GB1601030A

GB1601030A - Yielding mine arches

Info

Publication number: GB1601030A
Application number: GB1940378A
Authority: GB
Original assignee: Bochumer Eisenhuette Heintzmann GmbH and Co KG
Current assignee: Bochumer Eisenhuette Heintzmann GmbH and Co KG
Priority date: 1977-06-01
Filing date: 1978-05-12
Publication date: 1981-10-21
Also published as: ES470092A1; BE867622A; PL207195A1; FR2393139B1; FR2393139A1; DE2724588A1

Description

(54) YIELDING MINE ARCHES (71) We, BOCHUMER EISEN HÜTTE HEINTZMANN GMBH & CO., of No. 80, Bessemerstrasse, 4630 Bochum 1, Federal Republic of Germany, a Limited Liability Company organised under the Laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to yielding mine arches for underground galleries such an arch being composed of three or more segments of substantially U-shaped cross section and having flanges projecting laterally therefrom, adjacent end portions of the segments being internested in one another and being positively frictionally coupable to one another by clamps.

The assembly of yielding mine arches is effected manually in the course of advance of the gallery, in the vicinity of the working face, or at a site behind the advance apparatus where the gallery is excavated partly or fully mechanically. Space at these assembly sites, however, is restricted by the presense of the means for advancing the gallery, so that the work of assembling the arches is impeded, considerable skill on the part of the mines assembling the arches being required, if the assembly work is to keep up with the advance of the gallery. In order so to expedite the assembly work, it is also necessary to supply the segments from above ground in such a way that the proper segments are available to the miners at the right times.This is difficult, however, where the gallery is of large cross section and the arches are consequently composed of a plurality of different kinds of segments.

These problems can at least in part be solved by preassembling the arches above ground, whereby the more difficult underground assembly work can be limited to a few manual operations. It has been found that yielding arches composed of segments of substantially U-shaped, i.e. channel-shaped, cross section, are especially well suited for preassembly above ground.Having regard to the capacity of the means for transporting the preassembled arches to the site of use underground, and the paths along which they must be transported, as well as to the optimum segment lengths, it is readily possible to internest above ground, a plurality, e.g. three or four of the se.gments substantially throughout their entire lengths and temporarily to interconnect them by means of clamps serving to couple the segments in such a way that they remain coupled during their transport to the underground assembly site.

It has been found, however, when finally assembling the preassembled arches, that upon pulling apart, i.e. axially sliding away from one another, the internested segments, great care is required in order to avoid complete separation of a pair of adjacent segments instead of allowing the end portions of these segments to remain in overlapping relationship.

A six-part yielding mine arch, for example, is preassembled above ground in the form of two parts each composed of three segments (one roof segment and two wall segments), for transport to the underground site of assembly and erection. At this site, the two roof segments of the two parts are joined together by means, for example, of a connecting segment, ready for use, the two wall segments of each preassembled part of the arch remaining in their existing positions.

After the assembly of the roof segments, the arch so partially assembled is swung into a vertical position by means of positioning apparatus and is then raised. As the structure is raised, with the clamps loosened, the wall segments slide along the roof segments towards the gallery floor. However, if the structure is raised too rapidly, and the clamps are too loose, the wall segments may slide completely out of the roof segments. In such case, not only must the wall segments be reassembled, but there is also danger to the miners involved, as well as the risk of damage to adjacent equipment, when the wall segments fall from the roof segments, since these segments are of very substantial weight.

It may also occur that even if the wall segments do not slide completely out of the roof segments, they may slide out therefrom to an extent to reduce the length of overlap of the wall and roof segments below the required length. Similarly, the lower wall segments may slide out of the upper roof segments to an extent to reduce the required length of overlap between the upper and lower wall segments.

