Downlight luminaire baffles and baffle components

A baffle component for a luminaire includes a portion of opaque material that forms a front surface and a back surface as major surfaces. The front surface includes multiple ridges. The material also includes a top surface and a bottom surface, and a first end surface and a second end surface. The first end surface includes a first coupling feature, and the second end surface includes a second coupling feature that is configured to engage the first coupling feature of a second baffle component that is substantially identical to the baffle component. A baffle for a luminaire includes a plurality of such components. The baffle components engage with one another, with the first coupling feature of each of the baffle components engaging with the second coupling feature of another of the baffle components, to form a shape that surrounds a central opening of the luminaire.

BACKGROUND

Interior lighting luminaires (e.g., light fixtures) are often designed for aesthetic appeal when directly viewed, as well as for providing high quality illumination. To meet these objectives, ceiling-mounted downlight luminaires often include a housing that is mounted in and above the ceiling, and about flush with the ceiling surface; a light engine within the housing; and a baffle that extends between the light engine and the lower edge of the housing. The baffle is sometimes designed to provide visual interest as well as obscuring parts of the luminaire that would otherwise be viewable between the light engine and the lower edge of the housing. The baffle may also be used to limit the spread of light, for example to shield viewers from high-angle light output (glare).

SUMMARY

In various embodiments herein, downlight baffles are formed of manufacturable components that fit together to form shapes that may be square or rectangular, or may form any other polygonal shape, for use in downlighting or for other lighting applications.

In one or more embodiments, a baffle component for a luminaire includes a portion of opaque material that forms a front surface and a back surface as major surfaces. The front surface includes multiple ridges. The portion of opaque material also includes a top surface and a bottom surface that each extend from the front surface to the back surface, and a first end surface and a second end surface, that each extend from the front surface to the back surface, and from the top surface to the bottom surface. The first end surface includes a first coupling feature, and the second end surface includes a second coupling feature that is configured to engage the first coupling feature of a second baffle component that is substantially identical to the baffle component.

In one or more embodiments, a baffle for a luminaire includes multiple, substantially similar baffle components. Each such baffle component includes a portion of opaque material that forms a front surface and a back surface as major surfaces. The front surface includes multiple ridges. The portion of opaque material also includes a top surface and a bottom surface that each extend from the front surface to the back surface, and a first end surface and a second end surface, that each extend from the front surface to the back surface, and from the top surface to the bottom surface. The first end surface includes a first coupling feature, and the second end surface includes a second coupling feature that is configured to engage the first coupling feature of another one of the baffle components. The baffle components engage with one another, with the first coupling feature of each of the baffle components engaging with the second coupling feature of another of the baffle components, to form a shape that surrounds a central opening of the luminaire, an optical axis being defined as a centerline of the central opening. At least a portion of light emitted into the central opening can pass unobstructed from any point within or above the baffle, through the central opening, and can exit below the bottom surfaces.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described. Each example is provided by way of illustration and/or explanation, and not as a limitation. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a further embodiment. Upon reading and comprehending the present disclosure, one of ordinary skill in the art will readily conceive many variations, equivalents, extensions, and alternatives to the specific, disclosed luminaires and luminaire components, all of which are within the scope of embodiments herein.

In the following description, positional terms like “above,” “below,” “vertical,” “horizontal” and the like are sometimes used to aid in understanding features shown in the drawings as presented, that is, in the orientation in which labels of the drawings read normally. These meanings are adhered to, notwithstanding that luminaires herein may be manufactured in any orientation, and/or mounted to surfaces that are not horizontal.

A common configuration for downlight luminaires includes a recessed can-type housing, a round light engine and a round baffle. The baffle is often provided with ridges for visual interest and light scattering. Deep ridges are often considered visually desirable. When round baffles with deep ridges are formed by molding, a typical approach is to configure the ridges in a spiral configuration, so that the inner part of the mold can be unscrewed from the molded part after the molded baffle hardens. Otherwise, a simple, two piece mold cannot be used because deep circular ridges interfere with removal of the inner part of the mold. That is, the ridges themselves interfere with the features of the mold when attempting to remove the baffle from the mold. For similar reasons, it is not possible to mold a square baffle with deep ridges at all with a simple two part mold. Even if the ridges were to be designed as a spiral, the corners of the square, molded part make it impossible to unscrew an inner part of the mold. Sometimes baffles in square trims are formed in progressive steps for moldability, but these steps create large shadows and do not define crisp edges like deep ridges do. The finish provided by progressive steps may be considered aesthetically unappealing, and baffles with such steps may not reduce glare as well as deep ridges would.

