Patent Publication Number: US-11646559-B2

Title: Configurable electrical receptacles

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the benefit of priority as a continuation patent of U.S. Ser. No. 16/947,174 filed Jul. 21, 2020 entitled “Configurable Electrical Receptacles” which itself claims the benefit of priority of U.S. patent application Ser. No. 16/011,212 filed 18 Jun. 2018 entitled “Configurable Electrical Receptacles” which itself claims the benefit of priority from U.S. Provisional Patent Application 62/524,735 filed 26 Jun. 2017 entitled “Configurable Electrical Receptacles”, the entire contents of each being incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This patent application relates to configurable electrical receptacles and more particularly to electrical receptacles that accept in-situ replacement of an insert providing a specific functionality within an electrical receptacle which is configurable to function or user accessible feature. 
     BACKGROUND OF THE INVENTION 
     Home automation or smart homes (also known as domotics) refers to building automation for the home. It involves the control and automation of lighting, heating (such as smart thermostats), ventilation, air conditioning (HVAC), and security, as well as home appliances such as washer/dryers, ovens or refrigerators/freezers. Wi-Fi is often used for remote monitoring and control. Home devices, when remotely monitored and controlled via the Internet, are an important constituent of the Internet of Things. Modern systems generally consist of switches and sensors connected to a central hub sometimes called a “gateway” from which the system is controlled with a user interface that is interacted either with a wall-mounted terminal, mobile phone software, tablet computer or a web interface, often but not always via Internet cloud services. 
     Whilst today there are many competing vendors, there are very few worldwide accepted industry standards and the home automation market is heavily fragmented. Popular communications protocol for products include X10, Ethernet, RS-485, 6LoWPAN, Bluetooth LE (BLE), ZigBee and Z-Wave, or other proprietary protocols all of which are incompatible with each other. Manufacturers often prevent independent implementations by withholding documentation. The home automation market was worth approximately US$5.75 billion in 2015 and is predicted to have a market value over US$10 billion by the year 2020. 
     Home automation represents part of the building automation environment as in addition to residential deployments there are markets for commercial environments, manufacturing environments, public buildings, and retail environments. Typically, each element within such automation deployments is undertaken as a discrete deployment such that electrical power distribution for consumption, electrical power and switching for lighting, environmental sensors, security sensors etc. are all discrete. 
     Within the prior art approaches to combine disparate functionality within a single electrical receptacle exist such as those presented within U.S. Pat. Nos. 5,473,517; 6,010,288; 6,000,807; 6,045,232; and 6,805,469. These seeking to simply combine emergency lighting within electrical wall receptacles. 
     Accordingly, one of the inventors established a concept depicted and described in respect of  FIG.  1    wherein an electrical mains outlet receptacle was modified to accept a replaceable insert which provided a functionality according to the insert employed. Such inserts including, for example, elements comprising an optical emitter (e.g. LED lighting), an optical sensor, a chemical sensor, a biological sensor, a motion sensor, a rechargeable battery, a gas detector, a microphone, a loudspeaker, a DC power socket (e.g. USB), a low voltage power socket (e.g. 12V), wireless router, wireless networking interface, telecommunications network jack, and a telecommunications socket. This concept being presented within U.S. Pat. Nos. 8,496,342; 9,083,126; 9,214,773; and 9,520,671 wherein the insert is replaceable once the electrical receptacle has been installed and the cover plate attached. Accordingly, functionality can be defined once the building is wired according to the requirements of the owner/occupier and then subsequently revised according to the evolving requirements of the owner/occupier or a new owner/occupier etc. 
     However, it would be beneficial to enhance and extend such a methodology to support other electrical receptacles, such as switch receptacles for example, as well as providing configurable electrical receptacles that then support reconfiguration through the replaceable insert. In this manner, the electrical receptacles are defined to a first level when installed, e.g. power outlet or electrical switch, and then subsequently defined at a second level once the cover plate etc. have been attached. 
     Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to mitigate limitations within the prior art relating to configurable electrical receptacles and more particularly to electrical receptacles that accept in-situ replacement of an insert providing a specific functionality within an electrical receptacle which is configurable to function or user accessible feature. 
     In accordance with an embodiment of the invention there is provided a device for use in conjunction with a conventional electrical utility work box and a faceplate comprising:
     a housing to fit within an electrical utility work box comprising at least a front face; the housing comprising;   a first mounting means to affix the housing to the electrical utility work box;   a second mounting means to affix the faceplate to the housing;   a plurality of electrical interfaces, each electrical interface allowing connection to a predetermined electrical signal forming part of an electrical lighting circuit; and   a cavity disposed within the front face of the housing allowing the insertion and removal of a demountable insert into and from the front face of the housing when the housing is mounted within the electrical utility work box with the faceplate attached and comprising a first part of a retention means to retain the demountable insert when inserted into the cavity, the cavity accessible through a first opening in the faceplate and comprising a plurality of first contacts, each first contact electrically coupled to a predetermined electrical interface of the housing; wherein   the demountable insert is sized for insertion into the cavity within the front face of the housing and capable of insertion and removal when the faceplate is attached to the housing, the demountable insert comprising a second part of the retention means to retain the demountable insert when inserted into the cavity.   

