1981年在杜塞尔多夫矿山机械博览会上,带双纽线四连杆机构和铰接顶梁的二柱或四柱掩护式支架反映了博览会的盛况,而且为工作面支架的发展指明了方向。几年来,由许多单项发展构成的迅速发展,似乎打破了支架的发展到了终点的看法。四年后到了1985年,伯明翰矿业博览会提供了很好了机会,使人们确信,掩护式支架仍在继续向前发展。 In 1981 at the Messe Düsseldorf Mining Machinery, the two-post or four-post shield with double-lined four-bar linkage and articulated roof beams reflected the grand occasion of the fair and pointed the way to the development of face supports. In recent years, the rapid development resulting from many individual developments seems to have broken the view that the development of the stent has reached the end. Four years later, in 1985, the Birmingham Mining Fair provided a good opportunity to convince people that the shelves are still moving forward.