Abstract:
Wheeled automatic swimming pool cleaners are detailed. These cleaners may include mechanisms for tensioning drive chains associated with one or more of the wheels. They also may drive one or more wheels directly. Water-management systems within the cleaners may locate most or all wearing components so that merely removing a bottom cover causes these components to be accessible for repair or replacement.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/035,882 filed on Mar. 12, 2008, the contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to devices for cleaning swimming pools or other vessels and more particularly, although not necessarily exclusively, to wheeled, pressure-side automatic pool cleaners. 
       BACKGROUND OF THE INVENTION 
       [0003]    Commonly-owned U.S. Pat. No. 6,665,900 to Wichmann, et al., illustrates an exemplary automatic swimming pool cleaner. The cleaner may include a contoured external housing encasing a hydraulic drive system, which system drives multiple wheels. Also included as part of the cleaner may be a hydraulic vacuum system for drawing debris-laden fluid (e.g. pool water) through a bag to filter the debris from the fluid. According to the Wichmann patent, the cleaner
       has a modular construction with the hydraulic drive and vacuum system components mounted onto an internal frame . . . for easy access to the modular components by removal of the external housing
 
if repair or replacement of a component is necessary. See Wichmann, col. 4, 11. 28-32.
       
 
         [0005]    Also disclosed in the Wichmann patent are aspects of a drive unit for the cleaner. Forming parts of the unit are drive and idler sprockets as well as ladder-type drive chains. The drive sprockets engage the chains “at a common forward-drive rotational speed, for correspondingly driving the cleaner wheels to transport the pool cleaner over submerged floor and side wall surfaces of the swimming pool.” See id., col. 11, 11. 8-11 (numerals omitted). The contents of the Wichmann patent are incorporated herein in their entirety by this reference. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides alternatives to the pool cleaner shown in the Wichmann patent. These cleaners too may have external housings (contoured if desired) encasing hydraulic drive systems for rotating one or more wheels. They likewise may have hydraulic vacuum systems and utilize bags or other objects as filters. 
         [0007]    Preferably, however, cleaners of the present invention include mechanisms for tensioning drive chains. Such mechanisms may include one or more spring-loaded rollers for biasing the chains at selected locations. In at least some embodiments of the invention, further, a turbine or other hydraulic device may drive a wheel directly. 
         [0008]    Additionally included in cleaners of the current design are water-management and drive systems in which most—if not all—wearing parts are accessible at the bottom of the device. As a consequence, removing merely a bottom cover of the housing renders accessible many or all of these wearing parts. (Alternatively, some or all wearing parts may be positioned so as to be accessible from the top of the device following removal of a top cover.) Better control of the center of gravity (CG) of the cleaner also may be achieved by incorporating weighting into the frame of the cleaner. 
         [0009]    Innovative cleaners of the present invention additionally may include multiple openings at or adjacent the rears of their bodies. Such multiple openings allow water flow through the bodies, reducing drag as the cleaners move forward. The holes further may permit certain-sized debris to exit the cleaners rather than potentially being trapped within the bodies. 
         [0010]    Moreover, cleaners of the present invention may, if desired, include turbines with multiple side walls. Surrounding both sides of each turbine blade with walls admits more efficient power transfer from the pressurized water to the blades. Preferably one side wall is molded integrally with the blades to form a base assembly, while the other side wall is not. Instead, the non-integral wall preferably is snap fitted onto the base assembly, concurrently capturing a bearing between the walls. Nevertheless, persons skilled in the relevant art will recognize that the side walls and blades may be attached or connected in manners other than those expressly described and illustrated herein. 
         [0011]    It thus is an optional, non-exclusive object of the present invention to provide devices for cleaning fluid-containing vessels such as, but not limited to, swimming pools. 
         [0012]    It is an additional optional, non-exclusive object of the present invention to provide cleaners utilizing wheels for purposes of movement within the vessels. 
