US2580540A - Suspended ceiling with recessed lighting fixture - Google Patents

Description

SUSPENDED CEILING WITH RECESSED LIGHTING FIXTURE Filed Feb. 6, 1947 C. R. GRAVES Jan. 1, 1952 2 SHEETS-SHEET l w m m 7% & aim w m M m 5 w & Q 5.

' HIS ATTORNEYS.

Jan. 1, 1952 c. R. GRAVES 2,580,540

SUSPENDED CEILING WITH RECESSED LIGHTING FIXTURE Filed Feb. 6, 1947 2 SHEETS-SHEET 2 FIG.2. 5

HIS ATTORNEYS.

Patented Jan. 1, 1952 r UNITED STATES PATENT OFFICE SUSPEND%ECESSED Charles R Graves, Eureka, Mt, assignor to Day- Br'ite Lighting, Inc., St. Louis, Mo., a corporation of Missouri Application February 6, 1947, serial No. 726,809

V Claims. I

T is-invention relates to plaster ceilings of the kind'jthat are suspended from a metal flooring and have openings for electric lighting fixtures that are also suspended from said metal flooring. A serious objection to the above con struction is that in the event of fire the heat passes through the sheet metal fi ture housings and warps or otherwise damagejsthe metal floors ing and renders it unfit for further service; a and there is also the danger or the fixtures fallin and injuring persons or damaging objects lo-= cateu jtherehemw, The present invention has for its principal object to provide a simple and economical ceiling construction of the above type that will overcome (the objections above pointedout. The invention consists in the sus= pended ceiling and lighting fixture construction and in "the arts and combinations and arrange ments of parts hereinafter described and manned. In the accompan ing drawin s; which form part of this specification, and wherein like symbols refer to like arts wherever they occur,

1 is a fragmentary vertical sectional view of a floor-suspended ceiling and electric lighting fixture construction embodying my invention, the fixture and closure slab being shown in normal position.

Fig. 2 is a view similar to Fig. 1, showing the fixture and closure slab in released position,

Fig. 3 is a fragmentary vertical longitudinal sectional view on the line 3 3 in Fig. 2,

Fig. 4 is a perspective view of the closure slab; and

- Fig. 5 is a perspective view of the fusible fixture supporting plate.

As shown in the accompanying drawings, a ceiling l of plaster or other fireproof material is applied to the underside of metal lathingu2 that is "laced to the undersid'es of horizontal furring channels 3 which, in turn, are laced to horizontal runner channels 4 that extend across said furring channels and are suspended by means of wires 5 from a common type of sheet metal flooring 6 of hollow box-girder section provided with a concrete fioor covering 1. The furring channels 3 are cut away to accommodate and support a metal plaster frame 8 of angleshaped. cross-section; and the plaster ceiling I is laid up against said frame around the four sides thereof fiush with the lower edge thereof to provide an opening 9 in said ceiling for an elongated metal fluorescent electric lighting fix ture housing [0. The fixture housing In extends upwardly into the space between the plaster ceiling i and the metal flooring 6 and has out- 2 t standing base flanges II that seat against the underside of said ceiling around the opening defined therein by the metal plaster frame 8. g The elongated fixture housing [0 is suspended from the metal flooring 6 preferably by means of upright metal rods l2 whose upper ends are anchored in the metal floor B and whose lower ends are anchored in the top wall of said housing adjacent to the ends thereof. The lower end of each of the suspension rods 12 extends through arel'atively large circular opening lit in the top wall of the fixture housing l0 and has a nut H threaded o'n itslower end adapted to pass freely through said opening. Sleeved on the rod I2 is a crp'ss plate or hanger I5 which is made of metal or other suitable material which fuses at a com paratively low heat. The fusible plate I5 is supported by the nut I 4 on the lower end of the rod 12 and extends crosswise of the housing I!) beneath the top wall thereof so as to constitute a support therefor on o posite sides of the opening therein. The nut 14 is adjustable on the rod 12 so as to seat the base flanges ll of the housing [0 against the underside of the plaster ceiling I around the opening 9 defined therein by the plaster frame 8. The housing supporting plate 15 has an upstanding central circular boss l6, which fits opening 13 in the top wall of the housing ['0 and upstanding lugs 11 that fit in openings in said top wall and prevent relative rotary movement of said plate and housing. Each suspension rod 12 is also provided with a second, normally inoperative housing support comprising a flexible member preferably in the form of a loose chain I 8 having one end fixed to each said rod between the metal flooring 8 and the housing 10 and the other end fixed in an opening 19in the top of'said housingadjacentto'said'i'od. i

