Pool Cleaning Device With Adjustable Buoyant Element

[0001] The present application is a divisional application of, and claims the benefit of priority to, U.S. patent application Ser. No. 12/938,041, filed Nov. 2, 2010, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] The present disclosure generally relates to apparatus for cleaning a pool. More particularly, exemplary embodiments of the disclosure relate to automatic pool cleaning apparatus with adjustable features that effect the navigation path of a pool cleaning device.

[0003] Swimming pools commonly require a significant amount of maintenance. Beyond the treatment and filtration of pool water, the bottom wall (the “floor”) and side walls of a pool (the floor and the side walls collectively, the “walls” of the pool) must be scrubbed regularly. Additionally, leaves and other debris often times elude a pool filtration system and settle on the bottom of the pool. Conventional means for scrubbing and/or cleaning a pool, e.g., nets, handheld vacuums, etc., require tedious and arduous efforts by the user, which can make owning a pool a commitment.

[0004] Automated pool cleaning devices, such as the TigerShark or TigerShark 2 by AquaVac®, have been developed to routinely navigate over the pool surfaces, cleaning as they go. A pump system continuously circulates water through an internal filter assembly capturing debris therein. A rotating cylindrical roller (formed of foam and/or provided with a brush) can be included on the bottom of the unit to scrub the pool walls.

[0005] Known features of automated pool cleaning devices which allow them to traverse the surfaces to be cleaned in an efficient and effective manner are beneficial. Notwithstanding, such knowledge in the prior art, features which provide enhanced cleaner traversal of the surfaces to be cleaned, improve navigation and/or adapt a cleaner to a particular pool to achieve better efficiency and/or effectiveness remain a desirable objective.

[0006] The present disclosure relates to apparatus for facilitating operation of a pool cleaner in cleaning surfaces of a pool containing water. In some embodiments, the cleaner has a plurality of elements, including a housing directing a flow of water. The housing has a water inlet and a water outlet. The plurality of elements of the cleaner are composed at least partially of materials having a density greater than water, the cleaner having a center of gravity and an overall negative buoyancy. The cleaner has at least one buoyant element having a density less than water. The buoyant element is positionable at a selected position of a plurality of alternative positions relative to the center of gravity of the cleaner. The at least one buoyant element is retained in the selected position while the cleaner moves relative to the pool surfaces until being selectively repositioned at another of the plurality of alternative positions. The at least one buoyant element exerts a buoyancy force contributing to a biasing of the cleaner toward at least one specific orientation when the cleaner is in the water.

[0007] In accordance with a method of the present disclosure, the plurality of alternative positions relative to the center of gravity of said cleaner, each have an associated probability of inducing a motion path of a particular type when the cleaner moves. The buoyant element is positioned at one of the plurality of alternative positions, moving the center of buoyancy of the cleaner to a corresponding position. The cleaner is then operated, including moving the cleaner via motive elements thereof.

[0008] Additional features, functions and benefits of the disclosed apparatus, systems and methods will be apparent from the description which follows, particularly when read in conjunction with the appended figures.

[0051] According to the present disclosure, advantageous apparatus are provided for facilitating maintenance and operation of a pool cleaning device. More particularly, the present disclosure, includes, but is not limited to, discussion of a windowed top-access lid assembly for a pool cleaner, a bucket-type filter assembly for a pool cleaner, and quick-release roller assembly for a pool cleaner. These features are also disclosed in U.S. patent application Ser. No. 12/211,720, entitled, Apparatus for Facilitating Maintenance of a Pool Cleaning Device, published Mar. 18, 2010 as 2010/0065482, which application is incorporated herein in its entirety herein by reference. In addition, the cleaner may be provided with an adjustable buoyancy/weighting distribution which can be used to alter the dynamics (motion path) of the cleaner when used in a swimming pool, spa or other reservoir.

[0052] With initial reference to FIGS. 1-2, a cleaner assembly 10 generally includes a cleaner 100 and a power source such as an external power supply 50. Power supply 50 generally includes a transformer/control box 51 and a power cable 52 in communication with the transformer/control box 51 and the cleaner. In an exemplary embodiment, the pool cleaner 10 is an electrical pool cleaner, and sample electrical schematics for the cleaner assembly 10 generally are depicted in FIGS. 18A and 18B. Additional and/or alternative power sources are contemplated.

[0053] Referring to FIGS. 1-8 and 10, the cleaner 100 generally includes a housing assembly 110, a lid assembly 120, a plurality of wheel assemblies 130, a plurality of roller assemblies 140, a filter assembly 150 and a motor drive assembly 160, which shall each be discussed further below.

[0054] The housing assembly 110 and lid assembly 120 cooperate to define internal cavity space for housing internal components of the cleaner 100. In exemplary embodiments, the housing assembly 110 may define a plurality of internal cavity spaces for housing components of the cleaner 100. The housing assembly 110 includes a central cavity defined by base 111 and side cavities defined by side panels 112. The central cavity may house and receive the filter assembly 150 and the motor drive assembly 160. The side cavities may be used to house drive transfer system components, such as the drive belts 165, for example.

[0055] The drive transfer system is typically used to transfer power from the motor drive assembly 160 to the wheel assemblies 130 and the roller assemblies 140. For example, one or more drive shafts 166 (see, in particular, FIG. 10) may extend from the motor drive assembly 160, each drive shaft 166 extending through a side wall of the base 111, and into a side cavity. Therein the one or more drive shafts 166 may interact with the drive transfer system, e.g., by turning the drive belts 165. The drive belts 165 generally extend around and act to turn the bushing assemblies 135. Each mount 143 of the quick release mechanism includes an irregularly shaped axle 143B extending through complementary-shaped apertures within an associated one of the bushing assemblies 135 and an associated one of the wheel assemblies, such that rotation of the bushing assemblies 135 thereby rotates the irregularly shaped axle 143B, hence driving both the associated roller assembly 140 and the associated wheel assembly 130.

[0056] Regarding the position of the bushing assemblies 135, etc., the housing assembly 110 may include a plurality of brackets 116 each extending out from a side wall of the base 111 and having a flange parallel to said side wall, wherein a bushing assembly 135 can be positioned between the flange and side wall. The side walls and brackets 116 typically define a plurality of holes to co-axially align with an aperture defined through each bushing assembly 135. In exemplary embodiments, the axle 143B (discussed in greater detail with reference to FIG. 9B), may be inserted through each bracket 116, bushing assembly 135 and the corresponding side wall, defining an axis of rotation for the corresponding wheel assembly 130 and a roller assembly 140 associated with said axle.

[0057] The housing assembly 110 typically includes a plurality of filtration intake apertures 113 (see, in particular, FIGS. 8 and 10) located, for example, on the bottom and/or side of the housing assembly 110. The intake apertures 113 are generally configured and dimensioned to correspond with openings, e.g., intake channels 153, in the filter assembly 150. The intake apertures 113 and intake channels 153 can be large enough to allow for the passage of debris such as leaves, twigs, etc. However, since the suction power of the filtration assembly 150 may depend in part on surface area of the intake apertures 113 and/or intake channels 153, it may be advantageous, in some embodiments, to minimize the size of the intake apertures 113 and/or intake channels 153, e.g., to increase the efficiency of the cleaner 100. The intake apertures 113 and/or intake channels 153 may be located such that the cleaner 100 cleans the widest area during operation. For example, the front intake apertures 113 for the cleaner 100 can be positioned towards the middle of the housing assembly 110, while the rear intake apertures 113 can be positioned towards the sides of the housing assembly 110. In exemplary embodiments, intake apertures 113 may be included proximal the roller assemblies 140 to facilitate the collection of debris and particles from the roller assemblies 140 (see, in particular, FIG. 10). The intake apertures 113 can advantageously serve as drains for when the cleaner 100 is removed from the water.

[0058] In exemplary embodiments, the housing assembly 110 may include a cleaner handle 114, e.g., for facilitating extraction of the cleaner 100 from a pool.

[0059] In order to facilitate easy access to the internal components of the cleaner 100, the lid assembly 120 includes a lid 121 which is pivotally associated with the housing assembly 110. For example, the housing assembly 110 and lid assembly 120 may include hinge components 115, 125, respectively, for hingedly connecting the lid 121 relative to the housing assembly 110. Note, however, that other joining mechanisms, e.g., pivot mechanism, a sliding mechanism, etc., may be used, provided that the joining mechanism effect a removable relationship between the lid 121 and housing assembly 110. In this regard, a user may advantageously change the lid assembly 120 back and forth between an open position and a closed position, and it is contemplated that the lid assembly 120 can be provided so as to be removably securable to the housing assembly 110.

[0060] The lid assembly 120 may advantageously cooperate with the housing assembly 110 to provide for top access to the internal components of the cleaner 100. The filter assembly 150 may be removed quickly and easily for cleaning and maintenance without having to “flip” the cleaner 100 over. In some embodiments, the housing assembly 110 has a first side in secured relationship with the wheel assemblies 130 and a second side opposite such first side and in secured relationship with the lid assembly 120. The lid assembly 120 and the housing assembly 110 may include a latch mechanism, e.g., a locking mechanism 126, to secure the lid 121 in place relative to the housing assembly 110.

