Title of Invention

TWO-OR MULTIPLE-PIECE INSULATING BODY SYSTEM FOR PRODUCING MEDIUM HIGH VOLTAGE CABLE FITTINGS

Abstract A two- or multiple-piece insulating body system (1) for producing medium high voltage cable fittings with a self-locking, electrically insulating closure, for example, for holding cable connections, is described, at least comprising a first insulating body (2) with a linear, bulb-like locking element (3) established at a coupling surface (4), located on the face, which in the manner of a snap fit engages with a complementary receiving element (6) at the coupling surface (4), located on the face, of a second insulating body (5). The insulating bodies (2,5) forming the electrical insulation of a medium high voltage cable fitting each include an inner side (1.1) pointing to the cable connection and an outer side (1.2) pointing to the surrounding area, and at least one insulating body (2 or 5) covers the active voltage-carrying connection elements and the linear, bulb-like, closed locking element (3) forming the closure as well as the complementary receiving element (6) of both insulating bodies (2,5) to be connected in cross-section are established as convex-concave curvature pairing with a head area (7) of the locking element (3) and an opening area (7) of the receiving element (6) and each with a neck area (8) delimitable by the curvature points of inflection and each with a shoulder area (9) adjoining the neck area (8). Both insulating bodies (2,5) are provided with conductive layers (10,11) on the inner side (1.1) and the outer side (1.2), said layers extending at at least one of both insulating bodies (2,5) over the coupling surface (4), located on the face, into the head, or opening, respectively, area (7) at least up to the curvature points of inflection, being distanced here to each other. In joined state of both insulating bodies (2,5), the conductive layers (11.1,11.2) and (10.1,10.2) placed on the outer sides (1.2) and the inner sides (1.1), respectively, contact each other at least over the coupling surface (4), located on the face.
Full Text FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. ' TWO- OR MULTIPLE-PIECE INSULATING BODY SYSTEM FOR PRODUCING MEDIUM HIGH VOLTAGE CABLE FITTINGS.'
(A) CELLPACKGMBH
(B) A COMPANY INCORPORATED UNDER THE LAWS OF GERMANY.
(C) Carl-Zeiss-Strasse 20, 79761 Waldshut-Tiengen, Germany.
The following specification particularly describes the invention and the manner in which it is to be performed.
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The invention relates to a two- or multiple-piece insulating body system for producing medium high voltage cable fittings with a self-locking, electrically insulating closure, for example, for holding cable connections, according to the generic part of claim 1.
Those insulating body systems are above all needed where cable and line connections, particularly at operating voltages of more than 1000 V, have to be electrically insulated after the cable connection has been installed, or where it is necessary to provide an inspection hole for maintenance.
The demands made on operationally reliable insulating body systems are not confined to mechanically easy closure of the parts to be coupled of the insulating body system, but also include permanent prevention of humidity entry, gas entrapping and electrical breakdown as well.
From DE 4416 682 CI a cable protecting tube and a method to manufacture it are known. The cable protecting tube is composed of two protecting tube halves pivotically coupled to each other whereby a stripe-like deformable connection element is inserted. Either protecting tube half is provided at the edge toward the hinge with a cavity to receive a lateral cross-sectional portion of the connection element. The cross-sectional portion of the connection element is limited by an inner web which follows the internal profile of the protecting tube and an outer web which largely follows the external profile of the protecting tube. The cross-section of the connection element has a central portion bridging the space between both tube halves and laterally adjacent, preferably bulb-shaped edge portions, which are received by the cavities of the protecting tube halves.
From WO 99/22431 a corrugated tube is known for protectively sheathing electrical lines. The corrugated tube is provided with a slit-shaped opening running along a generatrix, whereby the slit-forming edges of the opening are equipped with closing de-
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vices that close the slit detachably, the corrugated tube being made of an elastic material. As soon as pressure is applied to the corrugated tube, the closing devices join over each other hooking with each other to form a closure. When pressure is no longer applied to the corrugated tube, the closure holds the closing position due to the stress the pressure has introduced into the corrugated tube.
In DE 198 56 605 Al a protecting tube system for electric lines, cables or a wiring harness to be used in automotive engineering is described. The protecting tube system comprises a flexible, bendable protecting tube, which is provided with a cavity to receive the electric lines, cables or a wiring harness. Further, the protecting tube has a continuous longitudinal slit, the longitudinal edges of which are fixable adjacently to each other or overlapping each other. At the inner side and at the outer side of the protecting tube a coating made of a conducting material is placed, or the protecting tube is completely made of a conducting material. In addition, an earth-contacting device is provided connected, on the one hand, to earth and, on the other hand, to the conducting coating or protecting tube material.
In WO 99/30399 a covering established against electrical breakdown for several cables is disclosed. The covering, which is later applied around the cables, has a longitudinal slit, whereby for closing the covering, both distal ends of the covering engage with each other in the manner of a tongue and groove joint. At the inner side of the covering directed toward the cables several webs are placed which establish several chambers electrically insulated from each other. At least one of these webs is curved, largely following the contour of a cable.
In DE 695 08 087 T2 a jointing sleeve with snap-in element and receiving element for medium high voltage cables is disclosed. For sealing and electrical insulation of the joint an oil-extended polymeric sealing material is used. An additional conductive element of the Faraday cage type is disposed around the joint, the conductive element coupled conductively to the joint and distancing the joint from the sealing material creating a clearance.
