Abstract:
The present invention relates to an assembly for the improved connection or termination of one or more minerally insulated cables, the assembly comprising an electrically insulating plate comprising one or more channels to accommodate and support one or more inward cables; one or more channels to accommodate and support one or more outward cables; one or more recesses to accommodate one or more electrical components; one or more terminal studs arranged to connect said at least one inward and outward cable; and a protective cover comprising one or more protective plates locatable over the electrically insulating plate and cables and further comprising one or more recesses located so as to provide access to each of the one or more terminal studs.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an apparatus for providing an improved assembly for the electrical connection or termination of one or more cables. In particular, it relates to an apparatus and method for connecting or terminating a minerally insulated cable whilst providing improved reliability and damage resistance. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the case of a typical connector and/or terminal for electrical applications, shaped conductors such as terminal tags are often clamped to a standard wire. As such, it is typical for connectors and terminals to use multiple connecting methods within a given assembly. Such methods typically include one or more of mechanical and/or electrical connecting means, wherein connectors or terminals project from an article for subsequent electrical connection. Accordingly, terminal tags provide a traditional means of mechanical and/or electrical connection. 
         [0003]    Most typically, wires are mechanically and/or electrically connected to terminal tags via soldering or crimping methods to provide a mechanical and electrical contact. As such, the terminal tags are shaped, for example, at one end to mechanically and electrically receive and prevent the withdrawal of a wire, whilst being shaped at the opposing end for mechanical and electrical interaction with a terminal or connection point. In use, the tag ensures that the wire is electrically connected to the connector and/or terminal via a means which is of increased reliability than via direct attachment of the wire. Thus, through insertion of the female portion of the terminal tag into the male portion of the connector and/or terminal, a reliable electrical contact may be established. 
         [0004]    In high temperature electrical applications, it is most typical for “Minerally Insulated” cable, also known as MI cable, to be used. Therein, a flexible metal tube/casing is typically filled with one or more wires, the wires of which are often prevented from coming into contact with both each other and the casing by filing the tube with a mineral powder to provide both an electrical- and heat-insulating portion. In particular, the incorporation of a heat-insulating portion makes MI cable particularly suitable for use in high-temperature environments or applications. 
         [0005]    Of particular difficulty when using MI cable is connection and termination of the cable within a given electrical system. In particular, pot seals are known as a viable means for both connecting and terminating MI cable. It is most typical for MI cable to be fed into a casing, which is most typically metal and thereby referred to as a pot. However, MI cable is notoriously difficult to terminate and/or connect to other components using these methods, and these terminations are easily damaged, rendering the connections unreliable. When using MI cable in a high temperature attachment, and wherein there exists a need to terminate and/or connect electrical applications, a pot seal may be used in conjunction with a terminal tag in order to provide a sufficient mechanical and/or electrical connection. It may also be required that the MI cable be subsequently welded, braised or soldered to the terminal tag in order to provide additional strength and or connectivity. 
         [0006]    In particular, it is well known that MI cable is notoriously difficult to terminate and/or connect whilst maintaining resistance to high temperature operating environments. In this regard, it will be appreciated that connecting or terminating MI cable in a high temperature environment exposes the delicate internal cabling to high temperatures, thus removing the benefit of the insulating portion. Furthermore, it is known that MI cable is notoriously prone to damage due to its brittle nature. In particular, damage often occurs to exposed MI cabling and/or pot seals through external interaction. For example, damage may occur through articles being dropped on to the cabling or terminating/connecting means or, for example, through differential vibration within the structure. 
         [0007]    It would therefore be advantageous to provide an improved connector suitable for the connection or termination of MI cable without the aforementioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention accordingly provides, in a first aspect, an insulating connector for the connection of two or more cables or wires, the assembly comprising an electrically insulating block, said block comprising one or more channels to accommodate and support one or more inward cables; one or more channels to accommodate and support one or more outward cables; one or more recesses to accommodate one or more electrical components; one or more terminal studs, each stud arranged to connect said at least one inward and outward cable; and, a cover, the cover comprising one or more protective plates locatable over the electrically insulating block and cables, the protective plates further comprising one or more recesses located so as to provide access to each of the one or more terminal studs. 
