Master arbor for milling machines

Claim 1

IN A MILLING MACHINE WITH A POWER DRIVEN SPINDLE HAVING THERETHROUGH A TAPERED BORE TERMINATING IN AN AXIAL BORE, AN EXTERIORLY TAPERED MASTER ARBOR NESTED IN SAID TAPERED BORE AND PROJECTING FROM THE SPINDLE, SAID MASTER ARBOR TERMINATING IN A CYLINDRICAL PORTION NESTED IN SAID AXIAL BORE AND INCLUDING AN INNER FIRST BORE EXTENDING FROM ONE END THEREOF AND A COMMUNICATING COUNTERBORE EXTENDING FROM ITS OTHER END; THE IMPROVEMENT COMPRISING AN EASILY REMOVABLE AND INTERCHANGEABLE TOOL ARBOR HAVING AN ELONGATED SHANK ADAPTED TO REMOVABLY MOUNT A CUTTING TOOL THEREON AND A CYLINDRICAL BODY AT ONE END OF SAID SHANK, REMOVABLY NESTED WITHIN SAID COUNTER BORE SPACED FROM ITS INNER END OPERATIVELY ENGAGING THE MASTER ARBOR AND INCLUDING AN AXIAL INTERNALLY THREADED BORE COMMUNICATING WITH THE MASTER ARBOR FIRST BORE, A DRAWBAR PROJECTED THROUGH THE AXIAL BORE OF SAID SPINDLE, THROUGH THE FIRST BORE OF SAID MASTER ARBOR AND AT ONE END THREADED INTO THE BORE OF SAID ARBOR BODY, THE OTHER END OF SAID DRAWBAR BEING THREADED AND PROJECTED OUTWARDLY OF SAID SPINDLE, A LOCKING NUT ADJUSTABLY THREADED ON SAID DRAWBAR OPERATIVELY ENGAGEABLE WITH SAID SPINDLE FOR REMOVABLY SECURING SAID TOOL ARBOR WITHIN SAID MASTER ARBOR AND FOR REMOVABLY SECURING SAID MASTER ARBOR WITHIN SAID SPINDLE, AND MEANS INTERLOCKING SAID TOOL ARBOR AND MASTER ARBOR, SAID SPINDLE BORES DEFINING IN SAID SPINDLE AN INNER RETAINING STOP, SAID MASTER ARBOR CYLINDRICAL PORTION COOPERATIVELY BEARING AGAINST SAID STOP LIMITING INWARD MOVEMENT OF THE MASTER ARBOR RELATIVE TO THE SPINDLE AND LIMITING FRICTIONAL ENGAGEMENT OF THE MASTER ARBOR WITH THE SPINDLE, THE SAID OTHER END OF SAID DRAWBAR BEING OF GREATER DIAMETER THAN THE INNER END OF SAID DRAWBAR DEFINING A STOP SHOULDER OPERATIVELY ENGAGING THE INNER END OF THE MASTER ARBOR IN END TO END AXIAL REGISTRY, THE MEANS INTERLOCKING SAID TOOL ARBOR AND MASTER ARBOR INCLUDING A TRANSVERSE SLOT IN ONE OF SAID TWO LATTER ARBORS AND A TRANSVERSELY EXTENDING KEY IN THE OTHER OF SAID TWO ARBORS, SAID INTERLOCKING MEANS PROVIDING THE ABOVE RECITED OPERATIVE ENGAGEMENT BETWEEN SAID MASTER ARBOR AND TOOL ARBOR, SAID TOOL ARBOR ON MERE LOOSENING OF THE DRAWBAR BEING REMOVABLE AND INTERCHANGEABLE WITH OTHER TOOL ARBORS HAVING DIFFERENT DIAMETER SHANKS TO ACCOMMODATE DIFFERENT SIZED MILLING TOOLS, ALL SAID TOOL ARBORS HAVING THE SAME BODY DIAMETER.