US2073490A - Underfloor duct system - Google Patents

Description

Marsh Q, 3193?, J, W. LEWIN UNDERFLOOR DUCT SYSTEM Filed Nov. 23, 1954 2 Sheets-Sheet l March 9p 1937. 1 W LEWIN UNDERFLOOR DUCT SYSTEM Filed Nov. 23, 1934 2 Sheets-Sheet 2 Z m 4 j. w L/ j wf ,WHW w@ w H f Patented Mar. 9, 1937 UNITED s'rares PATENT OFFICE 2l Claims.

This invention relates to underflocr duct systems, and more particularly to duct or conduit systems for the electrical wiring of large oiiice, mercantile, and manufacturing buildings, such 5 Systems preferably being adapted for installation in buildings during the course of their construction.

In buildings of this type, wherein multiple occupancy is inherent from the character of the l0 building, great flexibility is required in such wiring systems in order to meet the various needs and desires of a large number of tenants, and these needs and requirements are constantly changing as the tenancy of the building changes. l5 It is obvious that the wiring requirements for lighting, telephone service, electrical devices and other electrical apparatus necessitate an elaborate wiring system which can be readily varied or changed in accordance with individual needs. At the same time, the inherent dangers due to nre hazards, and the necessity for compliance with municipal and insurance codes impose rigorous requirements and limitations on the type of system that may be employed.

The iioors of all such types of buildings, in general, are formed in much the same manner, usually comprising an arch or slab cast or built on suitable forms, and having a relative rough upper surface, which may be finished in several ways. For example, wooden sleepers may be placed on the slab, and wood flooring laid over the sleepers, the space therebetween being employed as a runway for the conduits or ducts of the wiring system. in more modern constructions, the finished surface usually comprises a finishing layer of cement mortar, over which linoleum or some similar product is laid to provide the necessary resilience, or a tile or other iioor surface may be provided. Usually a cinder fill, comprising a cinder concrete with a small filling of cement, is interposed between the slab and the nishing layer, and the conduits or ducts are laid in this nll, either flush with the upper surface thereof or disposed a short distance below the upper surface.

The present invention, in its preferred embodiment, is directed to an underfloor duct system for electrical wiring in which two ducts, or a divided single duct, may be employed for carrying, in spaced relationship, the conductors of separate wiring systems, such as an electric light wiring system and a telephone wiring system, which are normally required to be carried in separate or spaced runways.

In such undercor duct systems, some means must be provided for the purpose of bringing out the wiring connections from the duct at the floor level to the device or apparatus which is to be supplied with current, which is usually placed upon a desk, or mounted in a position spaced from the floor surface. Preferably, extensive cutting through of the oor surface, with the customary patching thereof afterwards, is to be avoided. Further, it is desirable that a number of outlet openings, exceeding the probable demand for such openings, be provided so that there will always be an opening located adjacent to the position of the device or apparatus to be served.

It is a primary object of the present invention to provide an underiioor duct system having a plurality of openings spaced in definite relationship with respect to the length of the duct, and which are closed by suitable inserts or plugs, the ducts and plugs being disposed beneath the linoleum oor surface, or, if a cinder-cement fill is employed, being disposed within the fill and. having suitable extensions or collars extending upwardly to a point adjacent the oor surface.

Another object of the present invention is the provision of novel securing means for securing the inserts or plugs in position to close the outlet openings of the ducts, and the provision of means providing for a water-tight closure to prevent entrance of water or the like to the duct containing the electrical conductors.

A still further object of the present invention is the provision of means providing for the disposition of two individual ducts in the same runway, with means for clamping the ducts in predetermined position, the clamping means, in addition, serving as a means for holding the inserts or plugs in position.

Another object of the present invention is the provision of a standpipe or outlet nozzle, adapted to be secured in the outlet opening of the duct when the insert plug has beenv removed, and which is provided with a Siamese outlet having separate passageways communicating with each portion of the duct, or with each of the two ducts.

