GB2057707A

GB2057707A - Device for Transmitting Energy Through Electric Wire or Optical Cable Wound on Drum

Info

Publication number: GB2057707A
Application number: GB8027109A
Authority: GB
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 1979-08-20
Filing date: 1980-08-20
Publication date: 1981-04-01
Also published as: FR2463994B1; GB2057707B; FR2463994A1; DE3030361A1; DE3030361C2

Abstract

A device for transmitting signals or energy between a reel wound multi-core or multi-conductor (2) and a stationary terminal unit (8a, 8b, 8x, 8y, 8z) without the use of a sliding connector. Dummy bobbins (15x, 15y, 15z) are provided co-axially with and rotatable with the winding reel (1) with individual strands or conductors (2a) extending onto the winding surface thereof and wound thereupon. As the main cable is played out, the individual strands of wires are unwound from the dummy bobbins and then taken up by storage devices. In one embodiment, the storage devices are a second set of bobbins (18x, 18y, 18z), while in another embodiment the storage devices are constituted by stationary bundle receiving devices (54a, 54b, 54c) with pinch rollers (51a, 51b, 51c, 52a, 52b, 52c) provided for urging the individual strands or wires into the bundle receiving devices. A device of a further embodiment allows the transmission of electric signals, electric power or optical signals between an externally and stationarily disposed electric or optical device and an electrical wire or optical cable wound on a rotary drum through a lead wire or cable without using a rotary slide contactor. <IMAGE>

Description

SPECIFICATION Device for Transmitting Energy Through Electric Wire or Optical Cable Wound on Drum The present invention relates to an optical coupling device used for transmitting optical signals between a number of stationary terminal units and a movable element, in which the number of stationary terminal units coupled through the optical fibers of an optical cable to the movable element can be increased as required.

Where signals are transmitted through a multicore optical cable between a seabed sensor and a measuring instrument or a control unit on a ship, it is necessary, in playing out the optical cable connected between the seabed sensor and the measuring instrument or the control unit, to vary the length of cable played out depending on the depth of water. Therefore, it is necessary for the optical cable container to be so designed that the optical cable can be readily played out and wound in and that the space occupied by the container is small. Accordingly, the optical cable is usually wound on a drum. However, in this case a problem arises in that it is rather difficult satisfactorily to couple the optical cable (including optical fibers) wound on the rotating drum to the measuring instrument or the control unit which are relatively stationary.In addition to this problem there are inherent difficulties involved in connecting the optical fibers of the multi-core optical cable.

An example of a conventional optical coupling device is shown in Figs. 1 and 2. A two-core optical cable 2 is wound on a rotor 1 such as a drum. One end of the optical cable 2 is connected to a seabed sensor 3 while the other end of the optical cable 2 wound on the rotor 1 is inserted into a through-hole 1 a formed in the winding barrel of the rotor 1. The rotor 1 is hollow. Hollow rotating shafts 4 extend from both ends of the hollow rotor 1. A rotary joint 5 is provided at the end of each rotating shaft 4. The rotary joint 5 includes the end portion of the rotating shaft 4 and a closed-end cylinder 7 which is fixedly secured to a stationary frame 6. The optical cable 2 inserted into the through-hole is branched into two optical fibers 2a inside the hollow rotor 1.

The two optical fibers 2a pass through the rotating shafts 4 and are positioned at the ends of the rotating shafts 4 along the axes of the latter.

One end of an optical fiber 9 is connected to a stationary terminal unit 8 and the other end is positioned on the axis of the cylinder 7 at the joint 5 on each side of the rotor 1. The optical fibers 9 are suitably coupled to the optical fibers 2a for signal transmission as the end portions of the rotating shafts 5 are maintained in axial alignment with the cylinders 7 in such a manner that the shafts are slightly spaced from or in contact with the cylinders. In Figs. 1 and 2 reference numeral 10 designates bearings supporting the rotor 1.

The arrangement of the optical coupling device shown in Figures 1 and 2 is applicable to a twocore optical cable. However, it cannot be used with optical cables having more than two cores because the ends of corresponding fibers cannot then be kept in alignment.

The invention further relates to a device for transmitting electric signals, electric power or optical signals between an externally and stationarily disposed electrical device or optical device and an electrical wire or optical cable wound on a rotary drum through a lead wire or cable.

