U.S. patent application number 13/606796 was filed with the patent office on 2013-07-11 for run-flat support assembly for a pneumatic tired wheel and method for use of same.
This patent application is currently assigned to DYNAMIC RUNFLATS, INC.. The applicant listed for this patent is William W. Gardetto. Invention is credited to William W. Gardetto.
Application Number | 20130174954 13/606796 |
Document ID | / |
Family ID | 42036419 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130174954 |
Kind Code |
A1 |
Gardetto; William W. |
July 11, 2013 |
RUN-FLAT SUPPORT ASSEMBLY FOR A PNEUMATIC TIRED WHEEL AND METHOD
FOR USE OF SAME
Abstract
A run-flat support assembly for a wheel rim of a pneumatic tired
wheel and method for use of the same are disclosed. In one
embodiment, a tubular support structure is positioned in a tire
cavity of the pneumatic tired wheel and coupled to the wheel rim to
turn concurrently with an axis of rotation of the wheel rim. A
skeletal structure is disposed within the tubular support
structure. Circumferentially spaced linkages are displaceably
secured to respective mounting races of a body of the skeletal
structure. Each of the circumferentially spaced linkages is adapted
to plastically fail at a pre-determined moment load in a run-flat
condition, thereby pivoting relative to the respective mounting
race.
Inventors: |
Gardetto; William W.;
(Colleyville, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gardetto; William W. |
Colleyville |
TX |
US |
|
|
Assignee: |
DYNAMIC RUNFLATS, INC.
Indian Land
SC
|
Family ID: |
42036419 |
Appl. No.: |
13/606796 |
Filed: |
September 7, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12410319 |
Mar 24, 2009 |
8281835 |
|
|
13606796 |
|
|
|
|
61039033 |
Mar 24, 2008 |
|
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Current U.S.
Class: |
152/520 |
Current CPC
Class: |
B60C 17/041 20130101;
B60C 17/04 20130101; B60C 17/06 20130101 |
Class at
Publication: |
152/520 |
International
Class: |
B60C 17/04 20060101
B60C017/04 |
Claims
1. A run-flat support assembly for a wheel rim of a pneumatic tired
wheel, the assembly comprising: a tubular support structure
positioned in a tire cavity of the pneumatic tired wheel, the
tubular support structure operable to be coupled to the wheel rim
and adapted to turn concurrently with an axis of rotation of the
wheel rim; a skeletal structure disposed within the tubular support
structure, the skeletal structure including a body adapted to turn
concurrently with the axis of rotation; and a plurality of
circumferentially spaced linkages displaceably secured to
respective mounting races of the body, each of the plurality of
circumferentially spaced linkages adapted to plastically fail at a
pre-determined moment load in a run-flat condition, thereby
pivoting relative to the respective mounting races.
2. The run-flat support assembly as recited in claim 1, wherein the
tubular support structure comprises a polymer housing.
3. The run-flat support assembly as recited in claim 1, wherein
each of the plurality of circumferentially spaced linkages are
secured to the respective mounting races of the body by a retainer
member that is adapted to plastically fail at the pre-determined
moment load in the run-flat condition.
4. The run-flat support assembly as recited in claim 1, wherein
each of the plurality of circumferentially spaced linkages further
comprises an arcuate face, the arcuate face being contoured and
sized to be received in the mounting race in pivoting contact in a
run-flat condition.
5. The run-flat support assembly as recited in claim 1, wherein
each of the plurality of circumferentially spaced linkages comprise
an elongated beam having a pair of contact bearing surfaces at
opposite ends thereof.
6. The run-flat support assembly as recited in claim 5, wherein the
pair of contact bearing surfaces opposingly oscillate between
contact pressure with the body and contact pressure with an
interior wall of the pneumatic tired wheel in a run-flat
condition.
7. The run-flat support assembly as recited in claim 1, wherein the
run-flat condition comprises a flat condition selected from a group
consisting of under-inflated conditions and deflated
conditions.
