GB2542554A

GB2542554A - Cordless connectors

Info

Publication number: GB2542554A
Application number: GB1516341.3A
Authority: GB
Inventors: Hallam Wright Peter; Martin Gaeta Antonio; Neill Orritt Trevor; M Whiteley Simon
Original assignee: Otter Controls Ltd
Current assignee: Otter Controls Ltd
Priority date: 2015-09-15
Filing date: 2015-09-15
Publication date: 2017-03-29
Anticipated expiration: 2035-09-15
Also published as: GB201516341D0; CN206422354U; GB2542554B

Abstract

A cordless electrical connector 7 for a cordless electrical appliance is protected from any liquid which may fall from above by a protective cap or cover 10, which protects electrical terminals 9a, 9b, 9c of the plug connector 7 from the liquid. Alternatively, or in addition, the terminals may not extend outwardly of the body of the connector, see Fig 8a.

Description

Cordless Connectors Field of the Invention [0001] The present invention relates to electrical appliances and components therefor, and particularly, although not exclusively, cordless connectors for domestic appliances for heating liquids.

Background of the Invention [0002] In a cordless appliance, the appliance proper includes a cordless plug 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, 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 milk frothers, soup makers, soya milk makers, 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 the applicant’s patent publication WO-A1-94/06185, 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] Appliances such as milk frothers, soup makers and soya milk makers and the like often have mechanical stirrers to process the liquid being heated. In many cases the stirrers are driven by an electric motor situated beneath the heated vessel via a shaft which passes through the bottom of the vessel. These appliances may be of the cordless variety described above or of the kind with a fixed corded connection.

[0005] The shaft which passes through the bottom of the vessel is sealed to stop the liquid leaking out of the vessel but it is not uncommon that the seal fails, allowing milk in the case of a milk frother or some other liquid to leak into the cavity below the vessel. If this falls onto the top of the cordless plug connector or some other electrical component situated below the motor driving the stirrer there is a danger of an electrical insulation failure between the live and neutral or live and earth connections of the connector or other component, putting the user at risk of electrocution or potentially starting a fire. This problem can also be encountered in kettles having a component that extends through the floor of the vessel, such as a thermal sensor as shown in DE202005000950U1 or light source as shown in GB-A-2497978A.

[0006] In the past, attempts have been made to reduce these risks by covering or coating the otherwise exposed electrical connections and other components on the top of the cordless plug connectors with water-resistant polymer, such a room temperature vulcanizing rubber. These attempts are unreliable, labour intensive and relatively expensive. In addition the receptacles making the connections to the cordless plug connector in a typical appliance have to have additional protection added in the form of a sleeve, typically of the heat shrink variety over the receptacles and the joint between the receptacles and the insulation of the adjoining wires.

[0007] A partial solution to the problem is provided by WO-A-2008/012506A1 where parts of the terminals are protected by a sealant which waterproofs the plug connector. However this is comparatively expensive and it does not provide any protection for the wire terminals which connect the plug connector to the other components in the appliance. Another partial solution is disclosed in GB-A-2480360 but this suffers from similar limitations.

Statements of the Invention [0008] According to a first aspect of the present invention, there is provided a cordless electrical connector for a cordless electrical appliance, such as may be housed below a vessel in the appliance, wherein the top of the plug connector is protected from any liquid which may fall from above by a protective cap or cover. Preferably, the cap or cover protects electrical terminals of the plug connector from the liquid.

[0009] The protective cap may be a separate component which is placed in a position to protect the plug connector during the assembly of the appliance. This separate component can be fixed either to the plug connector itself, the bottom cover of the appliance or some other convenient part of the appliance. Alternatively in the case of a cordless plug connector in a cordless appliance it is possible to integrate the cap with the bottom cover moulding or integrate the cap into the cordless plug connector itself.

[0010] The design of the protective cap may incorporate one or more features to retain and guide any liquid which falls on it away to a safe place which may be outside the appliance, such as a curved or sloping upper surface.

[0011] According to a second aspect of the invention, there is provided a protective cap or cover as described above.

[0012] According to a third aspect of the invention, there is provided a cordless plug connector for a cordless liquid heating appliance, the cordless connector having one or more electrical terminals for connection to one or more electrical components within the appliance, wherein the terminals do not extend outwardly from the body of the cordless connector.

Brief Description of the Drawings [0013] 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 1 is a cut-away view of an appliance for heating liquid, incorporating a cordless plug connector.

