US 3679892 A
A lighting fixture has a reflector including disposable or expendable means forming a light-reflective surface which is attached to the fixture in a manner to be easily and readily removed and replaced, thereby enabling rapid, convenient and economical restoration of a soiled reflective surface without requiring the trouble and expense of manual cleaning of the surface.
Description (OCR text may contain errors)
United States Patent Shearer DISPOSABLE REFLECTORS FOR LIGHTING FIXTURES Jack F. Shearer, Lake Forest, 111.
Harvey Hubbell, Incorporated, Bridgeport, Conn.
March 12, 1970 Inventor:
U.S. Cl ..240/ 103, 240/134 Int. Cl ..F2lv 7/00 Field ofSearch ..240/103,134,133,135,l37,
References Cited UNITED STATES PATENTS Falk ..240/ l 03 51 July 25,1972
3,413,462 11/1968 Spero ..240/l03 1,045,588 11/1912 Mould .....240/l34 2,907,873 10/1959 Smith.... .....240/103 2,145,732 l/l939 Nickle... .240/103 X 3,552,835 1/1971 Benzles ..350/288 Primary Examiner-Richard C. Queisser Assistant Examiner-Ellen J. Kerl Att0rney--Hill, Sherman, Meroni, Gross & Simpson  ABSTRACT A lighting fixture has a reflector including disposable or expendable means forming a light-reflective surface which is attached to the fixture in a manner to be easily and readily removed and replaced, thereby enabling rapid, convenient and economical restoration of a soiled reflective surface without requiring the trouble and expense of manual cleaning of the surface.
4 Claims, 6 Drawing Figures PATENTEDJULZS I912 3.679.892
sum 1 0F 2 INVENTOR.
DISPOSABLE REFLECTORS FOR LIGHTING FIXTURES BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to lighting fixtures, and more particularly refers to a reflector having disposable or expendable means forming a light-reflective surface.
Although the present invention is disclosed in reference to suspended lighting fixtures of the type normally utilized in industrial work areas, it should be appreciated that the principles of the present invention are equally applicable to other types of lighting fixtures or lamps.
2. Description of the Prior Art It has been a recent trend in the construction of industrial and commercial buildings to increase the level of illumination over that heretofore utilized. In the past, seventy foot candles illumination at a work level was considered adequate. However, as the cost of electricity decreased and the efficiency of light sources increased, acceptable levels of illumination have increased steadily, until today, 125 foot candles is common, and 200 foot candles is not unusual, at the work level.
The higher levels of illumination are achieved by more efficient lamps, such as mercury vapor lamps, and by an increase in the quantity of lighting fixtures or lamps per unit of area. Although the higher levels of illumination result in higher initial installation costs, those costs are acceptable in a business installation because the higher levels of illumination have demonstrated improvements in business operating efficiencles.
However, the increased quantity of lighting fixtures per unit of area results in an increase in maintenance costs. The increased maintenance costs are directly related to the problem of maintaining fixture cleanliness, and in particular cleanliness of reflectors utilized for reflecting and directing the light to the work area. As the fixture reflector becomes dirty, by dust or film being deposited thereon, the quantity of light is drastically decreased, to as low as 50 percent of the initial or design output. Further, the soiled reflectors will absorb the light energy and convert the same to heat. Thus, the resultant effect is a decrease in business operating efficiency.
In order to maintain a consistently high level of illumination, it is necessary to maintain an established program of reflector cleaning on a periodic basis. Labor costs, of course, are considerable. Moreover, since lighting fixtures in an industrial or commercial building may be located twenty to seventy feet above floor level, cleaning at such heights may become a hazardous task, or to avoid cleaning at such heights, the fixture or reflector must be removed, cleaned elsewhere and replaced. Either technique is an undesirable operating expense.
To reduce frequency of cleaning, some lighting fixtures may be provided with a lens enclosing the reflector to preclude dirt and dust from being deposited directly on the reflective surface. However, it has been found that the lens may require as frequent cleaning as an uncovered reflector.
SUMMARY OF THE INVENTION In accordance with the principles of the present invention, a lamp or lighting fixture has reflector means, for reflecting and directing light to a work area, including means forming an expendable or disposable light-reflective surface. In thatv manner, the expensive and oftentimes hazardous task of cleaning lighting fixtures may be eliminated, thereby reducing maintenance costs. Further, since the soiled surface is replaced by a fresh light-reflective surface, the light reflecting qualities of the fixture are restored to their original condition, a result not always possible with the cleaning operation heretofore utilized.
