Note: Descriptions are shown in the official language in which they were submitted.
1 - I 334477
APPARATUS FOR ARRANGING A PLURALITY OF COATED
OPTICAL FIBERS
The present application has been divided out of
Canadian Patent Application Serial No. 558,195 filed
February 4, 1988.
The present invention generally relates to optical
fibers and more particularly, to an apparatus for arranging
a plurality of coated optical fibers at a predetermined
interval in a plane and a collective fusion splicing method
using the apparatus, in which the coated optical fibers are
collectively fusion spliced and reinforced.
The description of the background of the invention
makes reference to Figures la, lb, 2a and 2b thus for the sake
of convenience all of the drawings will be introduced briefly
as follows:
Figs. la and lb are perspective views of a ribbon type
multi-fiber optical fiber cable and a loose tube type
multi-fiber optical fiber cable, respectively;
2v Fig. 2a shows a prior art method of joining coated
optical fibers;
Fig. 2b is a sectional view of joints of the coated
optical fibers of Fig. 2a;
Fig. 3 is an explanatory view of a collective
fusion splicing method which is set out and claimed in the
parent application identified above;
Figs. 4a, 4b and 4c are sectional views of clamping
1 334477
devices employed in the method shown in Fig. 3;
Fig. 5 is an explanatory perspective view of
collective removal of coatings from coated optical fibers in
the method of Fig. 3;
Fig. 6 is an explanatory perspective view of
collective cutting of the coated optical fibers in the met'nod
of Fig. 3;
Fig. 7 is a perspective view of a fusion splicing
apparatus employed in the method shown in Fig. 3;
Figs. 8a and 8b are views showing the fusion splicing
apparatus of Fig. 7;
Fig. 9a is an explanatory view of one example of a
reinforced portion employed in the method of Fig. 3;
Fig. gb is a sectional view of the reinforced portion
of Fig. 9a;
Figs. lOa and lOb are views similar to Figs. 9a and
9b, respectively, particularly showing another example thereof;
Fig. 11 is a perspective view of an apparatus for
arranging the coated optical fibers which is the subject
matter of a further divisional application and which is
applicable to the method shown in Fig. 3;
Fig. 12 is a top plan view of the apparatus of Fig. 11;
Figs. 13a and 13b are explanatory views of operation
of the apparatus of Fig. 11;
Fig. 14 is a flow chart showing operation of the
apparatus of Fig. 11;
1 334477
Fig. 15 is a perspective view of an apparatus for
arranging the coated optical fibers according to the
present invention, which is applicable to the method shown
in ~ig. 3;
Fig. 16 is a fragmentary top plan view of the
apparatus of Fis. 15;
Fig. 17 is a sectional view taken along the line
XVII-XVII in Fig. 16;
Figs. 18a, 18b and 18c are explanatory views of the
operation of the apparatus of Fig. 15; and
Fig. 19 is a flow chart showing the operation of the
apparatus of Fig. 15.
Since optical fibers have been utilized for public
communication, there is, at present, a keen demand for the
rationalization and facilitation of the removal of coatings
from coated optical fibers and cutting and fusion splicing o
the coated optical fibers in the manufacture of optical fiber
cables.
Conventionally, in order to permanently join optical
fibers, a fusion splicing method is widely employed in which
the optical fibers are joined with each other through fusion
thereof with aerial discharge heat.
In response to recent increases in the use and
quantity of optical transmission lines, multi-fiber optical
fiber cables each having multiple coated optical fibers have
become necessary. To this end, there are ribbon type
1 334477
multi-fiber optical fiber cables in which a plurality of coated
optical fibers 1 are collectively formed into a ribbonlike
shape as shown in Fig. la and loose tube type multi-fiber
optical fiber cables in which a plurality of the coated optical
fibers 1 are inserted into a tube 2 at random as shown in Fig.
lb.
In the ribbon type multi-fiber optical fiber cable,
since it is possible to collectively perform the steps of
removal of the coatings of the coated optical Cibers 1, cutting
and fusion splicing of the coated optical fibers 1, the
manufacturing processes are simplified and the production cost
is reduced, thereby resulting in rationalization and
facilitation of the joining of the coated optical fibers 1.