         [0009]    Thus, in this way, the present invention provides an improved arrangement for the termination or connection of two or more minerally insulated (MI), insulated or non-insulated cable and/or wire, or any combination of the same, which provides improved reliability and damage resistance over connection means currently comprised within the art. Thus, in this way, the present invention provides a design of increased robustness and reliability through the pot seal and MI cable being positively held in to remove strain on the MI/Pot Seal junction, whilst shielding the connection means from foreign object interaction and/or impact associated damage. 
         [0010]    Optionally, one or more of the protective plates may be comprised of an electrically insulating material. 
         [0011]    Thus, in this way, the present invention provides a means for the electrical isolation from the substrate and/or a further insulating plate between the substrate and the further component as required. 
         [0012]    Optionally, one or more of the protective plates are of increased toughness relative to the protective cover and/or electrically insulating block. 
         [0013]    Thus, in this way, the one or more protective plates may be shatter resistant so as to maintain structural rigidity or integrity during instances of instantaneous or continuously applied stress and/or strain. Such instances may include tools being dropped onto the electrical connector or a catching of the cable on any further component during for example, fitment, service or overhaul of the gas turbine engine. 
         [0014]    Optionally, one or more of the protective plates may comprise a lid which is fixedly attached to a substrate. 
         [0015]    Thus, in this way, the present invention provides a means for protecting the terminal tag, pot seal, cables and/or wires, or any further means of connection from external interaction, such as, for example, operator induced or accidental damage. 
         [0016]    Optionally, the lid may comprise a recess or cavity. 
         [0017]    Thus, in this way, an operator may access predetermined areas upon the connector assembly without necessarily needing to dismantle the connector. Such access may be advantageous in instances where it is necessary to test the connection or termination of the cable. 
         [0018]    Optionally, the recess or cavity may be placed so as to allow access to each of the one or more terminal studs. 
         [0019]    Optionally, said inward or outward cable may be bifurcated within a pot seal, said pot seal being contained within a recess formed within the electrically insulating block. 
         [0020]    Optionally, said inward or outward bifurcated cable may thereon be connected to one or more inward or outward conductors protruding from said pot seal. 
         [0021]    Optionally, said inward or outward conductors may be connected to said one or more terminal studs by one or more connection terminals. 
         [0022]    Optionally, said connection terminals may be comprised of ring tags, said ring tags being arranged so that they may locate, in use, on respective terminal studs. 
         [0023]    Optionally, the slot width of each channel comprised within the insulating block may be approximately equal to or greater than the diameter of the cable to be located, in use, in each respective channel. 
         [0024]    Optionally, the slot width of each recess comprised within the insulating block varies to accommodate, in use, the respective pot seals, conductors, connection terminals and ring tag components. 
         [0025]    Optionally, said one or more inward cables may be supported before entry into the assembly by a cable location and support feature. 
         [0026]    Optionally, said one or more outward cables may be supported following exit from the assembly by one or more cable location and support features. 
         [0027]    Optionally, the electrically insulating block may comprise at least a sufficient number of channels and/or recesses to accommodate, in use, each cable and electrical component. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
           [0029]      FIG. 1  shows a terminal tag clamped to a wire or cable; 
           [0030]      FIG. 2  shows a cross-section through a pot seal; 
           [0031]      FIG. 3  shows an isometric view of a terminal tag and pot seal as part of an assembled connector; 
           [0032]      FIG. 4  shows an isometric view of the substrate and cable connection means; 
           [0033]      FIG. 5  shows an isometric view of the connector and ceramic felt; 
           [0034]      FIG. 6  shows an isometric view of the connector and protection means; 
           [0035]      FIG. 7  shows an isometric view of the connector and lid; 
           [0036]      FIG. 8  shows an isometric view of the connector and a partially removed hinged lid, in accordance with the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]      FIG. 1  shows a terminal tag  2  clamped to a wire  4 , the terminal tag  2  being most typically used for standard cabling and/or wires  4 . The arrangement shown includes both mechanical and electrical connecting means via a mechanical crimped joint  6  for the purpose of providing additional support to the tag, and an electrical crimped joint  8  for the purpose of providing a means of electrical connection. Most typically, wires  4  are mechanically  6  and/or electrically  8  connected to terminal tags  2  via soldering or crimping methods to provide a mechanical and electrical contact  6 , 8 . As such, the terminal tags  2  are shaped, for example, at one end to mechanically  6  and electrically  8  receive and prevent the withdrawal of a wire  4 , whilst further comprising a ring  10  or further means of electrical attachment at the opposing end for mechanical and electrical interaction with a terminal or connection point  12 . 
