crank

crank, mechanical linkage consisting of a bar attached to a pivot at one of its ends in such a way that it is capable of rotating through a complete circle about the pivot. One of the principal uses of a crank is to turn reciprocating, or back and forth, motion into rotary motion or vice versa. A bell crank is one designed to change the direction of a linear motion.

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crank

In mechanics, an arm secured at right angles to a shaft with which it can rotate or oscillate. Next to the wheel, the crank is the most important motion-transmitting device, because, with the connecting rod, it provides means for converting linear to rotary motion, and vice versa. The first recognizable crank is said to have appeared in China in the 1st century AD. The carpenter's brace was invented c. 1400 by a Flemish carpenter. The first mechanical connecting rods were reportedly used on a treadle-operated machine in 1430. About this time, flywheels were added to the rotating members to carry the members over the “dead” positions when the rod and the crank arm are lined up with each other.

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crank¹

1. a device for communicating motion or for converting reciprocating motion into rotary motion or vice versa. It consists of an arm projecting from a shaft, often with a second member attached to it parallel to the shaft

2. a handle incorporating a crank, used to start an engine or motor

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crank², cranky

(of a sailing vessel) easily keeled over by the wind; tender

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crank [kraŋk]

(mechanical engineering)

A link in a mechanical linkage or mechanism that can turn about a center of rotation.

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Crank

In a mechanical linkage or mechanism, a link that can turn about a center of rotation. The crank's center of rotation is in the pivot, usually the axis of a crankshaft, that connects the crank to an adjacent link. A crank is arranged for complete rotation (360°) about its center; however, it may only oscillate or have intermittent motion. A bell crank is frequently used to change direction of motion in a linkage (see illustration). See Linkage (mechanism)

Cranks (a) for changing radius of rotation, and (b) for changing direction of translation

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crank - (Automotive slang) Verb used to describe the performance of a machine, especially sustained performance. "This box cranks (or, cranks at) about 6 megaflops, with a burst mode of twice that on vectorised operations."