Chain for a work implement, method for producing a stud for a chain and method for producing a driving member for a chain

Patent metadata

Field	Value
Publication number	US-9573294-B2
Application number	US-201514667718-A
Country	US
Kind code	B2
Filing date	Mar 25, 2015
Priority date	Mar 25, 2014
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A chain for a work implement has lateral connecting members connected to central driving members via studs. The stud has two lateral portions spaced apart from one another by a collar. A driving member is mounted pivotably on the collar. At the collar the stud has a surface layer harder than the base material. For a high chain service life, the stud has a diffusion layer above a surface layer above the base material. To produce the stud, the stud is provided with a diffusion layer at least at the collar, and a surface region of the collar is hardened, such that a surface layer is formed between the diffusion layer and the base material of the stud. For a method for producing a driving member, the driving member is provided with a diffusion layer at least at a circumferential surface of a hole and the driving member is hardened.

First claim

The invention claimed is:

1. A chain for a work implement, wherein the chain comprises:
a plurality of connecting members,
a plurality of driving members, and
a plurality of studs,
wherein the connecting members are connected in an articulated manner to the driving members by way of the studs, wherein the studs and the driving members comprise steel,
wherein at least one stud comprises two lateral portions which are spaced apart from one another in the longitudinal direction of the stud and between which there is arranged a collar with an enlarged external diameter,
wherein at least two of the connecting members have at least one hole, through which a stud projects, wherein the connecting members are arranged on the lateral portions of the stud and are connected to the stud fixedly in terms of rotation and fixedly in the direction of the longitudinal central axis of the stud,
wherein a driving member is mounted pivotably on the collar of the stud through a hole in the driving member,
wherein at the collar the stud has a surface layer which has a greater hardness than a hardness of a base material of the stud, wherein the stud has a diffusion layer at least at the collar, and wherein the surface layer is arranged between the base material of the stud and the diffusion layer and forms a supporting layer for the diffusion layer.

2. The chain according to claim 1 , wherein said hole in the driving member comprises a circumferential surface, wherein said circumferential surface comprises a diffusion layer.

3. The chain according to claim 2 , wherein the thickness of the diffusion layer of the circumferential surface of the hole in the driving member corresponds at least to the thickness of the diffusion layer of the collar.

4. The chain according to claim 1 , wherein the hardness of a base material of the driving member is greater than the hardness of the base material of the stud.

5. The chain according to claim 1 , wherein the hardness of the base material of the stud is approximately 250 HV to approximately 500 HV.

6. The chain according to claim 1 , wherein the hardness of a base material of the driving member is approximately 350 HV to approximately 700 HV.

7. The chain according to claim 1 , wherein the hardness of the surface layer of the collar is approximately 600 HV to approximately 940 HV.

8. The chain according to claim 1 , wherein the hardness of a diffusion layer of the collar is approximately 1200 HV to approximately 2500 HV.

9. The chain according to claim 1 , wherein the thickness of the surface layer of the collar is approximately 0.1 mm to approximately 1.0 mm.

10. The chain according to claim 1 , wherein the thickness of the diffusion layer of the collar is approximately 5 μm to approximately 100 μm.

11. The chain according to claim 1 , wherein the stud comprises end portions formed for fixing the connecting members, wherein the end portions are located outside the lateral portions.

12. The chain according to claim 1 , wherein the diffusion layer of the stud is a layer comprising diffused boron, diffused chromium or diffused vanadium.

13. The chain according to claim 1 , wherein the chain is a chain for cutting mineral and metallic workpieces which bears grinding elements for removing material from the workpiece.

14. A method for producing a stud for a chain, wherein the stud comprises a collar with an enlarged diameter, wherein the stud comprises a diffusion layer at least at the collar, the method comprising providing a diffusion layer to the stud, further comprising hardening a surface region of the collar of the stud by a first hardening method in a subsequent step, such that a surface layer is formed between the diffusion layer and a base material of the stud.

15. The method according to claim 14 , wherein the entire surface of the stud is provided with the diffusion layer.

16. The method according to claim 14 , further comprising hardening the stud completely by a second hardening method after the diffusion layer has been introduced and before the surface region of the collar is hardened by the first hardening method.

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Buchholtz Jochen
• Schulz Matthias
• Gerstenberger Oliver
• Lux Thomas
• Apfel Norbert
• Regnet Nina

Classifications

• B27B33/14 Primary

  Saw chains {(saw chains for slotting or mortising devices B27F5/08)} · CPC title

• B28D1/124 Primary

  Saw chains; rod-like saw blades; saw cables · CPC title

• Y10T83/909

  Cutter assemblage or cutter element therefor [e.g., chain saw chain] · CPC title

• B21K1/58

  rivets · CPC title

• F16G13/00

  Chains (making thereof B21L) · CPC title