ROADHEADER AND CUTTER HEAD THEREFOR

Abstract

A transverse cutter head for a mining machine has an outer surface including a plurality of cutting tools. Tips of the plurality of cutting tools define a virtual contour line when viewed in a cutter boom longitudinal direction and a rotation of the cutter head is considered. The contour line is formed by at least four sections, namely a first section, a second section, a third section and a fourth section. The four sections are located adjacently in this order, wherein the first section is located closest to the cutter boom and the fourth section forms a side wall cutting area. The first section and/or the fourth section run substantially straight. Each one of the first section, the second section, and the third section has a pitch angle different from the pitch angle of the other two sections. A roadheader having such a cutter head is also provided.

Claims

1. A transverse cutter head for a mining machine comprises an outer surface including a plurality of cutting tools, wherein tips of the plurality of cutting tools define a virtual contour line when a rotation of the cutter head is considered, wherein the contour line is formed by at least four sections including a first section, a second section, a third section and a fourth section, the four sections being located adjacently in order from the first section to the fourth section, wherein the first section is located closest to a cutter boom of the mining machine and the fourth section forms a side wall cutting area, wherein the first section and/or the fourth section are substantially straight, and each one of the first section, the second section and the third section has a pitch angle different from a pitch angle of the other two sections.

2. The cutter head of claim 1, wherein the first section has a length L1 and the third section has a length L3, wherein L32.2L1.

3. The cutter head of claim 2 wherein L3 is a multiple of L1, and wherein the multiple is within the range of 2.2 to 2.8.

4. The cutter head of claim 2, wherein the second section has a length L2, and wherein L32.2L2.

5. The cutter head of claim 4, wherein L3 is a multiple of L2, and wherein the multiple is within the range of 2.2 to 2.8.

6. The cutter head of claim 2, wherein the fourth section has a length L4, wherein L32.2L4.

7. The cutter head of claim 6, wherein L3 is a multiple of L4, and wherein the multiple is within the range of 2.2 to 2.8.

8. The cutter head of claim 1, wherein the second section is a substantially straight

9. The cutter head of claim 1, wherein the second section has a pitch angle A2, and wherein 0.5A20.5.

10. The cutter head of claim 1, wherein the third section has a pitch angle A3, wherein 28A342.

11. The cutter head of claim 1, wherein the first section has a pitch angle A1, and wherein 42<A1<28.

12. The cutter head of claim 1, wherein the fourth section has a pitch angle A4, wherein 33A455.

13. The cutter head of claim 1, wherein each cutting tool of the plurality of cutting tools is fixed at an outer surface of the cutter head such that a longitudinal axis of a respective cutting tool is inclined to the outer surface and that each cutting tool tip points towards a rotation direction of the cutter head.

14. The cutter head of claim 1, wherein within at least one section selected from the first section, the second section, the third section and the fourth section includes at least two groups of cutting tools, each cutting tool group including at least two cutting tools arranged such that the tips of the cutting tools of a same group forms a virtual circle around an outer surface of the cutter head, and wherein two adjacent groups of cutting tools of the at least one section have a pre-defined distance, wherein the distance is measured substantially along the contour line within the same section, and a distance between two adjacent groups of cutting tools is substantially equal to that between other adjacent groups of cutting tools.

15. The cutter head of claim 1, wherein the cutting tool tips of the second section are at a greatest distance from a rotation axis of the cutter head compared to cutting tools of the first section, the third section, and the fourth section, wherein a ratio of a contour height to a contour length is greater than or equal to 0.3.

16. The cutter head of claim 1, wherein the third section is a substantially straight

17. A roadheader comprising: a main body; a cutter boom extending from the main body; and a plurality of cutter heads according to claim 1 rotatable about an axis extending transversally relative to a cutter boom longitudinal direction, wherein each cutter head extends from opposite side faces of the cutter boom at a cutter boom end section located opposite the main body.

18. The roadheader of claim 17, wherein the cutter boom is pivotable into a horizontal and/or vertical direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 is an embodiment of a roadheader in a perspective front view.

[0040] FIG. 2 illustrates a cutter boom with an embodiment of a cutter head provided at both sides of the cutter boom in a front view as well as the corresponding contour lines.

[0041] FIG. 3 illustrates the cutter boom with the cutter head of FIG. 2 in a side view.

[0042] FIG. 4 shows a longitudinal section of the cutter boom and the two cutter heads of FIG. 2 taken along the plane B-B (FIG. 3) without cutting tool holders and cutting tools.

[0043] FIG. 5 is a cross-section of FIG. 2 depicting the cutter head and the contour line in more detail.

[0044] FIG. 6 illustrates a contour line of another embodiment of a cutter head.

DETAILED DESCRIPTION

[0045] FIG. 1 shows a roadheader 1 with a main body 3 supporting and moving a cutting assembly 5. The main body 3 includes, for example, a gear box and an on-board control unit. Further, the roadheader 1 includes a travelling mechanism including a pair of endless tracks 6 for propelling the roadheader 1 over the ground within a mine into a heading direction 8. The heading direction 8 defines the front end of the roadheader 1 and of all its elements. The respective front end is in front when the roadheader 1 moves into the heading direction 8. Accordingly, the opposite end of the roadheader 1 having a conveyor belt 9 for mined rock or mineral transport forms its back end.