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In JP-08191519 A, a cable insulation established as radially split sleeve is described that is used for insulating cable ends to be joined. The sleeve comprises a cylindrical central piece and two conical end pieces that in assembled condition limit the central piece on its faces. In the interior of the central piece, a conductive element extending coaxially to the longitudinal axis of the central piece is placed to the axial ends of which both cable ends to be joined are mounted.
It is common to all electrical insulations mentioned above that they can be assembled particularly easily, providing sufficient protection against the entry of humidity. But a particular disadvantage of these insulations is the fact that at higher voltages above an operating voltage of 1000 V electrical breakdown of the current-carrying cable to adjoining cables cannot effectively be prevented. Another essential disadvantage is that using the simple mechanical closures, the entrapping of gases in the region of closure cannot effectively be prevented so that conditions of internal discharges are created.
The objective of the invention is now to propose a two- or multiple-piece insulating body system, which can easily be assembled, where the insulating materials forming the interface permanently lie on top of each other at a certain minimum pressure so that freedom of cavities with entrapped gases is achieved, reliably preventing electrical breakdown in the region of closure, also for use in the range of medium high voltages.
The concept of the invention provides that the insulating body system for producing medium high voltage cable fittings with a self-locking, electrically insulating closure, for example, for holding cable connections is established two- or multiple-piece and includes at least a first insulating body with a linear, closed, bulb-like locking element, which is formed on a coupling surface located on the face and which engages in the manner of a snap lock with a complementary receiving element on the coupling surface of a second insulating body, this coupling surface also being located on the face. At least one insulating body is provided with the necessary openings for inserting the cable ends. The insulating bodies forming the electrical insulation of a medium high voltage
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cable fitting each have an inner surface pointing toward the cable connection and an outer surface pointing toward the surrounding area. At least one insulating body covers the active voltage-carrying connecting elements. The linear, bulb-like locking element, which forms the closure, as well as the complementary receiving element of both insulating bodies to be joined are, in cross-section, established as convex-concave curvature pairing with a head area of the locking element and an opening area of the receiving element and with a neck area that can be delimited by the curvature points of inflection and with a shoulder area adjoining the neck area. The joint pairing locking element with receiving element in the head and opening area, respectively, is established as oversize fit such that at least in the lower neck area and in the adjacent shoulder area a permanent gap between both insulating bodies forms. Further, both the inner and the outer sides of both insulating bodies have conductive layers, which at least on one of both insulating bodies extend over the coupling surface, located on the face, up to the head or opening area, respectively, and are distanced here to each other. In joined state of both insulating bodies, the conductive layers placed on the outer sides and the inner sides, respectively, contact each other at least over the coupling surface, located on the face, or are direct-connected to each other in another way.
The conductive connection of the outer or inner, respectively, conductive layers can also take place inside by contact of both halves to the cable connection and outside in known way by contacting of both halves using a conductive band.
For practical considerations, the two- or multiple-piece insulating body system is established such that both the inner and the outer sides of the insulating body with bulb-like locking element are provided with conductive layers here distanced from each other, which extend over the coupling surface, located on the face, into the head area at least up to the curvature points of inflection. However, the insulating body with receiving element which is complementary to the insulating body with bulb-like locking element is only on its inner side provided with a conductive layer which, in joined state, is contacted over the coupling surface located on the face.
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The path of the inventive idea will not be left even if both the inner side and the outer side of both insulating bodies are provided with conductive layers here distanced from each other, which extend over the coupling surface, located on the face, into the head or opening area, respectively, at least up to the curvature points of inflection. In joined state of both insulating bodies, on the one hand, the conductive layers placed on the outer sides of the insulating bodies and, on the other hand, the conductive layers placed on the inner sides of the insulating bodies contact each other.
Cable connections, as defined by the invention, are fork terminals, screw terminals, terminal studs and the like.
The insulating body with receiving element and/or the insulating body with locking element are preferably made of an elastic insulating material, e.g. a silicone elastomer, in order to achieve the necessary electrical insulating properties on the interface between the head and opening areas.
Another essential advantage of the use of an elastic insulating material is that after joining, or coupling of both insulating bodies no entrapped gas remains in the interface area between the receiving element and the locking element, which at operational voltages as well as under testing conditions might cause the ignition of internal discharges (electrical partial discharges) with an inadmissible level.
The conductive layers placed on the inner sides of the insulating bodies have a first electric potential and the conductive layers placed on the outer sides of the insulating bodies have a different second electric potential with one of both potentials preferably being the earth potential.
While the thickness of each of these conductive layers is at least 10 ^m, the volume resistivity of each of these layers has a value of 5000 Wcm maximum.
The conductive layers can preferably be established to be a conductive polymer or a metallic coating. According to the invention the conductive layers continuously extend
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equally starting from the inner and outer sides of the insulating bodies over the shoulder area, the adjoining neck area at least up to the curvature points of inflection.
