CA1071985A - Pneumatic tire - Google Patents
Pneumatic tireInfo
- Publication number
- CA1071985A CA1071985A CA272,007A CA272007A CA1071985A CA 1071985 A CA1071985 A CA 1071985A CA 272007 A CA272007 A CA 272007A CA 1071985 A CA1071985 A CA 1071985A
- Authority
- CA
- Canada
- Prior art keywords
- tire
- sidewall
- beads
- rubber
- ply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C13/00—Tyre sidewalls; Protecting, decorating, marking, or the like, thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C17/00—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
- B60C17/0009—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising sidewall rubber inserts, e.g. crescent shaped inserts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C17/00—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
- B60C2017/0081—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising special reinforcing means in the crown area
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A pneumatic tire which can be operated in a deflated condition without damage to the tire, wherein the tire has a cord ply, a tread, a ply with wire cords in the crown, and thick sidewalls wherein the cord ply extends from the heel of the bead to a location closely adjacent to the outer sur-face of the midpoint of the sidewall and thence towards the inner surface of the crown. The interior portion of the sidewall rubber has a high dynamic modulus with low hysteresis properties and high aging properties.
A pneumatic tire which can be operated in a deflated condition without damage to the tire, wherein the tire has a cord ply, a tread, a ply with wire cords in the crown, and thick sidewalls wherein the cord ply extends from the heel of the bead to a location closely adjacent to the outer sur-face of the midpoint of the sidewall and thence towards the inner surface of the crown. The interior portion of the sidewall rubber has a high dynamic modulus with low hysteresis properties and high aging properties.
Description
~7~"31~5 BACKGROUND OF THE INVENTION
_________._____ This invention relates to pneumatic tires and more particularly to a new and improved safety tire for use in run-flat condition and to self-sealing tires. When a con-ventional tire is without inflation air, the opposite interior walls of the tire come into contact with the Local~ized`press`u're of the wheel toward the pavement, causing a severe flexing and buckling action to the cord fabric and the adjacent rubber compounds. Such very high stresses cause a heat build-up and a corresponding failure of the tire. In addition, the tire may separate from the rim impairing the drivers's abili-ty to maintain control of the vehicle.
_ MMARY OF THE INVENTION_ _ _ _ _ ~ ccording to the present invention, the tire i5 ~o constructed that even upon a sudden :Loss of air pressure within the tire, the tire will provide the usual comfort-able cushioning of the vehicle to permi-t the operator of vehicle to drive the vehicle a considerable distance without injury to -the tire or render the vehicle unmanageable. The sidewalls of the tire in accordance with the present invention have the sidewalls of substantial thickness and wi-th the cord re:Lnforcing ply extending from closely adjacent the toe of the tire to a point closely adjacent to the outer surface of the sidewall as it approaches -the midpoint of the tire and thence receding away from -the outer surface towards the inner surface at the shoulder such as -to lie closely adjacen-t to the inner circumferentially extending inner peripheral surface of the crown of the tire. That is, the cord reinforcing ply is oriented within the sidewall so that the thickest portion of the side-.
~ . :::
Z- ' ' ~L~7~t'3~5 wall rubber is between the inner surface exclusive o~ the .
inner liner or inner tube and the cord reinforcing ply, and also thickest between the outer surface of the tire and the cord reinforcing ply at the shoulder portion and the bead portion, although the sidewall is of approximately uniform thickness. Such sidewall as viewed in cross sec-tion presents a mass of rubber to the inside of the reinforcing ply that is crescent shaped whereby on comple-te deflation of the tire, the crescent shaped mass of rubber is put into compression while the cord reinforcing ply is put in tension thereby preventing collapse of the sidewall so that the respective inner wall surfaces of the tire do not contact or rub on each other. To ~urther enhance its run-:flat characteristlcs, a be:Lt with -transversely extend:lng w:ire cords :I.oc~ted above th~ cord re-in~orcing ply in -the crown is placed in compresslon to rein-force the run-flat condi-tions. Such circumferentially extending wire ply in the crown region of the tire cooperates with the novel sidewall construction to increase the deflated run-flat performance characteristics. Such wire ply has wire strands that .
run parallel to the axis of rotation of the tire and has the ends of the wire terminating at the juncture of the tread with the shoulders o.f the tire. Such sidewall is made o:~ a high dynamic modulus rubber, which as measured on the Goodrich ~lexometer : :
using the Dynamic Rate Calculation, has a range of values of 3500-5500 psi and an optimum range of 4500 -to 5500 psi. Such ; .
construction further maintains the tire on the rim without collapse when fully deflated even when braking and effecting sharp turns. Such tire, when fully deflated has good bead :
' - "
' ::
-~C37~ 5 seat retention, with no rim cutting or excessive heating.
Tests have indicated that such tires, in the fully deflated condition, have permitted a vehicle to transverse 300 miles at 45 mph or higher at 90% Tire and Rim Association rated load at 24 psi without adverse effects to the tire itself.
Such tire in the deflated condition is capable of the above described performance on conventional rims without requiring internal lubrication, or depending on a gas generating sub-stance to slightly inflate the tire.
A modification of the tire construction discussed above may include an external compressive mass of rubber or buttress at each of the shoulders o~ the tire, and an external compressive mass of rubber at the rim portion.
In accordance with a further aspect of the present invention there is provided a tire having a pair of spaced annular beads, a pair of annular sidewalls connected to said beads; a circumferentially extending tread portion joining said sidewalls; said tire having a thin air impervious liner on the inner surface thereof; a cord reinforcing material extending from one of said beads to the other of said beads through said sidewalls, and said tread, said reinforcing material being located in each of said sidewalls closely ad-jacent to itq inner wall surface in the sidewaLl portion adjacent to said beads and closely adjacent to the inner wall surface in the shoulders connecting said sidewalls and said tread; and said cord reinforcing material extending gradually from said beads to closely adjacent tha outer peripheral sur- ;
face in the sidewall portion exclusive of said air impervious liner and thence extending gradually away from said siclewall outer surface to closely adiacent the inner wall surface of said shoulders.
In accordance with a further aspect of the present .
