GB2237318A

GB2237318A - A mine roof support

Info

Publication number: GB2237318A
Application number: GB9023086A
Authority: GB
Inventors: David Chandler
Original assignee: Meco Mining Equipment Ltd
Current assignee: Meco Mining Equipment Ltd
Priority date: 1989-10-24
Filing date: 1990-10-24
Publication date: 1991-05-01
Anticipated expiration: 2010-10-24
Also published as: GB2237318B; GB8923952D0; GB9023086D0

Abstract

A mine roof support comprises a ground engageable base section (13), a roof engageable canopy (10), and hydraulic props (14) for raising and lowering the canopy relative to the base section. The canopy comprises a main part (16) and an extension part (17) which can be connected together by fastening means comprising a hook-shaped formation (19) on one of the parts and a substantially C-shaped formation (20) on the other part. When the parts are connected together an upper portion of the C-shaped formation (20) is hooked over the hook-shaped formation (19) and a lower portion of the C-shaped formation (20) bears against the said one part below the hook-shaped formation (19). The fastening means also comprises a locking element (29) which can be inserted through an aperture in the lower portion of the C-shaped formation (20) and into a space between the lower portion of the C-shaped formation and the hook-shaped formation. <IMAGE>

Description

A Mine Roof Support This invention relates to a mine roof support, and in particular to a mine roof support having a two part canopy.

Mine roof supports conventionally include a ground engageable base section, a roof engageable canopy, and hydraulic prop means for raising and lowering the canopy relative to the base section. It is known from GB 2138876 B to provide the canopy in two parts, i.e. a main part and an extension part, and to connect these parts together with a plurality of connecting members of dumb-bell profile. When the roof support is in use, the connection between the two parts is subject to very large horizontal forces and it is necessary, therefore, to make the connecting members of high tensile steel.

According to the present invention, there is provided a mine roof support comprising a ground engageable base section, a roof engageable canopy, and hydraulic prop means for raising and lowering the canopy relative to the base section, the canopy comprising a main part and an extension part which can be connected together by fastening means comprising a hook-shaped formation on one of the parts and a substantially Cshaped formation on the other part, arranged so that when the parts are connected together an upper portion of the substantially C-shaped formation is hooked over the hook-shaped formation and a lower portion of the substantially C-shaped formation bears against the said one part below the hook-shaped formation, the fastening means further comprising means for preventing such relative vertical displacement of the hook-shaped formation and the substantially C-shaped formation that would allow the hook-shaped formation and the substantially C-shaped formation to come apart freely.

Preferably, the hook-shaped formation has a first limb which projects substantially horizontally from an end of the said one part and a second limb which projects substantially vertically upwards from that end of the first limb remote from the said one part, and the upper end of the substantially C-shaped formation is hook-shaped and has a third limb which projects substantially horizontally from an end of the said other part and a fourth limb which projects substantially vertically downwards from that end of the third limb remote from the said other part.

Preferably, the lower portion of the C-shaped formation comprises a single limb which projects substantially horizontally from the said other part.

Advantageously, the said one part is provided with a plurality of hook-shaped formations which are spaced apart from one another in a horizontal direction transverse to the direction in which the two parts are co-extensive, when connected together, and the said other part has a plurality of C-shaped formations separated by webs which extend between upper and lower portions of the C-shaped formations and which, when the two parts are connected together, are positioned between respective pairs of adjacent hook-shaped formations.

Preferably, each set of formations is formed as an integral casting secured, such as by welding, to a respective part of the canopy.

Preferably, the displacement preventing means comprises a locking element which can be inserted through an aperture in the lower portion of the C-shaped formation and into a space between the lower portion of the C-shaped formation and the hook-shaped formation.