Thus, square or rectangular luminaires that emit light downwardly (sometimes simply called “downlights” herein) that are simultaneously attractive and inexpensive are relatively uncommon at present due to the molding issues noted above. Some square or rectangular downlights that are presently commercially available are believed to use more costly techniques than molding, such as machining or bending, to produce ridged baffles.

Downlight baffles, components thereof, and related systems and methods of manufacturing are disclosed according to various embodiments. Certain embodiments provide square or rectangular downlight baffles that can be used in downlight luminaires having corresponding square or rectangular form factors. The present technology can also be extended to create baffles of other form factors, as described below.

FIG. 1schematically illustrates an interior space partially bounded by walls15, a floor10and a ceiling5, with four square downlight luminaires100mounted therein. Details of luminaires100, such as ridges within the light-emitting portions of luminaires100, are not distinguishable at the scale ofFIG. 1.

FIG. 2Ais a schematic, upward looking perspective view,FIG. 2Bis a schematic, downward looking perspective view, andFIG. 2Cis a schematic, exploded view, that illustrate certain mechanical features of an exemplary downlight luminaire100. Electrical components of luminaire100are not shown, for clarity of illustration. Exemplary luminaire100is square in plan view, but this is not required. Luminaire100includes a housing110, a trim ring120, a baffle130(not visible inFIG. 2B) and mounting fixtures115. Mounting fixtures115may be, for example, springs that an installer can fold up in tension against sides of housing110to prepare for installation. The installer may insert an upper surface of housing110, and mounting fixtures115, into an aperture formed in a mounting surface (e.g., a piece of drywall or ceiling tile). Then, the installer can release mounting fixtures115so that they apply a downward force atop the mounting surface, pulling luminaire100into place with trim ring120abutting a lower side of the mounting surface. Trim ring120can thus hide any rough edges of the aperture, and/or any gaps between edges of the aperture and housing110. An optical axis125is also illustrated inFIGS. 2A and 2B; because exemplary luminaire100is square, optical axis125is a centerline of luminaire100in either horizontal direction. A light source will typically be mounted within luminaire100, and centered on optical axis125; the light source may be mounted above, about the same height as, or below the top of baffle130. Interior surfaces of baffle130face optical axis125.

FIG. 3is a downward looking perspective view of exemplary baffle130.FIG. 3shows that baffle130includes four exemplary baffle components135, each of which forms a side of baffle130. Each baffle component135is typically made of an opaque material, and is either formed of a light colored material or is coated (e.g., painted) so as to reflect light well. In some cases baffle component135is highly reflective (e.g., either formed of a highly reflective material such as metal, or provided with a reflective coating). In the exemplary embodiment shown inFIG. 3, baffle130is a square and each baffle component135is identical to the other components135, but it should be understood that this is not required. Each baffle component135forms one or more coupling features145that are configured to engage with corresponding coupling features145of an adjacent baffle component135, as discussed further below. In exemplary baffle components135, as shown inFIG. 3, coupling features145are tabs at one end of each component135, and coupling features145are slots at the other end of each component135, but other types of coupling features145are possible. Also, as few as one coupling feature, or any larger number of coupling features, may be present in each baffle component. Baffle components135are assembled such that front surfaces of each component face a central opening131, an aperture through which luminaire100will emit light, generally in the direction of optical axis125. Light from the light source of luminaire100will pass unobstructed through central opening131, and exit the luminaire below the bottom surfaces of baffle130.

Front surfaces of baffle components135desirably form ridges142that scatter light while reducing glare. As can be determined fromFIG. 3, if light emits in various directions from a light source slightly above, even with, or below the top surfaces of baffle130, a portion of that light may interact with ridges142, while another portion of that light will pass unobstructed through baffle130, and exit baffle130through the bottom surfaces. Ridges142may be contoured in various ways to promote light scattering in preferred directions. For example, in cross-section, ridges142may be simple curved shapes, angular sawtooth shapes, rectangular protrusions, or others, and any such shapes may form features such as flat or curved surface sections at the crest of each ridge (the place on the ridge that is furthest from the back surface) that may be shaped to scatter light in particular directions. In certain embodiments, ridges142are deep enough that they form re-entrant shapes along a direction of optical axis125. A “re-entrant shape” is defined herein as one that forms features that curve in and out of a given direction such that a mold could not release in that direction from those particular features. (For example, looking ahead toFIGS. 5A and 5B, mold piece210cannot release downwardly (or upwardly) from baffle component135because mold piece210will run into ridges142in that direction). Referring back toFIG. 3, in the illustrated embodiment, ridges142are substantially parallel with top and bottom surfaces of each baffle component135(“substantially parallel” meaning that their crests and troughs are parallel with the noted surfaces as designed, subject to normal manufacturing tolerances, not arranged in diagonal or spiral fashion). Upon reading and comprehending the present disclosure, one of ordinary skill in the art will readily conceive many variations, equivalents, extensions, and alternatives to the specifically disclosed ridge layouts and contours, all of which are within the scope of embodiments herein.

