Progressive passage device for progressive passage caps in coal mines

摘要

727,488. Roof supports for coal mines. BUSCHMANN, A. May 28, 1952 [Aug. 30, 1951], No. 13514/52. Class 20 (2). In a progressive roof support for coal mines a cap 5 is clamped in any desired position in a passage in the head 2 of a prop and is provided with a wedge 7, eccentric or screw to force the end of the cap away from the roof and thus to force the other end against the roof. The wedge 7 is mounted on the cap by an arm 8 and slot 9. The cap is clamped in the head by a transverse wedge 6. The passage in the head is flared out at each end to allow the cap to be inclined or to be swung laterally. The head rests on the prop by a dome-shaped part and is located by raised edges.