Note: Descriptions are shown in the official language in which they were submitted.
1
PNEUMATIC VEHICLE TIRE
Field
The invention relates to a pneumatic vehicle tire comprising at least one
planar element on at
least one sidewall, which element consists of a three-dimensionally structured
pattern with a
multiplicity of identically designed, regularly arranged depressions, the
greatest diameter of which
is 5 0.70 mm and the greatest depth of which is 5 0.60 mm.
Background
A pneumatic vehicle tire is known from WO 2014 040967 Al. The depressions take
up at least
60% of the pattern and are arranged in such a way that at least five
depressions per square
millimeter of the pattern are provided. The depressions have diameters of the
same size, of 0.03
mm to 0.5 mm. In the case of one embodiment of the invention, the depressions
are designed as
circular in plan view, in the case of another embodiment they are designed as
regular hexagons
directly adjoining one another. In the case of one variant, the depressions
that are circular at the
surface of the pattern extend into the rubber material of the sidewall in a
conical or frustoconical
form. The maximum depth of the depressions of a pattern, which is the same for
all of them, is
between 0.2 mm and 0.6 mm. If such patterns are used for creating inscriptions
or design
elements on an otherwise smooth region of the sidewall, the achievable
contrast in relation to the
smooth sidewall surface is particularly great, since the depressions only
reflect a small proportion
of the incident light.
Summary
The invention seeks to addresses the problem of reducing the reflectance of
such depressions
still further to increase the achievable contrast, especially to allow
inscriptions or design elements
that appear deep black to be produced on a tire sidewall.
The problem addressed is sought to be solved according to the invention by the
depressions
being created as substantially pyramidal, with a square, regular pyramid as
the basic form, and
being arranged in rows running perpendicularly to one another, their outer
delimiting edges, which
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extend along squares in a plan view of the pattern, running into the rubber
material of the sidewall
in the form of recesses.
According to a broad aspect, the invention provides a pneumatic vehicle tire
comprising at least
one planar element on at least one sidewall, the at least one planar element
defining a three-
dimensionally structured pattern with a multiplicity of identically designed,
regularly arranged
depressions, a greatest diameter of which is equal or smaller to 0.70 mm and a
greatest depth of
which is equal or smaller to 0.60 mm, wherein the depressions are
substantially pyramidal, in
each case with a square, regular pyramid as a basic form, and are arranged in
rows running
perpendicularly to one another, their outer delimiting edges, which extend
along squares in a plan
view of the pattern, running into the sidewall in the form of recesses.
A sidewall pattern comprising depressions designed in such a way, with
delimiting edges running
in the form of recesses, absorbs more light than the depressions designed in
the known way, so
that the contrast of the sidewall inscriptions or sidewall designs consisting
of such a pattern is
increased in comparison with the surrounding smooth surface of the sidewall.
Several advantageous configurations of the pattern according to the invention
allow influence to
be brought to bear on the desired contrast effect of the planar elements
provided with the patterns
structured according to the invention on the sidewall of a pneumatic vehicle
tire. In particular, the
creation of the pattern can be made to match the configuration of the planar
elements.
In the case of one of these preferred measures, the greatest depth of the
delimiting edges running
in the form of recesses is at most half the maximum depth of the depressions.
This measure
.. influences the extent of the absorption of incident light.
In the case of preferred embodiments, the delimiting edges running in the form
of recesses run in
either an arcuately curved or shallow V-shaped manner.
Also particularly preferred are embodiments of the pattern in which there are
between adjacent
depressions narrow webs, 0.01 mm to 0.04 mm wide, running in the form of
recesses in a way
analogous to the delimiting edges.
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Particularly great luminous reflectance is achieved in the case of a design
variant in which the
delimiting edges that run in a shallow V-shaped manner and the webs that are
possibly present
between the delimiting edges are created in the form of a series of steps down
to their lowest
point, the walls that delimit the depressions also in particular being formed
as a series of steps,
with the surfaces of the steps extending in a square manner in the plan view.
In this case, the
number of steps of the webs and the walls running in the form of a series of
steps, in each case
down to their lowest point, is three to five. The configuration in the form of
a series of steps is not
discernible to the naked eye and imparts a roughness to the areas concerned in
the pattern that
contributes to a particularly effective absorption of light.
Also particularly preferred is a design of the pattern in which the lowest
point of the depressions,
measured in the radial direction and from that plane in which the corners of
the delimiting edges
lie, is at a depth of 0.02 mm to 0.20 mm, in particular of 0.08 mm to 0.19 mm.
The radial distance of the lowest point of the delimiting edges from the plane
in which the corners
of the delimiting edges lie is 0.01 mm to 0.10 mm, preferably 0.01 mm to 0.03
mm. It is also
particularly advantageous for the achievable light absorption if the length of
the extent of the
delimiting edges in plan view of the pattern is 0.02 mm to 0.50 mm, preferably
0.10 mm to 0.30
mm, in particular 0.18 mm.
Brief description of the drawings
Further features, advantages and details of the invention will be discussed in
more detail on the
basis of the drawing, which illustrates exemplary embodiments. In the drawing:
Figure 1 shows an oblique view of a portion of a pneumatic vehicle tire,
Figure 2 shows an oblique view of a detail of an embodiment of a three-
dimensionally structured
pattern,
Figure 3 shows a plan view of the detail of the pattern from Figure 2,
Figure 4 shows a sectional representation along the line IV-IV of Figure 3,
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Figure 5 shows a plan view of a detail of a further embodiment of a three-
dimensionally structured
pattern and
Figure 6 shows a sectional representation along the line VI-VI of Figure 5.
