WO2001094132A1 - Tread design for a pneumatic tire - Google Patents

Abstract

The invention relates to a tread design for pneumatic tires, which is characterized by a novel design and which facilitates an optimum balance between the desired good roadholding and the resulting undesired rolling resistance. The tread design (1) comprises a tread (2) and the blades (3). In the center section of the tread design (1) the tread (2) is arched outwards to a conical area that has a flattened top and that is either symmetric to the center plane (5) of the pneumatic tire or that is off-set to one side.

Description

 Tire tread for a pneumatic tire

Pneumatic tires generally have to meet various and often contradicting requirements such as directional stability, mechanical stability, good traction or low friction during their use. It is desirable to use a low-relief tire profile with reduced friction at high driving speeds, which on the other hand complicates driving behavior in adverse driving conditions such as wet roads.

To improve the general driving characteristics, various developments have therefore been proposed over the years. In the published patent application DE 28 54 364 AI, a pneumatic tire is described which is supposed to offer a compromise between good adhesion, low and even wear, good tracking in the transverse direction and good water drainage by using specially arranged raised profile elements with an inclination increasing transversely to the edges become.

The published patent application DE 30 09 223 AI describes a pneumatic tire which, in addition to suction pins and additional strips, has raised cross profiles in the central region of the tread and is intended to ensure reliable grip in all weather conditions.

In the published patent application DE 31 51 231 AI, a pneumatic tire with variable traction is set out, which is equipped with a cavity and has circumferential stabilized treads, which should allow an adapted traction depending on the driving speed.

The published patent application DE 35 36 698 AI describes a pneumatic tire with a grid-shaped profile in a defined orientation to the direction of travel, the basis of which can be adapted to the requirements and improved accordingly. The US Pat. No. 4,700,762 describes a pneumatic tire development for high driving speeds, which is said to offer good driving properties and good grip on wet roads with reduced rolling resistance, in that the tread is partially left out in the central area of the tire and the tread lamellae are widened in an arc towards the outside of the tire.

Similar to this pneumatic tire, a profile is presented in the published patent application DE 37 20 908 AI which is intended to combine good driving performance in the corner region, in particular on wet road surfaces, with good lane keeping ability and high wear resistance. This is made possible by arched tread grooves, the outer surfaces of which are not perpendicular to the tread, but are at a defined angle, which increases with the distance between the tread groove and the central area of the tire.

US Pat. No. 4,785,861 describes a pneumatic tire whose profile properties and stability have been changed in favor of improved driving properties and grip in adverse conditions. This is achieved through a tire tread that expands radially when the tire is inflated and approximates an optimal tread.

The laid-open specification DE 37 20 854 AI sets out a tread pattern of a pneumatic tire, the special design of the circumferential and transverse grooves of which should ensure significantly improved absorption and displacement as well as drainage of the water absorbed by the tire on a damp road.

Likewise, the pneumatic tire described in the published patent application DE 38 34 383 AI should enable significantly better driving performance on a damp road. This is achieved through diagonal grooves that begin in the central area of the tire and end openly in the outer area of the tire via a kink.

In order to increase the directional stability of the pneumatic tire, an additional groove was introduced in the US Pat. No. 5,010,936 in the edge region of the tire, which is slightly inclined to the normal of the tire tread, with the aim of preventing unintentional deflection without having to accept uneven wear on the tread shoulders.

The same aim is pursued by the published patent application DE 43 37 572 AI, in which a tire profile is described with incisions in the circumferential direction in the tread, the directions of incidence of which are essentially oriented towards the center of the wheel.

In the published patent application DE 44 03 662 AI, a pneumatic tire is set out, the tire profile of which is said to be able to be changed even after manufacture in dependence on the condition of the road and to be adaptable to the given conditions.

The laid-open specification DE 196 50 702 AI describes a tire tread which consists of grooves which are inclined at different angles to the running direction and which are corrugated at least in an axial edge region in order to optimize grip on the ground in different weather conditions.

The object of the present invention is to create a tire tread which has improved grip with reduced rolling friction and good directional stability. In addition, the pneumatic tire is said to offer particularly high mechanical stability.

