Cutting insert adaptor and tool assembly

A cutting tool assembly comprising:

• an insert holder and a cutting insert adaptor;
• the insert holder comprising:
• opposite top and bottom sides;
• opposite first and second lateral sides connecting the top and bottom sides;
• opposite front and rear sides connecting the top, bottom, first lateral and second lateral sides;
• an elongated shank portion defining an elongation axis;
• and
• a cutting portion connected to the shank portion;
• a forward direction extending parallel with the elongation axis and from the shank portion towards the cutting portion, and a rearward direction opposite to the forward direction;
• an upward direction defined extending from the bottom side towards the top side and being perpendicular to the elongation axis, and a downward direction opposite to the upward direction;
• a first lateral direction extending from the first lateral side to the second lateral side and being perpendicular to both the elongation axis and the upward direction, and a second lateral direction opposite to the first lateral direction;
• and
• an insert pocket formed in the cutting portion at an intersection of the top side, front side and first lateral side, and comprising:
• a pocket base surface;
• and
• at least one pocket support surface extending upwardly from the pocket base surface;
• the cutting insert adaptor comprising:
• opposite adaptor top and bottom surfaces;
• an adaptor peripheral surface connecting the top and bottom surfaces, and comprising:
• a rearward-facing sub-surface;
• and
• a forward-facing sub-surface located on an opposite side of the adaptor peripheral surface to the rearward-facing sub-surface;
• the rearward-facing sub-surface comprising at least one pocket abutment surface;
• the forward-facing sub-surface comprising at least one insert abutment surface;
• a first leg;
• and
• a second leg connected to the first leg and extending non-parallel with the first leg;
• wherein:
• the cutting insert adaptor is mounted to the insert pocket such that the at least one pocket abutment surface abuts the at least one pocket support surface;
• the first leg comprises at least one of said insert abutment surfaces and at least one of said pocket abutment surfaces;
• the second leg comprises at least one other of said insert abutment surfaces and at least one other of said pocket abutment surfaces;
• and
• in a top view of the insert holder:
• each pair of opposing insert abutment surfaces and pocket support surfaces converge at a non-zero tool angle β fulfilling the condition:
• 0°<β≤30°;
• and
• each insert abutment surface is rotated relative to its opposing pocket support surface in the same rotational direction.

A cutting insert adaptor for an insert pocket, the cutting insert adaptor comprising:

• opposite adaptor top and bottom surfaces;
• an adaptor peripheral surface connecting the top and bottom surfaces, and comprising:
• a rearward-facing sub-surface;
• and
• a forward-facing sub-surface located on an opposite side of the adaptor peripheral surface to the rearward-facing sub-surface;
• the rearward-facing sub-surface comprising at least one pocket abutment surface;
• the forward-facing sub-surface comprising at least one insert abutment surface;
• a first leg;
• and
• a second leg connected to the first leg and extending non-parallel with the first leg;
• wherein:
• the first leg comprises at least one of said insert abutment surfaces and at least one of said pocket abutment surfaces;
• and
• the second leg comprises at least one of said insert abutment surfaces and at least one of said pocket abutment surfaces;
• and
• wherein, in a top view of the cutting insert adaptor:
• the insert adaptor's second leg is connected to the insert adaptor's first leg at a bend;
• in the first leg, the at least one insert abutment surface and the opposing at least one pocket abutment surface converge at a first non-zero adaptor angle, in a direction away from the bend;
• and
• in the second leg, the at least one insert abutment surface and the opposing at least one pocket abutment surface converge at a second non-zero adaptor angle, in a direction towards the bend.