Figure 3 shows a conventional system of this type, in which electrical signals or the like are transmitted through a cable 102 wound on a drum between a movable electric unit 103 connected to the cable 102 and a main electric device 104 which is provided separately from the drum 101 while the cable 102 is played out or wound on the drum 102. In this case, generally a rotary slide contactor 105 such as a slip ring is interposed between the cable 102 on the rotating drum 101 and the stationary main electric device 104 so as to transmit electrical signals between the movable electric unit 102 and the main electric device 104. Reference numeral 106 designates a lead cable connecting the main electric device and the slide contactor, 107 a drum driving motor, and 108 a drum drive transmission device.

However, the conventional system is disadvantageous in that the provision of the rotary slide contactor may generate noise, increase the circuit resistance, and make the electrical characteristics non-uniform. That is, it may result in various circuit losses. Accordingly, the conventional system is especially not suitable for high frequency signal transmission and it requires the provision of a special coupling system for optical communication.

In view of the above-described drawbacks, an object of the invention is to provide an optical coupling device in which the rotor can be satisfactorily coupled to the stationary terminal units even with an optical cable having more than two cores.

According to the invention, there is provided a device for transmitting signals between a movable unit, connected to one end of a multicore cable which is wound on a rotor, and stationary terminal units which are connected through dummy cables to the other end of said multicore cable, comprising dummy bobbins provided coaxially with and integrally rotatable with said rotor, said dummy cables being wound on said dummy bobbins, and cable storing devices arranged, in use, between said dummy bobbins and said stationary terminal units for storing said dummy cable.

A second object of the invention is to provide a coupling device capable of coupling great numbers of optical fibers while avoiding the use of a rotationally sliding contact at the coupling portion.

According to a further aspect of the invention, a device for transmitting energy between an electric wire or cable wound on a drum and a unit provided separately from said drum comprises a drum, a rotary reel connected directly to the drum so as to rotate with the drum, a lead cable connected to the unit provided separately from the drum, and wound on the rotary reel, and lead cable storing means disposed between the reel and the unit for storing a part of the lead cable which is played out from the reel.

Preferably said reel is coaxially connected to the drum so as to rotate with said drum, and the device also includes a stationary reel which is provided coaxially with the movable reel, and an intermediate guide interposed between the flanges of the movable and stationary reels, with the intermediate guide being rotated and driven along the flanges of the movable and stationary reels so that a lead cable connected between the cable wound on the drum and the unit provided separately from the drum is wound on the movable reel in one direction while the lead cable is wound on the stationary reel in the opposite direction.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a conventional optical coupling device; Figure 2 is a cross-sectional view of a conventional optical coupling device; Figure 3 is an explanatory illustration showing a conventional device for transmitting energy through a cable wound on a rotary drum disposed between a movable unit and a stationary unit; Figure 4 is a schematic illustration showing an arrangement of an optical coupling device according to a first embodiment of the present invention; Figure 5 is a schematic perspective view showing a part of the device in Figure 4; Figure 6 is a schematic perspective view showing a part of a modification of the optical coupling device according to the first embodiment of the present invention;; Figure 7 is a schematic illustration showing an arrangement of an optical coupling device according to a second embodiment of the present invention; Figure 8 is an explanatory illustration showing an example of a device for transmitting energy through a cable wound on a rotary drum between a movable unit and a stationary unit according to the present invention; Figure 9 is an explanatory illustration for a description of the principle of the device in Figure 8; Figure 10 is an explanatory illustration showing another example of a device for transmitting energy according to the present invention Figure 11 is a cross-sectional view showing a device for transmitting energy incorporating the concept illustrated in Figures 8 and 9;; Figures 12(a) and 12(b) are cross-sectional views taken along the line A-A in Figure 11 showing gear transmission means employed in the device of Figure 11; Figure 13 is a schematic illustration showing a device for transmitting energy according to a third embodiment of the present invention; and Figure 1 4 is a schematic illustration showing a part of a device for transmitting energy according to a fourth embodiment of the present invention.

A first preferred embodiment of the invention will be described with reference to Figures 4 and 5 in which those components which have been previously described with reference to Figures 1 and 2 are similarly numbered.

