WO1997002500A1

WO1997002500A1 - Device for connecting optical fibres

Info

Publication number: WO1997002500A1
Application number: PCT/FR1996/001037
Authority: WO
Inventors: Michel Louis Romain Dillat; Pascal Maurice Marie-Bernard Bouyer; Franck Rémi Yves Dominique CHOPIN; Laurent Raymond Rittener-Ruff; Elie Zajac
Original assignee: Proptic
Priority date: 1995-07-03
Filing date: 1996-07-03
Publication date: 1997-01-23
Also published as: FR2736442A1; AU6521896A; FR2736442B1

Abstract

A device for connecting at least one first and one second optical fibre by placing the end surfaces of the fibres in facing positions. The device comprises a control member (11) for controlling a fibre pressing portion (6, 7), said control member being actuatable from outside the device to move the pressing portion from the insertion position to the locking position, or vice versa, and lock said portion at least in the locking position.

Description

Device for connecting optical fibers.

The present invention relates to a device for connecting optical fibers and in particular optical fibers arranged in ribbon.

To connect two optical fibers, connectors are already known which comprise a connector and two end pieces each intended to be secured to the end of an optical fiber and to engage in the connector, which keeps the two end pieces aligned so that the end faces of the two facing fibers are properly positioned relative to each other.

If they ensure a good quality of transmission of the optical signals between the fibers, these connectors nevertheless have the drawbacks of being relatively expensive to produce and long to mount at the end of the optical fibers.

The present invention aims to solve these drawbacks in particular by proposing a simple and economical device for connecting optical fibers, by means of which two optical fibers can be connected quickly and without special preparation.

The subject of the present invention is a device for connecting at least first and second optical fibers by placing the end faces of said fibers facing each other, comprising: means for immobilizing the first optical fiber,

at least one channel, capable of receiving the second optical fiber and comprising an inner end portion, adjacent to and of axis aligned with the first optical fiber, when the latter is immobilized by said immobilization means, fiber receiving surface located in the inner end portion of the channel,

-a fiber presser opening into the channel at the fiber receiving surface, movable perpendicularly to this surface between an insertion position in which it allows the introduction of the second optical fiber into the channel, and a position of blockage in which it immobilizes the end of the second optical fiber, introduced into the channel, against said fiber receiving surface, characterized in that it comprises in addition a control member (11) of the fiber presser, operable from outside the device and making it possible to move the presser between its insertion position and its blocking position, and vice versa, and to lock it at least in its blocking position.

Preferably, the device according to the invention is symmetrical, that is to say that the means for immobilizing the first optical fiber comprise, as for the second optical fiber, a channel, a fiber receiving surface, a presser and a control member of this presser.

With the device according to the invention, it is possible to connect two optical fibers by simply engaging the end of these fibers in the channels and by maneuvering the control members of the pressers to immobilize each optical fiber in its channel.

According to the invention, the fiber receiving surface has relief shapes, such as grooves, capable of guiding the optical fiber or fibers introduced into the corresponding channel so that two opposite fibers are suitably aligned one compared to each other.

In a particular embodiment of the invention, each control member comprises a shaft perpendicular to the direction of movement of the presser and a cavity formed in the presser for the passage of the shaft, a cam being provided on the portion of the 'shaft crossing said cavity to push the presser in its insertion position or in its locking position, depending on the angular position of the shaft.

In this case, the control member makes it possible to lock the presser not only in its blocking position but also in its insertion position.

Preferably, each channel is rectilinear and the corresponding shaft is parallel to said channel and opens onto a face of the device which is the same as that on which said channel opens. In other words, if one designates by face of introduction of fibers the face of the device by which the optical fibers are introduced into the channel, the shaft opens onto this face of introduction of fibers, which presents the advantage that the locking and unlocking of the fibers inside the channel can be carried out at any time, even if the device according to the invention is mounted in an assembly and its other faces are made inaccessible.

In an advantageous embodiment, the device further comprises a sheath receiving surface, located in the channel upstream from the fiber receiving surface, in the direction of introduction of the second optical fiber into the channel, and a sheath presser opening into each channel at the sheath receiving surface, movable perpendicular to this surface so as to immobilize the sheath of an optical fiber against said sheath receiving surface.

In this embodiment, the device is intended to receive the end of a stripped optical fiber, the stripped part of the optical fiber coming to lodge against the fiber receiving surface where it is immobilized by the fiber presser, while that the non-stripped part of the fiber is housed against the sheath receiving surface while being immobilized by the sheath presser. According to a first variant of this embodiment, the fiber presser and the sheath presser are made in one piece and are arranged so that, during the movement of said pressers from their insertion position to their blocking position , the sheath presser immobilizes the sheath against the sheath receiving surface before the fiber presser immobilizes the stripped end of the optical fiber against the fiber receiving surface.

