The present invention relates to retaining mechanisms. In particular, the invention relates to mechanisms that resist unauthorised removal of a piece of equipment such as a lamp from a fitting, such as anti-theft lamp retaining means or child proof lamp retaining means.

US5788525A discloses an adapter for lamps and other electrical devices to be installed in standard lamp sockets and which prevents unauthorized removal of such lamps or other electrical devices. A screwshell means is placed upon a body member such that relative rotation between them is possible. A tool or key placed in aligned slots or keyways prevents relative rotation so that the adapter can be installed or removed from a lamp socket. The tool or key is then removed permitting relative rotation again, whereby the lamp or other electrical device cannot be removed from the lamp socket. Use of the tool or key fixes the two components with respect to one another and the adapter can be removed. This approach has a number of disadvantages. Because it is a separate adapter, not part of the lamp, it adds to the overall height of lamp holder/lamp combination. Space for this added height is not always available. It also adds to the cost because, by definition the end result must cost more than the lamp and lamp holder combination. Furthermore the tool or key is required to both fit and release the lamp from the adaptor, and the keyway in the adapter is associated with part of the lamp that fits into the lamp holder and thus is located in a region that is not accessible with all lamp holder designs. WO2010054913A1 discloses an LED lamp for insertion into a luminaire holder which has a lamp base, a light-emitting body which is connected to the lamp base and a locking apparatus which prevents the lamp from being removed from the luminaire holder in the locked state and allows the lamp to be removed from the luminaire holder in the unlocked state. The locking apparatus has an individualized lock which can unlock the locking apparatus. This last feature represents a disadvantage because a different key or key code will be needed for each light.

According to one embodiment of the present invention, there is provided an anti- theft lamp according to Claim 1. For example there is provided an anti-theft lamp which includes an anti-theft lamp retaining means for securing the anti-theft lamp into a conventional lamp holder. The anti-theft lamp retaining means comprises a first part adapted to engage with the lamp holder and a second part. A keyway extends substantially through the second part into the first part. When a key is inserted into the keyway, any substantial rotation of the second part with respect to the first part is prevented. This means that when the key is in position the lamp may be installed in or removed from the fitting, but when they key is removed with the lamp in place in the fitting, rotation of the second part with respect to the first part prevents the lamp from being removed from the lamp holder. Preferably, the first part and the second part of the anti-theft lamp retaining means are connected by means of a breakable connection. This means that the lamp can be provided to a user for installation without a key being present in the keyway, or without a key being required for installation of the lamp. Only if and when the breakable connection is broken is a key required to remove the lamp when required.

Preferably, the breakable connection between the first part and the second part is breakable in response to a rotational force applied between the two parts.

Preferably, the breakable connection between the first part and the second part is formed during manufacture of the anti-theft lamp retaining means.

Preferably, the breakable connection is adapted to withstand normal insertion and removal of the lamp into and from a lamp holder, but wherein the breakable connection breaks in response to continued rotational force applied to an inserted lamp.

In an alternative preferred embodiment, installation of an anti-theft lamp into a lamp holder requires a key to be inserted into the keyway. Preferably, removal of an anti-theft lamp from a lamp holder requires insertion of a key into the keyway.

Preferably, the first part is connected to a light emitting part of the anti-theft lamp.

Preferably, the first part and the light emitting part of the lamp are an integral unit. Preferably, the second part comprises substantially the whole outer part of the anti- theft lamp which is accessible when the lamp is inserted in the lamp holder.

Preferably, the first part and the second part are in close thermal contact, such that heat generated in the first part may be dissipated through the second part. Preferably, the second part incorporates heat dissipating fins.