For the avoidance of these disadvantages the present invention provides a yielding mine arch for an underground gallery, composed of three or more segments of substantially Ushaped cross section and having flanges projecting laterally therefrom, the segments being internested in one another and being positively frictionally couplable to one another by means of clamps, wherein the end portions of the segments, which portions overlap one another in the assembled condition of the arch, are provided in the regions of the bases of the segments, or in the regions of the flanges thereof, with protrusions which are aligned with one another so that the protrusion of each inner segment intersects the path of movement, in the axial direction of the segments, of a protrusion of the corresponding outer segment upon relative axial sliding movement between these segments, the protrusions being provided within the segments as seen in crosssection therethrough.

When therefore, during the assembly of a yielding mine arch, with the clamps loosened, the wall segments are pulled out from the roof segments manually or possibly by means of hydraulic piston-and-cylinder units, this can be done, only until the aligned protrusions engage one another. In this way the wall segments are prevented from sliding out of the roof segments beyond the minimum required length of overlap and indeed cannot become detached therefrom. The risk of accidents, or damage to the gallery advance apparatus is thereby avoided.

Further, since the minimum length of overlap of the segments is predetermined by the relative positioning of the protrusions lengthwise of the segments, the skill required to assemble the arch at the underground site is reduced, and the assembly of the arch is expedited. Also, the assembly of arches in the gallery can be better synchronized with the advance of the gallery. According to one embodiment of the invention, the overlapping portions of the segments are supported on one another by their flanges and by parts of their side walls adjacent to their flanges, so that the bases of the overlapping portions of the segments are spaced from one another, the protrusions of the inner segments being provided on the external surfaces of the bases of these segments and the protrusions of the outer segments being provided on the internal surfaces of the bases thereof.

The protrusions are accordingly accommodated between the bases of the inner and outer segments without impairing the functions of the segments.

According to another embodiment of the invention the overlapping end portions of the segments are supported on one another by their bases and by the parts of their side walls adjacent to their bases, so that the flanges of the overlapping portions are spaced from one another, the protrusions of the inner segments being provided on the under surfaces of their flanges and the protrusions of the outer segments being provided on the upper surfaces of their flanges.

In this embodiment, therefore the spaces between the lateral flanges of the inner and outer segments serve to accommodate the protrusions.

The protrusions may be associated with the segments in various ways. When, for example, the roof segment or segments is, or are, to be raised and the wall segments are to be pulled downwardly (i.e. towards the gallery floor) along the roof segment or segments with the clamps loosened, advantageously the protrusions of the outer segments are provided in the vicinity of the end faces of these segments, which faces are directed towards the roof when the arch is in use, the protrusions of the inner segments being spaced from the end faces of these segments, which faces are directed towards the floor when the arch is in use, by a distance which is substantially equal to the required length of overlap of the inner and outer segments.

In this embodiment therefore, the weight of the wall segments is utilized, during the assembly of the arch underground, to the effect that even if the clamps are too loose, the engagement of the protrusions is reliably effected, since as a result of the weight of the wall segments, their end portions which are directed towards the roof are urged against the roof segment or the roof segments.

When, however, the roof segment or the roof segments are to be raised along the wall segments, which are supported on the gallery floor, advantageously, the protrusions of the inner segments are provided in the vicinity of the end faces of these segments, which faces directed towards the floor when the arch is in use, the protrusions of the outer segments being spaced from the end faces of these segments, which faces are directed towards the roof when the arch is in use, by a distance which is substantially equal to the required length of overlap of the inner and outer segments.

The upper ends of the wall segments tend to tilt towards the longitudinal centre of the gallery so that the protrusions on the inner segments reliably engage the protrusions on the outer segments when the minimum required length of overlap between these segments has been attained by raising the roof segment or roof segments.

Conveniently, the protrusions are in the form of plates welded to the bases or to the flanges, of the segments, the thicknesses of each plate being slightly less than the spacing from one another of the bases or the flanges, of the overlapping portions of the segments.