~eanwhile, in the loose tube type multi-fiber optical fiber
cable, the coated optical fibers 1 are joined one by one with a
single-core type fusion splicing apparatus. Thus, in view of
the recent trend for multi-fiber optical fiber cables to
increase the number of coated optical fibers from 1 up to
~00-3,000 in response to the expansion of capacities of optical
transmission lines, the loose tube type multi-fiber optical
fiber cables have one drawbac~, that is the time period required
to join t'ne coated optical fibers 1 increases further.
Meanwhile, a technique for collectively fusion
splicing a plurality of coated optical fibers 1 and a technique
for collectively fusion splicing a plurality of coated optical
fibers 1 of the loose tube type multi-fiber optical fiber cable
~ 5 ~ l 33 4 4 77
with those of the ribbon type multi-fiber optical fiber cable
have not yet been developea.
Figs. 2a and 2b show a known method of joining the
coated optical fibers 1. As shown in Figs. 2a and 2b, the
coated optical fibers l accommodated in a multi-fiber optical
fiber cable 3 are separated from one another in the vicinity of
the end of cable 3 and glass portions 4 of the coated optical
fibers l are fusion spliced with corresponding ones of the
opposite coated optical fibers l individually, respectively
such that joints 5 of the glass portions 4 are produced. Each
of the joints 5 is reinforced by a reinforcing member such as a
neat-shrinkable tube 6. The heat-shrinkable tube 6 contains
hot-melt adhesive 8 in which a reinforcing core 7 is embedded.
However, the known joining method has several disad-
vantages including an operation which is quite troublesome and
time-consuming because a number of the coated optical fibers l
are joined with each other individually, and the joints 5
become large in size.
Accordingly, an object of the present invention is
to provide a collective fusion splicing method which speeds
up the joining of coated optical fibers and which reduces
the size of joints of the coated optical fibers as well as
joining the coated optical fibers of a loose tube type
multi-fiber optical fiber cable with those of a ribbon type
multi-fiber optical fiber cable.
Another important object of the present invention is
_ - 6 - 1 334 4 7 7
to provide, with a view to rationalization, facilitation and
speedup of joining of the coated optical fibers, an apparatus
of simple construction for easily arranging the coated optical
fibers, which forms the coated optical fibers of a loose tube
type optical fiber cable into those of a ribbon type multi-
fiber optical fiber cable.
In order to accomplish these objects the present
invention provides an apparatus for arranging a plurality of
coated optical fibers at a predetermined interval in a plane,
comprising: a positioning means for positioning the coated
optical fibers; the positioning means including a slot for
placing the coated optical fibers thereon, a guide member for
introducing the coated optical fibers into the slot, which is
provided along the slot, a plurality of positioning members
for positioning the coated optical fibers, which are provided
at one end portion of the slot and a rotational plate for
temporarily holding, through sequential rotation thereof, the
coated optical fibers accommodated and arranged in the slot by
the positioning members; a fixing means for temporarily fixing
distal end portions of the coated optical fibers arranged by
the positioning means; and a tape supply means for supplying
in a direction substantially perpendicular to optical axes of
the coated optical fibers, an adhesive tape for securing the
coated optical fibers arranged by the positioning means, with
an adhesive face of the adhesive tape confronting the slot.
Before the description of the present invention
proceeds, it is to be noted that like parts are designated by
like reference numerals throughout the various views of the
accompanying drawings.
- 7 ~ l 334 4 77
Figs. 3 to lO show a collective fusion splicing
method of the present invention. Operational steps of the
method are sequentially described, hereinbelow.
(1) Initially, a set of a plurality of coated optical
fibers 1 independent of one another are arranged in a plane
and are clamped, at the end portions thereof, by a clamping
device 11.
Examples of the clamping device 11 are shown in
Figs. 4a, 4b and 4c. In the clamping device 4a, an upper
lid 23 having an adhesive layer 24 provided on its inner
face is placed on a base 21 formed, on its upper face, with
a plurality of V-shaped grooves 22 for positioning the
coated optical fibers 1. In the clamping device 11 of Fig.
