Blind rivet fastening device

Abstract

A steel ball 11 is housed in a hole 10 which extends from an inner wall toward an outer wall of a nose piece 3 and obliquely rearward with respect to a rivet inserting port 6 as shown by an arrow A. An elastic ring 12 elastically pushes the ball 11 from the outer wall toward the inner wall so that a part of the ball 11 may project into the port 6 whereby the mandrel 5 is grasped. As the hole 10 extends obliquely rearward with respect to the port 6, the ball 11 can move easily when the mandrel 5 travels in the inserting direction but the ball 11 is difficult to move when the mandrel 5 travels in the direction opposite to the inserting direction. As a result, the ball 11 blocks the mandrel 5 from travelling.

1 . A blind rivet fastening device comprising a hollow nose housing for accepting a blind rivet, a nose piece provided on the front end of the nose housing and having a rivet insertion port for inserting the mandrel of a blind rivet, a jaw case provided adjacent to the rear of the nose piece so as to be able to move forward and rearward inside the nose housing and having an inner circumferential surface formed so the inner diameter becomes smaller towards the front end, a jaw provided inside the jaw case so as to hold the mandrel of a blind rivet inserted into the port and having an outer circumferential surface slidably contacting the inner circumferential surface of the jaw case, and a jaw pusher provided adjacent to the rear of the jaw and inside the nose housing for applying pressure to the jaw in the forward direction, the rearward movement of the jaw case with respect to the port and the narrowing of inner diameter of the jaw grasping the mandrel of the blind rivet in the jaw, and the rearward movement of the jaw case and jaw grasping the mandrel rupturing the mandrel of the blind rivet and fastening a component-to-be-fastened with the rivet body of the blind rivet, the blind rivet fastening device characterized in comprising a hole provided in the inner wall forming the port of the nose piece, an engaging means housed inside the hole, and a pressure-applying means for elastically pushing the engaging means towards the inner wall of the nose piece from the outer wall and causing a portion of the engaging means to protrude from the inner wall into the port, the hole extending from the inner wall towards the outer wall and rearward obliquely with respect to the rivet insertion port, and the front end of the hole opening into the port formed narrowly so the engaging means protruding into the port does not fall out. 
     
     
         2 . A blind rivet fastening device according to  claim 1 , wherein the engaging means is a spherical component. 
     
     
         3 . A blind rivet fastening device according to  claim 2 , wherein the spherical component is a steel ball. 
     
     
         4 . A blind rivet fastening device according to  claim 1 , wherein the engaging means is a cylindrical component. 
     
     
         5 . A blind rivet fastening device according to  claim 1 , wherein the engaging means is a bolt-shaped component. 
     
     
         6 . A blind rivet fastening device according to  claim 1 , wherein the pressure-applying means is an elastic ring. 
     
     
         7 . A blind rivet fastening device according to  claim 6 , wherein the elastic ring is an O-ring. 
     
     
         8 . A blind rivet fastening device according to any one of  claim 1 , wherein the pressure-applying means is a spring.