Note: Descriptions are shown in the official language in which they were submitted.
CA 02363412 2001-11-21
OPTICAL FIBER WINDING TOOL
FIELD OF THE INVENTION:
to The present invention relates to the general field of optical fiber
accessories and is
particularly concerned with an optical fiber winding tool.
BACKGROUND OF THE INVENTION:
The use of optical fibers for telecommunication systems and other applications
has
become increasingly prevalent over the past few years. As is well known in the
art,
optical fibers are typically hair thin structures, capable of transmitting
light signals at high
rates and with low signal loss. They are ideally suited to the high
requirements of digital
2o transmission and, hence, are well matched to the evolving worldwide
transmission
network.
The most popular medium for light wave transmission through optical fibers is
glass, a
solid whose structure is amorphous. Commercial optical fibers are drawn from a
pre-
form, an elongated cylinder of glass having an inner core and an outer
cladding, with the
thickness of the core and the cladding typically being in the same ratio in
the fiber as
they are in the pre-form. During the drawing process, the pre-form is fed into
a heated
region where it necks down to the fiber size as the fiber is pulled from the
heat zone. A
coating is applied to the freshly drawn fiber before it touches any capstans
or rollers.
3o The coating protects the fiber from the environment and cushions it from
external forces
that induce micro-bending losses. The drawn fiber is taken up on spools in
such a
manner that the end portions of the fiber on each spool are available for
testing. The
CA 02363412 2001-11-21
spools of drawn, tested fibers are subsequently used to supply ribbon and
cabling
processes and apparatus.
The winding parameters during take up must be carefully controlled. Collection
of the
fiber at low tension is necessary in order to minimize damage to the fiber or
coating
thereon and to reduce the effect of micro-bending and macro-bending losses on
the
transmission media. The winding tension is minimized and the distribution of
fiber
across a spool is controlled to provide a desired package profile and to
facilitate
unwinding at a subsequent operation. Hence, great care is usually taken in
order to
1o minimize potential damages to the fiber during the initial winding step
following the
drawing of the fiber. Unfortunately, such concern with the possible damages
resulting
from improper handling of optical fibers, particularly during the critical
winding steps, is
often neglected once the fiber leaves the fiber-manufacturing site.
i5 The specific handling requirements of optical fibers are directly linked to
their inherent
structure. Indeed, optical fibers being made of glass are characterized by
their
brittleness. A typical glass fiber will stretch elastically to about 7% strain
and break
abruptly without undergoing any permanent deformation. The actual breaking
strengths
between fibers will vary widely and depend on a variety of factors. The reason
for this
2o wide range is attributed to submicroscopic cracks in the fiber surface.
These cracks can
be inherent to the glass itself or a result of manufacturing processes and
handling of the
fiber.
The mere manipulation of the fiber, even by a skilled worker, may potentially
lead to
25 reduce mechanical and/or optical properties. Indeed, localized pressure on
the fiber
tends to deform the core, which is a softer glass than the cladding, causing
radiated
losses and mode coupling also referred to as micro-bending losses. Micro-bends
consist of microscopic random deviations of a fiber around its straight
nominal position.
The amplitude of the deviation is typically a few microns or less and their
period less
3o than a millimeter. In multi-mode fibers, micro-bends cause light to be
exchanged among
the various guided modes, some of which have higher losses than others. In
both multi-
mode and single mode fibers, light can couple into modes that escape from the
core.
The small deflections usually result from fiber coating, cabling, packaging or
other
CA 02363412 2001-11-21
localized forces. They can also be created during the manual handling of the
fiber by
squeezing the fiber between the fingers of the intended user. Although micro-
bending
losses typically return to zero when the localized forces are removed, they
may
potentially create permanent losses.
Fibers exposed to active environments and under stress, weaken with time
because
existing cracks grow. Termed static fatigue, this crack-growth phenomenon
limits the
residual stress that a fiber can sustain over a period of time and imposes a
minimum
bend radius on fibers. Indeed, bending a fiber produces tensile stresses along
its outer
io portion and compressive stresses along its inner portion. The minimum bend
radius
depends on various factors including specifications in given applications. For
most
applications, a 1" minimum bend radius is usually recommended as being a
comfortable
minimum bend radius for an installed fiber, both to minimize bending induced
loss and
also to preserve fiber lifetime. A minimum bend radius also needs to be
respected
i5 during winding operations. This tends to be difficult, especially with
relatively short strips
of optical fibers.
Hence, aside from breakage, optical fiber communication performance may be
degraded by micro-cracks or micro-bends in the fiber generated by bending or
other
2o stresses imposed on the fiber. Such damage to an optical fiber not only
reduces the
fibers long-term durability, but it also causes losses in optical signal
strength and
content. As mentioned previously, great care is usually taken during initial
handling and
winding of the fibers at the manufacturing site. In order to reduce the risks
of physically
damaging the fiber, the control of fiber tension during initial winding
immediately after
25 the drawing of the fiber requires relatively sophisticated equipment.
