CA1105816A - Pneumatic tire of elastic material without reinforcement - Google Patents
Pneumatic tire of elastic material without reinforcementInfo
- Publication number
- CA1105816A CA1105816A CA322,049A CA322049A CA1105816A CA 1105816 A CA1105816 A CA 1105816A CA 322049 A CA322049 A CA 322049A CA 1105816 A CA1105816 A CA 1105816A
- Authority
- CA
- Canada
- Prior art keywords
- pneumatic tire
- radius
- point
- crown
- curvature
- 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
- 239000013013 elastic material Substances 0.000 title claims abstract description 6
- 230000002787 reinforcement Effects 0.000 title claims abstract description 5
- 239000011324 bead Substances 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims description 13
- 238000004364 calculation method Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
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
- B60C5/00—Inflatable pneumatic tyres or inner tubes
- B60C5/01—Inflatable pneumatic tyres or inner tubes without substantial cord reinforcement, e.g. cordless tyres, cast tyres
-
- 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
- B60C3/00—Tyres characterised by the transverse section
- B60C3/04—Tyres characterised by the transverse section characterised by the relative dimensions of the section, e.g. low profile
-
- 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
- B60C9/02—Carcasses
- B60C9/0292—Carcass ply curvature
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE :
A pneumatic tire comprising a tread at a crown and a body which comprises, on both sides of the crown, a shoulder extended by a sidewall terminated by a bead, and formed of elastic material without reinforcement is characterized by the fact that the radius of curvature ?m of the meridian profile of the inner wall follows the law
A pneumatic tire comprising a tread at a crown and a body which comprises, on both sides of the crown, a shoulder extended by a sidewall terminated by a bead, and formed of elastic material without reinforcement is characterized by the fact that the radius of curvature ?m of the meridian profile of the inner wall follows the law
Description
~1~58~
The present invention relates to imprivements in pneumatic tires of elastic material without reinforcement. The absence of reinforcement, however, does not exclude the use, in the beads of these tires, of bead rings whouse function is to assure the seating and possibly tightness of the beads on the rim.
The crown of such tires may be formed of a single elastic material, for instance, the material forming the side-walls. However, it may also be formed of several super-imposed elastic materials adhering to each other, for instance, at least two materials one of which, arranged radially out~ard, is suitable to form the tread, while the other, arranged radial-ly on the inside of the tread, is suitable to form the mechanic-ally resistant body of the tire in the region of the crown.
The present invention applies to pneumatic tires whose crown is formed of one or more materials and, in the event that the crown is formed of several superimposed materials, it applies to the body of the tire located radially inward of the tread.
Tires of the type under consideration may assume, as a result of the inflation pressure, shapes which are ver~
different from the shapes of the uninflated tires.
The local deformation~ ~r in the radial direction and ~c in the circumferential direction which result therefrom produce shear deformations in the material or materials forming such tires. These deformations add on the the complex deform-ations due to travel under load. There results from this a decrease in the life of the tires of the type in question.
The object of the present invention is to eliminate this condition of shear deformations due to the inflation of the tire.
me invention therefore consists in providing the 5~6 meridian profile of the inner wall of a tire with a meridian radius of curvature p such that the radial deformation ~ is equal to the circumferential deformation ~c' that i5 to say that the shear deformation is zero. Since the determination of such a profile requires the use of expensive computer means, a preferred variant of the invention consists in using, in first approximation, the relationships servin~ for the calcula-tion of membranes in order to evaluate the meridian radius of curvature of such a profile.
The radius of curvature Pm of the meridian profile in accordance with the invention then follows the law :
Re2 ~a) p = Y ~
cos ~ 1 + Re2 In the accompanying drawing which is intended, to-gether with the corresponding portion of the present specific-ation, to facilitate an understanding of the invention, - Fig. 1 shows schematically half of the meridian profile of the inner wall of a tire in accordance with the invention with dimensions utiliæing the parameters which appear in the above-indicated law of variation, and - Fig. 2 illustrates a radial half section through a tire in accordance with the invention.
