Note: Descriptions are shown in the official language in which they were submitted.
, . CA 022~3038 1998-11-0~
HARTING KGaA
Marienwerderstr. 3 1998-10-16
D-32339 Espelkamp 9730 CA P L
Couplin~ for optical wave~uide cables
The invention relates to a coupling for optical waveguide cables, in particular
o for plastic optical waveguides.
Couplings of this kind serve for mechanically and optically connecting the
ends of optical waveguides. Under these circumstances, a coupling of this
kind must be mechanically stable and have adequate optical coupling of the
optical waveguides.
From the company publication "Suhner Fiberoptik, LWL-Komponenten, Ge-
samtkatalog" ["Suhner fbre optics, optical waveguide components, complete
catalogue"J, 05.96 reprint, by the company Huber + Suhner AG, Herisau,
Switzerland, it is known practice to provide optical waveguides with plugs for
the purpose of coupling their ends and to plug the said plugs, in an oppo-
sitely directed manner, into a coupling sleeve which is constructed to receive,
the plug pins.
2~ However, in this coupling, which is by and large satisfactory, the optical
waveguides have to be provided with suitable plugs. When doing so, vari-
ous tools are needed for fitting the plugs, in order to fasten the optical
waveguide fibers in the plug by crimping or gluing.
The underlying object of the invention is to construct a coupling for optical
waveguides of the initially mentioned type to the effect that the connection of
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the optical waveguides can be produced without special tools and that the
coupling as a whole can be manufactured at a reasonable price.
This object is achieved through the fact that the coupling has a coupling
sleeve in which the ends of the optical waveguides can be inserted, the said
coupling sleeve being provided with a through-bore matched to the optical
waveguides, that the ends of the coupling sleeve are provided with a thread
and have a cone at the end, that the ends provided with the threads are
provided with axial slots, and that a cap nut with an internal cone can be
screwed onto the ends, during the screwing-on of which cap nut the slotted
ends are compressed radially.
Advantageous refinements of the invention are indicated in claims 2 to 5.
The advantages achieved by means of the invention consist, in particular, in
the fact that no special tools are needed for producing the connection of two
optical waveguides, and the outlay is therefore extremely small. In addition,
the costs of an optical waveguide connection are diminished, compared with
known connections, because of the reduction in the components required.
Under these circumstances, the mounting volume is reduced at the same
time and assembly is possible even in the case of relatively short cable
lengths.
An exemplified embodiment of the invention is represented in the drawings
and will be explained in greater detail below.
Figure 1 shows a view of a coupling with optical waveguides introduced,
figure 2 shows a perspective view of the coupling according to figure 1,
figure 3 shows a view of a modified coupling,
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figure 4 shows a view of another modified coupling, and
figure 5 shows an exploded view of the coupling sleeve of the coupling
according to figure 4.
The coupling represented in figures 1 and 2 essentially consists of a cou-
pling sleeve 1 which is provided with a through-bore 2, the diameter of the
said bore being matched to the external diameter of the optical waveguides
3 to be introduced. The ends 4 of the coupling sleeve are provided, in each
case, with a thread 5 onto which a cap nut 6 can be screwed. In order to
facilitate handling of the parts, the central region of the coupling sleeve is of
thickened construction and is provided with knurling, and the cap nuts are
also equipped with external knurling. The ends 4 of the coupling sleeve are
also provided with axial slots 7 which extend approximately as far as the end
of the thread region. As a result of this, the ends 4 can be elastically com-
pressed in the radial direction.
The ends are also provided with an external cone 8, on which an internal
cone 9 in the cap nuts acts when the latter are screwed on, and compresses
the ends radially in the process.
As is represented in figure 1, the ends of two optical waveguides 3 are in- ,
serted in the through-bore 2 of the coupling sleeve in an oppositely directed
manner. In the process, the optical waveguides are, in each case, inserted
approximately as far as the center of the coupling sleeve and lie closely
against one another, so that transmission of optical signals from one optical
waveguide to the other is guaranteed. In order to fix the optical waveguides
in the coupling sleeve, the cap nuts are screwed on tightly, the ends 4 being
compressed and forced against the external sheathing of the optical
waveguides. In order to improve the clamping of the optical waveguides,
provision may optionally be made for the through-bore to have a roughened
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CA 022~3038 1998-11-0~
surface in the region of the slotted ends 4, it being possible to achieve this
by incorporating a thread 10.
Represented in figure 3 is a modified coupling which is essentially con-
s structed like the coupling described previously, and the same reference
symbols as in figures 1 and 2 have been used for the same parts. In this
coupling, the central section 11 of the coupling sleeve 1 is provided with an
external thread 12. As represented in the drawings, the coupling sleeve can
be inserted in a wall 14 provided with a suitable bore 13, and can be
o screwed down by means of nuts 15. Provision may also optionally be made
for the central section 11 to be provided with a collar, of which no further
details are represented here, and in addition, for only one nut to be needed
for the purpose of fastening in the wall.
lS Represented in figures 4 and 5 is a further modified coupling which is like-
wise essentially constructed like the coupling described previously and, here
too, the same reference symbols as in figures 1 and 2 have been used for
the same parts. The difference in this case consists in the fact that the
~ coupling sleeve 1' is assembled from two parts 16, 17. In this instance, the
part 16 of the coupling sleeve is provided with a bore 18 into which a pin-
shaped projection 19 on the part 17 of the coupling sleeve can be inserted.
Under these circumstances, the projection 19 is constructed to be only of
such a length that, after the assembling of the two parts, a groove 20 is
constructed inside the coupling sleeve. The two parts 16, 17 are preferably
2~ held together as a result of a press fit of the projection in the bore. Further-
more, the bore and the projection are so shaped that the groove 20 is situ-
ated approximately in the center of the coupling sleeve 1'. An elastic sealing
ring 21 is also inserted in the groove 20. For the purpose of coupling two
optical waveguides, the said sealing ring was introduced into the coupling
sleeve in such a way that their ends are located in front of one another in the
region of the sealing ring. Under these circumstances, the sealing ring then
protects the end faces of the fibers against moisture and mechanical con-
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CA 022~3038 1998-11-0~
taminants. A coupling constructed in such a way can thus be used even un-
der harsh environmental conditions.
As described above, the groove is formed by suitable construction of the two
parts of the bipartite coupling sleeve 1'. However, provision may also be
made for such a groove, in which a sealing ring 21 is then inserted, to be
molded in, even in the case of a one-piece coupling sleeve 1.
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