Optical fiber cross connection apparatus and method

Abstract: An optical fiber cross connection apparatus is provided for connecting and disconnecting input optical fibers to desired output optical fibers, each of the input optical fibers being equipped with a plug on a tip thereof. The optical fiber cross connection apparatus comprises an arrangement board installed approximately vertically, which has a plurality of alignment holes for releasably holding the plugs and for passing the input optical fibers therethrough, a connection board installed approximately vertically, on which a plurality of connection adapters are positioned to which the output optical fibers are connected and to which the plugs of the input optical fibers are connectable, a handling mechanism for drawing the input optical fibers from the arrangement board so that the input optical fibers are drawn through the alignment holes and for connecting the plugs thereof to desired connection adapters, a roll-up mechanism for paying out the input optical fibers when the fibers are drawn through the alignment holes by the handling mechanism, and traveling mechanisms for moving the handling mechanism and the roll-up mechanism to a desired position with respect to the connection board and the arrangement board.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to optical fibre cross connection apparatuses and methods to connect, disconnect, and exchange optical fibres automatically in optical communication systems. 2. Description of the Related Art With the advance of utilization of optical devices for communication systems, the progress of utilization of optical fibres in the communication systems and access network cables being connected thereto is advanced. Generally, each terminal is accommodated in an exchange office respectively through an access network cable and is connected to communication networks. In conventional metal-cable systems, cable overhead terminators (which are called "main distributing frames" (MDF)) are equipped at the junction points between access network systems and service network systems. Access network cables are terminated at the MDF. It is possible to implement the cross connection of communication facilities, which is accompanied introduction, movement, etc., of various communication services. Utilization of optical access network cables being accompanied by introduction of optical communication networks makes a cross connection apparatus for the optical cables necessary. In the case of using a metallic cable, because it is possible to cut and connect connection cables easily, operators can manufacture connection cables of required length while at work. However, in the case of using the optical cable, it is necessary to prepare beforehand a code (an optical fibre) with an extra length which is sufficient for connection thereof because it is difficult to cut and connect optical cables. In a general conventional technique, all operation of cross connection of the optical fibres is implemented manually. Therefore, there is a definite possibility of misconnection of the optical fibres and of contamination and damage of plug tips by careless handling of the optical fibres; therefore, the reliability of the operation tends to be low. Furthermore, sizes of plugs and adapters for the optical fibres have to be large enough for manual operation. Therefore, there was a problem in that optical fibre cross connection apparatuses need to be large. Patent Abstracts of Japan, vol. 018, n° 527 (E-1613), 5 October 1994 & JP-A-06 181 584 (NIPPON TELEGR & TELEPH CORP), 28 June 1994, disclose an optical fibre cross connection apparatus for connecting and disconnecting first optical fibres to desired second optical fibres. SUMMARY OF THE INVENTION The invention is directed to solving the problems as described above. It is an object of the invention to reduce the size of optical fibre cross connection apparatus and to improve reliability thereof. Therefore, the invention provides an apparatus and a method which enable the use of small adapters and plugs which are the parts for connection of optical fibres by employing a robot handling mechanism. The invention also provides an apparatus and a method to exchange connections of optical fibres automatically. The invention contemplates an optical fibre cross connection apparatus for connecting and disconnecting first optical fibres to desired second optical fibres, each of the first optical fibres being equipped with a plug on a tip thereof, which the apparatus comprises an arrangement board installed approximately vertically, and which has a plurality of alignment holes for releasably holding the plugs and for passing the first optical fibres therethrough; a connection board installed approximately vertically, and on which a plurality of connection adapters are positioned to which the second optical fibres are connected and to which the plugs of the first optical fibres are connectable; a handling mechanism for drawing the first optical fibres from the arrangement board so that the first optical fibres are drawn through the alignment holes, and connecting the plugs thereof to desired connection adapters; a roll-up mechanism for paying out the first optical fibres when the fibres are drawn through the alignment holes by the handling mechanism; and moving mechanisms for moving the handling mechanism and the roll-up mechanism to a desired position with respect to the connection board and the arrangement board. The invention also contemplates an optical fibre cross connection method, with an optical fibre cross connection apparatus for connecting and disconnecting first optical fibres to desired second optical fibres, each of the first optical fibres being equipped with a plug on a tip thereof the apparatus which comprises an arrangement board installed approximately vertically, and which has a plurality of alignment holes for releasably holding the plugs and for passing the first optical fibres therethrough; a connection board installed approximately vertically, and on which a plurality of connection adapters are positioned to which the second optical fibres are connected and to which the plugs of the first optical fibres are connectable; a handling mechanism which has a first plug grip device for drawing the plug from the alignment hole and for inserting the plug into the connection adapters and a second plug grip device for holding a plug, for drawing the first optical fibres from the arrangement board so that the first optical fibres are drawn through the alignment holes, and for connecting the plugs thereof to desired connection adapters; a roll-up mechanism for paying out the first optical fibres when the fibres are drawn through the alignment holes by the handling mechanism; and moving mechanisms for moving the handling mechanism and the roll-up mechanism to a desired position with respect to the connection board and the arrangement board, which the optical fibre cross connection method comprises, when connecting an objective plug of the plugs to an objective connection adapter of the connection adapters after disconnecting the other plug which has been already connected to the objective connection adapter, a step of disconnecting the plug from the objective connection adapter while the second plug grip device of the handling mechanism holds the objective plug which has been disconnected from one of the connection adapters; and a step of connecting the objective plug to the objective connection adapter. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a first preferred embodiment of an optical fibre cross connection apparatus according to the invention. Figs. 2A-2C are drawings showing the operation of the optical fibre cross connection apparatus shown in Fig. 1. Figs. 3A-3C are drawings showing the operation of the optical fibre cross connection apparatus shown in Fig. 1. Figs. 4A-4E are drawings showing the operation of the optical fibre cross connection apparatus shown in Fig. 1. Fig. 5 is a drawing showing an example of a U-shaped partition member which is attached on a fibre rest board which is one of the components of the optical fibre cross connection apparatus of the invention. Figs. 6A-6C are appearance drawings showing other arrangement examples of the connection board, the arrangement board, and the holding board, all of which are components of an optical fibre cross connection apparatus according to the invention. Figs. 7A and 7B are drawings showing other examples of the fibre rest board which is one of the components of an optical fibre cross connection apparatus of the invention. Fig. 8 is a plan view of the second preferred embodiment of an optical fibre cross connection apparatus according to the invention. Figs. 9A and 9B are, respectively, a side elevation view, partly in cross section, and a front view of finger 602 and optical fibre roll-up bobbin 612, which are provided to first robot hand 382 which is shown in Fig. 8. Figs. 10A-10N are drawings showing operation with the optical fibre cross connection method in the second preferred embodiment which is shown in Fig. 8. Fig. 11 is a side elevation view, partly in section, showing another preferred embodiment of a handling mechanism for optical connectors according to the invention. Fig. 12 is a side elevation view, partly in section, showing another preferred embodiment of a handling mechanism for optical connectors according to the invention. Figs. 13A-16C show operation of an optical fibre roll-up mechanism which is provided to an optical connector handling mechanism according to the invention, where Figs. 13A, 14A, 15A, and 16A are side views; Figs. 13B, 14B, 15B, and 16B are enlarged plan views of a part of corresponding Figs. 13A, 14A, 15A, and 16A; and Figs. 13C, 14C, 15C, and 16C are enlarged front views of a part of corresponding Figs. 13A, 14A, 15A, and 16A. Figs. 17A and 17B show operation of a linear moving type of the handling mechanism and a curved moving type of the handling mechanism, respectively. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, preferred embodiments according to the invention will be explained. First Preferred Embodiment and Modification Examples thereof Fig. 1 is a perspective view which shows appearance of a preferred embodiment of an optical fibre cross connection apparatus according to the invention. Optical fibre cross connection apparatus 10 which is shown in this figure is an apparatus for exchanging connection of arbitrary optical fibres between optical fibre group 31 on the side of input, which comprises multiple optical fibres, and optical fibre group 32 on the side of output, which comprises multiple optical fibres. This apparatus 10 comprises connection boards 21a and 21b, arrangement board 22, and holding boards 23a and 23b, which are used for connection and arrangement of each optical fibre. Connection boards 21a and 21b, arrangement board 22, and holding boards 23a and 23b are, vertically or approximately vertically provided, respectively. Connection board 21a, holding board 23a, arrangement board 22, holding board 23b, and connection board 21b are arranged on the same plane in this order from the left side of Fig. 1. While two connection boards 21a and 21b and two holding boards 23a and 23b have the same function, respectively, in this case, they are divided into two, respectively, to efficiently exchange connection of multiple optical fibres. Each optical fibre of optical fibre group 31 on the side of input has a plug at the tip, which is a connector on the side of insertion. Each plug is connected to one of multiple parts for connection, which may be comprised of adapters, jacks, or connectors on the side of insertion and are arranged at one of the surfaces of connection board 21a or 21b, which is the surface seen from the arrow A in this case, and is terminated. Each of the multiple optical fibres of optical fibre group 32 on the side of output also has a plug respectively at the tip. Each optical fibre 32 passes through any of the multiple through-holes in the direction of arrow Z, which are formed in holding boards 23a or 23b in array. These optical fibres 32 are connected to adapters on connection boards 21a or 21b, after further going through the holes on arrangement board 22 in the direction of arrow A. As a result, an arbitrary optical fibre of optical fibre group 31 on the side of input and an arbitrary optical fibre of optical fibre group 32 on the side of output are connected. In addition, stopper 42 (see Fig. 3C) is attached to each optical fibre of optical fibre group 32, which is fixed around a middle part of the fibre between a part where the fibre passes through a trough-hole in holding board 23a or 23b and a part where the fibre reaches a hole on arrangement board 22, which is fixed at the side seen from arrow A in this case. Stopper 42 is comprised of a cylindrical member, etc., having a size by which stopper 42 cannot pass through a hole on arrangement board 22. Each optical fibre 32 is fixed at a part where fibre 32 passes through a through-hole in holding board 23a or 23b by a fixation member. Therefore, each optical fibre 32 passes through a hole on arrangement board 22 and always forms a U-shape after passing through a through-hole in holding board 23a or 23b, even if the fibre 32 is pulled in the direction of arrow A from the side seen from the arrow Z of arrangement board 22. The length of each optical fibre 32, between the part where stopper 42 is attached thereon and the plug at the tip of the fibre, is desired to be sufficient to form a U-shape after passing through a hole on arrangement board 22. That is, the part of each optical fibre 32, where fibre 32 hangs down and forms a U-shape, can rest against fibre rest board 24 as illustrated in Fig. 1 after passing through a hole on arrangement board 22. Then, each optical fibre 32 has sufficient length as each plug thereof can be inserted into an arbitrary adapter on connection board 21a or 21b at this condition. Each of the holes on arrangement board 22 is comprised of a combination of two holes with different diameters, which form a through-hole having a smaller diameter and an opening having a larger diameter so that the former forms a through-hole and the latter forms only an opening; where only each optical fibre can pass through both the through-hole and the opening freely, but stopper 42 and a plug cannot pass through the through-hole while a part of stopper 42 and the plug can be embedded in the opening. Therefore, when drawing out an optical fibre from the opposite side, a part of stopper 42 or of a plug is held in the opening of a hole on arrangement board 22. Then, in the condition of the remaining part of stopper 42 or the plug being axially stuck out of the hole, stopper 42 or the plug are aligned on arrangement board 22. Fibre rest board 24 is located under connection boards 21a, 21b, arrangement board 22, and holding boards 23a, 23 b; and Fibre rest board 24 has a shape which hangs down vertically with forming a gentle curve R to project in the direction (the front side) of arrow A. First robot mechanism 25 which is a moving mechanism to move first handling mechanism 26 and first roll-up mechanism 27 in the axial directions of X, Y, and Z, and second robot mechanism 28 which is another moving mechanism to move second handling mechanism 29 and second roll-up mechanism 30 in the axial directions of X, Y and Z are installed on both sides of connection boards 21a, 21b, arrangement board 22, and holding boards 23a, 23b. First handling mechanism 26 holds and connects a plug of arbitrary optional optical fibre 32 to an adapter and removes the plug from the adapter. First roll-up mechanism 27 which has one set of roller mechanisms which can be freely opened and closed winds up and pays out optical fibre 32 whose plug is taken off from an adapter. Second handling mechanism 29 holds and releases optical fibre 31. Second roll-up mechanism 30 which has one set of roller mechanisms which can be freely opened and closed winds up and pays out optical fibre 32 whose plug is taken off from an adapter. Optical fibre 32 on the side of output passes through a through-hole of holding board 23a or 23b; and passes through a hole on arrangement board 22; and connects to an adapter of connection board 21a or 21b in the condition which hangs down onto fibre rest board 24 to form a U. First handling mechanism 26 with which first robot mechanism 25 is able to easily hold the plug which is connected to the adapter of connection board 21a or 21b by this U-shaped hanging of the optical fibre. That is, all optical fibres 32 whose plugs are connected change the direction thereof downward from the level direction and hang down in U's, except for the part thereof near to the plug. Then, the hanging down bottom part is located at the underside which is lower than the bottom part of holes on arrangement board 22 and the bottom part of the adapters on connection boards 21a and 21b. Therefore, simply by horizontal displacement of first handling mechanism 26 with which first robot mechanism 25 is equipped (in the Z axial direction), first handling mechanism 26 is able to hold an arbitrary plug. For comparison, here, supposing that an arrangement board and/or a connection board are installed horizontally instead of being installed perpendicularly and that the plug of an optical fibre is connected to an adapter from bottom to top, which is different from this preferred embodiment; in this case, each handling mechanism must advance through numerous optical fibres which are around an optical fibre for the purpose of holding an objective plug of the objective optical fibre. Therefore, it may be expected that the resistance of movement will be excessively large in that case. However, in the case of this preferred embodiment, such resistance of movement can be suppressed to a minimum. Also, by providing fibre rest board 24, an optical fibre which is newly connected can lie on top of the optical fibres of optical fibre group 32, which are already connected, without generating excessive internal stress. Next, the operation of optical fibre cross connection will be explained. Here, it is assumed that all optical fibres 31 on the side of input are already connected to either of adapters on connection board 21a or 21b, respectively; and moreover, there is about at least one unconnected adapter (an adapter to which no plug is connected) on either connection board 21a or 21b. Now, the case of connecting a plug which is connected to an adapter on connection board 21a to an unconnected adapter on connection board 21b will be explained as an example. In this case, first, the plug of an objective optical fibre 32 is held from the side which is seen from the direction of arrow Z by first handling mechanism 26 of first robot mechanism 25; and then the plug is pulled out from the adapter connected thereto on connection board 21a. Next, the optical fibre 32 is held by second handling mechanism 29 of second robot mechanism 28 from the side which is seen from arrow A of arrangement board 22. Then, second roll-up mechanism 30 winds up the optical fibre 32; and the plug of the optical fibre 32 is stored in a corresponding hole on arrangement board 22 to be aligned on the surface of the board, which is seen from the direction of arrow Z. Next, first handling mechanism 26 holds the plug which is now stored in the hole on arrangement board 22; and then first handling mechanism 26 is moved to an objective point by first robot mechanism 25 while first roll-up mechanism 27 winds up the optical fibre 32; and the plug is connected to an objective adapter on connection board 21b. The cross connection operation of one optical fibre is completed by this series of processes; a step of pulling-out (removal of a plug), a step of alignment, storage on an arrangement board, and a step of connection. Hereinafter, this operation will be explained in detail with reference to the drawings. Figs. 2A-2C are operational diagrams to explain the details of the operation to remove, by pulling out, a plug from connection board 21a. When pulling out the plug 701 at the tip of the objective optical fibre 321 from the adapter 711 of connection board 21a, to adjust the position of first handling mechanism 26 with which first robot mechanism 25 is equipped (see Fig. 1) to the position of the objective plug, first robot mechanism 25 is driven to move the base of first handling mechanism 26. First handling mechanism 26 is positioned correspondingly to the position of the plug 701 of the optical fibre 321 on connection board 21a; and plug 701 is held by finger 261 of first handling mechanism 26 (see Fig. 2A). First handling mechanism 26 is moved in the direction Z' which is opposite to the direction Z in the condition which holds the plug 701, and the plug 701 of the objective optical fibre 321 is pulled out and removed from the adapter 711 on connection board 21a (see Fig. 2B). Next, finger 261 of the first handling mechanism 26 opens and releases the plug 701 (see Fig. 2C). Figs. 3A-3C are operational diagrams to explain an operation for storing the optical fibre 321 which is pulled out and removed from connection board 21a on arrangement board 22. Figs 3A-3C are drawn from the direction of arrow A (see Fig.1). In the case of rolling up the optical fibre 321 which has been pulled out and storing and aligning the plug 701 thereof on arrangement board 22, second handling mechanism 29 of the second robot mechanism 28 is positioned at the position corresponding to the optical fibre 321 in the reverse of arrangement board 22. Then, finger 291 of second handling mechanism 29 holds stopper 42 (see Fig. 3A). While holding this stopper 42, second handling mechanism 29 moves in the axial direction of Z (i.e., in the direction of the front side of the figure); and the optical fibre 321 is drawn out to just front of second roll-up mechanism 30 (see Fig. 3B). Next, the roller of second roll-up mechanism 30 is closed to wind up the optical fibre 321 (see Fig. 3C). This roll-up operation continues until completion of storage and alignment of the plug 701 into the hole 721 of arrangement board 22 is detected. A proximity sensor which detects the approach of the metallic part of the plug 701 or a photoelectric sensor to detect reflected light therefrom may be used for this detection. Figs. 4A-4E are operational diagrams to explain an operation to connect the plug 701 to an objective adapter on connection board 21b after drawing out the plug 701 which has been stored and aligned into the hole 721 of arrangement board 22. First handling mechanism 26 of first robot mechanism 25 (see Fig. 1) is positioned at the position corresponding to the optical fibre 321 whose plug 701 is stored on arrangement board 22 to draw out the plug 701 of arrangement board 22. Then, finger 261 of first handling mechanism 26 holds the tip part of the plug 701 (see Fig. 4A). The plug 701 is drawn out by moving first handling mechanism 26 in the axial direction Z' which is opposite to the direction Z while the tip part of the plug 701 is held by finger 261 of first handling mechanism 26 (see Fig. 4B). The roller of first roll-up mechanism 27 equipped on first robot mechanism 25 is closed; and optical fibre 321 is paid out (see Fig. 4C). This paying-out is terminated is detected in which the condition where stopper 42 which is attached to optical fibre 321 (see Fig. 3C) is stored and aligned into hole 721 of arrangement board 22. Next, first handling mechanism 26 once releases the plug 701 and holds it again to turn over by 180 degrees the plug 701 of the optical fibre 321, which has been paid out to stopper 42. That is, the first handling mechanism 26 holds a portion near to the border of optical fibre 321 of the plug 701 from the direction of optical fibre 321 (not illustrated). First handling mechanism 26 in this operational condition is positioned at a part corresponding to an objective adapter 712 of connection board 21b (see Fig. 4D). Then, first handling mechanism 26 is moved in the axial direction of Z and first handling mechanism 26 connects the plug 701 to the adapter 712 (see Fig. 4E). By such operation as described above, an objective plug which is connected to an arbitrary adapter on connection board 21a can be connected to an arbitrary unconnected adapter on connection board 21b. In this preferred embodiment, since an optical fibre which is newly connected to an adapter is piled on the other already connected optical fibre group, this embodiment may realize a connection condition with high reliability. Fig. 5 is a drawing which shows a modified example of the fibre rest board 24 which is shown in Fig. 1. Fibre rest board 245 which is shown in Fig. 5 is different from fibre rest board 24 which is shown in Fig. 1 in that fibre rest board 245 has U-shaped partition member 51 on the upper and the centre part thereof. In this case, only one each of arrangement board 225, connection board 215, and holding board 235 are provided; the preferred embodiment shown in Fig. 1 also differs in this point. After a plug of an objective optical fibre 32 is pulled out and is removed from an adapter on connection board 215 by first robot mechanism 25 (see Fig. 1), second roll-up mechanism 30 (see Fig. 1) winds up this optical fibre 32. By this operation, the optical fibre 32 with the plug is aligned and stored on arrangement board 225. Because there is U-shaped partition member 51 is on fibre rest board 245 under holding board 235 in this case, this optical fibre 32 is wound up along the side wall of partition member 51. Therefore, optical fibre 32 forms a U-shape which has an arc which is larger than the arc of the side wall of partition member 51; and the plug at the tip thereof is stored and aligned on arrangement board 225. Therefore, this optical fibre 32 during the cross connection operation and the other connected optical fibres 32 may be prevented from excessive stress. Another arrangement example of the arrangement board, the connection board, and the holding board is shown in Fig. 6. In Fig. 6A, connection board 216 and holding board 236 are not divided in two, and they are arranged on the identical vertical surface on both sides of arrangement board 226. In Fig. 6B, holding board 236 is arranged between arrangement board 226 and connection board 216. In Fig. 6C, the holding board is divided in two boards 236a and 236b which are arranged on vertical surfaces above and below arrangement board 226; and connection board 216 and 226 are arranged on the flush surface. In addition, in the arrangement examples which are shown in Figs. 6A-6C, the width of fibre rest board 246 or 246b may be equal to the total X axial width of the arrangement board, the connection board, and the holding board, or be of a larger size. Although these examples are different from the example shown in Fig. 1 where connection boards 21a and 21b are divided into two (right and left) on both sides of arrangement board 22, a similar effect may be obtained by any examples even if a connection board is arranged at the centre, and an arrangement board is divided into two on the both sides of the connection board. Figs 7A and 7B are perspective views of other examples of the fibre rest member. Fig 7A shows an example which arranged fibre rest boards 64 and 68 (up and down). That is, fibre rest board 64 on the upper side is arranged between a group consisting of connection board 61, arrangement board 62, and holding board 63 on the upper side and another group consisting of connection board 65, arrangement board 66, and holding board 67 in the lower side. On the other hand, fibre rest board 68 is arranged under the lower group consisting of connection board 65, arrangement board 66, and holding board 67. In the example shown in Fig. 7B, fibre rest stick 69, which is a fibre rest member is arranged among connection board 61, arrangement board 62, and holding board 63 on the upper side, and connection board 65, arrangement board 66, and holding board 67 in the lower side. By the arranging fibre rest members on both upper and lower sides, it is possible to prevent optical fibres from being bent and to improve reliability of cross connection. In addition, although fibre rest members which are divided in two are shown only in Figs. 7A and 7B, the number of division is not limited by two, i.e., it may be several pieces or tens of pieces. Also, a connection board, a arrangement board, and a holding board have been explained as being stood in the vertical direction but they may be laid rather ahead. In this case, there is an advantage that transformation of optical fibres around the root thereof is eased. The case where the tip of an optical fibre on the side of input is always connected to an adapter of the connection board; and the plug at the tip of an optical fibre on the side of output is pulled out and removed from an adapter and is connected to the adapter is explained above. However, it is also possible to compose the apparatus as the tip of an optical fibre on the side of output is always connected to an adapter of the connection board; and the plug at the tip of an optical fibre on the side of input is connected to or remove from an adapter. As described above, because both a connection board and a arrangement board are arranged on a vertical surface in this preferred embodiment, there is an advantage that it is possible to work easier in a maintenance check compared with the case where these boards are installed in a horizontal plane. Also, there is an advantage that it is easy to make a connection board and a arrangement board as a module since both are arranged on a vertical surface, and, therefore, it is possible to implement an increase thereof by each module. Moreover, because large stress is not loaded on optical fibres by arranging a fibre rest board under the connection board and the arrangement board, the scale of connection terminals may be larger than conventional technique (e.g., more than the scale with 4000 input fibres and 4000 output fibres). As supposing a connection board and a arrangement board are arranged in a horizontal plane, if a connection scale is tried to be larger, a bunch of optical fibres between the connection board and the arrangement board would be a lump like a rigid body. Because it is difficult for the bunch of the optical fibres to be transformed when trying to connect a new plug to an adapter of the connection board in such a condition, there is fear which adds large stress to the optical fibres. Based on an estimation of the inventor, in such a case, it is difficult to make the scale of connection terminals more than 1000 connections. Second Preferred Embodiment Fig 8 is a plan view which shows a second preferred embodiment according to the invention, where each board is drawn as a section. Optical fibre cross connection apparatus 11 which is shown in this figure is comprised of optical fibres 312 (312a-312c) equipped with optical connector plugs 322 (322a-322c), optical fibres 332 (332a-332c) equipped with optical connector adapters 342 (342a-342c), arrangement board 352 for plugs 322, alignment holes 362 (362a-362c), connection board 372 for adapters 342, first robot hand 382, second robot hand 392, stoppers 402 which are respectively attached to optical fibres 312 (402a-402c), holding board 412 for optical fibres 312, fixation parts 422 for optical fibres 312 (422a-422c), first finger 502 of first robot hand 382, second finger 602 of first robot hand 382, bobbin 612 for winding up optical fibre 312, which is installed in first robot hand 382, finger 512 of second robot hand 392, and roller 522 for winding up and paying out optical fibre 312, which is installed in second robot hand 392. Multiple adapters 342, multiple alignment holes 362, etc. are arrayed on corresponding boards, respectively. In the case shown in this figure, arrangement board 352, connection board 372 and holding board 412 are arranged on an approximately identical and vertical surface. Optical fibre 312 and optical fibre 332 may be comprised of a single mode optical fibre, multi-mode optical fibre, etc. Plug 322 is attached to one end of optical fibre 312; and the other end thereof is, for example, connected to an optical fibre of a line. Optical fibre 312 passes through alignment hole 362 and is fixed by fixation part 422 on holding board 412. Moreover, stopper 402 is provided between plug 322 and fixation part 422 on optical fibre 312. Stopper 402 is attached on the opposite side of plug 322 to arrangement board 352. Alignment hole 362 has a size which plug 322 and stopper 402 cannot pass through. Adapter 342 is attached to one end of optical fibre 332; and the other end thereof is, for example, connected to an optical fibre inside an office. Adapter 342 is installed in connection board 372. This second preferred embodiment has a strong point that even if the number of adapters 342 is equal to the number of plugs 322, i.e., even if no extra adapter for cross connection is prepared, cross connection of optical fibres can be implemented. Since it is possible to open and shut the two roller parts of roller 522, when the two rollers are opened, finger 512 can pass between them. First robot hand 392 and second the robot hand 382 are installed to be movable horizontally and up and down to a vertical surface formed by arrangement board 352, connection board 372 and holding board 412. First finger 502 of first robot hand 382 pulls out an arbitrary plug 322 from alignment hole 362 of arrangement board 352, moves the plug 322 to the front of connection board 372, and inserts the plug 322 to an arbitrary adapter 342 of connection board 372. First finger 502 and second finger 602 hand over a plug to each other; and second finger 602 temporarily holds the plug. Bobbin 612 of first robot hand turns with second finger 602. This bobbin 612 winds up the optical fibre to which the plug 322 is connected, which first finger 502 is holding. Fig. 9A is a detailed enlarged view of second finger 602 and bobbin 612 which are installed in first robot hand 382; and Fig. 9B is a side view of Fig. 9A. Bobbin 612 is comprised of two parts like an arc, which have two brims and a hole in the centre thereof, and second finger 602 is installed in the centre hole of bobbin 612 and can move forward and backward in the direction of X. When second finger 602 and bobbin 612 turn, second finger 602 is dragged into the hole in the centre of two arc shaped parts of bobbin 612. At this time, a fibre is winded up between two brims of two arc shaped parts. An optical fibre cross connection method according to the invention which uses optical fibre cross connection apparatus 11 according to the invention, which is shown in Fig. 8, will be explained in following. At first, all plugs 322 are temporarily connected to optical connector adapters 342; and after that, this cross connection operation is implemented. An operation to exchange plug 322a and plug 322b which are shown in Fig. 8 will be explained as a concrete example of this cross connection operation. In this operation, plug 322a is moved from adapter 342b to adapter 342a and plug 322b is moved from adapter 342a to adapters 342b. Figs. 10A-N show this operation step by step. First, first robot hand 382 pulled out and removed plug 322b from adapter 342a (see Fig. 10A); and immediately plug 322b is released from finger 502. Then, second robot hand 392 draws out stopper 402b in front of one pair of rollers 522 which are opened at that time by using finger 512. Next, roller 522 is closed (see Fig. 10B); and optical fibre 312b is rolled up; and plug 322b is aligned to alignment hole 362b. Next, first robot hand 382 pulls plug 322b out of alignment hole 362b with finger 502 (see Fig. 10C). Plug 322b is drawn out in the direction of Z to a position where finger 502 does not touch other connected optical fibres 312a, 312c, etc. After that, plug 312a is held by second finger 602 instead of finger 502 (see Fig. 10D). Then, bobbin 612 rolls up optical fibre 312b. At the same time, second robot hand 392 pays out optical fibre 312b by roller 522 until stopper 402b hits roller 522. After that, finger 512 holds stopper 402b; and stopper 402b is moved through a pair of rollers 522 which are being opened until stopper 402b is moored at alignment hole 362b (see Fig. 10E). Next, first robot hand 382 moves to a position corresponding to adapter 342b which is the mating part of plug 322b while first robot hand 382 uncoils optical fibre 312b from bobbin 612 (see Fig. 10F). Then, finger 502 pulls out and removes plug 322a which is connected to adapter 342b (sec Fig. 10G). Finger 502 immediately releases plug 322a; and optical fibre 312a is winded up by second robot hand 392; and plug 322a is aligned to alignment hole 362a. At the same time, plug 322b is transferred from second finger 602 to first finger 502 of first robot hand 382 (see Fig. 10H). Then, plug 322b is connected to adapter 342b by first finger 502 (see Fig. 10I). After this, optical fibre 312a is winded up by bobbin 612 (Figs. 10J-10L). Then, plug 322a is connected to adapter 342a by the first finger 502 (see Figs. 10M and 10N). Here, cross connection operation for plugs 322a and 322b ends. This preferred embodiment has a feature to provide second finger 602 for holding a plug on first robot hand 382 in addition to first finger 502 which draws out the plug from an alignment hole, moves it, and inserts it to an adapter. With this feature of this preferred embodiment, in the case of connecting an arbitrarily plug A to an arbitrary adapter C to which another plug B is already connected, it is possible to keep the plug B held by second finger 602 after the plug B is pulled out from the adapter C. With this preferred embodiment, cross connection of two plugs can be completed only by two sets of basic operation consisting of a pulling-out step and an insertion step of the plugs. On the other hand, in the case of cross connection without second finger for holding a plug, it is necessary to prepare adapters which are more than plugs at least by one; and that the concerned plug must be temporarily sheltered in an empty adapter; and therefore, it is necessary to repeat the above-described basic operation three times to complete the cross connection of two plugs. As described above, this second preferred embodiment does not need any extra operation and can, therefore, realize time reduction of cross connection operation. Moreover, because no spare adapter for cross connection is necessary, any optical adapter is not long left in unconnected condition. Therefore, the probability that dust and/or dirt adhere into an optical adapter can be decreased. Therefore, possibilities that connection loss increases by dust and/or dirt adhering to an optical plug can be decreased. Third Preferred Embodiment and Modifications thereof Fig. 11 is a schematic view which shows another composition example of the handling mechanism or the robot hand in the first and the second preferred embodiments according to this invention. As shown in Fig. 11, in this preferred embodiment, handling mechanism 12 is comprised of finger mechanism 413 to hold plug 623, finger moving mechanism 423 to move finger mechanism 413 like an arc towards connection board 113, and roll-up mechanism 183 to roll up optical fibre 133. Finger moving mechanism 423 is comprised of rail 443 which arcs, driving mechanism 453, for example, such as a ball screw, etc. By driving this driving mechanism 453, finger mechanism 413 moves along circular arc-type rail 443. By this operation, finger mechanism 413 moves in optical fibre group 313 while finger mechanism 413 divides optical fibres 133 and tracks an