Abstract:
A fastener is provided. The fastener includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the annular flange. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of U.S. Patent Application No. 61/948,850, filed on Mar. 6, 2014, the entirety of which is hereby incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to fasteners. In particular, the present invention relates to a drive spike for driving into a substrate and preventing inadvertent removal of the drive spike from the substrate. 
       BACKGROUND 
       [0003]    Many types of fasteners are known in the art for firmly holding a variety of components together. For example, railroad drive spikes are used to hold tie plates to wooden ties. Drive spikes may also be used to hold together bridges, trestles, wooden piers, and docks. 
         [0004]    Typically, for railways, the steel rails have mounting flanges adapted to mate with metallic plates. The metallic plates also contact the wooden ties and are adapted to receive drive spikes to secure the rails to the ties. The spikes are inserted through openings or recesses in the metal plate and driven into the wooden ties. Thus, the steel rails are secured to the wooden ties via the metal plates and the drive spikes. 
         [0005]    In use, the drive spikes eventually loosen from the wooden ties as a result of events such as repeated train crossings and environmental conditions. The weight and vibrations from the passing trains cause the spikes to loosen and enlarge the entry holes within the wooden ties. Environmental conditions such as humidity, temperature changes, rain, snow, etc. may also cause the drive spikes to become loosed within the wooden ties. Additionally, vandals may purposely loosen or remove the drive spikes. As the drive spikes become loose, the holes into which the drive spikes are inserted in the wooden ties enlarge. The enlarged holes then become further exposed to environmental conditions, causing the wood to decay more quickly. 
         [0006]    Tightening or replacement of the drive spikes is often difficult and costly. Removal of a drive spike may cause further destruction to the wooden tie, making the replacement of the drive spike nearly impossible. Once the drive spike is loosened and/or the wood becomes damaged, the entire wooden tie often requires replacement in order to provide a steel rail that is securely fastened to the wooden tie. 
         [0007]    Similar to the railway example, the bridge, trestle, pier and dock drive spike connections are also subject to vibrational and environmental stresses, as well as vandalism, that cause unwanted loosening of the drive spikes within the substrate. Once the drive spike loosens, the substrate into which the spike is driven usually must be replaced in order to securely fasten the bridge, trestle, etc. to the substrate. Replacement of the drive spike itself is generally insufficient to securely fasten objects to the substrate. The enlarged hole in the substrate causes the substrate to become more quickly degraded and thus prevents the drive spike from securely gripping the substrate. 
         [0008]    Therefore, it is an object of the present invention to provide a drive spike that securely fastens an object to a substrate, such as wood, and prevents inadvertent loosening or removal of the drive spike from the substrate, thus further reducing the requirement for replacement of the substrate due to damage caused by the insecure fastening of an object to a substrate. 
       BRIEF SUMMARY 
       [0009]    In order to alleviate one or more shortcomings discussed above, a drive spike is provided herein. 
         [0010]    A fastener is provided. The fastener includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the annular flange. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section. 
         [0011]    In some embodiments, a fastener is provided that includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis and an abutment surface adapted to abut a substrate into which the fastener is driven. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the head portion. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section. 
         [0012]    In some embodiments, a fastener is provided that includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a first section extending along at least a portion of the shank and disposed adjacent to the annular flange, the first section having a first diameter. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the first section. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The smooth section has a second diameter that is smaller than the first diameter. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section. 
         [0013]    Advantages of the present invention will become more apparent to those skilled in the art from the following description of the preferred embodiments of the invention which have been shown and described by way of illustration. As will be realized, the invention is capable of other and different embodiments, and its details are capable of modification in various respects. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a side elevational view of a fastener according to some embodiments; 
           [0015]      FIG. 2  is a side elevational view of a fastener according to some embodiments; 
           [0016]      FIG. 3  is a side elevational view of a fastener according to some embodiments; 
           [0017]      FIG. 4  a top plan view of  FIG. 1 ; 
           [0018]      FIG. 5  is a sectional view through line A-A of  FIG. 2 ; and 
           [0019]      FIG. 6  is a sectional view through line B-B of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]      FIG. 1  shows a fastener  10  in the form of a drive spike, according to some embodiments. The lengths and diameters of the fastener  10  described herein are meant to be non-limiting examples and may be varied as will be understood by one of skill in the art. 
