Abstract: Relative movement of members (10,11) of a lock is normally obstructed by an element (14) which can be moved by a solenoid (18) entirely into a recess in one of the members so that the one (11) and the obstructing element (14) can turn together relative to the other member (10) and solenoid. The arrangement may be used to prevent turning of a key-receiving member relative to a housing or as a clutch between two members mounted rotatably in a housing.

Abstract: A lock has means (15,16) for reading from a key (11) a binary encoded number. If the number read from the key is a predetermined number, the lock will store in a memory (19) a further number read from a further key applied immediately after withdrawal of the first key. The device will then recognize the second key, when applied subsequently.

Abstract: A briefcase is provided with a two-part releasable fastening device, the first part of which includes a movable fastening member for releasably fastening the parts together. The first part of the device further comprises a ball which, when the case is inverted, is urged by gravity into a retaining position in which it prevents releasing movement of the fastening member. When the lid of the case is uppermost, the ball permits movement of the fastening member to release the second part of the device.

Abstract: A lock for operation by a magnetic key has locking elements in the form of rollers which can be moved along respective channels in the lock by the magnetic field of the key. Each channel is formed partly in the peripheral surface of a rotatable barrel of the lock and partly in a surrounding sleeve. The barrel can be rotated only when each sleeve is free to move axially relative to the barrel. In the absence of the key, the rollers prevent such axial movement. When the rollers are moved to predetermined releasing positions by the key, they are aligned with respective notches in the sleeves so that axial movement is permitted.