Assertion: cylindrical bore | /r/HasProperty | generated by excavating
Facets:
Source sentences:
text: The wheels 30 are preferably grouped and arranged to rotate in two perpendicularly related planes diametrically of the casing 25 and associated assembly and to define in each such plane a pattern such as to engage the outer are of the constituent wheels with and to roll along walls of the cylindrical bore generated by thev excavating head, one of the diametric planes containing the wheel pattern being preferably vertical and the other such plane horizontal, as is indicated by the views of the drawings.