JPS628324B2 - - Google Patents

Abstract

A tire 10 capable of operation inflated and deflated comprises shoulder portions 14 extending axially outward and radially inward from the tread portion to terminate in junction portions 22 from which sidewalls 16 extend axially and radially inward to rim-seating portions 18. The sidewalls 16 are shaped as shown such that inflation pressure causes them to be in compression between the rim 20 and junction portions 22, the tire having a reinforcement 30 extending from one portion 22 to the other. The shoulder portions 14 are reinforced on one or, as shown, both surfaces by a plurality of circumferentially spaced ribs 49 disposed in radial planes or at up to 10 DEG thereto, and one or more circumferentially annular ribs 53 may also be positioned on the exterior surface of each junction portion 22 to further reinforce the tire. The reinforcement 30 comprises a ply 32 which has cords disposed at 35-55 DEG to the circumferential and is folded around annular members 35 of elastomer or fibrous material, cross-laid plies 45, 46 being superposed on the ply 32. <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to compression sidewall tires, particularly tires suitable for running in deflated conditions.

Conventional pneumatic tires have a layered reinforcing structure that extends around a skeleton from bead to bead. Without such reinforcement, the tire tends to bulge outwards without tightening when its cavity is pressurized. In recent years, compression sidewall tires have been developed that do not require reinforcing cords in the sidewall and bead areas. Since these areas do not have such codes, the manufacture of this tire is
It is particularly suitable for methods such as casting, injection or injection molding.

In this compression sidewall tire, the outer wall is configured such that its radial cross section has a concave outer surface and a convex inner surface. As used herein, "radial surface" is the surface that encompasses the axis of rotation of the tire. When operating a compression sidewall tire, the sidewall is tightened between a rim at one end and a tightening device, such as a treadle belt, at the other end. When the tire cavity is inflated to normal inflation pressure, internal forces due to air pressure against the sidewall tend to compress the elastic material of the sidewall. If the elastic material is compressed beyond a certain point, the internal forces cause the sidewalls to expand axially outward. Therefore, the sidewalls must have sufficient flexural stiffness, curvature, and thickness, in accordance with good design practice, to resist the forces created here so that the sidewalls are clamped. Must be.

As with conventional tires when driving deflated, the first problem seen with compression sidewall tires is
When a tire moves through its tire footprint,
During the travel interval of each part of the tire, there is a destructive heat generation resulting from the friction of the inner surface of the tire. Another problem with compression sidewall tires running deflated is the friction of the shoulder and sidewall portions against the ground. This friction occurs because the shoulder and sidewall portions radially inward of the tread have a circumference that is smaller than the circumference of the tread. All parts of the tire must move at the same angular velocity, so the linear velocity of the sidewall and shoulder parts that contact the ground when the tire deflates must be greater than the linear velocity of the tread. Therefore, friction of the side walls and shoulders with the ground occurs under these conditions.

In the structure of the present invention, the tire is reinforced to minimize the wear and friction effects seen in deflated tires. The shoulders of the tire also extend outwardly, and the sidewalls fold in an orderly manner when driving in a deflated condition, and are located axially outwardly from the rim seating surface. As used in this specification and claims, the term "axial" refers to a direction along a line parallel to the axis of rotation of the tire. The term "radial" refers to the direction perpendicular to the axis of rotation of the tire.

When internal contact of the portions of the tire occurs during deflated use, the tire is configured such that this contact occurs primarily between the sidewall and the shoulder. Because the shoulders are configured to extend radially inwardly from the treads, wear between the inner surfaces is reduced. The shoulder also includes stiffening ribs to keep the tire from contacting the ground during use in the deflated condition. This helps eliminate friction while minimizing weight increase. To maintain the upright character of the shoulder, ring reinforcement is provided where the sidewall and shoulder meet (junction). This "ring reinforcement" refers to the reinforcement that occurs when a band or ring is placed around an object. This ring reinforcement also serves to tighten the side walls.