     In accordance with an embodiment of the invention there is provided a device for use in conjunction with a conventional electrical utility work box and a faceplate comprising:
     a housing to fit within an electrical utility work box comprising at least a front face; the housing comprising;
       a first mounting means to affix the housing to the electrical utility work box;   a second mounting means to affix the faceplate to the housing;   
       a plurality of electrical interfaces, each electrical interface allowing connection to a predetermined electrical signal forming part of an electrical lighting circuit;   a first cavity disposed within the front face of the housing allowing the insertion and removal of a first demountable insert into and from the front face of the housing when the housing is mounted within the electrical utility work box with the faceplate removed;   a second cavity disposed within the front face of the housing allowing the insertion and removal of a second demountable insert into and from the front face of the housing when the housing is mounted within the electrical utility work box with the faceplate attached.   

     In accordance with an embodiment of the invention there is provided a device for use in conjunction with a conventional electrical utility work box and a faceplate comprising:
     a housing to fit within an electrical utility work box comprising at least a front face; the housing comprising;
       a first mounting means to affix the housing to the electrical utility work box;   a second mounting means to affix the faceplate to the housing;   
       an electrical element providing a predetermined electrical function;   a plurality of electrical interfaces, each electrical interface allowing connection to a predetermined electrical signal forming part of an electrical circuit; and   a cavity disposed within the front face of the housing allowing the insertion and removal of a demountable insert into and from the front face of the housing when the housing is mounted within the electrical utility work box with the faceplate attached and comprising a first part of a retention means to retain the demountable insert when inserted into the cavity, the cavity accessible through a first opening in the faceplate and comprising a plurality of first contacts, each first contact electrically coupled to a predetermined electrical interface of the housing; wherein   the demountable insert is sized for insertion into the cavity within the front face of the housing and capable of insertion and removal when the faceplate is attached to the housing, the demountable insert comprising a second part of the retention means to retain the demountable insert when inserted into the cavity.   

     Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein: 
         FIG.  1 A  depicts a work box, receptacle and faceplate according to the prior art of the inventor; 
         FIG.  1 B  depicts a configurable electrical receptacle according to the prior art of the inventor; 
         FIG.  2    depicts a configurable electrical switch receptacle according to an embodiment of the invention; 
         FIG.  3    depicts restriction of inserts to electrical receptacles only, electrical switches only, and both electrical receptacles and switches according to an embodiment of the invention; 
         FIG.  4 A  depicts a configuration of insert and receptacle circuit board supporting restriction of receptacles such as depicted in  FIG.  3    according to an embodiment of the invention; 
         FIG.  4 B  depicts an exemplary pin—hole configuration for achieving the insert restrictions according to  FIG.  3    according to an embodiment of the invention; 
         FIG.  5    depicts an edge connection between the insert and receptacle circuit board according to an embodiment of the invention; 
         FIG.  6    depicts an internal ground bar configuration according to an embodiment of the invention providing grounding of the insert prior to electrical connectivity with the receptacle circuit board; 
         FIG.  7    depicts a sequential break down of an electrical receptacle according to an embodiment of the invention; 
         FIG.  8 A  depicts a configurable electrical receptacle according to an embodiment of the invention wherein the installed functionality can be set at installation leaving the post-installation receptacle configuration; 
         FIG.  8 B  depicts a configurable electrical receptacle according to an embodiment of the invention wherein the installed functionality can be set at installation leaving the post-installation receptacle configuration; 
         FIG.  9    depicts the configurable electrical receptacle and cover of the embodiment of the invention depicted in  FIG.  8 A ; 
         FIG.  10    depicts a configurable switch receptacle according to an embodiment of the invention wherein the installed functionality can be set at installation leaving the post-installation receptacle configuration; 
         FIG.  11    depicts a configurable receptacle and cover according to an embodiment of the invention; and 
         FIG.  12    depicts configurable receptacles according to embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention is directed to configurable electrical receptacles and more particularly to electrical receptacles that accept in-situ replacement of an insert providing a specific functionality within an electrical receptacle which is configurable to function or user accessible feature. 
     The ensuing description provides representative embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the embodiment(s) will provide those skilled in the art with an enabling description for implementing an embodiment or embodiments of the invention. It being understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims. Accordingly, an embodiment is an example or implementation of the inventions and not the sole implementation. Various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention can also be implemented in a single embodiment or any combination of embodiments. 
