Patent Publication Number: US-2022219495-A1

Title: Pneumatic Vehicle Tires having a marking Surface

Description:
The invention relates to a pneumatic vehicle tire having sidewalls and a tread and having at least one marking surface on at least one of the sidewalls and/or the tread, wherein the marking surface has two parallel sets of elongate elevations, wherein the two parallel sets intersect and form a parallelogram grid. 
     Such marking surfaces are generally molded into the tire in the course of the vulcanization of the tire by means of a shape-imparting vulcanization mold which has a negative contour of the marking surface. A structured surface of an already vulcanized tire can however also be achieved by removal, for example by means of engraving, or by an additive process. 
     Such marking surfaces are known. On the tire sidewall and/or on the tread, they are used for example to realize a marking. A marking may include images, characters, company names, company logos, designations, areas, etc. The marking surface may be part of the marking and/or may completely or partially surround the latter. 
     The scattering of light on the flanks of the elevations reduces the reflection of the light on the surface of the tire, which changes the brightness effect. In general, surface regions provided with transverse elevations appear darker than substantially smooth surface regions that are free from such elevations. This make it possible to realize a contrast in the inherently monochrome surface of the tire, in particular of the sidewall and/or of the tread. Depictions of markings can thus be made more clearly visible. 
     For example, DE 69 202 013 T3 has disclosed a pneumatic vehicle tire which, on its sidewall, has a diamond grid having an interior angle of 90° for a high-contrast surface design and accentuation of a marking. 
     A disadvantage of such embodiments is that the design options are limited. 
     The problem addressed is therefore that of influencing the contrast effect in even more targeted fashion, and further increasing the contrast effect. It is also the intention to realize easy producibility of the tire. 
     This is achieved in that the parallelograms of the parallelogram grid have an interior angle of 35° to 90°, and in that at least one parallelogram, preferably at least half of the parallelograms, particularly preferably all of the parallelograms, has or have an additional elevation within its or their areal extent. 
     It has been found that such a parallelogram grid produces a significantly greater contrast effect than a grid which is free from at least one additional elevation of this kind. 
     By means of the additional elevation within the areal extent, i.e. between the ridges of the elongate elevations forming the parallelogram, of a parallelogram, the density of surfaces inclined relative to the tire surface is increased. This increases the variation of surfaces and of the alignment thereof at which light can be reflected, scattered and absorbed in different directions. The additional inclined surfaces of the additional elevation increase the scattering, the multiple reflection and the absorption of light that is incident on the marking surface. In addition, the additional elevations create additional shadow effects which, particularly on the black rubber of the sidewalls, give rise to a clear accentuation of the marking surface in relation to the surrounding surface regions. Thus, the contrast effect can be influenced and improved even more selectively. 
     If half of all the parallelograms have such an additional elevation, it is possible, as with a chessboard pattern, for every second parallelogram to have the additional elevation. Particularly uniform distribution of the parallelograms with an additional elevation is thereby achieved. However, the parallelograms with additional elevations may also be arranged in alternate rows. 
     A further enhancement of these advantages is achieved by the fact that more than half, preferably all, of the parallelograms have such an additional elevation. 
     Limiting the interior angle to at least 35° furthermore ensures an advantageous capacity for venting and demolding the marking surface in the process of building the tire by means of a vulcanization mold. 
     One advantageous embodiment is provided by the fact that the interior angle is 35° to 55°, preferably 40° to 50°, particularly preferably 45°. 
     The interior angle of 35° to 55°, preferably of 40° to 50°, particularly preferably of 45°, brings about a higher density and variety of inclined surfaces for each area than a square grid of the same edge length. In addition, the regions around the acute interior angle create additional shadow effects which, particularly on the black rubber of the sidewalls, give rise to a clear accentuation of the marking surface in relation to the surrounding surface regions. Thus, the contrast effect can be influenced and improved even more selectively. 
     One advantageous embodiment is provided by the fact that the additional elevation of the parallelogram has an elongate extent with two end regions and that the additional elevation is attached to one of the elongate elevations of the parallelogram in precisely one end region of the two end regions, in particular at a height H 3 , which corresponds to at least ⅓ of the height H of the parallelogram grid. 
     The additional elevation thus has an elongate extent and is attached, i.e. connected, by one of its end regions to one of the elongate elevations of the parallelogram, in particular at a height H 3  which is at least ⅓ of the height H of the parallelogram grid. 
     The height H of the parallelogram grid can be the height averaged over all the elongate elevations along their longitudinal extent. Heights can be measured relative to a level that corresponds to a mean level of the marking base of the marking region. The level may also be the mean level of the lowest points of the parallelograms. Heights may also be measured with respect to a level that corresponds to a base level that is formed, for example, by a part of the outer surface of the pneumatic vehicle tire, in particular a base of a shallow depression formed on the surface of the tire. 
     Mean values generally correspond to the arithmetic mean value. 
     By means of attachment, an improved capacity for venting during the building of the tire is achieved. Furthermore, the additional elevation stabilizes the elongate elevation to which it is attached, thereby ensuring that the elongate elevation is more resistant to chafing during the use of the tire. 
     Thus, the additional elevation ends with the free, unattached end region within the areal extent of the parallelogram. The inclined surfaces of the free end region of the additional elevation cause additional scattering of the light in different directions. 
     One advantageous embodiment is provided by the fact that the elongate extent of the additional elevation is aligned largely parallel to one of the two parallel sets. 
     This keeps down the number of directions in which elevations or depressions have to be created to generate the corresponding structure during the production of the pneumatic vehicle tire. 
     One advantageous embodiment is provided by the fact that the additional elevation has a free end region which, at a height H 2  which corresponds to ⅓ of the height H of the parallelogram grid, has a clear spacing of 0.05 mm to 0.2 mm, preferably of 0.08 mm to 0.15 mm, with respect to the elongate elevation situated opposite the free end region. 
     Thus, the additional elevation ends with the free, unattached end region within the areal extent of the parallelogram. The inclined surfaces of the free end region of the additional elevation cause additional scattering of the light in different directions. The clear spacing of the free end region of 0.05 mm to 0.2 mm, preferably of 0.08 mm to 0.15 mm, with respect to at least one of the elongate elevations has proven particularly advantageous for an enhanced contrast effect with, at the same time, good demoldability. 
     One advantageous embodiment is provided by the fact that the parallelogram grid has a height H of 0.1 mm to 0.8 mm, preferably of 0.2 mm to 0.5 mm, particularly preferably of 0.25 mm to 0.35 mm. 
     By means of such a height H, advantageous dimensioning to the benefit of suitability for production is achieved. Furthermore, a good contrast effect can be achieved with such a depth, in particular in conjunction with a spacing of the parallel set of 0.4 mm to 1.0 mm, preferably of 0.5 mm to 0.7 mm, particularly preferably of 0.55 mm to 0.60 mm. 
     One advantageous embodiment is provided by the fact that the additional elevation has a lower height H′ than the height H of the parallelogram grid. 
     In this way, whilst achieving an advantageous support action of the short transverse elevations, the demoldability is simultaneously further improved. 
     One advantageous embodiment is provided by the fact that the elongate elevations of at least one, preferably both, of the two parallel sets are arranged at a spacing of 0.4 mm to 1.0 mm, preferably of 0.5 mm to 0.7 mm, particularly preferably of 0.55 mm to 0.6 mm. 
     Such a spacing of 0.4 mm to 1.0 mm, preferably of 0.5 mm to 0.7 mm, particularly preferably of 0.55 mm to 0.60 mm, makes an improved contrast effect possible with simultaneously low manufacturing outlay. The spacing can be measured between areas that run perpendicular to the tire surface and along the ridges of the elongate elevations of the parallel sets. 
     One advantageous embodiment is provided by the fact that the parallelogram grid is a diamond grid. 
     Thus, the two parallel sets have the same spacings. A particularly uniform structure is thereby brought about. It has proven particularly advantageous here if the two parallel sets have an identical spacing of 0.4 mm to 1.0 mm, preferably of 0.5 mm to 0.7 mm, particularly preferably of 0.55 mm to 0.60 mm. 
     One advantageous embodiment is provided by the fact that at least one of the elongate elevations has mutually opposite flanks which enclose an angle of at least 50°, preferably of 55° to 65°, with one another. 
