WO2003041229A1

WO2003041229A1 - Anti-theft device

Info

Publication number: WO2003041229A1
Application number: PCT/GB2002/004942
Authority: WO
Inventors: Nicholas Alexander Rutter; Matthew Quinn
Original assignee: Fireangel Limited
Priority date: 2001-11-09
Filing date: 2002-11-01
Publication date: 2003-05-15
Also published as: EP1444756A1; GB0126919D0; AU2002341164B8; EP1444756B1; AU2002341164B2

Abstract

An anti-theft device for hindering or substantially preventing the removal of an electrical device from a light fitting comprises a collar arranged to locate around at least a portion of the light fitting and a portion of the electrical device so as to enclose a connecting region of the light fitting and the electrical device. The collar includes an arrangement for hindering or substantially preventing relative movement between the light fitting and the electrical device so as to hinder or substantially prevent removal of the device from the light fitting.

Description

Anti-theft Device

The present invention relates to an anti-theft device.

It is known to use domestic lighting circuits as power supplies for electrical devices other than conventional filament light bulbs. Inparticular, conventional fight fittings, such as the bayonet-type or Edison Screw-type (ES) or halogen fittings, are often used as power sources for various forms of powered devices such as smoke detectors/alarms, night lamps, air fresheners or intruder alarms.

Such devices generally comprise a main body, containing the electronic circuitry and associated components for the device, and a male connector on an upper portion of the device which is suitable for connection to the light fitting to enable the alarm to be powered by the light fitting. The devices are also often provided with a female connector suitable for receiving, and electrically connecting to, a light bulb to enable the bulb also to be powered from the light fitting. Thus, in use, the device is interposed between the light fitting and the bulb with electrical power being transmitted from the light fitting, through the device to the bulb . An example of a smoke alarm having the above features is described in International patent application No. PCT/GB99/03326.

A disadvantage of such devices which are arranged to be powered by a conventional light fitting is the potential for theft of the device. Removal of the device from the light fitting is generally no more difficult than the removal of a conventional light bulb and large organisations such as Councils and Housing Authorities suffer greatly from the theft of what are often relatively expensive electrical items.

It would be advantageous to provide amethod or apparatus by which the theft of electrical devices which are powered by light fittings is hindered or substantially prevented.

According to one aspect of the present invention, therefore, there is provided an apparatus for hindering the removal of an electrical device from a light fitting, the apparatus comprising: collar means arranged to locate around at least aportion of said light fitting and aportion of said electrical device thereby substantially to enclose a connecting region of said light fitting and said electrical device;

wherein said collar means includes means for hindering or substantially preventing relative movement between said light fitting and said electrical device.

In a preferred embodiment, the collar means includes first abutment means arranged to abut with aportion of the light fitting and second abutment means arranged to abut with aportion of said electrical device thereby to hinder or substantially prevent relative movement of said light fitting and said electrical device in an axial direction of the light fitting.

In addition or alternatively, the collar means may include at least one proj ecting member which engages with the light fitting thereby to hinder or substantially prevent relative rotational motion between the light fitting and the electrical device.

The light fitting maybe a bayonet-type fitting or an Edison screw (ES) type fitting. The collar means maybe formed of at least two parts arranged to be positioned around at least aportion of the light fitting and at least aportion of the electrical device when the latter are connected, the two parts, in use, being j oined to form a substantially annular collar surrounding a connecting region between the light fitting and the electrical device.

The two parts of the collar means maybe locked together by locking means thereby to hinder or substantially prevent removal of the collar means and hence the electrical device. The locking means may comprise a snap fit or clip mechanism, an adhesive, screws, nuts andbolts or any anti-tamper variant of the above.

Advantageously, the collar means maybe fabricated from a flexible or rigid plastics material to enable more economical and faster manufacturing. The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a first perspective view of a preferred form of apparatus according to the invention prior to fitting;

Figure 2 is a second perspective view of the apparatus of Figure 1 prior to fitting;

Figure 3 is a perspective view of the apparatus of Figure 1 in use; and

Figure 4 is a perspective view of a modification to the smoke alarm illustrated in Figures 1-3.

In the following description, the apparatus of the invention is described in the context of its application to a smoke alarm such as that described in copending International Patent Application No. PCT/GB99/03326.Itwill be appreciated, however, that the invention is not confined to such use and maybe effective with any device which is powered from a conventional light socket, such as those described above.

In addition, the terms "upward movement" and "downward movement" are used to describe movement generally in the directions of arrows A and B, respectively.

