IL47438A

IL47438A - Gaskets for cable inlets

Info

Publication number: IL47438A
Application number: IL47438A
Authority: IL
Original assignee: Siemens Ag
Priority date: 1974-06-07
Filing date: 1975-06-06
Publication date: 1977-07-31
Also published as: DE2427677A1; IE41153B1; CH592971A5; BE829970A; ATA428875A; IE41153L; BR7503598A; AR203146A1; DE2427677B2; DK142385B; GB1506522A; LU72659A1; IN142777B; ZA753623B; IL47438A0; FR2274125B1; NL7506703A; DK142385C; IT1038717B; SE7506499L

Abstract

1506522 Cable glands SIEMENS AG 2 June 1975 [7 June 1974] 23801/75 Heading H2E A synthetic resin cable gland comprises one or more segments 8, 9, 10 each segment comprising a plurality of laminar sealing elements 2, held parallel and spaced apart by partitions 21, and means clamping together the segments. Fig. 2 shows the gland in the form of a blank having regions 12, 13, 14, 17, 18 which can be cut out as desired for the cable or cables to be supported by the gland; Fig. 3 shows region 12 cut out. In use, the segments are clamped about the cable or cables which have been coated in sealing compound (5), Fig. 1 (not shown), by, e.g., screws 11 in stiffening elements 11 within the spaces 3 between the sealing elements 2. The sealing elements extend around the extreme periphery of the gland and these may be sealed with compound (5<SP>1</SP>) and fitted into a clamp (6, 6<SP>1</SP>). [GB1506522A]

Description

Gaskets for cable inlets SIEMENS MSIENGESELLSGHAFT The present invention relates to sealing bodies which are made of a synthetic resin material and which are intended for leading cables in a sealed manner into longitudinally split cable fittings, using plastic sealing compounds.

A number of solutions have been proposed for solving the problem of leading cables in a sealed manner into cable fittings. According to one such proposal there is used in a longitudinally split sleeve, a synthetic resin sealing strip which is wound around a portion of the cable to be led into said fittings and which is bounded on both sides by synthetic resin plates. The thus prepared cable portion is then inserted into a sealing jacket provided for this purpose in the sealing chamber. The sealing compound of the wound sealing strip is uniformly distributed by the pressure exerted thereon when the separate portions of the split sleeve are assembled and screwed together, thereby to provide a reliable sealing of the lead-in. With such a seal, however, considerable force must be applied when tightening the sleeve and the measures which must e, taken to limit the sealing mass to the sealing chamber by means of synthetic resin plates are complicated.

German Patent Specification No. 2,235,415 proposes another solution, in which in a pressure-resistant cable terminal the sealing elements are, for example, in the form of two highly resilient sealing plates whose cable inlet opening has a slightly smaller diameter than the cable which is to be passed therethrough. German Patent Specification No. 1,958,155 discloses sealing elements of a slip-on sleeve which seal off the interior of the sleeve from the cable casing by means of one or several lips or a labyrinth. In both cases the seal is only established when the plates or lips are applied and the elastic forces of the material are required to press the latter onto the cable casing. In this case a particular disadvantage consists in the fact that unevenness in the cable casing, such as, e.g. fine grooves, can lead to breaks in the seal..

An object of the present invention is to simplify the construction and the assembly of the seals in cable entrances into longitudinally split cable fittings with^he aid of a sealing body comprising a synthetic resin material, to keep the closing forces required for sealing as small as possible, and to improve the sealing effect of such seals.

Accordingly, this invention consists in an elongate synthetic resin sealing body blank from which a sealing body for cable lead-ins can be made, wherein said blank comprises a plurality of segments, wherein each segment comprises a plurality of sealing 47438/2 members which extend transversely of the long direction of said blank and which are held apart in parallel spaced relationship by stiffening elements, to form a laminar structure, and wherein means are provided for clamping said segments in an assembled position.

So that the invention will be more readily understood and further features thereof made apparent, exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which ':- Figure 1 shows diagraininatically and in section a split sealing body having a series of laminar sealing elements and produced from a sealing body blank; Figure 2 shows diagrammatically and in end view a split sealing body blank which comp- » rises three segments; Figure 3 is a sectional view of the sealing body blank shown in Figure 2, taken along the line III-III in said Figure; and Figure 4 is a side view of the sealing body blank shown in Figure 2.

In Figure 1 there is shown a sealing body which is divided longitudinally of the cable direction into two segments 1 and 1·. Each segment has a series of body to a cable, such as the cable 7, a sealing compound 5 is applied to the cable and the segments 1 and 1' are positioned around said compound, as shown in the Figure. As pressure is exerted onto the segments to force said segments into the compound 5, the sealing compound is partially displaced by the sealing elements 2, 2' and flows into the cavities 3 -31 defined by said elements. This displacement of the sealing compound into the cavities 3 - 3' causes the sealing elements 2, 2* also to be partially wetted in the radial direction, as a result of which the effective sealing length along the sealing body is increased in a simple fashion. Also, as a result of the penetration of the sealing compound 5 into the cavities 3, 3', an excess pressure arises in the cavities which causes the sealing compound 5 present therein to be pressed onto the cable 7 also in these areas. Owing to the laminar structure, the' forces required in this respect are considerably lower than in the case of a seal having a sealing body in which the entire cylindrical surface is operative. Nevertheless the sealing properties of the laminar sealing body are not impaired for the reasons given above. As can also be seen from Figure 1, the external surface of the sealing body 1, 1· may be provided with laminar sealing elements around which a sealing strip 5' can be arranged so that when the cable fitting components 6, 6* are screwed onto each side (e.g. slotted sleeve tube), a seal is effected in a manner similar to that obtained by the sealing elements 2, 2» and the sealing compound 5.