According to another variant, the fiber presser and the sheath presser β are separate, and each shaft has a first cam capable of moving the fiber presser, and a second cam capable of moving the sheath presser.

In this case, the first and second cams are advantageously arranged to move the pressers from their insertion position to their blocking position during rotation of the shaft, the sheath presser being moved before the fiber presser.

In another embodiment of the invention, each control member is constituted by a lever capable of acting on the presser to place it in the insertion position while a return device returns the presser to the blocking position.

The lever is advantageously accessible from the fiber introduction face of the device.

Advantageously, the device according to the invention comprises a housing in which the channel (s) are formed and in which the presser (s) are housed as well as the control members of these pressers. In a variant, the device comprises, on the one hand, a female connector in which are formed portions of inner ends of channels and fiber receiving surfaces, and on the other hand, at least one plug in which are arranged a duct and a sheath receiving surface, and in which are housed a fiber presser and a sheath presser, as well as a control member for these pressers, said plug being capable of coupling with the female connector and being arranged so that the channel of the plug is aligned with the corresponding inner channel end portion of the female connector and that the fiber presser of the plug is facing the corresponding fiber receiving surface of the female connector.

Preferably, an interface is provided between the end faces opposite the optical fibers, so as to favor the transmission of the optical signals. Such an interface can be constituted by a membrane made of elastic material, index adapter, membrane against which the end face of an optical fiber can bear when inserting the optical fiber.

The interface can also consist of a gel introduced into the device up to the end faces opposite the optical fibers, for example through a chimney provided for this purpose in the device.

To position a fiber introduced into a channel, the device may also include a stop for the sheath of this optical fiber, previously stripped over an appropriate length.

_In order to better understand the invention, we will now describe embodiments given by way of nonlimiting examples, with reference to the appended drawing in which: FIG. 1 is a perspective view of a device according to a first embodiment of the invention,

FIG. 2 is a view in axial section of a device according to a second embodiment of the invention,

FIG. 3 is a sectional view along III-III of FIG. 2,

FIG. 4 is a perspective view of a device according to a third embodiment of the invention,

10 - FIG. 5 is a view in axial section of this device, according to V-V of FIG. 6,

FIG. 6 is a sectional view along VI-VI of FIG. 5,

- Figure 7 is an axial sectional view similar to Figure 5 of a device according to a fourth embodiment of

, ₅ the invention,

FIG. 8 is a top view of the housing of the device in FIG. 7,

FIG. 9 is a sectional view along IX-IX of FIG. 7,

FIG. 10 is a view in axial section of a device 2 _Q according to a fifth embodiment of the invention,

FIG. 11 is a view similar to FIG. 10,

- Figure 12 is an axial sectional view of a device according to a sixth embodiment of the invention.

The embodiment shown in Figure 1 makes it possible to clearly understand the operating principle of the device according to the invention.

A housing 1, of substantially parallelepiped shape and of square section, comprises a fiber introduction channel 2 which extends from one of its lateral faces 3a _^ to its face

Opposite side 3b. The faces 3a and 3b constitute the fiber introduction faces of the device.

The lower wall of the channel 2, with respect to the drawing, is provided with parallel V-shaped grooves dimensioned so as to be able to accommodate parallel fibers of the same ribbon.

35 On its upper face 4, the housing 1 comprises a parallelepipedic cavity 5 which opens at its lower part into the channel 2. Two pressers 6 and 7, housed in the cavity 5, are capable of moving vertically there between a high position or insertion position and a low position or blocking position.

An interface plate 8 supporting a membrane 9 made of elastic index-adapting material, is able to be housed between the pressers 6 and 7 to bear against the bottom wall of the channel 2 which advantageously has grooves.

The device works as follows:

The interface plate 8 being placed between the pressers, and the latter being held in the insertion position, a ribbon of optical fibers 10 is introduced into the channel 2 as indicated by the arrow in FIG. 1.

Preferably, the end of the fibers of the ribbon has been previously stripped.

The ribbon of optical fibers 10 is introduced into the channel 2 until the end face of the fibers bears against the sheet of elastic material 9.

The presser 6 is then placed in the low position, or blocking position, so as to immobilize the ribbon 10 in the housing 1.

Another ribbon, not shown, is introduced into the channel 2 through the introduction face 3b of the housing.

When this new strip is positioned in the channel so that the end face of its fibers bears against the membrane 9, the presser 7 is placed in the low position or blocking position.

