NZ214152A - Tyre reinforcement fabric: transverse threads overlying warps held by zigzag of fine fibre - Google Patents

Description

214152 Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "TIRE REINFORCED WITH WOVEN MATERIAL" 47WE SUMITOMO RUBBER INDUSTRIES, LTD. of No.1-1, Tsutsuicho 1-chome, Chuo-ku, Kobe-shi, Hyogo Japan, a Japanese company, hereby declare the invention, for which i/we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- by pjjje f A.' 2 14152 The present invention relates to a penumatic tire using a woven material for providing a reinforcing layer.

Pneumatic tire carcasses generally employ tire fabrics coarsely woven of tire cords as warp threads constituting reinforcements and weft threads finer than the warp threads for spacing out the warp threads.

The method of weaving the tire fabric includes making alternate sheds of warp threads, passing wept threads therethrough using a shuttle, making sheds of warp threads turned upside down and again passing the weft threads therethrough. To prepare, for instance, a bias tire using a tire fabric, the tire fabric is cut at an angle ranging from 2 0° to 70° with the direction wherein warp threads are arrayed and the cut fabrics are joined to prepare a ply. At least two sheets of plies are used to assemble a tubular carcass so that the warp threads may cross each other on a drum and then a toroidal tire is manufactured. The warp threads are however apt to slide because the warp and wept threads are insufficiently fixed in the aforementioned processes and, because of uneven end distribution, the non-homogeneity of the tire will deterioriate its durability. Because of the structure of the tire fabric, moreover, the warp threads become wavy, thus thickening the fabric itself. As a result, the thickness of the topping rubber must be increased to prevent the cords from touching each other, i.e., the disadvantage is that the weight of the tire can hardly be reduced. In addition to that disadvantage, there are others including the restricted production capacity because shedding is accompanied by the manufacture of the tire fabric and unfeasibility of use of filaments as weft threads because non-slip material must be chosen for warp and weft threads.

The present invention is intended to solve the aforementioned problems at one standing and it is therefore an object of the invention to provide lightweight uniform durable pneumatic tires for, for instance, passenger cars, light trucks, trucks; and low pressure tires of such quality for light vehicles including two-wheeled vehicles and bicycles.

The tire reinforced with a woven material comprising an unwoven combination of warp threads arranged in parallel with each other and weft threads arranged across said warp threads at an angle ranging from 60° to 90°, characterised in that fine fiber filaments of a weight of 5 to 50 denier, are entwined about the intersections of said warp and weft threads and woven together in the longitudinal direction of said warp threads.

BRIEF DESCRIPTION OF THE DRAWINGS: Figs. 1 and 2 are schematic drawings illustrating the obverse and reverse of a woven material woven of warp and weft threads.

Fig. 3. is a cross sectional view of a bias tire using the woven material for a carcass.

Fig. 4. is a cross sectional view of a radial tire using 21415 2 3. the woven material for a carcass.

Figs 5(i) and 5(ii) are diagrams illustrating the properties of the woven material.

Referring now to the drawings, an embodiment of the present invention will be described.

Figs. 1 and 2 are schematic diagrams illustrating the obverse and reverse of a woven material according to the present invention. In figs. 1 and 2, a woven material 10 comprises an unwoven combination of warps threads 11 arranged in parallel with each other and wefts threads 12 arranged on one side of, and in the direction roughly perpendicular to the warps threads; and a plurality of fine fibers 13 woven along the longitudinal direction of the warps threads to combine the warps and weft threads together. In that case, the widely employed conventional method of manufacturing tire fabrics is usable.

As materials usable for the warp thread, there are organic fibers of nylon, polyester, rayon or aromatic polyamide; and inorganic fibers of steel or glass.

Although the aforementioned weft thread may be prepared from any material conventionally used to make a tire fabric, it is unnecessary according to the present invention to select a particular material capable of controlling the movement of the weft thread. Moreoever, such a material should be strong enough to prevent itself from being cut by tension during and up to the bonding and rubberizing processes associated with tire 2 t 15 production, e.g., the material after being bonded should have a strength of 100 g/d or greater.

Furthermore, because the warp thread is slidable in plain weaving, a filament, though rarely used for the purpose, is also usable in the present invention.

The fine fiber used in the present invention should be prepared from material capable of undergoing the general bonding and heating conditions and of preferably bonding to rubber during the tire manufacturing process; e.g., a filament composed of an organic fiber of nylon 6, nylon 66 or polyester having a diamter of 5- 50 deniers and preferably a warp thread of 1/5 - 1/100 denier. When the filament diameter is 5 deniers or smaller, the warp and weft threads will insufficiently be fixed. On the other hand, when the filament diameter exceeds 50 deniers, the thickness of the woven material will increase, thus causing the ply gauge to increase, and this is disadvantagous in view of its weight reduction. Furthermore, the friction between the fine fiber and the warp thread will reduce its durability.

