Method of manufacturing rubber hose reinforced by steel cords, and rubber hose reinforced by steel cords

A method of manufacturing a rubber hose reinforced by a plurality of helically arranged steel cords comprising the steps of:

• fabricating a composite strip material comprising opposite side surfaces and opposite side edges, wherein the composite strip material comprises an unvulcanized rubber strip and a plurality of reinforcing steel cords provided in the unvulcanized rubber strip so as to be arranged in a mutually juxtaposed manner and extend in a longitudinal direction of the unvulcanized rubber strip;
• fabricating a flexible inner tube that forms an innermost layer of the rubber hose;
• and
• forming a laminated reinforcing layer comprising a plurality of the helically arranged steel cords around the inner tube by:
• winding the composite strip material around the inner tube;
• forming a wound body having a laminated structure formed by laminating a plurality of unit layers on each other, and, at that point, forming one unit layer on the inner tube and then sequentially forming another unit layer on the formed unit layer;
• and thereafter subjecting the unvulcanized rubber strip of the wound composite strip material to vulcanization;
• wherein
• when forming each of the unit layers, one side surface of the composite strip material is abutted against a base peripheral surface upon which the unit layer is formed;
• and a side edge of the composite strip material forming one turn of the helix and a side edge of the composite strip material forming the turn adjacent thereto are brought into close contact, and the composite strip material is helically wound on the base peripheral surface, so that the base peripheral surface is covered by the composite strip material;
• and, furthermore,
• when forming each of the unit layers, a single continuous strip of the composite strip material is used;
• and each of the unit layers is formed by alternately repeating a winding pass forming step in a first winding forward direction for helically winding the composite strip material in a first direction of the longitudinal direction of the base peripheral surface in a given helix direction, at a given helix angle, and at a given pitch of a whole number multiple of a width dimension of the composite strip material;
• and a winding pass forming step in a second winding forward direction for winding the composite strip material in a second direction that is a direction opposite the first direction of the longitudinal direction of the base peripheral surface in the given helix direction, at the given helix angle, and at the given pitch.