According to a further embodiment of the present invention, there is provided an anti-theft lamp retaining means (adaptor means) for securing a lamp into a lamp holder. The anti-theft lamp retaining means comprises a first part adapted to engage with the lamp holder and a second part. A keyway extends substantially through the second part into the first part. When a key is inserted into the keyway, any substantial rotation of the second part with respect to the first part is prevented. Preferably, the first part and the second part of the anti-theft lamp retaining means are connected by means of a breakable connection. This means that the lamp can be provided to a user for installation without a key being present in the keyway or without a key being required to install a lamp into a lamp holder. Preferably, the breakable connection between the first part and the second part is breakable in response to a rotational force applied between the two parts.

Preferably, the breakable connection between the first part and the second part is formed during manufacture of the anti-theft lamp retaining means.

Preferably, the breakable connection is adapted to withstand normal insertion and removal of the lamp into and from a lamp holder, but wherein the breakable connection breaks in response to continued rotational force applied to an inserted lamp.

Preferably, installation of an anti-theft lamp into a lamp holder requires a key to be inserted into the keyway.

Preferably, removal of an anti-theft lamp from a lamp holder requires insertion of a key into the keyway. It will be appreciated that the present invention has applications beyond lamps and lighting applications. It is equally applicable to pieces of equipment, particularly electronic equipment, that are or can be installed and removed by a rotational movement. So for example it would be applicable to an expensive and valuable item such as a CCTV camera mounted in an appropriate holder.

The invention will now be described with reference to the following drawings.

Figures 1A and 1 B show sectional and perspective views of an embodiment of the invention;

Figure 2 shows some examples of lamp fittings to which the present invention is applicable; Figures 3A and 3B show sectional and perspective views of an embodiment of the invention;

Figures 4A and 4B show an embodiment of the invention having a breakable anti- rotation mechanism;

Figure 5 shows lugs located at any point on an interior part of a lamp;

Figures 6A and 6B show sectional and perspective views of an embodiment of the invention; and

Figures 7A and 7B show an embodiment of the invention in the form of an adapter into which a lamp may be fitted;

Figure 8 shows a perspective view of a lamp including an anti-theft mechanism showing a key;

Figure 9 shows a cross-sectional view of the lamp of Figure 8;

Figure 10 shows a perspective view of the lamp of Figure 8 from a view without the key; Figure 11 shows a cross-sectional view of the lamp in Figure 1 1.

Referring now to Figures 1A and 1 B, which show sectional and perspective views of an embodiment of the invention, lamp 100 comprises a first part 102 of an anti-theft retaining means together with a second part 104. First part 102 is adapted to engage with a lamp holder (not shown). Second part 104 is rotatably attached to first part 102. A keyway 106 extends substantially through second part 104 into first part 102, and when a key 108 is present in keyway 106, rotation of second part 104 with respect to first part 102 is substantially prevented. It is to be understood that the term "substantially" here allows for some slight rotation between second part 104 and first part 102 as a result of play in the contact between key 108 and keyway 106.

This means that when key 108 is fitted into keyway 106, lamp 100 can be fixed in a suitable lamp holder by engaging first part 102 with a lamp holder. The means of engagement between first part 102 and the lamp holder can be any kind that involves a turning motion to secure lamp 100 in the lamp holder. Some examples are shown in Figure 2 but these are not intended to be exhaustive. The invention includes for example bayonet fittings such as B22, B15 and B15d lamp fittings.

When key 108 is fitted to keyway 106, lamp 100 can be fixed in or removed from a lamp holder by rotating second part 104, which in turn rotates first part 102, leading to an engagement or disengagement of lamp 100 with the lamp holder. When lamp 100 is engaged with the lamp holder and key 108 is removed from keyway 108, second part 104 is free to rotate with respect to first part 102, and thus the lamp cannot be disengaged from the lamp holder by turning second part 104.

It will be understood that the electrical connections between the base of the lamp that engages with the lamp holder and the LED light engine in the lamp do not rotate with the first or second part of the anti-theft lamp retaining means.

