US2969217A - Fixture hangers - Google Patents

Description

Jan. 24, 1961 J. w. POTTER 2,969,217

FIXTURE HANGERS Original Filed Oct. 7, 1954 3 Sheets-Sheet 1 5 Z3 3/ l V Jan. 24, 1961 J. w. POTTER 2,969,217

FIXTURE HANGERS Original Filed Oct. 7, 1954 3 Sheets-Sheet 2 Jan. 24, 1961 J- w. POTTER 2,969,217

FIXTURE HANGERS Original Filed Oct. 7, 1954 3 She'ets-Sheet 3 ates Patnt O C Patented Jan. 24, 19st Fig. 2 is' an enlarged section taken on the line 2--2 2,969,217 of Fig. 1;

FIXTURE HANGERS James W. Potter, Urbana, Original application Oct. 7, 1954, Ser. No. 460,941, new Patent No. 2,838,832, dated June 17, 1958. Divided and this application Apr. 11,1958, Se!- No. 727,829 1 Claim. (Cl. 248-205) This invention relates to hanging lighting fixtures, and more particularly to fixture hangers of the character CllS- closed in my copending application, Serial No. 460,941, filed October 7, 1954, now Patent No. 2,838,832, of which this is a division.

It will be understood that a joist type of ceiling structure is encountered in most buildings, and that the pattern for placement of lighting fixtures usually bears no relationship to the location of the joists, although it is generally necessary to support the lighting fixtures from the joists. The architectural plans specify the location of the fixtures by reference only to the perimeter of the ceiling, with the result that the hangers may be located at points between the joists. It will be apparent that it is ditficult to locate a point on the openwork ceiling structure, hence the installation of the ceiling fixtures is a tedious, awkward job, requiring much measuring, checking and manipulation of parts and equipment. Moreover, in oflice and public buildings where metal bar joists are customarily utilized, some difiiculty is experienced in attaching the fixture hangers to the joists.

The aforementioned divisional application discloses and claims a method of locating fixture hangers by means of a jig. This disclosure is more specifically directed to certain brackets and connecting bars for conveniently securing the hanger to the ceiling joists in proper positions between the joists.

In the attainment of this objective, briefly stated, an elongate jig is employed so as temporarily to hold a plurality of short, joist-bridging bars, at points corresponding to the placement of fixture hanger rods. While so temporarily held, these bars are fastened to the joists. The fixture hanger rods are then secured to the joists by means of brackets.

More particularly, joist-bridging bars are temporarily supported upon the several supports of the jig in position to bridge an adjacent pair of joists. While so supported against or closely adjacent the joists, the bars are secured thereto, preferably using a powder-actuated tool which drives a fastener through the ends of the bar and into the lower portions of the joists. Before removal of the jig, C-shaped clamping brackets are then utilized to secure the hanger rods. In one form, the bar is a channel member having slots extending substantially the entire length I along the center web thereof, which slots intersect with the slot in a jig-mounted bar-supporting element. Each of these clamping brackets has legs which reach over the top and bottom of the channel member, and these legs have openings which align with the slots in the bar. A fixture hanger rod is then inserted through the several openings of the clamping bracket, bar and bar support, and a set screw on the head of the clamp is screwed against one side of the bar to clamp the hanger tightly to the bar. The open slot on the bar-supporting element then permits the jig to be withdrawn sidewise clear of the secured parts. Other shapes of bars and hanger clamping brackets may be employed, however.

Other features of the invention will be in part apparent from and in part pointed out in the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a bottom plan view of a ceiling, illustrating features of this invention;

Fig. 3 is a section taken on the line 3--3 of 2; Fig. 4 is a sectional view on the line 4-4 of Fig. 3;

Fig. 5 is an oblique view of the jig shown in Figs. 2-4,.

prior to installation of the joist-bridging bars;

Fig. 6 is a view similar to that of Fig. 5, but showing ii v joist-bridging bar supported on the jig;

Fig. 7 is a view similar to that of Fig. 6 after attach ment of a fixture hanger rod;

Fig. 8 is a view similar to that of Fig. 7 after removal? of the jig;

Fig. 9 is an oblique view of a bar-supporting element of the jig;

Fig. 10 is an oblique view of a hanger rod clamp;

Fig. 11 is a view similar to that of Fig. 7, but illustrating an alternative form of joist-bridging bar; and

Fig. 12 is a cross-sectional view taken on the line 1212 of Fig. 11.

