Duct Terminator

Abstract

A duct terminator for use in the concrete wall of an underground vault, or the like, for housing electrical equipment, such terminator including a pair of barrier walls spaced apart at a distance substantially corresponding to the thickness of the concrete wall. A plurality of spaced receptacles extend between the barrier walls to form through passages for receipt of the extremities of a plurality of respective ducts whereby the terminator may be positioned in the concrete form for the vault wall and concrete poured thereinto to provide a plurality of spaced passages in the vault wall for receipt of the extremities of such ducts. The terminator may be made in modular form and may be formed with interlocking flanges whereby a plurality of modules may be assembled for forming a composite receptacle pattern of any desired configuration.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of my patent application Ser. No. 853,727 filed Aug. 28, 1969 and now abandoned.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to underground ducting for receipt of electrical cables, or the like, and more specifically to duct terminators which form passages extending through concrete walls of, for example, a vault at which the ducts terminate for receipt of the extremity of the ducts.

2. Description of the Prior Art

Prior art devices for termination of communication and power cables at a concrete wall are for single ducts only and are commonly referred to as end bells or coupling end bells. These end bells generally comprise a cylindrical receptacle projecting through the concrete wall and some versions thereof include an exterior flange disposed intermediate the ends of the receptacle and projecting radially outwardly for a relatively short distance. Since the end bell for each duct is an individual unit, it is necessary for the workmen building the concrete wall in which they are used to individually position each end bell to provide the desired duct spacing and to attach them individually to the form for the concrete wall or other supporting structure. Further, curing and consequent shrinkage of the concrete frequently causes it to shrink away from the exterior of the end bells thereby forming a peripheral crack through which water may pass to the interior side of the concrete wall.

SUMMARY OF THE INVENTION

The present invention is characterized by a duct terminator including a pair of spaced apart barrier walls having a plurality of receptacles extending therebetween and disposed in spaced relation with respect to one another. The receptacles form respective through passages for receipt of the extremities of ducts terminating at such wall. Thus, the terminator may be positioned within the form utilized for shaping the concrete wall and concrete may be poured between the two barrier walls and around the receptacles to thereby provide a continuous concrete wall having passages extending therethrough for receipt of the extremity of ducts leading to such wall.

It is an object of the present invention to provide a duct terminator of the type described which locates the duct receptacles in spaced relation with respect to one another.

It is another object of the present invention to provide a duct terminator of the type described which forms a barrier to prevent water seepage through the peripheral crack formed around the receptacle by the concrete curing and shrinking away from such receptacle.

It is still another object of the present invention to provide a duct terminator of the type described which is comprised of interconnecting modules whereby the size and arrangement of the receptacles may be selected in accordance with the particular installation.

A further object of the present invention is to provide a duct terminator arrangement employing a plurality of single passage units the sides of which are formed with complementary connection means so that such units may be employed singly or in groups.

Yet a further object is to provide a removable cap for duct terminators of the aforedescribed nature.

These and other objects and the advantages of the present invention will become apparent from the consideration of the following detailed description when taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partially broken away, of a concrete vault including a duct terminator embodying the present invention;

FIG. 2 is a vertical sectional view, in enlarged scale, taken along the line 2--2 of FIG. 1;

FIG. 3 is a top view taken along the line 3--3 of FIG. 2;

FIG. 4 is an end elevational view of a vault including a modification of the duct terminator shown in FIG. 1;

FIG. 5 is a vertical sectional view, in enlarged scale, taken along the line 5--5 of FIG. 4;

FIG. 6 is an end elevational view of a vault including a second embodiment of the duct terminator of the present invention;

FIG. 7 is a vertical sectional view taken along the line 7--7 of FIG. 6;

FIG. 8 is a modification of the duct terminator shown in FIG. 1;

FIG. 9 is a sectional view through the center of a receptacle including in a modification of the duct terminator shown in FIG. 1;

FIG. 10 is a sectional view similar to FIG. 9 of a second modification of the duct terminator shown in FIG. 1;

FIG. 11 is a perspective view of a concrete vault utilizing a single-passage duct terminator arrangement embodying the present invention;

