WELL COVER Russian patent published in 2012 - IPC E02D29/14 

FIELD: construction.

SUBSTANCE: in a well cover comprising a well cover with a hole, a support bushing with a hole fixed on a board, lock levers, every of which is hingedly joined with the board or the support bushing, and is also hingedly connected to a traction rod, the other end of which is hingedly connected to a sliding nut screwed on a lead screw as capable of displacement along the lead screw as it rotates, a shaft with a circular ledge in the upper part stretches through the support bushing hole, being joined with the lead screw, in the middle part of the support bushing hole there is a seat of larger diameter compared to the hole diameter in the lower part. In the seat there is a shaft circular ledge, the lower surface of which rests against the seat surface in the support bushing so that the shaft may rotate around its longitudinal axis. The screw axis may deviate from the shaft axis, the shaft connection with the lead screw is made as capable of transferring rotation of the axial force. Versions of cover design are provided.

EFFECT: increased reliability of underground utilities protection against unauthorised penetration into a control well by means of a cover detachment from a manway body due to reinforcement of a stop mechanism link with well structures and higher protection against unauthorised opening of a mechanism, by standard keys or tools.

7 cl, 3 dwg