The outlet nozzle of the present invention is provided with only a single securing member, whereby its assembly and installation is facilitated, and connection can thus be made with great rapidity and with relative simplicity.

In addition, the duct system of the present invention may be constructed so as to provide a relatively large opening at each of the outlets to facilitate drawing of the conductor through the duct, which opening is provided with a closure plate carrying the insert plug, the plate also serving as a support for the outlet nozzle when the plugs are removed to establish connection to the conductor in the duct.

Another object attained by the present invention is the provision of a divided duct, having separate passageways extending therethrough, which is formed with a single fiat strip of metal punched previous to its formation into a duct to provide the desired outlet opening and slots for receiving the securing member. The duct is then bent into form to provide a duct having a central or intermediatepartition running lengthwise thereof within the interior of the duct to provide two separate runways in the duct.

Other objects and advantages of the present invention, such as the provision of an underfloor duct system of economical and simplified design, which provides an easily accessible system of the desired type having great flexibility, will be more apparent from the following detailed description, which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art the construction and operation of a preferred form of the present invention.V

In the drawings:

Figure 1 is a perspective View of one embodiment of the present invention;

Figure 2 is a vertical sectional view taken through one of the outlet nozzles shown in Figure l;

Figure 3 is a. View corresponding to Figure 2, showing a modified type of outlet nozzle;

Figure 4 is a horizontal sectional view, taken substantially on the line ll-li of Figure 3;

Figure 5 is a vertical sectional view of the duct shown in Figure 3, provided with a suitable closure plug;

Figure 6 is a topl plan view of a modified form of duct;

Figure 7 is a sectional view of the duct in Figure 6, taken substantially on the line 'l-'I of Figure 6;

Figure 8 is a view corresponding to Figure 6, of a still further modified form of duct;

Figure 9 is a sectional View taken substantially on line 9--9 of Figure 8;

Figure 10 is a top plan View, partly in section, of another form of duct structure;

Figure 11 is an` elevational view of the duct and outlet nozzle shown in Figure 10;

Figure l2 is a vertical sectional View through the outlet nozzle and duct, taken on line I2-I2 of Figure l1;

Figure 13 is a vertical sectional view through the duct shown in Figure 11, taken on line I3-I3 of Figure 11;

Figure 14 is a sectional view through an outlet plug, .taken on line lli-I4 of Figure 10;

Figure 15 is a sectional View of a modified type of insert plug;

Figure 16 is a vertical sectional view of a modifled type of outlet nozzle;

Figure l7 is a vertical sectional View taken on the line ll--Il of Figure 16;

Figure 18 is a horizontal section taken on line lf3-i8 of Figure 17; and

Figure 19 is a sectional view taken Substantially on line lS-IS of Figure 17.

Referring now in detail to the drawings, in FigureV l I have disclosed two separate ducts, indicated at I0 and I2, of generally rectangular form, which may extend parallel to each other, or which may branch off, as shown; Each of the ducts is adapted to carry an electrical wiring system, the duct f, for example, carrying the conductor I3 providing for telephone connections or the like, while the duct I2 carries the conductors I@ providing for electric light service, or for other power service to electrical devices or apparatus. These particular classifications are, of course, optional.

At spaced intervals along the top surface of the duct, suitable outlet openings are provided, which are normally closed by closure plugs I5, the closure plugs being capable of removal to provide for insertion of the standpipe or outlet nozzle connections shown generally at I6. These connections are adapted to provide for leading out of the conductors, such as conductor il leading from one side of the nozzle I6 and corresponding to a branched conductor extending from the conductor I3 supplying telephone service or the like. Similarly, the conductor i@ may be branched up through the outlet nozzle I, and suitable plug receptacles, such as shown at i8, may be provided for the purpose of facilitating connection thereto of flexible conductors or cords leading to suitable` electrical appliances or the like. It is apparent that the standpipe provides for interchangeable use of either outlet with either runway, and only a single standpipe need be ernployed for two separate circuits, whether one or two ducts are used.

