Coal-cutting machine with cutters placed above slatted conveyor - delivers size-limited coals which are less likely to jam other machines

摘要

Cut coals leaving the seam must be broken down to a size that suits the conveyor in the gallery leading to the pit shaft. Large coals (and stones) leaving the coalface overburden the breaker, so smaller coal is supplied from the face by using a cutter with limited maximum clearance (4) above its associated conveyor (6). A cruciform axle (1) carriers several sabre-like cutters (2), side by side and arranged to secure inertial balance. Their cutting edges (3) are in the form of logarithmic spirals which slice steadily through the coal. A removable cover (12) gives access for damage cutters to be replaced. Water jets (27, 28) help to lay the dust in the vicinity of the cutter.