Abstract:
A fastener for securing deck boards to a support structure without the need for driving screws or nails through the deck boards. The fastener includes two horizontal flanges that fit into slots cut into the sides of adjacent deck boards, a center hole for securing the fastener to the support structure and deformable, resilient elements that bridge the gap between adjacent deck boards during fastening yet compress inward when the boards swell and expand.

Description:
FIELD OF THE INVENTION 
     The present invention relates to fastener for fastening deck boards to supporting structures and more particularly to a deck fastener for securing adjoining deck boards to a common joist. 
     BACKGROUND OF THE INVENTION 
     Conventional decks typically include horizontal floors raised above the ground and supported by an underlying structure. Decks are often attached to adjacent residential or commercial buildings. Deck boards are placed side by side during construction of a deck, and are typically arranged to cross the structures, such as joints at an angle perpendicular to the longitudinal axis of the joist. Other structures utilizing similar flooring techniques include boat docks, ramps, stairs, landings, bridges, platforms and for structures for surrounding or enclosing swimming pools and hot tubs. 
     Typically, decks are constructed to withstand exposure to the elements and are often constructed from pressure treated wood, plastic or, more recently, exotic hardwoods. Whether the deck boards, which form the flooring of the deck, are comprised of wood or plastic or other material, the substructure is typically formed of commonly available pressure treated lumber. The substructure is formed with joists and headers attached to posts. The deck boards are typically fixed transversely across the joists to the substructure, in a generally parallel relationship, by way of nails or screws, driven through the upper surface of the deck board into the joist below. 
     This manner of attaching deck boards to the substructure presents several disadvantages. If nails or screws are used, they typically cause discoloration of the surrounding wood surface over time. In addition, in driving the nail through the wood or plastic deck board, the surface of the board is often marred during hammering, causing unsightly dents and scratches to the top surface of the board. Both the discoloration of the wood and marring of the surface are of particular concern when exotic hardwoods are used. 
     In addition, nails have a tendency to work themselves loose from the board over time, projecting upward from the board&#39;s surface. Not only is this aesthetically unpleasing, it causes the deck board to loosen against the joist and also constitutes a safety hazard, particularly to individuals walking over the deck surface barefoot. In addition, both nails and screws are prone to rusting over time, causing failure to the attachment. Removal of one or more deck boards entails prying the nails loose which is both time consuming and causes damage to the surface of the board. 
     Since decks are constantly exposed to outside environmental conditions, the deck boards are exposed to extremes of both temperature and humidity. Both plastic and wooden deck boards will shrink and expand in response to temperature changes, and wooden deck boards will also shrink and expand as the moisture content of the board increases or decreases. Deficiencies in the attachment means in the prior art often cause attachment devices to loosen over time or to cause the deck boards to warp or crack because the attachment device does not provide for movement along with the board as it expands or contracts. 
     BRIEF SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a deck fastener that provides easy installation and removal of deck boards, avoids the difficulties presented by attachment devices in the prior art, provides for expansion and contraction of the boards after installation, and in particular, provides for post-installation expansion of adjoining deck boards. 
     In the construction of a deck or similar structure, the supporting substructure is built from weather resistant materials, typically pressure treated lumber, including vertical posts secured to the ground, spaced parallel joists extending between the posts, headers spanning the posts and connecting the ends of the joists to one another, and deck boards fixed transversely to the top of the joists to form a platform. While the substructure is generally comprised of pressure treated wood, the deck boards may be formed from pressure treated wood, plastic, exotic hardwoods or other resilient material. 
     The present invention includes a fastener for securing deck boards to a support structure without the need for driving screws or nails through the deck boards. The fastener includes two horizontal flanges that fit into slots cut into the sides of adjacent deck boards, a center hole for securing the fastener to the support structure and deformable, compression elements that bridge the gap between adjacent deck boards during fastening yet compress inward when the boards swell and expand. 
     To install deck boards, using a fastener of the present invention, slots are cut into the sides of the deck boards at the point where the deck board crosses an underlying joist. The slots are preferably two and one-half inches wide, one-half inch deep and one-eighth inch tall. The slots may be cut using known woodworking tools such as a biscuit joiner. 