8. A run-flat support assembly for a pneumatic tired wheel, the
run-flat support assembly comprising: a plurality of support
segments positioned in a tire cavity of the pneumatic tired wheel,
the plurality of support segments being abutted for end-to-end
mating engagement to provide a tubular support structure having an
interior circumference defined by respective radial surfaces of the
plurality of support segments; a plurality of skeletal structures
disposed within the plurality of support segments, each of the
plurality of skeletal structures including a body adapted to turn
concurrently with the axis of rotation, the plurality of skeletal
structures having respective torque flanges that extend through the
radial surface of the plurality of support segments to provide a
substantially circular body; a plurality of circumferentially
spaced linkages displaceably secured to respective mounting races
of the bodies of the skeletal structures, each of the plurality of
circumferentially spaced linkages adapted to plastically fail at a
pre-determined moment load in a run-flat condition, thereby
pivoting relative to the respective mounting races; and a split
wheel rim secured to the torque flanges.
9. The run-flat support assembly as recited in claim 8, wherein the
substantially circular body formed by the respective torque flanges
further comprises a plurality of mounting holes through the
substantially circular body, the plurality of mounting holes being
spaced to align with a plurality of standard wheel mounting holes
associated with the split rim.
10. The run-flat support assembly as recited in claim 8, wherein
the split wheel rim comprises two wheel half-sections.
11. The run-flat support assembly as recited in claim 8, wherein
the plurality of support segments remain substantially centered
with respect to interior walls of the pneumatic tired wheel during
the run-flat condition.
12. The run-flat support assembly as recited in claim 8, wherein
each of the plurality of support segments comprises a crown member
for engaging an inner wall of the pneumatic tired wheel in the
run-flat condition.
13. The run-flat support assembly as recited in claim 8, wherein
the tubular support structure engages an interior of the pneumatic
tired wheel between beads of the pneumatic tired wheel in the
run-flat condition.
14. The run-flat support assembly as recited in claim 8, wherein
the run-flat condition comprises a flat condition selected from a
group consisting of under-inflated conditions and deflated
conditions.
15. A method for supporting a pneumatic tire in a run-flat
condition, the method comprising: coupling a tubular structure to a
wheel rim in a tire cavity of the pneumatic tired wheel, the
tubular structure including a skeletal structure disposed therein
and adapted to turn concurrently with an axis of rotation of the
wheel rim; in response to a pre-determined moment load in a
run-flat condition, pivotally actuating a linkage displaceably
secured to a body of the skeletal structure; and periodically
deflecting the interior wall of the pneumatic tire with the linkage
as the wheel rim rotates.
16. The method as recited in claim 15, wherein pivotally actuating
a linkage displaceably secured to a body of the skeletal structure
further comprises plastically failing a retainer member coupled the
linkage to the body.
17. The method as recited in claim 15, further comprising selecting
the run-flat condition from a flat condition of a group consisting
of under-inflated conditions and deflated conditions.
Description
PRIORITY STATEMENT & CROSS-REFERENCE TO RELATED
APPLICATIONS
[0001] This application claims priority from the following commonly
owned, co-pending patent application: "Run-Flat Support System for
a Pneumatic Tired Wheel and Method of Installing Same" filed in the
name of William W. Gardetto on Mar. 24, 2008 and assigned
Application Ser. No. 61/039,033; which is hereby incorporated by
reference for all purposes.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates, in general, to pneumatic tires for
on and off road vehicles and, in particular, to a run-flat support
assembly having active, dynamic load responsive components for a
pneumatic tired wheel and a method for use of the same that
supports a tire in a deflated or run-flat condition.
BACKGROUND OF THE INVENTION
[0003] Pneumatic tired wheels are widely used in virtually all
types of land vehicles, including automobiles, trucks, trailers,
tractors, and other self propelled and unpowered vehicles, and
aircraft landing gear. The intense development activities involving
pneumatic tired wheels and tires has resulted in a highly developed
state of the art with respect to tire design, composition, function
and reliability.
