Warp stretch fabric and method

Abstract

A warp-directional stretch fabric that defines two right faces and is formed from warp yarns defined by a nylon and fill yarns defined by an aramid. The fabric can be incorporated into a toothed belt, for example a transmission belt, to produce a belt that has enhanced structural and resistance capabilities while capable of being produced at a lower cost than prior art belts. A method of producing an improved toothed belt including the fabric is also provided.

Claims

1. A method of producing a toothed belt comprising the steps of: providing a rubber core material, warp yams defined by a nylon material, and fill yams defined by a aramid material, molding the rubber core material into a circular belt with at least one exterior surface, weaving the warp yams and the fill yams into a double-faced fabric, whereby the double-faced fabric exhibits more than forty-five percent (45%) elongation in the warp direction and less than twenty-five percent (25%) elongation in the fill direction, attaching the double-faced fabric to the circular belt exterior surface, and molding the circular belt to define a plurality of teeth; whereby weaving the warp and fill yarns further comprises weaving the double-faced fabric via a four harness satin weave in a broken twill pattern.

2. The method of claim 1 whereby the nylon material is nylon 6, 6.

3. The method of claim 1 whereby the aramid material is meta-aramid.

4. The method of claim 1 whereby the aramid material is para-aramid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic representation of a toothed belt with warp stretch fabric;

(2) FIG. 2 pictures a perspective view of a first side of the warp stretch fabric of FIG. 1;

(3) FIG. 3 depicts a perspective view of a second side of the warp stretch fabric of FIG. 1; and

(4) FIG. 4 demonstrates an elevated side view of a cross-section of the warp stretch fabric of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND OPERATION OF THE INVENTION

(5) For a better understanding of the invention and its operation, turning now to the drawings, FIG. 1 schematically illustrates toothed belt 10 formed from interior or core material 11 defining at least one or more exterior surfaces 12 including a plurality of teeth 13. Toothed belt 10 is typically circular, but it should be understood that the exact measurements and configurations of toothed belt 10 should not be construed as a limitation on toothed belt 10. Embodiments of belt 10 are formed from interior materials such as rubber, polymeric derivatives, and other belt materials as are known in the art. Toothed belt 10 may be used in mechanical modes, for example in the automotive context to contact a drive motor shaft with one or more teeth 13 to transmit rotational energy for uses such as an alternator, power steering pump, water pump, air conditioning compressor, air pump and the like (not shown). Due to the harsh operating environments of toothed belt 10, for example when disposed as a belt-in-oil, it is not uncommon for a toothed belt 10 to degrade over time and structurally fail. Therefore, preferred toothed belt 10 further includes fabric 14 attached to one or more exterior surfaces 12 and covering a plurality of teeth 13. In addition to structural protection, embodiments of fabric 14 may convey abrasion resistance properties, chemical resistance properties, stretch resistance properties, or other desirable properties.

(6) Preferred fabric 14 is a double-faced (i.e. hybrid) woven webbing formed from one or more yarn types oriented in the warp (i.e. longitudinal) and fill (i.e. lateral) positions. Embodiments of fabric 14 may be formed with warp yarns 15 and fill yarns 16 formed from the same material, but preferred fabric 14 is formed with two right faces with warp yarns 15 formed from a first material and fill yarns 16 formed from a second material, it being understood that the first and second materials are different materials. A preferred embodiment of fabric 14 is formed from warp yams 15 formed from a polymeric material such as nylon 6, 6. A second preferred embodiment of fabric 14 is formed from fill yarns 16 formed from an aramid derivative such as meta-aramid or para-aramid materials. Nothing in these preferred embodiments should be construed as a limitation as to the materials used to form fabric 14, and it should be understood that one or more materials could be utilized as both warp yarns 15 and fill yarns 16 within the scope of the instant invention. Examples of such materials include, but are not limited to, polyamideimide (available under the tradename Kermel), polyarylate (also known as liquid crystal polyester, available under the tradename Vectran), polyphenlenebenzobisoxacole (available under the tradename Zylon), polybezimdazole (available under the tradename PBI Gold), polyphenylene sulfide (PPS), polytetrafluroethylene (PTFE), polyetheretherketone (PEEK), carbon, stainless steel, D and E glass (also known as fiberglass), basalt, and wool.

(7) Fabric 14 may be formed from a number of different methods such as knitting, weaving, braiding, extruding, or other textile construction methods as are known in the art but the preferred method of formation for fabric 14 is weaving the fabric and then attaching it to exterior surface 12 of toothed belt 10 as the belt is molded to define teeth 13. The weaving pattern in a woven pattern may be selected for aesthetics or visual appearance, but the preferred pattern may also convey structure advantages, such as enhanced structural stability or increased abrasion resistance and increased blocking of rubber from interior side of belt to flow through to the exterior surface. The weaving pattern may also affect the use of the fabric, as certain patterns may form spaces between warp yams 15 and fill yarns 16, for example allowing some fluids such as air or water to pass through the fabric while restricting other fluids such as oil or liquefied polymers and rubbers. An embodiment of fabric 14 may be double-faced, in that there are two right faces of the fabric. While the faces may be completely distinct and attached through non-textile means, for example an adhesive, the preferred configuration of fabric 14 is referred to as a warp twill, indicating that each respective face is formed primarily from either warp yarns 15 or fill yarns 16. An embodiment of the warp twill defined in fabric 14 may be referred to as a broken warp twill, a configuration that produces a diamond shape on the fabric surface. A schematic representation of such a pattern is shown in Table 1:

(8) TABLE-US-00001 TABLE 1 4 3 2 1 X X X 1 X X X 2 X X X 3 X X X 4

(9) Each face may be formed from a variety of stitch styles, but one preferred stitch type defined on both faces is generally referred to as a satin weave, though having an identical weave style on both faces is not a requirement. In addition to the weave configuration, fabric 14 preferably defines a warp yarn 15 and fill yarn 16 pattern known as a four harness pattern, meaning that at respective ends of fabric 14, ends of warp yarns 15 pass above four (4) crossing fill yarns 16 before passing below one (1) crossing fill yarn 16 on a first face, or ends of fill yarns 16 pass above four (4) crossing warp yarns 15 before passing below one (1) crossing warp yarn 15 on a second face. This pattern produces a first face of fabric 14 that is approximate seventy-five percent (75%) defined by warp yarns 15 and approximately twenty-five percent (25%) by fill yarns 16.

(10) Fabric 14 can be formed on a number of weaving machines, but preferred fabric 14 is woven with a straight draw on a weaving machine configured with highly polished reeds, heedles, and a plurality of groups of drop wires (not shown), such as a two hundred-twenty centimeter (220 cm) Picanol Optimax Rapier weaving loom. The preferred total reed spread is sixty-seven and two tenths of an inch (67.20) at fifteen and an eighth (15.625) dents per inch and four (4) dents per end, with a usable reed spread of sixty-five and forty-one hundredths of an inch (65.41) totaling one thousand fifty (1050) dents and one thousand twenty-two (1022) usable dents. This method of manufacture is capable of producing fabric 14 with a greige width of sixty-two to sixty-five inches (62.0-65.0) and a finish width between fifty-nine and sixty-one inches (59.0-61.0) while defining about sixty-five percent (65%) airspace within fabric 14 and weighing approximately four and eighty-eight hundredths ounces per square yard (4.88 oz/sq yard).

(11) A method of producing toothed belt 10 includes the steps of providing interior or core material 11 and molding it into a circular belt defining at least one exterior surface 12. The method also includes weaving fabric 14, for example on a two hundred-twenty centimeter (220 cm) Picanol Optimax Rapier weaving loom, by weaving high-stretch polymeric warp yarns 15 formed from a nylon material such as nylon 6, 6, among fill yarns 16 formed from an aramid material such as meta-aramid or para-aramid. The weaving step may further include weaving warp yarns 15 and fill yarns 16 in a satin weave, more specifically in a four harness satin weave, and more specifically still a four harness satin weave in a broken twill pattern. This passing of warp yarn 15 over four fill yarns 16 before passing below the next in a progressive (i.e. continuously moving the over/under pattern in successive warp ends) creates a diagonal pattern which produces the shape of a diamond on the surface of fabric 14. By utilizing different material for warp yarns 15 and fill yarns 16, these weaving steps produce a fabric with two right faces, capable of bestowing the resulting fabric with customizable stretch and resistance characteristics. An embodiment of fabric 14 may also include the weave of one or more catch-cords (not shown) formed from a polyester material. An alternate embodiment of fabric 14 includes a feathered edge selvage (not shown). One or more embodiments of fabric 14 may undergo bulking, slitting, drying, stabilizing, coating, or other finishing steps after which preferred fabric 14 is then molded to exterior surface 12 of toothed belt 10 and pressure is used to form teeth 13, producing belt 10 that needs less processing time and is lighter in weight than the prior art, while exhibiting stretch characteristics and abrasion resistance due to the nylon material defining warp yarns 15, chemical resistance and structural support to the aramid material defining fill yams 16, and improved noise reduction characteristics resulting from the double-faced fabric 14.

(12) The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.