Patent Publication Number: US-2023145696-A1

Title: Cooling Apparatus

Description:
TECHNOLOGICAL FIELD 
     Embodiments of the present disclosure relate to cooling apparatus. Some relate to cooling apparatus for cooling mobile electronic apparatus during contactless charging. 
     BACKGROUND 
     Contactless charging of a mobile electronic apparatus can lead to unwanted to heat being generated at the mobile electronic apparatus. As charging rates increase this may increase the amount of unwanted heat that is generated. This can be problematic for the apparatus being charged as the excess heat could lead to damage of the battery or other components of the mobile electronic apparatus. 
     BRIEF SUMMARY 
     According to various, but not necessarily all, examples of the disclosure there is provided charging apparatus comprising: charging means for inductively charging a separate, mobile apparatus; flow path means for providing a flow path for a phase-change cooling fluid to an interface with the mobile apparatus so as to enable cooling of, at least part of, the mobile apparatus when the mobile apparatus is being inductively charged by the charging means; and wherein the flow path means comprises wick structures that enable the phase-change fluid to be transported via capillary action. 
     The charging apparatus may comprise evaporator means for enabling evaporation of the phase-change cooling fluid wherein the evaporator means are provided at the interface with the mobile apparatus so as to enable cooling of, at least part of, the mobile apparatus. 
     The evaporator means may comprise one or more porous protrusions. 
     The evaporator means may comprise an electrically insulating material. 
     The evaporator means may enable the phase-change cooling fluid to be evaporated into the atmosphere. 
     The charging apparatus may comprise storage means for storing the phase-change cooling fluid. 
     The storage means may comprise a capillary structure. 
     The charging apparatus may comprise condenser means for condensing phase-change cooling fluid from the atmosphere to enable the condensed phase-change cooling fluid to be provided to the flow path. 
     The condenser means may comprise at least one of thermoelectric heat pump, electrocaloric heat pump. 
     The condenser means may be thermally coupled to a heat distributor means for directing heat away from the condenser means. 
     The charging apparatus may comprise filter means for filtering phase-change cooling fluid condensed out of the atmosphere. 
     The charging apparatus may comprise a plurality of separate flow path means for providing flow paths for the phase-change cooling fluid when the charging apparatus is in different orientations. 
     The phase-change cooling fluid may comprise distilled water. 
     The apparatus may comprise cleaning means for cleaning the flow path means. The charging means may comprise one or more induction coils. 
     According to various, but not necessarily all, examples of the disclosure there is provided charging apparatus comprising: charging circuitry configured to inductively charge a separate, mobile apparatus; one or more flow paths configured to provide a flow path for a phase-change cooling fluid to an interface with the mobile apparatus so as to enable cooling of, at least part of, the mobile apparatus when the mobile apparatus is being inductively charged by the charging circuitry; and wherein the one or more flow paths comprise wick structures that enable the phase-change fluid to be transported via capillary action. 
     The charging apparatus may comprise evaporators configured to enable evaporation of the phase-change cooling fluid wherein the evaporator means are provided at the interface with the mobile apparatus so as to enable cooling of, at least part of, the mobile apparatus. 
     The charging apparatus may comprise storage configured to store the phase-change cooling fluid. 
     The charging apparatus may comprise one or more condensers configured to condense phase-change cooling fluid from the atmosphere to enable the condensed phase-change cooling fluid to be provided to the flow path. 
     The charging apparatus may comprise one or more filters configured to filter phase-change cooling fluid condensed out of the atmosphere. 
     According to various, but not necessarily all, examples of the disclosure there is provided a system comprising a charging apparatus as described above and at least one mobile apparatus configured to be charged by the charging apparatus. 
     According to various, but not necessarily all, examples of the disclosure there is provided a mobile apparatus comprising flow path means configured to receive phase-change cooling fluid from a charging apparatus. 
     The flow path means within the mobile apparatus may provide a flow path for phase-change cooling fluid from an interface with the charging apparatus to another location within the mobile apparatus. The another location may be a thermally critical location. 
