GB2506682A

GB2506682A - Lamp apparatus

Info

Publication number: GB2506682A
Application number: GB1217983.4A
Authority: GB
Inventors: Pratik Sharma; Vivek Pradham
Original assignee: PREMIUM LIGHTING SOLUTIONS Ltd
Current assignee: PREMIUM LIGHTING SOLUTIONS Ltd
Priority date: 2012-10-08
Filing date: 2012-10-08
Publication date: 2014-04-09
Also published as: GB201217983D0

Abstract

A lamp assembly 10 has electrical terminals (22, 24, Fig. 2) attached to end fittings 12. The assembly couples into a live light fitting 14. The end fittings 12 include a housing located within one of which is a concealed switch (26, Fig. 2). The switch includes an actuator which is permanently biased to an open position by a spring and uncouples the terminals of the lamp 10. Opposite the actuator is a hole 30 in the housing. A clip 50 is used to activate the switch and includes a part circular clip element 52 and a pin 54. The pin 54 has a diameter which is less than the diameter of the hole 30 and a length sufficient to span the distance from the outside of the casing 14 to the point at which the actuator is depressed sufficiently to couple the terminals 22, 24 of the lamp to their respective conductors. The concealed switch ensures a person fitting the lamp into a live light fitting does not receive an electric shock.

Description

LAMP ASSEMBLY AND LIGHT APPARATUS

Field of the Invention

The present invention relates to a lamp and light apparatus such as a light fitting. The preferred embodiments are directed to a light of tube form.

Background of the Invention

Tube shaped lamps are in common use, particularly in commercial and healthcare environments but are also commonplace in domestic environments, as a result of the amount and quality of light they can generate as well as for their energy efficiency. Well known examples include fluorescent tubes. These and is similar tubes produce light by the ionisation of a gas within the volume of the tube.

More recently though, due to increasing need and pressure to improve efficiency, standard ionisation tubes are being replaced with solid state tubes, for example provided with light emitting diodes (LED5), which are considered more environmentally friendly and have greater working lives.

A problem is encountered, however, with the handling of these new tube technologies, particularly in the course of fixing them into the light fitting. A conventional tube poses no or little risk of the user being electrocuted since there is no electrical conduction from one end of the tube to the other until the gas inside the tube has been ionised. Thus, one end of the tube can be fitted into its associated socket of the light fitting, then the second end fitted into its associated socket with no risk of the fitter being given an electrical shock even if the fitter touches the electrical terminals at the second end of the tube.

By contrast, with more modern tubes which do not rely upon ionisation of gas within the tube to function, it is possible for the fitter to receive an electric shock during the fitting as once one end of the tube is positioned into its respective light fitting socket, the electrical terminals at the other end of the tube become live.

Attempts have been made to address this problem of electrocution, primarily by providing on the lamp tube assembly a switch which isolates the terminals at opposite sides of the tube from one another. The intention is that the terminals are isolated during fitting of the tube and only switched active once the tube is in place and its terminals properly housed in the sockets of the light fitting. However, this requires the switch to have been properly switched off prior to fitting of the lamp, and also that the switch is not inadvertently closed during the fitting operation.

The latter situation does though occur, leading to the fitter potentially receiving an electric shock.

Summary of the Present Invention

The present invention seeks to provide an improved lamp assembly and light fitting.

According to an aspect of the present invention, there is provided a lamp is assembly including an elongate light element having first and second ends and electrical terminal fittings provided at the first and second ends, each electrical terminal fitting including first and second electrical terminals, the first electrical terminals being electrically coupled together and the second electrical terminals being electrically coupled together, there being provided in at least one of the terminal fittings a concealed switch, the concealed switch being coupled to at least one of the first and second electrical terminals so as to couple and uncouple said at least one of the first and second electrical terminals.

In contrast to the prior art, the lamp assembly taught herein provides a concealed switch which cannot be inadvertently activated by a fitter, for example through clumsiness.

Advantageously, the concealed switch includes a biasing element which biases the switch to an open configuration. Thus, in the absence of a closing force, the switch will act to isolate the terminals to which it is connected. In other words, the terminals of the lamp will remain disconnected until the switch is forced closed.

In the preferred embodiment, the concealed switch is disposed inside a housing of one of the electrical terminal fittings, with an opening provided in the housing for access to the switch actuator. The opening is advantageously a small hole, significantly smaller than the thickness of a finger.

The lamp assembly also includes an actuator sized to fit into the opening and to operate the switch. In one embodiment, the actuator includes a protrusion or pin, preferably of non-conductive material.

