GB2449305A

GB2449305A - Two-part concealed cable connector for electrical fitting

Info

Publication number: GB2449305A
Application number: GB0709570A
Authority: GB
Inventors: Jennifer Sidana
Original assignee: QUICK CLIP SOLUTIONS Ltd
Current assignee: QUICK CLIP SOLUTIONS Ltd
Priority date: 2007-05-18
Filing date: 2007-05-18
Publication date: 2008-11-19
Also published as: GB0709570D0

Abstract

A two-part concealed domestic cable connector is adapted releasably to interconnect an electrical fitting with a power circuit during installation prior to mounting of that fitting. The connector comprises a first part 11 with terminals 26 for connecting a cable extending from the electrical fitting, and a second part 12 with terminals for connecting a cable forming part of the power circuit. The first and second parts have inter-engageable male and female parts 48, 27 adapted to join and electrically couple the first and second parts. Retention means 61, 62, 65, 66, 67 such as latch arms are provided releasably to secure the first and second parts together once joined. The connector may than be concealed by the mounting of the fitting. The connector may be used with a ceiling rose (Fig 4) or a two way light switch (Fig 5).

Description

A two-part concealed cable connector The present invention relates to a

two-part concealed domestic cable connector for electrically connecting an electrical fitting to a power circuit.

Modern homes have a ring main circuit to which standard wall mounted plug sockets, electrical radiators, fans and other electrical fittings are wired and also a lighting circuit to which ceiling roses, panel lighting and light switches are wired. When a residential dwelling is being built, altered or renovated the wiring for the ring circuit and light circuit are routed around the walls of the house from the consumer unit to a series of points at which electrical fittings are to be installed.

Most electrical fittings such as ceiling roses, light switches, plug sockets and the like include electrically conductive contacts to which wires are clamped by small screws or other suitable clamping means.

Furthermore, some electrical fittings, particularly light fittings, are reasonably compact and do not provide room for storing long lengths of wire and so it is usually necessary when installing such fittings to cut the wire as short as possible. Short wires are sometimes very difficult to connect because they require the electrical appliance to be held in very close proximity to the wall or ceiling while they are held in position and clamped onto the electrically conductive contacts. This is particularly difficult for non-professionals or for electricians or general workman with large hands or reduced manual dexterity and even more so when working in dark conditions.

Some wall mounted plug socket units and light switch units comprise a wall box which is to be located in a recess formed in the wall and a cover carrying the electrical components which is to be mounted on the wall box.

Wall boxes are often large enough to store some spare length of wire, which aids the connection of the wall fitting, but once the wires are connected their extra long length is then superfluous.

The apparent difficulties in connecting the wires of a ring circuit or light circuit to an electrical fitting are not only frustrating for the workman involved but also take a considerable length of time for carrying out what could otherwise be a simple task.

It is an object of the present invention to overcome the difficulties associated with the installation of electrical fittings. In particular by providing a device that assists in the easy installation and change of light fittings connected to permanent circuits.

According to the present invention there is provided a two-part concealed domestic cable connector adapted releasably to interconnect an electrical fitting with a power circuit during installation prior to mounting of that fitting, the connector comprising a first part provided with clamping means to which a cable extending from the electrical fitting is connected, a second part provided with clamping means to which a cable forming part of the power circuit is connected; the first and second parts having inter-engageable male parts and female parts adapted to join and electrically couple the first and second parts and attached cables; and retention means releasably to secure the first and second parts together once joined; whereby the connector may than be concealed by the mounting of the fitting.

Preferably, the first and second parts are adapted to interconnect a plurality of separate wires within one or more cable, whilst keeping those wires electrically isolated from each other. Since the connector is to be used to connect electrical fittings to domestic power circuits most connectors should accommodate cables having at least three wires (live, neutral and earth), though in some configurations four or five wire connections may require connection.