Fig. 1 shows, in part, half of a meridian profile 1 of the inner wall (11 in Fig. 2) of a pneumatic tire in accordance with the invention. The running point A of this profile is located at a distance y from the axis of rotation X-X' of the tire. The distance y is measured parallel to the trace Y-Y' of the equatorial plane of the tire. R is the radius of the point E of the inner wall which is located at the greatest axial distance from the equatorial line Y-Y~.
5~
Rs is the radius of the point S of the crown which is furthest from the axis of rotation X-X'. ~ is the angle ~ormed by the tangent AT to the inner profile 1 at the point A with the straight line AD passing through the point A and parallel to the axis of rotation X-X'. Pm is the meridian radius of curvature at the point A of the inner profile 1.
The calculation of the coordinates of the different points constituting the profile 1 is advantageously effected by means of a computer.
The tire 2 in accordance with the invention shown in radial half section in Fig. 2 is a pneumatic tire of milli-meter size 135-330. It comprises a tread 3 at a crown 5 and a body 4 which comprises, on both sides of the crown 5, a shoulder 6 extended by a sidewall 7 terminated by a bead 8.
The bead 8 is reinforced by at least one bead ring 9 and rests on a rim 10 (shown in part). The inner wall 11 has a trace in accordance with the invention. The value R of the radius of the crown is equal to 273 mm and the ratio Re/RS is equal to 0.79. The rim 10 is a standard 4-inch rim.
The object of the invention being essentially to avoid the creation of a state of shear deformations in the region of the crown and of the shoulders as a result of the placing of the tire under pressure, it may be sufficient to impart to the inner wall 11 a profile in accordance with the invention in the crown, the shoulders and the portions of the sidewalls radially outward of the points E where the inner wall 11 reaches its greatest distance from the equatorial line Y-Y'.
-~ However, it is pre~erable that the inner wall 11 follow the said meridian pro~ile from one bead 8 to the other.
The inner wall of the tire can be given a meridian curvature in accordance with the invention at the time of the manufacture of the tire. The tire can also be manufactured in - ~ -58~
such a manner that the merid.ian curvature in accordance with the invention is reached only when the tire is in position on its rim, but not inflated.
The tread may be of a suitable material different from the material or materials of the body of the tire, all of these materials adhering to each other.
In practice, the advantages of the invention are obtained when the meridian radius of curvature p defined above by law (a) is located between the two limits defined by the following relationships:
1 - ~
tb),lm = S Y- Y and cos ~ R 2 6 ~ 4 e (c) P2m = 4 Y R 2 cos ~ 3 - 5 e~
.~ .
:
The present invention relates to imprivements in pneumatic tires of elastic material without reinforcement. The absence of reinforcement, however, does not exclude the use, in the beads of these tires, of bead rings whouse function is to assure the seating and possibly tightness of the beads on the rim.
The crown of such tires may be formed of a single elastic material, for instance, the material forming the side-walls. However, it may also be formed of several super-imposed elastic materials adhering to each other, for instance, at least two materials one of which, arranged radially out~ard, is suitable to form the tread, while the other, arranged radial-ly on the inside of the tread, is suitable to form the mechanic-ally resistant body of the tire in the region of the crown.
The present invention applies to pneumatic tires whose crown is formed of one or more materials and, in the event that the crown is formed of several superimposed materials, it applies to the body of the tire located radially inward of the tread.
Tires of the type under consideration may assume, as a result of the inflation pressure, shapes which are ver~
different from the shapes of the uninflated tires.
The local deformation~ ~r in the radial direction and ~c in the circumferential direction which result therefrom produce shear deformations in the material or materials forming such tires. These deformations add on the the complex deform-ations due to travel under load. There results from this a decrease in the life of the tires of the type in question.
The object of the present invention is to eliminate this condition of shear deformations due to the inflation of the tire.
me invention therefore consists in providing the 5~6 meridian profile of the inner wall of a tire with a meridian radius of curvature p such that the radial deformation ~ is equal to the circumferential deformation ~c' that i5 to say that the shear deformation is zero. Since the determination of such a profile requires the use of expensive computer means, a preferred variant of the invention consists in using, in first approximation, the relationships servin~ for the calcula-tion of membranes in order to evaluate the meridian radius of curvature of such a profile.