In an embodiment, the actuator is in the form of a clip which fits onto the terminal fitting, the clip including the protrusion or pin. Advantageously, the clip self-locks onto the terminal fitting.

In another embodiment, the actuator is provided as a part of the light fitting and includes the protrusion or pin. Advantageously, in this embodiment the actuator is located on the light fitting at a position opposite the insertion direction.

The actuator need not be or is not coupled to the lamp assembly until the lamp has been placed into the light fitting. Thus, the terminals of the lamp fitting remain disconnected until they have been properly positioned in the light fitting, is with no risk of becoming active and thus of providing an electric shock.

Brief Description of the Drawings

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of one end of an embodiment of lamp assembly according to the present invention; Figures 2 are 3 are schematic diagrams of the internal components of the end of the lamp assembly of Figure 1, showing the concealed actuator; Figure 4 is a schematic diagram of the lamp assembly of Figure 1 in an operating state; and Figure 5 is a schematic diagram of one end of an embodiment of light fitting assembly according to the present invention.

Descrijtion of the Preferred Embodiments Referring to Figure 1, there is shown one end of a lamp assembly 10 according to an embodiment of the present invention. The lamp assembly 10 is of the tube type, having electrical terminals (not shown in Figure 1) at both ends attached to and/or extending beyond plastics end fittings 12. The lamp assembly couples into a light fitting 14 having electrical terminals 16 either end.

Typically, one or both of the ends 16 of the light fitting 14 is sprung such that the lamp 10 is held securely in the fitting 14 and also to facilitate its coupling into the 0 light fitting 14. Generally, one end of the lamp assembly 10 is positioned into one of the light fitting ends 16, with the other end 12 of the lamp 10 held above the fitting 14. The lamp 10 is then rotated to bring its other end 12 into engagement with its corresponding light fitting end 16. As soon as the first end 12 of the lamp is coupled to the light fitting 14 there is the risk and in some circumstances is such as in commercial establishments, hospitals and the like, the likelihood that the light fitting will be live at that time. In order to avoid the risk of giving the fitter an electric shock in such circumstances, the lamp assembly 10 includes a concealed switch, seen in schematic form in Figures 2 and 3, to which reference is now made.

The plastic end fittings 12 are in the form of housings and include a first housing side 18 into which the end of the lamp unit 10 fits and an opposite housing side 20 which supports the electrical terminals 22 and 24 of the lamp assembly 10, of which only the terminal connectors are shown. The electrical terminals 22 and 24 are typically the live and neutral terminals. They may be in the form of pins but could equally be flat terminals applied to an outer surface of the end fittings 12, or of other known form.

Located within one of the end fittings 12 is a concealed switch 26. The switch 26 includes an actuator or button 28 which is permanently biased to the open condition by a spring (not shown). Integral with the actuator 28 are electrical elements (not shown which can bridge a gap between the electrical conductors of the lamp and the electrical terminals 22 and 24 of that lamp end. The switch 26 is completely disposed within the housing 12 and thus its actuator 28 is not readily accessible from the outside by an operator. Opposite the actuator 28 is an opening 30 in the housing, which in the preferred embodiment is a small hole of a diameter of one millimetre or more. The hole 30 is preferably much smaller than a person's finger to ensure that a fitter cannot inadvertently depress the actuator 28 when coupling the lamp 10 to a light fitting 14. Of course, the hole 30 could be less than one millimetre if desired.

It is preferred that the switch 26 decouples both electrical terminals of that end 12 of the lamp assembly 10 but it is not excluded that it might decouple just the live terminal, leaving the neutral terminal permanently connected.

Referring to Figures 1, 2 and 3, these also show a clip 50 used to activate the switch 26 so as to connect the electrical terminals 22 and 24. The clip 50 is preferably made of insulating material such as a heat resistant plastics material, and may be of the same material as the end fittings 12. The clip 50 includes a part circular clip or gripper element 52 and, disposed on an interior surface of the clip is element 52, a protrusion 54 which in this embodiment is in the form of a pin. The pin 54 has a diameter which is less than the diameter of the hole 30 and a length sufficient to span the distance from the outside of the casing 12 to the point at which the actuator 28 is depressed sufficiently to close the electrical circuit, that is to couple the electrical terminals 22 and 24 to their respective conductors of the lamp. It is to be understood that Figures 1 and 4 show a prototype of the clip 50, using a screw as the pion 54. Production versions, represented by the views of Figures 2 and 3, are made entirely out of plastics material, the pin 54 included.

