Drill and clean-out for blind holes

Claim 2

A clean-out drill for drilling in concrete, and cleaning out the dust and residue of drilling concrete from, blind holes of a selected diameter and depth comprising, in combination: an elongated cylindrical drill shank of a length greater than the selected depth of the blind hole and terminating at a cutting tip in cutter edges sized to provide a hole of the selected hole diameter, relief flutes extending helically of the drill shank from the cutter edges a distance greater than the selected depth of the blind hole, a flat, rigid washer providing a flat front side that serves as an abutment for automatically limiting depth of penetration of the drill shank, said washer having a central circular hole of a dimension only slightly greater than the selected diameter of the blind hole to provide a slip fit of the washer onto the drill shank to surRound the drill shank and the relief flutes, and weld means rigidly mounting the washer concentrically of the fluted drill shank and at a distance from the cutting tip corresponding to the selected depth of the blind hole, whereby the circular hole of the washer cooperates with the relief flutes surrounded by the washer to provide passageways through which the residue of drilling is caused to be discharged upon continuing the rotation of the drill after the flat front side of the washer abuts the surface of the body being drilled to terminate cutting by the drill''s cutting tip.

Claim 3

A clean-out drill for drilling, and cleaning out the residue of drilling from, blind holes of a selected diameter and depth comprising, in combination: an elongated cylindrical drill shank of a length greater than the selected depth of the blind hole and terminating at a cutting tip in cutter edges sized to provide a hole of the selected hole diameter, relief flutes extending helically of the drill shank from the cutter edges a distance greater than the selected depth of the blind hole, a washer with a central circular hole of a dimension slightly greater than the selected diameter of the blind hole, and means mounting the washer concentrically of the fluted drill shank and at a distance from the cutting tip corresponding to the selected depth of the blind hole, whereby the circular hole of the washer cooperates with the relief flutes surrounded by the washer to provide passageways through which the residue of drilling is caused to be discharged upon continuing the rotation of the drill after the washer abuts to terminate cutting by the drill''s cutting tip, said drill shank being initially of greater diameter than the selected diameter of the blind hole, the cutting tip and adjacent shank portion of the drill being reduced from said greater diameter to the selected diameter of the blind hole to provide shoulder means in a plane spaced from the cutting tip of the drill, the washer''s central circular hole being of lesser diameter than said shoulder means, and the washer being positioned to abut said shoulder means and being welded only at points of abutment between the washer and shoulder means so as to leave the passageways defined between the washer and relief flutes unobstructed.

Claim 4

A clean-out drill for drilling, and cleaning out the residue of drilling from, blind holes of a selected diameter and depth comprising, in combination: an elongated cylindrical drill shank of a length greater than the selected depth of the blind hole and terminating at a cutting tip in cutter edges sized to provide a hole of the selected hole diameter, relief flutes extending helically of the drill shank from the cutter edges a distance greater than the selected depth of the blind hole, a washer with a central circular hole of a dimension slightly greater than the selected diameter of the blind hole, and means mounting the washer concentrically of the fluted drill shank and at a distance from the cutting tip corresponding to the selected depth of the blind hole, whereby the circular hole of the washer cooperates with the relief flutes surrounded by the washer to provide passageways through which the residue of drilling is caused to be discharged upon continuing the rotation of the drill after the washer abuts to terminate cutting by the drill''s cutting tip, said drill shank being initially of greater diameter than the selected diameter of the blind hole, the cutting tip and adjacent shank portion of the drill being reduced from said greater diameter to the selected diameter of the blind hole to provide shoulder means in a plane spaced from the cutting tip of the drill, the washer''s central circular hole being of lesser diameter than said shoulder means, and the washer being positioned to abut said shoulder means and being welded only at points of abutment between the washer and shoulder means so as to leave the passageways defined between the washer and relief flutes unobstructed.