Figure 2 is a perspective view of the bottom moulding of a typical appliance such as shown in Figure 1, complete with a cordless plug connector

Figure 3 illustrates a cover which can be fitted over the top of the cordless plug connector, in a first embodiment.

Figure 4a is a perspective view of the cover fitted over a typical cordless plug connector, in the first embodiment.

Figure 4b is a plan view of the cover of Figure 4a.

Figure 4c is a cross-sectional view through the section A-A in Figure 4b.

Figure 5 illustrates a cover which can be fitted over the top of the cordless plug connector, in a second embodiment.

Figure 6a is a perspective view of the cover fitted over a typical cordless plug connector, in the second embodiment.

Figure 6b is a plan view of the cover of Figure 6a.

Figure 6c is a cross-sectional view through the section A-A in Figure 6b.

Figure 7a is an exploded perspective view of a cordless connector and a cover integrated into the floor of the appliance, in a third embodiment.

Figure 7b is a vertical cross-section through the cover and cordless plug connector of the third embodiment.

Figures 7c and 7d are cut-away perspective views of the cordless connector fitted within the cover in the third embodiment.

Figure 8a is an exploded view of a cordless plug connector and cover in a fourth embodiment.

Figure 8b is a perspective view of the cordless plug connector of the fourth embodiment, with wire connectors attached.

Figure 8c is a perspective view of the cordless plug connector with wire connectors attached, fitted within the cover.

Detailed Description of the Embodiments [0014] Figure 1 illustrates schematically an appliance for heating liquid, such as milk, comprising a vessel 1 for containing the liquid. A heating element 2 is provided on the underside of the bottom of the vessel 1, or may itself form the bottom of the heating vessel 1. The heating element 2 may comprise a sheathed heating element or a thick film heating element, typically comprising a steel plate having the element resistor(s) formed on or attached to the underside thereof. Alternatively, an immersed heating element may be used.

[0015] A stirrer 3 or similar component is attached to a shaft 6 which passes through an aperture in the bottom of the vessel 1, through a seal (not shown) arranged to prevent liquid from the vessel 1 leaking out along the shaft 6. The shaft 6 is driven by a motor 4 fixed within a compartment 5 below the vessel 1. The wall of the compartment 5 comprises a bottom moulding 8 fixed below the vessel 1.

[0016] A cordless electrical connector 7 or similar component is situated below, but not necessarily directly below, the vessel 1 and motor 4. The connector 7 is preferably a 360° cordless connector, allowing electrical power connection to a cordless power base (not shown) in substantially any azimuthal orientation.

[0017] Figure 2 shows an example of the bottom moulding 8 for the appliance of Figure 1, incorporating the cordless electrical connector 7 such as a TP01 plug connector manufactured by the applicant under its Ketsol (RTM) brand. Terminations or terminals 9a, 9b and 9c are provided to make live, earth and neutral connections between the cordless plug connector 7 and other components in the appliance such as the heating element 2, motor 4 and/or a control device (not shown) for controlling the other components. It will be appreciated that these terminals 9a, 9b, 9c and the corresponding connectors for attachment to these terminals 9a, 9b, 9c are exposed to any liquid falling from above and that such exposure could cause significant safety issues.

[0018] The bottom moulding 8 may comprise a side wall 8a and a floor 8b forming the bottom of the appliance, either provided as separate components or integrated together. The floor 8b may be attached to the bottom of the vessel 1. The cordless electrical connector 7 may comprise a discrete component that is fixed within an aperture in the floor 8b during manufacture of the appliance.

[0019] Figure 3 shows an exploded view of a cordless plug connector 7 having a cap or cover 10 arranged to protect the terminals 9a, 9b, 9c in a first embodiment of the invention, while Figures 4a, 4b and 4c show the cover 10 in place, attached to the cordless connector 7. The cover 10 includes terminal cover portions 11a, lib, 11c arranged to protect the corresponding terminals 9a, 9b, 9c from liquid falling from above, while allowing corresponding wire connectors (not shown) to be connected to the terminals 9a, 9b, 9c, either before or after the cover 10 is attached to the cordless connector 7. In this embodiment, the terminals 9a, 9b, 9c are tab terminals to which crimped wire connectors may be attached.

