The Lever Lock Robert Barron invented the lever lock in 1778. This constituted a considerable improvement over the ancient warded lock. It was based on a series of several "levers" that must each be raised to their own set height. If a particular lever was lifted to high or not enough, then the lock would not open. When the proper key is inserted, the notches on the key raise all the lever tumblers the required distance, lining up all the gates, allowing the lock to be opened. Not only was this new lock much harder to pick, it offered up to ten billion possible keying combinations. (The amount of practical combinations is actually around fifty thousand) ##### __ ####### / \ ## ### #### ## ########### ## \ / ###### ####### ########### ## | | a lever or "lever tumbler" ########################### ## | | lock keyhole ####### |__| #### a lever tumbler lock key Since its design the lever tumbler lock has undergone numerous improvements. One of the is called the parautopic lock. The parautopic lock consisted of two sets of lever tumbler, where the first worked on the second. It also proved a plate that turned with the key so that one could not inspect the locks interior construction. Lever locks, though limited in use, can still be found today in some hospitals, suitcases, cabinets, fine furniture, and attache cases. Lever locks are also used on safe-deposit boxes, often with fifteen or more levers and sometimes requiring two keys. Picking Lever locks are a little harder to pick then the wafer and pin tumbler variety. In fact, the type of lever locks used on safe-deposit boxes are very difficult to pick indeed. To pick a lever lock requires that tension be placed against the deadbolt throughout the course of lifting one or more levers within the lock to the required alignment with the post. This requires the use of a "lever lock tension wrench" and a "hook" or "lifter" pick. [Picks are discussed later in the Lockpicking Tools section.] Insert the lever lock tension wrench (a bit different than a normal tension wrench) into the keyway, and exert torsional pressure. The long bit is the part you hold, the next bend runs to the bottom of the lock, and the final bend fits into the notch in the bolt. Unlike most other types of locks, the lever locks requires you to exert considerable pressure on the tension wrench while picking. Usually the lever springs provide enough force to cause the levers to drop back down once picked. Because of the greater pressure, lever locks may require a slightly thicker tension wrench then normal. Then insert the hook pick all the way into the lock. Locate the back lever and raise it gently until you FEEL or HEAR a slight "click". With the lever locks, the force required to push against the spring is substantially more than in other locks. Once it reaches the correct position, the gate will align with the post, and you should notice a slight "give" in the deadbolt, as there is now one less lever obstructing the lock from opening. You should note that once a lever has been picked, the amount of force required to lift that lever will be substantially less. Move on to the next lever by slightly withdrawing the pick and repeat the process. Each subsequent lever will require the use of slightly less tension then on the previous ones. Otherwise the increased tension could cause the lock to bind up. Once you have picked each individual lever, the lock should open. If it does not, then reinsert the pick (always maintaining tension with your wrench) and jiggle each lever slightly to ensure correct alignment. Each lever does not require very much lift. This is due to the fact that the maximum depth of the cut under any tumbler is no more than half the width of the key, and never more than two-thirds its width. You should therefore use a pick that does not have too much "hook" to it.