In many buildings, the ceilings are formed with a series of joists which constitute the principal load-sustaining portion of the ceiling. In installing ceiling lighting facili-' ties, it is usually necessary to suspend the luminaries from these joists, and when the hangers therefor are to be located between the joists, it is customary to bridge the joists with bars, the hangers being secured to these bars. Heretofore, this has not been a simple task. It has been necessary to locate the positions of the joist-bridging bars by measurements across the openwork ceilings. After the bars are located and are secured to the joists, it has been necessary to remeasure and locate the points on the bars where the fixture hangers are to be attached. Brackets 'were then attached to the bars in proper positions, and

the fixture hanging rods were cut or otherwise adjusted to proper length and secured to the brackets.

Referring now to the drawings, there is shown a ceiling,

the load-supporting portion of which is constituted by a Series of joists 1. In large buildings, such as used for commercial and public purposes, steel bar joists customarilv form this portion of the celing, such bar joists com prising flange-forming angle sections 3 and an open center web of bars 4. The ceiling lighting fixtures are supported from these joists by depending hangers, which are installed prior to closing over the ceiling with acoustical tile, gypsum board and the like. Where fluorescent lighting fixtures are utilized, it is customary to arrange them in rows, the hanger rods being spaced at four footintervals as indicated at X, this being a standard length for fluorescent luminaries.

The invention contemplates that the installation of the hanger rods will be made using an elongate jig generally designated 5, which may be made up from a plurality of sections of a conveniently handled length. For example, each section of the jig might be eight feet long and approximately one inch by one-half inch in crosssection. These" sections can be of a three-piece laminated construction, the center ply 7 thereof projecting atone end.

beyond the outer strips 9, and the outer strips projecting at the other end beyond the center ply, in order to provide for a tongue and slot connection of the several sections.

is threaded a set screw 19. Webs 21 project from the sides 17 over the top and bottom surfaces of the jig 5, and flanges 23 extend inwardly from the webs 21 over Also, the center ply 7 may project at one side- 11 slightly beyond the outer strips 9. Screws 13 are uti th'other side of the jig toward the lip 11 thereof. In

addition, a leg 25 projects outwardly from the side 23 of; the element at the bottom thereof, this leg -25 being slotted at 27 in a direction transverse to the jig.

In use, the jig is first laid out upon the floor of the room'in which fixtures are to be ins-ta'led, the jig extending in a direction transverse to the joistsl along a line defining the positions X of one row of fixture hanger rods. One end of the jig is aligned withone end of the room or ceiling, and the bar-supporting elements 15 are adjusted and secured by means of set screws '19 in positions With their'several slots 27 corresponding to the locations X of the fixture hanger rods, as measured from that 'end'of the room. Inasmuch as the locations of the fixtures are specified in the, architectural plans by reference 'to the perimeter of the room, it is a simple matter to determine the positions of the'bar-supporting elements as the'jig rests upon thefioor. y

The jigis then-elevated to the ceiling level and is temporari'y secured against the lower surfaces of the joists, as by C-clamps 23. It will be understood that the jig is aligned so that the centers of the slots 27 in the bar-supporting elements 15 lie on a line defining a rw of ffixture's, the positions of the hanger rods along this rown'ecessarily being determined by the slots 27. In its secured position, the jig supports a plurality of joistbridging bars generally designated 29, one form of which is shown in Figs. 28 to be a channel section.

Each of these bars 291s of a length sufficient to bridge a pair of joists '(a length of two and one-half feet being satisfactory for most installations), and the center Web thereof is formed with elongate slots 30 for accommodatinga fixture hanger rod at substantially any point between the joists. The 'exact position of the bar 29 isnot critical, provided the ends thereof overlap a pair of jofi'sts and one of the longitudinal slots 30 lies in intersecting relationship with the slot 27 in the b-arsupporting element 15, thereby predetermining the posit'ons of hanger-rods 31. While so supported, the several joistbridging bars '29 are fastened to the joists, and-thefixture hanging rods 31 are secured to these bars.

hangers 31 are attached to thebars 29 by means offU-shaped brackets generaly designated 33. As best shown in Fig. 10, the brackets 33 have a side or base portion 35 in which a set screw 37 is threaded. The prbjectinglegs 39 of the bracket are spaced to' extend acrossthe top and bottom of a joist-bridging bar- 29. and th'e'legs 38 are apertured at 39 to receive a fixture hangingrod 31.

, Although different sequences of steps may be followed in assembling the components, the recommended procedure involves fittin brackets 33 over the joist-bridging bars 29, inserting fixture hanging rods 31 through the openings defined at 3% and 3S, and temporarily tightening the set screws 37 so that the rods 31 become clamped between the brackets 33 and bars 2%.

