What Is A Lever Lock?

What Is A Lever Lock?

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" Valerie Olifent notes that "The doors of many historic churches still carry an old wooden lock although often you find that a modem 5-lever mortice lock has been installed along side it to meet insurance requirements.

openedChubb.jpg

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

Pic by euro-lock.co.uk

Here's a a great video showing you the inner workings of a british standard Lever lock.

[youtube]http://www.youtube.com/watch?v=r_OeKTiXuEU[/youtube]

Thank you Sneekypeeks

[Run4yourlife24x]

Yeah usmc, i call the skeleton keys.

they're not really that big, i would say a standard one is a little bit bigger than your middle finger

[Josh]

thats what comes to ming when i think of them too. but they are about the length of a car key with the remote on the blank...

[quaiboi]

is it the same principle in the lever padlock?

[uklockpicker]

yes quaiboi, except you would call them padlock lever picks

Yeah usmc, i call the skeleton keys.

Incorrect.

In general, in the same way you have Milled, Laser\Track and Dimple keys, these are called Bitted \ Double bitted keys (for double flagged version)

More specifically, these keys are either refered to by their classification "Pin", "Pipe", or "Mortice"

Pin refers to the tip being one solid steel pin. (Safes, cupboards, etc. entry to the lock from one side)

Pipe refers to the tip being a hollowed out pipe that rests on a pin inside the lock case. (Safes, cupboards, etc. entry to the lock from one side)

Mortice refers to keys that have a collar behind the flag, that stops the key going right through the lock case. (entry door locks, entry to the lock from both sides)


The term "skeleton key" refered to the old style warded mortice keys that were pre-cut from the manufacturer, in series of 10 to 50 keys for any lock of that series.
By cutting away all wardings, or "skelentonising", you could create a key, or set of keys, that would work any lock of the series they were made for.

[rphillips52]

Worth mentioning, for those whose experience is largely limited to Yales' lock invention, that lever locks ( i.e., locks with a lever key mechanism - not lever handles fitted with a cylinder lock) are used in many parts of Europe, Russia, and some parts of South America.
In addition to the basic lever mortice lock described by the OP, there are 'Italian-style' double bit locks, with sliding levers and each turn of the key moving the bolt a ½ throw. So a double-throw lock = 4 x ½ throws. These locks typically have 4 or 3 bolts each the same size as the bolt of a typical US tubular deadbolt lock. They are made in many versions, with and without a latch, with and without multipoint locking, and in rim and mortice fixing. Typically the bolt tail is in the middle of the lever pack - another challenge to the would-be lock-picker. Persons unfamiliar with these European lever doorlocks have sometimes supposed them to be safe locks or prison locks.
There are also many lever safe locks, with single- and double-bit keys.
Lever locks are typically larger and more robust than pin tumbler locks. Many lever locks are also designed to resist forcible attack - which they tend to do more successfully than typical pin tumbler locks.
They are made in a variety of sizes, and each size typically requires lockpick kit of a matching size. Not only does the gauge of the key shank vary; the height of the bit does too. So a pick (such as a Hobbs-type 2-in-1) for one lock could be too long for another; or short enough to enter the keyhole but too short to operate.

Many security lever locks include features designed to frustrate picking. It is easy to be mislead by seeing secure lever locks picked in a few minutes on Youtube, with seeming ease. The reality is a large investment in buying/making picking kit (which is much more expensive than that needed to pick pin tumbler locks) - and a large investment in time to practice and learn the skills to overcome the various features designed to frustrate picking.
And withall, picking a lever lock on a door, outside, with the rain trickling down your neck, in the dark, is just not as easy as in a warm, well-lighted workshop - believe me!
Although most lever locks have a more-or-less rectangular lockcase, there are also some cylinder lever locking devices - i.e., cylinder locking devices using a lever key mechanism. US readers might encounter the Ingersoll 'Impregnable' mechanism in padlocks made under licence by S&G for the US Department of Defence, chosen when DOD needed a secure padlock.

Finally, it's worth mentioning that the lever mechanism is immune from 'bumping'. And their bit keys are not 'skeleton' keys - although some lever locks do also have some wards in them. As an addition to movable detainers, wards do make a useful contribution. Pin tumbler locks, for example, are much more secure with warded keyways than without. So much so, that they have not been made without warded keyways since the end of the 19C.

[rphillips52]

Yeah usmc, i call the skeleton keys.

Incorrect.

IMore specifically, these keys are either refered to by their classification "Pin", "Pipe", or "Mortice"

Mortice refers to keys that have a collar behind the flag, that stops the key going right through the lock case. (entry door locks, entry to the lock from both sides)

Keys for lever locks which are operated from both sides need some means of preventing the key being pushed right through the lock. For many basic lever locks, a collar is used. Such locks may be fitted as either rim or mortice (and even, very rarely, as cut locks).
In Europe particularly, many privacy lever locks use bulleted keyholes. As the keyhole each side is a mirror reflection, the key cannot push right through.
Italian-style double-bitted keys commonly have bulleted keyholes, or the two bits of different sizes, and again, will not push all the way through the lock; and additionally, can only be removed after a complete turn, not at half-turns.

Keys for most two-sided lever locks are pin keys. Uncommonly, there are some lever locks with keyholes which do not go right through the lock. The keyholes on each side are not opposite, and pipe keys can be used. Such locks are usually fitted as mortice locks.