US2854205A

US2854205A - Supports for suspending fluorescent lighting fixtures

Info

Publication number: US2854205A
Application number: US555048A
Authority: US
Inventors: Kruger Michael Henry
Original assignee: A L SMITH IRON Co
Current assignee: A L SMITH IRON Co
Priority date: 1955-12-23
Filing date: 1955-12-23
Publication date: 1958-09-30
Anticipated expiration: 1975-09-30

Description

Sept 30, 1958 M. H. KRUGER SUPPORTS FOR SUSPENDING FLUORESCENT LIGHTING FIXTURES 3 Sheets-Sheet 1 Filed Dec. 23, 1955 SUPPORTS FOR SUSPENDING FLUORESCENT LIGHTING FIXTURES Filed Dec. 25, 1955 M. H. KRUGER Sept. 30, 1958 3 Sheets-Sheet 2 .IIIIVII I! I lllllllllll 4 INVENTOR. Mae ea flaw/9y 591/45 577'0F/Vfy .r' n Y J Sept. 30, 1958 M. H. KRUGER 2,854,205

SUPPORTS FOR SUSPENDING muomzscsm LIGHTING FIXTUR 3 Sheets-Sheet 3 Filed Dec. 23, 1955 United States r SUPPORTS FOR SUSPENDING FLUQRESCENT LHGHTENG FEXTURES Michael Henry Kruger, Chestnut Hill, Mass, assignor to A. L. Smith Iron Company, Chelsea, Mass, 2 vcorporation of Massachusetts Application December 23, 15 55, Serial No. 555,,il43

3 Claims. ((11. 248-343) This invention relates to fluorescent lighting fixtures in general, and more specially to supports for suspending fluorescent lighting fixtures to a building structure.

Among the-objects of the present invention, it is aimed to provide an improved support for suspending a fluorescent lighting fixture in a ceiling or the like Where the building structure on which the support rests consists in a pair of parallel rafters, cross beams, or the like, where the lighting fixture is disposed between such rafters and the distance between such rafters may vary, where the depth of projection upward between the rafters may vary according to the architects specifications, and where the strength of the rafters may vary depending upon the ceiling construction. In view of the foregoing, it is aimed to provide an improved support which (1) is adjustable and yieldable laterally, (2) is adjustable vertically, and (3) will reduce to a minimumany angular torsional strain on the rafters.

These and other features, capabilities and advantages of the invention will appear from the subjoined detailed description of specific embodiments thereof illustrated in the accompanying drawings, in which:

Fig. 1 is a front elevation of one embodiment of the improved support diagrammatically showing the trolfer and lighting fixture connected thereto.

Fig. 2 is a plan View of the support shown in Fig. 11.

Fig. 3 is a transverse section of one of-the connectors shown in Fig. 1.

Fig. 4 is a fragmental perspective of the support shown in Fig. l with the troffer and lighting fixture shown diagrammatically.

Fig. 5 isa front elevation of the support shown in Fig. 1 before the trofier .and lighting fixture are connected thereto.

Fig. 6 is an end elevation of the support shown in Fig. 5.

Figs. 7, 8, 9 and 10,-are fragmental front elevations of four embodiments of, connectors differing from one another and from the connector shown in Fig. 1.

Fig. 11 is an enlarged fragmental section of a part of the. bridge shown inFig. 5

Fig. 12 isa fragmental section on the line 1212 of Fig-11.

Fig. 13 is a fragmental section similar to Fig. 11 with the link shown in outwardly inclined position as distinguished from the inwardly inclined position of the link shown in Fig. 11.

The improved support shown inFig. .1 consists essentially in the one-piece metal bridge 1, L-shaped brackets 2 and '3, troffer-engaging links 4 and 5, and the rafterengaging connectors 6 ,and -7. The rafterrengaging ,connectors 6 and '7 adjustably connect thehorizontally extending rafters, such as theT-

bars

3 and 9 to the Lashaped brackets 2 and 3;,theginwardly and-horizontally extending limbs lfland ll ofzthe:brackets.2 and 3, respectively, slidably and adjustably connect theends ofthe bridge 1 in place; and thedepeuding links and e pivotally con- 2,854,205 Patented Sept. 30, 195.8

limbs 1t) and 11 and the ends of the bridge 1 provides for longitudinal adjustment of the support in a lateral direction of the trotfer 12; the adjustable connection between the connectors 6 and 7 and the vertical downwardly extending

