Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/14—Anti-skid inserts, e.g. vulcanised into the tread band
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/0306—Patterns comprising block rows or discontinuous ribs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/14—Anti-skid inserts, e.g. vulcanised into the tread band
  • B60C2011/145—Discontinuous fibres
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24058—Structurally defined web or sheet [e.g., overall dimension, etc.] including grain, strips, or filamentary elements in respective layers or components in angular relation
  • Y10T428/24124—Fibers

Definitions

• the present invention relates to an improvement of treads for tires intended to equip heavy goods vehicles; it relates in particular to the sculpture of these treads.
• This invention is particularly, but not exclusively, intended to be implemented for radial carcass tires and intended for steering axles of heavy vehicles. However, it can also be used for non-steering axles of heavy goods vehicles as well as for off-road vehicles such as agricultural machinery (forestry) or for civil engineering machinery.
• Such tires generally comprise a carcass reinforcement radially outwardly surmounted by a crown belt, itself covered with a tread.
• This tread is provided with a tread formed essentially of ribs of generally circumferential orientation delimited by grooves of the same orientation or blocks delimited by circumferential grooves and transverse grooves or a combination of blocks and ribs. Axially a tread is delimited by edge ribs.
• the present invention proposes to solve the technical problem exposed by allowing to avoid or at least to delay and strongly limit the eraser tear edge ribs, or even the bottom of the groove injury of a guide groove general circumferential load, which may result from severe stress such as climbing or lowering a sidewalk or impacting a sidewalk or other obstacles on the road surface or running surface without changing the geometry of the tread .
• the invention proposes to increase the shear modulus of the elastomeric material which constitutes the tread of the tire by at least a factor of three. reinforcing the gum by short fibers oriented substantially +/- 45 ° to a radial direction of the tire casing and thereby transforming it into a laminated composite material.
• US Patent 1746948 discloses a cross-ply tire tread comprising an elastomeric web comprising long textile fibers wound around a rubber core, these long fibers being inclined with respect to the surface of the tread and are flush with said running surface to form points of attachment to the roadway and thus prevent or delay the slippage of the tire on wet or slippery pavement.
• US Pat. No. 3,057,389 describes a tread of a passenger tire or a cross-ply tire having grooves of longitudinal general orientation and continuous relief in the circumferential direction, the rubber constituting the entire tread. being constituted by a stack of rubber plies reinforced with short textile fibers parallel to each other to increase the resistance of the tire to centrifugal forces tending to cause its destruction at high speed.
• the short fibers oriented parallel to each other may be arranged in the circumferential direction in a plane parallel to a plane tangential to the running surface and in the direction OX (OX being the direction circumferential) or be crossed with each other in a plane parallel to a plane tangential to the running surface and in the direction OY (OY being the direction of the axis of rotation) or the short fibers oriented parallel to each other and arranged in the direction circumferential in a plane parallel to a plane tangential to the running surface and in the direction OX may be between two sheets of short fibers crossed together in a plane parallel to a plane tangential to the running surface and in the direction OY respectively disposed above and below the web comprising the short circumferentially oriented fibers.
• Patent Application WO 2008/027045-A1 discloses a tread for a passenger tire and for a heavy-weight tire having grooves of longitudinal general orientation and a continuous relief in the circumferential direction and teaches that the use for the gum constituting the continuous circumferential ribs of plies or thin layers of rubber reinforced with short glass microfibers parallel to each other and being oriented circumferentially in the direction OX, or oriented in a plane YOZ (that is to say in a perpendicular plane) to the running surface of the tread containing a direction parallel to the direction of the axis of rotation and a direction perpendicular to the axis of rotation oriented according to the thickness of the relief in the direction OZ), are transversely oriented in a direction OY, are oriented substantially at + 45 ° or - 45 ° in a plane XOZ, or oriented at 45 ° in a plane X OY, provides a good compromise of properties, namely increased stiffness without penalizing, or even improving,
