Patent Publication Number: US-6711864-B2

Title: Wood deck plank with protective cladding

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of U.S. Provisional Patent Application No. 60/273,376 filed on Mar. 5, 2001, which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to planks for decks and, more specifically, to a plank with a protective cladding and connector clips. 
     BACKGROUND OF THE INVENTION 
     Outdoor decks are extremely popular in residential home construction. Homes and apartments, as well as a variety of other buildings, often incorporate exterior decks into their design. These decks provide convenient spaces for a variety of outdoor activities, including cookouts, dining and sunbathing, as well as other leisure activities. Moreover, decks typically are provided with a railing or perimeter fence to keep people from falling over the edge of the deck. Additionally, perimeter and accent fencing is commonly added onto landscapes, creating a boundary for foliage displays and garden areas. 
     Wood products traditionally have been the primary source of materials for use in decking and fence construction. However, wood products are becoming increasingly scarce due to the harvesting of trees at ever faster rates and the rather limited rate at which timber resources can be replenished. Also, environmental concerns and regulations directed to conservation or preservation of forests tend to restrict the availability of wood products. With the diminishing availability of timber resources, wood products are becoming increasingly expensive. There is, therefore, a substantial need for long-lasting substitute construction materials that can lessen the need to harvest timber resources. 
     One potential approach to addressing the above need is to provide substitute fence and decking products made of plastic, rather than wood. Such plastic products provide a long-lasting alternative to wood. In addition, plastic fence and deck products alleviate the need for costly painting and repainting. A variety of plastic building products are known. For example, U.S. Pat. No. 4,045,603 describes a three-layer synthetic construction material made from recycled waste thermoplastic synthetic resin material and cellulose fiber aggregate. This material includes face surfaces consisting essentially of re-hardened fused and rolled thermoplastic synthetic resin material bits, and an intervening core material consisting essentially of a compressed non-homogenous mixture of cellulose aggregate material bits and re-hardened fused thermoplastic synthetic resin material bits. Such plastic materials have been used to create decking and fencing elements, but have not proven entirely satisfactory. 
     Accordingly, a need yet remains in the art for decking system that can be quickly and easily installed, and that is made from a plentiful, light-weight, weather-resistant material. It is to the provision of such a fence system that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     Generally described, in a first preferred form the present invention provides a wood deck plank with a protective cladding. The plank comprises a wood core having a top surface and two sides, with a groove formed in each of the sides, and a cladding formed onto the top surface, with the cladding selected to provide weather protection and durability. In a preferred form, the wood core is laminated from a plurality of wood strips bonded together. In an alternative form, the wood core is provided by a plurality of wood chips bonded together. In either case, the wood core includes residual wood components instead of solid pieces of lumber. 
     In the preferred form, the cladding is provided by a sheet of a material such as a plastic, polyvinyl chloride (PVC), acrylic, polycarbonate, or composite thereof, that is bonded to the top surface. In the alternative form, the cladding is provided by two or another number of sheets of a material such as a polyester, phenol, epoxy, and composite thereof, that are sprayed or rolled onto the top surface. The cladding has an exposed surface that is textured by an impression technique, and the cladding is sufficiently thick so that the top surface remains substantially covered and protected by the cladding after the cladding is impressioned. The grooves have a rectangular shape and receive an arm of a T-shaped connector clip, for assembling the planks together and mounting them to a deck frame structure without putting holes in the planks. 
     Furthermore, there is provided a method of manufacturing the plank, which includes the steps of providing a wood core, forming a groove in each side of the wood core, applying a cladding onto the top surface of the wood core, where the cladding is selected to provide weather protection and durability, impressing a texture onto the exposed surface of the cladding, and providing connector clips receivable in the grooves for connecting adjacent planks together in the construction of a deck. 
     These objects, advantages and features of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The present invention will be better understood by reading the Detailed Description of the Preferred Embodiment with reference to the accompanying drawing figures, in which: 
     FIG. 1 is a cross-sectional view of the plank according to the present invention, showing a multi-ply core, a top cladding, side profiles, and connector clips. 
     FIG. 2 is a perspective view of one of the clips of FIG.  1 . 
     FIG. 3 is an alternative plank and clip according to the present invention. 
     FIG. 4 is a flow diagram describing a method for manufacturing the plank of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In describing the preferred and alternate embodiments of the present invention, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected. 
     Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views, FIG. 1 shows a plank  10  according to a preferred form of the invention. The plank  10  as depicted has a generally rectangular cross sectional shape and can be provided in various sizes. For example, the plank  10  can have a height H of between ¾ inches and 2 inches, a width W of a few inches or more, and a length of several feet. 