     Reference in the specification to “one embodiment”, “an embodiment”, “some embodiments” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment, but not necessarily all embodiments, of the inventions. The phraseology and terminology employed herein is not to be construed as limiting but is for descriptive purpose only. It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not to be construed as there being only one of that element. It is to be understood that where the specification states that a component feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included. 
     Reference to terms such as “left”, “right”, “top”, “bottom”, “front” and “back” are intended for use in respect to the orientation of the particular feature, structure, or element within the figures depicting embodiments of the invention. It would be evident that such directional terminology with respect to the actual use of a device has no specific meaning as the device can be employed in a multiplicity of orientations by the user or users. 
     Reference to terms “including”, “comprising”, “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, integers or groups thereof and that the terms are not to be construed as specifying components, features, steps or integers. Likewise, the phrase “consisting essentially of”, and grammatical variants thereof, when used herein is not to be construed as excluding additional components, steps, features integers or groups thereof but rather that the additional features, integers, steps, components or groups thereof do not materially alter the basic and novel characteristics of the claimed composition, device or method. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element. 
     An “electrical receptacle” as used herein and throughout this disclosure refers to, but is not limited, to a housing design designed to be inserted into a work box/electrical utility work box and connected to one or more electrical cables providing power distribution/signal distribution within the environment exploiting embodiments of the invention which may for example be residential, commercial, industrial, entertainment and retail for example. An electrical receptacle may be manufactured with a predetermined function, e.g. electrical outlet or lighting switch, or it may be configurable as described below in respect of embodiments of the invention. 
     An “electrical receptacle” as used herein and throughout this disclosure refers to, but is not limited to, simplex, duplex, commercial grade, residential (decorator) grade, hospital grade, ground fault circuit interrupter (GFCI), surge protective, arc fault circuit interrupter (AFCI), and tamper resistant. Electrical receptacles may be 110V/120V, 220V/230V/240V, 50 Hz, 60 Hz, 5 A, 6 A, 10 A, 13 A, 15 A, polarized, unpolarised, earthed, fused, ground fault interrupted and arc circuit interrupted. Typically, the electrical receptacle will include a retention means for fastening a faceplate onto the electrical receptacle covering the exposed portions of the electrical receptacle/electrical utility work box. 
     A “work box” or “electrical utility work box” as used herein and throughout this disclosure refers to, but is not limited to, the housing that an electrical receptacle is assembled into. As such a work box can include so-called handy box, junction box, new work boxes, old work boxes, outdoor boxes, standard rectangular boxes, square boxes, circular or octagonal boxes, and a ceiling box. A work box may be formed from metal, plastic or PVC. Some electrical utility work boxes are defined as being 1-gang/2-gang/3-gang/4-gang etc. which defines the width such that they may contain multiple electrical receptacles as a typical electrical power outlet or electrical switch is 1-gang wide (i.e. they can be ganged together within the work box). 
     An “electrical outlet” as used herein and throughout this disclosure refers to, but is not limited to, an electrical receptacle that is configured for providing electrical power, typically at so-called “mains” voltage being that supplied to the environment the outlet is deployed within by the electrical distribution network. As such the “mains” voltage is defined by region/country globally. Electrical receptacles may be 110V/120V, 220V/230V/240V, 50 Hz, 60 Hz, 5 A, 6 A, 10 A, 13 A, 15 A, polarized, unpolarised, earthed, fused, employ insulated pins, have an even number of pins, and have an odd or even number of pins etc. and employ ground fault and/or arc fault interrupter circuits that trigger under predetermined conditions to disable the outlet until the fault is corrected and the circuit reset. However, electrical outlets may provide DC power or AC power at a different current and/or voltage than that to which they are connected depending upon their configuration. 
     A “switch receptacle” as used herein and throughout this disclosure refers to, but is not limited to, an electrical receptacle that is configured for providing switching functionality, e.g. turning on/off a light or lights or an electrical device/system for which the switching functionality controls power. A switch receptacle may provide control of an electrical distribution circuit, e.g. be a circuit breaker, or distribution panel comprising other switch receptacles, e.g. circuit breakers. Accordingly, a switch receptacle may vary, for example, in the number of switches and their wired interconnection(s) such that the switch may be single pole, double pole, etc. The switch may control the same voltage and/or current as that which powers the switch receptacle to provide the inserts with functionality or alternatively, the switch may control connection and/or disconnection of a system at a different voltage either derived from the power supply that powers the receptacle or coupled to the switch receptacle via a separate connection. Accordingly, a switch may be powered from and/or controlling an electrical circuit at 110V/120V, 220V/230V/240V, 50 Hz, 60 Hz, 5 A, 6 A, 10 A, 13 A, 15 A, alternating current (AC), direct current (DC), 12V, 24V, and 48V. 
