GB2222450A - Multi arm light fitting - Google Patents

Abstract

The light fitting comprises a boss 12 having a substantially cylindrical body portion formed with a required number of circumferentially spaced openings; an elongate arm 16 for each opening; and support means, eg. in the form of a spider 14 for supporting each arm, with the support means being received at least partly within the boss 12 and with each arm 16 being engageable with the support means to project outwardly therefrom through one of the openings and to be supported at least partially by the support means in use. The boss engages the arms longitudinally when the spider 14 is fitted into it. <IMAGE>

Description

CONSTRUCTION OF A MULTI-ARM LIGHT FITTING FIELD OF THE INVENTION: This invention relates to the construction of a multi-arm light fitting and is concerned with the provision of a number of substantially standard components, some of which are interchangeable, that can readily be assembled using selected components to form a light fitting of a desired configuration. The invention is also concerned with the construction of the components such that, when assembled, they interlock so that suspended or cantilever components are firmly supported. Particularly, but not necessarily exclusively, most of the components are of an appropriate plastics.

SUMMARY OF THE INVENTION: One aspect of the invention provides a multi-arm light fitting comprising a boss having a substantially cylindrical body portion formed with a required number of circumferentially spaced openings intersecting at least one end of the cylindrical body; an elongate arm for each opening; and support means for supporting each arm, the support means being received at least partly within the boss and supporting each arm such that it extends through and projects outwardly from one of the openings, and the support means being constructed such that it is insertable longitudinally with respect to the cylindrical body of the boss into engagement with the boss.

Preferably the support means fits wholly inside the boss.

The light fitting may also include mounting means connectable to each arm at a position remote from the boss for supporting a lamp socket and housing if desired. The lamp housing may be a suitable lamp housing, such as a lamp shade or a lamp "glass", of glass or of a suitable plastics. The mounting means may be engageable with the end of the arm in at least two orientations with respect to the arm, so that it may support a lamp glass above or below it.

The boss may include an end plate closing off one side of the cylindrical body portion. A cover may be engageable with the other end of the boss. Conveniently the cover and boss engage via complementary clip formations.

Each arm is preferably a hollow cylinder, more preferably of polygonal cross-section, and is preferably slidably engageable along the direction of its length with the support means.

In one form of the invention the support means is a component separate from and engaged with each of the arms. The support means may comprise a spider having legs extending substantially radially with respect to the axis of the boss, each leg being engageable with an elongate arm and the legs corresponding in number and relative angular orientation to the openings in the boss. Each leg is preferably an interference fit inside an end region of an arm.

In a preferred construction the support means and boss in combination with each other support each arm and lock it in position. In this regard the support means preferably supports the arm in a direction transverse to its length and the boss engages the arm 1 ongi tudi nal ly.

The support means has openings for electrical wiring to pass from each arm into the boss from where it can be routed to a power source. Preferably the support means is in the form of a number of angularly intersecting channel sections that form the legs, with transverse openings being formed in at least some of the channel sections. The channel sections facilitate wiring-up and the openings permit routing of the wiring into the boss and thence to a power source.

In another form of the invention each arm is provided with a support means that comprises at least two pairs of locking wings, with the pairs being provided on opposed sides of the arm and the wings of each pair of locking wings being spaced from each other to be axially slidable with respect to the boss into engagement with the boss and to be an interference fit over the walls of the body defining the opening through which the arm passes, so that when engaged with the boss the support means locks the elongate arm laterally and longitudinally with respect to the boss. In this form the support means may be integral with the elongate arm on which it is provided. Preferably at least one locking wing of each pair of locking wings is shaped to conform to a portion of the profile of the cylindrical body portion of the boss straddling the opening through which the elongate arm extends.

Preferably the light fitting is mainly or wholly of appropriate plastics.

Another aspect of the invention provides a method of supporting a plurality of arms extending outwardly from a boss including the steps of engaging each of the arms with a support means by sliding each arm along its length into engagement with the support means; inserting the support means axially into a cylindrical boss havina circumferential openings corresponding in number and angular orientation to the arms to be supported; and engaging the boss with the support means to hold each arm longitudinally with respect to the boss.

Preferably the support means comprises a spider having a plurality of legs corresponding to the number of arms to be supported on the boss, and the method includes the step of sliding each arm along its length into engagement with a legof the spider to support each arm laterally in use and inserting the spider into the boss to hold each arm longitudinally with respect to the boss and the spider.

The invention is now illustrated by way of example in the following description made with reference to the accompanying schematic drawings.

BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1 shows a plan view of part of an embodiment of light fitting of the invention, the drawing illustrating the light fitting partially assembled; Figure 2 shows a perspective view of a boss for the light fitting Figure 1; Figure 3 shows a spider that fits inside the boss of Figure 2; Figure 4 shows an arm for the light fitting of Figure 1; Figure 5 shows a cover for the boss of Figure 2; Figure 6 shows a perspective view of a lamp base shown in Figure 1; Figure 7 shows a side view of a composite light fitting to illustrate various visually different light fittings that can be formed using the invention; Figure 8 shows a plan view of part of another embodiment of light fitting, the drawing illustration the construction for connecting an arm to a cylindrical boss; and Figure 9 shows a perspective view of the parts of Figure 8.