In order to control fiber tension in the freshly drawn fiber, the latter is
typically allowed to
form a catenary between the capstan and the take up. As the spool fills, the
catenary
tends to decrease in length and it becomes necessary to decrease take up motor
speed
3o under controlled conditions. This is typically accomplished with an electro-
optical
system including a closed circuit television camera, which detects any change
in the
height of the fiber catenary and causes changes in the take up motor speed.
Once
CA 02363412 2001-11-21
initially wound, the fiber is shipped on a spool to other companies or clients
that either
use the fiber or further process the latter.
There exists a plurality of situations wherein an optical fiber needs to be re-
wound into a
coil after the initial winding on a spool at the manufacturing site. Some
applications,
such as the manufacturing of optic sensing devices, inherently require winding
of the
fiber. Other situations are related to general handling of the fiber. For
example, it may
be desirable to mount optical devices, such as multiplexers, demultiplexers,
switches or
the like, on relatively short strips of fibers, commonly referred to as
"pigtails" that are
to eventually spliced to longer segments of optical fiber. The mounting of
such optical
components on strips of optical fiber requires handling and temporary storage
of the
fiber segments. The use of relatively sophisticated equipment and method
conventionally used for initially winding the drawn fiber as herein above
disclosed is not
well suited to this type of application.
In assembly lines wherein optical components are attached to strips of optical
fiber, the
latter is wound at various stations. For example, once the optical component
is attached
to a pigtail, the pigtail is typically manually wound into a coil prior to
shipment to an
intended customer. The manual winding of pigtails presents numerous drawbacks.
The
operation is both tedious and time consuming. Furthermore, it involves
repetitive and
relatively unergonomical movements that may potentially lead to work related
injuries
such as tendonitis or the like.
Furthermore, as mentioned previously, manual winding of the pigtails may
potentially
2s lead to damages in the fiber with resulting loss of efficiency and reduced
longevity.
Accordingly, there exists a need for an optical fiber winding device.
Advantages of the present invention include that the proposed optical fiber
winding tool
allows for the winding of a strip of optical fiber into a generally toroidal-
shaped coil with
low residual strain. Also, the proposed optical fiber winding tool reduces the
risks of
inducing mechanical stresses to the fiber during the winding operation,
thereby reducing
the risk of mechanically damaging the fiber and/or reducing its optical
performance by
micro-bending losses or other phenomena. Furthermore, the proposed optical
fiber
4
CA 02363412 2001-11-21
winding tool allows for winding strips of optical fiber while preserving a
predetermined
minimum bend radius throughout the winding process.
Still further, the proposed optical fiber winding tool allows for the winding
of strips of
optical fiber having optical or mechanical components attached thereto. The
proposed
optical fiber winding tool also allows for the winding of cables having a wide
range of
mechanical properties. Furthermore, the proposed optical fiber winding tool
allows for
the winding of both relatively short and relatively long strips of optical
fibers in various
contexts.
io
Still further, the proposed optical fiber winding tool allows for the winding
of strips of
optical fiber through a set of relatively easy and ergonomic steps, thus
reducing both
mental and physical fatigue. Furthermore, the proposed optical fiber winding
tool allows
for the winding of optical cables without requiring special tooling or manual
dexterity.
is The proposed optical fiber winding tool is designed so as to be compact and
easily
carried with minimal effort to diverse locations so that it can be used in
various settings
with reduced risks of damaging the optical fiber winding tool or strips of
fiber inserted
therein.
2o Furthermore, the proposed optical fiber winding tool is designed so as to
be
manufacturable using conventional forms of manufacturing and conventional
materials
so as to provide an optical fiber winding tool that will be economically
feasible, long
lasting and relatively trouble free in operation. The proposed optical fiber
winding tool is
designed so as to be relatively mechanically simple so as to provide a durable
winding
2s tool requiring relatively low maintenance.
Optionally, the proposed optical fiber winding tool only requires the
installation of a
segment of a strip of optical fiber within the tool, the winding operation
being performed
automatically without requiring manual intervention. Furthermore, the proposed
optical
3o fiber winding tool optionally allows for the simultaneous winding of more
than one strip of
optical fiber into a single coil.
CA 02363412 2001-11-21
In accordance with an embodiment of the invention, there is provided an
optical fiber
winding tool for winding a strip of optical fiber into a coil, the optical
fiber winding tool
being mountable on a generally flat supporting surface and allowing manual
winding of
the strip of optical fiber by the hands of an intended user, the strip of
optical fiber
defining a strip first longitudinal end, an opposed strip second longitudinal
end and a
strip intermediate section extending therebetween, the optical fiber winding
tool
comprising:a guiding body having a body outer surface and defining a guiding
recess,
the guiding recess defining a recess peripheral edge delimiting a recess
aperture
leading into the guiding recess, the recess aperture being in an aperture
geometrical
io plane; a recess peripheral wall having a recess peripheral surface that
extends inwardly
into the guiding body from the recess peripheral edge, the recess peripheral
surface
delimiting the boundary of the guiding recess; a fiber inlet aperture formed
in the guiding
body and leading into the guiding recess, the fiber inlet aperture being sized
for allowing
the slidable insertion of the strip of optical fiber into the guiding recess;
the recess
i5 peripheral wall being configured and sized such that when the recess
aperture is
mounted over the supporting surface and the strip of optical fiber is inserted
through the
fiber inlet aperture, the strip first longitudinal end contacts the supporting
surface and
the recess peripheral surface abuttingly guides the strip intermediate section
so that
further insertion of the strip of optical fiber into the guiding recess causes
the strip of
20 optical fiber to wind into a coil against the recess peripheral surface
adjacent the
supporting surface.