4b, the base 21 is formed, on its upper face, with a recess
25 for collectively accommodating a plurality of coated
optical fibers 1 arranged in a plane and the upper lid 23
having the adhesive layer 24 provided on its upper face is
placed on the base 21. Meanwhile, in the clamping device 11
of Fig. 4c, the base 21 is formed, on its upper face, with
the groove 25 and the upper lid 23 is pivotally provided so
as to be pivoted away from and towards the base 21 about a
hinge 26. At one side of each of the upper lid 23 and the
base 21 remote from the hinge 26, a pair of magnets 27 are
embedded in opposite faces of the upper lid 23 and the base
21, respectively.
- 8 - l 33 ~ ~ ~ 7
(2) By using a coating remover 14, coatings are
collectively removed from end portions of the coated optical
fibers 1 clamped by the clamping device 11 as shown in Fig.
S. Initially, the clamping device 14 is disposed at the
S position shown by the broken lines. After the coatings have
been cut by the coating remover 14, the clamping device 14
is displaced to the position shown by the solid lines, so
that the coatings are removed from the end portions of the
coated optical fibers 1 and thus, exposed fiber end portions
4 of the coated optical fibers 1 are obtained, respectively.
(3) The exposed fi~er end portions 4 are collectively
cut by a blade lS so as to obtain cut end faces of the
exposed fiber end portions as shown in Fig. 6.
(4) As shown in Fig. 7, the set Of exposed fiber
end portions 4 and another set f exFosed i~er--end
portions 4 prepared by the above processes (l) to (3) are
set on a coupling stage 17 of a multi-fiber collective
fusion splicing apparatus 20 so as to confront each other
and are collectively fusion spliced with each other through
aerial discharge, so that joints S of the two sets of
cut end faces are produced, respectively. The collective
fusion splicing apparatus 20 further includes a pair of
clamps 18 for clamping the two sets Of exposed fiber end
portions 4 onto the coupling stage 17, respectively and a
pair of discharge electrodes 19 for effecting aerial dis-
charge therebetween. In Fig. 7, the clamping device 11 is
9 1 334477
placed on a fine adjustment base 16 movable in three orthog-
onal directions shown by the arrows.
As shown in Fig. 8a, the coupling stage 17 is
formed with a slot 29 extending therethrough at a central
portion thereof. Two sets of a plurality of V-shaped
grooves 28 aligned with each other are formed at opposite
sides of the coupling stage 17 so as to interpose the slot
29 therebetween. As shown in Fig. 8b, the clamps 18 are
pivotally provided. Thus, when the exposed fiber end
portions 4 have been, respectively, fitted into the V-shaped
grooves 28, the clamps 18 are pivoted towards the coupling
stage 17 so as to depress the exposed fiber end portions 4
into the V-shaped grooves 28, respectively.
(5) The joined coated optical fibers 1 are taken out
of the collective fusion splicing apparatus 20 and are set
in a reinforcing device for reinforcing the joints 5. At
this time, one of the following three reinforcing methods
can be employed. In the first reinforcing method, the
joints 5 are reinforced integrally with the clamping devices
11 by reinforcing material 13 as shown in Fig. 3. In the
second reinforcing method, only the joints 5 are reinforced
and the clamping devices 13 are left as they are. In the
third reinforcing method, only the joints 5 are reinforced
and the clamping devices 13 are removed from the coated
optical fibers l such that a post handling step, e.g. rectifi-
cation of excessively long coated optical fibers
1,,is performed. Figs. 9a and 9b show one example of
-
lo - 1 334fi7~
reinforcement of the joints 5. In Figs. 9a and 9b, each of
a pair of reinforcing plates 30 includes a rectangular flat
plate 31 provided, on its inner face, with a hot-melt
adhesive layer 32. The joints 5 of the coated optical
fibers 1 are interposed between the reinforcing plates 30
such that the hot-melt adhesive layers 32 of the reinforcing
plates 30 confront each other. Then, the reinforcing plates
30 held in contact with each other through the joints 5 are
heated by a heating coil 33. Thus, the opposite hot-melt
adhesive layers 32 are melted together. As a result, the
exposed fiber end portions 4 are integrally embedded in the
hot-melt adhesive layer 32 between the flat plates 31 as
shown in Fig. 9b.
