GB2185863A

GB2185863A - Low voltage track lighting system

Info

Publication number: GB2185863A
Application number: GB08602073A
Authority: GB
Inventors: Mark Johnathan Sillett
Original assignee: ILLUMA DESIGNS Ltd
Current assignee: ILLUMA DESIGNS Ltd
Priority date: 1986-01-28
Filing date: 1986-01-28
Publication date: 1987-07-29
Anticipated expiration: 2006-01-28
Also published as: AU604669B2; GB8602073D0; AU6764287A; GB2185863B

Abstract

A low voltage track lighting system includes a track assembly comprising an elongate insulating support 2, and a pair of circular conductors 4 housed in open channels, the conductors 4 being resiliently held in each channel by a rib 2a. An adaptor fitting for the track assembly comprises an H- shaped clip 14 of resilient material with a pair of contacts 18 and 16 lining opposing inner faces of the upper limbs 14a and 14b of the clip 14. Each contact has an inwardly directed contact portion for engaging a respective conductive track 4. By squeezing the two lower limbs 14g and 14h of the clip together the two upper limbs 14a and 14b can be moved apart to release the contacts 16 and 18 from the tracks 4. Thus operation of the clip member 14 enables the light fitting to be readily removed from or fitted to any desired location along the track assembly. A lamp 10 clips into the lower end of a stem 8 of the adaptor. <IMAGE>

Description

SPECIFICATION Tracked lighting systems The present invention relates to a track lighting system.

Track lighting systems are known which comprise an inverted U-shaped channel supporting electrical conductors on the inner faces of the walls of the U-shaped channel.

The conductors are partially shielded by electrically insulating fins running on opposite sides of the conductors. Light fitting supporting stems are carried by adaptor blocks which are arranged to slidingly engage the U-shaped channel for supporting light fittings therefrom.

Also the adaptor blocks are operable to bring contacts carried by the adaptor blocks into contacting engagement with the tracks to supply power to the light fittings. Such systems are bulky and cumbersome to implement.

There has also been proposed a safety extra low voltage track lighting system (operating at 12 volts and 50 Hz) in which a generally inverted "T" shaped support carries a pair of conductors at opposite ends of the cross piece of the "T". A U-shaped adaptor block with inwardly directed flanges at the free ends of the two limbs of the block, is arranged to slidingly engage the inverted T-shaped support. Spring contact fingers on the inner faces of the two limbs of the U-shaped adaptor block are arranged to engage respective conductors on the T-shaped support to supply power to a lighting fitting mounted on a stem carried by the adaptor block.The disadvantage of this arrangement is that where a series of light fittings are fitted to the track they have to be slid along the track to desired positions so that when it is desired to change the position of the fittings have to be removed before fitting them into the track in the desired order.

Furthermore such tracks are fully exposed to the user who may inadvertently generate a short circuit. Also tracks, which are in the form of conductive strips adhesively secured to the outer surface of the cross piece of the T-shaped support, readily buckcle and become loosened.

It is an object of the invention to provide an improved track lighting system with an improved track assembly and adaptor fitting; the adaptor fitting being also capable of being used in conjuction with existing tracks.

According to the present invention there is provided an electrical lighting track assembly comprisng an elongate electrical insulating support member having a pair of lateral channels, an electrical conductor located in each said channel and exposed to the mouth of the channel to allow electrical contact therewith to be established by entering the channel with a contact, and means imprisoning each conductor in its corresponding channel.

According to the present invention there is further provided a adaptor for an electrical lighting track assembly comprising an electrically insulating clip member comprising a pair of cooperating limbs movable away from one another and urged towards each other by resilient means, a contact mounted on the inner face of each limb for engaging a respective electric conductor of a pair of conductors mounted on opposite flanks of an electrically insulating support, and means for supporting a light fitting from said clip member.

A tracked lighting system embodying the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 is a side elevation partially in section of the track lighting system; Figure 2 is a front elevation partially in section of the system of Fig. 1; Figure 3 is a section taken on the line A-A of Fig. 2; Figure 4 is a section taken on the line B-B of Fig. 2; Figure 5 is a section to an enlarged scale taken on the line C-C of Fig. 6; Figure 6 is a fragmentary view similar to Fig. 1 but with the adaptor fitting of the tracked lighting system fitted to a conventional track assembly; Figure 7 is a fragmentary view similar to Fig. 1 but with the adaptor fitting of the track lighting system fitted to a stacked track assembly; and Figure 8 is a front elevation of a contact member of the adaptor fitting; and Figure 9 is a stacked assembly of modified tracks.

