Patent Application
20130105056
The present invention generally concerns a pneumatic tire, and, more particularly, a pneumatic tire having a modular ply construction.
Tires are complex composites. As such, they contain a multitude of materials which, during manufacturing, are often placed in layers and then bonded together. Of the layers and materials, a tire may contain a ply or a sheet of material that is itself a composite. The ply may contain cords of another material that are radially oriented with respect to the rotational axis of the tire, that is, nominally at about 90° with respect to the centerline of the tread. The ply often extends from one bead to an opposing bead of the tire.
Tires that contain cords that are oriented in this direction are referred to as “radial” tires. This is in contrast to what are known as “bias” type tires in which the cords of the plies criss-cross one another and are oriented at a transverse angle (e.g., around 30° to 40°) relative to the center line of the tread. Thus, the cords in a bias tire are generally oriented more in the direction of the tire's rotation than are the cords in radial tires.
It is well-established that radial tires are, in many respects, superior to bias-type tires. Typically, for example, a vehicle having radial tires rides better, radial tires have better wear and traction than bias type tires, and radial tires are more fuel efficient than bias tires. However, radial tires often require additional belts beneath the tread, generally made of steel, to reinforce the tread.
In this regard, it is common for manufacturers to use two belts to reinforce the tread. Each may be made of steel cords which may be oriented at bias angles relative to the rotational axis. The belts are generally stacked one on top of the other adjacent the ply and are usually offset at each edge to produce a step off. It is known that belts affect vehicle ride and handling characteristics by restricting expansion of the ply cords and stabilizing the tread area. Belts also provide impact and penetration resistance.
However, addition of a belt to a radial tire tread is not without its drawbacks. Aside from an increase in the manufacturing and raw materials costs, a belt increases the weight of the tire and therefore increases the fuel consumption of the vehicle to which it is affixed. Other potential drawbacks include an increase in the running temperature of a tire. The running temperature of a tire ultimately affects the tire's performance.
In view of the above, tire manufacturing is also a complex process that may include applying multiple layers of different materials to a building drum. Once the other components of the tire are placed on the building drum, the layered structure may then be shaped into a general toroidal form of a tire. This so-called “green tire” is cured and molded by application of heat and pressure to obtain the desired tire.
Each of the processes affects the tire's shape. Therefore, it is not surprising, in light of the large number of variables that must be addressed to consistently manufacture tires of like shape and size, that development of a new tire design is often subject to some trial-and-error-type testing. More specifically, among the various steps in the manufacturing process of a radial tire, a ply is placed onto the building drum. During the curing process, when the green tire is molded into its final shape, improper tension in the ply may lead to unacceptable shape variability. To address this issue, the tension in the ply may be adjusted by changing the ply length and the gage of the ply. While appearing simple, the magnitude of the adjustment is often approached in a trial-and-error fashion. Ultimately, the imprecise nature of these adjustments increases the cost and time required to develop a new tire design and bring it to market.
In view of the aforementioned difficulties, there remains a need for a radial tire with improved performance while being more cost effective to develop and manufacture.
In one embodiment, a pneumatic tire for use on a vehicle comprises a first bead and a second bead each configured to anchor the tire to a rim of the vehicle. The pneumatic tire includes a pair of opposing sidewalls forming opposing shoulders and extending radially inward from a tread. A first ply forms a portion of one sidewall. The first ply extends from one shoulder around the first bead from outside to inside, so as to form a first inside turn-up. A second ply, separate from the first ply and forming a portion of the opposing sidewall, extends from the opposing shoulder around the second bead from outside to inside, so as to form a second inside turn-up. A first central ply adjacent the tread extends between and overlaps the first ply and the second ply. A second central ply adjacent the tread and the first central ply extends between and overlaps the first ply and the second ply. The overlap of the first central ply with each of the first and second plies forms a first overlap region separated from a second overlap region, respectively. The first overlap region is proximate the one shoulder and the second overlap region is proximate the opposing shoulder, each of the first and second overlap regions are sized to protect the tire from penetration by road debris during use of the tire. In one embodiment, the pneumatic tire is belt-less.
