The present invention relates to a portable electrical appliance. Portable electrical appliances are often provided with a battery pack, in order that the appliance may be used when a mains electricity supply is unavailable.

In particular the present invention relates to a portable electrical appliance which has one or more heaters powered by a battery pack, such as cordless hair care appliances, eg. a battery-powered hair straightener or battery-powered hair dryer.

Conventionally, such portable electrical appliances have a rechargeable battery pack comprising several cells. When the appliance is switched on, the battery pack will discharge through the heaters, thereby generating heat. In the unlikely event that the appliance is unintentionally switched on whilst the heated parts of the appliance are in contact with a flammable material, there could be a potential fire risk. It is known to provide a user-removable battery pack in portable electrical appliances to mitigate such a risk. However, it is then possible that the user may subsequently replace the battery pack with a third-party battery pack of inferior quality or even misplace the separated battery pack. It is therefore desirable to provide an improved safety system for a battery-powered appliance.

A first aspect of the present invention provides an electric appliance comprising a battery, a user removable electrical connector comprising a first contact, an electrical receptacle comprising a second contact, wherein the receptacle is arranged to receive the connector, and wherein the electric appliance is adapted to complete an electric circuit with the battery only when the connector is received into the receptacle such that the first contact and the second contact are engaged.

Preferably, one of the first contact and the second contact comprises at least one contact pin and the other of the first contact and the second contact comprises at least one socket. Further, the first contact may comprise four contact pins and the second contact may comprise four sockets, wherein the contact pins are arranged in a row.

The four contact pins may be joined in pairs by a common U-shaped metal portion. Advantageously, such an arrangement of two joined pins improves the tolerance of the contacts. The metal contact pins are preferably coated.

Preferably, the first contact comprises one contact pin and the second contact comprises two sockets which are axially aligned, and wherein the electric circuit is completed when the contact pin engages both of the sockets.

Further, the electrical receptacle may be located on an external face of the appliance to allow unhindered access for the user.

Preferably, the user removable electrical connector comprises a cover having means to attach and release the electrical connector from the appliance.

Preferably, the user removable electrical connector comprises a tether which extends between the connector and the appliance, and wherein the tether guides axial movement of the connector in order to engage with the receptacle.

Further, the electrical receptacle may be located within the appliance and adjacent to an opening in an external surface of the appliance. The electrical connector may comprise a single pin which is inserted through the opening and engages with the electrical receptacle.

The electric appliance may further comprise at least one heater.

The electric appliance may be a hair styling appliance. In order that the present invention may be more readily understood, an embodiment of the invention will now be described, by way of example, and with reference to the accompanying drawings, in which:

Figure 1 is an exploded view of an embodiment of a connector according to the present invention;

Figure 2 is a side view of the connector shown in Figure 1;

Figure 3 is an end view of the connector shown in Figure 1;

Figure 4a is a first perspective view of the connector shown in Figure 1;

Figure 4b is a second perspective view of the connector shown in Figure 1;

Figure 5 is a cross sectional view of the connector shown in Figure 1;

Figure 6 is a schematic view of an embodiment of a receptacle according to the present invention;

Figures 7a and 7b are a schematic illustration of an alternative embodiment of the connector and receptacle arrangement according to the present invention;

Figure 8 is a perspective view of a portable hair styling appliance incorporating a receptacle and connector arrangement of an embodiment of the present invention;

Figures 9a is an exploded view of an alternative embodiment of a connector according to the present invention;

Figures 9b and 9c are perspective views of the connector shown in Figure 9a. A connector 10 shown in Figure 1 comprises a moulded plastics body 12. Two metal contacts 14 16, each having two parallel straight pins joined by a U-shaped portion, are inserted through the body so that the four pins 18 20 22 24 protrude from a first major face 26 of the connector 10. The U-shaped portion of each metal contact 14 16 is held immovably within the body 12. A cover 28 comprising an insulating material fits over a second major face 30 of the body. The cover 28 also fits over the side faces 32 34 of the body and a snap-fit feature 36 is also part of the cover. An optional flexible tether 38 protrudes from the first major face 26 of the connector 10.

Figures 2 to 5 also show that each of the four pins 18 20 22 24 protrude from the first major surface 26 of the body by the same length. In an exemplary embodiment, this length, 1, is approximately 6mm to 8mm.

Figure 6 illustrates a receptacle 40 comprising four cylindrical sockets 42 44 46 48 supported in a linear arrangement in a PCB 50. A first socket 42 is electrically connected via a track to a heater harness 52. A fourth socket 48 is electrically connected via a track to a battery harness 54. A second socket 44 and a third socket 46 are electrically connected to each other in the PCB arrangement 50. Each socket is comprised of a metal material and is preferably coated in gold to reduce electrical resistance. The receptacle 40 is located in a body of a portable battery-powered appliance, such as the hair styling appliance 56 illustrated in Figure 8.

In use, the connector 10 is inserted into the receptacle 40 and each pin is received into a respective socket. Consequently, the first and second sockets 42 44 are electrically connected by the first and second pins 18 20, and the third and fourth sockets 46 48 are electrically connected by the third and fourth pins 2224. This results in the completion of an electrical circuit between the battery pack and heater(s), enabling the user to activate the heater(s) via an actuation switch (not shown). When the user wishes to securely disconnect the battery pack from the heater(s), the connector is removed from the receptacle, thereby breaking the electrical circuit. The receptacle is preferably located in an external face of the body of the battery-powered appliance in order to be easily accessible for the user.

