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US 12,434,308 B2Granted
Step drill bit
AssigneeMilwaukee Electric Tool Corporation
InventorsDouglas W. Allen, Courtney D. McCool, Smith C. Theiler, Richard Hohnl, Jr.
Life of this patent
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Abstract
A drill bit includes a shank and a body portion defining a plurality of axially stacked, progressively sized steps. The steps include a first step and a terminal step. The first step defines two tip flutes each disposed at a tip flute angle. The body portion defines a body flute extending through the steps. The drill bit also includes an indicator band formed on a portion of the body flute and a portion of an outer surface of one of the plurality of steps.
Claims20
A drill bit comprising:
- a shank extending along a bit axis;
- a transition portion coupled to the shank;
- and
- a body portion having a distal end and defining a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step coupled to the transition portion, each step including an axial relief formed on an upper edge of the step, the body portion further defining a body flute extending from the first step to the transition portion;
- wherein a difference in hole diameters formed by each pair of adjacent steps of the plurality of steps is less than 0.1 inches;
- and
- wherein the axial relief of each step is between approximately 0.007 inches and approximately 0.021 inches.
4 more elements
A drill bit comprising:
- a shank extending along a bit axis;
- a body portion coupled to the shank, the body portion having a distal end and defining a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step nearer the shank than the first step, each step including an axial relief formed on an upper edge of the step, the body portion further defining a body flute extending from the first step to the terminal step;
- and
- a bit tip disposed at the distal end of the body portion and having a chisel edge intersecting the bit axis, a first chisel surface being on one side of the chisel edge, and a second chisel surface being on an opposite side of the chisel edge, the first chisel surface defining a first relief angle that is between 10 degrees and 20 degrees, and the second chisel surface defining a second relief angle that is between 25 degrees and 35 degrees;
- wherein a difference in hole diameters formed by each pair of adjacent steps of the plurality of steps is less than 0.1 inches.
2 more elements
A drill bit comprising:
- a bit tip;
- a shank opposite the tip and extending along a bit axis;
- and
- a body portion having a plurality of axially stacked, progressively sized steps between the bit tip and the shank, the plurality of steps including a first step adjacent the bit tip and a terminal step adjacent the shank, each step including an axial relief formed on an upper edge of the step, the body portion further defining a body flute extending from the first step to the shank, the body defining a length between the first step and the terminal step in a direction parallel to the bit axis;
- wherein a difference in hole diameters formed by each pair of adjacent steps of the plurality of steps is less than 0.1 inches;
- and
- wherein one step of the plurality of steps has a greater step height than a plurality of consecutive adjacent steps, wherein the plurality of consecutive adjacent steps includes at least six steps, wherein the plurality of consecutive adjacent steps is closer than the one step to the bit tip, and wherein the one step is positioned at least midway along the length measured in a direction from the first step to the terminal step.
4 more elements
Dependencies are inferred from the claim text.