     A “plug” as used herein and throughout this disclosure refers to, but is not limited to, one half of an electrical connector with the other half being the socket. The plug is usually considered the male portion of an electrical connector and comprises one or more pins or jacks that are designed to mate with their corresponding socket. 
     A “socket” as used herein and throughout this disclosure refers to, but is not limited to, one half of an electrical connector with the other half being the plug. The socket is usually considered the female portion of an electrical connector and comprises one or more openings that are designed to mate with their corresponding plug pins or jack. 
     An “electrical connector” as used herein and throughout this disclosure refers to, but is not limited to an electro-mechanical device used to join electrical terminations and create an electrical circuit. Electrical connectors typically consist of plugs (male-ended) and jacks (female-ended). The connection may be made/unmade manually or may require a tool for assembly and removal. 
     A “faceplate” (also referred to as wall plate, outlet cover, or socket cover) as used herein and throughout this disclosure refers to, but is not limited to, a typically plastic cover designed to fit around and/or over an electrical receptacle or switch receptacle and enclose said receptacle within the work box whilst overlapping the surrounding wall/ceiling etc. to provide an aesthetically and/or functional cover. Some faceplates may include a cover to protect the socket when not in use such as in wet outdoor environments for example. 
     An “electrical contact” as used herein and throughout this disclosure refers to, but is not limited to, an electrical connection between a first element (e.g. a pin of a plug) with a second element (e.g. a receptacle within a socket). Such electrical contacts may be around the periphery of the pin, on a particular surface of the pin, or particular surface of the pin. Some electrical contacts may be sprung to maintain connection over a range of relative positions of the two elements. 
     A “demountable insert” or “insert” as used herein and throughout this disclosure refers to, but is not limited to, an assembly designed to be inserted within an opening/recess within an electrical and/or switch receptacle. Accordingly, a demountable insert may be inserted/removed through the faceplate without requiring the removal of the face plate. 
     A “retention means” as used herein and throughout this disclosure refers to, but is not limited to, a means of attaching one element to another element. As such a retention means may include, but not be limited, a screw, a bolt, a nut and bolt, a latch, a screw, and a clip. 
     An “electrical supply” as used herein and throughout this disclosure refers to, but is not limited to, an electrical power supply to which an electrical receptacle or switch receptacle is connected in order to provide electrical power for the receptacle, it&#39;s user accessible features such as a socket, switch, etc. and the provide power to the demountable insert(s) supported by the electrical receptacle. In most instances the electrical supply is the general-purpose alternating-current (AC) electric power supply received at the residence, retail building, office, commercial building etc. However, in other instances it may be a different AC electrical power supply derived from the general-purpose AC or another power supply such as a generator. In other instances, the electrical supply may be a direct-current (DC) electrical supply. General-purpose AC is typically 110V/120V or 220V/230V/240V at either 50 Hz or 60 Hz. However, in other instances it may be at other frequencies such as 400 Hz for example in avionics applications. 
     A “wireless standard” as used herein and throughout this disclosure refers to, but is not limited to, a standard for transmitting signals and/or data through electromagnetic radiation which may be optical, radio-frequency (RF) or microwave although typically RF wireless systems and techniques dominate. A wireless standard may be defined globally, nationally, or specific to an equipment manufacturer or set of equipment manufacturers. Dominant wireless standards at present include, but are not limited to IEEE 802.11, IEEE 802.15, IEEE 802.16, IEEE 802.20, UMTS, GSM 850, GSM 900, GSM 1800, GSM 1900, GPRS, ITU-R 5.138, ITU-R 5.150, ITU-R 5.280, IMT-1000, Bluetooth, Wi-Fi, Ultra-Wideband and WiMAX. Some standards may be a conglomeration of sub-standards such as IEEE 802.11 which may refer to, but is not limited to, IEEE 802.1a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.11n as well as others under the IEEE 802.11 umbrella. 
     A “wired standard” as used herein and throughout this disclosure, generally refer to, but is not limited to, a standard for transmitting signals and/or data through an electrical cable discretely or in combination with another signal. Such wired standards may include, but are not limited to, digital subscriber loop (DSL), Dial-Up (exploiting the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP)), Data Over Cable Service Interface Specification (DOCSIS), Ethernet, Gigabit home networking (G.hn), Integrated Services Digital Network (ISDN), Multimedia over Coax Alliance (MoCA), and Power Line Communication (PLC, wherein data is overlaid to AC/DC power supply). In some embodiments a “wired standard” may refer to, but is not limited to, exploiting an optical cable and optical interfaces such as within Passive Optical Networks (PONs) for example. 