~L~7~
invention there is provided a pneumatic tire ~aving a thin air impervious liner on the inner surface thereof, said tire comprising a carcass with a tread having c~ crown portion therebeneath, said crown portion having an inner circumferen-tially extending surface said carcass having a pair of spaced apart beads, each bead having a toe and heel portion, said . -carcass having a sidewall on each side o~ said tire extending from one of said beads to said tread, a cord reinforcing ply with radially disposed cords in said carcass extending from one of said beads to the other of said beads through each of said sidewalls and said crown, said cord ply lying closely :~
adjacent to the outermost surface of said sidewall at about said midpoint excluding the width o~ any air impervi.ous liner or inner tube, said cord ply extending gradually from about said midpoint in said sidewall to said toe of said bead and .
extending gradually in the other direction to said crown of .
said tire to be closely adjacent with the inner wall surface of said crown presenting a crescent shaped mass of rubber in vertical cross section of said tire carcass without any cord reinforcing material in said crescent shaped mass of rubber or inwardly to the inner wall surface of said carcass. .~
In accordance with a *urther aspect of the present ~ .
invention there is provided a pne~natic tire casing having a ~ .-thin air impervious liner on the inner surface thereof, said - -tire casing comprising a tire body having spaced-apart side- .
walls and a crown portion between said sidewalls, said crown portion having a circumferentially extending inner surface; a tread overlying said crown portion' beads at the inner radial ends of said sidewalls, each of said beads having a toe and heel portion, a cord reinforcing ply extending through said tire from bead to bead, said reinforcing ply extending gradually from the region closely adjacent to said toe of sai.d bead to 71~
an area closely adjacent to the outer surface of said sidewall exclusive of any liner and thence extending gradually to an area closely adjacent to the inner surface area of said crown region defining a crescent shaped mass of rubber, on the inner surface of said sidewall in radial cross-section; said cres-cent shaped mass of rubber being of substantially the same composition throughout with no cord reinforcing ply inwardly thereof to the inner wall surface of the tire, and the thick-est portion of said crescent shaped mass of rubber being at ;
the midpoint of its radial height, and wherein said thickestportion oE said crescent shaped mass of rubber is over 50%
of the entire thicknes~ of the sidewall taken in cross-section exclusive of any liner on the inner wall surface of said tire body.
In drawings which illustrate preferred embodiments of the invention: -Fig. 1 is a cross-sectional view of one embodiment of the tire of this invention.
Fig. 2 is a cross-sectional view of the tire shown in Fig. 1 in the fulLy deflated eondition when lt is mounted on a rim and is supporting the weight of a vehicle.
Fig. 3 is a cross-sectional view of a modified form of a tire of this invention.
Fig. 4 is a cross-sectional view of another modified form of a tire of this invention.
Fig. 5 is a ragmentary plan view of the tire, partly schematic with individual layers broken away in order to re-present the directions of the cord in the crown of the tireO
~ his invention can be used in any kind or size of pneumatic tire, but since a constantly increasing proportion of tires are being made with radial cord carcasses, the invention is illustrated in connection with radial cord, -4b-.
~L~97~ 5 tubeless passenger car tires.
Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a pneumatic tire 5 having a tread 6 and a pair of spaced sidewalls 7 and 8 which extend from the tread 6 to the respective annular beads 9 and 10. The tread 6 is made of abrasion-resistant rubber composition and extends across the road-engaging sur-face outside of the belt plies and is molded with a sui-table non-skid pattern. Tire 5 includes a conven-tional textile or metal cord in the ply 11 which reinforces the carcass. The ply 11 extends from bead 9 to bead 10 and as shown, extends around the beads and upwardly into the tire carcass sidewalls. ~M
'I'he cord reinforcing ply 11 and the beads 9 and 10 are embedded in rubber in the usual manner. The sidewall rubber :Ls of a consid~rab:le th:Lckness and has a high dynamic modulus so that it will be stiff enough to support the weigh-t on the wheel.
As measured on the goodrich Flexometer using dynamic rate calibrations, s~ch sidewall rubber has a range of 3500-5500 psi with an optimum of 4500-5000 psi, and as measured with a Duro-meter using the Shore hardness scale, Has a hardness of 60-80 with an optimum rating of 70-72. Using the Reolig Dynamic 'I'est Machine at 10% compression and a plu9 or minus 4% strain cycle, -the sidewall rubber shoudl have complex modulus valves (E*) with a range of valves from 900 -to 1150 psi or greater.
In addition such sidewall rubber should have a low hysteresis to minimize heat generation when the tire is run without in-flation. The construction of the tire is symmetrical in re-7~5 lation to the center plane of the tire. The tire is made to hold air in -the usual way by a separate inner tube or an integral thin impervious liner such as a butyl rubber, chlorinated butyl, or other suitable elastomer resistant -to diffusion of air.
A belt structure indicated generally as 12 is provided between tread 6 and the crown 13 of the tire carcass through which crown 13 the textile cord ply 11 ex-tends for reinforcing the tire 5.
The cord reinforcing ply 11 extends from the bead toe 14 radially outwardly along the i.nner surface of the tire and thence toward the outer surface of the sidewal:L 7 towards the mi~point M and thence al.ong such outer surface of -the sidewall 7. As such ply 11 approac:hes the shou:lder :reg:Lorl o:f.~ the tire 5, ply 11 again approaches the inner surface of the tire and extends along the inner wall surface of the crown 13 to the other shoulder portion of the tire and thence to --the bead 10 in the same manner as described. The thickness of the rubber from ply 11 to the outside surface of the tire at the thickest portion of the crescent shaped mass as compared to the thickness of the rubber from ply 11 to the inside sur-face of' the -tire is in the range of ratios 1:1.3 to 1:~ ex-clusive of the liner. As viewed in cross sec-tion, the sidewall rubber of the tire inside of -the reinforcing ply 11 has a con-cave shape with the thickest portion at about the.midpoint and tapers markedly towards the shoulder and bead regions to present a crescent shaped mass of rubber in cross section which acts as an internal COI~lpreSsive member as to be described. In a 60 series tire, the section height of the tire from the wheel to the :
' : ~ .. ' .
, ~7~ 3~35 : -tread is 60% of the section width of the tire. Before measuring, tires should be mounted and inflated to 24 psi for load Range B to 28 psi for load Range C and to 32 psi for load Range D, allowed to stand for 24 hours minimum at normal room tempera-ture and inflation pressures adjusted to 24 psi (load ~ange B), 28 psi (load Range C) and 32 psi (load Range D). Such crescent shaped mass of rubber has a ratio of radial height to maximum thickness (at its thickest point of about 9 to l. This ratio may vary somewhat with different size tires such as the 50,70, or 78 series tires, in a range of about 6:1 to 12:1. In a similar manner, the mass of rubber to the outside of the reinforcing ply 11 is leas-t at the thickest portion of the crescent shaped mass and greatest at a point above the rim adjacent to the bead and sholllder region of the t:ire. When measuring the radi.al height oE such crescent shaped mass, the height is measured radi.ally -from the top of the bead to the inner surface of the crown of the tire. The margin of ply ll extending from the bead radially outward and ending in the sidewall rubber is herein referred to as the reinforcing turn up ply 11' (Fig. 1) and provides additional means -to resist collapse of the tire. The ply ll' is shown as extending around the bead and outward through the sidewall rubber, spearated from the main part of ply :L] by a mass of sidewall rubber 20 of approximately uniform thickness. Such mass of rubber 20 acts as a lower in-ternal compressive member in a manner to be described, and helps to support the crescent shaped mass of rubber in the uninflated condition.
'' " : '''' ~7~ 5 The sidewalls of the tire between the shoulder and the rim engaging portion of the tire are of approximately uniform thickness, and of approximately the same thickness as the crown region inclulding the tread and all -the under-lying structure. At the beads the outside of the tire is shaped to fit the contour of the conventional rim. The portion of the sidewall closest to the rim ends in a substantial rim cushion 15, which is located between -the reinforcing cord ply 11' and the margin of the rim flange when the tire is mounted with a small clearance space between the tire and the outer edges of the rim flanges as illustrated in Fig.
