Patent ID: 7832172

Claim:
A grating assembly having longitudinal and axial directions comprising: a plurality of axially spaced metal longitudinal deep bars; a plurality of longitudinally spaced upwardly opening notches formed in each metal deep bar; a plurality of longitudinally spaced metal axial crossbars each disposed in a plurality of the notches; a plurality of longitudinally spaced axial filler bars seated on the deep bars between the crossbars; a plurality of longitudinal joining bars joined to the crossbars and filler bars; a first set of aligned holes formed through the crossbars and filler bars including one hole formed through three of the crossbars; a second set of aligned holes formed through the crossbars and filler bars including one hole formed through three of the crossbars; a first one of the joining bars extending through the first set of holes; and a second one of the joining bars extending through the second set of holes.