CA1160407A - Filled composite solid rubber tire for vehicles - Google Patents
Filled composite solid rubber tire for vehiclesInfo
- Publication number
- CA1160407A CA1160407A CA000357915A CA357915A CA1160407A CA 1160407 A CA1160407 A CA 1160407A CA 000357915 A CA000357915 A CA 000357915A CA 357915 A CA357915 A CA 357915A CA 1160407 A CA1160407 A CA 1160407A
- Authority
- CA
- Canada
- Prior art keywords
- mold
- tire
- pieces
- segment
- casing
- 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
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A consolidated filler segment for composite solid rubber tires is made by reducing scrap rubber articles to small pieces, placing the pieces in a mold having the configuration of the desired tire filler segment, heating the pieces in the mold while applying pressure thereto sufficient to consolidate the mold contents to a density of from 15 to 75 pounds per cubic foot, cooling the consolidated product, and removing it from the mold. The vehicle tire product comprises a tire casing and within the casing a filler comprising abutting seg-ments made from the molded and consolidated rubber pieces aforesaid.
A consolidated filler segment for composite solid rubber tires is made by reducing scrap rubber articles to small pieces, placing the pieces in a mold having the configuration of the desired tire filler segment, heating the pieces in the mold while applying pressure thereto sufficient to consolidate the mold contents to a density of from 15 to 75 pounds per cubic foot, cooling the consolidated product, and removing it from the mold. The vehicle tire product comprises a tire casing and within the casing a filler comprising abutting seg-ments made from the molded and consolidated rubber pieces aforesaid.
Description
0~07 FILLED COMPOSITE SOLID RUBBER TIRE FOR VEHICLES
BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to composite solid tires for vehicles and to a method of making a consolidated ~iller segment there~or.
Proposals hereto~ore have been made to make a composite solid rubber tire ~or vehicles by reducing scrap rubber articles to the form of small pieces, consolidating a quantity of such pieces into the shape of a solid rubber ring, and inserting the resulting ring into a tire casing. Such products have been hard to make~ almost impossible to inser~ inside the casing, and of relatively shor~ ser-vice life.
I the rings are made in segments and the segments inserted into the casing to form a jointed core, as also is shown in the prior art, the segments are prone to become dislodged during use of the tire. As a result, insofar as we are aware, there is no composite tire marketed today o~ the class under consideration.
There is need for such a product, however, particularly under heavy duty conditions, such as are met by lift truck tires, mobile irrigation sprinkler system carriage tires, certain truck tires, etc.
The need for such a tire exists particularly in order to provide a large scale commercial outlet for scrap rubber products, thereby con-serving the petroleum resource from which the rubber for present day~ires is produced, and to provide a serviceable, low cost, tire product.
It is the general obJect of the present invention to prov;de a composite solid tire made from consolidated scrap rubber pieces.
It is a ~urther object of the present invention to provide a method of making from scrap rubber pieces consolidated rubber tire filler segments suitable for use in such composite tires.
Broadly stated, the presently described method o~ making such segments comprises reducing scrap rubber articles to the ~orm of small pieces, placing the pieces in a mold having the configuration of the desired segment, and heating the pieces in the mold at a '~' l 1604~7 temperature of from 100 to 600F. while applying pressure of from 500 to 4,000 psi for a time sùfficient to bring the central portion of the mold contents to a temperature of from 200 to 300F. The mold contents are consolidated to a density of ~rom 15 to 75 pounds per cubic foot, after which the mold and contents are cooled. The consolidated mixture then is removed from the mold and applied to its intended use.
The herein described vehicle tire product comprises a tire casing and within the casing a filler comprising abutting segments resulting from the above described procedure.
DESC~IPTION OF SPECIFIC EMBODIMENTS
OF THE INVENTION
As stated above, the raw material for our invention preferably comprises scrap rubber articles reduced to the form of small pieces.
Such scrap rubber articles may comprise vehicle tires, tire tubes, shoe soles, rollers, rubber mats, etc. They preferably comprise scrap rubber tires available in substantially unlimited quantity at very low cost.
Another primary source of raw material for our new tire product comprises the waste rubber byproduct from the tire retreading indus-try. In this industry it is conventional to buff off with grindingwheels the tread and under tread rubber from the tires to be re-capped. This produces annually an enormous quantity of rubber par-ticles ranging in size from dust to about 1/4". This waste product poses a very real disposal problem to the retread houses. However, it is ideal for use in the composite solid rubber tire products of our invention.
The rubber raw material may be prepared in two principal cate-gories.