         [0013]    It is another optional, non-exclusive object of the present invention to provide cleaners supplying tensioning mechanisms for chains employed to drive one or more of the wheels. 
         [0014]    It is also an optional, non-exclusive object of the present invention to provide cleaners utilizing both direct and indirect drives of wheels. 
         [0015]    It is, moreover, an optional, non-exclusive object of the present invention to provide cleaners in which most, if not all, wearing parts are accessible merely by removing one cover of a housing. 
         [0016]    It is a further optional, non-exclusive object of the present invention to provide cleaners incorporating weighting into their frames for better CG control. 
         [0017]    It is yet another optional, non-exclusive object of the present invention to provide cleaners including multiple rear openings to reduce drag when travelling in the water. 
         [0018]    It is also an optional, non-exclusive object of the present invention to provide cleaners with turbines having side walls to both side of their blades, at least one of which walls may be snap fitted into place. 
         [0019]    Other objects, features, and advantages of the present invention will be apparent to those skilled in appropriate fields with reference to the remaining text and the drawings of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a right side elevational view of an exemplary cleaner of the present invention. 
           [0021]      FIG. 2  is a left side elevational view of the cleaner of  FIG. 1 . 
           [0022]      FIG. 3  is a front elevational view of the cleaner of  FIG. 1 . 
           [0023]      FIG. 4  is a rear elevational view of the cleaner of  FIG. 1 . 
           [0024]      FIG. 5  is a top plan view of the cleaner of  FIG. 1 . 
           [0025]      FIG. 6  is a bottom plan view of the cleaner of  FIG. 1 . 
           [0026]      FIGS. 7-8  illustrate, among other things, aspects of a drive chain assembly of the cleaner of  FIG. 1 . 
           [0027]      FIG. 9  is a perspective view of a turbine of the cleaner of  FIG. 1 . 
           [0028]      FIG. 10  is an exploded view of the turbine of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    Depicted in  FIGS. 1-6  is cleaner  10  of the present invention. Cleaner  10  may comprise housing  14  and one or more wheels  18 . As shown in  FIGS. 1-6 , cleaner  10  preferably (although not necessarily) includes three wheels  18 A-C, with two wheels  18 A-B positioned at right side  22  of housing  14  and one wheel  18 C positioned at left side  26  of the housing  14 . 
         [0030]    When in use, cleaner  10  is designed to traverse floors and side walls of a fluid-containing vessel such as a swimming pool. Debris-containing water is evacuated from the pool into mouth  30  of housing  14  and thence via outlet  34  into a bag or other structure. The bag or other structure preferably is porous and configured such that water may flow therethrough so as to return to the pool, whereas debris of certain size is retained therein. When the bag or other structure is partially or completely filled with debris, it may be separated from outlet  34  and emptied outside of the pool. 
         [0031]    Both the drive and vacuuming systems of cleaner  10  may be hydraulically powered. Preferred versions of cleaner  10  connect to a main filtration system of a swimming pool. In particular, these versions of cleaner  10  connect to filtration (or booster) pump outlets via a hose attached to mast  38  of housing  14 . Pressurized water exiting the pump travels through the hose into the housing  14  so as to supply power for the drive and vacuuming systems. Thrust jet  42  may be positioned at or near rear  46  of housing  14  and oriented to exhaust some of the pressurized water rearward of the cleaner  10  so as to assist forward movement thereof. Likewise positioned and oriented may be sweep hose fitting  50 , to which a sweep hose may be connected when cleaner  10  is in use. In at least some embodiments of cleaner  10 , thrust jet  42  may be configured to be reoriented (as by a user) in use to supply any or all of an upward, downward, or lateral vector to the exhausted water flow. 
         [0032]      FIGS. 7-8  illustrate aspects of chain drive assembly  54  of cleaner  10 . Assembly  54  is used to drive wheels  18 A-B concurrently, employing hydraulic power yielded by turbine  56  (see  FIGS. 9-10 ) within housing  14 . Those skilled in the art will recognize that other sources of power may be employed in connection with assembly  54 , however. 