limbs

13 and 14,, respectively, of the brackets 2 and 3, provides for vertical adjustment of the support and thereby vertical adjustment of the trofier 1 2 relative to the ceiling; and the bridge 1 in cooperation with the brackets 2 and 3 reduces to a minimum any angular torsional strain on the rafters, such as the T-bars "8, and 9. Furthermore, the limbs 10 and 11 are 'slidable. relative to the ends of the bridge 1. This slidable relationship together with the pivotal connection of the links ,4 and 5 carrying the troffer 12 relative to the bridge 1, will compensate for any building sway due to wind storms and the like, especially when the lighting fixtures are equipped in the upper floors of tall buildings; will compensate for expansion and contraction due to temperature changes; and will compensate for any structural reformations caused by settling of the building; and will reduceto a minimum any angular torsional strains that might be transmitted to the rafters, such as the T-bars 8 and 9 so that any injury due to twisting or the like to (the rafters, such as the T-bars '8 and 9, especially if composed of light weight material, will be entirely avoided.

Another advantage of this combination of bridge 1, L-shaped brackets 2 and 3, and trofier-engaging links 4 and 5, resides in the fact that it is extremely flexible so that it can be secured to practically an unlimited number .of ceiling constructions, not only to a ceiling construction equipped with bars, such as the T-bars 8 and 9, but also with ceiling constructions such as those illustrated in Figs. 7, 8, 9 and 10.

More specifically, the bridge 1 comprises a web 15 which has an intermediate portion 16,.two downwardly inclined or curved portions 17 and 18 and two outwardly extending ends or portions 19 and 29 substantially parallel to the intermediate portion 16. Preferably the intermediate portion 16 has formed therein an oblong longitudinally extending opening 21 to clear the supporting rod 22 which extends from the ceiling structure down to the trofier 12 and is connected thereto. Preferably also in the interest of rigidity and reenforcement, the web 15 has upwardly extending flanges 121 and 122 extending the full length of the web 15 from the lateral edges of the

portions

16, 17, 18, 19 and Zil.

In the curved portions '17 and 18 there are provided laterally extending openings 23 and 24, respectively, through which extend the links 4 and 5, respectively. Each of thelinks 4, '5, see Fig. 11, comprises a shank 25 having an outwardly extending plate or lip 26 at its upper end and a hook or hook formation 27 at its lower end consisting of an outwardly extending projection or portion 28, a downwardly extending portion 29, and an inwardly extending portion 30 extending to and beyond the shank 25 and terminating in an upwardly inclining lip 31. The lower faces of the portions 17 and 18 form abutments for the springs 32. Each spring 32 is tensed between a portion 17, 18 and the upper face of the portion 28. The shank 25 as aforesaid extends through the opening 23, 24 'with the portion 26 disposed above the upper face of the portion 19, 20, and the

portions

30, 28 and 26 and the portion 19, 20 having openings in alinement with one another to receive the screw 33 with the head 34 engaging the lower face of the portion 30 and the nut 35 screw-threadedly connected to the screw 33 abutting against the upper face of the portion'26. In order to aid in tilting the links 4 and 5 inwardly as shown in Fig. 5, the plate 36 isprovided which has a downwardly extending flange 37 which is wider than the width of the opening 23,24 so that its ends engage the lower face of the portion 17, 18, and the plate 36 rests on the upper face of the portion 19, 26. This plate 36 has an opening formed therein with the side pressed upwardly to form the upwardly extending flange 38, the edges of the opening and the inner face of the flange 38 being threaded to receive the screw-threaded shank portion 39 of the screw 33. In this way the plate 36 is rockably secured to the portion 17, 18 with the flange 37 engaging the lower face of the portion 17, 18, and the plate 36 engaging the upper face of the portion 19, 20, and the link 4, being pivotally mounted relative to the portion 19, 20 when the upper edges of the flange 37 act as the fulcrum during the pivotal movement of the link 4, 5 rela tive to the bridge portion 19, '20. The screw 33 will be screwed up into the plate 36 a sufl'icient distance to cause the angle between the plate 36 and its flange 37 freely to engage the upper face of the bridge portion 17, 18, and the springs 32 will normally swing the lower ends of the links 4 and 5 toward one another into the full line position shown in Fig. 5, where the plate portion 36 will rest flat on the bridge portion 19, 20. The spring 32 will in turn yield and allow the outer portion of the plate 36 to recede from the bridge portion 19, 20, when the link 4, 5 is swung into the dotted line position shown in Fig. 5 and full line position shown in Fig. 13. Although free movement of the link 4, 5 relative to the bridge portion 19, 20 is necessary, it is desirable that the lower ends of the links 4 and 5 be spaced a predetermined distance from the bridge 1 so that when the

