Metal cutting tools

Claim 1

A METAL CUTTING TOOL COMPRISING IN COMBINATION A SHANK ADAPTED FOR CONNECTION TO A TOOL HOLDER, A BIT SUPPORT, MEANS MOUNTING SAID BIT SUPPORT ON SAID SHANK FOR ANGULR MOVEMENT BETWEEN AN OPERATIVE POSITION AND AN INOPERATIVE POSITION, A FIRST BORE FORMED IN ONE OF THE PARTS CONSTITUTED BY THE SHANK AND THE BIT SUPPORT, SAID FIRST BORE EXTENDING PARALLEL TO THE AXIS ABOUT WHICH THE BIT SUPPORT MOVES ANGULARLY, TO SECOND BORE EXTENDING THROUGH SAID ONE PART AND INTERSECTING SAID FIRST BORE, A PIN EXTENDING FROM THE OTHER OF SAID PARTS INTO SAID FIRST BORE, A MEMBER CLOSING ONE END OF THE SECOND BORE, AND A SPRING ACTING BETWEEN SAID MEMBER AND SAID PIN TO URGE SAID BIT SUPPORT TO ITS INOPERATIVE POSITION, THE ARRANGEMENT BEING SUCH, THAT IN USE, WHEN A BIT IS HELD IN THE BIT SUPPORT, AND ADVANCED RELATIVE TO THE WORK, THE PRESSURE BETWEEN THE WORK AND THE BIT WILL HOLD THE BIT SUPPORT IN ITS OPERATIVE POSITION AGAINST THE ACTION OF SAID SPRING BUT AS SOON AS CONTACT OF THE BIT RELATIVE TO THE WORK CEASES, THE SPRING WILL MOVE SAID BIT SUPPORT TO ITS INOPERATIVE POSITION IN WHICH THE BIT IS OUT OF CONTACT WITH THE WORK.