Automatic shut-off tool

Claim 1

IN AN AUTOMATIC SHUT-OFF TOOL OF THE CHARACTER DISCLOSED, A DRIVE SPINDLE, A MOTOR FOR ROTATING SAID DRIVE SPINDLE, A ROTATABLE TOOL HOLDER HAVING A CAMMING CLUTCH, JAW, AN OPERATIVE CONNECTION BETWEEN SAID DRIVE SPINDLE AND SAID TOOL HOLDER COMPRISING A DRIVE CLUTCH JAW MEMBER CONTINUOUSLY MESHING WITH SAID CAMMING CLUTCH JAW, A TORQUE SPRING NORMALLY BIASING SAID JAWS TO FULL MESH WITH EACH OTHER, A DRIVE ELEMENT BETWEEN SAID DRIVE SPINDLE AND SAID DRIVE CLUTCH JAW MEMBER AXIALLY MOVABLE BY ENGAGEMENT OF A TOOL ELEMENT IN SAID TOOL HOLDER WITH THE WORK, A NORMALLY INOPERATIVE CONTROL MEANS FOR SAID MOTOR, AN OPERATIVE CONNECTION BETWEEN SAID DRIVE ELEMENT AND SAID CONTROL MEANS TO RENDER THE LATTER OPERABLE WHEN SAID DRIVE ELEMENT IS MOVED AXIALLY BY ENGAGEMENT OF THE TOOL ELEMENT WITH THE WORK, AND MEANS FOR RELEASING SAID CONTROL MEANS TO RETURN TO NORMALLY INOPERATIVE POSITION UPON SAID JAWS CAMMING TO A PARTIALLY UNMESHED POSITION RESPONSIVE TO PREDETERMINED TORQUE OF THE WORK, SAID LAST MEANS BEING MECHANICALLY ACTUATED BY THE RELATIVE MOVEMENT OF SAID JAWS DURING THE CAMMING ACTION AND AT A POINT IN SUCH ACTION SHORT OF UNMESHING OF SAID JAWS.