Preferably, the clamping means on the first and second parts are similar and may include a threaded bore and a screw arranged to engage the threaded bore, an electrical contact electrically connected to the male or female parts and against which a bare end of a wire may be clamped by tightening the screw. In one arrangement the electrical contact may comprise an electrically conductive body in which the threaded bore is provided and the screw is adapted to trap the bare end of the wire between its head and the electrically conductive body. In an alternative arrangement the electrical contact comprises an electrically conductive body in which the threaded bore is formed. The bare end of the wire locates in a second bore extending transversely to the threaded bore and through which the threaded bore extends, whereby tightening of the screw, which itself may be electrically conductive, clamps the wire to the body.

Furthermore, the first and second parts preferably have dimensions, such as height, width and length, independently in the range of 1 to 5cm, so that the parts can be inserted through small holes in substrates such as plasterboard and permanently concealed behind the electrical fitting. The size of the first and second parts is likely to be governed by the number of wires capable of being connected and the situation of use. For instance, first and second parts capable of connecting only two or three wires are likely to be smaller than first and second parts arranged to connect five wires. The size of the parts is critical because if they are too large they will not fit through holes in the substrate through which the wire hangs or behind the electrical fitting. Also, the clamping means must be manually operable and if they are too small the task of clamping the wires could become very difficult.

Preferably, the retention means comprises a first formation provided on one of the first and second parts and arranged selectively to engage a second formation provided on the other of said first and second parts, the engagement of the first and second formations preventing relative movement of the first and second parts to disengage them. For instance, when the male and female parts are inter-engaged, a small protuberance provided on the male part could locate in a small indentation provided on the female part.

Provided the male and female parts form a close fit the inter-engagement of a protuberance and indentation would adequately restrain the first and second parts from relative movement.

In a preferred embodiment, one of the first and second parts includes at least one limb on which one of the first and second formations is provided.

The limb is adapted to move between a locked position whereat the first and second formations inter-engage and an unlocked position whereat the first and second formations disengage. Such an arrangement provides added security which is particularly advantageous when the connector is to be hidden behind the substrate or concealed behind the electrical fitting and access thereto would be difficult.

Most preferably the limb is resiliently biased towards the locked position so that the inter-engagement of the male and female parts causes the first and second formations automatically to engage. The limb could be pivotally mounted or slidably mounted on the first or second part and the resilient bias could be provided by a spring arrangement. Alternatively, the limb could be rigidly mounted on the first or second parts and made of plastics so that the limb may be elastically deformed towards its unlocked position and capable of springing back to its locked position. For example, the first formation could comprise a flange provided midway along the limb and the second formation could comprise a recess in which the flange locates. The free end of the limb remote from the point at which it is mounted may be moved so as to disengage the flange and the recess.

In one arrangement the first and second parts include locating means so that a particular male part cannot inadvertently be connected to an incorrect female part. For example, in the absence of a locator it would be difficult to determine the correct orientation of the first and second parts and so the first part could be incorrectly connected to the second part if it was connected upside-down. The locating means could include indicia provided on the first and second parts to signal the correct orientation. As a more preventative measure, the locating means could comprise variously shaped or sized male and female parts which may be connected only when appropriately orientated. The female and male parts could have circular, rectangular, triangular or any other shape cross-section.

Preferably, the clamping means and other electrically conductive components of the connector are concealed within the body of the connector so that an electrician or other skilled person working in the vicinity of the connector is unlikely to receive an electric shock should they handle the connector.

The electrical fitting may comprise a range of different electrical components or goods which require installation to a wall, ceiling or like substrate. Use of the connector is particularly advantageous when little space is provided to connect the electrical fitting to the power circuit, which may indeed include other electrical components.

By way of example only one embodiment of the present invention and certain modifications thereof will now be described in detail, reference being made to the accompanying drawings in which: Figure 1 is a plan view of a connector according to the invention and having inter-engaged first and second parts; Figure 2 is a perspective view of the first part of the connector shown in Figure 1; Figure 3 is a perspective view of the second part of the connector shown in Figure 1; Figures 4A to 4C show a series of light fittings at different stages of the installation process; and Figure 5 is a schematic illustration of an alternative use of the connector according to the first embodiment of the invention, in which two wall mounted toggle switches are connected in a three way switch circuit.

Referring now to Figure 1, there is shown a connector generally indicated 10 and comprising interconnected first and second parts 11, 12 adapted to connect two cables 13, 14. The connector 10 of Figure 1 is adapted to connect a maximum of four wires, though it will become apparent in the foregoing text that the connector could instead be made to connect cables having more or less than four wires or indeed multiple cables.