     A “user” as used herein may refer to, but is not limited to, but is not limited to, an individual or group of individuals. This includes, but is not limited to, private individuals, employees of organizations and/or enterprises, members of community organizations, members of charity organizations, men, women and children. In its broadest sense the user may further include, but not be limited to, mechanical systems, robotic systems, android systems, etc. that may be characterised by an ability to exploit one or more embodiments of the invention. 
     A “sensor” as used herein may refer to, but is not limited to, a transducer providing an electrical output generated in dependence upon a magnitude of a measurand selected from the group comprising, but is not limited to, environmental sensors, medical sensors, biological sensors, chemical sensors, ambient environment sensors, position sensors, motion sensors, thermal sensors, infrared sensors, visible sensors, RFID sensors, and medical testing and diagnosis devices. 
       FIG.  1 A  depicts a work box, receptacle and faceplate according to the prior art of the inventor which provide a mechanism for making use of standard building wiring to provide additional functionality. As depicted in  FIG.  1 A  an electrical receptacle  100 A is provided which allows for an insert to be inserted into a cavity within the receptacle body. As depicted the standard electrical receptacle provides two outlets and is installed into an electrical utility work box  1100  once the electrical supply is coupled to the electrical receptacle  100 A via an electrical cable that is fed through an opening within the electrical utility work box  1100  which may be defined or established through an installing user selecting one “push-out” of a plurality of “push-outs” provided within the body of the electrical utility work box  1100 . Once the electrical receptacle  100 A is inserted into the electrical utility work box  1100  and retained in position, e.g. via bolts at upper and lower locations then a faceplate  1200  is typically applied. 
     Once the electrical receptacle  100 A has been connected to the electrical supply and inserted into the electrical utility work box  1100  and the faceplate  1200  attached then an initial blank cover  1300  for the cavity can be replaced with a replaceable insert such as depicted in  FIG.  1 B . Referring to  FIG.  1 B  there is depicted a configurable electrical receptacle  1000  comprising an electrical receptacle  100  which features a receptacle body  110  within which are disposed a pair of electrical sockets  120  and a cavity  130 . The configurable electrical receptacle  1000  being attached to the electrical utility work box, not shown for clarity, via the ground strap  140 . A replaceable insert may be disposed within the cavity  130  such as inserts  150 A to  150 N respectively which may comprise a blank insert  150 A, Wi-Fi node  150 B, nightlight  150 C, motion detector  150 D and smoke detector  150 N. Accordingly, electrical receptacle  1000  provides dual electrical sockets and a user selectable function with the one of the plurality of inserts  150 A to  150 N respectively. 
     In common with this approach embodiments of the invention may be designed with dimensions and retaining feature positions etc. to function with industry standard receptacle boxes and faceplates. Due to the position of the electrical receptacle cavity between the pair of electrical outlets the faceplate is similarly attached via upper and lower retaining features, e.g. bolts to threaded portions of the electrical receptacle. As will become evident in respect of  FIGS.  2  to  12    other designs may support faceplates with alternate mounting positions and “cut-out” design such as a single central retaining means for example. 
     Now referring to  FIG.  2    depicts a configurable switch receptacle  2000  according to an embodiment of the invention which comprises a switch receptacle  200  which features a receptacle body  210  within which is an electrical switch  220  and a cavity  130 . The configurable switch receptacle  2000  being attached to the electrical utility work box, not shown for clarity, via the ground strap  140 . A replaceable insert may be disposed within the cavity  130  such as inserts  250 A to  250 N respectively which may comprise a blank insert  250 A, motion detector  250 B, light  250 C, Bluetooth 250D and USB charger  250 N. Accordingly, switch receptacle  2000  as depicted provides a push type electrical switch  220  with an illuminated element to indicate status and a user selectable function with the one of the plurality of inserts  250 A to  250 N respectively. 
     Now referring to  FIG.  3    there are depicted application of insert restrictions to electrical receptacles only, electrical switches only, and both electrical receptacles and switches according to an embodiment of the invention. Accordingly, an electrical receptacle  100  is depicted wherein inserts from first insert group  300 A and second insert group  300 B can be inserted into its cavity and make the appropriate electrical and mechanical connections to power the insert and form configurable electrical receptacle  1000 . Similarly, switch receptacle  200  may be employed in combination with an insert selected from the second insert group  300 B and third insert group  300 C which when into the cavity makes the appropriate electrical and mechanical connections to power the insert and form and provide configurable switch receptacle  2000 . Accordingly, three classes of insert are defined:
         First class  300 A which fit the electrical receptacle  100  only;   Second class  300 A which fit either the electrical receptacle  100  or switch receptacle  200 ; and   Third class  300 C which fit the switch receptacle  200  only.       

