Flexible metal tube with closed section and flexible pipe comprising same

A flexible metal tube having a longitudinal axis, the tube comprising at least one strip of approximately constant thickness wound helically in turns about the axis, the strip having opposite first and second edges.

• the strip having at least one closed box element extending along the length of the strip and along the first edge, the box element having walls formed by portions of the same turn of the strip, the walls including an upper wall and a lower wall, the other second edge of the strip terminating in a free edge, the box element having a trapezoidal cross-section;
• a radial bulge directed radially towards the upper wall of the box element and located between the box element and the second free edge of the strip;
• and the box element has a wall adjacent to the radial bulge;
• the wall having a base that bears on the radial bulge.

A flexible metal tube having a longitudinal axis, the

• tube comprising at least one strip of approximately constant thickness wound helically in turns about the axis, the strip having opposite first and second edges,
• the strip having at least one closed box element extending along the length of the strip and along the first edge, the box element having walls formed by portions of the same turn of the strip, the walls including an upper wall and a lower wall, the other second edge of the strip terminating in a free edge, the box element having a trapezoidal cross-section;
• a radial bulge directed radially towards the upper wall of the box element and located between the box element and the second free edge of the strip wherein there are interjoint spaces between consecutive turns of the tube and a shaped wire covers the interjoint spaces between the turns of the said tube;
• and the shaped wire has a cross-section in the form of an inverted T, including a vertical arm of the T which extends in a corresponding one of the radial bulges.

Flexible metal tube wherein having a longitudinal axis, the tube comprising at least one strip of approximately constant thickness wound helically in turns about the axis, the strip having opposite first and second edges,

• the strip having at least one closed box element extending along the length of the strip and along the first edge, the box element having walls formed by portions of the same turn of the strip, the walls including an upper wall and a lower wall, the other second edge of the strip terminating in a free edge, the box element having a trapezoidal cross-section;
• a radial bulge directed radially towards the upper wall of the box element and located between the box element and the second free edge of the strip;
• and
• the second free edge of the strip comprises a second bulge shaped and placed for being inserted into the bulge adjacent to the box element of the adjacent turn of the strip.

A flexible metal tube having a longitudinal axis, the tube comprising at least one strip of approximately constant thickness wound helically in turns about the axis, the strip having opposite first and second edges.

• the strip having at least one closed box element extending along the length of the strip and along the first edge, the box element having walls formed by portions of the same turn of the strip, the walls including an upper wall and a lower wall, the other second edge of the strip terminating in a free edge, the box element having a trapezoidal cross-section;
• a radial bulge directed radially towards the upper wall of the box element and located between the box element and the second free edge of the strip;
• there are interjoint spaces between consecutive turns of the tube and a shaped wire covers the interjoint spaces between the turns of the said tube;
• and the interjoint spaces are below the bulge and are there covered by the shaped wire.

A flexible metal tube having a longitudinal axis, the tube comprising at least one strip of approximately constant thickness wound helically in turns about the axis, the strip having opposite first and second edges.

• the strip having at least one closed box element extending along the length of the strip and along the first edge, the box element having walls formed by portions of the same turn of the strip, the walls including an upper wall and a lower wall, the other second edge of the strip terminating in a free edge, the box element having a trapezoidal cross-section;
• a radial bulge directed radially towards the upper wall of the box element and located between the box element and the second free edge of the strip;
• the radial bulge has a height which is less than the height of a turn of the strip;
• and
• the lower wall of the box element is at a greater radial height above the turn of strip in a region across the strip between the edges than the height of the strip beyond the bulge toward the second edge.