Tool block

In combination:

• a tool block having a stop surface,
• a cutting insert holder movable on said tool block between clamping and non-clamping positions, said holder including means for mounting a cutting insert such that the insert is clamped against said stop surface when said tool holder is in said clamping position, and
• holder moving means for moving said insert holder into said clamping position and comprising:
• a lever having first and second portions and being rotatably mounted on said tool block intermediate said first and second portions,
• holder-engaging means at said first portion of said lever for engaging said holder and moving said holder to said clamping position in response to rotation of said lever in a first direction,
• biasing means arranged on said tool block for forcefully engaging said second portion of said lever to rotate said lever in said first direction so that said holder-engaging means moves said holder to said clamping position, and
• retracting means for retracting said biasing means to enable said lever to be rotated in a second direction opposite said first direction such that said holder is movable to said non-clamping position.