In one embodiment, the cords of at least one of the first central ply and second central ply is at least one of carbon fibers, or aramid fibers, or combinations thereof.
In one embodiment, a tire set comprises a first tire having a first section width and a first section height, and a second tire having a second section width and a second height. At least one of the first section width and the first section height differs from the corresponding one of the second section width and the second section height. Each of the first tire and the second tire includes a pair of opposing sidewalls forming opposing shoulders and extending radially inward from a tread and a pair of beads configured to anchor the respective tire to a rim on a vehicle.
Each of the first tire and the second tire comprises a sidewall ply forming a portion of each sidewall of the pair of sidewalls and defining an inside turn-up at one edge thereof with an opposing edge extending to a location proximate the corresponding shoulder. A central ply is positioned adjacent each tread and extends between and overlaps the corresponding sidewall plies so as to form at least two overlap regions. One overlap region is proximate each shoulder of each tire. Each of the sidewall plies and the central ply in the first tire are substantially the same width as each of the corresponding sidewall plies and the corresponding central ply in the second tire. At least one of the overlap regions in the first tire is substantially different in dimension from one of the overlap regions in the second tire. The difference in dimension being related to the difference between the first section width and the second section width and/or the first section height and the second section height.
In another embodiment, a method of making tires of different section width and/or section height comprises manufacturing a first tire and manufacturing a second tire. Manufacturing the first tire comprises applying a first set of plies to a first building drum. One ply is configured to form portions of each of a pair of opposing sidewall plies and at least one ply is configured to be adjacent a tread in the first tire. The opposing sidewall plies do not overlap and are spaced apart from each other on the first building drum. The ply adjacent the tread extends between and overlaps each of the sidewall plies.
Manufacturing the second tire comprises applying a second set of plies to a second building drum. At least one of the plies of the second set of plies is from a source of plies used for supplying at least one of the plies of the first set of plies during manufacturing of the first tire. One ply of the second set of plies is configured to form a portion of each of a pair of opposing sidewall plies and at least one ply is configured to be adjacent a tread in the second tire. The opposing sidewall plies of the second set of plies do not overlap and are spaced apart from each other on the second building drum and the at least one ply extends between and overlaps each sidewall ply. The first tire differs in dimension from the second tire in at least one of section width or section height.
“Bead” means a circumferentially substantially inextensible metal wire assembly that forms the core of the bead area, and is associated with holding the tire to the rim.
“Ply” or “Plies” means a calendared fabric thread coated with rubber and wound around at least one bead.
“Carcass” means the tire structure apart from the belt structure, tread, undertread, and sidewall rubber over the plies, but including the beads.
“Green” means material, typically rubber, which has not undergone a curing or pre-curing process.
“Inner Liner” means a molded rubber layer covering the inner side of the carcass and facing the air chamber when the tire is assembled.
“Pneumatic Tire” means a laminated mechanical device of generally toroidal shape, usually an open torus, having beads and a tread and made of rubber, chemicals, fabric, and steel or other materials. When mounted on the wheel of a motor vehicle, the tire through its tread provides traction and contains the fluid that sustains the vehicle load.
“Sidewall” means that portion of a tire between the tread and the bead area.
“Tread” means a molded rubber component which includes the portion of the tire that comes into contact with the road when the tire is normally inflated and under normal load.
