WO2011012891A2

WO2011012891A2 - Power connector system

Info

Publication number: WO2011012891A2
Application number: PCT/GB2010/051235
Authority: WO
Inventors: Robert Henry Hadfield; Trevor Neill Orritt; Simon Whiteley
Original assignee: Otter Controls Limited
Priority date: 2009-07-29
Filing date: 2010-07-27
Publication date: 2011-02-03
Also published as: GB2472233A8; GB0921767D0; CN202797536U; GB2472281A; WO2011012891A3; GB2472233B; GB2508311A; GB201401811D0; GB0913194D0; GB2508311B; GB2472233A; GB2472281B

Abstract

A power connector comprises a central terminal and at least three peripheral terminals distributed around the central terminal, the peripheral terminals being substantially equally spaced from the central terminal. This configuration may allow a smaller footprint for such a connector, thus enabling better sealing, lower cost and/or greater flexibility of application, while avoiding safety problems such as tracking.

Description

Power Connector System

Field of Invention

[0001] The present invention relates to a power connector system for electrical appliances and particularly, although not exclusively, domestic appliances that include some method of cordless electrical connection and preferably that require a part of the appliance to be waterproof.

Background of Invention

[0002] There are many types of cordless appliance. The first type, a small domestic appliance such as a kettle, coffee maker or iron, is made up of two discrete parts with the main appliance part including a cordless connector that is operable to cooperate with a corresponding connector on the power base part. Thus, when the appliance is mounted on the power base, power may be supplied to the electrical components in the appliance.

[0003] Such arrangements allow a power base to be connected to a domestic power supply (such as by a plug), whilst further allowing the appliance to be removed from the base at any time before, during or after the electrical cycle.

[0004] There are various type of cordless connectors suitable for use with this first appliance type, including three pin connectors described for example in EP-A-0441536 and GB-A-2376575. Further advances on cordless connectors have led to 360° connectors, as described for example in WO-A-94/06185.

[0005] A second type of electrical appliance such as deep fat fryers, food processors, barbeques and the like include cordless electrical sub assemblies within the main appliance part. The cordless function enables the electrical sub assemblies to be connected and disconnected easily so that, for example, in the case of a deep fat fryer it may be easier to empty the fat from the heating chamber or in the case of a food processor to remove the blending bowl so that the processed/blended food can be more easily dispensed by a user. The cordless connectors already described are suitable for this purpose along with others connectors such as described in EP-A-0587300.

[0006] In both the first type and the second type it may be necessary to provide some form of signal between the detachable part and the static part, for example to enable a user interface that governs a function or provides feed back between the parts. This signal can be achieved for example by providing additional terminals to the interface between the parts as described in EP-A-0380369 or using the live/neutral/earth connections to carry additional signals as described in WO-A-02/01918.

[0007] Furthermore it may also be necessary that the parts that are to be connected are compliant during assembly, and in use, so that the connection system is capable of overcoming tolerances and positional misalignment between the base part and the appliance part. For example connection systems based on EP-A-0441536 can accommodate both vertical and lateral movement between the parts, whereas 360° connection systems based on WO-A-94/06185 may accommodate vertical, lateral and rotational movement. Connection systems based on EP-A0922426 may also provide a degree of flexibility as regards the relative positions of the parts when they are plugged into each other.

[0008] As will be appreciated, appliances such as food processors, blenders and, to a lesser extent kettle jugs, need regular cleaning. In particular, cordless appliances for containing food or liquids other than water require cleaning after each use. Such a task is time consuming and may be difficult to perform manually.

[0009] Accordingly, it is desirable to provide an appliance that can be cleaned more easily.

In particular, it would be desirable to provide a cordless appliance where the detachable part of the appliance can be washed in a dishwasher, by immersion in water or otherwise easily cleaned.

[0010] EP-A-1401311 discloses a five-pin waterproof connection method whereby the connection pins incorporate a rubberised sleeving over a proportion of the outside surface.

Three of the pins supply live, neutral and earth with the fourth and fifth pins enabling a signal to be transmitted from the element back to the appliance control. The overall size and sealing method of the connection system is specific to the claimed embodiments making the components unsuitable for use on alternative appliances. Moreover the insertion and withdrawal forces of this system are very high which would negate the connection method being used in most small domestic appliances where ease of use is paramount.

[0011] The applicant's patent publication WO-A-08/012506 discloses a cordless electrical connector having current-carrying components sealed therein, and a washable electrical appliance incorporating such a connector. [0012] The applicant's patent publication GB-A-2460620 discloses further methods for sealing connection systems into water proof appliances along with solutions for dealing with associated problems such as expansion and contraction due to heating and cooling.

[0013] This application discloses additional improvements to provide discrete multi pin connection systems of a size, construction and function that can be incorporated in cordless appliances that may require one or more removable or detachable parts to be immersed in water.

[0014] Unless otherwise stated the waterproof part of the connector is the part which is designed to be installed in the removable or detachable parts of the appliance. That part is preferably a plug part.

Statement of the Invention

[0015] According to a first aspect of the present invention, there is provided a cordless power connector, comprising a central terminal and at least three peripheral terminals distributed around the central terminal, the peripheral terminals being substantially equally spaced from the central terminal. This configuration may allow a smaller footprint for such a connector, thus enabling better sealing, lower cost and/or greater flexibility of application, while avoiding safety problems such as tracking.

[0016] According to another aspect of the present invention, there is provided a cordless power connector socket having at least four terminals, including an insert-moulded seal arranged substantially to prevent ingress of liquid into the socket. This arrangement provides a particularly secure seal.

[0017] According to another aspect of the present invention, there is provided a cordless power connector for a domestic appliance, comprising at least four terminals arranged around the perimeter of a circle and a rotatable shutter arranged to provide access to the terminals when open and to protect the terminals from ingress of liquid when closed. This arrangement provides improved resistance to liquids.

[0018] According to another aspect of the present invention, there is provided a cordless connector comprising at least four peripheral terminals arranged around a mechanical coupling. This arrangement provides a particularly convenient connector for appliance parts that require both power and motorized mechanical connections, such as milk frothers, heated blenders, sauce makers and the like. [0019] According to another aspect of the present invention, there is provided a cordless power connection system comprising a first connector and a corresponding second connector, the first and second connectors having corresponding terminals arranged so that electrical connection is made between the corresponding terminals by relative rotation of the first and second connectors when coupled together. This arrangement is particularly advantageous for an appliance incorporating an interlock so that a part of the appliance cannot be energised until the appliance is in a certain orientation, or alternatively where a locking action is required to ensure that the detachable appliance part is securely in place before energisation.

[0020] According to another aspect of the invention there is provided a cordless power connection system in which there is compliance so that plug and socket parts which are not perfectly aligned can be connected together.

[0021] According to another aspect of the present invention, there is provided a discrete cordless power connector component having at least four terminals and having a plurality of fixing points for fixing the connector to the appliance part, the fixing points being unevenly distributed around the periphery of the connector. This arrangement may enable the component to be assembled into a restricted space in the appliance.

Brief Description of the Drawings

[0022] There now follows, by way of example only, a detailed description of preferred embodiments of the present invention, with reference to the figures identified below.

Figure Ia is an exploded isometric view of plug and socket parts of a first embodiment.

Figures Ib and Ic are isometric views respectively from above and below of the inner socket assembly or 'skeleton' of the socket part of the first embodiment.

Figures Id and Ie are plan views respectively from above and below of the inner socket assembly or 'skeleton' of the socket part of the first embodiment.

Figure If is an isometric view from above of a one-piece flexible water ingress shield for the socket part of the first embodiment.

Figures 2a and 2b are exploded isometric views respectively from below and above of plug and socket parts in a second embodiment including an appliance adaptor plate. Figures 3 a and 3b are isometric views respectively from above and below of plug and socket parts in a third embodiment.

Figures 4a and 4b are isometric views respectively from above and below of plug and socket parts in a fourth embodiment.

Figure 5 a is a plan view of the critical dimensions for a plug part with square or rectangular pins.

Figure 5b is a plan view of the critical dimensions for a plug part with round pins.

Figures 6a to 61 illustrate different pin configurations in embodiments of the invention.

Figure 7 is an isometric view of a plug and socket part in a fifth embodiment.

Figures 8a and 8b are isometric views respectively from below and above of a plug part in a seventh embodiment

Figure 9a is an isometric view of individual pins and corresponding connector part in an eighth embodiment.

Figure 9b shows the installation of the individual pins in an appliance.

Figures 10a and 10b are isometric views respectively from below and above of a tenth embodiment.

Figure 10c is a plan view of the plug part of the tenth embodiment.