     The flow path means within the mobile apparatus may comprise a wick structure 
    
    
     
       BRIEF DESCRIPTION 
       Some examples will now be described with reference to the accompanying drawings in which: 
         FIG.  1    shows an example apparatus; 
         FIG.  2    shows another example apparatus; and 
         FIG.  3    shows an example system. 
     
    
    
     DETAILED DESCRIPTION 
     Examples of the disclosure relate to a charging apparatus  101  for inductively charging a separate, mobile apparatus  201 . The charging apparatus  101  comprises a cooling system  103  which is configured to enable additional phase change cooling of the mobile apparatus  201  during inductive charging. 
       FIG.  1    shows an example charging apparatus  101  according to examples of the disclosure. The example charging apparatus  101  comprises charging means  105  and flow path means  107 . Only features referred to in the following description are shown in  FIG.  1    it is to be appreciated that the charging apparatus  101  could comprise additional features in other examples of the disclosure. 
     The charging means  105  may comprise any means which enable inductive charging of a separate, mobile apparatus when the mobile apparatus is positioned close to the charging apparatus  101 . In some examples the charging means  105  may comprise one or more induction coils  109 . The induction coils  109  may enable charging of the mobile apparatus by near-field inductive power transfer. 
     When the mobile apparatus is being charged it is positioned adjacent to the charging apparatus  101  so that a corresponding induction coil within the mobile apparatus can receive power from the induction coils  109  in the charging apparatus  101 . In the example of  FIG.  1    the mobile apparatus can be positioned on, or adjacent to, a surface  115  of the charging apparatus  101 . 
     The charging apparatus  101  also comprises a flow path means  107 . The flow path means  107  comprises any means which enables a phase-change cooling fluid  111  to be transported from one part of the charging apparatus  101  to another part. The flow path means  107  provides a flow path for the phase-change cooling fluid  111 . In some examples the flow path means  107  comprise a conduit for the phase-change cooling fluid  111  within the charging apparatus  101 . 
     The phase-change cooling fluid  111  comprises any suitable material which can undergo a phase change when it is transported to a position close to a charging mobile apparatus. In some examples the phase-change cooling fluid  111  can comprise distilled water. The distilled water has a large latent heat of vaporization which makes it suitable for use in the cooling system. Distilled water also has a high surface tension but low viscosity which enables if to flow through the wick structure by capillary action. Distilled water is also easily obtainable in that it can be condensed out of the atmosphere. 
     The flow path means  107  comprises wick structures. The wick structures extend for at least a portion of the flow path means  107 . The flow path means can comprise some portions that comprise wick structures and some portions that don&#39;t comprise wick structures. The wick structures comprise a plurality of capillary channels that enable phase-change cooling fluid  111  to be transported along the flow path means  107  via capillary action. The capillary action may enable the phase-change cooling fluid  111  to be transported to the interface with the mobile apparatus. 
     The interface with the mobile apparatus can comprise a region where the charging apparatus  101  contacts the mobile apparatus so as to enable inductive charging of the mobile apparatus. In some examples parts of the charging apparatus such as one or more evaporator structures can contact the mobile apparatus. In some examples a gap can be provided between the mobile apparatus and the charging apparatus at the interface. 
     In the example shown in  FIG.  1    the flow path means  107  is provided close to the surface  115  of the charging apparatus  101 . This helps to bring the phase-change cooling fluid  111  close to the mobile apparatus during use of the charging apparatus  101  and so helps to cool the mobile apparatus. The flow path means  107  is configured to transport the phase-change cooling fluid  111  to an interface with the mobile apparatus. In the example of  FIG.  1    the flow path means  107  is configured to transport the phase-change cooling fluid  111  to the surface  115  of the charging apparatus  101 . The surface  115  can provide an interface with the mobile apparatus. 
     In some examples the flow path means  107  can be configured so that, during use, the phase-change cooling fluid  111  is brought into direct contact with the mobile apparatus  101 . For instance, the phase-change cooling fluid  111  could be brought into contact with one or more surfaces of the mobile apparatus. In some exampled the flow path means  107  may enable the phase-change cooling fluid  111  to be transferred into a corresponding flow path means within the mobile apparatus. 
