An example of a steam-engine cross-head is shown in fig. 45. A is the
end of the piston rod which has forged upon it the cross-head B. The
cross-head pin shown at (_d_), fig. 42, and to which the connecting rod
is attached, works in the bearing C. Projecting pieces D, forged on the
top and bottom of the cross-head, carry the slide blocks E which work on
the slide bars, and thus guide the motion of the piston rod.
[Illustration: FIG. 45.]
EXERCISE 45: _Locomotive Cross-head._--In fig. 45 are shown side
and end elevations, partly in section, of the cross-head and slide
blocks for an outside cylinder locomotive. Draw these views half
size, showing also on the end elevation the cross-head pin and a
vertical section of the connecting rod end from fig. 42. The bush
in the cross-head which forms the bearing for the cross-head pin is
of wrought iron, case-hardened, and is prevented from rotating by
the key shown. The cross-head is of wrought iron, and the slide
blocks are of cast iron, and are fitted with white metal strips as
shown. A short brass tube leads oil from the upper slide block into
a hole in the cross-head as shown, which carries it to a slot in
the bush which distributes it over the cross-head pin.