CA1110957A - Closed tube simplified radial tire, tire/rim assembly and method of making same - Google Patents
Closed tube simplified radial tire, tire/rim assembly and method of making sameInfo
- Publication number
- CA1110957A CA1110957A CA331,497A CA331497A CA1110957A CA 1110957 A CA1110957 A CA 1110957A CA 331497 A CA331497 A CA 331497A CA 1110957 A CA1110957 A CA 1110957A
- Authority
- CA
- Canada
- Prior art keywords
- tire
- cords
- carcass ply
- ply
- closed tube
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000004873 anchoring Methods 0.000 claims abstract description 17
- 229920001971 elastomer Polymers 0.000 claims description 8
- 239000000806 elastomer Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- 239000004744 fabric Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 4
- 230000003014 reinforcing effect Effects 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 12
- 238000007493 shaping process Methods 0.000 description 5
- 230000000181 anti-adherent effect Effects 0.000 description 4
- 230000007704 transition Effects 0.000 description 4
- 230000002787 reinforcement Effects 0.000 description 3
- 239000011324 bead Substances 0.000 description 2
- 239000013256 coordination polymer Substances 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 239000005033 polyvinylidene chloride Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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)
- B29D30/08—Building tyres
-
- 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)
- B29D30/08—Building tyres
- B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
-
- 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
- B60C3/02—Closed, e.g. toroidal, 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
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/02—Carcasses
- B60C9/04—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship
Abstract
Abstract of the Disclosure In a tire and rim assembly a high pressure pneumatic tube tire formed of a single closed toroidal ply the cords of which are angled to the circumferential direction of the tire and a single belt ply of opposite and lower angle to the circumferential direction of the tire. Anchoring means such as one or more inextensible hoops are encompassed by the base area of the carcass ply to promote lateral stability and to provide engage-ment with the rim. Alternatively, the anchoring means may be eliminated by bonding the tire to the rim. The tire may be assembled on a conventional cylindrical tire building drum or upon the rim itself.
Description
Backeround ~f the InYention The foregoing abstract is not to be taken as limit-ing the invention of this application and in order to understand the full nature and extent of the technical disclosure of this application reference must be made to the accompanying drawings and the following detailed description.
mis invention relates generally to pneumatic tires and more particularly to tires of a closed toroidal type of simplified radial construction, to tire and rim assemblies incorporating same~ and to the method of making same.
"Closed tube tire" and "closed toroidal tire" as used herein will be understood to mean a tire providing a completely closed inflation chamber capable alone~
without being mounted on a rim~ of containing fluld pressure therein higher than the surrounding atmospheric pressure. In this specification, the terms "closed tube tire" and "closed toroidal tire" are used and intended to dlstinguish from open-base tires having generally horseshoe-shaped~ radial cross-sections and spaced apart beads, thus not being capable of containing fluid pressure without being mounted on a rim When used in this specification~ a substantially inextensible material refers to one whose elongation at tensile rupture does not exceed 5 percent. A cord formed of a substantlally inextensible material may have an elongation at tensile rupture in excess of ~ percent ~k i9S7 "Radial" when used herein with respect to the dlrection of the cords of any reinforcing ply means that such cords form an angle greater than 75 degrees.
All angles or incllnations of tlre components or portions thereof unless otherwise speci~ied herein are to be taken with respect to a plane which is perpendicular to the axls of rsvolution of the tire.
Radial plane of a tire means any plane passing through that tire and containing its axis of revolution.
m e state o~ development of pn~umatic automotive tires today is such that vehicle disablement due to tire failure is a relatively infrequent occurrence. Tires having radially oriented carcass plies are in widespread use Of growing importance is the need to conserve materials~ particularly those which are petrochemical in nature. It is desirable to reduce tire and rim weight to decrease vehicle fuel consumption~ These concerns have made it desirable to provide a lightweight pneumatic tire and rim assembly suitable for temporary use~ especially with vehicles equipped with radial tires. It is also desirable to provide a tire which is capable of increased load-carrying capacity for its size and weight in com-parison to known open-base tires. Although a closed tube tire may satisfy these requirements~ closed tube tires such as are known today are relatively complex structures. Manufacture of a closed tube tire having radial sidewalls acco~ding to known methods is quite costly. One method ln~olves winding the carcass cords or wrapping of the carcass ply about a toroidal mandrel, applying elastomer layers, belt reinforcement layers, and tread layers, curing of the assembly, and them removing the mandrel by dissolving same and washing out the residue through one or more valve openings. In another method, the tire carcass is formed upon a man-drel, then slit to remove it from the mandrel, then rejoined and inflated prior to completion of the assembly.
According to one aspect of the present invention there is provided a closed tube tire having a carcass ply of sub-tantially parallel cords extending continuously and com-pletely around a circumferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of said tire, said cords of said carcass p]y in the sidewalls of said tire being substantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown.
According to another aspect of the present invention there is provided a closed tube tire and rim assembly, said tire having a carcass ply of substantially parallel cords extending continuously and completely around a circumferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of .
~ `~
.
o~ said tire, said cords of said carcass ply in the sidewalls of said tire being substantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown, said tire being bonded at its base to an annular rim.