         [0038]    In use, the tag  2  ensures that the wire  4  is electrically connected to the connector and/or terminal via a mechanical means  10  which is of increased reliability over direct attachment of the wire  4 . Thus, through insertion of the female portion  10  of the terminal tag  2  onto the male portion of the connector and/or terminal  12  followed by subsequent fixation, a reliable electrical contact may be established. 
         [0039]    The inclusion of mechanically crimped parts  6  at the rear of each connector pair is often to provide a degree of support to the flexible wires  4 , thus reducing stress and the likelihood of damage on the crimped electrical connectors  8 . However, the inclusion of mechanically crimped parts  6  at the rear of each connector is often insufficient to prevent damage and ensure longevity of the tag  2 . 
         [0040]      FIG. 2  shows a cross section through a connector arrangement known as a Pot Seal  14  which is particularly suitable for the connection of minerally insulated (MI) cable  16 . As shown in the example arrangement of  FIG. 2 , a single MI cable  16  is shown as being fed into a pot seal  14 . Accordingly, the cable jacket  18  and conductor  20  is shown to be separated by an insulating portion  22 , the jacket  18  being typically connected to the Pot  24  by soldering and the conductor  20  being typically connected to a pin or socket  26  by soldering or crimping. In particular, the pot seal casing  24  may be filled with an insulator  28 , such as epoxy or glass, to electrically isolate the conductor  20  from the pot seal casing  24 , whilst also fulfilling the function of orientating and positioning the conductor  20  for further engagement and/or connection. The further connection may be male or female in form—if female the further connection is referred to as a socket  26 . If male the further connection is referred to as a pin, both of which may optionally include a shoulder  28  to grant improved mechanical integrity to the pin and/or socket  26 . 
         [0041]    Referring again to  FIG. 2 ,  FIG. 2  shows a female socket  26 , the respective socket  26  and pin attachment members being designed to be connected or disconnected as matching pairs to form a connector. In an alternative embodiment, there may be two or more such connectors within a given pot seal  14  arrangement. In particular, if there is more than one connector  26  within the pot seal  14 , it is necessary to orientate the two halves to ensure that matching male pin and female sockets  26  engage their respective portions. This would normally be achieved using, for example, a flat on the matching pots or alternate means of socket orientation to ensure that the pins and/or sockets  26  are correctly oriented before being bought into engagement. 
         [0042]      FIG. 3  shows an isometric view of a terminal tag  2  as part of a standard assembly. Accordingly, a single cable  30  comprising two or more wires  32  is shown to be fed through a supportive clip  34 , the clip  34  being attached to a substrate  36  via a mechanical fastening means such as, for example, a bolt  38  and a threaded support member  40 . As shown in  FIG. 3 , two wires  32  are shown to extend from the clip  34  and cable  30 , although it will be appreciated that, in use, one wire  32 , or multiple wires  32  may alternatively be used. Accordingly, each of the two wires  32  shown in  FIG. 3  are connected to a terminal tag  2  via, for example, the connection method shown in  FIG. 1 . Additionally, each terminal tag  2  is shown to be connected to insulated connection studs  12  projecting from an insulated ceramic connector block  42 , which is itself attached to the substrate  36  via a mechanical fastening means such as, for example, one or more bolts  38 . In use, it will be appreciated that connection of the terminal tags  2  to the connecting studs  12  creates an electrical connection or termination such that an electrical circuit may be completed. It will also be appreciated that the terminal tags  2  may be held in place by an additional mechanical connector such as, for example, by a nut as part of a threaded stud and nut assembly. 
         [0043]    In a further embodiment, the assembly may further comprise an insulating plate between the connecting studs  12  and the substrate  36  to provide further electrical and/or heat insulation therebetween. It may also be appreciated, in a further embodiment, that the insulated connection studs  12  are electrically connected to the substrate  36 , or any further component as required. 
