GB2477944A

GB2477944A - Cordless electrical appliance with optical coupling between power base and appliance

Info

Publication number: GB2477944A
Application number: GB1002777A
Authority: GB
Inventors: David Andrew Smith; Robert Henry Hadfield; Antonio Martin Gaeta; Ian Geoffrey White; Robin Keith Moore; Yuan An; Peter Hallam Wright; Jeremy Siddons; Andrew Hunt; Paul Boundy; Simon M Whiteley
Original assignee: Otter Controls Ltd
Current assignee: Otter Controls Ltd
Priority date: 2010-02-18
Filing date: 2010-02-18
Publication date: 2011-08-24
Anticipated expiration: 2030-02-18
Also published as: EP2536317A2; WO2011101642A2; JP2013519485A; CN102762135B; GB201017391D0; GB201003611D0; JP5950829B2; GB2478021A; GB2478026A; CN102762135A; GB201003471D0; GB201002777D0; GB201021926D0; GB201008015D0; GB2478163A; GB2478163B; WO2011101642A3; GB201019649D0; GB2477944B

Abstract

A cordless electrical appliance such as a kettle, food processor or blender, comprises an appliance proper 1, a power base 2, and a component fixed in the appliance by means of a seal (21) arranged to provide optical communication between the appliance proper 1 and the power base 2. The component may be a cordless 360° electrical connector 3, 4 and may be located in either the appliance proper 1 or the power base 2. The seal (21) may include an optical device and/or a light guide and may provide a 360° optical coupling. An optical transmitter (31) in the seal (21) may communicate a sensed property to a receiver (31) located in the power base 2, wherein the power base 2 switches power to the appliance proper 1 in response to the sensed property.

Description

Cordless Electrical Appliances

Field of the Invention

[0001] The present invention relates to cordless electrical appliances and components therefor.

Background of the Invention

[0002] In a cordless appliance, the appliance proper includes a cordless connector that is operable to cooperate with a corresponding cordless connector on a power base. Thus, when the appliance proper is mounted on the power base, power may be supplied to the appliance proper. Such arrangements allow a power base to be connected to a domestic power supply (such as by a plug), whilst further allowing the appliance proper to be removed from the base for various operations, such as dispensing heated liquid from a cordless liquid heating appliance. The above types of cordless electrical connectors have also found use on other domestic appliances, such as food processors, blenders and the like. This arrangement provides an advantage that the processed/blended food can be more easily dispensed by a user.

[0003] 360° cordless connectors, as described for example in WO-A-94/06185, allow the appliance proper to be rotated freely relative to the power base, so that the appliance proper may be positioned on the power base with any azimuthal orientation.

[0004] However, 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.

[0005] 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. Sealing arrangements for such a washproof appliance are disclosed in WO-A-09/109762.

[0006] It would be preferable to minimize the components in the appliance proper that need to be sealed, such as electrical components. For example, electrical power switching components may be located in the power base, but this requires some means of signalling the state of the appliance proper to the power base, so that power may be switched in response to the state of the appliance proper.

[0007] One way of signalling from the appliance proper to the power base is to provide additional electrical contacts therebetween, for example as disclosed in GB-A-23788 18 or in WO-A-01/282294. However, these additional contacts must themselves be sealed if the appliance proper is to be washable. Moreover, any debris on the low voltage contacts may prevent electrical contact from being made, and the debris will not be burnt away as might occur on high-voltage contacts.

[0008J WO-A-2008/155538 discloses a cordless appliance with wireless signalling between the appliance proper and the base, for example by means of a circular light guide concentric with a cordless electrical connector. Whilst this arrangement is advantageous in that it allows signalling between the appliance proper and the base while allowing the use of 3600 cordless connectors, the arrangement requires additional optical connecting components which add to the complexity of the arrangement.

