Note: Descriptions are shown in the official language in which they were submitted.
2~a2~97
Background of the Invention
The present invention relate~ to a method for
applying a E~ymbol onto a viRible surface of a tire
as well as a device for preforming the method, a
tire, and a method for manufacturing the tire.
Tires are known on which the ~idewalls are
provided with symbols, for example, in the form of
letters or numbers representing, for example, the
name of the manufacturer, the tire type, size or
other tire identification~ symbols. With known
tires it is conventional to imprint the respective
~ymbols already before beginning the vulcanization
process into the sidewalls while the tire is
positioned in the vulcanization mold. Thus, the
markings or symbols are already present at the
tire before the vulcanization process.
Furthermore it is known to provide tires with
symbol~ having a color that differs from the color
of the ~idewall of the tire. For manufacturing
such tires, a colored rubber strip is inserted
into a rece~;s of the outermost rubber layer in the
area of the ~idewall and is covered with a rubber
~trip corresponding to the color of the sidewall.
In the vulcanization mold the symbol is then
imprinted, before vulcanization takes place, into
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the rubber layer ~o that projectionl are formed
within the sidewall area of the tire which
corre~pond to the de~ired ~ymbol~. After
completed vulcanization the uppermost imprinted
rubber layer is then carefully removed by cutting.
Such method i8, for example, known from United
State~ Patent 1 448 286. From German Patent 30 46
664 it i8 kr~own to apply rubber Rtrip~ having
cutout portions correRponding to the de~ired
cymbol~ which are filled with a colored rubber
material. Thece ~trip~ are presced onto the
~idewall of the tire. During the ~ub~equent
vulcanization process the applied rubber ctrip i~3
fu~ed to the sidewall. For protecting the symbol~
on the tire again~t damage during the
vulcanization proceE~R, German Patent 30 46 664
suggest the u~e Df a protective layer which i~
removed after completed vulcanization. A tire
according to US Patent 1 448 286 aR well as a tire
according to German Patent 30 46 664 requires a
complete determination of the desired cymbol
before vulcanization of the tire. According to
the individual requirementEi with re~pect to the
~ymbol~ to be provided at each tire, re~pective
mold~ and forms for the imprinting proceR~ or
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molding process must ~e provided. Additional
symbols after completion of manufacture o the
tire in re8ponse to suddenly required individual
cpecifications can not be applied after
vulcanization is complete. The high expenditure
with respect to individual tools, the limited
possibilities for individual manufacture, and the
lack of a fle~ible supplemental application of
symbols have resulted in high costs and a
reluctant application of such 8ymbols on tires.
Furthermore, the determination of the symbols
before vulcanization also results in the higher
risk of a deviation of the prDduced symbol from
the desired symbol and thus in quality 1088 due to
the already preformed vulcanization process and
the subsequently re~uired ~urther i~reatment which
is only partly successful.
It i~ therefore an object of the present
invention to provide a method with which with
~imple means after completion of Vul(~ni7~t;~
symbols can be applied to the visible surfaces of
a tire accDrding to individual specification as
well as to provide a method for producing such
tires .
Summary of the Invention
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21~2~97
The method of applying at lea~t one symbol
onto a vi~ible rubber surface of a tire according
to the present invention i8 primarily
characterized by:
Vulcanizing at least the vi~ible rubber
surf ace of the tire; and
engraving at least one Elymbol into the
vicible rubber Gurface after the ~tep of
vulcanizing .
Preferably, in the ~tep of vulcanizing the
complete tire i8 vulcanized.
Advantageously, in the step of engraving the
at leaE3t one ~ymbol is etched into the sidewall of
the tire_
Preferably, the ~tep of engraving ~ include~
the ctep of changing the color of the surface area
where engraving i~ preformed.
Expediently, the ~tep of engraving include~
removing an outer rubber layer to make vi~ible at
lea~t one underlying rubber layer of a different
color .