Such plates can be produced at low cost and are readily secured to the segments in such a way that they can withstand engagement with one another under considerable force.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1 is a side view of a yielding mine arch according to a first embodiment of the invention, when preassembled above ground in two parts for transport to an assembly and erection site; Fig. 2 is a side view showing the arch at a first stage of its assembly and erection at the site; Fig. 3 is a side view showing the arch at a second stage of its assembly and erection at the site; Fig. 4 is a side view of the arch when fully assembled and erected at the site, also including a cross-sectional view of the arch; Fig. 5 is an enlarged view, shown partly in section, of detail V of Figure 3;; Fig. 6 is a view similar to that of Figure 5 but with parts broken away and being shown entirely in elevation and illustrating a second embodiment of the invention; Fig. 7 is a view similar to that of Figure 5 and illustrating a third embodiment of the invention; and Fig. 8 is a view similar to that of Figure 6 and illustrating a fourth embodiment of the invention.

Reference will now be made to Figures 1 to 5. The yielding mine arch 1, is, as shown in Figure 1 preassembled above ground in such way that it is comprised in two readily transportable groups A and B of parts, the parts in each group being secured together so that they remain so secured during their transport to an underground site at which the arch is to be assembled and erected for use.

The arch 1, when assembled, comprises two roof segments 2 and 3, two upper wall segments 4 and 5 and two lower wall segments 6 and 7, adjacent end portions of these segments being internested in one another. Both the roof segments and the wall segments are of generally U-shaped, i.e. channel-shaped, cross section having side walls 2", 3") 4", 5", 6" and 7", respectively, with the laterally projecting flanges, 2', 3', 4', 5', 6' and 7', respectively.

The said segments are so shaped that in the finally assembled condition of the arch 1 illustrated in to Fig. 4 (see the sectional view, which is taken through the region of overlap between the wall segment 4 and the roof segment 2) the overlapping end portions of the two adjacent segments 2 and 4 are supported on one another by their flanges 2' and 4' as well as by the parts of the side walls 2" and 4", which are adjacent to the flanges 2' and 4'.

As shown semi-diagrammatically in Figure 1, each two adjacent segments have been connected to one another by means of two clamps 8. In the group A, the roof segment 3 has connected thereto, in overlapping relationship, a short segment 9, by means of two clamps 8. The segment 9 projects beyond the left hand (as seen in Figure 1) end face 10 of the roof segment 3 to about the same extent as that to which the segment 9 is received in the roof segment 3.

Prior to their assembly to form the finished arch 1, the groups A and B are transported to the underground site at which the arch is to be assembled and erected for use, which may for example be directly in front of the working face of a gallery. At this site, the roof segments 2 and 3 of the groups A and B are brought into end to end abutment with one another and are then connected to one another by means of the segment 9 and clamps 8 as shown in Figure 2. During such assembly, the wall segments 4 and 6, and 5 and 7 which are received in the roof segments 2 and 3, respectively, remain in the positions in which they were preassembled above ground.

The groups A and B, when they have been connected as described above, are brought into a vertical position by means of positioning apparatus (not shown) which may conveniently be engaged in the vicinity of the junction between the roof segments 2 and 3.

After loosening the clamps 8 securing the upper wall segment 4 or 5 to the roof segment 2 or 3, as well as those securing the upper end portions of the lower wall segment 6 or 7 to the roof segment 2 or 3, the wall segments 4 and 6 or 5 and 7, which remain secured together by means of the clamps 8 at their lower ends, are slid downwardly, guided by the roof segments, until protrusions 14 (Figures 3 and 5) provided on the internal surfaces 11 of the bases 12 of the upper wall segments 4 and 5 and in the region of their upper end faces 13 (directed toward the gallery roof) engage protrusions 17 provided on the external surfaces 15 of the bases 16 of the roof segments 2 and 3.The protrusions 17 on the external surfaces 15 of the bases 16 of the roof segments 2 and 3 are spaced from the lower faces 18 (directed toward the gallery floor) of the roof segments 2 and 3 by a distance which corresponds substantially to the required length of overlap of the upper wall segments 4 and 5 and the roof segments 2 and 3.

