Patent ID: 8910816

Claim:
A tank hatch system comprising: a lower frame adapted for coupling to a collar surrounding an opening of a tank, said lower frame comprising a retaining member; an upper frame comprising: a hatch support plate having an external bottom side; a hatch suspended from said hatch support plate beneath said bottom side of said hatch support plate; a selectively inflatable member in contact with said bottom side of said hatch support plate and said hatch adjacent a center of said hatch, said inflatable member disposed to urge said hatch away from said external bottom side of said hatch support plate and toward the collar; a catch for limiting movement of said upper frame relative to the collar; and at least one compressible member adapted for lifting said hatch toward said hatch support plate; a hinge assembly coupled to said upper frame for supporting pivoting movement of said upper frame relative to said lower frame; an actuator coupled to said upper frame for pivoting said upper frame between an open position and a closed position; and a remote control for controlling said actuator and for controlling inflation of said inflatable member, wherein said actuator is actuated to pivot said upper frame between said open position and said closed position, when said upper frame is in said closed position inflation of said inflatable member causes said hatch to form a positive seal with the collar, and said retaining member and said catch limit vertical movement of said upper frame relative to the collar.