The sun., 1919-07-27
PIREOTONE DESIGN
is REAL NON-SKID
Gross and Square Tread Pat
tern Result Of Much Ex-
perimenting.

The survivors of a myriad Of ideas
serve the car owner of to-day. Only
subconsciously aware OF their presence
he can luxuriate In the comfort of ais
machine, confident that all is well as
the engine purrs and the tires grip the
road to speed him on his way, business
or pleasure bent.
There are some interesting stories
associated with the ideas that have
survived the tests and the competition
OF the automobile construction world.
Such tales are part of the romance of
modern business and contain scores OF
human interest features.
The automobile tire alone has behind
its perfection the thoughts OF thousands
of men through score OF years IN
tropical rubber growing plantation and
American manufacturing centre.
The Firestone company a short time
ago began placing the alternate cross
and square design on its cord tires Il.
p. Jones. who represents the company
in this city, learned the why's and
wherefores of the design when at the
big factory of the company at Akron
recently.
"I found that It takes a great deal Of
time and thought to originate real
non-skid tread for an automobile tire,
said Mr.. Jones yesterday. THE design
Of alternate crosses and squares was
adopted by our company only after
months of careful investigation, COM
parison and tests
"In designing q tread the first aim is
to produce a maximum flowing OF rub
ber Success in this means corre-
sponding success in the amount of trac-
tion obtained. This traction. with due
Iar N
should hold the car to the road.N Other
things being equal. the more angles and
the more lines of contact there are the
greater Is the gripping power. Figures
show the cross and square design has
more angles than any other tread de-
sign on the market.
Wear is also an important consldera-
ton. The higher the edge the stronger
the buwark raised against the attacks
of wear and stress from without. Be-
cause of its three projections In every
row from side to side the cross and
square design offers a maximum of wear
ing surface.
Everywhere the corner of the square
fits into the crotch of the Cross. A COM
pletely interloclxins. surface scheme Is
thus formed As the two figures arc
set turn and turn about long!tudinally
around the circumference of the tire and
also from side to side across the tread,
there cannot be such a thing as an un-
supported line where the tire comes In
contact with the road.
Straight lines and points as we'll as
concave and convex curves are pre-
sented. This Is another characteristic
that reduces slipping and facilitates the
handling of pleasure car or truck.
THE value Of the cross and square
design Is seen particularly along the
edges of the tire. The margin IL IT.
regular, because the point Of the square
and the two claws of the cross are set
alternately along the sides. This is q
great help in breaking up strains and
absorbing them, obviating a fault In the
majority of tread designs.
mot only along the edges but also all
over. through and around the tire the
cross and square design distributes VI
brations 4 balanced SERIES OF alter
nate crosses and squares has been at
tanned, resulting in uniform action OF
the tread rubber and better dstribu-
ton OF the strains to the carcass of the
tire. These things mean better adhesion,
longer wear from tread and extra mile
age from the carcass.
THE gum used In the tread has been
Increased in quantity in keeping with the
increased size of the tire. In some of
the sizes the amount used Is increased
by as much as 20 per cent The gum Is
selected and treated for those qualities
which will assure the maximum Of wear
ing and cushioning power"