Refeιτing to Figures 1 and 2, a known form of smoke detector or alarm which is arranged to be powered by a light fitting is shown generally at 10. The smoke alarm 10 has a core structure 60 in the form of a generally cylindrical tube 60. The tube 60 has a male bayonet fitting 62 at one axial end and a female bayonet fitting (not shown) at the other axial end. The male bayonet fitting 62 is arranged to be plugged into a conventional female bayonet light fitting 64 in the usual manner by means of a bayonet pin 61 on the male bayonet fitting 62 engaging with a channel 63 in the light fitting 64. Removal of the alarm 10 from the light fitting requires a first movement of the alarm in an axial direction towards the light fitting and then a rotational movement of the alarm relative to the light fitting to disengage the pin 61 from the channel 63. The male bayonet 62 fitting can thenbe withdrawn from the light fitting 64.

The alarm 10 has a main housing 68 which, in this embodiment, has a cross-section being substantially elliptical and which houses an ionisation chamber and the main circuitry (not shown) of the smoke alarm. The housing 68 has a central aperture 70 which has a greater diameter than the diameter of the tube 60. The alarm 10 is arranged such that the main housing 68 surrounds the tube 60 with the tube extending through the centre of the aperture 70. The housing 68 is spaced from, and connected to, the external surface of the tube 70 by means of one or more extension portions 66, thereby providing an annular air gap 73 between the housing and the tube.

hi Figures 1 and 2, a preferred form of apparatus according to the invention is also shown during the fittingprocess. The apparatus comprises a generally annular collar formed of two parts, a first part20 and a second part 22. Thecollaris sized and shaped such that, when fitted, it substantially surrounds or encloses the male bayonet fitting 62 and a lower portion 65 of the fight fitting 64, in close abutment thereto. As seen best in Figure 2, a radially inner surface 20a, 22aof the collar is contoured to match closely, and therefore lie in close abutment with, the radially outer surfaces of the connected light fitting 64 and male bayonet fitting 62.

More specifically, each collar part 20, 22 includes on its radially inner surface 20a, 22a aradially inwardly proj ecting portion defining first abutment means in the form of a step or shoulder 24 with the remainder of the collar. When fitted to the connected light fitting and smoke alarm, the shoulder 24 is positioned directly beneath the lower rim of the light fitting, closely adj acent or in direct abutment therewith. This substantially prevents any significant upward movement of the collar relative to the light fitting.

In addition, the lower rim or edge of the collar, defining second abutment means, is arranged to lie directly above, in close proximity to or in abutment with, the extension portions 66 of the tube 60. This arrangement substantially prevents any significant upward movement of the smoke alarm relative to the collar. It can be seen that the radially inwardly proj ecting portion of the collar, defining the shoulder 24, is effectively trapped between the extension portions 66 of the tube 60 and the lower rim of the light fitting 64, thereby preventing any significant upward movement of the smoke alarm relative to the light fitting, hi addition, the engagement of the bayonet pin 61 in the channel 63 substantially prevents any significant downward movement of the smoke alarm relative to the light fitting.

As a consequence, when the collar is fitted to the connected smoke alarm and light fitting, any axial movement of the smoke alarm relative to the light fitting, which is required in order to detach the smoke alarm from the light fitting, is substantially prevented.

As a further protective measure, the first and second parts 20, 22 of the collar are each provided withlocking means in the form of aradially inwardlyprojecting wall (not shown) whichis, when the collar is in position, arranged to extend into the generally L-shaped channel 63 disposed in the light fitting 64 with which the bayonet pin 61 is engaged. This arrangement inhibits movement of the bayonet pin 61 within the channel. Hence, rotation of the alarm relative to the light fitting, which is also required to remove the alarm, is substantially prevented.

A shade ring 59 is provided to replace the existing conventional skirt. The shade ring is axially shorter than the skirt to allow the lock collar 20, 22 to lock into position axially beneath the ring.

hi Figure 3, the collar is shown in its fitted position. The two parts 20, 22 of the collar are conjoined, in use, by means of a snap-fit catch arrangement, best illustrated in Figure 2. In particular, the second part 22 of the collar is provided, at each circumferential end thereof, with a respective tangentially extending latch clip 80 whichis arranged to snap-fitinto a respective catch aperture 82 in the first part 20 of the collar.

In this embodiment, a specialised U-shaped removal tool50is provided to disengage the latch clip

80 in the second part 22 of the collar from the catch aperture 82 in the first part 20 of the collar shoiύditberequ edtolegitimatelyremovemesmokealarmfrom eUghtfitting. Thetool50may be made of a rigid plastics material and when pressed against the latch clips 80 causes the latter to deflect generally radially inwardly thereby to disengage the latch clips from the catch apertures.

