FR2463487A1 - TUBULAR ENVELOPE RESISTANT TO HIGH PRESSURE AND HIGH TENSILE STRENGTH - Google Patents

Abstract

SOFT TUBULAR ENCLOSURE RESISTANT TO HIGH PRESSURES AND HIGH TENSILE STRENGTHS. IT IS THIN, CONTINUOUS AND RIBBED IN A PROPELLER WITH 3 DEEP RIBBLES, AND IT IS PROVIDED IN THE HOLLOWS OF ITS RIBBLES WITH A 4 HELICOIDALLY WELD WELD OF CROSS-DIMENSIONAL THICKNESS MULTIPLE THE THICKNESS OF THE ENVELOPE, AND NEAR L 'GAP BETWEEN THE EXTERNAL SURFACES OF TWO CONSECUTIVE RIBBONS AT THE HEIGHT OF THE MEDIUM FIBER OF THE YARN. APPLICATION TO UNDERWATER ELECTRICAL CONNECTION CABLES AND FLEXIBLE FLUID PIPES.

Description

The present invention relates to a flexible tubular casing

  resistant to high pressures and tensile forces. high.

  Such envelopes are required in particular for connection cables

  electric underwater or for flexible hoses carrying -

  fluids under pressure or subjected to strong external pressures. In the case of submarine cables, these shall be capable of being

  wound on drums or pulleys of reduced diameter.

  In that of flexible hoses for fluids, it is also appropriate that they can be wound on storage reels, and that they can be arranged on a path with radius elbows.

relatively weak.

  Hitherto, such cables or pipes have been made by surrounding the actual cable or pipe with several layers of superimposed armor formed of helically wound steel wires, the inner layers wound with a very short pitch essentially resistant to pressure and outer layers wound with a long pitch essentially resistant to tensile stresses. In some cases, the inner layers of armor are replaced by a steel hose. Such envelopes

  However, they do not offer sufficient flexibility and are necessary.

only thick and heavy.

  It has also been proposed flexible continuous tubular metal helical corrugated envelopes for cables or pipes resistant to pressure, the corrugations of the envelope increasing its moment of inertia and consequently its resistance to crushing or bursting under load . However, very high compressive strengths can not be achieved because the thickness of the metal shell must be limited to allow it some flexibility. On the other hand, the tensile strength of such envelopes is very low because the flutes tend to flatten and to stretch even under low stress

longitudinal.

  The object of the present invention is to provide flexible tubular casings resistant to both high pressure and high tensile forces, while remaining relatively thin and light and sufficiently flexible to be rolled over relatively small diameters. The tubular casing flexible according to the invention is characterized in that it is thin, continuous and grooved in helix -2 deep grooves, and in that it is provided in its grooves helicoldally rolled a reinforcing wire of transverse dimension constituting a multiple the thickness of the envelope, and close to the spacing between the outer surfaces of two consecutive grooves at the height of the average fiber of the wire.

  It also preferably responds to at least one of the characteristics

  following ticks: - The wire is of transverse dimension close to 8 times the thickness

of the envelope.

  - The wire is of circular cross section, and of neighboring diameter

double the radius of a groove.

  - The wire is of substantially semicircular cross section, and flat face in the extension of the tangent to the canrelures

parallel to the axis of the envelope.

  - The grooves are separated in cross section by flat portions of height equal to the width of the grooves, and a wire of

  Rectangular straight section is wound on these flat parts.

  - The casing is externally covered with a high tensile strength armor wrapped around it in a helix

with a long step.

  - A protective mattress is interposed between the envelope

fluted and armor of threads.

  - The rear of i1.s high resistance is surrounded by an anti-roll device formed of helically wound son in the opposite direction

from that of his own sons.

  Hereinafter, by way of example and with reference to the figures of the accompanying drawing, envelopes according to the invention for submarine cables are described. Figure 1 shows in elevation an envelope surrounded by a wire of circular cross section (assumed cut in the diametral plane). FIG. 2 is a sectional elevational view of the wire in the diametral plane, an envelope surrounded by a straight section wire

shaped like a semicircle.

  Figure 3 shows in elevation with section of the wire in the diametral plane, an envelope surrounded by a wire of rectangular cross section. Figure 4 shows in perspective with partial section

  an envelope covered with an armor of metallic threads.

