Radially balanced rotary drill
AssigneeSandvik Aktiebolag
InventorKurt H. A. E. Faber
Life of this patent
Estimating the term…
Abstract
A rotary drill comprises a shank, two axially extending chip removal recesses, and at least two radially oriented cutting inserts. One insert is peripherally located and is arranged adjacent one of the chip removal recesses. The edge of the peripheral insert extends radially so as to form the wall of the hole to be drilled. Another insert is located radially inwardly of the peripheral insert and is arranged adjacent the other chip removal recess. The inserts extend axially to generally the same extent. The inner insert is offset from a 180 degree relationship with the peripheral insert by an angle, which angle is of such magnitude that the drill is radially balanced.
Claims15
A drill for cutting holes comprising:
- a shank,
- two axially extending chip removal recesses, and at least two radially oriented cutting inserts,
- one insert being peripherally located and arranged adjacent one of said chip removal recesses, the edge of said one insert extending radially such as to form the wall of the hole, and
- another of said inserts being located radially inwardly of the cutting circle of revolution of said one insert and arranged adjacent the other chip removal recess,
- said inserts extending axially to generally the same extent,
- said other insert being offset from a 180 degree relationship with said one insert by an angle .gamma., wherein .gamma. is of such magnitude that the drill is radially balanced.
A method of radially balancing a hole-cutting drill comprising:
- providing a drill including a shank, two axially extending chip removal recesses, and at least two radially oriented cutting inserts, one insert being peripherally located and arranged adjacent one of said chip removal recesses, the edge of said one insert extending radially so as to form the wall of the hole, another of said inserts being located radially inwardly of the cutting circle of revolution of said one insert and arranged adjacent the other chip removal recess, said inserts extending axially to generally the same extent, and
- orienting said inserts such that said other insert is offset from a 180 degree relationship with said one insert by an angle .gamma., wherein .gamma. is of such magnitude that the resultants of the tangential and radial forces acting on the inserts are equal, opposite, and parallel, so that the drill is radially balanced.
Dependencies are inferred from the claim text.