     Referring to  FIG.  4    there is depicted a configuration of insert and receptacle circuit board supporting restriction of receptacles such as depicted in  FIG.  3    according to an embodiment of the invention. Referring to first image  400 A there is depicted a perspective view of parts of the receptacle, e.g. receptacle  100  and insert  150 / 250 . The receptacle portion depicted being the main PCB  450 . As depicted the insert portion comprises insert shell  410 , insert PCB  420 , insert latches  440  and USB socket  430  as the insert  150 / 250  provides a USB charger wherein the insert PCB  420  provides a stabilized USB interface supporting power and data. Optionally, a USB insert may be solely for charging an electrical device or it may support data communications through the USB to a device connected to it by a user which are then transmitted to/from the USB insert either via a wireless interface (forming part of the USB insert) or through power line communications (PLC) via the electrical supply to/from the insert. 
     Next in second image  400 B the PCB  450  is depicted absent any components for simplicity except electrical connector  480  visible through opening within the back wall of the insert shell  410  whilst the insert  150 / 250  now depicts only insert shell  410 , the insert latch portion  440  and its keyed openings  460 . Finally, third image  400 C depicts only the PCB  450  with electrical connector  480  and keyed posts  470 . 
     Accordingly, referring to  FIG.  4 B  there are depicted an exemplary post  470 —opening  460  configuration for achieving the insert restrictions according to  FIG.  3    according to an embodiment of the invention wherein a first class  300 A which fit the electrical receptacle  100  only, a second class  300 A which fit either the electrical receptacle  100  or switch receptacle  200 , and a third class  300 C which fit the switch receptacle  200  only. As depicted first to third rear views  4000  to  4200  depict the rear wall of the insert shell for the first, second, and third classes respectively. 
     First rear view  4000  depicts the openings  460 B and  460 C which are presented from the four potential opening positions  460 A to  460 D respectively. Now referring to first PCB configuration  4400  there are depicted the occupied posts  470 B and  470 C of the four potential post positions  470 A to  470 D respectively. Accordingly, when the openings  460 B and  460 C correspond to the posts  470 B and  470 C such that when the insert with first rear view is inserted into a receptacle with first configuration  4400  with posts  470 B and  470 C the combination allows the insert to be inserted fully engaging the electrical connector  480  on the PCB  450  to the electrical connections within the insert (not shown for clarity) and a latching mechanism within the receptacle, see for example receptacle latch portion  610  in  FIG.  6   , to engage with that of the insert, insert latch portion  440 . However, if the insert is instead inserted into a receptacle with second configuration  4500  the posts configured as depicted in positions  470 A and  470 B the insert cannot be inserted fully preventing the electrical connection being made and the engagement of the latching mechanism. 
     However, an insert with third rear view  4200  with openings  460 A and  460 B would align and be fully insertable with second configuration  4500 . It would be evident that the third rear view  4200  does not align with the posts of first configuration  4400  thereby preventing an insert with third rear view  4200  being inserted into a receptacle with posts in first configuration  4400 . However, second rear view  4100  has openings  460 A to  460 D and will accordingly accept posts in either of the first and second configurations  4400  and  4500  respectively. 
     It would be evident to one of skill that in each instance the insertion of the insert into a receptacle in an inverted position will not match any post configuration and accordingly an insert cannot be inserted upside down. Hence, in this manner a configuration of openings and posts as depicted in  FIG.  4 B  provides the three classes of inserts. It would be evident that other configurations of “posts” and “openings” may be employed to achieve the same result. It would also be evident that the configuration may be adjusted according to whether two, three, four or more classes of insert are intended for use in different subsets of two, three, four or more receptacles. 
     Now referring to  FIG.  5    there is depicted an edge connection between the insert and receptacle circuit board according to an embodiment of the invention for low complexity and low cost. Accordingly, there is depicted an insert PCB  500 A together with receptacle PCB  500 B as discrete elements and as assembled when the insert is inserted into a receptacle cavity keyed to access that insert. As depicted with insert PCB  500 A the edge of the PCB where it will about the electrical connector contacts  520  is castellated and the inner edge of each recess is metallized to form an electrical contact with its respective electrical connector contact  520  when the insert is fully inserted as depicted in assembly  500 C. In this manner, the mechanical positioning/retention of the insert relative to the receptacle cavity is managed by the latching/alignment mechanism, for example comprising insert latch portion  440  which engages receptacle latch portion  610  as depicted in  FIG.  6   , together with the posts/openings that define an allowable insertion. The electrical connection is a mechanical contact without additional complexity. It would be evident that within other embodiments of the invention the insert PCB  500 A may be configured with an electrical connector or electrical connectors in socket and/or plug whilst the receptacle PCB is configured with the matching plug and/or socket electrical connector or connectors. For example, these may include, but are not limited to single in-line (SIL) headers, dual in-line headers (DIL), card edge connectors, backplane connectors, micro-USB, and mini-USB. 