Briefly, one aspect of the present invention is an annular body made of an elastic material, a circumferentially extending ground-contacting tread portion on the outer periphery of the body, and a pair of joint portions connected to the tread portion and extending from the tread portion. a pair of shoulder portions extending axially outwardly and radially inwardly from said joining portion to a pair of spaced apart attachment portions for attachment to the rim; a pair of side walls extending inwardly in the direction;
a circumferentially continuous reinforcing layer structure extending between the joint portions; a plurality of circumferentially spaced reinforcing ribs on at least one surface of each shoulder portion; extending from the tread portion to the tread portion, and includes a tire suitable for running in an inflated state and a deflated state.

Another aspect of the invention includes an annular body made of a resilient material, a circumferentially extending ground contacting tread portion at the outer periphery of the body, joined to the tread portion;
a pair of shoulder portions extending axially outwardly and radially inwardly from the tread portion to a pair of joint portions; and a pair of spaced apart mounting portions from the joint portions for attachment to the rim. a pair of side walls extending radially and axially inwardly to;
a circumferentially continuous reinforcing layer structure extending between the joints; and at least one circumferentially continuous reinforcing rib on an outer surface of each joint, the rib extending completely around the tire. It includes tires suitable for running in both inflated and deflated conditions.

Yet another aspect of the invention includes an annular body made of an elastic material, a circumferentially extending ground-contacting tread portion on the outer periphery of the body, and a pair of joint portions connected to the tread portion and extending from the tread portion. a pair of shoulder portions extending axially outwardly and radially inwardly from said joining portion to a pair of spaced apart attachment portions for attachment to the rim; a pair of side walls extending inward; a reinforcing layer structure continuous in the circumferential direction extending between the joint portions; and the reinforcing layer structure comprising at least two reinforcing cords extending from the step portion to the joint portion. overlapping layers, the cords of one layer of the overlapping layers being in an opposite directional relationship to the cords of the other layer of the overlapping layers, and the cords of the overlapping layer being in contact with the circumferential surface of the tire. against 35
The tire is positioned at an angle of ~55° and encompasses tires suitable for driving in both inflated and deflated conditions.

According to yet another aspect of the invention, a compression sidewall tire suitable for running in a deflated condition is provided.

According to yet another aspect of the invention, a tire is provided that is easily manufactured by methods such as casting, injection, or injection molding.

According to yet another aspect of the present invention, a reinforced tire structure is provided that supports shoulders and sidewalls during inflated and deflated conditions.

Referring to FIG. 1, the present invention includes a circumferentially extending ground contacting tread 12, a pair of shoulders 14 joining the tread, and a pair terminating in a pair of mounting portions 18 for contacting a rim 20. The present invention relates to a pneumatic tire 10 having a sidewall 16 of. A pair of joints 22 connect shoulder 14 and sidewall 16. Each of these tire 10 sections is preferably made of a resilient material such as rubber or urethane. The tire 10 is symmetrical about its central circumferential plane MP. The central circumferential plane MP is a plane perpendicular to the axis of rotation of the tire and is the centerline between the two axially outer ends of the tire.

The width of the tread is limited by the axially outer edge of the tire that contacts the ground in the tire's footprint when the tire is under normal inflation pressures and loads. Tire footprint refers to the tread marks left by a tire that makes contact with the ground when it is mounted in the normal way on a normally loaded car and inflated to normal inflation pressure. Normal load inflation pressure is the pressure at which the tire is designed to operate under normal conditions.

Each of the shoulders 14 extends axially outwardly and radially inwardly from the tread surface 12. Each of the side walls 16 has a maximum cross-sectional width SD of the tire 10 at the joint portion 22.
Extending axially outwardly and radially outwardly from each of the respective attachment portions 18 so as to be in a position of . The maximum cross-sectional width of a tire is the transverse plane taken by the radial plane of the tire between the axially outermost surfaces of the tire, excluding text or landmarks, when measured in a line parallel to the tire's axis of rotation. This is the maximum distance between surfaces.
Thus, the joint portion 22 is the axially outermost portion of the tire 10 when the tire is under normal inflation pressures and loads.

