Abstract:
A gas turbine engine installation is provided that has a plurality of flexible printed circuit board (FPCB) harnesses to transfer electrical signals, including electrical power, around a gas turbine engine. The plurality of FPCB harnesses is held to the gas turbine engine installation using generally U-shaped clips that have a base from which first and second sidewalls extend. The FPCB harness is held between the tips of base-teeth extending from the base, and side-teeth extending from the first and second sidewalls. In this way, the FPCB harness can be held securely in position by the clip.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from British Patent Application Number 1119040.2 filed 4 Nov. 2011, the entire contents of which are incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a network for distributing signals and power around a gas turbine engine using a flexible harness. In particular, this invention relates to clips for holding a flexible harness for a gas turbine engine. 
     2. Description of the Related Art 
     A typical gas turbine engine has a substantial number of electrical components which serve, for example, to sense operating parameters of the engine and/or to control actuators which operate devices in the engine. Such devices may, for example, control fuel flow, variable vanes and air bleed valves. The actuators may themselves be electrically powered, although some may be pneumatically or hydraulically powered, but controlled by electrical signals. 
     Electrical power, and signals to and from the individual electrical components, are commonly transmitted along conductors. Conventionally, such conductors may be in the form of wires and cables which are assembled together in a harness. In such a conventional harness, each wire may be surrounded by an insulating sleeve, which may be braided or have a braided cover. The connections between the individual components and the conventional harness are made, for example, by multi-pin plug and socket connectors. Similarly, communication between the harness and power, control and signalling circuitry is achieved through a multi-pin connector. 
     By way of example,  FIG. 1  of the accompanying drawings shows a typical gas turbine engine including two conventional wiring harnesses  102 ,  104 , each provided with a respective connector component  106 ,  108  for connection to circuitry accommodated within the airframe of an aircraft in which the engine is installed. 
     The harnesses  102 ,  104  are assembled from individual wires and cables which are held together over at least part of their lengths by suitable sleeving and/or braiding. Individual wires and cables, for example those indicated at  110 , emerge from the sleeving or braiding to terminate at plug or socket connector components  112  for cooperation with complementary socket or plug connector components  114  on, or connected to, the respective electrical components. 
     Each conventional harness  102 ,  104  therefore comprises a multitude of insulated wires and cables. This makes the conventional harness bulky, heavy and difficult to manipulate. It is desirable to reduce the size and weight of components on gas turbine engines, particularly, for example, gas turbine engines for use on vehicles, such as aircraft. 
     It is proposed to replace at least a portion of, for example all of, the conventional harness with a flexible printed circuit board harness (FPCB harness). An example of a portion of such a flexible printed circuit board harness  20  is shown in  FIGS. 2 to 5 .  FIG. 2  shows a perspective view of the FPCB harness portion, and  FIGS. 3 ,  4 , and  5  show side, top, and cross-sectional views respectively. 
     Such an FPCB harness  20  may comprise a flexible (for example elastically deformable) substrate  40  with conductive tracks  30  laid/formed therein. The FPCB harness  20  may thus be deformable. In the example shown in  FIGS. 2 to 5 , the FPCB harness  20  extends along a length in the x-direction, a width in the y-direction, and a thickness (or depth or height) in the z-direction. The x direction may be defined as the axial direction of the FPCB harness. Thus, the x-direction (and thus the z-direction) may change along the length of the FPCB harness  20  as the FPCB harness is deformed. This is illustrated in  FIG. 3 . The x-y surface(s) may be said to be the major surface(s) of the FPCB harness. In the example shown in  FIGS. 2 to 5 , the FPCB harness is deformable in the z direction, i.e. in a direction perpendicular to the major surface. FPCB harnesses may be additionally of alternatively deformable about any other direction, and/or may be twisted about any one or more of the x, y, or z directions. 
     The flexible substrate  40  may be a dielectric. By way of example, the substrate material may be, by way of example only, polyamide. As will be readily apparent, other suitable substrate material could alternatively be used. 
