Patent ID: 7077606

Claim:
A drilling and chamfering arrangement for drilling and chamfering a countersunk hole in a workpiece, said arrangement comprising: a drill body; at least one cutting insert having a trapezoid shape and being configured and disposed to cut a countersunk hole; said at least one cutting insert comprising a first cutting insert comprising: a trapezoid-shaped upper side and a trapezoid-shaped underside opposite said upper side; a first angled side section comprising: a first flank and a first, active cutting edge; a second angled side section comprising: a second flank and a second, inactive cutting edge disposed diametrically opposite said first, active cutting edge; a front side section and a back side section disposed opposite one another and between said upper side and said underside; said back side section being longer than said front side section; and said back side section comprising a guide recess disposed to adjoin said underside; a chamfering collar being disposed around said drill body and being removably attached to said drill body; said chamfering collar comprising at least one seat being configured to seat a cutting insert; said at least one seat comprising a first seat being configured and disposed to seat said first cutting insert; said first cutting insert being removably attached to said chamfering collar at said first seat; said first seat having an interior edge being disposed immediately adjacent said drill body and being disposed to run parallel to said back side section of said first cutting insert; said first seat comprising a guide projection being disposed to project along a portion of said interior edge of said first seat; and said guide projection being matingly engaged with said guide recess of said first cutting insert to provide a friction fit between said first cutting insert and said first seat, and also being configured and disposed to prevent contact between said drill body and said first cutting insert.