NZ226835A - Weather proof lamp housing: adjustable angle retained by interengaging teeth - Google Patents

Description

Patform.#5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL NO: 226835 DATED: 4 November 1988 LIGHT FITTING I, Andrew Boyle, a New Zealand citizen of 197 Rangitira Road, Birkdale, Auckland, New Zealand do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: 3143nzcs/jw This invention relates to a light fitting and more especially a light fitting which is suitable for use out-of-doors and is thus exposed to the elements.

It is in general undesirable that electrical equipment should be located where it can get wet since, as is well known, water often causes short circuits in electrical equipment and this can lead to failure of the equipment as well as posing a danger of electrical shock to a person using or touching the equipment. This is especially true of equipment which operates at high voltages. It is therefore well recognised as being desirable that electrical equipment which must of necessity be operated out-of-doors should be operated at as low a voltage as possible.

To some extent the desirability of operating an out-of-doors light fitting at a low voltage is in conflict with the fact that, generally speaking, a low voltage lamp is less efficient in terms of the amount of light produced per watt of power consumed than a lamp of higher voltage.

The dangers of operating a light fitting out of doors can be reduced by sealing the fitting against the ingress of water or moisture. However in the case of light fittings or other electrical equipment which comprise two cr more components which are pivotable or otherwise movable in relation to one another known sealing arrangements have often proved inadequate. Moreover the sealing of an apparatus usually causes a lower rate of heat dissipation so again in the case of an out-of-doors light fitting the extra heat generated by the use of a low voltage lamp (if this is chosen for safety reasons) can be expected to cause problems.

According to the invention a light fitting includes first and second housing components for housing an electrical conductor which housing components are adapted to be joined together so that the first housing component can be pivoted in relation to the second housing component, an annular row of teeth being formed in the second housing component and the first housing component ?2 being provided with engaging means for engaging the teeth so that the first housing component can be pivoted and locked by interengagement of the engaging means with the teeth in a number of positions angularly spaced about a pivotal axis passing through the centre of the ro>£esealing means for preventing moisture passing past the teeth and engaging means into the housing components, each housing component being provided with a passage located inside the r&w^tfsxough. which passage the electrical conductor is able to pass from the first housing component into the second, housing, component.

In one form of the invention the engaging means comprises a second row of annular teeth formed in the first housing component, the teeth-in the second housing component being interengagable with the teeth in the first housing component.

According to one aspect of the invention the teeth in the second housing component are located in a wall thereof, and the engaging means are located in a wall of the first housing component, the said walls of the housing components having faces which are juxtaposed when the housing components are joined together.

In another aspect of the invention a spigot is provided in the said wall of one of the housing components which spigot embodies the passage for the conductor in the said one of the housing components and projects through the passage for the conductor in the other housing component, retaining means such as a circlip being mounted on a portion of the spigot which projects through the wall of the said other housing component to lock the two housing components together.

According to one aspect of the invention the first housing component houses an electrical lamp and has a longitudinal axis along which a beam from the lamp is directed and the pivotal axis is disposed transversely to the longitudinal axis.

^OCu>(/ 226S2Z In one form of the invention the second housing component comprises a first part which is arranged to anchor the fitting in its working position and a second part which is mounted on the first part at a joint which enables the first part to be pivoted in relation to the second part about a second pivotal axis which is disposed transversely to the pivotal axis of the housing components, sealing means being provided for preventing the passage of moisture into the two parts at the joint and a second passage being provided in each part for enabling an electrical conductor to pass from the first part into the second part at the joint.

In one form of the invention the first part is adapted to be mounted on a wall or other supporting surface. In an alternative form of the invention the first part is provided with a spiked formation which can be driven into the ground for anchoring the fitting in its working position. fitting is for use with In an important aspect of the invention the j a low voltage, and preferably what is known as an extremely low voltage, dichroic lamp.

The invention is further discussed with reference to the accompanying drawings in which one embodiment thereof is illustrated by way of example and in which: Figure 1 is a cross sectional elevation, drawn to scale, of a light fitting intended for out-of-doors use; Figure 2 is a plan view in larger scale showing an annular row of teeth with which one of the components of the fitting is provided; Figure 3 is a cross sectional view on arrows A - A in Figure 2.

Figure 4 is a fragmentary view of part of a modified light fitting; and Figure 5 is a fragmentary view of part of a second modified light fitting. ^2 6535 In the drawings the light fitting 10 comprises a mounting component 12 by means of which the fitting is mounted on a wall or other fixed surface 14; a lamp casing or housing 16; and an intermediate housing component 18 by means of which the mounting component is joined to the lamp casing.

The mounting component 12 is generally right-circular cylindrical having a disc-like base 20 from which arises an annular wall 22, the base and the wall having a common longitudinal axis 24. The base 20 is provided with a central aperture 26 through which the wires for conveying electrical power to the fitting are fed. The base 20 also comprises holes through which screws 28 or other suitable fastenings are passed to fix the base on the wall. The outer face of the wall 22 is provided with two spaced annular grooves. In the first groove an O-ring 30 is received for sealing the interface between the wall and a skirt 32 forming part of the intermediate component as will be described. The end of a screw 33 which is screwed into the skirt 32 is received in the second groove. By this means the intermediate component is locked onto the mounting component 12 while enabling the intermediate component to be rotated with respect to the mounting component about the axis 24. The mounting component is advantageously a plastics moulding and an abutment (not shown) may be formed in the second groove. By this means the intermediate component is prevented from being rotated more than one turn with respect to the mounting component and thus risking the wires from being twisted out of their mountings.

