Luminaire Support

Abstract

Industrial luminaire having an optical assembly mounted in offset relation to an associated ballast housing is suspended from a supporting conduit by a horizontally adjustable bracket by means of which the luminaire may be positioned with its center of gravity directly below the supporting conduit.

Description

The present invention relates to a supporting device, and particularly to an adjustable support for lighting fixtures and the like.

It is a general object of the invention to provide for suspending a fixture, such as a luminaire, from a support in balanced relation thereto.

It is another object of the invention to provide a lighting fixture, especially of industrial luminaire type, having an adjustable bracket for positioning the fixture relative to a support.

A specific object of the invention is to provide an adjustable bracket for an industrial luminaire with offset parts suspended from a support whereby the center of gravity of the luminaire may be aligned directly below the point of support.

Other objects and advantages will become apparent from the following description and the appended claims.

With the above objects in view, the present invention relates to a luminaire comprising, in combination, a lighting fixture comprising a housing for enclosing electrical operating components and an optical assembly attached to the housing in laterally offset relation thereto, and an adjustable bracket device for hanging the lighting fixture in balanced position on a support, the bracket device comprising an elongated member having opposite ends, first connecting means on the elongated member for attaching it to a support, second connecting means mounted on the member for movement along the same toward and away from the first connecting means and attached to the lighting fixture for movement therewith, and adjusting means on the elongated member for moving the second connecting means to a selected position relative to the first connecting means wherein the center of gravity of the fixture is aligned with the first connecting means for balancing the fixture on the support.

The invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view in elevation of an industrial luminaire including an adjustable support bracket constructed in accordance with the invention for suspending the luminaire from a conduit;

FIG. 2 is an enlarged view in perspective of the adjustable support bracket;

FIG. 3 is an end view of the adjustable support bracket;

FIG. 4 is a front elevational view of the adjustable support bracket with associated parts of the luminaire and conduit;

FIG. 5 is a cross-sectional view of the bracket shown in FIG. 4 taken along the line 5--5; and

FIG. 6 is a fragmentary front view, partly in section, of the adjustable bracket assembly.

Referring now to the drawings, and particularly to FIG. 1, there is shown a lighting fixture 1, such as an industrial luminaire for indoor lighting purposes, suspended from a conduit 2 fixed to and projecting downwardly from ceiling 7, the luminaire being suspended by means of adjustable bracket 10 constructed and arranged in accordance with the invention. Luminaire 1 comprises, in the illustrated embodiment, ballast housing 4 secured at its top to bracket 10 and an optical assembly 3, including lamp 6 and reflector 5, attached in laterally offset relation to ballast housing 4 by mounting arm 1a, which extends upwardly and outwardly from ballast housing 4. By such an arrangement, optical assembly 3 may be mounted at a higher level than if suspended from the bottom of ballast housing 4. Such offset mounting of the optical assembly and means providing for the same are disclosed in greater detail in copending application of Osteen et al., Ser. No. 882,885, filed Dec. 8, 1969, and assigned to the same assignee as the present invention. As there disclosed, lamp 6, which is typically of gaseous discharge type such as a mercury vapor lamp, is connected to electrical ballast components 8 in ballast housing 4 by suitable leads (not shown) passing through mounting arm 1a.

In normal installation, optical assembly 3 is positioned with its optical axis perpendicular to the floor to be illuminated thereby. With optical assembly 3 offset as shown, however, a substantial bending torque would be applied to rigid conduit 2 at its point of connection with the luminaire, especially when an optical assembly is employed which is relatively heavy in comparison to ballast housing 4. Even if the luminaire is suspended from a flexible support such as a chain or the like, instead of a rigid support, the results are undesirable since in such case the unbalanced luminaire assembly would hang at a substantial angle and the optical axis would no longer be perpendicular to the floor; hence, the light distribution therefrom would have an improper direction and pattern.

In accordance with the invention, the offset luminaire is secured to supporting conduit 2 by a bracket 10 which enables the luminaire to be horizontally moved relative to conduit 2 to a position in which its center of gravity is below and vertically aligned with the point of connection of bracket 10 to conduit 2, thereby bringing it into a balanced position relative to the suspension point.

In the illustrated embodiment, bracket 10 comprises an elongated tubular member or housing 11 closed at one end by wall 11a and at the opposite end by removable cap 12, and being formed with a slot 11b (see FIG. 5) extending along its bottom wall. An adjusting bolt 13 extends along the interior of tubular member 11 and is arranged with its head 13a outside end wall 11a for turning the bolt. As seen in FIG. 6, a U-shaped bracket 14 having an apertured bottom plate 14c rests on the bottom of housing 11 extending across the slot therein and is formed with spaced upstanding arms 14a, 14b having aligned holes through which bolt 13 passes. Bolt 13 is in threaded engagement with the apertured portion of arm 14b while it passes freely through the hole in arm 14a, so that turning of bolt 13 moves U-shaped bracket 14 along the bolt and hence along the interior of tubular member 11 adjacent slot 11b therein. Stop nut 13b on the inside of wall 11a spaced from bolt head 13a coacts with the latter to retain bolt 13 in axial position on member 11.

Inserted through slot 11b and the apertured bottom plate 14c of U-shaped bracket 14 is threaded conduit pipe 15 which is hung at its upper end from bracket 14 by means of lock nut 16 threaded on the end of pipe 15 and bearing on the upper surface of bracket 14. Indicator member 17 comprising a plate portion 17a and a bentup end portion formed with an indicator pointer 17b is arranged with the latter overlapping the front of tubular housing 11 and with plate portion 17a adjacent the bottom of the tubular housing 11 and extending across slot 11b therein. Plate portion 17a is formed with an aperture 17c which is slightly larger than the outer diameter of conduit pipe 15 so that the latter extends therethrough. Conduit pipe 15, indicator 17, U-shaped bracket 14 and tubular housing 11 are held in assembly as seen in FIG. 5 by interior locknut 16 and exterior locknut 18 threaded on conduit pipe 15.