     Referring to  FIG.  6    there is depicted an internal ground bar configuration according to an embodiment of the invention providing grounding of the insert prior to electrical connectivity with the receptacle circuit board with low complexity and low cost. A receptacle  600 A is depicted with ground strap  140  which provides the mounting points for the receptacle  600 A to its electrical utility work box (not shown for clarity) and the faceplate (not shown for clarity) to the receptacle  600 A such that ground connections can be made to protect the user. Accordingly, the ground strap  140  may be grounded to the electrical utility work box directly when it is metal or conductive plastic or via a grounding connection made to both the receptacle  600 A and the work box. Also depicted in receptacle latch portion  610  on the inner face of the opening within the receptacle  600 A. 
     However, it is not evident whether the insert is grounded prior to full insertion and the electrical connections being made between the insert  300  and the receptacle  600 A. Accordingly first to third assembly images  600 B to  600 D respectively depict the ground strap  140  absent all other elements of the receptacle  600 A wherein it is evident that the ground strap is formed such that it is around the cavity over at least part of the cavity width such that as the insert is inserted it makes electrical contact to the ground plane. Accordingly, either through a conductive plastic shell for the insert or metal contacts on the upper and/or lower surfaces of the insert a ground contact is made as the insert is partially inserted and maintained through to the electrical connection such that in the event of a fault the insert is always grounded even though the accessible contacts within the cavity may be limited to an acceptable DC or AC voltage, e.g. 12V such that a user contacting them does not suffer harm. Optionally, the electrical construction may be reversed to that shown in  FIG.  5    such that the “plug” portion of the electrical connector(s) on the insert—receptacle PCB connection are on the insert and the “socket” portion is on the receptacle PCB so that an errant finger cannot touch the electrical contacts. Also depicted in first to third assembly images  600 B to  600 D respectively are the insert latch portions  440  on the insert  300  which engage with the receptacle latch portions  610 . 
       FIG.  7    there is depicted a sequential break down of a receptacle according to an embodiment of the invention such that:
         First image  700 A depicts the full receptacle with front casing  710  and rear casing  720 ;   Second image  700 B with the front casing  710  removed showing the internal frame  730 ;   Third image  700 C with the rear casing  720  removed showing the receptacle PCB  740 ;   Fourth image  700 D wherein the receptacle PCB  740  has been removed showing more of the internal frame  730 ;   Fifth image  700 E with the internal frame  730  removed showing the insert  300  within the grounding strap  140 ; and   Sixth image  700 F with the insert  300  removed showing the ground strap  140  and first to third electrical straps  750  to  770  respectively which provide the connections to the live and neutral pins of the electrical sockets.       

       FIG.  8 A  there is depicted a configurable electrical receptacle according to an embodiment of the invention wherein the installed electrical functionality is set in two stages:
         Stage 1: configuration of mains supply electrical elements; and   Stage 2: configuration of insert.       

     Accordingly, as depicted in second image  800 B a series of elements are depicted which when assembled provide the receptacle depicted in first image  800 A. There is therefore a receptacle body  810 , an upper electrical element  820 , a lower electrical element  840  and a cover  830  together with insert  300 . At installation the first and second electrical elements  820  and  840  are inserted into first and third cavities  810 A and  810 C respectively whilst the insert  300  would be inserted into second cavity  810 B wherein the insert latch portions  440  on either side of the insert  300  engage the receptacle latch portions  610  on the inner lateral faces of the second cavity  820 B. Once the first and second electrical elements  820  and  840  are inserted into first and third cavities  810 A and  810 C respectively the cover  830  is attached and retained, for example, via one or more bolts through the rear of the receptacle body to the rear of the cover  830 . 
     Accordingly, as depicted in second image  800 B a series of elements are depicted which when assembled provide the receptacle depicted in first image  800 A. There is therefore a receptacle body  810 , an upper electrical element  820 , a lower electrical element  840  and a cover  830  together with insert  300 . At installation the first and second electrical elements  820  and  840  are inserted into first and third cavities  810 A and  810 C respectively whilst the insert  300  would be inserted into second cavity  810 B. Once the first and second electrical elements  820  and  840  are inserted into first and third cavities  810 A and  810 C respectively the cover  830  is attached and retained, for example, via one or more bolts through the rear of the receptacle body to the rear of the cover  830 . 
     Now referring to  FIG.  8 B  there is depicted a configurable receptacle according to the configuration depicted in  FIG.  8 A  wherein the installed functionality set at installation can be varied by changing the electrical element. As depicted alternate electrical elements  820 A to  820 D are depicted comprising electrical socket, dual USB interface, UK shaver plug socket, and 2.1 mm DC socket. As depicted the second element cavity is configured as a 180° rotation of the first element cavity such that, for example, first electrical element  820 A can be used in both cavities. Optionally, within other embodiments of the invention such a configuration may be limited such that different upper and lower elements are required. Further, the concept discussed supra in respect of configuring inserts to fit only certain receptacles can be applied such that only certain electrical elements can be inserted into one or other cavity or both cavities etc. 