Preferably, the guiding recess is configured and sized such that the strip of
optical fiber
maintains a predetermined minimal bend radius as it abuttingly contacts the
recess
25 peripheral surface during the winding of the strip of optical fiber into a
coil.
Conveniently, the recess peripheral surface has a generally frustro-conical
configuration
defining a recess apex region. Also, conveniently, the fiber inlet aperture is
positioned
adjacent the recess apex region.
3o Preferably, the guiding body also defines an alignment section having a
guiding channel
that extends from the body outer surface to the fiber inlet aperture, the
guiding channel
being configured and sized so that the strip of optical fiber maintains a
predetermined
minimal bend radius as it slides therethrough. Typically, the guiding body
includes a
CA 02363412 2001-11-21
removable body segment allowing selective lateral access to the interior of
the guiding
recess.
Conveniently, the optical fiber winding tool further comprises a fiber outlet
slot formed in
the guiding body for allowing an outlet segment of the optical fiber segment
to extend
out of the guiding recess in a direction substantially parallel to the
aperture geometrical
plane and tangential relative to the coil.
Preferably, the optical fiber winding tool further comprises a hand guiding
means
1o attached to the guiding body for guiding the hands of the intended user as
the intended
user drives the strip of optical fiber into the guiding recess. Conveniently,
the optical
fiber winding also further comprises a multiple fiber separating means mounted
on the
guiding body for physically separating and guiding at least two individual
optical fiber
strips when the at least two individual optical fiber strips are inserted
simultaneously into
15 the guiding recess through the inlet aperture.
Preferably, the fiber separating means includes a separating block mounted on
the
guiding body, the separating block having at least two separating slots formed
therein
for individually receiving one of the at least two individual optical fiber
strips.
Preferably, the optical fiber winding tool further comprises a driving means
attached to
the guiding body for driving the strip of optical fiber into the guiding
recess through the
fiber inlet aperture. Typically, the driving means includes a fluid guiding
means for
guiding the flow of a pressurized fluid in such a manner that the pressurized
fluid is in
contact with the strip of optical fiber and drives the strip of optical fiber
through the fiber
inlet aperture and into the guiding recess.
Preferably, the driving means includes a driving head attached to the guiding
body, the
driving head defining a driving head external surface and having a main fluid
channel
3o extending therethrough, the main fluid channel defining a main channel
longitudinal axis,
the main fluid channel being configured and sized for slidably receiving the
strip of
optical fiber and for allowing through flow of the pressurized fluid
therealong, the driving
CA 02363412 2001-11-21
head also including a fluid connecting means for allowing the main fluid
channel to be
connected to a source of pressurized fluid.
Conveniently, the driving head is provided with a head panel, the head panel
being
movable between a panel open configuration and a panel closed configuration,
wherein
when the head panel is in the panel open configuration the head panel allows
access to
the main fluid channel from a direction oriented at an angle relative to the
main channel
longitudinal axis and when the head panel is in the closed configuration the
head panel
prevents access to the main fluid channel from a direction at an angle
relative to the
1o main channel longitudinal axis.
Preferably, the driving means includes an auxiliary channel extending from the
driving
head external surface to the main fluid channel at angle relative thereto, the
auxiliary
channel being in fluid communication with the main fluid channel; the
auxiliary channel
is being provided with a fluid coupling means for coupling the auxiliary
channel to a source
of pressurized gas.
BRIEF DESCRIPTION OF THE DRAWINGS:
2o An embodiment of the present invention will now be disclosed, by way of
example, in
reference to the following drawings, in which:
FIGURE 1: in a perspective view, illustrates an optical fiber winding tool in
accordance
with an embodiment of the present invention.
FIGURE 2: in a front elevational view, illustrates the optical fiber winding
tool shown in
Figure 1.
FIGURE 3: in a front elevational view, illustrates the optical fiber winding
tool shown in
3o Figures 1 and 2 in an open configuration and with a strip of fiber being
manually wound
therewith.
CA 02363412 2001-11-21
FIGURE 4: in a partial perspective view with sections taken out, illustrates
the optical
fiber winding tool in an open configuration and about to be mounted on a
mounting
plate.
FIGURE 5: in an inverted perspective view, illustrates the configuration of
the bottom
section of the optical fiber winding tool shown in Figure 4.
FIGURE 6: in a perspective view, illustrates a removable peripheral wall
segment part of
the optical fiber winding tool in accordance with an embodiment of the present
invention.
