| 摘要 |
<p>A filter casing for the sepn. of radioactive substances from gas streams contains a cylindrical or annular filter drum, which pressed with its one end face against an aperture in a transverse partition wall inside the casing which divides the clean and dirty sides of the filter. The lid of the casing, which can be pivoted away to change the filter, also applies the pressure for holding the filter drum sealed against the opening in the partition. A closure arm, which holds this lid locked down in the closed position, transmits the closure thrust through a pair of thrust rods (14,15) articulated together to form a toggle mechanism. The centre pivot joint (21) of this mechanism is pulled/pushed by the piston rod (32) of a hydraulic cylinder mounted eccentrically to the pivot axis of the lid closure arm. The upper thrust rod (14) is formed as an in inverted U, the base (24) being traversed by the upper hinge pin (25) of the toggle mechanism, the two lateral arms or flanges (22) being journalled on the centre pin (21) of the mechanism to which the piston rod is also attached, and encompassing between them the two arms of flanges (23) of the lower thrust rod (15), which itself has the form of an upright U; thus the centre pin (21) passes through both sets of arms (22,23) and the piston rod head (32). The base of the lower thrust rod (15) is formed by the lowest hinge pin (26) of the toggle mechanism; this pin passes, at the centre between these two arms (23), through a spherical bearing (28) which permits rotation and some tilting and itself is mounted by its casing (29) on the lid (7) of the filter casing. Used for a radioactive materials filter where two modes of operation are required. The torsional stability and overall stability of the lid mounting are high, the accuracy of engagement and sealing are good. A certain tilted seating of the lid can be tolerated by the closure mechanism.</p> |
