GB2547414A

GB2547414A - Pendant lamp assembly

Info

Publication number: GB2547414A
Application number: GB1602267.5A
Authority: GB
Inventors: Chadwick Robert
Original assignee: One Electrical Ltd
Current assignee: One Electrical Ltd
Priority date: 2016-02-09
Filing date: 2016-02-09
Publication date: 2017-08-23
Also published as: GB201602267D0

Abstract

A pendant lamp assembly 1 has an integral light source, for example an LED bulb or an LED array (25, Fig. 4), housed within, and completely encapsulated in, a tamper resistant substantially sealed housing 10 that encases the light source fully so that the light source cannot be accessed without damaging the lamp assembly. A power cable 5 supports the housing and supplies power to the light source. The assembly also has a heat sink (112, Fig. 5) and vents (11v, Fig. 2) for dissipating heat generated by components within the assembly. The lamp assembly can have a detachable diffusing component 40 for diffusing the light emitted by the light source, which can also be used to affix a lampshade (50, Fig. 5).

Description

PENDANT LAMP ASSEMBLY

The present invention relates to a pendant lamp assembly.

BACKGROUND

Typically lighting assemblies and fittings for use in residential and/or commercial buildings provide a means of repeated access to the lamp or bulb so that it or other components can easily be changed during the life of the assembly.

SUMMARY

According to the present invention, there is provided a pendant lamp assembly comprising a light source housed in a tamper-resistant housing and a power cable adapted to support the housing and to supply power to the light source.

Optionally the light source can be integrated within the body of the housing. Optionally the light source is secured within the housing. Optionally the light source comprises at least one separate component which is optionally positioned within the body of the housing during manufacture, and then optionally fixed into place such that it cannot be removed without damaging the housing and/or light source.

The tamper-resistant housing results in a lamp assembly which resists the replacement of the various integral parts inside the housing with, for example, bulbs that do not meet desired safety or environmental standards. Additionally, the tamper-resistant nature of the lamp assembly combats the theft of bulbs and/or other component parts. Attempts to interfere with the lamp assembly to replace or remove the components will tend to cause damage to the lamp assembly and render it nonfunctional.

Optionally the lamp assembly can comprise a fitting for affixing the lamp assembly in the desired position for operation, said fitting being optionally adapted to connect to a power conduit to supply power to the cable.

The fitting permits flexibility in the positioning and placement of the lamp assembly, according to illumination requirements in different locations. As the fitting is optionally adapted to connect to a power conduit, this also offers flexibility in the power source that is used for the lamp assembly. The fitting can optionally comprise a ceiling rose or the like and may have electrical terminal blocks or similar components for making electrical connections between the cable and the power conduit, e.g. the mains power cable supplying the ceiling rose with electrical power.

Optionally the lamp assembly can be directly wired into a mains power cable. Optionally the lamp assembly can include a device for interfacing with a power socket, for example a plug.

Optionally the lamp assembly housing encases the integral light source fully such that said light source is inaccessible without causing damage to the lamp assembly and optionally thereby rendering the lamp assembly non-functional. Optionally the housing can be tamper-evident, leaving evidence of tampering in the event that the housing is opened. For example a component of the housing can be adapted to lose integrity in some way (for example to break, tear or split etc.) in the event of removal from the other components of the housing.

Encasement of the integral light source has the advantage that the light source and the other components within the housing can be substantially sealed inside the housing so as to be inaccessible without causing at least some damage to the housing. This helps to ensure that safety is maintained as if the lamp assembly is, for example, wired directly into mains power, accessing the internal components of said lamp assembly either for removal or replacement of parts may be hazardous. The encasement and tamper-resistant nature of the lamp assembly discourages attempts to remove the lamp assembly or to take it apart.

Optionally the light source is a low energy light source such as a light emitting diode (LED). More than one LED can be provided in the light source. Optionally the light source comprises an array of LEDs in a spaced relationship to one another. Optionally at least one LED is surface mounted, optionally onto a printed circuit board or other carrier. Optionally the carrier can be integrated into a component of the housing. Optionally the lamp assembly comprises an integral LED driver within the housing. Optionally the light source is connected via the LED driver to the cable. Optionally the cable transfers electrical power to the light source, e.g. to the printed circuit board in order to power at least one LED.

