CA1094270A - Method of retreading vehicles tyres - Google Patents
Method of retreading vehicles tyresInfo
- Publication number
- CA1094270A CA1094270A CA341,143A CA341143A CA1094270A CA 1094270 A CA1094270 A CA 1094270A CA 341143 A CA341143 A CA 341143A CA 1094270 A CA1094270 A CA 1094270A
- Authority
- CA
- Canada
- Prior art keywords
- tyre
- rubber
- flexible cover
- region
- needle
- 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
Abstract
ABSTRACT OF THE DISCLOSURE:
Method for repairing a vehicle type in which a repair region of the tyre is provided with rubber material to be bonded to the tyre by vulcanization, a flexible cover is applied to the rubber filled region, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre, the flexible cover is pierced with a hollow suction needle at one or more points over the repair region where air or other vapour has accumulated within the repair region, and the air or other gas or vapour is evacuated from the repair region at each of said points by applying a suction through the needle. Thereafter, the needle is removed from the flexible covering at each of the points after the air or other gas or vapour has been evacuated, the puncture opening is sealed off in the flexible cover made by the needle at each of the points, and the repair region is heated to vulcanize and bond the rubber filling to the tyre.
Method for repairing a vehicle type in which a repair region of the tyre is provided with rubber material to be bonded to the tyre by vulcanization, a flexible cover is applied to the rubber filled region, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre, the flexible cover is pierced with a hollow suction needle at one or more points over the repair region where air or other vapour has accumulated within the repair region, and the air or other gas or vapour is evacuated from the repair region at each of said points by applying a suction through the needle. Thereafter, the needle is removed from the flexible covering at each of the points after the air or other gas or vapour has been evacuated, the puncture opening is sealed off in the flexible cover made by the needle at each of the points, and the repair region is heated to vulcanize and bond the rubber filling to the tyre.
Description
The invention relates to a method of repairing vehicle tyres and is a division of Canadian application No 244,973, filed on June 30, 1976.
As regards retreading me-thods which are concerned here, a layer of vulcanizable rubber, called binding rubber, is laid on a prepared retread on repair region of the tyre carcass and thereafter a vulcanized tread strip in the form of a ring, a strip section or in the form of separate elements adjoining one another is placed thereon, with subse~uent sealing of this layer formation. At least the lateral outlet points of the binding rubber are sealed of, for example, by means of a flexible rubber covering of the tyre, at least in the region of the lateral outlet points of the binding rubber. Any occlusions of air or gas are now removed from the binding rubber region by using reduced pressure and/or excess pressure on the binding rubber region, and in the event of a casing or sleeve being used, by suitable application of reduced pressure and/or excess pressure to these latter. Then follows a treatment of the tyre as thus prepared in the autoclave, using pressure and heat, for the purpose of vulcanizing the binding rubber layer, which firmly unites the tread strip with the carcass in the vulcanized state.
With repairs to tyres having damaged positions, the procedure is similar, in that the vulcanizable rubber and other repair material are applied in the region of the damaged position on the tyre carcass, with subsequent sealing of the point of repair, for example, by covering the latter by means of a piece of a flexible rubber sleeve or cover which can be sealed off at its edge completely around the carcass.
In this case also, reduced pressure and/or excess pressure is applied to-the b~nding rubber region for the purpose of removing gas occlusions, whereafter the vulcanization of the qj~
109~270 binding rubber takes place as previously explained.
In both cases, reduced pressure or vacuum is usually exerted through a hose connection on the sleeve, cover or sheathing on the region beneath the latter. Vacuum connections with a corresponding screw coupling on the sheathing, however, generally project outwardly and consequently are capable of being easily damaged. In addition, the hose coupling interferes with the work carried out on the tyre, for example, the insertion of the completely prepared tyre in the autoclave. The vacuum effect is not always uniform. The region of the binding rubber which is in the vicinity of the hose connection is frequently exposed to a higher vacuum than other regions, to which the access can be obstructed, for example, by the binding rubber in this case acting as an undesired seal and blocking the dis-charge of air.
Consequently, the object is to simplify the use of vacuum in connection with repair operations.
