AU2020257742A1

AU2020257742A1 - Dozer blade cutting edge

Info

Publication number: AU2020257742A1
Application number: AU2020257742A
Authority: AU
Inventors: Timothy Stuart Falkenhagen
Original assignee: Track Shop Pty Ltd
Current assignee: Track Shop Pty Ltd
Priority date: 2019-04-16
Filing date: 2020-04-16
Publication date: 2021-11-04
Also published as: WO2020210872A1

Abstract

This invention relates to a cutting edge (10) for engaging ground of a dozer and wherein the cutting edge includes a major segment (11) that is fastened to the blade and at least one minor segment (12) that is releasably fastened to the major segment. The minor segments (12) each include a front face (21) and a rearwardly extending lower face (23) that converge to define a ground engaging edge portion.

Description

DOZER BLADE CUTTING EDGE

THIS INVENTION relates to a dozer blade cutting edge.

The invention has particular application to dozer blade cutting edges for use with bulldozers and the like in situations where particularly hard or abrasive ground is to be moved and/or shaped by a bulldozer, hereinafter referred to as a dozer. However, it will be appreciated, that the invention is not limited to this particular field of use.

Dozer blade cutting edges are provided frequently as a replaceable element. In the present specification, the term "cutting edge" is used to refer to such replaceable elements unless the context indicates otherwise. The replaceability of the cutting edge has improved the durability of the dozer blade as a whole, the cutting edge being provided as a single piece fastened to the remainder of the dozer blade by nuts and bolts in most cases. Some parts of the cutting edge wear more than other parts, depending on the application. The corner tips of the cutting edge are particularly prone to wear.

Cutting edges are provided along the lower edges of dozer blades to engage the ground and are normally replaceable. They are normally provided in a plurality of portions across the dozer blade. In this specification, the term "cutting edge" refers to the individual portions which make up the assembly, referred to herein as the "cutting edge as a whole". Some dozers have straight blades and some have curved blades. The cutting edges at each end of the cutting edge as a whole are sometimes provided in a different form from the remainder of the cutting edges, and are referred to herein as "corner tips". In other words, the term "corner tips" is used to refer to a special form of cutting edge that is located at one end of the cutting edge as a whole. Accordingly, in this specification, reference to a cutting edge refers incorporates corner tips unless the context indicates otherwise. Corner tips and the other cutting edges typically weigh around 200 kg and therefore require specialized handling equipment for lifting the individual cutting edges and for both mounting them on a dozer blade and for assisting with their removal. As a result, dozers requiring replacement of cutting edges are required to be returned to a workshop for refurbishment, with consequential downtime and associated costs and overheads .

Additionally, due to the mass of the cutting edges, there are limitations on the types of materials used in their construction due to the cost of materials and other factors.

The present invention aims to provide an improved cutting edge that alleviates at least some of the disadvantages associated with known cutting edges. Other aims and advantages of the invention may become apparent from the following description .

With the foregoing in view, the present invention resides broadly in a cutting edge for engaging ground for a dozer blade, said cutting edge including:

a major segment that is fastenable to the dozer blade, said major segment having an upper portion and a lower portion;

one or more minor segments that are each releasably fastened to said major segment by one or more fasteners in a manner whereby they extend from said lower portion, said minor segments each having a front face and a rearwardly extending lower face that converge to define a ground engaging edge portion .

Preferably, the front face and the rear face converge at an acute angle.

Suitably, the dozer blade also has apertures, each being sized for receiving a threaded fastener through an aperture penetrating through the minor segment and into the major segment, the length of the fasteners being selected so as not to penetrate through the major segment. The apertures in the major segment may in the alternative be blind apertures, the length of the fasteners being selected to be less than the depth of the blind apertures so that the shank or shaft does not bottom out in the blind end of the aperture. The fastener and the penetrating aperture have complementary mating faces, preferably in the form of countersinking. Preferably, a similar arrangement is provided for fastening the minor segment or segments to the major segment. That is, the major segment has a plurality of threaded apertures and the minor segment has a corresponding plurality of countersunk apertures penetrating therethrough.

