Countersinking tool

In combination, a rotatable holder and a cutting insert for use with said holder as a countersinking tool, said cutting insert comprising:

• an inside surface portion comprising means for seating said insert on said holder;
• a first peripheral portion comprising first surface means for locating said insert on said holder;
• a second peripheral portion adjoining and extending at an angle to said first peripheral portion, said second peripheral portion comprising second surface means for locating said insert on the holder;
• a peripheral cutting side opposite said first peripheral portion;
• and at least one cutting edge portion on said peripheral cutting side;
• said holder having an axis of rotation and comprising:
• a seating surface lying in a plane parallel to the axis of said holder and comprising means cooperating with said first inside surface portion on the insert to seat said insert;
• a first locating means on the holder for engaging said first surface means on the first peripheral portion of the insert;
• and second locating means on the holder, separate and discrete from the holder's first locating means, for engaging said second surface means on the second peripheral portion of said insert;
• said locating means on said holder and said peripheral surface means on said insert cooperating to mount said insert in a disposition in which said cutting edge portion on the insert defines an inverted frusto-conical surface of revolution when the holder is rotated about its axis;
• said first and second locating means on the holder each comprise a respective surface converging toward a corner;
• and a hole in said holder at said corner;
• said hole having one open end at said seating surface and another open end, opposite said one open end at a peripheral surface portion on the holder remote from said seating surface;
• said hole comprising means for removing material from the vicinity of said seating surface.

In combination, a rotatable holder and a cutting insert for use with said rotatable holder as a countersinking tool:

• said cutting insert comprising a peripheral cutting side having at least one cutting edge portion;
• said holder having an axis of rotation and comprising a seating surface lying in a plane parallel to the axis of said holder and comprising means for seating said insert;
• locating means on said holder and on said insert cooperating to mount said insert in a disposition in which said cutting edge portion on the insert defines an inverted frusto-conical surface of revolution when the holder is rotated about its axis;
• said holder comprising a main body portion and an intermediate portion adjacent said main body portion;
• said main body portion and said intermediate portion each defining a respective surface of revolution when the holder is rotated about its axis;
• the surface of revolution defined by said cutting edge portion of the insert lying outside the surface of revolution defined by said intermediate portion;
• at least a part of said seating surface on the holder being located on said intermediate portion;
• said intermediate portion having a peripheral part which is indented, relative to said surface of revolution defined by the intermediate portion, and having an unindented part;
• said indented peripheral part being angularly spaced about 45.degree. from said seating surface by said unindented part and trailing the seating surface when said holder is rotated in a countersinking operation;
• said indented peripheral part extending on the intermediate portion to at least a portion of the seating surface and comprising means for accommodating axially advancing movement of said intermediate portion into a countersunk hole during a countersinking operation;
• said unindented part being indented relative to the surface of revolution defined by said cutting edge portion on the insert.

In combination, a rotatable holder and a cutting insert for use with said holder as a countersinking tool, said cutting insert comprising:

• an inside surface portion comprising means for seating said insert on said holder;
• an outside surface portion;
• an opening in said insert extending from said outside surface portion to said inside surface portion and comprising means for receiving a retaining pin;
• and a peripheral cutting side having at least one cutting edge portion;
• said holder having an axis of rotation and comprising:
• a seating surface lying in a plane parallel to the axis of said holder and comprising means cooperating with said inside surface portion of the insert to seat said insert;
• locating means on said holder and on said insert cooperating to mount said insert in a disposition in which said cutting edge portion on the insert defines an inverted frusto-conical surface of revolution when the holder is rotated about its axis;
• a hole extending from said seating surface of the holder through said holder at an angle to the axis of the holder;
• a retaining pin comprising a first portion received wherein said hole in the holder, said first pin portion being coaxial with said opening in the insert and said hole in the holder;
• said first pin portion having a larger diameter than the opening in the insert;
• means on said holder and on said pin mounting said pin for rotation about the axis of said first pin portion;
• a stud portion extending integrally from said first pin portion and receivable within said opening in the insert;
• said stud portion having an axis parallel to and offset from the axis of said first pin portion;
• said stud portion having a smaller cross-section than said first pin portion;
• said stud portion having means for engaging the sides of said opening to urge said insert in a direction transverse to the axis of its opening in response to rotation of said pin about the axis of said first pin portion.