A floating canopy shade is constructed from a standard fixed or pop-up canopy by adding a set of floats adapted to hold the canopy legs and to provide drag to resist drifting and lifting in a small breeze. A kit converts a standard canopy assembly to a floating one.

CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application 61/366,155, filed Jul. 21, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to the field of water recreation, primarily in lakes or possibly in backyard pools. 
       BACKGROUND OF THE INVENTION 
       [0003]    Protection from the sun is desirable, and often necessary, for those engaged in water recreation. Boat canopies provide shade to those aboard, but swimmers, floaters, or those standing in shallow water would benefit from a canopy shading them as well. Standard pop-up canopies, sized between 6′×6′ (2 meters square) and 12′×12′ (4 meters square) are available, but these are designed to sit on the ground. 
         [0004]    The present invention provides a way to float a pop-up canopy, or any lightweight canopy with legs, on the surface of the water in a stable configuration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  shows a canopy floating on the water in accordance with one embodiment of the invention. 
           [0006]      FIG. 2  shows a canopy floating on the water in a different embodiment of the invention. 
           [0007]      FIG. 3  illustrates a typical canopy leg with a single hole. 
           [0008]      FIG. 4  illustrates a typical canopy leg with two holes. 
           [0009]      FIG. 5  shows a leg retainer in an embodiment of the invention. 
           [0010]      FIG. 6  shows a top view of a float having a mesh envelope surrounding a flotation element. 
           [0011]      FIG. 7  shows a cross section of the float of  FIG. 6 . 
           [0012]      FIG. 8  shows a bottom view of the float of  FIG. 6 . 
           [0013]      FIG. 9  shows a cross sectional view of a float having a mesh cover over the flotation element. 
           [0014]      FIG. 10  shows a float having a solid cover over the flotation element. 
           [0015]      FIG. 11  is a top perspective view of a float having a solid cover over the flotation element. 
           [0016]      FIG. 12  is a depiction of a cross section of a float with a canopy leg attached. 
           [0017]      FIG. 13  is a depiction of a cross section of a float with a canopy leg attached below the float. 
           [0018]      FIG. 14  is a depiction of a cross section of an alternative form of float with a canopy leg attached below the float. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Shade canopies are generally available for camping, boating, picnicking and other recreational activities. A common design is as seen in  FIG. 1 . Canopy ( 1 ) includes a fabric cover, a collapsible frame (not shown) to support the cover, rising to a central peak ( 5 ) and a plurality of legs ( 2 ) attached to the frame. The fabric cover is often made of canvas or one of a variety of polyvinyl materials. Commercially available collapsible or pop-up canopies are sold in a variety of sizes and shapes, with the most popular being a square frame about 6 feet on each side to about 12 feet on each side, with four supporting legs attached to the frame. 
         [0020]    Collapsible canopies commonly include a component to facilitate staking the canopy to the ground. As illustrated in  FIGS. 3 and 4 , the distal end of a canopy leg ( 2 ) includes a foot ( 11 ), usually a plate affixed to the leg, with one or two holes ( 12 ) for insertion of a ground stake or tying to a ground stake. An embodiment of the current invention makes use of the foot and hole(s) to attach the leg to a float. See  FIG. 5 . 
         [0021]      FIG. 2  illustrates one embodiment, in which each leg ( 2 ) is attached to the underside of a float ( 3 ) by a tie line ( 4 ). The tie line ( 4 ) may be of any suitable length, and an advantageous embodiment uses tie lines about 24 inches (60 cm) long. For a canopy with 6 foot (2 meter) legs, this configuration allows the canopy to float stably about 4 feet (1.2 meters) above the water, providing adequate shade to swimmers or waders. 
         [0022]    One version of the float is shown in  FIGS. 6 to 8 . A flotation element ( 6 ) is encased in an envelope ( 7 ). A convenient flotation element is a toroidal air-filled tube, such as the inner tube for a golf cart tire. The inner tube may be easily deflated for storage and inflated for use. As shown in  FIG. 6 , the flotation element ( 6 ) is surrounded by a fabric envelope ( 7 ). The envelope may be any suitably durable and flexible material, taking into consideration the sun and water environment in which it will be used. For example, high-density woven polypropylene mesh, used in many commercial tarp applications, is an option. A material used successfully in experimentation is a strong vinyl-coated polyester woven mesh sold by Phifer Corporation as SunTex® for exterior shade screening applications. Non-mesh canvas or tarp fabrics may also be used. 
         [0023]    In an embodiment, the top portion of the envelope may include an opening ( 8 ) with a plurality of radial slits ( 9 ) to facilitate insertion of an inflatable tube, in its un-inflated state, into the envelope. The opening also affords access to a valve for inflation. In an embodiment, a reinforcing strap ( 10 ) with an attachment base ( 13 ), such as a ring, a tab or a loop, may be affixed to the underside of the float envelope ( 7 ) by stitching or other suitable method. As alternatives to an inner tube, the flotation element ( 6 ) may be any of a variety of known flotation devices, including, for example toroids, blocks or multiple balls that may be hollow plastic or made of suitable grades of polyurethane, polystyrene, polyethylene or styrofoam, or other natural or synthetic buoyant materials. 
