Note: Descriptions are shown in the official language in which they were submitted.
CA 02348062 2001-05-17
METHOD FOR INSTALLING A FIBER OPTIC C'.ONDUIT SYSTEM
Field of the Invention
The present invention relates to a method for installing, for distribution and
networking,
telecommunication dedicated utility lines. More particularly, this invention
pertains to a method
for installing a fiber optic conduit for distribution and networking to
several end users.
Background of the Invention
Trenching and the installation of utility lines such as water, sewer and gas
service dates
1 o back to the nineteenth century. Those familiar with the more modern
approaches to trenching
and utility line installation will recognize that many of the conventional
methods of installing
these service lines has been carried over for use in installing modern
services such as
telecommunications and the like. In addition, often in the creation of a
residential or commercial
development area, the installation of utility lines, such as electrical,
water, gas and
1. 5 telecommunications services can be a considerable portion of the overall
development cost.
Various aspects of the installation of these services have been overlooked.
For example,
consideration of new types (or as yet unknown) of services, and service area
expansion have not
traditionally been given the importance they demand. 'I"his is particularly
the case in the initial
planning stages of these residential and commercial development areas. As
such, when new
2 o types of services become available or when service areas need to be
expanded, traditional
installation techniques may not provide the means or capabilities to do so in
an efficient and cost
effective manner, arid without undue disruption to existing services.
Several methods have been utilized to distribute utility lines and more
specifically, fiber
optic cable, from a distribution source to an end user. For example,
traditional systems employ
following a trench for electrical lines with separation at a higher trench
elevation for fiber optic
cable. Other methods utilize one major fiber optic, co-axial trunk conduit
that is spliced into
several service conduits that are eventually distributed to an end user.
However, because there
was only one splicing location, loclg service conduit runs became necessary.
These long runs,
however, often require routing to avoid obstacles between the splicing
location and the end user,
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CA 02348062 2001-05-17
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making it difficult to trench. This also typically results in forming numerous
bends in the service
conduit, causing cable placement tension.
Accordingly, there continues to be a need for a method for readily installing
a plurality of
utility services in a single trench, and specifically providing for an
efficient method for installing
a fiber optic cable and conduit system.
Summary of the Invention
The present invention is a method for installing a fiber optic conduit system
to a plurality
of end users. The method includes the steps of: ( 1 ) excavating a unitary
trench from a common
location; (2) positioning a fiber optic cable and electric line in the unitary
trench; (3) extending
the fiber conduit toward a local access pedestal; (3) networking and
distributing the fiber optic
conduit at the pedestal toward a plurality of service access points; (4)
splicing the fiber conduits
at the access points toward a plurality of distribution boxes; and (5)
splicing the fiber optic
conduit at the distribution boxes toward a plurality of end users.
T'he method of the present invention provides an efficient distribution of
fiber optic cable
to an end user- by utilizing the least number of local access pedestals,
service access points and
distribution boxes, to reduce costs. In addition, the present method allows
service runs between
the end user and distribution boxes to, generally, be less than 500 ft. and
have less than 360° of
total turns. Keeping service runs, between the distribution boxes and end
user, short reduces the
2 0 possibility of bends in the service runs. 'Those skilled in the art
recognize that bends in fiber
optic cable can cause undesirable cable placement tension. The present method
also has other
untold advantages over conventional methods used to install a fiber optic
conduit system.
In a preferred method, the unitary trench includes a base and generally
vertically
extending side walls that are between about 48 and 66 inches deep and about 24
inches wide.
2 5 The preferred method also includes the steps of positioning the electrical
utility line and the fiber
optic conduit at the lowest elevation of the unitary trench and positioning
the electrical utility
line and the fiber optic conduit so that they are at the same depth within the
unitary trench.
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Pursuant to a preferred method, filler can be replaced below the electrical
line and fiber optic
conduit to form a flat trench base below the electrical utility line and fiber
optic conduit.
Desirably, in the preferred method, the service access points are connected to
three
distribution boxes and the distribution boxes service up to about twenty end
users. The preferred
method can also include the steps of extending spare conduits from the, local
access pedestal,
service access points and distribution boxes to remote locations for possible
future development
or redevelopment.