[0061] The lid 121 is typically configured and dimensioned to cover an open top-face of the housing assembly 110. The lid 121 defines a vent aperture 122 that cooperates with other openings (discussed below) to form a filtration vent shaft. For example, the vent aperture 122 is generally configured and dimensioned to correspond with an upper portion of a vent channel 152 of the filter assembly 150. The structure and operation of the filtration vent shaft and the vent channel 152 of the filter assembly are discussed in greater detail herein. Note that the vent aperture 122 generally includes guard elements 123 to prevent the introduction of objects, e.g., a user's hands, into the vent shaft. The lid assembly 120 can advantageously includes one or more transparent elements, e.g., windows 124 associated with the lid 121, which allow a user to see the state of the filter assembly 150 while the lid assembly 120 is in the closed position. In some embodiments, it is contemplated that the entire lid 121 may be constructed from a transparent material. Exemplary embodiments of the lid assembly 120 and the lid 121 are discussed in greater detail below with reference to FIGS. 16-17.

[0062] The cleaner 100 is typically supported/propelled about a pool by the wheel assemblies 130 located relative to the bottom of the cleaner 100. The wheel assemblies 130 are usually powered by the motor drive assembly 160 in conjunction with the drive transfer system, as discussed herein. In exemplary embodiments, the cleaner 100 includes a front pair of wheel assemblies 130 aligned along a front axis A_f and a rear pair of wheel assemblies 130 aligned along a rear axis A_r. Each wheel assembly 130 may include a bushing assembly 135 aligned along the proper corresponding axis A_f or A_r, and axially connected to a corresponding wheel, e.g., by means of and in secured relationship with the axle 143B. As discussed herein, the drive belts 165 turn the bushing assemblies 135 which turn the wheels.

[0063] The cleaner 100 can include roller assemblies 140 to scrub the walls of the pool during operation. In this regard, the roller assemblies 140 may include front and rear roller assemblies 140 integrally associated with said front and rear sets of wheel assemblies, respectively (e.g., wherein the front roller assembly 140 and front set of wheel assemblies 130 rotate in cooperation around axis A_f and/or share a common axle, e.g., the axle 143B).

[0064] While the four-wheel, two-roller configuration discussed herein advantageously promotes device stability/drive efficiency, the current disclosure is not limited to such configuration. Indeed, three-wheel configurations (such as for a tricycle), two-tread configurations (such as for a tank), tri-axial configurations, etc., may be appropriate, e.g. to achieve a better turn radius, or increase traction. Similarly, in exemplary embodiments, the roller assemblies 140 may be independent from the wheel assemblies 130, e.g., with an autonomous axis of rotation and/or independent drive. Thus, the brush speed and/or brush direction may advantageously be adjusted, e.g., to optimize scrubbing.

[0065] The roller assemblies 140 advantageously include a quick release mechanism which allows a user to quickly and easily remove a roller 141 for cleaning or replacement. In exemplary embodiments (see FIG. 2), an inner core 141A and an outer disposable/replaceable brush 141B may cooperate to form the roller (not designated in FIG. 2). Note, however, that various other rollers 141 may be employed without departing from the spirit or scope of the present disclosure, e.g., a cylindrical sponge, a reusable brush without an inner core element, etc. The roller assemblies 140 and the quick release mechanism are discussed in greater detail with reference to FIGS. 9A and 9B. It is contemplated that the roller 141 can be integrally formed, such that the core and brush are monolithic, for example.

[0066] With reference now to FIG. 9A, an enlarged exploded view of the front roller assembly 140 of the cleaner 100 is depicted. The front roller assembly 140 is advantageously provided with a quick release mechanism for removing/replacing a roller. Referring now to FIG. 9B, an exemplary quick release mechanism for a roller assembly, e.g., the front roller assembly 140 of FIG. 9A, is depicted using a tongue and groove. Referring now to FIGS. 9A and 9B, the front roller assembly 140 typically includes a roller 141, end joints 142 and mounts 143. In exemplary embodiments, the end joints 142 include annular lipped protrusions 142C to secure the end joints relative to the ends of the roller 141. In exemplary embodiments, the annular lipped protrusions 142C are dimensioned and configured to be received by the core 141A of the roller 141. Generally, the end joints 142 may cooperate with the mounts 143 to removably connect the roller 141 relative to the cleaner during operation. Each mount 143, therefore generally includes an axle 143B which may include a flat surface, extend along the front axis A_f through an eyelet in the corresponding side wall of the base 111, through the corresponding bushing assembly 135, through an eyelet in the corresponding bracket 116, and secure the corresponding wheel assembly 130. The axle 143B may advantageously include a flat edge and the roller bushing assembly 135 and wheel assembly 130 have a correspondingly shaped and dimensioned aperture receiving the axle 143B, such that drive of the bushing assembly 135 drives the mount 143 and the roller assembly 140 generally (and the wheel assembly 130).

[0067] The roller assembly 140 disclosed herein advantageously employs a facially accessible, quick release mechanism wherein the roller 141 may quickly be removed from the mounts 143 for cleaning or replacement purposes. Thus, in exemplary embodiments, each roller end 142 may include a tongue element 142A configured and dimensioned to correspond with a groove element 143A defined in the corresponding mount 143. A fastener 144, e.g., a pin, screw, rod, bolt etc., may be inserted through a slot 142B defined radially in the tongue element 142B and into the mount to secure the roller in place. In this regard, the roller 141 can be positioned within a geometric space bound at locations proximal the ends of the roller 141, while still allowing for quick-release. In some embodiments, such as those shown, for example, a longitudinal side of the roller 141 remains unobstructed and the fastener-receiving passage is orientated radially, thereby allowing easy removal of the fastener through the unobstructed area. The tongue and groove configuration advantageously allows a user to remove/load a roller 141 from a radially oriented direction. Though the tongue and groove configuration is shown, it is contemplated that other suitable configurations can be employed, e.g., a spring release, latch, etc.

[0068] Referring now to FIGS. 2 and 11, the filter assembly 150 is depicted in cross-section and the motor drive assembly 160 is depicted generally. The motor drive assembly 160 generally includes a motor box 161 and an impeller unit 162. The impeller unit 162 is typically secured relative to the top of the motor box 161, e.g., by screws, bolts, etc. In exemplary embodiments, the motor box 161 houses electrical and mechanical components which control the operation of the cleaner 100, e.g., drive the wheel assemblies 130, the roller assemblies 140, and the impeller unit 162.

[0069] In exemplary embodiments, the impeller unit 162 includes an impeller 162C, an apertured support 162A (which defines intake openings below the impeller 162C), and a duct 162B (which houses the impeller 162C and forms a lower portion of the filtration vent shaft). The duct 162B is generally configured and dimensioned to correspond with a lower portion of the vent channel 152 of the filter assembly 150. The duct 162B, vent channel 152, and vent aperture 122 may cooperate to define the filtration vent shaft which, in some embodiments, extends up along the ventilation axis A_v and out through the lid 121. The impeller unit 162 acts as a pump for the cleaner 100, drawing water through the filter assembly 150 and pushing filtered water out through the filtration vent shaft. An exemplary filtration flow path for the cleaner 100 is designated by directional arrows depicted in FIG. 11.

[0070] The motor drive assembly 160 is typically secured, e.g., by screws, bolts, etc., relative to the inner bottom surface of the housing assembly 110. The motor drive assembly 160 is configured and dimensioned so as to not obstruct the filtration intake apertures 113 of the housing assembly 110. Furthermore, the motor drive assembly 160 is configured and dimensioned such that cavity space remains in the housing assembly 110 for the filter assembly 150.

[0071] The filter assembly 150 includes one or more filter elements (e.g., side filter panels 154 and top filter panels 155), a body 151 (e.g., walls, floor, etc.), and a frame 156 configured and dimensioned for supporting the one or more filter elements relative thereto. The body 151 and the frame 156 and/or filter elements generally cooperate to define a plurality of flow regions including at least one intake flow region 157 and at least one vent flow region 158. More particularly, each intake flow region 157 shares at least one common defining side with at least one vent flow region 158, wherein the common defining side is at least partially defined by the frame 156 and/or filter element(s) supported thereby. The filter elements, when positioned relative to the frame 156, form a semi-permeable barrier between each intake flow region 157 and at least one vent flow region 158.

[0072] In exemplary embodiments, the body 151 defines at least one intake channel 153 in communication with each intake flow region 157, and the frame 156 defines at least one vent channel 152 in communication with each vent flow region 158. Each intake flow region 157 defined by the body 151 can be bucket-shaped to facilitate trapping debris therein. For example, the body 151 and frame 156 may cooperate to define a plurality of surrounding walls and a floor for each intake flow region 157. Exemplary embodiments of the structure and configuration of the filter assembly 150 are discussed in greater detail with reference to FIGS. 12-15.