In a preferred embodiment of the invention, the end regions of the conductive layers of the insulating body with receiving element, which extend up to the area of the curvature points of inflection, are established as conductive elements with rounded edges and are embedded in the insulating material of the receiving element. These conductive elements established with rounded edges overlap the ends of the conductive layers of the insulating body with locking element by at least 1 mm.
A particularly advantageous embodiment of the invention consists in that the end regions of the conductive layers of the insulating body with receiving element, starting at least at the shoulder area, are established as refractive field control layer with a dielectric constant between 10 and 20. Hereby these end regions of the conductive layers of the insulating body with receiving element overlap the ends of the conductive layers of the insulating body with locking element also by at least 1 mm.
In order to ensure problem-free joining, or coupling, respectively, of both insulating bodies to each other, an electrically insulating pasty slip agent is provided in the interface between the locking element and the receiving element. By use of this slip agent, also repeated alignment of both insulating bodies can be realized with particular ease.
In another preferred embodiment of the invention, an additional layer is provided with a higher modulus of elasticity compared to the insulating material of the insulating body, this layer, in joined condition of both insulating bodies, together with the oversize fit ensuring an additional straining of both insulating bodies in the interface between the receiving element and the locking element in the head area or opening area, respectively. This layer can be placed at the level of the receiving element either on the outer and inner sides of the insulating body with receiving element or inserted into the insulating body with receiving element.
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The transitions from the neck area to the head area and from the neck area to the shoulder area of the conductive layers are preferably provided with a radius of curvature of at least 0.5 mm.
In a particularly advantageous embodiment of the invention, one of both insulating bodies is established as cover for closing an opening in the other insulating body covering the cable connection, in each case. The insulating body established as cover, for example, is provided with a locking element linearly extending over the periphery of the insulating body, the locking element engaging with the complementary, opposite receiving element of the second insulating body.
Further, the insulating body system is provided with at least one further opening that, for example, makes possible to insert an external taper appliance coupler or to fasten several screws of a screw terminal. This opening is then preferably closable with another cover.
According to the invention, both insulating bodies can also be established as covering bodies for voltage-carrying parts such as connectors of cable ends, complementing one another to form a casing. Using the receiving element, which is placed at the coupling surfaces located on the faces of both insulating bodies, as well as the complementary locking element both insulating bodies are coupled to each other.
For assembly one-piece insulating body systems have to be pushed on one side to a parking position at the conductor to be connected of the cable. For that, with three-conductor cables, the insulation of the cable has to be stripped off to such a length that a parking position for the total length of the insulating body system plus half the length of the cable connector is available. Many manufacturers of cable fittings demand this also in case of single-conductor cables, if the insulating body system cannot be parked over the cable sheath.
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Compared with this, an insulating body system according to the invention established as radially split joining sleeve, requires for both cable ends to be connected only one additional parking position each for both parts of the insulating body system, this parking position only being equal to the length of the cable connector. With a three-conductor cable such a distance is required for bending anyway. The force to be applied for pushing on both insulating bodies is much smaller compared to a single-part connecting sleeve, the distance necessary for moving is clearly shorter. This distinctly enhances the assembly friendliness. In addition, the total length of the sleeve is reduced by the value of the parking position saved. If the cable connector established as screw connector has a diameter larger than that of the insulating layer of the cable, further it is not required that the sensitive region for the insulation of the interface be moved over the cable connector at the stripping edge of the external conductive layers of the insulating body so that it need not be overstressed. In the area of the insulating body system established as connecting sleeve, an adequate distance between the cable connector and the inner surface of the inner conductive layers is provided. This avoids damage to the insulating body system due by burrs which might project over the surface of the cable connector after tearing off the heads of twist-off screws.
According to the invention, the insulating bodies established as covering bodies can consist of at least two axially or radially split half-shells. At the faces of these half-shells, these faces adjoining each other in joined state, either the locking element and the receiving element are placed in pairs and linearly, or the faces are established as such elements. In case of axially split half-shells, the inner conductive layers are sufficiently distanced to the distal ends of the insulating bodies in order to avoid electric breakdown, which would depend on the voltage level of the current-carrying conductors. Hereby the electric breakdown relates to values of the maximum field intensity in undisturbed as well as in disturbed continuous operation and on testing the cable joint.
In a particularly preferred embodiment of the invention, between the first insulating body and the second insulating body an intermediate piece may be disposed for extension. This intermediate piece has two coupling surfaces opposite to each other, whereby
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the first coupling surface is established as locking element and the second coupling surface is established as receiving element. In joined state, the locking element of the first insulating body engages with the receiving element of the intermediate piece by force and form closure. On the opposite coupling surface of the intermediate piece the locking element of the intermediate piece engages with the receiving element of the second insulating body.
