GB2029952A - Adjustable lamps - Google Patents

Abstract

A strip lamp mounted in a reflector 24 is adjustably connected to a support arm 12 by a hinge member comprising a tubular stem 32 rotatably received in the arm 12 and a cylindrical head 34 rotatably clamped between a first bracket 38, 40 and a second bracket 42 disposed on opposite sides of the end wall 44 of the lamp housing. A flexible cable 28 passes through the arm 12 and the hinge member and may be clamped in the head 34 by a grub screw 50. <IMAGE>

Description

SPECIFICATION Adjustable lamps This invention relates to hinge constructions such as are used in electric lamps of the kind comprising one partwhich is angularly adjustable relative to another. In practice this requires flexible electrical conductors. In the past the conductors have extended around the joint or joints which allow the angular adjustment. For example in one well known design using a pair of arms hinged together and also hinged at respective ends to the lampshade and to a base, the conductor cable has been led into one arm, out of the arm in a loop about the hinge joint with the shade. Further, to comply with safety regulations it has been necessary to provide clamps to fix the cable to the parts. The result has been what is now seen to be a slow and expensive assembly method, and an assembled lamp which is aesthetically lacking.

In accordance with the invention a hinge joint between two parts comprises a tubular member so that the flexible cable may extend through the hinge instead of about the hinge.

In a preferred version, the tubular member comprises a spigot which may be secured in one end of a first and tubular part, and a transversely extending cylindrical formation on the spigot providing trunnions which are engaged by a clip fixed to the other part which may mount a lamp, microphone or other appliance, the latter having an elongated aperture so that in angylar movement of the said other part about the trunnions axis the aperture remains registered with a bore extending both through the trunnions and the spigot, and the flexible conductor can extend along the tubular part, through that bore and into said other part without being visible at any point.

Preferably the cylindrical formation is also axially bored and threaded, and a grub screw or the like engages in the axial bore to clamp the conductor at this point.

One presently preferred embodiment of the invention will now be more particularly described with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a desk type lamp; Figure 2 is an enlarged scale exploded perspective view of a joint located generally in the vicinity indicated by the reference numeral A in Figure 1; and Figure 3 is a sectional elevation of the assembly shown in Figure 2.

Referring now to the drawings, the lamp compris es a base 10 on which arm 12 is pivoted at the point 14. A sliding friction clamp 16 is mounted on the arm 12 and pivotally mounts at 18 a stay 20 which is also pivoted within the base. As the arm 12 is swung for example from a near horizontal position to a near vertical position, the part 16 slides along the arm, and due to the frictional grip of the same on the arm tends to hold the parts in the adjusted position.

At the top end of the arm 12 is a lamp shade assembly, here illustrated as including a strip lamp 22 mounted in a reflector 24 which carries an operating switch 26, the assembly being connected to the arm via a swivel joint at the point A. It will be appreciated however that an incandescent lamp bulb mounted in a bulb holder and located in, for example, a circular lampshade could be provided instead.

The lamp is supplied with electric current via a flexible cable 28, which for aesthetic reasons and to protect it from damage is led through the parts comprising the lamp, for example along the interior of the arm 12 which may be tubular, through the joint provided in the area A and into the lamp housing 24. An additional advantage of this concealed electric cable, as compared to the situation if the cable for example extends in a loop or bight about each of the swivel joints, is that in the latter case the loop of cable offers a "convenient" point at which the lamp can be grasped, for example to be lifted, with risk of the cable being strained or the insulation damaged, even if the cable is clamped to the parts. The hidden arrangement of the invention avoids this risk.

It is in fact a requirement under the electrical safety regulations, that in an electrical device having movable parts, the cable should be clamped relative to the parts, and one such clamp is illustrated at 30 where the cable enters the base 10. A further clamp is provided in the joint A as will be explained hereinafter.