The invention will be described by way of example and with reference to the accompanying drawings in which:
To those and other ends, and with reference to
The supporting carcass 16 acts as a supporting structure for the tread 18 during use of the tire 10. To this end, the sidewalls 12a, 12b include multiple separate plies. For example, as shown in
As shown, the sidewall ply 24a has an edge 28a and may extend around the bead 14a with another edge 30a at location proximate the shoulder 20a. The curvilinear distance between the edge 28a and the edge 30a along the sidewall ply 24a in
Similarly, the sidewall ply 24b has an edge 28b and may extend around the bead 14b to terminate at a second edge 30b proximate the shoulder 20b. The curvilinear distance between the edge 28b and the edge 30b along the sidewall ply 24b of
The edges 30a, 30b are thus spaced apart and define a spaced apart region 31 adjacent or beneath the tread 18. By way of example, the spaced apart region 31 may form between about 10% and about 90% of the tread width of a newly constructed tire, and by way of further example, the spaced apart region 31 may form between about 30% and about 70% of the tread width. It will be appreciated, however, that embodiments of the invention are not limited to the particular relative distances shown in
In addition, the sidewall plies 24a, 24b may extend between the shoulders 20a, 20b and the beads 14a, 14b in other configurations. For example, the inside turn-ups 32a, 32b need not be similar in dimension or in configuration to each other, as one or both may extend to a lesser or a greater distance on the inside of the respective sidewall 12a, 12b than that shown. Moreover, it will also be appreciated that the carcass 16 may include other components not shown in
As set forth above, the carcass 16 includes two central plies 26a and 26b adjacent the tread 18. One or both of central plies 26a, 26b may extend between the corresponding sidewall plies 24a, 24b. That is, at least one of the central plies 26a, 26b may span at least the spaced apart region 31 between the edges 30a, 30b. Thus, the combination of the sidewall plies 24a, 24b and one of the central plies 26a or 26b is sufficient to provide the carcass 16 with at least a single ply thickness extending from the bead 14a to bead 14b.
Furthermore, at least one of the central plies 26a and 26b overlaps the sidewall ply 24a and at least one of the central plies 26a and 26b overlaps the sidewall ply 24b. In this regard, the same central ply may overlap both sidewall plies 24a, 24b or may overlap only a single one of the sidewall plies 24a or 24b with the remaining central ply overlapping the other sidewall ply 24a or 24b. However, for example, as shown in
As shown, the overlap regions 36a, 36b are positioned proximate the corresponding shoulder 20a, 20b and may form a substantial portion of the sidewalls 12a, 12b. By way of example, one or both of the overlap regions 36a, 36b may extend toward the corresponding bead 14a, 14b by a distance sufficient to cover up to 90% of the sidewall 12a, 12b, though the overlap regions 36a, 36b are proximate the corresponding shoulder 20a, 20b and may extend at least 10% of the sidewall 12a, 12b. As such, the overlap regions 36a, 36b improve the durability of each sidewall 12a, 12b as the carcass 16 includes at least a double-thick layer of plies at these locations.
In addition or as an alternative thereto, the central ply 26b may extend between the edges 30a and 30b adjacent the tread 18 to cover the spaced apart region 31 between the sidewall plies 24a and 24b. In this regard, the central ply 26b together with the central ply 26a may provide a double thickness of plies beneath the tread 18 in at least the spaced apart region 31. Similar to the central ply 26a, the central ply 26b may have an edge 38a proximate the shoulder 20a such that the central ply 26b may overlap the sidewall ply 24a between the edge 38a of the central ply 26b and the edge 30a of the sidewall ply 24a to form an overlap region 40a. The central ply 26b may also have an edge 38b proximate the shoulder 20b so as to form an overlap region 40b between the edge 38b and the edge 30b. The curvilinear distance between the edge 38a and the edge 38b along the central ply 26b of
With continued reference to
With regard to the relative dimensions of each of the overlap regions 36a, 36b and 40a, 40b, each may be of different dimension depending on the initial relative size of the respective plies and relative placement of the sidewall plies 24a and 24b and central plies 26a and 26b during the manufacturing process, described below. It will be appreciated that the relative size of the overlap regions 36a, 36b and 40a, 40b may be altered to achieve a particular function or enhance a property of the tire 10 in addition to providing the protective function set out above. In this regard, one or both overlap regions 36a, 40a may extend at least about 5% of the tire's section height (distance from the rim contact location to the tread 18). However, one or both overlap regions 36a, 40a may extend from about 10% to about 90% of the section height. Similarly, one or both of the overlap regions 36b, 40b may extend at least about 5% of the section height or from about 10% to about 90% of the section height. And, by way of further example, the overlap regions 36a and 40a and/or 36b and 40b may vary from about 10% to about 50% of the section height. In any respect, the overlap regions 36a, 36b, 40a, 40b extend a sufficient distance toward the respective bead 14a, 14b to provide enhanced protection to the corresponding sidewall 12a, 12b of the tire 10.
