GB2401262A

GB2401262A - Night light having detachable lamp unit

Info

Publication number: GB2401262A
Application number: GB0409324A
Authority: GB
Inventors: Anne West
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-02
Filing date: 2004-04-27
Publication date: 2004-11-03
Anticipated expiration: 2024-04-27
Also published as: GB0409324D0; GB2401262B

Abstract

The light comprises a base unit 10 for connection to a mains supply, a lamp unit 12 that includes a rechargeable battery and a lighting device 30, and a connecting lead 34. The lamp unit can be connected to the base unit to recharge the battery and to allow detection of the mains supply state. Connection can be made either by mounting the lamp unit directly upon the base unit or when the lamp unit is remote from the base unit, connection of the lamp unit to the base unit is made by the connecting lead. The night-light may also be used as an emergency light.

Description

Emergency Light This invention relates to an emergency light.

It is well known to provide emergency lights that operate to illuminate automatically in the event of mains power failure. These lights include a rechargeable battery that is maintained in a charged state from a mains supply. Upon detection of failure of the mains supply, the battery is connected to discharge through a lighting device (e.g., one or more incandescent lights or light-emitting diodes). While the mains supply is present, the light will normally remain off, although some emergency lights are provided with a switch that can be used to turn the light on manually. Such lights can provide valuable illumination in an emergency that causes a power failure. Many emergency lights have a manual override whereby they can be turned on permanently to provide illumination even while the mains supply is operational.

In the past, emergency lighting has been predominantly restricted to installation in industrial or commercial premises where they are required by law. However, they are also of use in domestic environments where lighting in the event of a power failure can be equally valuable. In contrast to the typical arrangement in commercial premises, an emergency light for domestic purposes will typically be connected to a power outlet socket, rather than being permanently wired to a mains supply.

It is also known to provide an emergency light that can provide portable illumination. In such devices, there is typically provided a base unit that is connected to a mains supply and a portable lighting unit. The portable lighting unit contains rechargeable battery.

The battery can be charged by mounting the lighting unit on the base unit. As with a standard emergency light, the lighting unit will illuminate under battery power upon loss of mains supply. Such devices are known that take the form of a handheld torch or of a table lamp, an example of the latter being shown in GB-A-2 380 541.

A limitation of these devices is that they can be used for a limited time only on battery power. They can only be used for long-term illumination while connected to a mains supply. However, it may be that there is no suitable mains outlet. In the case of lights described in the last paragraph, there is a risk that a user will use the light for an extended period in a preferred place without a mains connection, with the result that the battery will become completely discharged, thereby disabling the emergency capability of the light.

An aim of this invention is to provide an improved emergency light that can overcome or at least ameliorate the disadvantages of known emergency lights.

Therefore, this invention provides an emergency light comprising: a base unit for connection to a mains supply; a lamp unit that includes a rechargeable battery and a lighting device; and a connecting lead; wherein the lamp unit can be connected to the base unit battery (to recharge the and to provide an indication of the mains supply state) either by mounting the lamp unit directly upon the base unit or the lamp unit is remote from the base unit, in the latter case, connection of the lamp unit to the base unit being made by the connecting lead.

Thus, a light such as this can be used in a compact configuration, in which the lamp unit is mounted upon the base unit. When required, the lamp unit can be moved from the of the base unit to a place where light is required, but that is not close to a convenient mains power outlet, charge of the battery being maintained by interconnection of the units by the connecting lead. For short-term use, the lamp unit can be used autonomously, without any connection to the base unit. Typically, the lamp unit comprises a control circuit operative to illuminate the lamp unit upon detection of mains failure and to maintain charge of the rechargeable battery. (Alternatively, it is possible that the control circuit is provided in the base unit.) / Alternative configurations of the invention can be provided. In a first configuration, while the lamp unit is mounted on the base unit, electrical connection between the base unit and the lamp unit is made through the connecting lead. An advantage of this arrangement is that the lamp unit can be removed from or returned to the base unit without the user having to make or break any electrical connection between the lamp unit and the connecting lead. In such cases, the connecting lead is typically contained within a receptacle of the base unit and/or the lamp unit.

In an alternative configuration, while the lamp unit is mounted on the base unit, electrical connection between the base unit and the lamp unit is made through connections that are independent of the connecting lead. For example, such connection must be made automatically upon the lamp unit being mounted upon the base unit. An advantage of this arrangement is that it offers convenience when the lamp unit is frequently removed from the base unit for use autonomously under battery power. In such embodiments, there is typically provided a receptacle in the base unit within which the connecting lead can be stored while it is not in use.

