Field of the Invention

The present invention relates generally to tunnelling and, in particular, to a device for lifting cable bolts used for self-supporting a roof of a tunnel.

Background

'Rock bolts' (otherwise known as 'cable bolts') are essential to provide safety in mines and tunnels. Rock bolts, when installed in a 'roof' of such a structure, secure the roof to be self-supportive,

A roof bolter is used to install such rock bolts to the roof of the structure. The roof bolter operates by drilling a borehole into the rock strata of the roof. A resin sausage is inserted into a distal end of the drilled hole. Next, a cable bolt is inserted into the hole, with the distal end of the cable bolt penetrating the resin sausage. The cable bolt is then tightened to support the roof of the structure.

The length of the hole, and hence the length of the cable bolt, may exceed 8m in some applications. Each cable bolt has to be lifted into its hole, and then forced into the hole and through the resin sausage positioned at the distal end of the hole. Apart from the forces required to lift the weight of the cable bolt, to overcome frtetion, and to penetrate the resin sausage, the length of the cable bolt further increases the difficulty of inserting the cable bolt. A need exists for a device to assist an operator to lift the cable bolt into the drilled hole, and to force the distal end of the cable bolt through the resin sausage.

Summary

According to an aspect of the present disclosure, there is provided a device for lifting a cable bolt, the device comprising :

an elongate body;

a connector attached to a proximal end of the elongate body, the connector being for mounting the proximal end of the elongate body to a lifting device; and

a gripping assembly attached to a distal end of the elongate body, the gripping assembly having gripping means for gripping the cable bolt,

wherein, when the lifting device lifts the proximal end of the elongate body, the cable bolt gripped by the gripping assembly is lifted.

Other aspects of the invention are also disclosed.

Brief Description of the Drawings

One or more embodiments of the present invention will now be described with reference to the drawings, in which ;

Fig. 1 shows a side view of the device according to the present disclosure for lifting a cable bolt; and

Fig. 2 shows a perspective view of the device shown in Fig. 1. Detailed Description

Disclosed herein is a device for lifting a cable bolt into a drilled hole in a roof of a rock structure. More particularly, the disclosed device attaches to a lifting device in the form of a roof bolter, and uses a lifting force provided by the roof bolter, to lift the cable bolt.

Figure 1 shows a side view of the device 100 according to the present disclosure for lifting a cable bolt (not illustrated). Figure 2 shows a perspective view of the device 100.

The device 100 has an elongate body 110. The elongate body 110 preferably is generally S-shaped. A proximal end 111 of the elongate body 110 has a connector 122 for pivotably mounting the proximal end 11 of the device 100 to a female chuck (not illustrated) positioned in an upper end of the roof bolter. More particularly, the connector 122 comprises a shaft 120 extending therefrom having upper and lower co-axial parts (not illustrated), with the upper part being able to freely rotate relative to the lower part about the mutual axis. Accordingly, when the shaft 120 is mounted to the female chuck of the roof bolter, the elongate body 110 is able to freely rotate about a vertical axis. Importantly, should the operator of the roof bolter inadvertently activate a drill motor of the roof bolter, thereby causing rotation of the female chuck, the device 100 would not rotate with the female chuck. The elongate body 110 also rotates about a horizontal bolt 121 connecting the elongate body 110 to the connector 122. The connector 122 further comprises a spike 123 extending from a top portion. When the operator of the roof bolter operates the roof bolter to move the proximal end 111 vertically upwards, the spike 123 penetrates rock strata at the roof of the tunnel to temporarily secure the device 100 to the roof. This allows the device 100 to be clamped between the roof bolter and the roof to provide a stable base,

A distal end 112 of the elongate body 110 has rotatably attached thereto a gripping assembly 130 for gripping the cable bolt. The gripping assembly 130 is secured to a flange 113 extending from the distal end 112 of the elongate body 110 by means of another horizontal bolt 131 about which the gripping assembly 130 rotates. The gripping assembly 130 has two rollers 141 and 142, each connected in a fixed position. A third roller 143 is also provided, and is slidably connected by means of a slidable rod 145 to slide towards a position intermediate the rollers 141 and 142. A cable bolt positioned between the fixed position rollers 141 and 142 on the one side and the slidable roller 143 on the other side, is gripped by the rollers 141, 142 and 143 when the slidable roller 143 is urged towards the position intermediate the rollers 141 and 142.

A lever 150 is provided for urging the slidable roller 143 towards the position intermediate the rollers 141 and 142. More particularly, the attachment between the slidable rod 145 and a proximal end of the lever 150 provides an over centre latch, locking the slidable rod 145, and hence the slidable roller 143, in position to grip the cable bolt. When the device 100 is attached to the roof bolter, and a cable bolt is grasped by the gripping assembly 130 of the device, by operating the roof bolter to lift the proximal end 111 of the device 100, the device 100 lifts the cable bolt into a drilled hole in the roof of the rock structure.

The foregoing describes only one embodiment of the present invention, and modifications and/or changes can be made thereto without departing from the scope and spirit of the invention, the embodiments being illustrative and not restrictive.