As shown in FIGS. 1 and 3, the length of shoulder 14 is approximately the same as the length of sidewall 16, although the lengths of the shoulder and sidewall may vary for design reasons.
Further, the cross-sectional height (Sh) of each side wall 16 is preferably smaller than half of the cross-sectional height SH of the tire 10. The height (SH) of the cross section of this tire 10 is
For the purposes of this specification and claims:
When the tire is under normal inflation pressure and no load is applied, between the radially innermost seating surface of the mounting portion and the radially outermost point on the outside of the tread surface 12. It is the distance along a line perpendicular to the axis of rotation. The radially outermost point of the sidewall is defined as the radially innermost point Y of the cord of the reinforcing layer of the tire. The cross-sectional height (Sh) of each sidewall is perpendicular to the axis of rotation in the radial plane of the tire between the radially innermost seating surface of the mounting part and the radially outermost point of the sidewall. It is the distance along the line.

The sidewall 16 is preferably made of a high modulus of elastic material and has a concave outer surface 27, as shown in FIGS.
and a convex inner surface 29. Tires 10 with sidewall shapes of this type are well known in the art and are commonly referred to as "compression sidewall" tires. The sidewalls 16 have substantially thicker walls than those typically found in conventional tires. The shoulder 14 has a relatively thin wall;
The wall thickness of the shoulder portion is thinner than the thickness of the side wall 16.

The tire 10 also includes a reinforcing layer structure 30 extending between the joint portions 22. This structure 30 has a reinforcing cord layer 32. This layer 32 is the joining part 2
2 and within each junction thereof, the cord layer 32 is folded in overlapping relation around a rigid device or bead 35, forming a radially inner layer 32a and a radially outer layer 32b. Form.
In this embodiment, the bead 35 has an elastic modulus of at least 100 Kg/cm ² at 10% elongation, which strength is greater than the strength of the surrounding elastic material. The bead extends completely circumferentially around the tire 10 and is preferably, but not limited to, made of a resilient material, ie, rubber. for example,
The bead 35 can also be made of fibrous material.
The folded portion of the inner layer 32 in the radial direction around the bead 35 extends in a closed loop around the circumference of the tire 10 to transfer forces from the reinforcing layer structure 30 and between the rim 20 and the interface portion 22. side wall 1
6, effectively forming a rigid folded loop 36. The folding ring 36 is bent and has a concave inner surface 41 and a convex outer surface 43, as shown in FIG.

As shown in FIGS. 1 and 3, a virtually non-extensible annular tread reinforcing breaker structure 44 is located radially inboard of the tread 12. As shown in FIGS. As shown in FIG. 4, this structure 44 has two breaker layers 45, 46 of parallel cords oriented at an acute angle to the central circumferential surface MP of the tire 10. The angle of one layer is oriented in the opposite direction to the angle of the other layer. This annular breaker structure 4
4 extends circumferentially around the tire 10 for reinforcement of the tread 12 and is of conventional construction and of any desired material consistent with good engineering practice. The axial width of the outer breaker layer 45 in the radial direction is substantially equal to the axial width of the tread surface 12.
It is preferably equal and greater than the axial width of the inner breaker layer 46 in the radial direction so that the outer breaker layer overlaps the inner breaker layer in the radial direction.

A radially outer layer 32 extends from the fold ring 36 through the shoulder 14 and is preferably adjacent the axially outer edge of each of the radially inner breaker layers 46 and extends from the radially outer breaker layer 46 . It may extend to a point radially inboard of the tread surface 12 that is axially inboard with respect to the axially outer edge of the layer 45 . If the layer 32 extends axially completely across the crown portion 47 of the tire 10 radially inboard of the tread surface 12, as in this embodiment, the breaker structure 44 may be omitted. When included in breaker structure 44, layer 32
should extend axially inwardly from each shoulder 14 to a position overlapping the respective edge 48 of the annular breaker structure. In such a case, tire 1
Each shoulder section of the 0 is reinforced with a separate layer of reinforcing cord.

In a preferred embodiment of the present invention, the cord angle a of layer 32 is 45° with respect to the central circumferential plane MP of tire 10, but the angle is between 35° and 45°. The angle a of the cords in the radially inner layer 32a of layer 32 is opposite the angle b of the cords in the overlapping radially outer layer 32b of that layer 32. These cords of layer 32 primarily reinforce tire 10 against shear stresses.