         [0021]    The fastener  10  includes an elongated shank  20 , a head  22  at a first end portion  24  of the shank  20  and a tip  26  at a second end portion  28  of the shank  20 . The tip  26  may be any shape, including blunt and pointed. The fastener  10  has a longitudinal axis  30  extending from the first end portion  24  to the second end portion  28 . 
         [0022]    The head  22  further comprises an annular flange  32  that extends radially from the shank  20 . The annular flange  32  may include a dome-shaped upper surface  34  and a flattened lower surface  36  that extends radially beyond the shank  20 . The head  22  may further comprise a protrusion  37  that extends from the first end portion  24  of the shank  20 . The protrusion  37  may be hemispherical in shape and adapted to be engaged by a striking tool to drive the fastener  10  into a substrate S. The protrusion  37  is adapted to receive significant force and is further adapted to deform as a result of the striking force. 
         [0023]    The head  22  also comprises an outer surface  38  adapted to be engaged by a gripping tool such as a wrench or a socket that may be used to apply torque to the fastener  10  to drive the fastener  10  into the substrate S. In some embodiments, the outer surface  38  may be polygonally shaped. However, the outer surface  38  may be any shape that may be used with a variety of tools. Alternatively, the outer surface  38  does not need to be engaged to drive the fastener  10  into the substrate S. For example, a hole may be pre-drilled in the substrate S and the fastener  10  may be driven into the substrate S using a striking tool to strike the protrusion  37  of the head  22  and thereby insert the fastener  10  into the substrate S. As described below, additional features of the fastener  10  facilitate insertion of the fastener  10  into the substrate S using a driving force.  FIG. 4  shows a top view of the head  22  of the fastener  10 , according to some embodiments. By way of non-limiting example, the head  22  may have a square cross sectional shape having sides extending radially outwardly from the longitudinal axis  30 . Each side may extend about 0.75 to about 0.81 inches in some embodiments. 
         [0024]    As shown in  FIGS. 1 and 2 , the annular flange  32  extends radially from the longitudinal axis  30  of the fastener  10 . In some embodiments, the annular flange  32  extends beyond the circumference of the shank  20 . As shown in  FIGS. 1 and 2 , the annular flange  32  has a diameter D 1  that is greater than a diameter D 2  of a threaded portion of the shank  20  (described below). In some embodiments, the fastener  10  further includes a first section  40  adjacent to the annular flange  32 . The first section  40  may be cylindrically shaped and have a smooth surface. The first section  40  may also be polygonally shaped or may include one or more flattened sides. In some embodiments, the first section  40  is positioned directly adjacent to the annular flange  32 . The first section  40  includes an abutment surface  42  positioned apart from the annular flange  32 . The abutment surface  42  is configured to abut the substrate S into which the fastener  10  is driven so that the first section  40  is positioned above the substrate S when the fastener  10  has been driven into the substrate S. The abutment surface  42  has a diameter that is wider than the cavity of the tie plate so that it rests on the tie plate bearing surface. The first section  40  has a diameter D 3  that is less than the diameter D 1  of the annular flange  32  and greater than the diameter D 2  of the shank  20 . 
         [0025]    By way of non-limiting example, the diameter D 1  may be about 1.75 inches, the diameter D 2  may be about 0.94 inches, and the diameter D 3  may be about 1.25 inches. In some embodiments, the diameter D 1  is about 1.9 times wider than the diameter D 2 , and the diameter D 1  is about 1.4 times wider than diameter D 3 . In some embodiments, diameter D 3  is about 1.3 times wider than the diameter D 2 . The first section  40  may be sized and shaped to receive a tool (not shown) to remove the fastener  10  from the substrate S. The smaller diameter D 3  of the first section  40  relative to the diameter D 1  of the annular flange  32  allows the tool to contact the lower surface  36  of the annular flange  32  that is positioned above the substrate S so that the tool can pull the fastener  10  out of the substrate S. A length L 1  of the first section  40  may be provided so that the tool fits between the substrate S and the lower surface  36  of the annular flange  32 . By way of non-limiting example, the length L 1  may be about 0.38 inches. 