1. Such rim cushion 15 acts as an external compression mem-ber, together with the sidewall rubber 20 between ply 11 and the external marg:in of the ply l:L; to help suppor-t the wei~rh-t o~ the vehicle when the tire is uninflated, and thus alds -the crescent shaped mass of sidewall rubber ins:ide of ply 11 as described above. In the deflated condition of the tire, such rim cushion 15 increases the bead retention pro-perty of the -tire. Such rim cushion 15 may be referred to as a lower external compression member.
In the operation of such tire 5 as described, the tire is inflated -to the normal pressure as in conventional ;
tires, and cushions the vehicles in the ordinary way. ~lowever, upon a loss in air pressure due to road hazards, puncture of the tire, or other reasons, when the air pressure in the tire is substantially reduced or lost altogether, the weight of the vehicle will somewhat reduce the radial height o~ the tire 5 where it rests on the road, causing it to assume the shape shown in cross-section in Fig. 2. In -tha-t condi-tion, ~.~7~9~5 the crescent shaped mass of rubber in each sidewall, inside of the reinforcing ply ll, will be placed in radial com-pression while the reinforcing ply 11 will be placed in -tension, and at the same time, the soulder rubber and the rim cushion 15 will be placed in partly radial and partly axial compression, thereby resisting collapse of the tire and maintaining the respective sidewalls in a curved rather than a folded condition to eliminate rim cutting, chafing and excessive internal heating which ordinarily in this cir-cumstance cause rapid deterioration and ~ailure of -the tire sidewall. In the ordinary collapse of a tire under fu].l vehicle load, -the cords in the tire are subjected to a com-bination of forces including compressive forces which are part:Lcularly harmful to them, whereas in the present case th~ cords are subJected only to a tension load. The t:Lre descr-ibed above remains on the rim permitting considerable maneuverability even at rather high speeds such as ~ifty mph.
The~mass of rubber 20 separating the ply 11 and its margin 11' resists distortion by a combination of forces including radial compresion caused by the increased curvature of ply .`.
11 close to the bead 9 or 10, together with radial shear forces between ply ll and its margin ll'. These forces resist collapse -~
and increase lateral stability which is needed :in cornering.
~ modifica-tion o~ the invention as described above is shown in Fig. 3 consisting of the same type of construction ~.
having tread 6, sidewalls 7, 8., beads 9 and 10, and the cres-cent shaped mass of rubber 25 to the inside of the reinforcing ~
ply 11. In addition, such modified form of the tire has a . :
~ ..' 1~7~1 3S
.
buttress or upper external compressive member 21 at the shoulders of the tire on either side of the tread wlth a substantially cylindrical surface 23 on the radially outer face thereof, at a smaller distance from the axis -than the tread 6, so as not to make contact with the road under normal conditions with the tire fully inflated. The buttress 21 may be spaced from the tread by a shallow groove 24, and may project laterally so as to form a concavity 22 between the corner of the upper surface 23 and the adjacent sur~ace of sidewall 7 or 8. Such buttress or upper external com-pressive member 21 on deflation of the tire, when tread 6 loses support of inflation gas will have its upper surface 23 pressed against the road sur~ace and cooperating w:i-th the crescen-t shaped mass (designated 25 in Fig. 3) the lnterna:L
lower compressive member 20, and the lower external com-pressive member 15 to put the rein~orcing ply 11 in tension while the crescent shaped mass 25, the buttress 21, internal lower member 20 and lower external member 15 are put in com- -pression to support the load on the wheel. The tire in this condition provides adequate support ~or the vehicle and its load, permittlng it to transport the vehicle a considerable distance sa~ely at speeds above minimum expressway speeds.
In addltion to the internal cornpressive member 25, the in-ternal lower compressive member 20, the lower external com- ;
pressive rnember 15, and the upper external compressive member 21, a crown compressive ply 26 made up of relatively sti~f wire cords extending transversely across the crown o~ the tire is located under the tread 6, between the tread and the bel-t ~ ~7~5 12. The margins of the compressive ply 26 are located at the juncture of the tread and the shoulders of the tire.
In the normal situation when a conven-tional radial or bias ply tire loses air and becornes flat, the weight of the vehicle compresses the tire between the wheel rim and the road. This causes the sidewalls to move laterally apart and be pinched between the rim flanges and the road, and the considerable stiffness of the shoulders causes the center of the tread to buckle into the space between the rim flanges.
In this invention, the crown compressive ply 26 provides enough bending s-tiffness of the crown to prevent inward buclcling o~ the crown of the deflated tire. 'E`he transversely extendl~g w:lres in such ply 26 are placed ln compression in such a situation and effectively resist the . . .
compressive forces. This is similar to a beam supported at both ends and a load placed on the beam to deflect the beam.
The wire cords of ply 26 are placed in compression and the cords of ply 11 are placed in tension which action in co-operation with the placing of the crescent shaped mass 25 in `
compression effectively resis-ts the inward buckling action at the crown of the tire and effectively facilitates the tire's run-flat characteristics.
A further modification of -the invention is shown in Fig.4 wherein there is shown a pneumatic -tire 30 having a tread 31 and a pair of spaced sidewalls 32 and 33 which ex-tend from -the tread 31 -to their respective annular beads 34 ; `
and 35. The tread is made of abrasion-resistant rubber com-posi-tion and is molded with a suitable non-skid pattern. Tire ~7~
30 includes a conventional textile or metal cord ply 36 which reinforces the carcass plies. The ply 36 extends from bead 34 to bead 35 and as shown, ex-tends around -the beads and up-wardly into the tire carcass sidewalls. The sidwall rubber has a high dynamic modulus so that i-t will be stiff enough to support the weight on the wheels. The values stated above for the first described embodiment are applicable herein.
The construction of the tire is symmetrical in rela-tion to the center plane of the tire. The tire is made to hold air in the conventional manner as by a thin integral air impervious liner 38 or inner tube resistant to the diffusion of air.
A pair of circumferentially extending belt structures 39 and 40 are provlded between tread 31 and the liner 38 of the tire carcass. '['he textile cord ply 36 extends through the crown of the tire between the liner 38 and the :lower belt ~tructure 39.
The cord reinforcing ply 36 extends from the bead ~
toe 42 radially outwardly along the inner wall surface of -the ~:
tire and thence towards the outer surface of the sidewall (similar to that described in Figure 1,) and thence along -the .
outer sur~ace of the sidewall 33 gradually toward the inner wall surface of the tire at the shoulder region of the tire arld continue~ along the inner wall surface at the crown por-tion of the tire to the other shoulder portion of the -tire and -thence -to the bead 34 in the aame manner. The respective end portions of the reinforcing ply 36 extend around the re-spective beads 34 and 35 and extend into the lower portion of the sidewall terminating adjacent to the reinforcing ply 36.
At about the midpoint M' of the sidewalls 32 and 33, the thickness of -the rubber ~rom ply 36 to the outside surface ..
. .