The track lighting system show in Fig. 1 comprises an elongate electrically insulating track support 2 supporting a pair of electrical conductors 4 of circular cross-section, a adaptor block 6 for engaging the track support 2, and a stem 8 having an upper end portion carried by the adaptor block 6 and pivotally supporting a lighting fitting 10 at its lower end portion. The system is arranged to be energised from a 12 volt source.

The track support 2 as shown in Fig. 1 is generally rectangular in cross-section having a shaped channel 12 on its underside. The support 2 may be secured to the ceiling by drilling through holes in the base of the channel and inserting wood screws or other suitable fasteners into the through holes to screwthreadedly engaged the ceiling. The shaped channel 12 should accommodate the head of each screw and so the need to provide additional countersunk holes is obviated. Instead through holes may be preformed in the support at regular intervals along the base of the shaped channel 12.

A channel is provided along each flank of the support 2 to accommodate a respective conductor 4. The base of the channel is semi circular having a diameter generally equal to the diameter of the conductor 4. One wall of the channel is planar while the other wall has an inwardly directed rib 2a to hold the conductor 4 captive when accommodated in the base of the channel.

The material of the track support is generally of plastics and slightly deformable so that when fitting the conductors 4 to the support they can be pushed into respective channels past the rib 2a. During this action the walls of the channel will move apart and then under the resilience of the plastics material return to their initial position to hold the conductor 4 captive in the channel.

It will be appreciated that the track assembly is particularly thin and that one or more assemblies can be mounted in stacked relationship on the ceiling. This provides greater versatility to the system as will be described in more detail hereinafter.

The adaptor block 6 comprises a clip member 14 being generally H-shaped in cross-section and of an electrically insulating resilient material.

The clip member 14 acts in a similar manner to a conventional clothes peg type of clip: that is by squeezing the two lower limbs 14b and 14h together the two upper limbs 14a and 14b move apart and by releasing the two lower limbs, the two upper limbs return to their initial (albeit spaced) positions under the natural resilience of the material itself. Thus it will be seen that the clip member 14 of the terminal block can be used to clip the adaptor block 6 onto the track assembly or released from it.

On the inner face of each upper limb 14a and 14b there is provided a pair of spaced apart inwardly directed flanges 14f. The flanges 14f are arranged to engage respective channels in the track support and to rest on the lower wall (as viewed in Fig. 1) of the channel to bear the load of the adaptor fitting.

The adaptor block 6 supports a pair of contacts 16 and 18 and a locking member 20 which is arranged to lockingly engage the stem 8. Each contact 16 and 18 as shown more clearly in Fig. 8 comprises a profiled sheet of beryllium copper having a main planar region 16a which is arranged to lie flat against the inner face of an upper limb of the clip member 14 (see Fig. 5). The upper edge of the main planar region 16a is cut at two locations to allow a central contact portion 1 6a thereof to be bent inwardly to make contact with a conductor 4 (see Fig. 1) and the two lateral portions 1 6d to be bent outwardly each around a correspondingly recessed portion at the upper end of the upper limb (see Fig. 5) to hold the upper end of the contact captive to the limb.A rib 22 on the cross piece 14c of the clip member 14 running parallel to but spaced from the limb, constrains the lower edge of the main portion 1 6a of the contact 16 against the inner face of the limb. A depending portion 1 6e of reduced width passes through a slot in the cross piece 1 4c of the clip member 14 to project into the upper end portion of the stem 8 (see Fig. 1). The portion 16e supports a terminal fitting 16f to which a mating terminal supporting a wire can be clipped. It will be appreciated that the contact 18 is similar to the contact 16 and that parts of contact 18 similar to those of the contact 16 are designated with the same alphabetic reference.

The locking member 20 comprises a block 20a of rectangular configuration which is arranged to be seated on the cross piece 14c of the clip member 14. Opposite edges of the block 20a are arranged to engage the contacts 16 and 18 (see Fig. 5) to assist in urging the contacts 16 and 18 hard against the inner faces of the upper limbs of the clip member 14. Recesses are provided in the block 20 to accommodate the ribs 22. Further slots in the block 20 provide a passage for the depending portions 16e and 18e of the contacts 16 and 18 adjacent the positions where they pass through the cross piece 14c.

