1185results about "Heavy duty tyres" patented technology

A tire has an axis of rotation. The tire includes two sidewalls extending radially outward and a tread disposed radially outward of the two sidewalls and interconnecting the two sidewalls. The tread includes a main portion comprising a first compound and a reinforcing structure comprising a second compound having reinforcing short fibers oriented between −20 degrees to +20 degrees to a circumferential direction of the tread. The main portion of the tread includes at least one circumferential groove separating circumferential ribs. Each circumferential groove has two sides and a base therebetween. The reinforcing structure includes a layer of the second compound secured to the sides of each circumferential groove.

A heavy-duty tire comprises a tread portion provided with at least three circumferentially continuously extending ribs divided by at least two circumferential grooves extending straight in the tire circumferential direction, wherein the ribs have side edges adjacent to the circumferential grooves; each of the side edges is provided with edge sipes at intervals in the tire circumferential direction; each of the edge sipes extends parallel with the tire axial direction from the adjacent circumferential groove and terminates in the rib; each of the edge sipe has an axial length in a range of not less than 5% but not more than 15% of the axial width of the rib, a thickness in a range of not less than 0.3 mm but not more than 1.0 mm and a depth in a range of not less than 50% but not more than 100% of the depth of the circumferential groove; and the total number of the edge sipes per tire is in a range of from 4 to 8 times the value of the tire diameter in millimeter.

The present invention provides a pneumatic tire that inhibits any fatigue rupture at an edge portion of a circumferential-direction reinforcing belt layer and also inhibits any separation at an edge portion of crossed belt layers. In the pneumatic tire, at least two crossed belt layers are disposed on the outer circumferential side of a carcass layer in a tread portion. At least one circumferential-direction reinforcing belt layer with a width smaller than those of the crossed belt layers is disposed between the crossed belt layers. Moreover, a stress relaxation layer of a rubber composition having a fixed thickness is disposed between the crossed belt layers while lying adjacent to an edge portion of and outside, in the width directions of, the circumferential-direction reinforcing belt layer.

A vehicle tire has outer shoulders and two tread halves. The vehicle tire includes a tire tread having six block rows and a plurality of circumferential grooves. Mutually adjacent ones of the block rows are separated from each other by a corresponding one of the plurality of circumferential grooves. Each of the block rows has a plurality of individual blocks and the individual blocks of each of the block rows are separated from each other by mutually parallel essentially straight transverse grooves running at an angle to the axial direction of the tire. The circumferential grooves includes first circumferential grooves having a maximum profile depth and second circumferential grooves. The block rows are arranged such that each tread profile half has two pairs of block rows. The pairs of block rows of each tread profile half are separated from each other by a corresponding one of the first circumferential grooves. The block rows of each of the pairs of block rows are separated from each other by a corresponding one of the second circumferential grooves. The second circumferential grooves have a second profile depth less than the maximum profile depth. A first portion of the transverse grooves defines first outlet locations to the first circumferential grooves and a second portion of the transverse grooves has first outlet locations to the outer shoulders. The transverse grooves have a depth approximately corresponding to the maximum profile depth at the first outlet locations. The transverse grooves define second outlet locations to a corresponding one of the second circumferential grooves. The transverse grooves have a depth corresponding to the second profile depth at the second outlet locations.

It is a subject to restrict occurrence of deficient moldings and to improve the bead durability without harming the advantages provided through a bead wind structure, and for this purpose, a ply turn-up portion of a carcass comprises a winding portion, which continues from a main portion that is bent along a bead core, which extends while being spaced from the bead core, and which inclines at an angle θ that is smaller than 90°. A height of a tip end of the winding portion from an outer surface of the bead core is 3 to 15 mm. A cushion rubber having a complex elastic modulus E1* at 70° C. of 2 to 25 MPa is disposed in a region surrounded by a ply main body portion of the carcass, the bead core and the winding portion.