     The conductive tracks  30 , which may be surrounded by the substrate, may be formed using any suitable conductive material, such as, by way of example only, copper, although other materials could alternatively be used. The conductive tracks  30  may be used to conduct/transfer electrical signals and/or electrical power, for example around a gas turbine engine and/or to/from components of a gas turbine engine and/or an airframe attached to a gas turbine engine. The size (for example the cross-sectional area) and/or the shape of the conductive tracks  30  may depend on the signal to be transmitted through the particular conductive track  30 . Thus, the shape and/or size of the individual conductive tracks  30  may or may not be uniform in a FPCB harness  20 . 
     The example shown in  FIGS. 2 to 5  has 6 conductive tracks  30  running through the substrate  40 . However, the number of conductive tracks  30  running through a substrate  40  could be fewer than 6, or greater than 6. Indeed the number of conductive tracks  30  could be far greater than 6, for example tens or hundreds of tracks, as required. As such, many electrical signals and/or power transmission lines may be incorporated into a single FPCB harness. 
     A single FPCB harness  20  may comprise one layer of tracks, or more than one layer of tracks, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 layers of tracks. An FPCB harness may comprise significantly more than 10 layers of tracks, for example at least an order of magnitude more layers of tracks. In this regard, a layer of tracks may be defined as being a series of tracks that extend in the same x-y surface. Thus, the example shown in  FIGS. 2 to 5  comprises 2 layers of tracks  30 , with each layer comprising 3 tracks. 
     Using an FPCB harness to transmit electrical signals and/or power is therefore advantageous over a conventional harness, for example because of its reduced size, weight and/or complexity. 
     In order to attach a harness to a component (for example to a gas turbine engine or related airframe), a clip is required. An example of a clip that may be used to attach a conventional harness to a gas turbine engine is shown in  FIG. 7 . The clip  50  shown in  FIG. 7  is configured to hold a cable, or a bundle of cables which form at east a part of a conventional wire cable harness. The clip  50  has a generally cylindrical outer casing  52  with a diameter  58  and a structural internal element  54  configured to provide strength to the clip  50 . The clip  50  shown in  FIG. 7  also has teeth  56  configured to grasp the generally cylindrical conventional cable harness, although the teeth  56  may not be present in some conventional clips. 
       FIGS. 8 and 9  show an alternative clip  60  for holding a conventional cable harness. The clip  60  shown in  FIGS. 8 and 9  comprises two arms  64 ,  66  that define a space  62  therebetween for holding a conventional cable harness or bundle of cable harnesses. The space  62  defined between the two arms  64 ,  66  may be generally cylindrical. The two arms  64 ,  66  are sprung so as to be able to accommodate various diameters of conventional cable harnesses. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     FPCB harnesses have properties that present difficulties when considering how to attach them to components, for example of a gas turbine engine. For example, the FPCB harnesses may have mechanical properties that mean that known clips, such as those described above, are not suitable for attaching them to components. Purely by way of example only, the flexible substrate material may be relatively easily damaged (for example punctured or sliced) by conventional clips. 
     As explained herein, FPCB harnesses offer considerable advantages over conventional harness in terms of, amongst other things, size and weight. It is desirable to maximize this size/weight benefit by providing an attachment device for allowing the FPCB harnesses to be connected to components in a compact, efficient manner. Conventional clips are therefore not desirable, or even suitable. 
     According to the an aspect of the invention, there is provided a gas turbine engine installation comprising: a flexible printed circuit board harness arranged to transfer electrical signals around the engine installation: and at least one clip holding the printed circuit board harness, each clip comprising a generally U-shaped channel defined by a base with first and second sidewalls extending therefrom. The flexible printed circuit board harness is a thin, elongate member having upper and lower parallel major surfaces defined by a length and a width, and a thickness normal to the major surfaces. The first sidewall has a first side-tooth extending therefrom. The second sidewall has a second side-tooth extending therefrom. The base has a first set of base-teeth and a second set of base-teeth arranged such that a first portion of the flexible printed circuit board harness is gripped between tips of the first set of base-teeth and the first side-tooth, and a second portion of the flexible printed circuit board harness is gripped between tips of the second set of base-teeth and the second side-tooth. 
     Such an arrangement provides a particularly secure way of holding a FPCB harness and/or securing/attaching a FPCB harness to, for example, a gas turbine engine. The FPCB harness may be received by the generally U-shaped channel, and secured in position (or gripped) by the side-teeth and the base-teeth. 
