US 4,449,357 AGranted

Track chain link and forging process for the manufacture of track chain links

AssigneeCaterpiller Tractor Co.

InventorPaul Balitch

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Abstract

The invention described herein concerns a forging process for the manufacture of track chain links, especially for worksite machines and vehicles; this process produces links that conform to the tolerances required by the dimensions and the surface quality of opposed attachment mounting and link contact surfaces and nut seats of finished links without it being necessary to machine these surfaces or nut seats. This process includes heating a metal billet in an electric furnace, the billet having a mass that is approximately equal to that of a finished link, preforming the billet, then flat stamping the heated billet. A combined shaping and levelling step carried out on the stamped piece forms parallel opposed sides and nut seats in predetermined spaced relationship to each other. The resulting link is controllably sized and then subjected to a heat treatment. At the end of this process, which requires no machining, a link is obtained (1) whose opposed surfaces (10,11) and nut seats (32,33) have geometric and dimensional relationships that are conform to the limits of the required tolerances.

Claims10

Dependent claims

A forging process for the manufacture of track chain links, including the steps of:

heating a metal billet (1') having a mass substantially equivalent to that of a finished link and the mass of the flash (1") and burrs (1'") remaining after a subsequent levelling operation, said heating being carried out in an electric furnace;
preforming the heated billet (1') in a press to a first predetermined dimension, said first predetermined dimension being greater than final desired dimensions of the finished link in a heated state;
flat stamping the preformed piece to nominal dimensions of the finished link in a heated state;
simultaneously shaping and precision levelling the stamped piece in the heated state, including removing the burrs (1'") and flash (1") from the link and forming a plurality of parallel articulation planes (101, 103, 104, 105) on lateral surfaces of the link;
controllably sizing the link (1) including forming an attachment mounting surface (10) and an opposed link contact surface in parallel relationship (11) at a predetermined distance one from the other;
hardening and tempering the sized link (1);
and,
machining a pair of bores (20, 21) and drilling a pair of attachment holes (30, 31) for a track shoe in the hardened link (1).

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/398,176Filed 14 Jul 1982
Priority: FR 81 1449624 Jul 1981
Granted: 22 May 1984
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

B21K 23/02
Making other articles: members of endless tracks, e.g. track guides, shoes
B21J 5/027
Die forging; Trimming by making use of special dies ; Punching during forging: trimming
B21L 9/02
Making chains or chain links, the links being composed of two or more different parts, e.g. drive chains: of roller-chain or other plate-link type
B62D 55/32
Endless track vehicles: assembly, disassembly, repair or servicing of endless-track systems