         [0026]    As shown in  FIGS. 1 and 2 , the fastener  10  may also include a knurled section  44  adjacent to the first section  40  so that the first section  40  is between the annular flange  32  and the knurled section  44 . In some embodiments, the knurled section  44  is disposed between the first section  40  and a smooth section  46 . The knurled section  44  may be cylindrically shaped and may include a plurality of axial grooves  45  and peaks  47  as shown in the cross sectional view in  FIG. 4 . In some embodiments, the peaks  47  may include a leading edge. The knurled section  44  is configured to allow the fastener  10  to be driven into the substrate S and to resist removal of the fastener  10  from the substrate S. The knurled section  44  has a diameter D 4  measured at the peaks  47  that is slightly larger than the diameter D 2  and the diameter D 5  and less than the diameter D 3 . By way of non-limiting example, the diameter D 4  may be about 0.97 inches and the length L 2  of the knurled section  44  may be about 1.5 inches. For the knurled section  44  having a diameter of D 4  of about 0.97 inches, the number of peaks  47  is greater than 40. The peaks  47  may all be equal in size and shape extending around the shank  20 . In some embodiments, the depth of grooves  45  may be about 0.025 inches to about 0.035 inches. In some embodiments, the peaks  47  extend substantially parallel to the longitudinal axis  30  of the shank  20 . 
         [0027]    The shank  20  may also include a smooth section  46  adjacent to the knurled section  44 . In some embodiments, the knurled section  44  is directly adjacent to the smooth section  46 . The smooth section  46  may be cylindrically shaped and have a smooth surface. The smooth section  46  may also be polygonally shaped or may include one or more flattened sides. In some embodiments, the smooth section  46  is free from knurls, protrusions and threads. The smooth section  46  has a diameter D 5  that is less than the diameter D 1  and the diameter D 3 . In some embodiments, the diameter D 5  is about substantially the same as the diameter D 2  of the shank  20 . By way of non-limiting example, the diameter D 5  may be about 0.94 inches. The smooth section  46  is configured to be positioned within the substrate S. A length L 3  of the smooth section  46  may be about 0.25 inches. In some embodiments, a shank transition section (not shown, see  FIG. 3 ) may be included between the smooth section  46  and the knurled section  44 . The shank transition section may be a result of manufacturing and machining tolerances, limitations, and capabilities where the knurled section  44  does not extend all the way to the smooth section  46 . 
         [0028]    The shank  20  may also include a transition section  48  extending between the knurled section  44  and a threaded portion  50 . In some embodiments, the transition section  48  tapers inward from the knurled section  44  to the threaded portion  50  so that the threads  52  can be rolled on the threaded portion  50 . In some embodiments, the transition section  48  is disposed between the smooth section  46  and the threaded portion  50 . In some embodiments, the transition section  48  has a length L 4  of about 0.2 inches. In some embodiments, the transition section  48  may have a length L 4  that is less than about 0.1 inches. 
         [0029]    The shank  20  also includes a threaded portion  50  that includes one or more threads  52 . In some embodiments, the threads  52  may be helical fluted threads as shown in  FIG. 1 . The threads  52  extend from the transition section  48  to about the tip  26  of the shank  20 . The angle at the end of the threads  52  may be about 40° to about 50°, more preferably about 45°. In some embodiments, the threaded portion  50  may include  4  fluted threads  52 . 
         [0030]      FIG. 5  is a sectional view through line A-A of  FIG. 2 . As shown in  FIG. 5 , in some embodiments, a width  62  of each helical turn of the threads  52  is about 0.5 inches, although any width may be used. In some embodiments, a depth  64  of the threads  52  protruding from the shank  20  is about 0.13 inches, although any depth may be used. 