Reinforcing devices such as ribs 49 on the shoulder 14 support the shoulder so that the shoulder 14 remains out of contact with the ground when the tire 10 is deflated and under normal loads. The ribs 49, which are made of a solid material such as hard rubber, are located on both the inner surface 50 and the outer surface 51 of the shoulder 14 and are spaced circumferentially around the tire 10, as shown in FIG. Preferably, it consists of a plurality of positioned ribs. The ribs 49 on the inner surface 50 preferably extend from the joining portion 22 along the inner surface of the tire 10 to a position indicated by X in FIG. It is located inside in the axial direction. Preferably, each of the positions X is positioned as follows. That is, position X and the central peripheral surface
The distance D between MP and the tread surface 12 should not be smaller than the distance T between the position X and the outer edge E of the tread surface 12 in the axial direction. Preferably, the position X is positioned such that the distance D is approximately the same as the distance T. position
If the ribs 49 are located closer to the central peripheral surface MP, they will only increase the weight without increasing the effect of lengthening the ribs 49.

The rib 49 on the outer surface 51 of the shoulder 14 is connected to the tire 1.
0 and extending from the joint portion 22 to the outer edge E of the tread surface.

Ribs 49 are made of a resilient material, such as rubber, having properties suitable for reinforcing shoulder 14 as described herein. Examples of suitable materials include a Shore A hardness of 70-85, a static modulus of elasticity greater than 45 Kg/ ^cm2 , a low hysteresis value, and a
There are elastomeric rubber compounds that have compression set values as low as 10% when compressed by 25% in a time test.

Ribs 49 are preferably molded into each surface of tire 10 during curing or vulcanization. However, if desired, and in accordance with good engineering practice, they can be formed by any method and bonded to the respective tire surface in some way, either before or after curing the tire 10.

Referring to FIG. 2, the ribs 49 are spaced such that a plurality of grooves 52 alternate between the ribs 49 to provide a generally wavy appearance to the respective tire surface. Although the ribs 49 are each preferably located on a radial surface of the tire 10, the angle formed by the ribs and the radial surface passing through the ribs varies by as much as 10 DEG in either direction. A preferred cross-sectional shape of the rib 49 is a curved rotating body, as shown in FIG. However, other cross-sectional shapes can also be used, such as triangular or square teeth.

The action of the ribs 49 is to move the shoulder portion in a radial direction, i.e. in a direction approximately perpendicular to the road surface traversed by the tire 10, to prevent contact between the shoulder portion 14 and the ground as the deflated tire moves through the footprint. The purpose is to reinforce the Each of the ribs 49 is arranged to provide the most effective reinforcement with the least amount of material. The geometrical arrangement of the ribs 49 thus provides optimum strength while minimizing and without increasing weight.

To further improve the reinforcing properties of the ribs 49 in the radial direction, the ribs and grooves 52 on the inner and outer sides of the shoulder 14 are spaced congruently so that those on one side face those on the other side. It is located at a distance. Such spacing also prevents the corrugation of the cords of the layered reinforcement structure 30, which would normally occur during the curing process.

"Concordantly spaced apart" means that the ribs 49 and grooves 52 on the surfaces 50, 51 of the shoulder 14 are located opposite each other. As shown in FIG.
The minimum thickness e of the tire 10 at
and a maximum thickness t equal to the sum of the maximum rib thickness t and the maximum rib thickness t. The range of maximum thickness t at shoulder 14 depends on the load and tire dimensions. The ratio of the minimum thickness to the maximum thickness (e/t) is
0.3 to 0.7 is preferred. “Thickness” used here
The term refers to the size of the emitting surface along a line perpendicular to the structure being measured.

The width W of one rib 49 is the distance from one point in the groove 52 to the corresponding point in the adjacent groove. The total width of the number N of ribs 49 arranged horizontally at intervals is W×N
is equal to the product of The 2W/te ratio is preferably in the range of 0.5 to 5.

Referring again to FIGS. 1 and 3, the peripheral rib 53
Three circumferentially continuous reinforcing reinforcing members, such as , are formed on the outer surface of each joint portion 22 to strengthen it. Each rib 53 is attached to the tire 10 to strengthen the wheel.
Extends uninterrupted circumferentially around the . The ribs 53 are spaced apart to provide a corrugated surface and are made of a resilient material of sufficient strength to prevent bulging laterally outward in the axial direction of the tire when deflated during operation of the tire. Made. rib 5
3 also, when the tire 10 is inflated, the joint part 2
2 and the rim 20 to confine the side wall 16. Peripheral ribs 53 are molded to the surface of tire 10 during curing. However, if desired, those peripheral ribs 53 can be formed either before or after curing the tire 10, in a process and manner consistent with good engineering design, and the joining portion 2
It is joined to the surface of 2.

