GB2091314A

GB2091314A - Packing Means for Underground Passageways

Info

Publication number: GB2091314A
Application number: GB8138281A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-30
Filing date: 1981-12-18
Publication date: 1982-07-28
Also published as: DE3151761A1; GB2091314B

Abstract

Packing means for supporting the roof of an underground passageway comprise a bag (2) of a flexible material of a length at least equal to the height of the passageway, and resilient means (10) mounted on the bag (2). Releasable retaining means (not shown) hold the resilient means (10) and the bag (2) in a compressed condition until it is desired to install the packing means in the passageway; then, on release of said retaining means, the resilient means (10) extend and the bag (2) is drawn upwardly to abut the roof of the passageway after which a settable filler material is fed through an inlet (16) into the bag. <IMAGE>

Description

SPECIFICATION Packing Means for Underground Passageways This invention relates to packing means for underground passageways and more particularly to such means for location in a passageway to support the roof of said passageway.

As a coal face in an underground mine advances, it is necessary for the roof of the passageway so formed to be supported to prevent collapse thereof and this is normally done by arched girders. However it is advisable to supplement the support given by these girders, and one established method of providing this additional support is to use large cubic bags of flexible material which are suspended from the roof to be supported, adjacent the arched girders, and are subsequently filled with a settable mixture of, for example, water and cement, the bags, when filled, reacting between the floor and the roof of the passageway to support said roof.

Adjacent bags conveniently engage one another to provide a sealed barrier along the side of the passageway.

Such a system has many disadvantages. It is often difficult to gain access to the roof of the passageway to tie or otherwise secure the bags in position, while the bags, on being filled with the settable mixture, which is typically 85% water and 15% cement and catalyst/plasticiser, have a strong tendency for their vertical walls to bow out considerably so that they do not extend the full height of the passageway. It has therefore become common practice to support the sidewalls of the bags for example with sheets of wire mesh or complex mechanical shuttering extending between wooden props or the like the prevent such bowing. However it will be appreciated that the provision of support arrangements for the bags adds considerably to the expense, as well as the labour, involved.

According to the present invention there is provided packing means for an underground passageway comprising a bag of flexible material the length of which is at least equal to the height of the passageway to be packed, resilient means mounted on said bag and releasable means for retaining the resilient means in a compressed condition, the arrangement being such that, on location of the bag and the compressed resilient means on the floor of the passageway and on release of the retaining means, the resilient means extend the bag to abut said bag against the roof of the passageway, the bag being provided with inlet means for a settable filler material.

The resilient means preferably comprise at least one coiled compression spring the normal length of which is at least equal to the height of the passageway to be packed.

In one embodiment of the invention, a coiled compression spring is located within the bag to react between the lower and upper ends of the bag.

In an alternative embodiment of the invention, the bag is suspended within the coils of a coiled compression spring.

In both said embodiments it is preferred that the bag is of cylindrical shape, the diameter of the spring and the bag being substantially equal.

The shape of the bag may be other than cylindrical, for example half-cylindrical (i.e. semicircular in transverse section) or generally rectangular in transverse section. In the latter case, the resilient means may comprise one or more springs mounted to one or more of the sidewalls of the bag. The or each spring may be of strip material, for example of generally zigzag shape.

Conveniently the packing means further comprise a plurality of attachment means on the exterior thereof to enable connection to adjacent packing means within a passageway. Said attachment means may comprise a plurality of ties, for example of rope or wire, preferably carried on circumferential strengthening straps secured to the external surface of, to surround, the bag.

The packing means may further comprise attachment means on the upper surface of the bag such that, subsequent to extension of the bag, connection can be made to the roof of the passageway by way of said attachment means to assist in the retention of the bag in its extended condition.

The inlet means for the filler material conveniently comprises a tube feeding into the upper regions of the bag, for example through the upper end thereof.

By way of example only an embodiment of the invention will now be described in greater detail with reference to the accompanying drawing of which: Fig. 1 shows, side-by-side, packing means according to the invention one with a coiled spring in a compressed condition, and the other with a coiled spring in a normal extended condition; Fig. 2 shows detail of the spring in a bag of Fig.

1, and Figs. 3a and 3b are schematic plan views from above of two alternative arrangements for a plurality of packing means according to the invention within a passageway.

Referring to the drawings, the illustrated packing means comprises a cylindrical bag 2 of flexible material such as pvc-coated polyester nylon or the like, the bag being of circular transverse section and including a lower end wall 4, an upper end wall 6 and a cylindrical sidewall 8 defining a closed interior to the bag.

Located within the bag is a heavy duty coiled compression spring 10 of, for example, 12 mm diameter spring steel. The diameter of the coils of the spring 10 is substantially equal to the diameter of the bag 2, while the length of the spring in its normal condition (Fig. 2) is also substantially equal to the length of the bag 2, which length is at least equal to the height of the passageway in which the packing means is to be located for reasons which will become apparent.

A plurality of axially-spaced strengthening bands 12 are provided around the bag 2, each band having a series of ties 14 of rope or other suitable material secured thereto to enable adjacent bags to be attached to one another and/or to fixtures within the passageway on use of the packing means.

An inlet funnel 16 feeds through the upper end wall 6 of the bag to communicate into the interior of the bag.