Central opening131may be constant in cross-section—that is, components135may meet in such a way that the front surfaces of components135are vertical—but central opening typically expands, that is, central opening131is typically smaller at an upper end of baffle130, and wider at a lower end of baffle130, as shown inFIGS. 2A, 2B, 2C and 3. In embodiments where central opening131expands, the corresponding components135thus meet such that their uppermost edges are closer to optical axis125, and their lowermost edges are further apart than the uppermost edges.

FIG. 4Ais a front side perspective view, andFIG. 4Bis a back side perspective view, of exemplary baffle component135.FIG. 4Aillustrates ends of tabs150, which extend from a first end surface165of component135(seeFIG. 4B). First end surface165and a second end surface170of component135extend from front surface140to back surface155, and from a top surface175to a bottom surface180, of component135. Each of top surface175and bottom surface180, extend from front surface140to back surface155, as shown. Top surface175and bottom surface180are horizontal (e.g., orthogonal to optical axis125,FIG. 3) and planar as illustrated inFIGS. 3 and 4A, but this is not required.FIG. 4Aalso illustrates ridges142crossing a front surface140of component135; only some of ridges142are labeled, for clarity of illustration. As noted above, in certain embodiments ridges142are parallel with top surface175and bottom surface180. Front surface140and back surface155(FIG. 4B) are considered the major surfaces of component135, meaning they are the largest individual surfaces of component135by area.

Component135forms slots152and tabs150as examples of coupling features145, as discussed in connection withFIG. 3. Slots152are configured to receive tabs150, and extend within back surface155of component135, mostly out of sight inFIG. 4A, but ends of slots152are visible where they intersect a second end surface170of component135. Tabs150and slots152are examples of coupling features145, as discussed in connection withFIG. 3. Slots152and tabs150are shown as trapezoidal in shape inFIGS. 4A and 4B, but this is not required. Slots152and tabs150, or any other type of coupling features145, may be of any shape that can be molded, as described below. In the exemplary embodiment shown, first and second end surfaces165and170are angled with respect to front and back surfaces140and155respectively, so that when tabs150of one baffle component engage slots152of an adjacent baffle component135, end surfaces165and170contact one another in face-to-face relation (e.g., seeFIG. 2CandFIG. 3). In this way, when four components135are assembled as baffle130, the complete baffle130may appear as if it were a single piece. However, this is not required; that is, end surfaces of baffle components herein may be shaped in other ways that provide a visually attractive fit between baffle components. For example, edges of front surface140may be curved inward (e.g., so that front surface140is concave) such that adjacent components do not meet at an angle, but along a curved line, and the inner surface of finished baffle130can be a square with rounded inside corners. The same can be done with back surface155, if desired, so that the outside of finished baffle130has rounded outside corners, and the same techniques can be applied to baffle components for non-square baffles (seeFIGS. 6A-6D).

FIG. 4Billustrates tabs150extending from first end surface165of component135; ridges142are also shown where they intersect first end surface165. Also visible inFIG. 4Bare optional protrusions160from back surface155of component135. Optional protrusions160may be configured in some embodiments to couple with features of housing110(seeFIGS. 2A-2C) to mechanically retain baffle130within housing110, but this is not required. Similarly, optional protrusions160may or may not be present on all baffle components135used to form a baffle130. For this reason, recitations herein of baffle components that are “substantially similar” to one another specifically include cases in which some baffle components have such protrusions160, while others do not. A line5-5that passes through top surface175and bottom surface180of component135indicates the location of a cross-sectional view that is illustrated inFIG. 5.

By comparingFIGS. 4A and 4BwithFIG. 2CandFIG. 3, it can be seen that front surfaces140abut one another when baffle130is assembled, with ridges142extending inward therefrom, toward central opening131of assembled baffle130(FIG. 3). End surfaces165and170are configured to intersect back surface155at 45 degree angles (seeFIGS. 2A-2C) but this angle can be adjusted. Care may be taken to match the angles of end surfaces165and170so that end surfaces165and170abut when baffled components135are assembled, and so that the intersections of ridges142on adjacent components135match, for an aesthetically clean look.