DESCRIPTION OF PREFERRED EMBODIMENTS: In the drawings the same or similar parts are indicated by the same reference numerals.

Figure 1 shows a plan view of part of a light fitting 10 comprising a boss 12, a three-legged spider 14 inside the boss, an elongate arm 16 connected to one of the legs of the spider with another arm being shown spaced from the spider, and a mounting 18 at the end of the arm 16 remote from the boss 12 for a lamp socket and lamp housing. Also shown is some electrical wiring 19 including a connector 19.1 for joining the wiring pairs for each arm to a power source for the light fitting.

The components of the light fitting are now described in more detail with reference to Figures 2 to 6.

Figure 2 shows the boss 12 comprising a cylindrical body portion 20 having a stepped rim at one end to form an annular flange 22 extending longitudinally from one end of the body portion and an end plate 24 closing off the other end of the body portion. The end plate 24 has a central hole 28. Three equally spaced rectangular openings 28 are formed in the body portion 20, the openings extending through the annular flange 22 and stopping short of the end plate 24.

Figure 3 shows the spider 14 comprising legs 30.1, 30.2 and 30.3 as well as a tail 32 opposite the leg 30.2. The legs and tail are channel-shaped in cross-section. A thickened region 34 is provided hetween each pair of legs 30.1/ 30.2 and 30.2/30.3 to form shoulders 36 which limit the extent to which the arms 16 can be pushed over the legs 30. A lateral slot 38 is formed in each of the leps 30.1 and 30.3 to permit electrical wiring to pass through the spider whence it can be routed to the hole 26 in the boss.

Likewise slots 40 are formed in the tail region.

Figure 4 shows an arm 16 comprising a tube that is rectangular in cross-section and that has opposed pairs of ribs 42 adjacent one end and opposed clip formations 44 at the other end. The tube is dimensioned to he an interference fit internally over a leg 30 of the spider 14 and externally in an opening 28 in the boss. The spacing hetween the ribs of a pair of ribs 42 corresponds to the wall thickness of the boss.

Figure 5 shows a cylindrical cover 46 of the same shape as the boss 42 and having an internal annular recess forming a lip 48 which fits over the annular flange 22 of the boss 12. The mating surfaces of the lip 48 and flange 22 have complementary annular grooves and ribs for locking the boss and cover releasably to each other.

Figure 6 shows the mounting 18 comprising a lamp housing holder portion 50 and a stem portion 52. A rectangular opening 54 is formed in the stem portion to receive the end of an arm 16 with a close fit and releasably to lock with the clips 44 at the end of the arm.

In practice a three-arm light fitting is assembled as follows.

First, three arms 16 are slidahly engaged with the legs 30 of the spider 14 by pushing each arm in the direction of its length over the leg 30 until the end of the arm abuts the shoulder 36. Wiring 19 is threaded from each mounting 18 through the arm 16 to the spider 14 and connected into the connector 19.1. The mountings 18 are then engaged with the free ends of the arms by pushing the end of the arm 16 into the hole 54 until the clips 44 snap into engagement with the stem. The boss 12 is attached to a suitable support tube 56, see Figure 7, for suspending the fitting from a ceiling or a tube 56.1 for a free standing lamp. A power supply lead 19.2 is also connected to the connector 19.1 and threaded through one of the slots 38 or 40 and then through the opening 26 in the center of the boss 12 and along the tube 56.The spider 14 with the arms 16 attached is then fitted into the boss 12 with the edges of the openings 28 seated in the gaps between the pairs of ribs 42. Finally, the interior of the boss is concealed by fitting the cover 46 to the boss.

As will be appreciated the light fitting can be quickly and easily assembled even by relatively unskilled lahour. Also when assembled the fitting forms a reasonahly robust structure in the sense that the arms 16 are supported hy the spider against lateral movement, while longitudinal movement of the arms is restricted by the engagement of the boss with the ribs 42. At its outer end, each arm may be quickly secured to the mounting 18 with the clip formation being sufficiently robust to support the lamp base, bearing in mind that very little torque or hending moments are present between the mounting 18 and the end of the arm.

The components 12, 14, 16, 18 and 46 of the lamp fitting are of appropriate plastics and so are relatively inexpensive and suitable for mass production. The components can be suitably standardised, es. the arms and mounting may be standardised, while the boss 12 and spider 14 need only be varied to obtain a light fitting with a desired number of arms, say from 2 to 5 arms.

Figures 8 and 9 show part of another embodiment of light fitting 100. The fitting comprises a cylindrical body portion 102 having a base 102.1 and three circumferential openings 104 that open away from the base and three arms 106, only one of which is shown. Each arm has two, opposed l)airs of locking wings 108 that engage the body portion 102. The wings 108.1 and 108.2 are spaced apart such that when the arm is inserted axially with respect to the body portion 102 into the body portion the wings are a tight fit against the inner and outer walls of the body portion. The inner wings 108.2 are shaped to correspond to the inner profile of the body portion 102. In this embodiment the arms are each formed as channel sections to so that they may be injection moulded using a relatively simple, two part die.

