GB2624941A - Improvements to an electrical fitting - Google Patents

Abstract

The electrical fitting assembly 1, for recessing in an aperture of a panel, comprises a first unit 10 including means (e.g., spring arms 18) for securing to the panel and a second unit 20 including an electrical/electronic device. The second unit is releasably couplable to the first by a twist lock fitting (e.g., including fasteners 29). Coupling/uncoupling involves rotation of the second unit relative to the installed first unit. When coupled, the second unit receives power from the first unit. The second unit includes a retractable projection for gripping when coupling/uncoupling, which may be a ring pull 22 and/or may be rotatable between retracted and extended configurations. A bezel 30 may be releasably attachable to the first and/or second unit to conceal part of the second unit including the retractable projection. Also claimed is a lighting assembly comprising the electrical fitting assembly, wherein the electrical/electronic device includes a light source.

Description

Improvements to an Electrical Fitting The present invention relates to an electrical fitting adapted to be recessed in a partition/panel and support an electrical or electronic device. In particularly, but not exclusively, the invention relates to a downlight fitting comprising one or more solid state light sources GB2514685A describes an electrical fitting adapted to be recessed in a ceiling panel and support a light bulb or other electrical device The design advantageously allows for the light bulb to be removed and replaced without the need to remove the entire fitting from the panel, thus avoiding damage to the panel.

Mounting and removal of the bulb is complicated by it being recessed within the fitting The present invention was conceived to ameliorate this problem.

According to a first aspect of the invention there is provided an electrical fitting assembly adapted to be recessed within an aperture within a panel, the electrical fitting assembly comprising a first unit and a second unit; the first unit comprising means to be secured to the panel; the second unit comprising an electrical or electronic device; the first unit and second unit adapted to be releasably coupled together through a twist lock fitting through which, by rotation of the second unit relative to the first unit, the second unit can be coupled or uncoupled to/from the first unit whilst the first unit is secured to the panel, and through which, when the first and second units are coupled, -2 -the first unit provides an electrical power supply to the second unit to power the electrical and/or electronic device; and characterised in that the second unit comprises a retractable projection adapted, when in an extended configuration, to aid gripping of the second unit by a user rotating the second unit relative to the first unit to couple and/or uncouple the second unit onto/from the first unit The retractable projection allows a user to more readily gain purchase with their hand against the second unit for rotation relative to first unit for mounting and removal. By virtue of being retractable, the projection can be partially concealed and/or made less conspicuous once the second unit is supported onto the first unit.

The assembly may comprise a bezel that is releasably attachable to the first unit and/or second unit. The purpose of the bezel is primarily decorative. As such the bezel may be configured, when attached, to conceal a portion of the second unit including the retractable projection. The bezel may be retained to the first unit and/or second unit through a further twist lock fastening mechanism.

The retractable projection may be configured to rotate between a retracted configuration and the extended configuration The retractable projection may, when in the retracted position be at least partially housed within a recess of the second unit. -3 -

The retractable projection may project further away from the panel when in the extended position compared with in the retracted position.

Shallow bezel profiles (i.e. depth extending away from plane of panel) are necessary to provide a pleasing aesthetic. A retractable projection aids to provide this as when the projection is in a retracted configuration the overall size (e.g. depth away from panel or width across panel) of the visible profile may be reduced compared with when the projection is in an extended configuration. Favourably the projection is configured so that when retracted it does not contribute to the size of the visible profile on the underside of a ceiling panel and so does not necessitate a bezel with a greater profile to conceal the fitting.

The first unit may comprise a housing providing a cavity. The second unit may sit substantially entirely within the cavity when coupled to the first unit The first unit may comprise a socket unit that provides a first unit of the twist-lock fitting. The socket unit may be located within the cavity. The second unit may comprise projecting pin connectors configured to mate with the socket unit.

The second unit may comprise side walls and an end face. The retractable projection may be configured to retract into a recess provided in the end face. The second unit may comprise a housing that provides the side wall and end face and that houses the electrical arid or electronic device, When in the extended position, the retractable projection may protrude out of the plane of the end face away from the electrical or electronic device This arrangement is preferred, as compared with a radially extending -4 -projection, as means that the second unit siting substantially entirely within the cavity can have an external diameter that is very close to that of the internal diameter of the cavity of the first unit. However, in principle, if the second unit was made smaller, the retractable projection(s) could project radially away from the side wall.

