Abstract:
A fastener with shaving inhibitor for fastening a material such as a metal sheeting panel to a substrate such as metal or wood. The fastener has a notch angled leftwardly with respect to an axis of the fastener, the notch having a first end and a second end, a leading face and a trailing face, each face having outer edges and a common edge at their intersection. At least one of the leading and trailing faces may be substantially planar but may have other shapes, such as concave. Leftwardly angled notch with faces having outer edges may attract and then cut shavings formed from material being installed, thereby reducing the quantity and/or length of shavings, prolonging the life of the material or the structure to which the material is fastened.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a fastener for use in applications where installation into a material may result in a shaving or shavings of the material being created. In particular, the present invention may be particularly well-suited to installation in steel or steel mounted on wood. 
     2. Description of the Related Art 
     Fasteners are routinely used to install metal panels, such as roofing panels, or to secure metal panels to wooden backings or supports. In addition, a washer such as a rubber waterproofing washer may be installed between the metal and the underside of the fastener head. 
     During the installation process, one or more shavings of material may be formed from the hole in the panel made by the fastener. These shavings may work their way outward and have multiple detrimental effects. For example, the shaving may abrade the panel or may enlarge the hole beyond the minimum amount necessary, removing rust barriers such as the paint that may be on the panel, which may contribute to premature corrosion of the panel. In addition, the shaving may either cut or otherwise damage the washer, or it may inhibit the washer from mounting flushly between the panel and the underside of the fastener head. In either case, this may create a leak path underneath the washer, which, in the example of a fastener located on a roofing structure, may lead to roof leaks and premature deterioration of the structure. 
     To alleviate this problem, in the past, an installer would expend extra labor by attempt to manually remove as many shavings as possible and/or by pre-punching holes in the panels. In addition to being time consuming, this process was limited by the fact that the installer likely would not be able to remove the entirety of each shaving since at least a portion of the shaving would have been compressed between the fastener and the substrate. As one indication of the widespread nature of this issue, during testing, a traditional gimlet-pointed fastener such as the type shown in  FIG. 2  may have created shavings approximately 73% of the time during testing on 26 gauge steel panels. 
     Several attempts have been made to minimize the production of shavings. As seen in  FIGS. 3-5 , these attempts include removing portions of the fastener near the tip. For example, one proposed solution was to use a “type 17 point” fastener having a flute near the tip that consists of two sides, one side extending axially, each side extending radially and at about a 90 degree angle to one another, as seen in  FIG. 3 . This design slightly reduced the prevalence of shavings being formed, but only to the frequency of about 50%. 
     Another attempt to minimize the presence of shavings includes using a fastener having a rightwardly angled flute, such as the one shown in  FIG. 4 . This structure, however, is even less favorable than the gimlet-pointed fastener of  FIG. 2 , actually resulting in more shavings being formed, i.e., about 78% of the time during testing. 
     In an additional variation, an “X-point” tip, such as the one shown in  FIG. 5  has been used. This X-point tip may be formed by axially offsetting two halves of a generally conical drilling tip. This arrangement results in fewer shavings being produced as compared to a traditional gimlet-pointed fastener. However, it still produces shavings about 20% of the time. 
     What is needed is a fastener that can be used to install materials such as steel roofing panels or steel panels mounted on wooden substrates and that reduces or minimizes the frequency of shavings being formed. 
     BRIEF SUMMARY OF THE INVENTION 
     In one embodiment, a fastener, comprising a body having a proximal end, a distal end and an axis, a head at the proximal end, a drilling tip at the distal end, a thread extending radially outwardly from the body, the thread having a first end spaced from the drilling tip and a second end spaced from an underside of the head, and a notch in the body and thread, the notch having a first end, a second end, a leading face and a trailing face, wherein the leading face and trailing face may be angled about 20 degrees leftward with respect to the axis, the second end may be spaced about 4/10 inch from the drilling tip, the leading face is generally concave, the trailing face is generally planar, and the trailing face is generally perpendicular to a plane that is tangent to the body at an intersection of the trailing face and the body. 
     In another embodiment, a fastener, comprising a body having a proximal end, a distal end and an axis, a head at the proximal end, a drilling tip at the distal end, a thread extending radially outwardly from the body, the thread having a first end spaced from the drilling tip and a second end spaced from an underside of the head, and a notch in the distal end of the body and in the thread, the notch having a first end, a second end, a leading face and a trailing face, wherein the leading face and the trailing face are angled leftward with respect to the axis. Each of the leading and trailing faces, as well as the intersecting edge between the faces, may be angled substantially similarly with respect to the axis, for example, between about 10 degrees and about 30 degrees leftward with respect to said axis, preferably about 20 degrees. In addition, at least one of the leading and trailing faces may be generally planar, although the leading face may be concave. Moreover, when the fastener is installed in a substrate, the leading face may direct a shaving formed from the substrate into the notch, and an outer edge of the trailing face may cut the shaving away from the substrate. 
