Patent GB-1181108-A (GB)
Title: Door Apparatus for Pressure-Tight and Gas-Tight Lock
IPC: F16J13/12
Filed: 1967-03-22
Abstract: 1,181,108. Reactors. LICENTIA PATENTVERWALTUNGS-G.m.b.H., and MASCHINENFABRIK AUGSBURG-NURNBERG A.G. 22 March, 1967 [22 March, 1966], No. 13496/67. Heading G6C. [Also in Division F2] Apparatus for operating a gas-tight lock with two doors 1a, 1b, e.g. a lock of a nuclear reactor, is characterized in that each door is counterbalanced by two weights 10 suspended from it and is operated by an hydraulic motor 4 for lifting and lowering it. As shown, a door 1 of the lock is suspended by rods 2 from a carriage 3 which is upwardly and downwardly movable, to open or close the lock, by means of the hydraulic motor 4 carried by a beam 6 which is supported by tubes 7. The weight of the door is balanced by the two counterweights 10 which are suspended by ropes 11 and are housed in the tubes 7, the lower position of the door being determined by wheels 8 which bear against brackets 9 on the tubes 7. A nut 12, which co-operates with the spindle 5 of the motor 4, has pins 13 which are accommodated in slots 14 in the beam 3. To prevent the weights from falling should a rope 11 fail a safety catch, comprising spring-loaded levers which are adapted to dig into the wall of the tube 7 should the rope 11 break, is located below each weight. The door is locked by means of a number of circumferentially spaced dogs 18 on the door which are adapted to engage wedges 19 provided between the door and the body of the lock. After having been lifted, the door can be moved horizontally by a piston and cylinder motor (23), Fig. 7, not shown, which is connected to the door by a parallelogram linkage (24), the slots 14 in the carriage 3 allowing the door to move horizontally instead of upwards in an arc. The door is sealed by means of a rubber seal 30, a clamping ring 31, and a lip seal 32 which are all accommodated in a groove in the body of the lock. An electrohydraulic door actuation mechanism, Fig. 10, not shown, comprises a pump 37 which draws oil from a sump (38) and delivers it to a distributor (39) which decides whether oil is supplied to cylinders (41, 40) which respectively unlock and open the inner door 1a or, whether it is necessary to first close the outer door 1b which is actuated by cylinders (42, 43). The distributors (44, 45) ensure that the pivoting cylinder (42) or (40) can only operate after the operation of the respective unlocking cylinder (43) or (41). A more detailed circuit of this operation is described with reference to Fig. 11, not shown. When the lock body (25), Fig. 12, not shown, is mounted in the biological shield (26) of the reactor, the outwardly projecting end of the body (25) is balanced by a counterweight (74) and, if the lock is arranged in a spherical portion of the biological shield, horizontally extending end portions of the lock body are joined by a stepped portion which passes through the shield at right angles. If it is desired to remove, e.g. hot or moist air, from the lock, fresh air can be introduced into the lock from a fresh air reservoir 79 and a valve 78, Fig. 14, and is exhausted through a valve 82, a pressure relief valve 81 reducing the pressure after the air has been exchanged. The device may be installed in safety bunkers and other military installations.