[0073] With reference now to FIGS. 12-13, the body 151 of the filter assembly 150 is depicted with the frame 156 shown integrally formed therewith. The body 151 has a saddle-shaped elevation. The body 151 is configured, sized, and/or dimensioned to be received for seating in the base 111 and the frame 156 is configured, sized, and/or dimensioned to fit over the motor drive assembly 160. When the filter assembly 150 is positioned within the housing assembly 110, the motor drive assembly 160 in effect divides the original vent flow region 158 into a plurality of vent flow regions 158, with each of the vent flow regions 158 in fluid communication with the intake openings defined by the apertured support 162A of the impeller 162C (see FIG. 11). To facilitate proper positioning of the filter assembly 150 within the cleaner 100, the body 151 may define slots 151A for association with flanges (not depicted) on the interior of the housing assembly 110. Filter handles 151C can be included for facilitating removal and replacement of the filter assembly 150 within the housing assembly 110. Though the filter assembly 150 can be bucket-like and/or have a saddle-shaped elevation, it is contemplated that any suitable configuration can be employed.

[0074] The body 151 can define a plurality of openings, e.g., intake channels 153 for association with the intake flow regions 157 and the intake apertures 113 of the housing assembly 110. In exemplary embodiments, such as depicted in FIG. 12, the intake channels 153 define an obliquely extending structure with negative space at a lower elevation and positive space at a higher elevation in alignment therewith. A bent flow path of the intake channels 153 helps prevent debris trapped within the intake flow regions 157 from escaping, e.g., descending downward through the channels by virtue of gravity or other force. Note, however, that alternative embodiments are contemplated. Also, it is contemplated that intake channels might extend up along the outside of the filter body and traverse the body 151 through the sides. In exemplary embodiments, lattice structures, e.g., lattices 153A, are provided for drainage, e.g., when the cleaner 100 is removed from a pool.

[0075] As discussed, FIGS. 12-13 show a frame 156 designed to support filter elements, e.g., side and top filter panels relative thereto. Referring now to FIGS. 14-15, exemplary side filter panels 154 and top filter panels 155 are depicted. Each one of the filter panels 154, 155 includes a filter frame 154A or 155A and a filter material 159 supported thereby. The filter material 159 of the filter panels 154, 155 may be saw-toothed to increase the surface area thereof. Referring now to FIGS. 12-15, the frame 156 includes protrusions 156A for hingedly connecting the top filter panels 155 relative thereto. The side filter panels 154 fit into slots 156B in the body 151 and are supported by the sides of the frame 156. The top filter panels 155 may include finger elements 155B for securing the side filter panels 154 relative to the frame 156.

[0076] Note, however, that the exemplary frame/filter configuration presented herein is not limiting. Single-side, double side, top-only, etc., filter element configurations may be used. Indeed, filter elements and frames of suitable shapes, sizes, and configurations are contemplated. For example, while the semi-permeable barrier can be a porous material forming a saw tooth pattern, it is contemplated, for example, that the filter elements can include filter cartridges that include a semi-permeable material formed of a wire mesh having screen holes defined therethrough.

[0077] Referring to FIGS. 16 and 17, an exemplary lid assembly 120 for the cleaner 100 is depicted. Generally, the lid assembly 120 includes a lid 121 which is pivotally attached to the top of the housing assembly 110 by means of hinge components 115, 125 (note that the hinge component 115 of the housing assembly 110 is not depicted in FIG. 16). The hinge component 125 of the lid assembly 120 may be secured to the hinge component 115 of the housing assembly 110 using an axis rod 125A and end caps 125B. The lid assembly 20 advantageously provides top access to internal components of the cleaner 100. The lid 121 may be secured relative to the housing assembly 110 by means of a locking mechanism 126, e.g., a button 126A and spring 126B system. In some embodiments, it is contemplated that the lid assembly 120 is removable.

[0078] The lid 121 can include windows 124 formed of a transparent material. Thus, in exemplary embodiments, the lid 121 defines one or more window openings 121A, there-through. The window openings 121A may include a rimmed region 121B for supporting windows 124 relative thereto. Tabs 124A can be included to facilitate securing the windows 124 relative to the lid 121. The windows 124 may be advantageously configured and dimensioned to allow an unobstructed line of site to the intake flow regions 157 of the filter assembly 150 while the filter assembly 150 is positioned within the cleaner 100. Thus, a user is able to observe the state of the filter assembly 150, e.g., how much dirt/debris is trapped in the intake flow regions 157, and quickly ascertain whether maintenance is needed.

[0079] In exemplary embodiments, the lid 121 may define a vent aperture 122, the vent aperture 122 forming the upper portion of a filtration vent shaft for the cleaner 100. Guard elements 123 may be included to advantageously protect objects, e.g., hands, from entering the filtration vent shaft and reaching the impeller 162C. The lid 121 preferably defines grooves 127 relative to the bottom of the lid assembly 120. These grooves advantageously interact with ridges 151B defined around the top of the filter assembly 150 (see FIG. 12) to form a makeshift seal. By sealing the top of the filter assembly 150, suction power generated by the impeller 162C may be maximized.

[0080] Referring now to FIG. 19, the cleaner 100 of FIGS. 1-8 is depicted cleaning a pool 20. The cleaner 100 is advantageously able to clean both the bottom and side walls of the pool 20 (collectively referred to as the “walls” of the pool 20). The cleaner 100 is depicted as having an external power supply including a transformer/control box 51 and a power cable 52.

[0081] Referring now to FIGS. 20-21, an exemplary caddy 200 for the cleaner 100 of FIG. 1-8 is depicted. The caddy 200 can includes a support shelf 210 (configured and dimensioned to correspond with the bottom of the cleaner 100), wheel assemblies 220 (rotationally associated with the support shelf 210 by means of an axle 225), an extension 230, and a handle 240. In general the caddy 200 is used to facilitate transporting the cleaner, e.g., from a pool to a storage shed.

[0082] Referring now to FIGS. 1-21, an exemplary method for using the cleaner assembly 10 is presented according to the present disclosure. The power supply 50 of the cleaner assembly 10 is plugged in and the cleaner 100 of the cleaner assembly 10 is carried to the pool 20 and gently dropped there-into, e.g., using the cleaner handle 114 and or caddy 200. Note that the power cable 52 of the power supply 50 trails behind the cleaner 100. After the cleaner 100 has come to a rest on the bottom of the pool 20, the cleaner assembly 10 is switched on using the transformer/control box 51. The transformer/control box 51 transforms a 120VAC or 240VAC (alternating current) input into a 24VDC (direct current) output, respectively. The 24VDC is communicated to the motor drive assembly 160 via the power cable 52, wherein it powers a gear motor associated with the one or more drive shafts 166 and a pump motor associated with the impeller 162C. Note that in exemplary embodiments, the motor drive assembly 160 may include a water detect switch for automatically switching the gear motor and pump motor off when the cleaner 100 is not in the water. The motor drive assembly can include hardwired (or other) logic for guiding the path of the cleaner 100.

[0083] The gear motor drives the wheel assemblies 130 and the roller assemblies 140. More particularly, the gear motor powers one or more drive shafts 166, which drive the drive belts 165. The drive belts 165 drive the bushing assemblies 135. The bushing assemblies 135 turn axles 143B, and the axles 143B rotate the wheel assemblies 130 and the rollers 141 of the roller assemblies 140. The cleaner 100 is propelled forward and backward while scrubbing the bottom of the pool 20 with the rollers 141.

[0084] The motor drive assembly 160 can include a tilt switch for automatically navigating the cleaner 100 around the pool 20, and U.S. Pat. No. 7,118,632, the contents of which are incorporated herein in their entirety by reference, discloses tilt features that can be advantageously incorporated.

[0085] The primary function of the pump motor is to power the impeller 162C and draw water through the filter assembly 150 for filtration. More particularly, unfiltered water and debris are drawn via the intake apertures 113 of the housing assembly 100 through the intake channels 153 of the filter assembly 150 and into the one or more bucket-shaped intake flow regions 157, wherein the debris and other particles are trapped. The water then filters into the one or more vent flow regions 158. With reference to FIG. 11, the flow path between the intake flow regions 157 and the vent flow regions 158 can be through the side filter panels 154 and/or through the top filter panels 155. The filtered water from the vent flow regions 158 is drawn through the intake openings defined by the apertured support 162A of the impeller 162C and discharged via the filtration vent shaft.

[0086] A user may from time-to-time look through the windows 124 of the lid assembly 120 to confirm that the filter assembly 150 is working and/or to check if the intake flow regions 157 are to be cleaned of debris. If it is determined that maintenance is required, the filter assembly 150 is easily accessed via the top of the cleaner 100 by moving the lid assembly 120 to the open position. The filter assembly 150 (including the body 151, frame 156, and filter elements) may be removed from the base 111 of the cleaner 100 using the filter handles 151(C). The user can use the facially accessible quick-release mechanism to remove the rollers 141 from the cleaner 100 by simple release of the radially-extending fastener 144. The roller 141 can be cleaned and/or replaced.