[0004] The performance of pneumatic or gas charged tires is
substantially degraded by the loss of inflation pressure. Various
attempts have been made to eliminate loss of charge pressure due to
tire wall puncture and provide tire designs that will enable the
tire to continue to operate in a deflated or "run-flat" condition
ranging from modification of tire design to introduction of
materials and devices within the tire cavity to support the tire
during a deflation period.
[0005] Typical run-flat technology utilizes a passive approach
where a solid mass supports a load in a run-flat condition. During
such a condition, the rotating tire material, e.g., urethane, does
not respond normally and a hysteresis develops which causes heat
stress conditions. At particular frequencies, the rotating tire
material reacts slowly to the applied forces and "lags" or does not
completely return or rebound to its original state. The applied
forces at particular frequencies above a threshold deform the
rotating tire material and internal elastic and frictional stresses
are produced, which result in energy lost to heat and the
aforementioned heat stress conditions. Accordingly, there is a need
for run-flat technology which minimizes heat hysteresis and heat
stress conditions.
SUMMARY OF THE INVENTION
[0006] A run-flat support assembly and method for use of the same
are disclosed. The run-flat support assembly may be installed on a
pneumatic tired wheel within the tire pressure cavity to support
the tire when it is partially or completely deflated without
substantially reducing the wheel effective diameter so that the
vehicle stability and control is not compromised and the vehicle
operated with the tire deflated.
[0007] Properties of materials are structure sensitive and the
basis of materials design, therefore, is to control components and
substructures so as to achieve the desired mechanical and thermal
properties. Rather that implementing a passive approach like the
existing technology, principles of biomimetics and biomimicry are
utilized to produce a run-flat system for a pneumatic tired wheel
that meets the demand for run-flat technology which minimizes the
heat hysteresis and heat stress, among other negative
conditions.
[0008] In one embodiment, the run-flat support assembly for a wheel
rim of a pneumatic tired wheel includes a tubular support structure
that is positioned in a tire cavity of the pneumatic tired wheel
and coupled to the wheel rim to turn concurrently with an axis of
rotation of the wheel rim. A skeletal structure is disposed within
the tubular support structure. Circumferentially spaced linkages
are displaceably secured to respective mounting races of a body of
the skeletal structure by retainer members. Each of the
circumferentially spaced linkages is adapted to plastically fail at
a predetermined moment load in a run-flat condition, thereby
pivoting relative to the respective mounting race. In another
embodiment, RFID tags are associated with the respective plurality
of retainer members. Each of the RFID tags alters frequency in
response to the respective retainer member plastically failing. An
RFID detector aggregates data relative to the plurality of RFID
tags to measure moment load.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a more complete understanding of the features and
advantages of the present invention, reference is now made to the
detailed description of the invention along with the accompanying
figures in which corresponding numerals in the different figures
refer to corresponding parts and in which:
[0010] FIG. 1 is a front perspective view of one embodiment of
multiple instances of a run-flat support assembly being utilized on
a vehicle;
[0011] FIG. 2 is a perspective view of the run-flat support
assembly of FIG. 1 installed in a split wheel rim of a pneumatic
tired wheel, wherein the tire has been omitted for purposes of
illustration and explanation;
[0012] FIG. 3 is perspective exploded view of the run-flat support
assembly of FIG. 2;
[0013] FIG. 4 is a front elevation view of the run-flat support
assembly of FIG. 2 wherein portions of support segments of the
run-flat support assembly have been omitted for purposes of
illustration and explanation;
[0014] FIG. 5 is a side elevation view of an interior view of the
run-flat support assembly shown in FIG. 4;
[0015] FIG. 6 is a side elevation view of an exterior view of the
run-flat support assembly shown in FIG. 4;
[0016] FIG. 7A is a perspective view of one embodiment of an
outside skeletal member, which forms a portion of the run-flat
support assembly;
[0017] FIG. 7B is a perspective view one embodiment of an inside
skeletal member, which forms a portion of the run-flat support
assembly;
[0018] FIG. 8A is a cross-sectional view of the run-flat support
assembly of FIG. 1 installed in a split wheel rim of a pneumatic
tired wheel;
[0019] FIG. 8B is a cross-sectional view of the run-flat support
assembly of FIG. 8A supporting the pneumatic tired wheel in a flat
condition;
[0020] FIG. 9 is a cross-sectional view of the run-flat support
assembly of FIG. 8A supporting the pneumatic tired wheel in a flat
condition; and
[0021] FIG. 10 is a schematic diagram of one embodiment of a system
for monitoring the integrity of the run-flat support assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0022] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts which can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention,
and do not delimit the scope of the present invention.
