Bar assembly for use in gratings

Abstract

A grating including a bar assembly having bearing bars with a unique cross section connected to one another with crossbars. The bearing bars are generally hourglass-shaped in cross section and include a first region, a second region, and a third region interposed therebetween. The first and second regions flare outwardly away from opposite ends of the third region. The ends of the first and second regions are of a first width and the third region is of a smaller second width. First and second side sections of the third region connect to each of the first and second regions at an angle of greater than 90 degrees. Channels for the crossbars are defined in a first end of the first region of the bearing bar or form a hole extending from a first side section to a second side section of the third region of the bearing bar.

What is claimed is: 
     
         1 . A bearing bar comprising:
 a rolled member adapted for use in a metal grating to support a plurality of crossbars, said rolled member having:
 a first region and a second region located opposite one another; 
 a third region extending between the first region and the second region; 
 a first corner and a second corner provided where the first region transitions to the third region; 
 a third corner and a fourth corner provided where the second region transitions to the third region; 
 wherein the rolled member has an area moment of inertia equal to or greater than an area moment of inertia of an industry standard metal grating bearing bar of rectangular cross section and having similar dimensions to the rolled member; and 
 wherein the rolled member has a section modulus equal to or greater than a section modulus of the industry standard metal grating bearing bar. 
   
     
     
         2 . The bearing bar according to  claim 1 , wherein the third corner is opposite the first corner and the fourth corner is opposite the second corner. 
     
     
         3 . The bearing bar according to  claim 1 , wherein the first corner, the second corner, the third corner, and the fourth corner are each greater than 90 degrees. 
     
     
         4 . The bearing bar according to  claim 1 , wherein, when the rolled member is of a width of about 1 inch, the area moment of inertia of the rolled member is about 0.0154 inches 4  relative to the area moment of inertia of the industry standard metal grating bearing bar of about 0.0142 inches 4 ; and the section modulus of the rolled member is about 0.0292 inches 3  relative to the section modulus of the industry standard metal grating bearing bar of about 0.0289 inches 3 . 
     
     
         5 . The bearing bar according to  claim 1 , wherein, when the rolled member is of a width of about 1¼ inch, the area moment of inertia of the rolled member is about 0.0303 inches 4  relative to the area moment of inertia of the industry standard metal grating bearing bar of about 0.028 inches 4 ; and the section modulus of the rolled member is about 0.046 inches 3  relative to the section modulus of the industry standard metal grating bearing bar of about 0.045 inches 3 . 
     
     
         6 . The bearing bar according to  claim 1 , wherein, when the rolled member is of a width of about 1½ inch, the area moment of inertia of the rolled member is about 0.0516 inches 4  relative to the area moment of inertia of the industry standard metal grating bearing bar of about 0.0486 inches 4 ; and the section modulus of the rolled member is about 0.066 inches 3  relative to the section modulus of the industry standard metal grating bearing bar of about 0.066 inches 3 . 
     
     
         7 . The bearing bar according to  claim 1 , wherein the rolled member is symmetrical about a midline located equidistant between a first end of the first region and a second end of the second region. 
     
     
         8 . The bearing bar according to  claim 1 , wherein bearing bar has a weight reduction of from about 11.89% up to about 33.88% compared to a corresponding industry standard bearing bar. 
     
     
         9 . The bearing bar according to  claim 1 , wherein the first region and the second region each comprises:
 an end;   a first side section and a second side section opposite one another and extending outwardly from opposite sides of the end; and   a third side section and a fourth side section opposite one another and extending outwardly at an angle from a respective one of the first side section and the second side section.   
     
     
         10 . The bearing bar according to  claim 9 , wherein the angle is equal to or greater than five degrees and equal to or less than fifteen degrees. 
     
     
         11 . The bearing bar according to  claim 9 , wherein the first side section and the second side section are substantially equal in height with one another, and wherein the third side section and the fourth side section are substantially equal in height with one another. 
     
     
         12 . The bearing bar according to  claim 9 , wherein the first side section and the second side section are substantially perpendicular to the end. 
     
     
         13 . The bearing bar according to  claim 1 , wherein the third region comprises:
 a first side section and a second side section opposite one another and extending between the first region and the second region; and   wherein the first side section and the second side section of the third region are substantially parallel and equal in height to one another.   
     
     
         14 . The bearing bar according to  claim 1 , wherein:
 an end of the first region and an end of the second region are of a first width;   wherein the first width is measured between a first side section and a second side section of the respective first region and second region;   wherein the third region is of a second width measured between a first side section and a second side section of the third region, and   wherein the second width is smaller than the first width.   
     
     
         15 . The bearing bar according to  claim 1 , further comprising at least one channel defined in the rolled member, said at least one channel being configured to receive a crossbar of the grating therein. 
     
     
         16 . The bearing bar according to  claim 15 , wherein the at least one channel is defined in a first end of the first region and extends for a distance inwardly into the first region and towards the second region. 
     
     
         17 . The bearing bar according to  claim 15 , wherein the at least one channel extends from a first side section of the first region through to a second side section of the first region. 
     
     
         18 . A bearing bar for a metal grating comprising:
 a rolled member having a first end and a second end opposite one another and spaced a distance apart substantially equal to a first height;   a third region extending between the first end and the second end;   wherein the first end and the second end are substantially equal in width to one another and are of a first width;   wherein the third region is spaced substantially equidistant from the first end and the second end;   wherein the third region is of a second width and the second width is less than the first width;   wherein the third region is connected to the first end via a side section which is oriented at an angle of more than 90 degrees relative to the third region; and   wherein the third region is connected to the second end via another side section that is oriented at an angle of more than 90 degrees relative to the third region.   
     
     
         19 . The bearing bar according to  claim 18 , further comprising:
 a first side and a second side opposite and substantially equal in height to one another and extending between the first end and the third region; and   a third side and a fourth side opposite and substantially equal in height to one another and extending between the second end and the third region.   
     
     
         20 . The bearing bar according to  claim 18 , further comprising at least one channel defined in the rolled member, said at least one channel configured to receive a crossbar of the grating therein.