Pin tumbler lock
Encyclopedia
The pin tumbler lock (or Yale lock, after lock manufacturers Yale
) is a lock
mechanism that uses pin
s of varying lengths to prevent the lock from opening without the correct key
. Pin tumblers are most commonly employed in cylinder lock
s, but may also be found in tubular pin tumbler lock
s (also known as radial locks).
; the lock consisted of a wood
en post affixed to the door, and a horizontal bolt that slid into the post. The bolt had vertical openings into which fitted a set of pins. These could be lifted, using a key, to a sufficient height to allow the bolt to move and unlock the door.
In 1848, Linus Yale, Sr.
invented the modern pin-tumbler lock. In 1861, Linus Yale, Jr.
was inspired by the original 1840s cylindrical 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 plug has a straight-shaped slot known as the keyway at one end to allow the key to enter the plug; the other end may have a cam or lever which activates a mechanism to retract a locking bolt. The keyway often has protruding ledges which serve to prevent the key pins from falling into the plug, and to make the lock more resistant to picking
. A series of holes, typically five or six of them, are drilled vertically into the plug. These holes contain key pins of various lengths, which are rounded to permit the key to slide over them easily.
Above each key pin is a corresponding set of driver pins, which are spring-loaded. Simpler locks typically have only one driver pin for each key pin, but locks requiring multi-keyed entry, such as a group of locks having a master key, may have extra driver pins known as spacer pins. The outer casing has several vertical shafts, which hold the spring-loaded pins.
When the plug and outer casing are assembled, the pins are pushed down into the plug by the springs. The point where the plug and cylinder meet is called the shear point. With a key properly cut and inserted into the groove on the end of the plug, the pins will rise causing them to align exactly at the shear point. This allows the plug to rotate, thus opening the lock. When the key is not in the lock, the pins straddle the shear point, preventing the plug from rotating. Sets of locks with a master key will have one set of shear points that are identical to the others in the set and one set that is unique to that specific lock.
Yale (company)
Yale is a lock manufacturer owned by Assa Abloy. It is associated with the pin tumbler lock, which is often known as the Yale lock.- History :...
) is a lock
Lock (device)
A lock is a mechanical or electronic fastening device that is released by a physical object or secret information , or combination of more than one of these....
mechanism that uses pin
Pin
A pin is a device used for fastening objects or material together.Pin may also refer to:* Award pin, a small piece of metal or plastic with a pin attached given as an award for some achievement...
s of varying lengths to prevent the lock from opening without the correct key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
. Pin tumblers are most commonly employed in cylinder lock
Cylinder lock
A cylinder lock is a lock constructed with a cylinder that a locksmith can easily unscrew to facilitate rekeying. The cylinder may contain any of a variety of locking mechanisms, including the pin tumbler lock, the wafer tumbler lock and the disc tumbler lock....
s, but may also be found in tubular pin tumbler lock
Tubular pin tumbler lock
A tubular pin tumbler lock, also known as Ace lock; axial pin tumbler lock; or radial lock, is a variety of pin tumbler lock in which 6-8 pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape....
s (also known as radial locks).
History
The basic principles of the pin tumbler lock may date as far back as 2000 BC in EgyptEgypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
; the lock consisted of a wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
en post affixed to the door, and a horizontal bolt that slid into the post. The bolt had vertical openings into which fitted a set of pins. These could be lifted, using a key, to a sufficient height to allow the bolt to move and unlock the door.
In 1848, Linus Yale, Sr.
Linus Yale, Sr.
Linus Yale, Sr. was an American inventor and manufacturer of locks.He was born in Middletown, Connecticut, and later moved with his parents to Salisbury, New York. Yale opened a lock shop in the early 1840s in Newport , New York, specializing in bank locks. In 1850 his son, Linus Yale, Jr...
invented the modern pin-tumbler lock. In 1861, Linus Yale, Jr.
Linus Yale, Jr.
Linus Yale, Jr. was an American mechanical engineer and manufacturer, best known for his inventions of locks, especially the cylinder lock. His locks are still widely distributed in today’s society, and constitute a majority of personal locks and safes. Linus Yale, Jr. was born in Salisbury, NY....
was inspired by the original 1840s cylindrical 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.
Design
The pin tumbler is commonly used in cylinder locks. In this type of lock, an outer casing has a cylindrical hole in which the plug is housed. To open the lock, the plug must rotate.The plug has a straight-shaped slot known as the keyway at one end to allow the key to enter the plug; the other end may have a cam or lever which activates a mechanism to retract a locking bolt. The keyway often has protruding ledges which serve to prevent the key pins from falling into the plug, and to make the lock more resistant to picking
Lock picking
Lock picking is the art of unlocking a lock by analyzing and manipulating the components of the lock device, without the original key. Although lock picking can be associated with criminal intent, it is an essential skill for a locksmith...
. A series of holes, typically five or six of them, are drilled vertically into the plug. These holes contain key pins of various lengths, which are rounded to permit the key to slide over them easily.
Above each key pin is a corresponding set of driver pins, which are spring-loaded. Simpler locks typically have only one driver pin for each key pin, but locks requiring multi-keyed entry, such as a group of locks having a master key, may have extra driver pins known as spacer pins. The outer casing has several vertical shafts, which hold the spring-loaded pins.
When the plug and outer casing are assembled, the pins are pushed down into the plug by the springs. The point where the plug and cylinder meet is called the shear point. With a key properly cut and inserted into the groove on the end of the plug, the pins will rise causing them to align exactly at the shear point. This allows the plug to rotate, thus opening the lock. When the key is not in the lock, the pins straddle the shear point, preventing the plug from rotating. Sets of locks with a master key will have one set of shear points that are identical to the others in the set and one set that is unique to that specific lock.
See also
- Cylinder lockCylinder lockA cylinder lock is a lock constructed with a cylinder that a locksmith can easily unscrew to facilitate rekeying. The cylinder may contain any of a variety of locking mechanisms, including the pin tumbler lock, the wafer tumbler lock and the disc tumbler lock....
- Disc tumbler lockDisc tumbler lockA disc tumbler lock or Abloy Disklock is a lock composed of slotted rotating detainer discs. A specially cut key rotates these discs like the tumblers of a safe to align the slots, allowing the sidebar to drop into the slots, thus opening the lock. Unlike a wafer tumbler lock or a pin tumbler...
- Wafer tumbler lockWafer tumbler lockA wafer tumbler lock is a type of lock that uses a set of flat wafers to prevent the lock from opening unless the correct key is inserted. This type of lock is similar to the pin tumbler lock and works on a similar principle. However, unlike the pin tumbler lock, the wafer is a single piece...
- Tubular pin tumbler lockTubular pin tumbler lockA tubular pin tumbler lock, also known as Ace lock; axial pin tumbler lock; or radial lock, is a variety of pin tumbler lock in which 6-8 pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape....
- Key relevanceKey relevanceIn master locksmithing, key relevance is the measurable difference between an original key and a copy made of that key, either from a wax impression or directly from the original, and how similar the two keys are in size and shape...
- Lock pickingLock pickingLock picking is the art of unlocking a lock by analyzing and manipulating the components of the lock device, without the original key. Although lock picking can be associated with criminal intent, it is an essential skill for a locksmith...
- Magnetic-coded lockMagnetic-coded lockA magnetic-coded lock is a lock device that uses pins in combination with magnets to prevent entry by either non-matching keys by teething or magnetic polarity. Magnetic-coded locks encompass knob locks, cylinder locks, lever locks, and deadbolt locks as well as applications in other security...
External links
- The pin tumbler invention at Yale company site
- Popular Science, November 1946 How Your Home Lock Works