System and method of manufacturing a composite core for an electrical transmission cable.

COMPOSITE CORE MANUFACTURING SYSTEM AND METHOD FOR ELECTRICAL TRANSMISSION CABLE

Background of the Invention 1. Field of the Invention

The disclosure relates, generally, to electrical transmission and distribution cables and more particularly, relates to a system and method for manufacturing a composite core for use in an electrical transmission and distribution cable.

2, Previous Technique

The demand for transmission and distribution cables increases with the greater demand for electricity. As the appetite for energy increases, new electrical cables continue to be installed. Additionally, to increase capacity, existing electrical installations are rewired with larger capacity cables.

Traditionally, these electrical cables comprise a central core of stranded steel that is wrapped in a stranded aluminum conductor. These cables have been used for decades with very few changes. Among other drawbacks, these cables are susceptible to excessive buckling or flexing in certain climates and under certain operating conditions. Additionally, these cables are susceptible to corrosion in other environments.

To combat the drawbacks, other composite-based solutions have been developed. Certain solutions are described in US Patent No. 7,060,326; In United States of America Publications Nos. 2004-0131834; 20040131851; 2005-0227067; 2005-0129942; 2005-0186410; 20060051580; In United States provisional patent application No. 60/374,879; and in PCT publication No. WO 03/091008, the full descriptions of each of the foregoing are incorporated herein by reference in their entirety. Additionally, the patent incorporated above similarly proposes a solution.

While these solutions have been improved, it has been difficult to achieve improvements with respect to the uniformity of the cross-sectional configurations and the uniformity along a length of the cores formed for these electrical cables. This is especially difficult where different fibers (and possibly different resins) are used.

One solution that has been offered is described in the incorporated patent identified above, namely, the '242 patent. While the process described, which uses what has been called a loose mandrel process, has greatly improved the uniformity of cores subjected to the pultrusion process when multiple different materials and fibers are used, there is nevertheless room for a further improvement in the systems and manufacturing of these fibers (along with other types of fiber cross-sectional configurations). Furthermore, it is desirable to improve the uniformity and improve the characteristics of the resulting cores that will be used in electrical transmission and distribution cables.

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Summary of the Invention

In one aspect of the disclosure, the disclosure is directed to a system for manufacturing a composite core for an electrical cable comprising a fiber creel assembly, an alignment bushing system, a wetting tank, a curing die and a pultrusion assembly. The alignment bushing is positioned downstream of the fiber creel assembly and includes a first bushing, a second bushing, and a third bushing. The first socket includes a plurality of holes arranged as a matrix. A second bushing is positioned downstream of the first bushing. The second bushing includes a plurality of holes in a radial and circular configuration, with a central loose mandrel inner web hole. The third bushing is positioned downstream of the second bushing. The third bushing has a central hole and a plurality of radial holes. The central elongated socket member corresponds with the central hole. The wetting tank is positioned between the first bushing and the second bushing. A curing die is positioned after the alignment bushing system. The pultrusion assembly is positioned downstream of the curing die.

In some configurations, the central elongated socket member of the third socket is heated.

In some configurations, the third sleeve has a thickness and the central elongated sleeve member has a length. The length of the central elongated socket member is greater than the thickness of the third socket.

In some configurations, the holes of the first bushing are generally parallel to each other.

In some configurations, the second bushing holes are positioned concentric with respect to the central loose mandrel inner web hole.

In some configurations, the elongated socket member of the third socket extends out of the third socket and towards the second socket.

In some configurations, the holes of the second bushing are generally parallel to each other.

In some configurations, the center hole of the third bushing is larger than one web diameter

resulting R77C»n/77n7/3 /ΥΙΛΙ .

In some configurations, the wetting tank further includes a resin recirculation circuit.

In some configurations, the resin recirculation circuit further includes a resin inlet, a resin outlet, and a recirculation pump. The inlet and outlet are in fluid communication with an inner tank of the wetting tank.

