FI65035C - DAECK MED SIDOVAEGGSFIGURERING - Google Patents

Description

I.-.- = ^ - η Γβ1 .. ANNOUNCEMENT

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Patent * and Registry Office · / 44) Nlhtivikilpana «i J» kuLLullubun pvm. - -, η n Ai

Patent · och regieterstyreleen '7 ainMcm utiagd oeh utijkriftun puMmnd ju. ix. oj (32) (33) (31) Pyrd «« r «cuoikuut — Bugird prior * · * 23.12.77 23.12.77 England-England (GB) 5382U / 77, 53823/77 (71) Dunlop Limited, Dunlop House, Ryder Street, St. James's, London SWI, England-England (GB) (72) Tom French, Sutton Coldfield, West Midlands,

The present invention relates to tires, and more particularly to tires having treads or markings on the sidewalls. This invention relates to tires, and more particularly to tires having treads or markings on the sidewalls.......................................

The sidewalls and shoulder areas of the tires are prone to bending and the materials and detailed construction, especially in the support area near the tread edge, must be carefully selected to ensure the required tire performance while avoiding tire breakage and consequent breakage. Fracture can be promoted by any substantial tread pattern that is not actually needed for technical reasons, such as tread / sidewall joints, and is due to the concentration of stress caused by cross-sectional changes, and as a result the sidewalls of the tire are kept substantially smooth, except for important trademarks and markings.

Attempts to mark the sidewalls of a tire with distinctly colored markings that do not include relief patterns have been forced to be limited to features such as white sidewalls and are not suitable for more complex patterns because color markings, 1 ‘2 65035 cannot be accurately shaped on tires.

The materials for the sidewalls and shoulder support areas of the tires have been developed over the years and generally contain carbon black to provide the required properties, which prevents the use of colors even if it becomes possible to cast two colors accurately enough to form a reproducible pattern. In addition, in recent years, tires have been developed that can be driven in a collapsed or substantially collapsed condition and in such tires, to prevent rupture and subsequent premature tire rupture, it is even more necessary to reduce cross-sectional changes and surface irregularities or patterning in the shoulder support area. Such tires are even more reduced in sidewalls and support areas than conventional tires to maximize driving distance when compressed.

The object of the present invention is to provide a ring made of a known type of monochromatic material with a clearly distinguishable pattern or marking and which eliminates the above-mentioned problems.

The tire according to the present invention comprises a ground contact portion having opposite edges each connected to its own shoulder support portion and a sidewall of the tire, each shoulder support portion and the adjacent sidewall of the tire being made of black elastomeric material, a relief pattern formed integrally with the tire in at least a portion of the shoulder support region and a sidewall-defined surface, the relief pattern comprising grooves not exceeding 2 mm deep with inclined surfaces formed by the sidewalls at an angle of substantially 10 ° to 80 ° to the normal of the tire surface, the grooves being arranged in at least two adjacent sets of grooves, each set of grooves being parallel to each other, and in which the grooves of the second series form an angle with the grooves of the second series. The tire is characterized in that one of the two sets of grooves forms the mark on the ring and the other set of grooves forms the background of the mark.

The relief pattern is formed on a monochromatic ring, especially a ring made of normal black 3 65035 of this elastomeric material.

The depth of the relief pattern is preferably less than 1.5 mm. In addition, the angles of the inclined surfaces can be in the range of 20 ° -70 ° or preferably in the range of 30 ° -60 °. It has also been found that with a relief pattern depth of 1 mm, an angle of 45 ° is particularly advantageous.

All of the oblique surfaces may be planar surfaces or one or more of the oblique surfaces may be curved in cross section. In the latter case, at least part of the inclined surface must be shaped so as to be in the angular range shown. The radius of curvature of the inclined surface may vary along the width of the inclined surface and the surface may be convex or concave with respect to the outer surface of the ring. It is most suitable that the inclined surfaces are arranged so as to form grooves in the surface area so that each side of the groove reflects light differently and creates a visible opposite when looking at the ring. The grooves can be arranged at small intervals across one area of the ring to provide a contrast with the rest of the surface area. The grooves may be straight or curved and the adjacent grooves may differ in shape or curvature depending on the patterning required by different technical methods. In addition, the different oblique surfaces may form angles of different magnitudes and, in the case of a groove, the angle formed by one side thereof may be different from the angle formed by the other side.