[0023] Referring initially to FIG. 1, therein is depicted a
run-flat support assembly that is schematically illustrated and
generally designated 10. The run-flat support assembly 10 is being
employed by a vehicle 12, which may be a light, highly mobile,
diesel-powered, four-wheel-drive vehicle equipped with an automatic
transmission and configurable for various tasks. Power is
transferred to drive axles and onto rear pneumatic tired wheels 14
and 16 and pneumatic tired wheels 18 and 20 which are mounted with
split wheel rims 22, 24, 26, and 28, respectively. In one
embodiment, the tires for the pneumatic tired wheels 14, 16, 18,
and 20 may be 37.times.12.50R 16.5LT or larger radial tires and the
split wheel rims 22, 24, 26, and 28 are each of a two wheel
half-section design having a diameter of approximately 16.5 inches
or greater. Each tire associated with one of the pneumatic tired
wheels 14, 16, 18, and 20 includes a run-flat support assembly 10
to enable operation in a flat condition, e.g., when a tire is an
under-inflated or deflated condition.
[0024] It should be appreciated that although the run-flat support
assembly 10 is illustrated as being utilized by a vehicle 12
resembling a High Mobility Multipurpose Wheeled Vehicle (HMMWV),
which is also known as a "Humvee", in FIG. 1, the run-flat support
assembly 10 described herein may be utilized in a variety of
vehicles and, in particular, much heavier and larger vehicles. The
run-flat support assembly 10 described herein may be utilized with
virtually all types of land vehicles, including automobiles,
trucks, trailers, tractors, and other self propelled and unpowered
vehicles, and aircraft landing gear. Moreover, it should be
appreciated that tires of all sizes including both radial ply and
bias ply tires as well as wheel rims of all sizes are within the
teachings of the present invention.
[0025] With reference to FIGS. 2 and 3, as discussed, in one
implementation, the run-flat support assembly 10 may be utilized
with a split wheel rim, such as the split wheel rim 22 having rims
30, 32. The rim 30 includes a body 34 and a drop-center surface 36.
Mounting studs 38, which may be threaded, extend from the body 34.
Similarly, the rim 32 includes a body 40 having mounting holes 42
therethrough for mating with mounting studs 38. In one
implementation, a one-to-one correspondence exists between the
mounting holes 42 and the mounting studs 38 such that equal numbers
of mounting holes 42 and mounting studs 38 are present. Moreover,
the mounting studs 38 are spaced to mate with the mounting holes
42. Nuts 44 are releasably securable to the mounting studs 38.
Mounting holes 46 provide for the attachment of the run-flat
support assembly 10 to an axle of the vehicle 12. With respect to
mounting alignment, the run-flat support assembly is mounted
directly to the wheel of the vehicle 12 to create a line of force
transference to the wheel that furnishes a path of positive load
transfer.