In some configurations, the humidification tank further includes a heating assembly.

In some configurations, the heating assembly further includes an outer tank, a temperature control fluid, a climate control element, and a recirculation pump. The recirculation pump is configured to circulate the temperature control fluid close to the resin.

In some configurations, at least one post-curing oven is positioned downstream of the curing die.

In some configurations, at least the post-curing oven comprises at least two post-curing ovens positioned, sequentially, downstream of the curing matrix.

In some configurations, the system further includes a coating system positioned downstream of the curing die.

In some configurations, the coating system includes a tank configured to retain a coating fluid.

In some configurations, the system further includes a winding system configured to wind the composite core after pultrusion assembly.

In some configurations, the system further comprises a post-curing oven structurally configured to receive the composite core of the winding system.

In another aspect of the disclosure, the disclosure is directed to a system for manufacturing a composite core for an electrical cable comprising a fiber creel assembly, an alignment bushing, a wetting tank, a curing matrix, a coating, at least one heating oven, a pultrusion assembly, a winding system and a post-curing oven. The alignment bushing system is positioned downstream of the fiber creel assembly and includes a first bushing, a second bushing, and a third bushing. The first socket includes a plurality of holes arranged as a matrix. The second bushing positioned downstream of the first bushing. The second bushing includes a plurality of

R77CQn/77n7/3 /ΥΙΛΙ holes in a radial and circular configuration, with a central loose mandrel inner web hole. The third bushing is positioned downstream of the second bushing. The third bushing has a central hole and a plurality of radial holes. The central elongated socket member corresponds with the central hole. The wetting tank is positioned between the first bushing and the second bushing. The curing die is positioned after the alignment sleeve system. The coating system is positioned downstream of the curing die. At least the heating oven is positioned downstream of the coating system. The pultrusion assembly is positioned downstream of at least the heating oven. The winding system is configured to wind the composite core after pultrusion assembly. The post-curing oven is separated from the winding system, the post-curing oven is configured to receive the composite core from the winding system.

The method of manufacturing a composite core for an electrical cable comprises the steps of: providing a plurality of fibers and a resin; aligning the fibers through an alignment bushing system; providing the resin to a wetting tank; pulling the fibers through the wetting tank; pulling the fibers with resin, through a curing matrix; curing, at least partially, the resin within the curing matrix; winding or winding the fibers and resin after curing matrix; and placing the fibers and resin after the winding step, in a post-curing oven.

In some configurations, the method further comprises the step of pulling the fibers through at least one oven after the step of curing the resin within the curing matrix.

In some configurations, the method further comprises the step of coating the fibers and resin after the curing step, at least partially, with a coating.

In some configurations, the alignment step further comprises the steps of first aligning the fibers through a first ferrule; second, aligning the fibers through a second ferrule positioned downstream of the first ferrule; and third, align the fibers through a third ferrule.

In some configurations, the step of pulling the resin through the wetting tank is performed between the first and second alignment steps.

In some configurations, the winding step further comprises the step of winding the fibers and resin around a drum.

Brief Description of the Figures

Next, the disclosure will be described with reference to the drawings, where:

A schematic representation of the system of the present disclosure is shown in Figure 1 of the drawings;

A schematic side elevational representation of the fiber creel assembly of the present disclosure is shown in Figure 2a of the drawings;

A top plan schematic representation of the fiber creel assembly of the present disclosure is shown in Figure 2b of the drawings;

A perspective view of a spool retaining shaft of the fiber creel assembly of the present disclosure is shown in Figure 3 of the drawings;

A perspective view of the first bushing of the present disclosure is shown in Figure 4 of the drawings;

A perspective view of the second sleeve of the present disclosure is shown in Figure 5 of the drawings;

A perspective view of the third bushing of the present disclosure is shown in Figure 6 of the drawings;

A side elevational view of the third bushing of the present disclosure is shown in Figure 7 of the drawings;

A schematic top plan view of a humidification tank configuration of the present disclosure is shown in Figure 8 of the drawings;

A perspective view of the drum winding system of the present disclosure is shown in Figure 9 of the drawings; and

A perspective view of a schematic representation of a post-curing oven of the present disclosure is shown in Figure 10 of the drawings.