     The charging apparatus  101  can comprise one or more evaporator means which enable the phase-change cooling fluid  111  to be evaporated into the atmosphere. The evaporator means are coupled to the flow path means  107  so that phase-change cooling fluid  111  can flow from the flow path means  107  through the evaporator means and into the atmosphere. In other examples the flow path means  107  can comprise a closed circuit which retains the phase-change cooling fluid  111  within the flow path means  107 . In such examples a conduit may be provided from the interface with the mobile apparatus back to the flow path means  107  within the charging apparatus  101 . 
     The flow path means  107  is positioned within the charging apparatus  101  so that it does not interfere with the charging means  105 . The flow path means  107  can be configured so that the flow path means  107  does not intersect any of the coils  109  within the charging means  105 . 
     When the charging apparatus  101  is in use a mobile apparatus is positioned adjacent to the surface  115  of the charging apparatus  101  so that power can be transferred from the charging means  105  to a corresponding charging means in the mobile apparatus. This inductive charging generates heat at the interface between the charging apparatus  101  and the mobile apparatus. 
     The heat generated by the charging process creates an evaporator region  121  at the interface between the charging apparatus  101  and the mobile apparatus. At the evaporator region  121  heat generated by the charging process causes the phase-change cooling fluid  111  to evaporate and change phase from a liquid to a gas. The phase-change cooling fluid  111  in the gas phase will then flow to a region of lower vapour pressure and/or concentration and so will transfer heat away from the interface region and provide cooling to the mobile apparatus. 
     In the example shown in  FIG.  1    the evaporated phase-change cooling fluid  111  can flow into the ambient surroundings around the charging apparatus  101  as shown by the dotted lines  117 . In the example of  FIG.  1    the charging apparatus  101  also comprises a condenser region  123  which enables the phase-change cooling fluid  111  to be re-circulated back into the flow path means  105  after it has evaporated at the evaporator region  121 . The condenser region  123  has a cooler temperature than the evaporator region  121 . The cooler temperature of the condenser region  123  causes the phase-change cooling fluid  111  to condense into the liquid phase. In such examples the charging apparatus  101  can comprise a heat pump or any other suitable means to maintain the condenser region  123  at the lower temperature. In some such examples the charging apparatus  101  can also comprise a storage means for storing the phase-change cooling fluid  111  after it has been condensed from the atmosphere. 
     In other examples once the phase-change cooling fluid  111  has evaporated into the atmosphere it does not re-enter the charging apparatus  101 . This could occur if the charging apparatus  101  does not comprise a condenser region. This could also occur if the charging apparatus  101  is being used in surroundings which are too hot to enable the condenser region  123  to function correctly, for example, if the charging apparatus  101  is being used in a hot car. In these examples the charging apparatus  101  can comprise a storage means or reservoir for storing phase-change cooling fluid  111  for use during cooling. 
     In other examples the flow path means  107  can comprise one or more conduits which transfer the evaporated phase-change cooling fluid  111  back to the charging apparatus  101 . In some examples one or more conduits could be provided which enables the evaporated phase-change cooling fluid  111  to be transferred into the mobile apparatus. This may enable the phase-change cooling fluid  111  to be transferred to thermally critical locations within the mobile apparatus. 
       FIG.  2    illustrates a charging apparatus  101  being used to charge a separate mobile apparatus  201 . 
     The mobile apparatus  201  could be a mobile telephone, a laptop, a smart watch or any other suitable electronic mobile apparatus  201 . The mobile apparatus  201  is portable so that it can be easily carried by a user. The mobile apparatus  201  is separate to the charging apparatus  101  in that it can function independently of the charging apparatus  101 . 
     In the example shown in  FIG.  2    the mobile apparatus  201  comprises one or more induction coils  109 , a ferrite shield  211  a battery  207  and one or more electronic components  209 . Only components of the mobile apparatus  201  that are referred to in the following description are shown in  FIG.  2   . It is to be appreciated that the mobile apparatus  201  could comprise additional components that are not shown in  FIG.  2   . For instance, the mobile apparatus  201  could comprise components such as user interfaces and transceiver means. 
