WO2019089008A1

WO2019089008A1 - Non-pneumatic tire carcass

Info

Publication number: WO2019089008A1
Application number: PCT/US2017/059334
Authority: WO
Inventors: Kevin C. Miles; Steven M. Cron; Timothy Rhyne
Original assignee: Compagnie Generale Des Etablissements Michelin
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2019-05-09
Also published as: WO2019089726A1

Abstract

A non-pneumatic tire carcass (30) comprising an outer band (40) comprising a reinforced polymeric ring, the outer band (40) having a thickness bounded by an outer side (42) and an inner side (44), the inner side (44) being arranged radially inward of the outer side (42), the non-pneumatic tire carcass (30) also includes an inner hub (50) comprising a rigid annular member, the inner hub (50) having a radially outer side (52), the non-pneumatic tire carcass (30) further includes a plurality of spokes (60), each spoke (60) forming a composite structure including one or more spring steel inserts at least partially encapsulated within a polymeric body, the spokes (60) are generally V-shaped having an apex where the inner and outer legs converge at the apex and the polymeric body includes a thickened apex portion arranged on an interior side of the apex.

Description

NON-PNEUMATIC TIRE CARCASS

Field

[0001] Embodiments of this disclosure relate generally to non-pneumatic tires. BACKGROUND

[0002] Mechanical structures for resiliently supporting a load, such as spokes for use with non-pneumatic tires and tire carcasses, have been employed previously. However, prior spokes are difficult to manufacture and assemble. This disclosure provides resilient structures, in the form spokes for non-pneumatic tires and tire carcass, by example and without limitation, that are easier to manufacture, do not require pre-tensioning when forming the non-pneumatic tire, and are able to nest within an adjacent spoke during deflection events, in a way that prevents deformation beyond each spoke's yield strength (yield stress).

SUMMARY

[0003] Embodiments of the disclosure include a non-pneumatic tire, a non-pneumatic tire carcass, and a plurality of spokes for arrangement in either. In particular embodiments, the tire carcass comprises an outer band comprising a reinforced polymeric ring, the outer band having a thickness bounded by an outer side and an inner side, the inner side being arranged radially inward of the outer side. The tire carcass also includes an inner hub comprising a rigid annular member, the inner hub having a radially outer side. The tire carcass further includes a plurality of spokes, each spoke forming a composite structure including one or more spring steel inserts at least partially encapsulated within a polymeric body. Each spring steel insert of the one or more spring steel inserts has a thickness, a width, and a length, each of the thickness, width, and length extending perpendicular to the others at any location along the length, where a portion of the length extends between an outer mounting base and an inner mounting base of the corresponding spoke along a generally V-shaped path. The outer mounting base of the spoke is configured to operably attach to the outer band and the inner mounting base of the spoke configured to operably attach to the inner hub. The generally V- shaped path includes an inner leg, an outer leg, and an apex where the inner leg is located radially inward from the outer leg and where the inner and outer legs converge at the apex. The polymeric body includes a thickened apex portion arranged on an interior side of the apex for each of the one or more spring steel inserts. [0004] The foregoing and other objects, features, and advantages will be apparent from the following more detailed descriptions of particular embodiments, as illustrated in the accompanying drawings wherein like reference numbers represent like parts of particular embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a lateral side elevational view of a carcass portion of a non-pneumatic tire, the non-pneumatic tire carcass including a plurality of spokes affixed to an outer band and an inner hub, in accordance with an exemplary embodiment;

[0006] FIG. 2 is a side perspective view of a spoke of the tire shown in FIG. 1, the image showing an inner apex side of the spoke and a plurality of spring metal inserts arranged in an array within the spoke;

[0007] FIG. 3 is a side sectional view of the spoke shown in FIG. 2 taken along a width of the spoke;

[0008] FIG. 4 is a side sectional view of a spring metal insert representing any of the plurality of sheet metal inserts shown in FIG. 2 within the spoke;

[0009] FIG. 5 is an front view of the array of spring metal inserts shown in FIG. 2 within the spoke; and,

