Apparatus for placing a beam like a mine supporting crown in position beneath a surface like a mine roof

摘要

1,162,387. Lifting cradles. HOUILLERES DU BASSIN DU NORD ET DU PAS-DECALAIS. 25 Nov., 1966 [9 Dec., 1965], No. 52908/66. Heading B8H. [Also in Division E1] A device for positioning a mine roof support beam 13 comprises a cradle 2 having rocking arms 5, beam retaining means 11a, 12a at one end, a winch 4 and abutments 14a. The arrangement is such that the device can be lifted with the aid of a fixed beam 8 and moving about a fixed beam 15 to locate the beam 13 in its propping position.