摘要 |
<p>A pneumatically operated barrier lock is provided. The barrier lock includes a body and a locking pin slidably mounted on the body for movement along a path between an extended position for engaging a catch and a retracted position for disengaging the catch. The lock also includes a pneumatic cylinder in connection with a pressure source and actuating the locking pin between the extended position and the retracted position. An opposite end of the cylinder is adapted for connection to a relatively low second pressure source. A second pressure source connectable to end of the pneumatic cylinder biases the piston away therefrom and generates a first biasing apparatus, in form of a pneumatic spring, which biases the locking pin toward the retracted position. A blocking member is hingedly connected, about a pivot axis, to the body and is selectively movable between a first position and a second position.</p> |