Fig. 4 shows an embodiment of an optical coupling device of the invention in which a fivecore optical cable is employed. The five-core optical cable 2 is wound on a rotor 1 turned by two rotary shafts 4. The first end of the optical cable 2 is connected to a seabed sensor 3. The optical cable 2 is inserted through a through-hole 1 a in the rotor 1 where it is branched into five optical fibers 2a. A first one of the five optical fibers 2a is coupled through a rotary joint 5a provided on the end of one of the rotary shafts 4 to an optical fiber 9a which extends to a stationary terminal unit 8a. A second optical fiber 2a is coupled through a rotary joint 5b provided on the end of the other rotary shaft 4 to an optical fiber 9b which extends to another stationary terminal unit 8b.As is illustrated in Fig. 2, the optical fibers 2a are coupled to the optical fibers 9a and 9b on the axes of the rotary joints 5a and 5b, respectively.

A driven pulley 11 is mounted on the rotary shaft 4. The driven pulley 11 is coupled through a drive belt 14 to a driving pulley 13 fixedly mounted on the shaft of an electric motor 1 2. The rotary shaft 4 and accordingly the rotor 1 are rotated by the motor 12 through the pulleys 11 and 13 and the drive belt 14.

Dummy bobbins 1 sox, 1 sty and 1 5z and pulleys 1 6x, 1 6y and 1 6z are fixedly mounted on the other rotary shaft 4 so that the dummy bobbin, pulleys and rotary shaft rotate as a unit. The remaining three optical fibers pass through through-holes 1 5a formed in the dummy bobbins 1 sox, 1 sty and 1 Sz, respectively. Dummy optical fibers 1 7x, 1 7y and 1 7z are wound on the dummy bobbins 1 sox, 1 sty and 1 Sz, respectively. The second ends of the dummy optical fibers are connected to the three optical fibers which extend from the rotor 1 at the through-holes 1 spa, respectively, while the first ends of the dummy optical fibers extend to storage devices in the form of coupling bobbins 1 8x, 1 8y and 1 8z upon which the dummy optical fibers are partially wound. The first ends are then inserted into through-holes 1 8a formed on the coupling bobbins.

The coupling bobbins 1 8x, 1 8y and 1 8z are rotatably mounted on rotary shafts 4x, 4y and 4z which are independent from the rotary shafts 4.

Rotary joints 5x, 5y and 5z are provided at first ends of the rotary shafts 4x, 4y and 4z, respectively, and sliding joints 1 9x, 1 9y and 1 9z are provided at the other ends of the rotary shafts 4x, 4y and 4z, respectively. Driven pulleys 20x, 20y and 20z are coupled to the sliding joints 1 9x, 1 9y and 1 9z and are further coupled to the aforementioned pulleys 1 6x, 1 sty and 1 6z through belts 21 x, 21 y and 21 z, respectively.

First ends of optical fibers 9x, 9y and 9z are connected to the closed-end cylinders 7x, 7y and 7z of the rotary joints 5x, 5y and 5z, respectively, while the seconds ends thereof are connected to stationary terminal units 8x, 8y and 8z, respectively. The dummy fibers 1 7x, 1 7y and 1 7z extend to the through-holes 1 8a of the coupling bobbins 1 8x, 1 8y and 1 8z and further to the rotary joints 5x, 5y and 5z through the rotary shafts 4x, 4y and 4z, and are coupled to the optical fibers 9x, 9y and 9z, respectively.

As described above, the five-core optical cable 2 connected to the seabed sensor 3 is wound on the rotor 1 from which it is branched into five optical fibers 2a. Two of the optical fibers 2a extend to the rotary joints 5a, and 5b. The remaining three optical fibers are coupled to the dummy fibers 1 7x, 1 7y and 1 7z through the dummy bobbins 1 5x, 1 sty and 1 5z, respectively.

The dummy fibers 1 7x, 1 7y and 1 7z are wound on the coupling bobbins 1 8x, 1 8y and 1 8z and extend to the rotary joints 5x, 5y and 5z. Thus, the five optical fibers 2a are coupled through the rotary joints 5a, 5b, 5x, 5y and 5z and the optical fibers 9a, 9b, 9x, 9y and 9z to the stationary terminal units 8a, 8b, 8x, 8y and 8z, respectively.

