Tubular element with sealing means and a method for manufacturing the tubular element

A method of manufacturing a tubular element for use in a fluid-conducting duct system, in particular a ventilation duct system, in which an external, circumferential, flexible sealing ring is applied to the outer surface of a tubular body, the tubular element having a wall defining an outer surface, a circumferential groove formed in the outer surface of the wall, and a free end portion disposed at an end of the wall, said sealing ring having a base and a sealing lip extending substantially radially away therefrom, and in which the sealing ring is fastened to the tubular body by bending the free end portion of the tubular body radially outwards and backwards towards the wall of the tubular body, thereby clamping the base of the sealing ring between said bent end portion and said outer surface of the tubular body, the method comprising the steps of:

• forming a circumferential groove in the wall of the tubular body, said end portion of the tubular body being first bent to form a radially extending flange;
• placing the sealing ring in said groove which matches the sealing ring base, the sealing ring having a further lip which extends substantially radially from said base and which in this position extends adjacent to and substantially in parallel with the radial flange;
• and
• bending the flange further back towards the wall of the tubular body so that the further lip is bent down together with the flange and clamped against the sealing ring base.

A method of manufacturing a tubular element for use in a fluid-conducting duct system, in particular a ventilation duct system, in which an external, circumferential, flexible sealing ring is applied to the outer surface of a tubular body, the tubular element having a wall defining an outer surface, a circumferential groove formed in the outer surface of the wall, and a free end portion disposed at an end of the wall, said sealing ring having a base and a sealing lip extending substantially radially away therefrom, and in which the sealing ring is fastened to the tubular body by bending the free end portion of the tubular body radially outwards and backwards towards the wall of the tubular body, thereby clamping the base of the sealing ring between said bent end portion and said outer surface of the tubular body, the method comprising the steps of:

• forming a circumferential groove in the wall of the tubular body, said end portion of the tubular body being first bent to form a radially extending flange;
• axially displacing the sealing ring from an initial position on the tubular body to a position in the groove that matches the sealing ring base, the sealing ring having a further lip which extends substantially radially from said base and which in this position extends adjacent to and substantially in parallel with the radial flange;
• and
• bending the flange further back towards the wall of the tubular body so that the further lip is bent down together with the flange and clamped against the sealing ring base.

A tubular element assembly for use in a ventilation duct system, comprising an external, circumferential, flexible sealing ring mounted at an end of a tubular element, the tubular element having a wall defining an outer surface, a circumferential groove formed in the outer surface of the wall, and a free end portion disposed at an end of the wall, the sealing ring comprising:

• a base which is clamped against the outer surface of the tubular element by means of the free end portion of the tubular element, which is bent radially outwards and turned back towards the outer surface of the tubular element,
• a main sealing lip extending substantially radially away from said base and adapted to seal against an inner surface of an outer tube, in which the tubular element is inserted, the base of the sealing ring being disposed in the circumferential groove that is formed in the wall of the tubular element,
• a further lip or projection which is positioned adjacent to the end of the tubular element and which is axially spaced from the main sealing lip, said further lip clamped against said base by means of said free end portion by said bending, and
• at least one intermediate sealing lip which is disposed between said main sealing lip and said further lip or projection and which extends radially away from the sealing ring base, said intermediate sealing lip being adapted to seal against the inner surface of said outer tube.

A method of manufacturing a tubular element for use in a ventilation duct system, in which an external, circumferential, flexible sealing ring is applied to the outer surface of a tubular body, the tubular element having a wall defining an outer surface, a circumferential groove formed in the outer surface of the wall, and a free end portion disposed at an end of the wall, said sealing ring having a base, a main sealing lip extending substantially radially away from said base, a further lip or projection axially spaced from said main sealing lip, and at least one intermediate sealing lip disposed between the main sealing lip and the further lip or projection and which extends radially away from said base, and in which the sealing ring is fastened to the tubular body by bending the free end portion of the tubular body radially outwards and backwards towards the wall of the tubular body, thereby clamping the base of the sealing ring between said bent end portion and said outer surface of the tubular body, the method comprising the steps of:

• forming a circumferential groove in the wall of the tubular body, said end portion of the tubular body being first bent to form a radially extending flange;
• placing the sealing ring in said groove;
• and
• bending the flange further back towards the wall of the tubular body so that the further lip is bent down together with the flange and clamped against the sealing ring base.