GB2452522A

GB2452522A - A magnetic light fitting for screw threaded light bulbs

Info

Publication number: GB2452522A
Application number: GB0717327A
Authority: GB
Inventors: Anthony Giles Edmund Clough
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-06
Filing date: 2007-09-06
Publication date: 2009-03-11
Also published as: WO2009030917A1; GB0717327D0

Abstract

A magnetic connector magnetically connects a bulb 6 with an Edison screw fitting to a power supply and comprises a threaded first part 2 for connection to the thread 26 of a light bulb 6, and a second part 4 connected to a power supply. The first part 2 is receivable in the second part 4 and preferably the bulb 6 does not extend out of a light-fitting 8 more that if retained by traditional means. The second part 4 may be releasably screwed into a standard screw threaded light fitting 8 or it may be hard wired to a power supply. The second part 4 comprises electrical contacts (32, figure 7) to provide an electrical connection between the light bulb 2 and the power supply. Magnets are provided on either of the first and second parts to hold first and second parts in engagement. The screw thread of the bulb 2 may be of smaller diameter than the screw thread of the converted light-fitting 8

Description

A MAGNETIC LIGHT FITTING.

The invention relates to a magnetic light fitting, and more particularly to a magnetic light fitting for use with Edison screw fitting bulbs.

Light bulbs are consumable items which must be replaced periodically. The process of replacing a light bulb, while not troublesome to most, can prove highly inconvenient to those with reduced movement or low manual dexterity. Groups such as the elderly and amputees can find it difficult to change a light bulb unaided, due to the two handed operation that is typically required. Furthermore, when light bulbs are located in a high up, or otherwise inaccessible position, it can be desirable to leave one hand free during the bulb changing process so as to steady oneself while changing the bulb. Accordingly, it has long been desirable to provide a light fitting that allows a light bulb to be changed one handed. A solution that has often been proposed is to provide a magnetic attachment means between the bulb and the fitting or the electrical supply.

Two types of bulb fitting are commonly used, the bayonet fitting and the Edison screw.

Bulbs with a bayonet fitting typically comprise a pair of contacts on the end face of the neck of the bulb, which connect with contacts provided in the base of a light fitting.

Although correct alignment of the bulb is important in providing magnetic connectors for bulbs of this type, there is rarely a problem obtaining access to the contacts. Edison screw fittings rely on a first, central contact point, and a second contact point on the threaded wall of the screw fitting. Accordingly, while rotational alignment is not a significant issue for Edison screw fitting bulbs, the need to maintain both an end and side contact with the bulb has lead to problems with previous magnetic couplings for bulbs of this type. The usual solution is to provide a magnetic connection device which incorporates a complex arrangement of bridging contacts such that the contacts of the fitting and the bulb can be connected to one another. This often results in a connection of a greater length than a typical light fitting. Light bulbs are caused to extend out of the fitting further than would normally be the case. This can lead to problems with the bulb extending beyond the end of a light shade, or hanging down from a ceiling in a position which may interfere with the heads of people moving about a room.

It would be beneficial if a magnetic light fitting were available which did not have the above drawbacks.

It is an aim of the present invention to provide a magnetic light fitting, in particular for Edison screw fitting bulbs, which allows the bulb to be received at its usual depth in a light fitting.

According to the present invention there is provided a magnetic connector for connecting a bulb with an Edison screw fitting to a power supply, the connector comprising a first part with a threaded portion for connection to the thread of a light bulb, and a second part connected to a power supply, the first part being receivable in the second part, and the second part comprising contact parts to provide electrical contact between the bulb and a power supply. By receiving the first part of the connector, preferably fully, in the second part of the connector, the bulb extends out of the complete fitting substantially the same amount as it retained in a typical fitting by traditional means.

The second part of the magnetic fitting may be hard wired to an electrical supply or preferably, may be attachable to the screw fitting of a standard light fitting, perhaps though provision of a threaded outer surface on the second part. Where the second part is connectable to a standard fitting, it is beneficial if the screw fitting of the bulb is smaller in diameter than the screw fitting of the light fitting.

Guide means, perhaps comprising a plurality of, for example tapered, fins may be provided to aid assembly of the first and second parts. Any fins may be provided on either part of the connector, but are preferably provided on the first part of the connector.

The first and/or second parts of the connector are preferably open at both ends, one end to receive the bulb, and the other to allow access to electrical contacts.

Magnets to provide the magnetic connection may be provided solely on the first part of the connector, solely on the second part of the connector, or may be distributed between the two. Ferrous plates are preferably provided to engage with the magnets, and provide the magnetic connection.