         [0044]      FIG. 4  shows an isometric view of a substrate  36 , an insulated ceramic connector block  42  at least partially protruding from a substrate  36  and a two insulated connecting studs  12  in accordance with the present disclosure, wherein singular or multiple MI cables are, in one embodiment, fed into one or more pot seals  14 . In particular, whilst MI cable has been highlighted as a cable suitable for use in a preferred embodiment, it will also be appreciated that the arrangement may instead comprise insulated or non-insulated cable and/or wire, or any combination of the same. 
         [0045]    Referring again to  FIG. 4 , a single MI cable  16  on the left of the figure is fed into a pot seal  14 , as previously shown in  FIG. 2 . Thereafter, the one or more conductors  20  within the MI cable  16  may be split into one or more further conductors  46 , which are thereafter shown to be connected via connection terminals  44  to one or more terminal tags  2 . In the specific embodiment of  FIG. 4 , two conductors  46  are shown to protrude from the pot seal  14  and are terminated by two ring tags  2 , or one ring tag  2  per conductor  20 , 46 , although it will be appreciated that, in use, one or more conductors  20 , 46  may alternatively be used depending on the geometry and requirements of the MI cable  16  and/or pot seal  14 , or the specific requirements of the user. 
         [0046]    As shown in  FIG. 4 , each ring tag  2  is connected to a first terminal stud  12  which protrudes from, and is either electrically connected to, or is electrically insulated from the substrate  36 . Also attached to the said terminal stud is a second ring tag  48  which connects to standard cable  50 , although it will be appreciated that in a further embodiment, any such cable, including MI cable may also be used.  FIG. 4  also shows the MI cable  16 , pot seal  14 , conductors  46 , connection terminals  44 , ring tags  2 , terminal studs  12  and standard cables  50  being at least partially contained within an insulating block  42 , the insulating block  42  comprising a series of shaped recessed channels  52  suitable for the at least partial containment of said components. In particular, variable sizing of the cable-retaining features or channels  52  may allow varying cable  16 , conductor  46 , connection terminal  44  and terminal tag  2  sizes to be accommodated within the insulating block  42  arrangement. Accordingly, the insulating block  42  is mounted on a radially outer region of the substrate  36 , the terminal studs  12  being mounted within or alternatively through the insulating block  42  in order to insulate the components from the substrate  36 . In particular, the insulating block  42  may be preferentially made of a rigid insulating material such as for example, a ceramic, but could be alternatively comprised of a composite, or either of an elastomeric or polymeric material. Referring once again to  FIG. 4 , the outgoing standard flexible cables  50  are further supported by standard supportive clips  54 , the clip  54  being attached to the substrate  36  via a mechanical fastening means such as, for example, a bolt  56 . The inclusion of supports  54  at either the entry or exit of the connector provides a degree of support to the flexible wires  16 , 50  thus reducing stress and the likelihood of damage, especially at the pot seal  14 , electrical connectors  44  or ring tags  2 , 48 . 
         [0047]      FIG. 5  shows an isometric view of the connector previously described in  FIG. 4 , the connector additionally comprising a cover  60 , 62  to protect the MI cable  16 , pot seal  14 , conductors  46 , electrical connectors  44 , ring tags  2 , 48 , terminal studs  12  or standard cables  50  during use. Accordingly, the cover  60 , 62  locates over the serious of shaped recessed channels  52  suitable for the at least partial containment of said components. In particular, the cover  60 , 62  may be preferentially made of a rigid insulating material such as for example, a ceramic or ceramic felt, but, in a further embodiment, could alternatively be comprised of a composite or either of an elastomeric or polymeric material. Accordingly, in a further embodiment, the cover  60 , 62  may vary in terms of specific shape, thickness or material depending upon the application, location, likelihood of damage and/or level of insulation required. In particular,  FIG. 5  also shows a cover comprised of two individual sections  60 , 62 , however it may also be envisioned that the two sections  60 , 62  be replaced by a single plate further comprising one or more enlarged recesses, which may be so shaped to access terminal studs  12  or ring tags  2 , 48 , operable in use to allow access to the components for electrical checks. It will however be appreciated that in a further embodiment, any such recesses or holes may be included within the one or more covers  60 , 62  in order to access further contacts or electrical components as required. 
