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FIELD OF THE INVENTION 
       [0001]    This invention relates to discs and associated components of cleaners of liquid-containing vessels and more particularly, although not necessarily, to hydraulic automatic swimming pool cleaners (APCs) having discs with nominally upwardly protruding connectors. 
       BACKGROUND OF THE INVENTION 
       [0002]    U.S. Pat. Nos. 5,421,054 to Dawson, et al., and 5,465,443 to Rice, et al., describe various discs for, principally, APCs. Extending upward from the upper surfaces of the discs are multiple fins. Each disc includes a central aperture whose boundary is fitted into a separate footpad, which footpad in turn is connected to a cleaner body for use. 
         [0003]    U.S. Pat. No. 5,617,606 to Scott, II, et al., details other discs for APCs. Projecting above the majorities of the upper surfaces are one or more flutes, whose edges may be curved or straight as desired. Similarly projecting upward at boundaries of central apertures of the discs may be pins or stops. When a disc is fitted into a separate footpad, the stops may cooperate with the footpad to inhibit misorientation of the disc. 
         [0004]    Numerous other discs have been devised whose central apertures are received by separate footpads. U.S. Pat. Nos. 4,351,077 to Hofmann and 4,949,419 to Kallenbach illustrate examples of such discs also having radial ribs. U.S. Pat. No. 4,530,125 to Hofmann illustrates another such disc also having radial slots, while U.S. Pat. No. 5,418,995 to Rice, et al., depicts such a disc additionally including radially spaced apertures adjacent its outer periphery. Yet another disc having a central aperture whose boundary is designed for receipt by a footpad is shown in U.S. Pat. No. 5,433,985 to Atkins, with this particular disc folding into a “fan shape” for transport and storage. 
         [0005]    U.S. Pat. No. 6,122,794 to Atkins describes a component for a swimming pool cleaner identified as an integrally-molded footpad and disc. Notwithstanding the integral molding, the component continues to have a normally circular central aperture whose boundary (rim) is designed to “engage in a groove provided around the bottom of a pool cleaner body.” See Atkins, col. 2, 11. 39-40. Joining of the footpad and disc is accomplished via “a ring of thin sectioned material which provide[s] great flexibility of the disc relative to the foot.” Id., 11. 53-55 (numerals omitted). 
         [0006]    U.S. Pat. No. 7,987,542 to Moore, et al., finally, depicts various discs at least some of which may be multi-piece. Also illustrated are footpads and an apron. Rather than having circular grooves for receiving central circular apertures of discs, some footpads may be elongated as shown in FIG. 12 of the Moore patent. The footpads may, for example, connect directly or indirectly to the apron, especially if the apron is channeled. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a combined disc and footpad whose attachment to a cleaner body need not occur (or need not occur only) via receipt of a boundary of a central aperture into a groove. Instead, the disc and footpad may be integral and connect to other structure using one or more protrusions extending from the (nominally) main upper surface of the disc. Further, the combined disc and footpad may include a central aperture enabling fluid flow into the cleaner, notwithstanding that the aperture is not needed for attaching the combined device thereto. In certain respects the combined disc and footpad may be similar to that of the Atkins &#39;794 patent, in that the footpad may be considered a “central boss part” and the disc “an integral outer annular part” of the device. 
         [0008]    Generally, a combined device of the invention may include a substantially planar section having upper and lower surfaces. If desired, various slits and holes may extend from the upper surface to the lower surface through a thickness of the disc. An outer peripheral region of the disc optionally may include scallops, fins, or both scallops and fins (or other features). Presently-preferred versions of the disc contain only one piece, although multi-piece discs may be included within the scope of the invention as long as a footpad or equivalent is integral with at least one piece of the disc. 
