Roof Bolts For Use In Mines

A roof bolt comprises a shaft for insertion in a hole drilled in a mine roof and a head whereby the bolt may be rotated the head being offset with respect to the longitudinal axis of the shaft so that when the bolt is rotated by means of its head the shaft is caused to describe a circle of greater diameter than its own diameter and where the offset is at least 0 08 inch and not more than 0 25 inch.

Roof bolts for use in mines.

In many mines a stronger unit that is largely self supporting overlies a weak immediate roof layer figure 1b. The jm cable fully grouted cable bolt is proven to be a very versatile roof support due to its ability to control many different ground conditions from increasing the lifespan of standard cable bolt supports in long term main entry systems to stopping the ingress of water. A roof bolt comprises a shaft for insertion in a hole drilled in a mine roof and a head whereby the bolt may be rotated the head being offset with respect to the longitudinal axis of the shaft so that when the bolt is rotated by means of its head the shaft is caused to describe a circle of greater diameter than its own diameter and where the offset is at least 08 inch and not more than 0 25. Secondary function of roof bolts in weaker ground.

Experience has shown that roof bolts are extremely efficient in the suspension mode 6 7 8 though. Dsi has one of the strongest nuts on the market. Jennmar is the largest manufacturer of roof control products in the u s however we don t stop there. The invention comprises a roof bolt and nut in screw threaded engagement said bolt comprising a shaft for insertion in a hole drilled in a mine roof and a threaded portion engaged by the nut whereby the bolt may be rotated.

The nut is offset with respect to the longitudinal axis of the shaft of the bolt so that when the bolt is rotated by means of the nut the bolt is caused to describe a. Roof bolts in helping to create a stable rock structure are the first line of defence to protect mineworkers from fall of ground related hazards which highlights the importance of correct roof. Take a look at our capabilities and affiliates to learn more. We can supply the construction mining or tunneling industry with much more.

In these circumstances roof bolts act to suspend the weaker layer. The composite bolt is particularly interesting not only because of its high tensile strength which is double or triple the strength of the steel but it is also non sparking oler said. Cable bolting is sometimes used as primary support in coal mines experiencing difficult roof conditions.