     Such flank angles exhibit a good contrast effect. A corresponding negative shape of a molding tool such as a vulcanization mold can be created by means of laser engraving. It is particularly advantageous here if the mutually opposite flanks have such an angle over a vertical extent which corresponds to at least one quarter of the height H of the parallelogram grid. This is advantageous both at an angle of at least 50° and at an angle of 55° to 65°. 
     The advantage is also or additionally intensified if several, preferably all, elongate elevations of at least one parallel set are formed in this way. It is also advantageous if the elongate elevations of both parallel sets have flanks formed in this way. The angle can be measured between two crossing regions or between a crossing region and an attached end region. 
     One advantageous embodiment is provided by the fact that at least one of the elongate elevations and/or the additional elevation of a parallelogram has mutually opposite flanks which enclose an angle of 2° to 10°, preferably of 6° to 8°, with one another. 
     Multiple reflection and thus an improved contrast effect can be achieved with such a steep flank angle. A corresponding negative shape of a molding tool such as a vulcanization mold can be created by means of laser engraving of the molding tool. 
     It is particularly advantageous here if the mutually opposite flanks have such an angle over a vertical extent which corresponds to at least one quarter of the height H of the parallelogram grid. This is advantageous both at an angle of 2° to 10° and at an angle of 6° to 8°. 
     In the case of elongate elevations, the angle can be measured between two crossing regions or between a crossing region and an attached end region. In the case of an additional elevation, the angle can be measured between an attached end region and an unattached end region. 
     It is preferable if at least the additional elevation of the parallelogram has mutually opposite flanks which enclose an angle of 2° to 10°, preferably of 6° to 8°, with one another. An additional elevation of such narrow design can be excellent fitted into the areal extent of the parallelogram. 
     It may be expedient if the additional elevation has mutually opposite flanks which enclose an angle of 2° to 10°, preferably of 6° to 8°, with one another and, at the same time, has a mean width of 0.08 mm to 0.13 mm, preferably of 0.1 mm. The mean width is the arithmetic mean value of the width measured at different heights. 
     One advantageous embodiment is provided by the fact that at least one of the elongate elevations and/or at least one additional elevation has a cross section which, in the region of at least one flank, has a convexly curved and/or a linear and/or a concavely curved and/or a stepped and/or a bent and/or a structured region. 
     The cross section runs perpendicular to the direction of longitudinal extent of the respective elongate elevation or additional elevation. The cross section of an elongate elevation can be measured between two crossing regions or between a crossing region and an attached end region. The cross section of an additional elevation can be measured between an attached end region and a free end region. By means of such a cross section, the contrast effect can be influenced and further enhanced even more selectively. 
     It is particularly advantageous here if the correspondingly shaped region extends over a vertical extent which corresponds to at least one quarter of the height H of the parallelogram grid. 
     The cross section may be symmetrical. 
     The elongate elevation and/or the additional elevation can merge into a marking base at a sharp bend or at a rounded portion. 
     Irrespective of the precise embodiment, the elongate elevation and/or the additional elevation can have a flattened ridge. The ridge may comprise a plateau with a width of at most 0.1 mm, preferably of 0.03 mm to 0.06 mm. The ridge may also have irregularities in height which amount to a maximum of 5% of the height H. 
     Irrespective of the embodiments, the marking surface can have a marking base, in particular a planar marking base, which separates mutually opposite elongate elevations of a parallelogram from one another. 
     In one preferred embodiment, the marking surface is formed on one of the sidewalls of the pneumatic vehicle tire. 
     According to a further preferred embodiment, the marking surface is formed on the tread of the pneumatic vehicle tire. In this case, the marking surface may, in particular, also be applied to groove flanks and/or groove bases of grooves running in the tread, or at the tread outlet, that is to say at the shoulder flanks running outside the ground contact patch to the sidewalls, or on the outer surface of the tread, that is to say on treads that come into contact with the ground. 
    
    
     
       Further features, advantages and details of the invention will now be described in more detail on the basis of the drawing, which schematically shows exemplary embodiments of the invention. In the drawing: 
         FIG. 1  shows a pneumatic vehicle tire  1  having a marking surface; 
         FIG. 2  shows a marking surface; 
         FIG. 3  shows a marking surface; 
         FIGS. 4 a  to 4 g    show examples of cross sections. 