According to yet another aspect of the present invention there is provided a method of making a closed tube tire comprising forming a cylinder of a carcass ply of rubberized cord fabric the cords of which are sub~tantially parallel and which form an angle other than a right angle with the circumferential direction of said cylinder, adhering a layer of elastomer composition to the radially outermost surface of said carcass ply cylinder, forming an aperture through said cylinder and inserting a valve core into said aperture, lifting the edges of said carcass ply and elastomer composition layer : radially outwardly and drawing the edges of said carcass ply and said layer axially toward one another, joining said edges radially outwardly of the base of said tire to form a flattened tube, adhering to a radially outer surface of said tube, as a narrower ply a belt ply of substantially parallel cords with the cords of said belt ply being oppositely inclined to and forming a lesser angle than the radially outermost portion of the cords ... . .
of said carcass ply with the circumferential direction of said tube, and inflating said tube into a toroidal shape.
:
Brief Description of the Drawings Fig 1 is a perspective view of a broken away portion of the simplified radial tube tire with additional structure broken away to show internal ~ ~ :
detail;
Fig 2 is a radial cross-section of a portion of the building drum with the components of a simplified radial tube tire placed thereon but not yet made into a closed tube. The step of turning up the edges of the material to form a closed tube is indicated in dotted lines and the thickness of the plies somewhat exaggerated;
Fig 3a is a schematic plan view illustrating the cord arrangements of the green tire prlor to shaping from cylindrical to toroidal configuration;
Fig 3b illustrates schematically in plan view the cord arrangement of the tire after expansion into toroidal configuration;
Fig 4 is a radial cross-section of a rim suitable for use in building~ curing~ and operating the simplified radial tube tire.
DescriPtion of the Invention Referring to Fig 1, the general overall appearance of the completed closed tube simplified radial tire 10 is seen The elastomer-coated first or carcass cord ply 12 has three distinct angular regions~ according to location in the tire In the base or rim-contacting portion 14 of the tire 10 each cord 16 of the carcass ply 12 has an angle substantially identical to that of the carcass ply in the green tire~ e.g about 77 degrees. In the sidewalls 18~19 each cord 16 of the carcass ply 12 forms an angle of about 90 degrees; in the crown 20 each cord 16 o~
carcass ply 12 lies at a low angle~ e.g. about 45 degrees~
and is in the opposite direction when compared to the cords in the base 14. First transition zones 22~24 connect that portion of carcass ply 12 in base 14 and sidewalls 18~19~ respectively~ of tire 10. If~ as shown~
anchoring means are present~ first transition zones 22~24 begin at the axially outermost edges of the anchoring means 23 of tire 10. The path of each cord 16 in these first transition zones is curved. Second transition zones 25,26 exist at the shoulders 15~17~ respectively~ of the crown 20 of tire 10 and coincide approximately with the axially outermost edges 29,30 of the belt 28. The path of each cord 16 in ~ones 25,26 is also curved.
Each cord 16 of the carcass ply 12 completely encircles in predominantly axial direction a circumferentially elongated segment of the tire~ said segment being defined by two circumferentially spaced radial planes of the tire.
A single carcass ply cord 16 does not lie in a single radial plane. The ends of any given carcass ply cord 16 are circumferentially displaced from one another. me ends of the carcass ply cords 16 overlap in the crown 20 of the tire The amount of overlap may be minimal~ that is~ an amount sufficient to effect a splice and able to withstand shaping by inflation of the green~ i.e uncured, tire or may be equal to the belt ply 28 in width to provide additional reinforcement in the crown of the tire. me belt ply 28 is comprised of cords 31 which are substan-tially inextensible. The belt ply 28 is preferably of about the same width as the tread 36 of the tlre. Cords 31 of belt ply 28 lie at a very low angle~ for example~
about 15 degrees and are opposite in direction when com-pared to that portion of the cords 16 of the carcass ply 12 l~lng immediately radially inward thereof. Although a single belt ply is shown~ multiple belt plies may be employed Liner 32 is provided to prevent permeation of the inflation gas through the structure. It is believed that a cured elastomeric composition inflation tube could be substituted for liner 32 at the time of manufacture of the tire. Valve 34 is provided to enable inflation of the structure. Valve 34 could also be located in one of sidewalls 18~19 instead of in the base 1~ of the tire.
Conventional tread 36 and sidewalls 18~19 are placed radially outward of the carcass/belt structure to complete the tire.
Fig 2 illustrates a preferred method of fabrication of a simplified closed toroidal radial tire Sidewalls 18~19 are placed on the cylindrical drum or former 38. A carcass ply 12 of cord fabric, the cords 16 of which lie at a relatively high angle but less than 90 degrees, ~or example~ about 77 degrees with respect to the lengthwise direction of the carcass ply 12~ is placed upon the drum 38 and its longitudinal ends joined to form a complete cylinder. me angle Or the cords 16 of the carcass ply 12 is other than a right angle with respect to the circum-ferential direction of the cylinder. A layer 39 of elastomer composition is then added to form the impermeable inner liner 32 of the tire. Anchoring means 23 of a substantially inextensible material~ for example~ metallic wire~ fiberglass, or high modulus organic fiber~ or the like, such as hoops 40 are placed upon layer 39 at axially spaced apart locations corresponding to the width of the base 14 of tire 10 and centsred relative to the edges 41~42 of the ply 12. An aperture 44 îs formed through the carcass ply cylinder between the anchoring hoops 40~ and an inflation valve 34 is inserted therein.
