Spring (device) in the context of Additive map

A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The virus genomic component inside the capsid, along with occasionally present virus core protein, is called the virus core. The capsid and core together are referred to as a nucleocapsid (cf. also virion).

Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or more proteins. For example, the foot-and-mouth disease virus capsid has faces consisting of three proteins named VP1–3.

A couch, also known as a sofa, settee, chesterfield, or davenport, is a cushioned piece of furniture that can seat multiple people. It is commonly found in the form of a bench with upholstered armrests and is often fitted with springs and tailored cushion and pillows. Although a couch is used primarily for seating, it may be used for sleeping. In homes, couches are normally put in the family room, living room, den, or lounge. They are sometimes also found in non-residential settings such as hotels, lobbies of commercial offices, waiting rooms, and bars. Couches can also vary in size, color, and design.

A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, massometers, and weight balances.

The traditional scale consists of two plates or bowls suspended at equal distances from a fulcrum. One plate holds an object of unknown mass (or weight), while objects of known mass or weight, called weights, are added to the other plate until mechanical equilibrium is achieved and the plates level off, which happens when the masses on the two plates are equal. The perfect scale rests at neutral. A spring scale will make use of a spring of known stiffness to determine mass (or weight). Suspending a certain mass will extend the spring by a certain amount depending on the spring's stiffness (or spring constant). The heavier the object, the more the spring stretches, as described in Hooke's law. Other types of scales making use of different physical principles also exist.

A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. Winding the timepiece, by turning a knob or key, stores energy in the mainspring by twisting the spiral tighter. The force of the mainspring then turns the clock's wheels as it unwinds, until the next winding is needed. The adjectives wind-up and spring-powered refer to mechanisms powered by mainsprings, which also include kitchen timers, metronomes, music boxes, wind-up toys and clockwork radios.

Mainsprings appeared in the first spring-powered clocks, in 15th-century Europe. The mainspring replaced the weight hanging from a cord wrapped around a pulley, which was the power source used in all previous mechanical clocks.

Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word also refers to the materials used to upholster something.

Upholstery comes from the Middle English word upholder, which referred to an artisan who makes fabric furnishings. The term is equally applicable to domestic, automobile, airplane and boat furniture, and can be applied to mattresses, particularly the upper layers, though these often differ significantly in design. A person who works with upholstery is called an upholsterer. An apprentice upholsterer is sometimes called an outsider or trimmer. Traditional upholstery uses materials like coil springs (post-1850), animal hair (horse, hog and cow), coir, straw and hay, hessians, linen scrims, wadding, etc., and is done by hand, building each layer up. In contrast, today's upholsterers employ synthetic materials like dacron and vinyl, serpentine springs, and so on.

A switchblade (also known as switch knife, automatic knife, pushbutton knife, ejector knife, flick knife, gravity knife, flick blade, or spring knife) is a pocketknife with a sliding or pivoting blade contained in the handle which is extended automatically by a spring when a button, lever, or switch on the handle or bolster is activated. Virtually all switchblades incorporate a locking blade, a means of preventing the blade from being accidentally closed while in the open position. An unlocking mechanism must be activated in order to close the blade for storage.

During the 1950s, US newspapers as well as the tabloid press promoted the image of a new violent crime wave caused by young male delinquents with a switchblade or flick knife, based mostly on anecdotal evidence. In 1954, Democratic Rep. James J. Delaney of New York authored the first bill submitted to the U.S. Congress banning the manufacture and sale of switchblades, beginning a wave of legal restrictions worldwide and a subsequent decline in their popularity.

A torsion spring is a spring that works by twisting its end along its axis; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a torque in the opposite direction, proportional to the amount (angle) it is twisted. There are various types:

• A torsion bar is a straight bar of metal or rubber that is subjected to twisting (shear stress) about its axis by torque applied at its ends.
• A more delicate form used in sensitive instruments, called a torsion fiber consists of a fiber of silk, glass, or quartz under tension, that is twisted about its axis.
• A helical torsion spring, is a metal rod or wire in the shape of a helix (coil) that is subjected to twisting about the axis of the coil by sideways forces (bending moments) applied to its ends, twisting the coil tighter.
• Clocks use a spiral wound torsion spring (a form of helical torsion spring where the coils are around each other instead of piled up) sometimes called a "clock spring" or colloquially called a mainspring. Those types of torsion springs are also used for attic stairs, clutches, typewriters and other devices that need near constant torque for large angles or even multiple revolutions.

In physics, the restoring force is a force that acts to bring a body to its equilibrium position. The restoring force is a function only of position of the mass or particle, and it is always directed back toward the equilibrium position of the system. The restoring force is often referred to in simple harmonic motion. The force responsible for restoring original size and shape is called the restoring force.

An example is the action of a spring. An idealized spring exerts a force proportional to the amount of deformation of the spring from its equilibrium length, exerted in a direction oppose the deformation. Pulling the spring to a greater length causes it to exert a force that brings the spring back toward its equilibrium length. The amount of force can be determined by multiplying the spring constant, characteristic of the spring, by the amount of stretch, also known as Hooke's law.