The screw is conveniently provided in its head with a recess of hexagonal cross-section. A key (not shown) having a shank with a complementary hexagonal cross-section for engaging the recess is provided for turning the screw. The light fitting and the key are advantageously sold together as part of a kit.

If so desired a seal may be provided at the interface between the base and the surface 14. This seal may comprise, for example, a gasket or a proprietary sealing paste or the like.

As mentioned above the intermediate component 18 comprises,.the skirt 32^ t.tVi i r»H i c v ial +*H +ho avi 1A an/4 ie -i /-« 1 rvrn f i' 4- f Ka 1 1 "J "5 TVi ft conveniently called a connecting box 36 arises from the outer face of the cross wall, being integrally moulded therewith. The connecting box 36 comprises a 38 which is perpendicular to the cross wall 34; and a wall 40 which arises from the base 38. A cap 42 is mounted on the upper face of the wall 40 by means of screws 44. The cap provides access to the interior of the connecting box. The lower periphery of the cap engages a ring seal 46 to prevent moisture from entering the interior of the connecting box past the cap. A passage 48 is formed through the centre of the cross wall 34 and tapers to a smaller size before extending through the wall 40 of the connecting box. At the inner face of the cross wall 34 an annular wall 50 surrounds the passage 48 and forms an extension thereof. A rubber grommet 52 and an 0-ring seal 54 are inserted in the passage 48 and seal against the outer sheath of the electrical cable passing through the passage to prevent moisture from passing through the passage 48 into the interior of the connecting box. The conductors are joined to a standard ceramic connector block 53 shown in dotted outline only.

A round aperture 55 is provided at the centre cf the base 33 of the connecting box. This aperture receives a spigot 56 arising from the flat face 58 of a wall 5S of a projecting portion 60 forming part of the lamp casing 16 as will be described with particular reference to Figures 2 and 3. It will be noted that the common axis 61 of the aperture and the spigot is perpendicular to the base 38 and is perpendicular to the longitudinal axis 62 of the lamp casing along which the beam of a lamp mounted therein is directed. An O-ring seal 64 is located in a groove in the flat outer face 66 of the base 38. This seal bears against the face 58 of the projecting portion 60 and thus prevents moisture from passing into the interior of the connecting box 18 past the spigot 56. An annular row of radially disposed teeth 68 is formed in the flat face 58, the teeth being at equal angular spacings about the axis 61 of the spigot. In Figure 2 only a limited number of the teeth 68 have been drawn. A second annular row of teeth is formed in the face 66 of the base 33, these teeth fitting complementally into the teeth 68. The teeth in the two rows are held in mutual engagement by means of a circlip 69 which is located in an annular groove 67 near the end of the spigot which projects into the interior of the connecting box and holds the connecting box and the lamp casing together with the faces 58 and 66 in juxtaposition. The teeth are however of limited height and their O f 'J interengaging faces are angularly disposed to the plane of the faces so that when the lamp casing is rotated about the axis 61 the teeth in one row will ride up and over those in the other row, the wall 38 of the connecting box yielding elastically in the process to accommodate the slight movement of the face 58 along the axis 61 away from the face 66 in the process- The elasticity of the wall 38 serves to draw the two faces together so that the teeth re-engage and hold the lamp casing in position after it has been rotated. The lamp casing is thus positionable in a series of angularly spaced positions determined by the pitch of the teeth.

In an alternative construction shown in Figure 4, a second annular row of teeth 134 is formed in the face 66 of the base 38, located radially outwardly of the first row and concentric therewith. The recess for the 0-ring seal 64 is located between the two rows. The lamp casing may be locked against involuntary rotation by means of a screw 130 which is inserted in a threaded socket 131 in the wall 59. The end of the screw is pointed and, after the lamp casing has been rotated to its working position, the screw 130 is turned until the pointed end lodges between two teeth in the outer row of teeth 134. The screw 130 is advantageously provided with a so-called Allen head and is turned by means of an Allen key. The Allen key may advantageously be provided as part of the kit in which the light fitting is sold.

Referring again to Figure 1, An axial passage 70 is formed in the spigot and is linked to the interior of the lamp casing by means of a cross passage 72 formed in the projecting portion 60. Electrical conductors 74 from the connector block 53 pass through this passage 72 into the interior of the lamp casing. This arrangement enables the lamp casing to be pivoted about the intermediate component without fouling of the conductors 74.

The lamp casing 16 comprises a moulded or cast base 76 of which the projecting portion 60 forms a part; a tapered cylindrical housing 78; and a lens 80.

