GB2329463A

GB2329463A - Device for preventing the theft of light bulbs

Info

Publication number: GB2329463A
Application number: GB9720112A
Authority: GB
Inventors: Anthony John Morrey
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-09-23
Filing date: 1997-09-23
Publication date: 1999-03-24
Anticipated expiration: 2017-09-23
Also published as: GB2329463B; GB9720112D0

Abstract

An anti-theft device 30 for preventing the theft of light bulbs is in the form of a cylindrical sleeve which carries grub screws 32,34. Two grub screws 32 can be advanced to grip a lamp holder, thereby mounting the device 30 on the lamp holder. Grub screws 34 can then be advanced to interfere with the movement of a lamp bulb in the bayonet fitting of the lamp holder, substantially to prevent the lamp bulb being released from the lamp holder.

Description

Anti-Theft Device The present invention relates to an anti-theft device and in particular, to a device for preventing or deterring theft of light bulbs.

Modern, low energy light bulbs are becoming more widespread in use but remain relatively expensive in comparison with traditional light bulbs.

Commercial premises, such as hotels, increasingly install low energy bulbs for economic reasons. However, it has been found that guests will steal light bulbs, particularly low energy light bulbs, from hotel rooms and the like in order to gain the advantages of their use, without having to pay the relatively high price to purchase one of these bulbs.

The present invention provides an anti-theft device comprising mounting means operable to mount the device on a lamp holder, and retaining means operable, in use, to interfere with movement of a lamp bulb mounted in the lamp holder, substantially to prevent the lamp bulb being released from the lamp holder.

The device may comprise a sleeve locatable, in use, around the lamp holder.

The retaining means are preferably releasable. The device is preferably operable in conjunction with a bayonet mounting lamp holder and the retaining means are preferably operable to restrict movement along the slots of the bayonet mount, thereby to retain a bulb. The retaining means may be screw mounted in the device to move between a position at which the mounting means restrict movement along the slots, to a position at which movement as aforesaid is possible. The retaining means may be grub screws which advance, in use, into the slots.

The mounting means are preferably releasable and may be threadedly mounted on the device to be advanced to engage a lamp holder and retain the device mounted thereon. Preferably the mounting means comprise at least one grub screw.

The or each grub screw may be flush with, or rebated in the external surface of the device when in the operative position. The apparatus may further comprise cover means operable to cover the retaining and/or mounting means to substantially prevent access thereto from outside the device. The cover means may comprise a sheet member adhesively attachable to the device to cover the retaining and/or mounting means.

The device may further comprise further retaining means operable, in use, to retain a lamp shade ring on a lamp holder. Said further retaining means may be threadedly engageable with a lamp holder to trap a lampshade ring between the further retaining means and a surface of the lamp holder. The further retaining means may be attached to the device.

One example of the present invention will now be described by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 is a general perspective view of a conventional lamp holder; Fig. 2 is a perspective view of an anti-theft device according to the invention, for use with the lamp holder of Fig. 1; and Fig. 3 is a plan view of the device of Fig. 2 installed with the lamp holder of Fig. 1.

Fig. 1 shows a lamp holder 10 in which a bulb 12 is mounted. The lamp holder 10 consists of a cylindrical upper extension 14 in which a slot 16 is formed, being generally L-shaped and having a retaining notch 18 at the end of the slot 16. A pin 20 carried by the bulb 12 can run along the slot 16 but the bulb 12 is urged out of the extension 14 by means of spring-mounted electrical contacts (not shown in Fig. 1). Consequently, this bias must be overcome in order to move the pin 20 down the slot to the notch 18, whereupon the spring bias will hold the pin 20 in the notch 18, which is the condition for normal use.

A second slot and pin arrangement equivalent to that which has been described is provided diametrically opposite in the extension 14.

Below the extension 14, the body of the lamp holder has a threaded outer surface 22 bordered beneath by a flange 24, below which there may be a switch control 26.

Turning to Fig. 2, the anti-theft device 30 comprises mounting means in the form of two grub screws 32, operable to mount the device 30 on a lamp holder such as the lamp holder just described. Retaining means 34, again in the form of grub screws, are operable, in use, to interfere with movement of a lamp bulb 12 mounted in the lamp holder 10, substantially to prevent the lamp bulb 12 being released from the lamp holder 10.

In more detail, the device 30 is a cylindrical sleeve of appropriate size to fit around the extension 14 of the lamp holder 10. Two radial threaded bores are provided through the sleeve 30 at diametrically opposite positions, and accommodate grub screws 32 which can be tightened from outside the device 30, to grip tightly against the extension 14, thereby retaining the sleeve 30 in position around the extension 14.

Two further radial threaded bores, perpendicular to those just described, are provided to receive grub screws 34 and are so located in the device 30 as to allow the device to be positioned on the extension 14 to locate the retaining screws 34 at the position 36 indicated by broken lines in Fig. 1. When so located, there will be one of the screws 34 in each of the slots 16. The screws 34 can be turned from outside the device 30 to advance them into the slots 16, to a position at which they will block the slot 16, preventing the pin 20 moving from the notch 18 to the mouth 40 of the slot. By interfering with movement of the bulb in this way, the screws 34 serve to prevent the bulb 12 being released from the lamp holder 10.