     The battery  207  comprises means for storing electrical charge within the mobile apparatus  201 . The battery  207  is configured to be charged by inductive charging. The battery  207  could be a Lithium ion battery, a Lithium polymer battery or any other suitable type of battery. 
     The battery  207  is configured to provide power to the electronic components  209  of the mobile apparatus  201 . The electronic components  209  could comprise processors, controllers or any other suitable types of electronic components. The batter  207  provides power to the electronic components  209  so that the mobile apparatus  201  can operate independently of the charging apparatus  201 . 
     The ferrite shield  211  is provided between the induction coils  109  and the battery  207  and electronic components  209 . The ferrite shield  211  protects the battery  207  and the electronic components  209  from the electromagnetic fields in the induction coils 
     The induction coil  109  is provided close to a surface of the mobile apparatus  201  so as to enable inductive charging of the battery  207  when the mobile apparatus  201  is positioned close to the charging apparatus  101 . 
     The charging apparatus comprises  101  comprises charging means  105  and flow path means  107 . 
     In the example of  FIG.  2    the charging means  105  comprises an induction coil  109  that is positioned close to the surface of the charging apparatus  101 . 
     The charging apparatus  101  also comprises a ferrite shield  211 . The ferrite shield  211  is positioned between the induction coil  109  and one or more electronic components  213  of the charging apparatus  101 . The ferrite shield  211  is configured to protect the one or more electronic components  213  from electromagnetic fields generated by the induction coil  109 . 
     In the example of  FIG.  2    the flow path means  107  provides a flow path from a storage means  225  to evaporator means  227 . 
     The storage means  225  can comprise any means which are configured to store the phase-change cooling fluid  111  within the charging apparatus  101 . The storage means  225  can comprise one or more reservoirs or any other suitable means. The storage means  225  can store the phase-change cooling fluid  111  in a liquid phase. In some examples the storage means  225  can comprise a capillary structure to prevent unwanted movement, or sloshing, of the phase-change cooling fluid  111  when it is in the liquid phase. Two storage means  225  are shown in the charging apparatus  101  of  FIG.  2   . Other numbers of storage means  225  can be provided in other examples of the disclosure. 
     The storage means  225  are positioned within the charging apparatus  101  and coupled to the flow path means  107  so as to enable phase-change cooling fluid  111  to flow from the storage means  225  to the flow path means  107 . The phase-change cooling fluid  111  can flow from the storage means  225  to the flow path means  107  via capillary action. 
     The flow path means  107  provides a conduit between the storage means  225  and the evaporator means  227 . The evaporator means  227  comprise means for enabling evaporation of the phase-change cooling fluid  111 . The evaporator means  227  are provided on the surface  115  of the charging apparatus  101 . The evaporator means  227  are positioned within the charging apparatus  101  so that, when the charging apparatus  101  is being used to charge a mobile apparatus  201 , the evaporator means  227  are provided at the interface between the charging apparatus  101  and the mobile apparatus  201  so as to enable cooling of, at least part of, the mobile apparatus  201 . In the example of  FIG.  2    the evaporator means  229  are provided on the surface of the charging apparatus  101  so that when the mobile apparatus  201  is being charged, the evaporator means  229  is adjacent to the mobile apparatus  201 . 
     In the example of  FIG.  2    the evaporator means  229  comprises a plurality of porous protrusions  231 . The porous protrusions  231  project out of the surface  115  of the charging apparatus  101 . When the mobile apparatus  201  is positioned for charging the porous protrusions  231  contact a surface of the mobile apparatus  201 . The height of the porous protrusions  231  ensures that an air gap  203  is provided between the mobile apparatus  201  and the charging apparatus  101 . 
     The porous protrusions  231  have a pore size that is smaller than the diameter of the wick structure within the flow path means  107 . This ensures that, as phase-change cooling fluid  111  is evaporated from the porous protrusions  231  the phase-change cooling fluid  111  is transported from the storage means  225  to the porous protrusions  231 . 
     The porous protrusions  231  of the evaporator means  227  can comprise any suitable material. In some examples the porous protrusions  231  can comprise an electrically insulating material so as not to interfere with the inductive charging process. 