One form of the reflector means includes an inexpensive thin backing member such as paper having a configuration to be self-supporting and suitable for directing light to a work area and attachment means attaching the backing member to removal. The means forming the reflective surface may include' a metal layer directly deposited on the backing member. Alternatively, the entire backing member may be composed of a self-supporting foil insert having its own reflective surface and shaped to be received adjacent an inner surface of the backing member. An edge portion of the foil insert is clamped between the backing member and the base, or otherwise releasably attached to the lamp base.
Another form of the present invention contemplates providing a self-supporting, disposable foil member forming the reflective surface and attachment means for attaching the insen to the lamp base in a manner enabling rapid removal and replacement. If desired, framing members may be provided to engage the foil reflector so that the foil is held in a stretched or supported condition. The framing member may comprise a hoop engaging outer terminal edge portions of the foil reflector or a support configured to engage and support the foil along its entire surface area.
In order to further reduce time necessary to remove a soiled reflective surface and replace the same by a new surface, a plurality of foil inserts may be stacked and innerconnected in a manner to form a pad of foil inserts. With that embodiment of the present invention, the pad of inserts is secured to the lamp base so that a soiled one of the inserts may be selectively removed to expose a fresh, clean reflective surface formed on an underlying one of the inserts.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view illustrating reflector means embodying the principles of the present invention and attached to suspended lighting fixtures;
FIG. 2 is a side view of one of the lighting fixtures illustrated in FIG. 1 with reflector means constructed in accordance with one embodiment of the present invention shown in longitudinal cross section;
FIG. 3 is a view similar to FIG. 2 and illustrates an alternative embodiment of the present invention;
FIG. 4 is a view similar to FIG. 2 and illustrates another embodiment of the present invention; and
FIG. 5 is also a view similar to FIG. 3 and illustrates a further embodiment of the present invention;
FIG. 6 is a cross sectional view of a trough shaped reflector means utilized with tubular fluorescent light bulbs.
DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS Referring to the drawings, a conduit 10 having a plurality of junction boxes 11 spaced therealong supports a plurality of suspended lighting fixtures 12. Each lighting fixture 12 may be connected to an associated one of the junction boxes 11 by a depending conduit as at 13 having a lower end 14 threaded to engage complemental threads 16 formed in an upper portion of the fixture.
In accordance with the principles of the present invention, each of the lighting fixtures 12 comprises a base 17 and a reflector means generally indicated at 18 and having disposable or expendable means forming a reflective surface 19 for reflectingand directing light produced by the lighting fixture to a work area beneath the suspended lighting fixtures.
Although the drawings illustrate the reflector means 18 of the present invention as applied to a suspended lighting fix ture, which may be of the mercury-vapor type, the principles of the present invention are equally applicable to other types of fixtures or lamps. Also, the reflector 18 may be formed in a variety of shapes or configurations depending upon a desired distribution of the reflected light, a shape of the fixture base, type of fixture and other similar factors. For example, a trough shaped reflector can be employed with elongated fluorescent tubes forming the light source. If incandescent bulbs are employed, the reflector may conveniently comprise a surface of a base of the lighting fixture in a manner to enable ready revolution suchasacore or truncated core.
The fixture base 17 has a dome-shaped housing characterized by a cylindrical lower attachment portion or band 21 formed as a continuation of the domed configuration. Formed in a lower portion of the base 17 is a socket for receiving a light bulb 22 or other light source, which is electrically connected to suitable wires contained in the depending conduit 13.
In accordance with the principles of the present invention, as illustrated in FIG. 2, one form of the reflector 18 includes a backing member or shell 23 composed of any suitable selfsupporting, heat-resistant material capable of being molded, stamped or otherwise formed into a desired concave reflecting configuration. For example, well known cellulosic materials such as paper or cardboard could be used or synthetic material such as plastic sheet form material. In order to enable attachment to the base 17, the backing member 23 has a frustoconical configuration characterized by a smaller upper end portion sized complementally to the base attachment portion 21.
It is contemplated by the present invention that the reflective surface 19 may be formed by vapor depositing a reflective metal layer onto an inner surface 24 of the thin backing member 23. With that arrangement, the entire backing member 23 including the layer of deposited metal is removed and replaced by a similar unit whenever the reflective surface 19 becomes so soiled that the efficiency or light output of the fixture 12 is substantially reduced.
Also, the present invention contemplates providing a separate disposable foil insert as at 26 having its own reflective surface 19 formed on one surface thereof. The foil insert 26 is sized and conformally configured to be nestled within, and supported by, the backing member 23. As illustrated in the drawings, the insert 26 has a frusto-conical configuration sized complementally to the inner surface 24 of the backing member 23. The insert 26 may initially be provided as a planar member having a suitable developed configuration formable into a frustum, or a sheet of the foil material may be stamped in a manner to form a frustum.
With the reflective surface 19 formed integrally with the foil insert 26, it is only necessary to remove and replace the insert whenever the reflective surface becomes soiled or otherwise rendered substantially ineffective as a light reflector.
In order to enable ready removal and replacement of the reflector 18, resilient attachment means are provided for securing the reflector to the base 17. A circumferentially extending, outwardly opened groove 27 is formed in the cylindrical attachment portion 21 of the base 17 for receiving a resilient, complementally-formed ridge 28 on the reflector 23 in a snap-in relationship. To insure retention of the ridge 28 in the attachment groove 27, a garter spring 29 encircles the backing member 23 around an area radially outwardly of the ridge 28, thereby to urge the ridge 28 inwardly of the groove 27.
The foil insert 26 has an upper, circumferential end portion 31 captured within the groove 27 by the ridge 28 for retaining the reflector parts in an assembled. relationship.
In accordance with the principles of the present invention, as illustrated in FIG. 3, another form of reflector means 18a includes a self-supporting disposable member or insert 35 having an upper end portion 36 secured to the base 170 and a lower end portion 37 captured within a ring member 38. The fixture base 17a is of identical construction to that already described and like parts are identified by like numerals to which a suffix a has been added.
The insert or disposable member 35 may be composed of any suitable metal foil capable of providing the light-reflective surface 190 for reflecting and directing the light to a work area. As illustrated in the drawings, the insert 35 has a frustoconical configuration with the upper end portion 36 sized complementally to the cylindrical portion 21a of the base 17a.
To secure the disposable insert 35 to the base 17a, the upper portion 36 is deformed into the groove 27a and captured therewithin by a garter spring 39. Removal of the garter spring 39 enables ready detachment of the disposable insert 35 from the base 17a.
The ring member 38 has a radially inwardly opened, circumferential groove formed therein for receiving the lower end portion 37 of the disposable insert 35, thereby to retain the insert in a stretched condition for ensuring that the reflective surface 19a has the proper configuration. A snap ring 42 engages the lower end portion 37 of the insert 35 and forces that portion into the circumferential groove 41 in a manner to lock the support ring 38 in assembly with the insert. A pair of inwardly turned tangs 43, 43 form tool engagement portions to facilitate ready removal of the snap ring.
Thus, whenever the reflective surface 19a formed on the foil insert 35 becomes soiled, removal of the garter spring 39 and the snap ring 42 enables convenient replacement of the soiled insert by a fresh one to restore the fixture 12a to its maximum light-reflective condition.
Referring now to FIGS. 4 and 5, another form of the present invention contemplates providing a base 51 characterized by a permanently attached support or backing member 52 for receiving a disposable foil insert 53. The base 51 is structurally similar to the bases 17 and 17a described hereinabove and has a socket for receiving a light source 54.
The support or backing member 52, which may be a molded plastic element composed of suitable heat resistant material, has a main body portion 56 forming an outwardly and downwardly flared, frusto-conical surface 57. An inwardly turned annular flange 58 on the support 52 is secured by suitable means to a lower peripheral edge portion 59 of the base 51, thereby to provide a backing member integral with the base.
The disposable foil insert 53 has a generally frusto-conical configuration sized complementally to the surface 57 and may be formed as a stamping or as a sheet member having a developed configuration formable into a frustum. An inner surface 61 of the insert 53 provides a light-reflective surface for directing light produced by the light source 54 to a work area disposed generally beneath the lighting fixture.
In order to retain the insert 53 within the support 52 in a manner to enable ready removal and replacement of the insert, the support has a pair of inwardly opening, circumferentially extending grooves 62 and 63 respectively formed at upper and lower ends thereof for receiving upper and lower end portions 64 and 66, respectively, of the insert. A pair of snap rings 67 and 68 respectively engage the upper end portion 64 and the lower end portion 66 of the insert 53 and urge those portions into the grooves 62 and 63, thereby to releasably secure the insert 53 in an assembled relationship with the support 52. Inturned tangs as at 69 and 71 may be formed on the snap rings 67 and 68, respectively, to provide tool engagement portions for facilitating insertion and removal of the snap rings.
It is also contemplated by the present invention to provide a plurality of concentrically arranged, nestled inserts secured together in a manner to form a pad" of inserts, as illustrated in FIG. 5. In that manner, when an innermost one of the inserts becomes soiled, the soiled insert may be easily removed to expose a fresh reflective surface formed on an underlying one of the inserts. The base, support member and attachment means for the embodiment illustrated in FIG. 5 are substantially identical in construction to that described hereinabove for the embodiment shown in FIG. 4, and thus like parts are identified with like numerals to which a suffix a has been added.
A plurality of frusto-conically configured, foil members 74, each having an inwardly projecting, light-reflective surface 76 formed thereon, are secured to a backing sheet 77, which also may have a reflective surface formed thereon. The backing sheet 77 has upper and lower end portions 78 and 79, respectively, captured within the axially spaced grooves 620 and 680 by the snap rings 67a and 68a, whereas the foil inserts 74 have upper and lower end edges 81 and 82, respectively, terminat ing short of the retaining grooves 62a and 63a to prevent there being captured therewithin. A suitable non-setting adhesive joins the inserts 74 along the upper edge 81 and the lower edge 82 thereof with an outermost one of the inserts being joined to the backing sheet 77, thereby to form a pad of inserts which may be releasably secured to the support 52a. As the light-reflective surface 76 on the innermost one of the foil inserts 74 becomes soiled, that insert may be torn from the pad to expose a fresh reflective surface without the necessity of removing the snap rings 67a and 68a. When the entire pad has been exhausted, the snap rings 67a and 68a may be readily removed to enable convenient insertion of a fresh pad of inserts.
FIG. 6 shows a trough shaped reflector means 170 utilized with elongated fluorescent tubes as the light source as at 171. The expendable reflective surface means of the invention is shown at 172 and has cut-out portions 173 to accommodate insertion past the tube sockets 174. Retainer prongs 175 hold the replaceable reflective surface in place. The reflective surface means 172 is conformably shaped into a trough-like configuration thereby to collect and directionalize light rays from the tubes 171.
From the foregoing description, it should be noted that the present invention provides a reflector, for a lighting fixture, characterized by disposable means forming a light-reflective surface and resilient attachment means for enabling convenient replacement of the disposable means to provide a fresh reflective surface. In that manner, a lighting fixture may be restored to its initial light-reflective condition and thus maintain the desired high level of illumination at work areas.
Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
I claim as my invention:
1. A pendant light fixture with a reflector means of the type having a base with a light source attached to and depending from the base, comprising:
a thin, readily deformable foil insert formed with a reflective surface having the shape of an axially elongated surface of revolution configured to encircle the light source and directionalize light rays emitted therefrom; and attachment means for removably securing an upper end portion of said insert to the base, said means comprismg means attached to the lower end of the fixture base and forming an annular, radial groove spaced radially outwardly ofthe light source,
said insert being sized at said upper end portion to overlie said groove in close juxtaposition therewith when disposed with said upper end portion in radial alignment with said groove, a substantially circular, spring retainer engaging said insert on a surface thereof disposed oppositely of the surface 5 confronting said groove and being resiliently biased radially inwardly of said groove, said upper end portion of said insert being deformed into said groove by said retainer thereby clamping said insert in firm assembly with the base, whereby said insert may be readily removed and replaced by moving said spring retainer against the bias thereof and outwardly of the groove to release said insert once the same has become soiled or otherwise ineffective to efficiently reflect the light rays emitted by the light source.
2. A light fixture as defined in claim 1 and further characterized by:
a support means affixed to and depending from said base and having an inner surface thereof formed as a surface of revolution complemental to said insert reflective surface,
said support means being formed with first and second inwardly opening grooves adjacent the upper and lower ends thereof, said upper end groove constituting said rad ial groove, said insert comprising a backing sheet configured to be received in laminar adjacency with the inner surface on said support member and having upper and lower end portions thereof respectively deformed into said first and said second grooves formed in said support member and a plurality of concentrically arranged, stacked foil members each having axially spaced, opposite end portions formed conterminously with end portions of adjacent ones of said foil members; and
adhesive means releasably adhering each said foil member to an adjacent one of said members, with said foil member disposed adjacent said backing sheet being adhered to the inside of said backing sheet, whereby, whenever a reflective surface formed on an innermost one of said foil members becomes soiled, that member may be readily removed to expose another surface formed on an adjacent foil member.
3. The light fixture in accordance with claim 1 in which said groove opens outwardly of said fixture base, the upper portion of said insert fits over the outer surface of said fixture base, and the spring retainer is applied against the outer surface of said insert.
4. The light fixture in accordance with claim 1 in which said groove opens inwardly of said fixture base, the upper portion of said insert fits inside said fixture base and the spring retainer is applied against the inner surface of said insert.