FIGURE 7: in a exploded view, illustrates a driving head, part of the optical
fiber winding
tool in accordance with an embodiment of the present invention.
FIGURE 8: in a longitudinal cross sectional view, illustrates the internal
conOguration of
is a winding head, part of the optical fiber winding tool in accordance with
an embodiment
of the present invention.
FIGURE 9: in a partial cross-sectional view with section sections taken out,
illustrates a
portion of a base segment, part of the optical fiber winding tool in
accordance with an
2o embodiment of the present invention. The section of the base segment being
shown
mounted on a mounting plate and being used for guiding a segment of a fiber
strip.
FIGURE 10: in a schematic elevational view, illustrates a typical
configuration taken by a
strip of fiber as it is being wound by the optical fiber winding tool in
accordance with an
2s embodiment of the present invention.
FIGURE 11: in a perspective view, illustrates a strip of fiber having been
wound by the
optical fiber winding tool in accordance with the present invention and having
an optical
component attached thereto.
DETAILED DESCRIPTION:
CA 02363412 2001-11-21
Referring to FIGURE 3, there is shown an optical fiber winding tool (10) in
accordance
with an embodiment of the present invention. The optical fiber winding tool
(10) is
shown in an opened configuration in order to allow visualization of a strip of
optical fiber
(12) being wound therewith. The strip of optical fiber (12) is shown being
wound with
the help of the optical fiber winding tool (10) by the hand (14) of an
intended user. The
optical fiber winding tool (10) is shown mounted on a generally flat
supporting surface
(16).
The optical fiber winding tool (10) includes a guiding body (18) having a body
outer
1o surface (20) and defining a guiding recess (22). As shown more specifically
in FIGURE
5, the guiding recess (22) defines a recess peripheral edge (24) delimiting a
recess
aperture (26) leading into the guiding recess (22). The recess aperture (26)
and its
recess peripheral edge (24) both extend in a generally flat aperture
geometrical plane.
i5 The guiding recess (22) also defines a recess peripheral wall having a
recess peripheral
surface (30). The recess peripheral surface (30) extends inwardly into the
guiding body
(18) from the recess peripheral edge (24). The recess peripheral surface (30)
delimits
the boundary of the guiding recess (22). The recess peripheral surface (30)
preferably
has a generally smooth texture.
The optical fiber winding tool (10) also includes a fiber inlet aperture (32)
formed in the
guiding body (18) and leading into the guiding recess (22). The fiber inlet
aperture (32)
is sized for allowing the slideable insertion of the strip of optical fiber
(12) into the
guiding recess (22).
As shown schematically in FIGURE 10, the guiding recess (22) is configured and
sized
such that when the guiding recess (22) is mounted over the supporting surface
(16) with
the supporting surface (16) obstructing the recess aperture (26), the
insertion of the strip
of optical fiber (12) through the fiber inlet aperture (32) causes a strip
first longitudinal
3o end (34) to eventually contact the supporting surface (16). The guiding
recess (22) is
also configured and sized such that further insertion of the strip of optical
fiber (12)
through the fiber inlet aperture (32) eventually causes an intermediate
section of the
strip of optical fiber (12) located between first and second longitudinal ends
thereof to
to
CA 02363412 2001-11-21
contact the recess peripheral surface and allow the latter to guide the
optical fiber (12)
into a generally toroidal-shaped-like coil such as the coil (38), illustrated
in FIGURE 11.
Insertion of the optical fiber (12) into the fiber inlet aperture (32) is
indicated by arrow
(40) in FIGURE 10.
The configuration and size of the guiding recess (22) allows the segment of
optical fiber
(12) to abuttingly contact both the supporting surface (16) and the recess
peripheral
surface (30). The configuration and size of the guiding recess (22) combined
with the
inherent structural characteristics, such as rigidity and resiliency of the
segment of
optical fiber (12), causes the latter to eventually bend into a generally
parabolic-like
configuration as illustrated in full lines in FIGURE 10. FIGURE 10 also
illustrates,
schematically, that as the strip of optical fiber (12) is further inserted
into the guiding
recess (22), the segment of optical fiber (12) winds into the coil (38)
against the recess
peripheral surface (30) adjacent to the supporting surface (16) while the
parabolic
t5 segment rotates around the guiding recess (22) abuttingly sweeping against
the recess
peripheral surface (30). The phantom lines in FIGURE 10 illustrate the
evolving
configuration of the strip of optical fiber (12) sweeping against the recess
peripheral
surface (30).
2o The guiding recess (22) is configured and sized such that the strip of
optical fiber (12)
maintains a predetermined minimal bend radius as it abuttingly contacts and
sweeps
against the recess peripheral surface (30) during the winding of the strip of
optical fiber
(12) into the coil (38). In a preferred embodiment of the invention, the
recess peripheral
surface (30) has a generally frustro-conical configuration defining a recess
apex region
25 (44) and causing the strip of optical fiber to assume a generally parabolic-
like
configuration. The circumferential sweeping movement of the parabolic-like
segment of
the strip of optical fiber (12) is indicated by arrows (42) in FIGURE 10. When
the recess
peripheral surface (30) has a generally frustro-conical configuration, the
fiber inlet
aperture (32) is preferably positioned adjacent the recess apex region (44).