The retractable projection be mounted to the housing of the second unit for rotation relative to the housing. The retractable projection may comprise a pull ring. The second unit may be configured such that the pull ring is retractable into a recess provided in the end face. The pull ring may be hinged to the housing for rotation between the retracted and extended position and vice versa.

The electrical and/or electronic device may comprise a light source e.g. a solid state light source such as one or more light emitting diodes. The light source may emit light primarily in the visible light spectrum. The end face may be, at least in part, transmissive to the light emitted from the light source Favourably, the end face comprises a central aperture for transmission of light from the light source.

The housing of the second unit may provide mounting elements, e.g. trunnions, about which the pull ring is mounted to the housing of the second unit. The mounting elements may be located diametrically across the aperture in the end face.

The second unit may comprise a lens to focus or otherwise modify the direction of light emitted from the light source. The lens may include a reflector element. The lens may be housed within the housing of the second unit -5 -The bezel may comprise an aperture, which when the bezel is mounted on the first and/or second unit, lies directly over the region of the end face transparent to the light emitted from the light source.

The means to be secured to the panel may comprises a clamping means for clamping the first unit against opposite facing sides of the panel. The clamping means may comprise one or more spring clamping arms.

The invention will now be described by way of example with reference to the following figures in which: Figure 1 is an upwardly looking perspective view of the downlighter assembly viewed from the end carrying the bezel; Figure 2 is a view similar to Fig 1 with the bezel omitted to reveal the lighting unit with pull ring shown in a retracted position; Figure 3 is a view similar to Fig 2 showing the pull ring rotated into an extended, operational, position; Figure 4 is a downwardly looking perspective view of the downlighter with the lighting unit and bezel exploded from the first unit; Figure 5 is a downwardly looking perspective view of the downlighter with the lighting unit and bezel exploded from the first unit; Figure 6 is a first perspective exploded view of the second unit; Figure 7 is a second perspective exploded view of the second unit; and -6 -Figure 8 is a upwardly looking perspective view of the first unit.

The Figures illustrate a downlight assembly I adapted to be recessed within an aperture in a ceiling panel or the like.

The downlight 1 comprises a first unit 10, a second unit 20 (hereafter referred to as the lighting unit) comprising a light source, and a bezel 30. The first unit 10 is adapted to be secured to the ceiling panel and releasably support the lighting unit 20 thereto through a twist lock connection Electrical power is supplied through the twist lock connection from the first unit 10 to the lighting unit 20, when supported to the first unit 10, to power the light source.

The lighting unit 20 includes a pull handle 22 that aids rotation of the second unit 20 by a user relative to the first unit 10 for the purpose of attaching and removing the lighting unit 20 to/from the first unit 10 The purpose of the bezel 30 is decorative It is adapted to be releasably secured to the first unit 10 to conceal portions of the first and second unit 10, 20, including the pull handle 22, exposed on the underside of the ceiling panel.

The first unit 10 comprising a housing (often referred to as a can) 11 having a cylindrical side wall 11A and defining an opening 12 at one end to receive the second unit 20 in a cavity within the housing 11. Extending radially outwards from the side wall 1 IA around the opening 12 is circumferential rim H. The rim defines notches -7 - 13A. the housing is typically comprised from a metallic material, e.g. aluminium or steel.

As best seen in Fig 8, located within the housing 11 is a socket unit 14 providing a first part of the twist lock connection The socket unit 14 comprises a mounting ring 15 having an annular end face 15A. Within an aperture of the mounting ring 15 of the socket 14 is located a heatsink plate 17.

Defined within the end face 15A of the mounting ring 15 are two diametrically opposed slots 16, each having a relatively wide portion 16A and a relatively narrow portion 16B.

Retained within the housing 11, behind the mounting ring 15A are electrical connectors (not shown).

About an opposite end of the housing 11 to the opening 12, such as to be lie opposite side of the end face 15A to that of the opening 12, there is provided a further opening 11B through which an electrical supply cable (not shown) can be fed for connection to the electrical connectors in the socket unit 14.

Hinged to the side wall 11A on opposite facing sides of the housing 11 are two spring clamping arms 18 configured, in combination with the rim 13, to clamp the first unit 10 to the ceiling panel in a manner conventional to downlight assemblies, and well known by those skilled in the art.