A suitable recess 46 should be provided in the building drum 38 for acceptance of the valve. The radially outer~
-~ 57 most qurface 47 of the liner elastomer composition layer 39 is then treated with a suitable anti-adhesive selected from those well known in the art. It is preferable to utilize a plastic film (not shown) such as polyvinylidene chloride as an anti-adhesive to insure that the anti-adhesive does not flow into and contaminate the carcass ply/liner assembly splices. Following application of the anti-adhesive layer the edges 48~49 of the carcass ply/
liner assembly are li~ted radially outward from the drum 38 and pulled axially toward one another until they overlap in the radially outward portion of the structure. me overlapped carcass ply/liner assembly is shown by the dotted lines of Fig 2. These may be interleaved (not shown). The overlapped area need not be centered with respect to the centerplane CP of the structure~ but preferably is centered. m e overlapped area 50 is stitched tightly in conventional manner to form a flat tube. A
single belt ply 28 ha~ing cords 31 at an angle opposite to those o~ the crown area carcass ply 12 and much smaller~ e.g. about 20 degrees~ is then centered over the anchoring hoops 40 and stitched thoroughly to the carcass ply 12. The structure is completed by addition of a tread 36 as in a conventional tire The completed structure is then removed from drum 38 A slightly collapsible or tapered drum (neither is shown) may be used to facilitate removal of the completed green tire.
The green tire preferably is then placed in a suitable curing mold cavity (not shown) and the valve 34 coupled to an in~lation source. IJpon application of the inflation pressure the structure expands from a flat cross-sectional configuration to assume the internal shape of the mold~
that is, to a substantially toroidal configuration. ~or it to do so~ the carcass ply and belt ply cords 16~31 must undergo considerable movement relative to one another.
mese movements are schematica]ly illustrated in Figs 3A
and 3B. me initial arrangements of the cords 16,31 are shown in Fig 3A In Fig 3A, a single cord 16 of the carcass ply 12 forms an angle o~ about 77 degrees with the radially inner layer (indicated by IL) and radially outer layer (indicated by OL) being oppositely directed.
A single cord 31 of the belt ply 28 forms an angle in the opposite direction to the radially outermost layer (OL) of carcass ply 12 of about 20 degrees.
The final arrangements of the cords 16~31 are shown in Fig 3B. mat portion of each carcass ply cord 16 lying in the base 14 of the tire 10 and between the axially most distant extremities of the anchoring hoops 40 continues to lie at an angle of about 77 degrees. In other words, the base 1~ of the tire 10 does not undergo movement during shaping of the tire mat portion of each carcass ply cord 16 in the crown 20 of tlre 10 has moved radially outward from the base 14 and pantographed to a much lesser angle~ e.g. about 45 degrees~ and con-tinues to lie in the same direction. Both portions of each carcass cord 16 underlying the sidewalls 18,19 of the tire have increased in angle from their init~al angle to become substantially radial, and in the embodiment shown form an angle of about 90 degrees. Each belt ply cord 31 has pantographed from its initial angle to a reduced angle of about 15 degrees.
The anchoring means should be formed of a substantially inextensible material. Although the nominal level of stress imposed upon the anchoring means is conslderably less than that imposed upon the beads of conventional open-base tires, if the anchoring means are made o~ extensible mater~al, such extension may allow the tire to move laterally relative to the rim upon which it is mounted, which is undesirable One or more belts (not shown) of rubberized cord fabric may be substituted for hoops 40. The axially most distant edges of such belt or belts should lie at about the same location from the circumferential centerplane of the tire as do hoops ~0 The cords of such belt or belts should be of low angle~ preferably in the range of O to 10 degrees. When such anchoring belts are employed, the ~alve core 34 may be inserted through tha anchoring belt or belts.
The starting angle, i.e. in the unshaped green tire, for the cords 16 of carcass ply 12 should be relatively high~ that is~ greater than ~5 degrees but less than 90 degrees~ and preferably from about 60 degrees to 85 degrees.
In the cured tire~ the cords of the carcass ply in the sidewalls for at least 60 percent of the radial height o* the sidewalls should be substantially radial, that is~
at an angle of at least 75 degrees. The an~le of the cords of the carcass ply 12 in the sidewalls 18~19 of the cured tire will always be greater than the angle of the cords of the carcass ply in the crown 20 or base 14 of the cured tire. ~he angle of the cords of the carcass ply 12 in the crown 20 of the cured tire should be a relatively low angle~ that is~ not exceedlng 60 degrees.
The lower the angle of the cords of the carcass ply in the crown of the tire~ the greater their contribution to circumferential restriction of the tire.
"Blow-up ratio" as used herein is the ratio of the diameter of the crown portion of the carcass ply at the centerplane CP of the shaped tire to the diameter of the crown portion of the carcass ply after being formed into a flattened closed tube (on the building former) but prior to shaping by inflation. As the blow-up ratio of the tire i9 increased~ the amount of cord movement durlng shaping of the tire is increased~ for the cords of the carcass ply and for the cords of the belt ply.
m e starting angle for the cords of the carcass ply for a given desired cured angle is dependent~ in part~ on the blow-up ratio of the tire. As the blow-up ratio i5 increased~ the starting angle of the cords of the carcass ply for a given desired cured angle should be decreased.
me starting angle for the cords of the belt ply 28 or plies should be a relatively low angle~ that is~ less than ~5 degrees~ and preferably less than 35 degrees.