     The plank  20  has a wood core  12  that is laminated from a plurality of wood strips  14  bonded together by an adherent such as an epoxy suitable for subsequent pressure treating. In the preferred form, the strips  12  are each about ⅛ inch thick and arranged with parallel grain plies to minimize warping and cupping. The particular wood used can selected based on the desired strength, durability, cost, and other factors. Also, the wood core  12  can be pressure-treated with borates or other non-hazardous substances, and dried in a kiln or other device to the proper moisture, as may be desired. 
     The wood core  12  has a wear surface  14  (typically the top or exposed surface) that is coated with a cladding  16  for weather protection and durability. The cladding  16  is provided by a sheet of a material such as a plastic, polyvinyl chloride (PVC), acrylic, polycarbonate, composite thereof, or another material selected for weather protection and durability, that is bonded to the wear surface  14 . Alternatively, the cladding  16  can be provided by two or another number of sheets of a material such as a polyester, phenol, epoxy, composite thereof, or another material selected for weather protection and durability, that is sprayed or rolled onto the wear surface  14 . 
     The exposed surface  18  of the cadding  16  has a texture provided by embossing, stamping, or another technique. The surface texture  18  is selected to provide a natural wood grain appearance, and traction to prevent slips and falls by persons walking on a deck built from the planks. In order to create the textured surface  18  by an impression technique such as stamping, the cladding  16  must be sufficiently thick so that the wear surface  14  remains entirely (or at least substantially) covered and protected by the cladding  16  after the cladding  16  is impressioned. 
     Each side  20  of the plank  10  has a groove  22  defined therein for receiving a connector clip  24  for connecting the planks together onto a floor joist or other decking structure. The groove  22  can have a generally rectangular shape with at least one sidewall that is tapered. For example, each groove  22  can have an enlarged head space  21  within the plank and a narrower neck space  23  adjacent the plank side  20 , or another regular or irregular shape. 
     Referring further to FIG. 2, the clip  24  is generally T-shaped with two arms  26  that are shaped and sized to conform to and fit within the grooves  22  of adjacent planks when connecting the planks together to construct a deck. For example, each arm  26  can have an enlarged head  25  and a narrower neck  27 . The clips  24  can be extruded, molded, or made by another fabrication technique, from PVC, acrylic, polycarbonate, or another material. Each clip  24  has an aperture  28  defined therethrough for receiving a screw or another fastener, for connecting the clip  24  to a frame member upon which the deck is being constructed. Details of the construction and use of similar decking clips are provided by U.S. Pat. No. 5,660,016 to Errwin et al., which hereby incorporated by reference in its entirety. 
     The combination of the wood core  12 , the cladding  16 , and the side groove  22  and associated clips  24  provide several advantages over the prior art. The wood core  12  provides the high strength of real wood, the cladding  16  protects the otherwise exposed top surface  14  of the wood core  12  from deterioration such as by rotting, the textured surface  18  of the cladding  16  provides a natural wood appearance, and the side groove  22  and T-shaped clip  24  provide for assembling the planks to form a deck without sacrificing the integrity of the planks by creating nail or screw holes therein. Also, if the wood core shrinks over time, then the grooves will shrink onto the clips so that the clip connections will become tighter and more secure, ensuring a solid, lifetime fit. 
     Referring to FIG. 3, there is shown an alternative form of the present invention, referred to generally as the plank  100 . The alternative plank  100  is similar to the preferred plank  10 , in that the plank  100  has a wood core  102 , a top surface cladding  104 , and side grooves  106 . However, in this form, the wood core  102  is made from a plurality of pretreated wood chips that are bonded together with an adhesive such as a phenol. Also, the grooves  106  each have two tapered sidewalls to provide a route for moisture to seep downwardly therethrough and out of the plank, so that there is provided no place that will allow for an accumulation of standing moisture that could rot the wood core  102 . Accordingly, a clip  108  is provided that is similar to the clip  24 , except with arms shaped and sized to conform to the groove  106 . 
     Referring to FIG. 4, there is additionally provided a method of manufacturing the plank. The method comprises providing a wood core having a top surface and two sides; forming an groove formed in each of the sides; and applying a cladding onto the top surface, where the cladding is selected to provide weather protection and durability. The step of providing a wood core can include bonding a plurality of wood strips together or bonding a plurality of wood chips together. The cladding can be provided by a sheet of a material such as a plastic, polyvinyl chloride (PVC), acrylic, polycarbonate, or a composite thereof that is bonded to the top surface, or by two or another number of sheets of a material such as a polyester, phenol, epoxy, or a composite thereof, that are sprayed or rolled onto the top surface. Additionally, the step of applying a cladding onto the top surface can include impressing a texture onto the exposed cladding surface. Furthermore, the step of forming a groove in each of the side can include cutting a rectangular-shaped groove with at least one sidewall that is tapered. The method can also include providing at least one and preferably a plurality of connector clips each having a T-shape with two arms, wherein each arm is receivable within one of the grooves of the plank. 
     Having thus described the preferred forms of the present invention, those skilled in the art will additionally recognize that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the spirit and scope of the present invention as set forth in the following claims.