JPH04230823A - Method and apparatus for aligning optical fiber - Google Patents

Abstract

PURPOSE: To improve operativity relating to method and device for automatic alignment of an optical fiber at measurement. CONSTITUTION: A sample cable is positioned on a supporting body, and an oscillating device which makes the supporting body pivot-rotate around an fixed axis is assigned, and while the oscillating device is pivot-rotated around the axis, an end part of a measurement fiber is guided in the groove containing the end part of the measurement fiber. The device comprises a supporting body 17 which positions a cable 16, and an oscillating device with which, being attached to the supporting body pivot-rotated around an axis 19, an end part of the cable 16 is assigned in front of the measurement fiber attached to a movable supporting body in a groove 14 of Vshaped profile. Application: to align a measurement fiber to a fiber of flat cable.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention provides for positioning the fibers of a pre-stripped cable in a substantially V-shaped groove so that the axis of one or more measuring fibers and the axis of the cable fibers are aligned at least in their end portions. A method for automatically aligning optical fibers consisting of contacting one or more measuring fibers with the fibers of a cable so as to form an angle of less than 180 degrees on a part of the fibers, especially for optical transmission cables composed of flat ribbons. The present invention relates to a method and apparatus for arranging a plurality of measurement fibers simultaneously or one measurement fiber sequentially.

0002

BACKGROUND OF THE INVENTION French patent application No. 8,800,758 discloses a method and a device of this type with which fibers can be aligned.

0003

SUMMARY OF THE INVENTION With the apparatus disclosed herein, several operational difficulties are encountered in aligning the measurement fibers with the fibers of the flat cable, and the present invention addresses these. This is an attempt to solve the problem.

0004

SUMMARY OF THE INVENTION To this end, the method of the present invention involves first positioning the cable on a support, placing the support on a rocking device that pivots about a fixed axis, and so on. It is characterized by guiding the end portion of the fiber into the groove while pivoting around its axis.

[0005] Pivoting a rocker carrying a fiber support about an axis preferably disposed at a predetermined distance from the support, said distance being such that the free ends of the fibers of the cable are in the alignment groove. The distance is such that when curving internally it moves forward and is parallel to the groove by a minimum length.

The apparatus for carrying out the method comprises a support for positioning the cable, a means for attaching the support to a swinging device, and a pre-stripped end portion of the fiber that is not more than 180 degrees The device is characterized in that it includes means for pivoting the swinging device so as to be disposed in and parallel to the V-shaped alignment groove while forming an angle of .

According to a preferred embodiment of the device, the rocking device has a fixed pivot axis mounted at a predetermined distance d from the fiber attached to the fiber mounted on the support on the crosspiece. .

Preferably, this distance d is determined such that the end of the fiber moves forward as it curves in the groove as the rocker rotates. According to an advantageous embodiment, the rocking device moves axially on the crosspiece, and
Related to conical screws for initial fit.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the illustrated fiber alignment device 10 basically comprises a first portion 11 having support and positioning means for the fiber to be measured; The second part having 1
2 and a third part 13 arranged between the first part and the second part and having means for aligning the measuring fiber with the fiber to be measured.

The alignment means comprises a series or series of grooves 14 which are essentially V-shaped, parallel to each other, and arranged in the same plane. A series of such grooves 14 is illustrated in detail in FIG. In practice, this device may be configured to align the fiber to be measured with the measuring fiber, or to align a series of fibers, in particular fibers constituting a flat or ribbon cable, with one measuring fiber one after the other. , or simultaneously configured to align with the measuring fiber body. The grooves 14 are arranged in fixed or replaceable plates 15, the spacing between the grooves substantially corresponding to the spacing between the fibers in the fiber ribbon 16 being measured.

