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US 9,284,787 B2Granted
Drill bit and cutting head for drill bit
AssigneeBlack & Decker Inc.
InventorsAndreas Hammer, Steve Brocket, Christoph Gastinger, Christian Bluemel
Life of this patent
Estimating the term…
Abstract
A cutting head for a drill bit comprises four substantially identically shaped cutting arms extending radially from a common central axial point, each cutting arm comprising a cutting edge extending, outwardly and axially backwards from the common central axial point. The cutting edges are equianguiarly spaced apart from each other about the central axis of the cutting head. Each cutting, arm further comprises a side chamfer extending between its radially outer face and its rotationally trailing side face.
Claims20
A cutting head. for a drill bit, the cutting head comprising:
- a front end portion centered on a central axis of the cutting head;
- and
- at least four substantially identically shaped cutting arms extending radially outward from the front end portion a substantially identical radial distance from the central axis, and being substantially equiangularly spaced apart from each other about the central axis, each cutting arm including
- a cutting edge extending generally radially outward from the front end portion,
- a radially outer face extending generally axially rearward from a radially outermost end of the cutting edge,
- a leading face extending generally radially outward from, the front end portion and generally axially rearward of the cutting edge, and facing a rotational drilling direction of the cutting head,
- a trailing face extending generally radially outward from the front end portion and generally axially rearward of the cutting edge, and facing away from the rotational drilling direction of the cutting head, and
- a side chamfer surface extending at an angle between the radially outer face and the trailing face.
5 more elements
A cutting head for a drill bit, the cutting head comprising:
- a front end portion centered on a central axis of the cutting head;
- and
- at least four substantially identically shaped cutting arms extending radially outward from the front end portion a substantially identical radial distance from the central axis, and being substantially equiangularly spaced apart from each other about the central axis, each cutting arm including a cutting edge extending generally radially outward from the front end portion, each cutting edge including a first section, a second section, and a third section,
- wherein a first point angle is defined between the first section on a first of the cutting arms and the first section on a second of the cutting arms, a second point angle is defined between the second section on the first of the cutting arms and the second section on the second of the cutting arms, and a third point angle is defined between the third section on the first of the cutting arms and the third section on the second of the cutting arms, the first point angle being different from the second point angle, and the second point angle being different from the third point angle.
1 more element
A drill bit comprising:
- a fluted section defining a central axis;
- a cutting head coupled to an end of the fluted section, the cutting head including a front end portion centered on the central axis, and at least four substantially identically shaped cutting arms extending radially outward from the front end portion a substantially identical radial distance from the central axis, and being substantially equiangularly spaced apart from each other about the central axis,
- wherein each cutting arm includes a cutting edge extending generally radially outward from the front end portion, a radially outer face extending generally axially rearward from a radially outermost end of the cutting edge, a leading face extending generally radially outward from the front end portion and generally axially rearward of the cutting edge, and facing a rotational drilling direction of the cutting head, a trailing face extending generally radially outward from the front end portion and generally axially rearward of the cutting edge, and facing away from the rotational drilling direction of the cutting head, and a side chamfer surface extending at an angle between the radially outer face and the trailing face.
Dependencies are inferred from the claim text.