Figure 11a is an isometric view respectively from above of an eleventh embodiment.

Figure 1 Ib is an exploded view of the plug part of the eleventh embodiment.

Figure 1 Ic is a detail of the knurled pin of the eleventh embodiment.

Figure 1 Id is a plan view of the plug part of the eleventh embodiment.

Detailed Description of the Embodiments

[0023] In the following description, functionally similar parts carry the same reference numerals and letters between different embodiments. Reference numerals have three digits, the first of which refers to the numbering of the embodiment in which the part first appears. The second digit is used to designate common parts of the same assembly.

[0024] All electrical connecting means in the socket part will be referred to by letters, suffixed by a number 1. Corresponding terminals in the plug part will be referred to by the same letter but suffixed by the number 2. Where applicable, corresponding terminals in any appliance adaptor will be referred to by the same letter suffixed by the number 3 and so on for additional parts. [0025] Where a centre pin or terminal is present this always carry the letter A. Pins that are positioned peripherally around a centre pin commence with the letter B and will be notated in a clockwise direction.

[0026] All embodiments can be supplied as discrete components for fitting to any of a wide range of domestic electrical appliances designed to accommodate the connector. However, embodiments of the invention may also be applied to cordless electrical plugs that are integrated with a control such as a boil detector and/or dry boil control, such as in the applicant's Al integrated control. The control may be an electromechanical or electronic control. It is also preferred that a residual current protector is provided in either the appliance or the corresponding power base.

First Embodiment

[0027] The first embodiment is described with reference to Figures Ia to Ie. The drawing details the parts as follows.

Socket Part 100

[0028] Integrated tab terminal and resilient springs Al, Bl, Cl, Dl and El in the socket part 100 interface with corresponding pins A2, B2, C2, D2, and E2 in the plug part 150. In this embodiment the springs Al, Dl and El are side acting (i.e. the resilient spring portion is arranged to contact the side of the corresponding pin) and springs Bl and Cl are upward acting (i.e. the resilient spring portion is arranged to contact the end of the corresponding pin).

[0029] Socket inner moulding 110 acts as a housing for the springs Al, Bl, Cl, Dl and El. This moulding 110 may include features enabling the socket part 100 to function in adverse conditions including turrets 111 that act as guidance and insulation for the mating pins A2, B2, C2, D2, E2, walls 112 to support the socket part 100 against the docking of heavy appliances and to assist with electrical separation from the appliance, mouldings 113 to separate the socket part 100 from adjacent appliance parts to enhance drainage, sloping surfaces and a specified surface finish to enhance drainage.

[0030] The socket inner moulding 110 includes attachment points 115 symmetrically arranged around the periphery thereof, for attachment of the socket part 100 to a base portion of an appliance. [0031] The subassembly of the inner moulding 110 and the springs Al, Bl, Cl, Dl and El, as shown in Figures Ib and Ic, acts as a building block for the connection means in the socket part 100 and will be referred to as the 'skeleton'.

[0032] A socket cover moulding 120 may include a water ingress shield 130, made from flexible or resilient material such as silicone, that is attached to the cover moulding 120 during the moulding process, for example by an insert moulding or 'twin shot' manufacturing process. The ingress shield 130 includes apertures 131, such as slots or holes, positioned so that the pins A2, B2, C2, D2, and E2 can gain access into the socket part 100. The apertures 131 may comprise cross-slits that allow the pins A2, B2, C2, D2, and E2 to pass through, but otherwise seal the apertures 131.

[0033] The twin shot process may provide a seal between the side of the cover moulding 120 and the inner moulding 110. In an alternative embodiment, shown to the right hand side of Fig. Ia, the cover moulding 120 and the ingress shield 130 may be manufactured as separate parts, with the cover moulding having apertures 121 for the pins, and the ingress shield 130 having discrete silicone parts positioned in any area in which water ingress may occur. Alternatively, for easier assembly the silicone parts could be moulded together as one unit, as shown in Figure If. Each of these methods of attaching silicone sealing means would reduce the material and processing time requirements compared to a complete shroud of the same material.

[0034] In some embodiments the 'skeleton', comprising the inner moulding 110 and springs Al, Bl, Cl, Dl and El, may be installed in an appliance having a discrete appliance cover configured to act as the socket cover moulding 120.

[0035] It is desirable that the socket part 100 will shed liquid and in some cases may be classed as water proof, but it is still considered necessary to add the internal drainage and water shedding features described above in the case of the sealing means being damaged or in the case of a 'wet' plug part 150, for example if not fully dried after washing, being inserted in the socket part 100.

[0036] In the case that liquid enters the electrical enclosure area, such as the inner moulding 110, of the socket part 100, then the socket part 100 is further enhanced by the inclusion of gaps between moulded parts to act as 'capillary breaks' in order to prevent water moving from one area of the socket part 100 to another. [0037] The choice of material for the socket part 100 is also important. Ideally, the plastic surfaces should be as smooth as possible for example grade 12 or better on the VDI 3400 standard, with a high CTI rating.

Plug part

[0038] The plug part 150 is required to act as the water proof connection means into the detachable appliance part. The plug part 150 according to the first embodiment is made up of the following components.

[0039] A plug main moulding 160 supports the pins A2, B2, C2, D2, E2, and sealing means, and also acts as one half of a clamping face that attaches and seals the complete plug part 150 into the detachable appliance part. In this embodiment, the plug main moulding 160 includes bosses 161 which receive four screws 154 that act as clamping means to clamp a plug clamp moulding 180 against the plug main moulding 160.

[0040] A gasket seal 170 acts as a seal between the appliance part and the plug part 150, and is clamped between the plug clamp moulding 180 and the plug main moulding 160.

[0041] The electrical pins A2, B2, C2, D2 and E2 connect to the corresponding springs

Al, Bl, Cl, Dl and El in the socket part 100. In this embodiment the pins A2, B2, C2, D2 and E2 are sealed against the plug main moulding using silicone 'O' rings 171.

[0042] Resilient springs 152 attached to the proximal ends of the pins A2, B2, C2, D2 and

E2 are arranged to pass through apertures in the plug clamp moulding 180 and interface with corresponding electrical contacts in the appliance part, for example contacts on a thick film heating element. This arrangement allows the plug part 150 to be preassembled to an appliance cover and avoids the necessity to connect wires from the plug part to the appliance during assembly.

[0043] The plug clamp moulding 180 acts as the second part of the clamping face. In this embodiment, as illustrated, the threaded screws 154 act as the clamping means, however in alternative embodiments the clamping force may be achieved by other means, such as clips or push fit connections.

[0044] The current carrying parts of the plug part 150 may be sealed by means disclosed in

WO 08/012506 Al. Further methods of sealing and venting the complete plug part 150 within an appliance are disclosed in GB patent application 0804299.6, which are incorporated by reference and the full details of which need not be repeated herein.

[0045] The electrical connections are required to meet the clearance distances material group classification I l ia or any equivalent standard for onerous conditions. The cross shape format of the pins enables the four peripheral pins B2, C2, D2 and E2 to be positioned such that they are equally spaced apart from the central pin A2.

[0046] The final dimensions of the pin configuration will be defined by appliance type, power rating, voltage and the conditions for which the appliance is intended for use. The spacing must satisfy the special requirements of the plug part 150 and the conditions experienced in the corresponding connections in the socket part 100. Provision needs to be made to prevent electrical tracking or treeing in the socket and plug parts 100, 150 which will include the spacing required for the input and output electrical connections, for example tab terminal connectors.

[0047] It is also necessary to consider the possibility of liquids or other unwanted materials entering the area between the plug and socket parts 100, 150 during insertion and withdrawal. These unwanted materials can settle, for example, on the top surface of the socket part 100 or between the pins of the plug part 150. Alternatively these materials could enter the areas between the resilient springs Al, Bl, Cl, Dl and El and the mouldings 110, 120.

[0048] The electrical connecting parts of the springs Al, Bl, Cl, Dl and El and/or pins A2, B2, C2, D2 and E2 may be coated with an electrically conductive, relatively inert material, such as gold or silver plate, so as to reduce or overcome potential corrosion and/or galvanic reaction problems.

Second Embodiment

[0049] The contact arrangement of the resilient springs 152 of the first embodiment requires corresponding contacts to be provided in the appliance. In the second embodiment as shown in Figures 2a and 2b, an adapter 200 is provided to allow connection to an appliance not having such corresponding contacts. The adapter 200 may have the form of a plate. The adapter 200 may allow electrical connections between the plug portion 150 and an appliance not including a printed heating element. The adapter 200 may be configured to take the shape of a part of the appliance in which it is installed. In this embodiment the adaptor 200 is shaped to fit within the curved sheath of a mechanical or sheathed heating element.