As the rotor 1 is rotated, the optical cable 2 connected to the seabed sensor 3 is wound or unwound. In this operation, the optical fibers 2a in the rotor 1 are smoothly rotated with the rotor 1 while simultaneously the dummy fibers 1 7x, 1 7y and 1 7z on the coupling bobbins 1 8x, 1 8y and 1 8z are rotated together with the coupling bobbins 1 8x, 1 8y and 1 8z with the dummy fibers 1 7x, 1 7y and 1 7z being wound on the dummy bobbins 1 sox, 1 sty and 1 5z or the coupling bobbins 1 8x, 1 sty and 1 8z according to the direction of rotation of the rotor 1. Accordingly, the optical fibers 2a and the dummy fibers 1 7x, 1 7y and 1 7z are never twisted.

In the above described embodiment, the optical fibers 2a and the dummy fibers 1 7x, 1 7y and 1 7z are provided separately. However, the dummy fibers can be extensions of the cores, i.e.

the fibers 2a, of the multi-core cable. Thus the dummy fibres would be eliminated and the optical fibers, 2a would be further extended so that they are wound on the dummy bobbins 1 sox, 1 sty and 1 5z and on the coupling bobbins 1 8x, 1 8y and 1 8z. The winding direction of the dummy fibers 1 7x, 1 7y and 1 7z wound on the dummy bobbins 1 5x, 1 5y and 1 5z may be the same as or opposite to that of the optical cable 2 wound on the rotor 1.In the case where they are wound in the same direction, as the optical cable is played out from the rotor 1, the dummy fibers 1 7x, 1 7y and 1 7z are unwound from the dummy bobbins 1 5x, 1 sty and 1 Sz. In the case where the opposite winding direction is used, as the optical cable is played out from the rotor 1, the dummy fibers 1 7x, 1 7y and 1 7z are taken up on the dummy bobbins 1 5x, 1 sty and 1 Sz.

The length L of each of the dummy fibers 1 7x, 1 7y and 1 7z wound on the dummy bobbins 1 5x, 1 sty and 1 5z is set to satisfy the following equation: L Id/D where I is the length of the optical cable 2 wound on the rotor 1, D is the effective diameter of the rotor 1, and d is the effective diameter of each of the dummy bobbins 1 8x, 1 8y and 1 8z. In this case, even if the optical cable 2 of the rotor 1 is completely played out, some of the dummy fibers 1 7x, 1 7y and 1 7z remain on the dummy bobbins 1 sox, 1 sty and 1 5z and therefore the potential difficulty that the lengths of the dummy fibers 1 7x, 1 7y and 1 7z may be insufficient never arises.

In driving the dummy bobbins 1 5x, 1 sty and 1 5z and the coupling bobbins 1 8x, 1 8y and 1 8z, the dummy bobbins 1 sox, 1 sty and 1 5z are rotated with the rotor 1 and as the pulleys 1 6x, 1 6y and 1 6z mounted on the rotary shaft 4 are rotated, the driven pulleys 20x, 20y and 20z are rotated through the belts 21 x, 21 y and 21 z to thereby rotate the coupling bobbins 1 8x, 1 8y and 1 8z.

The speed of each of the driven pulleys 20x, 20y and 20z is slightly higher than that of each of the coupling bobbins 1 8x, 1 8y and 1 8z. The difference in speed between the coupling bobbins 1 8x, 1 8y and 1 8z and the driven pulleys 20x, 20y and 20z is compensated for by the sliding effect of the sliding joints 1 9x, 1 9y and 1 9z, and the dummy fibers 1 7x, 1 7y and 1 7z unwound from the dummy bobbins 1 sox, 1 sty and 1 5z are wound on the coupling bobbins 1 8x, 1 8y and 1 8z with the aid of tension generated by the sliding torques.When the dummy fibers 1 7x, 1 7y and 1 7z are wound from the coupling bobbins 1 8x, 1 8y and 1 8z to the dummy bobbins 1 sox, 1 sty and 1 5z, the sliding joints 1 9x, 1 9y and 1 9z are disconnected and the tension produced by the rotational torques of the coupling bobbins 1 8x, 1 8y and 1 8z is not utilized. If, in the latter case, brakes are provided for the coupling bobbins 1 8x, 1 8y and 1 8z, operational control will be improved.