Referring also to Figure 2, the first part comprises a rectangular body having a front face 15, a rear face 16 and an upper face 17. The rear face 16 is provided with a row of four generally cylindrical bores 18 arranged to receive four wires 19; each cylindrical bore has an electrical contact 20 against which the wire bears. A row of four threaded bores 25 are formed through the upper surface 17 of the first part 11 and these intersect the cylindrical bores 18, each threaded bore 25 being provided with a screw 26 arranged to bear against the wire 19 to hold it in place.

The front face 15 of the first part 11 is provided with four large openings 27 having generally square cross-sections and aligned with the four cylindrical bores 18. Each square opening 27 has an electrically conductive base plate 28 connected to the electrically conductive contacts 20 provided in the cylindrical bore 18 associated therewith, so that current may flow between the square openings 27 and the wires 19 secured to their corresponding cylindrical bores.

The second part 12 is similar to the first part 11 in that it comprises a generally rectangular body having a rear face 40 in which there is formed a row of four cylindrical bores 41 for receiving wires 42 and an upper face 45 in which there is formed a row of four threaded bores 46 provided with screws 47 to secure the wires 42 in place. Four pins 48 are arranged along the front face 49 of the second part 12 which pins align with the cylindrical bores 41 located in the rear face 40. The pins 48 have a square cross-section and sized to locate in the square openings 27 and form a close fit therewith.

Each pin 48 has a lower most face provided with an electrically conductive contact 50 which extends along the first part 11 and into the cylindrical bores 41. When the first and second parts 11, 12 are connected the electrically conductive contact 50 on each pin 48 engages the electrically conductive base plate 28 on the respective square opening 27. The first and second parts 11,12 are made of an electrical insulating material so that the wires 19,42 are all isolated from one another and the inter-engaged first and second parts may be handled without causing an electric shock.

A retention mechanism, generally indicted 60 is provided on the first and second parts 11, 12 to prevent inadvertent separation thereof. The retention mechanism 60 comprises a pair of cantilevered limbs 61 located on opposing side faces of the first part 11, each limb being rigidly mounted at one of its ends and arranged so that its free end 62 extends forward of the front face 15. U-shaped keep members 65 are provided on the opposing side faces of the second part 12 to define channels 66 through which the respective limbs 61 extend when the first and second parts 11, 12 are connected. Each limb 61 has a rear facing abutment surface 67 located adjacent its free end 62 which engages a rear face of its respective U-shaped keep member 65 to prevent disengagement of the first and second parts 11,12. The first and second parts may be disengaged by squeezing the free ends 62 of the limbs 61 towards one another so that the abutment surface 67 is free of the U-shaped keep member 65.

Referring now to Figure 4, there is shown a schematic representation of a large room 70 of a residential property having three lighting points 71A to 71C located in the ceiling 72 and defined by small holes formed therein. A consumer unit (not shown) is located outside room 70 and from which a lighting circuit 73 is routed around the property via lighting points 71A to 71C.

The supply of electricity to lighting points 71A to 71C is controlled by light switch 74 mounted on wall 75 of the room 70. Ceiling roses 76A to 76C are to be mounted on the ceiling at respective lighting points 71A to 71C and connected to the lighting circuit by the connector shown in Figures 1 to 3 but having only three wire clamps used on the first and second parts. Figure 1 shows the ceiling roses 76A to 76C during different stages of the installation process. A standard lighting cable 77 having three wires laid side by side in a PVC sheath is routed above the ceiling and through the hole of first lighting point 71A. A second length of lighting cable 78 is routed through the holes of lighting points 71A and 71B and a third length of lighting cable 79 is routed between the holes of lighting points 71 B and 71 C. The three wires of the first and second lighting cables 77, 78 are clamped in the cylindrical bores 18 or the first part 11. The second part 12 of the connector is connected to the ceiling rose 76A by three short wires 80 extending therebetween, which can be done away from the lighting point 71A or indeed supplied from the factory with the second part already. Once the first part is connected to the ceiling rose 76 and the second part connected to the wires of cables 77 and 78 the first and second parts can be clipped together to enable current to flow between the wall switch 70 and the ceiling rose 76A. Each ceiling rose 76 is provided with a cover 81 which conceals the wiring and the connector. In Figure 4, the ceiling rose 76A is fully installed, whereby the first and second parts 11,12 are connected, the connector is pushed into the void behind the ceiling and the hole then concealed by cover 81A. The first and second parts of ceiling rose 72B are clipped together but they are not concealed by the ceiling rose cove 81B. The first and second parts of the connector used at light point 71C are not yet connected in Figure 4.

