ZA200602503B

ZA200602503B - Welded connector for a tyre chain

Info

Publication number: ZA200602503B
Application number: ZA200602503A
Authority: ZA
Inventors: Dohmeier Hans-Otto
Original assignee: Dohmeier Hans-Otto
Priority date: 2006-01-01
Filing date: 2006-01-01
Publication date: 2007-04-25

Description

WELDED CONNECTOR FOR A TYRE CHAIN

TECHNICAL FIELD:

This invention relates to steel chain links, having application primarily, though not exclusively, in tyre chains for heavy duty vehicles, such as for mining, quarrying, earth-moving and forestry applications, to protect the rubber tyres on one or more axles of such vehicles and/or provide additional traction.

BACKGROUND ART:

Tyre chains of the type with which this invention is concerned have a tread portion spanning the tread of a tyre and two flanking side-wall portions that respectively span a portion of the inner and outer side-walls of the tyre. The chain is composed of vertical links that extend substantially normal to the surface of the tyre in use and horizontal links inter- connecting three or four vertical links to form a net of a desired pattern.

The vertical links for the tread portion are sometimes called "wear links" or "tread links". The horizontal links are sometimes referred to as connecting rings or connectors. This type of tyre chain is referred to as "a tyre chain of the type set forth" below.

The tread links may be rectangular plates or forged bodies having two spaced holes or a longitudinally extending elongate slot or they may be round or oval links. The connectors are basically round rings that must be closed to withstand the twisting and bending forces generated by the tread so links in use. Butt welded connectors are effective and are made in factories using suitable equipment which is costly. However, they are not suited for use as repair connectors on site. Thus connectors with the ends bent to face out of the ring have been developed as manufacturing and repair links, the legs being joined by welding or mechanically by ferrules, clips and the like.

The choice of material for vertical and horizontal links is important to ensure wear resistance and strength, whilst avoiding brittleness and

C2600DOHMEIER'H-O 28.03.2008 page 2 achieving an acceptable balance between cost and life of the chain. Thus combinations of hardened (e.g. carburised) steel, spring steel and alloy steels used with various vertical and horizontal links designs are known in the art.

This invention seeks to provide a connector that is suited for original : manufacture and repair use, is relatively inexpensive in cost having regard to manufacture and installation and can be used with spring steel.

DISCLOSURE OF THE INVENTION:

The invention provides a connector link comprising: -- a substantially circular body having spaced apart ends that form a gap between each other through which a links can be threaded; and -- a closing member positioned in the gap and welded to each of the ends to close the gap.

Preferably the closing member is a pin that is positioned to extend substantially radially with respect to the circular body. Preferably the pin has a portion that extends radially inwardly of the circular body for a distance sufficient to cause links threaded on to the circular body to be spaced away from the welded region in use.

Preferably the pin is round in cross-section to facilitate forming strong welds between the pin and ends of the circular body.

Preferably the pin is of a smaller diameter than the material of the circular body.

Preferably the circular body is of spring steel. Preferably the spring steel is of EN 45 or equivalent.

Preferably the steel is hardened to between 48 and 50 Rc (Rockwell

C-scale). However, the hardness may vary from about 40 Rc where strength is a prime requisite and wear resistance is a negligible consideration to as about 55 RC where wear resistance is paramount.

The pin maybe of similar spring steels and harnesses as the circular body, though it may be of any suitable weldable steel.

C2600DOHMEIER'H-O 28.03.2006 page 3

Preferably stainless steel is used to weld he closure member to the circular body.

Another aspect of the invention provides a tyre chain of the type set forth 5s in which at least some of the connectors are connectors of the invention as described above.

Further features, variants and/or advantages of the invention will emerge from the following non-limiting description of an example of the invention made with reference to the accompanying schematic drawings and from the claims, which are to be regarded as an integral part of this description.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 shows a plan view of a connector of the invention;

Figure 2 shows a side view of the connector of Figure 1;

Figure 3 shows an orthogonal side view of the connector of Figure 1;

Figure 4 shows a plan view of a portion of a tread portion of a tyre chain of the type set forth.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS:

In the drawings the same or similar parts have the same reference numbers, certain parts having sub-numbers to identify them as part of a component or as substantially equivalent parts in different embodiments.

Figures 1 to 3 of the drawings show a connector 10 for a tyre chain. The connector comprises a length of round, EN 45, spring steel rod bent to form a circular body 12 with spaced parallel ends 14 defining a gap 16 between them. A round pin 18 of narrower diameter than that of the rod of the body is welded between the ends to close the gap. The pin extends substantially radially with respect to the circular body and has an end portion 18.1 projecting into the body. An opposite end portion 18.2 projects beyond the body 12. The pin is also of EN 45 spring steel and is welded to the body by stainless steel material.