[0026] Support segments 50, which are individually numbered 50a,
50b, and 50c, are adapted for attachment to the split wheel rim 22
in order to provide support for the pneumatic tired wheel during a
run-flat or flat condition. With respect to the support segment
50a, a body 52a of sufficient hardness is included to maintain
shape under load. An inner radial surface 54a conforms to the shape
of the rim 30 and a torque flange 56a extends therefrom. Coupling
holes 58a are spaced circumferentially about the torque flange 56a
to align with a portion of the mounting studs 38 and be mounted
thereto such that the torque flange 56a interposingly secures the
support 50a between the rims 30, 32. In one implementation, 12
evenly spaced coupling holes are used to provide 6 coupling holes
per radians of torque flange or 4 coupling holes per support
segment 50a, 50b, 50c. The torque flange 56a is grooved with groove
60a to seat an "O" ring seal 62 that provides a substantially
airtight pneumatic cavity. Further, the torque flange 56a may have
a shape that complements rim 30 to ensure a formed fit. Moreover,
in another embodiment, a single piece torque ring, onto which the
support segments are attached, is utilized instead of the multiple
piece torque flange.
[0027] A crown member 64a of the body 52a is opposite the inner
radial surface 54a. In operation, the crown member 64a engages an
inner wall of the of the pneumatic tired wheel 20 during a flat
condition to support the split wheel rim 22 and associated load to
provide continued mobility. Radial end members 66a, 68a provide for
an end-to-end mating engagement of the support segment 50a with the
support segments 50b and 50c. More specifically, the radial end
member 66a includes a recess 70a and a passageway 72a as well as a
recess 74a and a passageway 76a. Similarly, the radial end member
68a includes complimentary recesses and passageways. In operation,
when radial end members of different support segments abut, the
passageways align and the recesses provide for the insertion of a
fastener 78a such as a bolt, lug nut, and washer. It should be
appreciated that the use of recesses and passageways is not
required by the present invention. For example, in another
embodiment, radial end members of adjacent support segments may
include complementary male and female portions that are operable to
be disposed in mating engagement when positioned for coupling to
the torque assembly. The components described herein, such as the
bodies 52a, 52b, and 52c of support segments 50a, 50b, and 50c may
be manufactured from a resin, elastomer or other material that
meets the requisite load and strength requirements. It should be
understood that corresponding parts of the support segments 50a,
50b, and 50c have the same number with an identifying letter, i.e.,
a, b, or c. Moreover, it should be appreciated that in particular
embodiments, the support segments are not symmetrical as suggested
by this numbering convention.
[0028] As alluded, torque flanges 56a, 56b, 56 radially align to
form torque flange 56, which sits upon drop-center surface 36 such
that the coupling holes 58a, 58b, 52c of the torque flanges 56a,
56b, 56c align with the mounting studs 38. Once the "O" ring seal
62 is positioned on the groove 60, then the rim 32 is set and
secured by the nuts 44. Using the passageways and recesses, such as
passageways 72a, 76a and recesses 70a, 74a, the fasteners 78a, 78b,
78c secure the support segments 50a, 50b, 50c to one another. It
should be appreciated that in another embodiment, the support
segments 50 are formed directly onto the split wheel rim 22 without
the need for the torque flange 56.
[0029] With reference to FIGS. 4 through 6, the run-flat support
assembly 10 is depicted with the bodies 52, i.e., bodies 52a-c
collectively, of the support segments 50 removed for purposes of
explanation to illustrate a skeletal structure 90 comprising
skeletal rings 92, 94, 96. In the illustrated embodiment, each
skeletal ring 92, 94, 96 includes three skeletal members
corresponding to each of the support segments 50. By way of
example, skeletal ring 92 includes skeletal members 98a, 98b, 98c;
skeletal ring 94 includes skeletal members 100a, 100b, 100c; and
skeletal ring 96 includes skeletal members 102a, 102b, 102c.
Skeletal members 98a, 100a, 102a form a portion of the support
segment 50a and are encased by the body 52a. Similarly, skeletal
members 98b, 100b, 102b form a portion of the support segment 50b
and skeletal members 98c, 100c, 102c form a portion of the support
segment 50c. As shown in FIG. 4, as well as FIGS. 8A and 8B, in
support segment 50a, a base 88 joins the skeletal members 98a,
100a, 102a, and the torque flange 56a extends therefrom. A similar
arrangement with a base and torque flange is found in the support
segments 50b, 50c as well. In one embodiment, the skeletal members,
the bases, and the torque flanges may comprise a metal alloy,
aluminum, or suitable material.