3~7~ 5 of the tire as compared to the thickness of the rubber from ply 36 to the inside surface of the tire exclusive of any inner tube or air impervious liner is in the range of` ratios 1:1.3 to 1:4. As viewed in cross section ~Fig. 4) the sidewall rubber of the tire inside of -the reinforcing ply 36, exclusive of the liner or inner tube, has a concave shape with the thickest portion at abou-t the midpoint and extends towards the shoulder and head regions to present a ~.
crescent shaped mass of rubber in cross section which acts ~... .
as an internal compressive member as to be described. With the reinforcing ply 36 turned up around the beads 3~ and -35, an annular mass of high modulus rubber ~3,44 on either side o-f the tire adjacent to the beads 34 and 35 provide an additonal compressive member that aids the tire in its run-:flat conditi.on.
I.ocated between the tread 3l and the belt structures . :
39 and ~0 is a circumferentially extending wire belt ~5 ..
whose strands are transversely disposed relative to the tire :
carcass i.e. the wire s-trands are generally parallel to the axis of rotation of the tire.
In the operation of such tire 30, the tire is :in- ~:
fla-ted to the normal pressure as in conventional tires, and cushions the vehicle in the ordinary way. Upon a loss of air pressure due to a road hazard such as the puncture of ..
the tire, the air pressure in the tire is substan-tially re-duced or lost altogether. The wiehgt of the vehicle will cause the tire disclosed in Fig. ~ to assume a shape disclosed in Figure 2, wherein the radial height of the tire 30 will .
be reduced. In this condition, the crescent shaped mass of rubber in each sidewall, inside of the reinforcing ply 36 will :.
:
637~ S
oe placed in radial compression, the reinforcing ply 46 will be placed in tension while the wire/~belt 45;~will'~berplaced in compression which action resists the collapse of the tire, maintaining the respective sidewalls in a curved rather than a folded condition to eliminate rim c-utting, chafing and heat build-up compared to the conventional tire. The con-ventional tire under a loss of air pressure would permit a buckling of the tread towards the wheel and would cause a chafing of the tire which would cause a movement of the side-walls away from the retaining bead portion of the rim flanges causing failure of the -tire and/or movement of the tire car-cass from the rim. In the tire described, the deflated tire under similar conditions would assume the cross-sectional shape shown in ~igure 2 and permit the operation of the vehicle safely at a su~icient rate of speed as discussed above to a servi.ce station or a safe location to permit the replace-ment and/or repir of -the deflated tire.
lires of this invention have demonstrated their ability to support automobiles adequately even when completely deflated so as to permit driving safely and comfortable for a ronsiderable distance on the de~lated flat tires until a destina-tion or a repair facility is reached.
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_________._____ This invention relates to pneumatic tires and more particularly to a new and improved safety tire for use in run-flat condition and to self-sealing tires. When a con-ventional tire is without inflation air, the opposite interior walls of the tire come into contact with the Local~ized`press`u're of the wheel toward the pavement, causing a severe flexing and buckling action to the cord fabric and the adjacent rubber compounds. Such very high stresses cause a heat build-up and a corresponding failure of the tire. In addition, the tire may separate from the rim impairing the drivers's abili-ty to maintain control of the vehicle.
_ MMARY OF THE INVENTION_ _ _ _ _ ~ ccording to the present invention, the tire i5 ~o constructed that even upon a sudden :Loss of air pressure within the tire, the tire will provide the usual comfort-able cushioning of the vehicle to permi-t the operator of vehicle to drive the vehicle a considerable distance without injury to -the tire or render the vehicle unmanageable. The sidewalls of the tire in accordance with the present invention have the sidewalls of substantial thickness and wi-th the cord re:Lnforcing ply extending from closely adjacent the toe of the tire to a point closely adjacent to the outer surface of the sidewall as it approaches -the midpoint of the tire and thence receding away from -the outer surface towards the inner surface at the shoulder such as -to lie closely adjacen-t to the inner circumferentially extending inner peripheral surface of the crown of the tire. That is, the cord reinforcing ply is oriented within the sidewall so that the thickest portion of the side-.
~ . :::
Z- ' ' ~L~7~t'3~5 wall rubber is between the inner surface exclusive o~ the .
inner liner or inner tube and the cord reinforcing ply, and also thickest between the outer surface of the tire and the cord reinforcing ply at the shoulder portion and the bead portion, although the sidewall is of approximately uniform thickness. Such sidewall as viewed in cross sec-tion presents a mass of rubber to the inside of the reinforcing ply that is crescent shaped whereby on comple-te deflation of the tire, the crescent shaped mass of rubber is put into compression while the cord reinforcing ply is put in tension thereby preventing collapse of the sidewall so that the respective inner wall surfaces of the tire do not contact or rub on each other. To ~urther enhance its run-:flat characteristlcs, a be:Lt with -transversely extend:lng w:ire cords :I.oc~ted above th~ cord re-in~orcing ply in -the crown is placed in compresslon to rein-force the run-flat condi-tions. Such circumferentially extending wire ply in the crown region of the tire cooperates with the novel sidewall construction to increase the deflated run-flat performance characteristics. Such wire ply has wire strands that .
run parallel to the axis of rotation of the tire and has the ends of the wire terminating at the juncture of the tread with the shoulders o.f the tire. Such sidewall is made o:~ a high dynamic modulus rubber, which as measured on the Goodrich ~lexometer : :
using the Dynamic Rate Calculation, has a range of values of 3500-5500 psi and an optimum range of 4500 -to 5500 psi. Such ; .
construction further maintains the tire on the rim without collapse when fully deflated even when braking and effecting sharp turns. Such tire, when fully deflated has good bead :
' - "
' ::
-~C37~ 5 seat retention, with no rim cutting or excessive heating.
Tests have indicated that such tires, in the fully deflated condition, have permitted a vehicle to transverse 300 miles at 45 mph or higher at 90% Tire and Rim Association rated load at 24 psi without adverse effects to the tire itself.
Such tire in the deflated condition is capable of the above described performance on conventional rims without requiring internal lubrication, or depending on a gas generating sub-stance to slightly inflate the tire.
A modification of the tire construction discussed above may include an external compressive mass of rubber or buttress at each of the shoulders o~ the tire, and an external compressive mass of rubber at the rim portion.
In accordance with a further aspect of the present invention there is provided a tire having a pair of spaced annular beads, a pair of annular sidewalls connected to said beads; a circumferentially extending tread portion joining said sidewalls; said tire having a thin air impervious liner on the inner surface thereof; a cord reinforcing material extending from one of said beads to the other of said beads through said sidewalls, and said tread, said reinforcing material being located in each of said sidewalls closely ad-jacent to itq inner wall surface in the sidewaLl portion adjacent to said beads and closely adjacent to the inner wall surface in the shoulders connecting said sidewalls and said tread; and said cord reinforcing material extending gradually from said beads to closely adjacent tha outer peripheral sur- ;
face in the sidewall portion exclusive of said air impervious liner and thence extending gradually away from said siclewall outer surface to closely adiacent the inner wall surface of said shoulders.