During transportation of the packing means and prior to installation in a passageway, the spring 10 and bag 2 are held in an axially compressed condition as illustrated in the righthand side of Fig. 1 by retaining means in the form of a releasable strap 1 8.

When it is desired to assist in the support of the roof of a passageway, for example as a coal face progresses and leaves a void behind it, and/or when it is desired to close off said void so formed from the passageway with a substantially air-tight seal, the above described packing means can be used as follows.

A packing means in its compressed condition is transported to the desired position in a passageway and located on the floor 20 of the passageway below the roof 22 to be supported.

The strap 1 8 is released, allowing the spring 10 to extend in the direction of arrows A in Fig. 1 towards its normal length, the spring carrying with it the flexible bag 2.

As mentioned above, the length of the spring 10 and the bag 2 is at least equal to the height of the passageway, so that the upper end wall 6 of the bag is urged by the spring 10 into engagement with the roof 22 of the passageway.

At this stage a settable filler material is pumped into the bag through the inlet funnel 16 to fill the bag, the filler material typically comprising 85% water and 1 5% cement and a catalyst/plasticiser. The filler material initially sets into a non-runny, plasticine-!ike state during which time the roof now being supported by the packing means converges and settles onto the top of the bag which in turn conforms with the contours of the roof. The filler material then sets hard within a few days.

In practice a number of packing means are located closely adjacent one another along the side of the passageway as shown, for example, in Figs. 3a and 3b. Adjacent bags can be connected to one another by means of the ties 14, which ties also permit the bags immediately adjacent the sidewalls of the passageway to be secured to fixtures, for example the arched girders, in the passageway. It will be appreciated that, prior to setting hard, the sidewalls 8 of a bag mould around the sidewalls of an adjacent bag to create a substantially airtight seal between said bags.

Although shown and described as being within the bag 2, the coiled compression spring 10 may be external of the bag 2, said bag 2 being suspended within the coils of the spring 1 0.

Thus there are provided self-erecting packing means which utilise the inherent energy of resilient means, typically a coiled compression spring, to extend a closed container the full height between the floor and the roof of a passageway to be supported or sealed, thus eliminating the necessity, as exists with established arrangements, for initially securing the bag or container to said roof prior to filling, said resilient means also serving to retain the bag in its fully extended position until the filler material sets hard. Although described and illustrated as having a vertical orientation, the springs may be located horizontally providing abutment of the bag with the roof is achieved on release of the retaining means.

The use of a cylindrical bag avoids the bowing out that occurs on filling a cubic-shaped bag, the forces present within a cylindrical bag on filling helping to create the desired circular shape and also serving to mould the bag around previously installed bags to create a substantially air-tight seal between said bags.

However it is possible to use bags of shape other than cylindrical, for example bags of semi-circular or rectangular transverse section, and to use resilient means other than coiled compression springs.

In t'ne case of a bag of rectangular crosssection, the resilient means may comprise springs of flat strip material bent into for example generally zigzag shape, one or more of said springs being mounted into one or more of the sidewalls of the bag. As well as effecting the necessary extension of the bag said springs may serve to reduce the bowing out of said sidewalls that might otherwise occur on filling of the bag with a filler material.

Other modifications and variations of the illustrated arrangement will be apparent to those skilled in the art.

Claims

1. Packing means for an underground passageway comprising a bag of flexible material the length of which is at least equal to the height of the passageway to be packed, resilient means mounted on said bag and releasable means for retaining the resilient means in a compressed condition, the arrangement being such that, on location of the bag and the compressed resilient means on the floor of the passageway and on release of the retaining means, the resilient means extend the bag to abut the bag against the roof of the passageway, the bag being provided with inlet means for a settable filler material.

2. Packing means as claimed in claim 1 in which the resilient means comprise at least one coiled compression spring the normal length of which is at least equal to the height of the passageway tobe packed.

3. Packing means as claimed in claim 2 in which a coiled compression spring is located within the bag to react between the lower and upper ends of the bag.

4. Packing means as claimed in claim 2 in which the bag is suspended within the coils of a coiled compression spring.

5. Packing means as claimed in claim 3 or claim 4 in which the bag is of cylindrical shape, the diameter of the spring and the bag being substantially equal.

6. Packing means as claimed in claim 1 in which the bag is of generally rectangular shape in transverse section.

7. Packing means as claimed in claim 6 in which the resilient means comprise one or more springs mounted to one or more of the sidewalls of the bag.

8. Packing means as claimed in claim 7 in which each spring is of strip material of generally zigzag shape.

9. Packing means as claimed in any one of claims 1 to 8 and comprising a plurality of attachment means on the exterior thereof to enable connection to adjacent packing means within a passageway.

10. Packing means as claimed in claim 9 in which the attachment means comprise a plurality of ties carried on circumferential strengthening straps secured to the external surface of, to surround, the bag.

11. Packing means as claimed in any one of claims 1 to 10 and comprising attachment means on the upper surface of the bag such that, subsequent to extension of the bag, connection can be made to the roof of the passageway to assist in the retention of the bag in its extended condition.

12. Packing means as claimed in any one of claims 1 to 11 in which the inlet means for the filler material comprises a tube feeding into the upper regions of the bag.

13. Packing means as claimed in claim 12 in which the tube feeds through the upper end of the bag.

1 4. Packing means for an underground passageway substantially as described with reference to and as illustrated by the accompanying drawings.