[0030] Each skeletal member includes a body having plurality of
apertures therethrough. By way of example, with reference to
skeletal member 98a, a body 104 is positioned to turn concurrently
with the axis of rotation of the pneumatic tired wheel 20. The
run-flat support assembly 10 is scalable and may be configured for
any application. As will be discussed in further detail
hereinbelow, although three skeletal rings and nine skeletal
members are depicted, the run-flat support assembly 10 is scalable
and may comprise any number of skeletal rings and skeletal members.
Moreover, multiple skeletal members may be laterally spaced with
the resin of the bodies 52 interposed therebetween to provide a
lateral heat barrier and/or to accommodate different widths of
tires.
[0031] FIG. 7A depicts one embodiment of an outside skeletal
member, skeletal member 98a, which forms a portion of the run-flat
support assembly 10. The body 104 includes mounting races 110, 112,
114, 116, 118, 120 which are circumferentially spaced therearound
to define a series of flat, hard contact surfaces, which in one
implementation may be ovalized. In one implementation, the skeletal
member 98a further comprises a complimentary plurality of
circumferentially spaced displaceable linkages 122, 124, 126, 128,
130, 132 that are respectively releasably rockably or swayably
disposed within each mounting race 110, 112, 114, 116, 118, 120.
Each of the linkages 122, 124, 126, 128, 130, 132 includes an
arcuate face 134, 136, 138, 140, 142, 144 that is contoured and
sized to be received in the mounting race in rollable or slidable
pivoting contact. Additionally, elongated beams 146, 148, 150, 152,
154, 156 respectively integrally form a portion of each of the
linkages 122, 124, 126, 128, 130, 132 such that the elongated beams
146-156 pivot relative to the respective mounting races
110-120.
[0032] A pair of contact bearing surfaces are also located at each
end of each linkage and, in one implementation, the contact bearing
surfaces may be separated by a concave portion. In another
implementation, the contact bearing surfaces may be continuously
formed. By way of example, with reference to the linkage 126,
contact bearing surfaces 174, 176 are located at each end and
separated by a contact bearing surface 178. As will be explained in
further detail hereinbelow, the contact bearing surfaces 174, 176
alternatingly make contact with the inner wall of the tire during
run-flat conditions as the linkage 126 pivots in order to actively
increase the footprint of the tire and encourage return or
rebound.
[0033] Each of the linkages 122-132 is displaceably secured to the
respective mounting race 110-120 with a retainer member 158, 160,
162, 164, 166, 168 that plastically fails at a pre-determined
moment load, but withstands normal operating loads and those loads
associated with an inflated condition. In one embodiment, the
retainer member may be a mechanically weakened section or fuse that
decouples by softening or releasing the linkage from the body 104
of the skeletal member 98a in response to a threshold being
surpassed during a run-flat condition. In the absence of the
threshold being surpassed the retainer member maintains the
stiffness of the linkage member. As such, each of the linkages
122-132 is displaceably secured to a respective mounting race
110-120 of the body 104 and adapted to plastically fail at a
predetermined moment load in a run-flat condition, thereby causing
the linkages 122-132 to pivot relative to the respective mounting
race 110-120.
[0034] As previously discussed, the skeletal structure 90 is
embedded in the bodies 52 of the run-flat wheel assembly by being
encased in a polymer housing, which provides structural
encapsulation. With respect to integrity holes, apertures, such as
apertures 170, 172, provide holes in the body 52a to permit the
polymer that forms a portion of the polymer housing or body 52a to
flow and set therethrough. This anchors the polymer within the body
52a and prevents sheering as well as increasing the adherence of
the elastomeric polymer material against the rigid skeletal
structure of the run-flat support assembly 10. It should be
appreciated that in one embodiment the skeletal members 98b, 98c,
102a, 102b, 102c may have a substantially similar structure and
function to that of skeletal member 98a.
