Lighting Fixture and Air Flow Support System

1. Field of the Invention

The present invention relates to a combination light and air ventilation fixture, and more particularly to such a fixture having a surrounding support frame, which is constructed primarily out of stamped metal formations, for use in a suspended ceiling grid system.

2. Description of the Prior Art

Suspended ceiling systems are extensively used throughout the construction industry, both in new building construction and in the renovation of older buildings. A suspended ceiling consists of a grid-like support base suspended from the "true" ceiling, the base supporting a layer of ceiling panels, typically acoustical tile. In addition, the suspended grid frequently serves as a support base for the lighting fixtures and heating and air conditioning outlet ducts. The available space between the true ceiling and the false or suspended ceiling enables the economical placement of the air ventilation ductwork required to supply the individual ducts in comparison to the previously utilized floor and/or wall constructions.

For many years after the introduction of forced-air heating and cooling systems, the ceiling ducts were essentially individual louvered openings located in the ceiling. These openings typically formed arrays corresponding to the location of the (sometimes hidden) ventilation ductwork. Incandescent light bulbs and their associated fixtures did not lend themselves toward the utilization of combined lighting and air ventilation systems. However, with the advent of fluorescent lighting, architects were provided with numerous large, rectangular ceiling light fixtures, with sufficient surface area to make concurrent usage for air ventilation practicable.

In some of these early combination fixtures, the forced air was introduced directly into the light reflection area with it exhausting into the room through the open bottom of the light fixture. Later, when the light fixtures were provided with translucent panels to help diffuse the light, air gaps were left along the sides of the panels to permit the discharge of the air into the room. In a slightly different construction, such light and air fixtures were provided with an outer covering or hood which surrounded the light reflection unit and created a passageway for the airflow. The hood portion terminated at the bottom of the light fixture, creating a surrounding, spaced border through which the air is discharged into the room. These fixtures could alternatively function as an air exhaust vent, removing air. The next progression found these fixtures providing the capability for complete air ventilation, both forced air supply and exhaust, in the same lighting fixture. Various baffles and plenums were used to segregate the two air streams. A lateral opening along each side of the fixture was provided, one for discharging air into the room and the other for exhausting it from the room. With the baffles and separate air passageways, these normally unitized lighting fixtures were somewhat complex in manufacture. In addition to their complexity, there normally was also an aesthetic requirement for a surrounding border construction for the fixture installation, complementing the two, lengthy lateral air openings. This resulted in additional labor requirements during installation.

The present invention has as an underlying objective, the improvement in the heretofore-known types of combination light and air ventilation suspended ceiling fixtures by the provision of an easily-manufactured surrounding support frame for the fixture. This surrounding support frame utilizes a minimal number of stamped metal formations, connected by a cast corner member. The resulting frame receives the light reflection unit, and the entire construction is then mounted in a ceiling grid structure. In addition to supporting the fixture, the support frame also contains separated passageways for the airflow into and out of the room. The support frame further simplifies installation into a ceiling grid by also functioning as an integral border, forming a simple and aesthetically acceptable connection with the surrounding acoustical tile.

This goal is inventively achieved by providing a surrounding support frame which utilizes a small number of readily interchangeable components. The basic parts for both the air inlet and air discharge portions of the frame are identical. Two complementary, predominantly planar stamped formations are placed on their sides, longitudinally opposite one another. Flanges are provided along the top and bottom lateral edges, and extend towards one another to form elongated openings. In the finished construction, an air supply source is placed adjacent the upper opening of the frame, with the air then passing vertically through the frame, to be discharged into the room through the lower opening. On the opposite side of the lighting fixture, a similar structure is provided, and the reverse process occurs. Air from the room enters the lower opening, passes through the frame, and is discharged into the space above the fixture through the upper opening of the frame.

