Abstract: A safety wheel designed so that when air sealed within a tire is lost, the vehicle may be supported by a flat protector device in place of air pressure within the tire. The safety wheel comprises a split rim, a tubeless tire and a flat protector device which comprises a flat protector seat portion annularly fixed along the outer peripheral surface of the split rim, and a flat protector body formed of at least one pipe annularly fixed along the outer peripheral surface of the flat protector seat portion.

Abstract: An insert for tubeless tires to maintain vehicle control and prevent tire collapse in the event of puncture or other loss of air pressure. The insert has a toroidal center core of solid material, a foam casing of compressible but resilient foam material annularly surrounding the cylindrical core, and a thin outer flexible shell annularly surrounding the casing.

Abstract: The invention relates to an emergency running ring for pneumatic tires mounted on vehicle rims. A lubricant is contained in cavities formed by virtue of the shape of the ring, or is contained in auxiliary members mounted in openings in the ring or mounted on the surface of the ring. In all instances, the loss of tire pressure due to emergency conditions causes the lubricant to be released so as to reduce the friction between the inner face of the tire cover and the ring.

Abstract: A semi-pneumatic tire body for assembly to the rim of a wheel comprises spaced tread and root portions interconnected with spaced sidewalls to define an annular cavity. An annular load-bearing rib is connected to the root portion and extends radially toward the tread portion to be normally spaced apart from the tread portion in the unloaded state in order to establish communication between the internal chambers of the tire for free gaseous interchange and for free response of the tire to load forces.

Abstract: An improved tire liner composed of high temperature and pressure (HPT) molded and vulcanized rubber with a cross-section having two opposite long sides and two opposite short sides is described. One long side of the liner to be positioned across the U-shaped surface of the tire casing or the inside air space of the casing is beveled along its edges so that it tapers into the short sides. In some instances both long sides are tapered along the edges into the short sides. The tire liner reduces flat tires caused by punctures through the tire casing.

Abstract: A run-flat support and tire assembly designed so that when air sealed within a tire is lost, the vehicle may be supported by support members in place of air pressure within the tire. The run-flat tire has a split rim, a tubeless tire mounted on the rim, and a plurality of annularly disposed circular support members. The support members each comprises a thin-wall casing body having lattice-like reinforcing ribs for partitioning the interior of the casing body into a plurality of chambers. Connecting protrusions project from the casing body. The connecting protrusions are detachably connected to one another for each incorporation of the support members into the tire.

Abstract: A toroidal insert for an inflated, tubeless, pneumatic tire. The insert comprises a preformed torus-like core, tire cord radially wound around the torus-like core, and at least one load bearing member having tire cord therein, said member being circumferentially wound around substantially the middle one third of the radially outer surface of the radially wound tire cord. The insert, when situated within the inflated tire, includes a cross-section having a thick, substantially oval, central portion extending between the beads of the inflated tire and a pair of thin end portions each extending from its respective side of the thick, oval, central portion along the adjacent sidewall of said inflated tire to about the midpoint of said adjacent sidewall, whereby, when the tire is deflated, the thick, oval, central portion of the insert supports the tread portion of the deflated tire and each of the thin end portions of the insert lies between and supports the adjacent, collapsed sidewall of the deflated tire.

Abstract: A safety tire and wheel assembly for pneumatic tires which includes a safety insert having an inner portion extending around the wheel rim base for clamping the tire bead toes against the opposing rim flanges and an outer portion projecting radially into the tire cavity. A band of resilient material such as rubber is carried by a circumferential array of bearing elements in a depression formed on the outer surface of the core outer portion for supporting the tire tread with respect to the wheel rim upon loss of tire inflation pressure. The wheel includes a two-piece rim comprising a first rim portion welded to a wheel disc and a demountable rim portion mounted by the circumferential array of clamps to the fixed rim portion. A sealing ring is disposed between the rim portions for sealing the tire cavity for tubeless operation.

Abstract: A structure for fitting around the rim of vehicle wheel and within the tire provides, on deflation of the tire, support for the tire at the ground bearing point and prevents dislocation of the tire beads thus enabling control and reasonable "run-flat" travel to be retained in the event of a puncture. The structure comprises a number of elongate block members (1, 2) which lie transversely across the well (10) in the rim of the wheel (3). The blocks are spaced and retained by reinforced rubber belts (13) and are dimensioned to prevent displacement of the tire beads (11). To enable a tire to be fitted or removed some, at least, of the blocks (1) are in two parts (6, 8) with a pivotal interconnection (15) allowing the center of the block to move away from the rim and the ends to move together thus allowing space for the tire bead to enter the well, this being effected automatically on insertion of a tire lever under the tire bead.

