U.S. patent application number 10/754855 was filed with the patent office on 2004-08-12 for plastic duct terminator.
Invention is credited to Sack, James A..
Application Number | 20040154239 10/754855 |
Document ID | / |
Family ID | 32829741 |
Filed Date | 2004-08-12 |
United States Patent
Application |
20040154239 |
Kind Code |
A1 |
Sack, James A. |
August 12, 2004 |
Plastic duct terminator
Abstract
A duct terminator and supplemental components of a terminator
system are described. The duct terminator includes a tubular body
having a distal end and a proximal end, the proximal end being
adapted to receive a conduit. A removable diaphragm is adjacent the
distal end. The terminator can include an inner mounting ring and
an outer mounting ring at the distal end. A single circumferential
collar extends around the outside of the tubular body. The
supplemental system components include a terminator seal, an
extender and a bell, each of which have a proximal end adapted to
engage the distal end of the duct terminator. The extender has a
distal end shaped to replicate the distal end of the duct
terminator.
Inventors: |
Sack, James A.; (Elverson,
PA) |
Correspondence
Address: |
John J. Marshall
Drinker Biddle & Reath LLP
Suite 300
1000 Westlakes Drive
Berwyn
PA
19312-2409
US
|
Family ID: |
32829741 |
Appl. No.: |
10/754855 |
Filed: |
January 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60439008 |
Jan 9, 2003 |
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Current U.S.
Class: |
52/144 |
Current CPC
Class: |
E03F 5/02 20130101; E03F
5/021 20130101 |
Class at
Publication: |
052/144 |
International
Class: |
E04B 001/82 |
Claims
What is claimed is:
1. A duct terminator comprising: a tubular body having a proximal
end and a distal end; a removable diaphragm adjacent the distal
end; the tubular body comprising a proximal section having a first
average internal diameter and a distal section having a second
average internal diameter, the proximal and distal sections being
separated by a step; a circumferential collar extending around the
outside of the proximal section; longitudinal proximal ribs
extending from the circumferential collar toward the proximal end;
and longitudinal distal ribs extending from the circumferential
collar toward the distal end.
2. The duct terminator of claim 1 wherein the internal diameters of
the proximal and distal sections are tapered less than about 0.40
degrees.
3. The duct terminator of claim 1 further comprising an inner
mounting ring and an outer mounting ring on the distal end.
4. The duct terminator of claim 3 wherein the removable diaphragm
includes a peripheral ring and the removable diaphragm can be
removed from the tubular body at an area of weakness between the
peripheral ring and the outer mounting ring.
5. The duct terminator of claim 1 wherein the circumferential
collar includes a portion that extends substantially concentrically
with the longitudinal axis of the tubular body.
6. The duct terminator of claim 1 wherein the longitudinal distal
ribs and the longitudinal proximal ribs are circumferentially
offset from one another.
7. A duct terminator comprising: an injection molded tubular body
having a proximal end and a distal end; a removable diaphragm
adjacent the distal end; and a circumferential collar reinforced by
distal longitudinal ribs extending from the collar toward the
distal end; the tubular body having an inside surface that is
tapered less than 0.40 degrees.
8. The duct terminator of claim 7 further comprising an inner
mounting ring and an outer mounting ring on the distal end.
9. The duct terminator of claim 8 wherein the removable diaphragm
includes a peripheral ring and the removable diaphragm can be
removed from the tubular body at an area of weakness between the
peripheral ring and the outer mounting ring.
10. The duct terminator of claim 7 further comprising proximal
longitudinal ribs extending from the circumferential collar toward
the proximal end;
11. The duct terminator of claim 10 wherein the proximal
longitudinal ribs are circumferentially offset from the distal
longitudinal ribs.
12. The duct terminator of claim 7 wherein the circumferential
collar includes a portion that extends substantially concentrically
with the longitudinal axis of the tubular body.