In another aspect, this invention relates to a cutting edge including : a major segment fastenable to a dozer blade; one or more minor segments fastenable to the major segment, the one or more minor segments having hardfacing applied to at least some of the external faces thereof for engaging the ground; the major and minor segments each having a plurality of apertures shaped to receive fasteners being so formed and arranged that the major segment may be fastened to the dozer blade and the minor segment fastened to the major segment for location within a predetermined range of tolerance.

In still yet another aspect, this invention relates to a dozer blade having a front face and a top edge portion and a bottom edge portion, said dozer blade including: a mould board that is mounted on said front face adjacent to said lower edge portion; a cutting edge including: a major segment that is fastenable to said mould board, said major segment having an upper portion and a lower portion; one or more minor segments that are each releasably fastened to said major segment by one or more fasteners in a manner whereby they extend from said lower portion, said minor segments each having a front face and a rearwardly extending lower face that converge to define a ground engaging edge portion . In order that the invention may be more readily understood and put into practical effect, the present invention will now be described with reference to a specific example which illustrates several preferred embodiments of the invention and in which: Figs. 1 to 3 collectively show a plan view flanked by two opposing end views of a two-segment corner piece according to the invention;

Figs. 4 to 6 collectively show a plan view flanked by two opposing end views of a three-segment corner piece according to the invention;

Figs. 7 to 9 collectively show a plan view flanked by two opposing end views of a three-segment corner piece similar to that illustrated in Figs. 4 to 6, but with an extra ground engaging portion;

Figs. 10 to 12 collectively show a plan view flanked by two opposing end views of a three-segment corner piece similar to that illustrated in Figs. 4 to 6, but with a jigsaw joint between two of the segments;

Figs. 13 to 15 collectively show a plan view flanked by two opposing end views of a three-segment corner piece similar to that illustrated in Figs. 4 to 6, and illustrating one arrangement for hardfacing on the minor segments;

Figs. 16 to 18 collectively show a plan view flanked by two opposing end views of the three-segment corner piece of Figs. 13 to 15, but with a different hardfacing pattern;

Figs. 19 and 20 collectively show a plan view and end view of a three-segment cutting edge according to the invention; and

Figs. 21 and 22 collectively show a plan view and end view of the three-segment cutting edge of Figs. 19 and 20, and illustrating an arrangement for hardfacing on the minor segments.

The cutting edges illustrated in the drawings all have some common features and therefore, the reference numerals used to particularly point out and teach the invention refer to those features. However, it will be appreciated that such reference numerals may not be provided in some views to avoid the drawings becoming cluttered. It will be appreciated also that the cutting edges illustrated in Figs. 1 to 18 are a special type of cutting edge referred to as a corner piece. There are further common features in all of the corner pieces and therefore the same reference numerals are provided in relation thereto even though there may be minor differences as to the form of such features. It will be further appreciated that the corner pieces illustrated are for one end of the cutting edge as a whole, and that a mirror image version of each would be provided for the other end of the cutting edge as a whole.

The corner piece 10 illustrated in Figs. 1 to 3 comprises a major segment 11 and a minor segment 12. The major and minor segments fit together by virtue of having complementary rebates at 13, the rebates being shown with the segments mated together. The minor segment has ten minor apertures shown typically at 14 penetrating therethrough each for receiving a fastener shown typically at 15. The minor apertures are aligned with ten corresponding threaded apertures shown typically at 16 penetrating through the major segment.