Figure 4 shows the connector 10 assembled into a tyre chain. As shown the connectors 10 have four vertical links 20 threaded on to them to form a four-sided or diamond chain pattern. In use the chain is stretched or bunched as the tyre on which the chain is mounted rotates causing the links and connectors to move relatively to one another. The portion 18.1 of the

C2600DOHMEIER'H-O 28.03.2006 page 4 pin inside the ring ensures that when this happens, then the links 20 are held away from the weld so as to inhibit stressing the welded region. The outwardly projecting portion 18.2 is used for holding the pin during welding and for increasing the coverage of the chain.

The connectors are easily made using relatively inexpensive equipment. For example the circular body is formed by winding a length of rod on to a mandrel, holding the wound rod circumferentially and then cutting the along the length of the mandrel to form a plurality of part circular bodies 10.

The pins 18 are cut from a rod of similar material, but small diameter.

The gap between the ends 14 is dimensioned to permit the links to be threaded on to the connector without having to force open the connector.

Likewise the smaller cross-section of the pin permits it to be easily inserted into the gap 16, with the clearance between the pin and ends permitting a good, deep weld to be achieved.

The link may be used for original manufacture in a factory or be used as a repair link on site.

The spring steel is heat treated in a known manner to create a desired hardness for wear resistance consistent with strength. Thus the hardness, which extends throughout the link may range from 40 to 55 Rc (Rockwell

C-scale), though a preferred range is 48 to 50 Rc. The surface region may also be carburised or nitrided, in known manner, to achieve a skin of 1 to 3 mm of 55 to 65 Rc for wear resistance, should costs allow in practice.

The invention is not limited to the precise details described above and shown in the drawings. Modifications may be made and other embodiments developed without departing from the scope of the invention as defined in the claims. For example, the portion of the pin outside the connector body may be formed into a hook or loop parallel to the surface of the tyre in use further to increase the coverage of the chain. A vertical link or plate may also be welded to the pin if desired.

C2600DOHMEIER™H-O 28.03.2006 page 5

Claims

CLAIMS:

1. A connector link comprising: -- a substantially circular body having spaced apart ends that form a gap between each other through which links can be threaded; and -- a closing member positioned in the gap and welded to each of the ends to close the gap.

2. The connector link of claim 1, wherein the closing member is a pin that is positioned to extend substantially radially with respect to the circular body.

:

3. The connector link of claim 2, wherein the pin has a portion that extends radially inwardly of the circular body for a distance sufficient to cause links threaded on to the circular body to be spaced away from the welded region in use.

4, The connector link of either of claim 2 or 3, wherein the pin is round in cross-section to facilitate forming strong welds between the pin and ends of the circular body.

5. The connector link of any one of claims 2 to 4, wherein the pin is of a smaller diameter than the material of the circular body.

7. The connector link of claim 6, wherein the spring steel is EN 45 or equivalent. ’

8. The connector link of any preceding claim, wherein the circular body has a hardness of between 48 and 50 Rc (Rockwell C-scale).

9. The connector link of any preceding claim, wherein the circular body has a hardness that ranges from about 40 Rc where strength is a prime requisite and wear resistance is a negligible consideration to about 55 RC where wear resistance is paramount. C2600DOHMEIER'H-O 28.03.2006 page 6

10. The connector link of any one of claims 2 to 9, in so far as any such claim is dependent on claim 2, wherein the pin of a similar material as that of the circular body.

11. The connector link of any preceding claim, wherein the closing member is of a suitable weldable steel.

12. The connector link of claims 1 to 11, wherein stainless steel is used to weld the closure member to the circular body.

13. A tyre chain comprising vertical links that extend substantially normal to the surface of a tyre in use and horizontal links interconnecting vertical links to form a net of a desired pattern, at least some of the horizontal links comprising a substantially circular body having spaced apart ends that form a gap between each other through which links can be threaded and a closing member positioned in the gap and welded to each of the ends to close the gap.

14. A tyre chain comprising vertical links that extend substantially normal to the surface of a tyre in use and horizontal links interconnecting vertical links to form a net of a desired pattern, at least some of the horizontal links being connector links as claimed in any one of claims 1 to

12.

15. A tyre chain repair kit comprising a substantially circular body having spaced apart ends that form a gap between each other through which links can be threaded; and a closing member positionable in the gap and weldable to each of the ends to close the gap.

16. A connector link substantially as herein described with reference to and as illustrated in the drawings. 4 / DATE 28 March 2006 Aes f co SAE 20 fe & CO. Applicant's Agents C2600DOHMEIER'H-O 28.03.2006 page 7