Abstract: A pneumatic tire and rim combination wherein the tire is captivated about the rim and a chamber is defined between the tire and the rim and a portion of the tire extends into the chamber within the carcass of the tire and serves as an annular support structure upon deflation of air within the tire, so that if it collapses, as by a blowout, a vehicle on which it is installed will continue to be supported by the tire as the interiorly extending annular portion of the tire engages the confronting surface of the rim.

Abstract: An emergency track ring for a tubeless pneumatic tire comprising a bottom reinforced flange for mounting the ring on such a tire rim. At least one opening is formed in the ring to permit air to be admitted to the interior of the tire. Groove means are formed in the ring for filling with a lubricating material, and sealing lips close the groove means and seal the lubricant therein when the tire is mounted on said rim and under pressure. Flange means are integrally formed with the sealing lips and extend upwardly for engagement by the inside of the tire cover during loss of air, the depressing of the flange means effecting a lever action which causes the sealing lips to move so as to open the grooves and permit and lubricating material to be released to reduce friction between the tire cover and the track ring.

Abstract: A pneumatic tire assembly is capable of supporting a vehicle wheel rolling for a limited distance when the air in the assembly has escaped. The tire of the assembly is prevented from going completely flat by an annular insert, preferably of a high modulus elastomeric material, that is placed inside the tire and fits over the wheel rim and between the beads of the tire. The annular insert is of a novel construction that is lightweight and flexible enough to be stretched over a conventional rim, yet is able to support the load normally borne by the inflated tire and also resists unseating of the beads.

Abstract: A pneumatic vehicle tire having an internal device to impart run-flat capability is described, the device being comprised of an outer ring member for rotational support when operating in the run-flat condition, and an inner support for the ring which is highly flexible before insertion within the tire and which becomes fixed and less flexible after insertion. In preferred aspects the ring is essentially a highly flexible porous body made up of successive circumferential windings of elastomer-coated filamentary material, and the support is a structure made up of a plurality of hinged bracing elements which move into a fixed position after insertion of the device within the tire.

Abstract: An insert to provide a run-flat capability to pneumatic vehicle tires comprises a flexible, compressible, porous ring comprised of a plurality of successively-wound, circumferential layers of an elastomeric binder-coated filamentary material, the coated filaments having voids therebetween and being bonded to one another by the binder. The insert has desirable properties including lightweight, flexibility, and good load-distributing properties which make it a practical and useful component of any run-flat insert design for pneumatic tires. In preferred embodiments, the insert is spaced and supported from the tire by a member which minimizes the overall weight added to the tire. It is also further desirable to provide the insert with means to reduce its expansion radially upon rotation of the tire.

Abstract: A unitary run-flat insert for inflatable tires is provided in the form of a split ring having sufficient flexibility, through separation at the split portion thereof, to pass over the rim flanges of a tire mounting rim and having an inner periphery closely and circumferentially engaging the rim when the split portion is closed, with lock means at said split portion adapted for automatic engagement as the ends forming said split portion are moved into juxtapositioned alignment. As closed by the lock means, the insert engages the rim in a manner to rotate therewith in normal operation, but to slip circumferentially thereof when riding on a deflated tire.

Abstract: A pneumatic tire and wheel rim assembly containing a support hoop which supports the vehicle to which the assembly is fitted when the tire deflates by contacting the inside of the tire tread at the top and bottom of the assembly. The dimensions of the hoop are such that its inner surface does not touch the rim whether the tire is inflated or deflated, and its outer surface does not touch the tire when inflated normally.

Abstract: A pneumatic insert for a pneumatic tire comprises a generally toroidal-shaped hollow tubular member with beads, that includes an insert inflation chamber pneumatically noncommunicable with the tire inflation chamber. A crown portion of the insert has a radially inner and a radially outer layer that define a closed lubricant chamber, also noncommunicable with the tire inflation chamber under normal running conditions. Lubricant release means such as valve or diaphragm provided in the outer crown layer permit release of the lubricant when the tread collapses against the insert crown during run-flat conditions.