[0010] FIG. 6 is a partial side view of the tire shown in FIG. 1 showing a portion of the tire engaging a ground surface while deflected under load, whereby corresponding portions of particular spokes are shown to engage an adjacent spoke in an exemplary embodiment.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0011] The present disclosure provides mechanical structures for resiliently supporting a load, as well as non-pneumatic tires and non-pneumatic tire carcasses (each forming a portion of a non-pneumatic tire) incorporating the mechanical structures, in the form of a spoke, where a plurality of spokes are employed by said non-pneumatic tire. For purposes of describing the invention, reference now will be made in detail to embodiments and/or methods of the invention, one or more examples of which are illustrated in particular figures, or in association with particular figures. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features or steps illustrated or described as part of one embodiment, can be used with another embodiment or steps to yield a still further embodiments or methods. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0012] The following terms are defined as follows for this disclosure:

[0013] "Axial direction" or the letter "A_d" in the figures refers to a direction parallel to the axis of rotation of for example, the outer band, tire, and/or inner hub as it travels along a ground surface.

[0014] "Radial direction" or the letter "R_d" in the figures refers to a direction that is orthogonal to the axial direction and extends in the same direction as any radius that extends orthogonally from the axial direction.

[0015] "Circumferential direction" or the letter "C_d" in the figures refers to a direction is orthogonal to the axial direction and orthogonal to a radial direction.

[0016] "Forward direction of travel" or the letter "F_d" in the figures refers to the direction the tire was designed to predominantly travel in for aesthetics and or performance reasons. Travel in a direction different than the forward direction of travel is possible and anticipated.

[0017] "Direction of rotation" or the letter "R" in the figures refers to the direction the tire was designed to predominantly rotate in for aesthetics and/or performance reasons. Rotation in a direction opposite than the direction of rotation is possible and anticipated.

[0018] "Lateral direction" or "widthwise direction" or the letter "Lat_d" is synonymous with axial direction.

[0019] "Elastic material" or "elastomer" as used herein refers to a polymer exhibiting rubberlike elasticity, such as a material comprising rubber, whether natural, synthetic, or a blend of both natural and synthetic rubbers.

[0020] "Elastomeric" as used herein refers to a material comprising an elastic material or elastomer, such as a material comprising rubber.

[0021] "Interior angle" or "internal angle" as used herein means an angle formed between two surfaces that is greater than 0 degrees but less than 180 degrees. An acute angle, a right angle and an obtuse angle would all be considered "interior angles" as the term is used herein.

[0022] "Exterior angle" or "External angle" or "Reflex angle" as used herein means an angle formed between two surfaces that is greater than 180 degrees but less than 360 degrees.

[0023] "Modulus" or "Modulus of elongation" (MPa) was measured at 10% (MA 10) at a temperature of 23 °C based on ASTM Standard D412 on dumb bell test pieces. The measurements were taken in the second elongation; i.e., after an accommodation cycle. These measurements are secant moduli in MPa, based on the original cross section of the test piece.

[0024] "Rigid" as used herein means unable to bend or be forced out of shape without plastic deformation; not flexible.

[0025] "Nominal load" or "design load" is a load for which the structure is designed to carry. More specifically, when used in the context of a wheel or tire, "design load" refers to the load for which the wheel or tire is designed to carry and operate under. The design load includes loads up to and including the maximum load specified by the manufacturer and, in the case of a vehicle tire, often indicated by marking on the side of a the tire. A loading condition in excess of the design load may be sustained by the structure, but with the possibility of structural damage, accelerated wear, or reduced performance. A loading condition of less than design load, but more than an unloaded state, may be considered a nominal load, though deflections will likely be less than deflections at nominal load.

[0026] With reference to an exemplary embodiment shown in FIG. 1, a non-pneumatic tire 10 is shown to include a tread 20 and a carcass portion 30 of non-pneumatic tire 10, all of which are annular. Carcass 30, and therefore tire 10, more specifically includes an outer band 40, an inner hub 50, and a plurality of spokes 60 arranged between outer band 40 and inner hub 50, and to which each of the spokes 60 are operably affixed. The rotational axis A of tire 10, carcass 30, and the components of each is also shown, and defines any radial or axial direction referred to herein unless otherwise noted.

