CA1078295A - Pre-molded ring tread for the rebuilding of pneumatic tires - Google Patents
Pre-molded ring tread for the rebuilding of pneumatic tiresInfo
- Publication number
- CA1078295A CA1078295A CA291,473A CA291473A CA1078295A CA 1078295 A CA1078295 A CA 1078295A CA 291473 A CA291473 A CA 291473A CA 1078295 A CA1078295 A CA 1078295A
- Authority
- CA
- Canada
- Prior art keywords
- tread
- tire
- molded
- face
- rebuilding
- 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
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
- B29D30/54—Retreading
- B29D30/56—Retreading with prevulcanised tread
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
- B29D2030/523—Ring-shaped treads
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tyre Moulding (AREA)
- Tires In General (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
Pre-molded ring tread, for the rebuilding of worn pneumatic tyres, that is made up of two pre-molded half-rings, each of which has a curved surface and each delimited, on the lower portion, by an arc and an elongated edge so as to cover the side of the pneumatic tyre. The tread is shaped so as to cover half of the surface of the pneumatic tyre, to be rebuilt obtained by cutting the pneumatic tyre along a plane perpendicu-lar to the rotation axis and passing through the largest diameter.
Pre-molded ring tread, for the rebuilding of worn pneumatic tyres, that is made up of two pre-molded half-rings, each of which has a curved surface and each delimited, on the lower portion, by an arc and an elongated edge so as to cover the side of the pneumatic tyre. The tread is shaped so as to cover half of the surface of the pneumatic tyre, to be rebuilt obtained by cutting the pneumatic tyre along a plane perpendicu-lar to the rotation axis and passing through the largest diameter.
Description
1(~78295 This invention relates to a pre-molded ring tread for use in the rebuilding of pneumatic tires, As is well known, pneumatic tires, especially if of large dimension, may be advantageously made or reutilized by the application on their carcass of a tread ring or band consisting of pre-molded rubber.
; The "cold-process" rebuilding methods, namely by pre-molded material, provide the use of a pre-molded band or ring having a width correlated to that of the pneumatic tire to be covered, being mounted on the pneumatic tire having been formerly worked so as to cover the surface to be regenerated.
It is likewise well known that for a good regeneration of a pneumatic tire it would be necessary that the covering layer be suitably extended on the sidewalls or flanks of the pneumatic tire itself.
In this manner, in fact, there would be obtained an almost total rebuilding of the carcass right up to the proximity of the beads of the pneumatic tire and hence right up to areas of the pneumatic tire away from the points subjected to heating and stress.
Consequently, in order to attain the aforesaid result, it would be necessary to make pre-molded rings provided with largely extended sides.
In practice, however, the building of such ring type tread of curved section, is practically impossible, especially ~ in the case of largely dimensioned pneumatic tires, such as ! pneumatic tires for aircrafts or earthmoving machines.
As a matter of fact, by using closed pre-molded rings, the difficulties arise in the execution of the same with extended sides and subsequent mounting on the already prepared pneumatic tire carcass.
1~78295 Conversely, by using a band pre-molded by means of linear moulds for the covering of tire carcass, the edges of the band may get down very little on the sidewalls of the pneumatic tire carcass.
This is due to the fact that the diameter of the pneumatic tire varies considerably from its larger section towards the sidewalls, its linear development varying conse-quently, whereas the retread band, being molded horizontally, shows a development of constant length.
According to the present invention a complete and perfect regeneration of a pneumatic tire with an extension of the covering layer along substantially all of each sidewall is obtained by a ring tread made up of two "cups" or~half-rings having been pre-molded, each of which shows a curved surface delimited on the lower portion by a circular arc and the extended edge is so shaped as to cover half of the surface of the pneumatic tire to be rebuilt in a plane perpendicular to the rotation axis and passing through the largest diameter.
The two half-rings are, of course, applied on two opposite sides of the pneumatic tire so as to touch each other slightly perfectly in the middle portion of the same.
Each half-ring, because of its particular structure, does not involve any working difficulties, since all diameters are degrading in one single direction.
Equally simple is their mounting on the surface of the pneumatic tire surface to be covered, inasmuch as the rings themselves have a section defined by a curved segment with tangents of diverging extremities.
The pre-molded half-rings according to the present invention can also be used on pneumatic tires of equal diameter, but haYing a grea-ter width.
In such case, in fact, it just suffices to place ~- - 2 -, ~'` 1078Z9S
between the two half-rings a circular ring of suitable width, grooved or not.
This possibility is most important in practice, inasmuch as it ensures to-arrange a plurality of half-rings of a determined diameter for the fabrication and rebuilding of pneumatic tires of equal diameter, but with different sections.