A vehicle tire inflation system includes an air supply source in fluid communication with multiple tires of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the tires. Means are fluidly connected to the pneumatic conduit for enabling selective inflation and deflation of the tires. The means include a first pneumatic circuit for inflation of the tires, and a second pneumatic circuit for deflation of the tires. The second pneumatic circuit is discrete from the first pneumatic circuit and is common to more than one of the tires. The means provides controlled deflation of the tires in the second pneumatic circuit based upon a predetermined condition, preventing deflation of the tires until the vehicle is parked, or limiting the deflation of the tires, which in turn enables the tire inflation system to accommodate a desirable increased pressure in the tires.

Wet performance and partial wear resistance of a tire are improved, and a noise generated during running of the tire is reduced.

At a tread portion 2, a plurality of land portions 20, 30, and 40 is defined by circumferential main grooves 10 and 11 extending in a zig-zag manner in a tire circumferential direction. In the center land portion 20 and the second land portion 30, a plurality of hexagonal blocks 21B, 22B, 23B, and 30B is provided, each gradually expanding to the both sides in the tire width direction from the both end portions in the tire circumferential direction toward the center. In the center land portion 20, the plurality of hexagonal blocks 21B, 22B, and 23B is arranged so as to be brought close to each other in the tire width direction while sandwiching a circumferential thin groove 24 extending in a zig-zag manner in the tire circumferential direction and to be defined by lug grooves 25, 26, and 27 in the tire circumferential direction. In the second land portion 30, the plurality of hexagonal blocks 30B is arranged so as to continue in the tire circumferential direction while sandwiching a sipe 31, and formed in a rib shape continuous in a ground-contacting surface.

A heavy duty tire comprises a bead filler disposed in each bead portion (4). The bead filler (8) comprises: a main layer (13) having a complex elastic modulus E*2 of from 2.0 to 6.0 Mpa; and a fastening layer (12) having a complex elastic modulus E*1 of from 20 to 70 Mpa. The fastening layer comprises a base portion (12B) and an axially inner portion (12A) to have a L-shaped cross section. The height Ha of the axially inner portion (12A) is 35 to 100 mm and not more than the height Hb of the main layer (13), and the radial height Hb is 40 to 100 mm, each from the bead base line. The thickness of the axially inner portion (12A) gradually decreases towards the radially outside so that, when measured along a straight line X1 drawn perpendicularly to the axially outer surface of the bead filler from a point P1 thereon at a distance of 25 mm radially outward from the bead base line: the thickness Tb from the axially outer surface of the bead filler to the interface between the axially inner portion (12A) and the main layer is 7.0 to 13.0 mm; the thickness Ta from the interface to the axially inner surface of the axially inner portion (12A) is 1.0 to 4.0 mm; and the ratio Ta/Tb is 0.1 to 0.35.

The present invention is directed to a pneumatic tire 1 comprising at least one pair of parallel annular beads; at least one carcass ply 3 wrapped around said beads; a tread 5; and first and second sidewalls disposed between said tread and one of said at least one pair of beads; as well as a belt portion 7 between the carcass ply 3 and the tread 5. In accordance with the invention, the tread 5 comprises a tread base layer 8 and a plurality of tread blocks 9, wherein the tread blocks 9 comprise at least two different rubber layers 15, 17, 19 arranged radially above each other, whereas the rubber layers 15, 17, 19 of different tread blocks are axially separate from each other.

An object of the present invention is to provide a tire for heavy load, which exhibits good performances in both fuel efficiency and drainage. One example of the pneumatic tire comprising a tread portion and a pair of circumferential main grooves formed in a ground contact surface of the tread portion to section the ground contact surface of the tread portion into the central region and respective side regions, wherein the tire further comprises three circumferential narrow grooves formed in the central region to demarcate four rib-like center land portions in the central region; and the central region has a structure in which openings of the circumferential narrow grooves are closed so that the rib-like center land portions adjacent to each other with the circumferential narrow grooves therebetween are in contact with and thus supported by each other when the tire is in contact with the ground.

