| 摘要 |
A tiltable table has a pneumatic actuator and a locking system for establishing and maintaining a table position. The locking system is operated by an air cylinder that engages a dog with a ratchet plate secured to the table. The ratchet permits the table to be raised but not lowered while locked. The ratchet must be unlocked before the table can be lowered. The dog is spring-biased to locking position, and is air-operated for release against the action of the biasing spring. On lowering the table, air from the actuator can be used to unlock the ratchet. The air can be permitted to escape through a restriction orifice at a slow enough rate to maintain sufficient air pressure to keep the locking system disengaged, but sudden release of all the air pressure will again permit the spring to re-lock the system to prevent a downward slamming of the table surface.
|