Preferably, the method further compri8es,
before the step of vulcanizing, the ~teps of
building a green tire with a ~idewall 13trip having
a re~e~, and bridgLn~ the rece~ w1th an o~ter
21~2897
rubber layer in the form of a rubber strlp that
orm a ~nn~;n~ us, recess-free surface with the
outer surface of the sidewall strip
Preferably, the method further includes the
step of arranging i-n the recess a plurality of
rubber layers of different colors adjacent to one
another in a ci~cumferential direction of the tire
for producing in the step of engraving symbols of
different colors. In the alternative, the ~Lethod
further includes the step of arranging in the
recess a plurality of rubber layers of different
color ad~ acent to one another in the radial
direction of the tire for producing`in the step of
engraving symbols of different colors. In yet
another embodiment of the present inv~ntion the
method further ;n~ the step of arranging in
the recess a plurality of rubber layers of
different colors a top one another in an axial
direction of the tire for producing in the step of
en~raving symbols of different colors.
Pref erably, in the step of engraving the at
least one symbol is engraved into the surface of
the inner liner of t~e tire
Advantageou31y, the step of engravi~g
lncludes the step of laser-etching the at least
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one symbol.
E~xpediently, the step of engraving includes
the step~ of applying liquified gases for removing
heat energy to the visible rubber 3urface in the
area where the at least one sytlbol i~ to be
engraved in order to make brittle the visible
rubber surface-and cutting the at least one symbol
with a mechanical engraving tool into the visible
rubber surf ace .
The present invention furthermore relates to
a device ior applying at least one symbol onto
visible rubber surface of a tire after vulcanizing
at least the visible rubber surface of the tire.
According to the pre~ent invention the device i~
primarily characterized by:
a means for receiving and holding a tire;
an engraving device for engraving at least
one symbol into a rubber surface of the tire;
a means for driving in a three-dimensional
relative m~,v~ t the means receiving and the
engraving device relative to Dne ~nother; and
means for controlling the means for driving
in order to preform the three-dimensional relative
r v~ ~nt according to a desired contour of the at
least one symbol.
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The present invention alæo relates to a tire
compri~ing engraved contour~ forming recesses in
a continuous surface area of the tire surface for
supplying inormation. ~referably, the bottom Df
the recesses i~ of a different color than the
continuous surface area in the sidewalls of the
rec~es. Advantageously, the tire urther
comprises a rubber layer of a different color
positioned between a reinforcement belt structure
and an outer rubber layer forming the l~tF~r; nr
tire: surface, wherein the rubber layer of a
different color forms the bottom of the recess.
The pre~ent invention also relates to a
method of producing a tire comprising engraved
contDurs forming recesses in a nr~nt;nl~nus surface
area of the tire surface for supplying
information, wherein the bottom of the recesses is
of a different color than the ~nnt;nllnu~ surface
area and the sidewalls of the recesses The
method according to the present invention is
primarily characterized by.
Building a green tire, including arranging at
least one colDred rubber layer on a reinforced
tire-building layer and placing a cover layer on
top of the colored rubber layer
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2152897
Vulcanizing the green tires; and
engraving at least one symbol into the cover
layer ~uch that the colored rubber layer is
vi:3ible within the area of the at least one
symbol .
Advantageously, the reinforced tire-building
layer i~ a sidewall strip of the tire.
sy engraving a symbol into the rubber surf ace
after completed vulcanization of the tire, arry
desired symbol, also symbolE~ that have been
decided on after completion of vulcanization, can
be applied to the tire without being ~ubjected to
any negative effects during the vulcanization
proces~. Special measure~ for protecting the
symbols during vulcanization are thus obsolete.
Furthf~ pecial individual tools su~h as
mold~ or a- plurality of different cutting stamps
for the individual tires are no- longer required.
The symbols, if necessary, can be applied to the
tire a long time after the vulcanization process.
It is even possible to provide such symbols after
production of a particular tire type has already
been digcnnt i n~
Advantageously, since especially suitable for
mass production and thus correspondingly sirnple
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21~897
and inexpensive, the entire tire is fist
vulcanized and only after cDmpletion of
vulcanization the symbol is engraved into the
rubber surf ace .