It should be
3o understood that the recess peripheral surface (30) could assume other
configurations
and that the fiber inlet aperture (32) could be positioned at other locations
without
departing from the scope of the present invention.
m
CA 02363412 2001-11-21
Referring back to FIGURE 3, there is shown that, the body outer surface (20)
preferably
defines a body main outer surface (46) having a generally frustro-conical
configuration.
The body main outer surface (46) defines a main outer surface first end (48)
adjacent its
apex and a main outer surface second end (50), adjacent its base. Preferably,
a body
base flange (52) extends integrally from the body main outer surface second
end (50).
The body base flange (52) typically extends radially outwardly from the body
main outer
surface (46). Typically, the body base flange (52) has a generally annular
configuration
defining a base flange spacing surface (54) extending substantially outwardly
from the
1o main outer surface second end (50). A base flange peripheral surface (56)
and a body
abutment surface (58) extending in a generally parallel relationship relative
to the base
flange spacing surface (54). Typically, the optical fiber winding tool (10)
includes a
generally frustro-conical wall defining both the frustro-conical recess
peripheral surface
(30), the body main outer surface (46), the body base flange (52) and the
annular body
is abutment surface (58).
As illustrated more specifically in FIGURE 5, the body abutment surface (58)
is
preferably provided with peripheral angled recesses (60) for facilitating the
manipulation
of the guiding body (18) and for reducing the density of the body base flange
(52). The
2o body abutment surface (58) is optionally provided with a base flange-to-
supporting
surface securing means for securing the relative positioning between the
guiding body
(18) and the supporting surface (16). The base flange-to-supporting surface
securing
means preferably includes at least one and preferably a set of magnet
components (62)
inserted in corresponding base magnet apertures (64) formed in the body
abutment
2s surface (58). The magnet components (62) are provided for generating a
magnetic
force adapted to releasably secure the body abutment surface (58) to the
supporting
surface (16) when the tatter is made out of a magnetizable material, such as a
metallic
alloy or the like.
3o As illustrated more specifically in FIGURES 4 through 6 and 9, the body
abutment
surface (58) is preferably further provided with pin receiving recesses (66)
formed
therein for receiving corresponding mounting pins (68) optionally extending
from the
supporting surface (16). Each mounting pin (68) typically includes a generally
cylindrical
12
CA 02363412 2001-11-21
pin spacing segment (70) extending substantially perpendicularly from the
supporting
surface (16) in a generally disc-shaped pin-retaining segment (72) mounted on
the pin
spacing segment (70) so as to extend in a direction generally parallel to the
supporting
surface (16). As illustrated more specifically in FIGURE 4, four mounting pins
(68)
typically extend from the supporting surface (16) and are strategically
positioned so as
to abuttingly retain the wound coil (38) of optical fiber (12). The mounting
pins (68) are
typically strategically positioned so as to preserve the minimum bend radius
and so as
not to create undue stress on the strip of optical fiber (12) as the latter
urges against the
mounting pins (68) as it tends to resiliently spring back to its uncoiled
state.
to
As illustrated more specifically in FIGURE 9, each pin receiving recess (66)
is
configured and sized so as to substantially fittingly receive a corresponding
mounting pin
(68). Furthermore, each pin receiving recess (66) is configured, sized and
positioned so
that the intersection (74) between the supporting surface (16) and both the
base of the
is pin spacing segment (70) and the recess peripheral edge (34) are
substantially in
register with one another while the pin retaining segment (72) remains
outwardly
positioned relative to the recess peripheral surface (30).
The intersection (74) is positioned such that when the guiding body (18) is
lifted away
2o from the supporting surface (16) for allowing retrieval of the coil (38) of
optical fiber (12),
the coil (38) of optical fiber (12) remains in abutting contact with a
retaining structure
having substantially the same diameter as the abutting section of the recess
peripheral
surface (30). The outward positioning of the pin-retaining segment (72)
relative to the
recess peripheral surface ensures that the pin-retaining segment (72) does not
interfere
2s with sweeping segments of optical fiber (12) being guided by the recess
peripheral
surface (30), during the winding operation.
As illustrated more specifically in FIGURES 3 through 5, the optical fiber
winding tool
(10) preferably includes a fiber outlet slot (76) formed in the guiding body
(18) for
3o allowing an outlet segment (12') of the strip of optical fiber (12) to
extend out of the
guiding recess (22) in a direction substantially parallel to the aperture
geometrical plane
and in a direction substantially tangential relative to the coil (38).
