Run-flat system with spring suspension

Abstract

A run-flat device (1) configured to be attached to an automotive tubeless mounting assembly including a wheel rim and a tire cover including a bead mounted against the edge of the rim comprises an annular support structure (100) configured to be mounted around the rim to support the cover after a drop in inflation pressure inside the mounting assembly, the annular support structure including three composite spring segments (2000) forming sectors of a circular arc and assembled circumferentially around the rim to form the annular support structure using transverse pins having asymmetric geometric shapes, and an arrangement configured to connect the annular support structure to these beads for locking the beads against the edge.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 386,574, filed December 8, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] The present invention relates to a lightweight flat-running device designed to be attached to an automotive tubeless mounting assembly, and to a mounted wheel assembly incorporating the device, which allows the mounting assembly to be driven at relatively high speeds over significant distances when partially or completely deflated. The flat-running device can be used, inter alia, on military vehicles designed to travel over all types of terrain, including sand. [Background technology]

[0003] Run-flat devices are designed to provide flat tire mobility for pneumatic tires used on automobiles, trucks, commercial vehicles, and military vehicles. Run-flat devices are typically installed in the "well" of the wheel. Many applications, particularly for military vehicles, require run-flat devices to be lightweight and capable of supporting heavy loads. To meet these objectives, it is known to utilize relatively rigid or inflexible materials for run-flat devices. Inflexible materials will typically have a higher durometer hardness than pneumatic tires. Tire durometers typically vary from about 70 Shore A for passenger cars to about 50 Shore D for truck-sized vehicles. Thus, it will be appreciated that the quantitative meanings of the terms flexible and inflexible as used herein may vary depending on the particular vehicle application.

[0004] The relatively rigid or inflexible material of a run-flat device provides for continued vehicle operation after a tire rupture, loss of tire pressure, or other tire damage. However, in such situations, the run-flat device may exert excessive impact against the tire's inner surface, and the stress applied between the run-flat device and the tire's inner surface may lead to premature tire liner failure. Similarly, when operating a vehicle over rough terrain, users often partially deflate the vehicle's tires to provide better traction and cushion the ride. In this deflated state, the run-flat device must support the vehicle while maintaining contact with the tire. Failure to do so can result in a lack of vehicle traction and immobilization.

[0005] Known flat running devices usually consist of a support ring mounted with clearance around the wheel rim inside the tire casing. Due to its width at its base, this ring exerts a force pressing the casing onto the rim. Sometimes rigid devices in several sectors mounted two by two are used. Thus, EP 1 541 384 A1, in the name of the applicant, presents a flat running device for a mounting assembly with a rim, with several bolted sections, comprising, on the one hand, a hollow support ring divided into at least two ring sectors designed to be mounted around the rim and mounted independently of each other, in order to ensure the drive function of the mounting assembly in the event of a reduction or even a zero pressure in the mounting assembly, and, on the other hand, means for locking the casing bead against the rim edge, designed to connect the ring sectors to the casing bead. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent Application Publication No. 1541384 Summary of the Invention [Problem to be solved by the invention]

[0007] The main drawbacks of known runflat devices are, among other things, the rigidity characteristics of the mounting sector and the weight of the device. Currently, runflat devices use elastomeric properties of rubber or rubber-like materials. However, such materials are dense and have increased weight characteristics, resulting in heavy runflats.

[0008] Therefore, there is an ongoing need for a runflat system that is relatively light in weight, capable of supporting heavy vehicle loads, and is flexible enough to mitigate vehicle operational disruptions. [Means for solving the problem]

[0009] In one example of the present disclosure, a run-flat device intended to be attached to an automotive tubeless mounting assembly including a wheel rim and a tire cover including a bead mounted against the edge of the rim includes an annular support structure configured to be mounted around the rim to support the cover after a drop in inflation pressure inside the mounting assembly, the annular support structure including at least one composite spring-type segment that is assembled circumferentially around the rim to form an arc that forms the annular support structure, and an arrangement configured to connect the annular support structure to these beads for locking the beads against the edge.

[0010] In another example of the present disclosure, the compound spring type segment further includes a plurality of quasi-elliptical springs, and is shaped for incorporation of the plurality of quasi-elliptical springs secured to an inner surface of the compound spring type segment, the plurality of quasi-elliptical springs being formed in tension and contacting each other upon the occurrence of a drop in inflation pressure inside the mounting assembly.

[0011] In another example of the present disclosure, the annular support structure further includes an end-to-end assembly of composite spring-type segments that allows for uniform stress distribution in tension across the width of the runflat.

[0012] In another example of the present disclosure, the compound spring type segment further includes an extended end configured to be attached to one of a plurality of quasi-elliptical springs for an end-to-end assembly.

[0013] In another example of the present disclosure, one of the plurality of quasi-elliptical springs is attached to two compound spring-type segments.

[0014] In another example of the present disclosure, the composite spring-type segment is in the form of a perfectly elastic spring that does not generate heat when cyclically deformed under the influence of a compressive load applied normal to the outer surface.

[0015] In another example of the present disclosure, the compound spring segment spans radially around the wheel in 120 degree segments, and four quasi-elliptical springs are fixed to a bottom surface of the compound spring segment, the quasi-elliptical springs being adjacently offset such that at least one of the four quasi-elliptical springs is at least partially radially outside the 120 degree segment.

[0016] In another example of the present disclosure, a composite spring is constructed from continuous reinforcing filaments impregnated with a thermosetting resin, allowing for variable mechanical strength and stiffness for a fixed geometry and size.