It does not conflict with the inventive concept if using the above mentioned intermediate piece both the first insulating body and the second insulating body at their coupling surfaces are established identical. In a first case, each of the insulating bodies is provided with a locking element and the intermediate piece is provided with a receiving element at each of its coupling surfaces. In a second case, however, both insulating bodies are provided with a receiving element each and the intermediate piece is provided with a locking element at each of its coupling surfaces.
The coupling surfaces of the intermediate piece therefore can be different or axially symmetric.
The significant advantages and features of the invention compared with prior art essentially are:
? Self-locking, electrically insulating closure of the insulating body system;
? High electric strength and high electrical insulation capacity of the locking element which is made of an elastomer, of the first insulating body and of the complementary receiving element of the second insulating body; and
? Combinability of surface insulations with conductive layers on both opposite surfaces with different electrical potential.
Further features and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of preferred embodi-
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ments when considered in the light of the accompanying drawings in which is shown by:
Fig. 1 a detailed representation of the first insulating body with locking ele-
ment and of the second insulating body with receiving element;
Fig. 2: a detailed representation of two insulating bodies joined to each other;
Fig. 3: a detailed representation of the second insulating body having an outer
layer with a higher modulus of elasticity compared with that of the insulating material of the insulating body;
Fig. 4: a detailed representation of the inner and outer conductive layers of both
insulating bodies;
Fig. 5: a detailed representation of a preferred embodiment of the end regions of
the conductive layers;
Fig. 6: a detailed representation of another preferred embodiment of the end
regions of the conductive layers;
Fig. 7: longitudinal section through an insulating body system including two
radially split half-shells with identically established conductive layers of both insulating bodies;
Fig. 8: longitudinal section through an insulating body system including two
radially split half-shells with differently established conductive layers of both insulating bodies.
The closing system according to the invention consisting of a locking element and a receiving element is always closed. Preferably being coverings of cable connections, each insulating body has an inner side and an outer side.
Fig. 1 shows a sectional representation of the closing region of the first insulating body 2 with locking element 3 and of the second insulating body 5 with the complementary receiving element 6. The first insulating body 2 is provided on its face with a coupling surface 4, where a bulb-like locking element 3 is formed. The locking element 3 comprises a head area 7, a neck area 8 adjoining the head area 7, and a shoulder area 9. The
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second insulating body 5 is also provided on its face with a coupling surface 4, where a receiving element 6 is formed, which comprises an opening area 7, a neck area 8 and a shoulder area 9. The opening angle of the opening area 7 of the receiving element 6, this angle marked by a peripheral double arrow, is in the range of between >180° and Fig. 2 illustrates a detailed representation of the oversize fit 21 of both insulating bodies 2,5 which, in joined state, engage with each other in the manner of a snap fit. The fundamental structure of both insulating bodies 2,5 corresponds with that of Fig. 1. According to the invention, the locking element 3 with the receiving element 6 in the head, or opening, respectively, area 7 is established as oversize fit 21. That means that the outside measure of the locking element 3 is always bigger than the inside measure of the receiving element 6. Exemplarily, the area of the oversize fit 21 is marked using a 270°-peripheral double arrow. In the neck area 8, however, the locking element 3 with the receiving element 6 is established as clearance fit 22. That means that the outside measure of the locking element 3 is, in joined state, always equal to or smaller than the inside measure of the receiving element 6. Due to the stress caused by the locking element 3 in the head and opening area 7 with an effect on the receiving element 6, in the head area 7 a permanent contact pressure develops. In the shoulder area 9, a permanent gap 20 has to be provided. The oversize of the locking element 3 in the area of the oversize fit 21 is preferably 10%.
Fig. 3 shows a detailed representation of the second insulating body 5 with an outer stronger layer 23 placed on the outside. This stronger layer 23 is disposed on the second insulating body 5 in the region of the receiving element 6 and ensures, in joined state of both insulating bodies 2,5, in connection with the oversize fit 21 described in Fig. 2 an additional stress in the closing region of both insulating bodies 2,5. The layer
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23 established of a harder but flexible material can extend as a partial or, preferably, complete sheath around the receiving element 6.
Fig. 4 shows a detailed representation of the inner and outer electrically conductive layers 10,11 of both insulating bodies 2,5. The fundamental structure of both insulating bodies 2,5 again corresponds to that of Fig. 1. The first insulating body 2 and the second insulating body 5 are provided each with an inner conductive layer 10.1,10.2 and an outer conductive layer 11.1,11.2. These conductive layers 10,11 are applied to the inner side 1.1 and the outer side 1.2, respectively, as metallic coatings, for example, on the insulating layer 17 of both insulating bodies 2,5. According to the invention, the conductive layers 10,11 extend equally starting from the inner side 1.1 and the outer side 1.2 of the insulating bodies 2,5 continuously over the shoulder area 9, the adjacent neck area 8 at least up to the curvature points of inflection.
In joined state, both the inner conductive layers 10.1,10.2 of both insulating bodies 2,5 and the outer conductive layers 11.1,11.2 of both insulating bodies 2,5 contact each other. Naturally, the inner conductive layers 10.1,10.2 contacting each other and the outer conductive layers 11.1,11.2 contacting each other have the same potential. According to the invention, however, the inner potential is different from the outer potential, the outer potential being, for example, the earth potential. Each transition from the neck area 8 to the head area 7 and from the neck area 8 to the shoulder area 9 of the conductive layers 10,11 is curved, or rounded, respectively, whereby the radius of curvature is about 0.5 mm.