To mount the first unit 10 into the ceiling panel, the first unit 10 is passed through a suitably sized aperture in the panel, with the spring arms 18 held in a radially inward -8 -position against the bias of their respective springs. Upon passing through the aperture, the arms 18 are released whereupon under the boas of the springs they rotate outwardly and laterally beyond the ceiling panel aperture to contact the upper side of the ceiling panel and urge the rim 13 upward against the underside of the panel around the aperture The assembly 1 includes a ring of intumescent material 19 mounted over the housing 11 to lie between the rim 13 and the underside of the panel when the fitting is installed.

Referring now to Figs 6 and 7, the lighting unit 20 comprises a housing 21, the pull handle 22, a lamp assembly 23, a rear cover ring 24, and a thermal grease sheet 25 The lamp assembly 23 comprises a circuit board 26 carrying one or more light emitting diode (LED) 26A light sources and associated driving circuitry (not shown), a frustoconical lens unit 27 and a correlated colour temperature (CCT) switch 28. The lens unit 27 is arranged to sit against the circuit board 26 surrounding the LEDs 26A to create a beam of light of the desired characteristics from the light emitted from the LEDs 26A. The lens unit 27 includes a transparent protective front face 27A through which the beam passes out of the lens unit 27.

The housing 21 of the lighting unit 20 comprises a cylindrical side wall 210 having an outer face 211 and an annular end wall 220 having an outer face 221. The annular end wall 220 surrounds an aperture 230. An arcuate recess 240 provided in the end of the housing 21 that opens to the end face and laterally outwards, gives rise to a radially inwardly recessed side wall outer face 212 and a recessed end wall face 222 Mounted -9 -to and extending radially outwards from the recessed side wall face 212 are trunnions 250. By virtue of the recess 240, the annular end wall face 221 comprises a portion 223 that has a relatively wide radial thickness and a portion 224 that has a relatively narrow radial thickness. A further aperture (not visible in Figs 6 or 7) is provided through end wall face 223 for the CCT switch 28 to extend through The pull handle 22 comprises an arcuate member with a radius of curvature that substantially matches that of the recess 240. Provided on inner faces about the free ends of the pull handle 22 are cavities 22A (only one visible in Fig 6) configured to receive the trunnions 250 for mounting the pull handle 22 onto the housing 21 and upon which the pull handle 22 can rotate relative to the housing 21 between a retracted (stowed) position as illustrated in Figs 2, 5 and 6 and an extended (operational) position illustrated in Figs 3 and 4 The pull handle 22 has overall outer dimensions that substantially match that of the arcuate recess 240 so that when in the retracted or stowed position the pull handle 22 does not protrude beyond the end wall face 221 nor outer side wall face 211. This ensures the handle 22 does not interfere with mounting of the bezel 30 onto the first unit 10 and thus allows for a bezel 30 with a low profile, which is important to provide an aesthetic desirable to many consumers.

To facilitate gripping of the pull handle 22 when in the retracted configuration, the pull handle 22 includes a hand-grip recess 22B -10 -When assembled, the lamp assembly 23 is mounted within the housing 21 with the front face 27A of the conical lens unit 27 exposed through aperture 230.

The end wall 221 functions as a bezel to hold the lens unit 27 in place The rear cover ring 24 is mounted onto the opposite end of the housing 21 to the end wall 221 with threaded metal fasteners 29, in this example screw fasteners. The threaded metal fasteners 29 pass through integrated bosses 24A of the rear cover ring 24 and into similar bosses 260 (only one visible) of the housing 21 to secure the cover 24 to the rear side of the housing 21. The fasteners 29 also pass through electrical boss connectors 26B that lie within through holes 26C within the circuit board 26. The electrical boss connectors 26B includes flanges 26D arranged to make physical and electrical contact with electrical contacts (not shown) on the upward face of the circuit board 26. When fastened, the heads 29A and optionally portion of the shaft 29B extending immediately from the head 29A protrude from the cover ring 25 to provide electrical pin connectors, providing the second part of the twist lock connection, for connection to the socket unit 14 of the first unit 10.

The thermally conducive grease sheet 25 is mounted onto the rear side of the circuit board 26 within the central aperture 24B defined by the rear cover ring.

To install the lighting unit 20 to the first unit 10, the lighting unit 20 is presented to the first unit 10 as illustrated in Fig 4, with the handle 22 lifted out into the operational position, and passed through aperture 12 in housing 11 until it abuts the socket unit 14 (Fig 3) The user, holding onto the pull handle 22, rotates the lighting unit 20 until the pin connectors 29 align with the relatively wide portions 16A which are large enough to receive the pin connector heads 29A. Once the pin connector heads 29A have passed fully through the slots 16 so as to lie on the opposite facing side of the mounting ring 15, further rotation of the second unit 20 causes the pin connectors 29 to move into and along the narrow portion 16B of the slots locking the second unit 20 against the end face 15A.