Preferably, a trunk conduit is used for runs between the distribution source
and the
pedestal, between the pedestal and the access points and between the access
points and
1 o distribution boxes while service conduits are used for runs between
distribution boxes and the
end users.
In addition, the preferred method advantageously includes the step of
embedding PVC conduit sleeves in foundations of the end users. 'The conduit
sleeves can be
Located at twelve to eighteen inches away from electrical panels of the end
users and rise
eighteen inches above grade
Brief Description of the Figures
Further objects of the invention, taken together with additional features
contributing
thereto and advantages occurring therefrom, will be apparent from the
following description of
2 0 the invention when read in conjunction with the accompanying drawings,
wherein:
FIG. I is a layout view of an embodiment of a fiber optic system installed in
accordance
with the principles of the present invention, the system configured to
distribute
telecommunication signals through fiber optic cables routed from a
distribution source to several
end users by using a local access pedestal, several service access points and
several distribution
2 5 boxes;
F1G. 2 is a cross-sectional view of an exemplary trench illustrating the
placement or
position of fiber optic cables and conduits relative to other service lines
and one another, within
the trench;
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FIG. 3 is a perspective view of a local access pedestal configured to receive
one trunk
conduit and send out several trunk conduits;
FIG. 4a and 4b illustrate an exemplary service access point configured to
receive one
trunk conduit and send out a plurality of trunk conduits. Fig. 4a being a
perspective view thereof
and Fig. 4b being a top view thereof;
FIG. Sa and Sb illustrate an exemplary distribution box configured to receive
one trunk
conduit and send out a plurality of service conduits. Fig. Sa being a
perspective view thereof and
F ig. 5b being a top view thereof;
FIG. 6 is a perspective view of a PVC sleeve embedded in an end user's
foundation; and
1 o FIG. 7 is a perspective view showing the location of the PVC sleeve with
respect to the
end user's structure.
Detailed Description of the Preferred Embodiments
While the present invention is susceptible of embodiment in various forms,
there is
shown in the drawings and will hereinafter be described a presently preferred
embodiment with
the understanding that the present disclosure is to be considered an
exemplification of the
invention and is not intended to limit the invention to the specific
embodiment illustrated.
Referring now to the figures, and in particular to FIG. 1, there is shown a
fiber optic cable
and conduit system 10 that has been installed in accord with the principles of
the present
2 o invention. In a present method, a common trench I 2 is used to route
utility lines I 4 from several
distribution sources 16 to end users 18. The utility lines 14 can include, but
are not necessarily
limited to, one or more gas distribution lines 14a, cable television lines
14b, fiber optic
telecommunication lines 24 and electrical or power lines 26. It is anticipated
that the application
of the present technologies and future technologies will permit the
transmission of all
2 5 telecommunication, including, for example cable television, along a single
signal carrier or line.
Advantageously, this present method allows a contractor to install a fiber
conduit system I 0 from
a distribution source 16 to an end user ~ 8 during the development of an area
or re-development
of an area and also allows the contractor to plan for possible future
expansion of the area.
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As shown in FIG. 2, an exemplary common trench 12 is to be about 48 to about
66 inches
in depth (D) (e.g., below grade) and about 24 inches in width (W).. In the
exemplary common
trench 12, all of the utility lines 14 are included within the single trench
12 having a base or
bottom 20 and generally vertically extending side walls 22. Fiber optic cable
24 and electrical
lines 26, if installed, would occupy the deepest layer of the trench. After
installation of these
lines, compacted soil filler (F) is returned below the electrical lines 26 and
fiber optic cable 24 to
provide a flat trench base 28. The flat trench base 28 assures that the lines
26 and cables 24 are
routed on a level and uniform surface, which, with respect to fiber optic
cables, reduces cable
placement tension. It has been observed that fiber optic cable can be
subjected to this tension
1 o when there are deviations in trench depth. After the filler (F) is
returned below the electrical
lines 26 and fiber optic cable 24, the trench 12 is filled with additional
filler (F).
Additional utility lines 14 may then be installed above the electrical lines
26 and fiber
optic cables 24 as desired. Those skilled in the art will recognize that any
or all of these lines, as
well as other utility services, may be necessary or desirable for installation
within an area under
development, or in an area that may be under re-development.