In the first, the scrap rubber articles are reduced severely to the form of very small pieces ranging in size from dust to par-ticles having a maximum screen size of about 1/4" mesh.
The other category comprises a quantity of larger pieces such as may be manu~actured by chipping the scrap rubber articles to the form of chips having a maximum size o~ approximately 3" x 3".
The first named category may readily be obtained as a by-pro-duct of the tire recapping industry, as outli.ned above. The second categDry may be produced inexpensively by chipping scrap automobile tires, including the whole casing with bead. The fabric content and wire content of the resulting chips does not interfere with the successful application of the material to our purposes and may even improve the properties of the resulting product.
The consolidated tire segments may comprise totally consolidated rubber pieces of the first category. However, they also may com-prise a mixture of small pieces of the first category and up to 75%
by weight of the chips of the second category, thus providing an inexpensive raw material.
As is clear from the foregoing discussion, scrap rubber tires are intended as a primary source of raw material for the practice of our invention. The chemical identity of the rubber suitable therefor accordingly is determined by the identity of the rubbers used in the tires. Such rubbers are:
isoprene-type rubber neoprene-type rubber butadiene-type rubbers Buna N
Buna L
Buna GRS
These materials may be used in admixture with each other and in admixture with a proportion of natural rubber, although the e~ten-sive use of natural rubber is discouraged by its high cost.
It is a feature of the invention that using the present day synthetic rubbers the scrap particles may be consolidated and wel-ded together under the influence of heat and pressure without the necessity of using a bonding agent and/or vulcani~ing agent. This is in counterdistinction to the rubber mixtures described in the prior art. It is an important consideration, since elimination of I lgO~O~
bonding and vulcanizing agents substantially simpliies the processing procedures and reduces the cost of the product.
In the fabrication of the rubber pieces described above into a consolidated rubber tire filler segment, a quantity of pieces of the desired size and characteristics first is formed.
This raw material then is charged into a mold of suitable con-tour having the configuration of the desired tire filler segment.
To be suitable for such application, the contour of the segment should be arcuate, with planar end faces. Where there are four segments for each tire, these faces should be substantially perpen-dicular to each other. As a result, when they are abutted in the tire casing, they meet face to face without a substantial gap be-tween.
Also, and importantly, the joints between the meeting spaces will not be perpendicular to the point of contact of the tire with the ground. As a consequence, the faces will overlie each o~her so that one face bears against the meeting face. This forms a unitary whole and prevents the individual segments from working out of place and distorting the casing in which they are contained.
The mold preferably is dimensioned to be somewhat wider than the cross section of the tire casing in which the molded segment is to be inserted. This insures a snug fit.
Within the mold, the pieces are first subJected to a preliminary consolidation to the desired density, e.g. a density of from 15-75 pounds per cubic foot. The mold and contents then are placed in an oven and heated at a temperature of from 100 to 600, preferably 350-450F. while applying a pressure of rom 500 to 4,000, preferably 1,000-3,000 psi.
The mold and contents are heated at this temperature for a time sufficient to bring the central portion of the mold contents to a temperature of from 200-300F. Under these conditions the individual pieces within the mold consolidate and bond to each other, either by sintering together or through chemical reaction. This may be accom-` tl~0~0~
plished without the use of a solvent~ or vulcanizing agent.
At the conclusion of the heat and pressure treatment, the moldand contents are cooled, the mold oper,ed and the finished tire fil-ler sègmen~ iemoved.
To incorporate the segments ili~ a composite solid tire, a conventional tire casing, which also may be a discarded used casing, is provided. The casing is spread and the segments inserted end to end. Thereupon they will nest snugly within the tire casing which next may be mounted on a suitable split rim for application to the intended use of providing a solid rubber tire ~or a vehicle.
As indicated above, such vehicles comprise especially automobi-les and trucks. However, they also may comprise lift trucks, golf carts, wheelbarrows, mobile irrigation equipment and the like. In this use the tires serve as efficient, heavy duty tires. Their use is attended by the further advantage that in the event the casing accidentally is slashed and rendered useless, the filler segments can be removed from the slashed casing and used in a replacemen~
casing.
EXAMPLE
To make a rubber tire filler segment for use in a composite industrial truck tire, the ollowing procedure is illustrative.
A mixture o 25% of up to 1/4" mesh rubber particles and 75%
o up to 3 x 3 inch rubber chips is prepared.
