The Shasta courier., 1872-05-04
GLASS BEARINGS.

The us of glass bearings for the wearing
surfaces Of cross heads, pistons, and other
working parts Of machinery which has re.
Gently been introduced into some parts Of
the Eastern States is steadily extending
and gaining favor. These bearings consist
of pieces Of glass inserted into the bearing
surfaces as hereinafter described. In the
slides of the cross head they are simply
imbedded in holes drilled or cast to receive
them, and in piston rings they are inserted
in grooves turned in the rings. The fol-
lowing directions are given by the maniac
turer for putting in such bearings:
"Drill the holes full one fourth of an
inch larger in diameter than the glars is.
and at least one-sixteeenth deeper than the
glass is thick. The holes should be chip.
ped under with center chisel in several
places in order to hold the babbit well.
Than take parallel piece of iron large
enough to cover the hole, and perfectly
smooth on one surface, place little oil on
the smooth surface aud press the piece of
glass to it. By this means you exclude the
air. and the glass and iron will stick To-
gether firmly: this is done in order to
hold the glass up fiom the bottom Of the
hole, aud thus allow the babbit to run
under as well as around it, forming per-
feet bed for the glass to rest on. Place
the piece of iron with tn glass fast to 1t
over the hole in such manner as to keep
the glass in the center, and also leave a
small space uncovered through which to
pour the babbit. The glass should be
above the surface of the working part, in
order to take the full bearing. Place at
least one thickness Of writing paper between
the parallel piece and the other surface ;
clamp the parallel piece to the GLIB or
other part, for if not camped the glass is
likely to rise too high above the surface
while the babbit is being pour. Caulk the
babbit in several places with blunt Cen
ter punch between the glass and iron. then
scrape it down to the surface Bearings
put in locomotive cross.heads should not
be more than flush with the surface
TO insert the bearings in cylinder pack
rings, eccentrics, etc., groove should be
cast or turned ia the center of sufficient
depth and width to allow the babbit to run
under aud around the glass the groove
should be turned under and also Clipped
rough on the sides. Then bend strip OF
sheet-iron to the exact radius, and make
the proper surface smooth, then stick FIVE
or six pieces of glass to the smooth surface
by means of putty or any other substance
that will stick we'll. Then clamp the sheet
iron with the glass fast to it to the ring or
other part close up one end. When the
glass is all inserted, take oil and emery
with file and grind the glass down to the
surface, making sure that not one of the
glasses are above the surface when the
r.ng is finished.
In parts where there is not sufficient
| thickness Of material to allow the babbit
metal to be run under the glass, one thick.
ness Of muslin may be used as bed for
the glass to rest upon"
These bearings are now very extensively
used in locomotives and stationary engines,
and the manufacturer is furnishing them
to all parts of the country and for all kinds
OF steam machinery Most persons, we BE-.
lieve, would be surprised to find how much
rough usage piece Of glass will bear if
properly embedded in soft metal If
they are well fitted they will stand con-
siderable number of quite severe blows
from hammer without being fractured.