The radius of curvature Pm of the meridian profile in accordance with the invention then follows the law :
Re2 ~a) p = Y ~
cos ~ 1 + Re2 In the accompanying drawing which is intended, to-gether with the corresponding portion of the present specific-ation, to facilitate an understanding of the invention, - Fig. 1 shows schematically half of the meridian profile of the inner wall of a tire in accordance with the invention with dimensions utiliæing the parameters which appear in the above-indicated law of variation, and - Fig. 2 illustrates a radial half section through a tire in accordance with the invention.
Fig. 1 shows, in part, half of a meridian profile 1 of the inner wall (11 in Fig. 2) of a pneumatic tire in accordance with the invention. The running point A of this profile is located at a distance y from the axis of rotation X-X' of the tire. The distance y is measured parallel to the trace Y-Y' of the equatorial plane of the tire. R is the radius of the point E of the inner wall which is located at the greatest axial distance from the equatorial line Y-Y~.
5~
Rs is the radius of the point S of the crown which is furthest from the axis of rotation X-X'. ~ is the angle ~ormed by the tangent AT to the inner profile 1 at the point A with the straight line AD passing through the point A and parallel to the axis of rotation X-X'. Pm is the meridian radius of curvature at the point A of the inner profile 1.
The calculation of the coordinates of the different points constituting the profile 1 is advantageously effected by means of a computer.
The tire 2 in accordance with the invention shown in radial half section in Fig. 2 is a pneumatic tire of milli-meter size 135-330. It comprises a tread 3 at a crown 5 and a body 4 which comprises, on both sides of the crown 5, a shoulder 6 extended by a sidewall 7 terminated by a bead 8.
The bead 8 is reinforced by at least one bead ring 9 and rests on a rim 10 (shown in part). The inner wall 11 has a trace in accordance with the invention. The value R of the radius of the crown is equal to 273 mm and the ratio Re/RS is equal to 0.79. The rim 10 is a standard 4-inch rim.
The object of the invention being essentially to avoid the creation of a state of shear deformations in the region of the crown and of the shoulders as a result of the placing of the tire under pressure, it may be sufficient to impart to the inner wall 11 a profile in accordance with the invention in the crown, the shoulders and the portions of the sidewalls radially outward of the points E where the inner wall 11 reaches its greatest distance from the equatorial line Y-Y'.
-~ However, it is pre~erable that the inner wall 11 follow the said meridian pro~ile from one bead 8 to the other.
The inner wall of the tire can be given a meridian curvature in accordance with the invention at the time of the manufacture of the tire. The tire can also be manufactured in - ~ -58~
such a manner that the merid.ian curvature in accordance with the invention is reached only when the tire is in position on its rim, but not inflated.
The tread may be of a suitable material different from the material or materials of the body of the tire, all of these materials adhering to each other.
In practice, the advantages of the invention are obtained when the meridian radius of curvature p defined above by law (a) is located between the two limits defined by the following relationships:
1 - ~
tb),lm = S Y- Y and cos ~ R 2 6 ~ 4 e (c) P2m = 4 Y R 2 cos ~ 3 - 5 e~
.~ .
:
Claims (4)
1. A pneumatic tire having an equatorial line, an axis of rotation and comprising a tread at a crown and a body which comprises, on both sides of the crown, a shoulder extended by a sidewall terminated by a bead, and formed of elastic material without reinforcement, characterized by the fact that the radius of curvature pm at a point A of the meridian pro-file of the inner wall of said tire follows the law (a) at least in the portion of the pneumatic tire located radially outward of the points where the meridian profile reaches its greatest axial distance from the equatorial line; wherein - ? is the angle formed by a tangent to said meridian profile at said point A with a straight line passing through said point A and being parallel to said axis of rotation;
- Y is the distance of said point A from said axis of rotation, measured parallel to said equatorial line, and - Re is the radius of the point of said meridian profile located at the greatest axial distance from said equatorial line.
- Y is the distance of said point A from said axis of rotation, measured parallel to said equatorial line, and - Re is the radius of the point of said meridian profile located at the greatest axial distance from said equatorial line.
2. A pneumatic tire according to claim 1, characterized by the fact that the radius of curvature pm of the meridian profile of the inner wall is located between the two limits defined by the following relationships:
(b) and (c)
(b) and (c)
3. A pneumatic tire according to claim 1 or claim 2, characterized by the fact that the radius of curvature pm of the meridian profile of the inner wall follows the said law from one bead to the other.