     The electrical signals can be of any type that may be transmitted along electrical conductors, for example electrical power transmission, and/or signals (for example control signals) to, from or between components (for example electrical components) of the gas turbine engine installation. The FPCB harnesses for transmitting the electrical signals may be as described herein, for example with reference to  FIGS. 2 to 5 . 
     The first and second set of base-teeth may, in some cases, have no gap between them such that they form a continuous set of teeth extending from the base. 
     The flexible printed circuit board harness may be gripped at the first portion between the first set of base-teeth on its lower major surface and the first side-tooth on its upper major surface. The flexible printed circuit board harness may be gripped at the second portion between the second set of base-teeth on its lower major surface and the second side-tooth on its upper major surface. The first portion may extend over at least a part of one half of the width of the FPCB harness, and the second portion may extend over at least a part of the other half of the width of the FPCB harness. 
     Both the first set of base-teeth and the second set of base-teeth may comprise at least two teeth. For example, both the first set of base teeth and the second set of base-teeth may comprise two teeth, three teeth, four teeth, five teeth, or more than five teeth, for example at least ten teeth. This may allow the FPCB harness to be particularly securely gripped by the clip. However, some embodiments may only have a single tooth in both the first set of base-teeth and the second set of base-teeth. 
     The base of the clip may extend in a direction that is generally parallel to the upper and lower major surfaces of the flexible printed circuit board harness. As such, the FPCB harness may be conveniently accepted into the U-shaped channel, with the bottom of the U-shaped channel being formed by the base of the clip. 
     The teeth of the first and second set of base-teeth may extend (that is to say, from the base to the tip of each tooth) generally perpendicularly from the base. As such, the first and second set of base-teeth may point in a direction that is generally perpendicular to the loser major surface of the FPCB harness. 
     The first side-tooth and the second side-tooth may extend in a direction that is generally perpendicular to the direction of the teeth of the first and second set of base-teeth. As such, the first and second side-teeth may partially close, or restrict, the opening to the U-shaped channel. In other words, the first and second side-teeth may extend, from root to tip, in a direction that is substantially parallel to (or at least has a component parallel to) the plane of the base. As such the first and second side-teeth may act to reduce the possibility of (or substantially prevent) the FPCB falling out of the clip through the top, i.e. through the opening in the U-shape, through which it may be inserted into the clip. 
     The tips of the first and second side-teeth may be angled in a direction that has a component pointing towards the upper major surface of the flexible printed circuit board harness. This may allow the tips of the side-teeth to directly contact, and thus grip, the upper major surface of the FPCB harness. Additionally or alternatively, it may facilitate biasing of the side-teeth towards the FPCB harness. 
     The tips of the first and second set of base-teeth may not be directly opposed to the tips of the first and second side-teeth. As such, the tips of the base-teeth and side-teeth may be offset in a width direction of the FPCB harness being held by them. 
     There may be a gap between the tips of the side-teeth and the tips of the corresponding base-teeth prior to insertion of the flexible printed circuit board harness into the clip. The gap may be less than the thickness of the flexible printed circuit board harness. This gap may be said to be in the thickness direction of the FPCB harness. This may allow the base-teeth and side-teeth to grip the FPCB harness more effectively, for example due to the teeth being biased towards the FPCB harness during use. 
     The tips of the side-teeth and the tips of the corresponding base-teeth may be intermeshed prior to insertion of the flexible printed circuit board harness into the clip. As such, the tips of the side-teeth and the tips of the corresponding base-teeth may be said to overlap in the thickness direction of the FPCB harness. This may be convenient for gripping particularly thin FPCB harnesses. 
     The side-teeth and the base-teeth may be elongate elements. The side-teeth and the base-teeth may have a longitudinal axis extending parallel to the length direction of the flexible printed circuit board harness. Thus, the teeth may be arranged to contact and grip the FPCB harness along a length portion thereof, thereby securing the FPCB harness in position. 
     The base and the first and second sidewalls (including the base-teeth and the side-teeth) may be formed using a material comprising one or more of: ethylene-propylene rubber, a silicone based compound, and a nitrile material. These materials may provide good grip to a FPCB harness whilst being compliant so as to minimize the possibility of damage to the FPCB harness. The particular material may be chosen depending on the application, for example the environment (for example in terms of temperature variation) in which the dip is to be used and/or the type of FPCB harness it is to be used with. 
