Tool adaptor having an insert receiving pocket and a fastening bore, and cutting tool assembly

A tool adaptor (20) having an adaptor axis (AA) defining an adaptor forward-to-rear direction (DF, DR), and comprising:

• a front retaining portion (22) having a base jaw (26), a clamping jaw (28), and an insert receiving pocket (30) located therebetween, the insert receiving pocket (30) having a lower support surface (32) and an opposing upper clamping surface (34), the lower support surface (32) defining a first plane (P1), and
• a rear mounting portion (24) located axially rearward of the front retaining portion (22), the rear mounting portion (24) having an axially rearward facing rear mounting surface (50) and a first fastening bore (54),
• wherein:
• the front retaining portion (22) includes a clamping bore (58) extending along a clamping axis (AC);
• a primary slot (42) separates the base jaw (26) from the clamping jaw (28) and merges with the insert receiving pocket (30);
• the clamping bore (58) has first and second clamping bore portions (58a, 58b) spaced apart by the primary slot (42);
• a secondary slot (52) transverse to the primary slot (42) separates the clamping jaw (28) from the rear mounting portion (24);
• and
• the first fastening bore (54) has a first bore axis (A1) which intersects the rear mounting surface (50) and the secondary slot (52).

A cutting tool assembly (74) comprising:

• a tool shank (76) longitudinally extending along a shank axis (AS) and comprising:
• a front mounting portion (78) having a front mounting surface (80) and a first shank bore (82) intersecting the front mounting surface (80);
• and
• a tool adaptor (20) removably secured to the tool shank's front mounting portion (78), the tool adaptor (20) having an adaptor axis (AA) defining an adaptor forward-to-rear direction (DF, DR), and comprising:
• a front retaining portion (22) having a base jaw (26), a clamping jaw (28), and an insert receiving pocket (30) located therebetween, the insert receiving pocket (30) having a lower support surface (32) and an opposing upper clamping surface (34), the lower support surface (32) defining a first plane (P1), and
• a rear mounting portion (24) located axially rearward of the front retaining portion (22), the rear mounting portion (24) having an axially rearward facing rear mounting surface (50) and a first fastening bore (54),
• wherein:
• a primary slot (42) separates the base jaw (26) from the clamping jaw (28) and merges with the insert receiving pocket (30);
• a secondary slot (52) transverse to the primary slot (42) separates the clamping jaw (28) from the rear mounting portion (24);
• and
• the first fastening bore (54) has a first bore axis (A1) which intersects the rear mounting surface (50) and the secondary slot (52);
• and wherein:
• the tool adaptor's rear mounting surface (50) interfaces the shank's front mounting surface (80), and
• a first fastening screw (84) occupies the adaptor's first fastening bore (54) and the shank's first shank bore (82) to secure the tool adaptor (20) to the tool shank (76).