Accordingly, the invention herein claimed is a method for repairing a vehicle tyre comprising the steps of: providing a repair region of the tyre with rubber material to be bonded to the tyre by vulcanization, applying a flexible cover to the region provided with the said rubber material, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre, piercing the flexible cover with a hollow suction needle at at least one point over the repair region where air or other vapour has accumulated within the repair region, evacuating the air or other gas or vapour from the repair region at each of said points by applying a suction through the needle, removing the needle from the flexible covering at each of said points after the air or other gas or vapour has ~ . ~
1'~)94270 been evacuated, sealing off the puncture opening in the flexible cover made by the needle at each of said points, and heating the repair region to vulcanize and bind the rubber filling to the tyre.
This salution permits avoiding the use of any fixed vacuum connections when employing a cover or sheathing. Instead, a sharpened hollow needle or one which is oblique or comes to a point at the forward end is used for penetrating into the cover, said needle being connected to a vacuum line.
If, when making repairs of damage and position , the repair point is prepared as indicated above, covered with a flexible piece of sheathing and the latter is itself sealed off on the carcass, it now only requires the use of the hollow needle, with which the cover is punctured at a position which depends on the size of place being repaired, whereafter a valve in the vacuum line is opened, so that it becomes possible for all air and gas occlusions to be removed by suction from the region beneath the cover and also from the surroundings of the raw rubber by means o the hollow needle.
After the suction has been completed, the perforation is sealed, preferably by sticking binding rubber on the said opening. This is simplest method of sealing, and the binding rubber is advantageously stuck on to ~he puncturing point before the insertion o the needle. ~
The suction method according to the invention can likewise also be used to advantage in connection with the retreading itselfl if the made-up tyre is completely or partially enclosed with a complete or partial cover. The suction procedure by means of a hollow needle here permits occlusions to be removed by suction from the layer structure of the tyre at different positions on the tyre periphery.
When using bonding rubber for sticking and sealing the perfora-~)94Z70 tion, the latter is automatically and permanently closed whenvulcanising the tyre, by vulcanization of the binding rubber used for sealing purposes.
The invention is hereinafter more fully explained by the description of constructional examples with reference to the drawings, wherein:
Fig. 1 is a perspective view of the upper half of a tyre with tread elements of an earth-moving machine with a position for repair, which is covered by means of a flexible covering as a sheathing;
Fig. 2 is a cross-sectional view of a tyre having a sheath or cover stuck and sealed off on the tyre walls;
On the tyre 1 of an earth-moving vehicle as shown in Figure 1 is to be seen a repair position indicated generally
As regards retreading me-thods which are concerned here, a layer of vulcanizable rubber, called binding rubber, is laid on a prepared retread on repair region of the tyre carcass and thereafter a vulcanized tread strip in the form of a ring, a strip section or in the form of separate elements adjoining one another is placed thereon, with subse~uent sealing of this layer formation. At least the lateral outlet points of the binding rubber are sealed of, for example, by means of a flexible rubber covering of the tyre, at least in the region of the lateral outlet points of the binding rubber. Any occlusions of air or gas are now removed from the binding rubber region by using reduced pressure and/or excess pressure on the binding rubber region, and in the event of a casing or sleeve being used, by suitable application of reduced pressure and/or excess pressure to these latter. Then follows a treatment of the tyre as thus prepared in the autoclave, using pressure and heat, for the purpose of vulcanizing the binding rubber layer, which firmly unites the tread strip with the carcass in the vulcanized state.
With repairs to tyres having damaged positions, the procedure is similar, in that the vulcanizable rubber and other repair material are applied in the region of the damaged position on the tyre carcass, with subsequent sealing of the point of repair, for example, by covering the latter by means of a piece of a flexible rubber sleeve or cover which can be sealed off at its edge completely around the carcass.
In this case also, reduced pressure and/or excess pressure is applied to-the b~nding rubber region for the purpose of removing gas occlusions, whereafter the vulcanization of the qj~
109~270 binding rubber takes place as previously explained.
