Patent ID: 6481938
Filing Date: 2002-11-19
Classification: B23B,Y10S,Y10T

Abstract:
A drilling tool comprising a rotary shaft and a cutting body detachably connected by a fastening screw in a seat formed in a front surface of the shaft;the seat including first and second spaced-apart protrusions projecting forwardly from a bottom surface of the seat and disposed on opposite sides of a center axis of the shaft; the protrusions including respective first and second inner surfaces facing one another; the first protrusion including a screw-threaded first hole extending into the first inner surface; the second protrusion including a supporting shoulder projecting from an end of the second inner surface located remotely from the first protrusion; the supporting shoulder including a first supporting surface facing generally in the same direction as the second inner surface, and a first abutment surface facing in a direction generally laterally of the direction in which the second inner surface faces; the first abutment surface facing generally in a direction toward an end of the second protrusion located proximate the first protrusion; a distance between the second inner surface and the first supporting surface defining a thickness of the supporting shoulder; the cutting body forming a cutting edge structure and including first and second flank parts disposed adjacent the first and second protrusions, respectively; the cutting body including first and second outer side surfaces facing the first and second inner surfaces, respectively; the second flank part including a recess in which the supporting shoulder is received, the recess including a second abutment surface, and a second supporting surface respectively facing the first abutment surface and the first supporting surface; a depth of the recess being less than the thickness of the supporting shoulder, wherein the first and second supporting surfaces abut one another, and the second side surface is spaced from the second inner surface; the first flank part including a non-threaded second hole extending therethrough and passing through the first and second side surfaces, wherein the fastening screw extends through the second hole and is threadedly secured in the first hole; the first and second holes being slightly non-aligned wherein a tightening of the fastening screw applies a first force pressing the first inner surface and the first side surface against one another and a second force pressing the first and second abutment surfaces against one another.