While described in additional detail below, with reference to
The cords in the central plies 26a, 26b are biased with respect to the EP. In this regard, the cords in one ply are transverse with respect to the EP or criss-cross in the region beneath the tread 18. This is shown in
In one embodiment, the central plies 26a, 26b collectively replace a steel belt package often used in radial ply tires. The plies 26a, 26b may be adjusted as to both thickness and material type for improved fuel economy, durability, and/or reduction in running temperature. However, the central plies 26a, 26b may not contain steel. The cords may be fibers of one or more of a variety of materials. For example, the cords in each of the sidewall plies 24a, 24b and each of the central plies 26a, 26b may be polyester, aramid, and/or carbon fibers, among others. In this regard, each ply may contain cords of a different material than the other three plies. In addition, the number of cords in each ply may differ according to one embodiment of the invention.
In one embodiment of the invention, a set of tires includes a plurality of tires that differ in at least one of section width and section height, though each of the tires in the set includes at least one ply that is similarly dimensioned and contains the same cord material. For example, a set of tires may include the tire 10, which may be manufactured utilizing a source of plies for any single one of the plies 24a, 24b, 26a, or 26b. A second tire may be manufactured using at least one of the same sources of plies as was used for one of the plies 24a, 24b, 26a, or 26b during the manufacturing of the tire 10.
Regarding tire sizes, a particular tire is made according to industry standard sizes. Standard industry nomenclature is used to indicate tire size. This nomenclature is composed of a series of numbers and letters that are arranged in a predetermined order and may appear on the tire. The series includes information regarding the section width and the aspect ratio, which is a ratio of the section height to section width, of the tire. Generally, the section width is the widest point between the outside surfaces of the sidewalls when the tire is mounted on a rim though the tire is not loaded. The section width is exclusive of any lettering, numbering, or decorative components. The section height is the distance from the rim contact location to outer diameter of the tire at the EP. The section height may be determined from the series by the aspect ratio and the section width. Generally, the larger the section height is, the taller the sidewall of the tire is.
In one embodiment, as introduced above, the set 100 of tires includes the tire 10, shown in
More specifically, a difference in at least one of the section height and the section width of the tires 10, 110, may be achieved according to one embodiment of the invention. To that end, the tire 110 includes opposing sidewalls 112a, 112b, inextensible beads 114a and 114b, a supporting carcass 116, and a tread 118. The sidewalls 112a, 112b extend radially inward from the tread 118 to join the respective inextensible beads 114a and 114b. Opposing shoulders 120a and 120b of the sidewalls 112a and 112b define the width of the tread 118. The tread 118 includes a running surface 122. All of which have similar functions to the functions of the corresponding component of tire 10, shown in
Furthermore, the supporting carcass 116 of the tire 110 includes multiple separate plies. For example, as shown in
The arrangement of the plies 124a, 124b, 126a, 126b relative to one another may be similar to the tire 10 depicted in
Similar to plies 26a and 26b, the central plies 126a and 126b span a spaced apart region 131 between the edges 130a and 130b of the sidewalls plies 124a, 124b and provide a double thick layer of plies adjacent the tread 118. The central plies 126a and 126b also overlap each of the sidewall plies 124a, 124b with one edge 134a, 138a terminating proximate the shoulder 120a and another edge 134b, 138b terminating proximate the shoulder 120b. The curvilinear distance between edges 134a and 134b and between edges 138a and 138b along the corresponding central plies 126a and 126b define the respective width of plies 126a and 126b. In one embodiment, the widths of the plies 126a and 126b are substantially the same and are substantially the same as the widths of plies 26a and 26b of the tire 10 shown in
Overlap regions 136a and 140a are formed proximate the shoulder 120a, and overlap regions 136b and 140b are formed proximate the shoulder 120b. As shown, the overlap regions 136a and 140a are similarly positioned with respect to each other, as are the overlap regions 136b and 140b. However, it will be appreciated that the invention is not so limited, as there may be no need to place the overlapping regions 136a and 140a and 136b and 140b in coinciding locations proximate the corresponding shoulder 120a, 120b. In this regard, the relative positions of the overlapping regions 136a, 136b, 140a and 140b may depend on the width of the respective ply and its placement during tire manufacturing, as described below.
