(under subclass 10) Process in which a step is included for preventing a mining shaft or tunnel sidewall, roof or floor from caving, shifting or heaving.
(1) Note. This subclass includes for example, a process including a step of constructing mine prop means, filling mine workings, controlling pressures in the mine to prevent dislocation of matter, removing pillars or other roof supports, etc. However, a process including a mere step of removing material to leave roof supporting sections or
columns of material in place is classified on other features.
SEE OR SEARCH CLASS
405, Hydraulic and Earth Engineering,
132+, for a process or apparatus for making a shaft or tunnel. Class 405 provides for (1) excavating a tunnel or shaft and lining it, or (2) preventing a tunnel shaft or sidewall, roof, or floor from caving, shifting, or heaving if not combined with an excavating step or means.