The object is achieved with the aid of the inventive training features of claim 1. Advantageous developments of the invention are the subject of the respective dependent claims. The proposed tire tread consists of several elements. The tread is not slightly curved as usual, but has a conical shape in the central area of the tire, which can be symmetrical or asymmetrical to the central plane of the tire. There are lamellas on the tread, which enable optimum grip. The tire tread can consist of one material or can be made of different materials to increase the mechanical properties at the most stressed points. In addition, to improve the mechanical properties, especially when cornering, an axially flexible, but laterally rigid flat profile can be integrated into the tread to avoid any deformation due to strong shear forces.

The proposed tire tread and the mode of operation described in the introduction are shown below with the aid of explanatory drawings. Show it:

Fig. 1 shows a cross section of the tire tread of the first

Variant, Fig. 2 shows a cross section of the tire tread of the second

Variant, Fig. 3 shows a cross section of the tire tread of the third

Variant, Fig. 4 shows a cross section of the tire tread of the fourth

Variant, Fig. 5 shows a cross section of the tire tread of the fifth

Variant, Fig. 6 shows a cross section of the tire tread of the sixth

Variant, Fig. 7 shows a cross section of the tire tread of the seventh

Variant, Fig. 8 shows a cross section of the tire tread of the eighth

Variant, Fig. 9 shows a cross section of the tire tread of the ninth

Variant, Fig. 10 shows a cross section of the tread of the tenth

Variant. Fig. 11 is a cross section of the tread pattern of the eleventh

Variant, Fig. 12 shows a cross section of the tread pattern of the twelfth

Variant.

1 shows the first variant of the tire tread. The tire profile 1 consists of the tread 2 with the sipes 3, which ensure optimum grip. In the central area of the tire tread 1, the tread 2 is curved conically outwards. The conical region 4 is either symmetrical to the central plane 5 of the tire or is shifted to one side. The tire profile 1 can differ in the central area of the cone, on its flank 6 and in the remaining area in its thickness. In a further variant, the tire profile 1 can have two or more conical regions 4 lying symmetrically or asymmetrically to the central plane 5 of the pneumatic tire.

The second variant (see FIG. 2) likewise has a central conical region 4, the tip of which is flattened in order to enable a better rolling effect during uniformly accelerated travel and thus a reduced fuel consumption. The thickness of the material can be in the central area of the cone, on the flank 6 and differentiate in the rest of the area. In a further variant, the tire tread 1 can have two or more conical regions 4 with a flattened tip that are symmetrical or asymmetrical with respect to the central plane 5 of the pneumatic tire.

The third variant (see FIG. 3) has, in addition to an otherwise similar structure, in addition to a flattened tip of the conical region 4, two flanks 6 of different lengths, so that the tread in the central region of the tire profile 1 is no longer perpendicular to the central plane 5 of the tire Pneumatic tire stands.

The fourth variant (see FIG. 4) consists of the tread 2 with the lamellae 3. The central area is cone-shaped and also curved outwards like a staircase. One or more stair-like steps can be used, which are each symmetrical or asymmetrical to the central plane 5 of the pneumatic tire.

The fifth variant is shown in FIG. 5 and, in addition to an otherwise similar structure to the first four variants, has a central web 7 which connects the attachment of the flanks 6 to the conical region 4 in order to close this part of the tire profile 1 which is subject to high mechanical stress stabilize. In a further variant, the central area between the conical area 4 and the central web 7 is connected via a channel to a valve leading to the outside, in order to be able to adapt the air pressure in this area to the external conditions, such as route properties or driving speed.

In a departure from the first variant, the sixth variant shown in FIG. 6 has an even more durable material 11 in the central cone-shaped area 4 than in the remaining portion of the tire profile 1. The thickness of the material can also be in the central area of the cone, on the flank 6 and distinguish in the rest of the area. The cone-shaped area 4 can be symmetrical to the central plane 5 or be shifted to one side. In a further variant, the tire tread 1 can have two or more conical regions 4 lying symmetrically or asymmetrically to the central plane 5 of the pneumatic tire, each of which is stabilized in the central region by more durable material 11.