arc towards connection board 113. Then, plug 623 on connection board 113 or arrangement board is held by opening and shutting the tip of finger mechanism 413. At that time, since the track which finger mechanism 413 traces is determined by the shape of circular arc-type rail 443, it is desirable to design the shape of circular arc-type rail 443 beforehand according to an orbit of desiring. In addition, if designing the shape of this circular arc-type rail 443 appropriately, it is obvious that it is also possible to make finger mechanism 413 move in the perpendicular direction to connection board 113 in front of connection board 113. In the above explanation, a case where finger mechanism 413 operates onto connection board 113 is described but if replacing connection board 113 with arrangement board, it is also obvious that to a finger mechanism may operate completely in the same way onto the arrangement board. On the other hand, when optical fibre 133 is pulled out and removed from connection board 113 and is once aligned on an arrangement board, and then is connected to another adapter 613 on connection board 113, an operation to draw out optical fibre 133 from the arrangement board is necessary. Optical fibre roll-up mechanism 183 to roll up optical fibre 133 which is drawn out from the arrangement board is provided at a position where finger mechanism 413 recedes, for this purpose. Another preferred embodiment of a handling mechanism which is different from what is shown in Fig. 11 is shown in Fig. 12. At this preferred embodiment shown in Fig. 12, the finger moving mechanism of handling mechanism 13 has 2-link structure. At the preferred embodiment which is shown in Fig. 11, the orbit of finger mechanism 413 is uniquely determined by the shape of circular arc-type rail 443. However, at this preferred embodiment shown in Fig. 12, freely movable operation of finger mechanism 413, which is combined by the angle change of each of first joint 913 and second joint 923 and the position change of up and down direction of second joint 923, which depends on the up and down movement of handling mechanism 13, is obtainable. With this structure, it may be possible to move a finger tip towards connection board 113 along an arbitrary orbit. In this case, the position in up and down direction of second joint 923 can be adjusted freely by using a mechanism like first robot mechanism 25 which is shown in Fig. 1. Since optical fibre roll-up mechanism 183 is provided at a position where finger mechanism 413 recedes as the preferred embodiment shown in Fig. 11, it is also possible to draw out an optical fibre having relatively long length by this preferred embodiment shown in Fig. 12. An operation to transfer plug 623 between finger mechanism 413 and hand 813 for rolling-up, which hand 813 corresponds to second finger 602 in Fig. 9A, which are shown in Fig. 11 or Fig. 12 will be explained referring to Figs. 14A-16C. First, plug 623 which is held by finger mechanism 413 is positioned on the turn axis of roll-up drum 823 (Figs. 13A-C). Next, hand 813 for roll-up advances on the turn axis of roll-up drum 823 to hold plug 623 which is held by finger mechanism 413; and finger mechanism 413 releases plug 623 simultaneously (Figs.14A-14C). Moreover, finger mechanism 413 turns and shelters; and hand 813 for roll-up retreats to drag plug 623 into the turning centre of roll-up drum 823 simultaneously (Figs. 15A-15C). At that time, it is also possible to move a whole handling mechanism 11 or 12 by a mechanism such as first robot mechanism 25 which is shown in Fig. 1. In this case, without changing the position of plug 623 to connection board 113, plug 623 can be dragged into the centre of roll-up drum 823. As a method to shelter finger mechanism 413, it is also possible to use a method for finger mechanism 413 itself to retreat further to shelter except a method by turning finger mechanism 413 as this preferred embodiment. While hand 813 for the roll-up holds plug 623 after plug 623 is transferred to hand 813 for roll-up, roll-up drum 823 turns with hand 813 for the rolling-up. Then, roll-up drum 823 winds up optical fibre 133 (Figs. 16A-16C). Therefore, optical fibre 133 is able to be drawn out from the arrangement board without moving handling mechanism 11 or 12 to draw out optical fibre 133. It is also possible to apply the optical fibre roll-up mechanism by this preferred embodiment to an exchange operation of a plug, which is necessary when connecting a plug on the arrangement board to an adapter on the connection board as described with regard to the first and the second preferred embodiments. That is, by turning plug 623 by 180 degrees, which is held by hand 813 at the same place without dragging the plug into the centre of roll-up drum 813 in the above-described optical fibre roll-up operation, the direction of plug 623 can be reversed. Therefore, it is not necessary to use a special plug transferring mechanism in a finger mechanism; which may make the concerned mechanisms simplified. Figs. 17A and 17B show orbits when finger mechanism 413 moves in the layer of optical fibre group 313, respectively. Fig. 17A shows the case where the hand moving mechanism by the third preferred embodiment is used; and Fig. 17B shows the case where the finger moving mechanism of going-straight type by the first and the second preferred embodiments is used. As shown in Fig. 17A, in either preferred embodiment shown in Fig. 11 or Fig. 12, finger mechanism 413 moves onto the arc along the direction of each optical fibre 133 in optical fibre group 313. Therefore, the finger moving mechanism 413 which is shown in Fig. 17B, compared with the straight line drive type which is shown in Fig. 17B, can pass more smoothly in optical fibre group 313. Also, in the apparatus shown in Fig. 17A, since finger mechanism 413 moves like an arc, a distance to connection board 113 and the arrangement board, which is needed for pulling-out and inserting, may be shorter; and it is possible to make the size of apparatus smaller. In addition, the technique to provide two finger parts which are the first and the second fingers to the hand robot, which technique is applied to the second preferred embodiment explained above, and the technique that the moving mechanism of the hand which is applied to the third preferred embodiment is an arc movement type or a link type are also possible to be used with a composition in which a connection board and a arrangement board are horizontally arranged in addition to the composition in which a connection board and a arrangement board are vertically arranged as explained above.

Claims: An optical fibre cross connection apparatus for connecting and disconnecting first optical fibres (32) to desired second optical fibres (31), each of said first optical fibres being equipped with a plug on a tip thereof, the apparatus comprising: an arrangement board (22) installed approximately vertically, and which has a plurality of alignment holes for releasably holding said plugs and for passing said first optical fibres therethrough; a connection board (21a, 21b) installed approximately vertically, and on which a plurality of connection means are positioned to which said second optical fibres are connected and to which said plugs of said first optical fibres are connectable; a handling mechanism (26) adapted to draw said first optical fibres from the arrangement board so that said first optical fibres are drawn through said alignment holes, and further adapted to connect said plugs to desired connection means; a roll-up mechanism (27); a moving mechanism (25) for moving the handling mechanism and the roll-up mechanism to a desired position with respect to the connection board and the arrangement board, the apparatus characterised by that said roll-up mechanism (27) is adapted to pay out said first optical fibres from the arrangement holes when the fibres are drawn through the alignment holes by the handling mechanism in order to connect the plugs to desired connection means. The optical fibre cross connection apparatus according to claim 1 which further comprises a fibre rest member (24) on which said first optical fibres lean while said first optical fibres hang from said connection board and said arrangement board. The optical fibre cross connection apparatus according to claim 1 wherein one of the connection board and the arrangement board is divided into at least two portions, and separately arranged on both sides of the other of the arrangement board and the connection board. The optical fibre cross connection apparatus according to claim 2 wherein one of the connection board and the arrangement board is divided into at least two portions, and separately arranged on both sides of the other of the arrangement board and the connection board. The optical fibre cross connection apparatus according to one of claims 2, 3, and 4, further comprising a partition member (51) provided on said fibre rest member. The optical fibre cross connection apparatus according to one of claims 2, 3, and 4, wherein, when the plugs thereof are connected to the connection means, lowest points of the first optical fibres connected to the connection board are located below the bottom of at least one of the lowest alignment hole or the bottom of the connection means. The optical fibre cross connection apparatus according to one of claims 2, 3, and 4, further comprising a partition member disposed on the fibre rest member wherein, when the plugs thereof are connected to the connection means, lowest points of the first optical fibres connected to the connection board are located below the bottom of at least one of the lowest alignment hole or the bottom of the connection means. The optical fibre cross connection apparatus according to claim 1 wherein the handling mechanism has a first plug grip means (502) adapted to draw said plug from said alignment hole and further adapted to insert the plug into said connection means and a second plug grip means (602) for holding said plug. The optical fibre cross connection apparatus according to claim 8 wherein the handling mechanism has a roll-up means adapted to wind up said first optical fibres. The optical fibre cross connection apparatus according to claim 9, wherein the roll-up means is comprised of a drum (612) adapted to turn with the second plug grip means, wherein the second plug grip means is positioned at the centre of rotation of the drum; and further comprising a movement means adapted to move the first plug grip means of the handling mechanism along the curve formed as a group of optical fibres which are connected to the connection board. A method of using the optical fibre cross connection apparatus according to claim 8, when connecting an objective plug (322) of said plugs to an objective connection means (342) of said connection means after disconnecting another plug already connected to the objective connection means, by performing the steps of: disconnecting the another plug from the objective connection means while the second plug grip means of the handling mechanism holds the objective plug previously disconnected from one of the connection means; and connecting the objective plug to the objective connection means. The method according to claim 11, comprising the additional step of winding up said optical fibres while the second plug grip means of the handling mechanism holds the objective plug which has been disconnected from one of the connection means. A method of using the optical fibre cross connection apparatus according to claim 10, by performing the steps of: moving the first plug grip means along the direction of the group of optical fibres which are connected to the connection board; and a step of winding up the optical fibres by turning the drum while transferring the plug which is held by the first plug grip means to the second plug grip means. The method according to claim 13, comprising the additional step of reversing the direction of the plug which the second plug grip means holds and transferring the plug which is held by the second plug grip means to the first plug grip means.

Inventors: KANAI TSUNEO, KANEKO KAZUMASA, NISHIDA YASUHIDE, SHOJI TETSUFUMI, TAMARU NAOYUKI, YAMAGUCHI JOJI, KANAI, TSUNEO, KANEKO, KAZUMASA, NISHIDA, YASUHIDE, SHOJI, TETSUFUMI, TAMARU, NAOYUKI, YAMAGUCHI, JOJI
Applicants: NIPPON TELEGRAPH & TELEPHONE, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Application year: 1996
Main classification: H04Q1
IPC codes: H04Q1, G02B6