Patent ID: 8714867
Filing Date: 2014-05-06
Classification: E02D

Abstract:
1. A manhole cover adapted to move from a seated position to an unseated position with respect to a frame to relieve pressure, the frame having a manhole cover receiving surface and a peripheral wall defining an access opening, said manhole cover comprising: a cover portion having an upper face, an outer peripheral edge, and an underside opposing said upper face, said underside including a first mounting tab; a first pivot leg and a control leg coupled to said cover portion whereby said first pivot control leg and said control leg are configurable between a restraint mode and a removal mode, wherein said first pivot leg is pivotally mounted to said first mounting tab, wherein said first pivot leg and said control leg extend away from said underside toward said access opening and each includes a foot at a first end thereof, said feet of said first pivot leg and said control leg projecting toward the peripheral wall in said restraint mode; an opening through the manhole cover from said upper face to said underside, wherein said control leg slides within said opening in said removal mode such that said control leg is movable away from the frame to enable removal of said manhole cover therefrom; whereby in response to pressure on said underside reaching a threshold in said restraint mode, said cover portion displaces from said seated position to said unseated position such that fluid flows through the access opening; wherein in said unseated position and in said restraint mode, said first pivot leg, said control leg, and said feet cooperate with the frame to enable said cover portion to have a range of movement with respect to the manhole receiving flange, wherein said feet contact the frame at a limit of said range to prevent said cover portion from moving beyond said limit of said range; and wherein in said removal mode, said first pivot leg pivots to enable removal of said manhole cover from the frame.