The support and positioning means for said first part 11 of the device have at least one standard support 17, which supports here fibers or preferably flat ribbons constituting a multi-fiber cable. Preferably, it is in the form of a holder to hold 16 in place. The standard support 17 is mounted on a rocker 18 arranged for pivoting about an axis 19 substantially parallel to the plane of the standard support and perpendicular to the axis of the fiber to be measured. It is installed. This rocking device and its operating principle will be described in detail later.

The support means for the measuring fiber(s) 9 are constituted by a turret 20 which is translated on a guide rail in a direction substantially perpendicular to the axis of these fibers. The end of the measuring fiber 9 is connected to the turret 2.
0 and is mounted in an end member 22 called a fiber holder.

In order to align the fiber to be measured with one or more measuring fibers, the fibers to be measured are mounted on their support 17 . After pre-baring and cutting the end portions a predetermined length from the front face of the support, the rocker 18 is pivoted about its axis 19 and the ends of the fibers are cut into the grooves 14 as shown in FIG. Curve inside. When using only one fiber to be measured, the end of the fiber to be measured can be pushed onto the end of each fiber to be measured in turn, without having to repeatedly pivot the rocker supporting the fiber to be measured. guess. When using the same number of measuring fibers as fibers to be measured, the ends of the fibers to be measured are simultaneously pressed against the ends of the measuring fibers.

In the example shown in FIG. 1, the plate 15 has four grooves 14. In this case, the device must have four rockers (only two of which are shown). These rocking devices are mounted on the crosspiece 23 via a pivot shaft 19, each rocking device preferably consisting of a conical screw 24;
It is associated with a transverse stop element by which the initial position of the corresponding rocking device on the transverse member 23 can be adjusted. This position must, of course, be precisely fixed so that each time a new ribbon 16 is placed in the rocker, the corresponding fibers can be aligned with the series of grooves 14 without readjusting the lateral position of the rocker. Must be.

As shown in FIG. 2, the bare portions 25 of the fibers of the ribbon 16 are positioned within the grooves such that they are inserted tangentially into the grooves 14. The contact at point A between the fiber 25 to be measured and the measuring fiber 9 takes place under slight pressure, which forces provide optimum contact between the two ends and also reduce the contact between these ends in the contact area. The end area rests against the bottom of the groove without any deflection that would cause it to lift.

In practice, the ribbon is fixed on a standard support and the fibers are then stripped for a predetermined length. The fibers are then cut together perpendicular to their axis at a predetermined length from the front surface of the support. This support is then placed on a rocker which is held in a raised position, protecting the fibers from contact with certain objects. This technique precisely positions the fibers without the need for individual mating of these fibers.Since the pre-positioning of the rocker is done, each bare end section of the fiber has a vertical position corresponding to the bottom of the V-shaped groove. located on the surface. When the operator rotates the rocker, each fiber is first guided into its corresponding groove and deflected until its end portion straightens a certain length and fits neatly into the groove.

In this position each fiber can come into contact with a measuring fiber located in the same groove and facing the fiber to be measured. Rotation of the rocker moves the end of the fiber stuck in the groove. This effect depends on the distance between the fiber and the axis of rotation of the rocker. This principle will be explained later in connection with FIGS. 3 and 4.

1, 2, 3 are respectively successive positions of the fibers attached to the rocker and attached to its support, A is the pivot axis of this rocker, and d
is the distance between axis A and the fiber positioned on the rocker. When d is approximately zero, tilting the rocker so that the fiber moves from position 2 to position 3 causes the end of the fiber to retract by a length -11. This phenomenon is shown in Figure 3.
is shown.

In the embodiment of FIG. 4, the distance d is greater than zero, in which case the end of the fiber is advanced by a length +l2.

[0020] A rocker device can be formed with an axis A arranged at a distance d0 from the fibers such that the advancement of the ends of the fibers in the alignment groove corresponds to a predetermined length +10. Select the optimal length l0 and determine the corresponding distance d0.