The protrusions 14 and 17 consist of weldedon plates the thickness of which are a little less than the internal distance between the bases 12 and 16, as will be apparent from Figure 5.

The protrusions 14 and 17 therefore not only ensure the integrity of the wall segments 4 and 5 and the roof segments 2 and 3 even if the wall segments are withdrawn from the roof segments at such speed that the protrusions strike each other with a substantial impact, but also ensure the minimum required length of overlap of the adjacent segments.

By further raising the arch 1 when it has been completed to the extent shown in Figure 3, the upper wall segments 4 and 5 being immovably clamped to the roof segments 2 and 3, respectively, by means of clamps 8, the lower wall segments 6 and 7 can be withdrawn from the upper wall segments 4 and 5 after loosening the clamps 8 connecting the segments 4 and 5 to the segments 6 and 7, respectively. In this case also, it may be necessary to provide protrusions 14 and 17 according to Figures 3 and 5 in the regions of overlap between the upper and lower wall segments. After the withdrawal of the lower wall segments, the clamps 8 are finally secured, fixedly to connect the upper and lower wall segments. The arch 1 is now fully erected as shown in Figure 4 and may be braced to a previously erected gallery arch.

As described above, during assembly and erection of the arch 1, the wall segments 4, 5 and 6, 7 are withdrawn downwardly, the roof segments 2 and 3 being moved upwardly.

The floor side end portions of the wall segments, as a result of their weight, accordingly tend to swing downwardly towards the centre of the gallery so that the upper end portions of the upper wall segments 4 and 5 are urged against the roof segments 2 and 3 whilst connected thereto by the loosened clamps 8. The path of movement of a protrusion 14 on the internal surface 11 of a base 12 of an upper wall segment is accordingly directed accurately towards the protrusion 17 on the external surface 15 of the base 16 of adjacent roof segment.

In the embodiment of Figure 6, the segments of a yielding gallery arch, which segments are of generally U-shaped, i.e. channel shaped, Wross-section are supported on one another by their bases and by the parts of their side walls adjacent to their bases. In this embodiment therefore the lateral flanges 2' and 4' of the segments in the regions of overlap thereof are spaced from one another. In Figure 6 one roof segment 2 and one wall segment 4 of the arch are shown. Protrusions 14' and 17' limiting the withdrawal from one another of the segments, or the length of the regions of overlap of the segments, are therefore provided on the flanges 2' and 4' of the segments, rather than on their bases. The corresponding seg ments of the other side of the arch, which are not shown, are similarly provided with pro trusions for the same purpose.

The protrusion 14' is provided on the upper surface of the flange 4' near the upper end face 13 of the segment 4, i.e. that end face which is directed towards the roof, while the protrusion 17' cooperating with the protrusion 14' is provided on the lower surface 20 of the flange 2' of the inner segment 2 and is spaced from the lower end face 18 of the segment 2, i.e.

that end face which is directed towards the gallery floor, by a distance which substantially corresponds to the required length of overlap of the segments 2 and 4.

Reference will now be made of the embodiment of Figure 7, when the arch 1 has been erected to the extent shown in Figure 2 and the upper wall segments 4 and 5, with the clamps 8 there about loosened, are moved along the lower wall segments 6 and 7, or the roof segments 2 and 3 with the clamps 8 similarly loosened, are moved along the upper wall segments 4 and 5, the upper ends of the lower wall segments 6 and 7 or of the upper wall segments 4 and 5 tend to swing, by virtue of the weight of these segments, towards the centre of the gallery.In this case it is convenient to provide a protrusion 17" in the vicinity of the face 18 of the inner segment 2, on the external surface 15 of the base 16 of the segment 2 and a cooperating protrusion 14" on the internal surface of the base 12 of the outer segment 4 and being spaced from the end face 13 of that segment substantially by the required distance of overlap between the segments 2 and 4.

