Roof drill bit with radial domed PCD inserts
OwnerWilliam J. Bradyinventor
Life of this patent
Estimating the term…
Abstract
A rotary drill bit having a head portion with at least two hard surfaced inserts having domed working surfaces and being oppositely oriented to face in the direction of rotation at positive rake angles, and a mounting adapter for removably securing the drill bit to a drilling machine.
Claims31
A rotary tool having a bit body with a shank portion constructed and arranged for attachment to a drill column for rotation on a central axis, and with a head portion constructed and arranged for drilling and boring as in roof bolting operations in tunnel construction and mining;
- at least two inserts each having a domed working surface formed from a super-abrasive material;
- said two inserts being rigidly mounted on said head portion and oppositely oriented with both of said domed working surfaces facing in the direction of rotation and being angularly disposed with the axis of each insert extending at a positive rake angle relative to an axially extending plane normal to the direction of rotation;
- and
- the domed surfaces having curved end caps disposed to define a predetermined bore diameter to be formed by the tool.
A rotary tool having a bit body with a shank portion constructed and arranged for attachment to a drill column for rotation on a central axis, and with a head portion constructed and arranged for drilling and boring as in roof bolting operations in tunnel construction and mining;
- at least two inserts each having a mounting base and a domed working surface formed on one end around a center axis, the working surfaces being formed from a super-abrasive material;
- said two inserts being constructed and arranged with the mounting bases rigidly mounted on said head portion, and being oppositely oriented with the axis of each said domed working surface extending angularly in the direction of rotation relative to the central axis of said bit body;
- and
- the outer rounded peak areas of said domed working surfaces being disposed to define a predetermined bore diameter to be formed by the tool.
A rotary tool having a bit body with a shank portion constructed and arranged for attachment to a drill column for rotation on a central axis, and with a head portion constructed and arranged for drilling and boring as in roof bolting operations in tunnel construction and mining;
- at least two inserts each having a domed working surface with a rounded peak end and being formed from a super-abrasive material;
- said two inserts being rigidly mounted on said head portion and oppositely oriented with both of said domed working surfaces facing in the direction of rotation and being angularly disposed with the axis of each insert extending at a negative skew angle relative to an axial plane normal to the direction of rotation;
- and
- the outer peak ends of said working surfaces being disposed to define a predetermined bore diameter to be formed by the tool.
A drill bit adapter for removably connecting a drill column and the shank portion of a roof drill bit having a bit body constructed and arranged for rotation on a central axis as for drilling and boring in roof bolting operations, the drill bit including at least two inserts each having a mounting base and a paraboloid PCD working surface formed around a center axis and being constructed and arranged for opposite orientation with the axis of each said paraboloid working surface extending angularly in the direction of rotation relative to the central axis of said bit body, and the outer rounded peak areas of said paraboloid working surfaces being disposed to define a predetermined bore diameter to be formed by the tool, the drill bit adapter comprising a first end for attachment to the drill column and a second end defining socket means constructed and arranged for removably receiving the shank portion of the drill bit, and other means constructed and arranged for channeling flushing fluids through the adapter from the drill column to the inserts.
Dependencies are inferred from the claim text.