Figs. 5 and 6 show particularly advantageous embodiments of the end areas 24 of the conductive layers 10,11 of both insulating bodies 2,5. In Fig. 5 the end areas 24, which extend up to the region of the curvature points of inflection, of the conductive layers 10.2,11.2 of the insulating body 5 with receiving element 6 are established as conductive control elements with rounded edges and embedded in the insulating layer 17 of the receiving element 6. The conductive layers 10.2,11.2 of the insulating body 5 with receiving element 6, in joined state of both insulating bodies 2,5, overlap the ends 24 of
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the conductive layers 10.1,11.1 of the insulating body 2 with locking element 3 by at least 1 mm. The end areas 24 of the conductive layers 10.2,11.2 of the insulating body 5 with receiving element 6 end in the region that is delimited by the maximum value and the minimum value marked as max and min, respectively. Fig. 6 shows, on the other hand, an end area 24 of the conductive layers 10.2,11.2 of the insulating body 5 with receiving element 6, the end area 24 being established as semi-conductive control layer. This semi-conductive control layer is embedded in the insulating layer 17 of the second insulating body 5 so that the inner contour of the receiving element 6 has no step-like shoulder or the like.
Fig. 7 illustrates a longitudinal section through an insulating body system 1 consisting of two radially split half-shells, in the type of a radially split joining sleeve in connection with two single-conductor cables coupled by means of a cable connection 18. The radially split joining sleeve consists of two radially split half-shells each with an outer side 1.2 pointing toward the surrounding area and an inner side 1.1 pointing toward the cable connection 18. A first half-shell, placed on the left side of the representation, hereby corresponds to the first insulating body 2 and the second half-shell corresponds to the second insulating body 5. Both the first insulating body 2 and the second insulating body 5 consist of an insulating layer 17, which is provided with an outer conductive layer 11.1,11.2 pointing toward the surrounding area and an inner conductive layer 10.1,10.2 pointing toward the cable connection 18. The first insulating body 2 comprises a coupling surface 4, located on the face, where a locking element 3 is disposed. This locking element 3 extends linearly over a periphery of the first insulating body 2. The second insulating body 5 also is provided with a coupling surface 4, located on the face, where a receiving element 6 complementary to the locking element 3 is placed. In joined state, as shown here, the locking element 3 of the first insulating body 2 engages, by force and form closure, with the receiving element 6, which extends linearly over a periphery of the second insulating body 5. The coupling surfaces 4 of both insulating bodies 2,5 are characterized by a shoulder area 9, a neck area 8 and a head or opening area 7. In the head or opening area 7 the locking element 3 and the receiving element 6 are established as oversize fit. In the neck area 8 and the shoulder area 9
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there is a permanent gap 20. The gap 20 is not electrically loaded by the opposite conductive inner and outer layers 10,11. In joined state of the insulating body system 1, the outer conductive layers 11.1,11.2 of both insulating bodies 2,5 contact each other as well as the inner conductive layers 10.1,10.2 of both insulating bodies 2,5. As can be seen, both inner conductive layers 10.1,10.2, which have an electrical potential different from that of the outer conductive layers 11.1,11.2, are partially connected to the cable connection 18, which is established metallic. The cables coupled to each other through the cable connection 18 and insulated by means of the insulating body system 1 each are established of an electrical conductor 16, an insulating layer 15 surrounding the electrical conductor 16 and an outer conducting layer of the cable 19, this layer being placed on the insulating layer 15. Except in the area, where the inner conductive layers 10.1,10.2 contact the cable connection 18, the cable connection 18 is coaxially surrounded by a cavity 14. The insulating layers 15 of both cables are surrounded at their distal ends each by a refractively acting field control element 13 in form of a sheath, the ends each being conductively connected to the accompanying inner conductive layers 10.1,10.2. The inner conductive layers 10.1,10.2 on their part contact each other within the area of the cable connection 18 and extend starting from the refractively acting field control elements 13 in direction of the coupling surfaces 4 of both insulating bodies 2,5 over the shoulder area 9, the adjoining neck area 8 up to the head area 7. In the area of the cable connection 18 the inner conductive layers 10.1,10.2 of both insulating bodies 2,5 are sufficiently distanced to the cable connection 18 so that during moving on, or joining, respectively, of both insulating bodies 2,5 damage due to possibly projecting burrs of the stripped-off conductors 16 of the cables is excluded. The outer conductive layers 11.1,11.2 extend starting from the outer side 1.2 over the shoulder area 9, the neck area 8 up to the head or opening area 7.
In order to avoid electrical breakdown, which would depend on the voltage level of the current-carrying conductors 16, the inner conductive layers 10.1,10.2 of both insulating bodies 2,5 are sufficiently distanced to the distal end of the insulating bodies 2,5.
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Fig. 8 also illustrates a longitudinal section of an insulating body system 1 consisting of two radially split half-shells as radially split joining sleeve following Fig. 7, but in a preferred embodiment. Doing without the illustration of the cable connection 18 and the accompanying cable 19, this embodiment of the invention according to Fig. 8 focuses to the representation of the differently established conductive layers 10.1,10.2 and 11.1,11.2 of both insulating bodies 2,5. The important difference to the insulating body system 1 of Fig. 7 consists in that only the inner side 1.1 and the outer side 1.2 of the insulating body 2 with bulb-like locking element 3 are provided with conductive layers 10.1,11.1, which here are distanced, extending over the coupling surface 4, located on the face, into the head area 7 at least up to the curvature points of inflection. The insulating body 5 with receiving element 6 complementary to the insulating body 2 with bulb-like locking element 3 is provided on its inner side 1.1 and its outer side 1.2 with the conductive layers 10.2 and 11.2, but these layers do not continue over the coupling surface 4, located on the face. Therefore, in joined state of both half-shells, only the conductive layers 10.1,10.2, placed on the inner sides 1.1 of both insulating bodies 2,5, contact each other at the common coupling surface 4.
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NOMENCLATURE
1 Insulating body system
1.1 Inner side
1.2 Outer side

