Abstract Surgical needles are attached to sutures with controlled pull-out characteristics by a short crimp--that is a crimp whose length is markedly less than the length of the end of the suture in the needle; with an essentially undistorted portion of the needle adjacent to where the suture emerges from the needle, and an essentially undistorted portion around the front of the suture, so that only a short section of the needle is crimped around the suture. This leaves the suture uncrushed where it emerges from the needle and hence of superior strength where sharp bends occur during use. It also leaves an undistorted portion of the suture ahead of the crimp so that on pull-out, the suture is retained not only by frictional engagement of the crimp but also by the forces required for the distortion of the head of the suture so that it will pull through the reduced section of the crimp.
A two-piece suymmetrical swaging die for swaging a narrow crimp in a surgical needle having a coaxial cylindrical blind hole in the blunt end to hold a surgical suture therein comprising: a swaging die having a land having a lap radius the center of which is about 0.0005 to 0.0015 inch outboard of the ends of said die, said lap radius being slightly less than the needle radius, said die having a width along the axis of the needle less than about half the blind hole depth, and an overlap radius the center of which is about 0.004 to 0.009 inch outboard of the face of said die to permit metal displacement.
Claim 2
Dependent Claim
112 words
A two-piece suymmetrical swaging die for swaging a narrow crimp in a surgical needle having a coaxial cylindrical blind hole in the blunt end to hold a surgical suture therein comprising: a swaging die having a land having a lap radius the center of which is about 0.0005 to 0.0015 inch outboard of the ends of said die, said lap radius being slightly less than the needle radius, said die having a width along the axis of the needle less than about half the blind hole depth, and an overlap radius the center of which is about 0.004 to 0.009 inch outboard of the face of said die to permit metal displacement.