While the tire 10 is running in a deflated state, the side wall 1
6 is bent so that the cross-sectional shape of the tire is effectively as shown in FIG. The side walls 16 are made of an elastic compound such that the modulus of elasticity is not less than 50 Kg/cm ² when measured at 10% elongation. This side wall 1
6 also has a combination of flexural rigidity, curvature and thickness, according to good engineering design, to confine the sidewall between the rim 20 and the joint 22 in all driving conditions of the tire 10. It is determined.

Cutting fibers or the like are provided in the radial ribs 49 and the peripheral ribs 53. Circumferentially extending bar members (not shown) may also be placed between the ribs 49 with cross-joints for further strength.
To reduce wear between the inner surfaces of the tire 10, a suitable lubricant 54 is placed in the cavity of the tire to provide cooling of the tire during deflated driving.

Since it is not necessary to provide the mounting portion 18 with a wire bead as is used in conventional tires, the rim 20 to which the tire 10 is mounted is configured to virtually surround the mounting portion as shown in the drawings, and is further deflated. A device is provided to hold the mounting portion on the rim when the tire is used in this condition.

As shown in FIG.
6 and two outer rings 58,60. The center ring 56 and one of the outer rings 58 or 60 are
Radially inwardly and axially inwardly surrounding each mounting portion 18 at the axially inward and lateral surface locations. Mounting seats 62, 64 are provided on the center ring 56 for sealing the mounting portion 18 to the rim 20 and sealing the tire cavity.

At least three self-locking retention latches 66 spaced around the circumference of the rim 20 secure the rim assembly and hold the outer rings 58, 60 against lateral forces, i.e., axially. to hold against forces acting on it. Additional safety screws (not shown) or similar fasteners may be added to ensure locking of the rim.

Although certain representative embodiments and details have been shown for the purpose of illustrating the invention, those skilled in the art will recognize that various modifications can be made without departing from the spirit and scope of the invention. It will be obvious to those who have done so.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view taken in a radial plane of a tire embodying the invention, the tire being shown mounted on a rim in an unloaded, inflated condition. 2 is an enlarged partial cross-sectional view of a portion of the tire taken along the line - in FIG. 1, and FIG. 3 is a partial cross-sectional view similar to that of FIG. It is shown in the deflated state under a load of . FIG. 4 is a partial view of the tread portion taken along the line - in FIG. 1, with a portion cut away to show the angular relationship of the cord between the breaker and the reinforcing layer. 10...Tire, 12...Ground contact tread, 1
4... Shoulder part, 16... Side wall, 18... Mounting part,
20... Rim, 22... Joint portion, 27... Concave outer surface, 29... Convex inner surface, 30... Reinforcement layer structure, 32... Layer, 32a... Inner layer in the radial direction,
32b... outer layer in the radial direction, 35... bead,
36...Folding ring, 41...Concave inner surface, 43...
... Convex outer surface, 44 ... Annular tread reinforcing breaker structure that does not extend virtually, 45, 46 ... Breaker layer, 46 ... Crown portion, 48 ... Edge of breaker structure, 49 ... Rib, 50 ... Inside of shoulder, 51 ... Outer surface of shoulder, 52 ... Groove, 53 ...
Peripheral rib, 54... Lubricating material, 56... Center ring, 58, 60... Outer ring, 62, 64...
Mounting seat.