When the connector 10 is fully inserted into the receptacle 40, the cover 28 may be contiguous with an external surface of the appliance 56. The texture and colour of the cover may match the outer surface of the appliance. Alternatively, the texture or colour of the cover may differ from the outer surface of the appliance in order to highlight the connector feature or enhance user grip on the connector component. The multiple-use cantilever snap-fit assembly 36 at one end or both ends of the body facilitates the removal and insertion of the connector for the user. Alternatively, a simple push-fit and pull-to-release type of attachment may be used.

The elongate tether 38, as illustrated in Figures 1 to 5, is composed of a flexible plastic such as polyurethane. A proximal end is securely attached to the connector and a distal end comprises a bulbous anchor form. During assembly of the battery-powered appliance, the distal end of the tether is inserted through an aperture located adjacent to the receptacle, such that the distal end is held permanently within the body of the appliance. The tether can move to and fro within the aperture to enable a user to insert and remove the connector from the receptacle. Advantageously, the user cannot misplace the connector when it is removed from the receptacle.

The connector arrangement in Figures 1 to 6 may have various embodiments within the concept described. For example, the diameter of each connector pin may reduce, gradually or in a stepped form, towards the distal end. Consequently, the diameter of the apertures in each respective socket must fit the diameter of the connector pin when the pin is fully inserted. Similarly, the cross-section of each connector pin may be circular, square or other regular shape, and the apertures in each respective socket must fit the cross-section of the connector pin when the pin is fully inserted. The receptacle PCB 50 shown in Figure 6 may be separate from a primary PCB of the appliance. Alternatively, the receptacle PCB 50 may be integral to a primary PCB of the appliance.

Alternative embodiments of the connector arrangement are possible within the scope of the invention. In an embodiment comprising four connector pins and four receptacle sockets, the connections between pins and between the sockets, battery and heater(s) may differ from the arrangement described above, but must ensure that at least one completed electrical circuit is formed when the connector is fully inserted into the receptacle. For example, the first and second pins may complete a circuit comprising a first heater and a cell, and the third and fourth pins may complete a circuit comprising a second heater and a cell. In an embodiment comprising two connector pins and two receptacle sockets, the connections between the sockets, battery and heater(s) may differ from the arrangement described above, but must ensure that a completed electrical circuit is formed when the connector is fully inserted into the receptacle.

An alternative embodiment of a connector and receptacle arrangement is shown in Figures 7a and 7b. The receptacle 58 comprises a first socket 60 and a second socket 62, both formed from a metal material and each socket having an aperture of similar dimensions. The first and second sockets 60 62 are located within the body of the appliance, and the apertures are aligned with one another along a longitudinal axis, x. Further, both apertures are aligned with an opening 64 in the external surface 66 of the appliance along the same longitudinal axis, x. The first and second sockets are electrically connected to the battery and heater(s), respectively, but are electrically isolated from one another.

In use, a connector component 68 is inserted through the opening 64 and through the first and second connectors 60 62. The connector component comprises a metal pin 70 having a diameter similar to the aperture of the first and second socket. A flush fit between the connector pin and the first and second sockets results in the completion of an electrical circuit between the battery pack and heater(s), enabling the user to activate the heater(s) via an actuation switch (not shown). When the user wishes to securely disconnect the battery pack from the heater(s), the connector 68 is removed from the receptacle 58 thereby breaking the electrical circuit. A head 72 of the connector is formed from an insulating material and has a shape which is convenient for the user to grasp.

The connector arrangement in Figure 7 may have various embodiments within the concept described. For example, the diameter of the connector pin 70 may reduce, gradually or in a stepped form, towards the distal end. The diameter of the apertures in the first and second sockets 60 62 must fit the diameter of the connector pin when the pin is fully inserted. Similarly, the cross-section of the connector pin may be circular, square or other regular shape, and the apertures in the first and second sockets must fit the cross-section of the connector pin when the pin is fully inserted.

Figures 9a, 9b and 9c illustrate an alternative embodiment of the connector arrangement 74 comprising two connector pins 76, 78 having a rectangular cross-section. In use, this connector 74 is inserted into a receptacle in the body of an appliance in a first position and each pin 76, 78 is received into a respective rectangular electrical socket (not shown). A completed electrical circuit is formed when the connector is fully inserted into the receptacle in the first position. In this embodiment, two rectangular storage sockets are provided in the receptacle, adjacent to the two electrical sockets. The storage sockets do not have any electrical connection and are formed of a suitable electrical insulator material. In use, the connector may be inserted into the receptacle in a second position and each pin is received into the respective rectangular storage socket. In order to change the connector from the first position to the second position, the user grasps and removes the connector from the first position, rotates it 180 degrees, and re inserts it in the second position. The connector arrangement 74 may also comprise a tether 80. A distal end of the tether comprises a bulbous anchor form which is located permanently within the body of the appliance. The tether 80 allows the connector arrangement 74 to move relative to appliance, but not to be entirely disconnected. In any embodiment of the connector arrangement, each socket is comprised of a metal material and is preferably coated in gold to reduce electrical resistance. When the appliance is activated, a reduced electrical resistance results in less heating of the components, thereby improving performance.

The connector embodiments illustrated in Figures 1 to 5 and 8 and 9 have a generally cuboid body, although other forms would be suitable.

The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.