It i8 especially preferred to engrave the at
least one symbol into the sidewall of the tire.
Especially in the area of the sidewall the
application of individual symbols is very
desirable. Depending on market requirements, on
government regulations etc. or changing customer
orders, it is thus po~sible to apply new, easily
recognizable symbols onto the tire even though the
tire production has already been completed.
Advantageous is a method for applying such
symbolc when during applying the color of the
rubber surface in the area of the symbol is
changed. The manufacturer or symbols that differ
in color form the surrounding surfaces can be
performed ~imply and reliably. The expensive and
unsatis:Eactory protective measure~ against
spreading of the color or blurring of the co~tours
during vulcanization can thus be avoided.
Especially preferred is the inventive method
in which the step of engraving includes removing
an outer rubber layer to make visible at least one
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underlying rubber layer of a different color.
Pursuant to individual order~ colored symbols can
be applied within a Yhort period of time with
simple means. Especially advantageous is a method
in which a green tire is build with a sidewall
strip having a recess and the recess is bridged
with an outer rubber layer in the form of a cover
strip that forms a continuoue recess-free surface
with the outer ~urface of the sidewall strip.
With these method steps symbols can be applied to
the tire without having to content with visible
deviations of the sidewall design of the tire.
Depending on the individual desire3 the tire can
be offered for ~iale with an exterior sidewall
provided without symbole of different color~, but
with symbols matching the color of the ~idewall so
as to have no apparent exterior deviations with
respect to conventional tire3, or with an exterior
sidewall having such colored (individual) Hymbols.
2 0 It i~ expedient to arrange in the recess a
plurality of rubber layer~ of different ~olors
adjacent to one another .in the Gircumferential,
axial or radial direction of the tire or
producing in the step of engraving symbols of
d i f f erent co 1 ors .
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By providing the symbol at the inner liner of
the tire, it is possible to provide the tire with
barcodes in a simple manner according to
individual specifications after vulcanization is
complete .
Preferably, these symbols are applied with
the aid of a laser because a laser requires only
a small amount of electrical c~rrent and also
provides for an especially exact engraving
process.
According to another embodiment of the
present invention, it is especially advantageous
to apply to the rubber surface to be engraved a
fluid which will remove heat energy from the
surface 80 that the surface area becomes brittle.
Subsequently, the symbol is engraved with simple
mechanical engraving tools.
The use of a laser allows, due to the
contac~-free engraving process free of mechanical
forces, a machining without having to take into
consideration the elasticity and plasticity of the
rubber. However, by making the surface brittle,
a highly precise symbol quality can be achieved
also with mechanical engraving tools. Undesirable
side effects due to the elastic properties of
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2~a289~
rubber are thus not encountered during m~rhln;nr,.
The pre~ent invention furthermore relates to
a device for preforming the inventive method. The
engraving device and the means for engraving and
holding the tire are three-dimensionally moved
relative to one another according to the desired
contour of the symbol It is thus possible to
engrave the tire while taking into account the
contour of the tire surf ace and to provide a
uniform symbol depth over the entire tire.
Advantageously, the engraving device is stationary
and the means for receiving and holding the tire
i~ moved three-dimensionally relative to the
engraving device. This allows ~or a separation of
the co~trol device for controlling the v~ t
from tho~e control sLevices for controlling the
engraving device and thus preventa problems
resulting from such a combined u~e. Xowever, it
i~ also possible to control the engraving device
three-dimen~ir,nally and to provide a stationary
means for receiving and holding the tire. It is
furthermore possible to control the movement of
the engraving device as well as the movement of
the means f or receiving and holding the tire 80 as
to move both o~ them relative to one another.
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21~289~
The inventive tire provide3 a symbol with
highly precise contours. The contour sidewalls
which are only partially and irregularly
detectable by the human eye show in conventional
colored symbols on tires with colored contour
sidewalls irregular colDr contours; in the
inventive tire the sidewalls do not have any
quality-reducing effects. Preferred, because
especially simple and easy to produce, is a tire
that comprises a rubber layer of a different color
positioned between the reinforcement belt
structure and the outer rubber layer forming the
exterior tire surface, wherein the rubber layer of
the different color formes the bottom o the
rece s s .