Thus, the two ribbons 10 were connected quickly and easily.

In FIG. 1, the control member which makes it possible to position the pressers 6 and 7 in the insertion position and in the blocking position has not been shown for reasons of clarity.

In the embodiment of FIGS. 2 and 3, there is the housing 1, the channel 2, the cavity 5, the pressers 6 and 7, the interface plate 8 and the membrane made of elastic material 9.

In this embodiment, the control member of each presser is constituted by a shaft 11 comprising a cam 12 which passes axially through the part of the housing between the face introduction 3a _. , 3b and the cavity 5, as well as the corresponding presser 6, 7.

As clearly seen in the sectional view of Figure 3, each presser 6, 7 comprises a rectangular bore 6a _. , 7Ά inside which the shaft 11 can rotate around its axis 13.

Compared to Figure 3, the width of the bore 6a. is equal to twice the radius of the shaft 11 at the top of the cam 12, while the height of the bore 6a _^ is equal to the sum of the radius ^of the shaft 11 excluding the cam and the radius of the shaft 11 at the top of cam 12.

Thus, it is understood that by rotation of the shaft 11, the presser 6 can be placed in the blocking position, as shown in FIG. 3, or in the insertion position when the cam 12 is located above the shaft. 11.

Each shaft 11 has, on its outer end face, which is slightly projecting from the insertion face 3a, 3b of the housing, a slot 14 allowing the shaft to rotate relative to its axis 13 to the using a screwdriver. As shown in FIG. 3, each presser 6,7 has an elastomer shoe 6b, 7b which allows it to clamp the optical fibers against the grooves of channel 2 without damaging them.

In the embodiment of Figures 2 and 3, a cover 15 closes the cavity 5 above the pressers 6 and 7. In the third embodiment, shown in Figures 4 to 6, the housing 1 comprises two channels 2a. and 2b of different widths, which allows the same device to be used to connect ribbons of two different widths.

For example 'channel 2a. can be used for 8 fiber ribbons, while channel 2b can be used for 4 fiber ribbons.

In this embodiment, each presser 6, 7 is arranged in a U at its lower part, so as to press simultaneously on the grooves of the two channels 2a _^ and 2b when they are in the locked position.

In this embodiment, the interface plate 5 and the cover 15 described above are replaced by a plate 16 which closes the cavity 5 and which is provided with two chimneys 17 extending from the upper face 4 of the housing 1 to the interior of the channels 2a _^ , 2b.

These chimneys 17 make it possible to introduce a liquid gel in the vicinity of the end faces of the optical fibers to be connected, so as to improve the transmission of the optical signals between these fibers.

In this third embodiment, each channel 2a, 2b comprises, in its inner end portion 18, a fiber receiving surface 19 which is common to the end portions

10 interior 18 of two opposite channels.

The fiber receiving surface 19 comprises a plurality of parallel longitudinal grooves suitable for receiving the stripped end portions 10a of the optical fibers of a ribbon 10. - ₅ Downstream of its inner end portion 18, each channel also comprises a sheath receiving surface 20 constituted by parallel longitudinal grooves capable of receiving the sheaths 10b of the optical fibers of a ribbon 10.

Because there is no membrane made of elastic material

20 separating two opposite channels, the axial positioning of a ribbon 10 introduced into a channel cannot be ensured by bringing the end faces of the fibers into abutment against such a membrane.

This axial positioning can be obtained thanks to the fiber receiving surface 19 which projects slightly from the bottom of each

25 channel 2a, 2b, and whose front faces 19a. serve as stops for the sheaths 10b of the optical fibers, during the introduction of the ribbons.

To properly position a first ribbon of optical fibers (on the left in FIG. 5), in such a device, it is

30 therefore preferable to strip its optical fibers over an appropriate length, corresponding substantially to half the length of the fiber receiving surface 19.

The second strip (on the right in FIG. 5), introduced opposite the first, can then be positioned with the end face _3ς of its fibers in abutment against the end face of the fibers of the first strip.

A gel is then introduced via the chimneys 17 to improve the transmission of the light signal. In a variant, the gel can be introduced beforehand into the chimneys and enclosed in them, for example by sticking a label (not shown) on the plate (16), at the mouth of the chimneys.

The fiber ribbons are then introduced into the channels (2a and 2b as explained above.

In this embodiment, each presser 6, 7 is made in one piece but includes two presser parts, namely a front part 21 located above the fiber receiving surface 19, and a rear part 22 located above the sheath receiving surface 20.