Statement of the Invention

[0009] According to one aspect of the present invention, there is provided a cordless electrical appliance comprising an appliance proper and a power base connectable together by means of respective cordless electrical connectors, the appliance proper having a component sealed therein by means of a seal and being arranged to communicate with the power base by means of electromagnetic radiation conveyed through the seal. Preferably, the electromagnetic radiation comprises light and the seal is arranged to act as a light guide for the light.

[0010] Advantageously, this arrangement allows wireless signalling between the appliance proper and the base without the need for an additional light guide, thereby allowing the appliance proper to be made washable with fewer components.

[0011] The seal may be concentric with the cordless electrical connector on the appliance proper, and the power base may include optical communication means arranged to interact with the seal when the appliance proper and the power base are connected electrically together, regardless of the relative rotation of the cordless electrical connectors.

Advantageously, this arrangement allows the use of 360° cordless connectors. The seal may be arranged to seal the cordless electrical connector within the appliance proper.

[0012] The seal within the appliance proper and/or the power base may include an optical transmitter and/or receiver located within the seal, for example within a pocket in the seal.

This arrangement improves the optical coupling between the seal and the transmitter and/or receiver.

[0013] An additional light guide may be positioned in optical communication with the seal and within the power base andior electrical appliance.

Brief Description of the Drawings

[0014] There now follows, by way of example oniy, a detailed description of preferred embodiments of the present invention, with reference to the figures identified below.

Figure 1 is a schematic cross-section of a cordless liquid heating appliance in an embodiment of the invention.

Figure 2 is a schematic diagram of the electrical and optical components of the cordless liquid heating appliance.

Figure 3a is an isometric view of a waterproof cordless connector for a vessel body in an embodiment of the invention.

Figure 3b is an exploded view of the underside of the waterproof cordless connector for the vessel body.

Figure 4a is an isometric view of a waterproof cordless connector for a power base in an embodiment of the invention.

Figure 4b is an isometric view of the underside of the waterproof cordless connector for the power base.

Figure 4c is an exploded view of the waterproof cordless connector for the power base.

Figure 5 is a cross-section of the waterproof cordless connectors for the vessel body and the power base, connected together.

Figure 6 is a side view of a waterproof cordless connector for the vessel body, in an alternative embodiment.

Figure 7 is a side view of a waterproof cordless connector for the vessel body, in another alternative embodiment.

Detailed Description of the Embodiments

[0015] In the following description, functionally similar parts carry the same reference numerals between different embodiments.

Cordless Electrical Appliance [0016] Figure 1 shows schematically a jug kettle with an electronic control, as an example of an appliance to which embodiments of the invention may be applied. In this example, the kettle is a cordless kettle comprising a vessel body 1 and a power base 2 having respective body and base cordless connectors 3 and 4, such as 360° cordless connectors of the type described in patent publication WO-A-94/06 185 and/or as sold by Otter Controls Ltd. under the CS4/CS7 (power base socket) and CP7 or CP8 (appliance plug) references. The power base is connectable by a power cord 13 to an electrical power outlet (not shown).

[0017] The vessel body 1 comprises a reservoir 5 for containing water to be heated, and a base section 6 having a sub-base 19, which forms the bottom surface of the vessel body 1.

The vessel body 1 is formed as a jug kettle and therefore has a spout 7, a lid 8 and a handle 9. Water is heated by an element plate 12 forming the base of the reservoir 5, and including a heating element on the underside (i.e. facing towards the base section 6), connected to receive electrical power from the body cordless connector 3. The element plate 12 may be fitted into the vessel body using the Easifix (RTM) fitting as described in WO-A-99/17645.

The element may comprise a sheathed element and/or a thick film element. Preferably, the element plate is composed of stainless steel. Most preferably, the element plate is substantially as described in WO-A-06/83 162. However, at least some embodiments of the present invention are applicable to a liquid heating vessels having an immersed heating element, rather than an element plate.