It is to be understood the invention is not limited to the precise constructional details shown in the drawings and described above and modifications may be made thereto and other embodiments will become apparent without departing from the scope of the invention as set out in the claims. For example, Figure 7 illustrates how light fittings of different appearances may be formed using standardised components, such as two sizes of mounting 18 and 18.1 and several embellishments 58.1 and 58.2 which can clip into engagement with the stem 52. In turn, the embellishments may be composed of two or more parts, each in several forms, which can be clipped together in different combinations to form embellishments of different appearance. Figure 7 also shows that the fitting may be suspended or he floor standing, additional covers 46 may be used, and the mountings may he used to support or suspend lamp glasses. Also, while a rectangular cross-section arm has been shown, any suitable polygonal cross-section may also be used.

Claims (22)

1. A multi-arm light fitting comprising; -- a boss having a substantially cylindrical body portion formed with a required number of circumferentially spaced openings intersecting at least one end of the cylindrical body; -- an elongate arm for each opening; and -- support means for supporting each arm, the support means being received at least partly within the boss and supporting each arm such that it extends through and projects outwardly from one of the openings, and the support means being constructed such that it is insertable longitudinally with respect to the cylindrical body of the boss into engagement with the boss.

2. The fitting of claim 1, wherein the support means is a component separate from and engaged with each of the arms.

3. The fitting of either of claims 1 or 2, wherein the support means fits wholly inside the boss.

4. The fitting of any of claims 1 to 3, wherein each arm is slidable along the direction of its length into engagement with the support means.

5. The fitting of any of claims 1 to 4, wherein the support means has a plurality of legs extending substantially radially with respect to the axis of the boss, each leg being engaged with an elongate arm and the legs corresponding in number and relative angular orientation to the openings in the boss.

6. The fitting of claim 5, wherein each leg of the support means is an interference fit inside an end region of the elongate arm with which it is engaged.

7. The fitting of any of claims 1 to 6, wherein the support means has openings for electrical wiring to pass from each arm into the boss from where it can be routed to a power source.

8. The fitting of any of claims 1 to 7, wherein the support means comprises a plurality of angularly intersecting channel sections having their openings facing in the same direction, with transverse openings being formed in at least some of the channel sections for electrical wiring to pass into the boss.

9. The fitting of any of claims 1 to 8, wherein the support means and boss in combination with each other support each arm and lock it in position.

10. The fitting of any of claims 1 to 9, wherein the support means supports an arm in a direction transverse to its length and the boss engages the arm longitudinally.

11. The fitting of claim 1, wherein each arm is provided with a support means and wherein the support means comprises at least two pairs of locking wings, with the pairs being provided on opposed sides of the arm and the wings of each pair of locking wings being spaced from each other to be axially slidable with respect to the boss into engagement with the boss and to be an interference fit over the walls of the body defining the opening through which the arm passes, so that when engaged with the boss the support means locks the elongate arm laterally and longitudinally with respect to the boss.

12. The fitting of claim 11, wherein the support means is integral with the elongate arm on which it is provided.

13. The fitting of either of claims 11 or 12, wherein at least one locking wing of each pair of locking wings is shaped to conform to a portion of the profile of the cylindrical body portion of the boss straddling the opening through which the elongate arm extends.

14. The fitting of any of claims1 to 13, wherein mounting means is provided for supporting a lamp socket at the free end of each arm, the mounting means being connectable to each arm at a position remote from the boss.

15. The fitting of claim 14, wherein the mounting means is engageable with the end of the arm in at least two orientations with respect to the arm.

16. The fitting of any of claims 1 to 15, wherein the boss includes an end plate closing off one side of the cylindrical body portion.

17. The fitting of claim 16, wherein a cover is engageable with at least one end of the cylindrical body portion.

18. The fitting of any of claims 1 to 17, which is mainly of an appropriate plastics material.

19. A multi-arm light fitting with a plurality of arms engaged with a boss substantially as herein described with reference to any of Figures 1 to 5, or Figures 8 and 9, or either of these figures as modified by Figures 6 or 7 of the accompanying drawings.

20. A method supporting a plurality of arms extending outwardly from a boss including the steps of: -- engaging each of the arms with a support means by sliding each arm along its length into engagement with the support means; -- inserting the support means axially into a cylindrical boss having circumferential openings corresponding in number and angular orientation to arms to be supported; and -- engaging the boss with the support means to hold each arm longitudinally with respect to the boss.

21. The method of claim 20, wherein the support means comprises a spider having a plurality of legs corresponding to the number of arms to be supported on the boss, and wherein the method includes the step of sliding each arm along its length into engagement with a leg of the spider to support each arm laterally in use and inserting the spider into the boss to hold each arm longitudinally with respect to the boss and the spider.

22. A method of constructing a multi-arm light fitting substantially as herein described with reference to Figures 1 to 7 or Figures 8 and 9 of the accompanying drawings.