     The multiple cavities within a receptacle body  810  and cover  830  are further depicted in  FIG.  9    according to the embodiment of the invention depicted in  FIG.  8 A . Accordingly, the receptacle  810  has first to third cavities  910  to  930  respectively within each being backplane connectors  910 A to  930 A respectively and keying posts  910 B to  930 B respectively. As depicted the cover  830  has three openings  970  to  990  that align with the first to third cavities  910  to  930  respectively. The design of the cover is such that when attached electrical elements cannot be inserted into the first and third cavities  910  and  930  through the cover openings  970  and  990  but an insert  300  (not depicted for clarity) can be inserted through opening  980  into second cavity  910 B. Within embodiments of the invention the sequence of which cavities permit use of inserts versus may change. Also depicted within the first to third cavities  910  to  930  are first to third receptacle latching portions  940  to  960  respectively. 
     Optionally, within an embodiment of the invention using an example of three cavities all three cavities may be identical but the sequence of which accept elements prior to installation and which accept inserts after installation is defined by the cover applied. Accordingly, the cover may restrict the cavity by projecting within the cavity such that the dimensions of an insert are smaller than that of an electrical element. In this manner the insert may be in the first, second, or third cavity based upon the cover applied. 
     Accordingly, it would be evident to one of skill in the art that this concept may be extended as depicted in  FIG.  10    for a configurable switch receptacle according to an embodiment of the invention wherein the installed switch functionality can be set at installation leaving the post-installation receptacle configuration via the insert(s). Accordingly, as depicted in second image  1000 B a series of elements are depicted which when assembled provide the receptacle depicted in first image  1000 A. There is therefore a receptacle body  1010 , an electrical element  1020  and a cover  1030  together with insert  300 . Also depicted are receptacle latch portions  610  within the openings within the receptacle body  1010  which mate with the insert latch portions  440  on the insert  300  to retain the insert  300  in position. In this manner as depicted in  FIG.  11    the receptacle  1010  may be configured with first to fourth switch elements  1020 A to  1020 D which depict push toggle switch  1020 A, rotary dimmer  1020 B, rocker switch  1020 C, and electrical socket  1020 D. 
     Further, as depicted in  FIG.  12    configurable receptacles according to embodiments of the invention may employ two or three (or potentially more) inserts. 
     It would be evident that the concepts described and depicted within  FIGS.  2  to  12    may be exploited in 2-gang, 3-gang, 4-gang etc. configurations as well as the 1-gang design depicted. Accordingly, this would reduce the number of electrical wiring connections to be made by providing a single receptacle which then supports a grid of configurable elements and/inserts. 
     Within embodiments of the invention depicted in respect of  FIGS.  2  to  12    the presumption has been that the removable inserts are removed manually without special tooling. However, within other embodiments of the invention a tool may be required to insert and/or remove the insert. Similarly, a tool may also be required to insert and/or remove electrical elements such as sockets, switches, dimmers, etc. 
     Optionally, within embodiments of the invention the electrical elements may be inserted and retained without an overlaying cover but are “latched” into position and then covered with the faceplate wherein this then covers the required access to remove the electrical elements with a tool, for example. As described and depicted within  FIGS.  4 A,  6 ,  8 A,  9  and  10    this latching may be provided via insert latch portions on the insert which engage receptacle latch portions within the recess within the receptacle body. In this manner, removal of the faceplate and use of the appropriate extraction tool allows the electrical elements to be reconfigured and then re-covered with the faceplate. Optionally, the electrical elements may be retained through screw/bolt fixtures through the rear of the receptacle or the front wherein these are then obscured/hidden via a cover and faceplate or just a faceplate. In each instance the removable inserts are inserted/removed from the receptacle when the cover and faceplate or just faceplate are in position. 
     Amongst the inserts the inventors have considered a USB plug and associated cable wherein the cable is wound in combination with a spring mechanism or other mechanism that allows for the cable to rewind automatically. Optionally, the cable may be pulled to the required length and ratcheted to lock and then if pulled to full extension the ratcheting disengaged and the cable rewinds. Alternatively, a button or other mechanism on the front of the insert removes the locking ratchet and allows rewinding. 
     Within another insert an emergency light is powered upon power failure based upon a capacitor within the insert rather than a battery. The capacitor being maintained at charge and connected based upon a switch defaulting to connect the light, e.g. LED, upon power failure. 
     Within the embodiments of the invention the presumption has been that the receptacles are powered from a mains supply, such as 120V 60 Hz in North America. Within other embodiments of the invention the power supply may be a low voltage supply such as 12V, 24V, or 48V DC. 
     Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
     The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents. 
     Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.