13. A duct terminator comprising: a tubular body having a distal
end and a proximal end, the proximal end being adapted to receive a
conduit; a removable diaphragm adjacent the distal end, the
removable diaphragm comprising a peripheral ring; an inner mounting
ring and an outer mounting ring at the distal end, the inner
mounting ring disposed on the removable diaphragm; the diaphragm
being removable at an area of weakness between the peripheral ring
and the outer mounting ring; and a circumferential collar extending
around the outside of the tubular body.
14. The duct terminator of claim 13 wherein the tubular body
comprises an internal diameter with a taper of less than 0.40
degrees.
15. The duct terminator of claim 13 wherein the tubular body
comprises a proximal section having a first average internal
diameter and a distal section having a second average internal
diameter, the proximal section and distal section being separated
by a step.
16. The duct terminator of claim 15 wherein the proximal section
and distal section each have a taper of less than 0.40 degrees.
17. The duct terminator of claim 13 further comprising distal
longitudinal ribs extending from the circumferential collar toward
the distal end and proximal longitudinal ribs extending from the
circumferential collar toward the proximal end.
18. The duct terminator of claim 17 wherein the distal longitudinal
ribs and proximal longitudinal ribs are circumferentially
offset.
19. The duct terminator of claim 13 wherein the circumferential
collar includes a portion that extends substantially concentrically
with the longitudinal axis of the tubular body.
20. A duct terminator system comprising: a duct terminator
comprising: a tubular body having a distal end and a proximal end,
the proximal end being adapted to receive a conduit, a removable
diaphragm adjacent the distal end, an inner mounting ring and an
outer mounting ring at the distal end, the inner mounting ring
disposed on the removable diaphragm, and a circumferential collar
extending around the outside of the tubular body; and at least one
supplemental system component comprising a proximal end adapted to
engage one or both of the mounting rings of the duct terminator,
the supplemental system component being selected from the group
consisting of a terminator seal, an extender and a bell.
21. The duct terminator system of claim 20 wherein the supplemental
system component is an extender having a distal end shaped to
replicate the distal end of the duct terminator.
22. The duct terminator system of claim 21 wherein the extender
includes a removable diaphragm adjacent the distal end, and an
inner and outer mounting ring at the distal end.
23. The duct terminator system of claim 22 wherein the removable
diaphragms of the extender and the duct terminator each include a
peripheral ring and each can be removed at an area of weakness
between the peripheral ring and the outer mounting ring.
24. The duct terminator system of claim 21 further comprising a
terminator seal, wherein the proximal end of the extender can be
engaged with the distal end of the duct terminator, and the seal
can be engaged with the distal end of the extender.
25. The duct terminator system of claim 21 further comprising a
bell, wherein the proximal end of the extender can be engaged with
the distal end of the duct terminator, and the bell can be engaged
with the distal end of the extender.
26. The duct terminator system of claim 20 wherein the supplemental
system component is a seal, the seal being reusable.
27. A duct terminator system comprising: a duct terminator
comprising a tubular body having a proximal end and a distal end,
and a universal mounting structure on the distal end; at least two
different supplemental system components each having a connecting
structure on a proximal end adapted to connect with the universal
mounting structure, the supplemental system components being
selected from the group consisting of a seal, an extender and a
bell.
28. The duct terminator system of claim 27 wherein one of the
supplemental system components is a reusable seal.
29. The duct terminator system of claim 28 wherein the connecting
structure of the reusable seal fits inside of the universal
mounting structure such that the seal does not become locked in
concrete when concrete is poured around a combined terminator and
seal.
30. The duct terminator system of claim 27 wherein one of the
supplemental system components is an extender.
31. The duct terminator system of claim 30 wherein the extender has
a distal end that replicates the universal mounting structure.
32. The duct terminator system of claim 27 wherein one of the
supplemental system components is a bell.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from U. S.
Provisional Application No. 60/439,008, filed Jan. 9, 2003, which
is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to duct terminators used to provide
knock-outs in ducting for into concrete structures.