[0018J A sensor 14 is arranged to sense the state of water in the reservoir 5. The sensor 14 is connected to an appliance control 15 which communicates with a base control 10 by means of an optical signal which is conveyed (as shown by a dashed line) through the cordless connectors 3 and 4. A user interface 11 allows the user to operate the vessel, and may provide a display of the operational state of the vessel. The user interface may be provided in the vessel body 1 and/or in the power base 2.

100191 The operational state of the vessel is controlled in response to the sensor 14 and the user interface 11, by means of communication between the appliance control 15 and the base control 10. One example will now be described with reference with Figure 2.

[0020] The optical communication link between the vessel body 1 and the base 2 comprises an optical emitter and/or detector 31 in the base 2, which communicate respectively with an optical emitter and/or detector 31 in the vessel body 1, by means of an optically transmissive seal 21 which allows 360° of relative rotation between the base 2 and the body 1.

[0021] A power control 18 is provided in the vessel body 1 and is arranged to switch the supply of electrical power to the element plate 12, under the control of the vessel control 15.

A vessel PSU (power supply unit) 17 provides a low voltage power supply to the vessel control 15, which may be a microcontroller. A base PSU 16 provides a low voltage power supply to the base control 10, which may be a microcontroller.

[0022] The user interface 11 may be divided between the base 2 and the vessel body 1 as follows. The base 2 includes LED status indicators 1 la, user input means 1 lb (such as push buttons or switches) and/or audible output means 11 c, such as a piezo sounder. The vessel body 1 may include lighting means lid arranged to illuminate a part of the vessel body 1 and/or the contents of the reservoir 5, so as to indicate the state of the vessel and/or to provide an aesthetic effect.

[0023J Hence, in this embodiment it is necessary for the base control 10 to communicate with the vessel control 15, for example to switch the power to the element plate 12 in response to a user input at the user input means 1 lb. This communication is provided by means of the optical communications link.

[0024] In other embodiments, the power control 18 may be provided in the base 2, so that it is necessary for the vessel control 15 to communicate with the base control 10 in order to switch power in response to an input from the sensor 14. Tn this embodiment, the optical communication may be unidirectional from the body 1 to the base 2, which is advantageous in that the optical communications link is simplified. However, the optical communication between the vessel body 1 and the base 2 may be unidirectional or bi-directional, depending on what information needs to be communicated. The same optical communications link may be used to support multiple functions between the power base 2 and the vessel body 1.

[0025] In an alternative embodiment, the vessel control 15 may simply communicate the output of the sensor 14 optically to the base control 10. In yet another embodiment, the vessel control 15 may be dispensed with altogether, and the sensor 14 may provide a direct optical output. For example, the sensor 14 may be arranged to detect light reflected off or passing through the surface of liquid in the reservoir 5, as described for example in WO-A- 2009/060 192. Light may also be conveyed to the surface of the liquid through the optical interface between the vessel body 1 and the base 2. In this embodiment, the sensor 14 may simply comprise a light guide, which therefore provides a very simple sensing arrangement within the vessel body 1.

[0026] It will be apparent from the above discussion that control, power switching, user interface and sensing functions may be distributed in many different ways between the body 1 and the base 2, any of which may require unidirectional or bidirectional optical communication between the body 1 and the base 2.

[0027] The vessel may have one or more additional features, such as a keep warm' feature, in which the liquid is maintained around a predetermined temperature, preferably after boiling; this may be done by intermittent activation of the main heating element, or by intermittent or continuous activation of a secondary heating element (not shown). The predetermined temperature may be just below boiling point, or a lower temperature such as 80°C, and may be selectable by the user.

[0028] Another heating feature is a sub-boil feature, in which the liquid is heated up to a predetermined temperature below boiling, such as 80°C for making coffee, and the heating power is then switched off or reduced, for example to activate a keep warm mode. The predetermined temperature may be selectable by the user.

[0029] Another heating feature is a prolonged boil feature, whereby the liquid is heated to boiling and then boiled for at least a predetermined time, such as 30 seconds to 2 minutes, to sterilize the liquid.