     These and other features and advantages are evident from the following description of the present invention, with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a front view of one embodiment of the inventive fastener. 
         FIG. 2  is a prior art, gimlet-point tipped fastener. 
         FIG. 3  is a prior art fastener employing a Type 17 point. 
         FIG. 4  is a prior art fastener employing a rightwardly facing flute. 
         FIG. 5  is a prior art fastener employing an “X-point” tip. 
         FIG. 6  is an enlarged front view of a portion of the fastener of  FIG. 1 . 
         FIG. 7  is an enlarged section view of a portion of the fastener of  FIG. 1 . 
         FIG. 8  is an enlarged front view of a portion of a second embodiment of the inventive fastener. 
         FIG. 9  is an enlarged section view of a portion of the fastener of  FIG. 8 . 
         FIG. 10  is a depiction of the fastener of  FIG. 1  entering a steel member overlying a substrate. 
         FIG. 11  is a depiction of the fastener of  FIG. 10  fully engaged with the steel member and substrate. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS.  1  and  6 - 9 , several embodiments of a novel fastener  10  are shown. Fastener  10  is for use in a material  1 , such as steel, mounted on a member or substrate, such as a wooden substrate  3 . Steel may be between, e.g., about 30 gauge and about 22 gauge, or between about 0.012 inches and about 0.03 inches. Fastener  10  has features to discourage and interrupt the formation of long shavings  2  when fastener  10  is being installed into and/or through the metal  1  and/or metal  1  and substrate  3 . This may be particularly useful when a long shaving  2  would be detrimental to the assembly and life of an assembly or building that is being constructed. 
     The novel fastener  10  has an elongated body  20  with an axis  26 , an enlarged head  12  having torque transmitting surfaces  16  disposed thereon, a proximal end  22  proximate head  12 , a distal end  24 , and a drilling tip  30  proximate distal end  24 , generally opposite head  12  and having a length TL. Body  20  has a threaded exterior such as threading  32  having a crest diameter CD and a root diameter RD, wherein threading  32  may extend from a first end  34  proximate distal end  24  to a second end  36  proximate proximal end  12 . Fastener  10  may further include an unthreaded portion  44  having a length WS between an underside  14  of head  12  and second end  36  of thread  32 . In addition, fastener  10  may include a second thread  38  having a first end  40  and a second end  42 , wherein first end  40  of second thread  38  is proximate first end  34  of thread  32  and second end  42  of second thread  38  is proximate second end  36  of thread  32 . Preferably, thread  32  and second thread  38  have substantially similar pitches such that second thread  38  winds around body  20  in between turns of thread  32 . 
     Fastener  10  may have a notch  50  on drilling tip  30  and/or distal end  24 . Preferably, notch  50  is angled leftward with respect to axis  26  to shorten, reduce or substantially eliminate shavings  2  formed when fastener  10  is driven into steel  1 . Notch  50  may have a first end  52  and second end  54  and may include a leading face  56  and a trailing face  60 . First end  52  may be located on drilling tip  30 , and in one embodiment may be spaced about 0.02 inches from end  31  of drilling tip  30 . Notch  50  may also be on drilling tip  30 , but preferably notch  50  is longer than drilling tip  30  such that second end  54  may be located on distal end  24 . In this manner, the hole formed in steel  1  may be at its substantially widest before second end  54  of notch  50  passes through steel  1 , which means that no additional shaving or only minimal, small shavings may be formed after shaving  2  is removed by cutter  70 . Alternatively, fastener  10  may have a plurality of notches spaced axially and/or circumferentially along a length of fastener  10 . 
     Leading face  56  may have an outer edge  58 , trailing face  60  may have an outer edge  62 , and notch  50  may further include an edge or intersection  64  of the leading and trailing faces  56 ,  60 . Leading face  56  and trailing face  60  may be offset from each other so as to form an angle β between them. Preferably, β may be between about 30 degrees and about 120 degrees, more preferably between about 45 degrees and about 90 degrees. 
     Intersection  64  may be generally collinear with axis  26  or may be spaced from axis  26  a distance ID. Preferably, ID may be between about 0 and about RD/4, which may allow notch  50  to be deep enough to admit more of shaving  2  prior to shaving  2  being cut off. 