[0017] In another example of the disclosure, a run-flat device intended to be attached to an automotive tubeless mounting assembly including a wheel rim and a tire cover including a bead mounted against the edge of the rim includes an annular support structure configured to be mounted around the rim to support the cover after a drop in inflation pressure inside the mounting assembly, the annular support structure including at least one compound spring-type segment assembled circumferentially around the rim and having at least one extended end, at least one quasi-elliptical spring formed from an incorporation of at least one elliptical multiple spring positioned under the compound spring-type segment such that the at least one compound spring-type segment is assembled circumferentially around the rim by securing an extended end of the at least one compound spring-type segment to the at least one quasi-elliptical spring, and an arrangement configured to connect the annular support structure to the beads for locking the beads against the edge, the at least one quasi-elliptical spring being formed in tension and compressed after a drop in inflation pressure inside the mounting assembly.

[0018] In another example of the present disclosure, a plurality of quasi-elliptical springs are formed in tension and contact each other upon the occurrence of a drop in inflation pressure inside the mounting assembly.

[0019] In another example of the present disclosure, the annular support structure further includes an end-to-end assembly of composite spring-type segments that allows for uniform stress distribution in tension across the width of the runflat.

[0020] In another example of the present disclosure, an extended end of a compound spring-type segment is configured to be attached to one of a plurality of quasi-elliptical springs, while a second extended end of a second compound spring-type segment is configured to be attached to the quasi-elliptical spring.

[0021] In another example of the present disclosure, the composite spring-type segment is in the form of a perfectly elastic spring that does not generate heat when cyclically deformed under the influence of a compressive load applied normal to the outer surface.

[0022] In another example of the present disclosure, the compound spring segments span radially around the wheel in 120 degree segments, and four quasi-elliptical springs are fixed to a bottom surface of the compound spring segments, the quasi-elliptical springs being adjacently offset such that at least one of the four quasi-elliptical springs is at least partially radially outside the 120 degree segment.

[0023] In another example of the present disclosure, a composite spring is constructed from continuous reinforcing filaments impregnated with a thermosetting resin that allows for varying mechanical strength and stiffness for a fixed geometry and size.

[0024] Another example of the present disclosure is a run-flat device intended to be mounted around a wheel rim and within a tire cover, the run-flat device including an annular support structure configured to be mounted around the wheel rim to support the tire cover after a drop in inflation pressure inside the mounting assembly, the annular support structure including at least one compound spring-type segment circumferentially assembled around the rim and having at least one extended end, and at least one quasi-elliptical spring configured to accommodate the incorporation of at least one elliptical multi-spring, the at least one compound spring segment being assembled circumferentially around the at least one quasi-elliptical spring by securing the at least one elliptical multi-spring to a bottom surface of the compound spring-type segment, the at least one compound spring segment being assembled circumferentially around the at least one quasi-elliptical spring, the at least one quasi-elliptical spring being formed in tension and being compressed after a drop in inflation pressure inside the mounting assembly.

[0025] In another example of the present disclosure, the width of the at least one compound spring-type segment is twice the width of the at least one quasi-elliptical spring.

[0026] In another example of the present disclosure, a compound spring segment extends radially around the wheel rim in 120 degree segments, and four quasi-elliptical springs are fixed to a bottom surface of the compound spring segment, the quasi-elliptical springs being adjacently offset such that at least one of the four quasi-elliptical springs is at least partially radially outside the 120 degree segment.

[0027] In another example of the present disclosure, an extended end of a compound spring-type segment is configured to be attached to one of a plurality of quasi-elliptical springs, while a second extended end of a second compound spring-type segment is configured to be attached to the quasi-elliptical spring.

[0028] In another example of the present disclosure, an extended end of a compound spring-type segment is configured to be attached to one of a plurality of quasi-elliptical springs, while a second extended end of a second compound spring-type segment is configured to be attached to the quasi-elliptical spring.

[0029] Advantageously, run-flat devices having the annular support structures described herein are substantially lightweight, contain reduced surface areas, and minimize heat generation.

[0030] The present disclosure includes springs that have the unique ability to recover up to 100% of their deformation energy under sudden deformation without generating heat. In the case of rubber or similar materials, hysteresis properties cause heat generation under sudden deformation. Springs made of composite or similar materials are characterized by the ability to produce an infinite variety of spring constants and mechanical resistances, particularly but not exclusively, with respect to load and strain. Composite springs can offer a wide range of load possibilities while maintaining elastic behavior under tension, compression, or shear loads, whereas rubber-based materials are limited to maintaining elastic behavior under compression. The properties of such composite materials allow for the creation of elastic hollow bodies, such as the runflat concept of the present disclosure. The advantage of elastic hollow bodies is that the exposed cross-section of the runflat is minimized, thereby reducing exposure to ballistic artillery shells or projectiles.

[0031] Another advantage is that the composite laminate has increased resistance to ballistic penetration due to its localized energy absorption capabilities.

[0032] Other characteristics, advantages and details of the invention will become apparent on reading the following description of some embodiments of the invention, given by way of example and not limitation, made with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a perspective view of an embodiment of a run-flat device. [Figure 2] 1 is an axial half-section view of a mounting assembly incorporating a flat running device according to an embodiment of the present invention incorporating rigid connection means between sectors. [Figure 3] FIG. 1 is a perspective view of an embodiment of an assembled annular support structure. [Figure 4] FIG. 12 is a perspective view of an embodiment of a compound spring type segment. [Figure 5] 1 is a perspective view of an embodiment of a connecting member bolt or pin. FIG. [Figure 6] FIG. 12 is a perspective view of an embodiment of a semi-elliptical spring. [Figure 7] FIG. [Figure 8] 10 is a perspective view of an embodiment of a connecting member for connecting compound spring-type segments. FIG. [Figure 9] FIG. 1 is a perspective view of an embodiment of a spacer. [Figure 10] FIG. 1 is a perspective view of an embodiment of a T-nut. [Figure 11] FIG. 10 is a perspective view of another embodiment of an assembled annular support structure. [Figure 12] FIG. 10 is a perspective view of another embodiment of a compound spring-type segment secured to another embodiment of a quasi-elliptical spring. [Figure 13] FIG. 10 is a perspective view of another embodiment of a connecting member bolt or pin. [Figure 14] FIG. 10 is a perspective view of another embodiment of a semi-elliptical spring. [Figure 15] FIG. 10 is a perspective view of another embodiment of an assembled annular support structure. [Figure 16] 1 is a graph displaying stiffness versus rotation measurements for a run-flat system with spring suspension. [Figure 17] 1 is a graph displaying force versus displacement measurements for a run-flat system with spring suspension. DETAILED DESCRIPTION OF THE INVENTION

[0034] Spatial orientation terminology used below for purposes of description shall refer to referenced embodiments arranged in the accompanying drawings and figures or in the following detailed description. However, it shall be understood that the embodiments described below may take on many alternative variations and configurations. It shall also be understood that the specific components, devices, features, and operating sequences illustrated in the accompanying drawings, figures, or described herein are merely exemplary and should not be considered limiting.

[0035] As used herein, the expressions "axially inner" and "axially outer" refer to the side of the wheel rim that is intended to face the inside and the side of the wheel rim that is intended to face the outside, respectively, of the motor vehicle when a mounting assembly including the wheel rim is mounted on the vehicle.

[0036] The present disclosure relates generally to run-flat systems, and more particularly to run-flat systems having spring suspensions. Certain preferred, non-limiting aspects of run-flat components are illustrated in Figures 1-10.

[0037] A flat running device 1 according to an embodiment of the present invention, shown in Figures 2-4, includes a wheel rim 2 having a first rim seat 4a and a second rim seat 4b, and an annular support structure 100 to which at least one compound spring-type segment 200 or spring segment 200 is fastened by a bolt-type attachment means (not shown). In one embodiment, there are three compound spring-type segments 200 fastened to each other by a bolt-type connecting member 400. The connecting member 400 may include a bolt sleeve 800 shown in Figure 7, a connector 700 shown in Figure 8, a spacer 900 shown in Figure 9, and a T-nut 950 shown in Figure 10. In another embodiment, shown in Figures 11-14, three spring-type segments 2000 are fastened to a quasi-elliptical spring 6000 or an elliptical spring 6000 by a bolt-type connecting member 4000. The connecting member 4000 may include an extended end 2100 of a spring-type segment 2000 that aligns with another extended end 2100 of another spring-type segment 2000, as shown in Figures 11-14.

[0038] The composite spring-type segment 200 includes an axial inner edge 202 and an outer edge 204, each bounded on a rim seat 4a, 4b extending axially from the edge 202, a tire casing 6 having a bead 8 mounted against the edge 202 and resting on the seat or edge 12, and a flat running device 1 mounted around the rims 2 and 4 inside the casing 6 and designed to support the casing 6 after a drop in inflation pressure inside the mounting assembly device 1.

[0039] In the example of FIG. 2, the device 1 is mounted on a rim bottom 14 which is of a substantially flat type. The device 1 comprises an annular support structure 100 designed to be mounted on the rim 2 to support the casing 6 after the drop in inflation pressure inside the mounting assembly 1, each of which is a hollow structure having a circular arc shape and connected to one another through connecting members 400, divided into a number of composite spring-type segments 200, preferably three but not limited to, suitable for forming the annular support structure 100 by arranging them in the circumferential direction of the annular support structure 100, and rubber-based connectors 700, each of which is a single piece and reinforced by a circumferential reinforcing element (not illustrated), for locking the bead 8 against the edge 12 and designed to connect the annular support structure 100 to the bead 8, which can be wedges that press laterally against the radially inner zone of the composite spring-type segment 200 that is placed facing the connecting members 400 so as to hold the composite spring-type segment 200 in place during running. Preferably, in this embodiment, three compound spring segments 200 are divided into 120 degree segments covering the rim 2. Each compound spring segment 200 is approximately equal in length to span a distance of the rim that is 120 degrees as measured radially from the center of the rim 2.

[0040] Each of the composite spring-type segments 200 is preferably made of a composite material, i.e., a material resulting from a combination of unidirectional fibers impregnated with a thermosetting resin matrix (epoxy, urethane), but is not limited to this; thermoplastic resins can also be used. The continuous reinforcing fibers are made of glass, carbon, basalt, aramid, or thermoplastic materials such as, but not limited to, Dyneema and Spectra. Metal filaments can be used to provide localized reinforcement at the joints of the inter-segment connectors. The composite spring-type segments 200 can be manufactured using processes such as, but not limited to, a filament winding process or a multiple reinforcing winding process, which may involve weaving or knitting non-crimped fabrics or staple fibers in addition to the unidirectional fibers. The winding of the continuous reinforcing filaments is circumferential for at least one of the two types of springs used. The spring constant or other characteristics of the composite spring-type segment 200 can be modified by winding the fibers to a specified thickness. The composite spring segment 200 may be radially coated with a protective coating, preferably based on rigid rubber or elastomer, although it is noted that, as a variant, this coating could be comprised of a flexible rubber / reinforcement element composite.

[0041] Regarding the geometric shape of each composite spring-type segment 200, in the example of Figures 3 and 4, each composite spring-type segment 200 has a substantially trapezoidal axial cross-section that widens in the axial direction to form a base 214 / 216 of the composite spring-type segment 200 on the radially inner surface of the composite spring-type segment 200 in the radially inner zone on which the locking wedge rests, and in the radially outer zone located thereon, has an axial cross-section that is substantially in the shape of an isosceles trapezoid with a larger base that coincides with the protective coating.

[0042] 3 and 4, the composite spring segment 200 has a first loop end 206 and two second loop ends 208 located on opposite sides of the first end 210, separated by and connected between a top surface 214 and a bottom surface 216. The overall geometry of the composite spring segment 200 may resemble a distorted ellipse or a banana, with the top surface 214 being longer than the bottom surface 216 due to the curvature of the composite spring segment 200. The edge 202 of the bottom surface 216 contacts the wheel rim 14, while the edge 204 of the top surface 214 contacts the casing 6 when a compressive force is applied to the casing 6 causing the tire to go flat or when the inflation pressure inside the flat running device 1 drops. The top surface 214 may act as a support surface for the cover 6. The second end 212 may include two first loop ends 206 and a second loop end 208 that may be configured to be attached to another first end 210 of another composite spring-type segment 200 via an attachment member 400.

[0043] As shown in the examples of Figures 3, 4, and 6-9, a connecting member 400 for connecting composite spring-type segments 200 to one another is positioned between the first loop end 206 of a first composite spring-type segment 200 and the first loop end 206 of a second composite spring-type segment 200. The first end 210 and the second end 212 include two concentric loop segments separated by another loop with a longer length from the outer and inner portions. This other loop may be considered a male connecting element. This loop may be attached to the second end 212 of another composite spring-type segment 200 via the second loop end 210 of this other composite spring-type segment 200, which also has two concentric loops separated by another loop with a shorter length from the outer and inner portions. These concentric loops may be considered female connecting elements. The attachment member 400 may connect each end as a connecting protrusion or pin 500 having a geometric shape that fits within the inner region of each loop end.

[0044] In the exemplary embodiment, the connecting member 400 is attached to and holds the connecting pins 500 shown in Figure 5, which facilitate the connection between the three compound spring segments 200. When the compound spring segments 200 are releasably secured or joined using the pins 500, the annular support structure 100 evenly contacts and conforms to the outer flat base diameter of the wheel rim 2 or rim bottom 14.

[0045] In the exemplary embodiment, three quasi-elliptical springs 600 or elliptical springs are positioned between the top surface 214 and bottom surface 216 of the composite spring segment 200 structure. In the exemplary embodiment, the quasi-elliptical springs 600 are preferably essentially elliptical in shape, but can be any shape that allows for spring action, specifically trapezoidal, kidney-shaped, or kidney-shaped. In particular, a kidney shape can include concave side portions. A quasi-elliptical shape can be any shape in which one radius is longer than the other radius. The quasi-elliptical springs 600 are preferably fabricated from the same or similar material as the composite spring segment 200. The quasi-elliptical springs 600 act as springs in tension or compression to maintain structural support for the composite spring segment 200 and allow the annular support structure 100 to pivot. This embodiment includes three quasi-elliptical springs 600, although the number of quasi-elliptical springs 600 can be varied depending on the resistance requirements under load and the desired uniformity of circumferential deformation of the annular support structure 100.

[0046] Furthermore, the individual thicknesses of the quasi-elliptical springs 600 can vary depending on the structural requirements and the composition of the laminates added by filament winding. Each of the quasi-elliptical springs 600 is preferably manufactured from a composite material, i.e., a material resulting from a combination of unidirectional fibers impregnated with a thermosetting resin matrix (epoxy, urethane), but is not limited to such a material; thermoplastic resins can also be used. The continuous reinforcing fibers are made from glass, carbon, basalt, aramid, or thermoplastic materials such as, but not limited to, Dyneema and Spectra. Metallic filaments can be used to provide localized reinforcement at the fitting joints between segments. The manufacture of the quasi-elliptical springs 600 can be carried out using processes such as, but not limited to, a filament winding process or a multiple reinforcing winding process, which may involve weaving or knitting non-crimped fabrics or staple fibers in addition to the unidirectional fibers. The winding of the continuous reinforcing filaments is circumferential for at least one of the two types of springs used. By winding the fibers to a specified thickness, the spring constant or other characteristics of the quasi-elliptical spring 600 can be modified. The quasi-elliptical spring 600 can be radially coated with a protective coating, preferably with a rigid rubber or elastomer base. However, it is noted that, as a variant, this coating could be comprised of a flexible rubber / reinforcement element composite.