In accordance with a further aspect of the present .
~L~7~
invention there is provided a pneumatic tire ~aving a thin air impervious liner on the inner surface thereof, said tire comprising a carcass with a tread having c~ crown portion therebeneath, said crown portion having an inner circumferen-tially extending surface said carcass having a pair of spaced apart beads, each bead having a toe and heel portion, said . -carcass having a sidewall on each side o~ said tire extending from one of said beads to said tread, a cord reinforcing ply with radially disposed cords in said carcass extending from one of said beads to the other of said beads through each of said sidewalls and said crown, said cord ply lying closely :~
adjacent to the outermost surface of said sidewall at about said midpoint excluding the width o~ any air impervi.ous liner or inner tube, said cord ply extending gradually from about said midpoint in said sidewall to said toe of said bead and .
extending gradually in the other direction to said crown of .
said tire to be closely adjacent with the inner wall surface of said crown presenting a crescent shaped mass of rubber in vertical cross section of said tire carcass without any cord reinforcing material in said crescent shaped mass of rubber or inwardly to the inner wall surface of said carcass. .~
In accordance with a *urther aspect of the present ~ .
invention there is provided a pne~natic tire casing having a ~ .-thin air impervious liner on the inner surface thereof, said - -tire casing comprising a tire body having spaced-apart side- .
walls and a crown portion between said sidewalls, said crown portion having a circumferentially extending inner surface; a tread overlying said crown portion' beads at the inner radial ends of said sidewalls, each of said beads having a toe and heel portion, a cord reinforcing ply extending through said tire from bead to bead, said reinforcing ply extending gradually from the region closely adjacent to said toe of sai.d bead to 71~
an area closely adjacent to the outer surface of said sidewall exclusive of any liner and thence extending gradually to an area closely adjacent to the inner surface area of said crown region defining a crescent shaped mass of rubber, on the inner surface of said sidewall in radial cross-section; said cres-cent shaped mass of rubber being of substantially the same composition throughout with no cord reinforcing ply inwardly thereof to the inner wall surface of the tire, and the thick-est portion of said crescent shaped mass of rubber being at ;
the midpoint of its radial height, and wherein said thickestportion oE said crescent shaped mass of rubber is over 50%
of the entire thicknes~ of the sidewall taken in cross-section exclusive of any liner on the inner wall surface of said tire body.
In drawings which illustrate preferred embodiments of the invention: -Fig. 1 is a cross-sectional view of one embodiment of the tire of this invention.
Fig. 2 is a cross-sectional view of the tire shown in Fig. 1 in the fulLy deflated eondition when lt is mounted on a rim and is supporting the weight of a vehicle.
Fig. 3 is a cross-sectional view of a modified form of a tire of this invention.
Fig. 4 is a cross-sectional view of another modified form of a tire of this invention.
Fig. 5 is a ragmentary plan view of the tire, partly schematic with individual layers broken away in order to re-present the directions of the cord in the crown of the tireO
~ his invention can be used in any kind or size of pneumatic tire, but since a constantly increasing proportion of tires are being made with radial cord carcasses, the invention is illustrated in connection with radial cord, -4b-.
~L~97~ 5 tubeless passenger car tires.
Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a pneumatic tire 5 having a tread 6 and a pair of spaced sidewalls 7 and 8 which extend from the tread 6 to the respective annular beads 9 and 10. The tread 6 is made of abrasion-resistant rubber composition and extends across the road-engaging sur-face outside of the belt plies and is molded with a sui-table non-skid pattern. Tire 5 includes a conven-tional textile or metal cord in the ply 11 which reinforces the carcass. The ply 11 extends from bead 9 to bead 10 and as shown, extends around the beads and upwardly into the tire carcass sidewalls. ~M
'I'he cord reinforcing ply 11 and the beads 9 and 10 are embedded in rubber in the usual manner. The sidewall rubber :Ls of a consid~rab:le th:Lckness and has a high dynamic modulus so that it will be stiff enough to support the weigh-t on the wheel.
As measured on the goodrich Flexometer using dynamic rate calibrations, s~ch sidewall rubber has a range of 3500-5500 psi with an optimum of 4500-5000 psi, and as measured with a Duro-meter using the Shore hardness scale, Has a hardness of 60-80 with an optimum rating of 70-72. Using the Reolig Dynamic 'I'est Machine at 10% compression and a plu9 or minus 4% strain cycle, -the sidewall rubber shoudl have complex modulus valves (E*) with a range of valves from 900 -to 1150 psi or greater.
In addition such sidewall rubber should have a low hysteresis to minimize heat generation when the tire is run without in-flation. The construction of the tire is symmetrical in re-7~5 lation to the center plane of the tire. The tire is made to hold air in -the usual way by a separate inner tube or an integral thin impervious liner such as a butyl rubber, chlorinated butyl, or other suitable elastomer resistant -to diffusion of air.
A belt structure indicated generally as 12 is provided between tread 6 and the crown 13 of the tire carcass through which crown 13 the textile cord ply 11 ex-tends for reinforcing the tire 5.
The cord reinforcing ply 11 extends from the bead toe 14 radially outwardly along the i.nner surface of the tire and thence toward the outer surface of the sidewal:L 7 towards the mi~point M and thence al.ong such outer surface of -the sidewall 7. As such ply 11 approac:hes the shou:lder :reg:Lorl o:f.~ the tire 5, ply 11 again approaches the inner surface of the tire and extends along the inner wall surface of the crown 13 to the other shoulder portion of the tire and thence to --the bead 10 in the same manner as described. The thickness of the rubber from ply 11 to the outside surface of the tire at the thickest portion of the crescent shaped mass as compared to the thickness of the rubber from ply 11 to the inside sur-face of' the -tire is in the range of ratios 1:1.3 to 1:~ ex-clusive of the liner. As viewed in cross sec-tion, the sidewall rubber of the tire inside of -the reinforcing ply 11 has a con-cave shape with the thickest portion at about the.midpoint and tapers markedly towards the shoulder and bead regions to present a crescent shaped mass of rubber in cross section which acts as an internal COI~lpreSsive member as to be described. In a 60 series tire, the section height of the tire from the wheel to the :
' : ~ .. ' .
, ~7~ 3~35 : -tread is 60% of the section width of the tire. Before measuring, tires should be mounted and inflated to 24 psi for load Range B to 28 psi for load Range C and to 32 psi for load Range D, allowed to stand for 24 hours minimum at normal room tempera-ture and inflation pressures adjusted to 24 psi (load ~ange B), 28 psi (load Range C) and 32 psi (load Range D). Such crescent shaped mass of rubber has a ratio of radial height to maximum thickness (at its thickest point of about 9 to l. This ratio may vary somewhat with different size tires such as the 50,70, or 78 series tires, in a range of about 6:1 to 12:1. In a similar manner, the mass of rubber to the outside of the reinforcing ply 11 is leas-t at the thickest portion of the crescent shaped mass and greatest at a point above the rim adjacent to the bead and sholllder region of the t:ire. When measuring the radi.al height oE such crescent shaped mass, the height is measured radi.ally -from the top of the bead to the inner surface of the crown of the tire. The margin of ply ll extending from the bead radially outward and ending in the sidewall rubber is herein referred to as the reinforcing turn up ply 11' (Fig. 1) and provides additional means -to resist collapse of the tire. The ply ll' is shown as extending around the bead and outward through the sidewall rubber, spearated from the main part of ply :L] by a mass of sidewall rubber 20 of approximately uniform thickness. Such mass of rubber 20 acts as a lower in-ternal compressive member in a manner to be described, and helps to support the crescent shaped mass of rubber in the uninflated condition.
