Lock (device)

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Padlock

Simple three-disc locking mechanism
from a wooden box recovered from
the Swedish ship Vasa, sunk in 1628

Medieval lock in Kathmandu

A lock is a mechanical fastening device which may be used on a door, vehicle, or container, restricting access to the area or property enclosed. Commonly, it can be released by using a key or combination.

1 History of locks
2 Famous locksmiths
3 Types of locks
4 References
5 See also
6 External links
7 Further reading

[edit] History of locks

Securing one's property has long been a concern of people throughout the world. Beyond hiding the objects or constantly guarding them the most frequently used option is to secure them with a device. Early solutions included knots to either detect, like the Thief knot, or hamper, like the Gordian knot.

Wooden locks and keys were in use as early as 4,000 years ago in Egypt [1]. The first known lock with a key is a pin lock. The lock is strung on a rope hanging out of a hole in a door. A cylinder of wood with a hole drilled through its axis is the key, the length of the cylinder being the critical factor. Then the key is inserted into the hole and the bolt is pushed the correct distance. To lock the door,they just pulled on the rope to extract the key cylinder and simultaneously pulling the bolt closed. This type of lock is still in use in certain parts of the world. A danger of this lock is a vandal can push the rope into the hole — an ancient equivalent of putting glue into a lock.

Early improvements in pin locks included increasing the number of pins to increase security, and changing the orientation of the pins to allow the key to provide the unlocking force instead of a rope. Thus establishing the principles of the modern pin tumbler lock.

Next was developed a warded lock that is still used in modern times when the security required is not high and cost is a significant factor. It is the first lock design to have a key recognizable to a modern western person. Lock puzzles were used to obscure the locking mechanism or even provide a nonfunctioning lock for the thief to waste time on.

[edit] Famous locksmiths

Robert Barrion patented a double-acting tumbler lock in 1778, the first reasonable improvement in lock security.
Joseph Bramah patented the safety lock in 1784. It was considered unpickable for many years.
Jeremiah Chubb patented his detector lock in 1818. It won him the reward offered by the Government for a lock which could not be opened by any but its own key.
James Sargent invented the world's first successful key-changeable combination lock in 1857. His lock became popular with safe manufacturers and the United States Treasury Department. In 1873, he patented a time lock mechanism, the prototype for those used in contemporary bank vaults.
Samuel Segal invented the first jimmy proof locks in 1916.
Harry Soref founded the Master Lock Company in 1921 and patented an improved padlock in 1924 with a patent lock casing constructed out of laminated steel.
Linus Yale, Sr. invented a pin tumbler lock in 1848.
Linus Yale, Jr. improved upon his father's lock in 1861, using a smaller, flat key with serrated edges that is the basis of modern pin-tumbler locks. Yale invented the modern combination lock in 1862.

[edit] Types of locks

A type of padlock side view.

Door with two locks, one in the doorknob and a separate deadbolt.

Locks may be entirely mechanical, or electromechanical. They may be operated by turning some form of removable key, by keying or dialing in a combination which directly or via electromechanical means operates the lock, with some form of magnetic or other card reader, or by moving a part on a safety lock intended to prevent accidental operation rather than to prevent unauthorised access.