As the light source is integral within the lamp assembly and optionally fully encased, it cannot be changed for a light source of lower efficiency or environmental benefit. Similarly, as the LED or LED array is not separately contained, for example within a bulb, should the lamp assembly be dismantled there is no part that is easily removed or replaced.

Optionally the light source is non-dimmable. Optionally the light source is dimmable. Optionally the power cable contains at least three core cables. Optionally the power cable contains at least two core cables. Optionally the core cables are held together and contained within an electrically insulated sheath. Optionally the sheath is fabric. Optionally the sheath is plastic. Optionally the core cables are individually sheathed and optionally twisted or braided together. Optionally the Optionally the housing comprises multiple components connecting together in a tamper-resistant manner, for example, a housing body and a cover connected with the housing body in a tamper-resistant manner. Optionally the cover can be formed from a transparent or translucent material and the light source is optionally covered by the cover and optionally emits light through the transparent or translucent cover. Optionally the cover can close off an open end of the housing body through which the light source emits light, and through which the light source and other internal components are optionally inserted into the housing body during an assembly process. Optionally the opening in the housing body is located at one end of the housing. Optionally the cover engages with the housing body to complete the encasement of the light source by the housing once the cover is fixed in position on the housing body. Optionally the housing body and the cover are glued together. Optionally the housing body and the cover are welded together. The connection between the cover and the housing body is optionally irreversible without damaging the housing. Optionally the cover can be adapted to dissipate light from the light source, changing the direction of the light, or suffuse the light emitted through the cover. For example, the cover can reflect or refract the light from the light source, so that the light from the pendant lamp assembly is more diffuse than the light emitted from the light source.

The gluing and/or welding together of the housing body and the cover as a final stage in the manufacturing process eases manufacture as the internal components of the lamp assembly are accessible e.g. through the opening in the end of the housing body. The gluing and/or plastic welding of the housing body to the cover also helps to ensure there is no reversible means of disassembling the housing without damaging the housing in the process.

Optionally the lamp assembly comprises a heat sink. Optionally the heat sink is disposed near the LED driver. Optionally the heat sink comprises a cavity for housing electrical components of the lamp assembly that are prone to generation of heat, such as the LED driver or transformer. Optionally the heat sink at least partially circumferentially surrounds the LED driver, which can be contained at least partially within the heat sink cavity. Optionally the heat sink cavity is at least partially cylindrical with at least one closed end, optionally in the form of a partial dome with an access hole for the power cable to interface with the LED driver or with the LED light source, and optionally has an open end to receive the LED driver within the heat sink cavity during assembly processes. Optionally the part of the heat sink that the power cable or cables passes through is flat. Optionally the closed end of the heat sink is closed by a plate disposed between components within the heat sink and the components of the light source, optionally with a flat outer surface on the end face. The flat end face of the heat sink is optionally disposed at the end of the cylinder adjacent to the cover. The outer surface of the flat end of the heat sink optionally provides a mounting for the LED board or other carrier on the outside of the heat sink.

Optionally cables from the LED driver pass through a hole in the heat sink and are connected to the LED or LED array on the outside of the heat sink.

Optionally the housing comprises vents or slots to allow and facilitate dissipation of heat generated by the lamp assembly. Optionally the vents or slots are located in a cap, which is optionally located above the open end of the heat sink. The vents optionally permit rising heat to leave the housing and are directed away from the light source. Optionally the heat sink comprises a metal sheet or case. Optionally the heat sink is formed from a ceramic material. Optionally the heat sink is formed from an alloy containing aluminium. Optionally the heat sink is formed entirely from aluminium. Optionally the heat sink is formed from copper, optionally from a copper alloy. Optionally the heat sink is located in the housing body. Optionally the circumferential sides of the heat sink are coated or cased in material that matches the cap. Optionally the circumferential sides of the heat sink are coated or cased in a thermally-insulating material. Optionally the heat sink outer casing is formed as a separate piece during manufacture, and is optionally attached to the cap and permanently fixed in position, optionally once the LED driver and optionally LED or LED array have been fitted inside the heat sink cavity. Optionally the heat sink outer casing is threadably connected at one end to the cap and at the other to the internal cover. Optionally, one or both ends clip, slide, or otherwise attach in a tamper-resistant manner onto the respective components of the cap and internal cover.