The resulting mixture is placed in a mold of arcuate contour representing 1/4 of the circumference of the finished tire. The material is compressed in the mold to a density of 45 pounds per cubic feet. This re~uires a pressure of about 2,000 pounds per squ-are inch.
The mold and its contained charge is placed in an oven and heated at 380-400F. until the material in the interior o the mold charge has attained a curing temperature of 230-280F. The cure time is approximately 4 hours.
The mold and contents are cooled to ambient temperature, the mold opened and the consolidated tire ~iller segment removed.
Four such segments then are inserted in an appropriately sized tire casing, which is mounted on a rim to produce the finished com-posite tire.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to composite solid tires for vehicles and to a method of making a consolidated ~iller segment there~or.
Proposals hereto~ore have been made to make a composite solid rubber tire ~or vehicles by reducing scrap rubber articles to the form of small pieces, consolidating a quantity of such pieces into the shape of a solid rubber ring, and inserting the resulting ring into a tire casing. Such products have been hard to make~ almost impossible to inser~ inside the casing, and of relatively shor~ ser-vice life.
I the rings are made in segments and the segments inserted into the casing to form a jointed core, as also is shown in the prior art, the segments are prone to become dislodged during use of the tire. As a result, insofar as we are aware, there is no composite tire marketed today o~ the class under consideration.
There is need for such a product, however, particularly under heavy duty conditions, such as are met by lift truck tires, mobile irrigation sprinkler system carriage tires, certain truck tires, etc.
The need for such a tire exists particularly in order to provide a large scale commercial outlet for scrap rubber products, thereby con-serving the petroleum resource from which the rubber for present day~ires is produced, and to provide a serviceable, low cost, tire product.
It is the general obJect of the present invention to prov;de a composite solid tire made from consolidated scrap rubber pieces.
It is a ~urther object of the present invention to provide a method of making from scrap rubber pieces consolidated rubber tire filler segments suitable for use in such composite tires.
Broadly stated, the presently described method o~ making such segments comprises reducing scrap rubber articles to the ~orm of small pieces, placing the pieces in a mold having the configuration of the desired segment, and heating the pieces in the mold at a '~' l 1604~7 temperature of from 100 to 600F. while applying pressure of from 500 to 4,000 psi for a time sùfficient to bring the central portion of the mold contents to a temperature of from 200 to 300F. The mold contents are consolidated to a density of ~rom 15 to 75 pounds per cubic foot, after which the mold and contents are cooled. The consolidated mixture then is removed from the mold and applied to its intended use.
The herein described vehicle tire product comprises a tire casing and within the casing a filler comprising abutting segments resulting from the above described procedure.
DESC~IPTION OF SPECIFIC EMBODIMENTS
OF THE INVENTION
As stated above, the raw material for our invention preferably comprises scrap rubber articles reduced to the form of small pieces.
Such scrap rubber articles may comprise vehicle tires, tire tubes, shoe soles, rollers, rubber mats, etc. They preferably comprise scrap rubber tires available in substantially unlimited quantity at very low cost.
Another primary source of raw material for our new tire product comprises the waste rubber byproduct from the tire retreading indus-try. In this industry it is conventional to buff off with grindingwheels the tread and under tread rubber from the tires to be re-capped. This produces annually an enormous quantity of rubber par-ticles ranging in size from dust to about 1/4". This waste product poses a very real disposal problem to the retread houses. However, it is ideal for use in the composite solid rubber tire products of our invention.
The rubber raw material may be prepared in two principal cate-gories.
In the first, the scrap rubber articles are reduced severely to the form of very small pieces ranging in size from dust to par-ticles having a maximum screen size of about 1/4" mesh.
The other category comprises a quantity of larger pieces such as may be manu~actured by chipping the scrap rubber articles to the form of chips having a maximum size o~ approximately 3" x 3".
The first named category may readily be obtained as a by-pro-duct of the tire recapping industry, as outli.ned above. The second categDry may be produced inexpensively by chipping scrap automobile tires, including the whole casing with bead. The fabric content and wire content of the resulting chips does not interfere with the successful application of the material to our purposes and may even improve the properties of the resulting product.
The consolidated tire segments may comprise totally consolidated rubber pieces of the first category. However, they also may com-prise a mixture of small pieces of the first category and up to 75%
by weight of the chips of the second category, thus providing an inexpensive raw material.
As is clear from the foregoing discussion, scrap rubber tires are intended as a primary source of raw material for the practice of our invention. The chemical identity of the rubber suitable therefor accordingly is determined by the identity of the rubbers used in the tires. Such rubbers are:
isoprene-type rubber neoprene-type rubber butadiene-type rubbers Buna N
Buna L
Buna GRS
These materials may be used in admixture with each other and in admixture with a proportion of natural rubber, although the e~ten-sive use of natural rubber is discouraged by its high cost.
