The Washington times., 1913-10-18
ROAD SHOCKS FORM
|. DIFFICULT PROBLEM
Feature Is One Of Most compI-
Gated Which Engineers Must
Solve.

The protection of the mechanism and
passengers of motor car from road
shocks is one of the most difficult and
complicated problems that an auto
|. mobile engineer has been called upon
to solve.
Interposed between the road inequali-
ties and the passenger are a series of
cushions made up of the tire, the car
springs. the shock absorbers. the con
troll. the rebound of the springs and
tires. and the springs in the seat cush-
ions
There are SO many different types
OF car springs and so-called shock abb
sorbers that 1t viii be well. betore
OF the various functions they are re-
quired to perform" said Fred NJ Prem
dergast, manager of the Foss-Hughes
branch. agent for the Pierce-Arrow.
1T must be constantly remembered
that road Inequalities need not, and
seldom do. occur equally upon beth
sides of car. One wheel may fall
into q hole at the same time that
another wheel mounts an obstruction.
The four points of contact Of a car
with the road are seldom In the same
plane, and the resulting weaving oil
the car must be so taken care OF By the
springs that the frame Of the car viii
remain as closely and constantly in
.If the springs be too light, when
a wheel drops into hole the cornet
of the car frame supported By that
wheel will follow. II the springs be
sufficiently stiff. It will act quickly,
hold the corner of the frame at
constant level. If, on the other hand'
the spring be too strong when the
wheel mounts a sudden, obstruction IL
wiz not compress rapidly enough unaeI
the shock to prevent the frame corner
from rising with the wheel.
$50 far as the direct action Oh the
springs is concerned. 1t will be seen
that, il all road shocks were OF equaI
intensity. it would be comparalNeSS
shocks so efficiently that the paraliei
level of the frame In relation TO the
average plane in which lie the 1oui
points of contact with the ground couio
be readily maintained Road snocks,
however, are of very varying degrees OF
intensity and each action OF sprins
has Its equal and counter-oalancins
reaction.
The pneumatic tire serves to en-.
tirely absorb numerous very smah
shocks. As the shocks become great
er. the springs come into action As
road shocks vary in intensity SO mucn
he springs action vary in intensity, ans
HE springs must be designed to op-
ers te in a progressive manner.
"It Is for this reason thdt idiSe
number of leaves are used in a cal
spring. The long and comparatively
nat leaves absorb the lighter shocks
and as these shocks increase in IN
Lensity. one after another, the shorter
and sitter leaves come into play
"While the relative and progressive
stiffness of springs govern their abii-
ty to absorb sudden shock, the rela-
i've weights and corresponding IN
,rtfas of the portions of the car above
inc below the springs play most
important part in the manner ir
which these absorbed shocks are
,iven up.
Most car users recognize that their
ars ride easier when fully loaded
han when empty. but not many oi
hem realize why this is the case
"The explanation-is very simple
AFTER a car spring has been COM
'ressed in receiving and absorbing
Dad shock, 1t has an immediate ten
ency to return to its original form
n doing so 1t gives up the energy
tored up in absorbing the shock. II
n the case OF a rear spring, the axle
nd wheel be very heavy and the
ody very light, the spring. in react
ng, will throw off the body more
apidly than It Will the axle and
'heel. The heavier the body and its
bad In relation to the axle, or the
ghter the axle in relation to the
ody and its load, the less will be the
fleet from the spring reaction no.
lceable =" the passengers in the car.