Provision of a tire with enhanced wet weather performance while maintaining resistance to uneven wear performance without entailing an increase in the tread rubber volume. A center block row (30) is formed extending along the tire circumferential direction U in a tread section (18). Blocks (33) configuring the center block row (30) when viewed from the tread face side are formed with long sides (34H) adjacent to respective main grooves (20L), (20R) and short sides (34S1), (34S2). Cutout portions (21) are formed in the blocks (33) on the sides of the long sides (34H).

A pneumatic tire construction is described suitable for severe loading conditions. The tire includes a bead portion further having an apex which extends radially outward of the bead core, and a first turnup pad located adjacent said chafer, and a second turnup pad located adjacent said first turnup pad, wherein the first turnup pad has a G′ less than the G′ of the second turnup pad. Alternatively, the first turnup pad may be located adjacent to the rim flange and the second turnup pad may be located axially inward of the first pad. The second turnup pad is preferably thicker and longer than the first turnup pad.

The present invention provides structures on the tread of a tire that improve the evacuation of mud, soil and the like. In particular, different tread features are provided that may improve the evacuation of mud, soil and the like by themselves or by strategically combining them. These different tread features may be tested to see how they affect mud evacuation at different rotational speeds by a test apparatus that mimics the performance of a tire. For example, a tread that has offset shoulder tread blocks, which shows good mud evacuation at lower speeds, may be combined with shoulder grooves with pockets that show good mud evacuation at intermediate speeds to see if this combination provides a solution that has the lowest change of speed necessary to evacuate 50-87% of the mud found in the grooves.

A heavy duty pneumatic tire is provided in the tread portion with six land portions (crown, middle and shoulder) divided axially by five main grooves. Each land portion is divided into blocks by axial grooves (crown, middle and shoulder). Each axial groove is provided with a tie bar. The tie bar in the shoulder axial groove is largest in the protruding height. The maximum widths Wcr, Wmi and Wsh of the crown, middle and shoulder land portions satisfy; 0.9=<Wmi/Wcr=<0.98 and 1.1=<Wsh/Wcr=<1.22.

An object of the present invention is to provide a tire for a construction vehicle which suppresses a trouble of the tire by enhancing a heat-radiation characteristic of a tire center portion.

A tire for a construction vehicle according to the present invention is provided with a plurality of lug grooves 22 in tread shoulder regions located at the both sides in the width direction of the tire. A plurality of widthwise-extending narrow grooves 24 extending generally along the width direction of the tire and having an end in the width direction of the tire terminated in the tread are disposed in a tire center portion C. This may improve the wear resistance characteristic and to enhance the heat-radiation characteristic by suppressing the decrease of the rigidity of the land portion. In addition, an equatorial shallow groove 26 extending in the circumferential direction of the tire is disposed on the tire equator CL. This allows the compressive stress acting on the tire center portion to be relaxed and the area for hear-radiation to be increased.

A heavy duty tire includes a tread portion with a pair of circumferentially extending crown main grooves and a pair of circumferentially extending shoulder main grooves to form a crown land portion, a pair of middle land portions and a pair of shoulder land portions, wherein crown main grooves have groove widths of 2-5% of a tread half width, shoulder main grooves have groove widths of 6-9% of the tread half width, crown lateral grooves are provided on the crown land portion to form a plurality of crown blocks, middle lateral grooves are provided on middle land portions, shoulder lateral grooves are provided on shoulder land portions, crown and middle lateral grooves have groove widths of 0.4-2.0 mm, and shoulder lateral grooves have groove widths of 6-9% of the tread half width.