When secured in position, the heatsink plate 17 lies directly in contact with the thermally conductive sheet 25 and partially compresses the thermally conductive sheet 25 against the circuit board 26. The grease sheet has a resiliently compressible characteristic which ensures good physical contact is established with both the heatsink plate 17 and circuit board 26 across the whole sheet 25, and thus provides a good thermal connection between the circuit board 26 and heatsink plate 17 to draw heat away from the circuit board 26 into the heatsink plate 17 whilst the light source is operating.

Once the light unit 20 is securely mounted to the first unit 10, the pull ring handle 22 is rotated into its stowed position within the recess 240 as illustrated in Fig 2. The decorative bezel 30 is then mounted onto the rim 13 of the first unit 10 through a twist lock action in which lugs 30B on the underside bezel pass to the upper side of the rim 13 through notches 13A and with rotation of the bezel 30 slide to lie against the upper side of the rim 13.

-12 -Once in place as illustrated in Figs IA and 1B, the bezel conceals the rim 13 and housing 21 of the lighting unit 21 including the pull ring 22.

In the event the lighting unit 20 needs removing, e.g. because one or more of the LEDs 26B have ceased functioning, the bezel 30 can be unscrewed from the first unit 10 to reveal the pull ring 22. The pull ring 22 is rotated to the operational position and then, whilst holding the pull ring 20, the light unit 22 is rotated in the opposition direction to which it was turned to install, until the second unit 20 is released from the socket 14.

A replacement lighting unit 20 can then be installed in its place. Advantageously, these steps can be performed without the need to remove the first unit 10 from the ceiling panel.

Although the afore-described example is directed to a downlight, the invention may be equally applicable to electrical fittings in which the second unit 20 carries an electronic or electrical device other than or in addition to a light source, such as a sensor, e.g. a smoke sensor or heat sensor.

The bi-pin twist lock lamp fitting is preferred, however, other types of twist lock fitting could be used such as screw fitting (Edison screw) or bayonet connector.

The CCT switch 28 is optional.

-13 -The pull ring 22 may instead comprise the trunnions and the housing the corresponding recesses. A pull ring is a favourable implementation of retractable projection as it easy for the user to hold and apply a rotational force to the lighting unit 20. Nevertheless, other forms of retractable projection may be used. For example, the retractable projection may be implemented by one or more spring loaded pins, stud, knob, boss or other projections seated in the housing 21 and biased to protrude out from the end face 221 and/or side face 211. The (or each) projection arranged to retract into the housing 21 against the force of a bias spring in response to contact with the bezel 30 when mounted to first unit.

The first unit may be clamped to the ceiling panel by other means, for example using the method described in GB2514685A.

Claims (2)

1. -14 -Claims An electrical fitting assembly adapted to be recessed within an aperture within a panel, the electrical fitting assembly comprising a first unit and a second unit; the first unit comprising means to be secured to the panel; the second unit comprising an electrical or electronic device; the first unit and second unit adapted to be releasably coupled together through a twist lock fitting through which, by rotation of the second unit relative to the first unit, the second unit can be coupled or uncoupled to/from the first unit whilst the first unit is secured to the panel, and through which, when the first and second units are coupled, the first unit provides an electrical power supply to the second unit to power the electrical and/or electronic device; and characterised in that the second unit comprises a retractable projection adapted, when in an extended configuration, to aid gripping of the second unit by a user rotating the second unit relative to the first unit to couple and/or uncouple the second unit onto/from the first unit.
2. 2. An electrical fitting according to claim 1 further comprising a bezel that is releasably attachable to the first unit and/or second unit and which when attached, conceals a portion of the second unit including the retractable projection.-15 -An electrical fitting according to claim 1 or 2 wherein the retractable projection comprises a ring pull.An electrical fitting according to claim 1, 2 or 3 wherein the retractable projection is configured to be rotatable between a retracted configuration and the extended configuration 5. A lighting assembly comprising the electrical fitting assembly of any previous claim and in which the electrical and/or electronic device comprises a light source The second unit of the electrical fitting assembly of any claim 1-4.