As seen in Figures 2 and 3, the joint comprises a generally T-shaped part of which the stem 32 is tubular, and is arranged to be at least a push fit into the end of the tubular arm 12. The part 32 may be provided with external ribs or serrations, or may be secured in place by an adhesive, but it is preferred to make it a stiff push fit and moreover to have the part 32 or circular cross-section (although in this instance the bore of the tube 12 is of square cross-section), so that the part 32 can rotate relative to the tube 12 as may be required if the lamp is to be angled transversely relative to the arm. Preferably the extent to which the lamp may be rotated is limited, for example by means of co-operation between a groove 60 whose peripheral extent may be for example about 180 ) and an internal projection (not shown) on the tubular arm 12.In this way, the ends of the groove 60 limit the rotational movement of the lamp.

Part 32 is integral with a cylindrical head 34 and the bore through the part 32 opens through the part 34 via a generally V-shaped extension 36 as seen in Figure 3. The part 34 provides a pair of co-axial trunnions w which are engaged by parallel portions 38 and 40 of a bracket, the stem 32 extending through the bracket between those portions. A second and generally similar bracket 42 is also provided, the two brackets being secured together so as to sandwhich the end wall 44 of a lamp housing portion between them, these parts being dixed together for example by screws 46 which may engage screw-tapped apertures 48 in the bracket 42, although alternative fastening means are possible.

The flexible cable 28 is led through the bore in the parts 32 and 34 to be connected to the switch and lamp.

As best seen by consideration of Figure 3, the lamp in 24 can swing relative to the arm 12 when the trunnions turn in the brackets, the cable 28 being free in all possible positions by virtue of the slot (42) and the V-shaped opening 36 in the part 34.

The part 34 is also bored axially, that is at right angles to the tubular part 32, and the bore is screw-threaded, so that a grub screw 50 can engage the cable 28 to clamp the same, thus providing a second cable clamp for greater security.

Whilst the invention is described above with reference to electric lamps, it will be appreciated that it may also be applied to other support stands such as are used for supporting microphones or other appliances requiring connection to an electrical conductor(s).

Claims (4)

1. An electric lamp comprising one part which is angularly adjustable relative to another part by way of a hinge joint which comprises a tubular member, a flexible electric conductorforthe lamp extending through the tubular member so as to be hidden at the hinge.

2. A lamp as claimed in claim 1 wherein said one part is tubular and the tubular member comprises a spigot which fits therein, the spigot having a transversely extending cylindrical formation providing trunnions for the hinge.

3. A lamp as claimed in Claim 2 wherein the hinge joint also comprises a clip having an elongated aperture through which the said tubular member extends, the clip abutting the trunnions and journalling the same, and the clip being fixed to said other part of the lamp.

4. An adjustable lamp substantially as herein described and illustrated in the accompanying drawings.

4. A lamp as claimed in Claim 1 wherein said tubular member provides a cable clamp for the electric conductor.

5. A lamp as claimed in Claims 2 and 4 wherein the cylindrical formation is axially bored and threaded, and a grub screw engages in the axiai bore to clamp the conductor.

6. An adjustable lamp substantially as herein described and illustrated in the accompanying drawings.

New claims or amendments to claims filed 19th October 1979 Superseded claims All claims New or amended claims:

1. An electric lamp comprising one part which is angularly adjustable relative to another part by way of a hinge joint which comprises a tubular member, a flexible electric conductor for the lamp extending through the tubular member so as to be hidden at the hinge, and the joint including a cable clamp for the electric conductor.

2. A lamp as claimed in Claim 1 wherein said one part is tubular and the tubular member comprises a spigot which fits therein, the spigot having a transversely extending cylindrical formation providing trunnions for the hinge, and the said formation being axially bored and screw-threaded to accommodate a grub-screw which forms said clamp.

3. A lamp as claimed in Claim 2 wherein the hinge joint also comprises a clip having an elongated aperture through which the said tubular member extends, the clip abutting the trunnions and journalling the same, and the clip being fixed to said other part of the lamp.