It is a feature of the invention that using the present day synthetic rubbers the scrap particles may be consolidated and wel-ded together under the influence of heat and pressure without the necessity of using a bonding agent and/or vulcani~ing agent. This is in counterdistinction to the rubber mixtures described in the prior art. It is an important consideration, since elimination of I lgO~O~
bonding and vulcanizing agents substantially simpliies the processing procedures and reduces the cost of the product.
In the fabrication of the rubber pieces described above into a consolidated rubber tire filler segment, a quantity of pieces of the desired size and characteristics first is formed.
This raw material then is charged into a mold of suitable con-tour having the configuration of the desired tire filler segment.
To be suitable for such application, the contour of the segment should be arcuate, with planar end faces. Where there are four segments for each tire, these faces should be substantially perpen-dicular to each other. As a result, when they are abutted in the tire casing, they meet face to face without a substantial gap be-tween.
Also, and importantly, the joints between the meeting spaces will not be perpendicular to the point of contact of the tire with the ground. As a consequence, the faces will overlie each o~her so that one face bears against the meeting face. This forms a unitary whole and prevents the individual segments from working out of place and distorting the casing in which they are contained.
The mold preferably is dimensioned to be somewhat wider than the cross section of the tire casing in which the molded segment is to be inserted. This insures a snug fit.
Within the mold, the pieces are first subJected to a preliminary consolidation to the desired density, e.g. a density of from 15-75 pounds per cubic foot. The mold and contents then are placed in an oven and heated at a temperature of from 100 to 600, preferably 350-450F. while applying a pressure of rom 500 to 4,000, preferably 1,000-3,000 psi.
The mold and contents are heated at this temperature for a time sufficient to bring the central portion of the mold contents to a temperature of from 200-300F. Under these conditions the individual pieces within the mold consolidate and bond to each other, either by sintering together or through chemical reaction. This may be accom-` tl~0~0~
plished without the use of a solvent~ or vulcanizing agent.
At the conclusion of the heat and pressure treatment, the moldand contents are cooled, the mold oper,ed and the finished tire fil-ler sègmen~ iemoved.
To incorporate the segments ili~ a composite solid tire, a conventional tire casing, which also may be a discarded used casing, is provided. The casing is spread and the segments inserted end to end. Thereupon they will nest snugly within the tire casing which next may be mounted on a suitable split rim for application to the intended use of providing a solid rubber tire ~or a vehicle.
As indicated above, such vehicles comprise especially automobi-les and trucks. However, they also may comprise lift trucks, golf carts, wheelbarrows, mobile irrigation equipment and the like. In this use the tires serve as efficient, heavy duty tires. Their use is attended by the further advantage that in the event the casing accidentally is slashed and rendered useless, the filler segments can be removed from the slashed casing and used in a replacemen~
casing.
EXAMPLE
To make a rubber tire filler segment for use in a composite industrial truck tire, the ollowing procedure is illustrative.
A mixture o 25% of up to 1/4" mesh rubber particles and 75%
o up to 3 x 3 inch rubber chips is prepared.
The resulting mixture is placed in a mold of arcuate contour representing 1/4 of the circumference of the finished tire. The material is compressed in the mold to a density of 45 pounds per cubic feet. This re~uires a pressure of about 2,000 pounds per squ-are inch.
The mold and its contained charge is placed in an oven and heated at 380-400F. until the material in the interior o the mold charge has attained a curing temperature of 230-280F. The cure time is approximately 4 hours.
The mold and contents are cooled to ambient temperature, the mold opened and the consolidated tire ~iller segment removed.
Four such segments then are inserted in an appropriately sized tire casing, which is mounted on a rim to produce the finished com-posite tire.
Claims (6)
1.
A method of preparing a consolidated rubber tire filler segment a plurality of which are capable of being arranged end to end within a tire casing to fill the latter, the method comprising:
a) reducing scrap rubber articles to the form of small pieces, b) placing the pieces in a mold having the configuration of the desired segment in which the opposite ends of the segment are so arranged that when a plurality of segments are assembled in a tire casing the confronting ends of adjacent segments abut without a substantial gap between them and form a joint having a plane that is not perpendicular to the point of contact of the tire with the ground, c) heating the mixture in the absence of a bonding agent or vulcanizing agent in a mold at a temperature of from 100 to 600 ° F. while applying pressure of from 500 to 4000 psi for a time sufficient to bring the central portion of the mold charge to a temperature of from 200 to 300° F., d) consolidating the hot pieces in the mold to a density of from 15 to 75 lbs/cubic foot,and e) cooling the consolidated product and removing it from the mold.