The seventh variant is shown in FIG. 7. The tire tread 1 consists of the tread 2 and the sipes 3. In the central area of the tread 1, the tread 2 is curved conically outwards. The conical region 4 is either symmetrical to the central plane 5 of the tire or is shifted to one side. The flanks 6 are made of a more durable material 11 in order to absorb the mechanical loads. The tire profile 1 can differ in the central region of the cone, on its flanks 6 and in the rest of the region in its thickness.

8 shows the eighth variant. The tire tread 1 consists of the tread 2 and the sipes 3. In the central area of the tire tread 1, the tread 2 is again conically curved outwards. The conical region 4 is either symmetrical to the central plane 5 of the tire or is shifted to one side. The tire profile 1 can differ in the central area of the cone, on its flank 6 and in the remaining area in its thickness. In contrast to the variants described so far, a metal strip 8 with a U jacket 9, which is intended to protect the rest of the material from being destroyed by the metal strip 8, is embedded in the tread in the conical region 4, in order to improve the stability of the pneumatic tire, especially when driving in Increase curves where the pneumatic tire is subjected to greater shear forces. Another variant consists in the use of two or more metal strips 8 which lie symmetrically or asymmetrically to the central plane 5 of the tire.

In the ninth variant (FIG. 9), the central cone is composed of lamellae 12 of different lengths, which are connected to one another by transverse webs 13 and are thereby stabilized. The lower part 14 of the slats 12 is formed in the connection area to the rest of the running surface 2 in a spiral, wave, angle or fold shape in order to be able to absorb the deformation energy better. The connection area between the slats 12 and the remaining running surface 2 is designed as an inwardly curved collecting trough 15. In a further embodiment, the conical region 4 is asymmetrical to the central plane 5 of the pneumatic tire. In addition, embodiments with a flattened central conical region 4 as in the second variant, with flanks 6 of different lengths as in the third variant and with a stair-like central region 4 of the cone as in the fourth variant are possible.

The tenth variant is shown in FIG. 10. The tire tread 1 consists of the tread 2 and the fins 3. The tread 2 consists in the central area of a cone, the flanks 6 of which are curved outwards from a hard-wearing material 16 with regularly arranged cavities 17. In the inner area, the cone has a collecting trough 15. With this construction, the cone proves to be very flexible and resistant. In a further embodiment, the conical region 4 is asymmetrical to the central plane 5 of the pneumatic tire. Further embodiments are possible with different long edges 6, as in the third variant, with a flattened central cone-shaped portion 4 as in _the second variant, ""-'und with a stair-like central region 4 of the cone as in the fourth variant. The eleventh and twelfth variants are shown in FIGS. 11 and 12, respectively. They are based on the tenth variant, but differ from this in that they use holes 18 in the hard-wearing material 16. While in the eleventh variant, the conical region 4 of the pneumatic tire has one or more rows of holes in the hard-wearing material 16, which are formed by holes 18 are marked, the twelfth variant shows a combination of holes 18 and cavities 17. In FIGS. 11a and 12a, partial views of the conical region 4 of the pneumatic tire are shown. One or more rows of holes with regularly or irregularly arranged holes 18 are embedded in the durable material 16 symmetrically to the central plane 5 of the pneumatic tire in order to improve the elastic behavior of the cone. In addition, in the twelfth variant (see FIG. 12a), regularly distributed cavities 17 are arranged in order to combine the advantages of the tenth with those of the eleventh variant. The cross sections indicated by the letter b are shown in Fig. 11b and Fig. 12b. They have the same orientation as the main cross sections in FIGS. 11 and 12 and show the regular arrangement of the holes 18 or the cavities 17 within the hard-wearing material 16. In further embodiments, the conical region 4 is asymmetrical to the central plane 5 of the tire. Furthermore, embodiments with flanks 6 of different lengths as in the third variant, with a flattened central conical region 4 as in the second variant and with a stair-like central region 4 of the cone as in the fourth variant are possible.