~he cured angle of the cords of the belt ply or plies should be less than 35 degrees, and preferably less than ~ 5 7 25 degrees me lower the angle of the cords of the belt ply or plies~ the greater their contribution to the circumferential restriction of the tire. The practical lower limit for the starting angle of the cords of the belt ply or plies is believed to be about 15 degrees with known cords and fabrics suitable for tire reinforce-ment. Lower angles are not practical because cord lock-up (physical interference) occurs at very low blow-up ratios~ unless the initial cord spacing is so increased that the fabric is not of sufficient strength.
me introduction of fabrics having higher tensile strength cords of smaller cross-sectional area and greater distance between the axes of ad~acent cords will permit use of lower starting angles for a given blow-up ratio ~he starting angle for the cords of the belt ply for a given desired cured angle is also dependent in part on the blow-up ratio of the tire. As the blow-up ratio of the tire is increased~ the starting angle of the cords of the belt ply for a given desired cured angle should be increased.
A tire according to the in~ention may be separately molded~ or integrally molded with a rim. In the latter case~ the tire is preferably built and cured upon the rim.
When the tire is bonded to the rim~ the need for anchoring hoops 40 or their equivalent is eliminated.
When the tire is built and cured upon its rim~ the carcass ply 12 prior to forming into a ~lat tube, may not form a true mathematical cylinder but may form a ~ 9 ~7 s]eeve of varying diameter along its axis of revolution according to the rlm configuration. In the following claims it is understood that the use of the word "cylinder" or "cylindrical" with reference to the carcass ply includes such a sleeve whose diameter varies with location along its axis of revolution, as well as one of un~aryin~ diameter5 An embodiment of a suitable rim is shown in Fig 4.
The rim 52 is of circular configuration and is adapted to be fastened to a vehicle wheel disc (not shown). me rim is preferably of least circumference at its axial centerplane 53 and increases in gradual manner in circum-ference from its axial centerplane to its axially most distant edges 54~55. me rim preferably is of a V-shaped cross-sectional configuration as shown or of arcuate cross-sectional configuration (not shown). A cylindrical rim of unvarying diameter along its axis of revolution may also be used.
While certain representative embodiments and details have been shown for the purpose of illustrating the in-vention~ it will be apparent to those skilled in the artthat various changes and modifications may be made therein without departing from the spirit or the scope of the invention.
mis invention relates generally to pneumatic tires and more particularly to tires of a closed toroidal type of simplified radial construction, to tire and rim assemblies incorporating same~ and to the method of making same.
"Closed tube tire" and "closed toroidal tire" as used herein will be understood to mean a tire providing a completely closed inflation chamber capable alone~
without being mounted on a rim~ of containing fluld pressure therein higher than the surrounding atmospheric pressure. In this specification, the terms "closed tube tire" and "closed toroidal tire" are used and intended to dlstinguish from open-base tires having generally horseshoe-shaped~ radial cross-sections and spaced apart beads, thus not being capable of containing fluid pressure without being mounted on a rim When used in this specification~ a substantially inextensible material refers to one whose elongation at tensile rupture does not exceed 5 percent. A cord formed of a substantlally inextensible material may have an elongation at tensile rupture in excess of ~ percent ~k i9S7 "Radial" when used herein with respect to the dlrection of the cords of any reinforcing ply means that such cords form an angle greater than 75 degrees.
All angles or incllnations of tlre components or portions thereof unless otherwise speci~ied herein are to be taken with respect to a plane which is perpendicular to the axls of rsvolution of the tire.
Radial plane of a tire means any plane passing through that tire and containing its axis of revolution.
m e state o~ development of pn~umatic automotive tires today is such that vehicle disablement due to tire failure is a relatively infrequent occurrence. Tires having radially oriented carcass plies are in widespread use Of growing importance is the need to conserve materials~ particularly those which are petrochemical in nature. It is desirable to reduce tire and rim weight to decrease vehicle fuel consumption~ These concerns have made it desirable to provide a lightweight pneumatic tire and rim assembly suitable for temporary use~ especially with vehicles equipped with radial tires. It is also desirable to provide a tire which is capable of increased load-carrying capacity for its size and weight in com-parison to known open-base tires. Although a closed tube tire may satisfy these requirements~ closed tube tires such as are known today are relatively complex structures. Manufacture of a closed tube tire having radial sidewalls acco~ding to known methods is quite costly. One method ln~olves winding the carcass cords or wrapping of the carcass ply about a toroidal mandrel, applying elastomer layers, belt reinforcement layers, and tread layers, curing of the assembly, and them removing the mandrel by dissolving same and washing out the residue through one or more valve openings. In another method, the tire carcass is formed upon a man-drel, then slit to remove it from the mandrel, then rejoined and inflated prior to completion of the assembly.
According to one aspect of the present invention there is provided a closed tube tire having a carcass ply of sub-tantially parallel cords extending continuously and com-pletely around a circumferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of said tire, said cords of said carcass p]y in the sidewalls of said tire being substantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown.
According to another aspect of the present invention there is provided a closed tube tire and rim assembly, said tire having a carcass ply of substantially parallel cords extending continuously and completely around a circumferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of .
~ `~
.
o~ said tire, said cords of said carcass ply in the sidewalls of said tire being substantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown, said tire being bonded at its base to an annular rim.
