Cam follower with sheet-metal rocker arm

Abstract

The space between the outer side-surfaces 17 of a pair of side-wall sections 4 is not parallel to each other due to differences in expansion amount during plastical deformation. In use, a load is applied to the pivot 3 from the side where the space between the outer side surfaces 17 is narrow to the side where the space is broad. A crimped section 13 a is formed on the outer periphery at the opposite end surfaces of the pivot 3 , on the half on the side where the space between the outer side surfaces 17 is narrow. Therefore, the outer peripheral surface of the opposite ends of the pivot 3 comes into contact with the inner peripheral surface of the through hole 11 on the load support side. Consequently, the load is sufficiently supported by the contact surface, and even after being used for a long time of period, lost motion is prevented from occurring on the support section at the opposite ends of the pivot 3 with respect to the pair of side-wall section 4.

In the claims:  
     
         1 . A cam follower comprising a rocker arm, pivot and roller, 
 (1) the rocker arm is: 
 (1a) made from a metal plate through a drawing process, and comprises  
 (1b) a pair of side-wall sections,  
 (1c) connecting sections to connect the pair of side-wall sections,  
 (1d) provided that the connecting section side is on the upper side while the opposite side to the connecting section side is on the lower side, the thickness of the pair of side-wall sections is gradually changed in the width directions such that the thickness of the pair of side-wall sections is thin on the upper side and thick on the lower side,  
 (1e) the space between the outer side surfaces of the pair of the side wall sections becoming larger going to the lower side, and  
 (1f) through holes being formed at locations in the pair of side wall sections in alignment with each other,  
   (2) the pivot: 
 (2a) is fitted into the pair of through holes to extend between the pair of side-wall sections,  
 (2b) the outer peripheral edge of the axially opposite end surfaces of the pivot being crimped onto the upper side of the pair of the through holes, and  
   (3) the roller being supported rotatably around the middle portion of the pivot.    
     
     
         2 . The cam follower of  claim 1 , 
 (1) wherein with the openings at the both ends of the through holes, the peripheral edge of the opening on the outer side surface of the pair of the side-wall sections is beveled, and    (2) wherein each of the opposite end surfaces in the axial direction of the pivot exists between the axial position of the highest point in the inner peripheral circle of the beveled section and the axial position of the lowest point of the inner peripheral circle.    
     
     
         3 . The cam follower of  claim 1 , wherein a middle portion of the pivot, facing the inner periphery side of the roller, is quench-hardened, and wherein the portion at the axially opposite end surfaces of the pivot to be crimped is kept as it is and not subjected to quench-hardening.  
     
     
         4 . The cam follower of  claim 2 , wherein the outer peripheral surface of the crimped portion formed on the outer peripheral edge of the axially opposite end surfaces of the pivot comes into contact with the beveled portion.