2 First insulating body
3 Locking element
4 Coupling area
5 Second insulating body
6 Receiving element
7 Head area, opening area
8 Neck area
9 Shoulder area
10 Inner electrically conductive layer

10.1 Inner electrically conductive layer of the first insulating body
10.2 Inner electrically conductive layer of the second insulating body
11 Outer electrically conductive layer
11.1 Outer electrically conductive layer of the first insulating body
11.2 Outer electrically conductive layer of the second insulating body

13 Field control layer, field control element
14 Cavity
15 Insulating layer of the cable
16 Conductor of the cable
17 Insulating layers
18 Cable connection
19 Outer conducting layer of the cable
20 Gap
21 Area oversize fit
22 Area clearance fit
23 Rigid element
24 End areas of the conductive layers
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WE CLAIM:
1. Two- or multiple-piece insulating body system (1) for producing medium high voltage cable fittings with a self-locking, electrically insulating closure, for example, for holding cable connections, at least comprising a first insulating body (2) with a linear, bulb-like locking element (3) established at a coupling surface (4), located on the face, which in the manner of a snap fit engages with a complementary receiving element (6) at the coupling surface (4), located on the face, of a second insulating body (5), whereby at least one insulating body (2 or 5) is provided with the openings required for inserting the cable ends and the insulating bodies (2,5) forming the electrical insulation of a medium high voltage cable fitting each include an inner side (1.1) pointing to the cable connection and an outer side (1.2) pointing to the surrounding area, and whereby at least one insulating body (2 or 5) covers the active voltage-carrying connection elements and the linear, bulb-like, closed locking element (3) as well as the complementary receiving element (6) of both insulating bodies (2,5) to be connected in cross-section are established as convex-concave curvature pairing with a head area (7) of the locking element (3) and an opening area (7) of the receiving element (6) and each with a neck area (8) delimitable by the curvature points of inflection and each with a shoulder area (9) adjoining the neck area (8), whereby the locking element (3) with the receiving element (6) in the head, or opening, respectively, area (7) are established as oversize fit such that at least in the lower neck area (8) and adjoining shoulder area (9) a permanent gap (20) between both insulating bodies (2,5) establishes, and both insulating bodies (2,5) are provided with conductive layers (10,11) on the inner side (1.1) and the outer side (1.2), said layers extending at at least one of both insulating bodies (2,5) over the coupling surface (4), located on the face, into the head, or opening, respectively, area (7) at least up to the curvature points of inflection, here being distanced to each other, whereby in joined state of both insulating bodies (2,5), the conductive layers (11.1,11.2) and (10.1,10.2) placed on the outer sides (1.2)
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and the inner sides (1.1), respectively, contact each other at least over the coupling surface (4), located on the face, or are direct-connected in another manner.
2. Two- or multiple-piece insulating body system (1) to claim 1 characterized by that both the inner side (1.1) and the outer side (1.2) of both insulating bodies (2,5) are provided with conductive layers (10,11), here being distanced, which extend over the coupling surface (4), located on the face, into the head, or opening, respectively, area (7) at least up to the curvature points of inflection, whereby in joined state of both insulating bodies (2,5), on the one hand, the conductive layers (11.1,11.2) placed on the outer sides (1.2) of the insulating bodies (2,5) and, on the other hand, the conductive layers (10.1,10.2) placed on the inner sides (1.1) of the insulating bodies (2,5) contact each other.
3. Two- or multiple-piece insulating body system (1) to claim 1 characterized by that both the inner side (1.1) and the outer side (1.2) of the insulating body (2) are provided with conductive layers (10.1,11.1), here being distanced, extending over the coupling surface (4), located on the face, into the head area (7) at least up to the curvature points of inflection and the insulating body (5) on its inner side (1.1) is provided with a conductive layer (10.2) which, in joined state, is contacted over the coupling surface (4), located on the face.
4. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 3 characterized by that the insulating body (5) with receiving element (6) and/or the insulating body (2) with locking element (3) are made of an elastic insulating material in order to achieve the required electrical insulation capacity in the interface between head and opening area (7).
5. Two- or multiple-piece insulating body system (1) to claim 4 characterized by that a silicone elastomer is provided as insulating material.
19

6. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 5 characterized by that the conductive layers (10.1,10.2) placed on the inner sides (1.1) of the insulating bodies (2,5) have a first electrical potential and the conductive layers (10.2,11.2) placed on the outer sides (1.2) of the insulating bodies (2,5) have a second electrical potential different from the first electrical potential.
7. Two- or multiple-piece insulating body system (1) to claim 6 characterized by that one of both potentials is the earth potential.
8. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 7 characterized by that the conductive layers (10,11) have a layer thickness of at least 10 um and a maximum volume resistivity of 5000 Wcm.
9. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 8 characterized by that the conductive layers (10,11) are established as metallic coating or electrically conductive polymer.
10. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 9 characterized by that the conductive layers (10,11) extend equally starting from the inner side (1.1) and outer side (1.2) of the insulating bodies (2,5) continuously over the shoulder area (9) and the adjoining neck area (8) at least up to the curvature points of inflection.
11. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 10 characterized by that the end areas (24) of the conductive layers (10.2,11.2) of the insulating body (5) with receiving element (6) are established as conductive elements with rounded edges and are embedded in the insulating material (17) of the receiving element (6), and overlap the ends of the conductive layers (10.1,11.1) of the insulating body (2) with locking element (3) by at least 1 mm.
20

12. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 11 characterized by that an electrically insulating pasty slip agent is placed in the interface between the locking element (3) and the receiving element (6).
13. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 11 characterized by that on each the outer side (1.2) and inner side (1.1) of the insulating body (5) with receiving element (6) a layer (23) with a modulus of elasticity higher than that of the insulating material of the insulating body is applied at the level of the receiving element (6), this layer (23), in joined state of both insulating bodies (2,5), in connection with the oversize fit ensuring an additional straining of both insulating bodies (2,5) in the interface between the receiving element (6) and locking element (3) in the head, or opening, respectively, area (7).
14. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 13 characterized by that a layer (23) with a modulus of elasticity higher than that of the insulating material of the insulating body is inserted at the level of the receiving element (6) into the insulating body (5) with receiving element (6), this layer (23), in joined state of both insulating bodies (2,5), in connection with the oversize fit ensuring an additional straining of both insulating bodies (2,5) in the interface between the receiving element (6) and locking element (3) in the head, or opening, respectively, area (7).
15. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 14 characterized by that the transitions from the neck area (8) to the head area (7) and from the neck area (8) to the shoulder area (9) each have a radius of curvature of at least 0.5 mm.
16. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 15 characterized by that both insulating bodies (2,5) are established as covering bodies for voltage-carrying parts completing each other to form a casing, for
21

example, for connectors (18) of cable ends, and are couplable to each other using the receiving element (6) placed at the coupling surfaces (4), located on the face, of both insulating bodies (2,5) as well as the complementary locking element (3).
17. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 16
characterized by that the insulating body system (1) consists of two axially or
radially split half-shells, at the adjoining faces of which, in joined state,
a. the locking element (3) and the receiving element (6), in pairs and
linearly, are placed, or
b. the faces are established as such elements, whereby
in case of axially split half-shells the inner conductive layers (10.1,10.2) are sufficiently distanced to the distal ends of the insulating bodies (2,5) in order to avoid an electrical breakdown depending on the voltage level of the current-carrying conductors (16).
18. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 16 characterized by that one of both insulating bodies (2,5) is established as cover for closing an opening in the other insulating body (5,2) covering the cable connection.
19. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 18 characterized by that the insulating body system (1) is provided with at least one further opening that, for example, makes possible to insert an external taper appliance connector or to fasten several screws of a screw terminal, and can be closed with a cover.
22

20. Two- or multiple-piece insulating body system (1) to one of the claims 1 to 19
characterized by that an intermediate piece with two coupling surfaces (4) is
provided which is placed between the first insulating body (2) and the second
insulating body (5), and the coupling surfaces (4) of the intermediate piece are
engaged with the respective coupling surfaces (4) of the first insulating body (2)
and that of the second insulating body (5), whereby
a. both coupling surfaces (4) of the intermediate piece are established
as receiving element (6) and the coupling surfaces (4) of both insu
lating bodies (2,5) to be coupled as locking element (3), or
b. both coupling surfaces (4) of the intermediate piece are established
as locking element (3) and the coupling surfaces (4) of both insulat
ing bodies (2,5) to be coupled as receiving element (6), or
c. a first coupling surface (4) of the intermediate piece is established as
locking element (3) and a second coupling surface (4) of the inter
mediate piece is established as receiving element (6) and the cou
pling surface (4) of the first insulating body (2) or the second insulat
ing body (5), respectively, as receiving element (6) and the coupling
surface (4) of the second insulating body (5) or the first insulating
body (2), respectively, as locking element (3).
21. A two- or multiple-piece insulating body system for producing medium high
voltage cable fittings as claimed substantially as herein described with forgoing
description and drawings.

