Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~017D~
The present invention relates to the manufacture
of tires and particularly to the manufacture of a tire
having a decor strip providing a tire of the type commonly
known as a white sidewall tire.
S The objects of the invention are an improved white
sidewall tire and a method of making such tire at less
cost.
In accordance w.ith one aspect of this invention there
is provided a tire having a white decor strip displayed cir-
cumferentially on a sidewall, said tire comprising a pair of
ribs formed integrally with said sidewall to extend circum-
ferentially of the tire and outwardly of the sidewall to
define an annular groove between the ribs, a strip formed
solely of white rubber compound not greater than two milli-
meters thick conforming to said groove and molded and cured
therein integrally with the tire r said strip having circum-
ferential edge portions extending outwardly in directio~s
normal to the sidewall region and substantially thinner than
the remainder of said strip and terminating outwardly of the
bottom of said groove and flush with the outwardly exposed
surfaces of the respective ribs, the mold contact surface of
said one sidewall being absent only from the terminii of
said edge portions and said surfaces, and wherein the
surface of said strip is completely exposed and free of
overlying black sidewall material, and wherein said rihs
comprise only black sidewall material.
In accordance with another aspect of this inven-tion
there is provided the method of ma~ing a tire having a white
sidewall comp~is.ing disposing a thin strip ~f white rubber
compound circumferentially about the ex-ternal surface of the
sidewall region of the tire in its uncured state, placing
the uncured tire in a tire curing mold with the thin strip
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,
exposed to direct contact with the mold, in the mold
displacing relatively of each other an intermediate portion
of the width of the thin strip inwardly and respective
margins of the width of the thin strip outwardly in direct-
ions normal to the sidewall region to form in said stripbetween said intermediate portion and each of said margins
a wall of substantially diminished thickness relative to
said intermediate portion and extending normal to the side-
wall region contour and circumferentially of said region,
curing and removing the tire from the mold, and removing an
outward portion of each wall.
In accordance with another aspect of this invention
there is provided the method of making a tire having a white
sidewall comprising disposing a thin strip of white rubber
: 15 compound circumferentially about the external surface of
the sidewall region of the tire in its uncured state, placing
the uncured tire in a tire curing mold with the thin strip
- iexposed to direct contact with the mold, in the mold dis-
placing relatively of each other an intermediate portion of
the width of the thin strip inwardly and respective margins
of the width of the thin strip outwardly in directions
normal to the sidewall region to form in said strip between
said intermediate portion and each of said margins a wall of
substantially diminished thickness relative to said inter-
mediate portion extending normal to the sidewall regioncontour and circumferentially of said region, displacing
portions of the tire sidewall underlying said margins con-
currently with displacement of said margins thereby to
stretch and thin each said wall and to form ribs carrying
the respective margins outwardly with respect to the inter-
mediate portion, and forming a flow stop ridge circumEeren-
tially of the tire on the surface of at least one of said
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ribs to inhibit mold flow of said margins outwardly alony
the surface of the respective rib away from said groove,
curing and removing the tire from the mold, and removing
an outward portion of each wall.
To acquaint those skilled in the related arts more
fully with the concept and practice of the invention, a
preferred embodiment illustrating the best mode of
implementation thereof will be described with reference
to the attached drawings forming a part of this specifica-
tion and in which drawings:
Fig. 1 is a partial view in axial cross-section,
and in approximately full scale, of a tire in accordance
with the invention;
Fig. 2 is a view of a portion of Fig. 1, enlarged
in scale;
Fig. 3 and Fig. 4 are views schematically illustrating
steps in the process of making the tire of Fig. 1.
A tire 10 in accordance with the invention and
illustrated in Figs. 1 and 2 comprises, in the sidewall
region 12 of the tire, a pair of ribs 14,16 which
extend circumferentially of the tire and define there-
between an annular groove 20 which has a strip 25 of
-2a-
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white rubbsr compound overlylng the surfaces 27~28~29
of the groove and molded and cured therein integrally
with the tire 10.
~ he arrangement provides two notable advantages.
~irst~ the white rubber strip is no more than about
2 millimeters in thickness9 thereby minlmizing the
quan~ity o~ white rubber compound requir~d to provide a
decorative white sidewallO Secondly~ the respectiva
ribs 1~16 and the underlying sidewall~ of convent onal
black rubber compound~ are completely free of any white
material thereinO ~his prevents the accidental spoiling
of the appearance o~ tha tlra by scuf~ing of the resp&c-
ti~e ribs. The elevation of tha ribs wlth respect to
the white strip 25 i~ tha groove 20 satisfactorily
protects the white sur~ace from stain~ng or discoloratio~0
The ~hit8 strip lylng within the groove 15 tu¢ned
outwardly of the tlre along the respecti~ely adjace~t
surfaces 27~29 of the ad~oining rlbs so that the
respeckive edges 31~32 Df the strip lie flush with the
outward sur~aces 35~36 o~ the raspective ribs~
Fig. 3 lllustrate a portion o~ the sidewall region
12' of a~ uncured tire 10' disposed o~ a tire bullding
surface ~0 and having t e customary black rubber compound
o~ the sidewall overlying the cord plies o~ the tire,.