[0050] The adapter 200 incorporates fixed contacts B3, C3, D3 and E3 that interface with the resilient springs B2, C2, D2, and E2 of the plug part 150. The adapter 200 also includes an aperture 201 allowing access from the plug part 150 through to the heating element so that the earth terminal Al of the plug part 150 can make direct electrical contact with the heating element. In alternative embodiments it may be possible to affix an earth pin Al directly to the appliance and configure the plug part 150 so that during assembly the earth pin Al is inserted through, and sealed within, the plug part 150. The pin Al would make direct contact with a corresponding terminal A2 in the socket part 100.

[0051] In the second embodiment the plug pins A2, B2, C2, D2, and E2 are rectangular in cross section, which in itself brings about some advantages. For example the rectangular shape will help prevent the rotation of the pins within the plug main moulding 160. The rectangular shape will assist in the fixing of the resilient spring terminals A2, B2, C2, D2, E2 or other connecting means.

[0052] The plug main moulding 160 may include clamping features 165 outboard of the sealing part, as illustrated. The clamping features 165 enable clamping of the plug part 150 onto the appliance. In this embodiment, the clamping features 165 are arranged symmetrically around the periphery of the plug main moulding 160.

[0053] In this embodiment the socket main moulding 110 and cover 120 are moulded as one piece. The earth terminal Al is a side acting resilient spring and the other terminals Bl, Cl, Dl and El are upward acting resilient springs. There may be a need for an additional flexible water ingress shield 130, as illustrated, which may take the form of a one-piece moulding which is placed over the socket cover 120 or preferably any of the options for flexible water ingress shields 130, detailed in the first embodiment, may be employed.

[0054] In all embodiments the pins A2, B2, C2, D2, E2 can be solid, stamped, drawn, hollow formed, folded or manufactured from any other process, but it is preferred that the outside edge thereof is smooth and free from cracks or slots that may compromise the seal or act as a means to hold dirt or debris.

[0055] In a variant of the second embodiment (not shown) the adapter 200 may be provided with resilient connectors and the plug part 150 with fixed contacts in place of the resilient springs 152. In another embodiment (not shown), the plug part 150 may be fitted to an appliance and act as an interconnect device between two interfacing socket parts with one socket fitted in the supply line connector and the other socket fitted within the appliance, the latter socket acting similarly to the adapter plate 200. In other words, the plug part 150 acts as a male-to-male connector, with one corresponding socket part 100 fitted internally within the appliance. Both sides of the plug part 150 may have pins of an identical shape and profile in which case components of the sockets may be identical, thus saving manufacturing costs. Each of the pins acting between the two sockets could be manufactured in two or more parts but preferably each pin will be one piece without the need for any connections. The pins on the appliance side of the plug part 150 are housed within the water proof part of the appliance therefore will not be subjected to the same conditions as the supply side in which case the pin profile may be shorter in length than on the opposite side of the plug. In addition the pin material, contacts or coating may be different on either side of the plug part 150. In this embodiment the socket part 100 within the appliance housing may not need a cover and could be installed in the form of a 'skeleton' sub assembly as illustrated in Figures Ib and Ic. Other combinations and methods of connections between the plug part 150 and the appliance socket part can be envisaged.

[0056] It will also be appreciated that none of the embodiments are limited to five connections, and that more or fewer connectors could be provided. It can also be appreciated that the designation of terminals for live, neutral, earth and signal can be varied to suit specific applications. For example in applications using multiple power connections to an appliance, such as the Multiplug™ as disclosed in WO-A-09/024777, the connector may incorporate two live poles and two earth poles. In applications using thick film elements with multiple heating tracks, separate live and neutral connections may be provided to each track. Applications requiring more than one signal connection may have a pair of terminals for each signal connection, or a shared reference voltage connection, or may use the earth connection as the reference voltage.

[0057] In embodiments that include higher voltage connections, it is expected that the earth terminal will make first and break last and that any live terminals will make last and break first. At the manufacturing stage the terminals can be modified to ensure the correct sequence of make and break for a specified application, for example by changing the length and/or positional height of specific pins, fixed contacts or resilient springs.

Third Embodiment

[0058] The third embodiment is described in relation to a modified version of the applicant's CP8 Series 360° waterproof cordless electrical connector. This embodiment utilises many of the same components, mouldings and sealing methods as the CP8 Series 360° waterproof cordless electrical connector but differs in the fact that the connection system has five poles and is designed for one orientation only. This orientation may be enforced by registration of corresponding parts (not shown) of the plug part 150 and socket part 100 and/or corresponding parts of the base and of the appliance.

[0059] Fig 3 a and 3b show isometric views respectively from above and below of both the plug part 150 and the corresponding socket part 100. The Earth pin A2 is formed in the centre of an aperture 351 of the plug part 150 and four equally spaced side acting resilient connection members B2, C2, D2 and E2 are formed on the outer surface of the inner ring member 352, equidistant from the earth pin A2. The plug part 150 is provided with an outer moulding or shroud 353 to prevent access to the live parts when in the process of being connected to, or fully connected to, the socket part 100. The plug part 150 may also be provided with an outer flange to accommodate a sealing and clamping member (not shown). The plug part 150 incorporates an additional moulding 352 between the centre connector and the peripheral connectors. This moulding 352 acts as support for the resilient springs 152 and also acts as a means to optimize creepage and clearance distances.

[0060] The earth pin A2 and resilient connection members B2, C2, D2 and E2 are sealed into corresponding discrete segments or sealant pockets of the top part of the plug main moulding 160 so as to prevent ingress of water through the plug part main moulding 160. These members B2, C2, D2 and E2 can then be electrically connected to the appliance via tab terminals, as shown on the outer connection members B2, C2, D2 and E2, or via resilient springs 152, as shown on the central earth connector A2. In this embodiment the earth pin A2 may connect directly to a metal part of the appliance via the resilient spring 152.

[0061] The upper end of the socket part 100 comprises an outer moulding 305 within which are located a resilient earth connector Al, and four separate fixed contacts Bl, Cl, Dl, El, which interface with the corresponding terminals A2, B2, C2, D2, E2 in the plug part 150. In this embodiment a shutter 332 is shown to assist in shedding water away from the internal electrical parts. The shutter 332 is opened by abutment with the inner ring member 352. As the plug part 150 is removed, the shutter 332 is returned to the closed position by an internal spring (not shown). This spring acts reduce the resistance to withdrawal caused by the side acting resilient springs.

[0062] The earth terminal is accessed through the central aperture of the socket part 100, which also acts as a drainage means. [0063] It will be appreciated that the resilient members and corresponding fixed contacts can equally be positioned in either the plug or socket parts 150, 100.

[0064] In an alternative embodiment, the plug and socket parts 150, 100 may enable 360° of relative rotation when connected together, although electrical connection is only made at predetermined relative orientations. For example, if the contacts Bl and D2 are live and the contacts Cl and El are neutral, then members B2, C2 and D2, E2 will form live and neutral pairs at any one of four relative orientations, 90° apart. In this way, switching of the connections between the plug and socket parts 150, 100 may be provided by relative rotation therebetween. However, this arrangement does not allow signal and power connections to be provided together.

[0065] The angular distance over which the connection is made may be increased by increasing the circumferential extent of one or other of the contacts Bl-El and members B2-E2, provided this does not cause shorting of the contacts Bl-El.

Fourth Embodiment

[0066] The fourth embodiment is a variant of the third embodiment in that the mouldings for the plug and socket parts 150, 100 are square rather than round in cross-section, with the peripheral connections B, C, D and E on respective sides of the square. This arrangement does not allow 360° of relative rotation, but does allow relative orientations at 90° apart, as in the alternative to the third embodiment described above.

[0067] Altering the shape of the outer perimeter from round in the third embodiment to square in the fourth embodiment will decrease the length of the perimeter by 6%, for a given separation of the connections A, B, C, D, E. Reducing the length of sealing surface for the perimeter of the plug portion 150 reduces the cost of the seal and increases the integrity of the seal.

Alternatively it may be beneficial to increase the creepage distance between the contacts. If the outer perimeter of the fourth embodiment is increased to match the outer perimeter of the round moulding in the third embodiment, then the creepage distance between the respective contacts would increase correspondingly compared to the round embodiment, while not increasing the mass of the moulding.

Contact Design

[0068] In all embodiments it is possible to 'mix and match' the shape and form of the fixed and resilient contacts and their corresponding position within the plug and socket parts 150, 100. For example the plug part may include three fixed contacts and two resilient contacts with the corresponding socket part including the relevant mating connectors, comprising three resilient contacts and two fixed contacts.

