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Publication numberUS1815447 A
Publication typeGrant
Publication date21 Jul 1931
Filing date13 Mar 1929
Priority date13 Mar 1929
Publication numberUS 1815447 A, US 1815447A, US-A-1815447, US1815447 A, US1815447A
InventorsRichardson Henry F
Original AssigneeA M Cregier, Allan Coggeshall, Alonzo B Bradley, Richardson Henry F, S R Bradley
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Underfloor wiring duct system
US 1815447 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

July 21, 1931. H. F. RICHARDSON 1,815,447

UNDERFLOOR WIRING DUCT SYSTEM Filed March 13. 1929 2 Sheets-Sheet 1 wmv E55 J y 21, 931- H. F. RICHARDSON 1,815,447



This invention relates to underfloor ducts for electrical conductors and has particular reference to buildings in which the flooring and ceiling supported by steel girders either resting on masonry walls or forming part of a steel structural building. In modern steel building construction, a concrete floor covering overlies the steel floor girders and underfloor ducts are often embedded therein and supported thereby. By placing the girders nearer together, it has been possible to materially reduce the thickness of the floor covering and thus reduce the overall thickness of floor and girder, but in doing this, the covering becomes too thin to permit of ducts of practicable size being embedded therein. In the present invention the necessity of embedding the ducts in the concrete floor covering is obviated by making the ducts an extension or part of the girders themselves, so that instead of the floor covering supporting the ducts, the floor or ceiling rests directly on the ducts and is supported thereby. I incorporate these steel ducts more or less intimately with the floor girders or with enough of them to give the desired distribution. In this way the duct may be made of any capacity without encroaching on the floor section, and it may not require separate laying as the placing of the girder may simultaneously establish the duct in the right place and in the proper alignment.

Other details and advantages will be described with reference to the accompanying drawings illustrating various embodiments of the invention, and in which Figure 1 is a plan view of the floor girders of a building.

Figure 2 is a vertical section on the line 22 of Figure 1.

- Figure 3 is a perspective view of one form of girder.

Figure 4 is a plan view partially in section showing the junction of two girders.

Figure 5 is a transverse section of a girder of the form shown in Figure 8, in line 5-5 of Figure 1, with the superposed flooring.

Figure 6 is a similar View of a transverse girder on line 6-6 of Figure 1.

Figures 7 and 8 are plan views of certain arrangements of girders and ducts.

Flgure 9 is a vertical section on line 9-9 of Flgure 8 showing an assembly of transverse truss girders on longitudinal I-beams.

Flgure 10 is a vertical section through the floor of a building showing a part of a longitudmal girder in side elevation.

F gures 11 and 12 are modified forms that my mproved girder may take.

F1gure 13 is a perspective view showing a glrder with a duct in both the upper and lower flange members.

Referring first to Figure 1, there is shownat 1 longitudinal girders supported on pillars 2. Upon these girders rest the ends of transverse glrders 3 in the well-known manner of constructing steel buildings.- As shown in Figure 3, the upper stress member of the glrder has its flanges 4 rolled in L or Z shape to form a longitudinal channel in the top of the beam. The flange 4 may have lip flanges 5 formed thereon providing at the upper ins1de edges of the channel, recesses 6 which may form seats for a longitudinal cover plate 7 (see Figures 1 and 5). The transverse beams 3 may be of the same general construction as the longitudinal beams 1, although they may be of smaller dimensions (compare Figure 6 with Figure ,5). Where the transverse beams meet the longitudinal beams, I provide orifices 8 in the vertical sides of the flanges 4 to furnish communication between the channels of the longitudinal girder and of the transverse girders. Not all of the transverse girders need be provided with ducts. As shown in Figure 1, two girders 9 having no ducts may be spaced between the duct girders. As is customary, the steel floor girders form only a framework upon which a flooring of some kind is supported, this flooring generally being of concrete, such as shown at 10, Figures 2, 5 and 6. At the junctions of the longitudinal and transverse channel girders, outlet boxes 11 are supported on the girders and rise to a level with the floor surface where they may have a proper outlet cover 12. These outlet boxes may fit within the recesses 6 between the ends of the cover plates 7 (Figure 1), thus forming a substantial steel to steel construction. The girders may take the form of a truss 13 as shown in Figure 9 where the longitudinal girder is of the usual I-bcam form and the transverse girders are of the open truss-work form with a channel duct rolled integral with their upper stress member forming a box-like stress member of great strength. Here a modified form of construction is shown in which a duct 15 is laid along the longitudinal I-beam on top of its top flange, the duct in this case being manufactured separate from the girder and only associated with it in the assembly of the building. \Vhen so assembled, however, it forms practically an extension of the girder for supporting the floor covering and is itself firmly supported throughout its length. Such a construction is shown in Figure 11 in cross-section with the supplemental duct 15 riveted to the top flanges of the I-beam, but I regard it within the scope of my invention to have the duct- 15 merely laid on the I-beam as shown in Figure 12. IVhcther made integral with the girder or built upon the girder, the duct must be made strong enough to support the floor and any loading thereof In certain parts of the floor as shown in Figure 7, a connection 14 in the form of a tube may be used to connect the outlet boxes in place of supplement duct 15.

In Figure 8 is shown a box-like duct 16 which is enclosed at top and co'mmunicates at its ends with covered outlet boxes 11.

It will be observed with reference to F igure 13 of the drawings that applicant may provide the wire receiving ducts in both the upper and lower stress members of the girders. It is obvious that when using the girders with ducts in their lower stress members, access to the intercommunicating girder ducts can be conveniently provided through the enclosing ceiling covering which extends over the ducts, whether above or below or both, in the same manner as above described with specific reference to the floor coverings. The expressions employed in the claims such as enclosing covering or floor or floor-like covering are intended to cover a floor, a ceiling or other building wall or partition, sup ported above or below the girder ducts having the defined characteristics of the invention.

It will be seen that the duct walls become really an extension of the girder and that the weight of the floor is transferred to the girder through them. As the ducts do not encroach on the space allotted to the floor covering, they may be made as large as desired. The ducts are laid in place in the ordinary process of erecting the steel and do not require many if any separate operations.

I claim 1. In an underfloor system of building construction, the combination of a longitudinal girder carrying a wire-receiving duct, transverse girders carrying wire-receiving ducts supported at their ends upon said longitudinal girder with their ducts in communication with the duct of the longitudinal girder, a floor-like covering supported upon said girders and extending over said communicating ducts, outlet boxes opening from said ducts at the points of communication of the transverse girder duets with the longitudinal girder duct, said outlet boxes extending through the floor-like covering.

2. A floor girder, a reinforcing metallic duct forming part of the girder, said duct having side walls with recessed lateral flanges at their upper edges, and a cover plate adapted to fit in said recesses.

3. A floor girder construction comprising a main girder member, reinforcing flange members forming a wire'duct, said flanges having recesses in their outer edges, a cover plate adapted to fit into said recesses and form a top for the duct, and outlet boxes adapted to fit into said recesses between the ends of the cover plates and extend upward to the floor level.

4. A floor girder construction comprising a longitudinal girder having a wire duct at its upper part, transverse girders with ducts in their upper members, the ends of which rest on the said longitudinal girder, outlet boxes interposed in said wire duct on the main girder at the ends of the transverse girders, and openings through the sides of the said outlet boxes into the ducts.

5. A floor construction comprising an interconnected system of floor girders having vertical webs with intercommunicating wiring conduits extending along a horizontal edge thereof and constituting a part of the vertical load support for the floor.

6. An underfloor wiring duct system comprising floor girders having open channels on their upper edges formed as part of the vertical stress members of the girders, the channels of the several girders interconnected to form a continuous conduit for wires, appli cable covers for said channels, floor material supported on said covers, and outlets connecting with the channels and embedded in the floor material.

7. A combined flooring and underfloor duct system comprising floor girders whose vertical stress members are partly formed by the walls of ducts or conduits for wires extending in the vertical plane of and above the body of the girder, and applicable covers for said ducts or conduits, the ducts or conduits of the several girders having connection with each other to form a continuous wire duct system extending throughout the structure and within the vertical dimensions of the said girders.

8. A combined structural frame and wire duct system for buildings, comprising floor girders constructed and supported to resist vertical stresses and having ducts at their upper edges below but adjacent to the floor surface, the ducts of the several girders being in communication to provide a continuous system of ducts for wires all contained within the vertical dimensions of the vertical stress resistant members of the building frame.

9. A combined floor structure and wiring 1o duct comprising girders whose vertical stress members have vertical extensions forming ducts for wires accessible through the material covering the girders, said ducts of the several girders being interconnected to form a wire duct system, and their lateral walls forming a part of the support of the vertical load on the girder as a whole.

10. A system of building construction, comprising floor girders so mounted as to resist vertical stresses, and having upwardly open channels on their upper edges, to afford passage for wires, applicable covers for said no channels, a flooring carried by said girders and covers, second floor girders similarly mounted and channeled, intersecting with the first and having passages connecting the channels of the one set of girders with those of the other, and outlets positioned over the channels and 'embedded' in the floor mate- 80 rial.

11. A floor construction for buildings, comprising vertically webbed floor girders having open channels on their upper edges close to but below the surface of the floor mate- 86 rial, and a second set of floor girders intersect ing therewith and similarly channeled, the channels of the two sets of girders having communicating passages to connect the whole into an electric wire duct system.

40 v 12. In a flooring construction, the combinadesired.

tion of a girder having an open channel to receive electric wires, cover plates for sealing the open channel and supporting the floor material and outlets embedded in the floor 46 material and communicating with said channel. v

13. In a flooring1 construction, the combination of a girder aving an open channel to receive electric wires, and an intersecting 60 irder similarly channeled, said girders having passageways provided. between their channels to afford passage of wires from the channel of one to that of the other.

14. A combined floor and duct structure having floor girders whose vertical stress members comprise ducts for wires, the ducts of the several. girders interconnected to form a connected system directly contiguousto the horizontal surface through which access is- HENRY RICHARDSON.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2905285 *27 Dec 195622 Sep 1959Ceco Steel Products CorpSplice sleeves for connecting electrochannel joists
US3001001 *2 Jun 195819 Sep 1961Tok Products CoLight fixture for suspended grid ceiling
US3336708 *16 Nov 196422 Aug 1967Rambelle Robert DShoring member for use as temporary support of concrete slabs
US3453791 *18 Oct 19678 Jul 1969Robertson Co H HUnderfloor electrical raceway crossover unit
US3894370 *30 Aug 197415 Jul 1975Parazader StephenReinforced structures incorporating strip deck material
US5065556 *15 May 199019 Nov 1991Westinghouse Electric Corp.Space dividing partition system having an electrical raceway
US6922949 *18 Apr 20032 Aug 2005Steelcase Development CorporationFurniture system
US20030200704 *18 Apr 200330 Oct 2003Steelcase Development CorporationFurniture system
U.S. Classification52/220.1, 174/486
International ClassificationE04B5/48
Cooperative ClassificationE04B5/48
European ClassificationE04B5/48