The major segment has nine major apertures shown typically at 17 penetrating therethrough for receiving fasteners, not shown for fastening the corner piece to the remainder of the dozer blade. The minor apertures each have a deep countersunk face shown typically at 18 and similarly the major apertures have a deep seated countersunk face shown typically at 19. The fasteners used for fastening the respective parts to each other or to a mould board of the dozer have complementary countersunk faces so that the parts are accurately aligned when the fasteners are tightened. The major apertures may have a square cross- section as illustrated. It can be seen that the corner piece is wider at the left hand end than the right hand end, firstly by virtue of the front edge at the bottom of the illustration diverging away from the rear edge from right to left. But also, the major segment has an obtuse angular bend or kink part way along its length - that is from right to left, so that the major segment is narrower from front to back at the left hand end as compared with the part of the major segment to the right of the bend. The rebate follows the bend or kink with the result that the width from front to back of the minor segment is further increased. It can also be seen that the bottom edge of the minor segment is longer than the top edge of the major segment, the left hand edge thereof being at an obtuse angle to the top or rear edge, though part of the left hand edge of the minor segment is parallel to the right hand edge, the right hand edge also being at right angles to the top or rear edge.

The minor segment has a front face 21, a rear face 22 parallel to the front face and a bottom face 23 at an acute angle to the front face. It will be appreciated that the corner piece is illustrated with the front and rear faces substantially vertical, but in use, the bottom face is closer to horizontal, in use being mounted somewhat counter clockwise to the orientation shown in Fig. 1. Single or multiple grooves 28 extend at least part way across the end faces of the minor segment to receive hardfacing material. The grooves 28 extend back from the bottom faces and are substantially parallel to the forward and rear faces 21 and 22.

There is also a chamfer 24 along the top edge of the rear face of the major segment.

The corner piece 20 illustrated in Figs. 4 to 6 is the same in every respect as that illustrated in Figs. 1 to 3 except that there are two minor segments which together have the same form externally as the minor segment 12 illustrated in Figs. 1 to 3. For convenience, the minor segments will be referred to as an outer minor segment 25 and an inner minor segment 26. Five of the minor apertures 14 are provided through each of the minor segments. The partition between the outer and inner minor segments runs from the bend or kink along the top edge of the major segment substantially straight to the front or bottom edge and almost parallel to the oblique part of the left hand or outer end. Single or multiple grooves 28 extend at least part way across the end faces of the minor segments to receive hardfacing material. The grooves 28 extend back from the bottom faces and substantially parallel to the forward and rear faces 21 and 22.

The corner piece 30 illustrated in Figs. 7 to 9 is the same in every respect as that illustrated in Figs. 4 to 6 except that both of the minor segments 31 and 32 include a extra forward projecting portion 33 along the lower edge. The bottom face of the projecting portion is an extension of the bottom face of the remainder of the minor segments and includes a projected front face 34 parallel to the rear face 22 and an upper face 35 parallel to the bottom face 23.

The corner piece 40 illustrated in Figs. 10 to 12 is the same in every respect as that illustrated in Figs. 4 to 6 except that the partition between the outer and inner minor segments shown at 41 is serpentine or "wavy" rather than straight. The purpose of this illustration is to equip the skilled addressee with an appreciation that the join between the minor segments does not have to be a straight line or planar, but may be varied to suit different applications, though it will be realized that a flat face join would be the simplest and least expensive form for the join to take. The other elements are the same as in Figs. 4 to 6 so the other reference numerals have been omitted.

The corner piece 50 illustrated in Figs. 13 to 15 is the same in every respect to that illustrated in Figs. 4 to 6 except that hardfacing 51 has been added to the external faces of the inner and outer minor segments. The end faces of the inner minor segments do not have hardfacing applied because they are mating faces for mating with adjoining elements, not external faces. The corner piece 60 illustrated in Figs. 16 to 18 is the same in every respect to that illustrated in Figs. 13 to 15 except that there is a plurality of additional grooves 61 along the bottom face and part of the rear face under the hardfacing. The grooves are filled with hardfacing, the layer of hardfacing 51 being overlaying the hardfacing in the grooves as well as the remainder of the hardfaced surfaces.

