Abstract: A lockable manhole cover system including a manhole cover and a locking mechanism attached to the bottom surface thereof and including a fixed end and an actuated end, each including locking pins movable between locked and unlocked positions. The actuated end includes a keyed lock. When in the locked position, the free ends of the locking pins extend beneath a flange prevent the cover from being lifted up. When the actuated side is moved to the unlocked position via the key, the locking pin free ends retract such that the cover is free to be lifted from the ring. On the fixed side, the locking pins are biased to move to their extended positions upon manual depression of a release stem located at the upper surface of the cover.

Abstract: A lockable manhole cover system including a manhole cover removably attached to a mounting ring secured to a surrounding structure such as an underground vault or concrete column, for example. A locking mechanism is attached to the bottom surface of the cover and includes a fixed end and an actuated end, each including at least one but preferably two locking pins which are movable between locked and unlocked positions. The actuated end includes a keyed lock. When in the locked position, the free ends of the locking pins extend beneath a flange extending radially inwardly on the inside surface of the ring thereby preventing the cover from being lifted up and off the ring. When the actuated side is moved to the unlocked position via the key, the locking pin free ends retract and locate radially inwardly of the flange such that the cover (and locking mechanism which is mounted thereto) is free to be lifted from the ring.