The woven material thus obtained is bonded and heated through the method generally conventionally adopted and subjected to the rubber topping process before being buried in the rubber layer to form a reinforcement.

Fig. 3 is a cross sectional view of a right-half bias tire with the aforementioned woven material applied to the carcass plies. The bias tire To in Fig. 3 comprises a pair of bead cores 1, two sheets or carcass plies 2, 3 folded back around the bead cores from the inside to outside thereof and hard bead apexes 4, having a JIS hardness of, for instance, 65° - 96°, arranged in between the carcass plies and their folded portions 2a, 3a.

The aforementioned woven material in place of the coventional tire fabric is used for the aforementioned carcass.

Fig. 4 is a cross sectional view of a right-half radial tire with the aforementioned woven material applied to the carcass. The radial tire Tl in Fig. 4 comprises a pair of bead cores 21, toroidal carcasses 22, 2 3 each with both ends folded back around the bead cores 21, a belt layer 25 arranged outside the crown of the carcasses in the circumferential direction of the tire at a relatively small angle, a tread 26 arranged outside the belt layer and relatively hard bead apexes 24 each arranged in between the carcasses 22, 23 and their folded portions 22a, 23a and extended in the side wall directions from the bead cores 21.

The aforementioned woven material instead of the conventional tire fabric is used for the carcass. 6. 2 1 41 When that woven material is used for a radial tire, the diameter of a filament as the fine fiber should be 5-80 deniers. When the diameter is 5 deniers or smaller, the warp and weft threads will be fixed unsatisfactorily. When the diameter exceeds 80 deniers, the thickness of the woven material will increase, thus causing the ply gauge to increase, and this is disadvantageous in view of its weight reduction. Furthermore, the friction between the fine fiber and the warp thread will reduce its durability. As for other fine fiber materials, the same description as what has been given above is applicable thereto.

The aforementioned reinforcements are replaceable with conventional tire and plain weave fabrics and also widely applicable to tire reinforcements, for instance, carcasses, belt layers, bead reinforcing layers or chafer and carcasses of radial tires for passenger cars and heavy vehicles.

The tire according to the present invention has the following advantages: (i) the end distribution is made uniform while a carcass ply is processed and molded because warp and weft threads constituting a woven material are fixed with fine fibers. Thus a tire can uniformly be built and the durability thereof is improved. 7. 21 "1 o2 (ii) An uneven surface inherent in a tire fabric is nullified because warp and weft threads are not woven together. Consequently, the thickness of a ply is not only decreased but also made uniform and this is advantageous in that the weight of a tire is reducible and its unformity is improvable. (iii) Filament yarn is usable because warp and weft threads are fixed with fine fibers. Moreoever, the weight of weft threads and their weaving cost become reducible and thus the weight of a tire is decreased because the weft threads can be coarsely spaced. (iv) Crimping of warp threads is nullified and material cost is reducible.

Referring to working examples, the present invention will subsequently be described in detail. However, embodiments of the present invention are needless to say not limited to these examples.

Examples Woven materials shown in Table 1 were prepared according to intended uses. 2 I 1 12 Table 1 Radial tire for passenger car Bias tire for two — wheeled vehicle Radial tire for passenger car Carcass Carcass Bead reinforcing layer Chafer iarp threac Denir,cord embedding density (pcs/5cm) Polyester (Note 1) 1500d/2,34(aonoply) 1000d/2,33(2—ply) 1000d/2f 40(aonoply) Nylon (Note 1) 840d/2 30-55 P 1260d/2 30~55 9 1890d/2 30—55 > (i) Nylon (Note 2) 840d/2,30 (ii) Alamid 1500d/2,35 Nylon (aulti filament) 840dx840d (30x30) Nylon (■ono filaaent) 450dx450d (45x45) Weft threac! Yarn nunber count (pes OLBOPLAST 29 in o (Note 3) 30x2 pes. /5cb) Polynosic (Note 3) 30x2 pes.

Polynosic (Note 3) 30x2 pes. rine fiber Polyester 30d Nylon 30d Nylon 30d for (i) above Polyester 30d for (ii) above Nylon 30d (Note 1) Cord embedding density in the crown portion of the tire (pcs/5cm) (Note 2) Cord embedding density at intermediate height in the bead reinforcing layer (pcs/5cm) (Note 3) Trade name.