However, at least one of the overlap regions 136a and 140a and 136b and 140b of the tire 110 shown in
Furthermore, it will be appreciated that increasing, or reducing, the overlap regions 136a and 140a and/or 136b and 140b relative to those of tire 10 may change the characteristics of the tire 110. In particular, for an increase in the overlap region dimensions, the tire 110 may exhibit further improved durability when exposed to road debris. That is, the increase in size of the overlap regions 136a and 140a and/or 136b and 140b may extend the region toward the respective bead 114a, 114b and form a larger portion of the respective sidewall 112a, 112b. Thus, the relative increase in the overlap may improve the resistance of the tire 10 to puncture during operation relative to the overlap regions 36a and 40a and/or 36b and 40b in tire 10. In addition, the overlap regions 136a and 140a and/or 136b and 140b may increase the stiffness of the tire 110 relative to the tire 10, particularly in the sidewalls 112a and 112b.
According to another embodiment of the present invention, a method is provided for manufacturing a set 100 of tires including at least two tires differing in section width and/or section height. The difference in section height and/or section width is achieved by changing the overlap between some or all of the plies during the building process. For example, one of the tires of the set 100 may include the tire 10, shown in
The central ply 26b may be applied to the drum 150 first from the spindle 152. However, the central ply 26b may be applied to the drum 150 after the sidewall plies 24a and 24b. Once applied to the drum 150, the sidewall plies 24a and 24b may then be folded over respective beads (not shown) in such a manner as to overlap the central ply 26b and space the edges 30a and 30b of each of the sidewall plies 24a and 24b apart from one another. The central ply 26a is then applied from the spindle 152, when it is determined that the width and cord material for the central ply 26a is to be the same as the width and cord material for the central ply 26b, or from another spindle of ply material to overlap each of the sidewall plies 24a and 24b and central ply 26b. As shown in
As set forth above, the plies 24a, 24b, 26a, and 26b include a plurality of cords. With reference to
As indicated above, during application of the plies 24a and 24b and central ply 26b to the drum 150, areas of overlap between the adjacent plies are created. For example, areas of overlap 142a and 142b may be formed between the sidewall plies 24a and 24b and the central ply 26b. The area of overlap 142a is generally determined by the distance between the edge 30a of the ply 24a and the edge 38a of the central ply 26b with direct contact between the sidewall ply 24a and the central ply 26b between the two edges 30a and 38a defining the area of overlap 142a. Similarly, the area of overlap 142b may be defined by the distance between the edges 30b and 38b and the contact between the central ply 26b and the sidewall ply 24b. These areas may generally correspond, or at least be related, to the dimensions of the overlap regions 40a and 40b, shown in
Additional areas of overlap may include areas 144a and 144b between the central ply 26a and the sidewall plies 24a and 24b. As with areas of overlap 142a and 142b, set out above, the areas of overlap 144a and 144b may each be determined by the distance between the respective edges 30a, 30b of the sidewall plies 24a, 24b and the edges 34a, 34b of the central ply 26a. These areas may generally correspond or at least be related to the dimensions of the overlap regions 36a and 36b. It will be appreciated that numerous other components may be applied to the drum 150 before, during, or after application of the plies 24a, 24b, 26a, and 26b to the building drum 150 though these additional components are not shown. For example, chafers, a liner, a pair of beads, and a tread to name only a few, may be included during the building process described above.