In the above-described embodiment, the rotary shafts 4x, 4y and 4z are driven by the torque of the rotary shaft 4. However, it should be noted that the invention is not limited thereto or thereby. That is, the rotary shafts 4x through 4z can be driven by other drive systems.

Fig. 5 shows the optical coupling arrangement of one of the optical fibers in the optical cable 2.

An optical cable 2 whose first end is connected to the movable unit 3 is wound on the rotor 1. The second end of the optical cable 2 extends through the interior of the rotary shaft 4 and a first one of the optical fibers of the optical cable 2 is introduced to the surface of the winding barrel of the dummy bobbins 1 5z through a through-hole 1 spa formed in the dummy bobbin 1 5z. One end portion of the dummy fiber 1 7z is wound on the dummy bobbin 1 5z and the other end portion of the dummy fiber 1 7z on the coupling bobbin 1 8z.

The first end of the dummy fiber 1 7z on the dummy bobbin 1 5z is coupled to the end of the first optical fiber of the optical cable 2. With this construction, according to the invention, the stationary terminal units 8a, 8b, 8x, 8y and 8z can be effectively and easily connected to the seabed sensor 3.

A modification of the above-described embodiment of an optical coupling device is shown in Fig. 6. In the modification, the rotary shafts 4 are bent in the form of cranks to couple the dummy bobbin 1 sox to the dummy bobbin 1 sty and to couple the dummy bobbin 1 sty to the dummy bobbin 1 5z therethrough.

The dummy fibers 1 7x, 1 7y and 1 7z, and the optical cable 2 are wound in and out while being wound on the dummy bobbins 1 sox, 1 sty and i 5z and the coupling bobbins 1 8x, 1 8y and 1 8z, and the rotor 1, respectively. Therefore, it is necessary that the optical fibers, the optical cable and their sheaths be relatively high in mechanical strength.

As is clear from the above description, according to the invention, the optical coupling of a multi-core optical cable between the movable element and the stationary terminal units is suitably achieved. Furthermore, the size of the optical coupling device can be reduced by setting the size of the dummy bobbins and the coupling bobbins appropriately in conformance with the aforementioned ratio d/D.

Therefore, a second embodiment of an optical coupling device according to the invention will be described with reference to Fig. 7 in which those components which have been previously described with reference to the first embodiment are therefore numbered.

In Fig. 7, the mechanism including the rotor 1 and the three dummy bobbins 1 sox, 1 sty and 1 5z and the components therebetween is the same as that in Fig. 4. Dummy fibers 60a, 60b and 60c wound on the dummy bobbins 1 sox, 1 sty and 1 5z are each a single optical fiber or an optical fiber bundle formed by assembling several strands of optical fibers.The optical fibers in the optical cable 2 are divided at the second ends thereof into individual optical fibers or bundles of optical fibers depending on the numbers of optical fibers connected to stationary terminal units 61 a, 61 b and 61 c and the individual optical fibers or the bundles of optical fibers are extended to the dummy bobbins 1 5x, 1 sty and 1 5z fixedly mounted on the rotary shaft 4 of the rotor 1, respectively. Accordingly, the dummy fibers 60a, 60b and 60c, the number of which are equal to the numbers of optical fibers connected to the stationary terminal units, are wound on the dummy bobbins 1 sox, 1 sty and 1 5z.The second ends of the dummy fibers 60a, 60b and 60c are coupled directly to the second ends of the optical fibers in the optical cable 2.

In Fig. 7, reference characters 54a, 54b and 54c designate bundle receiving devices which are positioned away from the dummy bobbins 1 5x, 1 sty and 1 5z or disposed at positions away from the positions of the rotary shaft 4. The first ends of the dummy fibers 60a, 60b and 60c extend through pinch rollers 51a and 52a, 51b and 52b, and 51 c and 52c to the bundle receiving devices 54a, 54b and 54c, respectively. The first ends of the dummy fibers are pulled out of the lower portions of the bundle receiving devices 54a, 54b and 54c and are then connected to the stationary terminal units 61 a, 61 b and 61 c, respectively.

The stationary terminal units 61 a, 61 b and 61 c may be of a single optical fiber type or of a multiple optical fiber type.

The bundle receiving devices 54a, 54b and 54c are adapted to receive the dummy fibers 60a, 60b and 60c unwound from the dummy bobbins 15x, 15y and 15z. The bundle receiving device may be simple containers such as stationary cylinders or may be such containers equipped with winding guides such as rotary arms (not shown) so that they dummy fibers 60a, 60b and 60c can be readily received therein.

The pinch rollers 52a, 52b and 52c depress the dummy fibers 60a, 60b and 60c with force supplied by springs 53a, 53b and 53c, respectively. The other pinch rollers 51 a, 51 band 51 c are driven by respective tensioning devices 50a. 50b and 50c constituted by electric motors with slip clutches. The pairs of pinch rollers 51 a and 52a, 51 b and 52b and 51 c and 52c clamp the dummy fibers 60a, 60b and 60c, respectively.

The pinch rollers 51a, 51b and 51 c and 52a, 52b and 52c apply a predetermined tension to the dummy fibers 60a, 60b and 60c to pull the latter out of the dummy bobbins 1 5x, 1 5y and 15z at all times.

The tensioning devices 50a, 50b and 50c are preferably constituted by electric motors and slip clutches as described above. However, other various tensioning devices may be employed. For instance, tensioning devices which are driven through belts and gears by the rotor 1 and have slip clutches in the power transmission paths may be employed.

The operation of the above-described optical coupling device of the invention is as follows: As the dummy fibers 60a, 60b and 60c are wound out from the dummy bobbins 15x, 15y and 15z, they are pushed into the bundle receiving devices 54a, 54b and 54c by the tension applied thereto by the pinch rollers 51 a, 51b and 51c and 52a, 52b and 52c, respectively.

When the rotor 1 is rotated in the opposite direction, the dummy fibers 60a, 60b and 60c are wound on the dummy bobbins 15x, 15y and 15z by a winding force which is produced against the tension provided by the pinch rollers 51 a, 51 b and 51c and 52a, 52b and 52c. When the durnmy fibers 60a, 60b and 60c unwound from the dummy bobbins 15x, 15y and 15z, they are coiled in the bundle receiving devices 54a, 54b and 54c there is some tendency for them to be twisted.

However, if the relationships between the diameter of each of the dummy bobbins 1 5x, 1 5y and 1 5z, and the diameter of each of the bundle receiving devices 54a, 54b and 54c is suitably selected, then the amount of twisting can be limited to less than the breakage twisting stress of each of the dummy fibers 60a, 60b and 60c.

Since the tension is continuously applied to the dummy fibers 60a, 60b and 60c by the pinch rollers 51 a, Sib and 51 c and 52a, 52b and 52c, the dummy fibers will not be kinked and can be wound tightly on the dummy bobbins 15x, 15y and 15z.

The optical coupling device according to the second embodiment of the invention is advantageous in the following points.

The dummy fibers 60a, 60b and 60c pulled out of the bundle receiving devices 54a, 54b and 54c are not rotated. Therefore, the dummy fibers can be coupled directly to the stationary terminal units 61 a, 61 b and 61 c such as measuring instruments or control units using conventional connectors without rotary joints. Therefore, the optical coupling device is single in construction and the reliability of the optical coupling parts is considerably improved. Since no rotary joints are required, the dummy fibers 60a, 60b and 60c are not limited to the above-described conventional single fibers 1 7x, 1 7y and 17z. That is, multi-core optical fibers can be used as the dummy fibers.

For the same reasons, the stationary terminal units 61a, Sib and 61e are not limited to the use of single-core optical fibers. That is, stationary terminal units of multi-core optical fiber type may be used with the optical coupling device of this embodiment of the invention. Therefore, even in the case of a multi-core optical cable, the number of dummy bobbins is remarkably reduced when compared with the number of cores in the optical cable by employing bundles of optical fibers as the dummy fibers 60a, 60b and 60c. In other words, even if the number of optical fibers in the optical cable 2 is extremely large, the optical coupling device of the invention needs only a small number of dummy bobbins.Thus, the optical coupling device can be manufactured as a compact unit. Thus, as is believed clear from the above description, the optical coupling device according to the invention has a high reliability in optical coupling and is simple in construction and small in size.