Inclusion of a heat sink can increase the operable lifetime of the LED or LED array. By partially surrounding the LED driver, the heat sink draws heat away from the LED or LED array. Vents or slots in the cap of the housing act as a conduit for rising heat to exit the lamp assembly, in the opposite direction to the LED or LED array. By protecting the LED or LED array in this way, the lifetime of the light source can be extended, and the need for replacement of the pendant lamp assembly can be reduced. Optionally the LED or LED array is further protected by use of insulating material disposed between the LED or LED array and the heat sink.

Ensuring that the sections of the heat sink that will be on the outside of the lamp assembly are thermally insulated, either in the same material as the cap or another material, both protects users from the heat generated by the LED driver should they touch the lamp assembly, and also assists in directing the removal of heat up through the cap and away from the LED or LED array.

Optionally the lamp assembly includes a removable diffuser component. Optionally the diffuser component is threadably or otherwise removably attached to the lamp assembly without damaging the lamp assembly or the diffuser component. Optionally the diffuser component can be detached to permit attachment of a lamp shade, wherein the diffuser component is optionally threaded onto the lamp assembly in order to hold the shade in position. Optionally, to constrain movement of the shade once it has been positioned on the lamp assembly, the lamp assembly further comprises a removable ring forming a flange extending radially outward from the housing on the outer surface thereof, to retain a lamp shade as required.

Although the lamp assembly itself is tamper-resistant and the components cannot be changed or removed without damaging the lamp assembly, inclusion of the diffuser component acts both to improve and/or change the lighting quality that is emitted from the lamp assembly, for example to soften or direct the light emitted or to reduce the effective power of the integral light source, and also to permit personalisation of the lamp assembly through the ability to attach and change a lighting shade or cover without tampering with the tamper-resistant housing of the lamp assembly.

The diffuser component can optionally take a variety of different shapes without affecting the function of the diffuser component. For example, the diffuser component can take the shape of the glass portion of a traditional tungsten bulb, or a candle bulb, or alternatively the diffuser component can take on a more modern shape such as a cuboid or a sphere.

The interchangeability of the diffuser components further enhances the personalisation of the lighting assembly.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one aspect can typically be combined alone or together with other features in different aspects of the invention. Any subject matter described in this specification can be combined with any other subject matter in the specification to form a novel combination.

Various aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary aspects and implementations. The invention is also capable of other and different examples and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, each example herein should be understood to have broad application, and is meant to illustrate one possible way of carrying out the invention, without intending to suggest that the scope of this disclosure, including the claims, is limited to that example. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having", "containing", or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Thus, throughout the specification and claims unless the context requires otherwise, the word “comprise” or variations thereof such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of”, "consisting", "selected from the group of consisting of, “including”, or "is" preceding the recitation of the composition, element or group of elements and vice versa. In this disclosure, the words “typically” or “optionally” are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples but which can be omitted in others without departing from the scope of the invention.

All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa. References to directional and positional descriptions such as upper and lower and directions e.g. “up”, “down” etc. are to be interpreted by a skilled reader in the context of the examples described to refer to the orientation of features shown in the drawings, and are not to be interpreted as limiting the invention to the literal interpretation of the term, but instead should be as understood by the skilled addressee.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a side view of a pendant lamp assembly;

Figure 2 shows a side view of the housing of the pendant lamp assembly of Figure 1;

Figure 3 shows the housing of Figure 2 with the diffuser removed;

Figure 4 shows the lamp of Figure 3 with the internal cover removed;

Figure 5 shows the housing of Figure 2 with the diffuser removed to permit attachment of a lighting shade;

Figure 6 shows a side view of a second example of a pendant lamp assembly;

Figure 7 shows a perspective view of the pendant lamp assembly of Figure 6;

Figure 8 shows the internal components of the pendant lamp assembly fitting;

Figure 9 shows the pendant lamp assembly comprising the housing of Figure 6;

Figure 10 shows the pendant lamp assembly of Figure 9 with the diffuser removed;

