DEVICE FOR LOCKING AND UNLOCKING OF INSPECTION WELL MANHOLE COVER Russian patent published in 2010 - IPC E02D29/12 

FIELD: construction.

SUBSTANCE: device for locking and unlocking of inspection well manhole cover lock, for instance of bayonet type, comprises mechanism of manhole cover grip, its turn for disconnection with bayonet lock and lift. Mechanism of manhole cover grip is arranged in the form of three-arm lever with central axis, arms of which are fixed movably around central axis, and at the free ends there are hooks mounted for according slots in windows of manhole cover. At two arms, hooks in radial direction are installed fixedly, in compliance with positions of windows on manhole cover, and the third arm is arranged with the possibility of hook displacement in radial direction with the help of slider, until engaged with slot of according cover window. After engagement, rigid fixation of movable hook position is carried out with window slot by means of helical pair, providing for rigid fixation with manhole cover for all three hooks. All three arms of grip mechanism are equipped with handles for convenience of cover rotation at a certain angle and its disconnection with manhole lock and then its manual lifting. Contact surfaces of hooks and slots of manhole cover windows have reciprocal surface. Arms around central axis are fixed hingedly with the possibility of compact folding in process of transportation, and also device is equipped with a transportation handle.

EFFECT: increased reliability and simplification of manhole cover locking device design.

4 cl, 2 dwg