Who Invented The Lock?
the earliest locks may no longer be around ,and there may be no written records of them.how likely it is for old locks to be found depends on the materials they were made from and on the climate and and various geological condition they have been subjected to over the years.there is evidence to suggest that different civilization probably developed the lock independently of each other.the egyptains,romans and Greeks are credited with inventing oldest known locks.
Egypt
the oldest known lock was found in 1842 in the ruins of emperor sargon II’s palace in khorsabad,Persia.the ancient Egyptian lock was dated to be about 4000 years old.it relied on the same pin tumbler principle that is used by many of today’s most popular locks.
the Egyptian lock consisted of three basic parts: a wood crossbeam,a vertical beam with tumblers,and a large wood key.the crossbeam ran horizontally across the inside of the door and was held in place by two vertically mounted wooden staples.part of the length of the crossbeam was hollowed out,and the vertical beam intersected it along that hollowed out side.the vertical beam contained metal tumblers that locked the two pieces of wood together. near the tumbler edge of the door there was a hole accessible from outside the door that was large enough for someone to insert the key and an arm.the spoon-shaped key was about 14 inches to 2 feet long with pegs sticking out of one end.after the key was inserted in the keyhole(or “armhole”),it was pushed into the hollowed out part of the crossbeam until its pegs were aligned with their corresponding tumblers.the right key allowed all the tumblers to be lifted into a position between the crossbeam and vertical beam so that the pins no longer obstructed movement of the crossbeam.then the crossbeam (bolt)could be pulled into the open position.
Greece
most early Greek doors pivoted at the center and were secured rope tied in intricate knots.the cleverly tied knots,along with beliefs about being cursed for tampering with them ,provided some security.when more security was needed,doors were secured by bolts from the inside.in the few cases where locks were used,they were primitive and easy to defeat.the Greek locks used a notched bolt work and were operated by inserting the blade of an iron sickle-shaped key,about a foot long,in a key slot and twisting it 180 degrees to work the bolt.they could be defeated just by trying a few different-size keys.in about 800 b.c.e. the Greek poet homer described that Greek lock in his poem “the odysseus”:…she went upstairs and got the store room key,which was made of bronze and had a handle of ivory;she than went with her maidens into the store room at the end of the house,where her husband’s treasures of gold,bronze and wrought iron were kept….she loosed the strap from the handle of the door,put in the key,and drove it straight home to shoot back the bolts that held the doors.
Rome
like the Greeks,the romans used notched bolt-work.but the romans improved on the lock design in many wats,such as by putting the boltwork in an iron case and using keys of iron or bronze.because iron rusts and corrodes,few early roman locks are in existence. but a lot of the keys are aroun.often the keys were orntly designed to be worn as jewelry,either as finger rings or as necklaces using string(because togas didnt have pockets).
two of the most importent innovations of the roman locks were the spring-loaded bolt and the use of wards on the case.the extensive commerce during the time of julius caesar led to a great demand for locks among the many wealthy merchnts and politicians.the type of lock used by the romans,the warded bit-key lock,is still being used today in many older homes.because the lock provides so little security,typically it’s found on interior doors,such as closets and sometimes bedrooms.
the romans are sometimes credited with inventing the padlocks,but that’s controversial.there is evidence that the chinese may have independently invented it before or about the same time.
the demeaned for locks declined after the fall of rome in the fifth century because people had little property to protect.the few locks used during the period were specially ordered for nobility and the handful of wealthy merchants.
Europe
during the middle ages,metal workers in england, Germany and France continued to make warded locks,with no significant security changes. they focused on making elaborate ornately designed cases and keys.locks become work of art.
keys were made that could move about a post and shift the position of a movable bar(the locking bolt).the first obstacles to unauthorized use of the lock were internal wards.medieval and renaissance craftsman improved on the warded lock by using many interlocking wards and more complicated keys.but many of the wards could easily be bypassed.
in France in 1767,the treatise the art of the locksmith was published ;it described example of the lever tumbler lock.the inventor of the lock is unknown.as locksmithing advanced,locks were designed with multiple levers,each of which had to be lifted and properly aligned before the bolt could move to the unlocked position.
in the fourteenth century the locksmith’s guilds came into prominence.they required journeymen locksmiths to creates and submit a working lock and key to the guild before being accepted as a master locksmith.the locks and keys weren’t made to be installed,but to be displayed in the guild hall.the guild’s work resulted in some beautiful locks and keys.the problem with the locksmith guilds is that they gained too much control over locksmith,including the regulating of techniques and prices.the guilds became corrupt and didn’t encourage technological advances.few significant security innovations were made because of the locksmiths guilds.the innovations included things like false and hidden keyholes.a fish-shaped lock,for instance,might have the keyhole hidden behind a fin.