BACKGROUND OF THE INVENTION
[0003] Concrete structures such as underground sewer, water and/or
electrical junctions, pump or transformer enclosures, culverts, and
similar vaults are often "precast` in standard configurations. The
structures are provided with cylindrical ducts through the walls to
pass electrical cables for electrical power, telecommunications, or
other conduits into the vault. Some of the ducts may not be used.
Consequently, it is common to originally terminate (close) the
ducts with a plastic diaphragm in each duct to provide a waterproof
seal. The diaphragm is a knock-out part that can be removed if the
duct will be used.
[0004] A conventional duct terminator is usually an injection
molded plastic part that is used as an insert in the concrete mold
to define the duct. It is typically a hollow cylindrical tube with
a diaphragm inside its barrel that seals the barrel and prevents
water from entering the vault if the duct is not used. The
diaphragm includes a "knock-out" line that is weaker than the
surrounding portions such that the diaphragm can be pushed out of
the terminator barrel to open the duct.
[0005] A conventional duct terminator has multiple ribs running
about the circumference of the part to anchor the terminator in the
concrete wall. To form the ribs, conventional terminators are
molded in an injection system that requires a two action molding
tool.
[0006] The configuration of the conventional terminator also
requires the molder to eject the part from the tool by pushing it
off from the far end "knock-out". Thus, the thickness of the rim on
the knock-out may be determined in part by the need to withstand
the mold ejection rods without punching out the diaphragm. A thick
rim withstands the action of the push rods, making it easier to
push the part off the tool. On the other hand, a thin rim makes it
easier to punch the diaphragm out while in a concrete wall, without
leaving any plastic chards on the rim.
[0007] As the injection molded part is pushed off the mold tool
from the far end, it tends to constrict, resisting its removal from
the mold. In order to minimize the effect of constriction, a
conventional terminator has a relatively large degree of taper, at
least about 0.5 degrees, and more commonly up to about 2 degrees,
to its internal diameter ("I.D."). A part with less taper would
allow for better adhesion between the pipe, which has no taper, and
the part when in use.
SUMMARY OF THE INVENTION
[0008] The invention relates to a duct terminator and to a
terminator system comprising a duct terminator with supplemental
components. The duct terminator includes a tubular body having a
distal end and a proximal end, the proximal end being adapted to
receive a conduit. A removable diaphragm is adjacent the distal
end. The terminator includes a universal mounting structure, such
as an inner mounting ring and an outer mounting ring at the distal
end, for receiving a supplemental component. A single
circumferential collar extends around the outside of the tubular
body closer to the proximal end than the distal end.
[0009] The duct terminator can be injection molded with an internal
diameter having a taper of less than 0.40 degrees. The taper can be
so small because the molded part can be ejected from the mold tool
at reinforced ejection points on the circumferential collar near
the proximal end.
[0010] The supplemental system components include a terminator
seal, an extender and a bell, each of which have a proximal end
adapted to engage the universal mounting structure on the distal
end of the duct terminator. The extender has a distal end shaped to
replicate the universal mounting structure of the duct terminator.
The supplemental components can be used in combination with the
duct terminator to allow a concrete vault builder to create points
of entry for conduits in walls of various thicknesses using only a
few stock components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For the purpose of illustrating the invention, there are
shown in the drawings forms which are presently preferred; it being
understood, that this invention is not limited to the precise
arrangements and instrumentalities shown.
[0012] FIG. 1 is a perspective view of the side and distal end of a
duct terminator according to an embodiment of the present
invention.
[0013] FIG. 2 is a perspective view showing the proximal end of the
duct terminator of FIG. 1.
[0014] FIG. 3 is a perspective view of a terminator seal according
to an embodiment of the present invention.
[0015] FIG. 4 is a perspective view of the seal of FIG. 3 engaged
with the distal end of the duct terminator of FIG. 1.
[0016] FIG. 5 is a cross-sectional view taken through line 5-5 in
FIG. 4.
[0017] FIG. 6 is a perspective view of an extender according to an
embodiment of the present invention.
[0018] FIG. 7 is a perspective view of a bell according to an
embodiment of the present invention.
[0019] FIG. 8 is a cross-sectional view of an assembly of the duct
terminator of FIG. 1, the extender of FIG. 6 and the bell of FIG.
