(See also [p. 88].)
[2170]. Carriage driving gear. The carriage wheel bears upward against the driving spindle which drives it by friction, or the latter is forced down into frictional gear with the carriage wheel by loading or by springs.
[2171]. Friction, spring clip, for giving tension to cotton thread passed between the convex discs.
Leather covered pinions geared with plain rimmed wheels or discs. These should always have the pinion as driver, otherwise the pinion is liable to wear in fits and become useless.
Section 39.—GUIDES, SLIDES, &c.
(See also [p. 90].)
[2172]. Engine crosshead, formed of two slide blocks, cast with the gudgeon in one piece and two caps bolted together, enclosing the piston rod end and bolted to the slide blocks.
[2173]. Crosshead single-bar guide, with or without the lower attachment for pump rod.
[2174]. Sliding bed guided by two square grooved strips (one of which may be fixed) adjusted by diagonal set screws.