Dated this 2nd Day of October, 2007.

23

ABSTRACT
A two- or multiple-piece insulating body system (1) for producing medium high voltage cable fittings with a self-locking, electrically insulating closure, for example, for holding cable connections, is described, at least comprising a first insulating body (2) with a linear, bulb-like locking element (3) established at a coupling surface (4), located on the face, which in the manner of a snap fit engages with a complementary receiving element (6) at the coupling surface (4), located on the face, of a second insulating body (5). The insulating bodies (2,5) forming the electrical insulation of a medium high voltage cable fitting each include an inner side (1.1) pointing to the cable connection and an outer side (1.2) pointing to the surrounding area, and at least one insulating body (2 or 5) covers the active voltage-carrying connection elements and the linear, bulb-like, closed locking element (3) forming the closure as well as the complementary receiving element (6) of both insulating bodies (2,5) to be connected in cross-section are established as convex-concave curvature pairing with a head area (7) of the locking element (3) and an opening area (7) of the receiving element (6) and each with a neck area (8) delimitable by the curvature points of inflection and each with a shoulder area (9) adjoining the neck area (8).
Both insulating bodies (2,5) are provided with conductive layers (10,11) on the inner side (1.1) and the outer side (1.2), said layers extending at at least one of both insulating bodies (2,5) over the coupling surface (4), located on the face, into the head, or opening, respectively, area (7) at least up to the curvature points of inflection, being distanced here to each other. In joined state of both insulating bodies (2,5), the conductive layers (11.1,11.2) and (10.1,10.2) placed on the outer sides (1.2) and the inner sides (1.1), respectively, contact each other at least over the coupling surface (4), located on the face.
Fig. 8

Documents:

1610-MUMNP-2007-ABSTRACT(19-4-2011).pdf

1610-mumnp-2007-abstract.doc

1610-mumnp-2007-abstract.pdf

1610-MUMNP-2007-CLAIMS(AMENDED)-(19-4-2011).pdf

1610-MUMNP-2007-CLAIMS(MARKED COPY)-(19-4-2011).pdf

1610-mumnp-2007-claims.doc

1610-mumnp-2007-claims.pdf

1610-mumnp-2007-correspondence(23-1-2008).pdf

1610-mumnp-2007-correspondence-others.pdf

1610-mumnp-2007-correspondence-received.pdf

1610-mumnp-2007-declaration(23-1-2008).pdf

1610-mumnp-2007-description (complete).pdf

1610-MUMNP-2007-DRAWING(19-4-2011).pdf

1610-mumnp-2007-drawing(4-10-2007).pdf

1610-MUMNP-2007-FORM 1(19-4-2011).pdf

1610-mumnp-2007-form 1(23-1-2008).pdf

1610-mumnp-2007-form 18(9-10-2007).pdf

1610-mumnp-2007-form 2(title page)-(4-10-2007).pdf

1610-MUMNP-2007-FORM 26(19-4-2011).pdf

1610-mumnp-2007-form 26(23-1-2008).pdf

1610-mumnp-2007-form 3(18-10-2007).pdf

1610-MUMNP-2007-FORM 3(19-4-2011).pdf

1610-mumnp-2007-form 3(23-1-2008).pdf

1610-MUMNP-2007-FORM 5(19-4-2011).pdf

1610-mumnp-2007-form 5(23-1-2008).pdf

1610-mumnp-2007-form-1.pdf

1610-mumnp-2007-form-2-1.doc

1610-mumnp-2007-form-2.doc

1610-mumnp-2007-form-2.pdf

1610-mumnp-2007-form-3.pdf

1610-mumnp-2007-form-5.pdf

1610-MUMNP-2007-REPLY TO EXAMINATION REPORT(19-4-2011).pdf

1610-mumnp-2007-wo international publication report(23-1-2008).pdf

abstract1.jpg


Patent Number 247732
Indian Patent Application Number 1610/MUMNP/2007
PG Journal Number 19/2011
Publication Date 13-May-2011
Grant Date 09-May-2011
Date of Filing 04-Oct-2007
Name of Patentee CELLPACK GMBH
Applicant Address CARL-ZEISS-STRASSE 20, 79761 WALDSHUT-TIENGEN.
Inventors:
# Inventor's Name Inventor's Address
1 HOFMANN JENS IM STUDACKER 5, 79790 KUSSABERG.
2 JACOB GERALD MUNCHNER STRASSE 48, 01187 DRESDEN
3 PILLING JURGEN SIEDLUNG 16, 02794 SPITZKUNNERSDORF
PCT International Classification Number H02G15/115
PCT International Application Number PCT/DE2006/000675
PCT International Filing date 2006-04-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102005017472.8 2005-04-12 Denmark