Thus, as will be apparent, the lamp assembly 10 can be fitted to a live light fitting with the end terminals 22 and 24 decoupled and thus with no risk of receiving an electric shock from the lamp. Only once the lamp assembly 10 has been properly positioned in the light fitting is the clip 50 fitted over its respective end fitting 12, with the pin 54 being fed into the hole 30 of the end fitting 12. As the clip 50 slides into position, the pin 54 will depress the actuator 28 of the switch 26 and thus activate the lamp 10. It will be appreciated that the clip 50 will be resilient so as to widen as it is pressed onto the end fitting 12 and will then spring closed again so as to engage the end fitting 12, thereby remaining in place. This is shown in Figure 3. The spring force generated by the clip element 52 is designed to be greater than the force required by the pin 54 to depress the actuator 24.

Figure 4 shows the clip 50 in place and the lamp assembly 10 illuminated in the light fitting 14.

If it is desired to remove the lamp 10, for instance for replacement or servicing of the light fitting 14, the clip 50 can be removed, which will cause the switch 26 to open and thus decouple the electrical terminals 22 and 24, thereby allowing the lamp 10 to be removed safely.

Referring now to Figures, there is shown another embodiment of the invention. The lamp assembly used for this embodiment is the same as that of the embodiment of Figures 1 and 2, the difference being with the device for actuating the switch 26. This embodiment does away with the need for a clip 50, by having a modified light fitting 70. As can be seen in Figure 5, the light fitting 70 includes an end terminal block 72, of standard design save for the fact that it is provided is with a protruding pin 74. This has the same characteristics as the pin 54 of the clip 50 and serves the same purpose. Specifically, the lamp assembly 10 has its first end positioned in its corresponding light fitting end and such that its second end fitting 12, that with the switch 26, oriented such that the hole 30 aligned with the pin 74. The second end fitting 12 can then be pressed into position, which action causes the pin 74 to pass through the hole 30 and close the switch 26. As with the first described embodiment, this embodiment ensures that the lamp terminals 22 and 24 remain disconnected until the lamp assembly 10 is properly fitted into the light fitting 70 and thus avoid any risk of the fitter receiving an electric shock.

It is to be understood that the teachings herein are not limited to a lamp assembly 10 having a single tube. They are equally applicable to a lamp assembly having a plurality of tubes, as well as to any lamp assembly which can be fitted in stages and wherein during the fitting procedure there is a risk of contact with live electrical terminals.

It is not excluded that the lamp assembly 10 could be provided with switches 26 at both terminal ends 12.

Claims

CLAIMS1. A lamp assembly including an elongate light element with first and second ends and electrical terminal fittings provided at the first and second ends, each electrical terminal fitting including first and second electrical terminals, the first electrical terminals being electrically coupled together and the second electrical terminals being electrically coupled together, there being provided in at least one of the terminal fittings a concealed switch, the concealed switch being coupled to at least one of the first and second electrical terminals so as to couple and uncouple said at least one of the first and second electrical terminals.
2. A lamp assembly according to claim 1, wherein the concealed switch includes a biasing element which biases the switch to an open configuration.is
3. A lamp assembly according to claim 1 or 2, wherein the concealed switch is disposed inside a housing of one of the electrical terminal fittings, an opening being provided in the housing for access to a switch actuator of the switch.
4. A lamp assembly according to claim 3, wherein the opening is a hole.
5. A lamp assembly according to claim 3 or4, including an actuator sized to fit into the opening and to operate the switch.
6. A lamp assembly according to claim 5, wherein the actuator includes a protrusion or pin
7. A lamp assembly according to claim 6, wherein protrusion or pin is made of a non-conductive material.
8. A lamp assembly according to claim 5, 6 or 7, wherein the actuator is in the form of a clip, the clip including the protrusion or pin.
9. A lamp assembly according to claim 8, wherein the clip is self-locking onto the terminal fitting.
10. A lamp assembly according to claim 5, 6 or 7, wherein the actuator is provided as a part of a light fitting and includes the protrusion or pin.
11. A lamp assembly according to claim 10, wherein the actuator is located on the light fitting at a position opposite the insertion direction.
12. A light fitting including first and second spaced electrical terminals and a lamp holding zone for receiving a lamp assembly according to any one of is claims 1 to 9, wherein at least one of the electrical terminals includes a protrusion or pin for operating the concealed switch of the lamp assembly.
13. A lamp assembly substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.
14. A light fitting substantially as hereinbefore described, with reference to and as illustrated in Figure 4 of the accompanying drawings.