| 摘要 |
<p>A closure device includes a door carrying a series of interconnected shear blocks and a keystone shear block designed to transfer stresses created by pressure acting on the door to a surrounding hub. Each interconnected shear block has limited rotation relative to its adjacent blocks. A holding band operating handle is in communication with a driving link which, in turn, is in communication with the keystone shear block. Actuating the handle causes the keystone shear block to move in an upward vertical direction. The linear movement of the keystone shear block allows the limited rotation of the interconnected shear blocks to occur, thereby causing the circumferential holding band to collapse within itself from an expanded-engaged position to a contracted-removed position relative to said hub. A pressure warning lock provides a safety device and prevents actuation of the holding band operating handle when the pressure chamber is under pressure.</p> |