Seated in the top of the fixture housing '9 is a preformed slab 2B of plaster or other fireproof material which is made larger than the ceiling opening 9 so as to overhang the ceiling l on all sides of said openingv The plaster slab 20 has a vertical openin 2| extending therethrough for each of the vertical suspension rods I! for the fixture housing I0, said opening being large enough to receive the upstanding central boss N5 of the fusible hanger plate [5 and the hanger chain I8 on said rod and to permit the rod, nut l4 and chain to slide freely through said opening when the housing supporting plate l5 fuses due to heat in the event of fire.

With the above arrangement, in the event of fire, the heat passing through the thin sheet metal fixture housing 10 melts the fusible hanger plate l5, thus releasing said housing and permitting it to drop under its own weight and under the weight of the slab 20 through the opening 9 in the plaster ceiling I. At the same time, the plaster slab 20 also drops under its own weight with the fixture housing I!) and seats on the plaster ceiling I around the fixture receiving opening 9 therein, thereby closing said opening and preventing the heat and flames from passing upwardly therethrough and damaging the metal flooring 6 thereabove. The downward movement of the fixture housing is arrested when the chain hangers l8 become taut, thus preventing said housing from falling and injuring per- 4. In a beam supported flooring structure having an apertured ceiling suspended therefrom in spaced relation to define a fire and heat protective zone below the flooring structure, the improvement which consists in a lighting fixture fitting into the ceiling aperture, a fixture suspending rod having one end connected with the flooring structure and its opposite end projecting into said fixture, a fusible element adapted for connecting said fixture with said suspending rod, said fusible element releasing the fixture from the ceiling aperture upon a predetermined I low temperature in the area below the ceiling sons or damaging objects located therebelow.- I

The chain hangers I8 are of sufiicient length to support the released fixture housing l0 just below and clear of the lowered plaster closure slab and said chain hanger also servesto guide said slab to closed position.

Obviously, the hereinbefore described construction admits of considerable modification without departing from the invention. Therefore, I do not wish to be limited to. the precise arrangements shown and described.

- What I claim is:

1. In a beam supported flooring structure having an apertured ceiling suspended therefrom in spaced relation to define a fire and heat protective zone below the flooring structure, the improvement which consists in a lighting fixture fitting into the ceiling aperture, fixture suspending means connected with the flooring structure, a fusible element adapted for connecting saidfixture with said suspending means, said fusible element releasing the fixture from the ceiling aperture upon a predetermined low temperature in the area below the ceiling reaching the fusible element to cause it to melt, and a fire and heat resistant closure normally supported on and above the ceiling aperture by said fixture, said closure moving over the ceiling aperture upon release of said fixture.

2. The improvement set forth in claim 1,

wherein flexible auxiliary hanger means is operatively connected between said fixture suspending means and said fixture, said hanger means suspending said fixture below the ceiling aperture following melting of said fusible element. 3. The improvement set forth in claim 1, wherein said closure rests upon said fixture and is formed with an opening, said suspending means extends through the opening in said closure, and auxiliary supporting means interconnecting said fixture and suspension means through the opening in said closure, said auxiliary means supporting said fixture below the ceiling opening.

reaching the fusible element to cause it to melt, and a fire and heat resistant closure formed with an opening to receive said rod and permit placement of the closure over said fixture, said closure being normally supported on and above the ceiling aperture by said fixture and moving over the ceiling aperture upon release of said fixture. 5. -In a beam supportedfiooring structure having an apertured ceiling suspended therefrom in spaced relation to define a fire and heat protective zone below the flooring structure, the improvement which consists in a lighting. fixture fitting into the ceiling aperture, a substantially rigid .fixture suspending member connected 'with the flooring structure and having one end'projecting into said fixture, a fusible element adapted for connecting said fixture with said suspending member, said fusible element being releasably retained over said one end of said rigid member to support said fixture, the fusible element releasing the fixture from the ceiling apertureupon a predetermined low temperature in the area below the ceiling reaching the fusible element to cause it to melt, and a fire and heat resistant closure normally resting upon. and maintained. above. the ceiling aperture by said fixture, said closuremoving over the ceiling aperture upon release of said fixture by said fusible element.

CHARLES R. GRAVES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS I OTHER REFERENCES Sweets Catalogue filesec.'249, mounting bracket #7130, 1942-.

Images