Baffle component135is advantageously made of a moldable plastic, for low cost. Suitable plastics include polycarbonate and acrylics. Advantageous materials are low in cost, moldable, opaque, dimensionally stable, not brittle (for reasons discussed below) and color stable, e.g., resistant to yellowing or other discoloration over time. Certain applications may benefit from materials that are resistant to high or low temperatures, or certain chemicals (e.g., chemical vapors that may be found in a factory or the like). Baffle component135may be used as molded, or may have surface treatments or coatings, for example paint or any treatment to produce a desired color or finish. However, such treatments or coatings are optional.

FIG. 5Ais a schematic cross-sectional illustration of a two piece mold200used to form baffle component135, taken along line5-5shown inFIG. 4B.FIG. 5Aillustrates how the shape of baffle component135solves the problem of molding components for a square baffle. Mold200includes a first mold piece210that forms front surface140of component135, and a second mold piece220that forms back surface155of component135, respectively. Mold pieces210and220meet at a parting line225that extends about component135, in and out of the plane ofFIG. 5A, above top surface175and below bottom surface180of component135, as shown. The locations of parting line225on each side may advantageously be chosen so as to minimize visual appearance of the parting line on baffle component135within a finished luminaire. For example, in the embodiment shown, parting line225is positioned at the rear corner of bottom surface180of baffle component135, where it will abut, or be covered by, trim ring120of luminaire100(seeFIGS. 2A, 2C). The parting line within top surface175will not be visible within luminaire100because it will be viewed from below. It will also be understood by one skilled in the art that designing top surface175and bottom surface180as flat surfaces may be advantageous because such surfaces will not interfere with release from mold pieces210,220and provide freedom in placement of parting lines225. (If either top or bottom surface were concave, it would form a re-entrant feature; if either were convex, parting line225would have to be arranged at the highest point of top surface175and the lowest point of bottom surface180.) A detail portion5B where first mold piece210abuts component135is shown at a larger scale inFIG. 5B.

When component135is molded, material is injected into the space between mold pieces210and220, the material hardens, and mold pieces210and/or220are withdrawn from one another along the directions marked H (horizontal, as shown inFIG. 5, although molding need not be performed in that orientation). One skilled in the art can see that component135will release from mold200when mold pieces210and/or220are moved in directions H, that is, no part of component135forms a re-entrant shape that would interfere with movement of either mold piece in directions H. This removes constraints on the ridge design such as direction of the ridges, since mold pieces210and220can be removed with simple horizontal movements, instead of an unscrewing motion required for circular baffles with spiral shaped ridges. That is, ridges142can be parallel with top surface175and bottom surface180, which may enable a cleaner look in the finished product. Also, ridges142can be deep enough that they would form re-entrant shapes in direction V, as shown inFIG. 5B. Direction V corresponds to a direction of optical axis125,FIG. 3, where deep ridges are desirable.

FIG. 5Bis a schematic, detail view of portion5B noted inFIG. 5A. As noted above, a “re-entrant shape” is defined herein as one that forms features that curve in and out of a given direction such that a mold could not release in that direction from those particular features. For example, inFIG. 5B, mold piece210forms baffle component135with ridges that preclude mold piece210from being withdrawn in direction V noted inFIG. 5A. Several ridges142are labeled inFIG. 5B, and an arrow V2is drawn from a point on a downwardly-facing face of one ridge142. Arrow V2is stopped by the upwardly-facing face of an adjacent ridge142. This is where the adjacent ridge142will mechanically interfere with withdrawal of mold piece210in the V direction. Because the presence of the mold is required to form a downwardly-facing face, the presence of any place where a line drawn downward from such a face would encounter another part of the molded shape represents a re-entrant shape—and thus a molding impossibility, if the mold must be withdrawn in that particular direction.

FIGS. 5A and 5Bthus demonstrate how component135solves the problem of molding a baffle of a rectilinear outline, with desirable ridges. Referring back toFIG. 3, if baffle130were a monolithic component with desirable ridges on all inner surfaces thereof, a mold for such component would have to have top and bottom pieces, with the top piece forming the outer surfaces (e.g., corresponding with four back surfaces155,FIGS. 4A, 4B) and the bottom piece forming the ridges. However, if the ridges are formed with a desirable depth and contour, they would not be removable from the bottom mold piece due to the re-entrant shapes that would exist in direction V (FIG. 5) or along optical axis125(FIG. 3).

