Roof drill bit, roof drill bit body and hard cutting insert for roof drill bit
AssigneeKennametal Inc.
InventorsChad A. Swope, Douglas E. Bise, Kris E. Strothmann, Tod D. Hill
Life of this patent
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Abstract
A roof drill bit has an elongate roof drill bit body, which has a forward end and a rearward end. The roof drill bit body contains a slot at the forward end. The roof drill bit body contains a dust port wherein the dust port has a central longitudinal dust axis. The roof drill bit further has a hard insert received within the slot wherein the hard insert has a leading surface. The leading surface of the hard insert is rotationally forward of the central longitudinal dust axis of the dust port.
Claims11
A roof drill bit comprising:
- an elongate roof drill bit body having a forward end and a rearward end, the roof drill bit body containing a slot at the forward end, and the roof drill bit body containing a dust port wherein the dust port having a central longitudinal dust axis;
- the roof drill bit further having a hard insert received within the slot, and the hard insert having a leading surface;
- and
- the leading surface of the hard insert being rotationally forward of the central longitudinal dust axis of the dust port.
A roof drill bit body comprising:
- an elongate body member having a forward end and a rearward end, the elongate body member containing a slot in the forward end thereof whereby the slot bisects the forward end of the elongate body member into opposite symmetric portions;
- the roof drill bit body further containing an interior bore therein;
- the roof drill bit body containing a pair of dust ports wherein each one of the dust ports corresponds with a corresponding symmetric portion;
- each of the symmetric portions having a twisted helical surface, and the twisted helical surface having an axial rearward termination at its corresponding dust port;
- each one of the twisted helical portions having a minimum transverse dimension;
- and
- the sum of the minimum transverse dimensions of the pair of the twisted helical portions being equal to the inside transverse dimension of the interior bore in the roof drill bit body.
A hard insert for use with a roof drill bit wherein the roof drill bit contains a roof drill bit body with a slot at the axial forward end thereof, the hard insert comprising:
- a hard insert body having a bottom surface with opposite transverse ends, and the bottom surface having one transverse surface adjacent one of the transverse ends and another transverse surface adjacent the other of the transverse ends, and the bottom surface having a mediate arched portion mediate of and contiguous with the one transverse surface and the other transverse surface.
Dependencies are inferred from the claim text.