7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] In the Figures, in which like numerals indicate like
elements, there is shown a duct terminator and terminator system
according to an embodiment of the present invention. As shown in
FIGS. 1 and 2, the system includes a duct terminator 10 having a
tubular body 12. The duct terminator 10 can be attached to a form
used for pouring a concrete structure, such as a wall of an
underground vault. The duct terminator's tubular body 12 defines an
opening in the poured concrete wall that can be used for receiving
conduit, such as a pipe carrying power, telecom or other wires,
cables or the like, into the structure.
[0021] The tubular body 12 has a distal end 14 and a proximal end
16. As used herein, the terms "proximal" and "distal" refer to the
intended position of the ends 14, 16 (or other component) relative
to an incoming conduit. Thus, a conduit coming into the structure
would be inserted into the proximal end 16 of the duct terminator
10.
[0022] The duct terminator 10 includes a single circumferential
collar 18. The circumferential collar 18 includes a portion 20 that
projects radially from the tubular body 12 and a portion 22 that
extends from the top of the radially projecting portion 20
substantially concentrically with the longitudinal axis of the
tubular body 12. The radially projecting portion 20 and
concentrically extending portion 22 together provide the
conferential collar 18 with an L-shape when viewed in
cross-section.
[0023] The duct terminator 10 includes distal longitudinal ribs 24
on the distal side of the circumferential collar 18 and proximal
longitudinal ribs 26 on the proximal side of the circumferential
rib 18. The distal longitudinal ribs 24 extend from the
circumferential collar 18 toward the distal end 14 of the duct
terminator. The distal longitudinal ribs 24 are preferably spaced
apart about thirty (30) degrees from one another. A series of
proximal longitudinal ribs 26, which extend from the collar 18
toward the proximal end 16, are also preferably spaced apart about
thirty degrees from one another. Although the distal ribs 24 and
proximal ribs 26 can be made in line with one another, it is
preferred that they be circumferentially offset by about 15 degrees
as shown in the drawings.
[0024] The duct terminator 10 includes a removable diaphragm 28
adjacent distal end 14. (As used herein, the term "adjacent" is
meant to include its broad meaning of "near" or "proximal to",
which may, but not necessarily be "bordering on" or "contiguous
with"). The diaphragm 28 can be designed with a frangible perimeter
for easy removal thereof. With specific reference to FIG. 2, the
inside of the frangible diaphragm 28 can be provided with raised
reinforcing elements to assist in ensuring that the diaphragm 28
can be removed as a unit. These reinforcing elements can include a
peripheral ring 30 and radial spokes 32. The area of weakness that
forms the frangible perimeter is formed just outside of the
peripheral ring 30. Being best seen in cross section, the area of
weakness is further described below with regard to FIG. 5.
[0025] The round inside surface of the duct terminator includes two
sections of different internal diameters, separated by a step 32.
The proximal section 34 has a length L.sub.A and an average
internal diameter ID.sub.A. The distal section 36 has a length
L.sub.B and an average internal diameter ID.sub.B, which is less
than ID.sub.A. The internal diameters ID.sub.A, ID.sub.B are
described as average values because the sections 34, 36 are each
produced with a slight taper, which can be less than 0.40 degree
and preferably about 0.25 degree. The taper is desirable to
facilitate ejection of the part from the tool when the part is
molded. However, it is also desirable to keep the taper slight so
that the inside of the terminator 10 can snugly receive a conduit,
which is not tapered. Thus, the smallest taper that permits easy
ejection from the mold tool is generally the most desirable.
[0026] The ID.sub.A of the proximal section 34 is selected to
receive a conduit of a first outer diameter. Preferably, the
ID.sub.A is selected to receive schedule 40 or schedule 80 conduit,
which have different inner diameters, but the same outer diameter.
To make the preferred ID.sub.A, Section 34 can be produced with an
internal diameter at the small end of from 4.500 to 4.510
inches.