     The fastener includes two flat, relatively narrow flanges that project or extend outward and fit into the slots of adjacent deck boards. The boards are then held in place by driving a screw or nail into the center hole of the device into a joist below. In order to facilitate use of the fastener during deck construction and to provide a means of assuring even gaps between boards throughout the deck structure, the device typically includes top and bottom tabs that project from the top and bottom of the flat horizontal surface of the device. These tabs also serve to stabilize the fastener when it is inserted into the slot of the first deck board, prior to engaging the adjacent board and subsequent fastening with a screw or nail. The device serves not only as an attachment means, but as a gauge to assure that gaps are evenly spaced throughout the deck to yield a more pleasing appearance. 
     Because the gap between adjacent boards will narrow or expand as a deck board responds to environmental conditions, compression elements may be integral with the tabs so that after installation the tab structure may compress in response to movement of, and pressure exerted by, the expanding boards. As the boards adjacent to the fastener expand in width, the compression elements deform to adopt a narrower profile. If the compression elements are formed of a flexible, resilient material such as plastic, they will tend to expand to fill the gap as it widens in response to subsequent shrinkage of the deck boards. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a deck board fastener in accordance with the principles of the present invention; 
         FIG. 2  is an end elevational view of the deck board fastener of  FIG. 1 ; 
         FIG. 3  is a side elevational view of the deck board fastener of  FIG. 1 ; 
         FIG. 4  is a top plan view of the deck board fastener of  FIG. 1 ; 
         FIG. 5  is a bottom plan view of the deck board fastener of  FIG. 1 ; 
         FIG. 6  is a reduced perspective view of a deck board fastener positioned for attachment to a joist; 
         FIG. 7  is an end view of a deck board fastener positioned between two adjacent deck boards drawn in phantom lines; 
         FIG. 8  is a partial, top diagrammatical view of a deck board fastener as initially positioned between adjacent deck boards immediately subsequent to installation; 
         FIG. 9  is a partial, top diagrammatical view of a deck board fastener positioned between adjacent deck boards showing deformation of the compression elements in response to expansion of the deck boards and narrowing of the gap between the boards; 
         FIG. 10  is a top plan view of a deck board fastener showing an alternative, circular compression element configuration; 
         FIG. 11  is a top plan view of a deck board fastener showing an alternative, rectangular compression element configuration; 
         FIG. 12  is a perspective view of an alternative embodiment of a deck board fastener illustrating horizontally diverging compression elements mounted to the undersurface of the top plate; 
         FIG. 13  is an end elevational view of the deck board fastener of  FIG. 12 ; 
         FIG. 14  is a side elevational view of the deck board fastener of  FIG. 12 ; 
         FIG. 15  is a top diagrammatical view of the deck board fastener of  FIG. 12  with the compression elements drawn in phantom lines to indicate placement below the top plate; 
         FIG. 16  is a perspective view of an alternative embodiment of a deck board fastener illustrating vertically diverging compression elements mounted to the upper and lower surfaces of the top plate; 
         FIG. 17  is a side elevational view of the deck board fastener of  FIG. 16 ; 
         FIG. 18  is an end elevational view of the deck board fastener of  FIG. 16 ; 
         FIG. 19  is a top plan view of the deck board fastener of  FIG. 16 ; and 
         FIG. 20  is a bottom view of the deck board fastener of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     Turning to the drawings, preferred embodiments of the device will be described by reference to the drawing figures wherein like numerals indicate like parts. 
       FIG. 1  provides a perspective view of a deck board fastener  100  in accordance with the principles of the present invention. The fastener  100  includes a horizontal top plate  102  having a first flange  104  and a second flange  106  projecting horizontally from the longitudinal axis of the top plate  102 . The fastener  100  also includes a hole  108  extending through the center vertical axis of the top plate  102 . As illustrated in  FIG. 1 , a first compression element  110  projects horizontally outward from the left edge of the top plate  102 . A second compression element  112  projects horizontally outward from the right edge of the top plate  102 . 