The inventive method of producing a tire by
building a green tire including arranging at least
Dn colored rubber layer on a rein~orced tire-
building layer and placing a cover layer on top of
the colored rubber layer, vulcanizing the green
tire, and engraving at least one symbol into the
cover layer such that the colored rubber layer is
visible within the area of the at least one
symbol, allows for the production of a tire with
symbols in a simple manner whereby colored symbols
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can be individually applied to the tire even after
vulcanization is complete.
Brief Description of the Drawings
The obj ect and advantages o the present
invention will appear rabre clearly from the
following specification in con~unction with the
accompanying drawings, in which:
Fig. 1 shows a sectional side view
showing the sidewall of the tire
with symbols;
Fig. 2 shows a part cross-sectional view
of the tire after completed
vulcanization;
Fig. 3 shows a part sectional view of the
tire ~f Fig 1 along section line
III-III with engraved syrnbols;
Fig. ~ shows a schematic representation
~or engraving symbols with the aid
o~ a laser into the sidewall of a
tire;
Fig. 5 is a schematic representation for
po~itioning a tire during laser
engraving; and
Fig. 6 shows a ~chematic representation
as in Fig. 4 but for engraving the
21~2~97
inner liner of a tire.
Description of Preferred Embodiments
The present invention will now be described
in detai~ with the aid of several specific
embodi ment g ut i l i z i ng f igure s 1 through 6 .
~ igures 1 through 3 show a tire of a
conventional construction with a carcass 3
~rtF~n~li n~ over the entire circumference of the
tire which in the axial direction of the tire
extendJ3 from the left (non-represented) bead core
across the left (non-representedl sidewall into
the right sidewall 1 and into the right bead core
7. Between the sidewalls 1, in a manner known per
se, belt plies 5 and on top thereof a tread strip
6 are applied radially outwardly of the carcass
layer. The tire, as is known per se, is also
provided with an inner liner 4 which extend over
the circumference of the tire and in the axial
direction from the right to the left bead cores 7.
The sidewall strip 2 of the sidewall 1 is
provided with a recess 8 which extends in the
circumferential direction over the entire tire.
The recess 8 is lined with a liner strip 9 and
placed on top is a colored rubber strip lo ~o as
to be flush with the recess contours. The rubber
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21528~7
strip 10 has a color that differs from the color
of the sidewall tire-building strip 2. Onto the
colored rubber strip 10 a cover strip ll made of
rubber material is applied which has the same
color as the side wall tire-b~ ; n~ strip 2
whereby the color strip is flush with the outer
contour of the sidewall tire-building strip 2
Cover strip 11 and outer contour of the side wall
tire=building strip 2 thus from a continuous,
uniform course of the outer contour of the
sidewall l. ~he liner strip 9 is made of a
material that is impermeable to polar substances
80 that such substances can not penetrate the
colored material. For example, it is posHible to
manufacture the strip 9 from bromobutyl rubber.
In caseE~ in which the transfer risk i~ low, it is
also poErsible to omit the strip 9
Af ter the tire building process the green
tire is vulcanized in a conventional manner. The
engraving of symbols takes place at any desired
point in time thereaf ter .
A8 shown in Fig. 4, a laser beam 14 emitted
by a CO;, laser with short pulsation rate, for
example, lOO ns and a fre~uency within the 10
hertz range, is guided through an aperture plate
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23 for forming the desired etching contour oi~ the
laser beam and via a focusing optic 15 and a
mirror 1~ is guided onto the sidewall 1 of the
tire The laser beam 14 impinges on the sidewall
at the point of engraving 17. At the point of
engraving 17 the laser beam causes the desired
removal of the exterior rubber layer. For
producing a desired, predet~orm;n~l engraving the
tire has assigned thereto a coordinate system K'
the point of origin of which is at the radial
center of the tire Such a coordinate system is
represented in a two--l; m~n~n~ional representation
in Fig. 5a. Fig. 5b ~hows a coordinate system K
corresponding to the focus of the optical laser
image with a point of origin within the removal
(etching) range 19 of the laser. For the
engraving process -the tire is positio~ed on a
three-dimensionally movable carriage that is moved
with the aid of a drive system of known
conetruction connected to a non-repre~ented
control computer in a manner known per se, and is
moved such that the point of origin of the
coordinate system K i~3 positioned at the desired
point of engraving 20 within the coordinate system
K' of the tire. By continuously comparing the
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. 2~52897
coordinate sy~tems, the carriage is moved with the
aid of the control computer so that the tire is
within the removal area of the laser for etching
(engraving) the desired symbol.
