key |
pliers |
top 10 words in brain distribution (in article): blade head cut metal century form shape type design modern |
top 10 words in brain distribution (in article): steel head cut handle metal form tool hand design edge |
top 10 words in brain distribution (not in article): iron plant steel fruit handle hair produce tool grow seed |
top 10 words in brain distribution (not in article): iron blade hair cell type size plant shape century nail |
times more probable under key 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under pliers (words not in the model) | |
A key'" is a device which is used to open a lock. A typical key consist 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 designed to open one specific lock, although master keys are designed to open sets of similar locks. Keys provide an inexpensive, though imperfect, method of authentication for access to properties like buildings and vehicles. As such, keys are an essential feature of modern living in the developed world, aing adorned by key fobs and known as a keychain. House keys. A house key'" is the most common sort of key. There are two main forms. The older form is for lever locks, where a pack of flat levers (typically between two and five) are raised to different heights by the key whereupon the slots or "'gates'" of the levers line up and permit a bolt to move back and forth, opening or closing the lock. The teeth or "'bittings'" of the key have flat tops rather than being pointed. Lever lock keys tend to be bigger and less convenient for carrying, although lever locks tend to be more secure. These are still common in, for example, many European countries. The more recent form is that for a pin tumbler cylinder lock. When held upright as if to open a door, a series of grooves on either side of the key (the key's "'profile'") limits the type of lock cylinder the key can slide into. As the key slides into the lock, a series of pointed teeth and notches allow pins to move up and down until those pins are in line with the shear line of the cylinder, allowing that cylinder to rotate freely inside the lock and the lock to open. These predominate in, for example, the United States of America. Car key. A "'car key'" or an "'automobile key'" is a key used to open and or start an automobile, often identified with the logo of the car company at the head. Modern key designs are usually symmetrical, and some | History. Pliers in the general sense are an ancient and simple invention, no singular point in history or singular inventor can be credited. Early metal working processes from several millennia BC would have required plier-like devices to handle hot materials in the process of smithing or casting. Development from wooden to bronze pliers would have probably happened sometime prior to 3000 BC. Among the oldest illustrations of pliers are those showing the Greek god Hephaestus in his smithy. Today, pliers intended principally to be used for safely handling hot objects are usually called tongs. The number of different designs of pliers grew with the invention of the different objects which they were used to handle: horse shoes, fasteners, wire, pipes, electrical and electronic components. Design. The basic design of pliers has changed little since their origins, with the pair of "handles", the "pivot" (often formed by a rivet), and the "head" section with the gripping jaws or cutting edges forming the three elements. In distinction to a pair of scissors or shears, the plier's jaws always meet each other at one pivot angle. Pliers are an instrument that convert a power grip—the curling of the fingers into the palm of the hand—into a precision grip, directing the power of the hand's grip in a precise fashion on to the objects to be gripped. The handles are long relative to the shorter nose of the pliers. The two arms thus act as first class levers with a mechanical advantage, increasing the force applied by the hand's grip and concentrating it on the work piece. The materials used to make pliers consist mainly of steel alloys with additives such as vanadium or chromium, to improve alloy strength and prevent corrosion. Often pliers have insulated grips to ensure better handling and prevent electrical conductivity. In some lines of fine work (such as jewellery or musical instrument repair), some specialised pliers feature a layer of comparatively soft metal (such as brass) over the two plates of the head of the pliers to reduce pressure placed on some fine tools or materials. Making entire pliers out of softer metals would be impractical, reducing the strength required to break or bend them. |