lower ends

138 and 139 of the trofier 12 rest on the portions 39 of the links 4 and 5, they will conform to the level predetermined for the

lower ends

138 and 139 of the trofler 12. When the trofler 12 as aforesaid so rests on the links 4 and 5, it may sway slightly to accommodate movement of the building, particularly if the lighting fixture is installed in one of the upper stories of a tall building, and in turn the links 4 and 5 may move toward or away from one another clue to expansion and contraction, bearing in mind the diiferent temperatures to which the lighting fixture may be subjected not only when illuminated as distinguished from being non-illuminated, but also the diiferent room temperatures to which the lighting fixture may be subjected from winter to summer and the like.

The lighting fixture 40 may be any of the well-known types, such as disclosed in United States Letters Patent No. 2,597,875, which may be attached to the troffer 12 in the manner shown in this patent. In order to ac commodate various widths between adjacent parallel rafters, such as the T-bars 8 and 9 shown in Fig. 1, the bridge portions 19 and 20 of the bridge 1 preferably are each provided with a pair of

elongated slots

41, 41 and 42, 42, extending longitudinally to the bridge 1. Through each of these pairs of slots 41 and 42 extend a pair of rivets 43, 43 and 44, 44, respectively, the rivets 43, 43 being secured to the horizontally extending limb of the bracket 2 and slidably mounted in the slots 41, 41, and the rivets 44, 44 being secured to the limb 11 of the bracket 3 and slidably mounted in the

slots

42, 42. This slidable relationship between the limbs 10 and 11 and the bridge portions 19 and 20, respectively, not only allows for varying widths between adjacent rafters, such as the T-bars 8 and 9, but also to supplement the pivotal mountings of the links 4 and 5 to; accommodate diiferences in temperature to which the lighting fixture 40, trotfer 12, bridge 1 and brackets 2 and 3 may be subjected, and also to the diiference in temperatures to which the T-bars 8 and 9 may be subjected. The bridge 1 with its pivotally mounted links 4 and 5 and slidable mounting of the brackets 2 and 3 relative to the bridge 1 all contribute, 1) to a flexible mounting which will accommodate itself to variations in width between the rafters, such as the T-bars Sand 9, movement of the building v 4 due to wind storms and differences in temperature without any resulting strain on any of the working parts of the mounting, and (2) also to reenforcing and bracing the brackets 2 and 3 so that notwithstanding the flexibility achieved by the combination aforesaid, including the bridge 1, brackets 2 and 3 and links 4 and 5, they will bar any torsional strain being transmitted to the rafters, such as the T-bars 8 and 9.

Due to the tendency in present building construction in the interest of reducing weight and costs, in turn to reduce the weight and size of the rafters, such as the T-bars 8 and 9, an increasing threat to twisting these rafters resulting from the weight of the light fixture has been encountered when the troifer 12 and lighting fixture .40

epended only upon the brackets 2 and 3 for support. A rigid bridge between the brackets 2 and 3 would invite other more serious risks. However, with the present flexible combination, including the bridge 1 slidably connected to the brackets 2 and 3, and the links 4 and 5 pivotally connected to the ends of the bridge 1 instead bf to the links 4 and 5, not only would the torsional strains on the rafters, such as T-bars 8 and 9, be entirely ohminated, but the equally injurious strains due to a r1g1d bridge connecting the brackets 2 and 3 would be positively eliminated.

Aside from the foregoing, the

vertical limbs

13 and 14 of the brackets 2 and 3 of this flexible bracing combination when provided with a succesion of openmgs-143 and 144 lend themselves admirably to accommodate any one of a number of connectors such as the connectors 6 and 7 of Figs. 1, 2, 3 and 6, or the connectors and 145 shown in Figs. 7 and 9, respectively, the connector 46 shown in Fig. 8, the connector 47 shown in Fig. 10, or any number of any connectors without departing from the spirit of the present invention.