A method of preparing a consolidated rubber tire filler segment a plurality of which are capable of being arranged end to end within a tire casing to fill the latter, the method comprising:
a) reducing scrap rubber articles to the form of small pieces, b) placing the pieces in a mold having the configuration of the desired segment in which the opposite ends of the segment are so arranged that when a plurality of segments are assembled in a tire casing the confronting ends of adjacent segments abut without a substantial gap between them and form a joint having a plane that is not perpendicular to the point of contact of the tire with the ground, c) heating the mixture in the absence of a bonding agent or vulcanizing agent in a mold at a temperature of from 100 to 600 ° F. while applying pressure of from 500 to 4000 psi for a time sufficient to bring the central portion of the mold charge to a temperature of from 200 to 300° F., d) consolidating the hot pieces in the mold to a density of from 15 to 75 lbs/cubic foot,and e) cooling the consolidated product and removing it from the mold.
2.
The method of claim 1 including the steps of :
a) reducing the scrap rubber articles to small pieces having a screen size of up to one-quarter inch mesh size, b) reducing a further quantity of rubber articles to the size of chips having a maximum size of approximately
The method of claim 1 including the steps of :
a) reducing the scrap rubber articles to small pieces having a screen size of up to one-quarter inch mesh size, b) reducing a further quantity of rubber articles to the size of chips having a maximum size of approximately
3" x 3", c) forming a mixture of the small pieces and up to 75% by weight of the chips, and d) placing the mixture in the mold, 3.
The method of claim 1 wherein the pieces are heated in the mold at a temperature of from 350 to 450° F,
The method of claim 1 wherein the pieces are heated in the mold at a temperature of from 350 to 450° F,
4.
The method of claim 1 wherein the pieces are compressed in the mold at a pressure of from 1,000 to 3,000 psi.
The method of claim 1 wherein the pieces are compressed in the mold at a pressure of from 1,000 to 3,000 psi.
5.
A composite vehicle tire comprising a tire casing and within the casing a plurality of identical filler segments arranged end to end, each segment comprising a mass heat and pressure-consolidated from resilient particulate rubber material in the absence of a bonding agent or vulcanizing agent and having an arcuate contour and a cross section substantially similar to the cross section of the inside of the casing but larger by an increment predetermined for a pressure fit, the opposite end faces of each segment being so arranged that the confronting ends of adjacent segments abut without a substantial gap between them and form a joint having a plane that is not perpendicular to the point of contact of the tire with the ground.
A composite vehicle tire comprising a tire casing and within the casing a plurality of identical filler segments arranged end to end, each segment comprising a mass heat and pressure-consolidated from resilient particulate rubber material in the absence of a bonding agent or vulcanizing agent and having an arcuate contour and a cross section substantially similar to the cross section of the inside of the casing but larger by an increment predetermined for a pressure fit, the opposite end faces of each segment being so arranged that the confronting ends of adjacent segments abut without a substantial gap between them and form a joint having a plane that is not perpendicular to the point of contact of the tire with the ground.
6.
The composite vehicle tire of claim 5 wherein there are four substantially identical filler segments, the end faces of each segment being planar and disposed substantially perpendicular to each other,
The composite vehicle tire of claim 5 wherein there are four substantially identical filler segments, the end faces of each segment being planar and disposed substantially perpendicular to each other,
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US14106780A | 1980-04-17 | 1980-04-17 | |
| US141,067 | 1980-04-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1160407A true CA1160407A (en) | 1984-01-17 |
Family
ID=22494022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000357915A Expired CA1160407A (en) | 1980-04-17 | 1980-08-08 | Filled composite solid rubber tire for vehicles |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1160407A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140090758A1 (en) * | 2011-04-14 | 2014-04-03 | Compagnie Generale Des Etablissements Michelin | Tire for a handling vehicle |
-
1980
- 1980-08-08 CA CA000357915A patent/CA1160407A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140090758A1 (en) * | 2011-04-14 | 2014-04-03 | Compagnie Generale Des Etablissements Michelin | Tire for a handling vehicle |
| US9783002B2 (en) * | 2011-04-14 | 2017-10-10 | Compagnie Generale Des Etablissements Michelin | Tire for a handling vehicle |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |