Two key lock double closing mechanism - has single key operated closure for bolt with two key opening stages

摘要

Two closing mechanisms, activated by two keys through a single keyhole, have tumblers acting in conjunction with two blocking pins directly connected to the bolt, in a lock, esp. as used on rented safe drawers in banks. The two pins (19',20') are firmly sited on a single bolt (18'). The opening thrust of this bolt is divided into two parts, one for each key. The corresponding closing thrust is effected only by the second key, acting alone (17'). The section (26') of the closing curve active during bolt closure is a component of a fishplate movably mounted on the bolt.