The present invention further relates to a novel connecting system for connecting an electrical cable 102 which may be wound around or released from a drum to an external main electric device 104 without employing slip riny contacts or the like. A preferred embodiment of this aspect of the invention is shown in Fig. 8.

A device for transmitting electric energy to an electric wire or cable wound on a drum as shown in Fig. 8 includes a drum 101, a rotary reel 110 coaxially coupled directly to the drum 101, a stationary reel 111 adjacent to the rotary reel 110 with the stationary reel 111 being disposed separately from but coaxially with the rotary reel 110, and an intermediate guide 112 in the form of a roller disposed between the flanges of the reels 110 and 111 wherein the intermediate guide 112 is rotated only in one direction at all times. A lead cable 106 is wound on both of the reels 110 and 111.

The intermediate guide 112 which is rotated only in a single direction at all times is provided with a mechanism which allows the guide 112 to slide in the opposite direction with a suitable tension. That is, it is provided with a clutch 11 5 in its drive system (elements 113 through 11 6). The lead cable 106 passes freely around the guide 112 and is wound on the two reels 110 and 111 in the opposite direction by means of the intermediate guide 112. Thus, the end of the lead cable 106 wound on the stationary reel 111 does not rotate and therefore it can be connected directly to the main electric unit 104. On the other hand, the end of the lead cable 106 wound on the reel 110 is rotated with the drum 101 and therefore it can be connected to the end of the cable 102 on the drum 101.

It is preferable that the diameter of the winding barrels of the reels 110 and 111 is larger than that of the winding barrel of the drum 101 on which the cable 102 is wound. The winding length of the lead cable 106 should be made longer than that of the cable 102 in proportion to the barrel diameter ratio. The drum is driven through a drive device 108 by an electric motor 107 similarly to a conventional device. In combination with this, a drive mechanism for rotating the intermediate guide 11 2 between the reels 110 and 111 of the lead cable 106 is provided according to a specific feature of the invention.

An example of the drive mechanism will be described with reference to Fig. 8. The output power of the motor 107 is transmitted through a drive shaft 11 3, a drive direction switching device 11 4, a clutch 115 which is loosely engaged with the intermediate guide 112 so that it can slip in a direction opposite to the direction of rotation of the intermediate guide 112, an intermediate guide drive transmission device 11 6 and the central shaft of the stationary reel 111 to the intermediate guide 112 so as to rotate the intermediate guide between the flanges of the reels 110 and 111.

When the cable 102 is played out from the drum or wound on the drum, the lead cable 106 is wound on the reels 110 and 111 as shown in Fig.

9. The lead cable 106 coupled directly to the cable 102 wound on the drum 101 is wound on the reel 110 connected directly to the drum while the same lead cable 106 is wound on the stationary reel 111 in the opposite direction.

When the drum 101 makes N revolutions in one direction to play out the cable 102, the lead cable 106 is wound on the reel 110 by a length 7rdN (where d is the diameter of the winding barrel of the reel 110) while the lead cable 106 is played out from the reel 111 by the length zdN.

While a length ndN of the lead cable 106 is shifted from the reel 111 to the reel 110, the intermediate guide 11 2 is moved in a direction opposite to the aforementioned direction to take up slack in the cable 106. As a result, the lead cable 106 is wound on both of the reels 110 and 111 under tension. In this case, a length ndN/2 of the lead cable shifted from the reel 111 to the reel 110 passes through the intermediate guide 112.

Therefore, the difference (-n) between the number of revolutions in the opposite direction of the intermediate guide 112 and the number of revolutions +N of the reel 110 is: xdN/2 n= =N/2 7d Therefore, the number of revolutions (Nr) of the intermediate guide 112 is: Nr=+ N-N/2=+N/2 The intermediate guide 112 is rotated in the same direction as the drum 101.

When, on the other hand, the drum 101 makes N revolutions in the opposite direction to rewind the cable 102 and a length 7:dN of the lead cable wound on the reel 110 is unwound. Therefore, a half of the length 7tdN must be shifted from the reel 110 to the reel 111 while the remaining length rrdN/2 must be wound on the reel 110.

