| Abstract |
A mining machine (7) comprises:a shearing head (9) mounted on a moveable carriage (17) ,moveable on rail means (19);co-ordinate position determining means (31,33) for determining an intended co-ordinate position of the rail means (19) in the form of at least 2D co ordinate position information, and means (35)for providing data signals representative thereof ;processing means (37)to receive the data signals and to generate output sig8nals to control the rail moving means (25),so that the rail moving means moving means (25)displace a trailing part of the rail means(25)a distance towards a seam based on the current co-ordinate position of that part of the rail means ,to assume a co-ordinate position of an intended profile for the next pass, the processing means (37) operating with the rail moving means (25) along the length of the rail means (19),so that on the next pass the shearing head (9) will attempt to cut to the intended profile, characterised by the co-ordination position determining means (31,33) being positioned to determine the absolute co-ordination position in space of the rail means (19) at each location along the rail means(19). |