In both cases, reduced pressure or vacuum is usually exerted through a hose connection on the sleeve, cover or sheathing on the region beneath the latter. Vacuum connections with a corresponding screw coupling on the sheathing, however, generally project outwardly and consequently are capable of being easily damaged. In addition, the hose coupling interferes with the work carried out on the tyre, for example, the insertion of the completely prepared tyre in the autoclave. The vacuum effect is not always uniform. The region of the binding rubber which is in the vicinity of the hose connection is frequently exposed to a higher vacuum than other regions, to which the access can be obstructed, for example, by the binding rubber in this case acting as an undesired seal and blocking the dis-charge of air.
Consequently, the object is to simplify the use of vacuum in connection with repair operations.
Accordingly, the invention herein claimed is a method for repairing a vehicle tyre comprising the steps of: providing a repair region of the tyre with rubber material to be bonded to the tyre by vulcanization, applying a flexible cover to the region provided with the said rubber material, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre, piercing the flexible cover with a hollow suction needle at at least one point over the repair region where air or other vapour has accumulated within the repair region, evacuating the air or other gas or vapour from the repair region at each of said points by applying a suction through the needle, removing the needle from the flexible covering at each of said points after the air or other gas or vapour has ~ . ~
1'~)94270 been evacuated, sealing off the puncture opening in the flexible cover made by the needle at each of said points, and heating the repair region to vulcanize and bind the rubber filling to the tyre.
This salution permits avoiding the use of any fixed vacuum connections when employing a cover or sheathing. Instead, a sharpened hollow needle or one which is oblique or comes to a point at the forward end is used for penetrating into the cover, said needle being connected to a vacuum line.
If, when making repairs of damage and position , the repair point is prepared as indicated above, covered with a flexible piece of sheathing and the latter is itself sealed off on the carcass, it now only requires the use of the hollow needle, with which the cover is punctured at a position which depends on the size of place being repaired, whereafter a valve in the vacuum line is opened, so that it becomes possible for all air and gas occlusions to be removed by suction from the region beneath the cover and also from the surroundings of the raw rubber by means o the hollow needle.
After the suction has been completed, the perforation is sealed, preferably by sticking binding rubber on the said opening. This is simplest method of sealing, and the binding rubber is advantageously stuck on to ~he puncturing point before the insertion o the needle. ~
The suction method according to the invention can likewise also be used to advantage in connection with the retreading itselfl if the made-up tyre is completely or partially enclosed with a complete or partial cover. The suction procedure by means of a hollow needle here permits occlusions to be removed by suction from the layer structure of the tyre at different positions on the tyre periphery.
When using bonding rubber for sticking and sealing the perfora-~)94Z70 tion, the latter is automatically and permanently closed whenvulcanising the tyre, by vulcanization of the binding rubber used for sealing purposes.
The invention is hereinafter more fully explained by the description of constructional examples with reference to the drawings, wherein:
Fig. 1 is a perspective view of the upper half of a tyre with tread elements of an earth-moving machine with a position for repair, which is covered by means of a flexible covering as a sheathing;
Fig. 2 is a cross-sectional view of a tyre having a sheath or cover stuck and sealed off on the tyre walls;
On the tyre 1 of an earth-moving vehicle as shown in Figure 1 is to be seen a repair position indicated generally
2, which has been prepared, roughened, filled with unvolcanized binding rubber 4 and smoothed, and thereafter has been closed off with a flexible cover 3a, for example of rubber material, provided as a sheath. The encircling edge 5 of the cover 3a is stuck by means of an adhesive material, in the present case a binding rubber material, along its entire length on the tyre and sealed off, that is to say, both along its path on the tyre wall ànd also over the tread lands and depressions.