Cordless Connectors 10030] The cordless connector 3 of the vessel body 1 will now be described in more detail with reference to Figures 3a, 3b and 5. The cordless connector 3 is attachable to the sub-base 19 by attachment means such as bosses 3a. A seal 21 is provided around the circumference of the connector 3 for sealing against the sub-base 19 to prevent liquid entering the base portion 6. The seal 21 preferably comprises a main body 22 that fits against the outer side wall of the connector 3, and one or more circumferential protrusions or fins 23 extending between the connector 3 and the sub-base 19. As shown in Figure 5, the fins 23 deform against a side wall of the sub-base 19 and thereby seal the gap between the connector 3 and the sub-base 19, which gap may be variable in size depending on the tolerances and/or thermal expansion of the components.

10031] At least the main body 22 of the seal 21 comprises a material that is both resilient and optically transmissive, such as a translucent silicone material. One possible material is disclosed in JP-A-2008291 124, in the context of a light conductive plate for illuminating the keypad of a mobile phone. The fins 23 need not be optically transmissive and may be made of a different material selected for resilience, for example.

[0032] The seal 21 may be a preformed seal that is assembled onto the connector 3, alternatively, the seal may be formed in the gap between the connector 3 and the sub-base 19, for example using a liquid sealant that sets within the gap. Alternatively, the seal 21 could be formed as part of the sidewall of the connector 3, such as a twin-shot seal.

[0033] The main moulding of the connector 3 includes one or more light emitter/receiver housings 32, each of which may hold a respective light emitting and/or receiving device 31, such as an LED or a photosensor. The wavelength of light that is transmitted and received may be in the visible range, or infrared for example. The wires of the or each device 31 are preferably held in place by wire supports 34 forming part of the main moulding. The wires are connected to the vessel controller 15.

[0034] As best shown in Figure 3b, the cordless connector 3 also includes live, neutral and earth terminals for connection to the element power control 18 and/or directly to the heating element.

[0035J The cordless connector 3 may be provided as a discrete component together with the seal 21 and optionally with the device(s) 31, for assembly into any suitable form of sub-base 19.

[0036] The cordless connector 4 of the power base 2 will now be described in more detail with reference to Figures 4a, 4b and 5. The cordless connector 4 includes an outer moulding 53 that fits within the cordless connector 3 of the vessel body 1. The live and neutral terminals of the cordless connector 4 are protected by a shutter seal 54 that is displaced by the cordless connector 3.

[0037] The cordless connector 4 includes an annular light transmitter 41 that is fitted onto an outer moulding 53, for example by means of corresponding click or bayonet fittings 43, 56. The annular light transmitter 41 is made from optically transparent or translucent material. Light emitting and/or receiving optical devices 31 are received in pockets or housings 42 in the annular light transmitter 41, to ensure good optical coupling between the devices 31 and the annular light transmitter 41. The housings 42 extend through apertures in the outer moulding 53 and the devices 31 are held in place against housing abutments 57 in the outer moulding 53 when the light transmitter 41 is fitted onto the outer moulding 53. A seal 44 is also held between the annular light transmitter 41 and the outer moulding 53, to prevent liquid ingress to the devices 31. The seal 44 in this case is not arranged to conduct light between the devices 31 and the light transmitter 41.

[0038] In an alternative embodiment, the annular light transmitter 41 may be integrated with the outer moulding 53, for example by means of a twin shot process, or the outer moulding may be substantially or entirely composed of optically transmissive material.

[0039] When the cordless connectors 3 and 4 are connected together as shown in Figure 5, light is conducted between the devices 31 of the power base 2 and of the vessel body 1 through the seal 21 and the annular light transmitter 41, regardless of the relative rotation of the cordless connectors 3 and 4. Precise alignment is not required between the optical devices 31 of the power base 2 and of the vessel body 1, because the seal 21 and/or the annular light transmitter 41 act as light guides or diffusers.