The lateral members located on opposite sides of the lighting fixture are connected to one another at both ends by cross members. These cross members are identical, stamped formations, which are substantially U-shaped in plan. The side walls extend below the floor of the "U", terminating in flanges which extend toward one another forming a false opening, which corresponds in width to the air discharge and air exhaust frame openings. In the completed construction, a continuous peripheral slot is thereby formed extending circumferentially around the exterior of the lighting fixture. This slot functions as the lower opening for the air discharge and exhaust systems as well as a decorative border. To prevent the aesthetically undesirable leakage of light from the area above the false ceiling through the air exhaust gap, a guard plate located directly above and adjacent the upper opening of the exhaust gap is provided. There is no light leakage problem with the remainder of the surrounding slot due to the connection with the air supply system and the false openings of the cross member.

The lateral members and the cross-connecting members are connected to one another by cast corner pieces. These corner pieces or members have extensions in two directions, one extension being received by the lateral member construction and the other by the U-shape cross member. The corner member is also provided with a floor or base which is sufficiently off-set so that the base of the cross member extension rests upon the floor of the U-shaped channel permitting the floor of the lateral member extension of the corner member to be coplanar with the bottom of the U-shaped cross member extension. The corner member is also sized so that when the cross member and lateral member are joined, the lower flanges for both of these members also lie in the same plane, thus obtaining a single level for the surrounding border/opening.

The connection of both of the cross members and the lateral members by the corner members, creates a surrounding supporting frame which is sized so as to receive and support a light reflection unit. Projecting shelves extending from the inside lateral members and the inside portion of the cross members, are provided for this purpose. Similarily, extending from the outside portions of the lateral members and cross members is a projecting ledge which is received by the lower flanges of the ceiling support grid structure, supporting the light and air fixture in the grid system.

The fixtures may be randomly placed throughout the ceiling grid or at pre-selected locations to form geometric patterns. To achieve the latter, slots are provided at regularly spaced locations in the top portion of the main and cross runners in the grid. Placement clips are attached to the cross runners of the support frame, and are received by the slots. In this manner, the fixtures can be easily arranged through the grid, in the pre-selected slot locations, forming regular patterns.

Various other objects, advantages, and features of the present invention will become readily apparent from the ensuing detailed description, and the novel features will be particularly pointed out in the appended claims .

FIG. 1 is a fragmentary bottom perspective view showing a suspended acoustical ceiling having light and air ventilation fixtures, as viewed from below;

FIG. 2 is a fragmentary bottom perspective view from above showing a suspended ceiling light and air ventilation fixture as placed in a suspended ceiling grid;

FIG. 3 is an enlarged perspective view showing a portion the invention comprising a suspended ceiling light and air ventilation fixture;

FIG. 4 is a side elevational view, in cross section, showing a suspended light and ventilation fixture as mounted in a ceiling;

FIG. 5 is a partial side elevational view, in section, showing the mounting of a suspended ceiling light and air ventilation fixture on a main runner of a ceiling grid system;

FIG. 6 is a partial perspective view showing a portion of a ceiling grid system member;

FIG. 7 is an exploded, partial perspective view, with portions broken away, showing a corner connection in a suspended support frame for a ceiling light and air ventilation fixture according to the present invention;

FIG. 8 is a partial perspective view showing channel stock utilized for air flow control, alternate lateral positions indicated in phantom;

FIG. 9 is an exploded, partial perspective view taken from below, showing a corner connection in a suspended support frame for a ceiling light and air ventilation fixture according to the present invention;

FIG. 10 is a fragmentary elevational view, in section, taken along the line 10--10 of FIG. 9, showing a vertical off-set in the bottom of a corner member, according to the present invention;

FIG. 11 is a partial perspective view taken from below with portions broken away, showing an assembled corner connection in a suspended support frame for a ceiling, light and air ventilation fixture according to the present invention;

FIG. 12 is a partial plan view with certain linear portions omitted, showing a corner connection of a surrounding support frame assembly for a suspended ceiling fixture according to the present invention;

FIG. 13 is an elevational view in section taken along the line 13--13 of FIG. 12, showing portions of surrounding support frame assembly for a suspended ceiling fixture according to the present invention; and

FIG. 14 is a fragmentary elevational view, in section, taken along the line of 14--14 of FIG. 13 showing a cross section of a lateral frame member of a surrounding support frame according to the present invention.

