Metal hose and its origins

Metal hose is a flexible metal wire element.There are two basic types of metal hose, which vary in design and application: coiled hose and corrugated hose.Spiral hose has high mechanical strength (e.g. tensile and tear strength).Corrugated hoses can withstand high pressures and provide maximum tightness due to their material.Corrugated hoses also exhibit corrosion resistance and pressure-tightness under the most extreme conditions, such as in corrosive seawater or at extreme temperatures found in space or when transporting cooled liquefied gases.They are especially suitable for conveying hot and cold substances.Metal hoses have a history of more than 100 years, and other flexible piping components have been derived, including metal expansion joints, metal bellows, and semi-flexible and flexible metal pipes. In Germany alone there are approximately 3,500 patents related to metal hoses.

The origins 

The first metal hoses were technically coiled hoses.It was invented in 1885 by jewelry maker Heinrich Witzenmann (1829-1906) in Pforzheim, Germany, together with French engineer Eugène Levavassèur.The hose is modeled on a goose throat necklace, a piece of jewelry composed of interlaced metal strips.The original design of the hose was based on a helically wound metal strip with an S-shaped profile.The profiles interlock along the windings of the helical coil.Due to the cavities between the interlocking profiles, a tight fit is not created.The cavity is sealed by a rubber thread.The result is a permanently flexible, sealed steel body of any length and diameter with high mechanical strength.It was patented in France on August 4, 1885 under patent number 170 479 and in Germany on August 27, 1885 under German patent number 34 871.From 1886 to 1905, Heinrich Witzenmann continued to develop many noteworthy profiles for hose production that are still of technical interest today. In 1894, he registered a patent for a bimetal hose, which consists of two coaxial metal hoses twisted in opposite directions.Further modifications to the original form focused on the use of different hose materials and different thread sealing substances, including rubber, textile thread, asbestos and wire.

An important variant of the metal hose can be attributed to inventor Siegfried Frank in Frankfurt, Germany.In 1894 he patented a method for rolling helical corrugations into smooth, rigid pipe. Weitzman had experimented in this direction several years ago, but did not pursue the effort to create patentable results.It was not until the 1920s and 1930s that Albert Dreyer, a hotel manager in Lucerne, Switzerland, succeeded in producing satisfactory annular corrugations for the manufacture of metal corrugated hoses