When alignment is made between a long movable fiber and a plurality of short measured fibers, the longitudinal force exerted by the contact of the movable fibers substantially changes the degree of deflection of these short fibers. It is so small that it causes It is therefore important that the quality of the alignment is such that the axis of the end of the short fiber is parallel to the groove, independent of the action of the moving fiber. The length of the fiber portions in contact with the grooves must also be minimal so as to keep their lateral supports (groove reaction) and longitudinal supports (moveable fiber pressure) as close as possible.

The tangent condition between the groove and the fiber at the end of the fiber is expressed by Equation 1.

[0023]

[Formula 1]

Here l is the free length of the fiber and l0
is the distance measured along the implantation axis to the groove.

This condition can be derived from equation 2, which relates the deflection y(l) to the angle y'(l) at the free end of the embedded fiber.

[0026]

[Formula 2]

The inclination angle θ0 and the height h of the embedding point above the groove are determined so as to satisfy the relationship of equation 1 when the degree of freedom l of the fiber is the standard length.

[0028] The invention is not limited to the embodiments described above, but includes any variations or modifications apparent to those skilled in the art.

[0029]

As described above, according to the present invention, it is possible to improve the operability particularly when aligning measurement fibers with the fibers of a flat cable.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the device of the invention.

FIG. 2 is a detailed perspective view of the device of FIG. 1;

FIG. 3 is an explanatory diagram showing the principle of operation of the rocking device.

FIG. 4 is an explanatory diagram showing the principle of operation of the rocking device.

FIG. 5 is a schematic diagram showing the tangent conditions between the fiber and the groove at the end of the groove.

[Explanation of symbols]

9 Measurement fiber 10 Alignment device 11 First part 12 Second part 13 Third part 14 Alignment groove 15 Plate 16 Flat ribbon 17 Support 18 Rocking device 19 Pivot axis 20 Turret 22 End member 23 Cross member 24 Conical screw 25 Fiber end part

Claims (6)

[Claims] 1. Pre-stripped fibers of the cable are positioned in a substantially V-shaped alignment groove, the axis of the one or more measurement fibers and the axis of the fibers of the cable being at least part of their end portions. A method for automatically aligning optical fibers consisting of contacting one or more measuring fibers with the fibers of a cable so as to form an angle of 180 degrees or less, in particular for multiple cables of an optical transmission cable constructed of flat ribbons. In the method of aligning multiple measurement fibers simultaneously or one measurement fiber sequentially, the cable is first positioned on a support, a rocking device is arranged to pivot the support around a fixed axis, and the A method for aligning optical fibers, which comprises guiding an end portion of the fiber into a groove while pivoting a swinging device around its axis. 2. A rocker carrying a support for the fibers is pivoted about an axis disposed at a predetermined distance from the support, the distance being such that the free end of the fiber of the cable is 2. The method of claim 1, wherein the distance is such that it advances when curving within the alignment groove and is parallel to the groove by a minimum length. 3. An automatic alignment device for optical fibers for carrying out the method of claim 1, in particular for aligning a plurality of measurement fibers simultaneously or in a single cable in a plurality of optical transmission cables composed of flat ribbons. A device for sequentially aligning measuring fibers, comprising a support (17) for positioning the cable (16), means for mounting this support on a rocking device (18), and a pre-stripped fiber. characterized in that it has means for pivoting the rocking device so that the end portion is located in and parallel to the V-shaped alignment groove (14) forming an angle of 180 degrees or less; Optical fiber alignment device. 4. The rocking device (18) has a fixed pivot shaft (19) mounted at a predetermined distance d from the fiber (16) mounted on the support (17) on the cross member (23). 4. Apparatus according to claim 3, characterized in that: [Claim 5] The end of the fiber is a rocking device (18).
5. Device according to claim 4, characterized in that the distance d is determined such that it moves forward when curving in the groove (14) with the rotation of the groove. 6. Device according to claim 4, characterized in that the rocking device (18) moves axially on the crosspiece (23) and is associated with an initial fitting conical screw (24).