Drill bit
AssigneeMapal Fabrik fur Prazisionswerkzeuge Dr. Kress KG
InventorsUlrich Krenzer, Peter Marz
Life of this patent
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Abstract
The invention proposes a drill bit (1) leaving at least one main cutting edge (3, 3′) and at least one center cutting edge (15, 15′), wherein the drill bit (1) comprises a longitudinal axis (13), and wherein the at least one main cutting edge (3, 3′) and the at least one center cutting edge (15, 15′) are each assigned a rake face (7, 7′, 11, 11′). The drill bit (1) is characterized in that the rake face (11, 11′) assigned to the at least one center cutting edge (15, 15′) has at least two part faces (19, 19′; 21, 21′) which—as seen as perpendicular to the longitudinal axis (13) of the drill bit (1)—form an obtuse angle with one another, so that the at least one center cutting edge (15, 15′) comprises at least two part cutting edges (23, 23′; 25, 25′).
Claims13
Drill bit with at least one main cutting edge (3, 3′) and at least one center cutting edge (15, 15′), wherein the drill bit (1) has a longitudinal axis (13) and wherein a rake face (7, 7′;
- 11, 11′) is assigned-to the at least one main cutting edge (3, 3′) and at least one center cutting edge (15, 15′), characterized in that:
- the rake face (11, 11′) assigned to the at least one center cutting edge (15, 15′) has at least two partial faces (19, 19′;
- 21;
- 21′;
- 41;
- 41′) that—seen perpendicular to the longitudinal axis (13) of the drill bit (1)—form an obtuse angle with each other so the at least one center cutting edge (15, 15′) comprises at least two partial cutting edges (23, 23′;
- 25, 25′;
- 43, 43′), and
- a front rake angle is assigned to the one main cutting edge (3, 3′) and the at least two partial cutting edges (23, 23′;
- 25, 25′;
- 43, 43′) of the center cutting edge (15, 5′), wherein the front rake angle has a value that increases with increasing radial distance of the assigned main cutting edge and/or partial cutting edge (3, 3′;
- 23, 23′;
- 25, 25′;
- 43, 43′) with respect to the longitudinal axis of the drill bit (1).
Dependencies are inferred from the claim text.