This invention pertains to the integration of a runflat system including a runflat ring comprised of interconnected sectors or segments into a wheel. More particularly, the system of the invention includes an easy to assemble open-bottom connection system incorporated directly into a runflat device that couples multiple sectors together to form a runflat ring. The quick assembly process inherent in the inventive concept does not require fastening hardware and supersedes the historic need for special tools or equipment to install runflats. In addition, in various optional embodiments, the invention includes connection means that allow rotation between sectors, latching means for holding sectors together, and structure(s) that help to eliminate frictional heating (and concomitant system failure) between the runflat ring/runflat sectors and the tire by making the runflat ring/sectors freely rotating with respect to the tire and/or by providing compensators between runflat ring/++sectors and tire that likewise serve to reduce friction and heating.
Prior art runflat designs have typically been produced from natural rubber, plastic or metal and have numerous disadvantages. Natural rubber runflat designs and runflat rings generally take the form of a continuous loop that needs to be compressed with a large press to insert into a tire. Removal is also difficult, as the runflat system must be pulled from the tire cavity after being manually collapsed with a large strap.
However, the available alternative—prior art plastic and metal runflats—even though produced in sectors rather than as a continuous loop, have their own problems. To begin with, current plastic and metal runflats require installation of hardware, often unique to the runflat design, to secure the unit on the wheel. In addition, neither natural rubber runflats (which are inherently single-piece designs) nor assembled plastic and metal runflats (which form rigid structures after assembly) allow rotation between sectors. Further, assembly of current plastic and metal designs require hardware and components that are generally only available through the original equipment manufacturer, that can be misplaced within the tire cavity, and that can thereby cause premature system failure. This hardware also requires tools that will not generally be readily available to soldiers, particularly soldiers in the field (who will be those most in need of making quick and effective repairs). Finally, when tightened, such hardware can strain the components of a plastic runflat system and create a plastic creep situation that causes the hardware to loosen as well as fatigue with time.
The improved runflat system described herein teaches a system comprising a plurality of arcuate sectors, each of said sectors being linked to at least one other sector such that said plurality of sectors form a substantially continuous ring around the wheel. These sectors are provided with and joined by integral overlapping and interlocking connector parts positioned at the ends of each sector. The structure of the connector parts in some embodiments allows rotation around an interconnection rotational axis, such that each sector can be bi-directionally rotated (i.e., clockwise and counterclockwise) around said interconnection rotation axis with respect to an adjacent sector.
The foregoing features and others of the inventive concept, as more fully described below, provide numerous advantages over the systems of prior art. First, the invention maintains runflat load integrity by restraining forces and absorbing shocks in the axial, radial and circumferential directions. Second, the invention can increase the ability of the runflat to absorb energy caused by wheel impact and will reduce the shock transmitted to the vehicle due to the foregoing. Third, the energy absorption characteristics of the invention can be modified by varying the support provided via the spacers of the invention by selecting different types of elastomeric, plastic, metallic or other spacer materials therefor. Fourth, the invention is quick and easy to assemble and requires neither hardware nor special tools. Fifth, its optional friction reducing features serve to eliminate a major cause of runflat/tire failure. Finally, its durability and effectiveness in its role, as well as the simplicity of construction and installation created by its innovative design features, makes it a system that is easy to use while remaining extremely sturdy and robust, making it ideal for the types of military uses and situations contemplated for the invention.
A first and more basic mode of implementing our invention is illustrated in
The runflat system of both modes of the invention is formed from a plurality of arcuate sectors 10, each of said sectors 10 being linked to at least one other sector 10 such that said plurality of sectors 10 forms a substantially continuous ring (as illustrated in
In addition, beadlock spacers 12A, 12B are also provided and used in both modes of the invention described herein. These are preferably formed as continuous bands so as to form rings around said wheel rim 3 intermediate the beads 5A, 5B of tire 5 and the sides of sectors 10 when mounted in operating position. The beadlock spacers 12A, 12B are important to the system for several reasons. First, they inhibit lateral movement of the runflat system with its plurality of sectors 10 (i.e., movement parallel to said rim axis) in both embodiments. Second, they assist in centering the runflat system of the invention with its sectors 10 in optimum operating position on wheel rim 3 between beads 5A, 5B within tire 5. Third, they serve to assist in the runflat operations of the system by locking beadlocks 5A, 5B in position against rim flanges 4A, 4B. Fourth, they interact with surfaces 10A of sectors 10 of the embodiment illustrated in
The function of the beadlock spacers 12A, 12B is advantageously supplemented by a stationary rim abutting element or elements that is/are adapted to abut and remain stationary with respect to the rim. In the embodiment illustrated in
A more detailed appreciation for the structure and innovations inherent in the integral overlapping and interlocking connector parts 11 of both the basic and the preferred embodiments illustrated can be obtained from review of
As will be obvious from the aforesaid drawing figures and discussions, two complementary connector parts 11 of adjacent sectors 10 (lower connector part 11A and upper connector part 11B) form an overlapping and interlocking connection when the upper connector part 11B is placed over the lower connector part 11A such that male connector portion 15A is inserted into female connector portion 16A. In this position, adjacent sectors are prevented from pulling away from each other via the connection between male/female portions 15A, 16A. And, in the embodiments illustrated in
A better understanding of the “rotation” feature described above can be obtained by review of
The preferred (and extremely simple) method of assembly of the embodiment of the invention illustrated in
After assembly, the foregoing parts cooperate synergistically to absorb radial, circumferential, and axial shocks in the absence of inflation in tire 5. From a radial standpoint, all shocks perpendicular to the central axis of wheel 2 (e.g., standard up/down shocks) are absorbed and buffered by the sectors 10 (including their overlapping sections 11A, 11B) and bottom spacer 13, and transferred by them to wheel rim 3 and ultimately in most cases to the shock absorbers of the vehicle. From a circumferential standpoint (i.e., for shocks conveyed along the loop formed by the assembled sectors 10), the connection between adjacent sectors 10 transmits such shocks to the assembly as a whole, which can dissipate such energy (even subject to the fact that bottom spacer 13 severely inhibits rotational movement with respect to and between the assembled sectors 10 and rim 3) via limited movement around and with respect to rim 3. From an axial standpoint, as more fully discussed in the following paragraph, the situation is more complex.