Table 2 Example 1 Exanple 2 Example 3 Comparative example 1.

Cat enss Fabric (Note 1) Warp thread (denier/quality) 1000d/2 polyester 1000d/2 polyester 1000d/2 polyester 1000d/2 polyester Veft thread OI.BOPLAST 29 (Note 2) 0LB0PLAST 29 0LB0PLAST 29 OLBOPLAST 29 (denier/quality) Fine fiber (denier/quality) 30d/nylon 66 filament 30d/polyester filament 20d/polyester filament woolly processed thread Nil ' Structure Fig. 1, Fig. 2 Fig. 1, Fig. 2 Fig. 1, Fig. 2 Conventioal tire fabric (drawing No) Crimp percentage 0.3% 0.2% 0.0% 1.1% 2.

Belt layer 1 x 5 x 0.25 1 x 5 x 0.25 1 x 5 x 0.25 1 x 5 x 0.35 steel cord, 2—cut ply steel cord, 2—cut ply steel cord, 2—cut ply steel cord, 2—cut ply 3.

Dead apex J IS Code 93' 93° 93° 93° Height (II) 45 mm 45 mm 45 mm 45 mm 4.

Topping rubber physical characte Clastic modulus (701C 2% ristics (F.*) ;distortion) ;60 kg/crf ;60 kg/of ;60 kg/erf ;60 kg/crf ;Topping rubber ;gauge (■/) A ;0.20 ;0.22 ;0.22 ;0.16 ;B ;0.21 ;0.23 ;0.22 ;0.14 ;C ;0.12 ;0.12 ;0.12 ;0.90 ;Uniformity ;97 ;95 ;95 ;100 ;Durability ;154 ;Over 200 ;Over 200 ;100 ;Slight Joosc in bead ;Generation of looser*^ portion in bead portion (Note 1) Cord embedding density N°te 2) Weft thread of Toyobo Co. comprising POY of polyester and cotton. of finished tire 3S pes./5cm. . 2 ' " i 5 2 Woven materials and conventional tire fabrics having specifications shown in Table 2 were used by way of trial to manufacture carcasses of passenger car radial tires 185/70R14 in size of Fig. 4. Plies prepared from the woven materials were assessed in terms of topping rubber gauges, fiber crimping, uniformity of the tires made on an experimental basis and durability. (i) The space (A) between ply cords in a cross sectional view of Fig. 5(i) and the space (C) between a cord and the boundary of the adjoining rubber layer different from the cord layer in a cross sectional view of Fig. 5 (ii) were measured to determine the topping rubber gauge. In the case of a conventional tire fabric, the pulsation width (W) of the cord within the same ply increases because of the "uneven structure" and naturally the topping rubber gauge became greater. (ii) Crimping of woven material Cords Lo long were used to make tire fabrics or woven materials and, when the length Lo of the cord becomes Li, the crimping of the woven material is expressed by Lo - Li/Lo x 100%, (iii) Uniformity Tires were fitted to rims and filled with air so that 2 the internal pressure might be set at 1.9 kg/crn . The tire was pressed against a drum with a load 2 14 15 11. of 404 kg and then the tire together with the drum was rotated to measure changes in vertical and horizontal stress relative to the wheel shaft and index the values obtained. The smaller the indexed value, the better the uniformity becomes. (iv) Durability Tires were filled with air so that the internal pressure might be set at 1.9 kg/cm^ and rotated on the drum while a load of 631 kg was applied until damage was caused thereto. The distances covered were indexed. The greater the indexed value, the better the durability becomes.

Although this invention has been described by way of example and with reference to possible embodiments thereof it should be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims. / 12 274152

Claims (5)

WHAT WE CLAIM IS:

1 A tire reinforced with a woven material 10 15 comprising an unwoven combination of warp threads arranged in parallel with each other and weft threads arranged across said warp threads at an angle ranging from 60° to 90°, characterised in that fine fiber filaments, of a weight of 5 to 5 0 denier, are entwined about the intersections of said warp and weft threads and woven together in the longitudinal direction of said warp threads.

2. A tire as claimed in claim 1 wherein said fine fiber comprises a filament of an organic fiber.

3. A tire as claimed in Claim 1 or Claim 2 wherein said filament has 1/5 to 1/100 denier of said warp thread.

4. A tire substantially as herein described with reference to Figures 1 or 2 or Figures 1 and 2 in conjunction with Figure 3, Figure 4 or Figure 5 of the accompanying drawings.

5. A tire substantially as herein described with reference to any one of the Examples 1, 2 or 3.