FIG. 1 shows a portion of a suspended grid support system 10, used to form a suspended or false ceiling. As seen from below, the grid system 10 includes a plurality of longitudinal beams 12, in a spaced, parallel relationship. Each longitudinal beam 12 comprises one or more main runners 14, connected in end-to-end relationship and spliced together (not shown). A plurality of cross runners 16 are positioned in parallel, spaced arrangement, normal to the adjacent longitudinal beams 12, and intersecting therewith. Thus, the cross runners 16 and the main runners 14, (which form the longitudinal beams 12), cooperate to form the grid system 10. As is also shown in FIG. 1, in addition to supporting ceiling panels 19 such as acoustical tile or the like, the grid system 10 also supports a plurality of fixtures 21, which provide artificial lighting and air ventilation.

As seen from above in FIG. 2, the bi-functionality of the fixture 21 is achieved by providing two separate systems in the fixture: air inlet/exhaust system and a lighting system. The lighting system is of a conventional fluorescent type having a light emitting source (shown schematically in FIG. 4) contained in a light reflection unit 23. The air inlet/exhaust system is then located on both sides of the light reflecting unit 23. As shown in FIG. 2, air enters the fixture 21 through an air inlet 27 directly into a plenum 25 located adjacent to a lateral side of the light reflection unit 23. Adjacent to the other side of the light reflection unit 23 is the air discharge system, having an air exhaust channel 28 laterally extending along the light reflection unit 23. An air discharge channel guard 29 is provided in a vertically superimposed relation to the exhaust channel 28. The fixtures 21 are also provided with a plurality of placement clips 31 which enable the placement of the fixtures 21 at pre-determined locations along the main runners 14 or cross runners 16.

As shown in FIG. 3, the composite fixture 21 consists of the light reflection unit 23 and a surrounding support frame 20. The air pathways located on both lateral sides of the light reflection unit 23 are each formed by a construction consisting of an outside lateral frame member 40 and an inside lateral frame member 41. A cross frame member 33 located at each end of the light reflection unit 23 completes the surrounding support frame 20. The lateral frame members 40,41 are joined together using a corner member 45 located at each end of the frame members 40,41. The corner member 45 is also utilized to join the lateral frame members 40,41 to the cross frame members 33, thus forming the surrounding support frame 20.

As is also shown in FIG. 3, the air discharge channel guard 29 is provided with bent, overhanging portions or eaves 29a and 29b along both lateral sides of the channel guard 29. The air exhaust channel 28 is thus formed on both lateral sides of the air channel guard 29 between the eves 29a, 29b and the upper portion of the lateral frame members 40, 41.

The outside lateral frame member 40 is provided with an outer wall 40a having a lateral frame supporting rib 46 formed therein, see FIGS. 4 and 7. Similarily, the cross frame member 33 has a cross frame supporting rib 47 formed therein. The supporting ribs 46,47 are of such a size so as to support the overall fixture 21 in the grid system 10 by resting upon an upper surface 48 of a flange portion 17 formed in the main and cross runners 14, 16. The placement clips 31, which are attached either to the cross frame member 33 or the lateral member 40 (not shown), do not support the fixture 21, but rather are utilized to position the fixture at selected locations which have been pre-determined according to the placement of a plurality of slots 32 formed in an upper box portion 15 of the main runners 14 and cross runners 16, as is shown in FIG. 6. The placement clips 31 are received by the slots 32, which enables the precise arrangement of the fixtures 21 (also see FIG. 5). In an alternate embodiment (not shown), where it is desired to provide a linear arrangement or row of the fixtures 21, each pair of placement clips 31 are off-set from one another to permit the end-to-end placement of the fixtures without interference between the respective pairs of replacement chips 31. The location of the slots 32 will, or course, conform to the location of these off-set placement clips 31.

