STRUCTURE OF HOSE
A hose includes at least an inner-layer tubular member, an intermediate layer, and an outer-layer tubular member. Both the inner-layer tubular member and the outer-layer tubular member are made of plastics. The intermediate layer is formed by wrapping a net. An outer surface of the intermediate layer is provided with a helical structure made of plastics and the outer-layer tubular member encloses the helical structure. The helical structure has a mechanical strength greater than the outer-layer tubular member. Since both the helical structure and the outer-layer tubular member are similarly made of plastics, the bonding strength therebetween can be enhanced. When the hose is subjected to bending, the helical structure helps to prevent the hose from being compressed and deformed, thereby maintaining the inside diameter of the hose to ensure smooth flow of liquid or gas through the hose.
1 . A hose comprising at least an inner-layer tubular member and an outer-layer tubular member, and characterized in that a helical structure made of plastics is arranged between the inner-layer tubular member and the outer-layer tubular member.
2 . The hose as claimed in claim 1 , wherein the helical structure has a cross-sectional dimension that is smaller than a wall thickness of the outer-layer tubular member.
3 . The hose as claimed in claim 1 , wherein the helical structure has a mechanical strength that is greater than mechanical strength of the outer-layer tubular member.
4 . The hose as claimed in claim 1 further comprising an intermediate layer interposed between the inner-layer tubular member and the outer-layer tubular member.
5 . The hose as claimed in claim 4 , wherein the intermediate layer comprises a net formed by yarns that are made of a material selected from a group consisting of nylon, cotton, and a mixture of nylon and cotton.
6 . The hose as claimed in claim 1 , wherein the outer-layer tubular member is made to has an outer surface following a helical configuration of the helical structure to form helical ridges.