     The clip may comprise a support structure configured to resist changes in shape of the dip under operational loads. The support structure may be relatively more stiff than the base and the first and second sidewalls. As such, the support structure may help to reduce, or substantially prevent, flexing of the clip, for example flexing of the external shape of the clip. This may help to ensure that the base and first and second sidewalls retain the desired shape under load. For example, it may help to ensure that the base-teeth and the side-teeth are not forced apart when a load is applied to the clip, for example when a load is applied to a sidewall of the clip. This may help to ensure that the FPCB harness is clamped with the desired force. 
     The clip may comprise a main body that incorporates the base and the first and second sidewalls. Thus, the main body may also include the base-teeth and the side-teeth. The support structure may extend around at least a part of the main body. This may be a convenient arrangement for providing structural support to the clip. 
     The support structure may be formed using a material comprising metal and/or a composite/fibre resin. The support structure may thus be constructed using a material that is more stiff than the main body and/or the jaw of the clip. This may allow the clip to be structurally stiff, whilst retaining compliant teeth for gripping the FPCB harness. 
     The support structure may further comprise an attachment portion used to attach the clip to the gas turbine engine, or a component thereof. Thus, the clip can be particularly compact, with a minimal number of parts required to attach it (and thus a FPCB harness) to a component. This may have further weight and/or size benefits. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described, by way of example only, with reference to the accompanying Figures, in which: 
         FIG. 1  shows a gas turbine engine with a conventional harness; 
         FIG. 2  shows perspective view of a portion of a flexible printed circuit board harness; 
         FIG. 3  shows a side view of the flexible printed circuit board harness of  FIG. 2 ; 
         FIG. 4  shows a top view of the flexible printed circuit board harness of  FIG. 2 ; 
         FIG. 5  shows a cross-sectional view of the flexible printed circuit board harness of  FIG. 2 ; 
         FIG. 6  is a cross-section through a gas turbine engine; 
         FIG. 7  shows a side view of a clip for holding a conventional harness in place; 
         FIG. 8  shows a perspective view of an alternative clip for holding a conventional harness in place; 
         FIG. 9  shows a side view of the clip shown in  FIG. 8 ; 
         FIG. 10  shows a front view of clip in accordance with the present invention; 
         FIG. 11  shows a perspective view of a clip according to  FIG. 10 ; and 
         FIG. 12  shows the clip according to  FIGS. 10 and 11  holding a FPCB harness. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIG. 6 , a ducted fan gas turbine engine generally indicated at  19  has a principal and rotational axis X-X. The engine  10  comprises, in axial flow series, an air intake  11 , a propulsive fan  12 , an intermediate pressure compressor  13 , a high-pressure compressor  14 , combustion equipment  15 , a high-pressure turbine  16 , and intermediate pressure turbine  17 , a low-pressure turbine  18  and a core engine exhaust nozzle  19 . The engine also has a bypass duct  22  and a bypass exhaust nozzle  23 . 
     The gas turbine engine  10  works in a conventional manner so that air entering the intake  11  is accelerated by the fan  12  to produce two air flows: a first air flow A into the intermediate pressure compressor  13  and a second air flow B which passes through the bypass duct  22  to provide propulsive thrust. The intermediate pressure compressor  13  compresses the air flow A directed into it before delivering that air to the high pressure compressor  14  where further compression takes place. 
     The compressed air exhausted from the high-pressure compressor  14  is directed into the combustion equipment  15  where it is mixed with fuel and the mixture combusted. The resultant hot combustion products then expand through, and thereby drive the high, intermediate and low-pressure turbines  16 ,  17 ,  18  before being exhausted through the nozzle  19  to provide additional propulsive thrust. The high, intermediate and low-pressure turbines  16 ,  17 ,  18  respectively drive the high and intermediate pressure compressors  14 ,  13  and the fan  12  by suitable interconnecting shafts. 
     The gas turbine engine  10  shown in  FIG. 6  may be at least a part of a gas turbine engine installation according to the present invention. The gas turbine engine  10  may comprise one or more FPCB harnesses (such as those described above in relation to  FIGS. 2 to 5 ) for transmitting/transferring electrical signals around the engine and/or to/from the engine  10  from other components, such as components of an airframe. The function and/or construction of the FPCB harnesses may be as described above and elsewhere herein. 