Additional details of the fixtures 21 and particularly the surrounding support frame 20 are shown in the cross sectional views of FIGS. 4 and 5. As is shown in FIG. 4, an air inlet duct 37 and an air exhaust duct 38 are constructed in substantially the same manner, consisting of the outside lateral frame member 40 and the inside lateral member 41. The lateral frame members 40,41 are complimentary, stamped formations, having an upper flange 43a,43b and lower flange 44a,44b, respectively. Both sets of flanges extend toward one another, the upper flanges 43a,43b forming a support shoulder 66 which receives the lower portion of the plenum 25. The lower flanges 44a,44b extend toward one another forming the lower opening for the air inlet duct 37.

A projecting shelf 54 is provided on an outer wall 41a of the inside lateral frame member 41 in each of the air ducts 37, 38. The projecting shelf 54 receives and supports a portion of the light reflection unit 23. A retaining means 58 is also used to attach the light reflection unit 23 to the inside lateral frame member 41. As is also shown in FIG. 4, the light reflection unit 23 is provided with an outer, light reflecting hood 53 and a light transmitting panel 55. A pair of panel retaining strips 56a, 56b, shown generally as retaining strip 56 in FIG. 11, receive the panel 55 and are themselves attached to the projecting shelves 54, which in turn support the light transmitting panel 55.

The function of the lateral frame supporting rib 46 will vary according to the location of the fixture 21 in the suspended grid system 10. Where the fixture 21 is adjacent to either the main runner 14 or the cross runner 16 (shown in phantom), the respective supporting rib 46,47 will be received by the upper surface 48. The respective supporting rib 46,47 will thus assist in the support of the fixture 21. However, when the fixture 21 is not adjacent to either the main runner 14 or the cross runner 16, the respective supporting rib 46,47 will receive and support the ceiling panels 19.

To control the amount of air flowing through the fixture 21, both the air inlet duct 37 and air exhaust duct 38 are provided with a mechanism that alters the size of the air passageway. A weir 71 (also see FIG. 8) is formed inside both of the air ducts 37,38 by a complementary pair of U-shaped channel stock 72a,72b. As is shown in FIG. 4, the weir 71 is received between the lateral frame members 40,41. The two channel stock members 72a,72b cooperate as a unit, the channel stock 72b is inverted and received by the channel stock 72a. As is shown in FIG. 8, this construction permits the lateral expansion of the weir 71, reducing the size of the air passageways and restricting the amount of air flow.

Unlike the lateral portion of the support frame 20 which consists of a construction of two separate members - the inside and outside lateral frame members 41,40, the cross frame member 33 is a single, unitary stamped formation of generally U-shaped design, see FIG. 5. The cross frame member 33 is provided with an outer sidewall 34 and an inner sidewall 35 joined together by a base or bed portion 84. The outer and inner sidewalls 34,35, extend below the base 84, terminating in a pair of lower flanges 81. The cross frame supporting rib 47 projects from the outer sidewall 34, and a projecting shelf 83 extends from the inner sidewall 35. Both the supporting rib 47 and the projecting shelf 83 are coplanar with the base 84. The projecting shelf 83 is sized to receive and support a portion of the outer reflecting hood 53. A retaining means 59 may also be used to secure the reflecting hood 53 to the inner sidewall 35 of the cross frame member 33. The projecting shelf 83 terminates in a lip 86 which, in conjunction with a hanger assembly 57, also assists in the support of the light transmitting panel 55.