[0027] With continued reference to FIG. 1, carcass 30 forms the portion of a non-pneumatic tire 10 to which annular tread 20 is operably attached. Tread 20 is arranged to extend around outer radial side 32 of carcass 30. Tread 20 defines an outer, ground-engaging side of non- pneumatic tire 10, which extends annularly around the non-pneumatic tire 10 and outer band 40.

[0028] In the embodiment shown in FIG. 1, the outer radial side 32 of carcass 30 is also an outer radial side of outer band 40. Outer band 40, which is also referred to as a shear band, comprises a reinforced polymeric ring including a plurality of reinforcement layers (not shown), each such layer formed of an elastomeric matrix including a plurality of elongate reinforcements. Therefore, outer band 40 is characterized as being a reinforced, flexible structure. Outer band 40 has a thickness bounded by an outer radial side 42 and an inner radial side 44, the inner side 44 being arranged radially inward of the outer side 42. Outer band 40 is not configured to retain any pressurized air.

[0029] Inner hub 50, also referred to as a central annular portion, forms an inner annular portion that is rigid and capable of being operably attached to a vehicle directly or by way of a wheel to which hub 50 is attached or of which hub 50 forms a portion thereof. By virtue of hub 50, non-pneumatic tire 10 may be installed on a vehicle to allow the vehicle to roll across a ground surface. It is appreciated that the non-pneumatic tire 10 may be mounted upon any desired wheeled vehicle, such as, but not limited to: passenger vehicles, heavy duty trucks, trailers, light trucks, off-road vehicles, ATVs, buses, aircrafts, agricultural vehicles, mining vehicles, bicycles, and motorcycles. Inner hub 50 includes an outer radial side 52 to which the plurality of spokes 60 are attached.

[0030] As noted previously, spokes 60 are attached to an outer radial side 52 of inner hub 50 and also to an inner radial side 44 of outer band 40. In each instance, spokes 60 may be attached in any manner, such as, for example and without limitation, by mechanical fasteners such as bolts, screws, clamps or slots, and/or by adhesives such as cyanoacrylates, polyurethane adhesives, and/or by other bonding materials or any combination thereof.

[0031] With additional reference to FIGS. 1 and 6, non-pneumatic tire 10, during operation when rolling along a ground surface G in direction F_d while exposed to a downward vertical load component, outer band 40 and spokes 60 each deform and flex as the outer band 40 and spokes 60 enter and exit a contact patch P, which is the area of contact between the tire 10 and the ground surface G. While smaller deflections may occur in each spoke 60 outside the contact patch P as each such spoke 60 rotates around the tire 10 and rotational axis A, the primary spoke deflection occurs as each spoke 60 enters, travels through, and exits the contact patch P. By virtue of employing a generally V-shape design (which also includes a U-shaped design), the spokes 60 shown and described herein are able to "nest" within an adjacent spoke 60 and give an essentially linear spring rate when deflected radially over a distance approximately equal to the tires vertical deflection. The nesting of the spokes 60 avoids adjacent spokes 60 from clashing under normal loading conditions, that is, loading conditions up to the design load. This nesting is shown in one example in FIG. 6.

[0032] With reference now to FIGS. 1-3, non-pneumatic tire carcass 30 includes a plurality of spokes 60 arranged between outer band 40 and inner hub 50. Spokes 60 are arranged in an array around inner hub 50 and rotational axis A. Each spoke 60 has a length Leo extending from inner hub 50 and to outer band 40 to define a height H₆₀ of the spoke 60. The length L₆₀ of each spoke 60 extends primarily in a radial direction of tire carcass 30. It is appreciated that when the quantity of spokes 60 is increased for any given non-pneumatic tire 10 or tire carcass 30, such tire or tire carcass is characterized as being stiffer (having a higher spring rate) and having a greater load capacity. The contrary is also true, meaning, that when the quantity of spokes 60 is decreased for the same non-pneumatic tire 10 or tire carcass 30, such tire or tire carcass is characterized as being softer (having a lower spring rate) and having a reduced load capacity.

[0033] With continued reference to FIGS. 2 and 3, with more specific regard to the plurality of spokes 60, each spoke 60 forms a composite structure including one or more spring steel inserts 70 at least partially encapsulated within a polymeric body 80, where each insert 70 operates as a reinforcement of body 80, which by analogy operates as a polymeric matrix in which each insert 70 (reinforcement) is arranged. "At least partially encapsulated" means 40% or more and up to all of the exterior surfaces of each insert 70 is covered by polymeric body 80. "Mostly encapsulated" means greater than 50%, while "substantially encapsulated" means that at least 85%, of the exterior surfaces of each insert 70 is covered by polymeric body 80. As can be seen in FIGS. 2 and 3, for example, each insert 70 is substantially encapsulated within polymeric body 80, as each terminal end 72 of each insert 70 is exposed, that is, each terminal end is not covered by body 80. It is also possible that any thickness Tgo of the body 80 shown along the length L₇o or width W₇o of each insert 70 may periodically or intermittently be absent to expose portions of the insert, whether intentionally or by virtue of any manufacturing imperfection, such that mostly or substantially all of each insert is surrounded by body 80.

[0034] It is appreciated that polymeric body 80 is made generally of any suitable polymeric material, such as, without limitation, any suitable thermoplastic, such as thermoplastic polyurethane (TPU), or any natural or synthetic rubber, or any blend thereof. In certain embodiments, suitable polymeric materials will have a Modulus of 2 to 200 megapascals (MPa). The configuration of the spokes as described herein lends to use of an injection molding operation to form such spokes, such that certain methods of forming any spoke described herein comprise injection molding one or more of the spokes. Of course, other manufacturing processes may be employed to form the spokes described herein, including without limitation any molding operation.

[0035] As for each spring steel insert 70, each is formed of spring steel. Spring steel refers to steels characterized as having sufficiently high yield strength. In particular instances, a spring steel has a yield strength (yield stress) of at least substantially 200 MPa or in other variations, of at least substantially 450 MPa, allowing the material to return to its original shape after notable deflection. Spring steels are commonly low-alloy Manganese, medium- carbon steel, or high-carbon steel, again, each being characterized as having a very high yield strength. Exemplary spring steel grades, without limitation, include SAE 1050 (ASTM A684), 1074 (ASTM A684), 1075 (ASTM A684), 1080 (ASTM A228), 1095 (ASTM A684), 4130, 5160 (ASTM 689), 50CrV4 (ASTM EN 10277), 9255, 301 (A666) spring-tempered stainless steel. Heat treatment of these grades or other grades of steel may, or may not, be performed to achieve the suitable characteristics desired to operate as spring steel, such as by way of hardening and tempering. Heat treatments include without limitation annealing, quenching, and tempering.

[0036] With reference to FIGS. 2-5, each spring steel insert 70 has a thickness T₇o, a width W₇o, and a length L₇o, each of which extend perpendicular to one another at any location along length L₇o. A portion 74 of the length L₇o extends between an outer mounting base 62„ of the corresponding spoke 60 and an inner mounting base 62, of the corresponding spoke 60 along a V-shaped path. In doing so, the V-shaped portion 74 (and the V-shaped path) includes an inner leg 76i and an outer leg 76₀ with an apex 78 arranged between the legs 76i, 76₀. Apex 78 forms the bend between legs 76i, 76₀, each of the legs 76i, 76₀ converging upon (and into or at) apex 78. It is appreciated that the inner leg 76i is located radially inward from the outer leg 76₀. It is noted that end portion 72„ of insert length L₇o is associated with outer mounting base 62„ of a corresponding spoke 60 while end portion 72i of insert length L₇o is associated with inner mounting base 62i of the same corresponding spoke 60. In the embodiment shown, apex 78 is rounded and not pointed. While certain use of certain materials may permit a pointed apex, use of rounded can better facilitate the avoidance permanent deformation of the insert 70 or more generally of the spoke 60 when any deformation exceeds the yield strength, such as when the normal deflection of the tire is exceeded, such as when striking a pot hole, curb, road debris, or the like. In the embodiment shown, the radius of curvature for the apex, taken midway through thickness T₇o is substantially 5 mm. Greater or smaller radii may be employed depending on the application, geometry, and material used to form insert 70. When apex 78 is defined by significantly larger radii, generally V-shaped portion 74 may more closely represent a U-shaped form.