In this case, conveniently, said locking element is in the form of a wedge which can be inserted through the aperture in the lower portion of the C-shaped formation and driven between the lower portion of the C-shaped formation and the hook-shaped formation.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of one embodiment of a mine roof support according to the invention, with the two parts of the canopy connected together, Figure 2 is a view similar to Figure 1, but showing the extension part of the canopy on top of the main part of the canopy, Figure 3 is a perspective view of one of the connecting members of the canopy, on an enlarged scale, Figure 4 is a perspective view of the other of the connecting members of the canopy,, on the same scale as Figure 3, and Figure 5 is a section through the connecting members of Figures 3 and 4, when connected together and on an even larger scale.

Referring firstly to Figures 1 and 2 of the drawings, the mine roof support shown therein comprises a canopy 10, a shield section 11, a lemniscate linkage arrangement 12, a base section 13, and four hydraulic props 14.

The shield section 11 is pivotally connected at one end to one end of the canopy 10, and the lemniscate linkage arrangement 12, which includes three links 15, is pivotally connected at one end to the other end of the shield section, and at the other end to the base section 13.

The canopy 10 comprises a main part 16 to which the shield section 11 and the props 14 are connected, and an extension part 17 which, as shown, has an articulated tip 18.

The two parts 16 and 17 of the canopy 10 are connected together by connecting members 19 and 20 secured, such as by welding, to adjacent ends of the two parts 16 and 17, respectively.

As best shown in Figures 3 and 5, the connecting member 19 comprises a bar 21 which is secured to the front end of the main canopy part 16 as shown in Figures 1 and 2, and a plurality of hook-shaped formations 22 which are spaced apart in a horizontal row along the longitudinal extent of bar 21. Each hookshaped formation 22 has a thick first limb 22a projecting substantially horizontally from the bar 21 and, hence, from the main part 16 of the canopy 10, and a second limb 22b which projects substantially vertically upwards from that end of the first limb 22a remote from the bar 21. The lower front portion of the first limb 22a is bevelled at 22c for a purpose which will become apparent hereinafter.

As best shown in Figures 4 and 5, the connecting member 20 comprises a bar 23 which is secured to the rear end of the extension part 17 of the canopy 10 as shown in Figure 1, a plurality of hook-shaped formations 24 projecting from the upper end of the bar 23, and a plurality of arms 25 projecting substantially horizontally from the lower end of the bar 23. Each formation 24 comprises a first limb 24a projecting substantially horizontally from the upper end of the bar .23 and, hence, from the extension part 17 of the canopy 10, and a second limb 24b which projects substantially vertically downwards from that end of the first limb 24a remote from the bar 23. Each formation 24 together with an associated arm 25 and the bar 23 define a C-shaped formation. The C-shaped formations are arranged in a row along the longitudinal extent of the bar 23 and adjacent pairs of C-shaped formations have a web 26 therebetween which extends between the hook-shaped formations 24 at the upper end of the bar 23 and the arms 25 at the lower end of the bar 23 to reinforce the formations 24 and the arms 25.

As shown in Figure 4, the C-shaped formations and the reinforcing webs 26 define a plurality of compartments 27 in the connecting member 20, each of which compartments is adapted to receive one of the hook-shaped formations 22 of the connecting member 19 and a locking element 29 (see Figure 5) which is inserted into a respective compartment through an aperture 28 in the arm 25.

The connecting members 19 and 20 are each formed as an integral casting.

The webs 26 serve to keep the height of the connecting members 20, and hence the overall thickness of the canopy, to a minimum. In the absence of the webs 26, the formations 24 would have to be thicker to prevent these formations peeling over the formations 22 when the canopy is set against a mine roof, and this would lead to a thicker canopy.

The chief reason for providing the canopy 10 in two parts 16 and 17 is to make it easier to transport the mine roof support to a required location.

When it is required to connect the two parts 16 and 17 together, the extension part 17 is presented to the main part 16 so that the hook-shaped formations 22 of the connecting member 19 can enter the compartments 27 in the connecting member 20 and the webs 26 can enter between adjacent pairs of formations 22.

The connecting member 20 is then lowered relative to the connecting member 19 so that the limbs 22b of the hookshaped formations 22 engage behind respective limbs 24b of the hook-shaped formations 24 and vice versa and the rear end of each arm 25 makes contact with the front face of the bar 21.

