FR2521765A1 - LONGITUDINAL-SENSITIVE PRESSURE-RESISTANT CABLE PASSAGE FOR THE PASSAGE OF ELECTRIC CABLES - Google Patents

Abstract

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

Description

252 1765

  The present invention relates to a grommet, resistant to pressure in the longitudinal direction, allowing the passage of an electrical cable containing insulated conductors through an opening of a pressure-resistant wall which, externally (pressure side), is in contact, in addition to the grommet, with a liquid or a gas under a comparatively high pressure, a comparatively low pressure internally on the other side, this grommet comprising a metal tubular housing

  fixed on the wall and a sealing body consisting of

  insulating material which seals in the longitudinal direction of a portion of the interior of the housing and which is pierced with holes, in each of which is inserted one of the insulated conductors.

  Such a cable gland is intended to be used on

  high pressure coils, for example submarines which include special pressure-resistant hulls, through which electrical conductors have to pass for various reasons The known grommets are

  however, very complicated and cumbersome and, consequently,

  ficiles to manipulate or have not proved sufficiently reliable

  leaks resulting in electrical overload or even short circuits between

  the various conductors constituting the cable This is due essen-

  the fact that the cable is not resistant to pressure in the longitudinal direction. The same is true for drivers

  and their insulation, between which a liquid or a gas may

nétrer.

  Accordingly, the invention aims at the realization of a

  cable that is resistant to high pressures, which is compact

  and which is comparatively simple in manufacture.

  According to the invention, this goal is achieved in that each

  is stripped on a portion extending from a point within the seal body spaced from the surface of the body nearest the pressure side of the housing to a point outside and close to the the opposite surface of the body closest to the inside of the wall, surface to

  contact of which a heat-sealing material is

  hardenable, having a great fluidity, which penetrates the capillary spaces between the stripped portions of the conductors

  and the walls of the holes of the sealing body, a ring of pres-

  pressure plate and a pressure plate urging a resilient sealing material against the surface of the sealing body opposite

  on the pressure side to get it into the holes of the body.

  Thanks to the presence of elastic sealing material located

  on the pressure side, material that is subject to

  pressure and renders the conductors and the associated holes of the seal body completely sealed, as well as the presence of a

  thermosetting sealing material of high fluidity

  On the opposite side of the body, which penetrates the narrow spaces between the walls of these holes and the stripped portions of the conductors, the cable gland can be used up to

  pressures of about 300 bar at temperatures between -

  400 C and + 1500 C. According to a particularly advantageous embodiment of the

  cable gland, each opening made in the sealing body

  tee is conical in the shape of its orifice.

  This arrangement allows the elastic sealing material to effectively seal

  between the opening and the insulation of the conductors.

  An embodiment of the present invention is hereinafter described by way of example with reference to the accompanying drawing, in which the single figure is a cross-sectional view of a

  cable gland according to the invention mounted on a wall.

  In the figure, we see the cable gland consisting of a tubular housing 3, made of a metal such as steel, this cable gland being mounted on a pressure-resistant wall 2, made of the same material, at the same time. using bolts or similar The outer side or pressure side of the wall 2 and the housing 3 is on the left in the figure and is in contact with a gas or a liquid, for example water, which can be subjected to pressure high of the aforementioned magnitude, while a comparatively low pressure, for example atmospheric pressure, prevails on the opposite inner side of the wall, to the right of the figure An electric cable (which is not described here in more detail) ) with insulated conductors 1 shall be inserted

  the pressure, in an opening of the wall 2.

  For this purpose, inside the housing 3 is provided a body

  4 which ensures the sealing of a portion of this inte-

  in the longitudinal direction and which is pierced with holes 5 having substantially the same diameter as the insulated conductors 1 Ce

  body 4 is made of bakelite or other insulating material

  similar mechanical properties If the interior is

  a circular cylindrical shape, the holes 5 can be distributed

  advantageously on concentric circles.

  1 are inserted in the holes 5 of the body 4 and are stripped on a portion la which extends from a point located at

  a certain distance from the surface of the body 4 facing the pres-

  to a point on the outside and near the side

  opposite of the body 1 facing the interior, the conductors

  1 being thereby isolated when crossing the

  of the interior not filled by the body 4, the most

  next to the inside of the wall 2.

  This portion of the interior is introduced into a material

  thermosetting waterproofing membrane 9 of great fluidity which penetrates

  in the capillary spaces between the stripped conductors 1a and the walls of the holes 5 of the body 4, to fill the space between the body 4 and the inner wall of the cavity. The material 9 may be an epoxy resin, for example having a low coefficient of expansion and a great fluidity, so that it has

  good penetration ability.

  On the pressure side of the sealing body 4, provision is made for a

  elastic closure blank 8 which covers the entire surface of the body located on the pressure side, and which is subjected to compressive forces as it enters the holes 5 and closes them

  around insulated conductors 1 To facilitate this penetration

  each hole 5 of the body 4 has a conical shape at the level of

  port facing the pressure side, as shown by the

  This sealing material 8 must have a compressibility

  high elasticity and elasticity but a low degree of compaction and relaxation; for example, a silicone rubber can be used.

  To subject the material 8 to the required pressure, a

  than pressure 7, metal or other similar rigid material,

  bears against the material 8 and has openings corresponding to

  corresponding to the holes 5 drilled in the sealing body 4 A pressure ring 6, provided with an external thread which cooperates with a corresponding thread formed inside the cavity, pushes the pressure plate 7 by a simple rotation of the ring 6, it is possible to apply an adjustable pressure on the plate 7

  and, therefore, on the material 8.

  Inside the plate 6, a replacement material is provided.

  pleating 10, such as a polyurethane, to hold the ring in the set position, while a ceramic material 11 fills the

  remainder of the interior of the housing 3 to provide an effect of

necessarily.

  To make a tight connection between the cable and the

  cable, special waterproof devices are available which do not

  not within the scope of the invention and which are therefore not

  not represented or described.

Claims (4)

  1 Cable grommet, pressure resistant in the longitudinal direction   dinal, allowing the passage of an electrical cable comprising insulated conductors (1) through an opening made in a sealed wall (2), which is in contact externally (pressure side), in addition to the cable gland, with a liquid or a gas under a comparatively high pressure, a comparatively low pressure prevailing on the other side, or on the inside, this cable gland comprising a tubular metal housing (3) fixed to the wall (2) and a sealing body ( 4) made of an insulating material which closes, in the longitudinal direction, a portion of the interior of the housing and which is pierced with holes (5) in which is inserted   one of the insulated conductors (1), characterized in that each   conductor (1) is stripped on a portion (1a) from a point within the sealing body (4) at a distance from the surface of the body (4) closest to the pressure side of the housing (3). ) to a point outside and close to   the opposite surface of the body (4) closest to the   the wall (2), a surface in contact with which is provided a thermosetting sealing material (9), having a high fluidity, which penetrates into the capillary spaces between the stripped portions (1a) of the conductors and the walls of the holes ( 5) formed in the sealing body (4), and in that a pressure ring (6) and a pressure plate (7) urge an elastic sealing material (8) against the body surface   sealing member (4) facing the pressure side so that   said material enters the holes (5) of the body (4).   Cable gland according to Claim 1, characterized in that each hole (5) of the sealing body (4) has a conical shape   at its orifice facing the pressure side.   3 cable gland according to claim 1 or 2, characterized in   the thermosetting sealing material (9) is a   epoxy sine with low coefficient of expansion.   Cable gland according to Claim 1, 2 or 3, characterized   in that the elastic sealing material (8) is a rubber   silicone rubber with high compressibility and low relaxation of efforts.