For an axial shock (i.e., a shock parallel to the central axis of wheel 2), two modes of shock absorption are readily available. As previously mentioned and discussed above, a shock parallel to the central axis of wheel 2 can be absorbed by rotation of a sector or sectors 10 away from the shock around the interconnection rotational axes 17 intermediate adjacent sectors 10. The energy of this shock is, however, also absorbed via the beadlocking spacer 12A, 12B on the same side as the shock, as the shock while forcing the outer periphery of the sector 10 to rotate away from its normal position perpendicular to the central axis of the wheel 2, will force inclined surfaces 10A of said sector 10 outwardly from the central axis, forcing the adjacent and abutting portion of the said beadlocking spacer 12A, 12B outwardly from wheel rim 3. The beadlocking spacer 12A, 12B, being formed of elastic materials then acts in a spring-like fashion to resist this movement and force the sector 10 back into proper aligned position perpendicular to the central axis, absorbing the shock and restoring stasis. In addition, slide gaps 18A, 18B are provided between the inward part of sectors 10 and/or bottom spacer 13, and interfering features/ledges of rim 3, allowing displacement of the entire assembly comprised of sectors 10 inwardly or outwardly in response to such axial shocks (as indicated by arrows 19A, 19B).
In addition to the features previously described, a latching system can, as illustrated in
Bolt stop 23 also has a rotational cam surface 23A at its upper end by which it interacts with bolt slot 20B and thereby with bolt 20. Rotational cam surface 23A includes, as is typical and well known in the mechanical arts, a raised portion 23A′ in one quadrant that smoothly transitions via two side quadrants to a lower opposite quadrant 23A″. Thus, by rotation of bolt stop 23 using a screw driver in slot 23B′ provided in lower bolt end 23B, raised portion 23A′ and lower portion 23A″ can be rotated so as to reverse position, forcing bolt 20 back into bolt sheath 21 as indicated by arrows 30.
The tapered cam surface 20A of bolt 20 allows the lower connector part 11A and the upper connector part 11B to be slid together in the manner previously described for assembly of the invention, as it forces the bolt to withdraw into bolt sheath 21 in a manner well known in the mechanical arts related to door bolts when the two parts are joined. And, as described in the preceding paragraph, bolt 20 can be withdrawn from upper connector part 11B by using a screwdriver to rotate bolt stop 23, allowing the operation to be reversed so as to allow these parts to be separated.
Further, it should be noted that the positioning of the respective latch parts in the manner shown is not required as the bolt 20 and its related parts could be positioned within the upper connector part 11B, and the latch aperture 24 could be positioned within the lower connector part 11A. In this configuration, to allow the parts to slide together and fasten in the manner described, the tapered surface 20A should face downward rather than upward as illustrated in the drawing figures. However, in either configuration, the latching system described provides a positive locking feature for the invention and securely locks the segments together during assembly. It is especially useful at high speeds in maintaining system integrity and, once again, requires no specialized assembly tools and equipment that could interfere with repair and use by soldiers in the field.
