Patent ID: 6746176
Filing Date: 2004-06-08
Classification: E01C

Abstract:
A rig mat for bearing and distributing weight on a surface, the rig mat comprising:a top plate and a bottom plate, each plate having an exposed surface, an interior surface and a perimeter edge, and the plates being disposed in parallel alignment with the interior surfaces of the plates juxtaposed to define a grating space between them; a spacer grate disposed within the grating space, the spacer grate further comprising: a plurality of pultruded grating bars disposed in a parallel spaced relationship to each other, each grating bar having a length of at least about 2 feet, a width of about 0.6 inches and a height of about 1.5 inches, with the width and the height defining the cross-section of the grating bar that is substantially oblong, and the spaced relationship of the grating bars is about 2-times the width of the grating bar, and the length defining the dimension of the grating bar that is in parallel with the other grating bars, and having a plurality of rod apertures passing through a surface of the grating bar perpendicular to the width of the grating bar the rod apertures having a thickness and disposed in alignment for closely passing cross-rods therethrough, a plurality of cross-rods disposed in a parallel spaced relationship to each other and in perpendicular relationship to the grating bars, the cross-rods passing through and attached to the grating bars to fix the spaced relationship of the grating bars, and each cross-rod having two spacer-rods separated by a wedge-rod, the spacer-rods having an outer engagement surface and an inner flat surface, the outer engagement surface having spaced engaging means for engaging the grate bar where the cross-rod passes through the rod-aperture, the engagement means being a plurality of notches in the outer engagement surface, for closely engaging the thickness of the rod-aperture as the cross-rod passes through the grate bar the notches being spaced apart to fix the spaced relationship of the grating bars, and the inner flat surface for slidably interfacing with the wedge-rod, and the wedge-rod having two similar opposite interface surfaces for slidably contacting the two spacer-rods and separating the spacer-rods apart and two similar opposite curvilinear surfaces disposed to closely pass through the rod-apertures, an adhesive fixing the inner flat surface of the spacer-rod to the wedge rod and the notches to the grating bar, and the spacer grate contacting and fixed to the interior surfaces of the top and bottom plates; and an edge binder disposed to engage the perimeter edges of the plates.