A better understanding of the present invention will be obtained from the following detailed description. The description is given by way of example only and makes reference to the accompanying drawings in which: Figure 1 is a perspective view of a magnetic light fitting in accordance with the present invention in a disassembled condition; Figure 2 is a perspective view of the first part of the magnetic fitting of Figure 1; Figures 3a and 3b show the attachment of the first part of the magnetic fitting to a light bulb; Figure 4 is a perspective view of a second part of the magnetic fitting of Figure 1; Figure 5 is an exploded view of the part shown in Figure 4; Figures 6a and 6b show the attachment of the second part of the magnetic fitting to a standard light fitting; Figure 7 is a perspective view showing the first and second parts of the magnetic fitting attached to a light bulb; Figure 8 shows the arrangement of Figure 7 ready for insertion into a standard light fitting; Figure 9 shows the magnetic light fitting in fully assembled condition; and Figure 10 is a cross-sectional view of the magnetic light fitting showing the electrical connections.

A magnetic light fitting 1 is shown in a disassembled state in Figure 1 of the accompanying drawings. A first, collar, part 2 of the magnetic connection means is attached to a light bulb 6 having a standard Edison screw fitting (not shown), and a second, socket, part 4 is attached to a standard light fitting 8. The socket part 4 comprises a number of small magnets 10 arranged around a bottom surface of its penphery, for engagement with ferrous metal plates (not shown) provided on the collar part 2. The central contact 12 of the bulb 6 is just visible protruding from the open end of the collar part 2. The internal dimensions of the socket part 4 are such that the collar part 2 can be completely received in the socket part 4.

The collar part 2 is shown in more detail in Figure 2. The collar part 2 is circular when view from above, and comprises a central tubular portion 14 extending from a flange portion 16, on which four ferrous plates 18 are provided at regular intervals. The tubular portion 14 has a threaded inner surface 20 for attachment to the thread of a light bulb 6.

The tubular portion 14 also comprises a wider base portion 22 to accommodate the change of section commonly found at the base of the threaded portion of a light bulb 6.

Angled fins 24 are provided at regular intervals around the tubular portion 14 to provide a tapered outside shape, serving as guide means to aid alignment and insertion of the collar part 2 into the socket part 4.

The assembly of the collar part 2 onto a light bulb 6 is shown in Figures 3a and 3b. The threaded section 26 of the light bulb 6 in Figure 3a is of a relatively small diameter. The fitting for the bulb shown could, for example, be designated E14 or E17. To assemble the collar part 2 onto the bulb 6 all that is required is to align the collar part 2 with the thread 26 of the bulb 6 and rotate the collar 2 in a clockwise direction (as viewed from above) until the collar part 2 is fully screwed down onto the thread 26 of the bulb 6. The collar part 2 is shown attached to the bulb 6 in Figure 3b. It can clearly be seen that the central contact 12 of the bulb 6 extends beyond the end of the collar part 2. What can also be seen is that a small portion of the threaded section 26 of the bulb 6 also extends beyond the end of the collar part 2. Accordingly, both the side and end electrical contact points of the bulb 6 remain accessible.

The socket part 4 is shown in greater detail in Figure 4. The socket part 4 essentially takes the form of a hollow tube, with a threaded outer surface 28 for engagement with the threaded portion of a light fitting 8. A number of protrusions 30 are provided around the base of the socket part 4, which receive a number of small magnets 10. The magnets are encased by the protrusions 30 and are, accordingly, not visible in the view of Figure 4.

The major part 31 of the socket part 4 is made of a plastics material so as to have an electrically insulating property. However, a small conducting section 32 of metal is provided at the top (as shown) of the socket part 4 to allow electrical contact between a bulb 6 and a light fitting 8. The conducting part 32 comprises two small tabs 34 extending inwardly, which contact the side of the threaded section 26 of a bulb 6 as will be explained later.

Figure 5 is, essentially, an exploded view of Figure 4. The major part 31 and conducting part 34 of the socket part 4 are shown as two separate pieces to be joined together by gluing or other suitable means. By providing two separate pieces, the safety of the device is improved. The plastic part 31 of the socket part 4 allows a user to attach and detach the socket part, with the conducting part 32 in contact with an electrical supply, without risk of electrocution.

The assembly of the socket part 4 to a light fitting 8 is shown in Figures 6a and 6b. The light fitting of Figure Ga is a typical Edison screw fitting of a reasonably large diameter.

Significantly, the internal thread 36 of the fitting 8 is of a larger diameter than the thread 26 of the bulb 6 shown in Figures 3a and 3b. The fitting 8 may, for example, be designated E26 or E27. The external threaded portion 28 of the socket part 4 matches the internal thread 36 of the fitting such that the socket part 4 can be attached to the fitting 8 by simply screwing the socket part 4 into the fitting 8. The assembled fitting 8 and socket part 4 can be seen in Figure 6b. The magnets 10 arranged around the base of the socket part 4 are clearly visible. The opening 38 in the interior of the socket part 4 is of a diameter large enough to accommodate the wider base portion 22 of the collar part 2.