In preferred embodiments, the base unit may be suitable for direct connection to a mains electrical outlet. For example, it may have two or three projecting conductive pins.

The lamp may be provided with a manual control that can configure the lamp to operate in one of several modes. For example, these modes may include a mode in which the lamp is on at all times, in which it is off at all times, or in which it is on only during such time as the mains supply is absent.

The lamp may be additionally provided with a light-sensitive device that causes the lamp to illuminate only when the ambient light level falls below a threshold. This can be used to provide the function of a night light. Embodiments of the invention may further include a timer to enable the hours of operation of the lamp to be restricted to selected hours of the day.

Embodiments of the invention may rely upon a single connector to make both an electrical and a mechanical connection between the base unit and the lamp unit.

However, for additional security of location, additional connection formations may be provided to enhance the mechanical interconnection between the units.

Advantageously, the connecting lead may have identical connections at both of its ends, the connectors of the base unit and of the lamp unit being suitably configured to co operate with the connectors. This arrangement allows the connecting lead to be brought into use without the user having to identify one end of the lead from the other.

An embodiment of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a schematic view of the three principal components of an emergency light being a preferred embodiment of the invention; and Figure 2 is a rear view of a base unit, being a component of the embodiment of Figure 1; Figure 3 shows the embodiment of Figure 1 with the lamp unit mounted upon the base unit; and Figure 4 is a rear view of a lamp unit, being a component of the embodiment of Figure 1.

The embodiment comprises a base unit 10, a lamp unit 12 and a connecting lead 14.

The base unit 10 is constructed as a sealed moulded plastic box within which is contained charging circuitry. The base unit 10 is intended to be connected to a mains electrical power outlet and has conductive pins 20 projecting from a rear surface, the pins being shaped and dimensioned to fit into a mains outlet socket. Naturally, the shape, size and position of the pins are varied in accordance with the relevant standard configuration of electrical socket (which typically is dependent upon national regulations) with which the lamp is to be used. When the base unit 10 is connected to the mains supply, it is supported and retained in place on the socket outlet by the pins 20.

A front surface of the base unit 10 has a step portion 24 that is horizontal and upward- facing when it is connected to a normally located mains outlet. A low- voltage electrical connector 22 is provided upon the step portion to project generally upwardly. A wall 26 extends upwardly from a rear edge of the step 24, a channel 28 extending vertically on the wall.

The lamp unit 12 includes lighting devices covered by a lens 30. The lighting devices may include incandescent lamps (which have the advantage of being of low cost) or light- emitting diodes (which have the advantage of being power efficient). The lamp unit 12 also includes a rechargeable battery pack that is suitable for powering the lighting devices and control circuitry. A rib 32 projects from the rear of the lamp unit 12 that is of a width and depth similar to the channel 28 of the base unit 10.

On a lower surface of the lamp unit 12 is a low-voltage electrical connector that is compatible with the connector 22 of the base unit. Thus, the lamp unit 12 can be mounted upon the base unit, with the electrical connections being interconnected, such that power can be supplied to the lamp unit 12 form the base unit 10. The rib 32 locates within the channel 28 to stabilise the lamp unit. A control switch 38 is provided upon the lamp unit where it is readily accessible by a user. In alternative embodiments, the rib and channel may be omitted, reliance being placed upon the electrical connector to maintain a mechanical interconnection between the base unit 10 and the lamp unit 12.

A handle 44 is provided on the upper surface of the lamp unit 12. As well as being used to carry the lamp unit 12, the handle 44 can be used to hang the lamp unit 12 from a suitable support when it is in use remote from the base unit 10. In this embodiment, the handle 44 can be folded into a recess in the upper surface of the lamp unit 12 (as shown in Figure 1) and pivoted upwards for use (as shown in Figure 4). Alternatively, a fixed handle might be provided.

At the lower extremities of each side wall of the lamp unit 12 is a cutaway section 46.

These allow the connecting lead 14 to pass out from under the lamp unit when connected to it. This allows the lamp unit 12 to stand on a flat surface.

The connecting lead 14 is a flexible electrical cord 34 that is terminated with connectors 36. One of the connectors can make a connection with the connector 22 on the base unit while the other can make a connection with the connector on the lamp unit 12.

Preferably, the connectors of the base unit 10 and the lamp unit 12 are symmetrical such that the connectors of the connecting lead are identical, so that the connecting lead 14 need not be connected in a particular direction.

