- 5 lever lock
The 5 lever lock is a type of lock often required for
home insurance and are generally recommended by the police for home security. There are various 'grades' but the current British Standard (BS3621:2004) is usually required for insurance purposes. The lever mechanism is really only seen in the UK and some parts of Scandinavia, and locks using this form of mechanism are frequently referred to as 'Chubb locks' although there are a great many manufacturers. The new BS 3621 calls for a bolt throw of 20mm rather than the 14mm of the old British Standard. In an article on "The Ancient Art of the Locksmith" [http://www.buildingconservation.com/articles/locks/locks.htm] Valerie Olifent notes that "The doors of many historic churches still carry an old wooden lock although often you find that a modern 5-lever mortice lock has been installed alongside it to meet insurance requirements."The lever
A flat, non ferrous metal, shaped double acting movable ‘detainer’ in a lock. Usually pivoted, but sometimes slide. The levers in a lock have to be moved by the key to operate the lock. The belly of the lever is cut away to various depths to provide different combinations. A lever will have pockets and gates through which the bolt stump moves during unlocking.
References
* http://www.met.police.uk/crimeprevention/garden2.htm
* http://www.lincs.police.uk/index.asp?docID=98
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