     The porous protrusions  231  can be provided in any suitable configuration. In the examples shown in  FIG.  2    the porous protrusions  231  are spaced from each other so that there are gaps between the porous protrusions  231 . The gaps provide, at least partially, a route for the evaporated phase-change cooling fluid  111  so as to enable the evaporated phase-change cooling fluid  111  to flow away from the porous protrusions  231  and facilitate the transfer of heat away from the mobile apparatus  201 . 
     In the example shown in  FIG.  2    the evaporator means  227  is configured to enable the phase-change cooling fluid  111  to be evaporated into the atmosphere. In other examples the flow path means  107  could comprise a closed loop and the evaporator means  227  could enable the phase-change cooling fluid  111  to be evaporated into a conduit which returns the phase-change cooling fluid  111  to the storage means  225 . In other examples the evaporator means  227  could be configured to enable the phase-change cooling fluid  111  to be provided into a conduit within the mobile apparatus  201  itself. This could allow for transfer of the phase-change cooling fluid  111  from the charging apparatus  101  to the mobile apparatus  201 . 
     In the example of  FIG.  2    the charging apparatus  101  comprises condenser means  233  for condensing phase-change cooling fluid  111  from the atmosphere. In the example shown in  FIG.  2    this enables the phase-change cooling fluid  111  to circulate from the evaporator means  227  back into the storage means  225  and flow path means  109 , 
     In the example of  FIG.  2    the condenser means  233  comprises a heat pump  235 . The heat pump  235  is positioned adjacent to the storage means  225 . The heat pump  235  helps to maintain the storage means  225  at a lower temperature than the evaporator means  227 . This helps to maintain the phase-change cooling fluid  111  in a liquid state and ensures that the phase-change cooling fluid  111  flows from the storage means to the evaporator means  227 . 
     The heat pump  235  can comprise any means for transferring heat from the storage means  225  to a heat distributor means  237  or other thermal reservoir. The heat pump  235  could comprise a thermoelectric heat pump, electrocaloric heat pump or any other suitable type of heat pump. 
     The condenser means  233  is thermally coupled to the heat distributor means  237  for directing heat away from the condenser means  233 . The heat distributor means  237  can comprise a metal, a graphite-based material, a low-profile vapor chamber, an oscillating heat pipe, or any other suitable means. The heat distributor means  237  may enable heat to be transferred to a substrate that the charging apparatus  101  is mounted on or to any other suitable location. 
     In the example of  FIG.  2    the charging apparatus  201  also comprises filter means  239 . The filter means  239  for filtering phase-change cooling fluid  111  condensed out of the atmosphere. In the example of  FIG.  2    the filter means  239  are provided at an inlet to the storage means  225 . The filter means  239  help to prevent impurities from entering the storage means  225  and flow path means  107 . 
       FIG.  3    shows another example embodiment. In this embodiment the charging apparatus  101  can be as shown in  FIG.  1    and the mobile apparatus  201  comprises flow path means  301  within the mobile apparatus  201 . 
     The flow path means  301  within the mobile apparatus  201  provide a flow path for phase-change cooling fluid  111  from the interface with the charging apparatus  101  to another location within the mobile apparatus  201 . The another location could be a thermally critical location such as location close to the battery  207  or a thermally sensitive electronic component. 
     The flow path means  301  within the mobile apparatus  201  comprises a wick structure so as to enable the phase-change cooling fluid  111  to flow though the flow path means  301  via capillary action. 
     The flow path means  301  couples the interface between the mobile apparatus  201  and the charging apparatus  101  with an evaporator means  303  within the mobile apparatus  201 . The evaporator means  303  could comprise any structure that is configured to enable the phase-change cooling fluid  111  to be evaporated so as to transfer heat away from the region around the evaporator means  303 . 
     In this example the interface between the charging apparatus  101  and the mobile apparatus  201  enables the phase-change cooling fluid  111  to flow from the charging apparatus  101  to the mobile apparatus  201 . In some examples the charging apparatus  101  could comprise a condenser means to enable phase-change cooling fluid  111  to be condensed from the atmosphere to refill the flow path means  107  and any storage means  225  within the charging apparatus  101 . 