The subsequent treatments to which the pneumatic tires covered with the ring tread of this invention are subjected are the traditional ones, namely in autoclave, with loose pneumatic tire; in autoclave with inflated pneumatic tire separately, closed between circles and elastic hose in order to prevent air from filtering between the ring tread and the carcass; under pressure by using heated moulds without -grooving and with pneumatic tire in inflated condition; at appropriate atmospheric pressure and temperature with the use of special putties, etc.
Accordingly, the invention as herein claimed is a pre-molded ring tread for rebuilding a worn pneumatic tire having a crown portion extending into sidewalls terminating into beads, this tread consisting essentially of two complementary annular pre-molded elements which, when assembled ; side-by-side in face-to-face relationship, form a tread having, in cross-section, a configuration resembling that of a horseshoe. Each element comprises: an upper surface formed with grooves; a lower surface curved so as to be flatly applied onto the tire and on one side of the longitudinal central plane of the tire; an inner surface along and substantially normal to the upper and lower surfaces and intended to be placed in the aforesaid face-to-face relationship with a like inner surface of the other complementary element to form the tread, and an outer tread side opposite the inner surface having an outer surface located between the outer edges of the _ 3 _ "~:~
upper and lower surfaces. The two outer surfaces of the elements, when the elements are assembled over the tire, are essentially radial with respect to,the tire axis and the outer tread sides each has a portion that extends in the proximity of the corresponding bead a distance such as to cover the sidewall of the tire away fro~ the areas subjected to heat and pressure when the tread is applied on the tire.
An embodiment of the invention will now be described with reference to the appended drawings wherein:
10- Fig. 1 shows in a perspective form the half-rings, removed from the pneumatic tire;
- Fig. 2 represents in a schematic form a section of the pneumatic tire covered with the half-rings as given in Fig. l; and - Fig. 3 depicts a pneumatic tire similar to that given in the preceding figures, but of larger section, covered with two half-rings as per Fig. 1 with the interposition of an ; annular member.
,Referring now particularly to the figures on the accompanying drawings, the pre-molded ring tread for the rebuilding of pneumatic tires is made up of two half-rings or ; cups 1 and 1', consisting of rubber, showing each a curved section delimited on the lower portion by a circular arc 2.
I Each half-ring 1 or 1' on the external surface is ! provided with suitable grooves 3 and shows the edge 4 elongated and extended downwardly so as to cover sufficiently one of the sidewalls 5 of the pneumatic tire 6 to be rebuilt.
Between the two half-rings 1 and 1' materializing the covering of the carcass of the pneumatic tire 6 there may be i'0 interplaced a ring 7 of substantially rectangular section so as to fully cover the active surface of the ring tread in case the two half-rings are not properly in contact with each other.
,~ ~
The ring 7 may show both a smooth surface and a grooved surface. From the foregoing and perusal of the figures on the accompanying drawings one may easily see the great functional character and practical application characterizing the pre-molded ring for the rebuilding of pneumatic tires according to the present ivention.
Several changes and modifications may be introduced, ; of course, upon carrying out this invention without departing from the scope and spirit of the invention itself.
; The "cold-process" rebuilding methods, namely by pre-molded material, provide the use of a pre-molded band or ring having a width correlated to that of the pneumatic tire to be covered, being mounted on the pneumatic tire having been formerly worked so as to cover the surface to be regenerated.
It is likewise well known that for a good regeneration of a pneumatic tire it would be necessary that the covering layer be suitably extended on the sidewalls or flanks of the pneumatic tire itself.
In this manner, in fact, there would be obtained an almost total rebuilding of the carcass right up to the proximity of the beads of the pneumatic tire and hence right up to areas of the pneumatic tire away from the points subjected to heating and stress.
Consequently, in order to attain the aforesaid result, it would be necessary to make pre-molded rings provided with largely extended sides.
In practice, however, the building of such ring type tread of curved section, is practically impossible, especially ~ in the case of largely dimensioned pneumatic tires, such as ! pneumatic tires for aircrafts or earthmoving machines.
As a matter of fact, by using closed pre-molded rings, the difficulties arise in the execution of the same with extended sides and subsequent mounting on the already prepared pneumatic tire carcass.
1~78295 Conversely, by using a band pre-molded by means of linear moulds for the covering of tire carcass, the edges of the band may get down very little on the sidewalls of the pneumatic tire carcass.
This is due to the fact that the diameter of the pneumatic tire varies considerably from its larger section towards the sidewalls, its linear development varying conse-quently, whereas the retread band, being molded horizontally, shows a development of constant length.