According to yet another aspect of the present invention there is provided a method of making a closed tube tire comprising forming a cylinder of a carcass ply of rubberized cord fabric the cords of which are sub~tantially parallel and which form an angle other than a right angle with the circumferential direction of said cylinder, adhering a layer of elastomer composition to the radially outermost surface of said carcass ply cylinder, forming an aperture through said cylinder and inserting a valve core into said aperture, lifting the edges of said carcass ply and elastomer composition layer : radially outwardly and drawing the edges of said carcass ply and said layer axially toward one another, joining said edges radially outwardly of the base of said tire to form a flattened tube, adhering to a radially outer surface of said tube, as a narrower ply a belt ply of substantially parallel cords with the cords of said belt ply being oppositely inclined to and forming a lesser angle than the radially outermost portion of the cords ... . .
of said carcass ply with the circumferential direction of said tube, and inflating said tube into a toroidal shape.
:
Brief Description of the Drawings Fig 1 is a perspective view of a broken away portion of the simplified radial tube tire with additional structure broken away to show internal ~ ~ :
detail;
Fig 2 is a radial cross-section of a portion of the building drum with the components of a simplified radial tube tire placed thereon but not yet made into a closed tube. The step of turning up the edges of the material to form a closed tube is indicated in dotted lines and the thickness of the plies somewhat exaggerated;
Fig 3a is a schematic plan view illustrating the cord arrangements of the green tire prlor to shaping from cylindrical to toroidal configuration;
Fig 3b illustrates schematically in plan view the cord arrangement of the tire after expansion into toroidal configuration;
Fig 4 is a radial cross-section of a rim suitable for use in building~ curing~ and operating the simplified radial tube tire.
DescriPtion of the Invention Referring to Fig 1, the general overall appearance of the completed closed tube simplified radial tire 10 is seen The elastomer-coated first or carcass cord ply 12 has three distinct angular regions~ according to location in the tire In the base or rim-contacting portion 14 of the tire 10 each cord 16 of the carcass ply 12 has an angle substantially identical to that of the carcass ply in the green tire~ e.g about 77 degrees. In the sidewalls 18~19 each cord 16 of the carcass ply 12 forms an angle of about 90 degrees; in the crown 20 each cord 16 o~
carcass ply 12 lies at a low angle~ e.g. about 45 degrees~
and is in the opposite direction when compared to the cords in the base 14. First transition zones 22~24 connect that portion of carcass ply 12 in base 14 and sidewalls 18~19~ respectively~ of tire 10. If~ as shown~
anchoring means are present~ first transition zones 22~24 begin at the axially outermost edges of the anchoring means 23 of tire 10. The path of each cord 16 in these first transition zones is curved. Second transition zones 25,26 exist at the shoulders 15~17~ respectively~ of the crown 20 of tire 10 and coincide approximately with the axially outermost edges 29,30 of the belt 28. The path of each cord 16 in ~ones 25,26 is also curved.
Each cord 16 of the carcass ply 12 completely encircles in predominantly axial direction a circumferentially elongated segment of the tire~ said segment being defined by two circumferentially spaced radial planes of the tire.
A single carcass ply cord 16 does not lie in a single radial plane. The ends of any given carcass ply cord 16 are circumferentially displaced from one another. me ends of the carcass ply cords 16 overlap in the crown 20 of the tire The amount of overlap may be minimal~ that is~ an amount sufficient to effect a splice and able to withstand shaping by inflation of the green~ i.e uncured, tire or may be equal to the belt ply 28 in width to provide additional reinforcement in the crown of the tire. me belt ply 28 is comprised of cords 31 which are substan-tially inextensible. The belt ply 28 is preferably of about the same width as the tread 36 of the tlre. Cords 31 of belt ply 28 lie at a very low angle~ for example~
about 15 degrees and are opposite in direction when com-pared to that portion of the cords 16 of the carcass ply 12 l~lng immediately radially inward thereof. Although a single belt ply is shown~ multiple belt plies may be employed Liner 32 is provided to prevent permeation of the inflation gas through the structure. It is believed that a cured elastomeric composition inflation tube could be substituted for liner 32 at the time of manufacture of the tire. Valve 34 is provided to enable inflation of the structure. Valve 34 could also be located in one of sidewalls 18~19 instead of in the base 1~ of the tire.
Conventional tread 36 and sidewalls 18~19 are placed radially outward of the carcass/belt structure to complete the tire.
Fig 2 illustrates a preferred method of fabrication of a simplified closed toroidal radial tire Sidewalls 18~19 are placed on the cylindrical drum or former 38. A carcass ply 12 of cord fabric, the cords 16 of which lie at a relatively high angle but less than 90 degrees, ~or example~ about 77 degrees with respect to the lengthwise direction of the carcass ply 12~ is placed upon the drum 38 and its longitudinal ends joined to form a complete cylinder. me angle Or the cords 16 of the carcass ply 12 is other than a right angle with respect to the circum-ferential direction of the cylinder. A layer 39 of elastomer composition is then added to form the impermeable inner liner 32 of the tire. Anchoring means 23 of a substantially inextensible material~ for example~ metallic wire~ fiberglass, or high modulus organic fiber~ or the like, such as hoops 40 are placed upon layer 39 at axially spaced apart locations corresponding to the width of the base 14 of tire 10 and centsred relative to the edges 41~42 of the ply 12. An aperture 44 îs formed through the carcass ply cylinder between the anchoring hoops 40~ and an inflation valve 34 is inserted therein.
