Mine roof reinforcing system as load indicator

Abstract

A component and method for evaluating load at a mine roof. An embossed bearing plate and a reinforcing washer are combined to thereby form a bearing system, wherein the bearing plate is a grade 2 plate (“x−1”), the bearing plate including a back surface which is adapted to contact a mine roof, an opposite surface and an aperture through which a shaft portion of a bolt can extend, the reinforcing washer including a rigid member having a first surface shaped to contact and complement the opposite surface of the bearing plate, a second opposing surface and a washer hole for alignment with the aperture through which the shaft can extend; driving a bolt with the shaft through the bearing system into a location of the mine roof, and, inspecting a curl of the grade 2 plate, wherein the curl and uniformity thereof is indicative of a load of around 20,000 pounds at the location.

What is claimed is: 
     
         1 . A component for mine roof bolt system, comprising:
 an embossed bearing plate, wherein said bearing plate is a grade x−1 plate, said bearing plate including: a back surface which is adapted to contact a mine roof, an opposite surface; and, an aperture through which a shaft portion of a bolt can extend;   a non-spherical, reinforcing washer including a rigid member having: a first surface shaped to contact and complement said opposite surface of said bearing plate; a second opposing surface; and a washer hole for alignment with said aperture through which said shaft can extend; and,   wherein said reinforcing washer is combined with said bearing plate, wherein, instead of said grade x−1 plate failing in response to a load, said grade x−1 plate uniformly curls in response to said load, thereby forming a load indicator for said mine roof.   
     
     
         2 . The component of  claim 1 , wherein said rigid member transitions to a slightly tapered annulus, and said annulus extends to a substantially planar portion. 
     
     
         3 . The component of  claim 1 , wherein said grade x−1 plate is a grade 2 plate, and wherein a grade x plate is a grade 3 plate. 
     
     
         4 . The component of  claim 1 , wherein said grade x−1 plate is a grade 3 plate, and wherein a grade x plate is a grade 4 plate. 
     
     
         5 . The component of  claim 1 , wherein said grade x−1 plate is a grade 4 plate, and wherein a grade x plate is a grade 5 plate. 
     
     
         6 . A method for evaluating load at a mine roof, comprising the steps of:
 combining an embossed bearing plate and a reinforcing washer to thereby form a bearing system, wherein said bearing plate is a grade x−1 plate, said bearing plate including: a back surface which is adapted to contact a mine roof, an opposite surface; and, an aperture through which a shaft portion of a bolt can extend, said reinforcing washer including a rigid member having a first surface shaped to contact and complement said opposite surface of said bearing plate, a second opposing surface and a washer hole for alignment with said aperture through which said shaft can extend;   driving said bolt with said shaft through said bearing system into a location of said mine roof; and,   inspecting, visually, a curl of said grade x−1 plate at its corners, wherein said curl is indicative of a load at said location.   
     
     
         7 . The method of  claim 1 , wherein said grade x−1 plate is a grade 2 plate, and wherein a grade x plate is a grade 3 plate. 
     
     
         8 . The method of  claim 1 , wherein said grade x−1 plate is a grade 3 plate, and wherein a grade x plate is a grade 4 plate. 
     
     
         9 . The method of  claim 1 , wherein said grade x−1 plate is a grade 4 plate, and wherein a grade x plate is a grade 5 plate.