The front 21 and rear 22 parts of each presser are located, with respect to the fiber receiving surface 19 and the sheath receiving surface 20, at a distance such that, when a ribbon of optical fibers is introduced into the channel and when the shaft 11 is rotated to move the presser from its insertion position to its blocking position, the rear part 22 comes to immobilize the fiber sheaths against the sheath receiving surface 20, before the front part 21 of the presser does not come to immobilize the stripped parts of the fibers against the fiber receiving surface 19.

Thus, in the event of traction on the strip 10, the stripped portion of the fibers is never stressed, whatever the position of the corresponding presser.

In the fourth embodiment, shown in Figures 7 to 9, each presser 6, 7 is divided into two separate parts which form, one a fiber presser 21, the other a sheath presser 22, corresponding to the front parts and rear of the pressers of figure 5.

To position the fiber 21 and sheath pressers 22, each shaft 11 comprises a first cam 12a. which allows the fiber presser 21 to be actuated, and a second cam 12b which enables the sheath presser 22 to be actuated.

As seen in the sectional view of Figure 9, the cam 12ja extends over a smaller angular sector than the cam 12b, so that the sheath presser 22 is always placed in its locked position before the presser fiber 21. In this embodiment, the box 1 is closed by a cover 15.

No interface between the front faces of the facing fibers has been shown here, but it is clear that the presence of a plastic membrane or a liquid gel is not excluded in this fourth embodiment.

In the top view of FIG. 8, we see the distribution of the fiber reception surfaces 19 and the sheath reception surfaces 20 for the two channels 2a, 2b, which have different widths as already explained with reference to FIGS. 4 to 6.

In the fifth embodiment of Figures 10 and 11, the device comprises, in place of the housing described above, a female connector 23 and two male end pieces 24 capable of engaging and immobilizing, for example by snap-fastening, in housings 25 provided for this purpose in the female connector 23.

An inner end portion of channel 26 for the passage of optical fibers passes through the female connector 23. A fiber receiving surface 9, formed by parallel grooves, lines the bottom wall of this portion of channel 26.

Each male end piece 24 comprises a channel 27 allowing the introduction of a fiber or a ribbon of fibers, channel 27 which is in alignment with the channel portion 26 of the female connector when the male end piece 24 is inserted. in its housing 25, as seen on the left of FIG. 10.

A sheath receiving surface 20 is provided in the front part of the channel 27.

A presser 6, 7, of the type described with reference to FIGS. 4 to 6, is mounted on each male end piece 24 while being operated by a camshaft 11.

The rear part 22 of each presser is distant from the sheath receiving surface 20 so that the sheath 10b of an optical fiber introduced into the channel 27 is immobilized against the sheath receiving surface 20 when the presser 6 is substantially halfway between its insertion position and its blocking position, the front part 21 of the presser is not yet in contact with the stripped part 10jι of the fiber. In this way, it is possible to lock the fiber inside the male end piece 24, for example by making the shaft 11 make a quarter turn. Once the male end piece 24 is thus secured at the end fiber, it can be engaged in its housing 25 in the manner of a conventional optical connector tip.

The fiber is then secured against the surface _of fiber receiving e 19 of the female connector 23 by a complementary single rotational movement of the shaft.

Conversely, each spigot 24 can be removed from the female _of raccor 23 without being separated from the optical fiber.

For this purpose, it suffices to rotate the shaft 11 a quarter of a turn to unlock only the stripped part of the optical fiber while maintaining the tightening of the sheath of the optical fiber.

It is thus possible to insert the male end piece 24 into another female fitting 23.

In the sixth embodiment, shown in FIG. 12, the control members and the pressers (sheath and fiber) are replaced by two pivoting parts 28.

In FIG. 12, the parts identical to those described in the previous embodiments bear the same reference numbers.

Each part 28 comprises a part 28a in the form of sheath and fiber pressers and a part 28b in the form of a lever, which is pivotally mounted about an axis 30.

Each lever protrudes from the corresponding introduction face 3a., 3b so that it can be operated from this face.

A leaf spring 29, secured to the housing 1, pushes each presser 28a into its blocking position, shown on the left side of FIG. 12.

Thus, each lever 28b is only used to pass the corresponding presser 28a into its insertion position shown on the right-hand side of FIG. 12. It can be noted that, in the embodiments described above, the cross section of the housing 1 or of the female connector 23 is square, which makes it possible to mount the device according to the invention in a given first position or in a position obtained by rotating the device a quarter turn around its longitudinal axis, without changing the size of the device.

In this way, it is possible to assemble devices along lines and / or columns, and this by orienting them indifferently in one or other of the two positions mentioned above, which makes it possible to connect ribbons oriented in several directions.

It is understood that the embodiments which have just been described have no limiting character and that they can receive any desirable modifications without departing from the scope of the invention.

