WO2024089581A1

WO2024089581A1 - Trenching

Info

Publication number: WO2024089581A1
Application number: PCT/IB2023/060679
Authority: WO
Inventors: Jan Gerhardus EHLERS
Original assignee: Ehlers Jan Gerhardus
Priority date: 2022-10-24
Filing date: 2023-10-23
Publication date: 2024-05-02

Abstract

The invention relates a digging element, which includes a curved cutter blade attachable to a trencher chain assembly and a composite bit extending from the curved cutter blade. The curved cutter blade is defined by a substantially s-shaped curve in any one or both a lateral and longitudinal direction. Furthermore, the composite bit comprises of Tungsten carbide and includes at least one wedge-shaped cutting edge. There is further provided a sacrificial plate, being shaped and dimensioned to match an outer profile of a roller chain link of the trencher chain assembly and an attachment portion of the digging element, which in use, provides for a wear barrier to the digging element from being abraded during digging operations.

Description

TRENCHING

FIELD OF THE INVENTION

This invention relates to trenching. In particular, the invention relates to a digging element, a cutter chain and a sacrificial plate.

BACKGROUND OF THE INVENTION

Trenching chains comprise of roller chain links onto which cutters or picks are mounted for cutting through rock, tarmac or other hard and soft surfaces. Cutters for such applications include case hardening steel portions on its cutting edges to reduce wear of the cutting teeth. In order to reduce friction on cutters, they are mounted in linear alignment with the direction of travel, thus making them efficient for cutting into a hard surface. Such cutters are often inefficient in removing loose gravel from a trench and ripping up the gravel.

In order to remove gravel from a trench that has been cut, a chain onto which so called cup cutters are installed is often used. A cup cutter has at least one surface that is oriented at an angle to the linear direction of travel, such that when two such opposing cup cutters are installed on a chain, they define a narrowing gravel catchment zone between their angled surfaces. When such a cup cutter chain is used, the gravel to be removed from the trench is momentarily retained between the cup cutters and thrown outside the trench, thus optimising gravel removal from the trench.

In order to optimise the cutting action and the gravel removal action trenching chains are often fitted with a combination of cutters/picks and cup cutters.

However, the inventor found that trenching chains with a combination of cutters/picks and cup cutters are very prone to wear and breakage as the cup cutters are often damaged by the friction with the gravel and cobbels. SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a digging element, which includes a curved cutter blade attachable to a trencher chain assembly; and a composite bit extending from the curved cutter blade.

According to another aspect of the invention, there is provided a cutter chain, which includes a digging element as described above.

The curved cutter blade may be defined by an attachment portion and cutting portion extending upwardly therefrom.

The attachment portion may include apertures, shaped and dimensioned to match corresponding apertures arranged on a roller chain link of the trencher chain assembly.

The composite bit may comprise of Tungsten carbide.

The composite bit may include at least one wedge-shaped cutting edge.

The cutting portion may be defined by an angled cup surface.

The Tungsten carbide bit may be attached onto the angled cup surface by means of a welding joint.

In one embodiment, the Tungsten carbide bit may extend from the cutter portion at a straight angle. In another embodiment, the Tungsten carbide bit may extend from the cutter portion at a slanted orientation.

The curved cutter blade may be defined by a substantially s-shaped curve in any one or both a lateral and longitudinal direction. In a preferred embodiment, curved cutter blade may be in the form of a sigmoid curve. According to yet a further aspect of the invention there is provided a sacrificial plate, which is shaped and dimensioned to match any one of an outer profile of a roller chain link of a trencher chain assembly, an attachment portion of a digging element, as described above, and a combination thereof.

The sacrificial plate may include an attachment formation, defined by apertures disposed thereon, which apertures may be indexed to corresponding apertures on any one or both of the roller chain link and the attachment portion of the digging element.

The sacrificial plate may comprise of a thickness to extend beyond roller chain link pins/bolts, in use to protect roller chain link pins/bolts from wear.

The invention will now be described, by way of example only, with reference to the following figures.

FIGURE(S)

In the figures:

Figure 1 shows a three-dimensional view of a digging element;

Figure 2 shows a front view of the digging element, shown in Figure 1 ;

Figure 3 shows a top view of trencher chain assembly onto which digging elements are retrofitted;

Figure 4 shows a three-dimensional view of the trencher chain assembly, shown in Figure 3; and

Figure 5 shows a three-dimensional view of a sacrificial plate.

In the figures, like reference numerals denote like parts of the invention unless otherwise indicated.

EMBODIMENT OF THE INVENTION

In the Figures reference numeral 10 refers to a digging element which includes a curved cutter blade (12) and a Tungsten carbide bit (14) extending therefrom at a slanted orientation. In use, the digging element (10) is retrofitted onto a trencher chain assembly (20), as shown in Figures 3 and 4.

The Tungsten carbide bit (14) is in the form of a cutting tooth, which comprises of a substantially trapezium shape composite body. The body includes a base portion (carbide) (14.1 ) and a hardened distal tip inlay (Tungsten) (14.2) extending therefrom.

