US 2016/0375500 A1Published application

Drill bit

AssigneeBlack & Decker Inc.

InventorsThomas R. KAYE, JR., David N. JOHNSON, Christian BLUEMEL

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Abstract

A drill bit has a shank, an intermediate shaft, and a cutting head and defines a longitudinal axis. The cutting head has a body having a front end, a rear end, and a peripheral sidewall, a primary cutting insert and a pair of auxiliary cutting inserts. The primary cutting insert is cross-shaped with a central portion with a cutting tip and four cutting arms each with a cutting edge extending radially outward from the central portion past the peripheral sidewall. The auxiliary cutting inserts are spaced radially outward from the central portion and circumferentially from the radial cutting arms, and have a cutting edge extending radially outward past the peripheral sidewall. A pair of primary dust egress slots and a pair of auxiliary dust egress slots are formed in the peripheral sidewall and configured to channel debris from the front end to the rear end of the body.

Claims25

Dependent claims

A drill bit comprising:

a shank having a rear end configured to be coupled to a rotary power tool;
an intermediate shaft defining a longitudinal axis and having a rear end coupled to a front end of the shank and at least one spiral flute;
and
a cutting head having:
a body having a rear end coupled to a front end of the intermediate shaft, a front end, and a peripheral sidewall:
a primary cutting insert coupled to a front end of the body, the primary cutting insert having a cross-shape with a central portion, and first, second, third, and fourth cutting arms extending radially outward from the central portion;
a pair of auxiliary cutting inserts coupled to the front end, each of the auxiliary cutting inserts spaced radially outward from the central portion and spaced circumferentially from each of the radial cutting arms, a first one of the auxiliary cutting inserts positioned between the first cutting arm and the second cutting arm and a second one of the auxiliary cutting inserts positioned between the third cutting arm and the fourth cutting arm;
a pair of primary dust egress slots formed in the peripheral sidewall of the body and extending from the front end of the body to the rear end of the body, a first of the primary dust egress slots positioned between the second and third cutting arms, and a second of the primary dust egress slots positioned between the first and fourth cutting arms;
and
a pair of auxiliary dust egress slots formed in the peripheral sidewall of the body and extending from the front end of the body to the rear end of the body, a first of the auxiliary dust egress slots positioned between the first and second cutting arms, and a second of the auxiliary dust egress slots positioned between the third and fourth cutting arms.

7 more elements

A cutting head for a drill bit comprising:

a body having a front end and a peripheral sidewall, and defining a longitudinal axis;
a primary cutting insert coupled to a front end of the body, the primary cutting insert having a cross-shape with a central portion, and first, second, third, and fourth cutting arms extending radially outward from the central portion;
a pair of auxiliary cutting inserts coupled to the front end, each of the auxiliary cutting inserts spaced radially outward from the central portion and spaced circumferentially from each of the radial cutting arms, a first one of the auxiliary cutting inserts positioned between the first cutting arm and the second cutting arm and a second one of the auxiliary cutting inserts positioned between the third cutting arm and the fourth cutting arm;
a pair of primary dust egress slots formed in the peripheral sidewall of the body and extending from the front end of the body to the rear end of the body, a first of the primary dust egress slots positioned between the second and third cutting arms, and a second of the primary dust egress slots positioned between the first and fourth cutting arms;
and
a pair of auxiliary dust egress slots formed in the peripheral sidewall of the body and extending from the front end of the body to the rear end of the body, a first of the auxiliary dust egress slots positioned between the first and second cutting arms, and a second of the auxiliary dust egress slots positioned between the third and fourth cutting arms.

3 more elements

A cutting head for a drill bit comprising:

a body having a front end, a rear end, and a peripheral sidewall, and defining a longitudinal axis;
a primary cutting insert coupled to a front end of the body, the primary cutting insert having a cross-shape with a central portion with a central cutting tip positioned on the longitudinal axis, and first, second, third, and fourth cutting arms each having a cutting edge extending radially outward from the central portion past the peripheral sidewall of the body;
a pair of auxiliary cutting inserts coupled to the front end, each of the auxiliary cutting inserts spaced radially outward from the central portion, spaced circumferentially from each of the radial cutting arms, and having a cutting edge extending radially outward past the peripheral sidewall of the body;
and
a plurality of dust egress slots formed in the peripheral sidewall and configured to channel debris from the front end to the rear end of the body.

2 more elements

Dependencies are inferred from the claim text.