The cross frame member 33 is joined to the lateral frame members 40,41 by the corner member 45, as is illustrated in detail in the exploded view provided by FIG. 7. Unlike the cross frame members 33 and the lateral frame members 40,41, both of which are extruded formations, the corner members 45 are cast formations having a cross frame extension 91 and a lateral frame extension 92 formed at a selected angle to one another, depending upon the chosen geometric shape of the surrounding support frame 20. For purposes of illustration, a rectangular shape has been shown in the Figures. The cross frame extension 91 consists of a cross frame outer sidewall 123a and a cross frame inner sidewall 123b with a cross frame end wall 125 connecting the sidewalls 123a,123b at their forward terminus. Similarly, the lateral frame extension 92 consists of a lateral frame outer sidewall 124a and a lateral frame inner sidewall 124b connected by a lateral frame end wall 126 at the forward terminus of the lateral frame extension 92. The corner member 45 is also provided with a floor 94, consisting of a cross frame base extension 121 and a lateral frame base extension 122 (see FIG. 9).

To form the connection between the cross frame member 33 and the lateral frame members 40,41, the adjacent ends of the lateral members 40, 41 and cross frame member 33 are mitered at the selected corner angle. The cross frame extension 91 is then received by the U-shaped channel of the cross frame member 33, with the cross frame base extension 121 resting upon the base 84 of the cross frame member 33. Similarly, the lateral frame extension 92 is received between the outside lateral frame member 40 and the inside lateral frame member 41. A top edge 98 of the lateral frame extension 92 receives the upper flanges 43a,43b of the lateral frame members 40,41.

In order to provide sufficient room for the weir 71 and also a quieter air flow, it is desirable to have a greater vertical height in the lateral frame members 40,41 than is necessary in the cross frame members 33. To enable the resulting support frame 20 to have the air inlet and air exhaust ducts 37,38 coplanar with the false air ducts 85 in the cross frame member 33, the lateral frame sidewalls 124a,124b are of a sufficient vertical dimension so that the lateral frame members 40,41 hang down from the top edge 98 to the correct, coplanar level. Since there is no similar requirement for vertical height in the cross frame extension 91, a vertical offset 95 is provided in the corner member 45 at the intersection between the lateral frame outer sidewall 124a and the cross frame outer sidewall 123a, as well as between the lateral frame inner sidewall 124b and the cross frame inner sidewall 123b. The vertical height of the cross frame sidewalls 123a,123b is desirably no higher than the outer and inner sidewalls 34,35 of the cross frame member 33.

To provide additional structural rigidity along the length of the lateral frame members 40,41, one or more spacer units 111 are provided. Each spacer unit 111 consists of a vertical member 112 separating three flanges 113a,113b,113c, which in turn form a lower slot 114 and an upper slot 115.

In addition to improving the stability for the lateral member construction (which forms the air inlet duct 37 and the air exhaust duct 38), the spacer units 111 also provide support for one end of the air flow weir 71. The U-shaped channel stocks 72a,72b is received by a platform 93 formed in the lateral frame end wall 126 of the corner member 45. From the platform 93, the channel stocks 72a,72b horizontally extend to the corresponding slot 114, 115 in the spacer unit 111. The spacer unit 111 is substantially symmetrical about its central axis and thus may be inverted without detrimental effect to its receiving of the channel stock 72a,72b. Both the platform 93 and the lower and upper slots 114,115 provide sufficient lateral space to permit the weir 71 to variably alter its lateral dimensions and thereby alter the air flow.

FIG. 7 also illustrates the air discharge channel guard 29 in greater detail. The channel guard 29 is a stamped, predominantly planar formation, consisting principally of a cover panel 101 and at least one and preferably two end support panels 103. The eaves 29a, 29b are located along the outer lateral edges of the cover panel 101. The end support panels 103 (only one is shown) are bent downwardly, substantially perpendicularly to the cover panel 101, and are further provided with an additional bend or crimp 107 to provide additional structural rigidity. A holding tab 105 or any such other like connector means is provided on the lower end portion of the end support panel 103, utilized to connect the end support panel 103 with the lateral frame end wall 126 of the corner member 45. When assembled, as shown in FIG. 3, the end support panel 103 maintains the cover panel 101 in a spaced-apart relationship to the upper flanges 43a, 43b of the lateral frame members 40, 41. The cover panel 101 and the eaves 29a, 29b prevent what would otherwise be direct visual access from below the fixture 21 into the area above the false ceiling. An insulation material 30 may also be provided to the underside of the cover panel 101, as is shown in FIG. 4.

