Hose construction and apparatus for and method of making same

In an apparatus for making a corrugated smooth bore hose construction comprising;

• means for forming a corrugated outer tube made of a polymeric material and having alternating projections and recesses with said recesses having inwardly facing convex surfaces;
• means for forming an inner tube made primarily of polymeric material and having smooth inside and outside surfaces;
• means for disposing said inner tube within said outer tube;
• and means for bonding said outside surface of said inner tube against said convex surfaces;
• the improvement in which;
• said means for forming said inner tube comprises means for forming said inner tube with at least one longitudinally extending polymeric portion provided as an integral part thereof and having electrically conductive particles embedded in a matrix-like portion thereof;
• said means for forming said inner tube being adapted to define said one longitudinally extending polymeric portion thereof as a ribbon-like portion which defines the entire wall thickness of a corresponding portion of the inner tube and blends smoothly with adjoining portions of the inner tube and said ribbon-like portion has a particular wall thickness which is the same as the wall thickness of said adjoining portions, and said means for bonding comprises, means for urging said inner tube radially to thereby urge said polymeric portion against said convex surfaces, and electrical induction coil means for disposition concentrically around said corrugated outer tube so that with said polymeric portion urged against said convex surfaces said induction coil means provides heating of said electrically conductive particles causing partial melting of parts of said outer tube which define said convex surfaces as well as partial melting of said matrix-like portion;
• said partially molten parts and matrix-like portion self-bonding upon cooling thereof.

In a method of making a corrugated-smooth bore hose construction comprising the steps of;

• forming a corrugated outer tube of a polymeric material and having alternating projections and recesses with said recesses having inwardly facing convex surfaces;
• forming an inner tube primarily of a polymeric material and having smooth inside and outside surfaces;
• disposing said inner tube within said outer tube;
• and bonding said outside surface of said inner tube against said convex surfaces;
• the improvement in which;
• said step of forming said inner tube comprises forming said inner tube with at least one longitudinally extending polymeric portion provided as an integral part thereof and having electrically conductive particles embedded in a matrix-like portion thereof;
• said step of forming said inner tube with said one longitudinally extending polymeric portion comprises forming said inner tube with said polymeric portion as a ribbon-like portion which defines the entire wall thickness of a corresponding portion of the inner tube and blends smoothly with adjoining portions of the inner tube and said ribbon-like portion has a particular wall thickness which is the same as the wall thickness of said adjoining portions, and said bonding step comprises the steps of, urging said inner tube radially to thereby urge said polymeric portion against said convex surfaces, and moving said corrugated outer tube with said inner tube disposed therewithin and with said polymeric portion urged against said convex surfaces through an electrical induction coil to thereby heat said electrically conductive particles and cause partial melting of parts of said outer tube which define said convex surfaces as well as partial melting of said matrix-like portion;
• and cooling said partially molten parts and matrix-like portion to self-bond same.