The crank was a Victorian instrument of punishment introduced in prisons and consisting of a handle attached to a wooden box. The prisoner had to turn the crank 10,000 revolutions each day, with so many revolutions required before each meal was supplied. Should a prisoner be too quick in completing the required revolutions, the warders could adjust the tension of the crank by means of a screw - from whence the expression 'screws' to describe prison warders - thereby making the labour on the crank more difficult. Research Crank
A crank is an axis with the end bent like an elbow, serving as a handle for communicating circular motion; as, the crank of a grindstone; or for changing circular into
longitudinal motion, as in some saw-mills, or longitudinal into circular motion, as in an engine. The single crank can only be used on the end of an axis. The double crank is employed when it is necessary that the axis should be extended on both sides of the point at which the reciprocating motion is applied. An exemplification of this arrangement is afforded by the machinery of boats. The bell-crank so called from its being much used in bell-hanging, is for a totally different purpose to the others, being used merely to change the direction of motion, as from a horizontal to a vertical line. Research Crank
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Research Crank