On the underside of the block 20a there is provided a downwardly depending bung portion 20b of circular cross-section flanked by a pair of legs 20d of arcuate cross-section. A circular opening in the centre of the cross piece 14c of the clip member 14 accommodates the bung portion 20b and the legs 20c.

The locking member 20 is of resilient plastics material so that the legs 20c can be deformed towards or away from one another.

The outer face of each leg 20c at its lower end portion, has a barb 20d in the form of a ramp (see Fig. 2). Below the barb 20d, each leg defines an interrupted external screw thread which can matingly engage a light fitting, when a short stem is used in place of the long stem shown in Fig. 2.

The stem 8 has an internal annular stop member 8b which is ramped in the opposite direction to the direction of the ramp of the barb 20d. Thus when the stem 8 is offered up to the underside of the cross piece 14c so that the legs 20c and bung portion 20b enter the central hollow of the stem 8, then the barbs 20d of the two legs 20c will engage the ramp of the annular stop member 8a to ride over it. In doing so the legs 20c will be moved towards one another until the barbs 20d have passed the stop member 8b whereafter the legs 20c will move apart under their own resilience. The stop member 8b will thus impede the movement of the barbs 20d in the opposite direction and so the stem 8 will be held captive by the locking member 20 to the cross piece 14c of the clip member. Preferably the stop member 20d of the stem is so positioned that it locks the legs at the point at which the upper extremity of the stem just engages the underside of the cross piece 14c.

The lower limbs 149 and 14h of the clip member 14 are each provided with a semicircular recess 14d (see Fig. 2) to accommodate the stem 8 when the two lower limbs 149 and 1 4h are urged together; otherwise the movement of the limbs 14g and 14h towards each other would be limited by the presence of the stem 8. The flank of each lower limb is strengthened by an arcuate portion 14e to improve the resilience of the limbs. Instead or in addition, curve leaf springs (not shown) may be secured between the lower limbs 149 and 14h to urge them apart.

The lower end of the stem 8 terminates in a pair of parallel support plates of semi-circular configuration. These plates support the light fitting 10. The light fitting has a pair of upstanding legs 10a and 10b. A stub shaft 10c projecting from the outer face of the leg 10b engages a corresponding recess 10c in the support plate 8f. This allows the light fitting 10 to pivot about the axis of the stub shaft 10c.

Also because the stem 8 is imprisoned by the barbs 20d it is free to rotate about its axis. The range of angular movement is limited by a stop member 30 (see Fig. 2) on the outer face of bung 20 engaging a stop 8C (see Fig. 1) on the innerface of the stem 8.

This ensures that the stem 8 cannot be rotated by more than 360" and so prevents the leads to the light fitting which pass down the stem from becoming unduly twisted.

In operation in order to couple the adaptor fitting to the conductor 4, the two lower limbs are squeezed together to cause the two upper limbs to open out more. The fitting is then offered up to the track support 2 and when the two central contact portions 16d are aligned with the conductive tracks 4, the lower limbs are released. The upper limbs under the resilience of the material of the clip resile to their original positions and in doing so bring the central contact portions 1 6d into engagement with the tracks 4 and the four inwardly directed flanges 14f into engagement with the walls of the channels accommodating the tracks. The flanges 14f are intended to bear the whole weight of the adaptor block, the stem 8 and the light fitting 10.With the adaptor fitting thus coupled to the conductive tracks, the energisation of the light fitting 10 is controlled by controlling the supply of power to the conductive 4.

In order to release the adaptor fitting from the conductors 4, the two lower limbs of the clip are again squeezed together to move the two upper limbs apart and away from the conductors. The terminal fitting can now be disengaged.

It will be appreciated that the operation of the clip member 14 enables the fitting to be readily released from the track assembly and refitted at a different location along the track assembly without disturbing any other fittings coupled to the track assembly 4.

The two planar regions 16a and 18a of the contacts 16 and 18 can be used to make contact with track strips 40 and 42 of a conventionl track assembly 44 when the clip member 14 is clipped thereto as shown in Fig. 6.

In another modification as illustrated in Fig.

7 the clip member 14 can selectively be secured to a pair of stacked track assemblies each as shown in Fig. 1. With this arrangement a plurality of terminal fittings can be secured along the composite track assembly with some being secured to the upper track assembly and some secured to the lower track assembly. This allows the fittings coupled to the lower track assembly to be energised independently of those coupled to the upper track assembly. It also doubles the maximum numbe of fittings which can be fitted to the composite track assembly because the maximum current rating of the composite assembly is double that of a single track assembly.