Abstract: An improved annular shaped tire liner which is adapted to fit inside of, around and in contact with a casing of a pneumatic tire and in compression by the casing and a method for preparing the tire liner is described. The liner has a thickness which provides substantial protection against penetration of the tire to the inside of the casing. The tire liner is characterized by having a section which is an annular strip of high pressure and temperature vulcanized and molded rubber, preferably of the type used for bonding to the outside of a tire casing as a tread, with ends joined by a thin section of low temperature and pressure vulcanized rubber. The low temperature and pressure vulcanized rubber is preferably derived from a vulcanizable rubber used to bond the molded rubber to a tire casing and is sometimes referred to as "cushion rubber".

Abstract: A pneumatic tire and wheel rim assembly of the type in which support means extends circumferentially around the rim between the bead seats to support the tire when in a deflated condition.The support means is rotatable relative to the rim when the tire is in a deflated condition and lubrication means is provided to release lubricant to facilitate said relative rotation.The lubrication means comprises a sealed container located in a recess in the radially inner surface of the support means which ruptures to release lubricant between the radially inner surface of the support means and a confronting running surface on the rim when the tire is in a deflated condition.

Abstract: In a pneumatic, tired wheel having a tubeless tire mounted on the rim of the wheel, the improvement comprising a toroidal support device to enable the tired wheel to travel in a flat state. The support device comprises an inflatable, toroidal, inner tube located on the rim for elastically clamping the tire beads against the rim flanges, said tube radially extending from the well of the rim to or slightly beyond the radially outer edges of the rim flanges, and a toroidal support element whose radially internal, circumferential wall section is impervious to puncture and lies adjacent the radially external, circumferential area of the inner tube, and wherein the outer surface area of the support element is spaced from the inner surface area of the tire when the tire is in its inflated state so that under normal travel conditions the support element does not contact the inner surface area of the tire.

Abstract: A safety support mounted on a rim inside a tire chamber to resiliently support the tread portion of the tire in the deflated condition and maintain the bead portions of the tire in a separated condition. The support is in the form of a ring member of flexible resilient material with an inner portion at the inner periphery having a diameter not greater than the diameter of the rim and a width substantially the same distance between the bead portions when mounted on the rim. The ring member also has an outer portion at the outer periphery with an outer diameter less than the diameter of the tread portion of the tire in the inflated condition and greater than the diameter of the bead portions. The outer portion and inner portion of the ring member are connected by an intermediate portion which includes a plurality of radially extending webs spaced apart circumferentially of the ring member. The outer portion and inner portion are reinforced by annular plies which may be of bias fabric and helically wound cords.

Abstract: A vehicle tire is disclosed herein having a central hub with attachment holes for wheel studs provided therein. The perphery of the hub is provided with an integral flange supporting a plurality of loops and spokes or braces arranged in spatial relationship about the entire circumference of the hub. A rubber or the like tire casing is carried over the plurality of loops or braces and the terminating edges and sides of the tire casing are vulcanized or otherwise bonded to the portion of the loops or braces and to the hub. Air is captured between the hub flange and inside surfaces of the tire casing so as to provide a soft vehicle tire reinforced by the loops and spokes or braces.

Abstract: A safety wheel designed so that when air sealed within a tire is lost, the vehicle may be supported by a flat protector and bead stopper members in place of air pressure within the tire. The safety wheel comprises a split rim, a tubeless tire mounted on the split rim, and a flat protector of an annular configuration. The flat protector is divided into a plurality of circular protector elements whose opposed opposite ends are connected with each other through the bead stopper members adapted to restrain relative movement between the bead portions of the tire and the split rim.

Abstract: A run-flat insert structure for a pneumatic tire is disclosed in which the insert structure comprises a homogeneous elastomeric material and is fully enclosed and pneumatically inflated. The insert structure is mounted within the cavity formed by the pneumatic tire and the wheel rim upon which the tire is mounted. The insert structure is shaped and spaced from the interior walls of the tire such that contact between the insert structure and the interior tire walls is minimized during rated load carrying and inflation conditions of the tire. The volume of the insert structure is less than 50% of the volume of the cavity formed by the tire and the wheel rim to thereby assist in avoiding undesirable contact between the insert structure and the tire. During the deflated condition of the tire, the insert structure supports the tire and its load at a deflection that prevents excessively rapid deterioration of the tire while running in the deflated, run-flat condition.