As was previously described, the bottom surfaces of the lower flanges 81 of the cross frame member 33 are coplanar in the assembled condition with the lower flanges 44a, 44b of the lateral frame members 40, 41, see FIG. 9. In addition, the bottom surface of the bed 84 of the cross frame member 33 is coplanar with the bottom surface of the lateral frame base extension 122. As is shown in FIG. 9, this is accomplished by providing a base offset 120 in the corner member 45. The base offset 120 corresponds in depth to the thickness of the bed 84 of the cross frame member 33. Thus, when the cross frame base extension 121 is received by the cross frame member 33, resting upon the upper surface of the bed 84, the lower surface of the bed 84 is coplanar with the bottom surface of the lateral frame base extension 122 of the corner member 45. The base offset 120 is shown in detail in FIG. 10, and the resulting connection is shown in FIG. 11.

FIG. 11 also illustrates the continuous nature of the ducts or openings, which is achieved by the coplanarity of the lower flanges 81 of the cross frame member 33 with the lower flanges 44a, 44b of the lateral frame members 40, 41. The false air duct 85 appears to be a continuous extension of both the air inlet duct 37 and the air exhaust duct 38. In the completed fixture 21, there is thus provided a continuous opening around the periphery of the fixture 10, consisting of the false air ducts 85 and the air inlet and air exhaust ducts 37, 38.

As is shown in FIGS. 12 and 13, the assembled construction is held together by a plurality of rivets or like connector means 117. Apertures 97 are formed in the corner member 45 and may be formed in the side walls 34, 35 of the cross frame member 33 and the lateral frame members 40, 41 during assembly. An aperture 96 is formed in the lateral frame end wall 126 of the corner member 45 to receive the holding tab 105 of the end support panel 103 for the channel guard 29. Additionally, one or more apertures 116 are provided in the spacer units 112 to receive connecting rivets 117.

As finally assembled, the lighting and air flow fixture 21, as shown in FIG. 4, provides for both lighting and air ventilation. Light is conventionally provided, utilizing the light-producing means 11 shown schematically inside of the light reflection unit 23. Air ventilation is provided utilizing the air inlet and air exhaust ducts 37, 38 located on each lateral side of the light reflection unit 23. The ducts 37, 38 are essentially identical in construction, forming a part of the surrounding support frame 20 for the fixture 21, distinguishable only by the provision of the plenum 25 for the air inlet duct 37 and the air discharge channel guard 29 for the air exhaust duct 38. As both of these items are readily interchangeable, the fixture 21 is readily adaptable to differing ventilation ductwork patterns.

The air flow through both the air inlet duct 37 and the air exhaust duct 38 is quite similar. Air is supplied to the fixture 21 by an air supply duct 63. From the supply duct 63, air enters into an air chamber 61 of the plenum 25 and is discharged through an air discharge opening 64, which is received by, and located between, the lateral frame members 40, 41. The air then moves vertically downward, passing the airflow control weir 71, and out through the opening formed between the lower flanges 44a, 44b of the lateral frame members 40, 41.

The air flow through the air exhaust duct 38 is essentially the reverse of the foregoing process. The air between the false and true ceilings is subjected to a slight reduction in pressure, as compared to the air in the space below the false ceiling. This pressure difference causes the air from below to enter the air exhaust duct 38 through the opening formed between the lower flanges 44a, 44b of the lower frame members 40,41. The air then flows past the airflow control weir 71 and out of the air exhaust duct 38 through the opening formed between the upper flanges 43a, 43b of the lateral frame members 40, 41 and the eaves 29a, 29b of the air discharge channel guard 29.

While I have disclosed an exemplary structure to illustrate the principles of the present invention, 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.