Dual diameter bushing/seal for mine roof bolt
AssigneeWaiamea Company, Inc.
InventorDavid C. Donan, Jr.
Life of this patent
Estimating the term…
Abstract
A bushing/seal assembly for providing an airtight seal between the shaft of a mine roof bolt and a roof bolt hole includes a body having first and second flexible skirts extending outwardly from the body, the diameter of the first skirt being less than the diameter of the second skirt in order to facilitate adequate sealing with both standard size and slightly overside roof bolt holes. A rigid stabilizing washer engages the flexible body, the roof bolt shaft and the wall of the roof bolt hole in order to prevent excessive tilting of the roof bolt assembly after anchoring thereof in the roof bolt hole.
Claims14
A bushing seal assembly for a mine roof bolt, said bushing seal assembly comprising in combination:
- a. a tubular body, said tubular body having an upper end and a lower end and also having a hole extending from the upper end to the lower end for receiving the shaft of a mine roof bolt, said mine roof bolt extending through said hole;
- b. seal means connected to said flexible body for producing an airtight seal between a shaft of said roof bolt and said flexible body;
- c. flexible upper skirt means connected to said flexible body around the outside surface of said flexible body for sealably engaging an interior wall of a first mine roof bolt having a first diameter to prevent entry of moist mine air from a mine tunnel into a portion of the first mine roof bolt hole located on the opposite side of said bushing seal assembly from said mine tunnel;
- d. flexible lower skirt means connected to said upper skirt means for sealably engaging an interior wall of a second mine roof bolt hole having a second diameter which is different than said first diameter to prevent entry of moist mine air from the mine tunnel into a portion of said second mine roof bolt hole located on the opposite side of said bushing seal assembly from said mine tunnel;
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- e. rigid stabilizing means disposed around said shaft of said mine roof bolt for engaging the wall of one of said first and second mine roof bolt holes in which said bushing seal assembly is to be installed to prevent said roof bolt shaft from moving close enough to said wall to prevent said first skirt and said second skirt from sealably engaging the wall of said one of said first and said second mine roof bolt holes.
Dependencies are inferred from the claim text.