Milling cutter and method of operating same, and other machine tools, and an adjustment mechanism therefor

A countersinking tool for finishing an existing hole in a workpiece to form a sealing seat, said countersinking tool comprising:

• a tool base body having a central, longitudinal axis of rotation;
• said tool base body comprising a shank being configured and disposed to be secured in a machine tool during operation and being configured and disposed to be set in a rotational motion about its central axis of rotation by a spindle;
• two front cutting inserts being configured and disposed to enlarge a diameter of a portion of a hole to a desired dimension;
• two rear cutting inserts being disposed axially set back from said two front cutting inserts along said longitudinal axis of said tool base body;
• said two rear cutting inserts being configured and disposed to further enlarge the diameter of the hole in a portion of the hole beyond the diameter of the hole formed by said two front cutting inserts;
• each of said cutting inserts being fastened to said tool base body by a clamping screw;
• said front cutting inserts being disposed on a front face of said tool base body and being disposed approximately 180° apart with respect to one another;
• said rear cutting inserts being disposed on said tool base body a distance away from said front face of said tool base body substantially along the longitudinal axis of said tool base body;
• said rear cutting inserts being disposed approximately 180° apart with respect to one another;
• said rear cutting inserts being disposed within a common chip space being shared with said front cutting inserts;
• each of said front cutting inserts and each of said rear cutting inserts comprising a cutting corner and a corresponding cutting side;
• each of said cutting corners being oriented toward its corresponding cutting side;
• each of said cutting sides being disposed on the periphery of said countersinking tool;
• each of said cutting corners being configured and disposed to engage a workpiece during machining;
• said cutting corners of said front cutting inserts and said cutting corners of said rear cutting inserts being disposed in different radial positions with respect to each other;
• said rear cutting inserts being larger than said front cutting inserts;
• said rear cutting inserts being configured and disposed to cut a larger hole circumference than said front cutting inserts to form a hole in said workpiece having a step which is configured to have a sealing element inserted thereon;
• said tool base body comprising insert seats being configured to receive each of said front cutting inserts and said rear cutting inserts;
• each of said insert seats comprising:
• supporting faces being configured to receive each of said front cutting inserts and said rear cutting inserts;
• an open portion toward the periphery of said tool base body being configured to receive said cutting side of cutting inserts;
• and
• a rear bearing wall substantially parallel to the longitudinal axis of said tool base body and being configured to receive a portion of said cutting insert opposite said cutting side;
• said front cutting insert seats comprising one lateral bearing wall and said front cutting insert seats being substantially open toward said front face of said tool base body;
• said rear cutting insert seats comprising two lateral bearing walls being substantially perpendicular to the longitudinal axis of said tool base body;
• said rear bearing wall of each of said rear cutting insert seats comprising a resiliently held web;
• each of said webs being a plate-like element and being connected to said tool base body on a fastening side only by a connection web portion;
• said tool base body comprising expanding slots being configured to separate a longitudinal side of said webs from said tool base body;
• adjusting screws being configured to be inserted into each of said expanding slots for fine adjustment of the radial position of each of said rear cutting inserts;
• each of said expanding slots comprising:
• a longitudinal leg;
• two transverse legs being disposed substantially transverse to said longitudinal leg;
• said longitudinal leg being disposed substantially parallel to said rear bearing wall;
• said transverse legs comprising:
• a first transverse leg being disposed substantially perpendicular to and between said longitudinal leg and said rear bearing wall;
• a second transverse leg being disposed substantially perpendicular to and between said longitudinal leg and said rear bearing wall and being disposed parallel to said first transverse leg;
• said tool base body further comprising an undercut being disposed to extend under said web at substantially oblique angles with respect to said longitudinal leg and each of said transverse legs and being disposed to extend from an area between said supporting face and said web at a substantially oblique angle toward said expanding slot;
• and
• each of said undercuts being disposed to extend more deeply in an axial direction into said tool base body than said expanding slot.