Tampering or unauthorised removal of the device 30 is prevented or deterred by various features of the device 30. First, the grub screws 32,34 can be of small size and thus difficult to turn without an appropriate tool. They may be Allen-headed to further deter interference. Furthermore, it is particularly preferred to provide an adhesive label 42 (Fig. 3), such as an adhesive vinyl label carrying tenacious adhesive. This label is applied over the heads of the screws 32,34 once they have been tightened as described above and may then hide the location of those screws1 and make access to them very difficult by virtue of the tenacious adhesive. The label could be printed with appropriate warnings, if desired.

Fig. 3 shows the device installed but without a light bulb, revealing the spring terminals 38 which bias the pin 20 into the notch 18.

The device 30 can be used as follows. First, the screws 32,34 are slackened off by turning to move them radially outwardly. The device 30 is then placed over the extension 14 before a bulb 12 is put into the lamp holder in conventional manner, until each pin 20 is located in a notch 18, thus holding the bulb 12 in the lamp holder 10. The device 30 can then be turned, if necessary, to align the screws 34 with the slots 16 and then the screws 32 can be tightened to hold the device 30 in that position, by engaging the extension 14.

With the device 30 mounted securely on the lamp holder 10, the screws 34 can then be tightened to block the slots 16 and prevent the lamp bulb 12 being released from the lamp holder 10. Finally, an adhesive label can be applied as described above.

It will thus be apparent that unauthorised removal of the lamp bulb is made considerably more difficult than is the case with a conventional lamp holder and this is expected to result in fewer losses by theft. However, an authorised person, for instance when replacing blown bulbs, can be provided with appropriate tools and/or adhesive solvents to allow the device 30 to be released, thereby allowing the bulb 12 to be removed and replaced. The theft problems are believed to relate primarily to opportunist theft and consequently, it is considered by the inventor that if unauthorised removal of bulbs is made sufficiently difficult, even if not impossible, an opportunist thief will be deterred and thus the property will be protected.

Fig. 2 also illustrates a modification which can be used when a lamp shade ring is in use to mount a lamp shade on the lamp holder 10. It is conventional to mount lampshades by providing a ring which sits on the flange 24 and is held there by a threaded collar engaging the surface 22. The device 30 shown in Fig. 2 has a collar extension 44 which is internally threaded to engage the surface 22 and be turned to tighten and retain a lampshade ring against the flange 24. Once the lampshade and lampshade ring are installed and held in this way, the device 30 can then be installed as described above, thus trapping the extension 44 between the device 30 and the flange 24.

Alternatively, the extension 44 could be formed integrally with the device 30, or formed separately but be attachable to the device 30, so that the device and extension are installed in a single operation.

Many variations and modifications can be made to the apparatus described above1 without departing from the scope of the present invention.

For instance, many alternative arrangements could be devised for mounting the device on the lamp holder, and for retaining the lamp bulb in the lamp holder.

The device will preferably be made primarily of a synthetic plastics material, such as an extruded material, but other materials could alternatively be used.

Grub screws are described, but other fastenings, particularly secure fastenings which cannot readily be removed, or cannot be removed without specialist tools, could alternatively be used.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. An anti-theft device comprising mounting means operable to mount the device on a lamp holder, and retaining means operable, in use, to interfere with movement of a lamp bulb mounted in the lamp holder, substantially to prevent the lamp bulb being released from the lamp holder.

2. A device according to claim 1, wherein the device comprises a sleeve locatable, in use, around the lamp holder.

3. A device according to claim 1 or 2, wherein the retaining means are releasable.

4. A device according to any preceding claim, wherein the device being operable in conjunction with a bayonet mounting lamp holder and the retaining means being operable to restrict movement along the slots of the bayonet mount, thereby to retain a bulb.

5. A device according to claim 4, wherein the retaining means are screw mounted in the device to move between a position at which the retaining means restrict movement along the slots, to a position at which movement as aforesaid is possible.

y

6. A device according to claim 4 or 5, wherein the retaining means are grub screws which advance, in use, into the slots.

7. A device according to any preceding claim, wherein the mounting means are releasable.

8. A device according to claim 7, wherein the mounting means are threadedly mounted on the device to be advanced to engage a lamp holder and retain the device mounted thereon.

9. A device according to any preceding claim, wherein the mounting means comprise at least one grub screw.

10. A device according to claim 9, wherein the or each grub screw is flush with, or rebated in the external surface of the device when in the operative position.

11. A device according to any preceding claim, and further comprising cover means operable to cover the retaining and/or mounting means to substantially prevent access thereto from outside the device.

12. A device according to claim 11, wherein the cover means comprises a sheet member adhesively attachable to the device to cover the retaining and/or mounting means.

13. A device according to any preceding claim, further comprising further retaining means operable, in use, to retain a lampshade ring on a lamp holder.

14. A device according to claim 13, wherein said further retaining means are threadedly engageable with a lamp holder to trap a lampshade ring between the further retaining means and a surface of the lamp holder.

15. A device according to claim 13 or 14, wherein the further retaining means are attached to the device.

16. An anti-theft device substantially as described above, with reference to the accompanying drawings.

17. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.