A synchronous belt with a tensile member layer having a tensile member embedded in an elastomeric body; a toothed surface with a plurality of regularly spaced, transverse teeth protruding from the body; and a jacket covering the toothed surface; wherein the teeth comprise a plurality of fabric insert layers that increase the stiffness of the tooth, the insert layers separated from each other by layers of an elastomer composition. The layers may be oriented parallel to the tensile member layer, perpendicular to the tensile member, or following the contour of the tooth. The layers may be a single piece of fabric folded into layers, or separate pieces of fabric.

A polymeric product with at least one surface subject to wear or abrasion, at least a portion of which product includes microcapsules of an indicator substance which is released to indicate a state of wear has been reached. The microencapsulated indicator substance may be a fragrance or a colorant. The indicating portion or zone may be a layer or a thin sheet of microcapsules in rubber or in the polymeric material making up the body of the product. There may be more than one indicating layer or zone in the product. The various zones may contain different fragrances or colorants, which may provide progressive indication of the state of wear.

A polymeric product with at least one surface subject to wear or abrasion, at least a portion of which product includes microcapsules of an indicator substance which is released to indicate a state of wear has been reached. The microencapsulated indicator substance may be a fragrance or a colorant. The indicating portion or zone may be a layer or a thin sheet of microcapsules in rubber or in the polymeric material making up the body of the product. There may be more than one indicating layer or zone in the product. The various zones may contain different fragrances or colorants, which may provide progressive indication of the state of wear.

A power transmission belt includes: a belt body and a cover fabric made of a fabric containing synthetic fibers as a main component and covering a surface of the belt body toward a pulley contact surface. The cover fabric has a surface toward the belt body, and the surface is in contact with a rubber composition containing cellulose-based short fibers. The rubber composition includes a rubber component in which the cellulose-based short fibers are dispersed. The cover fabric and the rubber composition containing the cellulose-based short fibers are exposed on a pulley contact surface.

A power transmission belt includes: a belt body and a cover fabric made of a fabric containing synthetic fibers as a main component and covering a surface of the belt body toward a pulley contact surface. The cover fabric has a surface toward the belt body, and the surface is in contact with a rubber composition containing cellulose-based short fibers. The rubber composition includes a rubber component in which the cellulose-based short fibers are dispersed. The cover fabric and the rubber composition containing the cellulose-based short fibers are exposed on a pulley contact surface.

Disclosed herein is an assembly, method of assembling, and kit for assembling an assembled flexible helical belt that is mounted within a mounting space defined by a continuous mechanical constraint of a device. Embodiments of the flexible helical belt include a flexible helical belt that has a plurality of belt teeth, where some of the belt teeth are each pierced by a through hole which extends through the respective belt tooth and where the flexible helical belt is of sufficient length such that, when the flexible helical belt is mounted within the intended mounting space, the flexible helical belt overlaps itself by at least one rotation such that each through hole is transversely aligned with at least one other through hole, enabling a transverse compression device to be fitted through the through holes, creating a transverse compressive force on the flexible helical belt to form a single continuous drive belt.

Disclosed herein is an assembly, method of assembling, and kit for assembling an assembled flexible helical belt that is mounted within a mounting space defined by a continuous mechanical constraint of a device. Embodiments of the flexible helical belt include a flexible helical belt that has a plurality of belt teeth, where some of the belt teeth are each pierced by a through hole which extends through the respective belt tooth and where the flexible helical belt is of sufficient length such that, when the flexible helical belt is mounted within the intended mounting space, the flexible helical belt overlaps itself by at least one rotation such that each through hole is transversely aligned with at least one other through hole, enabling a transverse compression device to be fitted through the through holes, creating a transverse compressive force on the flexible helical belt to form a single continuous drive belt.

A plied cord includes three or four first twist yarns containing para-aramid fibers, wherein: the para-aramid fibers have an average size of 1000-1250 dtex, a tensile elasticity of 55-70 GPa and a tensile strength of 2800-3500 MPa; and for the plied cord, the number of first twists when the number of the first twist yarns is three is 33-40 twists/10 cm and the number of first twists when the number of the first twist yarns is four is 42-52 twists/10 cm, the second twist direction is the opposite direction from the first twist, and the ratio of the second twist coefficient to the first twist coefficient is 0.25-1.

A rubber-reinforcing cord (12) of the present invention includes at least one strand. The strand includes at least one filament bundle and a coating provided to cover at least a portion of the surface of the filament bundle. The coating contains a polymer and cellulose nanofibers, and does not contain a resorcinol-formaldehyde condensate. The polymer contains at least one selected from a polyurethane and a rubber component. In the coating, the content of the cellulose nanofibers is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer. The proportion of the coating in the rubber-reinforcing cord is 18 vol % or more.

A rubber-reinforcing cord (12) of the present invention includes at least three strands. Each of the strands includes at least one filament bundle and a first coating provided to cover at least a portion of the surface of the filament bundle. The filament bundle consists essentially of aramid fiber filaments. The mass of the first coating is in the range of 14 to 25% with respect to the mass of the filament bundle. Each of the strands is given primary twists at a primary twisting rate of 50 to 100 twists/m. The at least three strands each given primary twists are assembled and given final twists at a final twisting rate of 120 to 200 twists/m.