Patent ID: 7704010
Filing Date: 2010-04-27
Classification: E02D

Abstract:
1. A manhole security device for securing a manhole access opening, comprising: a circular barrier adapted to rest on a manhole cover support flange of a manhole frame; locking members on said barrier; said locking members being movable between a locked position in which said locking members are adapted to engage said manhole frame and an unlocked position in which said locking members are not adapted to engage said manhole frame; a biasing mechanism on said barrier adapted to bias each of said locking members to said locked position; a rotatable locking mechanism on said barrier engaging said locking members and having a locking rotational position wherein said locking members are in said locked position and an unlocking rotational position wherein said locking members are in said unlocked position; said locking mechanism having a security lock adapted to receive a security key that applies a rotational torque to said locking mechanism; and a latch on said barrier adapted to releasably retain said locking mechanism in said unlocking rotational position without said security lock being engaged by a security key.