Tunnelling machine with two rotart cutters - has cutters on swinging arms for semicircular upper contour and interrupted lower contour

摘要

The tunnelling machine has two rotary cutters mounted at opposite ends of an arm (1) rotating about a central horizontal pivot axis (11), each cutter having its own drive motor. This pivot axis is formed by a member carried by a block (7) which can be raised and lowred between vertical guide surfaces (10) on the machine frame. The top end of the swining arm is connected to a shorter auxiliary arm (12) by a hinge (5) and the other end of the auxiliary arm is connected to another hinge (13) on the vertical centre line of the machine. This enables the lower cutter to make two interrupted cuts at floor level and the upper cutter to make a continuous curved cut at roof level.