Locking elements 29 are then inserted through the apertures 28 and into the space between the lower surfaces of hook-shaped formations 22 and the upper surfaces of respective arms 25, aided by the bevelled portions 22c of the formations 22. As shown, the locking elements are in the form of wedges, which are driven between the lower surfaces of the hook-shaped formations 22 and the upper surfaces of the respective arms 25, and which have integral handles 30 which enable the wedges to be prised out when the two parts 16 and 17 are to be disconnected.

Blocks loosely fitted into the spaces between the hook-shaped formations 22 and the arms 25 could be used as the locking elements instead of wedges provided that they are large enough to prevent such relative vertical displacement of the parts 16 and 17 that would allow the parts 16 and 17 to move apart freely.

When the mine roof support is in use and the canopy is set against a mine roof, the hook-shaped formations 22 and 24 will be in tension and the arms 25 will be in compression. In many circumstances, the connecting members 19 and 20 would alone be sufficient to connect the two parts 16 and 17 together without any need for the locking elements. However, it is not uncommon for props to be set under the extension part 17 and if this were to be done in the absence of the locking elements, there would be a risk of the extension part 17 coming away from the main part 16.

The above embodiment is given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention. For example, the connecting members 19 and 20 could be reversed, i. e. the connecting member 19 could be secured to the extension part 17 and the connecting member 20 could be secured to the main part 16. Also, the locking elements 29 could be replaced by any other appropriate means for preventing such relative vertical displacement of the connecting members 19 and 20 that would allow the connecting members 19 and 20 to come apart freely.

Claims

1. A mine roof support comprising a ground engageable base section, a roof engageable canopy, and hydraulic prop means for raising and lowering the canopy relative to the base section, the canopy comprising a main part and an extension part which can be connected together by fastening means comprising a hook-shaped formation on one of the parts and a substantially Cshaped formation on the other part, arranged so that when the parts are connected together an upper portion of the substantially C-shaped formation is hooked over the hook-shaped formation and a lower portion of the substantially C-shaped formation bears against the said one part below the hook-shaped formation, the fastening means further comprising means for preventing such relative vertical displacement of the hook-shaped formation and the substantially C-shaped formation that would allow the hook-shaped formation and the substantially C-shaped formation to come apart freely.

2. A mine roof support as claimed in Claim 1, wherein the hook-shaped formation has a first limb which projects substantially horizontally from an end of the said one part and a second limb which projects substantially vertically upwards from that end of the first limb remote from the said one part, and the upper end of the substantially C-shaped formation is hookshaped and has a third limb which projects substantially horizontally from an end of the said other part and a fourth limb which projects substantially vertically downwards from that end of the third limb remote from the said other part.

3. A mine roof support as claimed in Claim 2, wherein the lower portion of the C-shaped formation comprises a single limb which projects substantially horizontally from the said other part.

4. A mine roof support as claimed in any one of the preceding claims, wherein the said one part is provided with a plurality of hook-shaped formations which are spaced apart from one another in a horizontal direction transverse to the direction in which the two parts are co-extensive, when connected together, and the said other part has a plurality of C-shaped formations separated by webs which extend between upper and lower portions of the C-shaped formations and which, when the two parts are connected together, are positioned between respective pairs of adjacent hook-shaped formations.

5. A mine roof support as claimed in Claim 4, wherein each set of formations is formed as an integral casting secured to a respective part of the canopy.

6. A mine roof support as claimed in any one of the preceding claims, wherein the displacement preventing means comprises a locking element which can be inserted through an aperture in the lower portion of the C-shaped formation and into a space between the lower portion of the C-shaped formation and the hookshaped formation.

7. A mine roof support as claimed in Claim 6, wherein said locking element is in the form of a wedge which can be inserted through the aperture in the lower portion of the C-shaped formation and driven between the lower portion of the C-shaped formation and the hookshaped formation.

8. A mine roof support substantially as hereinbefore described with reference to the accompanying drawings.