 0.15 (1/8) inches. The height of the segments 122 varies as discussed below in further detail. The spacing between the rows of the segments 122 about the circumference of the roller 102 is approximately 0.32 (1/3) inch. The dimensions associated with the brush 100 are for illustrative purposes and are not considered limiting.

[0089] The heights of the fin segments 122 are varied such that the central portion of the brush has segments that are higher than the segments proximate the end caps 138. Preferably, the segmented fins 122 are varied in height to produce a bow-shaped profile for the brush assembly. For example, the two or three centrally located segments have a height of 0.70 inches, while the adjacent segments 122 along the row to the left and right of the two or three central segments are of reduced height such that the segments proximate the end caps have a height of 0.18 inches. Preferably, the shorter segments define an arcuate profile as shown in FIGS. 26-29.

[0090] Alternatively, the tops of the tapered segments can be linearly sloped downwards towards the end portions or end caps 138. A person of ordinary skill in the art will appreciate that the length and diameter of the brush, and the shape, dimensions and arrangement of and between the cleaning element segments 122 are provided for illustrative purposes only and are not to be considered as being limiting. Further, a person of ordinary skill in the art will appreciate that the mounting or securing of the web 120 that is wrapped around the outer surface of the roller 102 is not limited to the use of the C or U-shaped flanges 128 and channels 129, as other assembly arrangements are available including the use of adhesive, mechanical fasteners, among other well-known techniques for securing the web of material 120 over the roller 102.

[0091] Although the tapered brush assembly is illustratively shown formed with cleaning segments 122, such configuration is not considered limiting. For example, each row can be formed by a single elongated segment or cleaning element which has a central portion with a height that is greater than its height at the end portions. That is, each fin or cleaning element 122 extends across the entire row and the cleaning element can decrease in height in a linear, stepped, arced and/or other configuration or shape from the central portion to the opposing end portions. The spacings between each row are preferably sized to allow the cleaning elements 122 to bend without contacting each other, as well as to allow debris in the water and/or on the pool surface to be stirred up and flow towards the inlet by the rotating brush.

[0092] As compared to the roller brushes of the prior art, the reduction in height or tapering of the cleaning element/segments 122 from the center of the brush assembly towards the end portions and/or end caps 138 serves to reduce or minimize the drag as between the brush and the pool surface while the cleaner 10 is making a turn. That is, the cleaning elements 122 have a height suitable to stir up debris as the brush rotates, while also minimizing the drag effects along the outer portions of the brush 100 when the cleaner changes its direction of travel.

(00931 Although the roller brush 100 is illustrated and described as being implemented in a cleaner driven by an internal electric motor having opposing dual propellers, a person of ordinary skill in the art will appreciate that other types of self-propelled robotic pool cleaners can implement and benefit from the roller brush 100 of the present invention. For example, suction type cleaners 10 that implement an external pool pump system to drive an internal water turbine, which in turn drives the cleaner can also implement and benefit from the roller brush 100. For a better understanding of suction type and other types of cleaners for which the brush assembly of the present invention is suitable for implementation, the reader is directed to US publication no. 20130031734 to Porat, the contents of which are incorporated by reference herein in their entireties. The types of cleaners which can implement the roller brush 100 include belt driven and/or wheel driven cleaners, and the cleaner types are discussed for illustrative purposes only and are not considered limiting.

[0094] The roller brush assembly 100 has numerous advantages not seen in the prior art. One advantage is that a user can quickly and easily detach the roller brush assembly 100 from the housing by simply depressing the spring-loaded mounting hub 146 and lifting the end with the spring-loaded mounting hub 146 so that the entire roller brush assembly can slide out from beneath the cleaner 10. Replacement of the brush assembly 100 merely requires the reverse steps to insert the roller brush assembly back 100 on the cleaner. Another advantage is that the living hinge 110 of the cylindrical roller 102 enables the quick wrapping of the web 120 around the roller 102. Further, the U or C-shaped flanges 128 and corresponding channels 129 formed on the longitudinal edges of the web 120 advantageously secure the web 120 about the cylindrical roller 102. The end caps 138 are easily inserted between the web 120 and roller 102 at the opposing ends to secure the web to the roller 102 and prevent unravelling, as well as enable the entire roller brush assembly 100 to be transported as a single unit without undesirable component separation and then readily installed on the cleaner 10. One or both of the mounting hubs 146 can be keyed to enable positive rotation of the roller brush assembly 100 by a power train, such as an electric motor and gear drive arrangement or a water turbine/gear drive arrangement.

Alternatively, the mounting hubs 146 can be non-keyed (e.g., circular in shape) to enable free spinning of the roller brush assembly 100 when installed in the cleaner 10.

