Title:
Light projector fittings
Document Type and Number:
United States Patent 3892960

Abstract:
A modular light fitting system is based on a common lamp housing having an elliptical reflector and a parabolic reflector removably mounted in front of the elliptical reflector. Extension rods may be releasably secured to the housing to mount an interchangeable range of supplementary fittings such as a barn-door fitting for use with the parabolic reflector and a framing projector unit, colour change unit and lenses for use with the elliptical reflector.
Application Number:
05/457404
Publication Date:
07/01/1975
Filing Date:
04/03/1974
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Assignee:
Rotaflex
Limited (London, EN)
Primary Class:
Other Classes:
362/307
International Classes:
F21S8/00; F21V17/12; F21V17/00; F21V7/00
Field of Search:
240/41.35R,41R,41.15,41.5,44.1,46.23,46.27,46.45
US Patent References:
1711477April 1929Halvorson
1737995HeadlightDecember 1929Cooke
2026156Medical examination lampDecember 1935Alexander et al.
2218678Double reflector flashlightOctober 1940Hoffman
3348036Examination lightOctober 1967Bodian et al.
3578965FOLDABLE LUMINAIREMay 1971Tawil et al.
3622778VEHICLE HEADLAMP WITH TWO LIGHT SOURCESNovember 1971Cibie
Primary Examiner:
Moses, Richard L.
Attorney, Agent or Firm:
Finnegan, Henderson Farabow And Garrett
Claims:
I claim

1. A light projector comprising a lamp housing having a body, a source of light, an elliptical reflector, a parabolic reflector, means for mounting said reflectors on said body, at least one of said reflectors being removable from said body, and mounting means permitting the support of supplementary fittings on said body, said mounting means comprising a plurality of extension rods releasably securable to said body to project forwardly therefrom parallel with the common optical axis of said reflectors.

2. A light projector according to claim 1 wherein both said reflectors are adapted for concurrent mounting on said body, with one said reflector in its operative position being located within and shielding the other said reflector, which is rendered operative by removal of said one reflector.

3. A light projector according to claim 1, further comprising a range of supplementary fittings which are adapted for interchangeable mounting on said extension rods.

Description:
This invention relates to light fittings, such as spot-lights and special effect light.

Some light fittings require a parabolic reflector and others an elliptical reflector. For example a simple spot-light on a "barn-door" fitting both require the lamp housing to be fitted with a parabolic reflector. Elliptical reflectors are required, for use with for example, a lens and framing unit or pattern changing unit.

Any user wishing to change the basic characterisation of lighting effects has hitherto had to hold a stock of different, self-contained light fittings, involving substantial expense. The user can obtain a limited range of supplementary fittings such as alternative colour filters, supplementary projection lenses and the like, but to enable him to use the full range of effects mentioned above he must hold lamp housings with parabolic reflectors and others with elliptical reflectors.

The present invention provides a light fitting comprising a housing having an elliptical reflector and which is adapted for attachment to the housing of interchangeable supplementary fittings, in a manner known in itself, and is characterised by the fact that the housing is provided additionally with a parabolic reflector, at least one of the two reflectors being removable from the housing.

With this modification it becomes possible to provide a modular range of light fittings, whether requiring a parabolic or an elliptical reflector, in which a single, basic lamp housing provides the necessary light source. The user is thus able to provide for a wide range of lighting effects without the necessity to equip himself with two or more different lamp housing units.

Preferably one reflector usually the parabolic reflector, is removably mounted in front of and shielding the elliptical reflector, which may therefore be left permanently in position on the lamp housing.

It is also preferred to provide extension rods for secure attachment to the lamp housing, the rods extending forwardly of the housing, parallel with the optical axis of the reflectors, for mounting supplementary fitting in front of the said reflectors.

One constructional form of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are an axial section and front view of a basic lamp housing unit; and

FIGS. 3 to 6 are perspective views showing some different possible combinations of units added to the basic lamp housing unit.

The basic lamp housing L shown in FIGS. 1 and 2 comprises a body 1 having a lamp-holder 2 for a lamp 3, an elliptical reflector 4, a parabolic reflector 5 and a rear cover plate 6. The body is circular in cross-section and has four equispaced axially-bored lugs 7, for receiving fixing bolts, studs or rods, two diametrically opposed lugs receiving studs 8 for locating and receiving the reflectors in position with the aid of nuts 9.

The housing is shown with the parabolic reflector 5 in operative position shielding the elliptical reflector, and thus constitutes a simple spotlight fitting. The parabolic reflector is, however, detachable to render the elliptical reflector operative. If a low voltage lamp 3 is employed, a step-down transformer is required and this may be positioned remote from the housing and connected to the lamp holder by flex, but is preferably mounted immediately behind the lamp housing as shown in FIG. 3, in which the lamp housing L and transformer T are mounted together on a stirrup-like support bracket 10.

FIG. 4 shows the units T and L, still with the parabolic reflector 5 operative, supplemented by a barn-door fitting B having hinged plates 11, with non-reflecting surfaces. FIG. 5 shows a framing projector variant, in which the units T and L now with the parabolic reflector removed, are supplemented by a framing unit F and a holder H for a lens. Further holders H may be added, e.g. for a colour filter and a fresnel lens. The framing unit F is here shown with an adjustable plate framing assembly but an alternative unit has an iris diaphragm for forming circular beams of variable diameter. Another variant is shown in FIG. 6, in which a motorised effects unit E is mounted in front of the unit L, together with an effects cassette C, rotary colour wheel W and again, a holder H with a projection lens. The lamp-housing may conveniently be secured to the transformer by means of double-ended nuts or spacers, which are screwed onto threaded rearward extensions of the studs 8, and also onto threaded forward extensions of similar studs on the transformer body.

The units E and F are preferably mounted on the lamp-housing by means of extension rods 12 which are fast with the units and project to the front and the rear thereof. The rearward extensions pass through the spare lugs 7 on the lamp-housing (i.e., those lugs not occupied by the studs 8.) The upper of the two rods is extended rearwardly further than the other and has at its rear end a circlip 15 which prevents its inadvertent withdrawal through the lug 7. By this arrangement, the units E and F can be drawn forwardly to clear the lower rod from the lamp housing, whereupon the unit can be swung around the upper rod, to give access to the lamp-housing for changing the lamp, or for any other reason.

The units can be releasably locked in their normal, operative positions, for example by means of a screw extending through a threaded hole in the lower rod 12 to bear at its inner end against the inner surface of the groove in the respective lug 7.

The forward extensions of rods 12 provide a mounting for the holders H, which can be secured by screws 13. The barndoor unit B needs no forward supplementary attachments and has its own fixing rods extending rearwardly of the unit.

Many other variations and modifications will of course be possible with the scope of the invention.




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