Run flat tire systems are used on automobiles, commercial vehicles and military vehicles, among others, to provide for continued operation of vehicles (often at reduced speeds and for limited distances) after a tire blow out, reduced tire pressure or other tire damage. Generally, run flat tire systems consist of a support ring or toroid disposed within a rubber tire and attached to or aligned around a wheel.
With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiments, merely for purposes of illustration and not by way of limitation, the present invention provides a run flat system comprising one or more arcuate portions (200, 210, 220, 300, 310, 320) configured so as to extend radially outward from a wheel. Where two or more arcuate portions are used, they are configured and arranged so as to connect or join together to form a ring or toroid. One or more of said arcuate portions comprise an insert portion (201, 211, 221, 301, 311, 321) of relatively stiff or strong material (e.g. of a higher durometer or stiffness or greater strength than other parts or portions of the arcuate portion(s)). In one aspect, the insert portion is encapsulated by (in whole or in part) an outer portion (202, 212, 222, 302, 312, 322) of material which is relatively soft or which has less strength or stiffness, or lower durometer.
In one aspect, said arcuate portion(s) have apertures at a proximal end and a distal end, whereby a distal end aperture in a first arcuate portion may be aligned with an aperture in a proximal end of a second arcuate portion, whereby the arcuate portions may be joined or connected.
In one aspect, the run flat tire and system has a plurality of load bearing arcuate portions configured so as to extend radially outward from a wheel, wherein each of the arcuate portions is releasably secured to at least one other arcuate portion, and all arcuate portions are secured together to form a continuous ring or attachment around the wheel; and wherein at least one of the arcuate portions comprises an insert or encapsulated portion wholly or partially within, or surrounded or encompassed by an outer portion, wherein the insert portion is made from a material having a higher strength, durometer or stiffness than the outer portion. In another aspect, the outer portion is molded onto the insert portion.
In another aspect, the run flat tire and system has a plurality of load bearing arcuate portions configured so as to extend radially outward from the drop center of a wheel wherein each of the arcuate portions is releasably secured to at least one other arcuate portion, and all arcuate portions are secured together to form a continuous ring for attachment around the wheel drop center; wherein the outer surfaces of the arcuate portions are made from a polyester elastomer thermoplastic resin or similar material. In another aspect, the outer surface of an arcuate portion surrounds, wholly or partly, a corresponding insert portion, which insert portion has greater strength, hardness or stiffness than the outer surface, which insert portion may be made of reinforced polyamide 66 resin, polybutylene terephthalate resin or a similar material, and/or made of steel such as 4140 steel.
At the outset, it should be clearly understood that like reference numerals are intended to identify the same parts, elements or portions consistently throughout the several drawing figures, as such parts, elements or portions may be further described or explained by the entire written specification, of which this detailed description is an integral part. The following description of the preferred embodiments of the present invention are exemplary in nature and are not intended to restrict the scope of the present invention, the manner in which the various aspects of this invention may be implemented, or their applications or uses.
A preferred embodiment of the run flat tire system and device comprises one or more arcuate run flat portions 200, 210, 220, 300, 310, 320 (also referred to as arcuate sections, members or segments) assembled around a wheel or rim drop center. The arcuate portions are connected, secured or fastened together with nuts and bolts, or by other hardware. In a preferred embodiment, corresponding apertures in adjacent arcuate portions are aligned, and such hardware or other mechanism(s) are used to join or connect adjacent portions through the apertures. One embodiment of the invention is a lightweight design with a bead retainer for operating with high performance vehicles among others.
