Patent ID: 8251238

Claim:
A closure device comprising: a hub having an access port and being connectable to a pressure chamber; a door sized to close off the access port; and a circumferential holding band carried by said door; said circumferential holding band having a plurality of interconnected shear blocks and a keystone shear block, said keystone shear block being in communication with said plurality of interconnected shear blocks, each said shear block having a limited rotation relative to an adjacent shear block, a portion of each said shear block and said keystone shear block capable of engaging an interior profile of said hub; wherein a linear movement of said keystone shear block allows the limited rotation of each said shear block, the linear movement in one direction causing said circumferential holding band to collapse within itself from an expanded-engaged position to a contracted-removed position relative to said hub and the linear movement in an opposing direction causing said circumferential holding band to expand from the contracted-removed position to the expanded-engaged position.