       FIG. 3  is a side elevational view of the fastener  100  of  FIG. 1 . As illustrated, a first bottom tab  114  and a longitudinally opposed second bottom tab  116  project downward from the bottom surface of the top plate  102 . A first top tab  118  and a longitudinally opposed second top tab  120  project upward from the top surface of the top plate  102 . The first compression element  110  projects from the left side of the top plate  102 , the second compression element  112  projects from the right side of top plate  102 . In this embodiment, the top and bottom tabs are integral with the compression elements  110  and  112 . 
       FIG. 4  is a top plan view of the fastener  100  of  FIG. 1 .  FIG. 4  illustrates the top surface  124  of the top plate  102 , as well as the first and second flanges  104 ,  106 , the center hole  108 , and first and second compression elements  110  and  112 . As can be readily seen in  FIGS. 1 and 4 , compression element  110  includes transversely spaced prongs  110   a  and  110   b . Compression element  112  includes transversely spaced prongs  112   a  and  112   b.    
       FIG. 2  is an end elevational view of the fastener  100  of  FIG. 1  illustrating end views of the top plate  102 , first bottom tab  114 , and first compression element  110 . The view of compression element  110  is drawn in perspective rather than as a true elevation in order to convey the curvature and depth of space between the prongs  110   a  and  110   b.    
       FIG. 5  is a bottom plan view of the fastener  100  of  FIG. 1  illustrating the bottom surface  126  of top plate  102 , the first and second flanges  104  and  106 , the center hole  108 , the bottom surfaces of the bottom tabs  114  and  116 , and first and second compression elements  110  and  112 . 
     The top plate  102  is preferably approximately ⅛ inch in vertical thickness to fit the typical dimensions of a slot  10  cut by a biscuit joiner, see  FIG. 6 . In order to fit within the semicircular profile of the slot formed by a biscuit joiner, the outer margins of the flanges  104  and  106  may be similarly curved, see  FIGS. 4 and 5 . The top tabs  118  and  120 , and/or compression elements  110  and  112 , preferably project approximately ⅛ inch upward from the top surface  124  of the top plate  102 . The bottom tabs  114  and  116  preferably project ⅜ inch downwards from the bottom surface  126  of the top plate  102 . These vertical dimensions will tend to place the slot  10  near the vertical center of an edge  12  of a deck board  14 . In the case of typical “one-by” lumber, which is approximately ¾ inches in thickness, the slot  10  will be located approximately ⅜ inches from the bottom surface  16  of the board  14 , and 2/8 inches from the top surface  18  of the board  14 , leaving approximately a ⅛ inch clearance between the top surface of the top tabs  118  and  120  (and/or compression elements  110  and  112 ) and the top surface  18 . 
     In use, a first flange  104  of a deck board fastener  100  is inserted into a slot  10  in the side  12  of a deck board  14 , see  FIGS. 4 and 6 . A second deck board is then brought alongside the first so that the second flange  106  is moved into the slot of the second deck board.  FIG. 8  shows a fastener  100  with two adjacent deck boards,  14   a  and  14   b , positioned so that the flanges of the fastener  100  are inserted into the slots of the boards. An attachment means such as a nail or screw (not shown) is then driven downward through the center hole  108  of the top plate  102  and into an underlying support structure such as a joist  20 . The fastener  100  is thereby secured against the top surface of the underlying joist  20 . Preferably, the nail or screw is driven through the fastener  100  at an angle substantially perpendicular to the top surface  124  of the top plate  102 . It is typically not necessary or desired to drive the nail or screw at an angle such that it passes through one of the deck boards. Downward pressure exerted by the flanges  104  and  106  is transmitted to the lower surfaces of the slots  10 , thereby holding the deck boards  14   a  and  14   b  against the joist  20 . Therefore, as the fastener  100  is secured to the joist  20 , the flanges  104  and  106  of the fastener  100  likewise fasten the deck boards  14   a  and  14   b  to the joist  20 . 
     Preferably, the fastener  100  is formed so that upon installation a ¼ inch gap remains between adjacent boards that are joined by the fastener  100 . As may be readily observed through reference to  FIGS. 4 ,  5 ,  6  and  8 , the prongs of the compression elements  110  and  112  may act to limit the width of a gap between adjacent deck boards. As shown in  FIG. 3 , the compression elements  110  and  112  have an overall vertical height that exceeds the vertical thickness of the top plate  102 . It is important that the compression elements  110  and  112  are of sufficient vertical height to bridge the slot  10  in the side of a deck board  14 , see  FIG. 7 .  FIG. 7  is an end view of the fastener  100  positioned between two adjacent deck boards  14   a  and  14   b  drawn in phantom lines. As illustrated, compression element  110  extends both above and below the adjacent slots  10   a  and  10   b . Bottom tabs (see  114 ) typically rest upon the upper surface of the underlying joist  20 .  FIG. 7  also illustrates approximate placement of the flanges  104  and  106  within the slots  10   a  and  10   b , respectively. It should be appreciated that the slots  10   a  and  10   b  have been illustrated slightly oversized in order to show both the walls of the slots and the surfaces of the flanges  104  and  106 . In practice, at least the bottom surfaces of the flanges  104  and  106  are in contact with the bottom surfaces of the slots  10   a  and  10   b.    
     As can be seen in  FIG. 8 , when the fastener  100  is inserted into the slots of adjoining deck boards  14   a  and  14   b , the outer edges of the prongs  110   a  and  110   b  are in contact with the inner edges of the boards  14   a  and  14   b , thereby setting the width of the gap between the boards. A ¾ inch gap may be provided for by use of a fastener  100  with the following horizontal dimensions. The top  118 ,  120  and bottom  114 ,  116  tabs are preferably approximately 3/32 inch in horizontal thickness. The prongs, for example  110   a  and  110   b , may be approximately 3/64 inch in horizontal thickness, so that upon compression the prongs  110   a  and  110   b  will present an overall thickness similar to that of the top tab  118 , see  FIG. 9 . It should be appreciated that the above dimensions may be varied while still yielding a fastener  100  that provides for a ¼ inch gap. In addition, fasteners having other dimensions may be provided if a narrower or wider gap is desired. 
     Preferably, the fastener  100  is formed of a resilient material such as plastic. The material chosen should be rigid enough so that the top plate  102  tends to resist flexion when a screw or nail is driven through the center hole  108  into an underlying joist  20  or other substructure. In order to augment the rigidity of the top plate  102 , a ridge  122  may be provided on the underside of the top plate  102  such that it joins and is contiguous with bottom tabs  114  and  116 . This ridge  122  may be observed in elevation in  FIG. 3 . While the rigidity of the selected material must be sufficient to resist flexion of the top plate  102 , it should not be brittle. Preferably, the fastener  100  should be able to withstand impacts from tools such as hammers, as well as movement of the boards due to footfalls by persons walking over the deck structure, and movement due to shrinking and swelling of the boards themselves. The material selected should be resilient so that upon swelling of boards  14   a  and  14   b , the prongs  110   a  and  110   b  can compress inward, as shown in  FIG. 9 . Arrows  24  and  26  indicate inward movement of boards  14   a  and  14   b  due to swelling of the boards caused by environmental factors such as moisture and temperature. Although not necessary for the fastener  100  to be operable, the selected material is preferably of sufficient resiliency so that prongs  110   a  and  110   b  will rebound to their original position upon subsequent shrinkage of the adjacent deck boards  14   a  and  14   b.    
       FIG. 10  is a top plan view of a deck board fastener  200  having alternative circular compression elements  210  and  212 . Compression elements  210  and  212  include central open spaces  214  and  216 , respectively, to allow for compression of respective walls  218  and  220 . As illustrated, alternative fastener  200  includes a top plate  102  and center hole  108  substantially similar to fastener  100 . 
