Armoured door hydraulic or pneumatic controlled lock - has pump operated locking pistons responding to four combinations letter device, controlling liquid or gas to pump

摘要

The hydraulically or pneumatically controlled locking device is operated by means of four combination devices (C1-C4), each one showing on relative rotary knobs (28, 28') twenty-one letters, in opposite correspondence. Only one position of each combination device, corresponding to one chosen letter, allows the passage of the liquid (or the gas) through the same. Only by bringing all the four combination devices (C1-C4) into the positions corresponding to the letters chosen for each one of the same is the passage of the liquid allowed, and therefore the opening of the door. A pumping system operated by the inner and/or outer handle of the door makes it possible to build up the necessary pressure to make locking pistons re-enter cylinders to open the door.