The emergency light can be operated in various modes, as will now be described.

First, the emergency light can be used with the lamp unit 12 mounted directly on the base unit 10 as shown in Figure 3. In this configuration, the emergency light can operate in emergency mode, always-on mode or always-off mode, the mode being selected by the position of the control switch 38.

In always-on mode, the lamp unit 12 is illuminated permanently, power being supplied to the lamp unit 12 by the base unit 10. In always-off mode, the lamp is never illuminated.

In emergency mode, the lamp is not illuminated while the control circuitry detects that mains power is being supplied to the lamp unit 12 by the base unit 10. However, when the supply is interrupted, whether due to a power failure or due to the lamp unit 12 being lifted from the base unit 10, the lamp is then illuminated, being powered by the rechargeable battery pack.

The same three modes can be used while the lamp unit 12 is connected to the base unit 10 by the connecting lead 14 because the electrical connection between the base unit 10 and the lamp unit is functionally identical as it is when the lamp unit 12 is mounted directly onto the base unit 10. In this condition, the lamp unit 12 can be placed at a convenient location remote from the base unit and a power outlet.

While the lamp unit 12 is not connected to the base unit, the lamp will be illuminated if the switch 38 selects emergency mode or always-on mode. It can conveniently be used as a torch in this configuration.

The base unit 10 includes a recess 40 that is open to its front. The recess serves as a receptacle in which the connecting lead 14 can be stored, coiled up, while it is not in use.

This embodiment includes several further features that may be provided to add value and function to the lamp.

A first of these further features is a light sensor mounted in the lamp unit 12 under a transparent window 42. The sensor is configured to allow the lamp unit 12 to be illuminated only when the ambient light level falls below a threshold. If the emergency light is in always-on mode then the emergency light operates as an automatic night light.

If the emergency light is in emergency mode then the emergency light operates as an automatic emergency light, but will illuminate only if the ambient light is below a threshold level. The battery is therefore not discharged unnecessarily by operating the lamp unit 12 when the ambient light is sufficient to render it unnecessary. Optionally, the emergency light may be provided with a user control that can override the operation of the sensor to allow the lamp to illuminate irrespective of the level of ambient light.

Alternatively or additionally, the emergency light may be provided with a timer (not shown) to limit operation of the lamp to specific hours of the day.

Claims

Claims 1. An emergency light comprising: a base unit for connection to a

mains supply; a lamp unit that includes a rechargeable battery and a lighting device; and a connecting lead; wherein the lamp unit can be connected to the base unit either by mounting the lamp unit directly upon the base unit or with the lamp unit remote from the base unit, in the latter case, connection of the lamp unit to the base unit being made by the connecting lead.
2. An emergency light according to claim 1 in which while the lamp unit is mounted on the base unit, electrical connection between the base unit and the lamp unit is made through the connecting lead.
3. An emergency light according to claim 2 in which the connecting lead, when it is not in use, is contained within a receptacle of the base unit andlor the lamp unit.
4. An emergency light according to claim 1 in which, while the lamp unit is mounted on the base unit, electrical connection between the base unit and the lamp unit is made through connections that are independent of the connecting lead.
5. An emergency light according to claim 4 in which connection between the lamp unit and the base unit is made automatically upon the lamp unit being mounted upon the base unit.
6. An emergency light according to any preceding claim in which the lamp unit comprises a control circuit operative to illuminate the lamp unit upon detection of mains failure and to maintain charge of the rechargeable battery.
7. An emergency light according to any preceding claim in which the base unit is suitable for direct connection to a mains electrical outlet.
8. An emergency light according to claim 7 in which the base unit has two or three projecting conductive pins for making an electrical connection with a mains outlet.
9. An emergency light according to any preceding claim provided with a manual control that can configure the lamp to operate in one of several modes.
10.An emergency light according to claim 9 in which the modes include one or more of a mode in which the lamp is on at all times, in which it is off at all times, or in which it is on only during such time as the mains supply is absent.
11.An emergency light according to any preceding claim in which a single connector is provided to make both an electrical and a mechanical connection between the base unit and the lamp unit.
12.An emergency light according to any one of claims 1 to 10 having additional connection formations may be provided to enhance the mechanical interconnection between the units.
13.An emergency light according to any preceding claim in which the connecting lead has identical connections at both of its ends, connectors of the base unit and of the lamp unit being suitably configured to cooperate with the connectors of the lead.
14.An emergency light substantially as herein described with reference to the accompanying drawings.