Alternatively, the two parts of the collar maybe locked together in use by means of nuts andbolts, screws or anti-tamper variants of these.

hi Figure 4, a cover assembly is shown for use with the alarm shown in Figure 1. fn some instances where it is not desired to use the light fitting to power a light bulb, for example where wall-mounted light fittings or track lighting is used, the smoke alarm presents a potential safety hazard in that the exposed contacts of the female bayonet fitting at the lower axial end of the tube 60 may give an electric shock to any user who touches them. The cover shown in Figure 4 is arranged to blank off the female bayonet fitting in the smoke alarm to eliminate this risk.

The cover, shown generally at 400, is sized and shaped to substantially cover the lower surface of the smoke alarm to which it maybe connected by means of an adhesive, screws, other suitable fixings or by virtue of a close fitment of the cover over the smoke alarm. Apertures 402 are provided in the cover to correspond to the apertures in the smoke alarm to enable smoke, or other substances to be detected, to pass into the detection circuitry within the smoke alarm.

hi addition, in the illustrated embodiment, a central portion 404 of the cover, corresponding generally to the central aperture 70 in the smoke alarm, is provided with a low powered lamp or bulb 410. The bulb is connected to amalebayonet fitting (not shown) whichis arranged, in use, to engage with the female bayonet fitting in the smoke alarm to enable the bulb 410 to be powered thereby. The malebayonet fitting, where present, may provide the means by which the cover is connected to the smoke alarm and maay therefore be used in place oof fixings described above.

It is envisaged that the bulb could be used as a night light, causing the alarm to glow when the lighting circuit is energised. Alternatively, the bulb could be arranged to pulse thereby to indicate that the alarm is working correctly.

It can be seen that, in one embodiment of the invention, an apparatus is described which is arranged to substantially surround or enclose a connecting region of a light fitting and the bayonet fitting of an electrical device to be powered thereby, and to prevent significant axial and rotational movement of the electrical device relative to the light fitting so as to hinder or substantially prevent unauthorised removal of the device from the light fitting.

Jh a further embodiment of the invention, a cover is provided to blank off an unused female bayonet fitting of the electrical device to reduce and/or eliminate the risk of electric shock from any exposed contacts. The cover can connect to the female fitting by any suitable means such as the provision of a "dummy" male bayonet fitting attached to or an integral part of the cover. The cover can alternatively incorporate a male bayonet fitting to engage in the female bayonet fitting of the device in order to power a low powered bulb or indicator.

While the embodiments described and illustrated above discuss only bayonet type fittings, it will be appreciated that the invention maybe applicable to other types of light fitting, such as Edison screw (ES) fittings . Moreover, the collar canbe used for any electrical device which maybe powered from alight fitting, including light bulbs. In particular, it is envisaged that the invention has application where expensive long-fife bulbs are used to prevent their unauthorised removal from the light fitting.

Naturally, in such circumstances, the radially inner surface of the collar must be appropriately shaped to prevent relative movement of the electrical device and the hght fitting as described above.

hi addition, it is envisaged that, where mains track lighting is used in place of conventional light fittings, an adaptor could be provided incorporating a suitable fitting for plugging into the mains track lighting and a female bayonet or Edison screw-type fitting to enable a smoke alarm, such as that described above, or any other suitable electrical device to be powered therefrom. Alternatively, each device may be arranged to plug directly into the mains track lighting.

Claims

1. An apparatus for hindering the removal of an electrical device from a light fitting, the apparatus comprising:

collar means arranged to locate around at least aportion of said light fitting and aportion of said electrical device thereby substantially to enclose a connecting region of said light fitting and said electrical device;

2. An apparatus as claήned in claim 1 wherein said collar means includes first abutment means arranged to abut with aportion of said light fitting and second abutment means arranged to abut with aportion of said electrical device thereby to hinder or substantially prevent relative movement of said light fitting and said electrical device in an axial direction of said light fitting.

3. An apparatus as claimed in claim 1 or claim 2 wherein said collar means includes at least one proj ecting member for engagement with said light fitting thereby to hinder or substantially prevent relative rotational movement between said light fitting and said electrical device.

4. An apparatus as claimed in any preceding claim wherein said collar means comprises two parts arranged to be positioned around at least aportion of said light fitting and at least aportion of said electrical device when the latter are connected, the two parts, in use, being joined to form a substantially annular collar surrounding a connecting region between said light fitting and said electrical device.

5. An apparatus as claimed in claim 4 further comprising locking means for locking together said parts of said collar means thereby to hinder or substantially prevent removal of said apparatus and hence said electrical device.

6. An apparatus as claimed in claim 5 wherein said locking means comprises a snap fit or clip mechanism, an adhesive, screws, nuts and bolts or any anti-tamper variant of the above.

7. An apparatus as claimed in any preceding claim wherein said collar is fabricated from a flexible or rigid plastics material.