Lock screw assembly incorporating stress indicator means

Claim 1

A HIGH LOAD STRESS THREADED FASTENER COMPRISING A NUT DESIGNED FOR THE APPLICATION OF LOAD THERETO CIRCUMFERENTIALLY OF AN ANNULAR OUTER PERIPHERAL SURFACE IN AN AREA SPACED BETWEEN THE OPPOSITE AXIAL ENDS OF THE NUT THREADS, SAID NUT INCLUDING A CONTINUOUS RING OF HIGH ELASTIC TENSILE STRENGTH MATERIAL ENCIRCLING AND NESTED ABOUT SAID ANNULAR NUT SURFACE WITH ONE END FACE LYING IN A PLANE SPACED APPRECIABLY BEYOND THE INNER END FACE OF THE NUT WHEN IN NESTING CONTACT WITH THE SAID OUTER ANNULAR SURFACE OF THE NUT, THE TENSILE STRENGTH OF SAID RING BEING IN EXCESS OF THE TENSILE STRENGTH OF THE ADJACENT PORTION OF THE NUT ENCIRCLED BY THE RING WHEREBY SAID RING IS EFFECTIVE IN PREVENTING EXPANSION OF THE INNER END OF THE NUT OUT OF MATING ENGAGEMENT WITH THE THREADS OF THE SHANK EXTENDING THROUGH THE NUT, AT LEAST ONE OF THE CONTACTING NESTING SURFACES FLARING OUTWARDLY WITH RESPECT TO THE OUTER END OF THE NUT AT AN ANGLE OF AT LEAST 20 DEGREES WITH RESPECT TO THE NUT AXIS, THE INNER END FACE OF SAID NUT BEING SPACED INWARDLY OF THE ADJACENT END FACE OF SAID RING A PREDETERMINED DISTANCE SO RELATED TO THE TENSILE STRENGTH OF THE FASTENER WITH WHICH THE NUT IS TO BE USED AND TO THE TENSILE STRENGTH OF SAID RING THAT THE THREADED FASTENER IS LOADED TO A DESIRED LOAD STRESS WHEN SAID NUT HAS BEEN WRENCHED UNTIL THE INNER END FACE OF THE NUT LIES FLUSH WITH THE ADJACENT END FACE OF SAID RING, THE WRENCHING OF SAID NUT ONTO A THREADED SHANK BEING EFFECTIVE TO PRESS SAID END FACE OF SAID RING AGAINST PARTS BEING FASTENED TOGETHER CAUSING SAID RING TO BE PLACED IN HOOP TENSION WITH THE INNER END PORTION OF THE NUT ENCIRCLED BY SAID RING LOADED IN AXIAL TENSION AND THE OUTER END PORTION OF THE NUT LOADED IN AXIAL COMPRESSION THEREBY EFFECTING THE BENEFICIAL DISTRIBUTION OF LOAD STRESSES OVER ALL THE THREADS OF SAID NUT.