Insert having internal drive grooves

Claim 1

AN INSERT ADAPTED TO BE INSTALLED IN A WORKPIECE HAVING A BORE, COMPRISING: AN ELONGATED CYLINDRICAL BODY HAVING AN EXTERNAL THREAD FOR MOUNTING SAID INSERT WITHIN SAID BORE IN SAID WORKPIECE, SAID BODY HAVING A BORE INCORPORATING AN INTERNAL THREAD, AND HAVING A THIN WALL BETWEEN SAID INTERNAL AND EXTERNAL THREADS, ALL OF SAID INTERNAL THREADS BEING LOAD-CARRYING THREADS ENGAGEABLE BY A THREADED MEMBER ENTERING THROUGH THE UPPER EXTREMITY OF SAID BODY, SAID INTERNAL THREADS BEING CONSTITUTED BY A PLURALITY OF SUCCESSIVE CONVOLUTIONS HAVING MAJOR AND MINOR DIAMETERS, AND A PLURALITY OF LONGITUDINAL DRIVE GROOVES EXTENDING ACROSS ALL OF SAID INTERNAL THREADS AND BEING ENGAGEABLE BY A DRIVING TOOL THROUGH SAID UPPER EXTREMITY OF SAID BODY FOR DRIVING SAID BODY INTO SAID WORKPIECE, SAID DRIVE GROOVES HAVING THEIR BASES LOCATED INWARDLY OF SAID MAJOR DIAMETER AND OUTWARDLY OF SAID MINOR DIAMETER OF SAID INTERNAL THREADS, WHEREBY SAID DRIVE GROOVES DO NOT EXTEND INTO AND WEAKEN THE WALL BETWEEN SAID INTERNAL AND EXTERNAL THREADS, THE LIMITED DEPTH OF SAID DRIVE GROOVES LEAVING UNIMPAIRED CIRCUMFERENTIALLY CONTINUOUS MAJOR DIAMETER THREAD PORTIONS DISPOSED RADIALLY OUTWARDLY OF SAID DRIVE GROOVES, WHEREBY THE STRUCTURAL INTEGRITY OF THE MAJOR DIAMETER PORTIONS OF THE SUCCESSIVE CONVOLUTIONS OF THE INTERNAL THREADS IS MAINTAINED, SAID DRIVE GROOVES OCCUPYING A MINOR PORTION OF THE CIRCUMFERENTIAL LENGTH OF ANY GIVEN CONVOLUTION OF SAID INTERNAL THREADS, THEREBY FORMING CHORDAL ARC SEGMENTS IN SAID SUCCESSIVE CONVOLUTIONS, THE TERMINAL PORTIONS OF SAID SEGMENTS BEING TRIANGULAR AND BEING FORMED BY THE SIDE WALLS OF SAID DRIVE GROOVES, SAID DRIVE GROOVES PROVIDING MEANS THROUGH WHICH HIGH TORQUE CAN BE APPLIED IN DRIVING SAID INSERT WITHOUT CAUSING ANY SUBSTANTIAL REDUCTION IN THE STRENGTH OF SAID INTERNAL THREADS TO RESIST AXIAL STRIPPING WHEN A THREADED MEMBER IS TIGHTENED THEREIN.