Patent attributes
A manhole assembly includes a manhole cover and a manhole frame. The manhole cover is received on the manhole frame. A latch bolt attached to the manhole cover is movable between a latched position and a removal position. The latch bolt is biased toward the latched position by a spring. A security bolt received in the manhole cover is movable between a locked position wherein the security bolt engages the latch bolt to lock the latch bolt in the latched position and a removal position wherein the security bolt is disengaged from the latch bolt. An extraction tool is inserted through the manhole cover to remove the manhole cover from the manhole frame. The extraction tool engages a driven cam surface on the latch bolt to drive the latch bolt against a biasing force of the spring to move the latch bolt to the removal position.