Figure 11 shows the pendant lamp assembly of Figure 9 with the diffuser and the ring removed;

Figure 12 shows the heat sink outer casing removed from the cap;

Figure 13 shows an example of the invention with an array of LEDs on a printed circuit board;

Figure 14 shows a schematic diagram of the lamp assembly of Figure 6 with a lighting shade attached and the assembly attached to a ceiling;

Figure 15 shows an example of the lamp assembly with a diffuser in the shape of an elongate and thin traditional tungsten bulb;

Figure 16 shows an example of the lamp assembly with a diffuser in the shape of a candle bulb;

Figure 17 shows an example of the lamp assembly with a diffuser in the shape of a round traditional bulb;

Figure 18 shows an example of the lamp assembly with a diffuser in the shape of a cuboid;

Figure 19 shows an example of the lamp assembly with a diffuser in the shape of a large traditional bulb;

Figure 20 shows an example of the lamp assembly with a diffuser in the shape of a balloon;

Figure 21 shows an example of the lamp assembly with a diffuser in the shape of a cuboid with rounded corners.

DETAILED DESCRIPTION

According to a first example, a pendant lamp assembly 1 comprises a housing 10 suspended from a fitting by a power cable 5. The housing 10 is in a generally tubular form and comprises an integral light source encased within the housing 10 in a tarn per-resistant manner. The assembly 1 further comprises a diffuser 40 which can thread, slide, clip, or otherwise fix in a removable manner onto the tamper-resistant housing 10.

Referring to Figures 1 and 2, in this example, the pendant lamp assembly 1 comprises a fitting which here is in the form of a ceiling rose 8 and which attaches to the ceiling or another surface, and from which the power cable 5 and lamp assembly 1 is suspended in use in a manner that avoids excessive axial tension on the connections at upper and lower ends of the cable 5. The power cable 5 passes through a sheathed clamp 6 which transfers the weight of the lamp assembly 1 onto the outer sheath of the cable 5 which is capable of bearing the axial tension to support the lamp assembly from the ceiling rose 8. The lower end of the power cable 5 passes from the clamp 6 into a cap 11 forming an upper end of the housing 10. Cap 11 has vents 11v on its upper surface, which permit rising heat to exit the assembly as will be described below. The diffuser 40 is shown in position on the housing 10.

The power cable 5 terminates at its lower end in a connection to a light source. In this example the cores of the cable 5 terminate on a printed circuit board mounted within the housing 10 (optionally mounted at least partially within a tubular internal compartment arranged co-axially within the bore of the cap 11). The circuit board in this example has a transformer which transforms the mains voltage and mitigates fluctuations in the power supply that is fed to the integral light source, which in this example is in the form of an LED array 25 (described below). The transformer then supplies the LED array 25 with power. Heat generated by the transformer and other electrical components within the housing can rise through the housing 10 to leave the housing 10 through the vents 11 v in the cap 11.

This example of lamp assembly 1 optionally incorporates a heat sink as part of the housing 10. The heat sink here takes the form of a heat conductive core in the form of a sleeve made of metal or another conductive material, which forms a cavity in the form of a partial cylinder around at least a portion of the printed circuit board e.g. around the transformer, encircling the transformer circumferentially. In this example, the light source in the form of a circuit board carrying the LED array 25 is attached to the outer surface of the lower end of the cavity. The upper end of the heat sink cavity remains open in this example, allowing heat to rise and to dissipate through vents 11 v in the cap 11 of the housing 10. The heat sink core is made of metal. The heat sink core can have an outer casing forming a part of the housing around its circumference, and the outer casing can optionally comprise the same material as the cap 11, or optionally another non-conductive material.

Figure 4 shows the internal cover 15 removed from the boss 16. This exposes the array 25 of LEDs 22 that are surface mounted to a printed circuit board 23. The internal cover 15 is removable during the manufacturing process to allow fitting of the LED array 25 in place in the assembly. Once the LED array 25 is in place, the internal cover 15 is engaged onto the boss 16 and then permanently fixed in position. The permanent fixing can be by, for example, gluing or plastic welding. By permanently fixing the internal cover 15 over the LED array 25, driver, and connection point of the power cable 5 removal or replacement of the components in the housing 10 will necessarily damage the housing.