Furthermore, the Tungsten carbide bit (14) includes wedge-shaped cutting edges (14.3) arranged on a top and front cutting face thereof.

In this example, the curved cutter blade (12) is in the form of a cup cutter blade and defined by a sigmoid shaped curve.

The cup cutter blade (12) comprises of an attachment portion (12.1 ) and a cutting portion (12.2) extending upwardly from the attachment portion (12.1 ).

The attachment portion (12.1 ) includes a rectangular planar body with two apertures (12.1.1 , 12.1.2) disposed thereon. It is to be appreciated that, the apertures (12.1.1 , 12.1.2) is shaped, dimensioned and arranged to match corresponding apertures (22) arranged on a roller chain link (24) of the trencher chain assembly (20). Furthermore, the cup cutter blade (12) is attached to the roller chain link (24) by means of nuts and bolts, not shown.

The cutting portion (12.2) is defined by an angled cup surface, curved in both a lateral and longitudinal direction.

In an example not shown, the Tungsten carbide bit (14) is attached to a distal end of the cutting portion (12.2) by means of a nut and bolt arrangement.

In this example, the Tungsten carbide bit (14) is integrally formed with the cutting portion (12.2), in which the base portion (14.1 ) of the Tungsten carbide bit (14) is attached onto the distal end of the cutting portion (12.2) by means of welding joints. Figure 5 shows a sacrificial plate (30) which is shaped and dimensioned to match an outer profile of the roller chain link (24). The sacrificial plate (30) includes an attachment formation, defined by four apertures (32.1 , 32.2, 32.3, 32.4) disposed thereon, each aperture (32.1 , 32.2, 32.3, 32.4) spaced radially inwards from a respective corner of the sacrificial plate (30), which spacings are indexed to match apertures (22) on the outer profile of the roller chain link (24).

It should be appreciated that, the apertures (12.1.1 , 12.1.2) on the attachment portion (12.1 ) and the apertures (32.1 , 32.2) on the sacrificial plate (30), respectively, are complementary shaped and dimensioned. Furthermore, the apertures (32.3, 32.4) of the sacrificial plate (30) are shape and dimensioned to girdle the roller chain link’s (24) pins (26).

In use, and best shown in Figure 4, sacrificial plates (30) are attached to the outer profiles of each roller chain links (24) by means of nuts and bolts (both not shown). Furthermore, should the sacrificial plates (30) and digging elements (10) be attached to the same roller chain link (24), the same set of nuts and bolts are to be used for attachment.

Furthermore, the sacrificial plate (30) is of a thickness that extends beyond the roller chain link’s (24) pins (26), thereby in use, the sacrificial plates (30) provide for a wear barrier to the roller chain links (24) and pins (26) from being abraded during the rotational movement of the trencher chain assembly (20), during trench digging operations.

The inventor believes that the invention provides a novel digging element, a novel cutter chain and a novel sacrificial plate for optimizing both the cutting action and the gravel removal action of a trencher chain assembly, simultaneously provides a resistive means to abrasion of the trencher chain.

Claims

CLAIMS:

1 . A digging element, which includes a curved cutter blade attachable to a trencher chain assembly; and a composite bit extending from the curved cutter blade.

2. The digging element as claimed in claim 1 , of which the curved cutter blade is defined by an attachment portion and a cutting portion extending upwardly therefrom.

3. The digging element as claimed in claim 2, of which the attachment portion includes apertures, shaped and dimensioned to match corresponding apertures arranged on a roller chain link of the trencher chain assembly.

4. The digging element as claimed in claim 1 , of which the composite bit comprises of Tungsten carbide.

5. The digging element as claimed in claim 1 , of which the composite bit includes at least one wedge-shaped cutting edge.

6. The digging element as claimed in claim 2, of which the cutting portion is defined by an angled cup surface.

7. The digging element as claimed in claim 6, of which the composite bit is attached onto the angled cup surface.

8. The digging element as claimed in claim 2, of which the composite bit extends from the cutter portion at a straight angle or at a slanted angle.

9. The digging element as claimed in claim 1 , of which the curved cutter blade is defined by a substantially s-shaped curve in any one or both of a lateral and longitudinal direction.

10. The digging element as claimed in claim 9, of which the curved cutter blade is in the form of a sigmoid curve.

11. The digging element as claimed in claim 3, which includes a sacrificial plate, which is shaped and dimensioned to match any one of an outer profile of the roller chain link of the trencher chain assembly the attachment portion of the curved cutter blade, and a combination thereof.

12. The digging element as claimed in claim 11 , of which the sacrificial plate includes an attachment formation, defined by apertures disposed thereon, which apertures are indexed to corresponding apertures on any one or both of the roller chain link and the attachment portion of the curved cutter blade.

13. A cutter chain, which includes a plurality of digging elements as claimed in any of claims 1 to 12 attached together in a series of elements to define a closed loop chain.