Figure 5 shows a pair of connectors 10 used to electrically connect a pair of double pole single throw switches 90, also known as change over switches' that are used in two-way lighting circuits. Two-way lighting circuits are very common nowadays and provide the benefit of being able to control a light fitting at two different locations, which is particularly useful for corridors and large rooms. These types of switches have four terminals and so require a connecting cable 91 having four wires (three insulated cores and one earth). In view of the number of wires to be connected to these switches it is particularly difficult to install the switches in situ. Thus, the use of the connector is particularly useful because it enables the first part to be connected to the terminals of the switch away from the wall on which the switch is to be mounted. The second part could be build into a light fitting, so that a first part may simply be connected thereto.

Claims

1. A two-part concealed domestic cable connector adapted releasably to interconnect an electrical fitting with a power circuit during installation prior to mounting of that fitting, the connector comprising a first part provided with clamping means to which a cable extending from the electrical fitting is connected, a second part provided with clamping means to which a cable forming part of the power circuit is connected; the first and second parts having inter-engageable male parts and female parts adapted to join and electrically couple the first and second parts and attached cables; and retention means releasably to secure the first and second parts together once joined; whereby the connector may than be concealed by the mounting of the fitting.

2. A connector as claimed in claim 1 or claim 2, wherein the first and second parts are adapted to interconnect a plurality of separate wires within one or more cable, whilst keeping at least some of those wires electrically isolated from each other.

3. A connector as claimed in claim 1, wherein the clamping means on the first and second parts are similar.

4. A connector as claimed in any of the preceding claims, wherein the clamping means include a threaded bore and a screw arranged to engage the threaded bore, an electrical contact electrically connected to the male and female parts and against which a bare end of a wire may be clamped by tightening the screw.

5. A connector as claimed in any of the preceding claims, wherein the first and second parts have a length, width and height at least one of which is within the range of 1 to 5 cm, so that they can be inserted through small holes in substrates and concealed behind the electrical fitting.

6. A connector as claimed in any of the preceding claims, wherein the retention means comprises a first formation provided on one of the first and second parts arranged selectively to engage a second formation provided on the other of said first and second parts, the engagement of the first and second formations preventing relative movement of the first and second parts.

7. A connector as claimed in claim 6, wherein the first part includes at least one limb on which one of the first and second formation is provided, the limb being adapted to move between a locked position whereat the first and second formations engage and an unlocked position whereat the first and second formations disengage.

8. A connector as claimed in claim 7, wherein the limb is resiliently biased towards the locked position so that the inter-engagement of the male and female parts causes the first and second formations automatically to engage.

9. A connector as claimed in any of the preceding claims, wherein the first and second parts include a locating means to prevent an incorrect connection thereof.

10. A connector as claimed in any of the preceding claims wherein the clamping means are at least partially concealed by an electrical insulating material.

ii. A connector as claimed in any of the preceding claims, wherein the male and female parts have a generally rectangular cross-section.

12. A connector as claimed in any of claims ito 10, wherein the male and female parts have a generally circular cross-section.

13. A connector as claimed in any of the preceding claims, wherein the electrical fitting comprises a light fitting, switch, plug socket, fan or heater.

14. A connector as claimed in claim 1 and substantially as herein described with reference to and as illustrated in the accompanying drawings.

15. A method of installing a light fitting comprising the steps of: providing a connector according to claim 1, wiring the first part of the connector to the light fitting, wiring the second part of the connector to a power circuit running behind a substrate, connecting the first and second parts, fixing the light fitting to the substrate.