Meanwhile, Figs. lOa and lOb show another example
of reinforcement of the joints 5. In this example, a
heat-shrinkable tube 6 containing a reinforcing core 7 and
hot-melt adhesive 8 is first passed around one of the
two sets of coated optical fibers 1 as shown by the
solid lines and is, after collective fusion splicing of the
exposed fiber end portions 4, displaced to the position
shown by the broken lines, at which the heat-shrinkable tube
6 embraces the joints 5. Then, the heat-shrinkable tube 6
is heated by the heating coil 33 such that the hot-melt
adhesive 8 is melted and thus, the exposed fiber end por-
tions 4 and the rei~forcing core 7 are integrally embeddedin the hot-melt adhesive 8 as shown in Fig. lOb.
3 ~
In the multi-fiber collective fusion splicing
apparatus 20, since each pair of the opposite exposed fiber
end portions 4 are butt joined with each other through
their alignment based on their outside diameters, the
method described above is applicable to any type of optical
fiber regardless of whether the optical fibers are single-
mode optical fibers or multimode optical fibers. It is
apparent that the collective fusion splicing method is also
applicable to a ribbon type multi-fiber optical fiber cable
in which a plurality of the coated optical fibers are
arranged integrally as referred to earlier. Thus, a branch
portion from the coated optical fibers of the ribbon type
multi-fiber optical fiber cable to those of a loose tube
type multi-fiber optical fiber cable can be made compact in
size and can be rapidly produced.
As is clear from the foregoing description, in
accordance with the collective fusion splicing method
described above, operating time required for performing
collective fusion splicing is remarkably reduced as
compared with prior art methods in which the coated optical
fibers are fusion spliced with each other one by one and it
is possible to make the obtained joints compact in size.
Furthermore, in accordance with the present
invention, it is possible to fusion splice the coated
optical fibers of the ribbon type multi-fiber optical fiber
cable with those of the loose tube multi-fiber optical
`~ - 12 - l 3 3 4 4 7 7
fiber cable and obtain therebetween a compact branch joint
having a small connection loss.
Referring to Figs. 11 to 14, there is shown an
apparatus K1 for arranging the coated optical fibers 1 in a
plane. This apparatus K1 may be applicable to the above
described collective fusion splicing method. The apparatus
Kl mainly includes a rolled tape (tape feeding means) 44a for
feeding an adhesive tape 44 for bonding the coated optical
fibers 1 thereto, a tape fixing base (tape fixing means) 46
for fixing the adhesive tape 44 and a pair of positioning
slit portions (positioning means) 47 for arranging the coated
optical fibers 1. A plurality of coated optical fibers 1 are
inserted into loose tube 2 at random and are integrally held
by, for example, a clamp mechanism 43. This apparatus Kl is
provided along optical axes of the coated optical fibers 1
and the adhesive tape 44 is disposed substantially at right
angles to the optical axes of the coated optical fibers 1.
A fiber fixing member 45 for fixing end portions of
the coated optical fibers 1 is provided adjacent to one end
of a fixed base 49 remote from the clamp mechanism 43. In
the fiber fixing member 45, a block 45a of rectangular
parallelepiped stands and a double-sided adhesive tape 45b
having opposite adhesive faces is bonded to one side face of
the block 45a, which extends substantially in parallel with
the optical axes of the coated optical fibers 1. Meanwhile,
- - 13 - 1334477
it is to be noted that the clamp mechanism 43 and the fiber
fixing member 45 are not essential constituent elements of
the apparatus Kl but are subordinate constituent elements of
the apparatus Kl. Therefore, the clamp mechanism 43 and the
fiber fixing member 45 are not necessarily required for the
apparatus Kl.
Hereinbelow, construction of the apparatus Kl is
described. The rolled tape 44a is placed on the tape fixing
base 46 so as to be stretched in a direction substantially
perpendicular to the optical axes of the coated optical
fibers 1 such that an adhesive face of the adhesive tape 44
faces forwardly from the tape fixing base 46. The adhesive
tape 44 may be a heat-resistant adhesive tape. The rolled
tape 44a is placed at an upper portion of the tape fixing
base 46 but it is important that the adhesive face of the
adhesive tape 44 facés forwardly from the tape fixing base 46
so as to extend in a direction substantially perpendicular
to the optical axes of the coated optical fibers 1.