[0037] With reference to FIGS. 3 and 4, it is appreciated that the inner and outer legs 76,, 76„ of any insert 70 in accordance with any embodiment or variation may be separated by any desired interior angle a (where an exterior angle is arranged opposite the interior angle relative to the legs and apex), which may range from 70 to 140 degrees in particular exemplary embodiments, even though other angles may also be employed as may desired. Each such leg 76,, 76₀ is also biased from a radial direction R_d by a corresponding angle βΐ, βο, each of which may or may not be the same angle as the other depending on the location of apex 78.

[0038] With continued reference again to insert 70 in FIGS. 3 and 4, length L₇o of each one or more inserts 70 optionally extends substantially linearly along each inner and outer leg 76,, 76₀ from apex 78 and until reaching either a corresponding terminal end 72 of insert 70 or until reaching a transition portion 79 forming an end portion associated with terminal end 72. At the transition portion 79, the length extends along a contour into each corresponding inner and outer mounting base. In lieu of extending linearly, each inner and outer leg 76,, 76₀ may extend along any desired path, such as a contoured (that is, arcuate) path or any other nonlinear path. These characterizations regarding the extension of length L₇o along each inner and outer leg 76,, 76₀ and with regard to each terminal end 72 and the adjacent terminal end portion may also be used to characterize length L₆₀ in association with each inner and outer leg 66i, 66₀ and with regard to each terminal end 62 and the adjacent terminal end portion, in association with any variation or embodiment of insert 70.

[0039] With reference to FIGS. 2 and 3, in similar fashion to spring steel insert 70, each spoke 60 can be described as having a portion 64 of its length Leo extending between outer mounting base 62„ and an inner mounting base 62, along a V-shaped path. In doing so, the V-shaped portion 64, as with the V-shaped path, comprises an inner leg 66i and an outer leg 66₀ with an apex 68 arranged between the legs 66,, 66₀. Apex 68 forms the bend between legs 66i, 66₀, each of the legs 66,, 66₀ converging upon (and into or at) apex 68. It is appreciated that the inner leg 66, is located radially inward from the outer leg 66₀. Additionally, for each spoke 60, the polymeric body 80 includes a thickened apex portion 82 arranged on an interior side of the apex 78 for each of one or more inserts 70, as well as on an interior side of apex 68. This apex portion 82 may be arranged solely along apex 78 or may extend further outward along adjacent legs 76,, 76„, such as is shown in the figures in one example.

[0040] With continued reference to spokes 60 in FIGS. 2 and 3, as with each insert 70, length Leo of each one or more spokes 60 optionally extends substantially linearly along each inner and outer leg 66,, 66₀ from apex 68 and until reaching either a corresponding terminal end 62 of spoke 60 or until reaching a transition portion 69 forming an end portion associated with terminal end 62. At the transition portion 69, the length extends along a contour into each corresponding inner and outer mounting base. In lieu of extending linearly, each inner and outer leg 66,, 66₀ may extend along any desired path, such as a contoured (that is, arcuate) path or any other non-linear path. These characterizations regarding the extension of length Leo along each inner and outer leg 66,, 66₀ and with regard to each terminal end 62 and the adjacent terminal end portion may also be used to characterize length Leo in association with each inner and outer leg 66,, 66₀ and with regard to each terminal end 62 and the adjacent terminal end portion, in association with any variation or embodiment of spoke 60.