4. A pneumatic tire according to claim 1 or claim 2, characterized by the fact that its tread consists of a suitable tread material which is different from the material or materials of the body of the pneumatic tire.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7805154A FR2417404A1 (en) | 1978-02-21 | 1978-02-21 | PNEUMATIC IN ELASTIC MATERIAL WITHOUT REINFORCEMENT |
| FR7805154 | 1978-02-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1105816A true CA1105816A (en) | 1981-07-28 |
Family
ID=9204934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA322,049A Expired CA1105816A (en) | 1978-02-21 | 1979-02-21 | Pneumatic tire of elastic material without reinforcement |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS54122504A (en) |
| AU (1) | AU525474B2 (en) |
| BE (1) | BE874132A (en) |
| BR (1) | BR7901138A (en) |
| CA (1) | CA1105816A (en) |
| DE (1) | DE2906722A1 (en) |
| ES (1) | ES477866A1 (en) |
| FR (1) | FR2417404A1 (en) |
| GB (1) | GB2015938B (en) |
| IT (1) | IT1118391B (en) |
| LU (1) | LU80948A1 (en) |
| NL (1) | NL7901355A (en) |
| SE (1) | SE7901496L (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3358900B2 (en) * | 1993-12-16 | 2002-12-24 | 住友ゴム工業株式会社 | Pneumatic tire |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA7259B (en) * | 1971-01-16 | 1972-09-27 | Dunlop Ltd | Tyres |
| FR2314061A1 (en) * | 1975-06-12 | 1977-01-07 | Michelin & Cie | NON-REINFORCED TIRE COVERS, WITH REINFORCED SHOULDERS |
| FR2314060A1 (en) * | 1975-06-12 | 1977-01-07 | Michelin & Cie | IMPROVEMENTS TO TIRE PACKAGES |
| FR2314059A1 (en) * | 1975-06-12 | 1977-01-07 | Michelin & Cie | UNREINFORCED TIRE ENCLOSURES |
| US4006767A (en) * | 1975-10-08 | 1977-02-08 | The Firestone Tire & Rubber Company | Pneumatic tires |
-
1978
- 1978-02-21 FR FR7805154A patent/FR2417404A1/en active Granted
-
1979
- 1979-02-13 BE BE193431A patent/BE874132A/en not_active IP Right Cessation
- 1979-02-19 JP JP1828379A patent/JPS54122504A/en active Pending
- 1979-02-20 IT IT67374/79A patent/IT1118391B/en active
- 1979-02-20 LU LU80948A patent/LU80948A1/en unknown
- 1979-02-20 ES ES477866A patent/ES477866A1/en not_active Expired
- 1979-02-20 SE SE7901496A patent/SE7901496L/en not_active Application Discontinuation
- 1979-02-20 AU AU44390/79A patent/AU525474B2/en not_active Expired
- 1979-02-21 DE DE19792906722 patent/DE2906722A1/en not_active Ceased
- 1979-02-21 CA CA322,049A patent/CA1105816A/en not_active Expired
- 1979-02-21 GB GB7906096A patent/GB2015938B/en not_active Expired
- 1979-02-21 NL NL7901355A patent/NL7901355A/en not_active Application Discontinuation
- 1979-02-21 BR BR7901138A patent/BR7901138A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU525474B2 (en) | 1982-11-11 |
| JPS54122504A (en) | 1979-09-22 |
| BR7901138A (en) | 1979-10-02 |
| ES477866A1 (en) | 1979-08-01 |
| IT1118391B (en) | 1986-02-24 |
| AU4439079A (en) | 1979-08-30 |
| IT7967374A0 (en) | 1979-02-20 |
| NL7901355A (en) | 1979-08-23 |
| FR2417404A1 (en) | 1979-09-14 |
| GB2015938B (en) | 1982-07-14 |
| BE874132A (en) | 1979-05-29 |
| FR2417404B1 (en) | 1981-09-11 |
| SE7901496L (en) | 1979-08-22 |
| GB2015938A (en) | 1979-09-19 |
| DE2906722A1 (en) | 1979-08-23 |
| LU80948A1 (en) | 1979-06-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |