Apparatus for cutting an optical fiber

Abstract: An optical fiber cutting apparatus is provided which comprises a plurality of clamps (20, 62) for clamping an optical fiber (40). A scoring blade (52) is provided between two adjacent clamps (20, 62), for making a score on the optical fiber by moving within a plane substantially perpendicular to the optical fiber. A pushing member (54) is also provided for pushing the optical fiber from an opposite side of the score to cut the optical fiber. The apparatus provided further comprises, a set table (94) provided on a straight alignment line of the plurality of clamps on a side of an outermost one of the plurality of clamps and which has a guide groove (282) formed on a top surface thereon. An adapter (286A-286D) is further provided comprising a plate (284) having first and second guides (72, 80) formed in accordance with the type of optical fiber to be cut, and detachably fitable in the guide groove (282).

Description: The present invention relates to an apparatus for cutting an optical fiber according to the features as laid out in the preamble of claim 1. In order to properly join a pair of optical fibers, it is necessary that the surface of the connecting end of each fiber be flat and perpendicular to the fiber's axis. To provide such an end face, the distal end of each optical fiber needs to be properly cut prior to splicing the fibers. Conventionally, this fiber cutting has been done using a fiber cutting apparatus as shown in Figs. 1A to 1C. Fig. 1A illustrates an example of a conventional optical fiber cutting apparatus applicable to singlecore fibers. Reference numeral 10 denotes a first clamp, which comprises a clamp table 12 and a pincher 14. Pincher 14 is freely openable and closable to clamp table 12, and, when closed, it clamps a sheathed portion 42 of an optical fiber 40. Reference numeral 16 denotes a rubber member used to absorb the stress applied on sheathed portion 42 by pincher 14. In Figs. 1A-1C, pincher 14 is illustrated to move vertically with respect to clamp table 12. Actually, however, pincher 14 is often attached to clamp table 12 by means of a hinge 18 so as to be rockable to the clamp table, as shown in Fig. 2. The former design of first clamp 10 (see Figs. 1A-1C) is the same as the latter design (Fig. 2) in principle and is easier to see its operation. In this respect, therefore, a second clamp 20 is also illustrated in the same manner so that its pincher 24 is shown to move vertically with respect to a clamp table 22. Second clamp 20 comprises clamp table 22 and pincher 24. Pincher 24 is freely openable and closable to clamp table 22, and, when closed, it clamps an unsheathed or bare portion 44 (i.e., glass portion) of an optical fiber 40. Reference numeral 26 denotes a rubber member used to absorb the stress applied on glass portion 44 by pincher 24. Reference numeral 50 is a base for supporting clamp tables 12 and 22. Reference numeral 52 is a scoring blade provided between first clamp 10 and second clamp 20, which moves within a plane perpendicular to the axis of optical fiber 40 in the horizontal or arched direction and scores the optical fiber at the desired portion. Reference numeral 54 is a pushing member which applies bending stress on the scored optical fiber 40 from the opposite side of the score to cut the fiber. To clamp optical fiber 40, first, optical fiber 40 is placed on clamp tables 12 and 22, as shown in Fig. 1A, then first clamp 10 is closed (Fig. 1B), and finally, second clamp 20 is closed (Fig. 1C). Thereafter, scoring blade 52 is moved within a plane perpendicular to the axis of optical fiber 40 in the horizontal direction or the arched direction, to score the optical fiber at the desired portion. Then, pushing member 54 applies bending stress on the scored optical fiber 40 from the opposite side of the score to cut the fiber. As the pinchers of the individual clamps are sequentially closed, thus increasing the number of the clamping procedures, (1) the overall clamping operation is troublesome. And this operation would become more troublesome as the number of the clamps in use increases. (2) If wrong procedures are taken to close the clamps, it may twist or deform optical fiber 40. The conventional cutting apparatus further has the following shortcoming. Fig. 3 illustrates the cutting apparatus, applied to a single core fiber, in a different aspect. In Fig. 3, the same reference numerals as are used in Figs. 1A-1C are also used to specify the corresponding sections, thus omitting their otherwise redundant explanation. Reference numeral 62 is a third clamp. Scoring blade 52 is provided between second clamp 20 and third clamp 62 and is movable in the horizontal direction or in the arched direction, to score bare fiber 44 at the desired portion. To prepare an end face perpendicular to the axis of optical fiber 40, the score on the optical fiber should also be perpendicular to the fiber axis 88. To achieve this, optical fiber 40 needs to be clamped perpendicular to the moving direction 90 of scoring blade 52. However, sheathed portion 42 of optical fiber 40 is normally rolled and naturally curvy, so that the optical fiber even clamped may not be held straight as shown in Fig. 3. Therefore, the moving direction of scoring blade 52 is not perpendicular to the axis 88 of optical fiber 40 and the score would not be perpendicular to the fiber axis accordingly. The conventional cutting apparatus further has the following shortcoming. Fig. 4 illustrates the cutting apparatus, applied to a single core fiber, in another aspect. In Figs. 4, 5A and 5B, the same reference numerals as are used in the previously-described diagrams are also used to specify the corresponding sections, thus omitting their otherwise redundant explanation. Third clamp 62 comprises a clamp table 64 and pincher 66. Pincher 66 is freely openable and closable to clamp table 64, and, when closed, it clamps bare portion (i.e., glass portion) 44 of an optical fiber 40. Reference numeral 36 is a rubber member used to absorb the stress applied on glass portion 44 by pincher 66. Scoring blade 52 is moved in the horizontal direction or in the arched direction, to score bare fiber 44 at the desired portion, and then pushing member 54 is pressed against bare fiber 44, the fiber is cut (Fig. 5A). Pushing member 54 is then retracted (Fig. 5B), releasing the stress on the cut portions of bare fiber 44, so that the cut end of the fiber 44 and the end of a waste bare fiber 44A are likely to hit against each other. This may chip off or make a crack on the end face of bare fiber 44. The conventional cutting apparatus further has the following shortcoming. Figs. 6 and 7 illustrate the cutting apparatus, applied to a single core fiber, in a still different aspect. In Figs. 6 and 7, the same reference numerals as are used in the previously described diagrams are also used to specify the corresponding sections, thus omitting their otherwise redundant explanation. Reference numeral 92 is a base of the overall cutting apparatus, and numeral 94 is a set table. In the case where the diameter of the sheathed portion of the optical fiber is relatively large, and the optical fiber has a single core and needs a constant cutting length L, as shown in Figs. 6 and 7, sheathed portion 42 is stopped at the boundary between groove 82 and slit 84 of guide 80 so that the cutting length L becomes constant. On the other hand, if the diameter of the sheathed portion is relatively small (about 0.2S mm) and the cutting length L varies (see Fig. 8), sheathed portion 42 does not have a tendency to be curvy so that groove 82 is sufficient and it is unnecessary to form slit 84 in second guide 80. Sheathed portion 42 can freely be moved within grooves 76 and 82. Reference numeral 96 is a scale on which the end face of the fiber to be cut is aligned so as to determine the cutting length L. When this cutting apparatus is applied to cutting a multicore fiber, a stationary jig is mounted to optical fiber 40. As should be apparent from the above explanation given with reference to Figs. 6-9, different types of cutting apparatus should be conventionally provided depending on the types and uses of optical fibers to be cut and variation in the cutting length. It is therefore an object of this invention to provide an optical fiber cutting apparatus, in which the fiber is cut in a direction perpendicular to the axis thereof even if the fiber is curvy. A further object of the present invention is to provide an optical fiber cutting apparatus which can be applied to different types of the optical fibers. According to the present invention, there is provided an optical fiber cutting apparatus as defined in the claims. The apparatus comprises a main body comprising a plurality of clamps for clamping an optical fiber set straight, a scoring blade, provided between predetermined two adjacent clamps of said plurality of clamps, for making a score on said optical fiber, a pushing member for pushing said optical fiber from an opposite side of said score to cut said optical fiber, a base on which said plurality of clamps, said scoring blade and said pushing member are provided at predetermined positions, and a set table provided on a straight alignment line of said plurality of clamps on a side of an outermost one of said plurality of clamps and having a guide groove formed on a top surface thereof; and an adapter comprising a plate having first and second guides formed in accordance with a type of an optical fiber to be cut, and detachably fitable in said guide groove. According to an embodiment of this invention, there is further provided a stationary jig comprising a plate and a lid, for securing a multicore optical fiber therebetween, the sizes of said plate of said adapter and said plate of said stationary jig being substantially equal. This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: Figs. 1A to 1C respectively show schematic side views of a conventional optical fiber cutting apparatus; Fig. 2 shows a schematic side view of a clamp in the conventional cutting apparatus of Figs. 1A to 1C; Fig. 3 shows a schematic plan view of the conventional cutting apparatus to which a curvy optical fiber is applied; Fig. 4 shows a schematic plan view of the conventional cutting apparatus in which the cutting blade scores a fiber; Figs. 5A and 5B respectively show schematic plan views of the conventional cutting apparatus in which the fiber is pushed by the pushing member; Fig. 6 shows a plan view of the conventional cutting apparatus, somewhat in detail; Fig. 7 shows a schematic cross sectional view of the conventional cutting apparatus of Fig. 6, taken along the axis thereof; Figs. 8 and 9 respectively show schematic plan views of other conventional cutting apparatus; Figs. 10A and 10B are schematic side views of an optical fiber cutting apparatus according to an embodiment of this invention; Figs. 11A to 11C are schematic side views of an optical fiber cutting apparatus according to another embodiment of this invention; Fig. 12A is a schematic perspective view of an optical fiber cutting apparatus according to a still another embodiment of this invention; Figs. 12B and 12C are schematic plan views of adapters for use in the cutting apparatus as shown in Fig. 12A; Fig. 13 shows a plan view of the adapter used in the cutting device shown in Fig. 12A, with the lid opened; Fig. 14 shows a plan view of the adapter shown in Fig. 12B, with the lid opened; Fig. 15 is a schematic perspective view of an optical fiber cutting apparatus according to a still another embodiment of this invention; Fig. 16 is a schematic diagram illustrating another adapter; and Fig. 17 is a schematic perspective view of the adapter shown in Fig. 12C. Embodiments of this invention will be explained below with reference to the accompanying drawings. In the following description, the same reference numerals are used to specify corresponding portions of the conventional cutting apparatus and the cutting apparatus according to the embodiments for the ease of understanding. Figs. 10A and 10B schematically illustrate the basic arrangement of an optical fiber cutting apparatus. Reference numeral 10 denotes a first clamp, which comprises a clamp table 12 and a pincher 14. Pincher 14 is freely openable and closable to clamp table 12, and, when closed, it clamps a sheathed portion 42 of an optical fiber 40. Reference numeral 16 denotes a rubber member used to absorb the stress applied on sheathed portion 42 by pincher 14. In Figs. 10A and 10B, pincher 14 is illustrated to move vertically with respect to clamp table 12. Actually, however, pincher 14 is attached to clamp table 12 by means of a hinge (not shown) so as to be rockable to the clamp table. The former design of first clamp 10 (see Figs. 10A and 10B) is the same as the latter design in principle and is easier to see its operation. In this respect, therefore, a second clamp 24 is also illustrated in the same manner so that its pincher 24 is shown to move vertically with respect to a clamp table 22. Second clamp 20 comprises clamp table 22 and pincher 24. Pincher 24 is freely openable and closable to clamp table 22, and, when closed, it clamps an unsheathed or bare portion 44 (i.e., glass portion) of an optical fiber 40. Reference numeral 26 denotes a rubber member used to absorb the stress applied on glass portion 44 by pincher 24. Reference numeral 50 is a base for supporting clamp tables 12 and 22. Reference numeral 52 is a scoring blade provided between first clamp 10 and second clamp 20, which moves within a plane perpendicular to the axis of optical fiber 40 in the horizontal direction or the arched direction and scores the optical fiber at the desired portion. Reference numeral 54 is a pushing member which applies bending stress on the scored optical fiber 40 from the opposite side of the score to cut the fiber. Pincher 14 of clamp 10 is attached to a plate 212 by means of a spring 15, while pincher 24 of clamp 20 is directly mounted on plate 212. Pinchers 14 and 24 move integrally. That is, the cutting apparatus of this arrangement is designed such that pinchers 14 and 24 of clamps 10 and 20 provided on the respective sides of the fiber cutting section are made integral by plate 212. Operation: In the first step of cutting optical fiber 40, first clamp 10 and second clamp 20 are released and optical fiber 40 is placed on clamp tables 12 and 22, as shown in Fig. 10A. Then, as shown in Fig. 10B, pinchers 14 and 24 made integral by plate 212 are simultaneously closed to clamp optical fiber 40 at the same time. Thereafter, scoring blade 52 is moved within a plane perpendicular to the axis of optical fiber 40 in the horizontal direction or the arched direction, to score the optical fiber at the desired portion. Then, pushing member 54 applies bending stress on the scored optical fiber 40 from the opposite side of the score to cut the fiber. Figs. 11A to 11C illustrate another arrangement which further has a third clamp 62 in addition to first and second clamps 10 and 20, and first fiber guide 72 and second fiber guide 80. Third clamp 62 comprises a clamp table 64 and pincher 66. Pincher 66 is freely openable and closable to clamp table 64, and, when closed, it clamps bare portion 44 of an optical fiber 40. Reference numeral 36 is a rubber member used to absorb the stress applied on glass portion 44 by pincher 66. In Figs. 11A to 11C, all clamps 10, 20 and 62 are integrally formed. However, clamp 10 may be separate from clamps 20 and 62 which sandwich the fiber portion to be cut. Reference numeral 72 is a first guide, which is provided on the rear side (on the side of sheathed portion 42) of first clamp 10 (see the arrow 74 in Fig. 11A for the rear and front side) and has a groove 76 provided to receive sheathed portion 42, as shown in the lower left cross section in Fig. 11A. Reference numeral 80 is a second guide provided on the front side (on the side of bare fiber 44) of first clamp 10, and the second guide 80 has a groove 82 provided to receive sheathed portion 42 and a slit 84 to receive bare fiber 44, as shown in the lower left and right cross sections in Fig. 11A. The groove 82 and slit 84 are formed to be continuous to each other. The cutting apparatus of Figs. 11A to 11C may be applied to cutting a taped multicore fiber. In this case, a stationary jig is attached to optical fiber 40 and is clamped by first clamp 10, and scoring blade 52 is moved horizontally in a plane perpendicular to the axis of the fiber, to score the bare fiber portion. Operation: Optical fiber 40 is set such that its sheathed portion 42 is fit in groove 76 of guide 72 and groove 82 of guide 80 and its glass portion 44 is fit in slit 84 of guide 80. Then, plate 212 is moved downward, thus causing pincher 14 of first clamp 10 to contact sheathed portion 42 of optical fiber 40 to thereby clamp the fiber in the direction perpendicular to the moving direction of scoring blade 52. Plate 212 is moved further down, causing second and third clamps 20 and 66 to simultaneously clamp optical fiber 40. Consequently, optical fiber 40 can be properly scored by scoring blade 52. Each of the above two arrangements can be applied to both of single core and multicore optical fibers. Effects of the afore-mentioned arrangements: Since the pinchers of at least the clamps located on the respective sides of the optical fiber cutting section are formed integrally, the following effects are obtained. (1) The optical fiber can be clamped by a single operation, thus improving the operability. (2) A single opening/closing mechanism (such as a hinge) is sufficient for those two or three clamps, thus ensuring that the clamp structure can be simplified and can be made more durable and more compact. Fig. 12A illustrates an optical fiber cutting apparatus according to an embodiment of the present invention, which can be applied to cutting optical fibers with different sizes, types, cutting lengths, etc. This cutting apparatus differs from the conventional cutting apparatus shown in Figs. 1-9 in first guide 72, second guide 80 and the stationary jig. Clamps 66 and 20, scoring blade 52 and pushing member 54 are the same for both apparatus. According to this embodiment, as shown in Fig. 12A, the overall cutting apparatus are constituted by a combination of: (1) cutting apparatus body 252 in which two clamps 66 and 20, scoring blade 52 and pushing member 54 