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Master Keying
A master key operates a set of several locks. Usually, there is nothing different about the key. The differences are in the locks the key will operate. These master-keyed locks are configured to operate with two, or more, different keys: one specific to each lock (the change key), which cannot operate any of the others in the set, and the master key, which operates all the locks in the set. Locks that have master keys have a second set of the mechanism used to operate them that is identical to all of the others in the set of locks. For example, master keyed pin tumbler locks often have two shear points at each pin position, one for the change key and one for the master key. A far more secure (and more expensive) system has two cylinders in each lock, one for the change key and one for the master key. Master keyed lock systems generally reduce overall security. The fact that some pin chambers have two shear points allows for more options when picking and it also allows for more k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Key Turning In A Lock
Master, master's or masters may refer to: Ranks or titles In education: *Master (college), head of a college *Master's degree, a postgraduate or sometimes undergraduate degree in the specified discipline *Schoolmaster or master, presiding officer of a school In military: * Master (naval), a former naval rank *Master mariner, a licensed mariner who is qualified to be a sea captain in the merchant marine *Master or shipmaster, the sea captain of a merchant vessel * Master-at-arms, a naval police officer, often addressed as "Master" in the Royal Navy In orders and organizations: *Master craftsman, in the Medieval guilds In other: * Master (form of address), an English honorific for boys and young men * Master (judiciary), a judicial official in the courts of common law jurisdictions * Master (Peerage of Scotland), the male heir-apparent or heir-presumptive to a title in the Peerage of Scotland * Master of ceremonies, or MC (emcee), the host of an official public or private staged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pin Tumbler Lock
The pin tumbler lock, also known as the Yale lock after the inventor of the modern version, is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employed in cylinder locks, but may also be found in tubular pin tumbler locks (also known as radial locks or ace locks). History The first known example of a tumbler lock was found in the ruins of the Palace of Khorsabad built by king Sargon II (721–705 BC.) in Iraq.James, Peter, and I. J. Thorpe. Ancient Inventions. New York: Ballantine, 1994. Basic principles of the pin tumbler lock may date as far back as 2000 BC in Egypt; the lock consisted of a wooden post affixed to the door and a horizontal bolt that slid into the post. The bolt had vertical openings into which a set of pins fitted. These could be lifted, using a key, to a sufficient height to allow the bolt to move and unlock the door. This wooden lock was one of Egy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree (graph Theory)
In graph theory, a tree is an undirected graph in which any two vertices are connected by path, or equivalently a connected acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by path, or equivalently an acyclic undirected graph, or equivalently a disjoint union of trees. A directed tree, oriented tree,See .See . polytree,See . or singly connected networkSee . is a directed acyclic graph (DAG) whose underlying undirected graph is a tree. A polyforest (or directed forest or oriented forest) is a directed acyclic graph whose underlying undirected graph is a forest. The various kinds of data structures referred to as trees in computer science have underlying graphs that are trees in graph theory, although such data structures are generally rooted trees. A rooted tree may be directed, called a directed rooted tree, either making all its edges point away from the root—in which case it is called an arborescence or out-tree� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeleton Key
A skeleton key (also known as a passkey) is a type of master keying, master key in which the serrated edge has been removed in such a way that it can open numerous Lock and key, locks, most commonly the warded lock. The term derives from the fact that the key has been reduced to its essential parts. Master keys A skeleton key is a key that has been filed or cut to create one that can be used to unlock a variety of warded locks each with a different configuration of wards. This can usually be done by removing most of the center of the key, allowing it to pass by the wards without interference, operating the lock. To counteract the illicit creation of such keys, locksmiths can put wards not just in the center but on the outside as well, making the creation of a skeleton key more difficult. Lever tumbler lock, Lever lock skeleton keys are used in a lock with usually three or 5 lever lock, five levers and a set of wards that come into contact with the Bit key, bit of the key ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Brigade Key
Fire brigade keys are a set of standardized keys used in the United Kingdom to secure items which need to be kept locked against casual interference, but still need to be quickly and easily accessed in an emergency by fire brigades and other emergency services. Uses include securing areas such as common storage cupboards and equipment rooms and access control devices such as road barriers and movable bollards. Fire brigade keys are not secret or restricted, and are widely available for sale from locksmiths and hardware stores. Because of their widespread availability, they are only suitable for low-security applications. References See also * Fireman's switch A fireman's switch is a specialized switch that allows firefighters to quickly disconnect power from high voltage devices that may pose a danger in the event of an emergency. According to the Institution of Electrical Engineers, any electrical de ... * Secure information box Locksmithing Firefighting equipment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
