Steel truss fasteners for multi-positional installation

Abstract

The invention is directed generally toward a fastener for use in assembly of steel truss members which can be installed at an angular orientation relative to the truss member surface. The fastener comprises a shank having a tip and a head. The fastener shank further has threaded portions for engaging truss members and plate elements if present. The tip of the shank can have a self-tapping point. The head of the fastener has a tool engagement surface and a seating surface. The seating surface has a configuration that allows for a wider distribution of force at a truss assembly contact point. In particular, the configuration includes an arcuate contour that is generally convex.

1 . A truss fastener for multi-positional installation comprising: 
 a head and a shaft having a center axis extending between a tip and the head, said shaft having a first threaded portion and a second threaded portion, said first threaded portion being proximate the tip, and said second threaded portion being proximate the head, the head having a top surface, a tool engagement surface, and a lower surface, the lower surface having an arcuate contact surface which extends between the shaft and an edge of the head.    
     
     
         2 . The truss fastener for multi-positional installation of  claim 1  wherein the arcuate contact surface has arcuate portions from about 50 to about 25° relative to the shaft center axis.  
     
     
         3 . The truss fastener for multi-positional installation of  claim 1  wherein the arcuate contact surface has an arcuate portion proximate the edge of the head of about 20° relative to the shaft center axis.  
     
     
         4 . The truss fastener for multi-positional installation of  claim 3  wherein the arcuate contact surface has an arcuate portion proximate the edge of the shaft attachment of about 10° relative to the shaft center axis.  
     
     
         5 . The truss fastener for multi-positional installation of  claim 1  wherein the first and a second threaded portions are buttress threads.  
     
     
         6 . The truss fastener for multi-positional installation of  claim 1  wherein said arcuate contact surface is axially symmetrical about said center axis.  
     
     
         7 . A truss fastener and truss member arrangement comprising: 
 a shaft having a center axis extending between a tip and a head, said shaft having a first threaded portion and a second threaded portion, the head having a top surface, a tool engagement surface, and a lower surface defining an arcuate contact surface, said arcuate contact surface extends between the shaft and an edge of the head; and    a truss member having a first surface, said truss member engaged with the first threaded portion and the second threaded portion such that the center axis of the shaft is at an angle oblique to the first surface, and said first surface is in contact with a portion of the arcuate contact surface.    
     
     
         8 . The truss fastener and truss member arrangement of  claim 7  wherein the arcuate contact surface has arcuate portions from about 50 to about 25° relative to the shaft center axis.  
     
     
         9 . The truss fastener and truss member arrangement of  claim 7  wherein the arcuate contact surface has an arcuate portion proximate the edge of the head of about 20° relative to the shaft center axis.  
     
     
         10 . The truss fastener and truss member arrangement of  claim 7  wherein the arcuate contact surface has an arcuate portion proximate the shaft of about 10° relative to the shaft center axis.  
     
     
         11 . The truss fastener and truss member arrangement of  claim 7  wherein a portion of the arcuate contact surface defines an arcuate pathway between the shaft and the edge of the head such that about 10% of the arcuate pathway is in contact with the first surface.  
     
     
         12 . The truss fastener and truss member arrangement of  claim 11  wherein portions of the arcuate pathway have an angle from about 50 to about 25° relative to the shaft center axis.  
     
     
         13 . The truss fastener and truss member arrangement of  claim 7  wherein said first threaded portion is a buttress thread and is proximate the tip, and said second threaded portion is a buttress thread and is proximate the head, said second threaded portion being engaged with a portion of the first surface of the truss member and said first threaded portion being engaged with a portion of a second surface of the truss member.  
     
     
         14 . The truss fastener and truss member arrangement of  claim 7  wherein a plate is interposed between the arcuate contact surface and the truss member first surface.  
     
     
         15 . The truss fastener and truss member arrangement of  claim 13  wherein said first threaded potion is further engaged with a plate.  
     
     
         16 . A truss assembly comprising: 
 a chord member having opposite first and second walls defining a longitudinally extending channel, said first and second walls having first and second openings, respectively, said second opening being substantially radially oblique said first opening;    a tubular member disposed in said channel, said tubular member defining a longitudinally extending cavity and having third and fourth openings, said third and fourth openings being aligned with said first and second openings, respectively;    a fastener comprising:    a head comprising a top portion and an underside disposed adjacent said chord member, said underside having a symmetrically arcuate configuration; and    a shaft integrally extending from said underside through said first and third openings, said cavity, and said fourth and second openings, and terminating at a distal tip, said shaft comprising a proximal portion having a thread, a distal portion having a thread, an unthreaded shaft portion intermediate said proximal and distal portions, and self-drilling means adjacent said distal tip allowing self-drilling into said chord member and said tubular members;    wherein said thread of said proximal portion engages said chord member and said tubular member adjacent said first and third openings, said shaft portion is disposed in said cavity, and said thread of said distal portion engages said chord member and said tubular member adjacent said second and fourth openings.