Preferably, the outlet
slot (76) is formed by a slot recess provided in the body abutment surface
(58)
13
CA 02363412 2001-11-21
cooperating with the supporting surface (16) to allow a single outlet segment
(12') to
extend out of the guiding recess (22). The fiber outlet slot (76) is
particularly useful in
situations wherein, for example, an optical component such as the optical
component
(78) in FIGURE 11, is attached to the strip of optical fiber (12) adjacent a
strip second
longitudinal end (36). In situations of this type, the optical component (78)
may be
positioned outside of the optical fiber winding tool (12), adjacent the
latter, during the
winding operation with the outlet segment (12') extending through the fiber
outlet slot
(76) while the remainder of the strip of optical fiber (12) is being wound by
the optical
fiber winding tool (10).
to
The body outer surface (20) typically also includes a generally cylindrical
alignment
section (80) extending from the main outer surface first end (48). The
alignment section
(80) has a guiding channel (88) extending there through. The guiding channel
(88) is in
communication with the fiber inlet aperture (32). The guiding channel (88) is
configured
is and sized so that the strip of optical fiber (12) maintains a predetermined
minimal bend
radius as it slides there through and into the fiber inlet aperture (32). The
alignment
section (80) defines an alignment section first longitudinal end (82),
preferably merging
integrally with the main outer surface first end (48). The alignment section
(80) also
defines an alignment section second longitudinal end (84). The alignment
section
2o second longitudinal end (84), in turn, defines a generally disc-shaped
alignment section
attachment surface (86).
The alignment section (80) is provided with a guiding channel (88) extending
there
through from the alignment section attachment surface (86) to the fiber inlet
aperture
25 (32). Opposed longitudinal ends of the guiding channel (88) located
adjacent
corresponding alignment section first and second longitudinal ends (82) and
(84) are
provided with an outwardly widening generally conical taper (90), (92) for
ensuring that
the strip of optical fiber (12) maintains a minimal bend radius respectively
as it enters
the guiding recess (22) through the fiber inlet aperture (32) and as it passes
from
30 outside the guiding body (18) to the guiding channel (88).
The guiding body (18) preferably further includes a lateral access means for
providing
selective lateral access to the interior of the guiding recess (22).
Typically, although by
14
CA 02363412 2001-11-21
no means exclusively, the lateral access means includes a removable body
segment
(94), illustrated in greater details in FIGURE 6. In the preferred embodiment
wherein
the guiding body includes a generally frustro-conical wall defining both the
recess
peripheral surface (30) and the body main outer surface (46), the removable
body
segment (94) typically includes a longitudinal segment of the frustro-conical
wall having
flange and alignment section tongues (96), (98) extending substantially
circumferentially
therefrom for insertion into corresponding flange and alignment section
grooves (100),
(102) formed in circumferential wall surfaces (104) of the remaining guiding
body (18).
1o Typically, the circumferential base and alignment section tongues (98) and
the
circumferential base and alignment section grooves (100), (102) are provided
with
cooperating releasable locking means for releasably locking the removable body
segment (94) in a closed configuration wherein the recess peripheral surface
(30) forms
a continuous surface. The removable body segment releasable locking means
typically
15 takes the form of tongue and groove magnet components (108), (110).
The removable body segment defines a removable body segment circumferential
wall
(106) at the junction with the remainder of the guiding body (18). The
removable body
segment circumferential wall (106) is adapted to contact the circumferential
wall surface
20 (104) of the remainder of the guiding body (18) when the removable body
segment (94)
is in its closed configuration. The removable body segment (94) is adapted to
allow
lateral access to the interior of the guiding recess (22) in order to
facilitate installation of
the strip of optical fiber (12) prior to its winding as will be hereinafter
disclosed in greater
details.
As shown more specifically in FIGURES 1 and 2, the removable body segment (94)
is
typically provided with a grasping handle (112) extending from its outer
surface. The
grasping handle (112) is adapted to facilitate the manipulation of the
removable body
segment (94) between its opened configuration allowing lateral access to the
interior of
3o the guiding recess (22) and its closed configuration wherein the recess
peripheral
surface forms a substantial continuous surface.
CA 02363412 2001-11-21
Referring now more specifically to FIGURE 3 there is shown that the optical
fiber
winding tool (10) optionally further includes a hand guiding means attached to
the
guiding body (18) for guiding the hand (14) of the intended user as the latter
drives the
strip of optical fiber (12) into the guiding recess (22). The hand guiding
means typically
includes at least one and preferably two guiding rods (114) mounted in
corresponding
guiding rod apertures (116) formed in the alignment section attachment surface
(86).
The guiding rod apertures (116) are preferably positioned adjacent the
entrance of the
guiding channel (88) and in a diametrically opposed relationship relative to
each other.
Hence, the guiding rods (114) preferably extend in a predetermined spaced and
parallel
to relationship relative to each other along direction substantially parallel
to the guiding
channel (88}.