The manufacturing process further includes additional processes by which a tire is manufactured from the set of plies and the other components, as set out above or in an alternative method known in the art. By way of example, the drum 150 may be expanded to cause the above assembly of plies to form a generally toroidal shape (not shown). Additional components may then be added to the toroidal shape to form a green tire. By way of example, additional components may include a tread (not shown). However, as set forth above, no belt packages are included in the green tire. The green tire is subsequently cured in a mold under heat and pressure to form the tire 10. It will be appreciated that there are alternative processes for manufacturing a tire, other than that explicitly described herein. The general description of manufacturing given is thus in no way limiting to the application of the plies described herein. That is, building or layering the plies as described herein may be used in alternative tire building processes known in the art.
Advantageously, the overlapping configuration of the plies 24a, 24b, 26a, and 26b may aid manufacturing of the tire 10, particularly during process development for a new tire. In this regard, the time to develop and costs to bring a new tire design to commercial production may be reduced by utilizing the separate plies 24a, 24b, 26a, and 26b. For example, during curing, the plies 24a and 24b may move relative to the central plies 26a and 26b. This relative movement may change the areas of overlap 142a, 142b and 144a, 144b from the dimensions obtained when the plies 24a, 24b, 26a, and 26b were assembled on the drum 150. A change in dimension of the areas of overlap 142a, 142b and/or 144a, 144b may include relative movement between the edge 30a and the edges 34a, 38a and/or between the edge 30b and the edges 34b, 38b. The corresponding edges may move more closely together or further apart. Consequently, the corresponding overlap regions 36a, 36b, 40a, and 40b in the tire 10 may differ in dimension than the areas of overlap 142a, 142b and 144a, 144b formed during building of the tire by application of the plies 24a, 24b, 26a, and 26b to the drum 150.
Relative movement of the plies 24a, 24b, 26a, and 26b may be beneficial to the tire manufacturing process. In particular, relative movement may reduce the amount of experimentation required to achieve a desired or targeted tire design. This may be further explained by contrast to a green tire which includes a single ply that extends continuously from one bead to the opposing bead. In this situation, the beads hold the ply in position during curing. If the distance between the beads is too close or too far apart, the ply may be too tight or too loose during subsequent curing. As a result, the cured tire may not meet the required quality standards. The building process or design may then require an adjustment to tune the ply tension toward the desired value. Adjustments may include changing the dimension of the ply, such as, the ply width or the gage of the ply. Moreover, many adjustments may be required before the desired ply tension in the tire is realized. According to embodiments of the invention, however, rather than iteratively tuning a single, continuous ply, the overlap areas 142a, 142b and 144a, 144b allow the plies 24a, 24b, 26a, and 26b to self-adjust or float to a natural tension that is determined by the curing mold and the associated pressures and temperature. Thus, as long as there is sufficient overlap of the plies 24a, 24b, 26a, and 26b, they require little, if any, tension adjustment with respect to the ply dimensions, and a drawn out, iterative trial-and-error approach and the costs associated therewith are avoided.
In addition, according to one embodiment of the invention, manufacturing the set 100 of tires includes manufacturing a second tire that differs from the tire 10 in at least one dimension, such as, section width or section height. For example, manufacturing the second tire may include manufacturing the tire 110, shown in
To this end and with reference to
The sidewall plies 124a, 124b for tire 110 may then be applied to the drum 160 and folded so as to overlap the central ply 126b. The sidewall plies 124a and/or 124b may be from the same source 154 of ply material or a different source as the sidewall plies 24a and 24b. In the exemplary embodiment shown, each sidewall ply 24a, 24b, 124a, and 124b has the same width and cord material and thus may be supplied from the same source 154 of ply material.