The cutting edge illustrated in Figs. 19 and 20 has a single major segment 71 and two minor segments 72 of the form, but each being a mirror image of the other. The major and minor segments fit together by virtue of having complementary rebates at 13 in the same way as the complementary rebates illustrated and described with respect to the corner pieces in Figs. 1 to 18. There are provided four minor apertures in each minor segment with a fastener penetrating through each. The minor apertures are aligned with eight of the corresponding threaded apertures penetrating through the major segment, four for one of the minor segments and four for the other minor segment.

The major segment has eight of the major apertures penetrating therethrough for receiving fasteners, not shown for fastening the cutting edge to the remainder of the dozer blade. The form of the major and minor apertures and the threaded apertures is the same as for the corner pieces, but the number of and arrangement about the major and minor segments of the cutting edge are different from that of the corner pieces.

The cutting edge 80 illustrated in Figs. 21 and 22 is the same as that illustrated in Figs. 19 and 20 except that hardfacing is applied to part of the external faces of the minor segments in a similar fashion to that of the corner pieces illustrated and described with reference to Figs. 13 to 15. It will be appreciated that provision of the additional grooves for hardfacing illustrated and described with reference to Figs. 16 to 19 may be provided in corresponding fashion to the cutting edge described with reference to Figs. 21 and 22.

In use, a plurality of the cutting edges and one each of the opposite corner pieces according to the invention may be fastened to the mould board of a dozer, thereby providing a replaceable portion by virtue of the removable minor segments and a non-replaceable portion by virtue of the major segments herein described. Because the minor segments are smaller and lighter, they are easier to change, thereby eliminating the need for a crane in most instances and therefore enabling maintenance to be carried out in the field. Moreover, smaller replaceable elements also provides for different materials of construction - hardfacing or non-hardfacing for example, depending on the application. A much wider and/or thicker cutting edge may be specified and a wider range of steel material options are provided by the new form taught and described herein. For example, steels of higher hardness, such as 600 HBN Q&T steels, or chromium carbide cast white iron sections may be selected along with a range of cutting materials including ARM hardfacing variations of all of the materials suitable for welding.

The thickness of the wearing segment (minor segment) can be provided with a range of different thicknesses selected according to the application, based, for example, on the wear life of the wearing parts, to significantly improve the wear life and service or duty cycle for a dozer fitted with cutting edges according to the invention. Moreover, because maintenance can be carried out in the field, only those cutting edges or corner pieces which need replacing can be replaced rather than replacing the cutting edge as a whole which is generally the case when the dozer is returned to the workshop for maintenance. The cost savings will be significant for operating and maintaining a dozer fitted with cutting edges, including corner pieces, according to the present invention.

Although the invention has been described with reference to one or more specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms and fall within the broad scope and ambit of the invention as herein set forth and defined by the following claims .

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A cutting edge for engaging ground for a dozer blade, said cutting edge including: a major segment that is fastenable to the dozer blade, said major segment having an upper portion and a lower portion; one or more minor segments that are each releasably fastened to said major segment by one or more fasteners in a manner whereby they extend from said lower portion, said minor segments each having a front face and a rearwardly extending lower face that converge to define a ground engaging edge portion .

2. A cutting edge as claimed in claim 1, wherein said fasteners are bolts each having an enlarged head portion and a shank that extends therefrom and which has a threaded distal end portion, and wherein each of said minor segments is provided with at least one mounting aperture which is capable of being aligned with a respective threaded bore in said major segment, and whereby said distal end portions of said fasteners and said threaded bores have mating threads.

3. A cutting edge as claimed in claim 2, wherein each of said mounting apertures has a countersunk face that is capable of receiving said enlarged head portion.

4. A cutting edge as claimed in any one of the preceding claims, wherein each of said minor segments includes an upper portion having a rearwardly facing rebate that is adapted to mate with a forwardly facing rebate of said lower portion of said major segment.

5. A cutting edge as claimed in any one of the preceding claims, wherein said rebate of said major segment includes a side wall having diverging faces and wherein said upper portions of said minor segments are adapted to compliment said side wall.

