Beam having internal tensioning and methods

Abstract

A structural support member is provided. The structural support member includes a tensioning mechanism for applying a preload to a beam member of the structural support member. The tensioning mechanism acting on a loading pin causing the beam member to bend.

1 . A structural beam arrangement comprising:
 a beam member extending longitudinally between opposed first and second ends;   at least one tensioning mechanism, the tensioning mechanism being attached to the beam proximate the first end at a first attachment location and the second end at a second attachment location; and   a first intermediate loading pin attached to the beam member at a third attachment location, the tensioning mechanism acting on the first intermediate loading pin to impart a first preload on the beam member between the first and second attachment locations such that the beam member is bent absent any additional external loading.   
     
     
         2 . The structural beam arrangement of  claim 1 , wherein the beam member has a vertical height that is generally perpendicular to a longitudinal length of the beam member, the first attachment location being at a different vertical height than the third attachment location, the second attachment location being at a different vertical height than the third attachment location, the first and second attachment locations being on the top vertical side of the first intermediate loading pin. 
     
     
         3 . The structural beam arrangement of  claim 2 , wherein the tensioning mechanism includes a continuous cable extending substantially between the first and second attachment locations, the continuous cable passing vertically below a bottom side of the first intermediate loading pin, the bottom side being opposite of the top side and facing generally vertically away from the first and second attachment locations. 
     
     
         4 . The structural beam arrangement of  claim 2 , wherein the tensioning mechanism includes a continuous cable extending substantially between the first and second attachment locations, the continuous cable passing through the first intermediate loading pin vertically below the top side of the first intermediate loading pin and vertically above a bottom side of the first intermediate loading pin, the bottom side being opposite of the top side and facing generally vertically away from the first and second attachment locations. 
     
     
         5 . The structural beam arrangement of  claim 1 , wherein the first intermediate loading pin is equally spaced between the first and second attachment locations in a direction parallel to a longitudinal length of the beam member extending between the first and second attachment locations. 
     
     
         6 . The structural beam arrangement of  claim 1 , wherein the first intermediate loading pin is unequally spaced between the first and second attachment locations in a direction parallel to a longitudinal length of the beam member. 
     
     
         7 . The structural beam arrangement of  claim 1 , wherein the tensioning mechanism includes a pair of tensioning rods, one of the tensioning rods extending between the first attachment location and the first intermediate loading pin and the other one of the tensioning rods extending between the second attachment location and the first intermediate loading pin. 
     
     
         8 . The structural beam arrangement of  claim 1 , further including a second intermediate loading pin, the first and second intermediate loading pins being offset from one another along a longitudinal axis extending the length of the beam member between the first and second attachment locations. 
     
     
         9 . The structural beam arrangement of  claim 8 , further including a second tensioning mechanism acting on the second intermediate loading pin to impart a second preload on the beam member. 
     
     
         10 . The structural beam arrangement of  claim 9 , wherein the second preload acts in a generally opposite direction as the first preload. 
     
     
         11 . The structural beam arrangement of  claim 10 , wherein the magnitudes of the first and second preloads are different. 
     
     
         12 . The structural beam arrangement of  claim 8 , wherein the first and second intermediate loading pins are at different vertical heights. 
     
     
         13 . The structural beam arrangement of  claim 1 , further including a second intermediate loading pin and a third intermediate loading pin, the first, second and third intermediate loading pins being offset from one another along a longitudinal length of the beam member extending generally between the first and second attachment locations. 
     
     
         14 . The structural beam arrangement of  claim 13 , wherein at least two of the intermediate loading pins are at different vertical heights relative to one another in a direction perpendicular to the longitudinal length. 
     
     
         15 . The structural beam arrangement of  claim 1 , wherein the tensioning mechanism includes an elongated rod attached to the beam member at the first and second attachment locations, the elongated rod passing vertically below the intermediate loading pin and the first and second attachment locations being vertically above the loading pin. 
     
     
         16 . The structural beam arrangement of  claim 15 , wherein at least one end of the elongated rod is threaded and includes a nut thereon, the nut operably acting on the beam member such that adjustment of the location of the nut relative to the elongated rod increases the magnitude of the preload. 
     
     
         17 . The structural beam arrangement of  claim 1 , wherein the tensioning mechanism includes a cable and a pair of attachment mechanisms, one of the attachment mechanisms operably coupled to beam member at the first attachment location and the other one of the attachment mechanisms operably coupled to the beam member at the second attachment location, the attachment mechanisms operably coupling the cable to the beam member, the cable acting on a first side of the loading pin, the attachment mechanisms being positioned on an opposite side of the loading pin as the side upon which the cable acts. 
     
     
         18 . The structural beam arrangement of  claim 17 , wherein at least one of the attachment mechanisms permits adjustment of the tension of the cable. 
     
     
         19 . The structural beam arrangement of  claim 18 , wherein at least one of the attachment mechanisms includes an eyebolt, one end of the cable being connected to the eyebolt, adjustment of the position of the eyebolt relative to the beam member adjusting the tension of the cable.