[0087] FIGS. 22-31 show an alternative embodiment of a cleaner 300 in accordance with the present disclosure having variations relative to the cleaner 100 disclosed above. More particularly, the lid assembly 320 has a raised portion 301 that accommodates a plastic housing 369 containing an adjustable float 302 (shown in dotted lines). The adjustability of the float 302 may be accomplished by positioning the housing 369. The adjustable float 302 may be made from a polymeric foam, e.g., a closed cell polyethylene foam and may or may not be contained within a housing 369. A float position selector 303 passes through a selector aperture 304 (shown in dotted lines) extending through the lid assembly 320 proximate the vent aperture 322 and connects to the housing 369 that encloses the adjustable float 302 beneath the lid assembly 320. The position selector 303 has arcuate plates 305 extending from either side for occluding aperture 304 when the position selector occupies the optional positions available. The position selector 303 may be made from a polymer, such as polyoxymethylene (acetal). In the embodiment depicted, e.g., in FIG. 22, there are three alternative positions that the float 302 and selector 303 may occupy and these three positions are labeled with indicia 306 on the lid 320 proximate the position selector 303. Any number of alternative positions could be provided. The arcuate plates 305 may also have one or more teeth extending from a bottom surface thereof (not shown) which engage mating notches formed in an opposed surface of the lid assembly 320, the acuate plates 305 being resiliently deformable and the teeth and notches acting as a detent mechanism to retain the position selector 303 in a given position. As would be known to one of normal skill in the art, alternative position holding mechanisms could be employed, such as a spring urged detent ball in the lid assembly 320 and mating depressions formed in the position selector 303 or in the arcuate plates 305. As can be appreciated from FIGS. 22-28, the cleaner 300 has many components in common with the cleaner 100 described above. For example, the base 311, the motive/drive elements, such as wheel assemblies 330, drive belts 365 and rear roller/scrubber 340r, the cleaning/filtering apparatus and function including the impeller motor 360, intake apertures 313, intake channels 353, filter assembly 350 impeller assembly 362, vent channel 352 are all substantially the same and operate the in the same manner as in cleaner 100. As in cleaner 100, the cover 320 is hinged at hinge 315 to provide access to the interior of the cleaner 300. Other than the lid assembly 320, handle 314 configuration, front roller 340_f, transparent window 324 shape and other particular features and functions described below, cleaner 300 is constructed and operates in the same manner as cleaner 100 described above.

[0088] The front roller/scrubber 340_f. has a different configuration than in cleaner 100, in that it is shown as having a foam outer layer 370, e.g., made from PVA foam, over a PVC core tube 371, the interior of which contains an internal float 309, e.g., made from polyethylene foam, to provide enhanced buoyancy (see FIG. 28). The handle 314 of cleaner 300 is shorter than cleaner 100 for the purpose of realizing different buoyancy characteristics, as shall be explained further below, and may have a hollow 308, which may accommodate a float 307, e.g., made from polyethylene foam or other suitable materials, such as polyurethane foam or the like. Alternatively, the hollow 308 may be sealed and filled with air to provide a floatation function. The same may be said of any buoyant elements mentioned herein, i.e., they may be formed as a contiguous pocket of air or other gas, as in the motor box 361 (see FIG. 31—shown in phantom), a material containing a plurality of gas pockets, such as closed cell foam, or any material having a density less than water. As shown in FIG. 23, the window element 324 is smaller due to the raised area 301 and adjustable float 302. As can be appreciated, placing the adjustable float 302 beneath the lid 320 may permit a reduction in floatation function otherwise provided by other elements of the cleaner 300. For example, if the handle 314 has a floatation function and/or is utilized to apply twisting positioning forces on the cleaner 300, any reduction in handle 314 size or profile (e.g., making the handle shorter relative to the overall height of the cleaner 300) may have a beneficial effect on cleaner 300 performance. For example, a cleaner 300 with a shorter handle 314 will be more aerodynamic and will have a decreased tendency for the handle 314 to catch on pool features, such as ladders.

[0089] FIG. 29 shows that the adjustable float 302 may be formed from a plurality of subsections 302_a-302_f of floatation material, such as plastic foam. which may be glued together to approximate the internal shape of the adjustable float 302. Alternatively, the subsections 302_a-302_f may all be conjoined in a single molded float element. The adjustable float 302 may be contained within a housing 369 having an upper housing portion 369_a and a lower housing portion 369_b, e.g., formed from ABS plastic (not buoyant) which clip together to contain the float subsections 302_a-302_f. The upper housing portion 369_a and/or the lower housing 369_b, may be provided with drain holes/slits 369c (FIG. 30) to allow water to flow in and out. Drain holes may also be provided in the handle 314 and in the front roller 340_f to allow water to drain out of these elements. A fastener 303_a may be utilized to connect the position selector 303 to the adjustable float 302 and/or float housing 369 (as shown) and may also aid in retaining the upper housing 369_a and the lower housing 369_b in an assembled state.

[0090] FIG. 30 shows that the housing 369 may have a compound shape to fit and move within the internal confines of the cleaner 300 and lid assembly 320, in particular, within the raised portion 301, to establish a desired distribution of buoyancy.

[0091] FIG. 31 shows selected parts which contribute to mass/weight and to buoyancy, i.e., those elements that have a density lower than water. More specifically, the adjustable float 302, handle float 307, float 309 in front roller 340_f and motor box/casing 361, a total of four structures, are depicted as exhibiting buoyancy in water, as shown by the upwardly pointing arrows, B₁, B₂, B₃, and B₄, respectively. The impeller motor 360, drive motor and gear assembly 367 and balancing weight 368, all have a density greater than water, as indicated by downwardly pointing arrows G₁, G₂ and G₃, respectively. Since all parts of the cleaner 300 have a specific density, all components have an associated buoyancy or weight when in water. As a result, FIG. 31 is a simplified drawing which shows only selected downwardly directed weights and upwardly directed buoyant forces. The combination of motor box 361 and contained impeller motor 360, drive motor and gear assembly 367 and balancing weight 368 may exhibit an asymmetric weight/buoyancy or, by selecting an appropriate balancing weight 368, the weight/buoyancy can be symmetrically disposed from one or more perspectives, e.g., when the cleaner 300 is viewed from above, from the front and/or from the side. This balanced configuration is explained more fully below in reference to cleaner 400 of FIGS. 38-43.

[0092] FIG. 32 shows the cleaner 300 described in FIGS. 22-31 in various orientations relative to a pool surface PS, such as a pool floor, when submerged in water. The cleaner reference numbers 300 have been given subscripts, e.g., “AM” to indicate the position of the adjustable float associated with the specific orientation of the cleaner shown. More particularly, at the top of FIG. 32 a front view of three cleaners is shown and labeled “FRONT.” Cleaner 300_AM is shown lifted up on one side defining an angle a₁ relative to surface PS. Cleaner 300_AM depicts an orientation associated with moving the adjustable float 302 away from the drive motor and gear assembly 367 and towards the buoyant air pocket contained within the motor box 361. The various buoyant forces attributable to the various components of the cleaner which are lighter than water could be resolved into and expressed as a single buoyant force vector B which emanates from a center of buoyancy CB. Similarly, all components of the cleaner heavier than water can be resolved into a single downward force modeled by vector G emanating from a center of gravity CG. It is understood that the elements of the cleaner 30 having a positive buoyancy contribute to the center of gravity when above water, but not below water, and that the effective center of gravity will shift somewhat when the cleaner is placed in the water. This dynamic is understood and is incorporated into the term “center of gravity” as used herein when referring to the cleaner when in the water. The adjustable float 302 of the present disclosure permits the redistribution of buoyancy and weight and allows the center of buoyancy to be moved relative to the center of gravity (both when above and below water) in a controlled manner, thereby effecting the static orientation of the cleaner and the dynamics of the cleaner when it is operating/traveling over the surfaces (walls and floor) of a pool.

[0093] As shown in FIG. 32 at the top, when the adjustable float 302 is placed in a position away from the drive motor and gear assembly 367, as shown by cleaner 300_AM, the distance C₁ between the gravity vector G and the buoyancy vector B is large, resulting in a large tilt angle a₁, C₁ representing a torque arm over which buoyancy vector B may act to twist the cleaner about the center of gravity CG and on the pivot point established by the wheels 330 of the cleaner in contact with the pool surface PS (such as a pool floor). When the adjustable float 302 is moved to an intermediate position, the cleaner 300_I exhibits a decreased tilt angle a₂ because the center of buoyancy CB₂ acts through a smaller torque arm C₂ and because the cleaner has an overall negative buoyancy (depicted by gravity vector G being greater than buoyancy vector B, so the cleaner 300 sinks in all positions of the adjustable float 302). When the adjustable float 302 is positioned near the drive motor and gear assembly 367 and away from the buoyant air pocket captured in the motorbox 361, as shown in cleaner 300_NM, the lift angle a₃ and the distance C₃ are diminished further. All of the foregoing and following illustrations of force locations and magnitudes pertaining to buoyancy and weight are illustrative only and are not meant to express actual experimental values. FIG. 32 at the bottom, labeled, “SIDE,” depicts the orientation of the cleaner 300 as viewed from the side in various positions of the adjustable float 302. A reference line RL parallel to the pool surfaces shown in conjunction with each of the orientations, viz., PS_AM, PS_I and PS_NM, allows side-by side comparison of the respective, rear-to-front lift angles. More particularly, the cleaner 300_AM exhibits a higher tilt angle a₁ from the pool surface PS than either 300_I or 300_M, but the lift angle d₁ of 300_AM is less than the lift angle d₂ of 300_I where the adjustable float is positioned at an intermediate side-to-side position but extends rearward further than either 300_AM or 300_NM. From the side, the distance C₄ is greater than either C₃ in 300_AM or C₅ in 300_NM, a greater torque arm being consistent with a greater lift angle d₂.

[0094] FIG. 33 depicts the impact of the position of the adjustable float on the turning motion of the cleaner on the floor surface FS of a pool. More particularly, when the adjustable float is positioned away from the drive motor and gear assembly 367, as shown by cleaner 300_AM, the cleaner has a large side-to-side tilt angle a₁, as shown in FIG. 32. The minimal, one-sided contact of the motive elements, viz., the wheels 330, drive belt 365 and brushes 340_f and 340_r, leads to accentuated turning through an arc of small radius when going forward, as depicted by forward path FP₁. The reverse path RP₁ has an even smaller radius of curvature due to the lifting effect caused by the back-to-front lift angle d₁, as shown in FIG. 32. The back-to-front lift angle of the cleaner 300_AM may be utilized to allow the cleaner to over-ride obstacles protruding up from the pool surface PS, such as drain fittings, which would otherwise impede the motion path of the cleaner 300_AM. As the side-to-side tilt angle a₁ is reduced by moving the adjustable float 302 to the intermediate and near-the-motor positions, as depicted by cleaners 300_I and 300_NM, the turn radius is increased, as shown by forward paths FP₂ and FP₃, respectively.

[0095] FIG. 34 shows three alternative orientations for cleaners 300_AM, 300_I and 300_NM as they mount a wall surface WS₁ of a pool as influenced by the position of the adjustable float 302, viz., in the positions away from the drive motor and gear train 367, at an intermediate position, and near the drive motor and gear train 367, respectively. These positions for the adjustable float have corresponding distances C₁, C₂ and C₃ between the buoyancy vector and the gravitation vector G (these distances are measured as the perpendicular distance between the two vectors). The three orientations of cleaners 300_AM, 300_I and 300_NM show large, medium and small lift angles e₁, e₂ and e₃, respectively, associated with large, medium and small distances C₁, C₂ and C₃ (torque arms) and are intended to illustrate the increased probability of the cleaners 300_AM, 300_I and 300_NM achieving those orientations as the cleaners transition from traveling on the floor surface FS to the wall surface WS₁. The actual orientation of a particular cleaner in operation would also be effected by the frictional interaction between the motive elements of the cleaner and the pool surfaces FS and WS₁ and by the surface-directed counterforce exerted in reaction to the impeller flow out the vent aperture 322. That is, the impeller induced flow presses the cleaner 300 down against the surfaces FS and WS₁ on which it rolls. This “down force” is what allows the motive elements of the cleaner 300 (drive belts 365, wheels 330, rollers/brushes 340_f and 340_r) to frictionally engage the surfaces FS and WS₁ to traverse those surfaces and to climb the wall surface WS₁ against the force of gravity. Besides the effect of the impeller down-force, variations in the frictional interaction between the pool surfaces and the motive elements can be expected. For example, a gunite pool could be expected to have a surface roughness that enhances the frictional interaction with the motive elements of the cleaner as compared to a pool with a smoother surface, such as a fiberglass or tiled pool. Similarly, different types of coatings applied to the pool surfaces, such as paints, the presence of pool water treatment chemicals in the water and algae growth on the pool surfaces will impact frictional interaction between the pool surfaces and the cleaner. In addition, the composition of the motive elements of the cleaner will impact frictional interaction with the pool surfaces. In light of all the factors which can impact cleaner motion, it is therefore appropriate to describe influences on motion attributable to movement of an adjustable buoyant element, like float 302 in terms of increased or decreased probabilities of the cleaner to behave in a certain way.

[0096] In FIG. 34 cleaner 300_NM is shown near the floor surface FS with a small tilt angle e₃ due to a relatively small distance C₃ between the buoyancy vector B and the gravity vector G. In this state, there is an increased probability that the cleaner will have sufficient frictional interaction with the wall surface WS₁ to allow the cleaner to better resist the twisting torque exerted by the couple formed by the buoyancy B and gravity G vectors and track a substantially straight path FWP₁ in the forward direction on wall surface WS₁. As explained in greater detail below, in the event that the cleaner is executing a navigation algorithm which directs straight forward motion for the entire time that the cleaner 300_NM needs to reach the position of 300_NMNP, then the cleaner 300_NM may travel up to the water line WL, extend above the water line WL and fall back into the water under the influence of a diminished buoyancy due to rising out of the water. The up and down motion could also be induced by a loss of down-force due to the entrainment of air into the intake apertures. Further, the sensing of an out-of-water condition due to diminished electrical loading of the impeller motor or a signal generated by an out of water sensor, such as due to a variation in conductance between two conductor elements could be used as a signal to temporarily turn the impeller motor OFF to diminish down-force and cause the cleaner to slip back into the water. The cleaner can therefore be induced to oscillate about the water line for a period until either the navigation algorithm dictates a change in motion or the buoyancy characteristics of the cleaner overcome its bobbing motion. As shown in the position of cleaner 300_NMNP, the cleaner has an on-the-wall orientation where the buoyancy vector is directly opposed to the gravity vector and the center of buoyancy CB is directly above the center of gravity CG, such that there is no twisting torque exerted by the opposed vectors B and G. Since cleaner 300_NMNP has directly opposed vectors B and G, the buoyancy characteristics of the cleaner tend to twist it to this orientation. The probability of the cleaner executing a turn after reaching this position is therefore reduced (during the period that the navigation algorithm directs straight, forward or reverse motion).

[0097] FIG. 35 shows the cleaner 300 in three different orientations 300_AM, 300_I and 300_NM attributable to associated different positions of the adjustable float 302 (either away from the drive motor gear assembly 367, intermediate, or near the drive motor gear assembly 367, respectively) as it ascends a wall surface WS₁ in reverse (with the handle 314 pointing up) and proximate to the water line WL (which is depicted as a solid straight line to illustrate the angular orientation of the cleaner 300 relative thereto). Reference line RL₁ is substantially parallel to the line at the intersection of surfaces WS₁ and FS (assuming a flat floor surface FS). Since the center of buoyancy in each of these three positions is above the center of gravity, the cleaner does not have to invert to achieve a position of opposing buoyancy and gravity vectors (like 300_NMNP of FIG. 34). The probability of turning for a given path length is therefore reduced over that of the corresponding adjustable float position when the cleaner ascends the wall surface WS₁ in a forward (handle 314 down) orientation, like in FIG. 34. The probability of straight line motion and for the cleaner to reach the water line WL is increased by the handle-up orientation over that of the handle-down orientation (assuming a sufficiently large, buoyant handle 314/float 307). This is especially true of the orientation of cleaner 300_NM. The above-described cleaner dynamics are given by way of example only and could be changed by modifying the cleaner to have a different center of gravity and/or center of buoyancy in the water.

[0098] FIG. 36 shows a sample of paths that the cleaners 300_AM, 300_I and 300_NM could take if operated in the forward direction. Cleaner 300_AM would have a greater probability of traversing paths with more severe turns, such as paths FWP₂ or FWP₃, but, depending upon the frictional interaction of the cleaner 300_AM and the pool surfaces FS, WS₂ and WS₃, the other paths FWP₄ and FWP₅ shown are possible. Cleaner 300_I would have a greater probability of executing FWP₄ and FWP₅ than FWP₂ and FWP₃, but depending upon frictional interaction, could execute those paths, as well. Cleaner 300_I would likely execute paths FWP₂ and FWP₄, but the alternative paths shown are possible, as well, depending upon frictional interaction between the cleaner 300 and the pool surfaces. Note that FWP₅ executes a sawtooth pattern near the water line followed by an extended path approximately parallel to the waterline WL. The extended path parallel to the water line WL can continue all the way around the pool or be terminated due to buoyancy or frictional interaction factors or under algorithmic control, e.g., by turning the impeller motor OFF, to allow the cleaner to slide to the bottom of the pool.

[0099] FIG. 37 shows a sample of paths that the cleaners 300_AM, 300_I and 300_NM could take if operated in the reverse (handle up) direction, as shown in FIG. 35. Cleaner 300_AM would have a greater probability of traversing paths with more severe turns, such as path RWP₄, but the other paths illustrated could be taken, depending upon the frictional interaction of the cleaner 300_AM and the pool surfaces FS, WS₂ and WS₃. Cleaner 300_I would have a greater probability of executing RWP₁ and RWP₂ than RWP₃ and RWP₄, but depending upon frictional interaction, could execute those paths, as well. Cleaner 300_I would likely execute paths RWP₁ and RWP₂, but the alternative paths shown are possible, as well, depending upon frictional interaction between the cleaner 300_I and the pool surfaces. The paths shown in FIGS. 36 and 37 are examples only and an infinite number of possible paths are possible.

[0100] FIG. 38 shows an alternative embodiment of the present disclosure similar in all respects to cleaners 100, 300 except as illustrated and/or pointed out below. Cleaner 400 features an adjustable float 402 adjustably positioned along a float slide 405, e.g. by interaction of a tang 403a and toothed aperture 404. More particularly, a spring-loaded position selector button 403b connects to a shaft 403c the end of which has a laterally extending tang 403a. The tang 403a is receivable in one of a plurality of mating slots 403d in toothed aperture 404 to secure the adjustable float 402 in a selected position relative to the float slide 405. The adjustable float 402 may be made from a buoyant material, such as plastic foam. The adjustable float may optionally be inserted within a protective outer shell (not shown). Another alternative would be to encapsulate a pocket of air within a water-tight plastic shell. As indicated by the arrow SS, the adjustable float 402 may be moved to a selected position on the float slide 405 in a side-to-side movement. As indicated by arrow P, the float slide may be pivoted front-to-back at pivot attachment point 406 in slot 407, which pivotal attachment may be implemented by a wing nut or other conventional fastener. The underside of the float slide 405 and the outer surface of the lid assembly 420 may be dimpled or roughened in the area where these elements contact to enhance their frictional interaction to allow the float slide 405 to maintain a particular angular setting relative to the lid assembly 420 at the pivot point 406. The slot 407, which is preferably duplicated on the other side of the lid assembly 420, permits the float slide to be translated front-to-back as indicated by double-ended arrow FB and rotated about an axis RA as indicated by double-ended arrow R. While a separate handle 414 and float slide 405 are shown in FIG. 38, these two functions could be incorporated into a single element, e.g., a float slide 405 having a substantial thickness and sturdy attachment to the cleaner 400 to allow the cleaner 400 to be lifted by the float slide 405.

[0101] FIGS. 39 and 40 show how the center of buoyancy CB₁ associated with a first position of the adjustable float 402 is shifted to CB₂ associated with another position of the adjustable float 402_P2. FIGS. 39 and 40 illustrate a cleaner 400 having the lid assembly 420 and adjustable float 402 of the embodiment of FIG. 38, but utilizing a base 411, motive elements 430, 440_f, etc. corresponding to those of either of the above-disclosed cleaners 100 or 300. Cleaner 400 may have a geometrically centralized center of gravity, which can be readily achieved by distributing weight so that the cleaner is balanced at a central position. In the case of a cleaner 400 having a drive motor and drive gear assembly 367 that is disposed towards one side of the cleaner, like that shown in FIG. 31, the center of gravity may be shifted to the geometric center by selecting a suitable balance weight 368, such that the weight and position of the balance weight balances against the weight and position of the drive motor and gear assembly 367. Alternatively, additional floatation can be added over the assembly 367. In general, it is known that an object may be balanced in water by distributing weight and buoyancy to achieve balance at any point and that would include the geometric center in any and/or all planes of reference. Assuming a cleaner 400 having a geometrically centralized center of gravity, the adjustable float 402 can be placed in positions resulting in a buoyancy vector B₁ in direct opposition to the force of gravity considered as being exerted on the center of gravity CG, such that the cleaner 400 will tend to travel in a straight path either on a pool floor or on a pool wall. Moving the adjustable float to position 402_P2 shifts the buoyancy vector B₂ to one side or another (and/or to the front/back) such that the cleaner 400 will be induced to turn on the floor and the wall by offset buoyancy/weight as described above with respect to the cleaners 100 and 300.

[0102] FIGS. 41 and 42 show examples of the effect of different positions of the adjustable float 402 on a pool cleaner 400 with a centralized center of gravity when on a floor surface FS and with the impeller motor OFF. Cleaner 400_C illustrates a cleaner 400 where the float is positioned centrally causing the center of buoyancy CB₁ to be positioned directly above the center of gravity CG. Assuming the cleaner 400_C has an overall negative buoyancy, the cleaner 400_C will sit flat on the floor surface FS and will tend to move in a straight line unless induced to turn by other forces. Moving the float 402 to the right as shown by cleaner 400_R or to the left, as shown by cleaner 400_E will give rise to tilt angles b and a, respectively. The presence and magnitude of a tilt angle, such as angle a, is dependent upon the magnitude of the buoyancy force. Cleaner 400_RC illustrates the effect of moving the float to the right as with 400_R, but viewed from the side and with the float slide 405 in the vertical and central position. Cleaner 400_RB is viewed from the side and has the float 402 moved to the right and the float slide 405 is tilted back. Cleaner 400_RF shows the float 402 to the right and the float slide 405 tilted forward. In each of the side views, the point F indicates the front of the cleaner.

[0103] FIG. 43 illustrates cleaner orientation probabilities associated with different positions of the adjustable float 402 on a cleaner 400 having a geometrically centralized center of gravity. More particularly, cleaner 400_C shows a symmetrically placed float 402 which will increase the probability of the cleaner moving on the wall in a straight line as determined by the tread direction. Cleaner 400_RC has the float positioned to the right (when viewed from the front) of the center of gravity inducing a tilt angle e and a producing a twisting torque that tends to turn the cleaner 400_RC. Cleaner 400_RTC shows the float 402 positioned to the right and with the float slide 405 twisted clockwise, moving the center of buoyancy to the right and in front of the center of gravity CG. This position induces a twisting torque on the cleaner 400_RTC which will act on the cleaner 400_RTC until the buoyancy force acts directly in line with and opposite to the gravity force as shown by cleaner 400_RTCN. As noted below, the turning reaction of the cleaner in response to twisting torque will depend upon the frictional interaction between the motive elements of the cleaner 400RTC and the wall surface WS₁, e.g., due to impeller reaction force and the frictional coefficient of the wall surface and the motive elements of the cleaner. In the event that the frictional interaction is strong enough, the cleaner may resist the twisting torque and travel in a straight path, e.g., straight up the wall. Cleaner 400_LTCT has a float which is positioned to the left and with a float slide 405 that is twisted clockwise and translated rearward. As can be appreciated by 400_LTCTN, the neutral position of cleaner 400_LTCT (when the buoyancy and gravity forces are directly opposed along the same vertical line) differs significantly from that of 400_RTCN in that they are positioned in approximately opposite directions. As can be appreciated from FIG. 38-43 and the above description, cleaner 400 has the capacity to mimic the balance and motion characteristics of the cleaners 100 and 300, whether moving in forward or reverse directions on a floor or on a wall surface. Accordingly, depending upon the size and density of the adjustable float 402 relative to the overall weight of the cleaner 400 in the water, the float 402 can be set to increase the likelihood of traversing any of the paths shown in FIGS. 36 and 37. Note that cleaner 400 has a modified handle 414, which does not contain a buoyant element. As would be known to one of normal skill in the art, weight and buoyancy may distributed as needed to provide a balanced cleaner such that the center of buoyancy approximates any given position, including a central position, such that the adjustable float 402 can be utilized as the predominant element to control the position and direction of buoyancy.

[0104] As mentioned above and in U.S. Pat. No. 7,118,632, the cleaner 100, 300, 400 of the present disclosure can be turned on a floor surface of swimming pool by virtue of controlling the side-to-side tilt angle, the impeller motor ON/OFF state and the drive motor ON/OFF state. The cleaner 100, 300, 400 can therefore be programmed to execute a sequence of movements forward, backward and turning for selected and/or random lengths of time/distance to clean the floor surface of a swimming pool. One cleaning algorithm in accordance with the present disclosure executes a floor cleaning procedure which concentrates the cleaner motion to the floor area by utilizing a tilt sensor to signal when the cleaner attempts to mounts a wall surface. On receipt of a tilt indication, the algorithm can keep the cleaner on the floor by directing the cleaner to reverse direction and optionally to execute a turn after having returned to the floor followed by straight line travel either forward or backward. The navigation algorithm can include any number and combination of forward, backward and turning movements of any length (or angle, if appropriate). In certain circumstances, it may be desirable to clean the floor of a pool first, given that many types of debris sink to the floor rather than adhere to the walls and because the floor is a surface that is highly visible to an observer standing poolside.