'' " : '''' ~7~ 5 The sidewalls of the tire between the shoulder and the rim engaging portion of the tire are of approximately uniform thickness, and of approximately the same thickness as the crown region inclulding the tread and all -the under-lying structure. At the beads the outside of the tire is shaped to fit the contour of the conventional rim. The portion of the sidewall closest to the rim ends in a substantial rim cushion 15, which is located between -the reinforcing cord ply 11' and the margin of the rim flange when the tire is mounted with a small clearance space between the tire and the outer edges of the rim flanges as illustrated in Fig.
1. Such rim cushion 15 acts as an external compression mem-ber, together with the sidewall rubber 20 between ply 11 and the external marg:in of the ply l:L; to help suppor-t the wei~rh-t o~ the vehicle when the tire is uninflated, and thus alds -the crescent shaped mass of sidewall rubber ins:ide of ply 11 as described above. In the deflated condition of the tire, such rim cushion 15 increases the bead retention pro-perty of the -tire. Such rim cushion 15 may be referred to as a lower external compression member.
In the operation of such tire 5 as described, the tire is inflated -to the normal pressure as in conventional ;
tires, and cushions the vehicles in the ordinary way. ~lowever, upon a loss in air pressure due to road hazards, puncture of the tire, or other reasons, when the air pressure in the tire is substantially reduced or lost altogether, the weight of the vehicle will somewhat reduce the radial height o~ the tire 5 where it rests on the road, causing it to assume the shape shown in cross-section in Fig. 2. In -tha-t condi-tion, ~.~7~9~5 the crescent shaped mass of rubber in each sidewall, inside of the reinforcing ply ll, will be placed in radial com-pression while the reinforcing ply 11 will be placed in -tension, and at the same time, the soulder rubber and the rim cushion 15 will be placed in partly radial and partly axial compression, thereby resisting collapse of the tire and maintaining the respective sidewalls in a curved rather than a folded condition to eliminate rim cutting, chafing and excessive internal heating which ordinarily in this cir-cumstance cause rapid deterioration and ~ailure of -the tire sidewall. In the ordinary collapse of a tire under fu].l vehicle load, -the cords in the tire are subjected to a com-bination of forces including compressive forces which are part:Lcularly harmful to them, whereas in the present case th~ cords are subJected only to a tension load. The t:Lre descr-ibed above remains on the rim permitting considerable maneuverability even at rather high speeds such as ~ifty mph.
The~mass of rubber 20 separating the ply 11 and its margin 11' resists distortion by a combination of forces including radial compresion caused by the increased curvature of ply .`.
11 close to the bead 9 or 10, together with radial shear forces between ply ll and its margin ll'. These forces resist collapse -~
and increase lateral stability which is needed :in cornering.
~ modifica-tion o~ the invention as described above is shown in Fig. 3 consisting of the same type of construction ~.
having tread 6, sidewalls 7, 8., beads 9 and 10, and the cres-cent shaped mass of rubber 25 to the inside of the reinforcing ~
ply 11. In addition, such modified form of the tire has a . :
~ ..' 1~7~1 3S
.
buttress or upper external compressive member 21 at the shoulders of the tire on either side of the tread wlth a substantially cylindrical surface 23 on the radially outer face thereof, at a smaller distance from the axis -than the tread 6, so as not to make contact with the road under normal conditions with the tire fully inflated. The buttress 21 may be spaced from the tread by a shallow groove 24, and may project laterally so as to form a concavity 22 between the corner of the upper surface 23 and the adjacent sur~ace of sidewall 7 or 8. Such buttress or upper external com-pressive member 21 on deflation of the tire, when tread 6 loses support of inflation gas will have its upper surface 23 pressed against the road sur~ace and cooperating w:i-th the crescen-t shaped mass (designated 25 in Fig. 3) the lnterna:L
lower compressive member 20, and the lower external com-pressive member 15 to put the rein~orcing ply 11 in tension while the crescent shaped mass 25, the buttress 21, internal lower member 20 and lower external member 15 are put in com- -pression to support the load on the wheel. The tire in this condition provides adequate support ~or the vehicle and its load, permittlng it to transport the vehicle a considerable distance sa~ely at speeds above minimum expressway speeds.
In addltion to the internal cornpressive member 25, the in-ternal lower compressive member 20, the lower external com- ;
pressive rnember 15, and the upper external compressive member 21, a crown compressive ply 26 made up of relatively sti~f wire cords extending transversely across the crown o~ the tire is located under the tread 6, between the tread and the bel-t ~ ~7~5 12. The margins of the compressive ply 26 are located at the juncture of the tread and the shoulders of the tire.
In the normal situation when a conven-tional radial or bias ply tire loses air and becornes flat, the weight of the vehicle compresses the tire between the wheel rim and the road. This causes the sidewalls to move laterally apart and be pinched between the rim flanges and the road, and the considerable stiffness of the shoulders causes the center of the tread to buckle into the space between the rim flanges.
In this invention, the crown compressive ply 26 provides enough bending s-tiffness of the crown to prevent inward buclcling o~ the crown of the deflated tire. 'E`he transversely extendl~g w:lres in such ply 26 are placed ln compression in such a situation and effectively resist the . . .
compressive forces. This is similar to a beam supported at both ends and a load placed on the beam to deflect the beam.
The wire cords of ply 26 are placed in compression and the cords of ply 11 are placed in tension which action in co-operation with the placing of the crescent shaped mass 25 in `
compression effectively resis-ts the inward buckling action at the crown of the tire and effectively facilitates the tire's run-flat characteristics.
A further modification of -the invention is shown in Fig.4 wherein there is shown a pneumatic -tire 30 having a tread 31 and a pair of spaced sidewalls 32 and 33 which ex-tend from -the tread 31 -to their respective annular beads 34 ; `
and 35. The tread is made of abrasion-resistant rubber com-posi-tion and is molded with a suitable non-skid pattern. Tire ~7~
30 includes a conventional textile or metal cord ply 36 which reinforces the carcass plies. The ply 36 extends from bead 34 to bead 35 and as shown, ex-tends around -the beads and up-wardly into the tire carcass sidewalls. The sidwall rubber has a high dynamic modulus so that i-t will be stiff enough to support the weight on the wheels. The values stated above for the first described embodiment are applicable herein.
The construction of the tire is symmetrical in rela-tion to the center plane of the tire. The tire is made to hold air in the conventional manner as by a thin integral air impervious liner 38 or inner tube resistant to the diffusion of air.