Figure 3 shows the diffuser 40 having been removed from the housing 10 via threaded connector 46. Removing the diffuser exposes the internal cover 15 of the light source 20. As shown in this example, one example of the shape the internal cover 15 can take is circular, with a flat circumferentially extending side and the end that is furthest from the heat sink outer casing 12 having a slight curve.

Removal of the diffuser 40 allows fitting of a lamp shade 50 or other similar accessory, as shown in Figure 5, to the lamp assembly. This allows personalisation of the lamp assembly 101 without any loss of functionality, for example if the light emitted from the lamp assembly 101 is found to be too bright for the location it has been placed in. Fitting of a lamp shade 150 can then act to dim the emitted light. To allow different sizes of lamp shade 50 to be fitted, and to constrain movement of the lamp shade 50 once it has been fitted, a removable ring can optionally be provided as part of the lamp assembly that is placed between the heat sink outer casing 12 and the lamp shade 50, with the diffuser 40 then fixing into place underneath the lamp shade fitting. Alternatively, the ring can be formed as an integral part of the housing 10, for example a moulded ridge.

Alternatively, the LED array 25 can be of a dimmable type thereby permitting adjustment of the emitted light according to demand.

According to a second example, a pendant lamp assembly 101 comprises a housing 110 suspended from a fitting by a power cable 105. The housing 110 is in a generally tubular form and comprises an integral light source encased within the housing 110 in a tamper-resistant manner. The assembly 101 further comprises a diffuser 140 which can thread, slide, clip, or otherwise fix in a removable manner onto the tamper-resistant housing 110.

Referring to Figure 9, in this example, the pendant lamp assembly 101 comprises a fitting which here is in the form of a ceiling rose 108 and which attaches to the ceiling or another surface, and from which the power cable 105 and lamp assembly 101 is suspended in use in a manner that avoids excessive axial tension on the connections at upper and lower ends of the cable 105. The power cable 105 passes through a sheathed clamp 106 which transfers the weight of the lamp assembly 101 onto the outer sheath of the cable 105 which is capable of bearing the axial tension to support the lamp assembly from the ceiling rose 108. The lower end of the power cable 105 passes from the clamp 106 into a cap 111 forming an upper end of the housing 110. Cap 111 has vents 111v on its upper surface, which permit rising heat to exit the assembly as will be described below. The diffuser 140 is shown in position on the housing 110.

The power cable 105 terminates at its lower end in a connection to a light source. In this example the cores of the cable 105 terminate on a printed circuit board mounted within the housing 110 (optionally mounted at least partially within a tubular internal compartment arranged co-axially within the bore of the cap 111). The circuit board in this example has a transformer which transforms the mains voltage and mitigates fluctuations in the power supply that is fed to the integral light source, which in this example is in the form of an LED array 125 (described below). The transformer then supplies the LED array 125 with power. Heat generated by the transformer and other electrical components within the housing can rise through the housing 110 to leave the housing 110 through the vents 111 v in the cap 111.

This example of lamp assembly 101 incorporates a heat sink 112 as part of the housing 110. The heat sink 112 here takes the form of a heat conductive core 112h, as best seen in Figure 12, in the form of a sleeve made of metal or another conductive material, which forms a cavity in the form of a partial cylinder around at least a portion of the printed circuit board e.g. around the transformer, encircling the transformer circumferentially. In this example, the cavity has one open end at the top, through which heat can dissipate upwards, and a closed end at the bottom, which at least partially occludes the lower end of the cavity. In this example, the light source in the form of a circuit board carrying the LED array 125 is attached to the outer surface of the lower end of the cavity. The upper end of the heat sink cavity remains open in this example, allowing heat to rise and to dissipate through vents 111 v in the cap 111 of the housing 110. The heat sink core 112h is made of metal.

The heat sink core 112h can have an outer casing 112c forming a part of the housing around its circumference, and the outer casing 112c can optionally comprise the same material as the cap 111, or optionally another non-conductive material..

