Thread cutting apparatus

Claim 1

CUTTING APPARATUS COMPRISING AN ASSEMBLY INCLUDING A MOTOR AND A CASING SECURED TO THE MOTOR, A SHAFT SUPPORTED IN SAID CASING FOR ROTATION ABOUT AN AXIS AND ADAPTED FOR BEING COUPLED TO SAID MOTOR TO BE DIRECTLY DRIVEN THEREFROM, A PIN, MEANS DETACHABLY SUPPORTING THE PIN IN THE SHAFT SUCH THAT THE PIN EXTENDS AXIALLY AND ECCENTRICALLY FROM SAID SHAFT TO A POSITION OUTSIDE THE CASING, A CUTTING ASSEMBLY PIVOTALLY SUPPORTED ON SAID CASING AND INCLUDING FIRST AND SECOND BLADE MEMBERS EACH HAVING A ROW OF TOOTH ELEMENTS, SAID SECOND BLADE MEMBER BEING RETAINED ON THE FIRST BLADE MEMBER WITH THE ROWS OF TOOTH ELEMENTS OF SAID BLADE MEMBERS ADJACENT ONE ANOTHER, SAID SECOND BLADE MEMBER BEING RETAINED ON THE FIRST BLADE MEMBER FOR SLIDING MOVEMENT IN A DIRECTION PARALLEL TO THE ROWS OF TOOTH ELEMENTS AND DRIVE BLOCK MEANS RETAINED BETWEEN SAID BLADE MEMBERS AND INCLUDING A PAIR OF EXPOSED SPACED FLANGES FACING THE PIN EXTENDING FROM SAID SHAFT, SAID FLANGES EXTENDING PERPENDICULAR TO THE DIRECTION OF SLIDING OF THE SECOND BLADE MEMBER AND DEFINING A SLOT THEREBETWEEN, SAID PIN EXTENDING INTO SAID SLOT BETWEEN THE FLANGES, SAID FLANGES BEING EACH IN ENGAGEMENT WITH SECOND BLADE MEMBER TO MOVE THE SECOND BLADE MEMBER RECIPROCALLY WITH RESPECT TO THE FIRST BLADE MEMBER AS THE SHAFT UNDERGOES ROTATION, SAID CUTTING ASSEMBLY BEING PIVOTABLY MOVABLE ON SAID CASING FROM A FIRST OPERATIVE POSITION WHEREIN SAID PIN IS ENGAGED IN SAID SLOT TO A SECOND INOPERATIVE POSITION AWAY FROM SAID PIN, SAID CASING BEING PROVIDED WITH AN OPENING WHICH PROVIDES ACCESS TO THE MEANS WHICH DETACHABLY SUPPORTS THE PIN IN THE SHAFT TO PERMIT SAID PIN TO BE REPLACED IN THE SHAFT FROM OUTSIDE THE CASING WHEN THE CUTTING ASSEMBLY HAS BEEN MOVED TO ITS INOPERATIVE POSITION.