Lock is almost born with private ownership at the same time. As early as 3000 BC in the Yangshao culture site in China, there were wooden locks mounted on wooden frame buildings. In the Eastern Han Dynasty, the technology of the three spring lock made of Chinese iron had a rather high level. Three spring lock has been used for more than 1000 years.
In early eighteenth Century, the cam lock was invented by the British D. Potter. The key number is increased from more than 20 kinds of three reed locks to more than 80 kinds. In the middle of the nineteenth Century, European manufacturers reformed the slide lock on the basis of cam lock and three spring lock, and the key number could be up to 1600.
In 1848, American L. Hyeres invention adopts a cylindrical pin cylinder lock, the lock has become the most common lock used in the world. The structure of modern lock and new development, two-way, three to four, to the spring structure, and the plane, double-sided, double-sided, double multi, multi row multi cylinder structure and composite cylinder structure, thus greatly improving the security performance of the lock, the lock number from the original 2500 by "Xiang", the "surface" changes to a million.
In 1970s, with the application of micro electronics technology, the magnetic lock, voice activated lock, lock, lock, ultrasonic infrared electromagnetic lock, electronic card lock, fingerprint lock, lock, eight hundred retinal remote lock etc.. These locks have high security performance unmatched by mechanical structures. The modern lock can also realize the program control of the system according to the set logic relation in the specific system. Modern locks can be classified according to material, purpose, key, safety performance and structure.