If a vulcanization of the binding rubber only used for sealing \ purposes is not desired, raw rubber without sulphur, acceleratorm etc., is for example used. In this way, the repair point is enclosed all round by the cover 3a and sealed off, so that now it is possible for the cover 3a to be punctured by means of a hollow needle 16 which is provided with a handle 17 and which is connected to a controllable vacuum pipe, and the repair point 2 can be subjected to a pressure treatment by means of vacuum. For this purpose, the tip of the hollow needle 16 only penetrates to such an extent into the cover 3a ` 1094Z70 that the opening of the hollow needle 16 just reaches the space which is beneath the cover 3a. Now all air and gas occlusions in the interstice are removed. As soon as the cover 3a is bearing tightly everywhere on the repair point 2, because the suction effect has ended, the hollow needle 16 is retracted and the puncturing point is sealed off and stuck with binding rubber. Before introducing the hollow needle 16, binding rubber in the form of a rubber piece lOd is applied and pressed tightly on the puncturing position before the said rubber piece lOd and the cover 3a are then simultaneously punctured by the hollow needle 16. In this way, an immediate sealing of the puncturing point after withdrawal of the needle is very greatly simplified and made easier.
The vulcanization of the tyre as thus prepared can now take place in the autoclave. However, also a local heating is possible, as for example by heat radiation directed on to the repair position or by the fitting of heating elements into the cover 3a.
Figure 2 illustrates the use of a cover 3, the edges 5 of which are stuck by means of adhesive material 14 on to the carcass la and 6ealed off thereon. The figure shows a built-up tyre, on to the prepared carcass la of which has been applied a tread ll with interposition of a sheet 10 of binding rubber.
As can be seen, the sealing of the cover edges 5 is effected underneath the seams lOa of the binding rubber sheet 10 on the walls of the carcass la, this being effected on the left-hand part of Figure 2 by placing adhesive material 14, for example bonding rubber, beneath the edge or rim 5, while in the case of the right-hand part of Figure 2, this is effected by the interstice between the edge 5 of the cover3 and the carcass la being bridged over by a strip 14 of adhesive material, for example, binding rubber. The method is carried out in other respects as explained in connection with ~igure l, i.e. the harmful air and gas occlusions are withdrawn by suction from the space beneath the cover 3 ancl also from the inters-tices between the binding rubber plate or sheet lO and the carcass la, and also the tread 11, by means of the hollow needle 16. This suction process can if necessary take place at several positions on the tyre circumference. Always after the hollow needle 16 has been retracted, the point of puncture is once again sealed with binding rubber material, which advantageously also in this constructional example is already applied beforehand in the form of a piece of binding rubber lOd to the cover 3 and is punctured by the hollow needle 16, so that ultimately there is obtained a layer formation of the tyre which is free from air occlusions and which is enclosed by the cover 3.
If a vulcanization of the binding rubber only used for sealing \ purposes is not desired, raw rubber without sulphur, acceleratorm etc., is for example used. In this way, the repair point is enclosed all round by the cover 3a and sealed off, so that now it is possible for the cover 3a to be punctured by means of a hollow needle 16 which is provided with a handle 17 and which is connected to a controllable vacuum pipe, and the repair point 2 can be subjected to a pressure treatment by means of vacuum. For this purpose, the tip of the hollow needle 16 only penetrates to such an extent into the cover 3a ` 1094Z70 that the opening of the hollow needle 16 just reaches the space which is beneath the cover 3a. Now all air and gas occlusions in the interstice are removed. As soon as the cover 3a is bearing tightly everywhere on the repair point 2, because the suction effect has ended, the hollow needle 16 is retracted and the puncturing point is sealed off and stuck with binding rubber. Before introducing the hollow needle 16, binding rubber in the form of a rubber piece lOd is applied and pressed tightly on the puncturing position before the said rubber piece lOd and the cover 3a are then simultaneously punctured by the hollow needle 16. In this way, an immediate sealing of the puncturing point after withdrawal of the needle is very greatly simplified and made easier.
The vulcanization of the tyre as thus prepared can now take place in the autoclave. However, also a local heating is possible, as for example by heat radiation directed on to the repair position or by the fitting of heating elements into the cover 3a.
Figure 2 illustrates the use of a cover 3, the edges 5 of which are stuck by means of adhesive material 14 on to the carcass la and 6ealed off thereon. The figure shows a built-up tyre, on to the prepared carcass la of which has been applied a tread ll with interposition of a sheet 10 of binding rubber.