[0105] Because the side walls of the pool are visible and can also become dirty, e.g., by deposits that cling to the walls, such as algae growth, it is desirable for the pool cleaner 100, 300, 400 to have a wall cleaning routine as part of the navigation algorithm. The wall cleaning function may be performed by the cleaner either in conjunction with the floor cleaning function or sequentially, either before or after floor cleaning. In the case of conjunctive floor and wall cleaning, the algorithm may direct the cleaner 100, 300, 400 to advance forward or backward for a given time/distance regardless whether the cleaner mounts a wall during that leg of travel. For example, if the cleaner is directed to execute a forward motion for one minute, depending upon its start position at the beginning of the execution of that leg, it may travel on the floor for any given number of seconds, e.g., five seconds, and then mount the wall for the remaining fifty-five seconds. Depending upon the buoyancy/weight distribution and the frictional interaction between the cleaner 100, 300, 400 and the wall surface WS, (attributable to the reactive force generated by the impeller and the coefficient of friction of the wall and motive elements of the cleaner), the cleaner will take any number of an infinite variety of possible courses on the wall, examples of which are illustrated in FIGS. 36 and 37. If the cleaner 100, 300, 400 has a strong twisting torque applied by a widely separated buoyancy and gravitation force couple and the cleaner is on a slippery wall or has a reduced impeller reactive force, e.g., due to a reduced flow attributable to a filter bucket full of debris, then the cleaner has a greater probability of executing any turn needed to put the cleaner into a orientation where the buoyancy force and the gravitational force are directly opposing on a straight vertical line. The chemistry of the pool water and water temperature effect water density and can therefore also effect the interaction between the gravitational and buoyant forces. As shown by cleaner 300NMNP in FIG. 34, if this “neutral” orientation points the cleaner down towards the pool floor, then the cleaner (if it is moving in the forward direction) will likely return to the pool floor (if it is operated in the forward direction long enough). This could give rise to paths such as are illustrated in FIG. 36 as FWP₂, FWP₃, FWP₄ or RWP₄ in FIG. 37. In the event that the cleaner has a strong frictional interaction with the pool wall that resists twisting and it mounts the wall in a straight-up orientation, then it is possible that the cleaner will execute paths like FWP₅ of FIG. 36 or RWP₁ or RWP₂ of FIG. 37. Optionally, mounting the wall (as sensed by a tilt switch) may trigger an algorithm specifically intended for wall cleaning.

[0106] Cleaners like 300_NM of FIGS. 34 and 35 and 400_C and 400_RTC with a floatation/weight distribution that promotes straight line motion on the pool wall have a greater probability to execute straight line motion paths up the pool wall as are illustrated by paths FWP₅ of FIG. 36 and RWP₁ of FIG. 37. As noted above, a sawtooth motion path (see RWP₁ of FIG. 37), which crosses the water line WL may be accomplished by an algorithm that continues to direct a cleaner biased to go straight in a forward motion path. When the cleaner 300, 400 breaches the surface, the portion of the cleaner supported by the water progressively diminishes and at the point where the weight exceeds the capacity of the cleaner to resist downward motion via frictional interaction between the cleaner and the wall surface, the cleaner will slip back into the water, such that the cleaner bobs up and down proximate the water line. Because the cleaner falls off the wall temporarily, there is a good probability, especially in a cleaner that has asymmetric weighting/buoyancy, for the cleaner to reengage the wall surface at a new location and orientation, such that the cleaner travels along the length of the wall surface as it bobs up and down. The buoyant elements of the cleaner 300, 400 can be distributed, e.g., in the handle 314, front roller 340_f, etc., such that the cleaner maintains an orientation relative to the wall that permits reengagement and prevents the cleaner from falling to the bottom of the pool or rolling into a position with the motive elements pointed up (out of contact with the pool surfaces). This type of sawtooth motion can be effective for removing dirt which concentrates on the wall at the water line, e.g., dirt or oils that float. As noted below, this bobbing action can also be induced via sensing on diminished electrical loading of the impeller motor or by sensing an out-of-water condition by an out-of-water sensor. In this later approach, the controller may shut down the impeller motor temporarily so that the cleaner loses its grip on the wall surface or alternatively, the controller may reverse the direction of the drive motor gear assembly 367 to cause the cleaner to move back down the wall before climbing again.

[0107] The adjustable buoyancy/weight features of the present disclosure may be used to set the cleaner 300, 400 into different configurations which are suitable for different frictional interactions between the pool wall and the cleaner 300, 400. For example, a slippery wall may call for a more gradually sloping path in order to allow the cleaner 300, 400 to reach the water line. Since it is an objective for the cleaner to access and clean all surfaces of the pool, it is desirable for the cleaner to be adapted to climb a pool wall to the water line. As disclosed above, the adjustable float 302, 402 can be placed in different settings that induce the cleaner to travel straight up a pool wall or, alternatively, at an angle relative to the floor (assuming a floor parallel to the water line) and water line/horizon. The more gradually the cleaner attains height on the wall (moves toward the water line), the longer it will take to reach the water line and the longer the distance it must travel, but the less likely that it will slip on the wall for any given set of conditions pertaining to frictional interaction between the cleaner and the pool wall. Stated otherwise, the greater the rate of ascent (as determined by the angle relative to the floor surface/water line, the rate of tread movement being constant), the greater the likelihood that the cleaner will lose its grip on the wall surface. Similarly, an automobile climbing an icy, upwardly inclined road will have a greater tendency to spin its wheels as the rate of climb (the slope) increases. The adjustable float 302, 402 therefore allows the cleaner 300, 400 to be adapted to different wall conditions and types to enable the cleaner to reach the water line.

[0108] Since the cleaner 100, 300, 400 has the capacity to climb walls and because there are certain pool shapes, such as a pool with a gradual “lagoon style” ramp that leads to a deeper portion of the pool, the cleaner 100, 300, 400 may have the capacity to exit the pool. It is undesirable for the cleaner to continue to operate while out of the water because the cleaner could potentially overheat due to a lack of cooling water, destroy seals on the impeller motor 360, overload the drive motor gear assembly 367 and would waste electrical power and pool cleaning time. The present cleaner 100, 300, 400 has an algorithm that may include an out-of-water routine that is directed to addressing out-of-water conditions which occur while the cleaner 100, 300, 400 is conducting the cleaning function and on start-up. More particularly, the cleaner 100, 300, 400 includes circuitry that monitors the electrical current through (load on) the impeller motor 360. This circuitry may be utilized to prevent the cleaner from running unless it is placed in the water before or soon after start-up. More particularly, if the cleaner 100, 300, 400 is first powered-up when the cleaner is not in the water, the current load on the impeller motor 360 will be less than a minimum level which would indicate an out-of-water condition to the controller. If there is an out-of-the water condition on start-up, the controller will allow the impeller motor 360 to run for a predetermined period before it shuts down the cleaner and requires user intervention to re-power it. It is understood that proper operation of the cleaner requires an operator to place the cleaner in the water before turning it ON, but if the cleaner 100, 300, 400 is powered-up inadvertently, e.g., by resetting a breaker that controls a plug into which a cleaner is plugged, the cleaner having been left ON, then the short predetermined period of out-of-water running on start-up, described above should be less than that which would damage the cleaner.

[0109] After power-up and after the cleaner is operating in the water, the load on the impeller motor 360 is constantly monitored to determine whether the cleaner remains in or has traveled out of the water, an out-of-water condition being indicated by a reduction in current/load from the impeller motor 360. On sensing an out-of-water condition after the cleaner 100, 300, 400 has been operating in the water, an algorithm in accordance with the present disclosure may, upon first receiving an out-of-water indication, continue operating in the then-current mode of operation for a predetermined short period. The purpose of this delay would be to allow continued operation is to avoid triggering an out-of-water recovery routine in response to a transient condition, such as the cleaner sucking air at the waterline while executing a sawtooth motion or any other condition which creates a low current draw by the impeller motor 360. If a transient air bubble e.g., due to sawtooth action, is the source of out-of-water sensing, the delay allows the cleaner 100, 300, 400 an opportunity to clear the air bubble by continued operation, e.g., slipping back below the surface due to a decreased buoyancy, in accordance with normal operation. The current load on the impeller motor 360 is checked periodically to see if the out-of-water condition has been remedied by continued operation and, if so, an out-of water status and time of occurrence is cleared and the cleaner 100, 300, 400 resumes the normal navigation algorithm.

[0110] If the foregoing delay period does not remedy the out-of-water condition, then this is an indication that the cleaner 100, 300, 400 has either exited the water, e.g., climbed a wall and is substantially out of the water or has otherwise assumed an orientation/position where it is sucking air, e.g. is in a position exposing at least one intake to air or a mixture of air and water. In either case, in response, the controller triggers an out-of-water recovery routine in which the impeller motor is shut OFF for a predetermined period, e.g., 10 seconds. In the event that the cleaner 100, 300, 400 is on the wall sucking a mixture of air and water, then turning the impeller motor 360 OFF will terminate all down-force attributable to the impeller 162 and the cleaner will slide off the wall and back into the water. In sliding off the wall, the cleaner 100, 300, 400 will travel through the water in a substantially random path as determined by the setting of the adjustable float 302, 402, the shape of the cleaner, the orientation of the cleaner when it looses down-force, the currents in the pool, etc., and land on the bottom of the pool in a random orientation, noting that the cleaner may be provided with a buoyancy/weight distribution that induces the cleaner to land with motive elements 330. 366, 340 down.