Therefore, if the above described requirement is satisfied,
the rolled tape 44a can also be disposed at a lower portion
of the tape fixing base 46. The tape fixing base 46 has a
flat portion 46a disposed obliquely in a direction
substantially perpendicular to the optical axes of the coated
optical fibers 1 and a tape support portion 46b for
supporting the rolled tape 44a, which is disposed at an upper
portion of the tape fixing base 46. Meanwhile, a fixing
1 334477
- 14 -
,member 46c for fixing a distal end portion 44b of the
adhesive tape 44 is provided at a lower portion of the tape
fixing base 46. In the case where the rolled tape 44a is
disposed at the lower portion of the tape fixing base 46,
the fixing member 46c and the tape support portion 46b are,
respectively, provided at the upper portion and the lower
portion of the tape fixing base 46. The flat portion 46a
has at leastan area such as to enable the coated optical
fibers of the ribbon type multi-fiber optical fiber cable to
be arranged side by side. Meanwhile, it can also be so
arranged that the fixing member 46c is formed by a magnet
and the tape fixing base 46 is made of a magnetic metal such
that the distal end portion 44b of the adhesive tape 44 is
secured between the fixing member 46c and the tape fixing
base 46.
At an upstream side and a downstream side of the
tape fixing base 46 in the direction of the optical axes of
the coated optical fibers 1, a pair of positioning slit
portions 47 for arranging the coated optical fibers 1 in
parallel with each other at a predetermined interval either
in numerical order or according to colors are provided,
respectively. Each of the positioning slit portions 47 has
a slit 47a defined by opposite members 47b and 47c
therebetween. The slit 47a is so formed as to extend
substantially in parallel with the plane of the flat portion
46a of the tape fixing base 46 and the width of the slit 47a
- 1S - 1 3 34 4 77
is s~t 5~ as to be slightly larger than the outside diameter
of the coated optical fibers 1.
The width of the slit 47a can be changed if one of
the opposite members 47b and 47c is of a movable construction.
In this case, variation in size of the coated optical fibers
can be dealt with and the apparatus is applicable to the
coated optical fibers of various sizes. In this embodiment,
since the opposite members 47c can be depressed horizontally
in a direction substantially perpendicular to the optical
axes of the coated optical fibers 1 by the distal end of a
micrometer head 48 as shown in Fig. 12, the width of the
slits 47a can be increased. Meanwhile, since the opposite
members 47c and the tape fixing base 46 are secured to the
fixed base 49, the relative position of the opposite members 47c
lS and the tape fixing base 46 does not change.
Hereinbelow, operation of the apparatus K1 is
described with reference to Figs. 13a and 13b. As shown in
Fig. 13a, the coated optical fibers 1 are inserted into the
slit 47a either in numerical order or according to colors t
e.g. brown, red, black, etc. Since the opposite members
47c are of movable construction as described above, the
width of the slit 47a can be adjusted by screwing the
micrometer head 48 in the case where coated o~tical fibers 1 having a
larger outside diameter are inserted into the slit 47a.
~5 Fig. 13b shows a profile a (shown by the two-dot chain line)
of the flat portion 46a of the tape fixing base 46 and
profiles b and c (shown by the two-dot chain lines) of the
_ - 16 - l 3 3 4 4 7 7
opposite members 47b and 47c defining the slit 47a
therebetween. The coated optical fibers 1 are accommodated
between the two-dot chain lines b and c, i.e. in the slit
47a but the two-dot chain line a slightly deviates from the
two-dot chain lines b and c. Thus, the coated optical
fibers 1 are so disposed as to be depressed against the flat
portion 46a. Therefore, the coated optical fibers 1 can be
easily attached to the adhesive tape 44 secured to the flat
portion 46a.
