chain
2022-04-25 22:59:06

A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use:

• Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus shaped, which make the chain flexible in two dimensions (the fixed third dimension being a chain's length). Small chains serving as jewellery are a mostly decorative analogue of such types.?In geometry, a torus (plural tori) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. 手鐲/甜甜圈/洋蔥圈形
• Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets [鏈輪] of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chain.?A sprocket is a wheel with teeth around the outer edge that fit into the holes in a chain or a length of film or tape in order to move it round.

Two distinct chains can be connected using a quick link, carabiner, or clevis.?A carabiner or karabiner /?k?r??bi?n?r/ is a specialized type of shackle, a metal loop with a spring-loaded gate used to quickly and reversibly connect components, most notably in safety-critical systems.

?Clockwise from top left: D-shaped wire gate, D-shaped straight gate, oval straight gate, pear-shaped auto locker, D-shaped screw locker.

A clevis fastener is a three-piece fastener system consisting of a clevis, clevis pin, and tang. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is either partially threaded or is unthreaded with a cross-hole for a split pin. The tang is a piece that fits in the space within the clevis and is held in place by the clevis pin. The combination of a simple clevis fitted with a pin is commonly called a shackle, although a clevis and pin is only one of the many forms a shackle may take.

Clevises are used in a wide variety of fasteners used in farming equipment and sailboat rigging, as well as the automotive, aircraft and construction industries. They are also widely used to attach control surfaces and other accessories to servo controls in airworthy model aircraft. As a part of a fastener, a clevis provides a method of allowing rotation in some axes while restricting rotation in others.

A timing chain is used to transfer rotational position from the crankshaft to the valve and ignition system on an internal combustion engine, typically with a 2:1 speed reduction.?正時(shí)系統(tǒng)的傳動(dòng)件分為正時(shí)鏈條和正時(shí)皮帶兩種。

Roller chain or bush roller chain is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire- and tube-drawing machines, printing presses, cars, motorcycles, and bicycles.

A chain of office is a collar or heavy gold chain worn as insignia [官職的標(biāo)記](méi) of office or a mark of fealty [loyalty to a king, queen etc] in medieval Europe and the United Kingdom. 美劇《都鐸王朝》里常見(jiàn)。

An omega chain or omega necklace is a pseudo-chain made by assembling metallic plates on a wire or woven mesh. The plates give the appearance of links in a chain. The embedded wire provides the strength, so the plates can be designed to please the eye.

?

?

六級(jí)/考研單詞: serial, assemble, rigid, curve, tense, classify, dictate, hoist, dimension, tertiary, jewel, analogue, geometry, plural, revolve, axis, outer, loop, component, clockwise, oval, screw, fasten, pin, bolt, thread, equip, sail, rig, construct, accessory, rotate, valve, ignite, bush, convey, collar, medieval, unite, necklace, weave, embed