[0035] FIG. 7B depicts one embodiment of an inside skeletal member,
i.e., skeletal member 100a, which forms a portion of the run-flat
support assembly 10. With a structure having similarities to the
skeletal member 98a, a body 180 has linkages 182, 184, 186, 188,
190 circumferentially spaced and releasably secured thereto. By way
of example, with respect to the body 180 and the linkage 186,
arcuate face 194 of the linkage 186 is pivotally positioned in
mounting race 196 and held statically in place by a retainer member
198. The linkage 186 further includes an elongated beam 200 having
contact surfaces 202, 204. Skeletal members 100b, 100c may have
similar structure and function to the skeletal member 100a. Each of
the skeletal rings may be offset with respect to the ends of the
linkages 122-132 such that during the rotation of the tire, the
leading and trailing edges of the linkages 122-132 are positioned
adjacent to the void between adjacent linkages. Moreover, the
elongated beams of the skeletal members 98a-c, 100a-c, 102a-c and
of particularly laterally adjacent skeletal members 98a-c, 100a-c,
102a-c may vary in length to further minimize voids where no
linkages are radially present. By way of example, both of these
effects may be seen by referencing FIGS. 5, 6, 7A, and 7B.
[0036] FIG. 8A depicts one embodiment of the run-flat support
assembly 10 installed in the split wheel rim 28 of the pneumatic
tired wheel 20 which includes side walls 210, 212, treads 214, and
an inner wall 216 that defines a cavity 218. Additionally, beads
220 and 222 comprise loops of high-strength steel cables coated
with rubber that provide the pneumatic tired wheel 20 the necessary
strength to stay seated on the wheel rim 28. The support segment
50a is mounted to the wheel rim 28. The skeletal members 98a, 100a,
102a which are connected at the base 88 include the torque flange
56a which is removably coupled to the split wheel rim 28. As
depicted, pneumatic tired wheel 20 is properly inflated and
operational. In this condition, the support segment 50a rides
unobtrusively in the cavity 218.
[0037] FIG. 8B depicts the run-flat support assembly 10 supporting
the pneumatic tired wheel 20 which is in a flat condition. As
illustrated, the crown 64a of the support segment 50a engages the
inner wall 216 between the beads 220, 222 of the pneumatic tired
wheel 20 in order to support the pneumatic tired wheel 20 and the
load of the vehicle 12 in a flat condition. In particular, the
crown 64a maintains an operation similar to that of inflated
conditions since it is substantially centered with respect to the
side walls 210, 212. The centering is maintained even during
run-flat operation when relative motion occurs between the tire
sidewalls 210, 212 and the interior components occurs.
[0038] Moreover, in a run-flat condition, the skeletal members 98a,
100a, 102a are actuated from being purely static elements to
dynamic elements. Using principles of biomimetics and biomimicry,
the skeletal members 98a, 100a, 102a respond to the run-flat
conditions by becoming or transitioning into dynamic, active masses
that selectively increase the footprint of the pneumatic tired
wheel 28. It should be appreciated that the bead lock approach
described herein is not required for the practice of the invention.
Non-bead lock approaches which reduce the tread shoulder damage are
also within the teachings of the present invention. Moreover, as
shown, in one embodiment, the skeletal members of the skeletal
structure meet a common base which is connected thereto, by a wield
or integrally, for example. The torque flange then extends from
this common base of the skeletal rings.
[0039] With respect to thermal barriers and conveyances, heat can
be very difficult to expel from polymers such as polyurethane or
other elastomers that may be utilized in the construction of the
run-flat support assembly 10. In one implementation, heat barriers
of polyurethane are positioned between the skeletal members to
limit heat transfer in the lateral direction. The skeletal members,
which may comprise a conductive material such as aluminum or steel,
create thermal paths that compartmentalize the transfer of the heat
along radial axes toward the wheel. Ambient air is in contact with
the wheel to assist in the thermal mitigation.
