In machinery, a bell-crank is a rectangular lever by which the direction of motion is changed through an angle of 90 degrees, and by which its velocity-ratio and range may be altered at pleasure by making the arms of different lengths. It is much employed in. machinery, and is named from its being the form of crank employed in changing the direction of the bell-wires of house-bells. Research Bell-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
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Bell-Crank