     
    
    
       FIG. 1  shows a pneumatic vehicle tire  1  with sidewalls  2  and a tread  3  and with at least one marking surface  4  on at least one of the sidewalls  2  and/or on the tread  3 . In the case of arrangement on the tread  3 , the marking surface may, in particular, also be applied here to groove flanks and/or groove bases of grooves running in the tread  3 , or at the tread outlet, that is to say at the shoulder flanks running outside the ground contact patch to the sidewalls, or on the outer surface of the tread, that is to say on treads that come into contact with the ground. 
     The marking surface  4  has two parallel sets  5 ,  5 ′ comprising elongate elevations  6 ,  6 ′, wherein the two parallel sets  5 ,  5 ′ intersect and form a parallelogram grid. The parallelograms of the parallelogram grid have an interior angle  7  of 35° to 90°. At least one of the parallelograms, preferably at least half of the parallelograms, particularly preferably all of the parallelograms, has or have an additional elevation  8  within its or their areal extent. 
     One design variant of such a marking surface  4  is shown in  FIG. 2 . The illustrated sectional view of the marking surface  4  is configured in such a way that the parallelograms of the parallelogram grid have an interior angle  7  of 35° to 55°, preferably of 40° to 50°, particularly preferably of 45°, and that at least one parallelogram has an additional elevation  8  within its areal extent, i.e. between the ridges  11  of the elongate elevations  6 ,  6 ′ forming the parallelogram. At least half of the parallelograms preferably have such an elevation  8 . In the case illustrated, all the parallelograms have such an additional elevation  8 . 
     The additional elevation  8  of the parallelogram has an elongate extent with two end regions  9 ,  10 . Here, precisely one end region  10  is attached to an elongate elevation  6  of the elongate elevations  6 ,  6 ′ of the parallelogram, in particular at a height H 3  which corresponds to at least ⅓ of the height H of the parallelogram grid. 
     In this exemplary embodiment, the height H of the parallelogram grid is the height averaged in accordance with the arithmetic mean over all the elongate elevations along their longitudinal extent. Heights can be measured relative to a level  20  which corresponds to a mean level of a marking base  16 . The level  20  may also be the mean level of the lowest points of the parallelograms. The level  20  may also correspond to a base level that is formed, for example, by a part of the outer surface of the pneumatic vehicle tire, in particular a base of a shallow depression formed on the surface of the tire. 
     Here, the additional elevation  8  is aligned in its longitudinal extent largely parallel to the elongate elevations  6 ′ of the parallel set  5 ′. 
     The additional elevation  8  has a free end region  10  which, at a height H 2  which corresponds to ⅓ of the height H of the parallelogram grid, has a clear spacing  17  of 0.05 mm to 0.2 mm, preferably of 0.08 mm to 0.15 mm, with respect to the elongate elevations  6  situated opposite the free end region  19 . 
     The parallelogram grid has a height H of 0.1 mm to 0.8 mm, preferably of 0.2 mm to 0.5 mm, particularly preferably of 0.25 mm to 0.35 mm. 
     The parallelogram grid illustrated is a diamond grid. Both parallel sets  5 ,  5 ′ have an identical spacing  18  of 0.4 mm to 1.0 mm, preferably of 0.5 mm to 0.7 mm, particularly preferably of 0.55 mm to 0.60 mm. The spacing  18 ,  18 ′ can be measured between the centers or peaks of the ridges  11  of the elongate elevations. 
     The elongate elevations  6 ,  6 ′ may have mutually opposite flanks  12  which enclose an angle  13  of at least 50°, preferably of 55° to 65°, with one another. The angle  13  can be measured between two crossing regions  14  or between a crossing region  14  and an attached end region  10 . 
     At least one of the elongate elevations  6 ,  6 ′ and/or the additional elevation  8  of a parallelogram has mutually opposite flanks  12  which enclose an angle  15  of 2° to 10°, preferably of 6° to 8°, with one another. 
     The angle  15  can be measured between two crossing regions  14  or between a crossing region  14  and an attached end region  10  or between an attached end region  10  and an unattached end region  9 . 
     In the case illustrated, the elongate elevations  6 ,  6 ′ have mutually opposite flanks  12  which enclose an angle  13  of at least 50°, preferably of 55° to 65°, with one another. The additional elevations  8  furthermore have mutually opposite flanks  12  which enclose an angle of 2° to 10°, preferably of 6° to 8°, with one another. Here, the flanks  12  enclose the respective angles  13 ,  15  over a vertical extent which corresponds at least to one quarter of the height H of the marking region. 