Referring now in detail to Figure 2, which is a sectional view through one of the members i6, it will be noted that the concrete floor slab, or a similar floor surface, indicated at I9, is adapted to have formed on its upper surface, a suitable filler medium, -which may comprise wood, or may comprise a cinder ll or the like, indicated at 22. able runway 23 formed in the finishing ll or material 2i), and may be held in suitable spaced relationship by means of a U-shaped clamping strip 2G, which extends across the lower surface of the ducts I8 and l2, and is provided with upstanding end portions engaging the lateral outside surfaces of the ducts.

As shown more in detail in Figure 15, each of the ducts I and i2 is provided, at spaced intervals with respect to its length, with outlet openings preferably closed by suitable closure plugs I5, which closure plugs, in this embodiment of the invention, have a tapered exterior surface cooperating with a similarly formed tapered surface cut into the upper surface of the duct l0, whereby the closures or plugs I5 have sealing engagement within the openings in the duct, to provide water tight closures therefor. Suitable countersunk securing means 25, comprising a screw member or the like, are adapted to have threaded engagement in the lower or bottom wall section of the duct, and may be screwed thereinto for holding the plug I5 in proper sealing engagement. When it is desired to make an outlet connection at one of the openings in the duct, the member 25 is unthreaded, allowing removal of the closure plate l5, and, inasmuch as these plates are located at definite distances with respect to the length of the duct, the linoleum. need only be cut adjacent the opening I5,

and therefore there is no diiculty entailed in locating the duct opening.

Referring again to the outlet nozzle l shown in Figure 2, this outlet nozzle has a Siamese opening at its lower end, indicated at 25 and 27, providing two separate inlets into the nozzle, and these inlets are provided, adjacent their ends, with annularly flanged collars 28, which are adapted to have bearing engagement above the upper surface of the ducts lil and I2, there preferably being gaskets 29 interposed therebetween to provide suitable sealing engagement therewith. Extending outwardly from the collars or branches 28 are cylindrical projecting portions which engage within the openings 3? formed in the ducts I0 and I2, to center the outlets 2i? and 2l therein, so that the conductors may be led from the ducts I and i2 through the outlets 26 and 21 and upwardly through the nozzle l5 The ducts IIJ and I2 are disposed in a suitto the outlet connections or openings formed at the upper end thereof and comprising the horizontal semi-cylindrical portions 32 and S3 formed in the member I6, which portions are closed by a cap member 34 adapted to have seating engagement thereupon, forming laterally spaced open-ended cylinders.

Extending centrally through the cap member 513, through an enlarged bearing section 35 at the upper end of the member I 6, and through an enlarged bearing section 36 formed between the outlets 26 and 2l, is a securing member 3l, comprising an elongated bolt having a threaded en`d S8 adapted to thread into the clamping member 24 between the ducts Iii and i2. At its upper end, the member 31 is provided with a head portion 39, which has bearing engagement about the surface of the member 34 to clamp the same securely to the upper end of the member I6, and which is provided with a suitable slot for receiving a screw driver or other tool to facilitate threading of the member into the clamp 2li.

Extending coplanar with the member 37 on opposite sides thereof are web portions, indicated in dotted lines at 48 in Figure 2, which serve to provide for denite separation of the two outlet chambers 26 and 27 and corresponding outlets 32 and 33, so that the conductors in the duct It are separated from the conductors in the duct l2 when they are led to the outlet portions 32 and 33 of the member IS. In this manner, complete and effective separation of the conductors is obtained, and this separation is continued at the upper end of the member I6, so that the telephone or similar conductors Il will be in spaced relationship with the conductors leading to the plug receptacle I8 or similar instrumentality. It is to be noted that the single clamping member 3l holds all of the members in aligned position, and provides for positive pressure being maintained upon the gaskets 29 to secure sealing engagement of the flanges 28 with respect to the upper surfaces of the ducts I and l2, thus providing for water-tight connection thereto.