Referring now to Figures 3A and 3B, which show sectional and perspective views of an embodiment of the invention, lamp 100 comprises a first part 102 of and a second part 104. First part 102 engages with lamp holder 120. Second part 104 is rotatably attached to first part 102. Electrical and electronic components including the light engine and associated components 130 are located or supported within the lamp by first part 102, which ensures that these are fixed in place within the lamp and are non-rotatable. A keyway 106 extends substantially through second part 104 into first part 102, and when a key 108 is present in keyway 106, rotation of second part 104 with respect to first part 102 is substantially prevented. In this embodiment, key 108 folds back on itself or is re-entrant as it engages with keyway 106 located in or on an interior part of first part 102. It is therefore particularly preferred that the key has a substantially curvilinear shape as this arrangement means that is more difficult to achieve unauthorised removal of lamp 100 from lamp holder 120 when a key of the right shape is not available, and for example prevents use of a straight thin object such as a screwdriver being used as an improvised key. This makes the anti-theft mechanism more secure. It also means that the key can be inserted some considerable distance away from the lamp holder, which is a significant advantage in the case of longer or more elongate lamp holders that shroud a significant proportion of the lamp. In other aspects, engagement and disengagement of lamp 100 with the lamp holder is as described above.

Referring now to Figure 4, which shows an embodiment of the invention having a breakable anti-rotation mechanism, one or more breakable lugs 1 10 are located between first part 102 and second part 104. Lugs 110 prevent second part 104 rotating with respect to first part 102, and lamp 100 may be engaged or disengaged from the lamp holder without the need for a key. Once lamp 100 has been engaged with the lamp holder, extra or additional turning or rotational force causes lugs 110 to break, and the second part 104 is now rotatable with respect to first part 102. To remove lamp 100 from the lamp holder, key 108 is located in keyway 106 to prevent rotation of the second part 104 with respect to first part 102, and lamp 100 can be removed from the lamp holder as described above.

Breakable lugs 1 10 can be situated at any suitable location or locations within the interior of the lamp between first part 102 and second part 104. These lugs may take a number of different forms, as determined by a person skilled in the art. They could, for example, be formed during manufacture as one or more small connecting lugs between the two components. Or they could be one or more regions of perforations as described below. Importantly the breakable connection between the first and second part must be strong enough that it can withstand the rotational force(s) required to install the lamp in a lamp holder, and to uninstall if an anti-theft function is not required. However, if theft of the lamp is considered an issue, it must be possible to break the breakable connection by continuing to exert a rotational force on the lamp to snap the breakable connection, until the lamp spins freely in the lamp holder. Figure 5 shows interior parts of lamp 100, and lugs 110 can be located at any point on interior part 1 12 between points A and B provided that when broken, second part 104 is rotatable with respect to first part 102.

Referring now to Figure 6A and 6B, which show sectional and perspective views of a further embodiment of the invention, lamp 100 comprises a first part 102 of and a second part 104. First part 102 engages with lamp holder 120. Second part 104 is rotatably attached to first part 102. Electrical and electronic components including the light engine and associated components 130 are located or supported within the lamp by first part 102, which ensures that these are fixed in place within the lamp and do not rotate along with part 104. A keyway 106 extends substantially through second part 104 into first part 102, and when a key 108 is present in keyway 106, rotation of second part 104 with respect to first part 102 is substantially prevented. Breakable lugs 1 10 of the kind described above, for example in the form of perforations are located adjacent the portion of the first part 102 which engages with the lamp holder. In this embodiment, key 108 can engage with keyway 106 extending into first part 102. Once again the keyway may be located a considerable distance away from the region of the lamp that engages with the lamp holder. The light engine and associated components are located within first part 102, and second part 104 comprises substantially the whole outer part of lamp 100 which is accessible when the lamp is inserted in lamp holder 100. Figure 6B illustrates how first part 104 is hidden behind lamp holder 100, which means that when the lugs 110 are broken and key 108 is absent, there is no access to the first part 102, and lamp 100 cannot be removed from lamp holder 100, because the whole of the outer part (second part 104) including the lens and any heat sinks, are all rotatable.

