LAMPHOUSE

Abstract: A lamphouse for obtaining an elongated area of illumination upon a work-piece. An elongated source of light, such as a halogen lamp (6) is disposed at one focus of a cylindrical reflector (5) of elliptical cross-section. An outer housing (1) is the unifying support and holds a transparent planar element (4). An inner housing (2) provides a space between the inner and outer housings that receives a flow of cooling gas. The outer and inner housings are metal extrusions.

Description: LAMPHOUSE TECHNICAL FIELD This invention pertains to a lamphouse for obtain¬ ing an elongated area of illumination upon a work-piece, typically from an elongated source of high-intensity light. BACKGROUND ART Prior art lamphouses have typically employed parabolic reflectors for colli ating light to enter a lens, or for se i-collimating light to illuminate a wide area. Sheet metal construction has commonly been used for these housings. United States patent No. 4, 061, 912 discloses a spotlight lu inaire for stage lighting. The invention is a conveniently adjustable universal mounting for the lamp socket thereof. An ellipsoid of revolution shape is employed for the reflector, with the filament of the lamp coaxial with the axis of revolution of the reflector. The object is to obtain a circular spot of light upon a performer, as is well known; not a line of light upon a workpiece as according to the present invention. The "Set Light" brochure, No. 108-002, discloses a luminaire for stage lighting having a double-ended base halogen light source transversely disposed in a reflector of unstated but presumed parabolic shape. The object is to flood sets and/or backdrops with a large area of light, not a line of light. The "Broad" light brochure, No. 104-032, discloses a luminaire similar to the No. 108-002, but with broader light distribution. The statement "(field is elliptical)" therein refers to the shape of the area illuminated. It is 1.9 times wider than high at any distance from the luminaire. A line of light is not produced. SUMMARY OF THE INVENTION A semi-cylindrical outer enclosure is formed of a metal extrusion and supports a heat-absorbing transpar¬ ent element at the non-cylindrical aperture. A similar extrusion forms the inner enclosure, which encloses a cylindrical reflector of elliptical cross-section. An elongated, typically halogen, light source is dis¬ posed parallel to the cylindrical reflector at one focus of the elliptical cross-section. The space between the inner and outer enclosures is provided with a flow of cooling gas, which subsequently also flows pastthe heat-absorbing element, for cooling purposes. The elliptical reflector and elongated light source provide an elongated area of light upon a work- piece, which is positioned at the other focus of the ellipse. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a top sectional plan view of the invention. Fig. 2 is a side sectional elevation view of the invention. BEST MODE FOR CARRYING OUT THE INVENTION In Fig. 1, numeral 1 identifies an approximately semi-cylindrical outer enclosure. This shape is uniform from top to bottom of this piece, since it is advantag- eously formed of a metal extrusion. That is, it is the shape of a die through which hot metal is forced by a ram. Typically, lengths of a few meters long of the " • ϊiE A l OMPI shape are produced and the enclosure for one lamphouse is successively cut from that length by a power metal saw. A suitable metal is the aluminum alloy 6063 T4. Inner enclosure 2 also has an approximately semi- cylindrical shape, is a metal extrusion, and is smaller than outer enclosure 1 ' , so that it fits within the same. The shape is such that a relatively tight fit thereto is had between the open ends of inner enclosure at flanges 10 ' and 11 " . This tends to isolate halogen lamp 6, so that it can operate at a high temperature, as 3,000° Kelvin. Cylindrical reflector 5 has an elliptical cross- > section, and is positioned within the inner enclosure such that the source of elongated illumination within lamp 6 is at the focus of the reflector. It is held in place by a peripheral flange on the reflector being held between the oblique flanges 10 and 11 of the inner en¬ closure and the inner surface of the outer enclosure 1 at the oblique flanges. The elongated illumination at the focus within the reflector is concentrated at the second focus of the ellipse, as known from geometrical optics. This is arranged to be the plane of the work-piece, at which location an elongated area of illumination is formed. It is about 1 centimeter (cm) wide by 9 cm long at a distance of 14 cm in a preferred embodiment of this invention. • Halogen lamp 6 may be a General Electric 250 watt source of illumination. With the optical system of this invention a substantially uniform illumination on the work-piece of 61,700 nits (candelas/ sq. meter) is had. In Fig. 2 this lamp is shown oriented base up. The top and bottom portions, 5' and 5", of reflect¬ or 5 are relatively planar and are included to redirect spill light to the elliptical main part of the reflector. Transparent element 4 slides into slots formed in the outer enclosure extrusion 1 at the open front thereof, The element is preferably heat-absorbing glass approx- imately 0.3 cm thick, and may be of the dichroic type. A cooling flow of gas, typically air, is required for any lamp 6 that is of high wattage. Particularly, the cooling must be effective on outer enclosure 1 and transparent element 4, but with a halogen lamp that must operate at a high temperature, not within the inner enclosure. This is to prevent burns to personnel who might inadvertently come in contact with the outer parts during adjustments or service work. Outer enclosure 1 has a typically planar bottom enclosure 7, which may be fastened thereto by means such as machine screw 14 that is tapped into ridge 15 of the outer enclosure 1 extrusion. This construction is repeated at ridges 15* and 15". A similar top enclosure 8 is similarly fastened to the top of outer enclosure 1 by screw 14* at the top of ridge 15, and similarly at ridges 15' and 15". The top enclosure 8 has a forward down-turned lip 8' . Transparent element 4 is terminated below the top enclosure so that a downwardly directed path is formed across the outside front of the transparent member for air cooling thereof. Inner enclosure 2 is provided with a typically planar bottom enclosure 17 and top enclosure 18, which are fastened at three points to enclosure 2 by machine screws 19, 19', 19", in ridges 16, 16', 16". Opening 20 in bottom enclosure 7 allows incoming cooling gas to enter the structure. The opening may- have a diameter of 3.2 cm to allow a connection to a source of cooling gas having a pressure of a few kilograms per square meter. A flow of 0.7 cubic meters per minute is desired. This gas passes up and around in the space between outer and inner enclosures, as is indicated in Fig. 2 by arrows having tails. After reaching the top of this space the gas passes down over the outer surface of transparent element 4 for the cooling thereof, as has been stated. The surfaces of the enclosures may be left un¬ treated; however, it is preferable that the inner surface 3 of inner enclosure 2 be clear anodized. This treatment reflects infrared illumination and confines it to the lamp area. Preferably all of the surfaces of outer enclosures 1, 7 and 8 are black anodized for nominal wearing protection in use. In order to obtain the performance of this in¬ vention the elliptical shape of the reflector is to be retained for unalterable optical reasons. Also, the flow of cooling gas between the two enclosures is to be maintained. The use of extruded shapes for enclosures 1 and 2 is a significant manufacturing feature. These shapes may be altered in certain respects without departing from the invention. While an illustrative size and certain dimensions have been given herein the lamphouse may be embodied at any size.