A suitable recess 46 should be provided in the building drum 38 for acceptance of the valve. The radially outer~
-~ 57 most qurface 47 of the liner elastomer composition layer 39 is then treated with a suitable anti-adhesive selected from those well known in the art. It is preferable to utilize a plastic film (not shown) such as polyvinylidene chloride as an anti-adhesive to insure that the anti-adhesive does not flow into and contaminate the carcass ply/liner assembly splices. Following application of the anti-adhesive layer the edges 48~49 of the carcass ply/
liner assembly are li~ted radially outward from the drum 38 and pulled axially toward one another until they overlap in the radially outward portion of the structure. me overlapped carcass ply/liner assembly is shown by the dotted lines of Fig 2. These may be interleaved (not shown). The overlapped area need not be centered with respect to the centerplane CP of the structure~ but preferably is centered. m e overlapped area 50 is stitched tightly in conventional manner to form a flat tube. A
single belt ply 28 ha~ing cords 31 at an angle opposite to those o~ the crown area carcass ply 12 and much smaller~ e.g. about 20 degrees~ is then centered over the anchoring hoops 40 and stitched thoroughly to the carcass ply 12. The structure is completed by addition of a tread 36 as in a conventional tire The completed structure is then removed from drum 38 A slightly collapsible or tapered drum (neither is shown) may be used to facilitate removal of the completed green tire.
The green tire preferably is then placed in a suitable curing mold cavity (not shown) and the valve 34 coupled to an in~lation source. IJpon application of the inflation pressure the structure expands from a flat cross-sectional configuration to assume the internal shape of the mold~
that is, to a substantially toroidal configuration. ~or it to do so~ the carcass ply and belt ply cords 16~31 must undergo considerable movement relative to one another.
mese movements are schematica]ly illustrated in Figs 3A
and 3B. me initial arrangements of the cords 16,31 are shown in Fig 3A In Fig 3A, a single cord 16 of the carcass ply 12 forms an angle o~ about 77 degrees with the radially inner layer (indicated by IL) and radially outer layer (indicated by OL) being oppositely directed.
A single cord 31 of the belt ply 28 forms an angle in the opposite direction to the radially outermost layer (OL) of carcass ply 12 of about 20 degrees.
The final arrangements of the cords 16~31 are shown in Fig 3B. mat portion of each carcass ply cord 16 lying in the base 14 of the tire 10 and between the axially most distant extremities of the anchoring hoops 40 continues to lie at an angle of about 77 degrees. In other words, the base 1~ of the tire 10 does not undergo movement during shaping of the tire mat portion of each carcass ply cord 16 in the crown 20 of tlre 10 has moved radially outward from the base 14 and pantographed to a much lesser angle~ e.g. about 45 degrees~ and con-tinues to lie in the same direction. Both portions of each carcass cord 16 underlying the sidewalls 18,19 of the tire have increased in angle from their init~al angle to become substantially radial, and in the embodiment shown form an angle of about 90 degrees. Each belt ply cord 31 has pantographed from its initial angle to a reduced angle of about 15 degrees.
The anchoring means should be formed of a substantially inextensible material. Although the nominal level of stress imposed upon the anchoring means is conslderably less than that imposed upon the beads of conventional open-base tires, if the anchoring means are made o~ extensible mater~al, such extension may allow the tire to move laterally relative to the rim upon which it is mounted, which is undesirable One or more belts (not shown) of rubberized cord fabric may be substituted for hoops 40. The axially most distant edges of such belt or belts should lie at about the same location from the circumferential centerplane of the tire as do hoops ~0 The cords of such belt or belts should be of low angle~ preferably in the range of O to 10 degrees. When such anchoring belts are employed, the ~alve core 34 may be inserted through tha anchoring belt or belts.
The starting angle, i.e. in the unshaped green tire, for the cords 16 of carcass ply 12 should be relatively high~ that is~ greater than ~5 degrees but less than 90 degrees~ and preferably from about 60 degrees to 85 degrees.
In the cured tire~ the cords of the carcass ply in the sidewalls for at least 60 percent of the radial height o* the sidewalls should be substantially radial, that is~
at an angle of at least 75 degrees. The an~le of the cords of the carcass ply 12 in the sidewalls 18~19 of the cured tire will always be greater than the angle of the cords of the carcass ply in the crown 20 or base 14 of the cured tire. ~he angle of the cords of the carcass ply 12 in the crown 20 of the cured tire should be a relatively low angle~ that is~ not exceedlng 60 degrees.
The lower the angle of the cords of the carcass ply in the crown of the tire~ the greater their contribution to circumferential restriction of the tire.
"Blow-up ratio" as used herein is the ratio of the diameter of the crown portion of the carcass ply at the centerplane CP of the shaped tire to the diameter of the crown portion of the carcass ply after being formed into a flattened closed tube (on the building former) but prior to shaping by inflation. As the blow-up ratio of the tire i9 increased~ the amount of cord movement durlng shaping of the tire is increased~ for the cords of the carcass ply and for the cords of the belt ply.
m e starting angle for the cords of the carcass ply for a given desired cured angle is dependent~ in part~ on the blow-up ratio of the tire. As the blow-up ratio i5 increased~ the starting angle of the cords of the carcass ply for a given desired cured angle should be decreased.
me starting angle for the cords of the belt ply 28 or plies should be a relatively low angle~ that is~ less than ~5 degrees~ and preferably less than 35 degrees.