[0047] The semi-elliptical spring 600 can be wound in tension. When compressed, the semi-elliptical spring 600 remains in tension, allowing for improved load-strength resistance. When used in multiples, the semi-elliptical springs 600 push or deform against each other when force is applied, distributing the load among multiple such semi-elliptical springs 600. High-stress areas on a semi-elliptical spring 600 cause the elliptical shape of the spring to contact adjacent semi-elliptical springs 600, compressing all of the semi-elliptical springs 600. The controlled stiffness characteristics of the semi-elliptical springs 600 allow for controlled distribution of load forces. Increased distribution of load forces is necessary to maintain tire integrity when the tire is in a flat condition or when a drop in inflation pressure occurs inside the mounting assembly. The present disclosure of a flat running device 1 using an elliptical spring 600 that remains in tension is contrary to known methods that use elastomeric properties.

[0048] In an exemplary embodiment, three quasi-elliptical springs 600 are fixed within the compound spring segment 200. The quasi-elliptical springs 600 may be fixed to the compound spring segment 200 by bolting, riveting, gluing, mechanical interlocking between the springs, or any other relative fixing means. The fixing means is determined based on multi-directional mechanical stress, thermal expansion, performance requirements, or any other relevant factors.

[0049] According to an example embodiment, to put on the flat running device 1, the user advantageously proceeds in the following manner. That is, first, the composite spring type segments 200 are inserted inside the tire casing 6 with their ends aligned but not connected, and then the composite spring type segments 200 are positioned inside the casing 6 facing each other both axially and radially, as well as circumferentially, and the connecting members 400 are assembled (by axially inserting each protrusion or bolt 500 at the loop ends 206 / 208 on both sides into the corresponding loop ends 206 / 208 and connector 700), so that the composite spring type segments 200 are connected to each other inside the casing 6, and two locking wedges are positioned axially relative to the composite spring type segments 200 and radially facing the connector 700 so as to be connected thereby to hold the composite spring type segments 200 and connector 700 in place during running, and the flat running device 1 thus assembled is slid on the axial inner surface of the rim bottom 14 of the rim 18.

[0050] In another embodiment, the circumferential clamping of the composite spring-type segment 200 onto the wheel involves at least one of the pins 500 used having an oval geometry. At least one of the connectors 700 can provide a tensile movement within the double shear overlap of the connecting member 400. When installing the annular support structure 100 on the rim 2, under the rotational effect of the pins 500, which specifically contribute to this function of tensile movement, a circumferential clamping of the annular support structure 100 relative to the rim 2 is induced, preventing relative movement between the rim 2 and the annular support structure 100. In order to maintain a constant long-term circumferential grip between the annular support structure 100 and the rim 2, multiple elastomeric components can be used within the connecting member 400, inside which the pins 500 are installed.

[0051] Additionally, lubricant may be added to the rim 2 to lower the amount of potential friction between the annular support structure 100 and the rim 2 in order to reduce the amount of heat generated.

[0052] It should be noted that, as indicated above, the composite spring-type segments 200 and the overall annular support structure 100 can reversibly move relative to each other both axially and in the direction of twisting when the tire is in a punctured state or when the inflation pressure inside the flat running device drops, due to a combination of sliding and pivoting of the protrusions or pins 500 on the connectors 700, and also due to the flexibility of the locking wedges under the effect of lateral shear or compression forces applied to the casing 6.

[0053] When the tire is punctured or when the inflation pressure inside the flat running device 1 drops, the lack of inflation pressure causes the casing 6 to sag at the point of contact with the road surface and to the point where the inner surface of the casing 6 contacts the outer surface 214 of the composite spring-type segment 200 or the annular support structure 100. Depending on the size of the tire, the contact area between the inner surface of the casing 6 and the outer surface 214 of the composite spring-type segment 200 or the annular support structure 100 may vary. Preferably, the contact area is the product of a length of 5" to 7" and a width of 5". When the tire is punctured or when a drop in inflation pressure and rotation of the inner surface of the flat running device 1 occurs, the area may be approximately the length of the quasi-elliptical spring 600. Preferably, the use of two 2.5-inch wide quasi-elliptical springs 600 offset by 2.5 inches may be required to distribute the pressure evenly on the outer surface 214 of the composite spring-type segment 200 or the annular support structure 100. Thus, when placed under a circumferential load, tire rotation causes a wavy linear deformation of the composite spring segment 200. Thus, when referring to load forces, there is a discontinuity along the circumferential surface of the connecting member 400. The surface discontinuity, which may be located at 120 degrees of the circumference and is of a length similar to the length of the semi-elliptical spring 600 (approximately 4-5 inches), reduces the contact area, which is common to other known runflat designs.

[0054] In the example of Figure 11, similar to the examples of Figures 1 and 2, the device 1 is mounted on a rim bottom 14 which is of a substantially flat type. The device 1 comprises an annular support structure 100 designed to be mounted on the rim 2 to support the casing 6 after the drop in inflation pressure inside the mounting assembly 1, said annular support structure 100 being divided into a number of composite spring-type segments 2000 or spring segments 2000, preferably but not limited to three, each of which is arc-shaped and connected to one another at their extended ends 2100, suitable for forming the annular support structure 100 by arranging them in the circumferential direction of the annular support structure 100, and rubber-based connecting members 4000, each of which is a single piece and reinforced by a circumferential reinforcing element (not illustrated), designed to connect the quasi-elliptical springs 6000 or elliptical springs 6000 to the beads 8, wherein these quasi-elliptical springs 6000 can press laterally against the radially inner zone of the composite spring-type segments 2000, where they are placed to hold the annular support structure 100 in place during running. Preferably, three compound spring segments 2000 are divided into approximately 120 degree segments radially covering the rim 2. Each compound spring segment 2000 is approximately equal in length to span and cover a distance of the rim that is 120 degrees as measured radially from the center of the rim 2.