         [0009]    As noted above, discs of the invention may continue to have a central aperture. Such aperture need not necessarily be circular, however, nor need it be symmetric about a(n imaginary) center point of a disc. Preferred discs include at least one, and typically two, protrusions configured to attach to one or more other components of an APC. The protrusions may extend upward above the upper surface of the generally planar portion of the disc and, if desired, have complex, non-annular shape. A presently-preferred protrusion is elongate with at least a portion having a generally U- or mushroom-shaped cross-section. One or more alignment openings additionally may be present in the generally planar portion of a disc. 
         [0010]    Protruding from the lower surface of the generally planar portion of the disc in the region of the central aperture may be the integral footpad. The footpad may (but need not) resemble conventional separate footpads; regardless, it functions as a wear surface frequently in contact with a pool floor or wall undergoing cleaning. If present, cut-outs in the footpad may permit water to flow into the central aperture. 
         [0011]    The height of the (generally inflexible) footpad serves to space much of the lower surface from the pool floor or wall. However, because the generally planar portion of the disc is generally flexible, it tends to droop under force of gravity so that, absent countervailing forces, its periphery too contacts the pool floor or wall. Evacuating the pool cleaner under influence of a pump causes at least the peripheral portion of the disc to seal against the to-be-cleaned surface, allowing debris-laden water contained in the space to enter the central aperture and transit through the cleaner body to an appropriate filter. 
         [0012]    It thus is an optional, non-exclusive object of the present invention to provide components of equipment for cleaning fluid-containing vessels such as, but not necessarily limited to, pools and spas. 
         [0013]    It also is an optional, non-exclusive object of the present invention to provide combined discs and footpads for pool cleaners. 
         [0014]    It is another optional, non-exclusive object of the present invention to provide discs and footpads that are formed (as by molding) integrally. 
         [0015]    It is a further optional, non-exclusive object of the present invention to provide components of pool cleaners having generally planar portions and nominally upwardly-extending connectors. 
         [0016]    It is an additional optional, non-exclusive object of the present invention to provide components of pool cleaners in which footpads extend nominally downwardly from generally planar portions of the discs. 
         [0017]    Other objects, features, and advantages of the present invention will be apparent to those skilled in the art with reference to the remaining text and the drawings of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIGS. 1A-B  are perspective views of an exemplary component of the present invention showing, particularly, a nominally upper surface of a generally planar portion of the component. 
           [0019]      FIG. 1C  is a plan view showing, particularly, the nominally upper surface of  FIGS. 1A-B . 
           [0020]      FIGS. 2A-B  are perspective views of the component of  FIGS. 1A-C  showing, particularly, a nominally lower surface of the generally planar portion of the component. 
           [0021]      FIG. 2C  is a plan view showing, particularly, the nominally lower surface of  FIGS. 2A-B . 
           [0022]      FIGS. 3A-B  are elevational views of the component of  FIGS. 1A-C . 
           [0023]      FIG. 3C  is a cross-sectional view of the component of  FIGS. 1A-C  taken along line A-A of  FIG. 3B . 
           [0024]      FIG. 4  is a detailed view of a first portion of the component as shown in  FIG. 3B . 
           [0025]      FIG. 5  is a detailed view of a second portion of the component as shown in  FIG. 3C . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Illustrated in  FIGS. 1-5  is exemplary component  10  consistent with the present invention. Component  10  beneficially may be used as part of an APC—in particular, part of a suction-side hydraulic such cleaner—although it may be used otherwise as well. As shown in  FIGS. 1-5 , component  10  may include both disc  14  and footpad  18 . Disc  14  and footpad  18  advantageously are integrally molded, avoiding any need for the separate footpad of many conventional suction-side APCs. 
         [0027]    Disc  14  may comprise nominally upper and lower surfaces  22  and  26 , respectively. Each of the surfaces  22  and  26  may have a respective generally planar portion  30  or  34 . Component  10  additionally may define central aperture  38 , and generally planar portions  30  and  34  may terminate in respective peripheral regions  42  and  46  generally radially opposite central aperture  38 . Aperture  38  need not be exactly centered on component  10 , however, nor need it be circular in shape as was typical of the prior art. 
