Patent ID: 6851379

Claim:
A portlight assembly for installation in combination with an opening in a wall of a vessel, comprising a vessel having a wall with an opening through said wall; a portlight outer frame having a flange and a cylindrical wall portion extending from said flange, said flange overlying a portion of the outer surface of said vessel wall surrounding said wall opening, said cylindrical wall portion extending through said vessel wall opening and including a threaded section distal said flange, a window mounted to said outer frame and having an inner surface and an outer surface, an inner securing ring threadedly received onto said threaded section of said cylindrical wall portion and overlying a portion of the inner surface of said vessel wall, said inner securing ring including threads engaging said threaded section of said cylindrical wall portion, said outer frame including initial attachment means for holding said outer frame in place within said vessel wall opening pending threaded receipt of said inner securing ring onto said cylindrical wall portion, a first locking structure carried by said inner securing ring, and a second locking structure carried by said cylindrical wall portion and engaging said first locking structure to permit rotation of said inner securing ring in a first direction to tighten engagement between said inner securing ring and said vessel wall while resisting rotation in a second, opposite direction.