are provided on predetermined positions on base 92 and set table 94 having guide groove 282 on its top is provided at the rear of these clamps 66 and 20, and (2) plural types of adapters 286A, 286B, ..., in which first guides 72 and second guides 80 having different sizes and shapes in accordance with the sizes and shapes of single core optical fibers in use are mounted on respective plates 284 that can detachably be fit in guide groove 282. With the above design, the desired adapter having the proper guides 72 and 80 can be selected and used in accordance with the size and shape of a single core fiber in use, so that the cutting apparatus can be applied to optical fibers with different sizes and shapes. Cutting Apparatus Body 252: As shown in Fig. 12A, table 22 of clamp 20 and table 64 of clamp 62 are provided on base 92. Set table 94 of a rectangular parallelepiped shape, for example, is provided at the rear side of these tables 22 and 64 and is formed with guide groove 282 on its top. Lid 254 is openably attached to set table 94 by hinge 256. Reference numeral 292 is a spring. Lid 254 is made to contact set table 94 by the attraction between magnet 260 provided on set table 94 and contact metal 262 provided on lid 254. Scoring blade 52 is mounted to a block 294 provided on base 92 and is horizontally moved as shown by the arrow 238, thereby scoring the bare fiber. Alternatively, scoring blade may be moved in the arched manner. Arm 266 is attached to the side of set table 94 substantially horizontally and is vertically swingable. Arm 274 liftable in the direction perpendicular to the axis of arm 266 is attached to the distal end of arm 266, and pushing member 54 is attached to the bottom of the distal end of arm 274. Compression spring 276 is provided between base 92 and arm 266. When arm 274 is pulled down to push down pushing member 54, bare fiber 44 can be cut. Adapter 286A (Fig. 12A): This adapter is used for a single core fiber whose sheathed portion has a relatively large diameter and a constant cutting length L (corresponding to the case as shown in Figs. 6 and 7). The adapter can be used when sheathed portion 42 has a diameter of 0.25-0.9 mm, for instance. Reference numeral 284 is a plate which has the same size as guide groove 282 and can detachably be fit in the groove 282. Plate 284 has first guide 72 and second guide 80 formed in its top surface. Groove 76 of first guide 72 and groove 82 of second guide 80 have a width D1 of 1 mm, and slit 84 of second guide 80 has a width D2 of 0.13 mm (Fig. 13). Lid 296 is mounted to the side of plate 284 by hinge 298, and pushing rubber 300 is provided on the bottom of lid 296. Adapter 286B (Fig. 12B): This adapter is used for a single core fiber whose sheathed portion has a relatively small diameter and a variable cutting length L (corresponding to the case as shown in Fig. 8). The adapter can be used when sheathed portion 42 has a diameter of 0.25 mm and the cutting length L ranges between 6 to 20 mm, for instance. Groove 76 of first guide 72 and groove 82 of second guide 80 have a width D1 of 0.3 mm (Fig. 14). In this case, a scale 302 is integrally formed on plate 284. Operation: 1) Adapter 286A In Use: Sheathed portion 42 of optical fiber 40 is fit in grooves 76 and 82, bare fiber 44 is fit in slit 84, and lid 296 is closed (the optical fiber is not clamped yet in this state). Then, adapter 286A is accommodated in guide groove 282 of apparatus body 252. The adapter should not necessarily be fixed to apparatus body 252 but may be fixed thereto by a screw. When lid 254 of apparatus body 252 is closed, lid 296 of the adapter is pressed by spring 292 provided on lid 254 to securely clamp optical fiber 40. 2) Adapter 286B In Use: Sheathed portion 42 of optical fiber 40 is fit in grooves 76 and 82, and the end of the sheathed portion 42 is aligned with the figure of the cutting length L on scale 302. The other procedures are the same as those involved in using adapter 286A. Modifications of the cutting apparatus shown in Fig. 12A: (1) As shown in Fig. 15, no lid is provided on adapter 286C, and apparatus body 252 is modified. The modified portion is only shown for simplicity of illustration. Adapter 286C is accommodated in guide groove 282 of apparatus body 252 and is secured thereto by a screw or the like as desired.Optical fiber 40 is then set on adapter 286C, and first clamp 10 mounted on apparatus body 252 is closed to clamp the fiber by the help of the attraction between magnet 260 provided on first clamp 10 and contact metal 262 provided on set table 94, for example.Optical fiber 40 may be clamped only