~he numeral 10' identi~ies the tire in proce~s from
the fi~ished tire 10. ~kewi.se~ the ~'pr~me" distirlguishes
parts of the Nncured tire 10' from like parts of the
~ured tire 10~ A thin skrip 25' o~ white rubber compound
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is disposed circumferentially about the exterior surface
~2 of sidewall regio~ 12' and is conventionally spliced
to ~orm an endless white band about the uncured tire
which is ~n generally cylindrical form.
~he uncured tire 10' is then removed ~rom the
building surface ~0 a~d placed ln a tire cur~ng mold
tnot shown) with the thin strip 25' o~ whlte rubber
comp~und exposed to direct contact wlth the mold.
In the mold~ as il~ustrated in Fig~ 4~ the inter-
mediate portion 50 of the width of the strip 25; l.e.
that portion overly~ng the bottom 28 of the groove 20~
and the respective margi~s 52~54 thereo~ are displaced
rslative to each other i~ directions normal to the cont~ur
(indicatsd by the line 56) of the sidewall region 12 of
the tire 10 in its i~lated co~dition. The displace~ent
sffects a moveme~t~ ~ugge~ted by the arrows 58~ of the
underlying black ~idewall rubber compou~d outwardly
of the contour 56 to ~orm the pair of ribs lh~l6. ~he
movement of the black sidewall rubkar relative to the
white rubber strip 25 particularly along walls 27 and 29
tends not only to ~orm the strip walls 61~63 between
the i~termediate portlon 50 and the margins ~2~5~ but
to causa these walls of the strip to become thiNner as
tha movem0nt prograssesO Thls thin~ing ef~ect is lncreased
by ~orml~g the ribs 14~16 with surfaces 65966 inclined
: respectiv~ly ~rom a peak 68 adjacent to the groove 20
. a~d inwardly toward the sidewall contour.
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Also~ in accordance with the in~ention~ the flow
stop ridges 70 about semi-circular in cross-section
outllne a~d having a radius of about 1 millimeter ser~P
to prevent the respective white strip margins from
~lowing~ d~ring molding~ beyond the respective ridges.
~he surfaces 65~66 of the ribs are inclined inwardly
~rom the peaks 68 at angles of from 5 to 30 degreesO
m~s arrangement permits the formatio~ of the peak 68
to augment the th~nning effeck de~ired i~ the respeeti~e
walls 61~63 without increasing the black rubber required,
The width of the respective ribs 14~16~ mea ured
radiall~ o~ the tire~ allows considerable tolera~ce i~
the width of the white strip as well as in its location
radially of the tireO '~hus~ the respective edges o~
the strip 25~ after molding~ as sea~ in Fig. ~ may ::
terminate between the flow sto~ ridge 70 and the ap-
pro~mate mldpoint of the width of the inclined surface
65 or 66 of the respecti~e ribs.
~he tire~ ha~ing been molded a~d cured~ ls removad
from the mold and is than mounted and inflated~ ~he
margi~s 52~54 o~ the whlte strip and portions of the
r~bs 14~16 are then removed~ outwardly of a bu~ing
line 75 inward o~ tha respective margi~s 9~ tha whlta
strip and passlng through respective intermediate
portions of the respactive wall~. mus~ each margin
of white is removed and an outward portion of each wall
61~63 i5 also removed. me bu~fing line 75 may be
arranged to generally parallel the co~tour 56 of the
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sidewall regionO With no loss of appearance in the
finished tire~ the buffing line can be a straight line
whlch is more readily formed by the cylindrical surface
of a co~ventional ~uf~ing wheel.
~he present invention provides a ~umber of ad~antages.
In partlcularg the use of the thin strip of white compound
re~uires a mater~ally smaller amount of relatively
hig~-cost white material. Moreo~ar~ the entire outward
surface of the whlte rubber compou~d is e~posed and no
white material is buried in the sidewall or otherwise
covered. Hence~ there is no risk that additional white
may be accidentally e~posed by minor damage to a tire
thereby rendering the surface appearance thereof un-
satisfactor~O
Because the location of the thin white ~trip can
be seen thr~ughout the process in~tead of bei~g hidden
be:~eath an overlying black rubber material~ a mislocation
of tha white ca~ be seen and corrected be~ore the cost
of succeeding operations is incurredo ~he structural
i~tegrity of the underlying sidewall is not affec-ted
by the presence therein of white rubbar compound~
me surface finish o~ the thin white strip i~
provlded by its dlrsct contact wlth the tire curlng
mold and e~cept for the very thln edges of the strip
whlch terminate flush with the finlshed ribs~ the
surface is not r3ughened or made por~us by buffing
operationsO
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While certain representatlve embodiments and
details have been shown for the purpose of illustrating
the in~ention, it will be apparent to those skilled
in the art that various changes and modifications may
be made therein without departing ~rom the spirit or
scope of the invention.