[0027] The ID.sub.B of distal section 36 is selected to receive a
conduit of a second outer diameter that is smaller than the first
outer diameter. Preferably, the ID.sub.B is selected to receive
C-Duct type conduit, which is commonly used for telecom
applications. To make the preferred ID.sub.B, Section 36 can be
produced with an internal diameter at the small end of from 4.350
to 4.360 inches.
[0028] The respective lengths L.sub.A and L.sub.B of the sections
34 and 36 can be of different lengths, but are preferably of
substantially equal lengths. In a preferred embodiment, each of the
lengths L.sub.A and L.sub.B are approximately 3.8 cm (1.5 inches).
Thus, approximately 3.8 cm of contact can be achieved between the
inside of the duct terminator 10 and the conduit, regardless of
whether the conduit has the first outer diameter or the second
diameter. (Keeping in mind the taper of the internal diameters of
the sections 34, 36, it is understood that the term "contact", as
used herein, does not require precise uniformity.) It is also
possible to produce the terminator 10 with only one section 34 or
36.
[0029] Two mounting rings extend from the distal end of the
preferred duct terminator 10. The mounting rings include an inner
mounting ring 38 and an outer mounting ring 40. The mounting rings
38, 40 together form a receiving groove for accepting a
supplemental component of the duct terminator system. Before
describing the supplemental components, some of the advantages of
the present invention relating to the molding tools and process of
molding the duct terminator 10 will now be described.
[0030] The duct terminator can be injection molded from rigid PVC
or the like. Having only a single circumferential collar 18
eliminates the need for side actions in the molding process, which
are necessary in forming a conventional plastic duct terminator.
The L-shape of the collar 18 provides functionality and part
strength. The longitudinal ribs 24, 26 are inline with the mold
action. These features provide additional part strength with
minimum tool complexity. In addition, because the duct terminator
10 can be produced with ribs inline with the mold action and
without side action due to the single collar 18, multiple duct
terminator 10 parts can be produced using a multi-cavity tool in
the same machine, further lowering part cost.
[0031] Another advantage of the preferred duct terminator 10 is
that various features can be molded relatively thin. For example,
the circumferential rib 18 can be thin because of the manner in
which the duct terminator 10 can be injected from the mold tool.
After the part has been injection molded between a male and female
mold tool and the tools are separated, the part tends to remain on
the male mold tool. The part can be pushed off the tool using
ejector pins built into the male tool. The ejector pins can be
positioned to push against the circumferential collar 18 at points
42 immediately opposite distal longitudinal ribs 24. (There may be
provided as many ejector pins as there are distal longitudinal
ribs, or there may be provided as few as two or three, as desired.)
Thus, when the ejector pins actuate to push the part, the points of
contact 42 are well supported by the distal longitudinal ribs 24.
Due to the excellent support provided by the ribs 24 and the
stability of the collar provided by its L shape, the collar 18 can
be made quite thin, while still having adequate strength.
[0032] A further advantage achieved using the inventive molding
process is the small degree of taper needed. As noted above, the
inside sections 34, 36 of the preferred duct terminator 10 have a
small taper of less than 0.40 degree, and preferably about 0.25
degree. The push force of the ejector pins can be applied at points
42 on the collar 18, which is closer to the proximal end 16 than it
is to the distal end 14. (The position of the collar 18 relative to
the ends 14, 16 is most evident in FIG. 5.) Thus, as the part is
pushed off of the male tool in the direction of arrow "Pin Force"
(FIG. 2), the force along most of the length of the inside surface
in contact with the tool, including all of L.sub.B and a portion on
L.sub.A, is a pushing force, rather than a pulling force. The arrow
"Pin Force" is intended to be pointing into the page parallel with
the longitudinal axis of the terminator 10. Under such a pushing
force, the part tends to expand slightly, making ejection
relatively easy. (In contrast, a conventional duct terminator is
ejected from a male tool primarily with a pulling force, which
tends to cause constriction similar to that of a child's finger
trap toy.) Because the pushing force facilitates ejection without
substantial part constriction, a large degree of taper to the
inside diameter is not necessary. Thus, the duct terminator 10 can
be produced with a small taper of less than 0.40 degree.