[0069] Side acting resilient contact parts can increase the electrical contact force where required, for example for earth connections, but can also increase the resistance and withdrawal force needed to engage and disengage the plug part 150 from the socket part 100. This resistance may cause problems in appliances that are required to be easily removable and can be mitigated by the inclusion of vertically acting springs in the socket part that will assist in disengagement. Upwardly acting resilient spring contacts, for example, will act to overcome some of the resistive force. Means for biasing the socket and plug parts apart may be included, separately from the electrical contacts. For example, upward acting springs can be included in the socket part. Additionally or alternatively, it is advantageous to minimise the number of side-acting resilient connections. In embodiments that include an earth connector it is preferred that at least one part of the earth connecting means includes a side acting resilient spring with all other poles configured with upwardly acting resilient springs.

[0070] It is also important that, unless a separate locking device is included, the combined upward force between the plug and socket parts is less than the downward force of the appliance. It is preferred that the minimum downward force of the appliance should be 500 g (5 N).

[0071] In a five pin configuration with one side acting resilient spring arrangement and four vertical acting spring arrangements then the preferred upward force is less than 50O g (5 N) and the preferred resistance to withdrawal is less than 100 g (1 N).

Pin Configurations

[0072] The above four embodiments offer two types of construction for configuring the pins for the plug. The first type is an 'open architecture' where the pins have no additional insulation between the pins, and the second type includes enclosures and support around the pins or resilient springs that also act as additional electrical insulation.

[0073] There are appliances available in the market that include a five pin connection system of the open architecture type in which the pins are in line or alternatively in an arc shape. The pins are spaced apart to meet the requirements of the appliance, which has resulted in an elongate shape with a proportionately large footprint. These pins also include additional electrical insulation means along a specific proportion of their length

[0074] Configurations for optimising the shape and size of the plug part 150 of the 'open architecture' type will now be disclosed. These configurations are intended for use without the need to shroud or protect the individual pins with additional insulation material, but do not preclude this option. However it is envisaged that the plug or socket part may be provided with an outer moulding or shroud to prevent access to the live parts during the connection process, as outlined in the third embodiment.

[0075] The spacing of the pins in the waterproof plug part 150 cannot be treated in isolation. In fact, it is generally the conditions within, around and acting on the socket part 100 that affect the overall spacing for mating parts, in particular when the plug and socket parts are coupled. It is necessary to consider the appliance conditions in which the plug and socket parts will be used, for example power, current, creepage and clearance, material specification, drainage, capillary gaps, in addition to the size and type of connections to the socket part 100 and the size and type of contacts and resilient springs that connect from the socket part 100 to the plug part. It is important that the configuration maximises Live to Earth and Neutral to Earth distances in order to minimise safety critical faults.

[0076] The creepage and clearance distances for signal and/or lower voltage electrical connections are less than for mains voltage which is typically 90 to 250 volts. In any component where the low voltage is generated from the higher voltage, a failure can occur that can render the low voltage pin to be at the higher potential. Therefore all low voltage poles, generated from a higher source, need to be considered as high voltage potential when designing such components.

[0077] It is advantageous to position an earth pin between the neutral pole and live pole so that any tracking from neutral to live (or vice versa) will be interrupted by the earth. Therefore, in embodiments that include a central pin, it is preferred that the centre pin is earth potential.

[0078] Figures 5 a and 5b will be used to explain the spatial requirements of the pin configurations in open architecture plug designs. These 'open architecture' designs may have pin types that are of round, square or rectangular cross section. The round cross section pins preferably have diameters of between 2 mm and 3.25 mm, the square cross section pins have sides of between 2.5 mm and 3.5 mm and the rectangular cross section pins are typically between 1.5 and 2.5 mm on the shorter sides and 3.5 and 4.5 mm on the longer sides.

[0079] It would be expected that the different shapes of pins would significantly affect the spacing of the pins in the plug part 150; however it has been found that the spacing requirements in the socket part 100 override the minimum spacing that would be achieved if only the plug part 150 needed to be considered. Provided that the pin dimensions do not exceed the specified maxima, the separations between pins can be considered as centre-to- centre distances, without considering the pin cross-section.

[0080] The inventors have carried out significant test work and analysis and have arrived at a pin configuration that optimises the spacing between pins while still meeting the electrical requirements of the appliance type.

[0081] Figures 5 a and 5b show the critical dimensions required to determine the preferred pin configuration in an open architecture cordless plug. The two drawings show round and rectangular centres on a rectangular plug portion 150, but are applicable to any pin shape that falls within the tolerance guidelines below and most shapes of plug portion 150. Dimensions M, N and P are measured between centres of the relevant pins.

Dimension M - distance of Earth from any L, N or Signal pole: minimum 10.3 mm, maximum 13.3 mm.

Dimension N - minimum distance of any Live, Neutral or Signal pole from any adjacent Live, Neutral or Signal pole: minimum 8.8 mm, maximum 11.1 mm.

Dimension P - maximum distance of any Live, Neutral or Signal pole from any adjacent Live, Neutral or Signal pole: will be governed by dimensions M and N.

Dimension Q - maximum or major width of pin: minimum 1.5 mm, maximum 4.5 mm, dependant upon the cross sectional shape (rectangle or square) and the orientation of the pin.

Dimension R - minimum or minor width of pin: minimum 1.5 mm, maximum 4.5 mm, dependant upon the cross sectional shape (rectangle or square) and the orientation of the pin.

Diameter S - diameter of circular pin: minimum 2 mm, maximum 3.25 mm

[0082] Note all maxima are only suggested; it is possible to increase one or more of these dimensions if required particularly if the appliance requires pins with a larger cross section. The proportions laid out above may be increased proportionally to suit larger cross section pins. [0083] It is advantageous to reduce the size of the footprint of the plug part 150, not only in order to reduce the length of the seal or gasket 130, 170, but also any reduction in the footprint size will reduce the material content of the components which will save costs and also make the components more suitable for smaller appliances.

[0084] Furthermore there is a relationship between the shape of a component and the deflection of the component when a force is applied, such as the force that would need to be applied to compress a seal or gasket. The variables in the equation for calculating the deflection are as follows: Length of component, Width of component, Thickness of moulding, Modulus of elasticity, Force to be applied.

[0085] The equation is as follows:

Force Width x Modulus of Elasticity x Thickness ³ Deflection 4 x Length ³

[0086] Deflection is proportional to length cubed and inversely proportional to width and thickness cubed, therefore a plug part 150 that is to be used as a clamp for compression of a seal requires a different thickness of moulding dependant upon the aspect ratio of the moulding. For example a 4:1 aspect ratio rectangle would require 67% greater thickness than a 3:2 aspect ratio to achieve the same stiffness.

[0087] There are appliances available in which the pins are configured, side by side in an elongate manner, in the following format: Signal, Signal, Earth, Live, Neutral with the same distance being allowed between each connector. The inventors believe that reconfiguring the pins in a different manner can reduce the footprint substantially.

[0088] For the purposes of the following comparison and explanation it will be assumed that each pin will be a minimum 11 mm away from the nearest pin (measured from the centre of the pins), a distance which falls within the minimum tolerances bands of both dimension M and N of Figures 5 a and 5b.

[0089] However, with the different shapes considered, it is not always possible to stay within the maximum tolerance bands of dimensions M and N, for example with 5 pins in a square and circular shaped outer moulding. In this configuration, if the dimension N equals 11 mm and the four peripheral pins are equidistantly spaced then both dimension M and P would be equal i.e. approximately 16 mm which would fall outside the preferred tolerance band of M.

[0090] A minimum distance is required outboard of the pins so that the plug part can be provided with a water proof seal and for the purposes of the calculations it is assumed that this dimension is 9.5 mm, which is also a radius for rounded corners on all the shapes to assist with sealing.

[0091] For the purposes of the calculations it is assumed that the compression force applied will be in the same relative position for each component.

[0092] Figures 6a to 61 show the configurations used for Tables 1 and 2 below.