[0055] Each of the composite spring-type segments 2000 is preferably made of a composite material, i.e., a material resulting from a combination of unidirectional fibers impregnated with a thermosetting resin matrix (epoxy, urethane), but is not limited to this; thermoplastic resins can also be used. The continuous fibers are made of glass, carbon, basalt, aramid, or thermoplastic materials such as, but not limited to, Dyneema and Spectra. Metal reinforcing filaments can be used to provide localized reinforcement at the fitting joints between segments. The composite spring-type segment 2000 can be manufactured using a filament winding process or a multiple reinforcing winding process, and non-crimped fabrics or staple fibers can be woven or knitted in addition to the unidirectional fibers. The winding of the continuous reinforcing filaments is circumferential for at least one of the two types of springs used. The spring constant or other characteristics of the composite spring-type segment 2000 can be modified by winding the fibers to a specified thickness. The composite spring segment 2000 may be radially coated with a protective coating, preferably with a rigid rubber or elastomer base, although it is noted that, as a variant, this coating could be comprised of a flexible rubber / reinforcement element composite.

[0056] Regarding the geometry of each composite spring segment 2000, in the example of Figure 12, each composite spring segment 2000 has a radially inner surface 2160 to which the quasi-elliptical spring 6000 is fixed, and a radially outer surface 2140 located thereon, the radially outer surface 2140 having axial segments that coincide with the protective coating.

[0057] Regarding the geometry of each connecting member 4000, as shown in the examples of FIGS. 11, 12, and 15, the compound spring-type segment 2000 has at least one extended end 2100. The extended end 2100 can be aligned with the extended end 2100 of another compound spring-type segment 2000. The geometry of the extended end 2100 can be any symmetrical shape that mirrors or aligns with the geometry of the extended end 2100 of another compound spring-type segment 2000. The geometry or shape of the extended end 2100 can be curved such that the peak of one extended end 2100 aligns with the valley of the other extended end 2100. As shown in the example of FIG. 15, the extended end 2100 can be rectangular. The overall geometry of the compound spring segment 2000 is similar to one-third of a circumference, and due to the curvature or arc of the compound spring segment 2000, the length of the top surface 2140 is longer than the bottom surface 2160. The bottom surface 2160 contacts or is fixed to the quasi-elliptical spring 6000, while the edge 2040 of the top surface 2140 contacts the casing 6 when a compressive force is applied to the casing 6 causing the tire to go flat or when the inflation pressure inside the flat running device 1 drops. The top surface 2140 can act like a support surface for the cover 6.

[0058] In a preferred embodiment, twelve quasi-elliptical springs 6000 are positioned between the bottom surface 2160 of the compound spring segment 2000 and the rim bottom 14. As shown in the embodiment of FIG. 14 , the quasi-elliptical springs 6000 are preferably essentially kidney-shaped in shape, but can be any shape that allows for spring action, specifically trapezoidal, kidney-shaped, or kidney-shaped. In particular, a kidney shape can include concave side portions. A quasi-elliptical shape can be any shape in which one radius is longer than the other radius. In the embodiment of FIG. 15 , the quasi-elliptical springs 6000 are trapezoidal in shape. The shape of the quasi-elliptical springs 6000 may depend on the load capacity requirements; for example, in the embodiment of FIG. 15 , the load capacity is considered to be 12,000 pounds, and the shape of the quasi-elliptical springs 6000 is taller or more trapezoidal in comparison to the embodiment of the quasi-elliptical spring 6000 of FIG. 14 . The quasi-elliptical springs 6000 are preferably made of the same or similar material as the composite spring segment 2000. The quasi-elliptical springs 6000 act as springs in tension, maintaining structural support for the composite spring segment 2000 and allowing the annular support structure 100 to pivot. A preferred embodiment includes twelve quasi-elliptical springs 6000, although the number of quasi-elliptical springs 6000 can be varied depending on the resistance requirements under load and the desired uniformity of circumferential deformation of the annular support structure 100. The quasi-elliptical springs 6000 can be any width, but are preferably half the width of the composite spring segment 2000 so that the quasi-elliptical springs 6000 can be positioned adjacent to each other while remaining fixed to the composite spring segment 2000.

[0059] Furthermore, the individual shape and thickness of the quasi-elliptical spring 6000 can be varied depending on the structural requirements and the composition of the laminate applied by filament winding. Each of the quasi-elliptical springs 6000 can be preferably manufactured from a composite material, i.e., a material resulting from a combination of unidirectional fibers impregnated with a thermosetting resin matrix (epoxy, urethane), but is not limited to such. The continuous fibers can be manufactured from glass, carbon, basalt, aramid, or thermoplastic materials such as, but not limited to, Dyneema and Spectra. Metallic filaments can be used to provide localized reinforcement at the fitting joints between segments. The manufacture of the quasi-elliptical spring 6000 can be carried out using a filament winding process. The winding of the continuous reinforcing filament is circumferential for at least one of the two types of springs used. The spring constant or other characteristics of the quasi-elliptical spring 6000 can be modified by winding the fibers to a specified thickness. The semi-elliptical spring 6000 may be radially coated with a protective coating, preferably with a rigid rubber or elastomer base, although it is noted that, as a variant, this coating could be comprised of a flexible rubber / reinforcement element composite.