England
little progress was made in lock security until the eighteenth centiry.incentive was given in the form of cash awards and honors to those who could pick open newer and more complex locks.that resulted in more secure lock designs.in the forefront of lock designing were three englishmen:robert barron,joseph bramah and jeremiah chubb.
the first major improvement over warded locks was patented in england in 1778 by robert barron.he added the tumbler principle to wards for increased security.his double-acting lever tumbler lock was more secure than other locks.during that time and remains today the basic design for lever tumbler locks.like other lever tumbler locks,barron’s used ward.but he also used a series of lever tumblers,each of which was acted upon by a separate step of the key.if any tumbler wasn’t raised to the right height by the key,its contact with a bolt stump would obstruct bolt movement.barron’s lock corrected the shortcomings of earlier lever tumbler locks,which could easily be circumvented by any key or instrument thin enough to bypass the wards.barron added up to six of these doubl-lever action to his lock and thought it was virtually impossible to open it except by the proper key.he oon find out differently.
another Englishman,joseph bramah,wrote a dissertation on the construction of locks, which exposed the many weaknesses of existing so-called thiefproof locks and pointed out that many of them could be picked by a good specialist or criminal with some training in locks and keys.bramah admitted that barron’s lock had many good points but also revealed its major fault:the lever,when in the locked position,gave away the lock’s secret.the levers had uneven edges at the bottom;thus,a key coated with wax could be inserted into the lock and a new key could be made filing where the wax had been pressed down or scarped away.several tries could create a key that matched the lock.bramah pointed out that the bottom edges of the levers showed exactly the depths to which the new key should be cut to clear the bolt.bramah suggested that the lever bottom should be cut unevenly.then only a masrter locksmith should be able to open it.
using those guidelines,bramah patented a barre-shaped lock in 1798 that employed multiple sliders around the lock that were to be aligned with corresponding notches around the barrel of its key.the notches on the key were of varying heights.when the right key was pushed into the lock,all the notches lined up with the sliders,allowing the barrel to rotate to the unlocked position .
it was the first to use the rotating element in the lock itself.
during this period,burglary was a major problem.after the Portsmouth,england,dockyard was burglarized 1n 1817,the British crown offered a reward to anyone who could make an unpickable lock.a year later,jeremiah chubb patented his lock and won the prize money.
jeremiah chubb’s detector lock was a four-lever tumbler rim lock that used a barrel key.it had many improvements over barron’s.one of the improvements was a metal “curtain” that fell across the keyhole when the mechanism began to turn,making the lock hard to pick.chubb’s lock also added a detector lever that indicated whether the lock had been tampered with.a pick or an improperly cut key would raise one of the levers too high for the bolt gate.that movement engaged a pin that locked the detector lever.the lever could be cleared by turning the correct key backward and then forward.
chubb’s lock got much attention.it was recorded that a convict who had been a lock-master was on board one of the prison ships at portmouth dockyard and said he had easily picked open some of the best locks and that he could easily pick open chubb’s detector lock.he was given one of the locks and all the tools that he asked for,includind key blanks fitted to the drill pin of the lock.as incentive to pick open the lock ,Mr.chubb offered the convict a reward of more then $100- ,and the government offered a free pardon if he succeeded.after trying for several months to pick the lock,he gave up.he said that chubb’s lock was the most secure lock he had ever met with and that it was impossible for anyone to pick or open it with false instruments.the lock was improved on by jeremiah’s brother,charles chubb,and charles’ son john chubb in several ways,including the addition of two levers and false notches on the levers.
the lock was considered unpickable until it was picked open in 1851 at the international industrial exhibition in london by an american locksmith named alfred c.hobbs. at that event,hobbs picked open both the bramah and the chubb locks in less than half an hour.
