Gewerkschaft Eisenhutte Westfalia, Gmbh

Rolf Stoltz

Herbert Heitkamp

Wilhelm Stoltefuss

Teja Rostowski

A cutter bit for use with a cutting or winning machine has a generally cylindrical shank and a generally conical cutting head. The shank is rotatably received, in use, within a matched bore in a bit holder. The shank is formed with a reduced-diameter portion on which is rotatably mounted a bearing ring. A compressible locking ring surrounds and grips the bearing ring so that, in use, the locking ring frictionally engages the bore in the bit holder so as to restrain relative axial movement between the cutter bit and the holder.

Cutter bit assemblies

Apparatus is provided for controlling the advance of a tunnel drive shield. The drive shield is of the type having a plurality of elongate implements (or planks) which are supported and guided on a frame. Hydraulic rams are provided for moving the planks relative to the frame. The control apparatus comprises hydraulic ram means, which act between the frame and the permanent tunnel lining, and means for varying the pressure of hydraulic fluid applied to said hydraulic ram means. The frame can be advanced by applying hydraulic fluid to said hydraulic ram means and by simultaneously applying hydraulic fluid to at least one of said hydraulic rams. The direction of frame advance is controlled by varying the ratio of the pressures of the hydraulic fluid applied to said hydraulic ram means and to said at least one hydraulic ram.

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Bottrop, Germany

Rolf Stoltz