         [0024]    The canopy leg is attached to the float by a tie line ( 14 ) shown in  FIG. 7 . The tie line ( 14 ) may be a rope, a lanyard, a flexible cable, a chain, or any other line that is flexible and suitable for use in the water. As noted previously, the line may advantageously be about 2 feet long in some applications. The length of the line may be adjusted to suit the dimensions of the canopy and the desired height above the water. The tie line ( 14 ) has an attachment clip ( 15 ) which may be any appropriate connector compatible with the attachment base ( 13 ). In some embodiments, a spring clip, a D-ring or a carabiner clip would be used for easy attachment and detachment. The tie line is attached to the foot ( 11 ) of the leg ( 2 ) as shown in  FIGS. 13 and 14 . An appropriate attachment clip ( 27 ) is used to secure the line to the leg. The illustrated embodiment shows an attachment that takes advantage of the foot and staking hole present in commercially available pop up canopies, but other known methods to releasably attach the line to the leg may be used. 
         [0025]    In another embodiment, shown in  FIG. 14 , the float does not include a fabric envelope. Float ( 3 ) comprises a flotation block of appropriate buoyancy, and may be any buoyant material, from air-filled chambers to natural floats such as wood or cork, to synthetic materials or foams. Tie line ( 14 ) is attached to an attachment base ( 13 ), which may be a ring, tab or other appropriate shape affixed to the underside of the float ( 3 ). Attachment may be by an attachment clip such as the clip ( 15 ) in  FIG. 7 . The other end of the tie line ( 14 ) is attached to the canopy leg ( 2 ). 
         [0026]    In operation, the flotation system provides good stability for a floating canopy under light breeze conditions. Under most conditions, an anchor (not shown) of appropriate weight and shape will stabilize the lateral drift of the canopy. The preferred configuration would be to attach the anchor rope to the canopy frame at the center peak ( 5 ). When a breeze pushes against the canopy, the central anchor causes the force to induce rotational motion around the anchor. As the frame begins to rotate, each float ( 3 ) is pulled behind the moving leg to which it is attached, acting as a sea anchor and supplying drag to resist and retard the motion. Additionally, if a breeze applies lift to one side of the canopy, the rising legs on that side pull against the floats, again causing a drag that retards the motion. 
         [0027]    Another embodiment of the flotation system is shown in  FIGS. 9-12 . In one version, envelope ( 7 ) is configured to define a central basin ( 28 ) surrounded by the toroidal flotation tube ( 6 ) and having a basin floor ( 18 ). The envelope may be of the same mesh materials discussed above. The fabric should allow water to pass through. In this embodiment, the canopy leg sits atop the float rather than being suspended under it by a line. One leg retainer ( 20 ) for attachment of the leg is shown in  FIG. 5 . A quick release latch comprises a base ( 21 ) that is attachable to the basin floor ( 18 ) of the float ( 3 ), a support arm ( 22 ) rising vertically from the base ( 21 ) and a latch arm ( 23 ) that pivots on pin ( 24 ). When the latch arm is in vertical position ( 23   a ) it will pass through hole ( 12 ) in foot ( 11 ) of canopy leg ( 2 ). The latch arm ( 23 ) is then turned horizontal, where a détente (not shown) holds it in place and secures the foot ( 11 ) and canopy leg ( 2 ). Base ( 21 ) may be affixed to the basin floor ( 18 ) by a cap plate ( 25 ) or any other conventional manner. In one embodiment, as illustrated in  FIG. 9 , the leg retainer ( 20 ) is combined with an attachment base ( 13 ) that protrudes from the bottom of the float ( 3 ) making the float useable for a canopy sitting atop the float or suspended by a line below the float. 
         [0028]    In another embodiment, illustrated in  FIGS. 10 and 11 , the float has a water-impermeable skin, which may be a watertight fabric or another material, such as synthetic rubber, plastic or other lightweight waterproof material. Outer skin ( 17 ) defines a surrounding wall portion and a basin ( 28 ). This may be a plastic donut shape with air entrapped in the circular tube, or there may be flotation material inside. In this configuration, a leg retainer is affixed to the basin floor so the leg may be attached on top of the float. Alternately, an attachment base ( 13 ) may be added under the bottom of the float. When the skin is water impermeable, a plurality of holes ( 19 ) should be placed in the basin floor so water may enter the basin from below. While the donut shape for a float is very efficient, it is not the only useful configuration. A square or other multilateral general shape could be implemented. 
         [0029]    The buoyancy of the floats ( 3 ) will be affected by the materials used (inner tube in a fabric envelope, flotation foam in plastic housing, hollow plastic donut, etc.) and by the load applied (weight of the canopy as distributed on the legs). For effective operation, materials should be selected so that the loaded buoyancy of the set of floats is such that the floats sit partially under the water surface. For floats with a basin ( 28 ), the basin should be about half filled with water during stable operation, as shown in  FIGS. 12 and 13 . Under these conditions, the partially submerged float will act as a sea anchor to resist rotation of the canopy in a breeze, and the water in the basin will provide a resistance to lifting as it seeps out through the mesh or bottom holes. 
         [0030]    The foregoing description has been presented and is intended for the purposes of illustration and description. It is not intended to be exhaustive nor limit the invention to the precise form disclosed and many modifications and variations are possible in the light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application and to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out the invention.