Table 1

Mass to achieve

Thickness the same

ratio to Volume to stiffness

achieve achieve assuming

same same density of 1.7 g Mass per

Pins Shape stiffness stiffness per cc pin

Fig 6a Elongate 1.00 3584 6.09 1.22

Fig 6b Circular 0.64 2709 4.60 0.92

Fig 6c Square 0.44 1659 2.82 0.56

Fig 6d Rectangle 0.52 1764 3.00 0.60

Fig 6e Elongate 1.35 6640 11.29 1.61

Fig 6f Circular 0.64 2709 4.60 0.66

Fig 6g Rectangle 0.67 2980 5.07 0.72

Not illustrated Elongate 1.70 10631 18.07 2.01

Fig 6h Circular 0.71 4063 6.91 0.77

Fig 6i Rectangle 0.82 4512 7.67 0.85

Not illustrated 1 1 Elongate 2.05 15555 26.44 2.40

Fig 6j 1 1 Circular 0.77 5779 9.82 0.89

Fig 6k 1 1 Rectangle 0.97 6361 10.81 0.98

Fig 6I 13 Circular 0.77 5779 9.82 0.76 [0093] The tables detail selected configurations with five, seven, nine, eleven and thirteen pins. Larger measurements have been rounded to the nearest millimetre. The table details three main areas for comparison:

Perimeter Length - this bears directly on the length of the perimeter seal that is required to seal the component into the appliance.

Cross Sectional Area - this is directly relevant to the footprint of the component and is defined as area per pin. This is very relevant for circular configurations where it possible to add extra pins without necessarily increasing the size of the footprint.

Comparative Mass - this is based on the thickness of a component so that each component is capable of bearing the same compression force for a given deflection (i.e. the same stiffness) with the same number of compression points. The mass is calculated based on the ratio of comparative deflection multiplied by the volume and is then converted into mass based on a typical material density of 1.7 g per cc. This is defined as mass per pin.

[0094] It can be seen that with five pins the most effective configuration is a rectangle in that it has the shortest perimeter and the smallest area per pin; however in terms of mass per pin, the square configuration is marginally better despite dimension M being larger than in the rectangular configuration. Each of the rectangular and square configurations is considerably better than the circle, with the elongate configuration being the least effective in all aspects.

[0095] With 7 pins the most efficient configuration in all aspects is the circle. This is because it is possible to add two additional peripheral pins to the same size footprint as the 5 pin configuration while still keeping the gap between the peripheral pins within the preferred tolerances of Dimension M.

[0096] A seven pin rectangular shape is more efficient than a five pin rectangular shape for the perimeter per pin and volume per pin measurements but is less efficient in the mass per pin measurements as the aspect ratio is now less efficient. However for spatial requirements within the appliance it may be beneficial to choose this option. The 7 pin elongate shape is the least efficient in all aspects.

[0097] A square shape was not considered for the seven pin version, as it is not possible to add extra pins and keep the same shape. If six peripheral pins are positioned around a centre earth pin in a straight sided shape, the resultant hexagon shape is very close to being circular and in practice would have similar results to a circle. Furthermore, as a non-regular shape it would be more difficult to add equidistant compression points and as such has been precluded from the comparison for that purpose.

[0098] The results for 9 pins also show that a circular configuration is the most efficient; however in order to accommodate eight equidistant pins within the tolerance band of dimension M it is necessary to increase the dimension N to a tolerance band of approximately 14.8 mm to 17.8 mm. It would be possible for the same circular shape to incorporate up to 13 pins, as shown in Fig 61, if a second ring of peripheral pins were placed around a first ring of six.

[0099] The 9 pin rectangular version is becoming elongate and because of this the mass per pin is increasing however it is still significantly more efficient than the elongate version where the pins are in line.

[00100] By way of example, circular pins are shown but the configurations are applicable to pins of any cross section that fall within the ranges for dimensions Q, R and S above.

[00101] All peripheral pins on the circular and square embodiments are assumed to equidistantly spaced apart. Unless otherwise stated all peripheral pins on the circular and square embodiments are assumed to equidistantly spaced from the central pin and comply with the range for dimension N above.

[00102] With the seven and nine pin rectangular embodiments, the additional pins will be laterally positioned beyond the pin positions of the five pin configuration, relative to the central pin. The additional pins will comply with the requirements for dimension M both a lateral and vertical direction.

[00103] In most embodiments of the invention, it will be expected that the plug and socket parts will be shaped to take advantage of the optimised configurations. For example the 'skeleton' part in the first embodiment could be extended laterally to accommodate additional connections.

[00104] Figure 6b details a preferred configuration for a five pin connector with a circular shaped plug part.

[00105] Figure 6c details a preferred configuration for a five pin connector with square shaped plug part.

[00106] Figure 6d details a preferred configuration for a five pin connector with rectangular shaped plug part. [00107] Figure 6f details a preferred configuration for a seven pin connector with a circular shaped plug part.

[00108] Figure 6g details a preferred configuration for a seven pin connector with a rectangular shaped plug part.

[00109] Figure 6h details a preferred configuration for a nine pin connector with a circular shaped plug part. In this embodiment dimension N is increased so that eight peripheral pins can be equally spaced around the centre pin within the tolerances of dimension M.

[00110] Figure 6i details a preferred configuration for a nine pin connector with a rectangular shaped plug part.

[00111] Figure 6j details a preferred configuration for an eleven pin connector with a circular shaped plug part. In this embodiment dimension N is increased so that eight peripheral pins can be equally spaced around the centre pin. Figure 61 shows a variant in which it is possible for a circular shape with the same area as that of Figure 6j to incorporate up to 13 pins. In this variant, dimension N falls within the preferred tolerances with a second set of peripheral pins equidistantly spaced around the centre pin so that each of the second set of peripheral pins fall within the tolerance of Dimension M when measured from the first set of peripheral pins.

[00112] It is expected that the principles of the socket and plug parts 100, 150 from any of the first to fourth embodiments could be extended or modified to suit the requirements of any of the configurations of Figures 6a to 61.

[00113] Other embodiments that follow the same design rules and dimensional tolerances can also be envisaged, for example: connectors without earth pins, connectors with an even number of pins, connectors where the pins form a triangular pattern and also embodiments in which the cross-section of the plug part 150 is non-regular, for example ovoid, 'D '-shaped, rhomboid or trapezoid.

Fifth Embodiment

[00114] The fifth embodiment as shown in Figure 7 comprises a five pin connector system where the plug part 150 needs to be rotated within the socket part 100 in order for the electrical circuit to be made. This feature is particularly advantageous if the appliance incorporates an interlock so that, for example, a motor cannot be energised until the appliance is in a certain orientation, as for example in a blender or food processor, or alternatively where a locking action is required to ensure that the detachable appliance part is securely in place before energisation.

[00115] In this embodiment the plug part 150 has five equally spaced pins A2, B2,

C2, D2 and E2 positioned around an annular main moulding 160. The pins are designed to fit into five equally spaced slots 121 on the socket moulding 120, which is also annular. A rotating shutter 522 closes the slots 121 and is biased into a closed position. The slots 121 receive the pins, which force open the shutter 522; the electrical circuit is made when the plug part 150 is rotated towards the corresponding resilient connections positioned in the other end of the slot. The order in which the connections are made can be sequenced by the position of resilient spring contacts relative to the slots 121.

[00116] The plug part 150 and the socket part 100 include respective corresponding central apertures 555, 525, through which a mechanical coupling may be made, such as a spindle for a mixing arm.

[00117] In a variant of this embodiment some or all of the resilient connections could be positioned in the plug part 150 and some or all of the fixed contacts could be the positioned in the socket part 100.

[00118] The embodiment as illustrated shows the slots 121 in the socket part 100 protected by the shutter 522 but the shutter 522 may be omitted in other embodiments.

[00119] The slots 121 could be enlarged or chamfered at the point in which the pins enter the socket part 100 and the slots could become narrower into the socket part 100 to ensure correct interface with the mating electrical parts.

[00120] Registration means may be included to ensure ensuring that there is only one orientation in which that the plug part 150 can enter the socket part 100. For example, one or more of the pins of the plug part 150 and slots 121 in the socket part 100 could be shaped so that only one of the pins can enter a specific slot.

[00121] This embodiment will be suitable for configurations other than five pins. It is not expected that the spatial arrangements of the pins will fall within the preferred dimensions discussed above with reference to Figures 5a and 5b, because the earth pin is not equidistant from the other pins.

Sixth Embodiment

[00122] The sixth embodiment (not shown) is a variant on the fifth embodiment in which a 360° system as described in WO-A-08/012506 can be utilised to achieve a similar locking or interlock function as the fifth embodiment in applications in which no access through the centre of the connector is required, thereby reducing the footprint of the connector and in turn the length of the sealing means. In this case, if more than three pins are required, additional pin type connectors are mounted outboard of a 360° plug part (for example as in the third embodiment) on diametrically opposite arms. The socket part 100 may have matching slots outboard of the circular moulding intended to mate with the pins of the plug part. The plug part is positioned and turned in a similar manner to the fifth embodiment such that three of the connections are rotatably connected through the centre connector part and the addition connections are made outboard of the central connector.