~he cured angle of the cords of the belt ply or plies should be less than 35 degrees, and preferably less than ~ 5 7 25 degrees me lower the angle of the cords of the belt ply or plies~ the greater their contribution to the circumferential restriction of the tire. The practical lower limit for the starting angle of the cords of the belt ply or plies is believed to be about 15 degrees with known cords and fabrics suitable for tire reinforce-ment. Lower angles are not practical because cord lock-up (physical interference) occurs at very low blow-up ratios~ unless the initial cord spacing is so increased that the fabric is not of sufficient strength.
me introduction of fabrics having higher tensile strength cords of smaller cross-sectional area and greater distance between the axes of ad~acent cords will permit use of lower starting angles for a given blow-up ratio ~he starting angle for the cords of the belt ply for a given desired cured angle is also dependent in part on the blow-up ratio of the tire. As the blow-up ratio of the tire is increased~ the starting angle of the cords of the belt ply for a given desired cured angle should be increased.
A tire according to the in~ention may be separately molded~ or integrally molded with a rim. In the latter case~ the tire is preferably built and cured upon the rim.
When the tire is bonded to the rim~ the need for anchoring hoops 40 or their equivalent is eliminated.
When the tire is built and cured upon its rim~ the carcass ply 12 prior to forming into a ~lat tube, may not form a true mathematical cylinder but may form a ~ 9 ~7 s]eeve of varying diameter along its axis of revolution according to the rlm configuration. In the following claims it is understood that the use of the word "cylinder" or "cylindrical" with reference to the carcass ply includes such a sleeve whose diameter varies with location along its axis of revolution, as well as one of un~aryin~ diameter5 An embodiment of a suitable rim is shown in Fig 4.
The rim 52 is of circular configuration and is adapted to be fastened to a vehicle wheel disc (not shown). me rim is preferably of least circumference at its axial centerplane 53 and increases in gradual manner in circum-ference from its axial centerplane to its axially most distant edges 54~55. me rim preferably is of a V-shaped cross-sectional configuration as shown or of arcuate cross-sectional configuration (not shown). A cylindrical rim of unvarying diameter along its axis of revolution may also be used.
While certain representative embodiments and details have been shown for the purpose of illustrating the in-vention~ it will be apparent to those skilled in the artthat various changes and modifications may be made therein without departing from the spirit or the scope of the invention.
Claims (16)
1. A closed tube tire having a carcass ply of sub-stantially parallel cords extending continuously and completely around a circumferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of said tire, said cords of said carcass ply in the sidewalls of said tire being sub-stantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown.
2. A closed tube tire according to Claim l, wherein each of said cords of said carcass ply in passing from the base to a sidewall is connected by a first curved zone and in passing from a sidewall to the crown is connected by a second curved zone.
3. A closed tube tire according to Claim 2, wherein said second curved zone at least partially underlies the axial edges of said belt ply.
4. A closed tube tire according to Claim 1, wherein the ends of each of said carcass ply cords are overlapped in said crown
5. A closed tube tire according to Claim 1, wherein said belt ply cords are less inclined to said plane than said cords of said carcass ply in the crown of said tire.
6. A closed tube tire according to Claim l wherein said belt ply is formed of cords of substantially in-extensible material
7. A closed tube tire according to Claim l having anchoring means of substantially inextensible material in the base of said tire which means are enveloped by said carcass ply.
8. A closed tube tire according to Claim 7, wherein said anchoring means comprise a belt of substantially parallel reinforcing cords which are inclined to said plane an amount not exceeding about 10 degrees.
9. A closed tube tire and rim assembly, said tire having a carcass ply of substantially parallel cords extending continuously and completely around a circum-ferentially elongated segment of said tire, said cords of said carcass ply in the crown of said tire being inclined to a plane perpendicular to the axis of revolution of said tire said cords of said carcass ply in the side-walls of said tire being substantially radial, said cords of said carcass ply in the base of said tire being oppositely inclined to said plane an amount greater than in the crown of said tire, and in the crown of said tire a belt ply of substantially parallel cords which are oppositely inclined to said cords of said carcass ply in said crown, said tire being bonded at its base to an annular rim.
10. A closed tube tire and rim assembly according to claim 9, wherein said rim is of least circumference at its axial centerplane and increases in circumference in gradual manner from its axial centerplane to its axial extremities.
11. A closed tube tire and rim assembly according to Claim 10, wherein said rim is of arcuate radial cross-secton.
12. A closed tube tire and rim assembly according to Claim 10, wherein said rim is of V-shaped radial cross-section.
13. In a method of making a closed tube tire according to Claim 1, said method comprising forming a cylinder of a carcass ply of rubberized cord fabric the cords Or which are substantially parallel and which form an angle other than a right angle with the circumferential direction of said cylinder, adhering a layer of elastomer composition to the radially outermost surface of said carcass ply cylinder, forming an aperture through said cylinder and inserting a valve core into said aperture, lifting the edges of said carcass ply and elastomer composition layer radially outwardly and drawing the edges of said carcass ply and said layer axially toward one another, joining said edges radially outwardly of the base of said tire to form a flattened tube, adhering to a radially outer surface of said tube, as a narrower ply a belt ply of substantially parallel cords with the cords of said belt ply being oppositely inclined to and forming lesser angle than the radially outermost portion of the cords of said carcass ply with the circumferential direction of said tube, and inflating said tube into a toroidal shape.
14. In a method of making a closed tube tire according to Claim 13 in which the initial inclination of said carcass ply cords with respect to the circumferential direction of said cylinder is at least 60 degrees but less than 85 degrees and the initial inclination of said belt ply cords with respect to the circumferential direction of said tube is not greater than 35 degrees.
15, In method of making closed tube tire according to Claim 13, wherein a sidewall is added prior to application of said carcass ply and a tread is added prior to inflation of said tube.
16. In a method of making a closed tube tire according to Claim 13, in which anchoring means are applied over said carcass ply prior to joining the edges of said carcass ply to form a flattened tube, the axial extremities of said means substantially corresponding with the axial extremities of the base of said tire.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US92986178A | 1978-07-31 | 1978-07-31 | |
| US929,861 | 1978-07-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1110957A true CA1110957A (en) | 1981-10-20 |
Family
ID=25458577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA331,497A Expired CA1110957A (en) | 1978-07-31 | 1979-07-10 | Closed tube simplified radial tire, tire/rim assembly and method of making same |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5522594A (en) |
| AU (1) | AU523430B2 (en) |
| BR (1) | BR7904784A (en) |
| CA (1) | CA1110957A (en) |
| DE (1) | DE2931055A1 (en) |
| FR (1) | FR2432394A1 (en) |
| GB (1) | GB2026960B (en) |
| IT (1) | IT1123507B (en) |
| LU (1) | LU81548A1 (en) |
| SE (1) | SE444144B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4585044A (en) * | 1981-12-23 | 1986-04-29 | Pneumatici Clement S.P.A. | Tubular tire for cycles |
| NL9001739A (en) * | 1990-08-01 | 1992-03-02 | Weweler Nv | AIR VEHICLE SYSTEM FOR VEHICLES WITH VEHICLES FOR VEHICLES. |
| CZ279855B6 (en) * | 1993-10-11 | 1995-07-12 | Miloslav Ing. Klabal | Compact lightweight tubular racing tyre |
| DE10309755A1 (en) * | 2003-03-06 | 2004-09-16 | Continental Aktiengesellschaft | Tubular tire for bicycles, particularly racing cycles, has an air sealing layer adhered to fabric layer of carcass and an internal separating layer to prevent contact between walls of air chamber |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1047921A (en) * | 1963-01-31 | 1966-11-09 | Dunlop Rubber Co | Improvements in or relating to pneumatic tyres |
| FR1458973A (en) * | 1964-06-23 | 1966-04-29 | Us Rubber Co | Improvement in inflatable bodies |
| DE1579168B2 (en) * | 1966-01-19 | 1973-06-14 | Continental Gummi Werke AG, 3000 Hannover | BLANK TIRE FOR MANUFACTURING A BELT TIRE |
| NL135459C (en) * | 1966-08-01 | |||
| US4072550A (en) * | 1975-06-16 | 1978-02-07 | The Goodyear Tire & Rubber Company | Method and apparatus for building a closed torus tire |
| US4085786A (en) * | 1975-11-19 | 1978-04-25 | The Goodyear Tire & Rubber Company | Integrally built and cured tire and wheel assembly |
| US4057445A (en) * | 1976-01-05 | 1977-11-08 | The Goodyear Tire & Rubber Company | Closed torus tire |
| GB1584184A (en) * | 1976-10-07 | 1981-02-11 | Caterpillar Tractor Co | Road vehicle wheel |
-
1979
- 1979-06-28 AU AU48484/79A patent/AU523430B2/en not_active Ceased
- 1979-07-10 CA CA331,497A patent/CA1110957A/en not_active Expired
- 1979-07-17 FR FR7918471A patent/FR2432394A1/en active Granted
- 1979-07-18 GB GB7925105A patent/GB2026960B/en not_active Expired
- 1979-07-19 JP JP9104279A patent/JPS5522594A/en active Granted
- 1979-07-24 LU LU81548A patent/LU81548A1/en unknown
- 1979-07-26 BR BR7904784A patent/BR7904784A/en unknown
- 1979-07-27 DE DE19792931055 patent/DE2931055A1/en not_active Withdrawn
- 1979-07-30 SE SE7906476A patent/SE444144B/en not_active IP Right Cessation
- 1979-07-30 IT IT24777/79A patent/IT1123507B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| GB2026960A (en) | 1980-02-13 |
| FR2432394A1 (en) | 1980-02-29 |
| DE2931055A1 (en) | 1980-02-21 |
| JPS5522594A (en) | 1980-02-18 |
| JPS6241121B2 (en) | 1987-09-01 |
| IT1123507B (en) | 1986-04-30 |
| GB2026960B (en) | 1983-02-16 |
| AU523430B2 (en) | 1982-07-29 |
| SE7906476L (en) | 1980-02-01 |
| SE444144B (en) | 1986-03-24 |
| FR2432394B1 (en) | 1983-06-17 |
| LU81548A1 (en) | 1979-10-31 |
| BR7904784A (en) | 1980-05-06 |
| AU4848479A (en) | 1980-02-07 |
| IT7924777A0 (en) | 1979-07-30 |
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