         [0031]    In some embodiments, a length L 5  of the head  22  and the first section  40  and the protrusion  37  is about 1.38 inches. The protrusion  37  extends about 0.13 inches above the head  22 . The length L 5  represents the length that is positioned above the substrate S. The length L 6  of the shank  20  from the knurled section  44  to the tip  26  is about 6.5 inches. The length L 6  represents the length of the fastener  10  that is inserted into the substrate S. In some embodiments, the length of the fastener  10  may be about 7.88 inches and the knurled section  44  may be about ⅕ of the length of the fastener  10 . In some embodiments, the length L 6  may be about 4.7 times longer than the length L 5 . In some embodiments, the knurled section  44  may be spaced about 1.13 inches from the first section  40 . In some embodiments, the first section  40  may be about 1/21 of the length of the fastener  10 . In some embodiments, the length of the smooth section  46  may be about 1/32 of the length of the fastener  10 . In some embodiments, the length of the transition section  48  may be about 1/39 the length of the fastener  10 . Other lengths and diameters for each of the dimensions described herein may be used and remain within the scope of the invention. 
         [0032]    In some embodiments, the fastener  10  comprises a metal, more preferably iron or steel, most preferably carbon steel, for example C1035. Any material suitable for forming and having sufficient strength for the fastener may be used as will be understood by one of skill in the art. 
         [0033]      FIG. 3  shows a fastener  100  in the form of a drive spike, according to some embodiments. The lengths and diameters of the fastener  100  described herein are meant to be non-limiting examples and may be varied as will be understood by one of skill in the art. 
         [0034]    The fastener  100  includes an elongated shank  120 , a head  122  at a first end portion  124  of a shank  120  and a tip  126  at a second end portion  128  of the shank  120 . The tip  126  may be any shape, including blunt and pointed. The fastener  100  has a longitudinal axis  130  extending from the first end portion  124  to the second end portion  128 . 
         [0035]    The head  122  further comprises an annular flange  132  that extends radially from the shank  120 . The annular flange  132  may include a dome-shaped upper surface  134  and a flattened lower surface  136  that extends radially beyond the shank  120 . Although not featured, the head  122  may further include a protrusion that extends from the first end portion  124  of the shank  120 . The protrusion may be hemispherical in shape and adapted to be engaged by a striking tool to drive the fastener  100  into a substrate S 11 . The protrusion is adapted to receive significant force and is further adapted to deform as a result of the striking force. 
         [0036]    The head  122  also comprises an outer surface  138  adapted to be engaged by a gripping tool such as a wrench or a socket that may be used to apply torque to the fastener  100  to drive the fastener  100  into the substrate S 11 . In some embodiments, the outer surface  138  may be polygonally shaped. However, the outer surface  138  may be any shape that may be used with a variety of tools. Alternatively, the outer surface  138  does not need to be engaged to drive the fastener  100  into the substrate S 11 . For example, a hole may be pre-drilled in the substrate S 11  and the fastener  100  may be driven into the substrate S 11  using a striking tool to strike the head  122  and thereby insert the fastener  100  into the substrate S 11 . As described below, additional features of the fastener  100  facilitate insertion of the fastener  100  into the substrate S 11  using a driving force. By way of non-limiting example, the head  122  may have a square cross sectional shape having sides extending radially outwardly from the longitudinal axis  130 . Each side may extend from about 0.82 to about 0.88 inches in some embodiments. 
         [0037]    As shown in  FIG. 3 , the annular flange  132  extends radially from the longitudinal axis  130  of the fastener  100 . In some embodiments, the annular flange  132  extends beyond the circumference of the shank  120 . As shown in  FIG. 3 , the annular flange  132  has a diameter D 11  that is greater than a diameter D 12  and diameter D 13  of a threaded portion  150  of the shank  120  (described below). The annular flange  132  has a bottom surface  136 . The bottom surface  136  of the annular flange  132  comprises an abutment surface configured to abut the substrate S 11  into which the fastener  100  is driven so that the annular flange  132  is positioned above the substrate S 11  when the fastener  100  has been driven into the substrate S 11 . The annular flange  132  has a diameter that is wider than the cavity of the tie plate so that it rests on the tie plate bearing surface. 
         [0038]    By way of non-limiting example, the diameter D 11  may be about 1.75 inches and the diameter D 12  may be about 0.94 inches. The shank  120  may have an inner diameter D 13 . The inner diameter D 13  may be about 0.69 inches. In some embodiments, the diameter D 11  is about 1.9 times wider than the diameter D 12 , and the diameter D 11  is about 2.5 times wider than the inner diameter D 13 . In some embodiments, the diameter D 12  is about 1.4 times wider than the inner diameter D 13 . 
         [0039]    As shown in  FIG. 3 , the fastener  100  may also include a knurled section  144  adjacent to the annular flange  132 . In some embodiments, a shank transition section  140  may be included between the annular flange  132  and the knurled section  114 . The shank transition section  140  may be a result of manufacturing and machining tolerances, limitations, and capabilities where the knurled section  144  does not extend all the way to the annular flange  132 . The shank transition section  140  has a diameter that is less than diameter D 11  of the annular flange  132 . Although not featured in  FIG. 3 , the fastener may not include a shank transition section, according to some embodiments. In some embodiments, the knurled section  144  is disposed between the shank transition section  140  and a smooth section  146 . In some embodiments, the smooth section  146  is free from knurls, protrusions and threads. In some embodiments, the smooth section  146  has a length L 12  of about 0.2 inches. The knurled section  144  may be cylindrically shaped and may include a plurality of axial grooves and peaks. In some embodiments, the peaks may include a leading edge. The knurled section  144  is configured to allow the fastener  100  to be driven into the substrate S 11  and to resist removal for the fastener  100  from the substrate S 11 . The knurled section  144  has a diameter D 14  measured at the peaks that is slightly larger than the diameters D 12 , the inner diameter D 13 , and the diameter D 15  and less than the diameter D 11 . By way of non-limiting example, the diameter D 14  may be about 0.97 inches and a length L 11  of the knurled section  144  may be about 1.5 inches. For the knurled section  144  having a diameter D 14  of about 0.97 inches, the number of peaks is greater than  40 . The peaks may all be equal in size and shape extending around the shank  120 . In some embodiments, the depth of the grooves may be about 0.025 inches to about 0.035 inches. In some embodiments, the peaks extend substantially parallel to the longitudinal axis  130  of the shank  120 . 
         [0040]    In some embodiments, the shank  120  may also include a transition section (not shown) similar to the transition section  48  shown in  FIG. 1  and described above. The transition section extends between the smooth section  146  and a threaded portion  150 . In some embodiments, the transition section tapers inward from the knurled section  144  to threaded portion  150  so that the threads  152  can be rolled on the threaded portion  150 . In some embodiments, the transition section has a length L 12  that is less than about 0.1 inches. 
         [0041]    The shank  120  also includes the threaded portion  150  that includes one or more threads  152 . In some embodiments, the threads  152  may be helical fluted threads as shown in  FIG. 3 . The threads  152  extend from the smooth section  146  or the transition section where included to about the tip  126  of the shank  120 . The angle at the end of the threads  152  may be about 40° to about 50°, more preferably about 45°. In some embodiments, the threaded portion  150  may include  4  fluted threads  152 . 
         [0042]    Similar to  FIG. 5 , the width of each helical turn of the threads  152  at A 10 -A 10  is about 0.5 inches, although any width may be used. In some embodiments, a depth of the threads  152  protruding from the shank  120  is about 0.13 inches, although any depth may be used. 
         [0043]    In some embodiments, a length L 13  of the head  122  is about 1.25 inches. In some embodiments, the length of the outer surface  138  of the head  122  is about 0.88 inches. A Length L 13  represents the length that is positioned above the substrate S 11 . The length L 14  of the shank  120  from the knurled section  144  to the tip  126  is about 6.5 inches. The length L 14  represents the length of the fastener  100  that is inserted into the substrate S 11 . In some embodiments, the length of the fastener  100  may be about 7.75 inches and the knurled section  144  may be about ⅕ of the length of the fastener  100 . In some embodiments, the length L 14  may be about 5.2 times longer than the length L 13 . In some embodiments, the length of the smooth section  146  may be about 1/32 of the length of the fastener  100 . Other lengths and diameters for each of the dimensions described herein may be used and remain within the scope of the invention. 
         [0044]    In some embodiments, the fastener  100  comprises a metal, more preferably iron or steel, most preferably carbon steel, for example C1035. Any material suitable for forming and having sufficient strength for the fastener may be used as will be understood by one of skill in the art. 
         [0045]    Although the invention herein has been described in connection with a preferred embodiment thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions, and deletions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.