[0020] In this embodiment, the cordless connector 7 has an approximately cylindrical body 7a or main housing, with the terminals 9a, 9b, 9c extending approximately horizontally and generally outwardly on the top surface of the cordless connector 7. The cover 10 comprises an approximately disc-shaped surface 12 arranged to fit over the top of the cordless connector 7, and having a downwardly sloping edge extending radially beyond the side wall of the body 7a. The terminal cover portions 11a, lib, 11c are raised above the disc-shaped surface 212and have curved or pitched upper surfaces to assist in shedding any liquid falling thereon.

[0021] The cover 10 may be arranged to be removably or permanently fastened to the cordless connector 7, for example by means of cover fasteners 13, such as resilient clips or tongues, which engage corresponding features 14 on the cordless connector 7. Alternatively the cover 10 may be fixed to the floor 8b of the bottom moulding 8, to another part of the bottom moulding 8 or indeed any other suitable part of the appliance.

[0022] Figures 5 and 6a to 6c illustrate a second embodiment which is similar to the first embodiment except that the terminal cover portions 11a, lib, lie extend outwardly so as to cover wire connectors 20a, 20b, 20c, for attaching wires (not shown) to the terminals 9a, 9b, 9c. Typically, the wire connectors 20a, 20b, 20c will be attached to corresponding wires before attachment to the terminals 9a, 9b, 9c.

[0023] In a third embodiment as shown in Figures 7a to 7d, the cover 10 is integrated with the floor 8b of the appliance, which in turn may be integrated with or a separate component from the rest of the bottom moulding 8. The cordless plug connector 7 is assembled into an aperture in the floor 8b from below, as shown in Figure 7a, and includes a clip fitting 15 that secures the connector 7 in place in the floor 8b, under the cover 10. The feature 14 engages in an aperture 13 in the cover 10. Further details of the clip fitting 15 are shown in Figures 7c and 7d.

[0024] Figure 7b is a vertical section through the connector 7 when assembled into the integrated floor 8b and cover 10. This Figure shows that the terminals 9a, 9b, 9c lie below the upper surface 12 of the cover 10 and are accessible through corresponding apertures 19a to 19c in the cover 10.

[0025] The cover 10 includes guides 16 for guiding any liquid falling onto the cover 10 away from the apertures 19a to 19c and/or the apertures(s) 13. The guides 16 may have the form of substantially vertically extending ridges extending outwardly from the side walls of the cover 10, on either side of the apertures 13, 19a to 19c. Similar guides 16 may also be incorporated in the cover 10 of any of the preceding embodiments.

[0026] Figures 8a to 8c show a fourth embodiment, in which the cover 10 is integrated with the floor 8b of the appliance. In this embodiment, the cordless plug connector 7 has the terminals 9a, 9b, 9c arranged so that they and their associated wire connectors 20a, 20b, 20c lie substantially within the periphery of the connector 7 and do not extend outwardly from the cylindrical body of connector 7, thus reducing the size of the cover 10 needed to protect the terminals 9a, 9b, 9c. In this embodiment, the terminals 9a, 9b, 9c extend substantially parallel to each other, and a single aperture 19 provides access to the terminals 9a, 9b, 9c and wire connectors 20a, 20b, 20c. A guide 16 is provided to either side of this aperture 19.

Materials [0027] The cap or cover 10 in the above embodiments can be made from a variety of materials, such as metal, plastics or a non-metallic sheet material such as mica, electrical grade paper insulation or other similar material. A plastic cover 10 could be manufactured by injection moulding, vacuum forming, stamping or cutting from a sheet or any other suitable process.

[0028] Care should be taken in the design of the cap to take into consideration some of the difficulties experienced in the design of appliances of this kind, in particular those which ensure the safety of the user with respect to electric shock and fire. For example if the cap is made from a metal it has to be a prescribed distance from any exposed metal parts of the connector which may be live during the operation of the appliance. If it is made from a plastic, there will be no issues with electric shock or short circuit but there can be issues with initiation or propagation of fire. This can be overcome by ensuring there is sufficient distance between the plastic and the electrical connections. Care must be taken that the cap 10 cannot start or propagate fire if there is any overheating of the electrical connections.

[0029] It can be seen that these problems can be relatively easily overcome provided there is excessive space in the bottom part of the appliance. However in practice this is not the case due to pressure from the user for appliances to be as compact as possible.

[0030] Another solution is to use a relatively expensive engineering plastic to produce the cap. This will have sufficient fire retardant properties to ensure that fire is not initiated or propagated. However this solution is undesirable because of the commercial pressure to reduce the cost of manufacture of appliances.