Considering now Figure 3, which is a view corresponding to Figure 2 of a modified form of outlet nozzle, the outlet nozzle I6 of this embodiment is provided with outlet openings 25 and 21', corresponding to the openings 2S and 2l of Figure 2, but the ducts Iii' and I2' of this embodiment have their outlet openings formed in the upper surfaces of the ducts adjacent the inner surfaces thereof, these comprising only semicylindrical openings, and the iiange 23 completely surrounds both openings, and comprises a single unitary flange formed adjacent the oblong end at the lower end of the member I. As will be noted, the ducts are disposed closer together in this embodiment, and, as shown in Figure 4, the flange 28 extends completely across the space between the two ducts. The member I6 is similarly provided with integral partitions il@ on opposite sides of the securing means 3l, to provide for complete separation of the two passageways d2 and 43 extending upwardly through the member I6 from the ducts lil and I2 to the portions 32 and 33 of the member I6', which portions are closed by closure plates 34, as described in connection with Figure 2.

As shown in Figure 5, the duct Iil, when the outlet member I6 is not employed, has its outlet opening closed by a suitable plug member l5',- comprising a semi-circular member having a peripheral tapered edge portionfl, and having a defining lip portion 45 engaging the inner lateral surface of the duct IG to align the member in position. Securing means is employed to hold the plug I5 in position when the outlet opening is not in use.

The member I6 is adaptable for use when the ducts are spaced relatively closely to each other, and when the wide spacing of the outlet openings and 2l of member i3 could not be suitably employed. However, it is to be noted, in connection with the embodiment shown in ure l, that the member It may be slanted angularly with respect to the ducts Iii and I2 in order to accommodate differences in alignment between the outlet openings in the ducts, without in any way departing from the scope of the present invention.

In Figures 6 and 7 a modified type of duct shown, indicated at 5e, formed from a suitable flat metallic sheet which is stamped or punched to provide an outlet opening therein of a size greater than the normal opening provided by moval of the insertable plug. In this embodiment, the duct includes a substantially intermediate vertically extending portion 52, which, ai; spaced intervals, is provided with a slet accom modating the securing means 53, and which is bent around to provide a bottom wall an outside lateral wall 55, a top wall 55, shown Figure 6, a second outside lateral wall 5l, and a second bottom wall 58 which may be wel-ded as shown to the rst bottom wall 54 and the in vrdly extending intermediate dividing wall 52. The securing means 5S is threaded at its lower end and is adapted to be threaded into a tapped opening formed at the meeting juncture of the walls and 58.

Preferably the upper or top surface wall of the duct 59 is provided with a rectangular cutout portion, and the lateral walls and 5l e provided with inwardly extending tab portions having their upper surfaces lying flush with t, lower surface of the top wall 56, a rectangular closure plate S2 being applied over the cut-out portion of the duct, and secured to the tabs means of countersunk screw members ES.

The cover plate 62 is provided with a central opening adapted to receive a closure plug oorresponding to the closure plug I5, which is heldin engagement by means of the securing means extending downwardly through the duct in slot formed in the intermediate dividing wall When it is desired to gain access to the interior of the duct for pulling conductors theretl or for any other reason, the entire plate removed in order to facilitate entering into o duct. is connection thereon, the plug 54 is removed by unscrewing in the securing member 53, thus pro-- viding an outlet opening, corresponding to opening 3l! of Figure 2, in which the outlet mel ber, such as the member I6, may be secured.

