Patent ID: 7770649

Claim:
A locking device for a subsea housing having an insertion opening, comprising: a unit having at least a portion receivable within the insertion opening; a rotary sleeve being rotatable in a flange housing detachably connected to the subsea housing, wherein the insertion opening is formed by a housing opening and an inner opening of the flange housing to receive the unit; locking elements adjustable between an insertion position and a locking position, wherein in the insertion position, the unit can be inserted into and removed from the insertion opening and in the locking position, the unit can be locked relative to the housing; the locking elements including first thread segments spaced apart by insertion gaps in a circumferential direction and arranged on the outside of the unit and alignable with the insertion opening; second thread segments arranged on an inner side of the rotary sleeve rotatable relative to the housing; the first thread segments being arranged in an insertion direction at a gap between the second thread segments and the first and second thread segments being in thread engagement in the locking position; and drive means to rotate the rotary sleeve and the second thread segments less than a full rotation into engagement with the first thread segments to the locking position, wherein rotation of the rotary sleeve back to the insertion position allows for removal of the unit without further disassembly, wherein the unit and the housing comprise alignment members to align the thread segments and gaps prior to the thread segments being wherein the alignment members substantially prevent rotation of the unit during rotation of the rotary sleeve.