Turn cutter with concave base surfaces and a holder for such a cutter

Claim 1

A CUTTING TOOL COMPRISING A HOLDER HAVING A FIRST BIT-SUPPORTING SURFACE, A SECOND BIT-SUPPORTING SURFACE DISPOSED AT AN ANGLE TO SAID FIRST SURFACE, A CUTTER BIT DISPOSED IN THE ANGLE BETWEEN SAID TWO BIT-SUPPORTING SURFACES AND ADAPTED TO BE TURNED AND TILTED INTO ADJUSTED WORKING POSITIONS WITH RESPECT TO SAID SURFACES, SAID BIT HAVING A PLURALITY OF CUTTING EDGES FOR RELEATIVE USE, A CLAMPING MEMBER LOCATED ADJACENT SAID BIT ON THE SIDE THEREOF TOWARD SAID SECOND SURFACE, SAID BIT BEING PROVIDED WITH A RRECESS IN ITS SIDE TOWARD SAID CLAMP, SAID CLAMP HAVING A PROJECTION EXTENDING INTO SAID RECESS ANGULARLY INWARDLY IN THE DIRECTION OF SAID FIRST SURFACE, AND MEANS FOR PRESSING SAID CLAMP TOWARD SAID FIRST SURFACE WHEREBY SAID PROJECTION PRESSES SAID BIT TOWARD SAID FIRST BIT-SUPPORTING SURFACE, AND DUE TO ITS ANGULAR DIRECTION OF EXTENT, ALSO DRAWS SAID BIT TOWARD SAID SECOND BIT-SUPPORTING SURFACE, SAID HOLDER BEING PROVIDED WITH A THIRD BIT-SUPPORTING SURFACE ARRANGED AT AN ANGLE TO EACH OF SAID TWO OTHER BIT-SUPPORTING SURFACES, AND A SECOND CLAMPING MEANS PRESSING SAID BIT TOWARD SAID THIRD SURFACE, SAID BIT ALSO HAVING ANOTHER RECESS IN ANOTHER SIDE FOR CLAMPING COOPERATION WITH SAID PROJECTION WHEN SAID BIT IS MOUNTED IN SAID HOLDER IN POSITION FOR CUTTING WITH A DIFFERENT ONE OF ITS CUTTING EDGES.