| 摘要 |
A self advancing mine-roof support (10) comprises two spaced floor beams (12) interconnected at least at one end by a bridge 16 and advanceable by a ram 66, front and rear props (22, 24) mounted on each floor beam supporting a canopy (26), and linkages (42) disposed between the front and rear props (22, 24) which constrain the canopy against movement relative to the longitudinal direction of the floor beams. The linkages (42) shown have an upper link (48) pivoted to the canopy and to two unequal length lower links (56, 58) pivoted to the floor beams. The linkages are disposed close to one of the props (24) so as to minimise obstruction of the passage through the support. <IMAGE> |
