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Title: Mine roof support method and apparatus

Patent ·
OSTI ID:5723749

A rock formation, such as the roof of a mine tunnel, is reinforced by use of the apparatus of the invention to provide an anchor for a rock bolt which is tensioned to hold a support plate or similar structure in firm engagement with the face of the rock structure. The apparatus includes an elongated bar threadedly engaged with one end of an open, cylindrical coupling member, the other end of which is threaded to receive the rock bolt. One or more fixed members, preferably in the form of integral, dieformed ears, extend outwardly from the bolt shank a predetermined distance from the end of the threaded portion. Prior to threading into the coupling member the end of the bolt is inserted through an open, cylindrical collar having an internal radius greater than that of the bolt shank but less than the radial distance by which the fixed members project outwardly therefrom. The bolt is threaded into the coupling members until the collar is firmly engaged between the fixed members on the bolt shank and the end of the coupling member. Rotation of the bolt may thus be transmitted to the coupling member and bar to break a resin cartridge within a blind drill hole in the rock formation. After the resin grouting mix hardens sufficiently to prevent further rotation of the bar and collar sufficient torque is applied to the bolt to break at least one of the collar and fixed members, thereby permitting threaded advance of the bolt into the coupling member to bring a support plate into engagement with the surface of the rock formation surrounding the drill hole and tensioning the bolt to the desired degree.

Assignee:
Eastern Co
Patent Number(s):
US 4193715
OSTI ID:
5723749
Resource Relation:
Patent File Date: Filed date 12 May 1978; Other Information: PAT-APPL-905124
Country of Publication:
United States
Language:
English