[0033] As shown in FIG. 3, a first supplemental component of the
duct terminator system can be a terminator seal 50. The seal 50 is
a deformable, elastomeric member, formed from flexible PVC or the
like, which in use will compress to fill space between the distal
end 14 of the terminator and a form wall. The seal 50 includes a
connecting ring 52, which is sized to be slightly larger than the
space between the inner 38 and outer 40 mounting rings of the duct
terminator. The seal 50 also includes a bell or parabolic shaped
portion 54 for deforming against a form wall. An internal support
structure 56 may be integrally molded with the seal if desired.
[0034] As shown in FIGS. 4 and 5, in use, the seal 50 can be
engaged with the duct terminator 10 by inserting the connecting
ring 52 between the inner and outer mounting rings 38, 40. During
insertion, the connecting ring 52 compresses between the mounting
rings 38, 40. The inward facing edges of the rings 38, 40 may be
beveled, as shown in the drawings, to assist with insertion. Once
inserted, the tendency of the connecting ring 52 to expand back to
its initial size tends to hold the connecting ring in place between
the mounting rings 38, 40.
[0035] The duct terminator 10 and seal 50 may be sized such that
the combination is appropriate for use in a form constructed to
pour a four inch concrete wall. When installed in such a form, the
seal 50 can deform so that the combined unit fits the form with
very good precision. After the wall has been poured and cures, the
seal 50 can be deformed away from the concrete and removed from the
wall if desired. The engagement of the seal connecting ring 52 with
the inner and outer mounting rings 38, 40 prevents the seal from
becoming locked in the concrete. Thus, the seal 50 can be reused
several times prior to it being discarded (or left permanently in a
cured wall).
[0036] Referring specifically to FIG. 5, it will now be explained
how the removable diaphragm 28 can be removed after a wall has been
poured and it is desired to run cables or wires through the wall.
As described above, the terminator 10 is formed with an area of
weakness adjacent (immediately outside of) the peripheral ring 30
of the diaphragm 28. The area of weakness is identified in FIG. 5
by reference numeral 44, which is an area disposed between the
peripheral ring 30 on the inside of the frangible diaphragm and the
outer mounting ring 40. The area of weakness can be thinned to
about thirty thousandth of an inch to create the shear point 44
around the perimeter of the diaphragm 28.
[0037] Once the diaphragm 28 has been removed or "knocked out", the
inside surface of the outer mounting ring 40 can become the inner
most (i.e., radially closest to the longitudinal axis) portion of
the duct terminator 10, because the inner mounting ring 38, spokes
32 and peripheral ring 30 are removed along with the diaphragm 28.
The radial distance between the inside surface of distal section 36
and the inside surface of the outer mounting ring 40 (if it were
extended into distal section 36) can be proportioned to replicate
the thickness of a conduit having the above-mentioned second
diameter, such as a C-Duct conduit. Thus, if such a conduit is
inserted into the section 36, the inside surface of the outer
mounting ring 40 will replicate an extension of the inner diameter
of the conduit.
[0038] Another advantage of the combined terminator 10 and seal 50
is the concrete coverage that forms around the distal end 14 of the
terminator when the structure is poured. Concrete can fill around
the tubular body 12 and around the distal end 14, contacting the
outer mounting ring 40. This concrete fill creates a stable ring of
concrete around the distal end 14. The stable ring of concrete is
advantageous because, in use, a builder can insert conduit into the
proximal end 16 of the terminator 10 using forceful means, such as
hammering the conduit with a heavy object from outside of the
structure. The stable ring of concrete at the distal end 14 helps
support the terminator 10 under the force, thereby helping to
ensure that parts of the terminator do not break under the force.
Otherwise, parts of the terminator and bits of concrete could
become dislodged from the structure under the hammering force,
ending up on the floor inside the structure.