The connectors 6 and 7 are particularly adapted for the T-bar rafters 8 and 9, respectively, and consist essentially of an outer bracket 48 having a jaw 49'to engage the outer extension 50 of a T-bar, such as the T-bar 8. This jaw 49 has extending at right angles thereto the plate 51 having inwardly extending flanges 52 and 53, see Figs. 1, 2 and 3, to grip the edges of the limb 13 of the bracket 2. On the plate 51 there is pivotally mounted the locking plate 54 whichhas an outwardly extending gripping lip 55 and two inwardly extending prongs 56. The inwardly extending

prongs

56, 56 enter a pair of alined openings 143 and 144, see Fig. 6. Besides the outer bracket 48, this connector 6, 7 also has an inner bracket 57 having a jaw 58 to grip the inner extension 59 of the T-bar 8. This bracket 57 also has two upwardly ex-- tending flanges 60, 60 which extend through an opening in the plate 51 and abut against the limb 13. The limb 13 thus anchors the brackets 57 and 48 to one another and to the T-bar 8, and the prongs 56 of the plate 54 anchor the brackets 48 and 57 to the limb 13.

In the embodiment shown in Fig. 7 the outer bracket 61 of the connector 45 has a gripping jaw 62 to engage the outer flange 63 of the I-beam 64. This bracket 61 also has an upward extension 65 similar to the upward extension 51 of the bracket 48 which has jaws 66 to engage the edges of the limb 67 similar to the limb 13 of the embodiment illustrated in Fig. 6. The plate 65 has pivotally connected to it a plate 68, similar to the plate 54 of the embodiment illustrated in Fig. 6, which in turn has prongs 69 to engage openings in the limb 67, such as the openings 143 and 144 of the limb 13. This connector 45, however, dispenses with an inner bracket, such as the bracket 57 of the embodiment shown in Figs. 1 and 2, and relies upon the limb 67 extending down and engaging the inner flange of the I-beam 64.' In this.

69 of the plate 68 in turn connect the limb 67 to the bracket 61 and the I-beam 64.

In the embodiment shown in Fig. 9 the connector 145,

substantially identical tothe connector 45 shown inFig. 7,

relies upon the limb 71 to engage theinner face of the U-shaped'rafter 72 while the jaw engages the upper outwardly extending flange 74 of-thisra-fter 72. In'turn, the connector 145- alsohas pivotally connected toit a'plate 75 similar to the plate 54 of the embodiment illustrated in Figs. 1, 2 and 6, which has prongs 76 extending into openings formed in the limb 71 similar to the prongs 56 of the embodiment illustrated in Figs. 1, 2 and 6.

The connector 46 shown in Fig. 8 differs from the connectors 45 and 145 shown in Figs. 7 and 9 primarily in dispensing with the pivotally mounted

plates

68 and 75, respectively, the connector 46 having an upwardly extendin g portion 77 through which extend two bolts 78 and nuts 79. These bolts 78 replace the prongs 69 of the plate 68 disclosed in Fig. 7. In turn the two bolts 78 enter a pair of openings in the limb 80, such as a pair of openings 143 and 144 disclosed in Fig. 6. Preferably the bolts 78 yieldably connect the upwardly extending portion 77 of the connector 46 to the limb 80 by having a coil spring 81 wound around the shank of the bolt 78 and tensed between the upwardly extending portion 77 and the nut 79. Preferably as shown, the head of the bolt 78 engages the inner face of the limb 80 and the spring 81 engages the outer face of the upwardly extending portion 77 of the connector 46. The connector 46 in the present instance has a jaw 82 larger than the jaw 62 of the connector 45 to engage the outer extension 83 of the U-shaped rafter 84. In assembled position as shown the limb 80 extends down on the inside of the inner extension 85 of the rafter 84 so that the bolts 78 not only connect the upwardly extending portion 77 to the limb 80, but also anchor the jaw 82 and the limb 80 to the rafter 84.

The connector 47 shown in Fig. 10, similar to the connector 46 shown in Fig. 8 dispenses with the pivotally mounted plate of the connector 45 shown in Fig. 7. In this embodiment the connector 47 consists of a plate 86 having a jaw 87 at its lower end to engage the lower.

extension 88 of the rafter 89. The limb 90 engages the inner face of the arm 91 of the rafter 89. The plate 86 is provided with two bolts 92 similar to the bolts 78 shown in Fig. 8 which extend through a pair of openings in the plate 86 and into a pair of openings in the limb 90 similar to a pair of openings 143, 144 in the limb 13 illustrated in Fig. 6. The heads of the bolts 92 engage the inner face of the limb 90. The bolts 92 in turn have nuts 93 on their outer ends between which and the plate 86 are tensed the springs 94. Here, somewhat like the disclosure of Fig. 8, the bolts 92 not only connect the plate 86 to the limb 90 but anchor the connector 47 and limb 90 to the rafter 89 by the engagement of the extension 88 of the rafter 89 by the jaw 87 and by the engagement of the inner face of the plate 91 of the rafter 89 by the limb 90.

