| 摘要 |
<p>The device comprises, for shutting off compressed air flow to the operating chamber (61) of the cylinder-piston unit (6), a valve with a valving element (20) normally closing an access port (12) to said cylinder-piston unit (6) but openable by electromagnetic means; said valve is arranged to normally maintain the valving element (20) in its closure position independently of the pressure upstream of the access port (12), but to maintain the valving element (20) in a stable opening position after having been operated by the electromagnetic means, even after these electromagnetic means have been deactivated, as long as the pressure upstream or downstream of the access port (12) exceeds a limiting value (P'). <IMAGE></p> |