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Detailed Description of the Disclosure

While this disclosure is susceptible to embodiment in many different forms, a specific embodiment(s) is shown in the drawings and described in detail herein with the understanding that the present disclosure will be considered as an example and is not intended to be limited to the illustrated modalities.

It will be understood that the same or analogous elements and/or components, referred to herein, could be identified through the drawings by the same reference characters. Furthermore, it will be understood that the drawings are only schematic representations of the invention and some of the components may be distorted from the actual scale for purposes of schematic clarity.

Next, with reference to the drawings and in particular, Figure 1, the system for manufacturing a composite core for an electrical cable is shown, generally, at number 10. The system includes a fiber creel assembly 12 , the alignment bushing system 13, the wetting tank 14, the curing die 15, the coating system 16, the pultrusion assembly 17, the winding system 18 and the post-curing oven 19. It will be understood that the pultrusion assembly 17 comprises grippers and pulling structures that are known to a person skilled in the art as pultrusion equipment, namely, equipment that can pull a row of fibers through a matrix and the It directs, generally, in a linear direction along a pultrusion table. It will be understood that the manner in which these rows of fibers are pulled through a matrix and the particular holding and pulling mechanism may be varied and these are known to those of skill in the art. Generally, as described herein, the subsequent elements are understood to be downstream of the previous elements in a progression from the fiber creel assembly to the winding system and the subsequent curing oven.

The system is configured to form a core that can be used to support a conductor that forms an electrical transmission and/or distribution cable. This cable that could be formed is described in the incorporated patents above which are cross-referenced. Obviously, other souls and configurations could also form. The present system provides a consistent and improved core in cross section to be manufactured, which presents superior properties due to the level of control and the level of precision in the manufacturing process and due to the configuration of the system.

The fiber creel assembly 12 is shown in Figures 2a and 2b comprising the frame 20, the spool retaining shaft 22, the spool tension assembly 24, the distribution rollers 26 and the distribution guides 28. The frame is an elongated member having a first side 30, a second side 31 and a distribution end 32. A plurality of spool retaining shafts extend outwardly from each of the first side and the second side of the frame 20. As will be understood, each spool retainer shaft is configured to retain a fiber spool, such as spool 313. In the configuration shown, an array of spool retainer shafts is provided to include 28 columns and 7 rows. , each of which can receive a spool of fibers 313. It will be understood that a number of different configurations are contemplated and matrices of different sizes can be used. In the configuration shown, the reel retention shafts are generally parallel to the ground surface and are generally perpendicular to the frame from which the shafts extend, while variations are contemplated.

Each of the spools could include a clutch or delay structure in the form of a spool tension member 24 to provide tension in each of the fibers so that they are pulled from the fiber spool 313. In particular, it is contemplated that the spool tension assembly can resist rotation and therefore can apply a tension when the fibers are pulled from the fiber spool 313. It is contemplated that the tension could be between 1 and 500 grams of tension. It is contemplated that the tension is generally maintained as the fiber is pulled from the spool and preferably is constant throughout the entire spool as the fiber is removed. That is, it is preferred that the tension remain the same as the spool is consumed with fiber. Variations between different fiber spools are contemplated, while it is also contemplated that all spools could be groups of spools that could be at substantially identical tensions.

When the fibers are pulled, they can move along the length of the frame and through the distribution rollers 26 and the distribution guides 28. In the configuration shown, a plurality of structures is provided along the frame with the distribution rollers 26 and distribution guides 28 which are positioned at the distribution end 32.

