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US 12,485,494 B2Granted
Spade drill bits
AssigneeBlack & Decker Inc.
InventorsPaulo Sergio Dos Santos Pelentir, Ricardo Casagranda Dendena
Life of this patent
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Abstract
A spade drill bit includes a shank extending along an axis from a rear end to a front end, the rear end configured to be coupled to a tool holder of a power tool, a blade including a paddle extending along the axis with a front portion and rear portion coupled to the front end of the shank, and a tip coupled to the front portion of the paddle. First and second primary cutting edges are disposed on a front edge of the front portion of the paddle and extend radially outward from the tip. At least the rear portion of the paddle is composed of a first steel alloy. The primary cutting edges are composed of a second steel alloy that has a greater hardness than the first steel alloy.
Claims20
A spade drill bit comprising:
- a shank extending along an axis from a rear end to a front end, the rear end configured to be coupled to a tool holder of a power tool;
- a blade including a paddle extending along the axis with a front portion and rear portion coupled to the front end of the shank;
- a tip coupled to the front portion of the paddle and extending along the axis;
- and
- first and second primary cutting edges disposed on a front edge of the front portion of the paddle and extending radially outward from the tip,
- wherein the paddle includes a first face with a first concave surface and a first convex surface on opposite sides of the axis, and a second face opposite the first face with a second concave surface and a second convex surface on opposite sides of the axis, the first concave surface opposite the first convex surface and the second concave surface opposite the second convex surface,
- wherein the first concave surface has a first portion closer to the first primary cutting edge with a first radius of curvature and a second portion closer to the rear portion with a second radius of curvature that is greater than the first radius of curvature,
- wherein the rear portion of the paddle is composed of a first steel alloy, and
- wherein the front portion of the paddle is composed of a second steel alloy that has a greater hardness than the first steel alloy.
6 more elements
A spade drill bit comprising:
- a shank extending along an axis from a rear end to a front end, the rear end configured to be coupled to a tool holder of a power tool;
- a blade including a paddle extending along the axis with a front portion and rear portion coupled to the front end of the shank;
- a tip coupled to the front portion of the paddle and extending along the axis;
- first and second primary cutting edges disposed on a front edge of the front portion of the paddle and extending radially outward from the tip;
- and first and second secondary cutting edges disposed on first and second chamfered corner edges of the front portion of the paddle, the first and second chamfered corner edges tapering radially outward and axially rearward from the first and second primary cutting edges toward the rear portion, wherein at least the rear portion of the paddle is composed of a first steel alloy, wherein the primary and secondary cutting edges are composed of a second steel alloy that has a greater hardness than the first steel alloy, wherein the paddle includes a first flat face with a first recessed surface extending rearward from the first primary cutting edge along at least a portion of the paddle, and a second flat face opposite the first face extending rearward from the second primary cutting edge along at least a portion of the paddle, the second recessed surface on an opposite side of the axis from the first recessed surface, and wherein each of the recessed surfaces is concavely curved with a first portion closer to the front edge of the paddle with a first radius of curvature and a second portion closer to the rear portion of the paddle with a second radius of curvature that is different from the first radius of curvature.
2 more elements
A spade drill bit comprising:
- a shank extending along an axis from a rear end to a front end, the rear end configured to be coupled to a tool holder of a power tool;
- a blade including a paddle extending along the axis with a rear portion coupled to the front end of the shank and a front portion coupled to a front end of the rear portion at a joint;
- an at least partially threaded frustoconical tip coupled to the front portion of the paddle;
- first and second primary cutting edges disposed on a front edge of the front portion of the paddle and extending radially outward from the tip;
- and
- first and second secondary cutting edges disposed on first and second chamfered corner edges of the front portion of the paddle, the first and second chamfered corner edges and tapering radially outward and axially rearward from the first and second primary cutting edges toward the rear portion;
- wherein the paddle includes a first face with a first concave surface disposed on a first side of the axis and extending rearward from the first primary cutting edge along at least a portion of the paddle, and a second face opposite the first face with a second concave surface disposed on a second side of the axis opposite the first side and extending rearward from the second primary cutting edge axis along at least a portion of the paddle, wherein the first concave surface has a first portion closer to the first primary cutting edge with a first radius of curvature and a second portion closer to the rear portion with a second radius of curvature that is greater than the first radius of curvature, and wherein the rear portion of the paddle is composed of a first carbon steel or low alloy carbon steel, and the front portion of the paddle, which includes the primary and secondary cutting edges, is composed of a second high chromium steel alloy or a high speed steel or tool steel alloy that has a greater hardness than the first steel alloy.
4 more elements
Dependencies are inferred from the claim text.