The finishing of the oblique surfaces may be the same as the finishing of adjacent non-oblique areas or, alternatively, the surface finishing may be different in the oblique area.

The surface roughness of the oblique surfaces should preferably be less than 0.8 micrometers R on the surface roughness scale of British Standard BS 1134: Part d 1: (1972) and is preferably less than 0.5 micrometers Ra · Such a surface is obtained when the tire mold is finished by average grinding. Such a finishing of the sloping surfaces provides a pattern that can be clearly seen from several different perspectives.

In addition, the surface roughness of the rest of the surface area is preferably greater than 5 micrometers Ra.

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4,650,355 Other embodiments of the present invention will become apparent from the following description, in which only some embodiments of the invention are described by way of example, with reference to the accompanying schematic drawing, in which:

Fig. 1 shows a side view of a molded tire according to an embodiment of the invention, showing a sector of the tire provided with a rack-type pattern in the shoulder chain region and another ring portion having a name in the center side region.

Fig. 2 shows a partial cross-section along the line (II) - (II) in Fig. 1.

Figures 3, 4, 5 and 6 show alternative cross-sectional shapes compared to Figure 2.

The second sector of the ring shown in Fig. 1 has a toothing pattern formed by a plurality of parallel grooves having a depth of only 1 mm. The grooves themselves consist of two oblique surfaces 1 and 2, which are straight in cross section and form an angle of 45 ° with the normal of the sidewall of the ring. (See enlarged section in Figure 2). The oblique surfaces 1 and 2 were cast against a finely ground surface of a ring mold.

The second sector shown in Figure 1 has the word "Dunlop" to illustrate the use of the invention when it comes to labeling a tire. The letters of the word rise 1 mm from the sidewall surface of the ring and a number of parallel grooves 3 are cast across each letter: ^ Each groove 3 consists of a pair of oblique surfaces 4 and 5 which, as in the previous example, form an angle of 45 ° with the normal and were cast against a finely ground surface of a tire mold and are 1 mm deep.

We have found that when the tires fitted to a vehicle are illuminated by stray light, they reflect at an angle of 45 ° to the inclined surfaces. In addition, the alternating inclination of the inclined surfaces to different sides of the normal causes a considerable contrast between adjacent inclined surfaces and, surprisingly, this effect can be observed without having to observe the ring from a certain angle. The pattern formed by this method is thus clearly visible at most points next to the ring. The resulting strong contrast between the bevelled surfaces gives the pattern an appearance that appears deep cut. However, the grooves in Figure 5 65035 are in fact only 1 mm deep, and such depths do not form damaging stress concentration points on the sidewall of the tire, and thus the pattern does not pose a risk of the tire sidewall cracking when the tire is used.

In each of the above examples, each pair of adjacent sloping surfaces forms a groove. It is obvious that the grooves can be straight or curved depending on what the pattern should look like. For example, we have found that several coaxial circles form a distinct pattern.

It is obvious that in the case of letters or numbers, these may be projecting from the side, as shown, or they may be embedded in the side.

When using inclined surface angles other than 45 °, different contrast effects can be achieved and grooves in which the angle of one side is different from the other are also included within the scope of the invention as long as the angles are within the agreed framework.

We have also examined the reflection of oblique surfaces with a curved surface when inspecting the cross-section, and Figures 3, 4 and 5 show a concave pattern with a radius of curvature of 1 mm and a depth of 1 mm, a convex pattern with a radius of curvature of 1 mm and a depth of 1 mm, respectively, concave. a pattern having a radius of curvature of 1 mm and a flat area of 2 mm between adjacent concave grooves.

Finally, the example shown in Fig. 6 shows a 1 mm deep rectangular pattern consisting of rectangular grooves, each side of which is at an angle of 30 ° and in which there are 1 non-wide flat areas between adjacent grooves. Very many other forms are possible and these include combinations of different forms.