The proposed tire tread has significant advantages over the widespread and pneumatic tires described in the patent literature. The cone-shaped area 4 enables the tire profiles presented to make a good compromise between a desired good one Grip and the resulting undesirable rolling resistance. In addition, the conical area 4 increases the vehicle suspension and thus the driving comfort due to its elasticity. If the acceleration changes during braking or starting, the cone deforms inward due to the high forces that occur and thus increases the proportion of the tread pattern 1 that is in contact with the roadway. The interface between the tread pattern 1 and the roadway takes shape during accelerated driving which can be described as a central contact surface with two D-shaped domes. This behavior of the pneumatic tire during accelerated driving can be described as a double D effect. No high forces occur during the non-accelerated drive, so that the cone retains its original shape. This keeps the contact area between the road surface and the tire tread and the rolling resistance small. Overall, this can reduce fuel consumption. In addition, the possibility of additional stabilization of the tire tread by recessed coated metal bands is particularly noticeable in the curve area. As a result, the greater shear forces occurring in the curve area can be better absorbed, deformations avoided and the durability of the tire increased.

Claims

claims 1. Tire profile for a pneumatic tire, characterized in that the tread (2) with slats provided (3) of the tire profile in the central region of the tire profile one or more symmetrical or asymmetrical to the central plane (5) of the pneumatic tire (s), conical has outwardly arched area (s) (4). 2. Tire tread according to claim 1, characterized in that the tire tread in the central area of the / the conically outwardly curved areas (s) (4), on the flanks (6) of this / these areas (s) and in the remaining area a different Can have thickness. 3. Tire tread according to one of the preceding claims, characterized in that the tip of the / the conically curved areas (s) (4) is flattened. 4. Tire profile according to one of the preceding claims, characterized in that the flanks (6) have a different length, so that the tread (2) in the central area is no longer perpendicular to the central plane (5) of the pneumatic tire and / or the flanks (6) have one or more stair-like gradations that are symmetrical or asymmetrical to the central plane (5) of the pneumatic tire. 5. Tire profile according to one of the preceding claims, characterized in that a central web (7) is provided, which the approach of the flanks (cone-shaped outwardly curved region (s) (4) to 6) on the externally curved region (s) (4th ) to 6) on which stabilization connects. 6. Tire profile according to claim 5, characterized in that the central area between the / the konusför ig outwardly curved area (s) (4) and the central web (7) is connected via a channel to an outwardly leading valve for adjusting the air pressure in this area. 7. Tire profile according to one of the preceding claims, characterized in that the central region of the / the conically outwardly curved regions (s) (4) and / or the flanks (6) made of a more durable material (11) than the rest of the tire profile are manufactured. 8. Tire profile according to one of the preceding claims, characterized in that in the / the conically outwardly curved region (s) (4) in the tread one or more metal strip / metal strips (8) with a casing (9), the / the is / are symmetrical or asymmetrical to the central plane (5) of the tire, is / are provided for stabilization. 9. Tire profile according to one of the preceding claims, characterized in that the / the cone-shaped outwardly curved (n) area (s) (4) for stabilization by transverse webs (13) connected slats of different lengths (12) in the connecting area remaining tread (2) on the lower part are spiral, wave, angle or wrinkle-shaped, and there is the connection area between the slats (12) and the remaining tread (2) is designed as an inwardly curved trough (15). 10. Tire profile according to one of the preceding claims, characterized in that the / the cone-shaped outwardly curved area (s) (4) flanks (6) made of a durable material (16) with regular therein arranged / cavities (17) and the / the inner area (s) of the cone-shaped outwardly curved area (s) (4) (a) arched trough (s) (15) has / on iron. 11. Tire profile according to one of the preceding claims, characterized in that the / the cone-shaped outwardly (n) region (s) (4) flanks (6) made of a hard-wearing material (16) / have symmetrical to the central Level (5) of the pneumatic tire one or more rows of holes with regularly or irregularly arranged holes (18) is / are inserted, and the inner area (s) of the cone-shaped outwardly curved area (s) (4) (a) curved collecting trough (s) (15). 