FIG. 12 is a front view in enlarged scale of one of the single-passage terminators shown in FIG. 11;

FIG. 13 is a broken front view showing a plurality of the single-passage duct terminators in an interconnected configuration;

FIG. 14 is a rear elevational view of the duct terminators shown in FIG. 13;

FIG. 15 is a vertical sectional view taken in enlarged scale along line 15--15 of FIG. 11;

FIG. 16 is a vertical sectional view taken in enlarged scale along line 16--16 of FIG. 11;

FIG. 17 is a side elevational view of a cap member which may be utilized with the duct terminator of FIGS. 11-16; and

FIG. 18 is a front view of said cap member.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, generally the duct terminator 19 of the present invention is particularly adapted for use in the vertical wall of a concrete underground vault 21 for housing electrical utility equipment (not shown) or the like. Referring to FIGS. 2 and 5, the duct terminator 19 may be molded by the vacuum process disclosed in U.S. Pat. No. 3,256,565 and includes a pair of vertical side walls 27 and 29 which are spaced apart at a distance substantially equivalent to the thickness of the wall of the vault 21 in the area in which the terminator is installed and a plurality of tubular receptacles 31 extend between such walls and form through passages 33 for receipt of the extremities of ducts 35. The terminators 19 may include interfitting male and female groove type flanges 37 and 39, respectively formed by the respective lower and upper extremities of the walls 27 and 29 whereby such terminators may be coupled together in stacked relation as shown in FIG. 1 to provide the desired number and arrangement of receptacle passages 33. Thus, the terminators 19 may be installed in a concrete form 41 for the wall of the vault 21 and concrete may be poured thereinto. The concrete 45 will flow in and around the receptacles 31 and when such concrete cures, a continuous wall will be provided with passages 33 extending therethrough for receipt of the extremities of the ducts 35 interconnecting adjacent vaults and the walls 27 and 29 will act as barriers against penetration of dirt or water around the outer periphery of the respective receptacles 31.

Referring to FIG. 2, the upper extremities of the walls 27 and 29 of each of the duct terminators 19 are formed with outwardly opening horizontally extending grooves which define the female interlocking flanges 39. The lower extremities of the walls 27 and 29 are formed with inwardly projecting horizontally extending tongues which define the male flanges 27 that interlock with the female flanges 29 of the respective adjacent terminators 19.

Referring to FIG. 5, the receptacles 31 each include a slightly frusto-conical shaped portion 47 which receives the extremities of the respective ducts 35 and reduced-in-diameter area defining a rounded shoulder 49 against which the end of the duct 35 may abut. The receptacle 31 flares radially outwardly from the shoulder 49 to define a bell shaped flare 51 over which electrical cables and/or conductors threaded through the ducts 35 may ride.

In operation, when a vault 21 is to be poured the inner and outer forms 41 are assembled to provide a space defining the thickness of the vertical walls of such vault. The terminators 19 may then be assembled together to provide the desired number of receptacles 31 and spacing therebetween. In this regard, it is important to note that duct terminators 19' (FIG. 4) having relatively large receptacles may be assembled with the smaller terminators 19 to provide a composite terminator assembly for receipt of ducts 35 having different diameters.

After the terminators 19 are assembled and positioned within the form 41, vertical and horizontal reinforcing rods 61 and 63, respectively, may be installed and wired in position to provide the desired reinforcement for the concrete. It is important to note that the receptacles 31 may be arranged to provide duct spacing to conform to the functional requirements for the individual power or communication installation while providing spacing between the receptacles 31 for projection of the reinforcing rods 61 and 63 therebetween to thereby provide reinforcement, where needed, between adjacent receptacles 31. The concrete 45 is then poured into the forms 41 and, if necessary, vibrated and will flow in between the adjacent receptacles 31 to provide a continuous concrete wall that extends through the space between the vertical walls 27 and 29 of the terminators 19 through which the receptacles 31 define passages for receipt of the extremities of the ducts 35.

