Patent ID: 7166349
Filing Date: 2007-01-23
Classification: D04H,Y10T

Abstract:
1. A protection grid for mining purposes, comprising: first and second groups of parallel, load-bearing strands, wherein the strands of the first group extend in a longitudinal direction of the grid and the strands of the second group extend transversely to the longitudinal direction of the grid and the strands of both groups are joined together at their points of intersection, and wherein the grid alternatingly includes first portions and second portions disposed adjacently with respect to one another and which extend at least in the direction of the strands of one of the two groups, wherein the strands of one of the two groups have a large spacing in the first portions between the strands and a small spacing in the second portions between the strands, said large spacing being larger in extent than said small spacing, wherein said large spacing is repeated substantially throughout said first portions and said small spacing is repeated substantially throughout said second portions, and wherein a tensile strength of each of said second portions is higher than a tensile strength of each of said first portions to allow for said second portions to be fastened to, and support a tensile load from, a wall or roof of a mining structure, wherein an extent of each of the first portions is approximately two to six times as great as an extent of each of the second portions in the transverse direction of the grid, wherein the large spacing between the strands in the first portions is approximately three to ten times a width of a strand, and wherein said width of a strand is in a range of approximately 5 mm to 16⅔ mm.