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In one embodiment, three arcuate sections are assembled around the rim drop center of a tire, and may be configured and arranged to operate with high performance vehicles with central tire inflation systems (CTI). The inner circumference of the run flat device 10 may be designed and configured (by way of a mold fitted to the wheel or by machining, for example) so as to correspond to the profile of the wheel drop center to further reduce or eliminate lateral movement. In addition, the outer circumference of the run flat device, which comes into contact with a tire when the tire is deflated, may include a plurality of parallel circumferential channels or ribs, as shown at the top of the main body portion in the example illustrated in
A method of installation of a run flat tire and system is described hereafter. First, a high temperature lubricant may be applied on the wall of a tire. Second, each arcuate section of the run flat tire device and system is inserted inside a tire. Another step of the installation process includes aligning the separate sections of the run flat device and system inside the tire and connecting such sections with nuts and bolts (or another mechanism for connection of aligned openings) in the respective sections of the run flat device. A further step is centering the run flat relative to the opening in the tire. The tire with run flat as assembled is placed over the bottom half of a wheel 100. The assembled parts are then pushed or pressed so that the bottom tire bead is seated against a wheel flange and the run flat device/system is located in the corresponding area in the wheel drop center. A further step includes tightening the nuts and bolts (or other hardware) in the run flat tire system. Finally, the top part 103 of the wheel corresponding to the bottom part is pressed into the opening of the run flat and against the surface of the bottom half of the wheel and secured.
The run flat tire and system may be manufactured through the use of a mold through an extrusion process (e.g. through a conventional or general purpose extruder), melt casting or injection molding, for example. Raw material in the form of plastic pellets, such as the material described in the previous paragraph, may be introduced into a hopper; thereafter, the plastic pellets may be heated and homogenized in an extruder until they become fluid enough to inject into a mold; whereupon the fluid plastic is pushed from the extruder by feed screws through a die and into a mold, where the material hardens.
A preferred embodiment of the run flat tire and system comprises an insert or encapsulated portion made of a relatively strong and/or stiff material on the inside of (wholly or partially inside), or encapsulated by, a relatively soft material molded, formed or fitted on the outside of the insert portion, together forming a run flat segment or arcuate portion. Examples of such preferred embodiments are shown in
The configuration of the insert or encapsulated portion in this embodiment corresponds to or complements the design of the outer portion, the insert portion being located within, encompassed, surrounded or encapsulated by (in whole or in part) the outer portion. For example, the inner surface (relative to a wheel) of an insert portion may abut the wheel, with the remaining surfaces of the insert portion surrounded by an outer portion (e.g. the outer portion is molded around only the upper surfaces of an insert portion). As used herein, “encapsulated” includes any of the foregoing.
The insert or encapsulated portion may comprise DuPont Zytel® glass fiber reinforced polyamide 66 resin and/or DuPont Crastin® polybutylene terephthalate resin and/or steel such as 4140 steel. The outer portion may comprise a polyester elastomer thermoplastic resin such as Dupont PDHTR888860 or PDHTR863660.
Alternatively, the outer portion may comprise HYTREL 5556, HYTREL 7246, CRASTIN SK605 and CRASTIN ST820. In another embodiment, the foregoing materials are included in the following proportions: about 43% HYTREL 5556; about 15% HYTREL 7246; about 11% CRASTIN SK605; and about 31% CRASTIN ST820.
The preferred embodiment with insert or encapsulated portion(s) may be manufactured by injection molding, melt casting or molding through an extrusion process (e.g. through a conventional or general purpose extruder) as described above. The insert portion is first made using one such technique; then, one method of manufacture provides that the insert portion is placed inside another mold, and the softer or less stiff or lower durometer material is molded around or directly onto the insert portion. Another method provides that the parts/portions are manufactured separately and fitted together. The embodiments illustrated in
While there has been described what is believed to be a preferred embodiment of the present invention, those skilled in the art will recognize that other and further changes and modifications may be made thereto without departing from the spirit of the invention. Therefore, the invention is not limited to the specific details and representative embodiments shown and described herein. The terminology and phraseology used herein is for purposes of description and should not be regarded as limiting. Accordingly, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit or scope of the invention.
The present application claims priority to Provisional Patent Application No. 61/247,074, filed Sep. 30, 2009, incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US09/68930 | 12/21/2009 | WO | 00 | 4/26/2012 |
Number | Date | Country | |
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61247074 | Sep 2009 | US |