In Figures 2, 3 and 4 there is shown a sealing body which comprises three segments 8, 9 and 10 and in which, for large-capacity cables, up to three cable lead-in openings 12, 13 and 14 can be cut or drilled. Since the sealing body is split longitudinally into segments it can be assembled very easily, and can also be used with continuous cables, since the cuts which divide the sealing body into the segments 8, 9 and 10 are preferably located in such a way that the cable lead-in openings are halved. If required, the cable lead-in openings can be cut away to correspond to the diameter of the cable which is to be introduced therein. A special cutting tool can be used to cut away the sealing body on both sides; in this case it can be advantageous for the number of laminations to preferably amount *to an even-numbered multiple.

From Figure 3, it can be seen that the sealing body has laminar sealing elements arranged in series in the axial direction, and this Figure also shows the form of the laminar elements 2, 2* and the cavities 3, 3' formed therebetween after the cable inlet opening 12 has been cut away. Laminar indentations 20 are also provided in the region of clamping devices 11, so that here too the same conditions prevail. Also shown are laminations provided on the outer periphery of the sealing body, these laminations also being shown in Figure 4. Subsequent to applying a sealing compound to a cable which is to be introduced into the lead-in, or, when said cable has been inserted into the corresponding cable lead-in opening, subsequent to coating the laminations in the dividing planes of the sealing body between the segments 8, and 9, and 9 and 10, with a plastics sealing compound, the segments are pressed towards one another and onto the cable casing by means of the clamping devices 11, which may comprise screws and threaded bushes provided in the sealing bodies, or a clamping element which embraces the sealing body. The screws also serve to guide the segments in relation to one another. The above-described conditions come into effect at the sealing points. The sealing body can also be used when all of the provided cable lead-ins are not required, since a seal can be effected by coating the uncut dividing plates 8, 9, and 9, 10 with a sealing compound and , subsequent clamping. The clamping devices 11 can each be surrounded by a sharp-edged punch which serves to punch out the applied sealing compound in the region of the clamping devices when pressure is applied to said segments. When the punched sealing compound has been extracted, the screws can be readily inserted. Stiffening elements 15 may be provided in the sealing body to produce the desired mechanical stability of the sealing body, thereby enabling it to retain its shape when compressed.

The centres of the cable inlet openings provided are either provided with conical recesses 16 for the application of a drilling tool or are provided with cylindrical recesses 16 so that on account of the reduced wall thickness of the sealing body, the latter can be penetrated in order to introduce a cutting tool for large-diameter bores. To assist drilling, circular marks representing the various cable diameters can be provided centrally around these recesses. Instead of the cable lead-in 12, 13 or 14, it is possible to cut-in two smaller cable lead-ins, such as e.g. 17 and 18, in which case two additional recesses 16 in the dividing plane are required. „

Claims

47348/2 WHAT WE CLAIM IS :-

1. An elongate synthetic resin sealing body blank from which a sealing body for cable lead-ins can be made, wherein said blank comprises a plurality of segments, wherein each segment comprises a plurality of sealing members which extend transversely of the long direction of said blank and which are held apart in parallel spaced relationship by stiffening elements, to form a laminar structure, and wherein means aire provided for clamping said segments in an assembled position.

2. A sealing body blank as claimed in Claim 1, wherein a recess is provided at the dividing planes of adjacent segments to facilitate the drilling of a cable lead-in in said blank.

3. A sealing body blank as claimed in Claim .1 or Claim 2, wherein cutting devices are provided at said dividing planes, ceutrally of said clamping devices.

4. A sealing body blank as claimed in Claim 3, as dependent on Claim 2, wherein the position of said recess is determined by the position and/or diameter of the hole to be drilled in said body.

5. A sealing body blank as claimed in Claim 4, wherein a circle corresponding to the desired hole diameter is inscribed around said recess.

6. A sealing body blank substantially as hereinbefore described with reference to and as shown in Figures 2, 3 and 4 of the drawings forming part of this specification.

7. An elongate, synthetic resin sealing body produced from a sealing body blank as claimed in any one of the preceding Claims, wherein said body comprises a plurality of segments, wherein each of said segments has radially extending sealing elements arranged in spaced relationship along its length, and wherein means are provided for clamping said segments together.

8. A sealing body as claimed in Claim 7, wherein said sealing elements are provided on the internal and external surfaces of said segments.

9. A sealing body, substantially as hereinbefore described with reference to and as shown in Figure 2 of the drawings.

10. A sealed cable lead-in substantially einbefore described, with reference to and n in Figure 1 of the drawings.