Patent ID: 7127849

Claim:
A manway lift device comprises a first and a second upper hinge bracket, a third and a fourth lower hinge bracket, at least two smooth bore bushings, at least two internally threaded bushings and at least one adjustable biasing assembly, said upper hinge brackets arranged in a parallel relationship with each other, spaced apart from each other and rigidly attached to a manway cover to be lifted, said lower hinge brackets arranged in a parallel relationship with each other, spaced apart from each other and rigidly affixed to a manway collar assembly for receiving said manway cover, said first upper hinge bracket aligned with said third lower hinge bracket thus constituting a first aligned pair of said brackets, said second upper hinge bracket aligned with said fourth lower hinge bracket thus constituting a second aligned pair of said brackets, said first aligned pair of said brackets receiving one of said smooth bore bushings therein from a first direction and receiving one of said internally threaded bushings therein from a second direction opposite to said first direction, said one of said smooth bore bushings and said one of said internally threaded bushings comprising a first bushing set, said second aligned pair of said brackets receiving the other one of said smooth bore bushings therein from a third direction and receiving the other one of said internally threaded bushings therein from a fourth direction opposite to said third direction, said other one of said smooth bore bushings and said other one of said internally threaded bushings comprising a second bushing set, at least one of said bushings of said first bushing set having a first end thereof protruding beyond an exterior face of said third lower hinge bracket, said at least one bushing having dogs disposed on a second end thereof opposite to said first end thereof, said dogs engaged in dog holes disposed through said first upper hinge bracket, said smooth bore bushing of said first bushing set receiving a bolt through the internal bore thereof, said internally threaded bushing of said first bushing set threadedly receiving the threaded end of said bolt, said bolt thus rigidly affixing said first bushing set to said first upper hinge bracket and thereby rotatably affixing said manway cover to said manway collar assembly, said at least one bushing of said first bushing set having said adjustable biasing assembly associated therewith for biasing said manway cover into an open position with respect to said manway collar assembly.