Padlock

A modern padlock.

Viking Age padlock found at Birka.

A padlock is a simple type of detachable lock, with a hinged or sliding shackle designed to pass through a ring or staple on a door, chest, etc. While some modern padlocks do not require a key to be closed, others do require it, most often as a security measure against leaving the key inside the location being locked. Image File history File links Padlock. ... Image File history File links Padlock. ... ImageMetadata File history File links Padlock_klódka_ubt. ... ImageMetadata File history File links Padlock_klódka_ubt. ... Image File history File links Viking_Age_lock. ... Image File history File links Viking_Age_lock. ... The Viking Age is the name of the period between 793 and 1066 AD in Scandinavia and Britain, following the Germanic Iron Age (and the Vendel Age in Sweden). ... Location in Sweden During the Viking Age, Birka or Birca  , on the island of Björkö (also Bierkø, literally: Birch Island) in Sweden, was an important trading center which handled goods from Scandinavia as well as Central and Eastern Europe and the Orient. ... Padlock 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. ... A hinge is a mechanical device that connects two solid objects, allowing rotation between them. ... A shackle is a U-shaped piece of metal secured with a pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. ...

In Victorian times, English locksmiths made giant padlocks which they challenged all-comers to open (or "pick") in order to claim a prize. This was supposed to demonstrate how secure their devices were to the public. The type of padlock made from layers of laminated steel was invented by Harry Soref in 1919. Locksmithing is the science and art of making and defeating locks. ... 1919 (MCMXIX) was a common year starting on Wednesday (see link for calendar). ...

Combination locks

Main article: Combination lock

Combination padlocks do not use keys. Instead, the lock opens when its wheels are lined up correctly to display the correct combination. Often the lock is re-programmable by holding the shackle in a special position while turning the wheels, allowing the number to be changed if necessary. A combination lock is a type of lock in which a sequence of numbers or symbols is used to open the lock. ...

It should be noted that - with patience - every mechanical combination padlock can be cracked without any special skill, unlike the key version.

Uses

Padlocks are used by consumers, commercial businesses, utilities, railroads & our government on various applications (most common is the hasp, chain, or padlock eye) for the purpose of impeding theft, vandalism, sabotage (as in the case of railroad switches), espionage (such as when our government used them to lock up classified information stored in filing cabinets), or even to protect people from harm (i.e. when power companies lock their equipment or as used as OSHA safety lockouts).

History

In the late 17th century Christopher Polhem started a factory in Stjärnsund that among other things produced a padlock of his own invention, the Scandinavian padlock ("Polhem locks"). Christopher Polhem on the Swedish 500 kronor bank note. ...

Harry Soref founded the Master Lock Company in 1921 and patented an improved padlock. In April 1924, he received a patent (U.S #1,490,987) for his new lock casing. Soref made a padlock that was both strong and cheap using a case constructed out of layers of metal, like the doors of a bank vault. He designed his padlock using laminated steel. Master Lock is a manufacturer of padlocks and combination locks. ...