The news scimitar. (Memphis, Tenn.) 1907-1926, 1920-08-06

being difficult these are seldom pro-
vtded for and what little wear takes
place Is usually corrected by slightly
shortening the control rods. With the
foot or service brake the conditions are
different. =
It is very severely used-if not abused
thus requiring rather frequent adjust
ment and thus must be accessible, so it
is generally in the form of flexible
/ steel, fabric lined band, arranged to be
contracted upon and to grip the out
side of the brake drum AS all its parts
are exposed, 1t is readily gotten at and
the manufacturer usually provides full
means for adjusting the band and other
parts TO compensate for the effects of
wear.
Details as to brake-band adjustment
vary with different designs, but there
are certain general principles that ap-
'ply to all. The band, when in it's re-
leased position and should be free of
the drum throughout it's length, as 9TH
eerwise there Is a dragging action at all
times and power Is continuously wasted,
but the clearance allowed the band is
usually very small--not more than 1-32
inch and unless the band naturally tends
10 assume nearly circular form 1t
can hardly be adjusted so as to clear
the drum at all points.
II its natural curvature is irregular
or otherwise Incorrect. bending into
shape is the usual remedy. A badly
curved band also tends to bear mainly
y,
unequally, develops squeaking and chat
tering and Is lacking in power In the
case of a badly worn band lining which
stands too far away from the drum, es-
pecially at a point opposite from the
contracting mechanism, 1t may be found
necessary to adjust it closer by screw
ing in on the band support usually pro-
vided at this point.
In practically all external brakes the
ends of the band, when in the release
a hnld fixAH fCto AT
by spring, and when the brake is APP
piled the two ends of the band are
both moved and are drawn together by
a sort of toggle action. This consti-
,tutes a doube-acting brake that acts
equally well to resist forward and re-
verse motion.
AS the lining wears, a greater move
ltent of the togglejoint is required to
contract the band upon the drum eff
fectively and when too great a move
ment is called for the brake ceases to
act. The adjustment then required is
the shortening of the distance between
the ends of the band by slightly short
ening the fulcrum pin of the toggle
Joint and this is generally accomplish ed
pin.
Before making this adjustment the
pull-rod end is usually disconnected in
order to leave the brake mechanism free
and the setting is made so that the
toggle again assumes the same position
that it occupied before wear took place,
thus assuring 70 full brake application.
Since both ends of the band should grip
the drum equally, in order to insure full
contact of the lining and perfect dou-
ble-acting qualities. there Is quite often
a second adjustment, by which the po-
sition of the fulcrum pin can be so al
tered as to change the relative clearance
of the upper and lower halves of the
band with the drum.
A necessary preCaution in adjusting
brakes is to make sure that the rear
springs are securely clipped to the axle
housing, for otherwise operating the
brake lever and pedal may only shift
the axle forward and produce no re-
tarding effect