Subsequently the forms 41 are removed and the ducts 35 may be installed in trenches extending between adjacent vaults and the ends thereof abutted against, or positioned in confrontation with, the shoulders 49. It is noted that the slight frusto-conical shape of the passages 33 provide for convenient insertion of the duct extremities to provide a tight fit. The extremities may be cemented in the passages 33 to provide a tight seal. Electrical cables may then be fed through ducts 35 and the lead end thereof will pass up and over the rounded shoulders 49 and such cables will ride down over the bell shaped flare 51 to be connected with equipment installed within the vault. It is noted that the shoulder 49 is somewhat thicker than the wall of the duct 35 whereby equal outer diameter ducts 35 having thicker walls may conveniently be installed therein. After installation of the duct 35 is complete, the trench between the ducts 35 may either be filled with concrete or soil may be thrown back into the trench and compacted. A particularly noteworthy advantage of the terminators 19 of the present invention is that the vertical walls 27 and 29 will provide a water barrier to prevent admission of water within the cracks which are frequently formed by the curing concrete drying and shrinking and pulling away from the outer periphery of the receptacles 31.

The terminator shown in FIG. 6 is similar to that shown in FIG. 1 except that the entire pattern of receptacles forming the passages 33 are formed by a unitary terminator, generally designated 67, including single vertical outer and inner walls 69 and 71, respectively, (FIG. 7). The trench leading to the vault 73 shown in FIG. 7 is filled with concrete 75 which surrounds and supports the ducts 35. It will be clear from FIG. 7 that even though the curing concrete may shrink and pull away from the outer periphery of the receptacles 31 leaving cracks 76, the flat walls 69 and 71 will force any water from the surrounding ground to follow a labyrinth in behind the wall 71, through the cracks 76 and then out from behind the wall 69 thereby effectively blocking entry to the vault.

The duct terminators, generally designated 81, shown in FIG. 8 are substantially similar to that shown in FIG. 1 except that one terminator is shifted longitudinally with respect to the other to provide staggered, spaced relationship between the passages 33 whereby cables and/or conductors fed through parallel ducts connected therewith will not interfere with the cables and/or conductors fed in the same direction through the passages 33 in the adjacent terminators.

The receptacles 31' shown in FIG. 9 are similar to those shown in FIG. 5 with the inclusion of centrally located webs, generally designated 85, which are formed by layers 87 and 89 resulting from the forming process employed to form the receptacles 31' from the respective walls 27 and 29. The webs 85 are formed with peripheral weakened outlines 91 for convenient removal of such webs after the terminators have been installed. Thus, a duct terminator employing the web 85 may be installed and dirt and soil will be prevented from entering the concrete vault until such web is removed. The web 85 may then be conveniently removed immediately prior to the installation of the ducts 35. Thus, extra reserve duct terminators may be installed at the time of vault construction for future expansion and addition of more ducts 35 at a later date.

The terminators shown in FIG. 10 are substantially similar to those shown in FIG. 1 except that the barrier walls 27 and 29 are formed with respective top and bottom male and female flanges 95 and 97 which interfit to maintain the duct terminators positioned with respect to one another. Obviously, these flanges could take many different forms.

Referring now to FIGS. 11-16 there is shown a single-passage duct terminator, generally designated 100, embodying the present invention. With particular reference to FIG. 11, a plurality of twelve such duct terminators 100 are shown arranged in the vertical wall 102 of a concrete vault 104 to which a plurality of ducts 108 are affixed and terminated. Note that the ducts 108 are not shown in FIG. 13 in the interest of clarity. Each of the duct terminators 100 is of like construction and utilizes a pair of vertical barrier walls 110 and 112 which are spaced apart at a distance substantially equivalent to the thickness of the wall 102 of the vault 104 in the area where the terminators are installed. An integral tubular receptacle 116 extends between the side walls 110 and 112 to form the passage 114 for receipt of the extremity of one of the ducts 108.

The upper edge and left-hand edges of the side walls 110 and 112 are formed with male flanges 120 and 122, respectively, that complementarily interfit female grooves 124 and 126 formed along the lower edge and right-hand edge of the other duct terminators whereby the plurality of terminators may be coupled together in the stacked relationship shown in FIG. 11.