Obviously two or more supports, each including a bridge 1, brackets 2 and 3, links 4 and 5, and connectors 6 and 7, will ordinarily be required to support an average lighting fixture, and the hook formations at the lower ends of the links 4 and constituting the direct supporting engagement may assume formations other than the hook formations without departing from the general spirit of the invention.

It is obvious that various changes and modifications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

I claim:

1. The combination of a support for a fluorescent lighting fixture having a trotfer, with two parallel horizontally extending rafters, said support including a metal one-piece upwardly arched bridge having upwardly extending reenforcing flanges at the longitudinally extending edges thereof, two L-shaped brackets extending toward one another, each having a horizontally extending limb and va downwardly extendinglimb, the ends of the bridge being slidably mounted on said horizontally extending limbs, means fixing said bridge in adjusted position on the horizontally extending limbs of said brackets, a row of openings extending longitudinally on said downwardly extending limbs, two connectors, each connector attached to and securing one of said downwardly extending limbs to one of said rafters, means on said connectors entering one of the openings in said downwardly extending limbs to support the trolfer at the horizontal level corresponding to the opening selected, depending links pivotally connected to said bridge adjacent the ends thereof between said brackets and including projections beneath said bridge, a spring mounted on each link tensed between one of said projections and said bridge and normally urging said link to incline in wardly, and a portion at the lower end of each of said links in supporting engagement with opposite sides of said troffer.

2. The combination of a support for a fluorescent lighting fixture having a trofier, with two parallel horizontally extending rafters, said support including a bridge having a main portion, two horizontally extending outer ends and outwardly extending and downwardly inclined portions intermediate said main portion and said horizontally extending outer ends, two brackets having inwardly extending limbsQthe outwardly extending outer ends of said bridge resting upon and slidably mounted into adjusted position upon said inwardly extending limbs, means fixing said bridge in such adjusted position on said inwardly extending limbs, two connectors, each connector. attached to and securing one of said brackets to one of said rafters, depending links pivotally connected to the inclined portions of said bridge, a lip on each of said links extending above the inclined portionsof said bridge, a projection on each link beneath said bridge, a spring mounted on each link and tensed between its projection and said bridge normally urging the lip of each link into engagement with its adjacent inclined portion in turn normally to incline its link inwardly, and means at the lower ends of said links extending toward one another into supporting engagement with opposite sides of said troifer, said links being deflected outwardly by said lighting fixture in opposition to said springs when the lighting fixture is raised into supporting position and thereby positioning the lower ends of said links into supporting engagement with said troffer.

3. The combination of a support for a fluorescent lighting fixture having a troffer, with two parallel horizontally extending rafters, said support including a one-piece metal bridge having a main portion, horizontally extending ends and outwardly and downwardly inclined portions intermediate said main portion and said horizontally extending ends, two brackets each having an inwardly horizontally extending limb and a downwardly extending limb, the horizontally extending ends of said bridge resting upon, and slidably mounted into adjusted position on said horizontally extending limbs, means fixing said bridge in such adjusted position on said horizontally extending limbs, two connectors, each connector attached to one of said rafters, means adjustably connecting said connectors to said downwardly extending limbs in a vertical direction to assume a predetermined horizontal level, depending links extending through. said bridge, lips on said links extending across the downwardly inclined portions of said bridge, projections on said links beneath said bridge, springs on said links tensed between said projections and said bridge and normally urging said lips to cooperate with said downwardly inclined portions of said bridge to incline said links inwardly, and hook formations at the lower ends of said links extending toward one another, said springs enabling said links to be deflected outwardly when said lighting fixture is raised into engagement with the same and urging said hook forma- .tul'e when position.

tion s into supporting engagement with said lighting fixsaid lighting fixture is raised into supporting References Cited in the file of this patent -8 Walker et a1. Mar. 9,:1943 Terr Feb.. 15,11949 i Neysmith Mar. 1 ,1949 Kruger 'May 27, v 1952 Janness June 16, 1953