Abstract: A tire/wheel assembly comprised of (A) a pneumatic tire axially mounted on a centered, wheeled rim, said assembly having attached therein a receptacle containing a coolant composition comprised of water and a low molecular weight polyethylene glycol, and (B) means for releasing said coolant composition onto the inner surface of said pneumatic tire. The invention has a particular purpose of inhibiting or retarding a rapid rate and temperature build-up caused by pneumatic tire being at least partially inflated primarily due to a reduction in its inflation pressure.

Abstract: A vehicle wheel having an annular emergency support arranged within the hollow space of a pneumatic tire mounted on the wheel. The annular support is supported on the rim of the wheel between the two beads of the tire and next to the drop center of the rim by means of a projection located on the inner periphery of the annular support. The projection extends radially inwardly and may be introduced into the drop center to facilitate mounting and removal of the annular support.

Abstract: Support ring assembly for tires comprising a rigid ring of I-shaped cross-section having an outer diameter less than the inner diameter of the tire tread when the tire is under load and having an inner diameter greater than the outer diameter of the cylindrical wheel rim is improved due to the fact that the assembly further comprises at least one solid annular part of elastic material which is mountable between the rim and the rigid ring, the annular part having an outer diameter substantially equal to the inner diameter of the rigid ring and having an inner diameter and width such that after the tire has been mounted on the rim, the fastening of the assembly on the rim is assured by compression of the elastic material of the annular part.

Abstract: The drawings disclose a pneumatic tubeless tire including circumferentially oriented runner segments or a running band. Each segment or band includes support means abutted against the drop center of the wheel rim and an outer portion capable of supporting the weight of the vehicle once the tire becomes deflated. More specifically, in one embodiment, the outer portion extends laterally across the tire, abutting against the oppositely disposed inner surfaces of the tire sidewalls, and in each embodiment, bolts, pins, or hinges are included to serve as the support means for radially supporting and retaining the segments or band in place when the tire becomes deflated.

Abstract: The drawings illustrate a pneumatic tubeless tire including internal support means. The internal support means comprises a three component system including an inner circumferentially oriented preloaded portion abutted against the wheel rim and normally supporting an outer portion consisting of an endless resilient ring, and an intermediate circumferentially split resilient ring. The latter ring is formed to include side surfaces which match the inner surfaces of the beaded ends for seating thereon when the tire becomes deflated, at which time the inner preloaded portion compresses.

Abstract: A safety wheel including a combined flat protector and bead stopper structure radially fitted in the tire around the inner periphery thereof and having a closed frame-like cross-sectional configuration of a substantial modulus of section. The flat protector, being made itself of an elastic material in a substantially H-shaped cross section, is easily deformable and can be readily inserted in the tire and, once combined with the bead stopper, which clamps the opposite side wall portions of the flat protector and the respective bead portions of the tire against the rim flanges, exhibits a substantial rigidity enough to support the vehicle weight, as when the tire is punctured. The rigidity of the flat protector per se is also increased by means of reinforcing cords of unstretchable material embedded therein.

Abstract: In a pneumatic, tired wheel having a tubeless tire mounted on the rim of the wheel, the improvement comprising a toroidal support device to enable the tired wheel to travel in a flat state. The support device comprises an inflatable, toroidal, inner tube located on the rim for elastically clamping the tire beads against the rim flanges, said tube radially extending from the well of the rim to or slightly beyond the radially outer edges of the rim flanges, and a toroidal support element whose radially internal, circumferential wall section is impervious to puncture and lies adjacent the radially external, circumferential area of the inner tube, and wherein the outer surface area of the support element is spaced from the inner surface area of the tire when the tire is in its inflated state so that under normal travel conditions the support element does not contact the inner surface area of the tire.

Abstract: A safety tire and wheel rim assembly having a safety support member comprising a plurality of arcuate segments of rigid material coupled together at their ends and mounted in a channel-shaped bearing ring mounted on the wheel rim wherein the bearing ring is located against tire beads to retain them in position.