         [0048]      FIG. 6  shows an isometric view of the connector and cover arrangement previously described in  FIG. 5 , the arrangement comprising an additional protective cover  64 , 66  to protect the MI cable  16 , pot seal  14 , conductors  46 , ring tags  2 , 48 , terminal studs  12 , standard cables  50  and cover  60 , 62  during use, in accordance with the present disclosure. Accordingly, the additional protective cover  64 , 66  locates over the cover  60 , 62  to provide additional containment, support and protection of the electrical components. In particular, the additional protective cover  64 , 66  may be preferentially made of a rigid insulating material such as for example, a ceramic or ceramic felt, but could alternatively be comprised of a composite or either of an elastomeric or polymeric material. Accordingly, the additional protective cover  64 , 66  may, in an alternative embodiment, be one or more of variable shape, thickness and/or material. In particular,  FIG. 6  also shows an additional protective cover  64 , 66  comprised of two individual sections, however it may also be envisioned that the two sections  64 , 66  may be replaced by a single plate with an enlarged recesses, which may be so shaped to access terminal studs  12  or ring tags  2 , 48 , operable in use to allow access to the components for electrical checks. It will however be appreciated that in a further embodiment, any such recesses or holes may be included within the one or more covers  64 , 66  in order to access specific contacts or electrical components. 
         [0049]      FIG. 7  shows an isometric view of the connector previously described in  FIG. 6 , the connector additionally comprising a protective lid  68  in accordance with the present disclosure. In particular,  FIG. 7  shows a lid  68  hingedly connected to the substrate  36  and operable in use to locate over the connector in order to locate against the additional protective cover  64 , 66 . In particular, the embodiment shown in  FIG. 7  provides a metal tang  70  bent at a right angle which fits into a slot  72  in the substrate  36 , although it will be appreciated that in a further embodiment, the hinge formed by the tang and  70  and slot  72  may be replaced by any similar connecting, coupling or joining means. It will be appreciated that in the embodiment shown in  FIG. 7 , the protective lid  68  may be configured in use so as to apply a compressive load to the additional protective cover  64 , 66  in order to hold the connector together. It will be appreciated that in a further embodiment, the protective lid  68  may simply locate over the connector assembly, the assembly instead being held together by a mechanical or other such means of fastening such as, for example, a threaded screw or nut assembly. As shown in  FIG. 7 , the protective lid  68  is fastened to the substrate  36  via a hinge member provided on one side of the protective lid. The opposite side of the lid  68  is provided with a means of fixation to the substrate  36 . As shown in  FIG. 7 , the means of fixation formed by the tang and  70  and slot  72  may, for example, include a plate comprising one or more holes, through which a bolt may be passed for mechanical attachment. However, it will be appreciated that the lid  68  may be connected to and tightened against the substrate  36  via cooperable screw threads, alternate joining means, or any such means of fixation. 
         [0050]    In particular, the additional protective lid  68  may be preferentially made of a rigid insulating material such as for example, a ceramic or polymeric material, but could alternatively be comprise a metallic, composite, polymeric or elastomeric material. Accordingly, the additional protective lid  68  may, in an alternative embodiment, be one or more of variable shape, thickness and/or material. In particular,  FIG. 7  also shows a protective lid  68  comprised of one single section, the section comprising an enlarged recess  74  which may be so shaped to access terminal studs  12  or ring tags  2 , 48 , operable in use to allow access to the components for electrical checks. However it may also be envisioned that the single section  68  be replaced by two or more sections such that a recesses is provided. It will however be appreciated that in a further embodiment, any such recesses or hole may be included within the cover  68  in order to access specific contacts or electrical components. 
         [0051]      FIG. 8  shows an isometric view of the connector and hinged lid  68  connected to the substrate  36  in accordance with the present disclosure and in accordance with the embodiment of  FIG. 7 . In particular,  FIG. 8  shows MI cable  16  feeding into the connector, and standard cable  50  feeding out of the connector. However, it will be appreciated that in a further embodiment, the connector may be used to connect a MI cable  16  to a further MI cable  16 , a standard cable  50  to a standard cable  50 , or any such combination comprising any such further cable or wire known to exist within the art.