A pair of circumferentially extending belt structures 39 and 40 are provlded between tread 31 and the liner 38 of the tire carcass. '['he textile cord ply 36 extends through the crown of the tire between the liner 38 and the :lower belt ~tructure 39.
The cord reinforcing ply 36 extends from the bead ~
toe 42 radially outwardly along the inner wall surface of -the ~:
tire and thence towards the outer surface of the sidewall (similar to that described in Figure 1,) and thence along -the .
outer sur~ace of the sidewall 33 gradually toward the inner wall surface of the tire at the shoulder region of the tire arld continue~ along the inner wall surface at the crown por-tion of the tire to the other shoulder portion of the -tire and -thence -to the bead 34 in the aame manner. The respective end portions of the reinforcing ply 36 extend around the re-spective beads 34 and 35 and extend into the lower portion of the sidewall terminating adjacent to the reinforcing ply 36.
At about the midpoint M' of the sidewalls 32 and 33, the thickness of -the rubber ~rom ply 36 to the outside surface ..
. .
3~7~ 5 of the tire as compared to the thickness of the rubber from ply 36 to the inside surface of the tire exclusive of any inner tube or air impervious liner is in the range of` ratios 1:1.3 to 1:4. As viewed in cross section ~Fig. 4) the sidewall rubber of the tire inside of -the reinforcing ply 36, exclusive of the liner or inner tube, has a concave shape with the thickest portion at abou-t the midpoint and extends towards the shoulder and head regions to present a ~.
crescent shaped mass of rubber in cross section which acts ~... .
as an internal compressive member as to be described. With the reinforcing ply 36 turned up around the beads 3~ and -35, an annular mass of high modulus rubber ~3,44 on either side o-f the tire adjacent to the beads 34 and 35 provide an additonal compressive member that aids the tire in its run-:flat conditi.on.
I.ocated between the tread 3l and the belt structures . :
39 and ~0 is a circumferentially extending wire belt ~5 ..
whose strands are transversely disposed relative to the tire :
carcass i.e. the wire s-trands are generally parallel to the axis of rotation of the tire.
In the operation of such tire 30, the tire is :in- ~:
fla-ted to the normal pressure as in conventional tires, and cushions the vehicle in the ordinary way. Upon a loss of air pressure due to a road hazard such as the puncture of ..
the tire, the air pressure in the tire is substan-tially re-duced or lost altogether. The wiehgt of the vehicle will cause the tire disclosed in Fig. ~ to assume a shape disclosed in Figure 2, wherein the radial height of the tire 30 will .
be reduced. In this condition, the crescent shaped mass of rubber in each sidewall, inside of the reinforcing ply 36 will :.
:
637~ S
oe placed in radial compression, the reinforcing ply 46 will be placed in tension while the wire/~belt 45;~will'~berplaced in compression which action resists the collapse of the tire, maintaining the respective sidewalls in a curved rather than a folded condition to eliminate rim c-utting, chafing and heat build-up compared to the conventional tire. The con-ventional tire under a loss of air pressure would permit a buckling of the tread towards the wheel and would cause a chafing of the tire which would cause a movement of the side-walls away from the retaining bead portion of the rim flanges causing failure of the -tire and/or movement of the tire car-cass from the rim. In the tire described, the deflated tire under similar conditions would assume the cross-sectional shape shown in ~igure 2 and permit the operation of the vehicle safely at a su~icient rate of speed as discussed above to a servi.ce station or a safe location to permit the replace-ment and/or repir of -the deflated tire.
lires of this invention have demonstrated their ability to support automobiles adequately even when completely deflated so as to permit driving safely and comfortable for a ronsiderable distance on the de~lated flat tires until a destina-tion or a repair facility is reached.
.' ' .
.. . .
Claims (14)
1. A tire having a pair of spaced annular beads;
a pair of annular sidewalls connected to said beads; a circumferentially extending tread portion joining said sidewalls; said tire having a thin air impervious liner on the inner surface thereof; a cord reinforcing material ex-tending from one of said beads to the other of said beads through said sidewalls, and said tread; said reinforcing material being located in each of said sidewalls closely ad-jacent to its inner wall surface in the sidewall portion adjacent to said beads and closely adjacent to the inner wall surface in the shoulders connecting said sidewalls and said tread; and said cord reinforcing material extending gradually from said beads to closely adjacent the outer peripheral sur-face in the sidewall portion exclusive of said air impervious liner and thence extending gradually away from said sidewall outer surface to closely adjacent the inner wall surface of said shoulder.
a pair of annular sidewalls connected to said beads; a circumferentially extending tread portion joining said sidewalls; said tire having a thin air impervious liner on the inner surface thereof; a cord reinforcing material ex-tending from one of said beads to the other of said beads through said sidewalls, and said tread; said reinforcing material being located in each of said sidewalls closely ad-jacent to its inner wall surface in the sidewall portion adjacent to said beads and closely adjacent to the inner wall surface in the shoulders connecting said sidewalls and said tread; and said cord reinforcing material extending gradually from said beads to closely adjacent the outer peripheral sur-face in the sidewall portion exclusive of said air impervious liner and thence extending gradually away from said sidewall outer surface to closely adjacent the inner wall surface of said shoulder.
2. A tire as set forth in claim 1 wherein the material of said sidewall between said air impervious liner and said cord reinforcing material is crescent shaped in radial cross section and has a ratio of radial height to maximum thickness in the range from 6:1 to 12:1.
3. A tire as set forth in claim 1 wherein said tire has a plurality of circumferentially extending belts positioned between said tread and said cord reinforcing material; one of said belts having a plurality of wire strands lying parallel to the axis of rotation of said tire; and said one belt being closer to said tread than any other of said belts.
4. A pneumatic tire as set forth in claim 3 wherein said cord reinforcing material is wrapped around said beads and terminates in said sidewall adjacent to said cord rein-forcing material that extends to said sidewall.
5. A pneumatic tire as set forth in claim 4 wherein said sidewall has a high dynamic modulus rubber in the range of values of 3500 to 5500 psi.
6. A pneumatic tire having a thin air impervious liner on the inner surface thereof, said tire comprising a carcass with a tread having a crown portion therebeneath, said crown portion having an inner circumferentially extending surface, said carcass having a pair of spaced apart beads, each bead having a toe and heel portion, said carcass having a side-wall on each side of said tire extending from one of said beads to said tread, a cord reinforcing ply with radially disposed cords in said carcass extending from one of said beads to the other of said beads through each of said side-walls and said crown, said cord ply lying closely adjacent to the outermost surface of said sidewall at about said mid-point excluding the width of any air impervious liner or inner tube; said cord ply extencing gradually from about said midpoint in said sidewall to said toe of said bead and extending radually in the other direction to said crown of said tire to be closely adjacent with the inner wall surface of said crown presenting a crescent shaped mass of rubber in vertical cross section of said tire carcass without any cord reinforcing material in said crescent shaped mass of rubber or inwardly to the inner wall surface of said carcass.