In a preferred system, electrical lines 26 and fiber optic cable 24 are routed
in the same
trench I 2 and are at the same depth within the trench 12. By utilizing the
same trench for routing
electrical lines and fiber optic cable, the present system advantageously
eliminates the
requirement for additional telecommunication facility installations and allows
access to both
2 o electrical and telecommunication lines at the same location. The
conventional approach invoked
following the electrical trench with separation at a higher trench elevation
for the fiber optic
cables. When, as anticipated, the fiber facility becomes the only
telecommunication means
needed, the present system has the net effect of reducing work for the
installation contractor vis-
a-vis conventional methods; e.g., only one trench need be excavated.
2 5 As can be seen from FI(J. 2, a Gammon trench can be used to route gas 14a,
water I 4b,
electrical 26 and fiber optic telecommunications 24, including cable
television lines, from a
plurality of primary utility trenches 30 in a preferred system. It will of
course be recognized that
the tiber optic cable 24 can be used for all telecommunication services
including, but not limited
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to telephone, cable television service, other data and voice communication
signals including
computer signal transmission. It is also anticipated that, given technological
advances
unforeseen, other, not presently known telecommunications or like signals can
be transmitted via
these cables.
As shown in FIG. 1, the lines 14 are routed from the primary trenches 30 to a
receiving
region 32 for the common trench 12. In a most preferred method, as shown in
FIG. 1, the fiber
optic cable 24 is routed through the common trench 12 to a local access
pedestal ("LAP")
indicated at 34. The LAP 34 is used to further distribute and route fiber
optic cable 24. In the
preferred system, the fiber optic cable '?4 is further distributed to a
service access point ("SAP")
36. From the SAP 36, the fiber optic cable 24 is further routed to a
distribution box 38, from
which it is routed to an "end user" 18, such as a commercial or residential
structure 40. In the
most preferred system, each "end user" 18 has a network access panel ("NAP")
42 mounted on,
for example, a wall of their commercial or residential structure 42.. The
fiber optic run terminates
at the NAP.
A preferred method utilizes trunk conduits 44 fox trunk runs between
distribution sources
16 and LAPS 34, between LAPS 34 and SAPS 36, between two SAPs 36, between SAPS
36 and
distribution boxes 38, between two distribution boxes 38 or sometimes, in the
case of
commercial buildings, between a distribution box 38 and a commercial building.
The trunk
conduits 44 are generally formed from two inch db60 conduit or other
previously installed
2 0 electrical conduits as may be found to be suitable. In this method,
service conduit 46 can be used
for service runs between distribution boxes 38 and end users 18. The service
conduit 46
typically consists of three-quarter inch silicone lined flexible conduit.
Service conduit 46 is
desirable since preformed bends are not required. In addition, a worker may
roll a "bend", or
form the service conduit 46 for insertion into an LAP box 34, SAP box 36 or
distribution box 38
2 5 without the use of heat tools, even in sub-freezing weather. Furthermore,
the service conduit 46
allows up to two thousand feet for service rucvs_ In the most preferred
installation, however, as
discussed below, the service runs are limited to five hundred feet or less.
.. CA 02348062 2001-05-17
An efficient method to distribute fiber optic cable 24 is realized when the
fiber conduit
system 10 of the preferred method is used. The LAP 34, SAP 36, and
distribution boxes 38 are
expensive fiber optic splicing, switching and networking devices. The cost of
a fiber optic
conduit system 10, therefore, can be greatly reduced by allowing the highest
number of end users
18 to be reached while using the least number of LAPS 34, SAPs 36, and
distribution boxes 38.
The present method of installing a fiber optic conduit system 10 does this by
locating the
LAPS 34, SAPs 36, and distribution boxes 38 in strategic locations, as will be
described below.
In addition, the trunk conduits 44 and service conduits 46 utilized in the
preferred method
facilitate reducing costs by obviating the need for heat tools during
installation.