Figure 12 shows the heat sink core 112h within the heat sink outer casing 112c, separated from the LED driver 127 within the cap 111. In the base of the heat sink core 112h, there is a central aperture 113 through which the power cable or cables from the LED driver 127 can pass and thereby connect to the board carrying the LED array 125 (see Figure 13). The transformer of the LED driver 127 generates heat as it converts mains AC electricity to DC electricity in order to supply a stable voltage and current to the LEDs on the array. The heat sink 112h core absorbs this heat and exhausts it upwards through the open upper end of the heat sink cavity and thereby draws the heat away from the LED array, protecting the LEDs from excess heat which could degenerate the LEDs over time. The heat from the heat sink 112 exits the lamp assembly through vents 111 v in the cap 111, see for example Figure 10.

The heat sink core 112h is formed from aluminium in this example, but it can be manufactured from an aluminium alloy, ceramics, copper, copper alloy, or any other material that has heat conductive properties and can be shaped into the desired form.

The LED driver 127 slides into slots moulded on the inner surface of the tubular internal compartment of the cap 111. The slots are of sufficient width that the circuit board of the driver is secured against lateral movement, thus protecting it from damage, and ensuring it remains in an optimal position within the heat sink cavity.

During manufacture, the carrier for the LED array 125 is fixed onto the base of the heat sink 112 as shown in Figure 13, outside the heat sink core on the outer end face of the heat sink, and optionally at least partially thermally insulated therefrom, for example, by the heat sink casing 112c and/or by another layer of thermally insulating material. The LEDs 122 are carried on a printed circuit board (PCB) 123 in this example, which is circular in shape in this case, but could be of different shapes as desired.

It is desirable during the manufacturing process that the components of the lamp assembly 101 are accessible for connection and fitting before the housing 110 is secured in a tamper-resistant manner. Accordingly, the lamp assembly 101 comprises an internal cover 115 adapted to fit over the LED array 125 once the components of the lamp assembly 101 have been fitted, and which is initially removable from the other components of the housing e.g. from the heat sink casing 112c. The lower end of the heat sink outer casing 112c that faces away from the cap 111 has a boss 116 forming a circular protrusion from the end of the heat sink outer casing 112. The outer diameter of the boss 116 is slightly less than that of the heat sink outer casing 112c to allow clearance for a diffuser component 140, described below.

The diameter of the PCB 123 is equal to or slightly smaller than the boss 116 for the internal cover to engage with, slide, or thread onto, to allow passage of the internal cover 115 for fitting in position.

The LED array 125 is covered by the internal cover 115 to complete encapsulation of the light source 120 within the housing 110. After the components of the light source have been fitted into place during manufacture, the internal cover 115 is then fixed in place in a tamper-resistant manner to close the housing 110 and seal the components inside the housing 110 in a tamper-resistant manner once the assembly is complete. The cover 115 can be either threadably fixed before permanent fixation, or it can slide, clip, or otherwise fix into place, in such a way that removal of the cover 115 from the boss 116 is not possible without damaging the housing 110 in some way.

Figure 13 shows the internal cover 115 removed from the boss 116. This exposes the array 125 of LEDs 122 that are surface mounted to a printed circuit board 123. The internal cover 115 is removable during the manufacturing process to allow fitting of the LED array 125 in place in the assembly. Once the LED array 125 is in place, the internal cover 115 is engaged onto the boss 116 and then permanently fixed in position. The permanent fixing can be by, for example, gluing or plastic welding. By permanently fixing the internal cover 115 over the LED array 125, driver, and connection point of the power cable 105 removal or replacement of the components in the housing 110 will necessarily damage the housing.

The lamp assembly 101 also comprises a detachable diffuser 140, which is a rounded tubular shape, but can take other shapes. The detachable nature of the diffuser 140 allows fitting of a lamp shade 150 or other similar accessory to the lamp assembly 101. To allow different sizes of lamp shade 150 to be fitted, and to constrain movement of the lamp shade 150 once it has been fitted, a removable ring 141 can optionally be provided as part of the lamp assembly that is placed between the heat sink outer casing 112 and the lamp shade 150, with the diffuser 140 then fixing into place underneath the lamp shade fitting. Alternatively, the ring 141 can be formed as an integral part of the housing 110, for example a moulded ridge.