[0040] FIG. 9 is a cross-sectional view of the run-flat support
assembly 10 of FIG. 8A supporting the pneumatic tired wheel 20
which is in a flat condition. As mentioned, the run-flat support
assembly 10 is an active assembly which responds to load. As the
pneumatic tired wheel 20 rotates in a run-flat condition, the
retainer members 158-168 fail and the linkages 122-132 of the
skeletal member 98a utilize biomimicry to deflect the interior wall
216 of the tire and thereby increase the footprint of the exterior
wall of the tire, displace load, and minimize heat stress condition
due to hysteresis.
[0041] The linkages 122-132 of the skeletal member 98a may act as
levers, each having a fulcrum or pivot point near its center as
represented by the arcuate faces 134-144 contacting the mounting
races 110-120. Additionally, the retainer members 158-168 or fuses
may fail in a series when exposed to the pre-determined load as a
result of the run-flat condition. With reference to a particular
linkage, the linkage 126, during rotation of the pneumatic tired
wheel 20 in a run-flat condition, contacts the ground and deflects
the interior wall 216 of the pneumatic tired wheel 20 to increase
the footprint of the tire 212. More specifically, as the contact
surface 176 is driven towards the body 104 by the road in the flat
condition, retainer member 162 plastically fails, thereby
permitting the linkage 126 to pivot the contact surface 176 of the
elongated beam 150 towards the body 104 and the contact surface 174
towards the tire wall 212, thereby increasing the surface area of
the tire wall 212 proximate to the contact surface 174. This
increases the load over a larger area. That is, as depicted, force
is applied by contact proximate to the ground at the contact
bearing surface 176 of the linkage 126 which rotates about the
arcuate face 138 into contact with the body 104. Reciprocally, the
contact bearing surface rotates 174 at the mounting race 114 away
from the body 104 about the arcuate face 138 into contact with the
interior surface 216 of the tire, thereby increasing the footprint
of the tire. As shown, this same trailing edge effect is also
present with linkage 124.
[0042] It should be understood that the linkages 122-132 contacting
the ground create a symmetrical leading edge effect as well. The
linkage 128 contacting the ground deflects the interior surface of
wall 216 of the pneumatic tired wheel 20 to increase the footprint
of the tire and spread load. When force is applied by contact with
the ground, the linkage 126 pivots with respect to the body 104
within the mounting race 116 to press against the interior wall 216
of the tire, thereby increasing the footprint of the tire. As
shown, thus the leading edge effect is also present with linkage
130. That is, in response to a pre-determined moment load in a
run-flat condition, the linkage 130 is pivotally actuated from
being displaceably secured to the body 104. The linkage 130 then
periodically deflects the interior wall of the pneumatic tire with
the elongated beams of the linkage 130 as the wheel rim
rotates.
[0043] FIG. 10 is a schematic diagram of one embodiment of a system
for monitoring the integrity of the run-flat support assembly 10.
RFID tags are associated with the retainer members; for example,
RFID tag 240 is embedded within retainer member 158. In response to
a retainer member plastically failing as discussed above, the
frequency of the RFID tag is altered. An RFID detector 242 may
aggregate data relative to the plurality of RFID tags to measure
moment load for purposes of sensing or inspection, for example. By
way of example, each RFID tag emits a frequency prior to failure.
This data is aggregated by the RFID detector 242 and is
representative of a fully intact run-flat support assembly 10. As
the run-flat support assembly 10 is subjected to a load in a
run-flat or flat condition, such as an under-inflated or deflated
condition, retainer members may fail and alter frequency or not
provide a frequency. The reduction on the number of detectable RFID
tags indicating the approximate wear and integrity of the run-flat
support assembly. The RFID detector may be associated with the
vehicle or hand-held at a maintenance facility, for example, and an
interface 244 may be provided for showing this data with a
user.
[0044] While this invention has been described with reference to
illustrative embodiments, this description is not intended to be
construed in a limiting sense. Various modifications and
combinations of the illustrative embodiments as well as other
embodiments of the invention, will be apparent to persons skilled
in the art upon reference to the description. It is, therefore,
intended that the appended claims encompass any such modifications
or embodiments.
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