Evening star. [volume] (Washington, D.C.) 1854-1972, 1913-06-01
Making Automobile Tires.

These strips are always cut on the bias.
generally at a forty -ive-degree angle with
| the edge of the roll. All these were
formerly cut on a cutting table. about
fifty feet long and six feet wide
and covered with sheet metal. The cut
ting was done by two men. each having
a knife and each cutting half way across
the cloth, along the line of straight
edge. so arranged as to be always set at
forty-five degrees with the edge Of the
table.
This method of cutting is gradually be-
ing put aside by the use of the bias cut
ter, an extremely up-to-date machine
having jaws which ride up to the end or
the fabric and pull it for a certain DIS
lance under a knife set at a forty-hve-
degree angle. the knife being set to cut
just when the jaws have arrived at the
limit of their motion. The action is re-
peated so that the strips which are cut
by the machine are fed onto series of
belts which carry them to where they are
placed by boys into book having leaf
of cotton cloth between the strips of gum
fabric to prevent the strips from stick
ing together.
The majority of automobile tires today
are built by the hand method, and I'm
this process the books of fabric are laid
up and spliced into proper lengths to go
around the tire and allow a proper tap
ping for the spices. The proper number
of these laid-up pieces, or plies as they
are called, are placed together with cot
ton cloth between and taken to the tire
builder The tire builder mounts the
core, upon which the tire is to be built,
on the building stand, generously cement
ing it so that the first ply OF fabric will
stick in place The first ply is then
rolled down with hand roller on to the
sides of the core and trimmed with a
knife az the base.
Method of Curing Tires.
The following plies are put on and
rolled down in the same manner, the
beads being put on at the proper time
according to the size and number of the
plies used. After all the plies have
been put on to the core, the so-called
cover rubbe: IS put on. This cover is
generally a sheet of rubber about one
sixteenth os an incl. thick or more and
is of the same compound as the rubber on
the fabric
In the case of the machine-built tire
the result is the same, but the stock is
handled as follows: After the rubber
coated fabric has been cut the bias
cutter the strips are spliced and rolled
UP in rolls on spindle which is
placed on the tire-building machine. The
tire core is mounted on a stand attached
to the machine so that 1t can be re-
volved by power and the fabric is drawn
onto the core from the spindle from a
certain definite tension
The tire machines roll the fabric down
by power and the heads are put into
place before the tire and core are
removed from the machine Thereafter
the process is the same as in the case
of the head-built tires. After the cover
rubber is in place the tire is ready to
have the tread applied. The tread is
made up independently of the tire by
laying up narrow strips of rubber in
different widths in such way that the
center of the tread is thicker than the
edges In the case of the so-called
single cure tires, which wholly vul-
caniZed at one time. this tread is APP
piled to the tire directly after the cover.
a strip of fabric called the breaker
strip generally being placed under
meath and the building of the tire so
completed.
In the general methods of curing. the
tire is allowed to remain on the core
and is either bolted up in mold and
put into an ordinary heater or it is
laid in a mold and put into heater
press where the hydraulic pressure
keeps the two halves of the mold forced
during the vulcanizing process. After