The guiding rods (114) define a rod spacing (117) there between. The rod
spacing
(117) is typically sized so as to allow at least partial insertion of the
distal interior pulp of
15 the distal phalanx of opposed fingers (118) such as the thumb and index, or
other finger
of the hand (14) of the intended user so that a segment of the strip of
optical fiber (12)
may be grasped between opposed fingers (118) of the hand (14) between the
guiding
rods (114) that serve as guides for the opposed grasping fingers (118). The
guiding
rods (114) thus greatly reduce the risk of inadvertently bending the strip of
optical fiber
20 (12} in a direction perpendicular to the geometrical plane formed by the
alignment of the
guiding rods (114) and also reduce the risk of bending the fiber in the
geometrical plane
formed by the alignment of the guiding rods (114).
Since it is sometimes necessary to simultaneously wind more than one strip of
optical
25 fiber (12) into a single coil, the optical fiber winding tool is optionally
further provided with
a multiple fiber separating means mounted on the guiding body (18) for
physically
separating and guiding at least two individual optical fiber strips (only one
of which is
shown throughout the FIGURES) when at least two individual optic fiber strips
are
inserted simultaneously into the guiding recess (22) through the inlet
aperture (32). As
3o illustrated more specifically in FIGURES 1 through 3, the fiber separating
means
typically includes a separating block (120) mounted on the guiding body (18).
The
separating block (120) is typically provided with at least one and preferably
two block
channels (122) extending there through for allowing the separating block (120)
to be
16
CA 02363412 2001-11-21
frictionally mounted on the guiding rods (114). The separating block (120)
typically
defines at least two separating slots (124) provided with a preferably tapered
separating
tongue (126) extending there between for individually receiving one of the at
least two
individual strips of optical fiber (12). The strips of optical fiber (12)
being guided and
separated adjacent their entrance into the guiding channel (88), hence greatly
reducing
the risk of having the optical fibers tangled in each other.
The optical fiber winding tool (10) is optionally further provided with a
driving means
attached to the guiding body (18) for driving the strip of optical fiber (12)
into the guiding
1o recess (22) through the fiber inlet aperture (32). As illustrated more
specifically in
FIGURES 7 and 8, the driving means typically includes a fluid guiding means
for guiding
a flow designated by arrows (128) of a pressurized fluid in such a manner that
the
pressurized fluid is in contact with the strip of optical fiber (12) and
drives the latter
through the fiber inlet aperture (32) and into the guiding recess (22).
is
Typically, the driving means include a driving head (130) attached to the
guiding body
(18). Typically, the driving head (130) is attached to the guiding rods (114)
opposite the
guiding body (18). The driving head (130) has a main fluid channel (132)
extending there
through. The main fluid channel (132) defines a main channel longitudinal axis
(133).
2o The main fluid channel (132) is configured and sized for slideably
receiving the strip of
optical fiber (12) and allowing through flow (128) of the pressurized fluid
there along.
The driving head (130) also includes a fluid connecting means for allowing the
main fluid
channel (132) to be connected to a source of pressurized fluid. Typically, the
fluid
2s connecting means includes a coupling component (135) extending radially
from the
driving head (130) for coupling a source of pressurized fluid such as a source
of
compressed air, nitrogen or the like. The coupling component (135) is
pneumatically
coupled to an auxiliary fluid channel (134) in fluid communication with the
main fluid
channel (132) and typically extending at an angle relative to main fluid
channel
30 longitudinal axis (133). Typically, the longitudinal ends of the main fluid
channel (132)
are provided with outwardly diverging conical tapering sections (136) for both
allowing
the strip of optical fiber (12) to maintain a minimal bend radius and for
creating a
Venturi-like effect.
17
CA 02363412 2001-11-21
Referring now more specifically to FIGURES 3 and 7, there is shown that the
driving
head (130) is typically provided with a head panel (140) movable between an
opened
panel configuration shown in FIGURE 3 and a closed panel configuration shown
in
FIGS. 1 and 2. In the opened panel configuration, the head panel (140) allows
lateral
access to the main fluid channel (132) from a direction oriented at an angle
relative to
the main fluid channel longitudinal axis (133). When the head panel (140) is
in its
closed configuration, the head panel (140) prevents access to the main fluid
channel
(132) from a direction at an angle relative to the main fluid channel
longitudinal axis
(133).
Typically, the head panel (140) includes a segment of the driving head (130),
pivotally
mounted to the remainder of the driving head (130) by a pivotal link such as a
pivotal
axle (142) inserted into pivotal axle apertures (145) formed in corresponding
supporting
tongues (144) and (146). The head panel (140) is preferably further provided
with a
releasable head panel locking means for releasably locking the head panel in
its closed
configuration. The releasable head panel locking means typically includes a
pair of
magnet components (148), (150) respectively mounted in a locking tongue (152)
extending from the head panel (140) and a locking recess (154) formed in the
remainder
2o of the driving head (130). The head panel (140) is also preferably provided
with a head
panel handle (156) extending therefrom for facilitating handling of the head
panel (140)
between its opened and closed configurations.
In use, the strip of optical fiber (12) is initially mounted to the optical
fiber winding tool
(10) through a set of easy and ergonomic steps. The removable body segment
(94) is
initially removed and the head panel (140) is initially pivoted to its open
configuration in
order to allow lateral positioning of the intermediate segment of the strip of
optical fiber
(12) into the guiding channel (88) and into the main fluid channel (132).