[0041] In FIGS. 2 and 3, with the exception of apex portion 82, the body thickness Tgo is constant along V-shaped portion 64 of each spoke 60. In such instances, while body thickness Tgo may be any desired thickness, in certain exemplary embodiments, body thickness Tgo is equal to or less than 3 millimeters (mm) or less than 1 mm, but in any event, greater than zero. It is appreciated, however, that the thickness of body in these locations may be variable as may be desired. With regard to the apex portion 82 of body 80, it can be sized as needed to alter the stiffness and resiliency of each spoke 60.

[0042] With reference to FIGS. 1-3, while it is appreciated that apexes 68, 78 may be arranged at any radial location between inner mounting base 62, than outer mounting base 62„ (and therefore any location between outer band 40 and inner hub 50), in the embodiment shown, each apex 68, 78 is arranged closer to inner mounting base 62i than outer mounting base 62„ (and therefore closer to inner hub 50 than outer band 40). In this embodiment, this radial location is selected to suspend the apex 68, 78 of each spoke within the contact patch between the inner and outer mounting bases as long as possible as tire deflection is increased. When tire 10 is loaded to its design load, at its maximum, such as is shown by example in FIG. 6, apexes 68, 78 are each located such that during tire operation, one spoke leg 66₀,, 66, engages one of the mounting bases 62„, 62, as the spokes 60 enter a contact patch P while the other spoke leg 66₀,, 66i engages the other of the mounting bases 62„, 62; as the spoke 60 exits the contact patch P. More specifically, in the embodiment shown, outer spoke leg 66„ engages outer mounting base 62„ as the corresponding spoke 60 enters contact patch P while inner spoke leg 66i engages the inner mounting base 62,- as the corresponding spoke 60 exits contact patch P. When, however, tire 10 is in an overload condition, the apex 68 of each spoke 60 will contact one of the inner mounting base 62i and the outer mounting base 62„ as the spoke 60 enters the contact patch P, while apex 68 of each spoke 60 will contact also the other of the inner mounting base 62i and the outer mounting base 62„ as the spoke 60 exits the contact patch P based upon the geometry and material selection of the spoke and of the non-pneumatic tire itself and its other components to prevent each spoke from exceeding its maximum yield strength. Of particular note, a contact patch is the area of contact between the tire and a ground surface. The desire to facilitate contact is intended as a mechanism to prevent a spoke 60 from deflecting beyond its yield strength, such that it returns elastically to its original arrangement. Based upon this desire, apex 68 of any spoke 60 may be arranged at any location along the length Leo of the corresponding spoke 60 such that the V-shaped portion 64 or more specifically any apex 68 or associated leg 66₀, 66i is configured to contact both the inner mounting base 62,- and the outer mounting base 62„ when the tire is deflected a particular amount. For uniformity in deformation, in particular embodiments, all apexes 68 for all spokes 60 are arranged at substantially the same radial distance from the inner hub 50 or from the rotational axis A, as is shown in one example in FIG. 1.

[0043] It is appreciated that inner and outer mounting bases may each take any desired form, irrespective of the other. In the exemplary embodiment shown in FIGS. 2 and 3, for each spoke 60, inner mounting base 62i includes an inner deflection stop surface S62i and outer mounting base 62„ includes an outer deflection stop surface S62o- In the embodiment shown, each inner deflection stop surface S62i and each outer deflection stop surface S62o is associated with a thickened portion 84 of body 80. While this thickened portion may provide certain protective and energy-absorption benefits, it is optional and may not be present in other variations. With reference now to FIG. 6, a partial side view of the non-pneumatic tire of FIG. 1 is shown deflected during tire operation, where the tire is deflected under a load sufficient to cause each spoke to engage an adjacent spoke, and more specifically, each outer band-engaging surface S62o while entering a contact patch P and each inner hub-engaging surface S62i while exiting the contact patch P.