In the examples presented so far, a ring mold with finely ground surfaces has been used. However, an important embodiment of the present invention comprises that alternative surface treatments can be used to further increase the resulting contrast effect when observing different oblique surfaces. The fine grinding treatment of a tire mold is most typically about 0.5 micrometers Ra on a surface roughness scale according to British Standard BS 1134: (1950). Other finishes can be used and a very useful finish to provide a contrast with a 0.5 micrometer R finish is 5 micrometer R = last a cl tely.

6 6 5 0'3 5

Another important advantage of the invention, apart from the fact that it can provide clearly distinguishable sidewall patterns that appear remarkably deep without the risk of rupture, is that very small grooves do not have such an insignificant effect on tire cooling as the surface area increases. The cross-sectional shape shown in Fig. 2, in which the oblique surfaces of the rubbers are also at an angle of 45 °, increases the surface area by 41.4%. The patterns shown in Figures 3, 4, 5 and 6 increase the surface area by 57.1%, 57.1%, 28.5% resp. 50%.

When convection is natural in the static state of the ring, it is important as the ring rotates and is forced to grow. The calculations also include a vertical convection coefficient determined as follows: 0.424 x 10 ^ (Dt) cal sec-1 cm ^ deg ”1.

As the velocity of the air flow increases steadily, the heat loss is almost directly proportional to the square root of the velocity until turbulence begins, and thereafter the heat loss increases very rapidly.

Increasing the surface roughness of the tire effectively reduces the rate at which turbulence occurs.

The general formula for forced convection is: _0L_ - p flvp) F (κθ 1V η) 2 \ kl) where lvp is known as the Reynolds number (defined in a system where the slip is a certain type en is Prandf's number kl hl is Nusself's number κθ F1 and F2 are unknown functions, and 65035 h = heat loss / unit area 1 = non-linear of the heat sink k = thermal conductivity Θ = overtemperature v = air flow rate p = coolant density η = coolant viscosity c = thermal capacity / coolant volume also in this case, the surface of the ring corresponds almost to a black body with an emission capacity close to 1.0.

The total emission power of the black body is determined by the formula: 2ir5 k4.

E - S-J- T4

15h JCT

where k = Boltzmann's constant T = absolute temperature ~ 27 h = 6.62 x 10 erg sec (Planck's constant) C = speed of light

It is possible to determine the energy loss due to surface radiation in watts / m for materials with an emission value of one. We have shown with a thermographic unit that infrared radiation with wavelengths of 2 to 5.6 micrometers is detectable.

Each form of heat loss is directly proportional to the surface area, which, according to the above, grows efficiently with low relief pattern.

Improved cooling is a useful advantage, especially in high-speed tires and compressed tires, which generate significant amounts of heat on the sides due to bending.

The low patterns of this invention are particularly advantageous on normal black ring sides, but the effect is also evident in colored materials. However, we have found that other colors do not provide as much contrast between the sloping surfaces as in the black elastomeric material. It will be appreciated that the patterns utilizing the aforementioned invention are useful in any part of the tire and the visual appearance may be provided in the tread pattern itself, if desired. Alternatively, the treads can be provided with a pattern that provides a contrast with the tread.

Claims (9)

1. A tire comprising a tread portion in contact with the ground, the opposing edges of which are connected to each of its shoulder attachment portions and the sidewall of the tire, which is covered with each shoulder attachment portion and adjacent sidewall is made of black elastomeric material, an embossed pattern having an embossed pattern a portion of the surface determined by the shoulder attachment portion and the adjacent sidewall of the tire, the relief pattern comprising a maximum of 2 mm deep grooves with facets formed by the sidewalls, which lie at a substantially 10 ° -80 ° angle to a normal to the tire surface; which rafters are arranged at least in two adjacent series of rafters, in which each series of rafters are mutually parallel and in which one series of rafters forms an angle with the other series of rafters, characterized in that one of the two series of rafters forms a brand of tire and the second series of rafters form the brand's background. Tire according to claim 1, characterized in that the facets of the latch to its transverse cross-section are beak-shaped. Tire according to claim 2, characterized in that the bending radius of the oval facets varies over the surface of the facets. Tire according to claim 2, characterized