The alignment bushing system 13 comprises a

R77C»n/77n7/3 /ΥΙΛΙ set of three bushings that are spaced apart and positioned between the distribution end 32 of the fiber creel assembly frame 12 and the curing die 15. These bushings include the first bushing 60 , the second bushing 70 and the third bushing 80. In the configuration shown, the first bushing 60 is positioned before the wetting tank 14 with the second bushing 70 and the third bushing 80 being positioned after the wetting tank 14.

In the configuration shown, the first bushing includes the first side 61 (which is the recessed side) and the second side 62 with a plurality of holes extending through the bushing, such as hole 63. In the configuration shown, The holes 63 are placed in a matrix of separate rows positioned in vertical columns. This provides for the vertical alignment of a plurality of fiber bundles or rows. A central loose mandrel inner core hole 64 is located centrally within the bushing. In the configuration shown, the holes are substantially parallel to each other and are substantially perpendicular to the surfaces defined by the first and second sides. In the configuration shown, this bushing could be formed from two substantially identical plates or from a single plate of material. The first bushing is positioned close to the inlet of the wetting tank 14 so that before entering the wetting tank, the fibers have passed through the first bushing and have been initially aligned. Furthermore, it is contemplated that the first ferrule could be heated to heat fibers passing through the ferrule prior to entry or as the fibers enter the wetting tank. In other configurations, a separate heater could be used to heat the fibers before entering the dampening tank.

The second bushing 70 includes the first side 71 and the second side 72 with holes extending therethrough, such as holes 73 along with a central loose mandrel inner core hole 74. In the configuration shown, the holes 73 are positioned in a radial and circumferential pattern radially outward of the central loose mandrel inner core hole 74 and are generally centered around the central loose mandrel inner core hole 74. In the configuration shown, the holes are substantially parallel to each other and are spaced apart from each other and are substantially perpendicular to the surfaces defined by the first side and the second side. Additionally, in the configuration shown, the holes are placed in successive radially outward circular configurations that are centered around the central hole of the loose mandrel web. In settings

R77CQn/77n7/3 /ΥΙΛΙ shown, a total of four separate circles are shown extending in a radially outward direction, with the innermost circle being radially separated from the central loose mandrel inner web hole by a substantially larger distance that the separation between each successive circle of the holes that extend in a radial direction outward from them.

The third bushing 80 includes the bushing plate 81 and a central elongated bushing member 86. The bushing plate 81 includes the first side 82 and the second side 83 with the central hole 84 and the radial holes 85. The central elongated member of Bushing 86 includes the first end 87, the second end 88 and the hole 89. The first end 87 extends outward from the first side 82 of the gland plate 81 and has a length that is greater than the thickness of the gland plate 81, in the configuration shown. It is contemplated that the central elongated sleeve member 86 could be heated to be at a temperature that is higher than ambient temperature.

It is contemplated that the radial holes 85 are radially spaced from the central hole 84 and are generally centered around the central hole 84. Generally, the central hole 84 is sized larger than the resulting web that is produced, since there is a shrinkage of the resin that occurs or occurs during the curing process. For example, the central hole 84 could be 1-1.5% larger (or more generally, preferably, 0.2-3% larger) than the resulting dimensions of the portion of the web preceding therethrough. (i.e., that portion of cured core that corresponds to the fibers passing through the central elongated ferrule 86).

In the configuration shown, the central elongated sleeve is heated so that the resin temperature is approximately -15-10 °C (5-50 °F) and more preferably -12.2222-(-1.11111) °C ( 10-30°F) below the initial gel run time of the resin system. A DSC test can be performed on the resin mixture and the temperature drop of the central elongated bushing can be adjusted and adjusted accordingly. It has been found that the viscosity of the resin is decreased, thereby maximizing fiber wetting.