Similar to the building process of tire 10 described above, areas of overlap 162a and 162b may be formed between the sidewall plies 124a and 124b and the central ply 126b. These areas may generally correspond or at least be related to the dimensions of the overlap regions 140a and 140b, shown in
The manufacturing process further includes additional processes by which a tire is manufactured from the plies 124a, 124b, 126a, and 126b as set out above. By way of example, the drum 160 may be expanded to form a generally toroidal shape (not shown). Additional components may then be added to the toroidal shape to form a green tire (not shown). By way of example, additional components may include a tread (not shown). The green tire is subsequently molded under heat and pressure to cure the green tire and to form the tire 110.
As shown, the section width of the tire 110 differs from the tire 10 though the dimension (e.g. width) of at least one of the plies 24a, 24b, 26a, 26b of tire 10 is similar to the plies 124a, 124b, 126a, and 126b of tires 110. The difference in section width is achieved by variation in the dimension of the areas of overlap 162a and 162b and 164a and 164b relative to one or more of the areas of overlap 142a, 142b and/or 144a, 144b. In particular, a smaller relative section width may be achieved by increasing in the areas of overlap 162a and 164a and/or 162b and 164b during assembly of the plies 124a, 124b, 126a, 126b. It will be appreciated that the dimensions of each of the areas of overlap 162a, 162b, 164a, and 164b may be changed to reduce the section width of the tire 110 relative to that of the tire 10. For example, the dimensions of each areas of overlap 162a, 162b, 164a and 164b may be reduced by an equivalent amount or in a manner that is symmetrical relative to the EP. However, it will be appreciated that embodiments of the invention are not limited to symmetrical configurations as only a single pair of 162a and 164a or 162b and 164b may be changed to reduce the section width of the tire 110 relative to the tire 10. Such a configuration may therefore be asymmetrical relative to the EP. In addition, though not shown, the section height in addition, or as an alternative, to the section width may be changed by further modification of the dimensions of the areas of overlap 162a, 162b, 164a, and/or 164b during the building process.
In one embodiment, the set 100 of tires is manufactured from a single source of plies for both plies 24a, 24b and 124a, 124b and a single source of plies for plies 26a, 26b and plies 126a and 126b. In this regard, at least two tires are manufactured during which areas of overlap 162a and 162b and/or 164a and 164b differ in dimension from areas of overlap 142a and 142b and/or 144a and 144b such that at least one of the section width or section height as between the tires in the set 100 is different. However, as set forth above, it will be appreciated that each of the plies 24a and 24b may be supplied from different sources. Similarly, each of the plies 26a and 26b may be supplied from different sources. This may occur where each ply contains a different cord material. In this manner, the tire 10 may include different cord material in each of the plies 24a, 24b, 26a, 26b. A total of four separate sources of plies may therefore be used to manufacture each tire. However, at least one of the same source of plies for tire 10 is used to supply a corresponding ply during the manufacturing of another tire. For example, the same four sources of plies may supply other tire production lines although the other lines produce different sized tires. In view of the above, the set 100 of tires may include a range of tire sizes each having different section widths and/or section heights though they share at least one source of plies.
Embodiments of the invention advantageously reduce the costs associated with manufacturing tires generally because a single source of plies may supply multiple tire building processes. In other words, the tire 10 may be built on one production line while the tire 110 may be built on another production line with both production lines using the same source of plies for at least one of plies 24a, 24b, 26a, 26b, 124a, 124b, 126a, and/or 126b. It will be appreciated, that tires 10, 110 may be manufactured at the same time or at different times using the same source of plies. Reducing the inventory of different sized plies reduces cost associated with maintaining a large inventory of different sized plies and eliminates waste associated with excess material.
While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantage and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants' general inventive concept.