         [0033]    Coupled to the power source are drive sprockets  58 A-B, one associated with (and connected directly or indirectly to) each of wheels  18 A-B. Positioned about and engaging both sprockets  58 A-B is continuous chain  62 . Chain  62  also engages idler sprocket  66  positioned between sprockets  58 A-B. 
         [0034]    Additionally included as part of assembly  54  may be tensioning mechanism  68 , which includes rollers  70  and  74 , connector  78 , and (coil or other) spring  82 . Although each of rollers  70  and  74  is adapted to rotate about its respective axis  86  and  90 , rollers  70  and  74  are coupled via connector  78  so they move together linearly. Stated differently, at all times the distance between axes  86  and  90  should be the same. 
         [0035]    Furthermore, roller  74  is connected to an end of spring  82 , whose opposite end is connected to internal frame  94 . Spring  82  biases roller  74  downward (in the direction of arrow A of  FIG. 7 ). Because of the connection between rollers  70  and  74 , roller  70  is biased downward as well. 
         [0036]    Rollers  70  and  74  may be spool shaped (see  FIG. 8 ) and receive chain  62  about their central cores. By threading chain  62  about rollers  70  and  74  below their respective axes  86  and  90 , both rollers  70  and  74  push the chain  62  downward because of the biasing force of spring  82 . Should any slack occur in chain  62 , such slack will result in spring  82  expanding, forcing rollers  70  and  74  downward so as to increase slightly the travel path of chain  62 . This increase in travel path operates to remove the slack from chain  62 , hence tensioning it. 
         [0037]    Other features of cleaner  10  include weighting incorporated into frame  94  and buoyancy means  98  incorporated into cowling  102 . Incorporating weighting into the frame  94  allows better control over the CG of cleaner  10 . Fixing position of buoyancy means  98  (which may be a float) relative to cowling  102  allows for balancing cleaner  10  without concern about buoyancy means  98  moving in use. 
         [0038]    Depicted in  FIG. 6  is bottom cover  106  of housing  14 . Cover  106  may be attached either to internal frame  94  or to another portion of housing  14 . Although  FIG. 6  illustrates three screws  110  connecting cover  106  to frame  94 , more or fewer screws may be utilized as desired, as may fasteners other than screws. Merely removing cover  106  (see, e.g.,  FIG. 8 ) allows ready access to most—if not all—wearing components within housing  14  should any need replacement or repair. 
         [0039]    Body  14  additionally may incorporate at least one, and preferably multiple, openings  112  located at or near rear  46 . Openings  112  allow water within body  14  to exit as cleaner  10  moves forward in pool water, thus reducing drag experienced by the cleaner  10  while in transit. Openings  112  also may help prevent debris from being trapped within, and possibly clogging, body  14 , by providing the debris multiple opportunities to exit the body  14 . 
         [0040]      FIGS. 9-10  illustrate turbine  56  of cleaner  10 . As shown especially in  FIG. 10 , turbine  56  may comprise base assembly  114 , bearing  118 , and first side wall  122 . Assembly  114  in turn may comprise second side wall  126 , boss  130 , upstanding wall  134 , and multiple curved blades  138  extending from the upstanding wall  134 . Components of assembly  114  preferably are integrally formed (as by molding), although such integral formation is not absolutely necessary. 
         [0041]    Boss  130  may be centrally positioned radially relative to second side wall  126 . To form turbine  56 , bearing  118  may be placed within boss  130 , with first side wall  122  then being snap fitted onto assembly  114 . So fitting first side wall  122  captures bearing  118  between the first and second side walls  122  and  126 . It also provides walls to both sides of each blade  138 . 
         [0042]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. Directional terms such as “right” and “left” (as well as “front,” “rear,” “top,” and “bottom”) are relative and defined for purposes of this application as though cleaner  10  were upright and operating in its most frequent direction of travel. These terms are not absolute, however.