Several such bars are fitted to the jig prior to its elevation and positioning against the joists, the brackets- 33 resting upon the supports 25, and the rods 31 being received in the slots 27. Upon secure'rnent of the jig against the joists, bars 29 are held in position by lateral engagement with the projecting side portion 11 of the jig and by engagement with the lower surfaces of the joists 1. As ilustrated in Fig. 2, the thickness of the bracket 33 and bar 29 are such that when the jig is clamped against the joists, the upper surfaces ofthe bars engage with the lower surfaces of the joists. Should the initial positioning of a bracket 33 on a bar 29 be such as to prevent the bar from overlapping a pair of joists, the set screw 37 may be loosened, the bar slipped 1ongitudinally over the support 25 to proper position, the set screw 37 then being tightened. The set screws 37 also facilitate vertical adjustment of the hangers 31 so that the bases 39 thereof are at proper elevation. I

The installation is completed by securing the bars 29 to the joists, this attachment preferably being "accomplished by means of penetrating fasteners 41, which are driven with a powder-actuated tool. Once the bars are fastened at the joists, the jig .may be removed, the slots 27 in the bar supports. permitting lateral Withdrawal of the jig. A second rowf of fixture hanger rods may then be installed, and in most-instances it will not be necessary to readjust the positions of the elements 15.

Whereas Figs. 110" illustrate a joist-bridging bar which is in the form of a slotted channel member, other forms might be utilized. For example, Figs. 11 and 12 show a bar 129 formed from a fiat strip, an elongate center portion 130 thereof being double-folded at right angles to the relatively short end portions 132. A U- shaped clamping bracket 133 is employed in attaching the hanger rods to the bar 129 in the manner described heretofore; but in this instance, the hanger rod 131 is held against one side of the-elongate vertical center web 130 of'the bar 129 by the bracket133.

The arrangement ofFigsi' 11 and 12 is somewhat advanta'g'eous inthat very little of theb-ar 129 projects below thejoists; It is necessary, however, to thicken the bar supports 125, so that the end-portions 132 of the bar sat against the lower surfaces of the joists. When the jig is to be used for installing-both types of joist-bridgingbars, filler blocks 126 would be provided for removable attachment to the supports 125, these blocks being secured on opposite sides of the slot in the support.

Otherwise, the adjustable elements 115 and the jig are identical to those described heretofore.

In'addition, Fig. 11 illustrates an alternative arrange ment, whereby wires 141'are'utiliz'ed to secure-the'bridg ing bars to the joists.

From the above,it will be apparent that the invention considerablysimplifies the-task of placing and-attaching fixture hangerrods to an 'openwork ceiling structure, such as that formed by a series of joists. Most of the m'easur ing and assembly work can be carried outat' floor level,

the apparatus not only holding the parts in position dur ing attachment of the bridgingbars to the joists, but also serving to locate th'e fixture hanging rodsand facilitate" their attachment to the joist-bridging bars.

Althoughseveral embodiments have been disclosed in detail, it is to be understood thatthe invention is'not limited thereto, but the drawings and description thereof are to be understood as being merely illustrative. It is realized that many modifications and variations will present'thernselves to those skilled in the art Without'departing from the spirit' of this" invention or the scope the of as 'set forth in the appended claim.-

H'aving thus described the invention, What isclaimed andde sired to be secured by Letters Patent is:

An apparatus for attaching a lighting fixture rod in an open joist ceiling structure comprising incornbination a barbridging at-least two ofthe said joists, said bar containing longitudinal elongated apertures more than su'fficient to receivethe s'aid'rcd and allow same" to be ad-' jus'table longitudinally with respectto said bar, said elongated apertures being evenly spaced throughout the length of 'said'bar, a C-shaped clamp havingopenings in the legs thereof suflicient to receive the said rod, the clamp being so mounted as to "embrace the bar and substantially align the openings thereof with portions of the elongated apertures of the bar, said clampcontaining anadjustable member to secure-the 'rod and bar at any desired POSlIIOll.

References Cited in the file of this patent UNITED STATES PATENTS 843,375 Thompson Feb. 5, 1907 2,208,358 Chandler July 16, 1940' 2,529,173 Moyer Nov. 7, 1950' 2,670,917 Hoffman Mar'. 2, 1954 2,691,720 Si'mmons- Oct. 12, 1954 2,763,521 Fuge Sept.- 18', 1956" 2,770,436 Linhardt Nov. 13, 1956

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