Optionally, a
source of vacuum may be connected to the auxiliary fluid channel (134) so that
the a
3o segment of the strip of optical fiber (12) fiber may be temporarily
suctioned and retained
against the surface of the main fluid channel (132).
1s
CA 02363412 2001-11-21
The removable body segment (94) is then moved back to its closed configuration
wherein the recess peripheral surface (30) forms a generally continuous
surface and the
head panel (140) is pivoted back to its closed configuration wherein the main
fluid
channel (132) forms a generally continuous surface. When the optical component
(78)
is attached to the strip of optical fiber (12), the outlet segment (12') to
which it is
attached is allowed to extend outwardly on the supporting surface (16) through
the fiber
outlet slot (76). Initially, both the doors are moved to their opened
configuration allowing
lateral installation of the fiber into the guiding recess and the guiding
channel.
to A driving force that may either manual, hydraulic, pneumatic or otherwise
is then used to
drive the strip of optical fiber (12) into the guiding recess (22). As
mentioned previously,
when the strip of optical fiber (12) is manually wound, the guiding rods (114)
act as
guides for the hand (14) of the intended user during the pulling movement
indicated by
arrow (138) in FIGURE 3.
When the strip of optical fiber (12) is pneumatically wound, air or another
suitable gas of
low moisture content is introduced into the auxiliary fluid channel (134) at a
relatively
high pressure and flows into the main fluid channel (132) through the Venturi-
type
conduit formed by the main fluid channel (132). The high-pressure gas
frictionally drives
2o the optical fiber (12) towards the inlet aperture (32) as indicated by
arrow (138) in
FIGURE 8. As is well known in the art, a Venturi-like structure exploits the
property of a
gas flow passing through a constriction. Within the constriction, the axial
pressure
distribution exhibits a minimum.
2s The dimension of the Venturi, the values of the supplied pressure and the
mass flow of
air are typically selected so that the minimum pressure is below atmospheric
pressure.
In some practical embodiments, the velocity of the gas flow and the
constriction flow
reach the speed of sound. In other embodiments, the flow throughout the
Venturi will
remain entirely subsonic. In either case, the Venturi produces a steep rising
pressure
3o gradient, accompanied throughout by continued forward flow over a short
region within
the main fluid channel (132).
19
CA 02363412 2001-11-21
The flow of gas, which results from atmospheric pressure at its upstream end
and the
sub-atmospheric pressure at its downstream end, assists in moving the strip of
optical
fiber (12) through the main fluid channel (132). On the downstream side of the
pressure
gradient region, viscous drag on the strip of optical fiber (12) increases
considerably due
to the high velocity thus assisting in injecting the strip of optical fiber
(12) in the guiding
recess (22). Depending on the length and diameter of the main fluid channel
(132) the
conditions within the latter will need to be varied to achieve optimum
performance.
The air inlet pressure controls the mass flow of air through the main fluid
channel (132)
to so as to maintain appropriate viscous drag on the strip of optical fiber
(12) and
appropriate pressure so as to reduce the risk of damaging the strip of optical
fiber (12).
Optionally, various auxiliary fluid channels (134) could be formed and
positioned so as
to deliver pressurized fluids at multiple locations around the periphery of
the main fluid
channel (132) so as to reduce the risk of inducing micro-bending stresses into
the strip
15 of optical fiber (12).
The guiding rods (114) are also adapted to act as a spacing means for
providing a
spacing between the outlet of the main fluid channel (132) and the entrance
(92) of the
guiding channel (90) so as to prevent a build-up of pressurized gas within the
guiding
2o recess (22). The spacing provided by the guiding rods (114) allows the
pressurized gas
emanating from the outlet of the main fluid channel (132) to diffuse into the
environment
instead of flowing into the guiding recess (22) through the fiber inlet
aperture (32). The
guiding rods (114) are thus adapted to act both as a guiding means and as a
spacing
means respectively when a manual or a pneumatic method of drawing the strip of
25 optical fiber (12) into the guiding recess (22) is used.
Regardless of the method used for drawing the strip of optical fiber (12) into
the guiding
recess (22), the segment of the optical fiber (12) within the guiding channel
(88) remains
substantially rectilinear while the segment of the optical fiber (12) within
the guiding
3o recess (22) is bent into an arc typically although by no means exclusively
having a
generally parabolic-like configuration. The arched segment of optical fiber
(12) within
the guiding recess (22) abuttingly sweeps in circles against the recess
peripheral
CA 02363412 2001-11-21
surface (30) and transitions smoothly into convolutes of fibers (12) resting
on the
supporting surface 16.
Once the strip of optical fiber (12) has been wound into the coil (38), the
optical fiber
winding tool (10) is lifted from the supporting surface (16) leaving a
generally toroidal-
shaped coil (38) of optical fiber (12) resting on the supporting surface (16)
resiliently
urging against the mounting pins (68) or other suitable structures.
21
