Patent Application
20240388013
The present invention is related to electrical connectors, in addition to materials and electrical insulating apparatus. More particularly, the present invention is related to electrical piercing connectors endowed with high piercing and electrical insulating capacity.
Electrical connectors are broadly known in the state of the art, functioning by way of piercing busbars which pierce the insulating cover of electrical cables reaching the electricity conductor wire, making electrical contact between the conductors. Said piercing connectors can be applied both in a more controlled environment, as in installations located underground, as in less controlled environments, as in outdoor powered grids.
In general, the field of application of the piercing connectors for outdoor powered grids of the state of the art is geared towards low voltage electrical systems (up to 1 kV), which do not require a high level insulation. This guarantees the safety of the operator, as same will not be subject to electric shocks (due to the low voltage) when installing connectors on the power grid cables. The piercing connectors described in patent documents GB2266416 (A) and CN201699141 (U) are cited as examples.
Piercing connectors applicable to high voltage are generally more robust and less practical, generally requiring more than one operator for the installation thereof and/or that the network be temporarily disconnected.
Therefore, there is no knowledge of piercing connectors that can be used in outdoor, high-voltage power grids, that are easy to apply (they can be installed by just one person) and that guarantees the safety of the operator during installation. This is because the connectors of the state of the art, in general, do not comprise piercing busbars sufficiently robust to break through cables comprising thicker insulating polymers and/or do not have insulating means which at the same time are practical and efficient for the operator.
For example, many of the connectors in medium voltage protected networks are installed by mechanically withdrawing the polymer covering the conductor for applying the bare mains connector. Subsequently, the polymer mantle is applied, which resets the protected/insulated condition of this conductor, making the procedure more laborious and hazardous for the operator.
It is also known that thermoplastics reinforced with long fibers are a recent development in new technologies, where polypropylene (PP) or other thermoplastic material is combined with long glass fibers for subsequent molding. Technologies in long fiber thermoplastics are surging in the automobile industry today and they are the most important current trends in the plastics processing industry. Glass fibers measuring ½″ (12 mm) up to 2″ (50 mm) provide much greater stiffness, resistance and tenacity to the material than conventional short fibers measuring ⅛″ (3 mm), the later having been used to reinforce thermoplastics for decades. Therefore, thermoplastics reinforced with long fibers (LFRT) have excellent mechanical properties and stiffness to weight ratio, which is of major interest to the industry in general.
However, the application and the properties of this material in electrical insulation are not known.
A first objective of the present invention is to provide a piercing connector that comprises a constructivity which allows same to pierce relatively thick cable insulations.
A second objective of the present invention is to provide a piercing connector that comprises a practical and safe installation for the operator.
A third objective of the present invention is to provide a piercing connector with high electrical insulation capacity, enabling same to be applied in high voltage.
These objectives and other advantages of the present invention will become clearer from the description below and the accompanying drawings.
In order to achieve the objectives described above, the present invention provides a piercing connector, comprising (i) an upper busbar assembly, (i) a lower busbar assembly, (ii) at least one tightening means; an upper counter busbar assembly; a lower busbar assembly, wherein this upper busbar assembly and lower busbar assembly comprises a support means endowed with an opening where a piercing means is fixed.
The present invention also provides for the use of a thermoplastic material reinforced with long fiber as electrical insulation and with mechanical support.
Lastly, the present invention provides a piercing connector, comprising a coating made from an electrical insulation thermoplastic material reinforced with long fiber.
The detailed description presented ahead draws reference to the accompanying drawings, wherein:
The description below will start from a preferred embodiment of the invention. It will become obvious for any person skilled in the art, however, that the invention is not limited to this particular embodiment.
The piercing connector 10 according to the preferred embodiment of the present invention comprises a compatible constructivity base 12 for encasing a cover 14. Both the base 10 and the cover 14 are preferably polymer, made from materials suitable for the level of electrical voltage to which said piercing connector 10 will be subjected. The greater the electrical voltage in the grid where the piercing connector 10 of the present invention will be installed, the more insulating the polymer material of the base 12 and of the cover 14 should be to guarantee the safety of the installation and of the operator.
Both the base 12 and the cover 14 comprise cavities 12a, 14a adapted to receive the network and branch cables, each on one side, which will be pierced simultaneously.
At least two busbar assemblies, namely an upper and a lower one, are disposed between the base 10 and the cover 14. At least one of the busbar assemblies, preferably the lower one, as illustrated in
The openings 18 penetrate the body of the support means 16 up to a given point, as illustrated in the cutaway view of
Preferably, the piercing means 20 are fixed on the openings 18 by at least one cold-welding, hot-welding, refurbished, interference fit or screwing transverse to the plane of the openings 18 (not shown).
Even more preferably, the support means 16 can be made from a material endowed with high thermal conductivity, such as aluminum or copper, capable of quickly and efficiently dissipating the heat generated in the connector.
The upper busbar assembly may comprise a pair of copper strips 24, each of them having two sets of piercing upper elements 24a at their ends. The copper strips 24 that make up the upper busbar assembly can be housed directly in grooves of the cover 14 (not shown), if a support means 16 like in the lower busbar assembly is not used. Alternatively, the upper busbar assembly is similar to the lower busbar assembly, also comprising a support means 16.
Preferably, the contact elements of the piercing connector, namely piercing means 20 and copper strips 24, are made from a relatively resistant material with high electric conduction capacity, like a tinned copper alloy. The resistance of the contact elements for the piercing process and the quality of the electrical contact is thus guaranteed.
Preferably, so as to improve the electrical insulation of the piercing connector 10, coating elements 26 are provided for the upper and lower busbar assemblies. These coating elements 26 are preferably made from an elastic electrically insulating material, such as insulating rubber.
Further preferably, at least one resilient element 28, such as a spring, is provided between the base 12 and the support means 16, the function of which is to maintain normal power generated by the electrical contact of the contact elements 20, 24 against the cables of the network and branch conductors.
The base 12 and the cover 14 are coupled by way of a tightening means comprising, preferably, a screw 30, washer 32, nut 34 and torqueable fuse head 36, which breaks when the tightening attains the specified torque, sealing the piercing connector 10.
Preferably, the base 12 comprises a hollow cylindrical duct 12a through which the screw 30 passes. The cylindrical duct 12a may also act as guide for encasing the support means 16 at the base 12, and, in this case, the support means 16 would comprise a central hole, as illustrated in
The present invention also provides for the innovative use of a thermoplastic material reinforced with long fibers as efficient electrical insulation.
The material used is a thermoplastic polymer comprising a resin matrix that can be at least one of polypropylene, PA, PPA, PBT and POM.
In proof tests carried out, namely thermal cycle tests with short-circuit, according to NBR 9326, and electric tracking tests, according to NBR 10296, the use of all the resins listed above demonstrated optimal performance as electrical insulation.
Preferably, the base 12 and the cover 14 piercing connector 10 according to the present invention are made of a thermoplastic material reinforced with long fibers to guarantee a high level of electrical insulation of the assembly.
Accordingly, the present invention provides a connector endowed with a high capacity of electrical insulation and of coating piercing of relatively thick cables (high voltage). Additionally, the present invention also innovates through the pioneer use of a thermoplastic reinforced with long fibers as electrical insulation, in particular, coating the piercing connector described above.
Countless variations falling within the scope of protection of the present application are permitted. Emphasis is therefore placed on the fact that the present invention is not limited to the particular configurations/embodiments described above.
