| 摘要 |
The mechanism for locking the main boltwork of a safe or vault door includes a lock having a bolt 1 with a pivoted drop-arm 3 engageable in the slot 10 of a rotatable drive disc 6. For enabling and disabling the coupling of the arm 3 to the disc 6 there is an electromechanical actuator 12. This comprises a magnetisable element 11 pivoted within a coil 13 and a passing between the poles of a permanent magnet 14. Reverse pulses of current through the coil 13 therefore cause the element 11 to flip between two stable positions. In the locking position of the actuator (Fig 1) the element 11 prevents the arm 3 from dropping into the slot 10. When a correct code is entered into an associated user-authentication device the coil 13 is pulsed to flip the element 11 clear of the arm 3. The disc 6 can therefore be turned to pick up the head of the arm 3 (Fig 2) and withdraw the bolt (Fig 3). |