         [0028]    Disc  14  may, but need not, be generally circularly shaped if desired. Extending radially inward toward central aperture  38  from peripheral regions  42  and  46  may be one or more slits  50  each terminating in an opening  54 . Similarly present in peripheral regions  42  and  46  may be multiple openings  58 . As shown in  FIGS. 1-2 , openings  58  may be positioned in sets resembling non-circular portions of “peace” signs. Openings  58  need not be present or, if present, need not be positioned in the depicted manner, however. Slits  50  and openings  54  likewise are optional and, if present, may differ in size, number, and configuration from those shown in the drawings. 
         [0029]    Peripheral regions  42  and  46  may be scalloped, incorporating a plurality of scallops  62 . Scallops  62 , if present, may be spaced regularly or irregularly about the peripheral regions  42  and  46  and have any suitable shape. Moreover, fins  66  may extend upward and outward from scallops  62  over at least a portion of peripheral region  42 . 
         [0030]    Surrounding part or all of central aperture  38  is footpad  18 . Footpad  18  may resemble the separate footpad conventionally used with some APCs. It need not necessarily do so, however, and thus “footpad” as used herein is not intended to equate solely to prior art footpads. As shown in  FIGS. 1-5 , footpad  18  may include nominally lower portion  18 A extending (nominally downward) from lower surface  26  as well as upper portion  18 B extending (nominally upward) from upper surface  22 . 
         [0031]    Lower portion  18 A of footpad  18  functions in part as a bearing or wear surface when its associated APC is in use. Lower portion  18 A thus is designed for repeated contact with to-be-cleaned surfaces of pools and spas. It thus preferably is thicker and less flexible than disc  14 , notwithstanding that it may be made of the same moldable material. One or more cut-outs  70  may be present in lower portion  18  to allow water to flow from areas adjacent lower surface  26  into central aperture  38 . Lower portion  18 A additionally may, if desired, include support structure  74  for protrusions  78  and support structure  82  for alignment openings  86 . 
         [0032]    Upper portion  18 B of footpad  18  may include protrusions  78  and the alignment openings  86 . Preferably two protrusions  78  extend outward (nominally upward) from upper surface  22  and are spaced radially opposite an (imaginary) approximate center point C of aperture  38 . More or fewer protrusions  78  may be used, however, and protrusions  78  may be spaced and positioned differently than as shown in the figures. 
         [0033]    Protrusions  78  preferably are elongate, with at least portions having generally U-shaped (or mushroom-shaped) cross-section. Regardless of cross-sectional shape, however, protrusions  78  are configured to attach component  10  to a body or other component of an APC. In particular, protrusions  78  are designed to be frictionally received into channels of complementary shape to effect the attachment. One or more alignment openings  86  additionally may receive hooks or other extensions of the body, for example, so as to ensure proper relative orientations of the attached objects. 
         [0034]    Accordingly, component  10  effectively combines both sealing and bearing functions in a unitary, integral object. Hence, no separate footpad need ever be created. Moreover, because disc  14  and footpad  18  are integral, no mismatch of the two may occur (as currently happens at times when after-market discs with incorrectly sized or shaped central apertures are attempted to be connected to existing footpads). Protrusions  78  provide positive frictional connections to other components, avoiding any requirement for a boundary of central aperture  38  to be fitted into any groove. These and other features of component  10  enhance its usefulness in connection with many APCs. 
         [0035]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptation 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. Additionally, words such as (but not limited to) “upper,” “lower,” “upward,” and “downward” are used as though component  10  is in a default position as it would be when attached to a typical APC which is upright. In use, however, the APC—and consequently component  10 —likely will not always be upright, at which times an “upper” object may be below a “lower” object, for example. The entire contents of all patents identified in the section of this application headed “Background of the Invention” are incorporated herein by this reference.

Summary:
Detailed are components of cleaners of fluid-containing vessels such as pools and spas. The components may incorporate combined discs and footpads and attach to other components of a cleaner other than by receipt of a boundary of a central aperture into a groove. The components nevertheless may continue to include central apertures as appropriate.