Claims: CLAIMS 1. A lamphouse comprising; (a) an approximately semicylindrical outer enclosure (1) , (b) an approximately semicylindrical smaller enclosure (2) , spaced from said outer enclosure in part, (c) a substantially planar transparent element (4) closing said outer enclosure where it departs from a cylindrical shape, (d) a cylindrical reflector having an elliptical cross-section disposed within said inner enclosure, (e) an elongated source of illumination (6) disposed at the focus of the reflector, (f) a bottom enclosure (7) having an opening (20) for admitting cooling gas to flow between said outer and said inner enclosures, and (g) a top enclosure (8) shaped to direct said cooling gas over said inner enclosure and downward over the outer surface of said transparent element. 2. The lamphouse of claim 1, in which; (a) the outer enclosure (1) is a metal extrusion having a constant cross-section, and (b) the inner enclosure (2) is a metal extrusion having a constant cross-section and a length less than that of the outer enclosure to allow cooling gas to flow under, around and over said inner enclosure. 3. The lamphouse of claim 1, in which; (a) the transparent element (4) is a heat-absorbing glass. 4. The lamphouse of claim 1, in which; (a) said elongated source of illumination (6) is a halogen lamp. 5. The lamphouse of claim 1, in which; (a) both said outer and said inner enclosures have substantially uniform longitudinal ridges (L5,16) at plural spaced positions around the periphery of each to receive fasteners (14,19). 6. The lamphouse of claim 1, in which; (a) the outer enclosure (1) is formed with opposed longitudinal slots where it departs from a cylindrical shape (10,11) to receive said transparent element (4) . 7. The lamphouse of claim 6-, in which; (a) the extremities of the inner enclosure are formed with outwardly extending oblique flanges (10,11) to lie in contact with the inner surface of the outer enclosure (1) at that point. ____-_L P i-_ 8. The lamphouse of claim 7, in which; (a) the cylindrical reflector (5) is held between said oblique flanges (10,11) of said inner enclosure, and the inner part of the opposed longitudinal slots of the outer enclosure. 9. The lamphouse of claim 1, in which; (a) the inner surface (3) of said inner enclosure (2) has a light reflecting surface.

Inventors: ROLLER THOMAS WALTER, ROLLER, THOMAS, WALTER
Applicants: TERMINAL DATA CORP, TERMINAL DATA CORPORATION
Application year: 1983
Main classification: F21V9
IPC codes: F21V9, F21V15, F21V29