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.=

See also No. 714.

The engineer's sketch-book of mechanical movements, devices, appliances, contrivances and details employed in the design and construction of machinery for every purpose · 第 40 / 46 章