Abstract:
A fastener for driving into a substrate has a head having an upper surface and a lower surface, a penetrating tip and a shank extending from the lower surface of the head to the penetrating tip. At least one deformable feature is formed on the head. The deformable feature is configured to absorb energy and to deform. When a driving element is driven onto the head to drive the fastener into the substrate, the deformable feature absorbs energy and is deformed as the head contacts the substrate.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention pertains to fasteners. More particularly, the invention pertains to a fastener having a deformable portion for absorbing excess drive energy. 
         [0002]    Fasteners, such as nails, have been produced for hundreds of years. Round nails are presently the most common type of nail and are the easiest type of nail to manufacture, because of their symmetrical shape. Moreover, round nails exhibit relatively predictable, uniform properties, when driven into a substrate, such as wood. 
         [0003]    Many of today&#39;s fastening (nailing) applications, in particular in the construction industry, use powered or fastener driving tools, also referred to as nailers or nail guns. These tools can be pneumatic driven, combustion driven, electric or the like. In a typical tool, a reciprocating drive blade is brought into contact with the fastener head, separates the fastener from a fastener strip, and drives the fastener out of the tool and into the substrate. 
         [0004]    In use, fasteners are driven into different types and thicknesses of material (substrates). A typical application is the nailing of two pieces of wood (lumber) to one another. The lumber can be relatively soft (such as spruce, pine or fir), or relatively hard, such as oak, ash or the like. Moreover, some applications require the use of a joining member, such as a metal joist hanger or plate, through which the fastener must also be driven. 
         [0005]    When using a joining member, there is little margin for over driving (over travel) of the nail. Accordingly, the depth of drive must be precisely adjusted to prevent the tool and specifically the drive blade from experiencing an excessive shock when the fastener head abruptly stops on a hard, non-compliant metal surface. Moreover, this precise adjustment is even more impractical in that different, and even similar woods have varying hardnesses and densities, contain imperfections, natural inconsistencies (such as knots), dimples, dents and the like. 
         [0006]    Accordingly, there is a need for a fastener that absorbs excess drive energy. Desirably, such a fastener can be used in a conventional fastener drive tool. More desirably, such a fastener absorbs a wide range of excess energy without structural damage to the fastener, the tool or the substrate. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    A nail for driving into a substrate has a head having an upper surface and a lower surface, a penetrating tip and a shank extending from the lower surface of the head to the penetrating tip. At least one deformable feature is formed on the head and is configured to absorb energy and to deform when a driving element is driven onto the head to drive the fastener into the substrate and the head contacts the substrate. The fastener can be used in a conventional fastener drive tool and absorbs a wide range of excess energy without structural damage to the fastener, the tool or the substrate, except for the deformation of the deformable feature. 
         [0008]    In a present fastener, the deformable feature is formed softer than the nail shank. In one embodiment, the shank is heat treated (for hardening) and the head, including the deformable feature, is not heat treated. 
         [0009]    The deformable feature can be formed on the upper surface of the nail head, in which case the deformable feature projects upwardly from the upper surface. Alternatively, the deformable feature can be formed on the lower surface, in which case the deformable feature projects downwardly from the lower surface. The deformable feature can be formed as an upwardly or downwardly projecting winding projection. 
         [0010]    Alternatively, the deformable feature can be is formed as a series of features. The series of features can have differing heights or a uniform height as measured from the surface from which the features extend. 
         [0011]    The series of features can be a series of rings formed extending from one or both of the upper and lower surfaces of the head, a series of pimples, or other shaped features. 
         [0012]    Recesses can be formed in head adjacent to the deformable features to accommodate material as the features are deformed. 
         [0013]    These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]    The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying illustrations and drawings, wherein: 
           [0015]      FIG. 1A  is a front cross-sectional view of an embodiment of a shock absorbing fastener embodying the principles of the present invention, the view being taken along line  1 A- 1 A of  FIG. 1B ; 
           [0016]      FIG. 1B  is a top view of the fastener of  FIG. 1A ; 
           [0017]      FIG. 2A  is a front cross-sectional view of an alternate embodiment of a shock absorbing fastener; 
           [0018]      FIG. 2B  is a top view of the fastener of  FIG. 2A ; 
           [0019]      FIG. 3A  is a front cross-sectional view of still another embodiment of a shock absorbing fastener; 
           [0020]      FIG. 3B  is a bottom view of the fastener of  FIG. 3A ; 
           [0021]      FIG. 4A  is a front plant view of yet another embodiment of a shock absorbing fastener; 
           [0022]      FIG. 4B  is a top view of the fastener of  FIG. 4A ; 
           [0023]      FIG. 5A  is a front plan view of still another embodiment of a shock absorbing fastener; and 
           [0024]      FIG. 5B  is a top view of the fastener of  FIG. 5A   
           [0025]      FIGS. 6A-6C  illustrate still another embodiment of the shock absorbing fastener; and 
           [0026]      FIGS. 7A-7C  illustrate yet another embodiment of the shock absorbing fastener. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described several preferred embodiments with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
         [0028]    It should be further understood that the title of this section of the specification, namely, “Detailed Description of the Invention,” relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein. 
         [0029]    Referring to the figures and in particular to  FIGS. 1A and 1B , there is shown an embodiment of a shock absorbing fastener  10  in accordance with the principles of the present invention. The illustrated fastener  10  is a nail and includes a head  12 , a shank  14  and a penetrating tip  16 . The nail  10  includes one or more deformable features  18  on the nail head  12 . In the illustrated embodiment, a series of deformable features  18   a - c  is shown as rings of uniform height h 18  that are formed on the upper surface  20  of the nail head  12 . In the illustrated embodiment, the rings  18   a - c  are concentric relative to an axis A 10  of the nail  10 . 
         [0030]    Referring briefly to  FIGS. 2A and 2B , an alternate embodiment of the nail  110  is shown with the features  118   a - c  having differing heights h 118a -h 118c , that is the ring  118   a  that is first contacted by the driver blade being outermost and rings  118   b - c  of lesser heights being formed inwardly of the outer ring  118   a.    
         [0031]    It will be appreciated that the features can also be, for example, as shown in  FIGS. 4A and 4B , raised projections  218  formed as a series of dots or pimples, or other shaped features. The features can have varied heights or uniform heights as desired. It will be also be appreciated that the features or structures can be formed as a single feature or structure, for example, an elongate, single feature or structure (e.g., a single winding raised projection), or the like. 
         [0032]    It will be understood from the drawings that the features serve to increase the deceleration time of the blade relative to the head  12  after the fastener  10  head has been fully seated on the substrate. That is, the features are sufficiently stiff and strong to not collapse as the driver blade contacts the head  12  and drives the fastener  10  into the substrate. However, when the head  12  fully seats on the substrate, the blade, which continues to move into the head  12 , deforms or collapses the features  18 . The energy expended by the blade in deforming the features  18  would then reduce the energy that is seen by the blade contacting the now-seated nail head  12 . This reduces the force that the blade would otherwise be subjected to if the blade did not deform the feature(s). 
         [0033]    To this end, the deformable feature(s)  318  can be located on the lower surface  322  or underside of the head  312 , such as that shown in  FIGS. 3A and 3B , in which case the blade and head would exhibit an increase in the deceleration time relative to the substrate. 
         [0034]    Sill another embodiment of the shock absorbing fastener  410  is illustrated in  FIGS. 5A and 5B . In this embodiment, the deformable features  418 , which are shown as elevated ridges running along the upper surface  420  of the head  412 , alternate with recesses or valleys  424 . The recesses or valleys  424  are formed to provide regions in which the material from the deformable features (ridges)  418  can spread as they are deformed. It will be understood that the recesses or valleys  424  can be formed in any of the previously shown and described embodiments of the fastener  10 ,  110 ,  210 ,  310 . 
         [0035]    For example, the embodiment of the fastener  510  illustrated in  FIGS. 6A-6C  include a head  512  with concentric upwardly extending deformable features  518  (rings) and valleys  524  into which material can move when the features  518  are deformed. Likewise, the fastener  610  in  FIGS. 7A-7C  has concentric upwardly extending deformable features  618  and valleys  624  in conjunction with downwardly extending deformable features  626  (from the lower surface  622  of the head  612 ) and adjacent valleys  628 . 
         [0036]    There are numerous ways in which the deformable features  18 ,  626  can be formed. For example, the fastener shank  14  (nail shank) can be heat treated to prevent the nail  10  from bending when it is driven, while the head  12  and deformable features  18 ,  626  are not heat treated, which will result in the deformable features being less hard than the shank  14 . The deformable features  18 ,  626  can be formed form a different, softer material than the fastener  10 , which features  18 ,  626  are then subsequently applied to the fastener  10 . Forming the deformable features  18 ,  626  as smaller width w 18 , greater height h 18  elements (thin, tall profile) can also serve to promote and enhance the deformable function of the feature(s)  18 ,  626 . 
         [0037]    In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. 
         [0038]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure. 
         [0039]    From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.