US 5,105,538 A · Low-cost method of making cracked connecting rods comprised of forged wrought steel

Abstract

Method of making exactly remateable cracked connecting rods comprised of forged wrought steel possessing typical ductility, said rods having a big end with a big bore therein and an arm-like body extending therefrom with a small end at its extremity, the big end having crack initiating crevices formed therein to promote a cracking plane, comprising the following steps: (a) placing the big bore of an uncracked connecting rod onto a nestable separable pair of cantilevered hemispherical blocks complementary to the internal shape of the big bore; (b) continuously and uniformly separating the cantilevers of said blocks to initially assure contact of said blocks with the rod at a tangent point aligned substantially on the longitudinal axis of the uncracked connecting rod, and thereafter to exert sufficient force through said cantilevers to the blocks to pull apart the connecting rod at the cracking plane determined by said crack initiating crevices, the connecting rod cap and body being free to experience small but independent macro-rotation relative to the connecting rod axis during such cracking separation.

Claims19

Dependent claims

A method of making remateable cracked connecting rods comprised of forged wrought steel possessing typical ductility, said rods having a big end with a big bore therein and an arm-like body extending therefrom with a small end at its extremity, the big end having crack initiating crevices formed therein to promote a cracking plane, the method comprising the following steps:

(a) placing the walls of the big bore of an uncracked connecting rod onto a nestable pair of cantilevered hemispherical blocks complementary to the internal shape of the big bore;
(b) continuously and uniformly separating the cantilevers of said blocks to initially assure contact of said blocks at a tangent point aligned substantially on the longitudinal axis of the uncracked connecting rod, and thereafter to exert sufficient force through said cantilevers to the blocks to pull apart the connecting rod at a cracking plane determined by said crack initiating crevices, the connecting rod cap and body being free to experience small but independent macro-rotation relative to the connecting rod axis during such cracking separation.

A method of making a bipartite connecting rod of forgeable ductile steel, said rod having a big bore, comprising:

(a) preparing a forged steel one-piece connecting rod with at least one pair of spaced stress riser grooves to define a common cracking plane extending through each side of said rod and bisecting said big bore;
(b) continuously pulling apart said prepared rod by use of relatively separable cantilevered pull blocks extending into said big bore and having surfaces generally complementary to the internal surfaces of said big bore, said blocks being effective to initially contact the internal surface of said big bore at a pair of tangent points lying on the longitudinal axis of said rod, separated pieces of said rod being free to experience small but independent macro-rotation during such unlimited continuous separation except as inhibited by frictional contact with said blocks;
and
(c) remating said pieces by use of bolts extending therebetween and threaded into one of said pieces, said pieces being free to adjust laterally of the axis of said rod during such remating except as limited by the clearance of the bolt within its unthreaded opening, said bolts being torqued sufficiently to exert a clamping force on the ridges of said cracked plane reshuffling them into substantial rematch and thereafter the clamping force adjusting such ridges to promote exact remating.

1 more element

Dependencies are inferred from the claim text.

Low-cost method of making cracked connecting rods comprised of forged wrought steel

Life of this patent

Low-cost method of making cracked connecting rods comprised of forged wrought steel

Life of this patent

Abstract

Claims19