America
During America’s early years,england had a policy against its skilled artisans leaving the country.that was to keep them from running off and starting competing foreign companies.locks made by early american locksmiths didn’t sell well.in mid-1700s few colonists used door locks,and most that were used were copies of european model.more often,american used lock bolts mounted on the inside of the door that could be opened from the outside by a latchstring,hence the phrase,”the latchsring’s always out”.at night,the string would be pulled inside,”locking” the door.of cource,someone had to be inside to release the bolt.an empty house was left unlocked.as the country settled,industry progressed and theft increased,increasing the demand for more and better locks.american locksmiths soon greatly improved on the english locks and were making some of the most innovative locks in the world.before 1920,american lockmakers patented about 3000 different locking devices.
in 1805,an american physician,Abraham O.Stansbury,was granted an english patent for a pin tumbler lock that was based on the principles of both the egyptain and bramah locks.two years later,the design was granted the first lock patented by the U.S. patent and trademark office.stansbury’s lock used segmented pins that automatically relocked when any tumbler was pushed too far.
the double -acting pin tumbler lock was never manufactured for sale.
in 1836,a new jersey locksmith,Solomon a Andrews,developed a lock that had adjustable tumblers and keys,wich allowed the owner to re-key the lock anytime.because the key could also be modified,there was no need to use a new key to operate a re keyed lock.but few homeowners used the lock because re keying it required dexterity,practice ,and skill.the lock was of more interest to banks and busnesses.
in 1850s two inventors,Andrews and Newell,were granted patented on an important new feature-removable tumblers that could be disassembled and scrambled.the keys had interchangeable bits that matched the various tumbler arrangements.after locking up for the night,a prudent owner would scramble the key bits.even if a thief got possession of the key,it would take hours to stumble onto the right combination.in addition to removable tumblers,this lock featured a double set internal levers.
Newell was so proud of this lock that he offered a reward of $5,000.00 to anyone who could open it .a master mechanic took him up on the offer and collected the money.this experience convince Newell that the only secure lock would have its internals sealed off from view.university,the sealed locks appeared on bank safe in the form of combination locks.
until the time of A.C. Hobbs,who picked the famed English locks with ease,locks were opened by making a series of false keys.if the series was complete,one of the false keys would match the original.of course,this procedure took time.thousands of hours might pass before the right combination was found.Hobbs depended upon manual dexterity.he applied pressure on the bolt while manipulating one lever at a time with a small pick inserted through the keyhole.
as each lever tumbler unlatched,the bolt moved a hundredth of an inch or so.
Hobbs patented what he called “protector” locks.they weren’t invincible either .in 1854,one of Chubb’s locksmiths used special tools to pick open one of Hobb’s locks.
until the early nineteenth century,locks were made by hand .each locksmith had his own ideas about the type of mechanism-the number of lever tumblers ,wards,and internal cams to put into a given lock.keys contained the same individuality.a lock could have 20 levers and weight as much as 5 pounds.
in 1844,Linus Yale,Sr.,of Middletown,Connecticut,patented his “Quadruplex” bank lock,which incorporated a combination of ancient Egyptian design features and mechanical principal of the bramah and stunsbury locks.the Quadruplex had a cylinder subassembly that denied access to the lock bolt.in 1948 Yale patented another pin tumbler design based on the Egyptian and the bramah locks.his early models had the tumblers built into the case of the lock and is credited with inventing the modern pin tumbler lock.
Arguably, the most important modern lock developments is the Yale Mortise cylinder lock ,U.S. patent 48,475 , issued on june 27 1865,to Linus Yale ,Jr.it turned the lock-making industry upside down and established a new standard.Yale,Jr.’s, lock not only could easily be re keyed ,but it also provided a high level of security ,could easily be mass produced, and could be used on doors of various thicknesses .his lock design meant that keys no longer had to pass through the thickness of the door to reach the tumblers or bolt mechanism,which allowed the keys to be made thinner and smaller .(linus yale,Jr’s,first pin tumbler locks used a flat steel key rather than paracentric cylinder type often used today).
This entry was posted on Tuesday, May 27th, 2008 at 7:25 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.