Detailed description of embodiments
Variants, examples and preferred embodiments of the invention are described
are described
hereinbelow. The pneumatic vehicle tire shown in Figure 1 has a tread 1, bead
regions 2 and
sidewalls 3. On at least one sidewall 3, preferably in a region provided with
a smooth surface,
there are formed areal elements, for example letters of a logo or decorative
elements, that are
formed from a three-dimensionally structured pattern according to the
invention. Indicated in
Figure 1 is a detail 4 of the pattern of which two design variants are
explained in more detail on
the basis of Figures 2 to 6.
Figures 2 to 4 consequently show greatly enlarged a detail 4 with an
embodiment of a pattern 5
that has a multiplicity of depressions 6. The depressions 6 have substantially
the form of regular
square pyramids, are all identically designed and are arranged in two rows
running
perpendicularly to one another. The square detail 4 that is shown comprises
four horizontal rows
and four vertical rows of depressions 6, therefore altogether sixteen
depressions 6. Each
depression 6 is delimited on the outer side of the pattern by delimiting edges
7 which extend along
the sides of a square and the length I of extent of which, determined in plan
view, is 0.02 mm to
0.50 mm, preferably 0.10 mm to 0.30 mm, in particular 0.18 mm. The mutual
distance 131 between
the delimiting edges 7 running parallel to one another of adjacent depressions
6 is 0.01 m to 0.04
mm. The delimiting edges 7 and the narrow webs 7a between the depressions 6
run in the form
of recesses inwardly in the direction of the interior of the depression,
preferably in a concavely
curved manner. The lowest point of each delimiting edge 7 is in its middle,
the distance a in the
radial direction of the lowest point from the plane in which the corners of
the delimiting edges lie
being 0.01 mm to 0.10 mm, preferably 0.01 mm to 0.03 mm. The edges 7 are
adjoined in the
radial direction by triangular delimiting walls 8 running down to the tip of
the pyramid at the lowest
point of the depressions 6 and respectively forming the side faces of the
pyramids. The lowest
point of the depressions 6 in the radial direction, measured from the plane in
which the corners of
the delimiting edges lie, is at a depth ti of 0.02 mm to 0.20 mm, in
particular of 0.08 mm to 0.19
mm, where t1 is at least twice the distance a. The depressions 6 take up at
least 80% of the
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surface area of the pattern 5. The size of the intermediate areas is
correspondingly small. In the
case of an embodiment that is not shown separately, the depressions 6 may
adjoin one another
directly, so that in the case of adjacent depressions 6 delimiting edges 7
respectively delimit two
depressions 6.
Figures 5 and 6 show a square detail of a further embodiment of a pattern 5'
with identically
designed depressions 6', which are arranged in rows running perpendicularly to
one another and
are likewise formed in principle in the form of pyramids with a regular,
square pyramid as the
basic shape. On the outer side of the pattern 5', the delimiting edges 7' of
the depressions 6
extend in plan view along squares, in a way similar to the first embodiment,
but in the same way
as the webs 7'a between the edges 7' of adjacent depressions 6' run inwardly
in the form of
recesses, in the direction of the interior of the depressions 6'. The webs 7'a
run in the form of a
series of steps down to their lowest point in the middle, the distance a of
which from the level of
the corners of the edges 7' corresponds to the aforementioned distance a. The
number of steps
of a series 10 on each side of the lowest point is between three and five; in
the case of the design
shown, four steps 10 are provided. Down to the lowest point of each depression
6', which in the
radial direction is at the aforementioned depth tl, the four walls 8' of the
depressions 6' are also
created in the form of a series of steps and formed with surfaces of the steps
extending around a
square in plan view that progressively become smaller from step 11 to step 11.
At the lowest point
of the depression 6', there is a tiny square. Discounting the lowest point ¨
the number of steps
11, in particular matching the number of steps 10 in the webs 7'a, is between
three and five, in
particular four. The steps 10, 11 have in particular step heights of the same
size and step surfaces
of the same width. The tiny steps 10, 11 have the effect of imparting a
roughness to the areas
concerned, which contributes to a particularly effective absorption of light.
The configuration according to the invention of the depressions 6, 6', in
particular of the delimiting
edges 7, 7' at the outer surface of the pattern that run in the form of
recesses in the direction of
the interior of the depressions, reduces the reflection of light to a very
small proportion. Areal
elements covered with such patterns 5, 5' in the sidewall 3 of tires therefore
appear deep black
in comparison with the surrounding surface of the sidewall. As a result of
their very small
dimensions, the individual depressions 6, 6' that make up the patterns 5 5'
are not discernible to
the naked eye.
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For producing patterns 5, 5' according to the invention, correspondingly fine
structures are
introduced by means of laser engraving into the side shells of a tire heating
mold that form the
sidewalls. For producing the pattern 5', the laser works in a correspondingly
controlled manner
according to a grayscale bitmap layer by layer into the material of the side
shells.
List of designations
1 ............. Tread
2 ....... Bead region
3 ............. Sidewall
4 ............. Detail
5, 5' ........ Pattern
6, 6' ......... Depression
7, 7' .. Delimiting edge
7a, 7'a ....... Web
8, 8' ........ Delimiting wall
10,11 ........ Step
a ............. Distance
I ....... Length of extent
t1 ............ Depth
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