GB2215361A - Apparatus for positioning support arches in mine roadways - Google Patents

Abstract

Apparatus for positioning support arches in mine roadways includes a lifting rig (24) having at least two shoe or cradle parts (32, 34) in which at least two crown portions for or forming part of two support arches can be engaged. The shoe or cradle part (34) is movable relative to the shoe or cradle part (32). In a second embodiment clamps are used to engage the support arches. <IMAGE>

Description

Mechanical handling apparatus.

The invention relates to mechanical handling apparatus for use in positioning support arches in mine roadways, such support arches being spaced apart at intervals along the length of the roadway, the spacing being dependent upon the strata through which the roadway is being driven.

When constructing a mine roadway support arch one method is to connect together three lengths of rolled steel joist sections which are to constitute a pair of upstanding but inwardly inclined side supports at the opposite sides of the roadway and a horizontal length, usually termed the crown, connected at its opposite ends to the respective side supports. In this case it is usual to use bolted connections including fish-plates to connect together the adjacent lengths of rolled steel joist sections and in some cases it is thought to be easier and safer to make these connections with the three lengths of material flat down on the mine roadway floor rather than in the position in which the erected arch is to occupy. However, the completed arch is fairly heavy and would be dangerous to manhandle into position.

Another method is to build the support arch in the position in which it is to be used, that is to say to erect the side supports or legs in their final position and then to bolt the horizontal length or crown portion in position to extend between their upper ends. However, this method of erection is fairly slow and laborious.

A further complication is that, again depending upon the strata through which the roadway is being driven, it is sometimes necessary to use areas of steel mesh extending between the crown portions of adjacent arches to guard against the hazards of pieces of rock falling from the roof between the arches. This is a difficult task to carry out with either one of the methods of support arch construction referred to.

The invention has for its object to at least alleviate all of these problems.

According to the invention, there is provided apparatus by means of which at least the crown portions of support arches can be positioned in a mine roadway, the apparatus including a boom pivotally connected to a trolley mounted for movement along a track secured to support arches already fixed in position, a lifting rig being pivotally connected to a free end of the boom, said lifting rig being provided with at least two shoe or cradle parts in which at least two crown portions for or forming part of two support arches can be engaged to be lifted simultaneously into position at required spacings.A hydraulic ram will preferably be provided for pivoting the lifting rig relative to the boom in accordance with the pivotal movement of the boom relative to the trolley so that the at least two crown portions for or forming part of support arches can be lifted into position simultaneously.

The lifting rig may include a main body part having structure forming a fixed shoe or cradle, structure forming a movable shoe or cradle being adjustable in position towards or away from said fixed shoe or cradle according to the required spacing of the support arches. Means whereby the movable shoe or cradle can be locked in position at an adjusted spacing from said fixed shoe or cradle may be constituted by a pair of removable pins or the like which can be inserted through holes formed in parts of said movable shoe or cradle and through selected pairs of holes spaced apart at intervals along a part of said main body.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which:- Figure 1 is a side view of apparatus embodying the invention, Figure 2 is a side view of a lifting rig forming part of the apparatus, this being drawn to a somewhat larger scale than Figure 1, Figure 3 is a plan view of the lifting rig, and Figures 4 and 5 are views which will be referred to when describing a possible modification.

Referring now to Figure 1 of the drawings, the apparatus there illustrated and being used in one mode of operation for positioning roof beams in a mine roadway includes a trolley 10 suspended by wheel units, generally indicated 12, from a track 14 secured (by means not shown) to roof beams 15 already fixed in position. The track 14 is constituted by a single length of R.S.J. section secured to the roof beams substantially midway of the width of the roadway.

A boom 16 is pivotally connected by means of a pivot pin 18 to a leading end of the trolley. A hydraulic ram 20 is pivotally connected at its opposite ends between side plates 22 depending from the trolley and between side plates which form part of the boom. The hydraulic ram is operable to lift or lower the boom about the pivot pin 18 as shown in Figure 1.

At its free end the boom is pivotally connected to a lifting rig, generally indicated 24, by means of a pivot pin 26. The lifting rig can be pivoted relative to the boom 16 by means of a hydraulic ram 28.

Referring now in particular to Figures 2 and 3, the lifting rig 24 is such that it can be used in this first mode to lift adjacent pairs of preformed roof arches into position simultaneously, as indicated in chain-dotted lines in Figure 1. As shown, the lifting rig includes a main body part constituted by a pair of parallel box-section members 30,30 connected at their forward ends by fabricated structure forming a fixed shoe 32 for the reception of a horizontal length or crown portion of a pre-formed arch as shown in chaindotted lines in Figure 1.Mounted on the boxsection members intermediate the length of the rig is a fabricated structure constituting a movable shoe 34 capable of being adjusted in position towards or away from the fixed shoe, said movable shoe also having been designed for the reception of a horizontal length of a pre-formed arch also as shown in chain-dotted lines in Figure 1. Sleeve members 36 which are carried by the movable shoe are slidably mounted on respective slide bars 38 forming part of the main body, thus maintaining the movable shoe in parallel relationship with the fixed shoe.Means whereby the movable shoe can be locked in position at an adjusted spacing from the fixed shoe are constituted by a pair of removable pins (not shown) which can be inserted through holes formed in brackets 40,40 carried by the movable shoe and through selected pairs of holes 42 spaced apart at intervals along the box-section members 30,30 of the main body.