Figure 10 shows the diffuser 140 having been removed from the housing 110 via threaded connector 146. Removing the diffuser exposes the internal cover 115 of the light source 120. As shown in this example, one possible shape the internal cover 115 can take is circular, with a flat circumferentially extending side and the end that is furthest from the heat sink outer casing 112 having a dome-shaped hemi-spherical curve.

Removal of the diffuser 140 allows fitting of a lamp shade 150 or other similar accessory, as shown in Figure 14, to the lamp assembly. This allows personalisation of the lamp assembly 101 without any loss of functionality, for example if the light emitted from the lamp assembly 101 is found to be too bright for the location it has been placed in. Fitting of a lamp shade 150 can then act to dim the emitted light.

Alternatively, the LED array 125 can be of a dimmable type thereby permitting adjustment of the emitted light according to demand.

Figures 6, 7, 9 and 10 show the lamp assembly with an optional ring 141 between the cap 111 and the diffuser 140. This can improve grip when attaching a shade and also provides increased resistance to hold the light shade in place when the diffuser 140 is screwed back into position.

Figure 9 shows the full lamp assembly 101 with the ceiling rose 108, power cable 105, sheathed connector 106, cap 111, ring 141, and diffuser 140. In Figure 10, the diffuser 140 has been removed to show a second, more rounded example of the internal cover 115, with an increased curve on the dome-shaped end that is furthest from the cap 111 when compared with the previous example.

Figure 11 shows the diffuser 140 and the removable ring 141 detached from the lamp assembly housing 110. The dome-shaped internal cover 115 is in place attached to the heat sink outer casing 112, which is in turn fixed to the cap 111. In this example, the internal cover 115 slidably clips onto the heat sink outer casing 112, which in turn slidably clips into the cap 111. The inner diameter of the ring 141 is slightly larger than the protruding threads on threaded connection 146, so that the ring 141 merely slides over the threads and then is held in place when the diffuser 140 is threaded back onto the housing 110.

The power cable 105 connects to mains electricity through the fitting, which can be in the form of a ceiling rose 108, disposed at one (upper) end of the cable 105. At the other (lower) end, the cable 105 enters the housing 110 through a clamping sheath 106 or other device that acts to clamp onto the cable and maintain the relative positions of the cable 105 and the housing 110 in order to suspend the weight of the lamp assembly 101 from the ceiling rose 108 without transferring the load onto the connections inside the housing 110. The clamping sheath 106 is attached to a cap 111 forming a part of the housing 110 and secured to the housing in a tamper-resistant manner) e.g. by gluing, welding etc.

Figure 8 shows the internal components of the ceiling rose 108. Within the housing of the ceiling rose 108 is a mount 109 which can be affixed to the ceiling, optionally by threaded fixings. There are holes provided in the mount 109 for the passage of fixings therethrough. The mount 109 also serves as the connection point between the power conduit and the power cable 105.

Figure 14 shows a schematic example of the current example fixed in position to a ceiling via ceiling rose 108. A shade 150 is fully fitted and in place with the cap 111 and heat sink outer casing 112 extending towards the ceiling above the shade 150, and the rest of the housing 110 hidden from view. The shade 150 is held in place between the ring 141 and the diffuser 140 being threadably connected to the heat sink outer casing 112.

Figures 15-21 show variously shaped examples of the diffuser, 240-840. The remaining components of the lamp assembly 201-801 are unchanged from lamp assembly 101 previously described.

Claims

1. A pendant lamp assembly comprising a light source housed in a tamper-resistant housing and a power cable adapted to support the housing and to supply power to the light source.

2. A pendant lamp assembly as claimed claim 1, wherein the light source is a low energy light source.

3. A pendant lamp assembly as claimed in any preceding claim wherein the light source comprises at least one light emitting diode (LED).

4. A pendant lamp assembly as claimed in claim 2 or claim 3, wherein at least one LED is a surface mounted LED mounted on a carrier.

5. A pendant lamp assembly as claimed in claims 2-4, wherein the lamp assembly comprises an integral LED driver within the housing.

6. A pendant lamp assembly as claimed in claim 5, wherein the light source is connected via the LED driver to the power cable.