by second and third clamps 20 and 62, without using first clamp 10. (2) As shown in Fig. 16, lid 296 of adapter 286D is designed to be able to sandwich optical fiber 40 by the help of the attraction between magnet 260 provided on plate 284 and contact 262 provided on lid 296. Reference numeral 300 denotes a rubber member used to absorb the stress applied on the optical fiber. Adapter 286D sandwiching optical fiber 40 is accommodated in guide groove 282 of apparatus body 252 and is fixed by closing first clamp 10. Optical fiber 40 may be clamped only by second and third clamps 66 and 20, without using first clamp 10. An adapter (Fig. 12C) comprising stationary jig 98 used for a multicore fiber can be applied to the cutting apparatus shown in Fig. 12A, in addition to adapter 286A or 286B used for a single core fiber. To realize the above, the plate 402 of jig 98 which constitutes the main body of the adapter is designed to have the same size of guide groove 282 of apparatus body 252, i.e., the same size as plate 284 of adapter 286A or 286B. An example of the adapter comprising stationary jig 98 is illustrated in Fig. 17. Plate 402 has a groove 408 formed to receive optical fiber 40, and a liftable lid 404 is attached to the plate 402. Lid 404 has a rib 408 with a wave shape, as shown in Fig. 17, to restrict the lateral movement of optical fiber 40. Multicore optical fiber 40 is sandwiched between plate 402 and lid 404 of stationary jig 98 is fit in guide groove 282 and is clamped by first clamp 10. Operation: Stationary jig 98 sandwiching optical fiber 40 is fit in guide groove 282 of the cutting apparatus of Fig. 21A and is then pressed by spring 292 by closing lid 254. In this case, the movement of scoring blade 52 is restricted only to the horizontal direction. Effects of the embodiments of Figs. 12A to 17: (1) A single type of cutting apparatus can be applied to cutting optical fibers of various types and various cutting lengths L by the selective use of the proper adapters. (2) This can advantageously eliminate the need to provide different cutting apparatuses. (3) The productional and sales managements of the cutting apparatus of this invention is easy, which will reduce the cost of the apparatus.

Claims: An optical fiber cutting apparatus comprising a plurality of clamps (20, 62) for clamping an optical fiber (40) set straight, each of said clamps comprising a pincher (24, 66) and a table (22, 64), a plate member (254), a scoring blade (52) provided between predetermined two adjacent clamps (20, 62), for making a score on said optical fiber by moving within a plane substantially perpendicular to said optical fiber, and a pushing member (54) for pushing said optical fiber from an opposite side of said score to cut said optical fiber, characterized in that the apparatus further comprises, a set table (94) provided on a straight alignment line of said plurality of clamps on a side of an outermost one of said plurality of clamps and having a guide groove (282) formed on a top surface thereof, and, an adapter (286A-286D) comprising a plate (284) having first and second guides (72, 80) formed in accordance with the type of optical fiber to be cut, and detachably fitable in said guide groove (282). The cutting apparatus according to claim 1, the apparatus further comprising a stationary jig (98) comprising a plate (402) and a lid (404) for securing a multicore optical fiber therebetween, the sizes of said plate (284) of said adapter and said plate (402) of said stationary jig being substantially equal. The cutting apparatus according to claim 1 or 2, characterized in that said one clamp (62) clamps a sheathed fiber portion (42) of said optical fiber (40) and said other clamp (20) clamps a bare portion (44) of said optical fiber. The cutting apparatus according to claim 1 or 2, characterized in that both of said predetermined two adjacent clamps clamp a bare fiber portion (44) of said optical fiber (40). The cutting apparatus according to claim 1 or 2, characterized in that said scoring blade (52) horizontally moves within said plane substantially perpendicular to said optical fiber so as to score said optical fiber. The cutting apparatus according to claim 1 or 2, characterized in that said scoring blade (52) moves within said plane substantially perpendicular to said optical fiber in a circumferential direction so as to score said optical fiber.

Inventors: OSATO YASUKUNI, SASAKI KATSUMI, SUDA HIROHISA, OSATO, YASUKUNI, SASAKI, KATSUMI, SUDA, HIROHISA
Applicants: FUJIKURA LTD, FUJIKURA LTD.
Application year: 1988
Main classification: G02B6
IPC codes: G02B6