The interaction between the collar portion 2 and the socket part 4 is shown in Figure 7. A collar part 2 has been attached to a light bulb 6 as previously described, and has then been received in a socket part 4. The assembly is held together by the interaction of the magnets (not shown) located in the protrusions 30 of the socket part 4, with the ferrous plates 18 provided on the flange portion 16 of the collar part 2. It can be clearly seen that the collar part 2 is completely received within the socket part 4. Significantly, the tabs 34 of the metal conducting part 32 are in contact with the end of the threaded section 26 of the bulb 6. The electrical contact to the side of the threaded section 26 of the bulb 6 is, therefore, extended to the outside of the socket part 4. The central contact 12 of the bulb 6 is still accessible beyond the end of the socket part 4.

Figure 8 shows the arrangement of Figure 7 ready for connection to a light fitting 8. It can be preferable to assemble the collar part 2 and socket part 4 onto a bulb 6 as shown in Figures 7 and 8 before inserting the device into a light fitting 8 for the first time, since the screwing of the socket part 4 into the fitting 8 can otherwise be difficult and possibly dangerous. Small vertical protrusions (not shown) may be provided on the flange portion 16 of the collar part 2, perhaps between the ferrous plates 18, to prevent rotation of the collar part 2 relative to the socket part 4 when this approach is taken. Once the arrangement shown in Figures 7 and 8 has been screwed into a fitting 8 for the first time, the socket part 4 can remain in the fitting 8 allowing subsequent bulbs 6 provided with a collar part 2 to be readily replaced. The provision of angled fins 24 on the collar part 2 (see Figure 2) means that the collar part 2 presents a smaller cross section at the end that first enters the socket part 4 than at the end provided with the flange portion 16. The shape provides a degree of guiding when second and subsequent replacements of a bulb 6 are carried out.

The magnetic fitting 1 is shown in fully assembled state in Figure 9. The collar part 2 and socket part 4 are obscured by the exterior of the light fitting 8, but their arrangement is as shown in Figure 7. It is clear from Figure 9 that the light bulb 6 is held in the fitting 8 at substantially the same height as if the bulb 6 were screwed into the fitting 8 in the usual way. The replacement of a bulb 6 is, however, greatly simplified.

The electrical connections of the magnetic light fitting 1 are shown in the cross sectional view of Figure 10. The standard electrical connections 40,42 of the fitting 8 are unchanged from their usual configuration. The central connection 40 contacts directly with the central contact 12 of the bulb 6, which extends through the open ends of both the collar part 2 and the socket part 4. The side connection 42 contacts with the metal conducting part 32 of the socket part 4, and is connected to the top of the threaded section 26 of the bulb 6 by the tabs 34 provided on the conducting part 32. The electrical contacts 40,42 of the fitting are, therefore, connected to the bulb 6 as required for operation. The cross sectional view of Figure 10 also shows that the collar part 2 has been completely received within the socket part 4. The magnets 10 located within the protrusions 30 of the socket part 4 are attracting the ferrous plates 18 of the collar part 2 to retain the assembly together. The tapered cross section of the collar part 2, created by the fins 24, is also clearly visible within the opening 38 of the collar part 4.

The above description is included only to clarify the substance of the invention, and is not intended to in any way limit the protection sought. Numerous modifications are possible.

For example the shape and composition of the various components may vary from those shown. The magnets and ferrous plates could be placed on the collar part and socket part respectively, or the magnets could be distributed between the two parts. The materials specified may be replaced with alternative materials having the same properties. Although the embodiment refers to an E14 or E17 bulb, and an E26 or E27 fitting, smaller bulbs such as E5, ElO and E12, and/or larger fittings such as E39 and E40 could be used as required. Indeed, with smaller bulb sizes smaller fitting sizes may also be suitable.

Claims

CLAIMS: 1. A magnetic connector for connecting a bulb with an Edison screw fitting to a power supply, the connector comprising a first pail with a threaded portion for connection to the thread of a light bulb, and a second part connected to a power supply, the first part being receivable in the second part, and the second part comprising contact parts to provide electrical contact between the bulb and a power supply.
2. A magnetic connector according to claim 1, wherein the second part of the magnetic fitting is hard wired to an electrical supply.
3. A magnetic connector according to claim 1, wherein second part of the magnetic fitting is attachable to the screw fitting of a light fitting.
4. A magnetic connector according to claim 3, wherein the screw fitting of the bulb is smaller in diameter than the screw fitting of the light fitting.
5. A magnetic connector according to any of the preceding claims, wherein guide means are provided to aid assembly of the first and second parts.
6. A magnetic connector according to claim 5, wherein the guide means comprise tapered fins.
7. A magnetic connector according to claim 6, wherein the tapered fins are provided on the first part of the connector.
8. A magnetic connector according to any of the preceding claims, wherein the first part of the connector is open at both ends.
9. A magnetic connector according to any of the preceding claims, wherein the second part of the connector is open at both ends.
10.A magnetic connector according to any of the preceding claims, wherein at least one magnet is provided on the first part of the connector.
11.A magnetic connector according to any of the preceding claims, wherein at least one magnet is provided on the second part of the connector.

1 2.A magnetic connector substantially as herein described with reference to the accompanying drawings.