7. A pendant lamp assembly as claimed in claims 1-6, wherein the lamp assembly comprises a heat sink.

8. A pendant lamp assembly as claimed in claim 7, wherein the heat sink forms a cavity within the housing in which at least one electrical component is disposed.

9. A pendant lamp assembly as claimed in claim 8, wherein the heat sink is disposed between the electrical component and the light source .

10. A pendant lamp assembly as claimed in claim 8 or claim 9, wherein the heat sink at least partially circumferentially surrounds an electrical transformer contained at least partially within the heat sink cavity.

11. A pendant lamp assembly as claimed in claims 8-10, wherein the heat sink cavity is at least partially cylindrical with at least one partially closed end, wherein the partially closed end has an access hole for a cable.

12. A pendant lamp assembly as claimed in claims 8-11, wherein the heat sink cavity has an open end to receive the electrical component within the heat sink cavity during assembly.

13. A pendant lamp assembly as claimed in claims 11-12, wherein the closed end of the heat sink is closed by a flat plate disposed between the electrical component within the heat sink and the light source.

14. A pendant lamp assembly as claimed in claims 11-13, wherein the outer surface of the flat end of the heat sink provides a mounting for the PCB on the outside of the heat sink.

15. A pendant lamp assembly as claimed in claims 8-14, wherein the heat sink comprises a metal.

16. A pendant lamp assembly as claimed in claims 8-15, wherein the heat sink is coated in non-conductive material.

17. A pendant lamp assembly as claimed in claims 8-16, wherein the light source and heat sink are separated by a layer of thermally insulating material.

18. A pendant lamp assembly as claimed in claims 1-17, wherein the housing encases the light source fully such that said light source is inaccessible without causing damage to the lamp assembly.

19. A pendant lamp assembly as claimed in claims 1-18, wherein the housing comprises a housing body and a cover connected with the housing body in a tamper-resistant manner.

20. A pendant lamp assembly as claimed in claim 19, wherein the cover has at least a portion formed from a transparent or translucent material and the light source arranged such that it emits light through the transparent or translucent portion of the cover.

21. A pendant lamp assembly as claimed in claim 19 or claim 20, wherein the cover is adapted to close off an open end of the housing body through which the light source emits light, and through which the light source and other internal components are inserted into the housing body during an assembly process.

22. A pendant lamp assembly as claimed in claim 21, wherein the open end of the housing body is located at one end of the housing, and the cover engages with the housing body to complete the encasement of the light source by the housing once the cover is fixed in position on the housing body.

23. A pendant lamp assembly as claimed in claims 19-22, wherein the housing body and the cover are glued together such that the connection between the cover and the housing body is irreversible without damaging the housing.

24. A pendant lamp assembly as claimed in claims 19-23, wherein the housing body and the cover are welded together such that the connection between the cover and the housing body is irreversible without damaging the housing.

25. A pendant lamp assembly as claimed in claims 19-24, wherein at least a portion of the cover is adapted to dissipate or diffuse light from the light source.

26. A pendant lamp assembly as claimed in claims 1-25, wherein the housing comprises vents adapted to facilitate dissipation of heat generated by the lamp assembly.

27. A pendant lamp assembly as claimed in claim 26, wherein the vents are located in a cap, wherein the cap is located at an upper end of the housing, and wherein the vents are adapted to permit rising heat to leave the housing in a direction that is away from the light source.

28. A pendant lamp assembly as claimed in claims 1-27, wherein the lamp assembly includes a removable diffuser component.

29. A pendant lamp assembly as claimed in claim 28, wherein the diffuser component is adapted to be removably attached to the lamp assembly such that it can be removed and reattached without damaging the lamp assembly or the diffuser component.

30. A pendant lamp assembly as claimed in claim 28 or claim 29, wherein the diffuser component is detached to permit attachment of a lamp shade, wherein the diffuser component is connected to the lamp assembly in order to hold the lamp shade in position.

31. A pendant lamp assembly according to any preceding claim, wherein the light source is integrated into the housing.

32. A method of manufacturing a pendant lamp assembly, wherein the method comprises securing a light source within a tamper-resistant housing and connecting a power cable to the housing, wherein the power cable is adapted to support the housing and to supply power to the light source