[0095] Advantageously, the core and web elements can be assembled contemporaneously. As well, the core and web elements can be manufactured contemporaneously. For example, the core and web elements can be injected individually or over injected together.

[0096] Moreover, the fins of the web can be tapered across the brush such that the ends of brush have fins with reduced heights as compared to centrally located fins. The tapered arrangement of the brush helps to reduce drag as between the brush and the pool surfaces when the cleaner changes its direction during a cleaning operation.

[0097] While the foregoing is directed to embodiments of the present invention, other and further embodiments and advantages of the invention can be devised by those of ordinary skill in the art based on this description without departing from the basic scope of the invention, which is determined by the claims that follow.

Claims

We claim;

1. A rotatable brush assembly for a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprising:

an elongated cylindrical roller having a longitudinal axis;

a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that one or more cleaning elements positioned at a central portion of each row has a height greater than adjacent cleaning elements in the row; and

opposing ends of the brush assembly configured for attachment to die self-propelled robotic cleaning apparatus.

2. The rotatable brush assembly of claim 1 , wherein the cleaning elements that are positioned adjacent to the central portion in the row are tapered.

3. The rotatable brush assembly of claim 1 , wherein the cleaning elements that are positioned adjacent to the central portion in the row define an arcuate profile.

4. The rotatable brush assembly of claim 1 , wherein the cleaning elements that are positioned adjacent to the central portion in the row define a stepped profile.

5. The rotatable brush assembly of claim 1 , wherein gaps between the outwardly extending cleaning elements in adjacent rows are offset from each other.

6. The rotatable brush assembly of claim 1 , wherein gaps between the outwardly extending cleaning elements in alternate rows are aligned with each other.

7. The rotatable brush assembly of claim 1 in which the web is molded from a thermoplastic elastomer material exhibiting high tensile strength and resistance to abrasion.

8. The rotatable brush assembly of claim 1 further comprising end caps provided at the opposing ends of the elongated cylindrical roller.

9. The rotatable brush assembly of claim 1 , wherein a generally central portion of the brush assembly has a diameter that is greater than a diameter proximate the ends of the brush assembly.

10. The rotatable brush assembly of claim 1 , wherein the diameter of the brush assembly decreases from a generally central portion towards the opposing ends.

11. The rotatable brush assembly of claim 1 , wherein the diameter of the brush assembly decreases linearly from a generally central portion towards the opposing ends.

12. A rotatable brush assembly for a self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprising:

an elongated cylindrical roller having a longitudinal axis; and

a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that a central portion of each row of the cleaning elements has a height greater than the height at an end portion in the row.

13. The rotatable brush assembly of claim 12, wherein the height of each cleaning element decreases linearly from the central portion to the end portion in the row.

14. The rotatable brush assembly of claim 12, wherein the height of each cleaning element decreases along a curved pattern from the central portion to the end portion in the row.

15. The rotatable brush assembly of claim 12, wherein the height of each cleaning element decreases in a stepped pattern from the central portion to the end portion in the row.

16. The rotatable brush assembly of claim 12 further comprising end caps provided at the end portions of the elongated cylindrical roller.

17. A self-propelled robotic cleaning apparatus for cleaning a submerged surface of a pool or tank comprising:

a housing including an upper portion disposed over a lower portion to define an interior chamber therein, the lower portion including a water inlet and the upper portion having a water discharge port;

rotatably-mounted supports supporting and guiding the cleaner along the pool surface; a water pump assembly for drawing water and debris through the inlet, the debris being retained by a filter and filtered water being discharged through the water discharge port during a cleaning operation; and

a brush assembly having a central portion and a tapered end portion rotatably mounted in a direction substantially normal to a forward direction of movement of the cleaner.

18. The apparatus of claim 17, wherein the rotatable brush assembly comprises: an elongated cylindrical roller having a longitudinal axis; and

a web of flexible material having a width such that an inner surface of the web wraps around and directly contacts an outer surface of the elongated cylindrical roller, a plurality of spaced-apart cleaning elements extending radially outward from the surface of the web and arranged in rows that extend substantially parallel to the longitudinal axis of the roller and configured such that a central portion of each row of the cleaning elements has a height greater than the height at the end portion in the row.

19. The rotatable brush assembly of claim 18, wherein the height of each cleaning element decreases linearly from the central portion to the end portion in the row.

20. The rotatable brush assembly of claim 18, wherein the height of each cleaning element decreases along a curved pattern from the central portion to the end portion in the row_*

21. The rotatable brush assembly of claim 18, wherein the height of each cleaning element decreases in a stepped pattern from the central portion to the end portion in the row.

22. The rotatable brush assembly of claim 18 further comprising end caps provided at the end portions of the elongated cylindrical roller.