In Figures 8 and 9 I have shown a modified form of construction, in which the closure plate 62' for the duct 50 is provided with downturned side wall portions 55, which locate the plate positively with respect to the duct 5G', and the plate, together with the closure plug 5ft', are secured in fixed position on the duct by r the securing means 53 threaded into wall of the duct. When it is desired to ed ci n access to the duct or to provide an outlet connection thereto, the member 53 is unthreadel, thereby allowing removal of either the plug Gil', or the plate, if desired. This provides a large opening through which conductors may be drawn Cil When it is desired to mount an outlet within the duct, and also serves as a supporting means for the outlet nozzle connections when they are mounted over the openings provided in the top wall of the plate.

Referring now to the embodiment of the invention shown in Figures 10 to 14, inclusive, in this embodiment of the invention provide a duct member l5, comprising a single duct having a dividing wall 'l2 extending therethrough to provide two parallel runways 'I3 and lli through the duct. At spaced intervals along the length ci the duct, I provide slots 'I5 in the wall l2, which slots are adapted, as shown in Figure 14, to reeeive securing means 'i6 comprising a screw member threaded at "i into the base or bottom wall or" the duct l'i, and at the top engaging a suitable closure plug member i3 which has a flanged shoulder portion 'ES extending into an opening Se formed in the top surface of the duct, and provided with a gasket member 82 having bearing engagement on the top surface of the duet for providing a water tight closure therewith.

The duct lil is adapted to set upon a floor slab or surface S3, and suitable wood ooring, such as indicated at Sli, is spaced apart to provide a runway for the duct. Preferably, the ooring 34 is oi the tongue and groove type, as shown by the groove 85, and the duct member is provided with a spring tongue portion 8S adapted to have engagement within the groove 35, to lock the duct in position therewith.

A suitable finishing floor of linoleum or the like Yis indicated at 22', and extends partially over the duct, being cut away adjacent the plug 18, so that the plug position may be denitely ascertained. When an outlet connection is desired, the member 'ifi is unthreaded, so that the plug 18 may be removed.

As shown in Figure 12, an outlet nozzle or standpipe, indicated at 9b, and having a flanged collar, S32, is then inserted into position in the opening 8B, the collar 92 bearing upon a suitable gasket @3 about the peripheral surface of the opening. The member Sii is provided with two semi-cylindrical outlet portions at Se and 95, and is also provided with a central partition indicated at 95 in Figure l2, and which is slotted to receive the securing means 91 threading into the lower wall of the conduit ld. The upper end of the member 'l is provided with a head portion 98 bearing against a cap member 99 coresponding to the cap member Se or Figure 2, which cap member completes the cylindrical outlet lopenings for the member Si), so that plug connectors or receptacles it@ may be mounted in one of the cylindrical portions, such as the portion gli, for connection to devices such as desk lamps, dictaphones, fans or the like, while the opposite cylindrical portion 95 may be provided with suitable connectors for leading out telephone wire connections or buzzer connections or the like.

If the openings at the opposite ends of the cylindrical portion of the outlet 95 are not to be used, the plugs 18, removed from the openings 80, may

' be employed for closing this outlet until such time as connections are to be taken therefrom.

With the Siamese connection as shown, the conductors in the duct 'l0 are separated at all times, since when passing through the neck of the member 96 the partition walls S6, together with the securing member Sl, prevent any possibility of these conductors coming into contact with each other. At the same time, by the cylindrical construction of the outlet connection at the upper endoi the member Si), connections can be taken from opposite ends thereof, which iurther increases the eiiicicncy of the outlet connection. The duct 10, if desired, may be a drawn tubular member, in which case the intermediate wall l2 is formed integral with the outer defining wall of the duct 7|), or may be formed in any suitable manner, such as disclosed in Figures 6 to 9, inclusive. n

Referring now to the embodiment of the invention disclosed in Figures 16 to 19, inclusive, this particular embodiment discloses a concrete iioor slab indicated at |05, upon which is disposed a cinder-lill |06 formed of cinder concrete with a mixture of cement, and above this illl may be provided a floor surface, such as the wooden door members |01, or a linoleum surface, as desired.