7. A pneumatic tire as set forth in claim 6 wherein said cord reinforcing ply is positioned at the thickest portion of said crescent shaped mass to divide said sidewall rubber into a ratio having one-third of the thickness of the sidewall to the outer surface thereof and to provide two-thirds of the thickness of the sidewall rubber to the inner wall surface of the tire excluding any air impervious liner or inner tube.
8. A pneumatic tire as set forth in claim 6 wherein said cord reinforcing ply is positioned adjacent said thickest portion of said crescent shaped mass of rubber in said sidewall with its distance from the outer surface of the sidewall having a ratio to its distance from the inner surface of the sidewall exclusive of any liner or inner tube in a range of ratio of 1:1.3 to 1:8.
9. A pneumatic tire as set forth in claim 6 wherein said carcass has a plurality of circumferentially extending belts positioned in said crown portion between said tread and said cord reinforcing ply, one of said belts having wire strands extending transversely across said crown portion lying in a plane that contains the axis of rotation of said tire, and said one belt being closer to said tread than the remaining ones of said belts to place said wire strands of said one belt in compression and said cords of said reinforcing ply in tension in said crown portion upon deflation of said tire while placing said crescent shaped mass of rubber in compression.
10. A pneumatic tire as set forth in claim 8 wherein each of said sidewalls has a lower external compress-ive member adjacent to the said beads.
11 A pneumatic tire as set forth in claim 10 wherein said tire has an upper external compressive member at the shoulder area of said tire.
12. A pneumatic tire as set forth in claim 11 wherein said tire has a lower internal compressive member adjacent to said beads.
13. A pneumatic tire casing having a thin air impervious liner on the inner surface thereof, said tire casing comprising a tire body having spaced-apart sidewalls and a crown portion between said sidewalls; said crown portion having a circum-ferentially extending inner surface; a tread overlying said crown portion; beads at the inner radial ends of said sidewalls;
each of said beads having a toe and heel portion, a cord rein-forcing ply extending through said tire from bead to bead; said reinforcing ply extending gradually from the region closely adjacent to said toe of said bead to an area closely adjacent to the outer surface of said sidewall exclusive of any liner and thence extending gradually to an area closely adjacent to the inner surface area of said crown region defining a crescent shaped mass of rubber, on the inner surface of said sidewall in radial cross-section; said crescent shaped mass of rubber being of substantially the same composition throughout with no cord reinforcing ply inwardly thereof to the inner wall surface of the tire; and the thickest portion of said crescent shaped mass of rubber being at the midpoint of its radial height, and wherein said thickest portion of said crescent shaped mass of rubber is over 50% of the entire thickness of the sidewall taken in cross-section exclusive of any liner on the inner wall surface of said tire body.
each of said beads having a toe and heel portion, a cord rein-forcing ply extending through said tire from bead to bead; said reinforcing ply extending gradually from the region closely adjacent to said toe of said bead to an area closely adjacent to the outer surface of said sidewall exclusive of any liner and thence extending gradually to an area closely adjacent to the inner surface area of said crown region defining a crescent shaped mass of rubber, on the inner surface of said sidewall in radial cross-section; said crescent shaped mass of rubber being of substantially the same composition throughout with no cord reinforcing ply inwardly thereof to the inner wall surface of the tire; and the thickest portion of said crescent shaped mass of rubber being at the midpoint of its radial height, and wherein said thickest portion of said crescent shaped mass of rubber is over 50% of the entire thickness of the sidewall taken in cross-section exclusive of any liner on the inner wall surface of said tire body.
14. A pneumatic tire as set forth in claim 13, wherein said sidewall rubber has a high dynamic modulus in the range of 4500-5000 psi.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/685,346 US4067374A (en) | 1974-10-09 | 1976-05-11 | Pneumatic tire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071985A true CA1071985A (en) | 1980-02-19 |
Family
ID=24751794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA272,007A Expired CA1071985A (en) | 1976-05-11 | 1977-02-17 | Pneumatic tire |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS52137802A (en) |
| CA (1) | CA1071985A (en) |
| DE (1) | DE2720265A1 (en) |
| FR (1) | FR2350973A2 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2425333A1 (en) * | 1978-05-10 | 1979-12-07 | Kleber Colombes | SAFETY TIRES |
| FR2425334A1 (en) * | 1978-05-11 | 1979-12-07 | Kleber Colombes | Sub-tread reinforcement of run-flat pneumatic tyres - using rubber supported hoop plies for a high lateral tread stiffness wt. ratio |
| ZA817371B (en) * | 1980-11-24 | 1982-10-27 | Goodyear Tire & Rubber | A pneumatic safety tire |
| IT1160797B (en) * | 1983-04-18 | 1987-03-11 | Pirelli | SELF-SUPPORTING TIRE |
| TR23054A (en) * | 1984-10-12 | 1989-02-14 | Pirelli Cordwamento Pneumatici | EXTERIOR TIRES THAT RESISTANCE TO RESISTANCE IN AN EXPLOSION OR LOCKING |
| US4929684A (en) * | 1988-06-17 | 1990-05-29 | Bridgestone/Firestone, Inc. | Stiff sidewalls for pneumatic tires |
| US5263526A (en) * | 1992-09-30 | 1993-11-23 | The Goodyear Tire & Rubber Company | Pneumatic tire having specified bead structure |
| US5529105A (en) * | 1992-12-24 | 1996-06-25 | Bridgestone Corporation | Pneumatic tire including at least one tie-element layer with substantially orthogonally oriented cords |
| JP3645277B2 (en) * | 1992-12-24 | 2005-05-11 | 株式会社ブリヂストン | Pneumatic tire |
| DE19722521A1 (en) * | 1997-05-30 | 1998-12-03 | Continental Ag | Pneumatic vehicle tires |
| CN100467289C (en) * | 2001-09-17 | 2009-03-11 | 普利司通株式会社 | Pneumatic tire |
| CN110303827A (en) * | 2019-07-22 | 2019-10-08 | 东营市方兴橡胶有限责任公司 | A kind of all steel run-flat radial and its manufacturing method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE756840A (en) * | 1969-10-04 | 1971-03-01 | Pirelli | IMPROVEMENT IN INTERMEDIATE STRUCTURES OF RADIAL PNEUMATIC BANDAGES |
| GB1487997A (en) * | 1973-10-20 | 1977-10-05 | Dunlop Ltd | Pneumatic tyres |
| AU7835775A (en) * | 1974-02-26 | 1976-08-19 | Dunlop Ltd | Sidewalls with compressed rubber fillets |
| US3949798A (en) * | 1974-04-23 | 1976-04-13 | The Firestone Tire & Rubber Company | Pneumatic tire |
-
1977
- 1977-02-17 CA CA272,007A patent/CA1071985A/en not_active Expired
- 1977-05-03 DE DE19772720265 patent/DE2720265A1/en active Pending
- 1977-05-10 FR FR7714301A patent/FR2350973A2/en active Pending
- 1977-05-11 JP JP5416277A patent/JPS52137802A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2350973A2 (en) | 1977-12-09 |
| JPS52137802A (en) | 1977-11-17 |
| DE2720265A1 (en) | 1977-11-24 |
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