[0031] The applicant has observed that the fire retardant properties of plastic materials are very dependent on the thickness of the component manufactured from the material. The common perception is that thicker components are more flame retardant that thinner ones and this appears to be the case over a limited range of thicknesses. The theory is associated with the ratio of surface area to thermal mass and the amount of flame retardant chemicals available to extinguish any flames. However the applicant has observed that when the sections of plastics are very thin another mechanism dominates giving plastics with thicknesses in the region of 0.5mm relatively good flame retardant properties. The flame retardant properties of plastics are often assessed by testing with a

glow wire test, in which a wire heated by an electrical current is applied with a specified force to the surface of the material. The hotter the wire during the test the better the plastic’s flame retardancy is judged to be. This is often expressed as the glow wire ignition test rating, or GWIT rating of the material. The applicant has found that a typical material may have GWIT ratings at different thicknesses as follows:-Thickness 3 mm GWIT rating 800°C

Thickness 1.5mm GWIT rating 700°C

Thickness 0.5mm GWIT rating 775°C

Alternative Embodiments [0032] Alternative embodiments may be conceived on reading the above description, which may nevertheless fall within the scope of the claims. For example, the cover 10 could also be an integral part of the cordless plug connector 7. Alternatively, the cover portions 11a to 11c may comprise discrete covers, each attachable to the cordless connector so as to cover the respective terminals 9a, 9b, 9c.

Claims

1. A cordless connector (7) for a cordless liquid heating appliance, the cordless connector (7) having one or more electrical terminals (9a, 9b, 9c) for connection to one or more electrical components within the appliance, the cordless connector (7) having a cap or cover (10) arranged to protect the terminal(s) (9a, 9b, 9c) from liquid falling thereon.

2. The connector (7) of claim 1, wherein the cap or cover (10) is attachable to the cordless connector (7).

3. The connector (7) of claim 2, wherein the cap or cover (10) is removably attachable to the cordless connector (7).

4. The connector (7) of claim 2 or claim 3, wherein the cap or cover (10) has one or more fastening portions (13) for attachment to one or more corresponding features (14) on the cordless connector (7).

5. The connector (7) of any preceding claim, wherein the cap or cover (10) is integral with a bottom portion (8b) of the appliance.

6. The connector (7) of any preceding claim, wherein the cap or cover (10) has one or more terminal cover portions (11a, lib, 11c), each arranged to cover a corresponding one of the electrical terminals (9a, 9b, 9c).

7. The connector (7) of claim 6, wherein the one or more terminal cover portions (11a, lib, 11c) extend beyond the corresponding one of the electrical terminals (9a, 9b, 9c) so as to protect a corresponding wire connector (20a, 20b, 20c) connected thereto.

8. The connector (7) of any preceding claim, where the cover (10) includes one or more guides (16) for guiding the liquid away from the terminals (9a, 9b, 9c).

9. The connector (7) of any preceding claim, wherein the cap or cover (10) has one or more apertures (19; 19a, 19b, 19c) for providing access to the electrical terminals (9a, 9b, 9c).

10. The connector (7) of any preceding claim, wherein the terminals (9a, 9b, 9c) do not extend outwardly from the body (7a) of the cordless connector (7).

11. The connector (7) of any preceding claim, wherein there are a plurality of the electrical terminals (9a, 9b, 9c) extending substantially parallel to each other.

12. The connector (7) of any preceding claim, wherein the cap or cover (10) is of a plastic material.

13. The connector (7) of claim 12, wherein the plastic material is less than 1.0mm thick.

14. The cap or cover (10) of any preceding claim.

15. A cap or cover (10) for a cordless connector (7) for a cordless liquid heating appliance, arranged to protect terminals (9a, 9b, 9c) of the cordless connector (7) from liquid falling thereon.

16. A cordless connector (7) for a cordless liquid heating appliance, the cordless connector (7) having one or more electrical terminals (9a, 9b, 9c) for connection to one or more electrical components within the appliance, wherein the terminals (9a, 9b, 9c) do not extend outwardly from the body (7a) of the cordless connector (7).

17. A cordless connector (7) and/or cap or cover (10) substantially as herein described with reference to and/or as shown in the accompanying drawings.

18. A liquid heating appliance having a cordless connector (7) as claimed in any one of claims 1 to 13, 16 or 17.