[0060] The semi-elliptical spring 6000 can be wound in tension. When compressed, the semi-elliptical spring 6000 remains in tension, allowing for improved load-strength resistance. When used in multiples, the semi-elliptical springs 6000 push or deform against each other when force is applied, distributing the load among multiple such semi-elliptical springs 6000. High-stress areas on the semi-elliptical spring 6000 cause the kidney-shaped shape of the spring to contact adjacent semi-elliptical springs 6000, compressing all of the semi-elliptical springs 6000. The controlled stiffness characteristics of the semi-elliptical spring 6000 allow for controlled distribution of load forces. Increased distribution of load forces is necessary to maintain tire integrity when the tire is in a flat condition or when a drop in inflation pressure occurs inside the mounting assembly. The present disclosure of a flat running device 1 using an elliptical spring 6000 that remains in tension is contrary to known methods that use elastomeric properties.

[0061] In a preferred embodiment, twelve quasi-elliptical springs 6000 are secured within three connected composite spring segments 2000. The quasi-elliptical springs 6000 can be secured to the composite spring segments 2000 by bolting, riveting, gluing, mechanical interlocking, or any other means of securing relative to one another. The securing means is determined based on multi-directional mechanical stress, thermal expansion, performance requirements, or any other relevant factors. An exemplary securing means is shown in FIG. 13 , including a locking hex nut 5000, a flat washer 5100, and a bolt 5200. Each quasi-elliptical spring 6000 is secured to the composite spring segment 2000 preferably using four bolts, although any number of bolts may be used. The twelve quasi-elliptical springs 6000 are secured to the composite spring segment 2000 and are equally spaced radially around the rim 2. Each composite spring-type segment 2000 can have preferably four quasi-elliptical springs 6000 secured to the bottom surface 2160, although any number of quasi-elliptical springs 6000 can be used. The four quasi-elliptical springs 6000 are aligned in pairs, each pair being adjacently offset such that the quasi-elliptical springs 6000 are arranged in a staggered manner such that the extended end 2100 of a quasi-elliptical spring 6000 aligns with the central segment 6100 of the adjacent quasi-elliptical spring 6000. Preferably, the quasi-elliptical springs 6000 are secured to the spring-type segment 2000 and adjacently offset such that the extended end 2100 of the spring-type segment 2000 is radially aligned with the central segment 6100 of the secured quasi-elliptical spring 6000. This advantageously provides additional structural support at the extended end 2100 of the spring-type segment 2000.

[0062] Figure 16 shows a graph displaying stiffness versus rotation for a run-flat system with spring suspension, where stiffness is measured in N / mm and angular displacement is measured in degrees, with upper and lower limits set for stiffness.

[0063] Figure 17 shows a graph displaying force versus displacement, where force is measured in N and displacement is measured in mm, while the function is approximately linear as force and mm increase.

[0064] According to one example of a preferred embodiment, to mount the flat running device 1, the user proceeds in the following manner: fastening the quasi-elliptical springs 6000 to the compound spring segments 2000 with the bolt-type connecting members 4000, positioning these quasi-elliptical springs 6000 in a staggered manner so that their ends 6200 are aligned with the central segments 6100 of adjacent quasi-elliptical springs 6000, and then inserting the compound spring segments 2000 end-to-end but not connected to each other into the tire casing 6, and positioning these compound spring segments 2000 so that their respective extended ends 2100 are aligned adjacent to each other. The composite spring-type segments 2000 are connected to each other inside the casing 6 by assembling the connecting member 4000 by positioning them inside the casing 6 facing each other both axially and radially, as well as circumferentially, aligning the extended ends 2100 of the spring-type segments 2000, and bolting the extended ends 2100 of the spring-type segments 2000 to the quasi-elliptical spring 6000, and the flat running device 1 thus assembled is slid over the axial inner surface of the rim bottom 14 of the rim 18.

[0065] Additionally, lubricant may be added to the rim 2 to lower the amount of potential friction between the annular support structure 100 and the rim 2 in order to reduce the amount of heat generated.

[0066] When the tire is punctured or when the inflation pressure inside the flat running device 1 drops, the lack of inflation pressure causes the casing 6 to sag at the point of contact with the road surface and to the point where the inner surface of the casing 6 contacts the outer surface 2140 of the composite spring-type segment 2000 or the annular support structure 100. Depending on the size of the tire, the contact area between the inner surface of the casing 6 and the outer surface 2140 of the composite spring-type segment 2000 or the annular support structure 100 may vary. Preferably, the contact area is the product of the length of 5" to 7" and the width of 5". When the tire is punctured or when a drop in inflation pressure and rotation of the inner surface of the flat running device 1 occurs, the area may be approximately the length of the quasi-elliptical spring 6000. Preferably, the use of two 2.5-inch wide quasi-elliptical springs 6000 offset by 2.5 inches may be required to distribute the pressure evenly on the outer surface 2140 of the composite spring-type segment 2000 or the annular support structure 100. Thus, when placed under a circumferential load, a near-linear deformation of the composite spring segment 2000 occurs due to tire rotation. Thus, when referring to load forces, there is a discontinuity along the circumferential surface of the connecting member 4000. The surface discontinuity, which may be located at 120 degrees of the circumference and is of a length similar to the length of the semi-elliptical spring 6000, which is about 4-5 inches, reduces the contact area, which is common with other known runflat designs.

Claims

1. 1. A run-flat device configured to be mounted on a tubeless-mounted wheel assembly for a motor vehicle, the tire cover including a wheel rim and a tire cover including a bead mounted against an edge of the rim, the run-flat device comprising: an annular support structure configured to be mounted around the rim to support the cover after a drop in inflation pressure inside the mounting wheel assembly; The annular support structure comprises: at least one composite spring segment forming an arc and mounted circumferentially around the rim to form the annular support structure; an arrangement for locking the bead against the edge, the arrangement being configured to connect the annular support structure to the bead; Including, Run-flat device.

