Apparatus for controlling the position of a mineral mining machine

In apparatus for controlling the position of a mineral mining machine movable along guide means and comprising bracket means connected to said guide means, at least one elongate beam displaceable relative to a roof support, connection means effecting pivotal connection between the guide means and said beam and at least one inclined piston and cylinder unit connected between the connection means and the bracket means and operable to adjust the position of the guide means;

• the improvements comprising:
• the unit is connected to the connection means with a ball-and-socket joint, the connection means takes the form of a multi-part head-piece with a main body for resting on the floor of the mine working and a detachable complimentary part, said main body having means for effecting pivotal connection with the guide means, means for fixing the body to said at least one beam, a curved recess in the body forming part of the socket of said ball-and-socket joint and an inclined upper mounting surface on the body which extends to a lower region of the curved recess, and said complimentary part having a curved recess which forms the remaining part of said socket with an inclined lower mounting surface on said complimentary part which is engageable with said inclined surface of the main body, the body and the complimentary part having alignable bores which are inclined away from the bracket means and receive fixing bolts which detachably secure the complimentary part to the main body.