Sheet metal rocker arm with integrally formed cross member

Abstract

A sheet metal rocker arm of the end pivot rocker arm type formed by bending into a U shape a precursor sheet metal piece and characterized by having a reinforcing cross member which is integrally formed by bending a tab that is cut in the central portion of the connecting part of a U-channel element to yield a reinforcing cross member to provide a unitary structure that introduces substantially enhanced stiffness to the rocker arm. The method of creating integrally formed reinforcing cross-members by appropriately cutting slits that provide reinforcing members can be applied to any stamped rocker arm that has a U-channel architecture, e.g., including, for example, rocker arms for pushrod type valvetrains as well as roller finger follower type rocker arms. Provision of the integrally formed cross member abutting the inner wall of the sides of the U-shaped rocker arm renders stiffness to the rocker arm that enables an engine to operate at a higher rpm and thereby improves horsepower output.

1 . A method for manufacturing a sheet metal rocker arm having integrally reinforcing cross members and substantially enhanced relative structural integrity and stiffness comprising
 (a) bending a patterned sheet metal precursor blank to form a longitudinal U-channel with straight sides generally conforming to a rocker arm and a central portion connecting the sides and having dimensions; and   (b) lancing a shaped opening comprising a tab in the central portion; and   (c) bending the end of said tab inwardly into the U-channel to form a cross-member transverse to sides of the U-channel and such that side edges of said tab abut against the inner sidewalls of the U-channel sides; and   (d) securing said tab side to the inner sidewalls of the U-channel to integrate said tab and said side members to produce a rigid structure.   
   
   
       2 . The method of  claim 1  wherein the shaped opening in the central portion comprises a U-shape to produce a single tab yielding a single cross-member between the U-channel sides. 
   
   
       3 . The method of  claim 1  wherein the slit generally comprises an H-shape to produce two tabs to yield a pair of cross-members between the U channel sides. 
   
   
       4 . The method of  claim 2  wherein the tab has one or more holes to reduce the total mass of the rocker arm. 
   
   
       5 . The method of  claim 3  wherein a portion of one or both tabs is discarded to reduce the total mass of the rocker arm. 
   
   
       6 . A rocker arm formed by the method of  claim 1 . 
   
   
       7 . A rocker arm formed by the method of  claim 2 . 
   
   
       8 . A rocker arm formed by the method of  claim 3 . 
   
   
       9 . A rocker arm formed by the method of  claim 4 . 
   
   
       10 . A rocker arm formed by the method of  claim 5 .