According to the present invention a complete and perfect regeneration of a pneumatic tire with an extension of the covering layer along substantially all of each sidewall is obtained by a ring tread made up of two "cups" or~half-rings having been pre-molded, each of which shows a curved surface delimited on the lower portion by a circular arc and the extended edge is so shaped as to cover half of the surface of the pneumatic tire to be rebuilt in a plane perpendicular to the rotation axis and passing through the largest diameter.
The two half-rings are, of course, applied on two opposite sides of the pneumatic tire so as to touch each other slightly perfectly in the middle portion of the same.
Each half-ring, because of its particular structure, does not involve any working difficulties, since all diameters are degrading in one single direction.
Equally simple is their mounting on the surface of the pneumatic tire surface to be covered, inasmuch as the rings themselves have a section defined by a curved segment with tangents of diverging extremities.
The pre-molded half-rings according to the present invention can also be used on pneumatic tires of equal diameter, but haYing a grea-ter width.
In such case, in fact, it just suffices to place ~- - 2 -, ~'` 1078Z9S
between the two half-rings a circular ring of suitable width, grooved or not.
This possibility is most important in practice, inasmuch as it ensures to-arrange a plurality of half-rings of a determined diameter for the fabrication and rebuilding of pneumatic tires of equal diameter, but with different sections.
The subsequent treatments to which the pneumatic tires covered with the ring tread of this invention are subjected are the traditional ones, namely in autoclave, with loose pneumatic tire; in autoclave with inflated pneumatic tire separately, closed between circles and elastic hose in order to prevent air from filtering between the ring tread and the carcass; under pressure by using heated moulds without -grooving and with pneumatic tire in inflated condition; at appropriate atmospheric pressure and temperature with the use of special putties, etc.
Accordingly, the invention as herein claimed is a pre-molded ring tread for rebuilding a worn pneumatic tire having a crown portion extending into sidewalls terminating into beads, this tread consisting essentially of two complementary annular pre-molded elements which, when assembled ; side-by-side in face-to-face relationship, form a tread having, in cross-section, a configuration resembling that of a horseshoe. Each element comprises: an upper surface formed with grooves; a lower surface curved so as to be flatly applied onto the tire and on one side of the longitudinal central plane of the tire; an inner surface along and substantially normal to the upper and lower surfaces and intended to be placed in the aforesaid face-to-face relationship with a like inner surface of the other complementary element to form the tread, and an outer tread side opposite the inner surface having an outer surface located between the outer edges of the _ 3 _ "~:~
upper and lower surfaces. The two outer surfaces of the elements, when the elements are assembled over the tire, are essentially radial with respect to,the tire axis and the outer tread sides each has a portion that extends in the proximity of the corresponding bead a distance such as to cover the sidewall of the tire away fro~ the areas subjected to heat and pressure when the tread is applied on the tire.
An embodiment of the invention will now be described with reference to the appended drawings wherein:
10- Fig. 1 shows in a perspective form the half-rings, removed from the pneumatic tire;
- Fig. 2 represents in a schematic form a section of the pneumatic tire covered with the half-rings as given in Fig. l; and - Fig. 3 depicts a pneumatic tire similar to that given in the preceding figures, but of larger section, covered with two half-rings as per Fig. 1 with the interposition of an ; annular member.
,Referring now particularly to the figures on the accompanying drawings, the pre-molded ring tread for the rebuilding of pneumatic tires is made up of two half-rings or ; cups 1 and 1', consisting of rubber, showing each a curved section delimited on the lower portion by a circular arc 2.
I Each half-ring 1 or 1' on the external surface is ! provided with suitable grooves 3 and shows the edge 4 elongated and extended downwardly so as to cover sufficiently one of the sidewalls 5 of the pneumatic tire 6 to be rebuilt.
Between the two half-rings 1 and 1' materializing the covering of the carcass of the pneumatic tire 6 there may be i'0 interplaced a ring 7 of substantially rectangular section so as to fully cover the active surface of the ring tread in case the two half-rings are not properly in contact with each other.
,~ ~
The ring 7 may show both a smooth surface and a grooved surface. From the foregoing and perusal of the figures on the accompanying drawings one may easily see the great functional character and practical application characterizing the pre-molded ring for the rebuilding of pneumatic tires according to the present ivention.
Several changes and modifications may be introduced, ; of course, upon carrying out this invention without departing from the scope and spirit of the invention itself.