It will be apparent to one skilled in the art that when top surface175and bottom surface180are planar and horizontal surfaces, as shown, the location where mold pieces210and220meet may be anywhere along such surfaces. If top surface175and/or bottom surface180form variations in height, mold pieces210may be arranged so that parting line225is formed along an uppermost region of top surface175and along a bottommost region of bottom surface180. Also, slots152can be formed by using pins inserted into prearranged locations in one mold piece or the other (usually mold piece220that forms the features corresponding to back surface155). As is known in molding, the pins can be inserted before molding, then removed from the molded component135before it is separated from the appropriate mold piece, allowing component135to separate easily from both mold pieces. Alternatively, slots152can be machined into components135after molding is complete.

When four baffle components135are assembled to form a complete baffle130(e.g.,FIG. 3) it may be necessary to bend tabs150slightly. This is because when three baffle components135are assembled together, the three components will interfere with a position of the fourth component that would be needed for tabs150to slide into slots152. In practice, an assembler may bend the three assembled baffle components135slightly, away from one another, to allow positioning of the fourth baffle component135so that its tabs150can enter slots152of an adjacent component135, and vice versa. It is because of this that the material of components135should be slightly flexible, and not brittle.

FIGS. 6A, 6B, 6C and 6Dschematically illustrate how the principles taught above with respect to a square baffle can be used to manufacture baffle components that can be assembled to form baffles of other geometries.FIG. 6Aschematically illustrates a triangular baffle330that is formed of three baffle components335, each pair of which are coupled at coupling features345. Baffle330is centered about optical axis125, which extends in and out of the plane of each ofFIGS. 6A, 6B, 6C and 6D. Baffle components335are shown schematically in that slopes of the components along a direction of optical axis125, and/or optional features that may be present on front or back surfaces of components335, are omitted for clarity of illustration. InFIG. 6A, numeral345denotes the coupling features of both adjacent components335. The shape of coupling features345does not indicate their physical shapes, but rather their complementarity, in which the coupling feature345at one end of a component335will engage the coupling feature345at the other end of an adjacent component335. Baffle components435,535and635, and their coupling features445,545and645discussed below, are similarly not illustrated to indicate physical shapes, but rather to show their arrangements and complementarity.

InFIG. 6A, end surfaces of components335are provided with thirty degree angles relative to their back surfaces (measured in what would typically be a horizontal plane in use, orthogonal to optical axis125). These angles enable substantially face-to-face contact when engaged, for a clean aesthetic look.

FIG. 6Bschematically illustrates a (non-square) rectangular baffle430that is formed of two baffle components435, and two baffle components436that are longer than baffle components435. End surfaces of components435are provided with forty-five degree angles relative to their back surfaces, measured orthogonal to optical axis125, to enable substantially face-to-face contact when engaged. By using complementary coupling features445for both baffle components435and436, it is possible to combine them in the pairs shown to create rectangular baffle430. Or, for manufacturing flexibility, it would be possible to combine four of baffle components435to form a square baffle of one size, or four of baffle components436to form a square baffle of a larger size. Upon reading and comprehending the present disclosure, one of ordinary skill in the art will readily conceive many equivalents, extensions, and alternatives. For this reason, references herein to baffle components that are “substantially similar” to one another also specifically include cases in which some baffle components have different lengths from one another, as well as including optional features (such as, for example, protrusions160,FIG. 4B) or variations of the optional features, as long as other recited features are present.

FIG. 6Cschematically illustrates a pentagonal baffle530that is formed of five baffle components535that couple with coupling features545. End surfaces of components535are provided with fifty-four degree angles relative to their back surfaces, measured orthogonal to optical axis125, to enable substantially face-to-face contact when engaged.FIG. 6Dschematically illustrates a hexagonal baffle630that is formed of six baffle components635that couple with coupling features645. End surfaces of components635are provided with sixty degree angles relative to their back surfaces, measured orthogonal to optical axis125, to enable substantially face-to-face contact when engaged. Like baffle430,FIG. 6B, identical baffle components635can be coupled with one another to form the hexagonal shape shown. In other embodiments, combinations of similar baffle components having the same end surface angles and coupling features, but differing lengths, can form baffles that have similar shapes but are longer or shorter on two opposing sides. In still other embodiments, two or more baffle components can be combined into a single, moldable baffle component with multiple sides, as long as the sides do not form a re-entrant shape that would be impossible to mold. Doing so can advantageously reduce the number of molded components that must be assembled to form a complete baffle. Upon reading and comprehending the present disclosure, one of ordinary skill in the art will readily conceive many variations, equivalents, extensions, and alternatives to the specifically disclosed baffle components, all of which are within the scope of embodiments herein.