The output of the laser, as well as the drive
speed of the carriage are adjusted relative to one
another such that corre~ponding to the shape of
the desired symbol 24, as represented in Fig. 1,
the cover strip 11 is removed by the laser. As
represented in Fig. 3, the area 12 of the cover
ctrip which corre3ponds to the symbol is removed
with a constant sharp contour line so that the
sidewall 21 of the thus produced symbol 24
corresponds to the color of the sidewall 2 and the
bottom of the symbol 22 corresponds to the color
of the colored rubber strip 10.
It is possible to embody the aperture plate
23 depending on :the desired application for
forming the point of engraving 17, for example, as
a pictogram, as a ~3imple point, or as a line.
~t i8 also possible to provide one or more
moveable def lecting mirrors 16 and to engrave or
etch the desired contour of the symbol by the
controlled movement of the defIecting mirrors 16
while the laser 13 and tire are stationary.
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It is also possible to provide the 3trip 10
only over a portion of the circllmference of the
tire. Also, a plurality of strips 10 of different
colors can be arranged in the circumf erential
direction and/or in the radial direction adj acent
to one another or spaced from one another. With
this measure it is possible to produce symbols of
different colors in certain sections. It is also
possible to provide a plurality of strips lO of
different color~3 atop one another within the
reces~ whereby onto the axially outwardly
positioned colored rubber strlp the c~ver strip 11
is applied in the same manner as disclosed above.
~y engraving to two different depths, it is
possible to provide symbols of different colors in
any desired arrangement adj acent to one another .
A8 repre~ented in Fig. 6, it is also possible
to guide the laser beam produced by the laser 13
via a plurality of mirror~ 16, 16', 16' ' into the
interior of the tire in order to provide the inner
liner 4, having a corresponding layer
construction, with symbols, ~or example, bar
codes. ~t is also possible, when designing the
inner liner correspondingly, to provide colored
clymbol~ improve recognition of the symbols within
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~ 2152~97
the inner portion of the tire. In this context it
i3 also po33ible to apply to the inner liner or to
a recess within the inner liner a colored rubber
layer and to cover thi3 colored rubber layer with
an additional rubber layer . Af ter vulcanization
a colored 3ymbol can be engraved with the aid of
the laser 13.
It i3 also po33ible to employ a multi-
functional laser in or~er to use it al30 for other
processing 3teps. For example, it is po33ible to
remove the burr3 or cut of f the venting nipples
resulting from the vulcanization mold with the aid
of the laser.
In3tead of the colored rubber material for
the strip lo it i3 also pos3ible to use colored
materials which have 3imilar ela3tic or plastic
properties as rubber, for example, silicone.
It i3 also feasible to make brittle the area
of the tire to which the desired symbol iB to be
applied by applying fluid3 that remove heat from
the tire, for example, liquid nitror~en, and to
3ubsequently engrave with the aid of fine
mechanical cut~er3 or millers in the thus prepared
rubber material the de3ired symbol by removing the
cover strip. After r-rh1n;ng the rubber material
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will become elastic due to t~e higher ambient
temperature . However, in this context it must be
taken into consideration that the rubber material
should not be adversely aifected in its desired
properties due to the temporary brittleness.
The present invention is, of course, in no
way restricted to the specific disclosure of the
3pecification and drawings, but also ~n~ ~-R8e8
any modifications within the scope of the appended
claims.
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