Having discussed many features common to both the more basic and the preferred embodiments of the invention, the distinctive features of the preferred embodiment are more easily highlighted. To begin with, in the preferred embodiment (as best seen in
In addition, runner 30 also replaces the lower portion of the sectors 10 adjacent rim 3 and abutted by firmly beadlocking spacers 12A, 12B, taking over the role played by this portion of sectors 10 in the embodiment described in
The reason it is important for sectors 10 to slide/rotate in the manner described is related to the function this innovation serves in eliminating friction between sectors 10 and tire 5. Generally, friction and frictional heating generated by contact between the portions of runflat devices extending transversely to the axis of rim 3 (which serve to support a tire 5 when it is flat) and the tire itself are a leading cause of runflat/tire failure. This friction is generated by the fact that, e.g., the inner surface 5A of tire 5 has a greater circumference than that of sectors 10. This means that where the inner surface 5A is pressed against sectors 10 in a runflat situation, it slides relative to sectors 10, generating immense amounts of friction and frictional heating. This frictional heating is a major cause of runflat failure and tire failure when operating in a runflat condition. Consequently, in order to minimize this, it is necessary to minimize tire 5 slide and/or the effects of tire 5 slide relative to sectors 10.
In the preferred embodiment, this is accomplished by the positioning of a low friction member 40 intermediate sectors 10 and rim 3 on runner 30. In the preferred embodiment illustrated, low friction member 40 takes the form of a planar sheet of materials provided with perforations allowing it to be fitted to runner 30 over extensions 33. It can be further stabilized in position on runner 30 via screwing it to runner 30 with screws placed intermediate extensions 33 or via adhesion, or using other means known to those skilled in the art. Extensions 33 also serve as centering guides for sectors 10, fitting into an extension slot 50 provided in the bottom of the sectors 10 of the preferred embodiment, and assisting in holding said sectors 10 in their preferred and necessary operating position (as illustrated in
In addition, assembly of the preferred embodiment (like the more basic embodiment) remains simple. First, referring generally to
Finally, and in addition to the aforesaid friction reducing innovations, our invention can also include circumferential compensators 60 mounted to the circumference of sectors 10 intermediate sectors 10 and tire 5. (See, e.g.,
To envision the operation of compensators 60, consider that they are mounted with their sliding end 62A directed in the direction of circumferential motion of tire 5 and sectors 10 when in normal forward motion. Thus, as sectors 10 with compensators 60 roll underneath the vehicle and are compressed between the inner surface of tire 5 and the outer circumference of a sector 10, apex 63 initially contacts the inner surface of tire 5 and then, due in part to its pointed wedge shape, adheres to the inner surface of tire 5 (due to mechanical forces) in more-or-less the same position at which it contacts the inner surface of tire 5, minimizing sliding vis-à-vis the compensator 60. Then, as compensator 60 is further compressed, apex 63 travels with the inner surface of tire 6, pivoting over from its initial position (with first end 61A acting as a pivot point) until it is flat against sector 10. In doing this, compensator 60, via the use of apex 63 as a pivoting contact with the inner surface of tire 5, allows tire 5 inches of circumferential slide relative to the outer circumference of sector(s) 10, as well as acting as a shield between (and minimizing contact between) sectors 10 and the inner surface of tire 10. Then, once the said compensator 60 (by further rotation of its sector 10 out from the under the vehicle) is no longer compressed between tire 5 and compensator 10, it is free to resume its initial configuration.
The amount of slide will, in fact, be approximately equal to the length of leg 61 in the preferred configuration illustrated and discussed herein. However, while the geometry and form specified is considered advantageous, it should be remembered that the invention can take other forms. Its most important aspect is the provision of a member (in this case leg 61) that is connected to and extends transversely to sector 10, which member will contact and adhere to the inner surface of a tire 5 at its other end (in this case apex 63) and which end will thereafter rotate, pivot or otherwise move along with tire 5 in the direction of circumferential motion of the tire 5 and sector 10, so that it lays down flat therebetween as it is compressed and after being so compressed, resumes its former position.
Finally, the materials utilized in forming sectors 10 are extremely important. In this regard, the materials chosen should ideally offer superior compression loading strength with overload capabilities if required by tactical situations. In addition, they should safeguard vehicle occupants by absorbing curb shock energy. This can best be accomplished by utilizing a material formulated to provide deceleration of energy that traditionally was conducted through stiffer materials (such as metallic materials), or rebounded with less stiff materials (such as rubber). Energy absorption is the best solution to maintain vehicle control and reduce operator injury. Further, the material should be compliant to varying load conditions and keep the tire tread firmly secured to the road surface for maximum vehicle control and traction. It should also reduce vehicle weight over existing runflat designs and be operable at extreme temperatures. Ideally, it should also be ballistic resistant and maintain ballistic resistance down to −40 degrees F.
However, numerous variations in terms of material as well as in regard to other features of the invention are possible without deviating from and/or exceeding the spirit and scope of the invention. In addition, various features and functions disclosed above, or alternatives thereof, may be desirably combined into many other different systems or applications. Further, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the claims that follow.
This application claims an invention which was disclosed in a U.S. provisional patent application filed Jul. 24, 2008, Ser. No. 61/135,978, entitled “Runflat System with Rotating Interconnected Sectors”. Priority benefit of the said United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2009/004311 | 7/24/2009 | WO | 00 | 5/26/2011 |
Number | Date | Country | |
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61135978 | Jul 2008 | US |