[0040] In order to provide a 360° optical coupling, it is not essential that both the optical connections on the power base 2 and the vessel body 1 subtend 3600; only one or neither of the connections may do so, provided that there is always some optical coupling between them, for example as a result of overlap between them. For example, in an alternative embodiment, each of the emitters acting through the seal 21 in the appliance may have an effective range or spread of 120° in which case the sensor 31 in the base 2 can be positioned at any po mt beneath the seal 21, and there would be no need for an annular light transmitter 41 inthe base 2.

[0041] Figure 6 shows a variant of the cordless connector 3 of the vessel body 1, in which the seal 21 includes a pocket 24 into which the optical device 31 fits, so as to improve the optical coupling between the device 31 and the seal 21.

100421 Figure 7 shows another variant of the cordless connector 3 of the vessel body 1, in which an annular light transmitter 46 is disposed between the optical device 31 and the main body 22 of the seal 21, so as to improve the optical coupling between the device 31 and the main body 22 of the seal 21. The annular light transmitter 46 has a housing 45 into which the optical device 31 fits, so as to improve the optical coupling between the device 31 and the annular light transmitter 46.

[0043] In each embodiment, the optical device(s) 31 and any housing 45 or pocket 24 therefor may be arranged at an angle to the annular light transmitter 41, 46 or the seal 21 respectively, to improve the optical coupling thereto, or to enhance the light guiding effect of the annular light transmitter 41, 46 or the seal 21 Alternative Embodiments [0044] In the above embodiments, the cordless connectors 3 and 4 could be reversed, so as to be provided respectively in the power base 2 and the vessel body 1. Alternatively, the power base 2 and the vessel body 1 may both have cordless connectors in which a seal is used to provide an optical coupling.

[0045] In an alternative embodiment, a seal other than that around the cordless connector may be used to provide an optical coupling between the power base 2 and the vessel body 1: for example, a seal between the sub-base 19 and the side wall of the vessel 1.

[0046] Some of the light generated by the optical device(s) 31 may be diffused in such a way as to be visible to the user when the vessel 1 is connected to the power base 2, for example to indicate to the user that optical communication is taking place, or for aesthetic effect.

[0047] The embodiments described above are illustrative of rather than limiting to the present invention. Alternative embodiments apparent on reading the above description may nevertheless fall within the scope of the invention.

Claims

Claims 1. A cordless electrical appliance comprising an appliance proper and a power base, the appliance having a component sealed therein by means of a seal arranged to provide an optical coupling between the appliance proper and the power base.
2. The appliance of claim 1, wherein the component comprises a cordless electrical connector.
3. The appliance of claim 2, wherein the seal is concentric with the cordless electrical connector.
4. The appliance of claim 2 or 3, wherein the cordless electrical connector is a 3600 cordless connector.
5. The appliance of claim 4, wherein the optical coupling is a 3600 optical coupling.
6. The appliance of any preceding claim, wherein the component is sealed within the appliance proper.
7. The appliance of any preceding claim, including an optical device optically coupled to the seal.
8. The appliance of claim 7, wherein the optical device is located within the seal.
9. The appliance of any preceding claim, including a light guide optically coupled with the seal.
10. The appliance of any preceding claim, wherein the appliance proper includes an optical transmitter arranged to communicate through the seal to an optical receiver in the power base.
11. The appliance of claim 10, wherein the optical transmitter is arranged to communicate a sensed property of the appliance proper to the optical receiver.
12. The appliance of claim 11, wherein the power base is arranged to switch power to the appliance proper in response to said sensed property.
13. An electrical component having a seal for sealing the component within an appliance and/or power base, and optical communication means for optical communication through the seal.
14. The component of claim 13, comprising a cordless electrical connector.
15. A cordless electrical appliance substantially as herein described with reference to and/or as shown in the accompanying drawings.
16. A cordless electrical connector, seal and optical communication means substantially as herein described with reference to and/or as shown in the accompanying drawings.