     Notch  50  may comprise a shaving director  66  to guide or force shaving  2  into notch to prepare to be cut. Notch  50  may further have a shaving attractor or entrance  68  through which shaving  2  may pass as shaving  2  passes director  66 . Entrance  68  may also provide clearance for shaving  2  to enter notch  50  as shaving  2  is formed. In addition, notch  50  may comprise a shaving cutter  70  to remove or detach shaving  2  from steel  1  or other material through which fastener  10  is driven as shaving  2  is formed. 
     Leading face  56  and trailing face  60  may each have a depth, LD and TD, respectively. As seen in  FIGS. 6-7 , trailing face  60  may be substantially planar and leading face  56  may be concave. In another embodiment, as shown in  FIGS. 8-9 , leading face  156  may be substantially planar and trailing face  160  may be concave. In this second embodiment, 100s prefixes are used to identify similar features in the embodiment of  FIGS. 6-7 . In addition, other combinations of planar and concave faces are within the scope of the invention. 
     Turning to  FIGS. 1 and 6 , trailing face  60  and, particularly, outer edge  62  may be angled leftward with respect to axis  26  to form an angle α between axis  26  and outer edge  62 . Angle α may be between about 0 degrees and about 45 degrees, and in one embodiment, as seen in  FIGS. 1 and 6 , α is about 20 degrees. Outer edge  58  of leading face  56  may form a similar angle with respect to axis  26  when measured proximate first end  52  of notch  50 . This slot or notch angle may position a cutting edge of fastener such as outer edge  62  in an optimum direction to cut shavings  2 . 
     In another embodiment, as seen in  FIG. 8  where trailing face  160  is concave, α may be about 15 degrees when measured at outer edge  62  proximate second end  154  of notch  150 . In addition, outer edge  158  of leading face  156  may form a similar angle with respect to axis  126 . 
     The use of fastener  10  with leftwardly angled notch  50  may reduce labor costs by reducing the time an installer may take to remove or sweep away shavings  2  in order to reduce an opportunity for rust or other corrosion in material  1  caused by the exposed material of the shaving  2 . In addition, fastener  10  may reduce the probability of roof leaks by eliminating leak paths and may further reduce the probability of roof leaks by reducing the occurrence of torn or otherwise damaged waterproofing fastener washers. In contrast to the prior art fasteners described above, fastener  10  surprisingly may reduce the occurrence of shavings  2  to a frequency of about 10% or less. 
     An exemplary fastener  10  of the type shown in FIGS.  1  and  6 - 7  may have the following dimensions. Fastener  10  may be between about 1 inch and about 3 inches long, preferably between about 1½ inches and about 2½ inches long, and in one embodiment about 2⅜ inches long. Fastener  10  may have a crest diameter CD of between about ⅛ inch and about ⅜ inch, preferably between about ⅛ inch and about ¼ inch, and in one embodiment about 3/16 inches. Fastener  10  may also have a root diameter RD of between about 1/16 inch and about 3/16 inches, and in one embodiment, about ⅛ inch. 
     Notch  50  may be sized and oriented so as to more effectively attract, cut and remove shavings  2  than fasteners having other features. Notch  50  may have a first end  52  depth FD between about 1/16 inch and about ⅛ inch from tip  31 , and in one embodiment about 0.08 inches from tip  31 , a second end  54  between about ¼ inch and about ½ from tip  31 , and in one embodiment about 0.4 inches from tip  31 . Fastener  10  may further have a distance ID of between about 0 inches and about 1/32 inch from intersection  64  and axis  26 , and in one embodiment about 0.02 inches from intersection  64  and axis  26 . In addition, notch  50  may have a maximum width NW between outer edge  58  of leading face  56  and outer edge  62  of trailing face  60 , forming shaving attractor or entrance  68 , of about 0.065 inches. Moreover, outer edge  62  of trailing face  60  may form an angle of about 20 degrees with respect to axis  26 . 
     These dimensions are exemplary, and other dimensions or embodiments may be within the scope of the invention. In addition, while dimensions have been provided, these dimensions may also be used to calculate proportions between elements of fastener  10  in order to modify fastener  10  and notch  50  for an intended purporse. Moreover, notch  50  may be used on various types of fasteners  10  having varied thread forms, which is beneficial as different types of fasteners may be employed for different applications. 
     Notch  50  may be formed in a number of ways. For example, notch  50  is preferably formed by milling fastener  10  using a milling cutter, which may allow for the formation of sharper corners at outer edge  58  of leading face  56 , intersection  64  and, preferably, at outer edge  62  of trailing face  60 , which may serve as shaving cutter  70 . 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific exemplary embodiments and methods herein. The invention should therefore not be limited by the above described embodiments and methods, but by all embodiments and methods within the scope and spirit of the invention as claimed.