Then, operation of the apparatus K1 in the case of
a loose tube type multi-fiber optical fiber cable 2 having
12 coated optical fibers is described with reference to a
flow chart of Fig. 14. Initially, at step S101, the 1~
coated optical fibers 1 in the loose tube 2 are longitudi-
nally equally arranged at distal ends thereof and are
collectively clamped, at a location thereof spa~ed about
20cm from the distal ends, by the clamp mechanism 43. Then,
at step S102, a first one of the 12 coated optical fibers 1
is selected and is inserted into the two slits 47a. Subse-
quently, at step S103, the coated optical fiber 1 is slid tothe bottom of the slits 47a so as to be in a linear state
and a predetermined tensile force is applied to the coated
optical fiber 1. Thus, the coated optical fiber 1 is
attached to the adhesive tape 44 at step S104. Thereafter,
at step S105, a distal end portion of the coated optical
fiber l is secured to the fiber fixing member 45 such that
the coated optical fiber 1 is kept in a clamping state.
- _ - 17 - l 334477
The above described steps are repeated for the
re~ining coated optical fibers 1. If it is found at steP
S106 that all 12 coated optical fibers 1 have been
arranged side by side in the slits 47a, the distal end
portion 44b of the adhesive tape 44 is folded back so as to
embrace the 12 coated optical fibers 1 such that the 12
coated optical fibers 1 are clamped by the adhesive tape 44
at step S107. Then, at step S108, an end portion of the
adhesive tape 44 is cut so as to be separated from the 12
coated optical fibers 1 embraced by the distal end portion
44b. Subsequently, at step S109, the clamp mechanism 43 is
released such that the 12 coated optical fibers 1 are taken
out of the slits 47a. At this time, the coated optical
fibers 1 are of a ribbon type multi-fiber optical fiber cable
construction.
As will be seen from the description given so far,
in the present invention, the coated optical fibers can be
easily arranged in a predetermined order by the apparatus of
simple construction. Therefore, in accordance with the
apparatus of the present invention, the coated optical
fibers of the loose tube type multi-fiber optical fiber
cable can be easily formed into those of the ribbon type
multi-fiber optical fiber cable, thereby resulting in
rationalization, facilitation and a speeding up of the joining
of the coated optical fibers.
Referring to Figs. 15 to 19, according to
the present invention, there is shown an apparatus K2
for arranging the coated optical fibers 1 in a
1 334477
- 18 -
plane. The apparatus K2 is applicable to the collective
fusion splicing method described above. In Fig. 15,
the apparatus K2 is used to arrange 12 coated optical
fibers l of the loose tube type multi-fiber optical fiber
cable 2 into those of the ribbon type multi-fiber optical
fiber cable. A slot 52 is formed in a lon~itudinal
direction on â fixed base 51 having a substantially rectan-
gular parallelopiped shape. Three pairs of guide pins 53
and 53', 54 and 54' and 55 and 55' stand on the fixed base
51 along and at opposite sides of the slot 52. The guide
pins 53 and 53' are provided at one end of the fixed base
51, while the guides pins 54 and 54' and the guide pins 55
and 55' are provided relatively adjacent to one another.
In order to prevent the positioned coated optical
fibers 1 from being readily displaced, it can also be so
arranged that a plurality of V-shaped grooves are formed on
a bottom of the slot 52 at an interval equal to that for
arranging the coated optical fibers 1. In this case,
positional deviation of the coated optical fibers 1 can be
obviated and positioning of the coated optical fibers 1 can
be easily performed.
Furthermore, in order to not only increase the
frictional force between the coated optical fibers 1 and the
bottom of the slot 52 but to protect the coate~ optical~fibers
1, an elastic material, e.g. .ubber may be bonded to the
bottom of the slot 52. Thus, positional deviation of the
- 19 - 1334477
coated optical fibers 1 can be prevented and it becomes
possible to prevent damage to the coated optical fibers 1
due to an excessive force produced by improper mounting of
an e~uiangular plate 59.
