Concrete fastener

Abstract

A fastener includes a shank having a first end and a second end defining a length. The fastener includes a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, the thread includes a leading edge and a trailing edge, each edge forming an angle with a surface of the shank, the leading edge forming a non-normal angle with the surface of the shank and the trailing edge forming an angle about normal to the surface of the shank. The fastener may include an arcuate detent region in the shank between respective turns of the thread, the detent region having a length, the length decreasing from the first end toward the second end between the respective turns. The fastener may include a plurality of flutes positioned along a length of the shank.

What is claimed is: 
     
         1 . A fastener, comprising:
 a shank having a first end and a second end defining a length; and   a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, wherein the thread extends from the first end adjacent to a tip of the shank, and a plurality of flutes are positioned along a length of the shank in the first region from the tip toward the head.   
     
     
         2 . The fastener of  claim 1  wherein each flute comprises a recessed region in the shank having a first side and a second side extending from the tip toward the head, and an end between the first side and the second side. 
     
     
         3 . The fastener of  claim 1  wherein each flute intersects at least two turns of the thread. 
     
     
         4 . The fastener of  claim 1  wherein the plurality of flutes are oriented equidistantly relative to a circumference of the shank. 
     
     
         5 . The fastener of  claim 1  wherein each of the plurality of flutes comprise a recessed region having a semi-circular cross section having a radius, and the plurality of flutes have the same radius. 
     
     
         6 . The fastener of  claim 1  wherein each of the plurality of flutes has a length which is positioned at an angle parallel to a center axis of the shank. 
     
     
         7 . The fastener of  claim 1  wherein a portion of the thread includes a sawtooth structure comprising a plurality of shell-shaped teeth in the first region. 
     
     
         8 . The fastener of  claim 1  wherein the thread includes a Sawtooth comprising a plurality of teeth each having a triangular leading edge followed by a shell-shaped trailing edge. 
     
     
         9 . A fastener, comprising:
 a shank having a first end and a second end defining a length; and   a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, the thread includes a leading edge and a trailing edge, at least a portion of the thread including a sawtooth structure comprising a plurality of shell-shaped teeth having a leading edge and a trailing edge intersecting the leading edge of an adjacent tooth of the structure.   
     
     
         10 . The fastener of  claim 9  wherein each leading edge has a triangular shape and each trailing edge has a shell-shape, the trailing edge having an arcuate top edge intersecting the leading edge of the adjacent tooth. 
     
     
         11 . The fastener of  claim 9  wherein each leading forms an angle normal to a surface of the shank. 
     
     
         12 . The fastener of  claim 9  wherein each leading forms an angle which is not normal to a surface of the shank. 
     
     
         13 . The fastener of  claim 10  wherein the sawtooth structure extends at least three turns of the thread from a tip of the shank at the first end toward the head at the second end. 
     
     
         14 . The fastener of  claim 10  further including a plurality of flutes are positioned along a length of the shank in the first region. 
     
     
         15 . A fastener, comprising:
 a shank having a first end and a second end defining a length;   a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, the thread includes a leading edge and a trailing edge, wherein the thread extends from the first end adjacent to a tip of the shank, and a plurality of flutes are positioned along a length of the shank in the first region from the tip toward the head; and   at least a portion of the thread including a sawtooth structure comprising a plurality of shell-shaped teeth having a leading edge and a trailing edge intersecting the leading edge of an adjacent tooth of the structure.   
     
     
         16 . The fastener of  claim 9  wherein each leading edge has a triangular shape and each trailing edge has a shell-shape, the trailing edge having an arcuate top edge intersecting the leading edge of the adjacent tooth. 
     
     
         17 . The fastener of  claim 15  wherein the thread includes a leading edge and a trailing edge, each edge forming an angle with a surface of the shank, the leading edge forming a non-normal angle and the trailing edge forming an angle normal to the surface. 
     
     
         18 . The fastener of  claim 15  wherein each flute comprises a recessed region in the shank having a first side and a second side extending from the tip toward the head, and an end between the first side and the second side. 
     
     
         19 . The fastener of  claim 15  wherein each flute intersects at least two turns of the thread. 
     
     
         20 . The fastener of  claim 15  wherein the plurality of flutes are oriented equidistantly relative to a circumference of the shank.