Ballast housing 4 of luminaire 1 is suspended from conduit pipe 15 (see FIG. 4) by any suitable means, which may include, for example, locknut 19 threadably engaging a connecting member (not shown) inside the upper wall of housing 4. A suitable connecting means for this purpose is shown in copending application of Grindle, Ser. No. 860,676, filed Sept. 24, 1969 now U.S. Pat. No. 3,561,719 and assigned to the same assignee as the present invention, and the disclosure of which is incorporated herein by reference.

The top wall of tubular housing 11 near end cap 12 is formed with an aperture for receiving the lower end of threaded conduit 2. Preferably a reinforcing plate 21 is secured to the underside of the top wall at that region and has a corresponding aperture which is aligned with the top wall aperture and is threaded to engage the threaded end of conduit 2. Locknut 22 serves to secure tubular housing 11 to the end of conduit 2.

When locknut 18 below housing 11 is slightly loosened, turning of head 13a of bolt 13 will result in shifting U-shaped bracket 14 along the axis of housing 11, so that conduit pipe 15 and the parts attached thereto including luminaire 1 will be horizontally shifted in a corresponding manner. Indicia marks 20 provided on the exterior surface of housing 11 adjacent the path of indicator pointer 17b indicate the position of the axis of conduit pipe 15 relative to housing 11 and the relative distance thereof from conduit 2.

In a typical procedure for making use of the invention, a luminaire of offset type such as shown in FIG. 1 with attached bracket 10 is first secured to a flexible vertical support such as a chain, the latter being attached at its lower end to tubular housing 11 at the region of the latter where it is subsequently to be attached to a rigid conduit or other permanent support in the ultimate installation. With the luminaire thus hanging from the chain and with a suitable level placed on the flat top of optical assembly 3 or against the cover glass at its bottom, bolt 13 is rotated in the desired direction for moving the luminaire horizontally to a position in which the level is horizontally oriented, thus indicating a balanced position of the luminaire, i.e., one in which its center of gravity is vertically aligned with the vertical supporting chain and the optical axis of the optical assembly is normal to the floor. The particular indicia mark 20 indicated by pointer 17b in such adjusted position thus is the mark to which all luminaires of this type should be adjusted relative to bracket member 11 for assuring that they will be in balanced position on the supporting conduit or other support to which they are to be connected, without necessitating a specific determination of the location of the center of gravity of each individual unit.

If desired, an annular spacer (not shown) thicker than the bottom wall of housing 11 may be arranged on conduit pipe 15 between U-shaped bracket 14 and indicator member 17, and within slot 11b, so that when locknut 18 is tightened, sufficient spacing may be maintained between bracket 14 and indicator member 17 to ensure free movement of those parts along slot 11b upon turning of bolt 13.

Conducting leads (not shown) may pass from the open bottom of conduit 2 in the interior of tubular housing 11 through the open top of conduit pipe 15 for passage therethrough for connection to the electrical operating components in ballast housing 4. Where appropriate, the ends of leads coming up through conduit pipe 15 into tubular member 11 may be joined to the ends of leads coming down from conduit 2 by virtue of the access opening provided by removal of end cap 12 of member 11.

While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the scope of the invention. Accordingly, we wish to have it understood that we intend herein to cover all such modifications as fall within the true spirit and scope of our invention.

Claims

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A luminaire comprising, in combination, a lighting fixture comprising parts arranged in laterally offset unsymmetrical relation, and an adjustable bracket device for hanging said lighting fixture in balanced position on a support, said bracket device comprising an elongated member having opposite ends, first connecting means on said elongated member at one end thereof for mounting the same in operative position on a support, second connecting means mounted on said member for movement along the same toward and away from said first connecting means and attached to one of said laterally offset parts of said lighting fixture for movement of the fixture therewith, and adjusting means on said elongated member for moving said second connecting means and said lighting fixture to a selected position relative to said first connecting means wherein the center of gravity of the lighting fixture is aligned vertically below said first connecting means for balancing said fixture on the support.

2. A luminaire as defined in claim 1, said elongated member having a longitudinal axis, said second connecting means comprising a hollow conduit arranged with its axis transverse said longitudinal axis and a movable member secured to and movable with said hollow conduit along said elongated member, said movable member having a portion extending transverse said longitudinal axis, said adjusting means engaging said transverse portion of said movable member for moving the same.

3. A luminaire as defined in claim 2, said elongated member comprising a housing having a wall formed with a slot extending along said longitudinal axis, said hollow conduit extending into said housing through said slot, said movable member being arranged within said housing and movable with said hollow conduit along said slot.

4. A luminaire as defined in claim 3, said adjusting means comprising a bolt extending in said housing along said longitudinal axis and threadably engaging said transverse portion of said movable member.

5. A luminaire as defined in claim 4, said movable member being U-shaped with opposite parallel arm portions connected to said bolt and a base portion secured to said hollow conduit.

6. A luminaire as defined in claim 5, and indicating means attached to and movable with said second connecting means adjacent said elongated member for indicating said selected position of said second connecting means relative to said first connecting means.

7. A luminaire as defined in claim 6, said elongated housing member being open at said one end and closed at said other end, detachable cover means closing said open end, said adjusting bolt extending through said other end and having an enlarged head portion on the outside of said other end for turning the bolt.

8. A luminaire as defined in claim 1, said lighting fixture comprising a housing for enclosing electrical operating components and an optical assembly attached to said housing in laterally offset relation thereto, said housing being connected to said second connecting means.