An adhesive tape 57a for securing the coated
optical fibers 1 is supplied between the guide pins 54 and
55 and the guide pins 54' and SS'. The adhesive tape 57a
may be a heat-resistant adhesive tape and is drawn from a
rolled tape 47 contained in a tape case 56. The adhesive
tape 57a is used for bonding thereto the coated optical
.
fibers 1 arranged in the slot 52 and the tape 57a extends in a
direction substantially perpendicular to the longitudinal
direction of the slot 52 such that the adhesive face of the
adhesive tape 57a confronts the slot 52. Therefore, the tape
case 56 is provided such that not only reel shaft 57b of the
tape case 56 extends in parallel with the longitudinal
direction of the slot 52 but tape outlet 56a of the tape case
56 is disposed at one side of the tape case 56 adjacent to the
slot 52.
In the vicinity of the guide pins 3 and 3', a
clamp mechanism 58 for collectively holding a plurality of
coated optical fibers 1 supplied from the loose tube
type multi-fiber optical fiber cable 2 is mounted on the
fixed base 51. Between the guide pins 53 and 53' and the
guide pins 54 and 54', the equiangular plate 59 having 12
angles is mounted on the fixed base 51 so as to be rotated
about a vertical rotational axis S9a. Figs. 16 and 17 show
- - 20 - l 3 34 4 7 7
a state in which the 12 coated optical fibers 1 are tempo-
rarily held by the equiangular plate 59. Gradations "O" to
"12" are allotted to ,~.e vertexes of the 12 angles, such
that the distance from the rotational axis 59a to each of
the vertexes increases in proportion to the number of the
gradations "0" to "12". For example, assuming that charac-
ter L denotes a distance from the rotational axis 59a to the
slot 52 as shown in Fig. 16 and character d denotes an
outside diameter of the coated optical fibers 1 as shown in
Fig. 18b,the width of the slot 52 assumes a value of 12d as
shown in Fig. 17 and thedistance between the angle "0" and
the rotational axis 59a assumes a value of L as shown in
Fig. 18a. The distance between the angle "1" and the rota-
tional axis 59a assumes a value of (L+d) as shown in Fig.
18b andthedistance between the angle "2" and the rotational
axis 59a assumes a value of (L+2d) as shown in Fig. 18c.
Li~ewise,the distance between the angle "12" and the rota-
tional axis 59a assumes a value of (L+12d) as shown in Figs.
16 and 17. Therefore, when the first coated optical fiber 1
is positioned, the angle "1" is set to a point A shown in
Fig. 16 and thus, only the first coated optical fiber 1 is
secured between the equiangular plate 59 and the slot 52 as
shown in Fig. 18b. It is to be noted that point A is
located on a line drawn at right angles to the longitudinal
direction of the slot 52 from the rotational axis 59a. At
this time, the equiangular plate 59 does not pose any
- 21 - l 3 3~4 4 7 7
problem for insertion of the second coated optical fiber 1
into the slot 52.
The equiangular plate 59 may be formed by an
eccentric circular plate in which an eccentricity between
its rotational axis and its circular center is at least
twice the width of the slot 52. Since the circular plate is
simpler in construction than the equiangular plate 59, the
circular plate has the advantage that it is easy to manufac-
ture.
In order to arrange the coated optical fibers 1
accurately at a predetermined interval, it is desirable that
the equiangular plate 59 be provided in the vicinity of the
adhesive tape 57a. Thus, the equiangular plate 59 is
provided adjacent to the guide pins 54 and 54'.
Meanwhile, 12 positioning pins Pl to P12 are
driven into the slot 52 at predetermined intervals so as to
be disposed gradually forwardly in the longitudinal direc-
tion from the guide pins 55 and 55' and deviate gradually
from one side to the other side of the slot 52. As shown in
Fig. 15, the positioning pins ~1 to P12 are so formed as to
become larger in height as the positioning pins Pl to P12
come closer to the adhesive tape 7a such that the coated
optical fibers 1 can be easily hung from the corresponding
positioning pins Pl to P12. The positioning pins Pl to P12
are positioned at an interval of at least 10 times the
outside diameter of the coated optical fibers 1, i.e. at an
- - 22 - 1334477
interval of not less than lOd in the longitudinal direction
of the slot 52 and at an interval equal to the outside
diameter of the coated optical fibers 1, i.e. at an interval
of d in a lateral direction perpendicular to the longitudi-
nal direction of the slot 52. Therefore, the coated opticalfibers 1 can be positioned easily without applying a large
bending stress to the coated optical fibers 1.