[00123] In a further variant (not shown) the connecting function can be achieved by using one central connector A2 in the plug part 150 about which two or more pins are positioned outboard of the central connector A2. On insertion into the socket part 100 the pins would be positioned into reciprocating slots 121 similar to the fifth embodiment and rotated to make the electrical connection. It is expected that in this embodiment the spatial requirements of the pins would fall within the preferred dimensions discussed above.

Seventh Embodiment

[00124] In the seventh embodiment, illustrated in Figures 8a and 8b, a plug part 150 has pins A2-E2 insert moulded therein such that the pins are shrouded over the majority of their length with just the tips projecting from the moulding. The pins interface with corresponding upward facing resilient springs Al-El in the socket part 100. The advantage of this embodiment over the previous embodiments is that the elongated shroud may assist with both waterproofing and electrical isolation.

[00125] The pins may be surrounded by an O-ring pocket 700 into which an O-ring is fitted during installation of the plug part 150 into a detachable appliance. The O-ring is of suitable resilient sealing material, such as silicone. The O-ring may be compressed against a cover of the detachable appliance by compression means such as screws fitted through screw fittings 705.

[00126] As shown in Figure 8b, the tab terminals A2-E2 are insert moulded within a sealant pocket 356 that is filled with sealant, and the sealant is cured during assembly so as to provide improved insulation between the terminals. Eighth Embodiment

[00127] In this embodiment it is envisaged that the individual pins A2-E2 and corresponding resilient springs Al-El and support mouldings 160 (as illustrated in Figure 9a) can be supplied to the manufacturer as separate components and then installed into the appliance in a manner that matches the spatial requirements of that appliance. The appliance manufacturer would need to install the parts within guidelines so that the spacing and height will meet the standards required for waterproof connectors.

[00128] The pins could be supplied so that that they can be sealed into an appliance housing 800 with an 'O' ring seal 171 as illustrated in Figure 9b or alternatively the pins could be sealed by compression or glued, screwed, crimped or clamped into the housing. The pins could be supplied with a connecting means for attaching onto the appliance, for example resilient springs, as illustrated in Figure 9b or alternatively could be supplied so that the manufacturer attaches the connectors for example as illustrated in Figure 9a.

[00129] The pins would interface with corresponding individual connecting parts which are secured in the base or non detachable part. The securing means is not illustrated.

[00130] This embodiment may be especially useful when one connecting part, such as the earth, of the detachable part is positioned away from the main plug and socket so that, for example, a five pin socket could be used for the main connections with the additional connection being met by the separate connecting means.

[00131] In further embodiments it will be possible to utilise individual pins in the appliance part which then interface with a 'skeleton' for example, as illustrated in Figure Ib or a complete socket assembly. The earth pin may be fitted to the appliance and interface directly with a corresponding connector in the base part. The appliance and base part could be configured to incorporate features from any of the embodiments.

Ninth Embodiment

[00132] The ninth embodiment (not shown) is advantageous in appliances that require at least two parts to be washproof. For example, in some appliances liquids may spill from the appliance part onto the base part. In a standard waterproof appliance the appliance part can be disconnected from the base part in order to be washed however the base part, which includes the socket and possibly the controls, will not be suitable for immersion in water. Another example may be an appliance that incorporates two separate cooking or heating means, such as an electrical barbeque. [00133] This problem can be solved by supplying the power to the base part, and the interconnection from the base part to the appliance part, via a one centrally located intermediate connecting means to which power is supplied, and which may for example be wired via a plug into a wall socket. The connecting means incorporates female electrical connection points on at least two separate or opposing faces which for example may be similar to the socket part 100 in the first embodiment. One face of the socket would interface with the base unit and the other face of the socket would interface with the appliance part(s). Both the base unit and the appliance parts would incorporate connecting plugs which, for example, may be similar to the plug parts 150 in the first embodiment. If the appliance part(s) or the base part needs to be washed, then either of these may be disconnected from the corresponding socket of the intermediate connecting means. If all of the parts needed to be washed then each could be disengaged leaving the intermediate connecting means safely plugged into the wall socket. The intermediate connecting means may include a support, such as feet, so that it is supported when not connected to either the appliance or to the base part.

[00134] The intermediate connecting means could, for example be configured so that it supplies the live, neutral and earth into either or all of the detachable parts. The intermediate connecting means could also include addition connections so that, for example, signals can pass from one detachable part to the other, or from the intermediate connecting means to any of the detachable parts. The intermediate connecting means may provide a bus connection for exchange of signals between each of the detachable parts and/or the intermediate connecting means. The detachable parts may be operably interactive, for example so that the power switching state of one detachable part is dependent on the sensed state of another detachable part. For this reason, a large number of connecting terminals may be required; also, each part may have a plurality of independently switchable power loads. The intermediate connecting means may include an electronic control for the detachable parts.

[00135] It is envisaged that the intermediate connecting means may be assembled from individual complete socket components or may alternatively be an integrated unit.

[00136] It would be advantageous to provide a locking means so that the intermediate portion may be firmly connected to each of the detachable portions. This could take the form of a simple latching mechanism or alternatively an electromechanical latching system, for example comprising a magnet or relay. [00137] If the sum of the loads was greater than that could be supplied through one socket then a multiple power connecter such as the Multiplug™ as described above could be employed to supply power to the intermediate connecting means; alternatively the appliance could include some form of power sharing means.

Tenth Embodiment

[00138] The tenth embodiment is a variant of the first and second embodiments in which the components have been designed to accommodate a specific shaped appliance in which there is a restricted area within the detachable appliance part that impinges on the space available for the plug part 150. The system has a rectangular profile as described above with critical dimensions as follows:

Dimension M 11.18 mm

Dimension N 10.00 mm

Dimension P 20.00 mm

Dimension Q 4.00 mm

Dimension R 2.00 mm

[00139] The socket part 100 has five resilient springs contacts with contact Al being side acting and contacts Bl, Cl, Dl and El being upward acting.

[00140] This embodiment includes a flexible water ingress shield 130 that can be attached as a separate part or insert moulded into the socket part 100.

[00141] The plug part 150 has five rectangular shaped pins A2-E2 that are sealed into the main moulding 160 with silicone sealant. Each of the pins A2-E2 interfaces with corresponding resilient springs Al-El in the socket part 100. In this embodiment the earth pin A2 is connected to an appliance body via an earthing bridge, while pins B2, C2, D2 and E2 are connected to contacts B3, C3, D3 and E3 in the adapter 200 via upward acting resilient springs.

[00142] The clamping means 115 are not equidistantly spaced around the periphery of the plug part 150, to enable the plug part to be assembled into a restricted space in the appliance. In this embodiment the space is restricted on one side of the appliance and two of the clamping means 115 have been positioned on the shorter sides of the rectangular plug part 150 thereby leaving one long side free to enable the plug part 150 to be installed within the space available. It is expected that other appliances may have restrictions in alternative positions for the plug part. It may be uneconomical to provide specific plug mouldings for each type of appliance, therefore it is envisaged that the tooling for the plug part 150 may have inserts so that the position and type of clamping means 115 on the plug part moulding can be adapted to suit specific appliance requirements.

[00143] The adapter 200 is designed to fit within the same appliance requirements and it is also envisaged that the tooling for the adapter could have selectable inserts, to avoid providing separate tools for each variant.

Compliance

[00144] In any of the embodiments, some form of compliance may be included to enable plug 150 and socket 100 parts to mate easily. In some embodiments it may be necessary for two parts of the appliance to dock separately during use; for example, the first parts to dock may form a water conduit connection and the second parts may form an electrical connection in which the tolerances for the first connection are tighter than the tolerances required for the electrical connection.

[00145] In other embodiments the first connection may be a centrally mounted motor which exerts force on the peripherally mounted second electrical connector during use, for example, as the motor changes direction or speed.

[00146] In further embodiments there may be a locking mechanism that adds lateral or vertical pressure onto the electrical connection and it may be important that this pressure does not cause unnecessary stress on the electrical connection. Vertical tolerance may be achieved with either upward- or sideways-acting resilient springs 152 connecting with corresponding pins.

[00147] Lateral compliance can be provided in a number of ways. In its simplest form this lateral tolerance can be provided by the apertures 121 of the socket 100 being wider than the male pin parts so that, providing the electrical connecting parts are resilient to sideways movement, a lateral tolerance is achieved.

