Lock bolt sealing collar and method of installing the same

Claim 1

A LOCK BOLT JOINT COMPRISING A PLATE HAVING AN APERTURE THERETHROUGH, A LOCK BOLT HAVING A SHANK EXTENDING THROUGH AND FITTING SNUGLY IN SUCH PLATE APERTURE AND HAVING A PORTION PROJECTING OUTWARD BEYOND THE ADJACENT SURFACE OF SAID PLATE, A LOCK COLLAR CONTIGUOUSLY ENCIRCLING SAID PROJECTING PORTION OF SAID LOCK BOLT, AND AN ANNULAR PORTION OF THE SURFACE OF SAID PLATE BENEATH SAID LOCK COLLAR BEING SLIGHTLY DEPRESSED BY AN ANNULAR RIB ON THE END OF SAID LOCK COLLAR NEXT TO SAID PLATE HAVING BEEN SWAGED INTO FLATTENED SHAPE AGAINST SUCH SURFACE PORTION OF SAID PLATE, SAID LOCK COLLAR, BY ITS ENGAGEMENT WITH SUCH PROJECTING PORTION OF SAID LOCK BOLT, MAINTAINING UNDER SUSTAINED COMPRESSION STRESS THE SLIGHTLY DEPRESSED SURFACE PORTION OF SAID PLATE BENEATH SAID LOCK COLLAR AND THE PORTION OF THE LOCK COLLAR END ENGAGED THEREWITH, WHICH COMPRESSIVE STRESS IS CONCENTRATED IN AN ANNULATION OF A WIDTH RADIALLY OF SAID LOCK COLLAR LESS THAN THE MAXIMUM RADIAL THICKNESS OF SAID LOCK COLLAR AND IS LOCATED NEARER THE INNER PERIPHERY THAN THE OUTER PERIPHERY OF SAID LOCK COLLAR, THE COMPRESSIVE STRESS IN THE SLIGHTLY DEPRESSED SURFACE PORTION OF SAID PLATE IN SUCH ANNULATION BEING GREATER THAN IN THE REMAINDER OF THE SURFACE PORTION OF SAID PLATE BENEATH SAID LOCK COLLAR.