[0044] It is further noted that each spoke 60 may include, in association with each inner mounting base 62,, an inner hub-engaging surface Seoi for engaging inner hub 50. Likewise, each spoke 60 may include, in association with each outer mounting base 62„, an outer band- engaging surface S₆o_0> for engaging outer band 40. In the embodiment shown, each inner hub-engaging surface Seoi and each outer band-engaging surface S₆o₀ is associated with a thickened portion 86 of body 80. While this thickened portion may provide certain protective and energy-absorption benefits, it is optional and may not be present in other variations.

[0045] It is appreciated that each spoke may include one or more spring steel inserts. With regard to the exemplary embodiment shown in FIGS. 2 and 5, each spoke 60 in tire 10 includes a plurality of spring steel inserts 70 arranged in an array extending in a widthwise direction (the direction of width W6o) of the spoke 60. By virtue of employing multiple inserts 70, tire 10 may be more compliant across its width, as impacts and objects may impact only a portion of the tire width. In the array, the plurality of inserts 70 and the widths W₇o of the plurality of inserts 70 are arranged in a side-by-side and spaced apart arrangement. It is appreciated that the spacing Δ₇ο may remain constant or vary between any pair of adjacent inserts 70 and from one pair to another pair of inserts 70. In the embodiment shown, each spacing Δ₇ο is a constant width spacing and all spacings Δ₇ο between all inserts 70 are the same.

[0046] It is appreciated that the spokes 60 are commonly installed without any intended applied radial tension, other embodiments may employ a degree of pre-tension or pre- compression, such as to improve the ease of manufacturing or assembly, or to improve any desired tire performance characteristic, such as ride comfort, noise, load carrying capacity, for example.

[0047] To the extent used, the terms "comprising," "including," and "having," or any variation thereof, as used in the claims and/or specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms "a," "an," and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The terms "at least one" and "one or more" are used interchangeably. The term "single" shall be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as "two," are used when a specific number of things is intended. The terms "preferably," "preferred," "prefer," "optionally," "may," and similar terms are used to indicate that an item, condition or step being referred to is an optional (i.e., not required) feature of the embodiments. Ranges that are described as being "between a and b" are inclusive of the values for "a" and "b" unless otherwise specified.

[0048] While various improvements have been described herein with reference to particular embodiments thereof, it shall be understood that such description is by way of illustration only and should not be construed as limiting the scope of any claimed invention. Accordingly, the scope and content of any claimed invention is to be defined only by the terms of the following claims, in the present form or as amended during prosecution or pursued in any continuation application. Furthermore, it is understood that the features of any specific embodiment discussed herein may be combined with one or more features of any one or more embodiments otherwise discussed or contemplated herein unless otherwise stated.

Claims

CLAIMS What is claimed is:

1. A non-pneumatic tire carcass, the tire carcass comprising:

an outer band comprising a reinforced polymeric ring, the outer band having a thickness bounded by an outer side and an inner side, the inner side being arranged radially inward of the outer side;

an inner hub comprising a rigid annular member, the inner hub having a radially outer side;

a plurality of spokes, each spoke forming a composite structure including one or more spring steel inserts at least partially encapsulated within a polymeric body; each spring steel insert of the one or more spring steel inserts having a thickness, a width, and a length, each of the thickness, width, and length extending perpendicular to the others at any location along the length, where a portion of the length extends between an outer mounting base and an inner mounting base of the corresponding spoke along a generally V-shaped path, the outer mounting base of the spoke configured to operably attach to the outer band and the inner mounting base of the spoke configured to operably attach to the inner hub, the generally V-shaped path including an inner leg, an outer leg, and an apex where the inner leg is located radially inward from the outer leg and where the inner and outer legs converge at the apex; the polymeric body including a thickened apex portion arranged on an interior side of the apex for each of the one or more spring steel inserts.

2. The non-pneumatic tire carcass of claim 1, where each spoke has a thickness, a width, and a length, each of the spoke thickness, width, and length extending perpendicular to the others at any location along the spoke length, where a portion of the spoke length extends along a V-shaped path associated with the V-shaped path of the corresponding insert, the spoke V-shaped path including a spoke apex corresponding with the spring steel insert apex, an inner spoke leg corresponding to the inner spring steel leg, an outer spoke leg corresponding to the outer spring steel leg, where the inner spoke leg is located radially inward from the outer spoke leg and where the inner and outer spoke legs converge at the spoke apex.