[0039] Convenient sizes for the combined terminator and seal
include a length of 4 inches or 21/2 inches (which can be slightly
less than 4 inches or 21/2 inches to provide room for an attachment
device, such as a piece of plywood, inside a four-inch wide form)
and an approximate internal diameter of 4, 5 or 6 inches. Others
lengths and diameters are also possible.
[0040] Additional supplemental system components can be provided so
that the same terminator 10 can be used with forms for thicker
walls. Such additional supplemental components can be made of PVC
or other plastic material and can include an extender 60 shown in
FIG. 6, or a bell 80 shown in FIG. 7. Both the extender 60 and bell
80 are adapted to connect to the duct terminator 10. One or more
extenders 60 and bell 80 can also be used in combination as shown
in cross section in FIG. 8.
[0041] The extender 60 includes a tubular body 62 with a distal end
64 and a proximal end 66. The proximal end 66 is adapted to engage
the distal end 14 of the terminator 10 by gripping the outside of
the outer mounting ring 40. If desired, the junction between the
proximal end 66 of the extender and the distal end 14 of the duct
terminator can be glued.
[0042] The proximal end 66 of the extender can include a
circumferential L-shaped collar 68 that is similar to the collar 18
of the duct terminator 10. The extender 60 can also include
longitudinal ribs 70 that are similar to the distal ribs 24 of the
terminator 10. These features provide the extender 60 with support
and strength so that the amount of plastic used to mold the part
can be minimized.
[0043] The distal end 64 of the extender 60 can be made with inner
and outer mounting rings 72, 74 that replicate the mounting rings
38, 40 at the distal end 14 of the terminator 10. Similar to that
of the terminator 10, the inner mounting ring 72 can be mounted on
a removable diaphragm 76, which, if desired, may be made with the
same features described above with regard to diaphragm 28. The
diaphragm 76 can be removable at an area of weakness. In FIG. 8,
the diaphragm 76 has been removed from the extender 60. The area of
weakness where the diaphragm was attached (prior to removal) is
identified by the numeral 78.
[0044] If the duct terminator 10 has a length that is proportioned
to fit, in combination with the seal, a form for a four inch wall,
the extender can be formed with a length so that the combination of
a duct terminator 10, extender 60 and seal 50 fits within a form
for pouring a six inch wall. Two extenders 60 can be used if an
eight inch wall is to be poured.
[0045] The bell 80 includes a distal end 82 and a proximal end 84.
The proximal end 84 is adapted to engage the distal end 14 of the
terminator 10 or the distal end 64 of the extender 60. The bell 80
engages the distal end of either part by gripping the outside of
the outer mounting ring 40 (of the duct terminator) or 74 (of the
extender). If desired, the junction between the proximal end 84 of
the bell and the distal end 14 (of the duct terminator) or 64 (of
the extender) can be glued.
[0046] The distal end 82 includes a bell or parabolic shape to
provide a curved surface in a concrete wall for cables passing
through the wall. Such a surface may be desirable, for example, if
the cables have a limited bending radius. If the cable must be
terminated near the point of entry, it is, therefore, desirable to
begin the turn in the cable toward the point of termination at the
curved surface provided in the wall.
[0047] The duct terminator 10, seal 50, extender 60 and bell 80 can
be provided individually or as part of a modular duct terminator
system that allows a vault builder to accommodate vault walls of
various sizes while stocking only a few parts. This is possible by
providing the duct terminator with a universal mounting structure
on the distal end, such as the mounting rings described above. The
supplemental system components each have a connecting structure on
a proximal end adapted to connect with the universal mounting
structure, such as the connecting ring of the seal or the proximal
ends of the extender walls. Because the extender can be formed with
a distal end that replicates the universal mounting structure, one
or multiple extenders can be stacked and used in combination with
the duct terminator and/or other supplemental components.
[0048] A variety of modifications to the embodiments described will
be apparent to those skilled in the art from the disclosure
provided herein. Thus, the present invention may be embodied in
other specific forms without departing from the spirit or essential
attributes thereof and, accordingly, reference should be made to
the appended claims, rather than to the foregoing specification, as
indicating the scope of the invention.
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