| 摘要 |
FIELD: construction. ^ SUBSTANCE: well cover comprises a board with an opening for a key, a supporting bush fixed on the lower side of a board, and a screw of the cover locking mechanism passes through its hole. The screw rests onto the supporting bush with its upper end so that it may rotate around the longitudinal axis of the supporting bush. The cover board is hingedly linked to locking levers of the locking mechanism, every of which is hingedly connected to a traction rod, which in its turn is hingedly connected to a lead nut arranged on the screw so that it may move along the screw as it rotates. The locking levers, number of which is at least two, are arranged along the circumference around the screw. Connection of the screw upper end to the supporting bush is arranged with the possibility to divert the screw from the geometric axis of the supporting bush towards any side. ^ EFFECT: improved reliability of well cover locking. ^ 10 cl, 4 dwg |