A duct |538, shown in detail in Figure 19, is provided, and is preferably formed of a sheet metal rectangular tube provided with an intermediate wall |39 which may be welded, as at lil, or otherwise suitably secured in position with respect to the duct |08. The duct is disposed directly on the top surface of the floor slab |95, and does n'ot extend the entire height or the concrete illl |535. It is therefore necessary, in this embodiment of the invention, to provide spaced collars or sleeve members H2, which may be welded or otherwise secured about the openings H3 formed at spaced intervals along the lengths of the member or duct |68, and which at their upper ends are adapted to receive closure plugs corresponding to the closure plugs 'I8 of the embodiment shown in Figures 10 to 12, or the closure plug i5 shown in Figure 15.

The sleeves l |2 extend up to the top surface of the cinder-dll IBS, and, when an outlet connec-l tion is to be secured thereto, the outlet connection is provided with a depending cylindrical portion li of an external diameter equivalent to the internal diameter of the sleeve H2, and with a radially extending flange portion H5 limiting the downward position of an outlet connecting member H6, so that the member is disposed in rigid alinement within the sleeve l2.

The member H6 extends upwardly from the interior of the sleeve H2, and at its upper end is divided into semi-cylindrical spaced portions Hi and H8, corresponding to the portions 955 and 95 of the member 9|). As shown in Figure 18, the member H5 is provided with inwardly extending partition walls |53 having a slot therebetween through which securing means '|253 is adapted to extend. This eiectually divides the member ||6 in the same manner that the duct |138 is divided by the interior wall 69, and the intermediate wall |09 is correspondingly slotted to receive the securing member |20, which threads at its lower end into the lower wall of the duct |98.

Adapted to be mounted upon the upper end of the member l I6 are a pair of spaced semicylindricral closure members forming an integral closure plate |22, which closure plate |22 corresponds to the closure plate lit of Figure 2, or the closure plate S9 of Figure- 12. The closure plate |22, shown in detail in Figure 17, is provided with an enlarged portion |23 serving as a bearing for the securing screw 22, to maintain this screw in alinement and provide a suitable bearing surface therefor. The screw |23 extends outwardly through the closure plate l2? and the member H6 between walls il@ to the lower end of the duct |23, and, upon being threaded into the lower wall of the duct iet, draws the closure plate |22 in tight engagement upon the top of the member H6. Suitable plug receptacles E24 may be mounted in one of the cylindrical outlet connections ll, for the purpose of providing for connection of plugs from flexible electric cords or the like thereto, while the opposite cylindrical portion H8 of the member H6 mag,7 be provided with suitable bushings or sleeves 25 at opposite ends thereof, as shown in Figure 18, for the purpose of vproviding outlets for telephone service wires or the like. Preferably a suitable collar 26 is provided about the member i i6, to close the opening in the floor surface Ill'l through which the member extends. This is optional.

While I have shown my invention as applied to a particular type of floor construction, it is to be understood that the invention is not to be thus limited, since the broad underlying principles of the same may be applied equally well to underoor duct systems employed in connection with other types o1" oor constructions, since the particular type of floor construction has no controlling eifect upon the operation or use of the duct system.

Also, it is to be noted that the system is adapted for use with either a single divided conduit, or with separate conduits, and is capable of ilexibility in both design and in operation, since the outlet nozzles or standpipes may be disposed angularly with respect to the conduit, or may be disposed at any desired relative position with respect thereto.

Further, it is to be pointed out that the Siamese connection at the upper ends of these standpipe outlet nozzles provides for connection to either plug type receptacles for electric light service, or similar electrical service, or can be employed as outlet connections for telephone service wires or the like, thus providing a system which has great adaptability for complying with the particular needs or desires of the tenants in the building.

