Low profile cable bolt headers

Abstract

Improved roof cable bolts with reduced protrusion from a mine roof. Particularly, a roof cable bolt head can preferably be dimensioned such that most of its length fits inside a drilled hole in the mine roof.

1 . A low profile roof bolt head comprising:
 a first section adapted for insertion into a roof hole, said first section having a first end surface of the roof bolt head;   a second section adapted for accommodating a tightening tool, said second section having a second end surface of the roof bolt head, wherein said second end surface has an outer cross-sectional diameter;   a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion; and   a second throughhole portion extending through said second section and forming an opening in said second end surface for accommodating a second bolt portion;   said first section having an end portion opposite said first end surface, said first section tapering in outer cross-sectional diameter from said end portion to said first end surface;   wherein said second section has a roof plate contacting portion disposed adjacent said end portion of said first section for contacting a roof plate upon initial insertion of said first section into the roof hole and having a diameter larger than the outer cross-sectional diameter of said end portion of said first section;   wherein said outer cross-sectional diameter of said second end surface is less than the outer cross-sectional diameter of said end portion of said first section.   
     
     
         2 . A low profile roof cable bolt comprising:
 a cable bolt body;   a cable bolt head disposed at an end of said cable bolt body;   said cable bolt head comprising:   a first section adapted for insertion into a roof hole, said first section having a first end surface of the roof bolt head;   a second section adapted for accommodating a tightening tool, said second section having a second end surface of the roof bolt head, wherein said second end surface has an outer cross-sectional diameter;   a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion; and   a second throughhole portion extending through said second section and forming an opening in said second end surface for accommodating a second bolt portion;   said first section having an end portion opposite said first end surface, said first section tapering in outer cross-sectional diameter from said end portion to said first end surface;   wherein said second section has a a roof plate contacting portion disposed adjacent said end portion of said first section for contacting the roof plate upon initial insertion of said first section into a roof hole and having a diameter larger than the outer cross-sectional diameter of said first section;   wherein said outer cross-sectional diameter of said second end surface is less than the outer cross-sectional diameter of said end portion of said first section.   
     
     
         3 . A method of installing a low profile roof cable bolt, said method comprising the steps of
 providing a low profile roof cable bolt comprising:
 a cable bolt body; and 
 a cable bolt head disposed at an end of the cable bolt body, the cable bolt head comprising a first section adapted for insertion into a roof hole, said first section having a first end surface of the roof bolt head, a second section adapted for accommodating a tightening tool, said second section having a second end surface of the roof bolt head, wherein said second end surface has an outer cross-sectional diameter, and a first throughhole portion extending through said first section and forming an opening in said first end surface which accommodates the cable bolt body, a second throughhole portion extending through said second section and forming an opening in said second end surface for accommodating a bolt portion, said first section having an end portion opposite said first end surface, said first section tapering in outer cross-sectional diameter from said end portion to said first end surface, a roof plate contacting portion disposed adjacent said end portion of said first section for contacting a roof plate upon initial insertion of said first section into the roof hole and having a diameter larger than the outer cross-sectional diameter of said first section, wherein said outer cross-sectional diameter of said second end surface is less than the outer cross-sectional diameter of said end portion of said first section; 
   disposing the cable bolt body and the first section of the cable bolt head into a roof hole; and   rotating the second section of the cable bolt head with a tightening tool thereby rotating the cable bolt body within the roof hole.   
     
     
         4 . A low profile roof cable bolt comprising:
 a cable bolt body;   a cable bolt head disposed at an end of said cable bolt body;   said cable bolt head comprising:   a first section adapted for insertion into a roof hole, said first section having a first end surface of the roof bolt head;   a second section, said second section having a second end surface of the roof bolt head, wherein said second end surface has an outer cross-sectional diameter;   a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion; and   a second throughhole portion extending through said second section and forming an opening in said second end surface for accommodating a second bolt portion;   said first section having an end portion opposite said first end surface, said first section tapering in outer cross-sectional diameter from said end portion to said first end surface;   wherein said second section has a roof plate contacting portion disposed adjacent said end portion of said first section for contacting a roof plate upon initial insertion of said first section into the roof hole and having a diameter larger than the outer cross-sectional diameter of said first section;   wherein said outer cross-sectional diameter of said second end surface is less than the outer cross-sectional diameter of said end portion of said first section.