Claims

1. Device for connecting at least first and second optical fibers by placing the end faces of said fibers facing each other, comprising:

means for immobilizing the first optical fiber,

at least one channel (2, 2a., 2b, 26, 27) capable of receiving the second optical fiber and comprising an inner end portion, adjacent to and of axis aligned with the first optical fiber, when the latter is immobilized by said immobilization means,

a fiber receiving surface (19) located in the inner end portion of the channel,

-a fiber presser (6, 7) opening into the channel at the fiber receiving surface, movable perpendicular to this surface between an insertion position in which it allows the introduction of the second optical fiber into the channel , and a blocking position in which it immobilizes the end of the second optical fiber, introduced into the channel, against said fiber receiving surface, characterized in that it further comprises a control member (11) of the fiber presser (6, 7), operable from outside the device and making it possible to move the presser between its insertion position and its blocking position, and vice versa, and to lock it at least in its blocking position.

2. Device according to claim 1, characterized in that the control member (11) allows to lock the presser in each of its two positions.

3. Device according to any one of claims 1 and 2, characterized in that each control member (11) comprises a shaft (11) perpendicular to the direction of movement of the presser (6, 7) and a cavity (6EL , 7a.) Formed in the presser for the passage of the shaft, a cam (12, 12a, 12b) being provided on the portion of the shaft passing through said cavity to push the presser back into its insertion position or into its locking position, depending on the angular position of the shaft.

4. Device according to claim 1, characterized in that each control member is constituted by a lever (28bJ able to act on the presser (28a.) To place it in the insertion position while a return device ( 29) returns the presser (28aJ to the locked position.

5. Device according to claim 4, characterized in that the lever (28b) and the presser (28aJ are one and the same piece (28), pivotally mounted.

10 6. Device according to any one of claims 1 to 5, characterized in that it further comprises a sheath receiving surface (20), located in the channel upstream of the fiber receiving surface (19 ), in the direction of introduction of the second optical fiber into the channel, and a sheath presser (7) emerging

, -. in each channel at the sheath receiving surface (20), movable perpendicular to this surface so as to immobilize the sheath (10b) of an optical fiber against said sheath receiving surface.

7. Device according to claim 6, characterized by the

20 the fact that the fiber presser and the sheath presser are made in one piece (6,7) and are arranged so that, when moving said pressers from their insertion position to their locking position, the sheath presser immobilizes the sheath (10b) against the sheath receiving surface (20) before the presser

25 of fibers does not immobilize the stripped end (10a.) Of the optical fiber against the fiber receiving surface (19).

8. Device according to claims 3 and 6, characterized in that the fiber presser (21) and the sheath presser (22) are separate, and that each shaft (11) has a first cam

30 (12a.) Able to move the fiber presser (21), and a second cam (12b) able to move the sheath presser (22).

9. Device according to claim 8, characterized in that the first (12a) and second (12b) cams are advantageously arranged to move the pressers (21, 22) from

35 their insertion position to their locking position during the rotation of the shaft (11), the sheath presser (22) being moved before the fiber presser (21).

10. Device according to any one of claims 1 to 9, characterized in that it comprises a housing (1) in which are formed the channel or channels (2, 2a, 2b) and in which are housed the pressers (6, 7) as well as the control members 11 of these pressers.

11. Device according to any one of claims 6 to 9, characterized in that it comprises, on the one hand, a female connector (23) in which are formed portions of interior ends (26) of channels and fiber receiving surfaces (19), and on the other hand, at least one plug (24) in which are formed a channel (27) and a sheath receiving surface (20), and in which a presser are housed fiber (6, 7) and a sheath presser (6,7), as well as a control member (11) of these pressers, said plug (24) being capable of coupling with the female connector (23) and being arranged so that the channel (27) of the plug is aligned with the corresponding inner channel end portion (26) of the female connector (23) and that the fiber presser (6,7) of the plug (24) is located opposite the corresponding fiber receiving surface (19) of the female connector (23).

12. Device according to one of claims 1 to 11, characterized in that it comprises an interface between the terminal faces opposite the optical fibers, so as to promote the transmission of optical signals.

13. Device according to claim 12, characterized in that the interface consists of a membrane (9) made of elastic material, index adapter, membrane against which the end face of an optical fiber can bear during the insertion of optical fiber.

14. Device according to claim 12, characterized in that the interface consists of a gel introduced into the device up to the end faces opposite the optical fibers, for example through a chimney provided for this purpose.

15. Device according to any one of claims 1 to 14, characterized in that it comprises a stop (19a) for the sheath (10b) of an optical fiber, previously stripped over an appropriate length.