Again referring to FIG. 11 it will be noted that four horizontal rows of interlocked vertically spaced, single-passage duct terminators 100 are shown. The top row of duct terminators does not support ducts 108, but instead each terminator is provided with a cap, generally designated 130. The details of such caps 130 are shown in FIGS. 16, 17 and 18. Referring to the latter figures, each cap 130 includes a cylindrical neck 132 formed at its inner end with a plurality of like, radially extending locking lugs 134. The opposite end of the neck 132 is formed with a dome-shaped cover 140. The mid-portion of the cover 140 is formed with a hexagonal-shaped boss 142 to receive a wrench (not shown) for a purpose to be described hereinafter. As shown at 144 in FIG. 17, the outwardly-facing surfaces of locking lugs 134 are tapered.

The locking lugs 134 of each cap are designated to enter complementary radially outwardly extending openings 146 formed in the periphery of the inner and outer ends of the passages 114 of the receptacles 116 of each duct terminator 100. The relative size of the locking lugs 134 and their respective openings 146 should be such that the locking lugs can be inserted axially through the openings. Thereafter, the cap 130 will be rotated, as by the application of a wrench to the boss 142, so as to cam the tapered surfaces of the locking lugs 134 into tight engagement with its respective duct terminator 100. In this manner the locking lugs will serve to restrain the cap 130 against inadvertent reverse rotation and provide increased sealing pressure at the interface between the cap and its duct terminator.

Referring to FIG. 15 it should be noted that the vertical or horizontal spacing between the centers of the ducts 108 may be extended by the use of a pair of like, elongated male extender elements 150. The upper edge of each male extender element 150 is provided with a male flange 152 which interfits with the complementary female groove 124 formed in the lower edge of each upper duct terminator 100. The lower edge of each of the male extenders 150 is formed with female grooves 156 which in turn complementarily interfit with the male flanges 120 of the lower edge of each duct terminator 100.

To assembly the duct terminators 100 into the arrangement shown in FIG. 11, individual rows of three duct terminators 100 will be pre-assembled by means of their male and female flange and groove connections. Preferably, a suitable cement is applied to the mating surfaces. After the desired number of rows have been so pre-assembled, proximate edges of the rows will be interfitted, an adhesive again being applied to the the mating surfaces. The provision of the caps 130 permit one or more of the duct terminators 100 to be initially sealed for later reception of a duct 108. With this arrangement the concrete vault 104 is provided with extra duct capacity when such vault is constructed and accordingly will not require costly reworking at such time as additional ducts are needed. The caps 130 may be rendered watertight by utilizing a non-hardening sealant. Alternatively, if a cap is to be permanently sealed relative to its respective duct terminator a suitable cement will be employed. Where a cap 130 is cemented in its duct terminator the dome 140 thereof may be sawed off the neck 132 along a line designated 150 in FIG. 16 to permit reception of a duct 108. Note that the caps 130 may also be employed to seal the inner end of the passages 114 of the duct terminators. Also, where cables and/or conductors are not initially installed in a duct 108 between adjacent vaults it may be necessary to seal the respective openings to prevent the passage of gasses from one vault to another. The caps 130 may be utilized with the duct terminator arrangements shown in FIGS. 1-10 if openings 146 are provided in such duct terminators.

From the foregoing detailed description it will be clear that the duct terminator of the present invention provides a practical and convenient means for forming passages in the concrete walls of underground vaults for conveniently receiving the extremities of ducts extending between adjacent vaults. The terminators conveniently locate a plurality of receptacles in spaced relationship and provide a barrier to prevent the entry of dirt and water around the peripheral crack left on the outside of the receptacles when the concrete cures and shrinks thereawayfrom.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

Claims

I claim:

1. Duct terminator apparatus to be positioned in the concrete wall of an underground vault or the like at which a plurality of ducts are to terminate, said apparatus being positioned in the form used to shape said wall and said apparatus comprising:

a plurality of terminator modules each including respective pairs of barrier walls spaced apart at a distance corresponding substantially to the thickness of said concrete wall and formed at their one extremities with respective female flanges and at their opposite extremities with male flanges for interfitting the female flanges of adjacent modules, each of said modules further including receptacles extending between said barrier walls to form through passages from one of said barrier walls to the other, and with said modules being assembled by interfitting the male and female flanges of adjacent modules whereby concrete poured between said vertical walls during pouring of said vault will position said modules in said vertical walls to form spaced passages for receipt of the extremities of said ducts.

2. A duct terminator apparatus as set forth in claim 1 wherein:

the intermediate portion of each of said receptacles are formed with peripheral shoulders for abutment with the extremities of the respective ducts.

3. A duct terminator apparatus as set forth in claim 1 wherein:

each of said receptacles if formed with a frustoconical shaped portion defining a passage which progressively decreases in cross-sectional area toward the wall opposite to the wall from which said ducts enter to assist in leading said ducts thereinto.

4. A duct terminator apparatus as set forth in claim 1 wherein:

said receptacles are disposed in spaced-apart relationship for receiving concrete reinforcing bars therebetween.

5. A duct terminator apparatus as set forth in claim 2 wherein:

said receptacles are disposed in spaced-apart relationship for receiving horizontal and vertical concrete reinforcing bars therebetween.

6. A duct terminator apparatus as set forth in claim 1 wherein:

said passages flare radially outwardly away from the wall through which said ducts enter to provide tapered surfaces over which conduits fed through said ducts may ride.

7. A duct terminator apparatus as set forth in claim 1 wherein:

certain of said modules include receptacles formed with passages having a selected cross-section and in other of said modules the receptacles thereof are formed with passages having a second cross-section.

8. A duct terminator apparatus as set forth in claim 1 wherein:

said female flanges are in the form of grooves and said male flanges are in the form of tongues for interlocking in said respective grooves.

9. A duct terminator apparatus as set forth in claim 8 wherein:

the grooves forming said female flanges are elongated whereby said tongues may be shifted longitudinally therein to re-position the receptacles of certain modules with respect to the receptacles in other modules.

10. A duct terminator to be positioned in the concrete wall of an underground vault or the like at which the duct is to terminate, said duct terminator being positioned in the form used to shape said wall, and said duct terminator comprising:

a pair of barrier walls spaced apart at a distance substantially corresponding to the thickness of said concrete wall for receipt of concrete therebetween;

receptacle means extending between said barrier walls and forming through passage means from one of said barrier walls to the other of said barrier walls, the ends of said receptacle means being integral with said barrier walls whereby said terminator may be positioned in said form and concrete poured into said form to provide a concrete wall having passage means extending therethrough for receipt of the said duct; and

with the intermediate portion of said receptacle means being formed with a peripheral shoulder for abutment with the extremities of said duct, said receptacle means being provided with a radially outwardly extending flare at its end opposite the end from which said duct is received.

11. A duct terminator as set forth in claim 10 wherein:

said receptacle means includes a web normally blocking communication through said passage means and which may be removed before said duct is installed.

12. A duct terminator as set forth in claim 10:

wherein the edges of said barrier walls are formed with complementarily interfitting connection means whereby a plurality of said duct terminators may be coupled together.

13. A duct terminator as set forth in claim 10:

which further includes cap means removably secured to said barrier walls to selectively block communication through said passage means.

14. Duct terminator apparatus to be positioned in the concrete wall of an underground vault or the like at which a plurality of ducts are to terminate, said apparatus being positioned in the form used to shape said wall and said apparatus comprising:

a plurality of like terminator modules each including respective pairs of barrier walls spaced apart at a distance corresponding substantially to the thickness of said concrete wall and formed at their edges with complementary male and female flanges and grooves for coupling said edges together, each of said modules further including a receptacle extending between said barrier walls to form a through passage from one of said barrier walls to the other, and with said modules being assembled by interfitting the male and female flanges of adjacent modules whereby concrete poured between said vertical walls during pouring of said vault will position said modules in said vertical walls to form spaced passages for receipt of the extremities of said ducts.

15. A duct terminator apparatus as set forth in claim 14:

which further includes cap means removably secured to said barrier walls to selectively block communication through said passage means.