As can be seen, the sealing of the cover edges 5 is effected underneath the seams lOa of the binding rubber sheet 10 on the walls of the carcass la, this being effected on the left-hand part of Figure 2 by placing adhesive material 14, for example bonding rubber, beneath the edge or rim 5, while in the case of the right-hand part of Figure 2, this is effected by the interstice between the edge 5 of the cover3 and the carcass la being bridged over by a strip 14 of adhesive material, for example, binding rubber. The method is carried out in other respects as explained in connection with ~igure l, i.e. the harmful air and gas occlusions are withdrawn by suction from the space beneath the cover 3 ancl also from the inters-tices between the binding rubber plate or sheet lO and the carcass la, and also the tread 11, by means of the hollow needle 16. This suction process can if necessary take place at several positions on the tyre circumference. Always after the hollow needle 16 has been retracted, the point of puncture is once again sealed with binding rubber material, which advantageously also in this constructional example is already applied beforehand in the form of a piece of binding rubber lOd to the cover 3 and is punctured by the hollow needle 16, so that ultimately there is obtained a layer formation of the tyre which is free from air occlusions and which is enclosed by the cover 3.
Claims (5)
1. A method for repairing a vehicle tyre comprising the steps of:
- providing a repair region of tyre tyre with repair material including rubber material to be bonded to the tyre by vulcanization;
- applying a flexible cover to the region provided with said rubber material, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre;
- piercing the flexible cover with a hollow suction needle at at least one point over the repair region where air or gas, or other vapour has accumulated within the repair region;
- evacuating the air or other gas or vapour from the repair region at each of said points by applying a suction through the needle;
- removing the needle from the flexible covering at each of said points after the air or other gas or vapour has been evacuated;
- sealing off the puncture opening in the flexible cover made by the needle at each of said points, and - heating the repair region to vulcanize and bind the rubber filling to the tyre.
- providing a repair region of tyre tyre with repair material including rubber material to be bonded to the tyre by vulcanization;
- applying a flexible cover to the region provided with said rubber material, attaching the flexible cover to the tyre with an adhesive that can withstand the vulcanization temperature of the rubber filling around the border of the flexible cover to provide a seal between the flexible cover and the tyre;
- piercing the flexible cover with a hollow suction needle at at least one point over the repair region where air or gas, or other vapour has accumulated within the repair region;
- evacuating the air or other gas or vapour from the repair region at each of said points by applying a suction through the needle;
- removing the needle from the flexible covering at each of said points after the air or other gas or vapour has been evacuated;
- sealing off the puncture opening in the flexible cover made by the needle at each of said points, and - heating the repair region to vulcanize and bind the rubber filling to the tyre.
2. A method for repairing a vehicle tyre according to claim 1 wherein the repair region is filled completely with vulcanizable binding rubber.
3. A method for repairing a vehicle tyre according to claim 1, wherein the repair region is the tread region and as rubber material there is applied a prevulcanized rubber tread to the tread region of the tyre with a vulcanizable binding rubber layer between the tyre carcass and the rubber tread before applying a flexible cover.
4. A method for retreading a tyre as claimed in claims 1, 2 or 3, wherein the puncture opening is sealed off by means of a vulcanizable binding rubber.
5. A method for repairing a vehicle tyre according to claims 1, 2 or 3, wherein the puncture opening is sealed off by pressing a piece of vulcanizable binding rubber on to the proposed point of puncture before the said piece of rubber and the flexible cover are penetrated by the suction needle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA341,143A CA1094270A (en) | 1975-01-31 | 1979-12-04 | Method of retreading vehicles tyres |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2503973A DE2503973C2 (en) | 1975-01-31 | 1975-01-31 | Procedure for repairing and retreading vehicle tires |
| DEP2503973.0 | 1975-01-31 | ||
| CA244,973A CA1086461A (en) | 1975-01-31 | 1976-01-30 | Method of retreading vehicle tyres |
| CA341,143A CA1094270A (en) | 1975-01-31 | 1979-12-04 | Method of retreading vehicles tyres |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094270A true CA1094270A (en) | 1981-01-27 |
Family
ID=27164315
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA341,143A Expired CA1094270A (en) | 1975-01-31 | 1979-12-04 | Method of retreading vehicles tyres |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1094270A (en) |
-
1979
- 1979-12-04 CA CA341,143A patent/CA1094270A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |