Process for producing a hybrid flexible hose

Claim 1

A mandrel free process for producing hybrid flexible hose having a core tube of synthetic resin, a rubber layer over said core tube, a braided fabric reinforcement over said rubber layer and an outer rubber layer over said fabric reinforcement, the steps comprising: preparing a hollow cylindrical core tube of synthetic resin having an inner diameter less than the inner diameter of the flexible hose to be produced and having open ends; applying a rubber layer over the exterior surface of said core tube of synthetic resin; braiding a fabric reinforcement onto the exterior surface of said rubber layer with a braiding angle less than the braiding rest angle to be formed in the flexible hose at the inner diameter to be produced; applying an outer rubber layer over said fabric reinforcement; sealing the opposite ends of said hollow cylindrical core with said rubber layer, fabric reinforcement and outer rubber layer thereon, and applying an internal pressure to said sealed core; and, with said internal pressure applied, applying heat to said sealed core and expanding said sealed core and said rubber layer over the exterior surface of said synthetic resin core tube and increasing said braiding angle of said braided reinforcement with said internal pressure and said applied heat to said rest angle and fitting said exterior surface of said synthetic resin core tube to the interior surface of said rubber layer and, with said pressure and heat applied, vulcanizing said hose and fixing said braiding angle at said rest angle.