Having described my invention in accordance with the patent statutes, what I claim as new and desire to secure by Letters Patent is:

l. A concealed wiring system for buildings comprising a duct lying wholly within the floor structure and below the floor surface, said duct having a longitudinally extending partition wall dividing the same into two separate runways, said duct having spaced openings in its top surface communicating with both said runways, slots out in said partition wall beneath said openings, and closure means for said openings comprising plate members extending across the entire top surface of said duct and secured thereto, said members having centrally disposed coplanar removable closure plugs provided with detachable securing means passing through said slots and engaging the bottom wall of said duct.

2. A concealed wiring system for buildings comprising duct means lying within the floor structure and providing two separate conductor runways, said means having spaced openings in the top thereof each providing an outlet for both said runways, closure means for said openings and extending coplanar with the top of said duct means, and screw members extending through said closure means and threading into the bottom wall of said duct means for detachably securing said closure means in position.

3. The combination with an underloor duct system having a longitudinally divided duct provided with an outlet opening in the top surface thereof communicating with said duct on opposite sides of the longitudinal division thereof, of a closure member for said opening comprising a tapered plug having seating engagement in said opening and having the top surface thereof lying substantially flush with the top surface of said duct, and means extending through said closure means and duct for detachably securing said closure means in position.

Ll. In an underfloor duct system for electrical wiring, a duct having an intermediate partition dividing the same into two separate conductor runways, said partition being cut away at spaced intervals, said duct having openings in the top surface thereof at said cut away portions of said partition, closure means for said openings, and detachable securing means for said closure means extending through the cut away portions of said partition and engaging the bottom wall of said duct.

5. A duct for an underoor wiring system comprising a substantially rectangular hollow conduit having an intermediate partition dividing said conduit into two runways, said conduit having spaced openings in the top wall thereof communicating with both said runways, said partition having a cut away portion below each of said openings, closure means comprising a plug tting into each of said openings, and means extending downwardly through said plug and cut away portion and engaging in the bottom wall of said conduit for detachably securing said plug in position.

6. In a concealed wiring system for a building having a floor structure comprising a floor slab, the combination of a wiring duct lying on said slab, said duct having spaced openings in the top surface thereof, cylindrical collar members secured to the defining surfaces of said openings and extending upwardlly to the top surface of said structure, closure means for said collar members, and means extending through said closure means and collar members and engaging in the bottom of said duct for detachably securing said closure means in position.

7. A concealed wiring system for a building having a floor structure including tongue and groove flooring lying upon a slab, and a linoleum floor thereon, comprising a duct member lying on said slab and having spring means for locking said duct with respect to the groove in said flooring, said duct lying below the linoleum ooring.

8. The combination with an underiioor duct system lying beneath a door surface and comprising duct means having separate parallel conductor runways therein, said duct means having spaced outlet openings along the top surface thereof, of an outlet connection for leading out conductors from said runways through one of said openings comprising a standpipe having a central partition and engaging in said opening, laterally spaced outlet openings at the upper end of said standpipe, a closure plate extending over both of said outlet openings of said standpipe, and securing means for said standpipe bearing against the upper surface of said plate and extending downwardly through said partition and duct means and engaging in the bottom wall of said duct means.

9. A standpipe for an underiioor duct system comprising a depending cylindrical portion having an annular flange adjacent its lower end, vertically extending transverse partitions extending from diametrically opposite sides of said standpipe toward the center thereof, upwardly opening semi-cylindrical portions on opposite sides oi said partitions, and closure means for said standpipe comprising an integral member having downwardly opening semi-cylindrical portions engaging said rst named portions to deiine two separate cylindrical open-ended outlets for said standpipe.

l0, The combination with an underiloor wiring duct having separate conductor runways, of a standpipe providing outlet connection for said runways and havingV a central partition dividing said standpipe into two separate outlet passageways, and horizontal open-ended cylinders at the upper end of said standpipe, each of said cylinders communicating with one of said passageways.

