See [Section 13]. Crushing, grinding, &c.
Section 55.—PARALLEL MOTIONS.
Purpose: to maintain rectilinear motion of a rod or equivalent detail coupled to a lever without employing guide bars.
[1009]. Watt’s parallel motion for a beam engine.
[1010]. Rack and segment motion.
[1011]. Epicycloidal parallel motion. The pinion is one-half the diameter of the wheel at the pitch lines, and the gudgeon is fixed upon the pitch line of the pinion.
[1012]. Peaucellier’s parallel motion. A is a fixed centre; B (for parallel motion) must be one-half way to C; power is applied to C; D parallel centre gudgeon.
[1013]. Beam, with rocking fulcrum. A A are equal, as also B B.
[1014]. Single radius bar and link; the radius bar to be same length as the half beam and the link hinged on its centre.