     The FPCB harnesses may be attached to any part of the engine installation (of which the engine  10  may be a part) using a clip such as the clip  200  shown in  FIGS. 10 and 11 . Any one or more than one of the clips  200  could be used to hold one or more than one FPCB harness and thereby attach one or more FPCB harnesses to the engine. Other types of clip could be used in conjunction with that clip  200  shown in  FIGS. 10 and 11 .  FIG. 12  shows the clip  200  of  FIGS. 10 and 11  being used to hold a FPCB harness  20 . In  FIGS. 10 and 11 , the clip  200  is shown without any FPCB harness inserted, and thus in an undeformed state without any force applied to it. 
     The clip  200  has a base  210 , from which a first sidewall  220  and a second sidewall  230  extend. The base  210 , first sidewall  220 , and second sidewall  230  form a substantially U-shaped channel. 
     The base  210  comprises a first set of base-teeth  212  and a second set of base-teeth  216 . The first set of base-teeth  212  comprises two teeth  213 ,  214 , and the second set of base-teeth  216  comprises two teeth  217 ,  218 . In other embodiments, the first and second set of base-teeth  212 ,  216  may comprise other numbers of teeth. 
     The first sidewall  220  comprises a first side-tooth  222 . The second sidewall  230  comprises a second side-tooth  232 . The first and second side-teeth  222 ,  232  may partially block-off, or partially close, the entrance to the U-shaped channel, as clearly seen in  FIGS. 10 and 11 . The tips  223 ,  233  of the side-teeth  222 ,  232  are directed, or bent, towards the base  210 , i.e. towards the tips of the base-teeth  213 ,  214 ,  217 ,  218 . Thus, the tips  223 ,  233  of the side-teeth  222 ,  232  are directed, or bent, towards the FPCB harness  20  so as to grip the FPCB harness  20  when installed, as shown in  FIG. 12 . As such, the side-teeth  222 ,  232  may be said to have a hook, or bent, shape in cross-section. Other embodiments may have other shapes of side-teeth. 
     In the arrangement of  FIGS. 10 and 11 , the tip  223  of the first side-tooth  222  is between the teeth  213 ,  214  of the first set of base-teeth  212 . Similarly, the tip  233  of the second side-tooth  232  is between the teeth  217 ,  218  of the second set of base-teeth  216 . As such, in the undeformed state of  FIGS. 10 and 11 , the first and second side-teeth  222 ,  232  intermesh with the corresponding first and second set of base-teeth  212 ,  216 . In other embodiments, there may be a gap provided between the tips of the base-teeth  213 ,  214 ,  217 ,  218  and the tips  223 ,  223  of the side-teeth when the dip is in the undeformed state (i.e. when no FPCB harness is inserted into the clip). 
     During assembly, one side the FPCB harness  20  may be inserted into one side of the clip  200 , for example the left hand side as shown in  FIG. 10 . The other side of the FPCB harness  20  may then be pushed downwards into the other side for example right hand side shown in  FIG. 10 ) of the clip  200 , such that it displaces the side-tooth  222  and also displaces (for example compresses) the base-teeth  213 ,  214 . When the FPCB harness has been moved far enough down into the clip, by sufficient displacement of the base-teeth  213 ,  214 , the side-tooth  222  may then spring back into position. 
     As shown in  FIG. 12 , after insertion of the FPCB harness  20  into the clip  200  (which may be by the above method or any other method), the first and second sets of base-teeth  212 ,  216  grip the lower major surface  26  of the FPCB harness  20 , and the side teeth  222 ,  232  grip the upper major surface  24  of the FPCB harness  20 . In this regard, the upper and lower major surfaces  24 ,  26  extend in the length direction x and the width direction y of the FPCB harness  20 . The FPCB harness  20  is thus gripped on one side (i.e. over at least a part of one half of its width) between the first side-tooth  222  and the first set of base-teeth  212 , and on the other side (i.e. over at least a part of the other half of its width) between the second side-tooth  232  and second set of base-teeth  216 . 