To the same end, as shown in Figure 8, where the segments are supported upon one another in the manner described with reference to Figure 6, a protrusion 17"' is provided on the lower surface 20 of the flange 2' of the segment 2, in the vicinity of the end face 18 of the segment 2, a cooperating protrusion 14"' provided on the upper surface 19 of the flange 4' of the segment 4, being spaced from the end face 13 of the segment 4, by a distance corresponding to the required distance of overlap between the segments 2 and 4.

In the case of the embodiments of Figures 7 and 8, in respect of which only two of the segments of the arch are shown and described, it is to be understood that other corresponding segments of the arch are similarly provided with protrusions.

WHAT WE CLAIM IS: 1. A yielding mine arch for an underground gallery, composed of three or more segments of substantially U-shaped cross section and having flanges projecting laterally therefrom, the segments being internested in one another and being positively frictionally coupable to one another by means of clamps, wherein the end portions of the segments, which portions overlap one another in the assembled con dition of the arch, are provided in the regions of the bases of the segments, or in the regions of the flanges thereof, with pro trusions which are aligned with one another so

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The protrusions 14 and 17 therefore not only ensure the integrity of the wall segments 4 and 5 and the roof segments 2 and 3 even if the wall segments are withdrawn from the roof segments at such speed that the protrusions strike each other with a substantial impact, but also ensure the minimum required length of overlap of the adjacent segments. By further raising the arch 1 when it has been completed to the extent shown in Figure 3, the upper wall segments 4 and 5 being immovably clamped to the roof segments 2 and 3, respectively, by means of clamps 8, the lower wall segments 6 and 7 can be withdrawn from the upper wall segments 4 and 5 after loosening the clamps 8 connecting the segments 4 and 5 to the segments 6 and 7, respectively. In this case also, it may be necessary to provide protrusions 14 and 17 according to Figures 3 and 5 in the regions of overlap between the upper and lower wall segments. After the withdrawal of the lower wall segments, the clamps 8 are finally secured, fixedly to connect the upper and lower wall segments. The arch 1 is now fully erected as shown in Figure 4 and may be braced to a previously erected gallery arch. As described above, during assembly and erection of the arch 1, the wall segments 4, 5 and 6, 7 are withdrawn downwardly, the roof segments 2 and 3 being moved upwardly. The floor side end portions of the wall segments, as a result of their weight, accordingly tend to swing downwardly towards the centre of the gallery so that the upper end portions of the upper wall segments 4 and 5 are urged against the roof segments 2 and 3 whilst connected thereto by the loosened clamps 8. The path of movement of a protrusion 14 on the internal surface 11 of a base 12 of an upper wall segment is accordingly directed accurately towards the protrusion 17 on the external surface 15 of the base 16 of adjacent roof segment. In the embodiment of Figure 6, the segments of a yielding gallery arch, which segments are of generally U-shaped, i.e. channel shaped, Wross-section are supported on one another by their bases and by the parts of their side walls adjacent to their bases. In this embodiment therefore the lateral flanges 2' and 4' of the segments in the regions of overlap thereof are spaced from one another. In Figure 6 one roof segment 2 and one wall segment 4 of the arch are shown. Protrusions 14' and 17' limiting the withdrawal from one another of the segments, or the length of the regions of overlap of the segments, are therefore provided on the flanges 2' and 4' of the segments, rather than on their bases. The corresponding seg ments of the other side of the arch, which are not shown, are similarly provided with pro trusions for the same purpose. The protrusion 14' is provided on the upper surface of the flange 4' near the upper end face 13 of the segment 4, i.e. that end face which is directed towards the roof, while the protrusion 17' cooperating with the protrusion 14' is provided on the lower surface 20 of the flange 2' of the inner segment 2 and is spaced from the lower end face 18 of the segment 2, i.e. that end face which is directed towards the gallery floor, by a distance which substantially corresponds to the required length of overlap of the segments 2 and 4. Reference will now be made of the embodiment of Figure 7, when the arch 1 has been erected to the extent shown in Figure 2 and the upper wall segments 4 and 5, with the clamps 8 there about loosened, are moved along the lower wall segments 6 and 7, or the roof segments 2 and 3 with the clamps 8 similarly loosened, are moved along the upper wall segments 4 and 5, the upper ends of the lower wall segments 6 and 7 or of the upper wall segments 4 and 5 tend to swing, by virtue of the weight of these segments, towards the centre of the gallery.In this case it is convenient to provide a protrusion 17" in the vicinity of the face 18 of the inner segment 2, on the external surface 15 of the base 16 of the segment 2 and a cooperating protrusion 14" on the internal surface of the base 12 of the outer segment 4 and being spaced from the end face 13 of that segment substantially by the required distance of overlap between the segments 2 and 4. To the same end, as shown in Figure 8, where the segments are supported upon one another in the manner described with reference to Figure 6, a protrusion 17"' is provided on the lower surface 20 of the flange 2' of the segment 2, in the vicinity of the end face 18 of the segment 2, a cooperating protrusion 14"' provided on the upper surface 19 of the flange 4' of the segment 4, being spaced from the end face 13 of the segment 4, by a distance corresponding to the required distance of overlap between the segments 2 and 4. In the case of the embodiments of Figures 7 and 8, in respect of which only two of the segments of the arch are shown and described, it is to be understood that other corresponding segments of the arch are similarly provided with protrusions. WHAT WE CLAIM IS:

