Manway open and close assist device

A manway open and close assist device comprising:

• a threaded input screw mounted for rotation on a first end member and a second end member;
• one or more anti-rotation member fixed to said first end member, said first end member operably connected to a first lower hinge member;
• a piston mounted on said one or more anti-rotation members, said piston including a plurality of teeth disposed on an outer surface of said piston, and said piston having an internal aperture having a threaded surface, said threaded input screw being received and threadedly engaged with said internal aperture, wherein a rotation of said input screw causes a linear displacement of said piston;
• a tubular housing for receiving said threaded input screw, said one or more anti-rotation member, and said piston, wherein said tubular housing has a plurality of helical grooves disposed on an inner surface of said tubular housing, said plurality of helical grooves receiving said plurality of teeth of said circular piston;
• said tubular housing operably connected to at least one upper hinge member;
• wherein said linear displacement of said piston within said tubular housing causes a rotation of said tubular housing due to engagement of said plurality of helical grooves on said inner surface of said tubular housing with said plurality of teeth of said piston, thereby causing a pivoting movement of said at least one upper hinge member.