     The base-teeth  213 ,  214 ,  217 ,  218  and the side-teeth  222 ,  232  in the clip  200  shown in  FIGS. 10 to 12  are elongate elements with a longitudinal axis extending in the length direction x of the FPCB harness  20  when installed. In the clip  200  of  FIGS. 10 to 12 , the base-teeth  213 ,  214 ,  217 ,  218  and the side-teeth  222 ,  232  have a constant cross-sectional shape that extends along their longitudinal axis. The tips of the base-teeth  213 ,  214 ,  217 ,  218  and the side-teeth  222 ,  232  grip the lower major surface  26  and the upper major surface  24  respectively along a portion (for example a thin portion, such as a line) extending in the length direction x of the FPCB harness  20 . 
     The clip  200  shown in  FIGS. 10 to 12  has a support structure  400 . The support structure provides support to the base  210  and first and second sidewalls  220 ,  230  of the clip  200  so as to restrict or minimize flexing/bending of the clip  200 . The support structure  400  may thus be stiffer, for example constructed from a stiffer material, than the main body of the clip  200 . The support structure  400  shown in the Figures is attached (for example bonded) to external surfaces of the base  210  and first and second sidewalls  220 ,  230  of the clip  200 . However, other arrangements of support structure  400  may be used. For example, the support structure may penetrate into the material of the base  210  and/or first and second sidewalls  220 ,  230  of the clip  200 . The support structure  400  shown in the Figures comprises two parts  410 ,  420 , that may be attached together (for example by welding) to produce the final support structure  400 . Again, other constructions could be used in clips for alternative embodiments. 
     The support structure  400  shown in the figures has an attachment portion  430  (which in the illustrated example comprises a hole for receiving a fixing element, such as a screw, bolt, or rivet) that is configured to allow the clip  200  to be attached to a component, for example of the gas turbine installation. As mentioned above, this may be a particularly convenient, lightweight and compact arrangement for connecting the clips  200 , and thus the FPCB harnesses  20 , to components. However, some clips for use in embodiments of the invention may not have a support structure  400  at all, or may have a support structure  400  without an attachment portion  430 . 
     Any suitable material may be used to manufacture the base  210  and first and second sidewalls  220 ,  230  of the clip  200 , which may include the base-teeth sets  212 ,  216  and the side-teeth  222 ,  232 . For example, the material may comprise one or more of ethylene-propylene rubber, a silicone based compound, and a nitrite material. In clips which have a support structure  400 , the support structure  400  may be constructed from a stiffer material than the base  210  and first and second sidewalls  220 ,  230 , for example from a metal and/or a resin/fibre composite. 
     The clip  200  could be any suitable size required to hold a FPCB harness  20 . Purely by way of non-limitative example, and with reference to  FIG. 11 , the length of the clip  200  may be in the range of from 5 mm to 200 mm, for example 10 mm to 150 mm, for example 25 mm to 100 mm, for example on the order of 50 mm. The width ‘w’ of the clip  200  may be in the range of from 5 mm to 500 mm, for example 10 mm to 200 mm, for example 25 mm to 100 mm, for example on the order of 50 mm. The height ‘h’ of the clip  200  may be in the range of from 0.5 mm to 50 mm for example 2 mm to 10 mm, for example 3 mm to 8 mm, for example on the order of 5 mm. In other embodiments, the dimensions ‘l’, ‘h’, and ‘w’ may be outside these ranges. 
     Where reference is made herein to a gas turbine engine installation, it will be appreciated that this term may include a gas turbine engine and/or any peripheral components to which the gas turbine engine may be connected to or interact with and/or any connections/interfaces with surrounding components, which may include, for example, an airframe and/or components thereof. Such connections with an airframe, which are encompassed by the term ‘gas turbine engine installation’ as used herein include, but are not limited to, pylons and mountings and their respective connections. The gas turbine engine itself may be any type of gas turbine engine, including, but not limited to, a turbofan (bypass) gas turbine engine, turbojet, turboprop, ramjet, scramjet or open rotor gas turbine engine, industrial 
     It will be appreciated that many alternative configurations and/or arrangements of the clip  200  other than those described herein may fall within the scope of the invention. For example, alternative arrangements of the first and second sets of base-teeth  212 ,  216 , side-teeth  232 ,  233  support structure  400 , and/or FPCB harness  20  may fall within the scope of the invention and may be readily apparent to the skilled person from the disclosure provided herein. Furthermore, any feature described and/or claimed herein may be combined with any other compatible feature described in relation to the same or another embodiment.