1. A yielding mine arch for an underground gallery, composed of three or more segments of substantially U-shaped cross section and having flanges projecting laterally therefrom, the segments being internested in one another and being positively frictionally coupable to one another by means of clamps, wherein the end portions of the segments, which portions overlap one another in the assembled con dition of the arch, are provided in the regions of the bases of the segments, or in the regions of the flanges thereof, with pro trusions which are aligned with one another so

that the protrusion of each inner segment intersects the path of movement, in the axial direction of the segments, of a protrusion of the corresponding outer segment upon relative axial sliding movement, away from one another, between these segments, the protrusions being provided within the segments as seen in cross-section therethrough.

2. An arch as claimed in claim 1, wherein the overlapping portions of the segments are supported on one another by their flanges and by parts of their side walls adjacent to their flanges, so that the bases of the overlapping portions of the segments are spaced from one another, the protrusions of the inner segments being provided on the external surfaces of the bases of these segments and the protrusions of the outer segments being provided on the internal surfaces of the bases thereof.

3. An arch as claimed in claim 1, wherein the overlapping end portions of the segments are supported on one another by their bases and by the parts of their side walls adjacent to their bases, so that the flanges of the overlapping portions are spaced from one another, the protrusions of the inner segments being provided on the under surfaces of their flanges and the protrusions of the outer segments being provided on the upper surfaces of their flanges.

4. An arch as claimed in any one of the preceding claims, wherein the protrusions of the outer segments are provided in the vicinity of the end faces of these segments, which faces are directed towards the roof when the arch is in use, the protrusions of the inner segments being spaced from the end faces of these segments, which faces are directed towards the floor when the arch is in use, by a distance which is substantially equal to the required length of overlap of the inner and outer segments.

5. An arch as claimed in any one of claims 1 to 3, wherein the protrusions of the inner segments are provided in the vicinity of the end faces of these segments, which faces are directed towards the floor when the arch is in use, the protrusions of the outer segments being spaced from the end faces of these segments, which faces are directed towards the roof when the arch is in use, by a distance which is substantially equal to the required length of overlap of the inner and outer segments.

6. An arch as claimed in any one of the preceding claims, wherein the protrusions are in the form of plates welded to the bases or to the flanges, of the segments, the thicknesses of each plate being slightly less than the spacing from one another of the bases or of the flanges, of the overlapping portions of the segments.

7. A yielding mine arch for an underground gallery, substantially as herein described and illustrated by the accompanying drawings.