• the invention relates to a tire tread provided with a running surface intended to be in contact with a road surface, this tread comprising a tread formed by relief elements separated from one another by grooves, this tread being formed by a rubber consisting of thin layers of rubber stacked against each other, each thin layer comprising short reinforcing fibers parallel to each other in the layer and oriented unidirectionally in the plane of the layer according to the same angle.
• the tread is characterized in that the thin layers are stacked against each other so that the short fibers are crossed between them from one layer to the next.
• the short reinforcing fibers are thus alternately oriented symmetrically from one layer to the adjacent layer in the circumferential direction at an angle ranging in absolute value from 10 ° to 80 ° with respect to a radial direction in the plane of the layer.
• the short fibers are oriented at an angle ranging in absolute value from 30 ° to 60 ° with respect to a radial direction in the plane of the layer.
• the orientation of the short reinforcing fibers may vary in the plane of intersection and not be symmetrical. Similarly a variation of the crossing angle can also be made in the circumferential direction (in a direction tangent to the circumferential direction).
• the short reinforcing fibers are alternately oriented from one layer to the adjacent layer circumferentially at an angle of substantially + 45 ° and -45 ° over the entire width of the tread.
• substantially equal to an angular value, it is necessary to understand an angle that may be different from this angular value of at most 3 ° in absolute value.
• each thin layer reinforced with short fibers is inclined relative to a radial direction (direction perpendicular to the running surface) of an angle at most equal to 45 °.
• the natural or synthetic organic or inorganic fibers known to those skilled in the art and commercially available such as, for example, cotton, rayon, cellulose fibers
• aromatic polyamide fibers such as aramid fibers, for example Kevlar® fibers sold by the company Dupont de Nemours, of aliphatic polyamides such as nylon 46 and nylon 66, made of polyester, polyethylene terephthalate (PET), polyethylene naphthalates (PEN), polyimides, polyvinyl alcohols, carbon fibers, glass fibers.
• the short reinforcing fibers are aramid. May also be suitable for short length wires.
• the reinforcing fibers may have a length equal to or less than 10 mm, advantageously ranging from 5 ⁇ m to 10 mm and preferably ranging from 3 mm to 8 mm, a mean diameter ranging from 0.2 ⁇ m to 0.1 mm, their section may to be circular or not, they may or may not be hollow.
• the fiber content in the gum constituting each layer of oriented fibers can range from 0.1% to 45% by weight of the rubber and preferably from 0.5% to 10% by weight of the rubber.
• any range of values designated by the expression “between a and b” represents the range of values greater than the value a and lower than the value b (ie, limits a and b excluded). while any range of values designated by the expression “from a to b” represents the range of values from the value a to the value b and including the terminals a and b.
• the tires comprising a tread according to the invention are preferably radial carcass reinforcement and particularly intended to equip the steering axles of heavy goods vehicles intended for use related to a regional market for the delivery of goods. They may also be used for non-steering axles of heavy goods vehicles (tractors and trailers), for off-road vehicles such as agricultural (forestry) machinery or for civil engineering equipment operating very often on lots of obstacles or foreign bodies to be crossed and subjecting the tires has large shear forces or other transport or handling vehicles.
• the invention also relates to a tire envelope comprising a tire tread having the characteristics defined above.
• An advantageous embodiment of a tire casing comprising a tread according to the invention consists, thanks to a calendering using a cylindrical tool, to produce unvulcanized elastomer plates containing the short reinforcement fibers, then to cut these plates and to extradite them by means of a micro nozzle to make strips of elastomer in which the short reinforcing fibers are oriented in the direction of the extrasion.
• the tread is then obtained by superposition on a rotary forming drum of several layers, preferably four, strips juxtaposed and alternately arranged at + (plus) or - (minus) 45 °; this stack is then cut in the circumferential direction to produce a number of semifinished product profiles corresponding to the number (n) of rib (s) of reinforced circumferential general orientation (s) chosen for the element (s) in relief of the tread, which sections are contiguously arranged on the raw tire itself arranged on the tire building drum.
• FIG. 1 shows two thin layers each layer comprising fibers oriented either with an angle or with the opposite angle (this stack is noted in the following manner layer + and layer -);