Abstract: A safety support for mounting on a split rim inside a tire chamber to resiliently support the tread portion of the tire in the deflated condition and maintain the bead portions of the tire in separated positions. The support is in the form of an annular ring of resilient material having a base with a relatively wide radially inner surface for seating on the rim and separating the bead portions. A flange extends radially inward from the radially inner surface of the base for gripping by the rim sections to seal the space within the tire and retain the ring on the rim. The radially outer portion of the support has a diameter less than the diameter of the tread portion of the tire in the deflated condition and greater than the diameter of the base portion.

Abstract: A tubeless tire and rim assembly including an annular bead lock in the form of an endless train of lock elements interconnected by flexible joints. The bead lock can have not only a fully expanded circular configuration to fit over the rim base but also a partly folded configuration to lie within the inner peripheral circle of the tire. This particularly facilitates the mounting of such bead lock while effectively preventing any improper positioning thereof. An embodiment incorporating a flat-protector together with the bead lock is also contemplated to further improve the driving safety.

Abstract: A segmental annular tire safety support for mounting on a wheel rim to support a pneumatic tire in the deflated condition. The safety support includes a segmental curved member having a generally cylindrical radially outer supporting surface of revolution with a substantially constant radius circumferentially of the tire safety support. The ends of the curved member have radially outer end surfaces which are relatively flat and are spaced from the axis of the support a distance less than the length of the radius of the outer supporting surface of the curved member to reduce the stresses generated at the end edges and to provide warning vibrations and noise during operation of the tire in the deflated condition.

Abstract: The drawings disclose a pneumatic tubeless tire including either one or two load support running bands adapted to support the weight of a vehicle should the tire become deflated. The circumferential centers of the support bands are substantially coplanar with the planes of respective annular tire beads. In one embodiment the applicable bead is a third bead integrally formed adjacent one of the normal beads on the inner surface of the beaded edge of the tire. Double rows of circumferentially oriented, spaced apart tension spokes, with alternate pairs thereof oppositely angularly disposed so as to cross one another, rigidly connect each support band to the respective annular bead. An annular ridge is formed on the rim adjacent the inner edge of each beaded end to retain the beaded ends in position during deflated tire conditions.

Abstract: The drawings disclose a pneumatic tubeless tire including a self seating stabilizer formed of a plurality of segments, each having a centrally located flange formed on the inner surface thereof. A fastener ring is secured to the segmented flanges during assembly for retaining the segments as a unit between the inner surfaces of the usual two sidewalls radially intermediate the widest portion thereof and the beaded ends thereof. The segments may be formed of any suitable material, such as thermoplastic material containing glass fiber reinforcement or aluminum. The annular stabilizer unit provides lateral and radial support for the tire sidewalls, particularly when the tire becomes deflated.

Abstract: The drawings disclose a pneumatic tubeless tire including oppositely disposed annular support members attached to the inner surfaces of the usual two sidewalls at substantially the widest portion thereof, and a plurality of ribs formed of a suitable thermoplastic material containing glass fiber reinforcement, and each having one end thereof integrally formed with one annular support member and extending across the tire in an alternately spaced relationship from the annular support member either to the inner surface of the oppositely disposed beaded end or to the other annular support member, the annular support members and the plurality of bridging ribs providing lateral and radial support for the tire sidewalls, particularly when the tire becomes deflated.

Abstract: A support member curved about an axis of revolution for mounting on a wheel rim inside a tire chamber to support the tire in a deflated condition. The support member has a generally U-shaped cross section and may have open ends or the ends may be closed with webs having edges joining the radially inner and outer peripheral edges of the support member.A relatively lightweight high-strength material such as reinforced plastic may be used in the construction of the support member with relatively long fibers of reinforcing material extending generally in planes containing the axis of revolution and relatively short fibers of reinforcing material extending generally circumferentially of the support member and in planes perpendicular to the axis of revolution. Heat-conducting material in the form of wire screen or short lengths of wire may be embedded in the support member to conduct heat away from the surface engaged by a deflated tire.

Abstract: A zero pressure device is composed of either a microcellular or homogeneous polyurethane made by reacting an organic polyisocyanate with at least three polyols, a monomeric polyol of 2 to 3 hydroxyls having a molecular weight less than 250, a polyether triol having a molecular weight of 4600 to 6000 and a polyether glycol having a molecular weight of 3500 to 4200. When the zero pressured device is a run-flat ring for a tire wheel assembly, it has an average density of 60 to 65 pounds per cubic foot and 30 to 42 pounds per cubic foot when it is a tire.

