Hole-drilling device for drilling hole with expanded diameter hole portion
AssigneeKabushiki Kaisha Miyanaga
InventorMasaaki Miyanaga
Life of this patent
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Abstract
A device for drilling a hole with an expanded diameter includes: a body, a shank; a sleeve; a compression spring; a drill bit body; an expanded diameter hole portion forming member attached to a side surface of the drill bit body and configured such that a cutting bit protrudes laterally from the drill bit body when the expanded diameter hole portion forming member moves forward on the side surface; a compression spring, which urges the expanded diameter hole portion forming member rearward relative to the drill bit body; and a cam. The expanded diameter hole portion forming member is configured to move forward on the side surface of the drill bit body owing to rotation of the cam when the body moves forward relative to the sleeve.
Claims4
A hole-drilling device for drilling a hole with an expanded diameter hole portion, the hole-drilling device comprising:
- a body including a shank at its rear part;
- a sleeve attached to a front part of the body such that the sleeve is movable relative to the body in a front-rear direction over a predetermined range, the sleeve including a contacting portion at its front end, the contacting portion coming into contact with a surface of a drilling object;
- a first urging unit that urges the sleeve forward relative to the body;
- a drill bit body provided with a drilling bit at its distal end, the drill bit body being configured such that a proximal end portion of the drill bit body is inserted in a bottomed insertion hole formed in the front part of the body, the drill bit body being inserted in and attached to the sleeve such that the drill bit body is movable in the front-rear direction;
- an expanded diameter hole portion forming member provided with a cutting bit at its distal end and attached to a side surface of the drill bit body such that the expanded diameter hole portion forming member is movable in the front-rear direction, the cutting bit protruding laterally from the drill bit body when the expanded diameter hole portion forming member moves forward on the side surface of the drill bit body;
- a second urging unit that urges the expanded diameter hole portion forming member rearward relative to the drill bit body;
- and
- a cam rotatably supported by the body and provided with contacting portions at both sides with respect to a rotation center, one of the contacting portions being contacted by a predetermined portion of an inner wall of the sleeve, the other contacting portion being contacted by a proximal end portion of the expanded diameter hole portion forming member, wherein
- the expanded diameter hole portion forming member is configured to move forward on the side surface of the drill bit body owing to rotation of the cam when the body moves forward relative to the sleeve.
Dependencies are inferred from the claim text.