Low profile cable bolt headers
View Patent ↗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; and
a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion;
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 dimension 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 dimension of said first section;
wherein said second section has a height dimension, in parallel to a central longitudinal axis of said roof bolt head, that is less than or equal to 0.75 inch;
wherein said first and second sections have a combined height dimension, in parallel to the central longitudinal axis of said roof bolt head, that is less than or equal to 1.75 inches;
wherein said first throughhole portion and said second throughhole portion form a common throughhole extending through said first and second sections; and
wherein said throughhole has a constant slope of 3° from vertical extending from said first end surface to said second end surface.
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; and
a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion;
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 dimension 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 the roof plate upon initial insertion of said first section into a roof hole and having a diameter larger than the outer cross-sectional dimension of said first section;
wherein said second section has a height dimension, in parallel to a central longitudinal axis of said roof bolt head, that is less than or equal to 0.75 inch;
wherein said first and second sections have a combined height dimension, in parallel to the central longitudinal axis of said roof bolt head, that is less than or equal to 1.75 inches;
wherein said first throughhole portion and said second throughhole portion form a common throughhole extending through said first and second sections; and
wherein said throughhole has a constant slope of 3° from vertical extending from said first end surface to said second end surface.
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, 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 dimension 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 dimension of said first section, wherein said second section has a height dimension, in parallel to the central longitudinal axis of said roof bolt head, that is less than or equal to 0.75 inch, wherein said first and second sections have a combined height dimension, in parallel to a central longitudinal axis of said roof bolt head, that is less than or equal to 1.75 inches, wherein said first throughhole portion and said second throughhole portion form a common throughhole extending through said first and second sections; and wherein said throughhole has a constant slope of 3° from vertical extending from said first end surface to said second end surface;
disposing the cable bolt body and the first section of the cable bolt head into the roof hole; and
rotating the second section of the cable bolt head with the 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; and
a first throughhole portion extending through said first section and forming an opening in said first end surface for accommodating a first bolt portion;
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 dimension 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 dimension of said first section;
wherein said second section has a height dimension, in parallel to a central longitudinal axis of said roof bolt head, that is less than or equal to 0.75 inch; and
wherein a portion of said second section has a diameter dimension, perpendicular to and centered on the central longitudinal axis of said roof bolt head, that is greater than or equal to 1.75 inches.