[0046] The cutting assembly 5 includes a cutter boom 10, which is vertically and horizontally pivotable mounted at the main body 3. The cutter boom 10 is, for example, pivotable about a first horizontal axis 11 and a second vertical axis 12. Further, the cutter boom 10 may be telescopically extendable and retractable along a direction of a longitudinal axis 15 of the cutter boom 10.

[0047] Two cutter heads 20 are rotatably mounted to a front end section of the cutter boom 10 opposite the main body 3. Both cutter heads 20 are jointly driven by a drive gear accommodated within the cutter boom 10 and a joint driven shaft 21 (FIG. 4). Accordingly, the rotation of the two cutter heads 20 is provided about a joint rotation axis 23. The two cutter heads 20 are mounted mirror-inverted to the front end section of the cutter boom 10, wherein the mirror plane includes the longitudinal axis 15 of the cutter boom 10.

[0048] Each cutter head 20 includes a housing 24 with an outer surface 25. As one can derive at best from FIGS. 2 and 4, the outer form of the housing 24 is conical. The embodiment of one cutter head 20 shown in FIGS. 2 to 4 includes at its outer surface 25 a number of (e.g. in total 54) cutting tools (picks) 27. The cutting tools 27 are numbered, wherein the numbers of the cutting tools 27 are marked with a circle encircling the respective number to distinguish them from the reference numbers of this description (see FIGS. 3 and 5). The reference numbers do not have any marking. Each one of the 54 cutting tools 27 are fixed to the surface 25 of the cutter head 20 by means of a holder 28 that is welded to the outer surface 25 of the housing 24. Each holder includes an opening into which the respective cutting tool 27 is removably mounted. The cutting tools 27 are mounted such that they point into the rotation direction, wherein the rotation direction is depicted in FIG. 3 by arrow 29. The cutting tools 27 are inclined with regard to a tangent at the outer surface 25 of the housing 24 at the position of the holder 28 by an angle in the range of 40 to 55.

[0049] As can be best derived from FIG. 5, with regard to each cutter head 20 a contour line 30 may be drawn, wherein the contour line 30 is defined within the plane of one longitudinal section of the cutter head 20 and contains the positions of all the tips 31 of the cutting tools 27 within this plane when the cutter head 20 provides a full rotation about its rotation axis 23. The position of the tips 31 of the cutting tools 27 are marked by crosses 33 at the contour line 30.

[0050] In FIGS. 2 and 5, above each cross 33 the numbers of the respective three cutting tools 27 to which the respective cross 33 belongs too are shown. Accordingly, the cutting tools 27 are grouped into 18 groups of three cutting tools 27, each of which are located at the outer surface 25 of the cutter head 20 such that they form a virtual circle when the cutter head 20 rotates. Adjacent groups of cutting tools 27 have a distance ranging from 15 mm to 65 mm, depending on the rock type to be cut and the available cutter motor power (determined in a direction along the contour line 30).

[0051] As one can derive from the structure of the contour line shown in FIGS. 2 and 5, the distances of the groups of cutting tools 27 are approximately similar indicating that the cutting tools are uniformly distributed over the outer surface 25 of the cutter head 20. Further, as one can derive from FIG. 3, the cutting tools 27 of adjacent groups are arranged off-set relative to the circumferential direction.

[0052] As indicated in FIG. 5, the contour line 30 includes four sections, namely a first section A (closest to the cutter boom 10 and its drive gear), a second section B, a third section C and a fourth section D (farthest from the cutter boom 10). All the four sections A, B, C and D are substantially straight, wherein the pitches of the second section B, the third section C and the fourth section D are different. The overlapping of the frames depicting the four sections A, B, C and D show, that some points 33 of the contour line 30 belong to two different, directly adjacent sections, for example the point 33 of the cutting tools 27 with the numbers 43, 44, 45 belong to the first section A and the second section B. The same applies to the point 33 of the cutting tools with the numbers 37, 38, 39 (sections B and C), and the point 33 of the cutting tools with the numbers 10, 11, 12 (sections C and D). In this embodiment, the pitch of the first section A is 40, the pitch of the second section B is 0 (i.e. the second section B of the contour line 30 runs horizontally, parallel to the rotation axis 23), the pitch of the third section C (main section) is 30 and the pitch of the fourth section D is 40, wherein the pitch is measured in relation to the rotation axis 23 of the cutter head 20.

[0053] The contour height H at section B (i.e., the distance of section B from the rotation axis 23) is, for example, 690 mm and the contour length L is, for example, 820 mm (see FIG. 5). Accordingly, the ratio of the contour height and contour length is 0.84.

[0054] A second embodiment of a cutter head is depicted in FIG. 6 by means of its contour line 30 drawn through points 33 representing the position of cutting tool tips within one longitudinal section of the respective cutter head considering one full rotation of this cutter head. The second embodiment includes a longer first section A compared to the first section A of the first embodiment (see FIG. 5). Accordingly, the third section C is shorter than the third section C of the first embodiment. In this embodiment, the pitch of the first section A is 32, the pitch of the second section B is 0, the pitch of the third section C (main section) is 32 and the pitch of the fourth section D is 53. Further, contour height at section B is, for example, 650 mm and the contour length is, for example, 940 mm. Accordingly, the ratio of the contour height and contour length is about 0.7. The advantage of a cutter head having such contour line 30 is that, optimum cutting parameters at all periods of the cutting process can be achieved; which ends up in optimum cutting rates at minimum and equal wear of cutting tools, reduced maintenance, and optimum cutting behavior, which means minimum vibration of cutting head, cutting boom and cutting machine.

[0055] Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.