  Figure 5 shows in perspective with partial section an envelope surrounded by two armors of metal son of opposite winding direction. In FIG. 1, the envelope generally designated 1, and of internal surface 2, is shaped grooved helically

according to turns such as 3.

  A steel wire of circular cross section 4 is wound in the form of a helical spring in the hollows formed by the grooves between their peaks 5. Its diameter is a little smaller than the spacing A

  outer surfaces of the turns at the height of its axis.

  By way of example, for grooves of straight cross-section and a spring formed of a wire of diameter substantially equal to twice the radius of a groove, the crush resistance is twice as high, for a corrugated envelope reinforced by a spring wire, in the case of a 0.5 mm thick envelope and 2 mm radius grooves, for an unreinforced envelope. However, a maximum crush resistance with a constant outside diameter is obtained with a substantially semicircular cross-section wire 14 (FIG. 2) whose base diameter 14A is in the extension of the tangent 16 at the vertices. splines 13

parallel to the axis of the envelope.

  It is also possible to use (FIG. 3) an envelope 21 having an internal surface 22 with corrugations 23 spaced apart from vertices 25, and spacing equal, for example, to their width and of semicircular cross-section, separated by a thread 24 of rectangular or square straight section,

  side parallel to the axis equal to the spacing of the flutes.

  FIG. 4 represents a casing similar to that of FIG. 1, furthermore provided with armor 30 formed of high-strength steel wires, such as 31, wound in a long-pitch helix ensuring a better tensile strength. . A mattress made of jute or elastic material can be interposed between the casing and the armor of steel wires. It is known that an armor of helically wound steel wires at an angle CS around a cable of diameter D exerts on it a total pressure -4 - p2 T tg2 6 D 2 when subjected to a tensile force T. A corrugated shell reinforced by a coil spring resists much better

  at such a pressure that an unreinforced envelope.

  As an armor formed of wires wound in a helix in one direction tends to rotate the cable about its axis and to unwind when it is subjected to a tensile force, it can advantageously double the first armor by a second 40 (fig. .5) formed of steel wires such as 41 helically wound in opposite directions, or winding only on the armor one or more turns of opposite winding direction, consisting of one or more solid or divided wires, of which The effect is to cancel the twisting forces of the envelope. The armor can be separated by mattresses or sheaths of plastics or elastomers, or be covered by external sheaths of metal strips or strips, or plastics or elastomers. The armor threads can be massive

  or wired, bare or individually isolated.

  Although the tubular envelopes which have just been described with reference to the figures appear the preferable embodiments, it will be understood that various modifications can be made without departing from the scope of the invention. In particular, the cross-section of the wire

  reinforcement may be other than circular, semi-circular or rectangular

  gular, and for example sheptic or trapezoidal. -

-5 -

Claims (8)

  1 / flexible tubular casing resistant to high pressures and high tensile forces, characterized in that it is thin, continuous and grooved in a deep spline helix (3), and in that it is provided in the recesses of its grooves a reinforcing wire (4) wound helicoldalement transverse dimension constituting a multiple of the thickness of the envelope, and neighbor   the spacing between the outer surfaces of two grooves   tives (3) at the height of the average fiber of the wire.   2 / envelope according to claim 1, characterized in that the wire is of transverse dimension close to 8 times the thickness of the envelope.   3 / envelope according to claims 1 or 2, characterized in that   that the wire is of circular cross-section, and of neighboring diameter double the radius of a groove.   4 / envelope according to claims 1 or 2, characterized in that   the wire is of substantially semicircular cross-section (14, FIG. 2), and plane face (14A) in the extension of the tangent   flutes parallel to the axis of the envelope.   5 / envelope according to claims 1 or 2, characterized in that   that the grooves (23, fig 3) are separated by plane portions (27), of height equal to the length of the flutes, and in that a rectangular cross-section wire (24) is wound on these flat portions.   6 / Envelope according to one of claims 1 to 5, characterized in   the casing is externally covered with armor (30) of high tensile yarns (31) wrapped around it in helix with long pitch.   7 / envelope according to claim 6, characterized in that a protective mat is interposed between the fluted envelope and the armor of son.   8 / envelope according to claims 6 or 7, characterized in that   the armor of high-strength threads is surrounded by an anti-roll member (40) formed of threads (41) helically wound in one direction   opposite of that of his own sons.