The wetting tank 14 is shown in Figure 8 comprising the inner tank 34, the resin circulation circuit 36 and the heating assembly 38. The inner tank 34 includes the fiber inlet 40 and the fiber outlet 42. The inner tank 34 is configured to retain an amount of resin to allow the fiber to pass through the inner tank and to be substantially completely wetted and ready for processing in the die. The fiber inlet and fiber outlet could be configured to minimize resin loss through them. And, it will be understood that the fibers could be dipped into the resin by dipping, when the resin is sprayed or dropped into the resin, or by any of a number of different combinations of the above, among others. In the configuration shown, the wetting tank is positioned between the first and second bushings.

The resin recirculation circuit 36 comprises a resin inlet 44, a resin outlet 45, a circulation pump 46 and a secondary tank 47. Preferably, the resin is circulated between the inner tank 34 and the secondary tank 47 and return to the inner tangue 34. This recirculation has been found to reduce the change in gel time and improve viscosity uniformity. In the configuration shown, the circulation pump achieves this circulatory effect. In other configurations, multiple pumps could be used between the inner tank and the secondary tank, both for removal and resupply of the resin to the inner tank.

The heating assembly 38, in the configuration shown, comprises an outer tank 50, a temperature control fluid 52, a climate control element 54 and a circulation pump 56. In the configuration shown, the

R77C»n/77n7/3 /ΥΙΛΙ temperature control fluid 52 comprises water and the climate control element 54 heats the water or cools the water to maintain the water, preferably between 21.1111 and 48.8889 ° C (70 and 120 °F) (obviously, other temperature ranges are contemplated). The circulation pump 56 helps maintain temperature uniformity within the outer tank 50. In other configurations, the inner tank body could be heated through conduction or convection directly through a heating or cooling element (such as an electrical structure) or through convection by having, for example, air directed over or through the inner tank. In this configuration, the outer tank can be removed, or channeled or similar (or a distributor) or could be provided in its place.

Additionally, the inner tank could also include a heater so that the fibers can be heated before being moistened within the dampening tank. In some configurations, the heater could be incorporated into the first gland, while in others, the heater could be a separate structure positioned between the first gland and the inner tank.

The curing die 15 comprises an elongated heated member having a first end 90, a second end 92, an orifice 94 and a heating element 96. As will be

R77CQn/77n7/3 /ΥΙΛΙ understood by a person skilled in the art, the hole 94 has a cross-sectional configuration that matches the desired properties of the core and a length that provides sufficient time for the resin to cure sufficiently to in order to maintain the desired shape of the soul. It will be understood that the heating element 96 can control the heat that is applied to the resin and the core that is being pulled through the hole 94 between the first and second ends.

In the configuration shown, the curing die comprises a hot die of metal and more preferably, a polished 440C stainless steel material having a hardness of 60-61 RC with the radius dimensions of OD and ID and (R. 25) and a surface finish that is in a tolerance of 0.0000635-0.00002032 cm (0.25-8 micro inches) and preferably, 0.0000254-0.00001524 cm (1-6 micro inches) and preferably, at least 0.0000127 cm (5 micro inches). ).

The coating system 16 is positioned downstream of the curing die 15 and includes the tank 100, the first fiber hole 102 and the second fiber hole 104. In the configuration shown, the fiber is pulled through the first fiber hole 104. fiber 102 and into the tank 100 and then out through the second fiber hole 104. An acrylic material is positioned with the tank and is applied to the outside of the forming and curing core. The heat of the core is sufficient to initiate the reaction to cure and solidify the acrylic material on the outside of the core.