2. 10. A runflat as set forth in claim 1, wherein said compound spring segment further comprises a plurality of elliptical springs and is shaped to incorporate said plurality of elliptical springs secured to an inner surface of said compound spring segment.

3. 2. A runflat as set forth in claim 1 wherein said annular support structure further includes an end-to-end assembly of said composite spring segments that provides uniform stress distribution in tension across the width of said runflat.

4. 4. A runflat as set forth in claim 3 wherein said compound spring segment further includes an extended end configured to be attached to one of said plurality of elliptical springs for said end-to-end assembly.

5. 5. A runflat as set forth in claim 4 wherein one of said plurality of elliptical springs is attached to two compound spring segments.

6. 10. A runflat as set forth in claim 1 wherein said composite spring segment is in the form of a perfectly elastic spring that does not generate heat when cyclically deformed under the influence of a compressive load applied normal to its outer surface.

7. 2. A runflat as set forth in claim 1 wherein said compound spring segment spans radially around said wheel in 120 degree segments, and wherein four elliptical springs are secured to a bottom surface of said compound spring segment, said elliptical springs being adjacently offset such that at least one of said four elliptical springs is at least partially radially outward of said 120 degree segments.

8. 10. The runflat of claim 1, wherein said composite spring segment is constructed from continuous reinforcing filaments impregnated with a thermosetting resin that allows for variable mechanical strength and stiffness for a fixed geometry and size.

9. 1. A run-flat device configured to be mounted on a tubeless-mounted wheel assembly for a motor vehicle, the tire cover including a wheel rim and a tire cover including a bead mounted against an edge of the rim, the run-flat device comprising: an annular support structure configured to be mounted around the rim to support the cover after a drop in inflation pressure inside the mounting wheel assembly; The annular support structure comprises: at least one compound spring segment circumferentially assembled around the rim and having at least one extended end; at least one elliptical spring, the at least one composite spring segment being shaped for incorporation of a plurality of elliptical springs disposed beneath the composite spring segment such that the at least one composite spring segment is assembled circumferentially around the rim by fastening the extended end of the at least one composite spring segment to the at least one elliptical spring; an arrangement for locking the bead against the edge configured to connect the annular support structure to the bead; and Including, the at least one elliptical spring is formed in tension and is compressed after a drop in inflation pressure inside the mounting assembly; Run-flat device.

10. 10. A runflat as set forth in claim 9 wherein said plurality of elliptical springs are formed in tension and contact one another upon the occurrence of a drop in inflation pressure inside said mounting assembly.

11. 10. A runflat as set forth in claim 9 wherein said annular support structure further includes an end-to-end assembly of said composite spring segments that allows for uniform stress distribution in tension across the width of the runflat.

12. 10. The runflat of claim 9, wherein the extended end of the compound spring segment is configured to be attached to one of the plurality of elliptical springs, while a second extended end of a second compound spring segment is configured to be attached to the elliptical spring.

13. 10. A runflat as set forth in claim 9 wherein said composite spring segment is in the form of a perfectly elastic spring that generates reduced heat when cyclically deformed under the influence of a compressive load applied normal to its outer surface.

14. 10. A runflat as set forth in claim 9 wherein said compound spring segment spans radially around said wheel in 120 degree segments, and wherein four elliptical springs are secured to a bottom surface of said compound spring segment, said elliptical springs being adjacently offset such that at least one of said four elliptical springs is at least partially radially outward of said 120 degree segments.

15. 10. The runflat of claim 9, wherein said composite spring is constructed from continuous reinforcing filaments impregnated with a thermoset resin that allows for varying mechanical strength and stiffness for a fixed geometry and size.

16. 1. A run-flat device configured to be mounted around a wheel rim and within a tire cover, comprising: an annular support structure configured to be mounted around the wheel rim to support the tire cover after a drop in inflation pressure inside the mounting assembly; The annular support structure comprises: at least one compound spring segment circumferentially assembled around the rim and having at least one extended end; at least one elliptical spring configured to incorporate at least two elliptical springs, one of the elliptical springs being secured to a bottom surface of the compound spring segment such that the at least one compound spring segment is assembled circumferentially around the at least two elliptical springs; and Including, the at least two elliptical springs are formed in tension and are compressed after a drop in inflation pressure inside the mounting assembly; Run-flat device.

17. 17. A runflat as set forth in claim 16 wherein the width of said at least one compound spring segment is twice the width of said at least one elliptical spring.

18. 17. A runflat as set forth in claim 16 wherein said compound spring segment extends radially around said wheel rim in 120 degree segments, and wherein four elliptical springs are secured to a bottom surface of said compound spring segment, said elliptical springs being adjacently offset such that at least one of said four elliptical springs is at least partially radially outward of said 120 degree segments.

19. 17. A runflat as set forth in claim 16, wherein the extended end of the compound spring segment is configured to be attached to one of the plurality of elliptical springs, while a second extended end of a second compound spring segment is configured to be attached to the elliptical spring.

20. 20. A runflat as set forth in claim 18, wherein the extended end of the compound spring segment is configured to be attached to one of the plurality of elliptical springs, while a second extended end of a second compound spring segment is configured to be attached to the elliptical spring.

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