12. Tire tread according to one of the preceding claims, characterized in that the / the cone-shaped outwardly (n) region (s) (4) flanks (6) made of a hard-wearing material (16), in the symmetrical to the central Plane (5) of the tire is regularly arranged cavities (17) and one or more rows of holes with regularly or irregularly arranged holes (18) is / are, and the inner (n) area (s) of the cone-shaped outwards Areas (s) (4) (a) arched trough (s) (15) has / have. CHANGED REQUIREMENTS [Received at the International Bureau on September 17, 2001 (September 17, 2001); original claims 1-12 replaced by new claims 1-11 (2 pages)] 1. Pneumatic tires with - A tread (2) with slats (3) provided thereon, the profile of which in a central area has at least one conically curved area (4), characterized in that each curved area is formed by curving the tire material in the area to the outside , 2. A pneumatic tire according to the preamble of claim 1, characterized in that each curved area (4) has flanks (6) made of a hard-wearing material (16) with cavities (17) arranged therein and an inner area of each cone-shaped curved area towards the outside ( 4) has a curved collecting trough (15). 3. A pneumatic tire according to claim 1 or 2, characterized in that the tire tread in the central area of each conically curved area (4), on the flanks (6) of this area and in the remaining area can have a different thickness. 4. A pneumatic tire according to one of the preceding claims, characterized in that a tip of each conically shaped region (4) is flattened. 5. Pneumatic tire according to one of claims 3 or 4, characterized in that the flanks (6) have a different length, so that the tread (2) in the central region is no longer perpendicular to the central plane (5) of the pneumatic tire and / or the flanks (6) have one or more stair-like gradations that are symmetrical or asymmetrical to the central plane (5) of the pneumatic tire. 6. A pneumatic tire according to one of claims 3 to 5, characterized in that a central web (7) is provided which connects an attachment of the flanks to one another at the conically curved region (4) for stabilization. 7. A pneumatic tire according to claim 6, characterized in that a central area between each conically curved area (4) and the associated central web (7) is connected via a channel with a valve leading to the interior of the tire for adjusting the air pressure in this area. 8. A pneumatic tire according to one of the preceding claims, characterized in that the central region of each conically curved region (4) and / or its flanks (6) are made of a more durable material (11) than the rest of the pneumatic tire. 9. A pneumatic tire according to one of the preceding claims, characterized in that in the at least one conically curved area (4) in the tread at least one metal band (8) with a casing (9) which is symmetrical or asymmetrical to the central plane (5th ) of the pneumatic tire is provided for stabilization. 10. A pneumatic tire according to one of claims 2 to 9, characterized in that at least one row of holes with regularly or irregularly arranged holes (18) is embedded in the flanks (6) symmetrically to the central plane (5) of the pneumatic tire. 11. A pneumatic tire according to the preamble of patent claim 1, characterized in that the at least one region (4) that is curved conically outwards consists of lamellae of different lengths (12) connected for stabilization by transverse webs (13). spiral, wave, angle or wrinkle-shaped are formed on the lower part, and the connection area between the slats (12) and the rest of the running surface (2) is designed as an inwardly curved collecting trough (15). DECLARATION REFERRED TO IN ARTICLE 19 (1) The new claims have been delimited from US 5,810,953 and instead of the tread pattern they claim a pneumatic tire with a special tire profile. In contrast to US Pat. No. 5,810,953, where the curved area is designed as a full-walled attachment on the tread and does not protrude from it (column 4, line 43), the figures in this application clearly show that the curved area is formed by the tire material being curved outwards is. The new claim 2 is based on the combination of the original claims 1 with 10. The new claims 3 to 10 correspond to the original claims 2 to 8 and 1, with adjustment of the back reference. The new claim 6 was adapted to the description on page 6, paragraph 4. The new claim 11 corresponds to the combination of the original claims 1 with 9. This application is based on the unified inventive idea of creating a tire with good traction and advantageous rolling resistance by arching out a tire area that is not fully walled, which increases driving comfort due to its elasticity.