Self drilling roof bolt
AssigneeSandvik AB
InventorsSteven Lee Weaver, Michael Andrew McLean, Eric Ivan Johnson
Life of this patent
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Abstract
An elongate roof bolt includes a bolt body having an axially extending central bore and defining a leading end. The leading end includes a pair of axially extending abutment elements formed by machining. Each abutment element includes an abutment face for engagement with a drill tip on opposite sides thereof, to transmit rotary forces during drilling. The drill tip extends across the leading end of the bolt body and is bonded to the abutment elements by welding, soldering or brazing. The bore opens out of said bolt bonded adjacent said leading end.
Claims15
An elongate roof bolt comprising a bolt body and a drill tip attached thereto, the bolt body having an axially extending central bore and defining a leading end;
- said leading end including a pair of axially extending machined abutment elements, the abutment elements including respective abutment faces arranged for engagement with respective opposite sides of the drill tip to transmit rotary forces to the drill tip during drilling, said drill tip extending across said leading end and being bonded to the abutment elements, said bore opening out of said bolt adjacent said leading end.
Dependencies are inferred from the claim text.