• Figure 2 shows a partial view of a sculpture of a tire tread according to the invention for which the entire strip is formed by a plurality of thin layers + and -;
• Figure 3 shows a plan view of a tread according to the invention that only the edge portions are reinforced with thin layers
• Figure 4 shows an alternative tread according to the invention, the blocks are formed of thin layers.
• FIG. 1 shows two successive layers C1, C2 of rubber material reinforced by short fibers oriented in each layer at a positive angle A, called the layer (+) or at a negative angle B, called the layer. (-).
• FIG. 2 shows an alternative embodiment of a tire according to the invention.
• This tire for a heavy vehicle comprises a tread 1 having a running surface formed by the surfaces radially outwardly of the various elements in relief of which said band is provided.
• the tread is provided with two circumferential grooves 21, these grooves 21 delimiting an intermediate rib 32 and two edge ribs 31, these ribs being circumferentially continuous.
• the tread is formed of a composite material comprising a very large number of layers C1, C2 stacked against each other, each layer being either a layer having short reinforcing fibers oriented at an angle A (layer +) or a layer having short fibers oriented at an angle B (- layer).
• the layers are stacked against each other so that the short reinforcing fibers of each layer are crossed with each other and the stack of layers is made in the circumferential direction (indicated by the arrow T in the figure ).
• Each layer comprises a rubber material in which a plurality of PET short fibers of length equal to 3 mm and of diameter equal to 12 ⁇ m are embedded. the fiber density of each layer is 2% by weight.
• the aramid fiber has also been tested. In the present case, all the short fibers are of the same nature and of the same orientation in absolute value in each layer C1, C2.
• the grooves of this tires have newer depths greater than the average length of the short reinforcing fibers (as a rule, the depths of the truck tire grooves are at least 10 mm).
• Figure 3 shows a variant of the invention according to which, a tread comprises three circumferential grooves delimiting intermediate ribs 32 and edge ribs 31. The latter are located axially at the edge of the tread and they are formed in a composite material as defined by the invention.
• the layers (+) and the layers (-) are arranged so as to make on the rolling surface an angle C with a direction tangent to the circumferential direction (represented by the arrow T in FIG. 2).
• this angle C is, with the sign, the same on both edges and equal to 30 °.
• the tread acquires a kind of directionality by the arrangement of the layers of materials reinforced by short fibers.
• the two intermediate rows between the edge rows are formed in homogeneous materials not reinforced by short fibers.
• FIG. 4 shows another variant of tire according to the invention for which its tread comprises a plurality of blocks 4 delimited by circumferential and transverse grooves 22.
• Each block 4 is formed of a composite material resulting from the stacking in the transverse direction of layers C1, C2 reinforced with short reinforcing fibers, these layers being stacked against each other, so as to alternate the layers having short fibers oriented at a positive angle (+) and the layers having short fibers oriented at a negative angle (-).
• some blocks may be formed by a stack of the same direction as that shown in Figure 3 and the others according to a steering stack as shown in Figure 4.
• the examples described here show thin layers diposées against each other in a radial direction, that is to say not inclined relative to a direction perpendicular to the axis of rotation of the tire.
• the invention covers the variants according to which these thin layers may have a small inclination other than zero with a radial direction to generate, for example, a directional effect.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)
• Reinforced Plastic Materials (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42272097

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (12)

Citations (3)

Family Cites Families (14)

• 2009
  • 2009-12-08 FR FR0958729A patent/FR2953456B1/fr not_active Expired - Fee Related
• 2010
  • 2010-12-03 IN IN4970DEN2012 patent/IN2012DN04970A/en unknown
  • 2010-12-03 US US13/514,555 patent/US20120312439A1/en not_active Abandoned
  • 2010-12-03 EA EA201290472A patent/EA021640B1/ru not_active IP Right Cessation
  • 2010-12-03 WO PCT/EP2010/068881 patent/WO2011069924A1/fr not_active Ceased
  • 2010-12-03 BR BR112012013567A patent/BR112012013567A8/pt not_active IP Right Cessation
  • 2010-12-03 JP JP2012542476A patent/JP5859453B2/ja not_active Expired - Fee Related
  • 2010-12-03 CN CN201080055843.1A patent/CN102753366B/zh not_active Expired - Fee Related
  • 2010-12-03 EP EP10784819.4A patent/EP2509805B1/fr not_active Not-in-force

Patent Citations (3)

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