     The elongate elevation  6 ,  6 ′ and/or the additional elevation  8  may have a flattened ridge  11 . The ridge may comprise a plateau with a width of at most 0.1 mm, preferably of 0.03 mm to 0.06 mm. The ridge may also have irregularities in height which amount to a maximum of 5% of the height H. 
     The marking surface may have a marking base  16 , in particular a planar marking base  16  which separates mutually opposite elongate elevations  6 ,  6 ′ of a parallelogram from one another. 
     The elongate elevations  6 ,  6 ′ have a height H of 0.1 mm to 0.8 mm, preferably of 0.2 mm to 0.5 mm, particularly preferably of 0.25 mm to 0.35 mm. Here, the height H can be measured between crossing regions  14  and away from attached end regions  10 . 
     The elongate elevations  6 ,  6 ′ and/or the additional elevations  8  have a cross section which has a linear region in the region of at least one flank  12 . As illustrated, this may merge into the marking base  16  at a sharp bend or else in a curved manner. The cross section of the elongate elevations  6 ,  6 ′ and/or of the additional elevation  8  may be of symmetrical design. 
       FIG. 3  shows a further marking region  4 . It differs from the marking region  4  shown in  FIG. 2  at least in that the two parallel sets  5 ,  5 ′ differ from one another in their spacing. The spacing  18 ′ of parallel set  5 ′ is less than the spacing  18  of parallel set  5 . Furthermore, they differ in that the elongate elevations  6 ,  6 ′ also have mutually opposite flanks  12  which enclose an angle  15  of 2° to 10°, preferably of 6° to 8°, with one another. The additional elevations  8  have a lower height H′ than the height H. 
       FIGS. 4 a  to 4 g    show examples of cross sections of the elongate elevations  6 ,  6 ′ and/or of the additional elevations  8 . The cross sections are suitable for the marking regions  4  illustrated in  FIGS. 2 and 3 . Here, the cross section runs perpendicular to the direction of longitudinal extent of the respective elongate elevation or additional elevation. The cross section of an elongate elevation  6 ,  6 ′ can be measured between two crossing regions  14  or between a crossing region  14  and an attached end region  10 . The cross section of an additional elevation  8  can be measured between an attached end region  10  and a free end region  9 . Without limitation of generality, the cross sections are shown as being of symmetrical design. 
       FIG. 4 a    shows a cross section which has a linearly running region  19  in the region of the flanks  12  and wherein the flanks  12  enclose an angle  13  of at least 50°, preferably of 55° to 65°, with one another. 
       FIG. 4 b    shows a corresponding cross section which has a linearly running region  19  in the region of the flanks  12  and wherein the flanks  12  enclose an angle  15  of 2° to 10°, preferably of 6° to 8°, with one another. 
       FIG. 4 c    shows by way of example that, irrespective of the exact design of the cross section, the flanks  12  may also merge into the marking base  16  with a curvature. 
       FIG. 4 d    shows a cross section which has a convexly curved region  19  in the region of the flanks  12 .  FIG. 4 e    shows a cross section which has a stepped region  19  in the region of the flanks  12 . 
       FIG. 4 f    shows a cross section which has a structured region  19  in the region of the flanks  12 .  FIG. 4 g    shows a cross section which has a concavely curved region  19  in the region of the flanks  12 . 
     In all of  FIGS. 4 a  to 4 g   , the correspondingly shaped region  19  may extend over at least one quarter of the height H of the parallelogram grid. 
     LIST OF REFERENCE SIGNS 
     
         
           1  Pneumatic vehicle tire 
           2  Sidewall 
           3  Tread 
           4  Marking surface 
           5 ,  5 ′ Parallel set 
           6 ,  6 ′ Elongate elevation 
           7  Interior angle 
           8  Additional elevation 
           9  Free end region 
           10  Attached end region 
           11  Ridge 
           12  Flank 
           13  Angle 
           14  Crossing region 
           15  Angle 
           16  Marking base 
           17  Clear spacing 
           18 ,  18 ′ Spacing of the parallel set 
           19  Region 
           20  Level 
         H′ Height of the additional elevation 
         H Height of the parallelogram grid 
         H 3 , H 2  Height