3. The non-pneumatic tire carcass of claim 2, where for each spoke, each spoke apex is arranged at a radial location between inner mounting base and outer mounting base, the radial location being selected to suspend the spoke apex between the inner and outer mounting bases of an adjacent spoke within which the spoke nests while within the contact patch until reaching an overload condition.

4. The non-pneumatic tire carcass of any one of claims 2 and 3, where for each spoke, each spoke apex is arranged at a radial location between inner mounting base and outer mounting base, the radial location being selected such that during tire operation at the maximum design load, one of the inner spoke leg and the outer spoke leg engages one of the inner and outer mounting bases of an adjacent spoke within which the spokes nests as the corresponding spoke enters a contact patch and while the other of the inner and outer spoke legs engages the other of the inner and outer mounting bases of the adjacent spoke as the corresponding spoke exits the contact patch.

5. The non-pneumatic tire carcass of any one of claims 1 to 4, where for each spoke, the insert apex is arranged closer to the inner mounting base than the outer mounting base.

6. The non-pneumatic tire carcass of claim 2, where the spoke apex is arranged at a radial location such that in an overload condition the spoke apex contacts one of the inner mounting base and the outer mounting base of an adjacent spoke within which the spoke nests as the spoke enters the contact patch and while the spoke apex contacts the other of the inner mounting base and the outer mounting base of the adjacent spoke as the corresponding spoke exits the contact patch.

7. The non-pneumatic tire carcass of any one of claims 1 to 6, where for each spoke, the insert apex is rounded.

8. The non-pneumatic tire carcass of any one of claims 1 to 7, where for each spoke, the length of each one or more spring steel inserts extends substantially linearly along each inner and outer leg until reaching a transition portion along each inner and outer leg, where the length extends along a contour into each corresponding inner and outer mounting base.

9. The non-pneumatic tire carcass of any one of claims 1 to 8, where the one or more spring steel inserts form a plurality of spring steel inserts arranged in an array extending in a widthwise direction of the spoke.

10. The non-pneumatic tire carcass of claim 9, where in the array the widths of the

plurality of spring steel inserts are arranged in a side-by-side and spaced apart arrangement.

11. The non-pneumatic tire carcass of any one of claims 1 to 10, where for each spoke, the thickened apex portion is also arranged along each of the inner and outer legs of each of the one or more inserts.

12. The non-pneumatic tire carcass of any one of claims 1 to 11, where for each spoke, the polymeric body includes at each inner and outer mounting base a deflection stop surface configured to engage an adjacent spoke of the plurality of spokes when the tire is deflected and reaches a particular deflection amount.

13. The non-pneumatic tire carcass of claim 12, where each deflection stop surface is associated with a thickened stop portion of the body.

14. The non-pneumatic tire carcass of any one of claims 1 to 13, where for each spoke, the inner mounting base includes an inner hub-engaging surface and where the outer mounting base includes an outer band-engaging surface.

15. The non-pneumatic tire carcass of claim 14, where each of the inner hub-engaging surface and the outer band-engaging surface is associated with a thickened portion of the body.

16. The non-pneumatic tire carcass of any one of claims 1 to 15, where for each spoke, the body has a thickness of 1 mm or less on each side of the leg between the thickened apex portion and each inner and outer mounting base.

17. The non-pneumatic tire carcass of any one of claims 1 to 16, where for each spoke, the inner and outer legs for each insert of the plurality of inserts are arranged relative to one another by an angle equal of 70 to 140 degrees.

18. The non-pneumatic tire carcass of any one of claims 1 to 17, where for each spoke, the body is formed of rubber or thermoplastic polyurethane.

19. The non-pneumatic tire carcass of any one of claims 1 to 18, where for each spoke, the body is injected molded around the one or more inserts.

20. The non-pneumatic tire carcass of any one of claims 1 to 19, where for each of the spokes, the V-shaped portion is U-shaped.