Fig. 16 shows the state in which the 12 coated
optical fibers 1 are positioned by the positioning pins P1
1~ to P12, respectively. As shown in ~ig. 16, a double-sided
adhesive tape 62 having opposite adhesive faces is bonded to
the fixed base 51. The coated optical fibers 1 hung from
the respective positioning pins P1 to P12 are ~emporarily
attached to the adhesive tape 62 so as to be ke~t in ~s
state.
Hereinbelow, operation of the apparatus K2 is
described with reference to a flow chart of Fig. 19.
Initially, at step S201, the 12 coated optical fibers 1 in
the loose tube 2 are longitudinally equally arranged at
distal ends thereof and are bundled, at a location thereof
spaced about 20cm from the distal ends, into a parallel
state so as to be collectively held and clamped by the clamp
mechanism 58. Then, the gradation "0" of the equiangular
plate 59 is set to the point A at step S202 as shown in Fig.
18a. Subsequently, at step S203, a first one of the coated
optical fibers 1 is selected and is inserted into the slot
52 along the guide pins 53', 54' and 55'. Thereafter, at
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step S204, the first coated optical fiber 1 is positioned by
hanging the first coated optical fiber 1 from the position-
ing pin P1. Then, at step S205, an end portion of the first
coated optical fiber 1 is attached to the adhesive tape 62
while being slightly stretched so as to be ~ept in the
positioning state.
Then, at step S206, the equiangular plate 59 is
rotated so as to set the gradation "1" to the point A such
that the first coated optical fiber 1 is retained between
the equiangular plate 59 and the slot S2. Furthermore, by
repeating the above described steps, the second coated
optical fiber 1 is inserted along the first coated optical
fiber 1 into the slot 52 and is hung from the positioning
pin P2 such that an end portion of the second coated optical
fiber 1 is attached to the adhesive tape 62. Subsequently,
the gradation "2" of the equiangular plate 59 is set to the
point A such that the positioned two coated optical fibers 1
are retained between the equiangular plate 59 and the slot
52 as shown in Fig. 18c.
By sequentially repeating the above described
steps, the 12 coated optical fibers 1 are clamped in paral-
lel with each other in the slot 52. If it is found at step
S207 that all the 12 coated optical fibers 1 have been
arranged in the slot 52 either in numerical order or accord-
ing to colors, the adhesive tape 57a is drawn from the tape
case 56 and is attached to upper portions of the 12 coated
optical fibers 1 at step S20~. Namely, in Fig. 15, the
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1 334477
adhesive tape 57a has an adhesive face confronting the fixed
base 51. Then, at step S209, the end portions of the coated
. optical fibers 1 are removed from the adhesive tape 62 and
thus, the coated optical fibers 1 are unclamped by setting
s the gradation "0" to the point A and releasing the coated
optical fibers 1 from the clamp mechanism 58. Subsequently,
at step S210, a distal end portion of the adhesive tape 57a
is folded back to a lower side of the coated optical fibers
1 so as to embrace the coated optical fibers 1. Subsequent-
ly, at step S211, an end portion of the adhesive tape 57a is
cut so as to be separated from the coated optical fibers 1
embraced by the distal end portion of the adhesive tape 57a.
Thus, a ribbon type multi-fiber optical fiber cable having
the 12 coated optical fibers 1 is obtained, thereby result-
ing in completion of arrangement of the 12 coated optical
fibers 1.
As will be apparent from the foregoing, in the
present invention, a plurality of the coated optical fibers
can be arranged at a predetermined interval and in a prede-
termined order. Therefore, in accordance with the apparatusof the present invention, the coated optical fibers of the
loose tube type multi-fiber optical fiber cable can be
easily formed into those of the ribbon type multi-fiber
optical fiber cable, thereby resulting in rationalization,
facilitation and the s~P~;n~ up of the joining of the coated optical
fibers.
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1 334477
Although the present invention has been fully
described by way of example with reference to the accompany-
ing drawings, it is to be noted here that various changes
and modifications will be apparent to those s~illed in the
art. Therefore, unless otherwise such changes and modifica-
tions depart from the scope of the present invention, they
should be construed as being included therein.
