The Washington times., 1912-06-29
QUESTION Of BRAKE
IS STILL PONDERED
BY MOTOR MAKERS
The Self-Wrapping Type and
Others Are Being Always
Experimental With.

In the early days Of the automobile
the difficulty was not in stopping q car,
but In starting II, and the average user
was glad when his machine kept going.
Brakes were a matter OF last consider
alton from the manufacturers view
point, for the reason that most Of their
customers were accustomed to the
gradual slowing of horse-driven
vehicle, and did not expect very much
from the automobile in the way of
prompt stopping.
Some of the earliest designs had no
brakes at all. Others showed very
wheels. with possibly a service brake
on the propeller or jack shaft A dis
advantage Of the latter schemes was
that severe stress was thrown on the
chains or universal joints. as the case
might be. though. from the designer 5
standpoint, this was a very easy and
economical way Of solving the brake
question. A strong feeling arose con-
cerning brakes that had to operate
through any of the driving parts. be-
ably easy to stop when moving In a
forward direction, could not be held
when going backward. as in the case
of car starting to back down hill
And SO the single acting brake, as It
was known. began to get the reputation
that ii deserved.
Good practice next demanded brakes
which operated directly on the rear
wheels, Shoes acting on the tires being
out of the question. the necessary action
was obtained by steel drums bolted to
the spokes. One Of the most efficient
brakes designed At this time was the
rigidly fastened at one end, the free end
Of which. upon application OF the brake
lever was pulled toward its fixed end.
The result Of this was that the friction
around the brake drum. This severe
brake action frequently locked the
wheels. causing them to slide and dam
age the tires.
Besides this disadvantage II Is a well
known fact In mechanics that the re-
tarding action is not so great when the
wheel is slipping. Another objection
was that the retarding action OF the
self[,wrappinE type Of brake could not be
pressure on the pedal served to start
the brake Ito wrap itself up" AS a
consequence. attempts were made to
design brakes that would be just as
effective in their action but which would
not have the serious disadvantages just
mentioned
Shoe brakes then lad a considerable
vogue. bit the lining used was such as
to cause disagreeable squeakng when
being accentuated by the irelasticity OF
the shoe, on account OF which the lat
ter would not make as even an appli-
cation as braxe with a partially fiex-
p"rfest automobile brake, as 1t ex-
lists today. embo1es an internal ex-
pandlhg member lined with a non
burning friction material made OF as
bestos fbcr, into 'he fabria of which
a fine copper wire is woven so as to
rive It sufficient tensile strength BY
the use of this material high CO.
efficient friction Is obtained and by
running a little leakage into the brake
drur, no difficulty due to the lining
h1rning up Is experienced, even in de-
sccnding long hills or in other emer-
gerc!es where an excessive appli cation
of the brake Is required.
To an unthialking person the question
CT brake design may seem a co:nEara-
lively simple matter. But as a matter
OF fact. thousands Of hours OF thought,
collectively speaking. together with an
indefinite amount Of patience have been
expended to obtain brakes of really
good quality.