A modified stacked track assembly is illustrated in Fig. 9. As can be seen each track 102 is provided with a pair of spaced upstanding ribs 104 and a pair of spaced feet 106. When in stacked relationship the feet 106 of the upper track are located between the ribs 104 of the lower track so as to limit lateral movement between the tracks 102.

Also the upstanding ribs 102 assist in reducing problems with abutment against uneven ceilings.

Claims

1. An electrical lighting track assembly comprising an elongate electrical insulating support member having a pair of lateral channels, an electrical conductor located in each said channel and exposed to the mouth of the channel to allow electrical contact therewith to be established by entering the mouth of the channel, and means for imprisoning each conductor in its corresponding channel.

2. An assembly according to Claim 1 wherein each said conductor is of circular cross-section and the portion of the channel in which said conductor is located is of complementary cross section.

3. An assembly according to Claim 1 or to Claim 2 wherein said imprisoning means comprises a rib running along the inner face of one wall of said channel.

4. An assembly according to Claim 3 wherein said support member comprises a resilient plastics material which is deformable to an extend sufficient to allow each conductor to be located in said channel by aligning it with the mouth of the channel and progressively forcing it past said rib.

5. An assembly according to any preceding claim including a groove in the underside of the support member running parallel to said channels and arranged to accommodate in a countersunk manner the heads of screws caused to traverse said support member.

6. An adaptor fitting for an electrical lighting track assembly comprising an electrically insulating clip member comprising a pair of cooperating limbs movable away from one another and urged towards each other by resilient means, a contact mounted on the inner face of each limb for engaging a respective electric conductor or a pair of conductors mounted on opposite flanks of an electrically insulating support, and means for supporting a light fitting from said clip member.

7. An adaptor fitting according to Claim 6 wherein said clip member is H-shaped in cross-section, the limbs on one side of the cross piece of the clip member carrying said contacts and the limbs on the other side of said cross piece being operable to move the limbs carrying the contacts apart.

8. An adaptor fitting according to Claim 6 or to Claim 7 wherein the resilient means comprises the resilience of the material of the clip member.

9. An adaptor fitting according to any one of Claims 6 to 8 wherein the resilient means includes a leaf spring.

10. An adaptor fitting according to any one of Claims 6 to 9 wherein each said contact member comprises a planar contact surface extending parallel to the face of the limb on which it is mounted, and a projecting contact portion extending in a plane lying generally perpendicular to the contact surface.

11. An adaptor fitting according to Claim 10 wherein each limb includes a pair of inwardly directed flanges flanking each said projecting contact portion.

12. An adaptor fitting according to Claim 10 or to Claim 11 wherein a portion of the contact adjacent opposite flanks of the projecting contact portion is deformed around part of a corresponding limb to lock the contact to that limb.

13. An adaptor fitting according to any one of Claims 6 to 12 wherein said supporting means comprises a stem located on one side of a body portion of the clip member, and a locking member having a main portion located on the other side of the body portion of the clip member, and means coupling the stem to the locking member through an opening in said body portion.

14. An adaptor fitting according to Claim 13 wherein the coupling means comprises a pair of legs rigid with said body portion and extending through said opening and means on said stem for engaging said legs to lock said legs against retraction through said opening.

15. An adaptor fitting according to Claim 13 or to Claim 14 wherein said stem is rotatable relative to the body portion about the stem axis, and means for limiting the range of angular movement of the stem about the stem axis being.limited by a projection in the inner face of the stem co operating with a stop on the outer face of the locking member.

16. An adaptor fitting according to any one of terminal fitting according to any one of Claims 13 to 15 including a light fitting pivotally supported by said stem.

17. An electric lighting track system comprising an assembly according to any one of Claims 1 to 5 and a fitting according to any one of Claims 6 to 16.

18. An electric lighting track system comprising a pair of vertically stacked assembly each according to any one of Claims 1 to 5 and a pluarlity of adaptor fittings each according to any one of Claims 6 to 16 one group of fittings being electrically coupled to one assembly and another group of fittings being electrically coupled to the other assembly.

19. An electric adaptor fitting substantially as hereinbefore described with reference to the accompanying drawings.

20. An electrical track assembly substantially as hereinbefore described with reference to any one of Figs. 1 to 5, 8 or Fig. 9.