       FIG. 11  is a top plan view of a deck board fastener  300  having alternative rectangular compression elements  310  and  312 . Compression elements  310  and  312  include central open spaces  314  and  316 , respectively, to allow for compression of respective walls  318  and  320 . As illustrated, alternative fastener  300  includes a top plate  102  and center hole  108  substantially similar to fastener  100 . Is should be appreciated that compression elements may take other forms than illustrated such as multi-sided or polygon shapes, the controlling factor being the ability to compress in a lateral direction. 
       FIG. 12  is a perspective view of an alternative embodiment of a deck board fastener  400 . The fastener  400  includes a top plate  402  and center hole  408  substantially similar to those disclosed in prior embodiments  100 ,  200  and  300 . Rather than compression elements projecting from the longitudinal ends  410  and  412  of the top plate  402 , however, fastener  400  includes a pedestal structure  404  projecting downward from the lower, center surface of top plate  402  and enclosing center hole  408 . A first compression element  414  projects horizontally outward from pedestal  404  in the direction of end  410 . A second compression element  416  projects horizontally outward from pedestal  404  in the direction of end  412 . The compression elements  414  and  416  include prongs  414   a ,  414   b ,  416   a  and  416   b , as indicated in  FIG. 12 . Preferably, pairs of prongs, such as  414   a  and  414   b , are spaced so that the device  400  sets a ¼ inch gap between adjacent deck boards. 
       FIG. 13  is an end elevational view of fastener  400  showing the pedestal  404  connecting the top plate  402  to compression element  414 .  FIG. 14  is a side elevational view of fastener  400  also showing pedestal  404  projecting from the bottom surface of top plate  402  from which extend compression elements  414  and  416 . It should be appreciated the compression elements  414  and  416  are not directly attached to top plate  402 . Therefore, fastener  404  also allows for unrestricted inward compression of compression elements  414  and  416  upon swelling of adjacent deck boards.  FIG. 15  is a top diagrammatical view of fastener  400 , with the pedestal  404 , prongs  414   a  and  414   b  of compression element  414 , and prongs  416   a  and  416   b  of compression element  416 , drawn in phantom lines to indicate placement of these elements below the top plate  402 . As shown, center hole  408  is preferably of a diameter sufficiently large to allow the passage of a nail or screw, and sufficiently small to allow enclosure within pedestal  404 . As may also be seen in previous illustrations, the center hole  408  may be bounded on the upper surface of top plate  402  by a circular bevel  418  for receiving the head of a nail or screw. 
       FIG. 16  is a perspective view of another alternative embodiment of a deck board fastener  500  including compression elements  510  and  512  projecting upward from the top surface  504  of top plate  502 , and compression elements  514  and  516  projecting downward from the bottom surface  506  of top plate  502 . Unlike previous embodiments, fastener  500  includes compression elements having vertically diverging prongs, such as  510   a  and  510   b , and  514   a  and  514   b , see  FIG. 18 . As with the prior embodiments, fastener  500  provides a means of fastening adjacent deck boards to an underlying joist, while setting a uniform gap spacing and providing for expansion of the boards and concomitant compression of the gap space-limiting elements, the compression elements.  FIG. 17  is a side elevational view of the fastener  500  of  FIG. 16 .  FIGS. 16 and 17  indicate a space  518  between compression elements  514  and  516  to allow for unobstructed travel of a nail or screw and for independent flexion of compression element prongs associated with elements  514  and  516 . It should be appreciated that due to the gap between the prongs, such as illustrated in  FIG. 18  between prongs  514   a  and  514   b , elements  514  and  516  could be joined to form a single compression element. 
       FIG. 19  is a top plan view of fastener  500  showing placement of compression elements  510  and  512  upon the top surface  504  of top plate  502 .  FIG. 20  is a bottom view of fastener  500  showing placement of compression elements  514  and  516  upon the bottom surface  506  of top plate  502 . Although shown in  FIG. 16 through 20  as being set back slightly from the longitudinal ends of the top plate  502 , it should be appreciated that the compression elements  510 ,  512 ,  514  and  516  may extend to the longitudinal ends of the top plate  502 , or maybe set back further inward. 
     It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable equivalents thereof.