[0111] In the event that the cleaner 100, 300, 400 has “beached itself” by climbing a sloping floor or pool steps leading out of the pool, continued impeller 162 rotation will have no effect on the motion of the cleaner since there will be no down-force exerted by the impeller action when it is out of the water. As a result, the cleaner does not have the capability of turning via an uneven buoyancy, as when the cleaner is in the water. Accordingly, turning the impeller motor 360 OFF in this circumstance is an aid in preventing overheating of the impeller motor/ruining the seals, etc.

[0112] At about the same time that the impeller is shut OFF, the drive motor gear assembly 367 is stopped and then started in the opposite direction to cause the cleaner 100, 300, 400 to travel in a direction opposite to the direction in which it was traveling when it experienced the out-of-water condition. More particularly, if the cleaner 100, 300, 400 was traveling with the front of the cleaner advancing, then its travel direction will be reversed, i.e., so the rear side advances and vice versa. This travel in the opposite direction may be conducted for a length of time exceeding the delay time after first sensing an out-of water condition (before the out-of-water recovery routine is triggered). For example, if the delay time was six seconds (as in the above example) the reverse/opposite travel time could be set to seven seconds.

[0113] In the event that the cleaner 100, 300, 400 was on the wall when the recovery routine began, and subsequently slipped to the floor when the impeller motor 360 was shut OFF, the reverse travel time is not likely to be executed in the same direction as the direction that led to the cleaner exiting the pool and will likely be of a shorter duration than that which would be needed to climb the pool wall to the surface again, even if it were heading in the direction of exiting the pool. In the event that the cleaner had exited the water, e.g., by moving up a sloped entrance/exit to the pool (a lagoon-style feature), then the seven seconds of reverse direction travel will likely cause the cleaner to return to the water, since it is opposite to the direction that took it out of the water and is conducted for a longer time/greater distance. Once positioned back in the water at a lower level, the likelihood of the cleaner replicating an upward path out of the water is also decreased by the increased probability that the cleaner will experience some degree of slipping on the pool wall during ascents up the wall against the force of gravity.

[0114] After traveling in the opposite direction as stated in the preceding step, the cleaner has either re-entered the water or not. In either case, the recovery routine continues, eventually turning the impeller ON for a period, to push the cleaner towards a pool surface (wall or floor—depending upon the cleaner position at that time). The impeller is then turned OFF and the cleaner executes one or more reversals in drive direction. This ON and OFF cycling of the impeller motor 360 in conjunction with ON and OFF cycling and reversing of the drive motor gear assembly 367 may be conducted a number of times. In the event that the cleaner is in the water, (either at the bottom of the pool or partially submerged on a lagoon-style ramp, these motions reorient the cleaner and reduce the probability that the cleaner will be in the same orientation that led it out of the pool, when it resumes normal operation. In the event that the cleaner is completely beached, then the impeller motor 360 state will have no effect and the one or more reversals in drive direction with the impeller motor 360 OFF will translate into one or more straight line motions (assuming no other obstacle is encountered or that there is no other factor that impacts the straight line path of the cleaner). The one or more reversals in drive direction may have varying duration, and may be interspersed with periods of having the impeller motor 3600N for straight line motion, all of the foregoing alternatively being randomized by a random number generator. The out-of-water recovery routine may be timed to be completed within a maximum out-of-water duration, e.g., sixty seconds, and the impeller motor load checked at the end of the completion of the recovery routine. If that final check indicates an out-of-water condition, then the cleaner is powered down and requires overt operator intervention to re-power it. Otherwise, normal operation is resumed. As an alternative, the out-of-water condition may be periodically checked during the recovery routine and the routine exited if impeller motor load indicates that the cleaner has returned to the water. After returning to normal operation, the impeller motor 360 load is continuously monitored and will trigger the foregoing recovery routine if a low load is sensed.

[0115] The period over which the out-of-water recovery routine is executed may be longer, e.g., sixty seconds, than the period that the cleaner 100, 300, 400 remains powered after an out-of-water condition is detected on start-up (fifteen seconds), in order to permit the cleaner a reasonable opportunity to return to the water. This period is warranted by the fact that it is more probable that an operator will be present on start-up than during cleaning, which may take place when the pool is unattended. In the event that the out-of-water condition is not remedied within the allowed period in either case, the cleaner will be de-powered and require overt user intervention to re-power it. This step of de-powering requiring intervention is avoided until it is reasonably certain that the out-of-water condition can not be remedied, because once the cleaner is de-powered it stops cleaning. If the cleaner were to immediately de-power upon first sensing an out-of-water condition and immediately require intervention, in the case of an unattended pool, the cleaner would waste time sitting out of the water in an OFF state when it could find its way back into the water to continue cleaning by executing repositioning movements according to the present disclosure.

[0116] In the case of a pool system that has a tendency to allow a pool cleaner to exit the water, such as those that exhibit a high frictional interaction between the cleaner and the pool and those with gently sloping walls, the cleaner 100, 300, 400 may, in accordance with the present disclosure, be equipped with a flow restrictor, such as a constrictor nozzle and/or plate that connects to the cleaner near the outlet and/or inlet apertures to reduce the impeller flow, thereby lessening the reactive force of the impeller flow, which presses the cleaner into contact with the pool surface. The reduction in impeller flow and down-force reduces the likelihood that the cleaner will have sufficient frictional interaction with the pool surfaces to allow it to escape the water and/or to go above the water line and trap air.

[0117] The cleaner 100, 300, 400 may also respond to greater than expected loading of the impeller motor 360 which could indicate jamming, by turning the power to the cleaner 100, 300, 400 OFF after a suitable short period, e.g., six seconds, and requiring operator intervention to re-power the cleaner 100, 300, 400.

[0118] Given the foregoing disclosure, the cleaners 300, 400 disclosed herein can be adjusted via the adjustable floats thereof 302, 402 to execute different motion paths—even when using the same navigation algorithm. Further, the motion paths associated with different float adjustment configurations can be associated with probabilities of different motion paths on the walls of the pool. Further, given the adjustable buoyancy characteristics of the cleaner 300, 400, the cleaner can be adjusted to accomplish motion paths based on the present needs for cleaning different parts of the pool (walls vs. floor) and may be adjusted to more suitably accommodate pools that have different surface properties, such as different coefficients of friction. Further, the cleaner of the present application can be adjusted sequentially to obtain cleaning in a sequential manner based upon observed behavior of the cleaner and observed coverage of the cleaner of the desired area to be cleaned. More particularly, given a particular pool with specific conditions, the cleaner can be adjusted to a first buoyancy adjustment state and then allowed to operate for a given time to ascertain effectiveness and cleaner behavior. In the event that additional cleaner motion paths appear to be desirable, the cleaner can be readjusted to accomplish the desired motion paths to achieve cleaning along those motion paths.

[0119] While various embodiments of the invention have been described herein, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the present invention. The disclosed embodiments are therefore intended to include all such modifications, alterations and adaptations without departing from the scope and spirit of the present invention as set forth in the appended claims. For example, it should be appreciated that the relative locations of the centers of buoyancy and gravity can be moved by moveable weights, as well as by moveable buoyant elements, either in conjunction with moveable or fixed buoyant elements. Any number, type, shape and spatial location of weight and buoyant elements may be utilized to control the relative positions of the center of buoyancy and the center of gravity. As one example, the adjustable buoyant member 302, 402 could be replaced with one or more moveable weights and one or more stationary buoyant elements (or balance weight(s) could be eliminated, repositioned or reduced in size).

[0120] The buoyant and weight elements attached to the cleaner could be removable in whole or part to adapt the cleaner to specific pool cleaning conditions. While the cleaner described above has a buoyant element with a limited range of arcuate motion about the central axis of the impeller aperture, the arcuate range could be increased to 360 degrees or decreased as desired or extended into other planes (Z axis).

[0121] While a manually moved adjustable buoyant element is disclosed above, one could readily supply a mechanical movement using gears, chains, belts or wheels and driven by a small motor provided for that purpose under control of the controller of the cleaner, e.g., to move a rotatable adjustable buoyant element or to pull or push such an element along a slide path to a selected position. In this manner, the capacity to control the movement of the cleaner provided by the adjustable buoyant or weight elements can be automatically and programmatically moved in accordance with a navigation algorithm. As an alternative, the navigation algorithm can receive and process empirical data, such as location and orientation data, such that the weight/buoyancy distribution/positioning can be automatically adjusted in light of feedback concerning the path of actual cleaner traversal as compared to the path of traversal needed to clean the entirety of the pool.

[0122] The pool cleaner may be equipped with direction and orientation sensing apparatus, such as a compass, GPS and/or a multi-axis motion sensor to aid in identifying the position and orientation of the cleaner to the controller such that the controller can track the actual path of the cleaner and compare it to a map of the pool surfaces that require cleaning. Alternatively, the cleaner motion can be tracked and recorded via sensing on cleaner position relative to reference locations or landmarks, e.g., that are marked optically (pattern indicating location), acoustically or via electromagnetic radiation, such as light or radio wave emissions that are read by sensors provided on the cleaner. Comparison of actual path information to desired path information can be converted to instructions to the mechanism controlling the adjustable weight/buoyancy distribution and location to steer the cleaner along a desired path.