A cable cup can be mounted in an optimal location on the wall of an
otherwise inaccessible duct, so that, above all, inlets into the duct are
not obstructed. A mounting device has a carriage that is movable in the
longitudinal direction of the duct. A supporting unit for the cable cup
is mounted on the carriage. A carrier is pivotally connected to the
carriage via a longitudinal shaft. A directing unit supports the cable
cup and is movable toward the wall of the duct. A drilling device and a
screwdriver device are longitudinally movable on the shaft. By pivoting
the support and thus the directing unit, the cable cup is fixed in the
desired position on the wall, a hole is drilled through the cable cup and
into the wall of the duct and a screw is screwed into the hole by the
screwdriver device.