hanneman

Claim 1

A DRILLING AND THREAD CUTTING SCREW OF THE TYPE DESCRIBED COMPRISING AN ELONGATED SHANK, AND MEANS AT ONE END OF SAID SHANK COOPERABLE WITH A TOOL FOR TURNING THE SCREW, SAID SHANK INCLUDING AN ENTERING END PORTION HAVING A FIRST PREDETERMINED DIAMETER, SAID ENTERING END PORTION HAVING A CENTERED TIP ABOUT THE LONGITUDINAL AXIS OF THE SCREW AND COMPRISING A TERMINAL RIDGE EDGE INTERSECTING AND SUBSTANTIALLY PERPENDICULAR TO THE LONGITUDINAL AXIS OF THE SHANK WITH SYMMETRICALLY DISPOSED SUBSTANTIALLY FLAT SIDE SURFACES ON EACH SIDE OF SAID TERMINAL RIDGE EDGE EACH DIVERGING ANGULARLY OUTWARDLY AND EACH INTERSECTING SAID SHANK INTERMEDIATE THE TERMINAL RIDGE EDGE AND SAID MEANS FOR TURNING THE SCREW, SAID SHANK INCLUDING A TRAILING PORTION HAVING A PLURALITY OF INTEGRAL AND COMPLETE THREAD CONVOLUTIONS WITH THE GREATEST DIAMETER OF THE THREADS BEING GREATER THAN THE DIAMETER OF THE PREDETERMINED DIAMETER AT THE ENTERING END PORTION, SAID SHANK INCLUDING AN INTERMEDIATE THREADED PORTION JOINING SAID ENTERING END AND TRAILING PORTIONS AND HAVING A PROGRESSIVELY INCREASING DIAMETER FROM SAID ENTERING END PORTION TO SAID TRAILING PORTION, SAID ENTERING END PORTION, SAID INTERMEDIATE PORTION AND PART OF SAID TRAILING PORTION OF THE SHANK HAVING A PAIR OF OPPOSITELY DISPOSED SUBSTANTIALLY LONGITUDINALLY EXTENDING SLOTS THEREIN RESPECTIVELY DEFINED BY FIRST AND SECOND SIDE SURFACES DISPOSED SUBSTANTIALLY AT RIGHT ANGLES TO EACH OTHER AND HAVING INTERMEDIATE UNINTERRUPTED SHANK PORTIONS BETWEEN THEM TO PROVIDE OPPOSED BEARING SURFACES WHICH AFFORD STRENGTH TO THE SLOTTED SCREW SHANK AND ASSURE SUFFICIENT BEARING SURFACE FOR EFFICIENT DRILLING AND THREAD CUTTING ACTION, SAID FIRST SIDE SURFACES OF SAID SLOTS RESPECTIVELY BEING INCLINED AT AN ANGLE WITH RESPECT TO A PLANE CONTAINING THE LONGITUDINAL AXIS OF THE SHANK WITH THE ANGULAR INCLINATION OF SAID FIRST SIDE SURFACES BEING SUCH THAT THE PORTION OF THE FIRST SIDE SURFACE OF EACH OF SAID SLOTS LOCATED IN THE TRAILING PORTION OF THE SHANK LIES ON A LINE TRAVERSING THE SAID PLANE AT AN ACUTE ANGLE INTERMEDIATE THE TIP PORTION OF THE SCREW AND THE MEANS PROVIDED AT THE OTHER END OF THE SHANK FOR TURNING THE SCREW, CUTTING EDGES LOCATED AT THE INTERSECTIONS OF SAID FIRST SIDE SURFACES OF SAID SLOTS AND SAID SYMMETRICALLY DISPOSED SUBSTANTIALLY FLAT DIVERGENT SIDE SURFACES IN THE VICINITY OF SAID POINTED TIP, THE CUTTING EDGES SO PROVIDED BEING DISPOSED AT AN ANGLE OF LESS THAN 45* TO SAID TERMINAL RIDGE EDGE THEREBY PROVIDING A RELIEF BEHIND SAID CUTTING EDGES TO ASSURE THEIR AGGRESSIVE EXPOSURE AS THEY ARE EXPOSED TO A WORKPIECE, EACH OF SAID FIRST SURFACES OF SAID SLOTS EXTENDING FROM THE THREADED SHANK PERIPHERY RADIALLY INTO AND BEYOND SAID TERMINAL RIDGE EDGE AND INTERSECTING BOTH OF THE SYMMETRICALLY DISPOSED FLAT SIDE SURFACES AT OPPOSITE SIDES OF SAID TERMINAL RIDGE EDGE, SAID POINTED TIP PRESENTING A SMALL CENTRALLY LOCATED AXIALLY EXTENDING PROJECTION INCLUDING THE AFOREMENTIONED TERMINAL EDGE TOGETHER WITH PORTIONS OF SAID FLAT SIDE SURFACES ON EITHER SIDE THEREOF FOR INITIALLY ENGAGING AND REMOVING MATERIAL FROM A WORKPIECE, AND SAID FIRST SIDE SURFACES OF SAID SLOTS PROVIDING THE CUTTING EDGES RADIALLY OUTWARDLY OF SAID POINT PORTION TO THE FIRST PREDETERMINED DIAMETER OF THE ENTERING END PORTION OF THE SCREW AS WELL AS THE EDGES ALONG THE INTERMEDIATE AND TRAILING THREADED SHANK PORTIONS TO EFFECT CUTTING OF A THREAD IN THE COMPLEMENTARY WORKPIECE APERTURE PREVIOUSLY DRILLED.