Previous fiber conduit systems incorporated one major fiber optic, co-axial
trunk conduit
that was spliced into several smaller service conduits that were eventually
distributed toward an
end user. Because there was only one splicing location, the previous system
required long
service conduit runs from the splicing location to the end user. The long
runs, however, would
often have to be routed to avoid obstacles between the splicing location and
the end user, making
it difficult to trench, and also often resulting in several bends in the
service conduit. As will be
recognized by those skilled in the art, bends in the service conduit runs can
cause undesirable
cable placement tension.
In the most preferred method, an LAP box 34, such as the exemplary box
illustrated in
FIGS. 3, is installed. 'fhe I,AP box 34 is a major fiber networking device
which receives a trunk
2 o conduit 44 from the distribution source 16 and distributes the conduit
toward several SAPs 36
upstream. Preferably, a conduit spare 48 that extends to the project limits to
account for
anticipated or unanticipated development expansion is connected to the LAP box
34. Typical
LAP boxes 34 include provisions for Emergency and routine rerouting and are
also electrically
controlled. To this end, the LAP box 34 has access to uninterruptible 120 volt
electrical power.
2 5 As a result, in the most preferred method, the LAP box 34 is strategically
located so it can be
connected to a plurality of SAI' boxes 36 upstream and so that the box 34 has
access to an
uninterruptible 120 volt power source.
CA 02348062 2001-05-17
The method can further include installing several SAP boxes 36, as depicted in
FIGS. 4a
and 4b. The SAP boxes 36 receive a trunk conduit 44 from the LAP box 34 and
distribute the
conduit 34 to several distribution boxes 38. In addition, SAP boxes 36 used in
carrying out the
most preferred method preferably have one conduit spare 48 extending toward
the project limits
to account for possible area expansion. It should also be noted that SAP boxes
36 may not be
required in early development projects but can be installed nonetheless to
permit later planned or
unplanned area expansion.
Generally, SAP boxes 36 are both fiber splicing locations and signal switching
locations.
In addition, SAP boxes 36 are electrically controlled and have access to
uninterruptible 120 volt
1 o electrical power. In the most preferred method, SAP boxes 36 are located
so they can be
connected to at least three distribution boxes 38 upstream and so that the
boxes 36 have access to
an uninterruptible 120 volt power source.
The present method, in addition, can include the installation of several
distribution boxes
38, as shown in FIGS. Sa and Sb. F~ach distribution box 38 receives a trunk 44
or service conduit
1.5 46 from the SAP boxes 36 and distributes it to a plurality of end users
18. Typically, distribution
boxes 38 are fiber splicing locations that do not have additional signal
modifying equipment.
Rather, they are distribution and splicing locations that are capable of
providing service to up to
about twenty-six end users 18. Distribution boxes 38 used in carrying out the
most preferred
method, however, only service up to about twenty end users 18, and have a
conduit spare 48 that
2 0 runs toward the project limits for possible development expansion. In
addition, distribution
boxes 38 are desirably situated so that they are relatively distant from
customer service locations,
while being central to a group of end users 18, so that the service runs from
the distribution box
38 to the NAPs 42 are less than about S00 feet and so that service runs from
the distribution box
38 to the NAPS 42 require less than 360° of total turns.
2 5 As depicted in FIG. 6, the most preferred method can also include
embedding a one-and-
one-half inch PVC conduit sleeve 50 in the end user's foundation 52 at least
about twelve to
about eighteen inches away from the end user's electrical panel 54, which
conduit rises about
eighteen inches above grade (G). 'The PVC'. conduit 50 facilitates later
installation of a flexible
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service conduit 46. As shown in FIG. 7, the end user can then elect to install
a NAP 42 at the
end of the PVC conduit 50, at about eighteen inches above grade (G) and about
twelve to about
eighteen inches from the end user's electrical panel 54. The NAP 42 typically
terminates the
fiber service run and translates light signals into other signal media for use
in the home such as a
television, computer networking topology, and telephone when installed at the
end user's
structure.
From the foregoing it will be observed that numerous modifications and
variations can be
effectuated without departing from the true spirit and scope of the novel
concepts of the present
invention. It is to be understood that no limitation with respect to the
specific embodiments
1 o illustrated is intended or should be inferred. The disclosure is intended
to cover by the appended
claims all such modifications as fall within the scope of the claims.