In use of the apparatus in this first mode of use, the movable shoe of the lifting rig will be adjusted in position according to the required spacing of adjacent support arches which are to be lifted into position. With the lifting rig resting on the floor of the mine roadway, as shown in chain-dotted lines in Figure 1, a pair of preformed support arches can be positioned in the shoes 32 and 34 of the lifting rig, the boom 16 can be raised to a substantially horizontal position, as shown in full lines in Figure 1, and the entire apparatus then advanced by a forward movement of the trolley 10 to bring the two arches to appropriate positions in advance of the last two arches already fixed in position, and shown in full lines in Figure 1.A final lifting movement of the boom will then position the horizontal lengths or crown portions of the pair of arches simultaneously, the precise positioning of the lower ends of their upstanding but inwardly inclined side supports being effected manually.

It has been found that the erection of a series of mine roadway support arches in this way can be effected safely and in a relatively short space of time. If it is found that the strata through which the roadway is being driven changes so that a different spacing of the support arches is appropriate this can very easily be effected by adjusting the spacing of the movable shoe from the fixed shoe.

Referring now to Figures 4 and 5, these indicate a possible modification whereby the apparatus can be used in a different mode when it is desired to build a support arch by a different method, that is to say by erecting the side supports or legs in their final position and then bolting the horizontal length of crown portion in position to extend between their upper ends. In this mode of use, the horizontal lengths or crown portions for the support arches concerned are engaged in the shoe or cradle parts of the lifting rig so that they can be lifted simultaneously into position at required spacings, as indicated in Figure 4.

The modification referred to is the addition of pairs of beam clamps, generally indicated 44, to the lifting rig 24, said beam clamps having been arranged one on each side of each of the fixed and movable shoes of the rig.

Each beam clamp is constituted by a bell crank lever 46 acted upon by a trunnion mounted double acting hydraulic ram 48, the arrangement being such that when the ram is extended, as shown in full lines in Figure 5, the bell crank lever is pivotted to a position in which its clamping end is brought into engagement with the lower flange of the horizontal length or crown portion of an arch which is located in the shoe portion concerned. The modification is such that the horizontal or crown portions are held very securely and safely in the lifting rig until released by the retraction of the hydraulic rams 48, by which time the side supports or legs will have been erected and secured to the opposite ends of said horizontal or crown portions.

A further advantage is that each horizontal or crown portion remains fixed in position in the lifting rig throughout the lifting of the latter from its lowered position to its fully raised position instead of being obliged to rotate, as in the previously described mode of use, during the erection of the complete arch. This facilitates the fixing of areas of steel mesh between each pair of horizontal or crown portions before they have been raised to roof height in the mine roadway concerned. In Figure 4 there is shown such an area of steel mesh M extending between the pair of horizontal or crown portions located in the lifting rig. As indicated in chain-dotted lines, the horizontal or crown portions have been placed in position in the lifting rig, and the area of steel mesh secured to them, with the lifting rig suspended at a convenient working height above the floor of the mine roadway.

Various other modifications could be made. For example, the means for varying the spacing of the movable shoe from the fixed shoe could be differently arranged. In fact it would not be outside the scope of the invention for the lifting rig to be provided with a plurality of fixed shoes which could be used in selected pairs according to the required arch spacing.

Claims (5)

CLAIMS:

1. Apparatus by means of which at least the crown portions of support arches can be positioned in a mine roadway, the apparatus including a boom pivotally connected to a trolley mounted for movement along a track secured to support arches already fixed in position, a lifting rig being pivotally connected to a free end of the boom, said lifting rig being provided with at least two shoe or cradle parts in which at least two crown portions for or forming part of two support arches can be engaged to be lifted simultaneously into position at required spacings.

2. Apparatus according to claim 1, in which a hydraulic ram is provided for pivoting the lifting rig relative to the boom in accordance with the pivotal movement of the boom relative to the trolley so that the at least two crown portions for or forming part of support arches can be lifted into position simultaneously.

3. Apparatus according to either one of claims 1 and 2, in which the lifting rig includes a main body part having structure forming a fixed shoe or cradle, structure forming a movable shoe or cradle being adjustable in position towards or away from said fixed shoe or cradle according to the required spacing of the support arches.

4. Apparatus according to claim 3, in which means whereby the movable shoe or cradle can be locked in position at an adjusted spacing from said fixed shoe or cradle are constituted by a pair of removable pins or the like which can be inserted through holes formed in parts of said movable shoe or cradle and through selected pairs of holes spaced apart at intervals along a part of said main body.

5. Apparatus by means of which at least the crown portion of support arches can be positioned in a mine roadway, the apparatus being constructed, arranged and adapted to be used substantially as hereinbefore described with reference to and -as illustated by Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.