First part 102 and second part 104 are thus close thermal contact, which means that heat generated in first part 102 by the light engine and associated components may be dissipated through second part 104. To assist in heat dissipation, heat dissipating fins may be incorporated into second part 104. Referring to Figures 7 A and 7B, which show sectional and perspective views of another embodiment of the invention, adapter 700 comprises a first part 702 of an anti-theft retaining means together with a second part 704. First part 702 is adapted to engage with a lamp holder (not shown). Second part 704 is rotatably attached to first part 702. A keyway 706 extends substantially through second part 704 into first part 702, and when a key 708 is present in keyway 706, rotation of second part 704 with respect to first part 702 is substantially prevented. It is to be understood that the term "substantially" here allows for some slight rotation between second part 704 and first part 702 as a result of play in the contact between key 708 and keyway 706. In other aspects, engagement and disengagement of adapter 700 with the lamp holder is as described above for lamp 100. Referring again to Figure 7A, which shows an embodiment of the invention having a breakable anti-rotation mechanism, one or more breakable lugs 710 are located between first part 702 and second part 704. Lugs 710 prevent second part 704 rotating with respect to first part 702, and adapter 700 may be engaged or disengaged from the lamp holder without the need for a key. Once adapter 700 has been engaged with the lamp holder, extra or additional turning or rotational force causes lugs 710 to break, and the second part 704 is now rotatable with respect to first part 702. To remove adapter 700 from the lamp holder, key 708 is located in keyway 706 to prevent rotation of the second part 704 with respect to first part 702, and adapter 700 can be removed from the lamp holder as described above.

A further embodiment is illustrated in Figures 8 to 11 inclusive. These Figures show a lamp 200 with an E27 screw-type fitting, although this embodiment would be equally applicable to any of the lamp fittings shown in Figure 2 or described above. The lamp base 202, and internal parts of the lamp extending up from the lamp base, are formed of separate components but are joined together during assembly to form a unitary construction such that these parts all form a single unit and rotate along with the screw cap end of the lamp base. This base part includes the light engine PCB 230 and associated electronic components (not shown). Rotatably mounted with respect to part 202 is diffuser and shroud 204. The diffuser and shroud also form a unit and rotate together, rotating independently of base 202 in the absence of key 208. Importantly, substantially the whole of the outside of the lamp other than the screw cap fitting is free to rotate unless key 208 is inserted in to keyway 206. The key 208, which in this embodiment can be inserted from quite high up on the lamp body, prevents the two parts 202 and 204 from rotating independently and allows the lamp to be screwed in or unscrewed as desired.

To increase security a number of dummy keyways are provided in this design and only one keyway has the ability to accept the key. This is a further deterrent to any would-be thief who wants to steel the lamp.

In order that parts 202 and 204 can rotate freely of each other a lubricating ring is include at a suitable point where the two parts contact each other. This lubricating ring can take a number of forms. It could consist of two low friction surfaces that abut one another, such as two silicone rings. Or it could be a pre-lubricated sealed for life ball race. The presence of this lubricating ring makes it virtually impossible to remove the lamp 200 from its lamp holder without the key 208. Downward pressure on the diffuser alone does not allow the lamp base to be unscrewed because of the substantially frictionless lubricating ring.

It will be apparent from the above description that the present invention extends to a complete lamp including an anti-theft retaining means, an adapter for a lamp including an ant-theft retaining means, and an anti-theft retaining means per se. It will also be appreciated that this technology is not limited to just lamps, lamp fittings and lighting applications. It is equally applicable to pieces of equipment, particularly electronic equipment, that are or can be installed and removed by a rotational movement. So for example it would be applicable to expensive and valuable items such as a CCTV camera mounted in an appropriate holder.