GB2071180A

GB2071180A - Installing tunnel roof supports

Info

Publication number: GB2071180A
Application number: GB8106815A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-03-05
Filing date: 1981-03-04
Publication date: 1981-09-16

Abstract

A lifting apparatus for use in installing roof-supporting members in a tunnel, for example a mine roadway, comprises a main frame 4 having clamps 5 which engage upon two or more of the existing roof supports to suspend the apparatus. A pair of lifting arms 20 are pivotally mounted on the main frame and can pivot forwardly thereof. The arms 20 are adapted to engage a new roof-supporting arch to lift it into position in the tunnel, hydraulic rams 21 serving to move the arms through pin and control slot drive arrangements 24, 25, 27. The apparatus allows precise control of lifting while leaving the tunnel beneath it clear for access to the portion of the tunnel ahead of the apparatus from behind the apparatus. <IMAGE>

Description

SPECIFICATION Installing tunnel roof supports This invention relates to an apparatus for use in and a method of installing tunnel roof supports, for example in a mine roadway.

Mine roadway roof supports normally take the form of steel girders, forming either a rectangular or a semi-circular or other rounded open frame conforming with the shape of the roadway. The girders are typically of I-beam form. The supports are conventionally installed manually, the frame being built up of shorter lengths of girder, bolted together in situ.

This operation can be extremely hazardous, as the roof is supported during this time only by temporary cantilever beams extending forwardly of the existing roof supports.

According to the present invention, there is provided a lifting apparatus for use in installing roof-supporting members in a tunnel, which comprises a main frame having gripping means engageable upon two or more roof-supporting members installed in said tunnel, whereby the main frame may be suspended from said members, a lifting arm pivotally mounted on the main frame and capable of extending forward thereof, the lifting arm being adapted to engage a roofsupporting member to be installed in said tunnel, and drive means for moving the lifting arm about the pivot thereof.

The apparatus enables a complete roof support to be assembled flat on the floor of the tunnel, lifted up into the vertical position and then secured relative to the existing supports. The lifting can be carried out while all personnel are clear of the section of tunnel where the support is to be installed. When the support is vertical, it can provide protection during the manual operations required to secure it.

Reference is made to the drawings, in which: Figure 1 shows a side view of a lifting apparatus according to an embodiment of the invention; Figure 2 is a perspective view of the leading portion of the apparatus shown in Figure 1; and Figure 3 is an enlarged perspective view of the pivot arrangement for one of the lifting arms of the apparatus shown in Figure 2.

A mine roadway 1 has regularly-spaced generally semi-circular I-beam roof support 2. A lifting apparatus 3 comprises a main frame 4 having relatively slidable clamps 5 which engage the roof supports 2 to suspend the apparatus therefrom and to enable it to be advanced along the roadway. The main frame part of the apparatus is of the general form described in U.K.

Patent Application No. 7916673, published under No. 2 021 662 A, and will not be described herein in detail.

The main frame 4 includes a pair of forwardly extending beams 1 3 each of which can be slid longitudinally of the remainder of the frame, and riased or lowered to a small degree about a pivot, mounted in a movable carriage 131, by means of a vertical ram in a guide housing 1 5. Each beam 1 3 has a lifting arm 20 pivotally mounted at the free end thereof and acted upon by a hydraulic ram 21 mounted on the beam.The mounting of each lifting arm 20 is described in detail hereinafter, and permits the arms to move through about 1 800 so as to retract so that the free ends of the arms are directed rearwardly and the arms 20 lie generally parallel to the beams 13, and to extend, through a generally vertical position with the free ends of the arms near the floor of the roadway (Figure 2), to a position in which the arms are generally horizontal and project forwardly of the apparatus (Figure 1).

Referring particularly to Figures 2 and 3, each arm 20 is held by a pair of pivots 30 (Figure 3) passing through an extension 31 of the beam 13.