Abstract: A pneumatic tire for a vehicle wheel, according to which in the hollow chamber of the pneumatic tire there is arranged a hollow emergency ring or an emergency tube with one or more peripheral protrusions having running-up flanks which when moving into the respective flattened effective surface are substantially located in the elongation of an imaginary secant determined by the respective flattened effective surface.

Abstract: A resilient pneumatic tire which is reinforced by a radially stabilized compression element such that the vehicle on which the tire is mounted can be operated safely in an essentially normal manner regardless of the state of pressurization of the tire. The compression element can be a solid flexible band of high-strength metal or plastic, or can comprise a layered construction having at least a pair of concentric metal bands which have a resilient material sandwiched therebetween. The compression element is stabilized by radial means such as plies comprising radial cords or wires. The radial elements have freedom in shear with respect to one another and they share radial loads imposed on the compression element and tire such that they reinforce and stabilize the compression element and tire. Alternately, the radial stabilizing means can be radial rib-like elements cast or formed integrally in the sidewall of the tire.

Abstract: A pneumatic tire and wheel assembly containing an enclosing means for a lubricating material. The enclosing means will release the lubricating material into the tire when the tire becomes deflated.

Abstract: An integral tire and rim assembly in which the tire is built and cured on the rim. The tire is a closed torus crown over-lap type having a pair of annular inextensible beads. The rim is an annular and axially continuous unitary rigid member with flanges that extend radially outwardly beyond the minimum diameter of the inextensible bead cores. A run-flat device is included in the tire cavity.

Abstract: A pneumatic tire and wheel rim assembly capable of being driven with the tire deflated comprising at least one circumferential band of magnetized rubber or plastics material on an interior surface of the assembly which contacts and is required to move relative to a further such surface when the tire is deflated and a magnetized liquid lubricant maintained in position by the band to facilitate relative movement between the contacting surfaces within the assembly when the assembly is driven with the tire deflated.

Abstract: A pneumatic tire and wheel assembly containing an enclosing means for a lubricating material. The enclosing means will release the lubricating material into the tire when the tire becomes deflated.

Abstract: A pneumatic vehicle tire having a run-flat capability and a hub adapted for use with such a tire are disclosed. The tire includes a carcass, a tread overlying the crown region of the carcass, sidewalls overlying the lateral portions of the carcass, the sidewalls terminating in respective beads at their radially inwardmost ends and merging into the tread at their radially outwardmost ends and an annulus of elastomeric material positioned between the inner surfaces of the beads for maintaining the beads in firm contact with the hub. Each of the sidewalls has an annular groove formed therein between its inwardmost and outwardmost ends for establishing the flexure zone of the tire and thereby controlling the folding point of the tire upon its deflation. The hub includes a rigid annulus, a first annular flange extending from one side of the annulus and permanently attached thereto and the second annular flange extending from the other side of the annulus, the second flange being removably attached to the annulus.

Abstract: A fluid-containing bag of sheet material mounted on the radially inner surface of a stabilizer ring as by an adhesive or metal clips for retaining fluid during normal inflated operation of the tire and releasing the fluid in response to rotation of the tire tread portion in engagement with the radially outer surface of the stabilizer ring. The fluid may be released by an increase in temperature softening a plug in the wall or the adhesive in a seam between walls of the bag. The fluid may also be released by the rupture of a flexible tube extending from the bag to the radially outer surface of the stabilizer ring.

Abstract: A pneumatic tire and wheel assembly containing an enclosing means for a lubricating material. The enclosing means will release the lubricating material into the tire when the tire becomes deflated.

Abstract: a run-flat system comprising, in combination, a vehicle wheel having a tubeless tire mounted thereon and a run-flat support structure within the tire comprising a plurality of arcuate segments interposed between the rim of the wheel and the tread section of the tire. The segments are fastened to the rim and in normal inflated condition of the tire are radially spaced from the tire tread section. The improvement comprises each arcuate segment having an elongated hollow base section seated in the drop center channel of the wheel rim, side walls extending outwardly from the base wall toward the tubeless tire retention beads, and a compression resistant wall spanning the segment base section side walls. An energy absorbent elastomeric arcuate liner externally covers the upper section of the segment base section, the liner extending over the side edges of the segment base section in abutting relation to the retention beads to compress the latter against the retention flanges of the rim.