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.

[1015]. All the radius bars to be of same length as the half beam.

[1016]. Two equal radius bars connected by a link, the main gudgeon in its centre.

[1017]. Beam of the 2nd order with rocking fulcrum, A and A being equal.

[1018]. Sector and rack motion.