Claims (2)
1. A pre-molded ring tread for rebuilding a worn pneumatic tire having a crown portion extending into sidewalls terminating into beads, said tread consisting essentially of two complementary annular pre-molded elements which, when assem-bled side-by-side in face-to-face relationship, form a tread having, in cross-section, a configuration resembling that of a horseshoe; wherein each element comprises: an upper surface for-med with grooves; a lower surface curved so as to be flatly ap-plied onto said tire and on one side of the longitudinal central plane of said tire; an inner surface along and substantially normal to said upper and lower surfaces and intended to be pla-ced in said face-to-face relationship with a like inner surface of the other complementary element to form said tread, and an outer tread side opposite said inner surface having an outer surface located between the outer edges of said upper and lower surfaces; wherein said outer surfaces of said elements, when said elements are applied onto said tire, are essentially radial with respect to the tire axis and said outer tread sides each has portion that extends in the proximity of the corresponding bead a distance such as to cover the sidewall of the tire away from the areas subjected to heat and pressure when the tread is mounted in the tire.
2. A pre-molded ring tread according to claim 1, which additionnally comprises a third element of substantially rectan-gular cross-section placed between said inner surfaces of the two pre-molded elements which are placed in face-to-face rela-tionship to each other.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT3088776A IT1066840B (en) | 1976-12-24 | 1976-12-24 | TIRE PROVIDED WITH PRE-PRINTED RINGS, CONCAVE SECTION, SUITABLE TO ALLOW THE MANUFACTURE OR RECONSTRUCTION OF TIRES, EVEN OF LARGE DIMENSIONS AND RELATIVE MANUFACTURING METHOD |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078295A true CA1078295A (en) | 1980-05-27 |
Family
ID=11232663
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA291,473A Expired CA1078295A (en) | 1976-12-24 | 1977-11-22 | Pre-molded ring tread for the rebuilding of pneumatic tires |
Country Status (9)
| Country | Link |
|---|---|
| AT (1) | AT358407B (en) |
| BE (1) | BE860127A (en) |
| CA (1) | CA1078295A (en) |
| CH (1) | CH620155A5 (en) |
| DE (1) | DE2750647A1 (en) |
| ES (1) | ES464581A1 (en) |
| FR (1) | FR2375029A1 (en) |
| GB (1) | GB1577154A (en) |
| IT (1) | IT1066840B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2763883A1 (en) * | 1997-05-30 | 1998-12-04 | Michelin & Cie | MANUFACTURE OF A TIRE IN WHICH THE TREAD IS MADE FROM SEVERAL PREVULCANIZED PARTS |
| GB2327392A (en) * | 1997-07-23 | 1999-01-27 | Holroyd Associates Ltd | Tyre tread package and tyre manufacture |
| BR112015024701A8 (en) * | 2013-03-31 | 2018-01-02 | Michelin & Cie | IMPROVED METHODS FOR RETREADING TIRES WITH REST TREADS |
| CN105050803A (en) * | 2013-03-31 | 2015-11-11 | 米其林集团总公司 | Improved methods of tire retreading using preassembled treads |
| CN103223820B (en) * | 2013-05-04 | 2015-03-25 | 吉林大学 | High-trafficability simulated sand crossing wheel face structure |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB744827A (en) * | 1952-12-24 | 1956-02-15 | Channel Islands Tyre Company L | Improvements in and relating to the retreading of tyres |
| FR1221414A (en) * | 1959-03-26 | 1960-06-01 | Process for retreading tires by means of bands applied without molding, and bands applicable according to said process | |
| FR1411387A (en) * | 1964-08-19 | 1965-09-17 | Vulcanization process | |
| FR2030005A5 (en) * | 1969-07-03 | 1970-10-23 | Schelkmann Wilhelm | Vulcanising profiled treads onto tyres starting by |
-
1976
- 1976-12-24 IT IT3088776A patent/IT1066840B/en active
-
1977
- 1977-10-26 GB GB4456077A patent/GB1577154A/en not_active Expired
- 1977-10-26 BE BE182074A patent/BE860127A/en unknown
- 1977-11-09 DE DE19772750647 patent/DE2750647A1/en not_active Withdrawn
- 1977-11-11 AT AT805177A patent/AT358407B/en not_active IP Right Cessation
- 1977-11-17 CH CH1407377A patent/CH620155A5/en not_active IP Right Cessation
- 1977-11-22 CA CA291,473A patent/CA1078295A/en not_active Expired
- 1977-11-29 ES ES464581A patent/ES464581A1/en not_active Expired
- 1977-12-20 FR FR7738724A patent/FR2375029A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| ATA805177A (en) | 1980-01-15 |
| AT358407B (en) | 1980-09-10 |
| FR2375029A1 (en) | 1978-07-21 |
| GB1577154A (en) | 1980-10-22 |
| CH620155A5 (en) | 1980-11-14 |
| ES464581A1 (en) | 1978-09-01 |
| IT1066840B (en) | 1985-03-12 |
| BE860127A (en) | 1978-02-15 |
| DE2750647A1 (en) | 1978-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |