MANUFACTURING METHOD OF FLEXIBLE TUBES ON ELASTIC MANDREL Russian patent published in 2012 - IPC F16L11/04 B29C35/00 

FIELD: machine building.

SUBSTANCE: elastic mandrel is formed in the form of tight chamber formed with closed elastic cylindrical cover from vulcanised material with ends. Ends are rigidly fastened with bolt connections between two fixed cylindrical shells and two movable cylindrical flanges, which are concentrically installed on central hollow rod. Distance between flanges is equal to length of flexible tube located between elastic mandrel and radial deformation limiter. Limiter is made from fabric in the shape of cover made as detachable cylinder. Elastic cover is arranged coaxially on cylindrical surfaces of shells. Air is pumped through nozzle located on the edge of one of the shells to tight chamber of mandrel till elastic cover forms cylindrical frame of mandrel equal to inner diameter of flexible tube. Multi-layer flexible tube is assembled from industrial rubber materials on the formed mandrel. Radial deformation limiter is installed coaxially to flexible pipe on its external wall. Pressure test is performed prior to flexible tube vulcanisation by additional pumping of air through nozzle to tight chamber till the required pressure is created. Vulcanisation of pressure-tested tube is performed on elastic mandrel. After vulcanisation is completed, air pressure in mandrel chamber is released through nozzle till it looses frame structure. Limiter cloth is loosened on external wall of tube and the tube is removed from elastic mandrel.

EFFECT: simpler flexible tube manufacturing technology; higher reliability and quality; and reduction of metal consumption of cylindrical mandrel.

2 dwg