A plurality of post-curing ovens 19 could be provided. For example, an in-line post-curing oven 130a could be provided. The post-curing oven 130a includes a first end 132, a second end 134, and a heating element 136. The post-curing oven 130a is positioned beyond the coating system and the curing die (or at least beyond the curing die) as the core is pulled along a post forming table ( since a person skilled in the art will understand that it is common with pultrusion equipment). In the configuration shown, the post-curing oven 130a includes a hinged portion to allow access to interior portions of the cover. In the configuration shown, the post-curing oven 130a is 3,048 m (10 feet) in length and is configured to heat the internal heated area to approximately 260 ° C (500 ° F) (while other temperatures are contemplated). Additionally, in the configuration shown, a total of three ovens are positioned in series, namely, the post-curing ovens 130a, 130b and 130c. It will be understood that the furnaces may be operated at different temperatures, the furnaces may be of different lengths, and the furnaces may be energized, so

R77CQn/77n7/3 /ΥΙΛΙ selective, depending on a number of different factors.

Additionally, it is contemplated that a winding system 18 and an additional post-curing chamber 140 could be provided in some configurations. The winding system is shown in Figure 4 which comprises the drum shaft 120, the drum motor 122 and the controller 124. This structure is configured for use in association with the drum 320 which includes a pair of opposing side panels 322, 324 and a central cylinder 326 having an outer surface 328. The winding system is configured to receive the drum 320 on the drum shaft 120 and then the drum motor 122 winds the drum to wind the cured (or at least partially cured) cable. Once it is wound as desired (and it will be understood that the speed may be varied in the winding process), the entire wound drum can be placed in the heated chamber 140 (or oven) as a total coil at the desired temperature during the winding. desired amount of time.

In operation, the user first provides the desired spools of fibers that will be used to form the core of the present disclosure. Once provided, these spools are mated with the desired spool retention shafts of the fiber creel assembly. The individual spool fibers are then guided through the distribution rollers and guides.

Once properly guided, the fibers are selectively and carefully placed through the holes of the first matrix. The particular placement and pattern depends on the final core fiber configuration, core size and other factors. The fibers are then directed through the wetting tank and then carefully directed through the appropriate holes in the second die. At the same time, the central core (where the loose mandrel process is used) is directed through the first bushing, the wetting tank and the second bushing.

The fibers are then directed through the appropriate holes in the third ferrule, then through the curing die, the coating system, the ovens of the post-curing oven system and into the winding system. The fibers are introduced to the pultrusion tensile system to be pulled through the process. In the configuration shown, the pultrusion tensile system comprises a plurality of fastening members that can move in a linear direction along the path of the web and that can collaborate to handle tensile loads of the web between the fastening members.

Once the fiber is properly positioned, or at the same time, the resin is placed in the inner tank and prepared to be recirculated within the resin recirculation circuit. The bushings are heated as is the resin to operating temperatures. Additionally, where used, the coating system tank 100 is filled with the appropriate acrylic material.

Once the systems have been established, operation toward and into the continuous or ready state can begin. In particular, the traction system pulls the fibers from the spools through the system. In the configuration shown, as the fibers are pulled, the fiber creel assembly provides the necessary tension to the fibers so that the desired level of fiber tension across the die can be established and maintained. The fibers continue through the first matrix, they are heated and moistened in the wetting tank. These then continue through the second die along with the resin and the third die with the resin. Eventually, the fibers moistened with resin are directed towards the curing matrix. As the now-formed core (which is still curing, although it has cured enough to maintain shape) exits the curing die, it may be directed through one or more post-curing ovens and the coating system ( to have an acrylic application to the outer surface of it). In some configurations, the coating system could be positioned before ovens 130a-130c, while in other configurations, the coating system could be positioned after ovens 130a-130c. In still other systems, a coating system could not be used. Similarly with post-curing ovens, i.e. in some configurations these could be removed or not used.

The formed (and cured) core is then directed to the winding system and wound onto a drum. Once the drum is filled to the desired capacity, the drum can be placed in chamber 140 for a desired time at the desired temperature. In other configurations, the use of a separate chamber or oven after winding can be eliminated.

The foregoing description only explains and illustrates the disclosure and the disclosure is not limited thereto except insofar as the appended claims are so limited, since those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the disclosure.