A method for fitting tires (P) to a driving axle of a vehicle carrying heavy loads, which consists, after having determined the type of journey made by said vehicle, in:

• • when the route is of type A (ascending under load with a driving torque and descending empty with a braking torque), fitting to each driving axle tires such that for each transverse groove (31) in the edge portions (B) of the tread (1), the angle of inclination of the rubber faces (310, 311) delimiting the transverse grooves (31) which first come into ground contact is smaller than the angle of inclination of the rubber face opposite delimiting the same transverse groove, or
  • when the route is of type V (ascending empty and descending under load with a braking torque), fitting to each driving axle tires such that for each transverse groove (31) in the edge portions (B) of the tread, the angle of inclination of the rubber face (310, 311) delimiting said transverse groove which first comes into ground contact is larger than the angle of inclination of the rubber face opposite delimiting the same transverse groove. A tire (P) appropriate for implementing the method described.

A circumferential sipe extends continuously in the circumferential direction of the tire in the center region of the tread surface section of a rib defined between circumferential grooves. Widthwise sipes are disposed at prescribed intervals in the circumferential direction of the tire in the tread surface section, the widthwise sipes extending in the widthwise direction of the tire in crossing relationship to the circumferential sipe, the widthwise sipes each having opposing terminal ends open to the circumferential grooves. The circumferential sipe changes in depth periodically in such a manner that the circumferential sipe is shallow between adjacent widthwise sipes. The widthwise sipes changes in depth in such a manner that they are greater in depth in the center region and end regions of the tread surface section.

A pneumatic tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions with a bead core therein, and a carcass ply extending between the bead portions through the tread portion and sidewall portions and wound around the bead core in each of the bead portions from the axially inside to the axially outside of the tire so as to form a pair of wound portions and a main portion therebetween, wherein the bead core has a cross sectional shape elongated in a direction substantially parallel to the bottom of the bead portion so that the width (WC) thereof measured in this direction is in a range of from 1.5 to 2.5 times the height (HC) thereof measured perpendicularly thereto, and the bead core is covered with a high modulus rubber layer having a complex elastic modulus E*1 of from 20 to 100 Mpa and a thickness t1 of from 0.5 to 3.0 mm.

A heavy duty tire comprises a tread portion provided with a central circumferential groove, a crown circumferential groove on each side thereof and crown axial grooves extending therebetween so as to for crown blocks. The crown block is circumferentially subdivides into two block pieces by a crown narrow groove. The crown axial groove is provided in the groove bottom with a tie bar rising therefrom and connecting the circumferentially adjacent two crown blocks each other. The crown axial grooves are inclined at an angle α of from 10 to 30 degrees with respect to the tire axial direction. The central circumferential groove and an axially inner part of the crown axial groove which part is axially inside the tie bar, are shallower than the crown circumferential groove.

A pneumatic tire has a tread pattern designed to provide improved heat dissipation properties, wear resistance, and uneven wear resistance. The tire has arranged in a tread (2) two circumferential fine grooves (10) disposed on opposite sides of the equatorial surface (CL) of the tire and extending in the circumferential direction of the tire, and the circumferential fine grooves (10) define a center land section (11). In the center land section (11) are formed oblique fine grooves (12) each having a first small groove (13) extending in the tire's circumferential direction, a second small groove (14) extending obliquely relative to the circumferential direction from one end of the first small groove (13) toward one circumferential fine groove, and a third small groove (15) extending obliquely relative to the circumferential direction from the other end of the first small groove (13) toward the other circumferential fine groove.

In a pneumatic tire, a belt layer includes six superposed belt members. The edge of the fourth belt member on the tire-width direction outer side and the edge of the sixth belt member on the tire-width direction outer side are at approximately the same position in a tire width direction.

A pneumatic tire has a unidirectional tread pattern. The land ratio of an imaginary crown region 5A is 0.75 to 0.85. The land ratio of an imaginary middle region 6A is 0.65 to 0.75. Crown axial grooves 4A and middle axial grooves 4B are inclined to the intended tire rotational direction toward the axially inside of the tire. The widths of the crown axial grooves 4A and the middle axial grooves 4B are 4.0 to 7.0 mm. The width of the crown axial grooves 4A is more than the width of a central main groove 3A and less than the width of middle main grooves 3B.