[00148] The cross section of apertures 121 of the socket should not be increased above a dimension that allows the user access to live parts (determined by the short test probe 13 of IEC 61032), therefore the maximum amount of compliance is limited to the difference between the cross section of the aperture 121 and the cross section of the pins. In practice, with pins of 2 mm cross-section, the maximum lateral compliance is approximately 1 mm. In some cases, 1 mm lateral compliance may not be sufficient. [00149] A shutter 332 may be used to assist in preventing user access to live parts so that where a shutter is employed the apertures 121 can be made larger and the lateral compliance increased. The fifth embodiment includes one such example of this method, where the interface between the socket 100 and plug 150 parts are outboard of a central aperture 525. The apertures 121 include a rotating shutter 522 and the whole assembly facilitates a lateral compliance as the plug 150 and socket 100 parts dock and then provides rotational compliance around the central aperture to compensate for forces applied by, for example, a motor and/or a locking mechanism.

[00150] For mating plugs 150 and sockets 100 without shutters, one way of increasing the lateral compliance is to allow at least one of the components to slide in the direction that the compliance is required. Given that the plug part 150 is sealed into the appliance, it is expected that the lateral compliance will be provided by the socket part 100. In sockets that rely upon a flexible water ingress shield 130 it is not expected that an enlarged aperture 131 in the flexible water ingress shield will prevent access to live parts. Therefore if the shield aperture 131 is increased in size, it will still be necessary to limit the size of the socket aperture 121 and if the socket aperture 121 is increased in size it will be necessary to limit the size of the shield aperture 131.

[00151] One solution is for the entire plug part 100 (including a flexible water shield if fitted) to be clamped within the appliance base such that the plug part has lateral compliance in any direction. This could be achieved by enlarging the aperture (not shown) in the appliance base through which the plug part 100 is mounted such that the flange 114 is slidably clamped beneath the base aperture. In other embodiments where the lateral compliance is only required in one plane, for example from side to side, then the aperture in the appliance base may made wider in that plane only. In both embodiments it would be necessary to ensure that the flange 114 is of a sufficient size such that it is wider than the base aperture (not shown) at the extremes of the compliance.

[00152] In other embodiments it may be possible to incorporate a fixed flexible water shield 130 on the top side of the appliance aperture with enlarged apertures 131 and a slidably clamped socket part 100 beneath it.

[00153] In a further embodiment, the flexible water shield 130 and the plug part 100 may be clamped around an aperture so that both parts move relative to the aperture. The flexible water shield may be sized such that the movement of the plug 150 relative to the base aperture (not shown) is not visible to the user. Angular compliance, if required, could be achieved by a combination of the abovementioned solutions for vertical and lateral compliance. In each of the embodiments it may be necessary to provide an external stop to limit the lateral, vertical and/or rotational movement of the appliance before the maximum compliance of the electrical connections is achieved. The stop could be provided within the appliance proper or within the appliance base part or within the plug 150 and socket 100 parts or a combination thereof. In further embodiments, this stop could take the form of a damping mechanism, for example, a spring or resilient material that effectively restricts the speed and force of the movement between the appliance and the base part.

Eleventh Embodiment

[00154] The eleventh embodiment, which is illustrated in Figures 11a to Hd, is a variant of the first, second and tenth embodiment. The system has a rectangular profile including round pins with critical dimensions as follows:

Dimension M 10.97 mm

Dimension N 9.00 mm

Dimension P 20.00 mm

Diameter S 3.00 mm

[00155] The socket part 100 has five resilient springs contacts (not illustrated) with contact Al being a double side acting earth connection and contacts Bl, Cl, Dl and El being upward acting.

[00156] The main socket moulding 110 includes additional shrouding 116 to cover the electrical connections Al, Bl, Cl, Dl and El. The main socket moulding includes five circular apertures 121 and a flange 114.

[00157] This embodiment includes a flexible water ingress shield 130 that can be attached as a separate part. The water shield 130 and socket 100 can be installed as detailed above to provide lateral compliance in this embodiment, in which case it may be necessary to increase the size of the flange 114 so that the socket 100 can be slidably mounted to provide lateral compliance.

[00158] The preferred material for the flexible shield is rubber or equivalent, for example, a silicone-based compound. The plug part 150 has five circular shaped pins A2- E2 that are sealed into the plug sealant pockets 357. The pins may be insert moulded into plug moulding 160. The pins may include knurls 167 so that they are better secured in the seal and/or moulding, for example, to prevent being pushed through the moulding and/or seal if excessive upward force is applied to the pins. In further embodiments the pins may be secured, for example by insert moulding, without the need for the additional sealant

357.

[00159] Each of the pins A2-E2 interfaces with corresponding resilient springs Al-

El in the socket part 100. In this embodiment the earth pin A2 is connected to an appliance body via an earth link 117 which is resiliently clamped to the metal body during the assembly of the plug 150 to the appliance (not shown). Pins B2, C2, D2 and E2 are connected to resilient contacts within the adapter 200 or directly to the appliance (not shown).

[00160] The footprint of the plug part 150 has been further reduced by bringing the two attachment points 115 on the longer sides of the plug 150 closer to the earth terminal.

The plug 150 is provided with a shaped O-ring 172 having re-entrant sides adjacent the attachment points 115 on the longer sides of the plug 150. This arrangement provides uniform bolt spacing and thus pressure on the O-ring.

Alternative Embodiments

[00161] The above embodiments are described purely by way of example, and features may be combined between the embodiments unless they are mutually incompatible. The embodiments are not limiting on the scope of the invention as defined by the accompanying claims.

Claims

1. A power connector for a domestic appliance, comprising a central terminal and at least three peripheral terminals distributed around the central terminal, the peripheral terminals being substantially equally spaced from the central terminal.

2. The connector of claim 1, comprising at least four said peripheral terminals.

3. The connector of claim 1 or 2, wherein the peripheral terminals are arranged in a rectangular configuration around the central terminal.

4. The connector of claim 3, wherein the peripheral terminals are arranged in a square configuration around the central terminal.

5. The connector of claim 3 or 4, comprising four said peripheral terminals arranged at the respective corners of a peripheral rectangle having the central terminal substantially at the centre thereof.

6. The connector of any one of claims 3 to 5, further comprising a plurality of additional terminals arranged further from the central terminal than said peripheral terminals.

7. The connector of claim 6, wherein the additional terminals and the peripheral terminals are arranged around the perimeter of an additional rectangle.

8. The connector of claim 1 or 2, wherein the peripheral terminals are arranged in a circular configuration around the central terminal.

9. The connector of claim 8, wherein the peripheral terminals are substantially equally spaced around the perimeter of a peripheral circle having the central terminal substantially at the centre thereof.

10. The connector of claim 9, comprising six said peripheral terminals.

11. The connector of claim 9, comprising eight said peripheral terminals.

12. The connector of any one of claims 8 to 11, further comprising a plurality of additional terminals arranged in an additional circle having the central terminal substantially at the centre thereof and having a radius greater than that of the peripheral circle.

13. The connector of claim 12, wherein the additional terminals are substantially equally spaced around the perimeter of the additional circle.

14. The connector of any preceding claim, wherein at least one of the terminals comprise a projecting pin.

15. The connector of claim 14, wherein the projecting pin is substantially free of insulating material.

16. The connector of claim 14, wherein the projecting pin comprises an insulating shroud from which the distal end of the pin projects.

17. The connector of any one of claims 14 to 16, wherein the projecting pin is sealed within a housing by a pin seal.

18. The connector of claim 17, wherein said pin seal comprises a sideways compression seal.

19. The connector of any one of claims 14 to 18, wherein a portion of the pin secured within the housing has a textured surface.

20. The connector of claim 19, wherein the textured surface comprises a ridged, grooved and/or knurled surface.

21. The connector of any one of claims 14 to 20, wherein a resilient contact is provided on or around an end of the pin.

22. The connector of claim 21, including an adapter comprising a contact portion connected to said resilient contact and an adapter terminal electrically connected to or integrated with the contact portion.

23. The connector of claim 22, including an aperture allowing connection to the central terminal therethrough.

24. The connector of claim 22 or 23, wherein the adapter is arranged to be mountable on a part of an appliance.

25. The connector of any one of claims 14 to 24, wherein at least one of the projecting pins has a rectangular cross-section.

26. The connector of claim 25, wherein the major dimension of the rectangular cross- section is between 1.5 mm and 4.5 mm.

27. The connector of claim 25 or 26, wherein the minor dimension of the rectangular cross-section is between 1.5 mm and 4.5 mm.

28. The connector of claim 25, wherein at least one of the projecting pins has a square cross-section.

29. The connector of claim 28, wherein the square cross-section has a side of between 1.5 mm and 4.5 mm.

30. The connector of any one of claims 14 to 29, wherein at least one of the projecting pins has a circular cross-section.

