Who First Used Keys?
The first known form of lock and key was used by the Assyrians in the Middle East about 4,000 years ago. This was revealed by the discovery of such a lock in the ruins of the palace of the Assyrian Kings of Khorsabad, near the site of the city of Nineveh on the River Tigris in modern Iraq. The lock was made of wood with the bolt held in a closed position by several loose wooden pins.
The lock could be operated by inserting a long wooden key also fitted with pins, which would raise the loose pins enough to allow the bolt to be withdrawn. This type of lock was apparently known to the Egyptians. It has also been found in Japan, the Faroe Islands and Norway. The long keys were carried on the shoulder, a fact which accounts for the verse in Isaiah 22-22: “And the key of the house of David will I lay upon his shoulder.”
Another ancient type of lock known to the Chinese and the ancient Egyptians was the tumbler lock, improved versions of which are still in use today. This lock has small movable levers or “tumblers” and is opened with a key whose indentations will raise each tumbler exactly to the proper height. Metal locks and keys were invented by the Romans. They designed a lock with a number of ridges or “wards” on the inside. These prevent the turning of the key unless the grooves on it coincide with the wards.
The warded lock was also present from antiquity and remains the most recognizable lock and key design in the Western world. The first all-metal locks appeared between the years 870 and 900, and are attributed to the English craftsmen. It is also said that the key was invented by Theodore of Samos in the 6th century BC.
Affluent Romans often kept their valuables in secure boxes within their households, and wore the keys as rings on their fingers. The practice had two benefits: It kept the key handy at all times, while signaling that the wearer was wealthy and important enough to have money and jewelry worth securing. With the onset of the Industrial Revolution in the late 18th century and the concomitant development of precision engineering and component standardisation, locks and keys were manufactured with increasing complexity and sophistication.
The lever tumbler lock, which uses a set of levers to prevent the bolt from moving in the lock, was perfected by Robert Barron in 1778. His double acting lever lock required the lever to be lifted to a certain height by having a slot cut in the lever, so lifting the lever too far was as bad as not lifting the lever far enough. This type of lock is still currently used today.
The lever tumbler lock was greatly improved by Jeremiah Chubb in 1818. A burglary in Portsmouth Dockyard prompted the British Government to announce a competition to produce a lock that could be opened only with its own key. Chubb developed the Chubb detector lock, which incorporated an integral security feature that could frustrate unauthorised access attempts and would indicate to the lock’s owner if it had been interfered with. Chubb was awarded £100 after a trained lock-picker failed to break the lock after 3 months.
In 1820, Jeremiah joined his brother Charles in starting their own lock company, Chubb. Chubb made various improvements to his lock; – his 1824 improved design didn’t require a special regulator key to reset the lock, by 1847 his keys used six-levers rather than four and he later introduced a disc that allowed the key to pass but narrowed the field of view, hiding the levers from anybody attempting to pick the lock. The Chubb brothers also received a patent for the first burglar-resisting safe and began production in 1835.
The designs of Barron and Chubb were based on the use of movable levers, but Joseph Bramah, a prolific inventor, innovated an alternative method in 1784. His lock used a cylindrical key with precise notches along the surface; these moved the metal slides that restricted the turning of the bolt into an exact alignment, allowing the lock to open. The lock lay at the cutting edge of the precision machine tooling capabilities of the time and was deemed by its inventor as unbreakable.
In the same year Bramah started the Bramah Locks company at 124 Piccadilly, and displayed the “Challenge Lock” in the window of his shop from 1790, challenging “…the artist who can make an instrument that will pick or open this lock” for the reward of £200. The challenge stood for over 67 years until, at the Great Exhibition of 1851, the American locksmith Alfred Charles Hobbs was able to open the lock and, following some argument about the circumstances under which he had opened it, was awarded the prize. Hobbs’ attempt required some 51 hours, spread over 16 days.
The earliest patent for a double-acting pin tumbler lock was granted to American physician Abraham O. Stansbury in England in 1805, but the modern version, still in use today, was invented by American Linus Yale, Sr. in 1848. This lock design used pins of varying lengths to prevent the lock from opening without the correct key.
In 1861, Linus Yale, Jr. was inspired by the original 1840s pin-tumbler lock designed by his father, thus inventing and patenting a smaller flat key with serrated edges as well as pins of varying lengths within the lock itself, the same design of the pin-tumbler lock which still remains in use today. The modern Yale lock is essentially a more developed version of the Egyptian lock. Despite some improvement in key design since, the majority of locks today are still variants of the designs invented by Bramah, Chubb and Yale.