Patent ID: 9157212
Filing Date: 2015-10-13
Classification: E02D,Y10T

Abstract:
1. A corrosion-resistant self-locking manhole cover, comprising: a cover plate comprising nonmetallic corrosion-resistant material, said cover plate being adapted to rest on a manhole cover support surface of a manhole frame so as to be substantially flush with a top portion of said manhole frame and a surrounding surface in which said manhole frame is situated; an anchor on said cover plate comprising nonmetallic corrosion-resistant material, said anchor being adapted to engage said manhole frame at a first location in a manner that resists lifting of said cover plate proximate to said first location; a locking member on said cover plate comprising nonmetallic corrosion-resistant material, said locking member being movable between a locked position in which said locking member is adapted to engage said manhole frame at a second location in a manner that resists lifting of said cover plate proximate to said second location, and an unlocked position in which said locking member is not adapted to engage said manhole frame; said locking member being biased by a biasing force to said locked position; a drive mechanism operable to retract said locking member against said biasing force from said locked position and retain said locking member in said unlocked position; said drive mechanism comprising a security lock on an upper side of said cover plate and engageable by a key to operate said drive mechanism to retract said locking member; a quick-latch mechanism operable without using a key or other tool to interact with said drive mechanism to release said locking member from said unlocked position to allow said locking member to return to said locked position; said quick-latch mechanism comprising a plunger that can be actuated from an upper surface of said cover plate; and wherein said plunger does not extend above said upper cover plate surface when said locking member is in said locked position, and wherein said plunger extends above said upper cover plate surface when said locking member is in said unlocked position.