11. In combination, a pair of conductor runways, a plurality of spaced openings in the topv surface of said runways, a standpipe having the lower end thereof fitting into one of said openings, a partition extending vertically through said standpipe, and laterally spaced horizontally extending outlets at the upper end of said standpipe communicating with said lower end at each side of said partition.

l2, In combination, in an underfloor wiring ssytem, a pair of parallelly extending duct runways, said runways having spaced outlet openings in the top surface thereof, and standpipes adapted to be secured to said openings each oomprising a hollow member having an extension at the lower end thereof adapted to t into a corresponding opening in said runways, means at the top of said member providing laterally spaced outlets, means extending vertically through the body of said member partitioning said member into two vertical passageways, and securing means comprising a bolt engaging the top of said standpipe and extendingV downwardly through said member and between said runways and engaging the bottom wall of said runways for detachably securing said standpipe in position.

13. In combination, a duct having two separated conductor runways therein, an outlet opening in the top surface of said duct providing communication with both said runways, a standpipe engaging in said opening and having spaced lateral outlets, a partition dividing said standpipe to form two separate passageways therein from said outlet opening to said laterally spaced outlets, and a bolt extending downwardly through said standpipe for securing said standpipe in position over said outlet opening.

14. In an underoor wiring system, duct means providing two separated conductor runways, a standpipe extending into the top of said duct means and providing two separated vertical outlet passageways, laterally spaced horizontally extending troughs at the upper end of said passageways, a cap member having corresponding laterally spaced inverted troughs forming horizontally extending cylindrical outlets with said firstnamed troughs, and means for detachably securing said cap member to said standpipe and said standpipe to said duct means.

l5. In a duct having two separated conductor runways and having an access opening extending entirely across the top of said duct, the combination of a closure plate positioned over said opening and having a copianar removable center plug, and securing means extending through said plug and engaging the bottom wall of said duct for clamping said plate and plug in position over said opening.

16. A standpipe for leading out conductors from an underoor wiring runway comprising a cylindrical body member divided into two vertical passageways, detachable means at the upper end of said body member providing laterally sp-aced horizontally extending tubular wiring outlets and including means preventing communication between said outlets, and means at the lower end of said body member providing for communication between said passageways and said runway.

17. A wiring system of the class described comprising two parallel duct runways having a longitudinally extending partition wall therebetween, said runways having spaced openings extending entirely across the top surfaces thereof, closure plates over said openings, and central removable plug members carried by said plates and providing access to both said runways, said plug members having means extending therethrough and through said partition wall and engaging the bottom wall of said runways for securing said plug members in fixed position with respect to said runways.

18. A standpipe for leading out conductors from an underiioor wiring runway comprising a body member having means at the lower end thereof providing for communication between said runway and the interior or said body member, a cap member mounted on the top of said body member and providing therewith two laterally spaced horizontal extending wiring outlets, and means in said body member and cap niember separating said outlets and providing individual non-communicating passageways from said outlets downwardly through said body member to said runway.

19.1'n combination, an underoor member having two separated conductor passagewaysl therein, said member having an outlet opening at the top thereof providing communication with both of said passageways, a standpipe having separate vertically extending passageways communicating respectively with said separated pasf sageways through said opening, laterally spaced outlet means at the top of said standpipe in respective communication with said vertically extending passageways, and means carried by said standpipe for detachably securing said standpipe to said underfloor member.

20. In combination, .an underfloor member having two separated conductor passageways therein, said member having an opening in the top surface thereof communicating with both said passageways, a standpipe having the lower end thereof engaging over said opening, a partition extending vertically through said standpipe, and laterally spaced outlets at the upper end of said standpipe communicating with said lower end at each side of said partition.

21. An underfloor conductor member comprising a pair of enclosed separated parallel passages, said member having its top wall discontinuous .at longitudinally spaced points to provide access to both said passages, a closure plate extending over and secured to said member at said points, and centrally located detachable means carried by said plate and providing a closure for an outlet opening extending over a portion of both of said passages.

JACOB W. LEWIN.

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