The housing 78 has an annular cross wall 82 adja abutment with the end face of an annular wall 15JUN!9?o^: face of the base 76. An 0-ring seal 86 Is located between the cross wall 82 and the base 76 and prevents moisture from entering the interior of the housing 78 through the interface between the base 76 and the cross wall 82. Bayonet projections 88 are formed at intervals in the end face of the wall 84. These projections 88 engage in keyhole shaped slots in well known manner to hold the housing on to the base 76. A dowel 90 is forced through a dowel-receiving pillar 92 formed in the cross wall 82 and into a recess 94 in the annular wall 84. The dowel locks the base 76 and the housing 78 together against rotation and consequent disengagement. Two further pillars 96 (only one of which is shown) are formed in the cross wall 82. A standard 3-in-l pin block 98 is mounted on the pillars 96 by means of screws 100. The conductors 74 pass through the aperture in the cross wall 82 and are connected to the pin block 98. The use of a 3-in-l pin block enables the fitting to be used either with a standard commercially available 12v halogen lamp or what is known as an extremely low voltage dichroic lamp, also of 12v. Although these voltages have been specified, lamps of other suitable voltage could also be used. The fitting illustrated in the drawing is provided with a reflector 102 for a dichroic light, the reflector seating on three seating pillars 104 moulded integrally with the housing. The reflector directs and focuses the beam of the lamp along the axis 62 so that the fitting, in the present case for example, acts as a spot light.

Tv The lens comprises a Pyrex " heat resistant glass 106 held against the outer end of the housing 78 by a collar 108 with a seal 110 therebetween.

The construction provides a low voltage high emission light fitting which, by virtue of the manner of interconnection enables the beam to be directed over a very wide angular range and at the same time ensures that there is very little chance that water will leak into the interior of the fitting.

In an alternative construction, a spiked projection is moulded integrally with the base 20 of the mounting component, the screw holes in this construction being omitted. The spiked projection enables the fitting to be driven into the ground instead of mounted on a wall.

In yet another alternative construction shown in Figure 5, what may be called an insulating cradle 120 is interposed between the pin block 98 and the ends of the pillars 96. The cradle is provided with integrally moulded hollow legs 99 which fit over the pillars and locate the cradle in position. The cradle is a glass filled polyester moulding so as to be an effective insulator for heat and electricity. It may be noted that in this construction the dowel is not used and the pillar 92 is therefore omitted. " 11 AU61992.V . /

Claims (3)

1. ( * - 10 - WHAT 1/WE CLAIM IS: 1. A light fitting including first and second housing components for housing an electrical conductor which housing components are adapted to be joined together so that the first housing component can be pivoted in relation to the second housing component, an annular row of teeth being formed in the second housing component and the first housing component being provided with engaging means for engaging the teeth so that the first housing component can be retained by interengagement of the engaging means with the teeth in a number of positions angularly spaced about a pivotal axis passing through the centre of tfii trow^ sealing means for preventing moisture passing past the teeth and engaging means into the housing components,/second housing component being provided with a passage located inside ?neteerow/ through which passage the electrical conductor is able to pass from the first housing component into the second housing component.
2. 2. A light fitting according to claim 1, in which the engaging means comprises annular ;a second/row of teeth being formed in the first housing component, the teeth in the second housing component being interengagable with the teeth in the first housing component.
3. 3. A light fitting according to claim 1, in which the teeth in the Becond housing component are located in a wall thereof, and the engaging means are located in a wall of the first housing component, the said walls of the housing components having faces which are juxtaposed when the housing components are joined together. ' \ « • £ M, , v 11 A light fitting according to any one of claims 1 to 3 in which a spigot is provided in the said wall of one of the housing components which spigot embodies the passage for the conductor in the said one^ of the housing components and projects through the passage for the conductor in the other housing component, retaining means such as a circlip being mounted on a portion of the spigot which projects through the wall of the said other housing component to lock the two housing components together. A light fitting according to any one of claims 1 to 3 in which the first housing component houses an electrical lamp and has a longitudinal axis along which a beam from the lamp is directed and the pivotal axis is disposed transversely to the longitudinal axis. A light fitting according to any one of claims 1 to 5 in which the second housing component comprises a first part which is arranged to anchor the fitting in its working position and a second part which is mounted on the first part at a joint which enables the first part to be pivoted in relation to the second part about a second pivotal axis which is disposed transversely to the pivotal axis of the housing components, sealing means being provided for preventing the passage of moisture into the two parts at the joint and a second passage being provided in each part for enabling an electrical conductor to pass from the first part into the second part at the joint. 7. A light fitting according to claim 6 in which the first part is adapted to be mounted on a wall of a building or other supporting surface. 8. A light fitting according to claim 6 in which the first part is provided with a spiked formation which can be driven into the ground"'1 for ' anchoring the fitting in its working position. 5. 72 12 - A light fitting according to claim 5 in which the lamp is a low voltage lamp. 10. A light fitting according to claim 9 in which the lamp is an extremely low voltage, dichroic lamp. 11. A light fitting substantially as herein described with reference to Figures 1 to 3, 4 or 5 of the accompanying drawings. James W. Piper & Co. Attorneys for the Applicant Andrew Boyle