A bayonet mount (mainly as a method of mechanical attachment, such as fitting a lens to a camera using a matching lens mount) or bayonet connector (for electrical use) is a fastening mechanism consisting of a cylindrical male side with one or more radial pegs, and a female receptor with matching L-shaped slot(s) and with spring(s) to keep the two parts locked together. The slots are shaped like a capital letter L with serif (a short upward segment at the end of the horizontal arm); the peg slides into the vertical arm of the L, rotates across the horizontal arm, then is pushed slightly upwards into the short vertical "serif" by the spring; the connector is no longer free to rotate unless pushed down against the spring until the peg is out of the "serif".

The bayonet mount is the standard light bulb fitting in the United Kingdom and in many countries that were members of the British Empire including Australia, Hong Kong, Fiji, India, Pakistan, Sri Lanka, Ireland and New Zealand, parts of the Middle East and Africa and, historically, in France and Greece.

A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car radios, and microwave ovens.

A VFD operates on the principle of cathodoluminescence, roughly similar to a cathode-ray tube, but operating at much lower voltages. Each tube in a VFD has a phosphor-coated carbon anode that is bombarded by electrons emitted from the cathode filament. Each tube in a VFD is a triode vacuum tube because it also has a mesh control grid.

A push-button (also spelled pushbutton) or simply button is a simple switch mechanism to control some aspect of a machine or a process. Buttons are typically made out of hard material, usually plastic or metal. The surface is usually flat or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. Buttons are most often biased switches, although many un-biased buttons (due to their physical nature) still require a spring to return to their un-pushed state.

Terms for the "pushing" of a button include pressing, depressing, mashing, slapping, hitting, and punching.

A spring scale, also known as a spring balance or newton meter, is a type of mechanical force gauge or weighing scale. It consists of a spring fixed at one end with a hook to attach an object at the other. It works in accordance with Hooke's law, which states that the force needed to extend or compress a spring by some distance scales linearly with respect to that distance. Therefore, the scale markings on the spring balance are equally spaced.

A spring balance can be calibrated for the accurate measurement of mass in the location in which they are used, but many spring balances are marked right on their face "Not Legal for Trade" or words of similar import due to the approximate nature of the theory used to mark the scale. Also, the spring in the scale can permanently stretch with repeated use.

Spring steel is a name given to a wide range of steels used in the manufacture of different products, including swords, saw blades, springs and many more. These steels are generally low-alloy manganese, medium-carbon steel or high-carbon steel with a very high yield strength. This allows objects made of spring steel to return to their original shape despite significant deflection or twisting.

A spring rider or spring rocker is a bouncy, outdoors playing device, invented in the 1960s in Italy by the company Pozza. It mainly consists of a metal spring beneath a plastic or wooden central beam or flange, with 1 to 4 plastic or fiberglass seats above it. When a person sits on it, the structure moves and bounces. Spring riders are common in many playgrounds. They are often designed to look like an animal or a vehicle.

Prior to this, the horse spring toy was patented in 1956 in Pasco, Washington.This toy is commonly known as a rocking horse or spring toy. This is because it has a great resemblance to these things.

A garage door is a large door allowing access to a residential garage that opens either manually or via a motorized garage door opener. Garage doors are large enough to accommodate cars and potentially other vehicles. The operating mechanism is usually spring-loaded or counterbalanced to offset the door's weight and reduce the human or motor effort required to operate the door.

Garage doors are made of wood, metal, or fiberglass, and may be insulated to prevent heat loss. Less commonly, some garage doors slide or swing horizontally.

Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. The suspension is crucial for maintaining consistent contact between the road wheel and the road surface, as all forces exerted on the vehicle by the road or ground are transmitted through the tires' contact patches. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.

A box-spring (or divan in some countries) is a type of bed base typically consisting of a sturdy wooden frame covered in cloth and containing springs. Usually, the box-spring is placed on top of a wooden or metal bedframe that sits on the floor and acts as a brace, except in the UK where the divan is more often fitted with small casters. The box-spring is usually the same size as the much softer mattress placed on it. Working together, the box-spring and mattress (with an optional bed frame) make up a bed. It is common to find a box-spring and mattress being used together without the support of a frame underneath, the box spring being mounted directly on casters standing on the floor.

In physics, Hooke's law is an empirical law which states that the force (F) needed to extend or compress a spring by some distance (x) scales linearly with respect to that distance—that is, F_s = kx, where k is a constant factor characteristic of the spring (i.e., its stiffness), and x is small compared to the total possible deformation of the spring.

The law is named after 17th-century British physicist Robert Hooke. He first stated the law in 1676 as a Latin anagram. He published the solution of his anagram in 1678 as: ut tensio, sic vis ("as the extension, so the force" or "the extension is proportional to the force"). Hooke states in the 1678 work that he was aware of the law since 1660. It is the fundamental principle behind the spring scale, the manometer, the galvanometer, and the balance wheel of the mechanical clock.