Withdrawal unit for support shields in underground operation

摘要

In a withdrawal unit for support shields in underground operation, to which the support shields are attached with the bar tip to the front in the withdrawal and transport direction and are dragged on the floor out of the face cavity, the invention provides for a crawler tractor with a crane attachment, the crawler tractor having a trough connected to both crawler units by a pivot bearing with a horizontal axis of rotation. The pivot pins of the pivot bearing are fixed to in each case one crawler unit and are adjustable via crank arms with pressure-medium-actuated working cylinders for oscillating the trough. Provided on the trough are pivot-pin bearings which are adjustable with pressure-medium-actuated working cylinders for level compensation. In this arrangement, the crane has a luffing jib on a slewing mechanism with a perpendicular axis of rotation.