The extension 31 is in the form of downwardlyfacing open channel. The arms 20 each comprise a first channel-section member 22 and a second member 23 mounted on and extending forwardly of the top face, considered when the arm is extended forward, of the first member 22. Each first member has an axially-extending slot 24 therethrough at the level of the pivot 30 when the arm 20 is fully extended. A pin 25 passes through each slot 24 and is held in a yoke 32 (Figure 3) at one end of the hydraulic ram 21, which is pivotally mounted at the other end thereof at the underside of the beam 1 3, beneath the extension 31, by a mount 33.

A pair of opposed guide plates 26 is provided on the end of each extension 31, having aligned slots 27 for guiding the movement of the pin 25 and thus controlling the lifting of the arm 20. Each slot 27 has a short generally horizontal portion 27a, a relatively shallower gradient portion 27b leading through a lowermost curved portion 27c into a relatively steeper gradient portion 27d.

When the arms 20 are fully retracted, the pins 25 are at the uppermost ends of the steeper gradient portions 27d. As the rams 21 are extended, the arms move downwardly about the pivots 30, the downward movement being controlled by pins 25 as they move downwardly through the steeper gradient portions 27d towards the lowermost curved portion 27c, at which the pins 25 hold the arms 20 generally vertically downwards. Further extension of the rams 21 forces the pins 25 into the shallower gradient portions 27b, and as each pin moves along the axially-extending slots 24 in the first member 22 of the arm 20 and up the shallower gradient 27b, the arm is caused to pivot upwards.The angle of the shallower gradient portion 27b is chosen so that maximum lifting force from the rams is transferred to the arms while still retaining control of the movement of the arms to give a controlled rate of lifting and lowering relative to the rate of extension and retraction of the ram. The horizontal portion 27a of the slot 27 serves to enable the pin 25 to lock the arm 20 in its extended position. Each arm has a supporting bracket 28 (Figure 2), for carrying a roof support 29, at the free end thereof.

In use, the roof support 29 is assembled on the floor of the roadway by bolting together three I-beam sections. The middle section 29a is held in the supporting brackets 28 on the two arms 20, initially vertical. The rams 21 are extended to lift the arms 20 together and raise the support 29 into a vertical position. With the support 29 held by the apparatus, packing may be installed against the roof of the roadway, and the support 29 may be secured to the preceding support, already installed, using connecting bars. The arms 20 can then be lowered and retracted and the apparatus advanced along the roadway by one support, in the manner described in Specification No 2021 662, for example.

Claims

1. A lifting apparatus for use in installing roofsupporting members in a tunnel, which comprises a main frame having gripping means engageable upon two or more roof-supporting members installed in said tunnel, whereby the main frame may be suspended from said members, a lifting arm pivotally mounted on the main frame and capable of extending forward thereof, the lifting arm being adapted to engage a roof-supporting member to be installed in said tunnel, and drive means for moving the lifting arm about the pivot thereof.

2. An apparatus according to Claim 1, comprising a pair of the lifting arms capable of engaging and lifting a roof-supporting member together.

3. An apparatus according to Claim 1 or 2, wherein the main frame comprises at least one beam slidable forwardly of the remainder of the main frame, and the or each lifting arm is pivotally mounted at the forward end of the beam or a respective one of the beams.

4. An apparatus according to Claim 3, wherein the or each lifting arm is mounted so as to be pivotable from a rest position, wherein the or each arm lies substantially horizontally, beneath the beam or the respective one of the beams, through a downwardly-directed arc to a working position in which the or each arm extends forwardly of the beam or the respective one of the beams.

5. An apparatus according to Claim 4, wherein the or each lifting arm is moved between the rest position and the working position thereof by a ram pivotally mounted on the beam and driving a bar extending through and freely movable in control slots in both the lifting arm and at least one guide plate secured to the end of the beam.

6. An apparatus according to any preceding claim, wherein the gripping means are relatively slidably longitudinally of the apparatus, whereby the apparatus may be advanced along the tunnel.

7. A lifting apparatus for use in installing roofsupporting members in a tunnel, substantially as described with reference to, or as shown in, the drawings.