Claims (1)

[Claims] 1. An annular body made of an elastic material, a ground-contacting step portion extending circumferentially around the outer periphery of the main body, each axially outer end of the step portion, and axially outward and a shoulder portion extending radially inwardly, a pair of spaced apart mounting portions for mounting over the rim, a side wall extending axially and radially outward from each mounting portion, and each of the shoulder portion and side wall a pair of joint portions connected to the tire, and when the tire is under normal inflation pressure and load, the tire width at the joint portion is the maximum cross section, and the thickness of the shoulder portion is thinner than the thickness of the sidewall; It extends toward the outer circumference of the tire and passes through each shoulder.
and a layer of reinforcing cord extending to at least an axially inward point of the tread; and means for maintaining ground contact on the outside of the shoulder portion when the tire is deflated under normal loads; a plurality of circumferentially spaced ribs on the inner and outer surfaces of each shoulder portion, each rib being disposed at an angle of 0° to 10° with respect to a radial plane of the tire passing through the rib; ribs on the inner surface of each shoulder portion extending from each joint on each axial outer edge of the tread; ribs on the outer surface of each shoulder portion extending from each joint on each axial outer edge of the tread; The ribs on the inner and outer surfaces are in congruent locations such that each shoulder has a minimum thickness equal to the thickness of the shoulder without any ribs formed thereon, and , has a maximum thickness that is the sum of the maximum thickness of the ribs on the inner surface of the shoulder portion and the maximum thickness of the ribs on the outer surface of the shoulder portion,
A pneumatic sidewall tire that runs well in an inflated or deflated state. 2. The pneumatic sidewall tire of claim 1, wherein the ratio of the minimum thickness to the maximum thickness of each shoulder portion is between 0.3 and 0.7. 3 The ratio of twice the width of each rib to the value obtained by subtracting the minimum thickness from the maximum thickness of each shoulder portion is 0.5 to 5.
The pneumatic sidewall tire according to claim 1, which is located between. 4. Beads are disposed at each of said joints, a reinforcing cord layer in each joint is folded to form a fold around one of said beads, each bead being of an elastic material and having an elongation rate.
Pneumatic sidewall tire according to any one of claims 1 to 3, having a modulus of elasticity at 10% of at least 100 Kg/cm ² . 5. A plurality of circumferentially continuous reinforcing ribs are provided on the outer surface of each of the joint parts, and each of the circumferentially continuous reinforcing ribs extends so that the hoop strength is not interrupted with respect to the tire, and the elastic material is ,
Any of claims 1 to 3, constructed to have sufficient strength to limit lateral bulge of the tire axially outward during operation when the tire is deflated. The pneumatic sidewall tire according to any one of the above. 6. A plurality of circumferentially continuous reinforcing ribs are provided on the outer surface of each of the joint portions, and each of the circumferentially continuous ribs extends so that the hoop strength is not interrupted with respect to the tire, and the elastic material is such that the tire is Said circumferentially continuous reinforcing ribs are constructed to have sufficient strength to limit the lateral bulge of the tire axially outward during deflation action, and each of said circumferentially continuous reinforcing ribs has a weight capacity of 50 Kg at 10% elongation. / ^cm2
Claim 1 having a larger elastic modulus
The pneumatic sidewall tire according to any one of items 1 to 3. 7. A plurality of circumferentially continuous reinforcing ribs are provided on the outer surface of each of the joint portions, each of the circumferentially continuous ribs extends so as not to interrupt the hoop strength with respect to the tire, and the elastic material is such that the tire is constructed to be of sufficient strength to limit lateral bulge of the tire axially outward during deflation action, and with beads disposed at each of said joints to provide reinforcement at each joint; The cord layer is folded to form a fold around one of said beads, each bead being of elastic material and having an elongation of at least 100 Kg/cm ² at 10%.
A pneumatic sidewall tire according to any one of claims 1 to 3, having an elastic modulus of . 8. A plurality of circumferentially continuous reinforcing ribs are provided on the outer surface of each of the connecting portions, each of the circumferentially continuous ribs extends so as not to interrupt the hoop strength with respect to the tire, and the elastic material is such that the tire is Said circumferentially continuous ribs are made of sufficient strength to limit the lateral bulge of the tire in the axially outward direction during deflation action, and said circumferentially continuous ribs have an elongation of not less than 50 kg/cm ² at a rate of 10%. having a modulus of elasticity, and a bead is disposed at each of said joint sections, the reinforcing cord layer of each joint section is folded to form a fold around one of said beads, and each bead is made of an elastic material. A pneumatic sidewall tire according to any one of claims 1 to 3, having a modulus of elasticity of at least 100 Kg/cm ² at 10% elongation.