     The configuration shown in  FIG.  3    enables cooling of thermally critical components of the mobile apparatus  201 . In other examples the phase-change cooling fluid  111  could be transferred from the charging apparatus  101  to the mobile apparatus  201  so as to enable charging of a thermal battery within the mobile apparatus  201 . 
     It is to be appreciated that examples of the disclosure could comprise variations and modifications to the examples described above. For instance, in some examples the charging apparatus  101  can comprise cleaning means for cleaning the flow path means  107 . The cleaning means could comprise titanium dioxide or any other suitable means which can act to clean the capillary structures of the flow path means  107  and porous structures  231  when exposed to ambient ultra-violet (UV) light. In some examples the cleaning means could comprise means for preventing biological growth within the flow path means  107  and porous structures  231 . In these examples the cleaning means could comprise one or more light emitting diodes configured to provide UV-C light, copper particles, silver particles or any other suitable means. 
     In some examples the charging apparatus  101  could be configured to switch between different modes of operation. For example, the charging apparatus  101  shown in  FIG.  2    can operate in a closed loop mode or in an open mode. In the closed loop mode the phase-change cooling fluid  111  is circulated from the evaporator means  227  back into the storage means  225  and flow path means  107  via the condenser means  233 . In the open mode the phase-change cooling fluid  111  could be evaporated into the atmosphere and not returned to the storage means  225  or flow path means  107 . The open mode could be used if the ambient temperature is too high for the condenser means  223  to operate effectively. In such examples the charging apparatus  201  could comprise sensor means for sensing the ambient temperatures. If the ambient temperature is determined to be above a threshold of operation for the condenser means  233  then the charging apparatus  101  can turn the heat pump off  235  and enable the charging apparatus  101  to operate in the open mode. 
     If the charging apparatus  101  is to be operated in open mode then the storage means  225  need to contain sufficient phase-change cooling fluid  111  to maintain cooling of the mobile apparatus  201  while it is being charged. As an example, if the mobile apparatus  201  has a battery  207  with an energy capacity of 40 kJ and the inductive charging is 75% efficient then an energy load of 10 kJ will need to be dissipated by the phase-change cooling fluid  111 . If distilled water with a latent heat of 2, 260 kJ/kg is used this would require a mass of approximately 4.5 g of distilled water. This is similar in volume to a teaspoon. 
     In the examples shown the charging apparatus  101  is used in a horizontal configuration and so the phase-change cooling fluid  111  does not need to do any work against gravity as it is transported along the flow path means  107 . In other examples the charging apparatus  101  could comprise a plurality of different flow path means  107  coupled to different storage means  225 . The different flow path means  107  and storage means  225  can be separate from each other so that the phase-change cooling fluid  111  does not flow between the different flow path means  107  within the charging apparatus  101 . The different flow path means  107  can be configured to that the phase-change cooling fluid  111  can still be transported to the interface with the mobile apparatus  201  even when the charging apparatus  101  is in a vertical orientation as this would provide lower pressures within the phase-change cooling fluid  111  as compared to a single interconnected flow path means  107 . 
     In the examples of the disclosure the phase-change cooling fluid  111  is transported through the flow path means  107  via capillary action. In other examples a small-scale fluid pump could be provided within the charging apparatus  101  so as to assist with the transport of the phase-change cooling fluid  111 . 
     Examples of the disclosure therefore enable cooling of a mobile apparatus  201  during indictive charging. The use of a phase-change cooling fluid  111  such as distilled water enables the heat to be transferred away from the mobile apparatus by the phase-change cooling fluid  111 . Using distilled water as the phase-change cooling fluid  111  ensures that a supply of the phase-change cooling fluid  111  can be obtained from the atmosphere. 
     The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one . . . ” or by using “consisting”. 
     In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’, ‘can’ or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example. 
     Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims. 
     Features described in the preceding description may be used in combinations other than the combinations explicitly described above. 
     Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. 
     Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not. 
     The term ‘a’ or ‘the’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use ‘a’ or ‘the’ with an exclusive meaning then it will be made clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning. 
     The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result. 
     In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described. 
     Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the Applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not emphasis has been placed thereon.