6. A cutting edge as claimed in claim 5, wherein there are two minor segments that abut up against each other and which are separated by a partition that extends from a line where said diverging faces meet to said ground engaging edge portion.

7. A cutting edge as claimed in claim 6, wherein said minor segments interlock with one another along said partition.

8. A cutting edge as claimed in any one of the preceding claims, wherein each of said minor segments includes a rear face and two opposing end faces separating said front and rear faces, and wherein at least one of said end faces includes one or more grooves filled with hardfacing.

8. A cutting edge as claimed in any one of claims 1 to 7, wherein each of said minor segments includes a rear face and opposing end faces separating said front and rear faces, and wherein said front face and/or said lower face and/or at least one of said end faces is at least partially covered by hardfacing .

9. A cutting edge as claimed in any one of the preceding claims, wherein said major segment is provided with at least one mounting aperture.

10. A cutting edge as claimed in any one of the preceding claims, wherein said minor segments are both smaller and lighter than said major segment.

11. A cutting edge as claimed in claim 10, wherein said minor segments and said major segment are made from different materials .

12. A cutting edge as claimed in claim 11, wherein the material from which said minor segments are manufactured have a higher hardness than the material from which said major segment is manufactured from.

13. A dozer blade having a front face and a top edge portion and a bottom edge portion, said dozer blade including: a mould board that is mounted on said front face adjacent to said lower edge portion; a cutting edge including: a major segment that is fastenable to said mould board, said major segment having an upper portion and a lower portion; one or more minor segments that are each releasably fastened to said major segment by one or more fasteners in a manner whereby they extend from said lower portion, said minor segments each having a front face and a rearwardly extending lower face that converge to define a ground engaging edge portion .

14. A dozer blade as claimed in claim 13, wherein said fasteners are bolts each having an enlarged head portion and a shank that extends therefrom and which has a threaded distal end portion, and wherein each of said minor segments is provided with at least one mounting aperture which is capable of being aligned with a respective threaded bore in said major segment, and whereby said distal end portions of said fasteners and said threaded bores have mating threads.

15. A dozer blade as claimed in claim 14, wherein each of said mounting apertures has a countersunk face that is capable of receiving said enlarged head portion.

16. A dozer blade as claimed in any one of claims 13 to 15, wherein each of said minor segments includes an upper portion having a rearwardly facing rebate that is adapted to mate with a forwardly facing rebate of said lower portion of said major segment .

17. A dozer blade as claimed in any one of claims 13 to 16, wherein said rebate of said major segment includes a side wall having diverging faces and wherein said upper portions of said minor segments are adapted to compliment said side wall.

18. A dozer blade as claimed in claim 17, wherein there are two minor segments that abut up against each other and which are separated by a partition that extends from a line where said diverging faces meet to said ground engaging edge portion.

19. A dozer blade as claimed in claim 18, wherein said minor segments interlock with one another along said partition.

20. A dozer blade as claimed in any one of claims 13 to 19, wherein each of said minor segments includes a rear face and two opposing end faces separating said front and rear faces, and wherein at least one of said end faces includes one or more grooves filled with hardfacing.

21. A dozer blade as claimed in any one of claims 13 to 19, wherein each of said minor segments includes a rear face and opposing end faces separating said front and rear faces, and wherein said front face and/or said lower face and/or at least one of said end faces is at least partially covered by hardfacing .

22. A dozer blade as claimed in any one of claims 13 to 21, wherein said major segment is provided with at least one mounting aperture .

23. A dozer blade as claimed in any one claims 13 to 22, wherein said minor segments are both smaller and lighter than said major segment .

24. A dozer blade as claimed in claim 23, wherein said minor segments and said major segment are made from different materials .

25. A dozer blade as claimed in claim 24, wherein the material from which said minor segments are manufactured have a higher hardness than the material from which said major segment is manufactured from.