31. The connector of claim 30, wherein the diameter of the circular cross-section is between 2 mm and 3.25 mm.

32. The connector of any preceding claim, wherein at least some of the terminals comprise resilient contacts.

33. The connector of claim 32, wherein at least some of said resilient contacts are arranged to contact the distal end of a corresponding connecting pin so as to exert a force against the distal end.

34. The connector of claim 32 or 33, wherein at least some of said resilient contacts are arranged to contact the side of a corresponding connecting pin.

35. The connector of any preceding claim, wherein at least some of the terminals are sealed within the connector with a sealant.

36. The connector of claim 35, wherein the sealant is provided in discrete portions for the respective said terminals.

37. The connector of any preceding claim, wherein at least an electrical contact part of one or more of the terminals is coated with an electrically conductive, inert material.

38. The connector of any preceding claim, including means for biasing the connector away from a corresponding connector during separation thereof, the means for biasing being discrete from said terminals.

39. The connector of any preceding claim, wherein the central terminal is arranged as an earth terminal.

40. The connector of any preceding claim, wherein the peripheral terminals are arranged to include at least one live terminal.

41. The connector of any preceding claim, wherein the peripheral terminals are arranged to include at least one neutral terminal.

42. The connector of any preceding claim, wherein the peripheral terminals are arranged as alternating live and neutral terminals.

43. The connector of any preceding claim, wherein the peripheral terminals are arranged to include at least one low voltage signal terminal.

44. The connector of any preceding claim, wherein the centre separation of the peripheral terminals from the central terminal is between 10.3 mm and 13.3 mm.

45. The connector of any preceding claim, wherein the minimum centre separation of any of the peripheral terminals from an adjacent one of the peripheral terminals is between 8.8 mm and 11.1 mm.

46. The connector of any preceding claim, including a shroud arranged around the peripheral terminals.

47. The connector of any preceding claim, configured as a plug part.

48. The connector of claim 47, wherein the plug part includes a gasket seal.

49. The connector of any preceding claim, configured as a socket part.

50. The connector of claim 49, including a seal arranged substantially to prevent ingress of liquid into the socket part.

51. The connector of claim 50, wherein the seal is insert moulded into the socket part.

52. The connector of claim 50, wherein the seal is provided as a discrete shield for the socket part.

53. The connector of any one of claims 49 to 52, wherein the seal includes seal apertures allowing corresponding pins to pass therethrough.

54. The connector of claim 53, wherein the seal apertures comprise slits.

55. The connector of claim 49, including a shutter arranged substantially to prevent ingress of liquid into the socket part.

56. A cordless power connector socket having at least four terminals, including an insert moulded seal arranged substantially to prevent ingress of liquid into the socket.

57. A cordless connector comprising at least four peripheral terminals arranged around a central aperture.

58. The connector of claim 57, wherein the central aperture contains a mechanical coupling.

59. A cordless power connector for a domestic appliance, comprising at least four terminals arranged around the perimeter of a circle and a rotatable shutter arranged to provide access to the terminals when open and to protect the terminals from ingress of liquid when closed.

60. The connector of any preceding claim, configured as a discrete component for assembly into an appliance part.

61. A power connector comprising a discrete component having at least four terminals and having a plurality of fixing points, arranged around a substantially rectangular periphery of the connector, for fixing the component to the appliance part, wherein at least one longer side of the rectangular periphery is re-entrant such that one of the fixing points arranged on said longer side is positioned towards the centre of the connector.

62. A power connector comprising a discrete component having at least four terminals and having a plurality of fixing points for fixing the connector to the appliance part, the fixing points being unevenly distributed around the periphery of the connector.

63. The connector of claim 62, wherein one side of the periphery of the connector is free from said fixing points.

64. The connector of claim 62 or 63, wherein the periphery of the connector is substantially rectangular.

65. The connector of claim 64, wherein a long side of the rectangular periphery is free from said fixing points.

66. The connector of any one of claims 61 to 65, wherein the fixing points are arranged to clamp a compression seal between the connector and the appliance part.

67. The connector of claim 66, wherein the compression seal comprises a ring corresponding substantially to the shape of the periphery of the connector.

68. The connector of any preceding claim, having a thermal control integrated therewith.

69. The connector of any preceding claim, configured as a cordless connector.

70. The adapter of any one of claims 22 to 24.

71. An appliance having an internal plug part as claimed in claim 47 and a corresponding internal socket part as claimed in claim 49.

72. The appliance of claim 71, having a further, external plug part as claimed in claim 47, for detachable connection to a corresponding socket part.

73. The appliance of claim 71 or 72, configured as a cordless appliance.

74. A cordless base including the connector of any one of claims 1 to 69.

75. A detachable appliance part including the connector of any one of claims 1 to 69.

76. The appliance part of claim 75, including a thick film heating element, wherein at least one of the terminals is connected to a heating track of the heating element by means of a resilient contact.

77. The appliance part of claim 75, including a thick film heating element having a plurality of heating tracks connected to respective ones of the peripheral terminals.

78. An appliance having a power connector, comprising a central terminal and at least three peripheral terminals distributed around the central terminal, the peripheral terminals being substantially equally spaced from the central terminal.

79. A connection system comprising a plug part as claimed in claim 47 and a corresponding socket part as claimed in claim 49.

80. The connection system of claim 79, wherein corresponding terminals of the plug and socket parts are arranged to make electrical contact at a plurality of different relative rotational orientations thereof.

81. The connection system of claim 80, including registration means arranged to restrict the relative rotational orientations at which the plug and socket parts may be coupled to those at which the corresponding terminals of the plug and socket parts are arranged to make electrical contact therebetween.

82. The connection system of any one of claims 79 to 81, wherein there is compliance between the plug part and the socket part.

83. The connection system of claim 82, wherein the compliance comprises lateral compliance.

84. The connection system of claim 82 or 83, wherein the compliance comprises compliance in the direction of coupling of the plug part and the socket part.

85. The connection system of any one of claims 82 to 84, wherein the compliance comprises rotational compliance.

86. The connection system of any one of claims 82 to 85, wherein at least a component of the plug and socket parts is slideable in the direction of compliance.

87. An appliance including the connection system of any one of claims 79 to 81.

88. The appliance of claim 87, configured as a cordless appliance.

89. A connection component comprising a first connector as claimed in any one of claims 1 to 59 and a second connector as claimed in any one of claims 1 to 59, corresponding terminals of the first and second connector being connected together within the connection component.

90. An appliance having a connection part comprising a plurality of connectors, each as claimed in any one of claims 1 to 59, and a corresponding plurality of detachable parts each connectable to the connection part by means a corresponding connector as claimed in any one of claims 1 to 59.

91. The appliance of claim 90, wherein the connection part is connectable to a power supply so as to provide electrical power to the plurality of detachable parts.

92. The appliance of claim 90 or 91, wherein the connection part is arranged to make a signal connection to at least one of the detachable parts.

93. The appliance of claim 92, wherein the connection part is arranged to make a signal connection between at least a first and a second one of said detachable parts.

94. The appliance of claim 93, wherein said first and second detachable parts are arranged to be operably interactive.

95. The appliance of any one of claims 92 to 94, wherein the connection part provides a signal bus.

96. The appliance of any one of claims 92 to 95, wherein the connection part includes an electronic control.

97. The appliance of any one of claims 90 to 96, wherein a first of said detachable parts comprises a base part and the second of the detachable parts comprises an appliance part supportable by the base part.

98. The appliance of claim 90 to 96, wherein said detachable parts comprise discrete heating parts.

99. The appliance of any one of claims 90 to 98, wherein the connection part includes a support for supporting the connection part when disconnected from said detachable parts.

100. A power connection system comprising a first connector and a corresponding second connector, the first and second connectors having corresponding terminals arranged so that electrical connection is made between the corresponding terminals by relative rotation of the first and second connectors when coupled together.

101. The power connection system of claim 100, wherein the corresponding terminals each comprise a pin and a resilient contact arranged to contact the pin when the first and second connectors are rotated relative to each other.

102. The power connection system of claim 100 or 101, wherein the corresponding terminals are arranged around the perimeter of a circle.

103. The power connection system of claim 102, including at least one set of additional corresponding terminals outside said circle.

104. The power connection system of claim 102 or 103, including a mechanical coupling arranged within the perimeter of the circle.

105. The power connection system of any one of claims 102 to 104, wherein the corresponding terminals are arranged to make electrical contact at a plurality of different relative rotational orientations of the first and second connectors.

106. The power connection system of any one of claims 100 to 105, configured as a cordless power connection system.