Accordingly, it is necessary to rotate the intermediate guide 11 2 at a speed which is faster by as much as -n=-dN/2/itd=-N/2 than a speed corresponding to the number of revolutions (-N) of the drum 101 or the reel 110. Thus, the intermediate guide should be turned at a speed corresponding to Nr=-N-N/2=-3N/2.

As is apparent from the above description, the cable 102 can be played out and wound in with the cable 102 connected to the lead cable 106.

The ratio of the length L of the cable 102 to the length I of the lead cable 106 is substantially proportional to the ratio of the diameter D of the winding barrel of the drum 101 to the diameter d of the winding barrel of each of the reels 110 and 1-11, that is: L/l=D/d. Therefore, the length of the lead cable can be reduced by decreasing the diameter d of the reels 110 and 111. This is considerably effective in practical use.

In the case where the length of the lead cable 106 is considerable it is preferable that the lead cable 106 be wound regularly on the reels 110 and 111. For this purpose, a technique may be employed in which, as shown in Fig.10, a support 122 supporting rollers 120 and 121 is moved horizontally in association with the rotation of the intermediate guide 112.

Figs. 11 to 12(b) show a device for providing electrical energy transmission between an external electrical unit and a cable wound around or released from a drum utilizing the concept described with reference to Figs. 8 to 1 0. In the drawings, a stationary reel 111 and a rotary reel 110 are incorporated in a drum 101 and a mechanism is provided for driving an intermediate guide 11 2 in a predetermined direction in response to the rotation of the drum 101. The device as shown in Fig. 11 is of small portable type. The cable 102 can be played out and wound in by manually rotating the drum 101. A technique for winding a lead cable 106 on the reels 110 and 111 and the operation of the intermediate guide 112 are similar to those described with reference to Fig. 8.

A specific feature of the arrangement shown in Fig. 11 resides in that the rotation of the drum 101 is transmitted through a frictional mechanism (132, 1 35 and 136) and a drive conversion device (136 through 140) to the intermediate guide 112 so that the intermediate guide 112 is moved in a predetermined direction and is turned suitably irrespective of the direction of rotation of the drum 101. This operation and structure will be described in more detail below.

A washer 1 32 is fitted on a shaft 131 which is connected directly to the rotary drum 101. The washer 1 32 is suitably depressed by a spring 1 33 so that the washer 1 32 is rotated with the shaft 1 31. The depression force applied to the washer can be appropriately adjusted by turning a nut 1 34. The washer 132 is in contact with a brake plate and gear 136 through a multi-plate type disc brake 1 35 so as to apply a suitable frictional force to the gear 136 to turn it. The rotation of the gear 136 is transmitted through a group of gears 137, 138 and 139 to an internal gear 140 which is engaged with the drive shaft 141 of the intermediate guide whereby the drive shaft 141 is turned.

In the example shown in Fig. 11, the direction of drive of the intermediate guide 112 is maintained unchanged by means of the group of drive gears 136 through 140 irrespective of the direction of rotation of the drum 101. For this purpose, the directions of rotation of the gears 136 and 140 are reversed by employing a technique with which the gears 138 and 139 which are maintained in engagement with each other are engaged with the gear 137 and the gear 140 respectively, as shown in Fig. 1 2(a) or a technique with which only the gear 138 is engaged with the gears 137 and 140 as shown in Fig. 12(b).

It is preferable that the lead cable 106 be sufficiently flexible that its characteristics do not change when it is played out from the reels 110 and 111 or wound on the latter.

In the case where the cable 102 is used for optical transmission, a system may be employed in which an electrical transmission lead cable is employed as the lead cable 106 extending to the drum and optical energy is converted into electrical energy by a converter provided on the drum and vice versa. With the device of the invention, the lead cable wound on the reels 110 and 111 can be automatically wound in and played out by the intermediate guide. Therefore, it is unnecessary to interpose a rotary slide contactor between the electric wire or cable wound on the drum and the lead cable. That is, the cable on the drum can be connected directly to the lead cable. Thus, the device of the invention is suitable especially for high frequency signal transmission or optical transmission.

Figs. 1 3 and 14 show still further embodiments for transmitting energy between an external main electrical unit and a cable wound around or released from a drum. According to the embodiment shown in Fig. 13, only a lead cable 106 is used to connect a cable which is played out from a drum 101 or wound on the drum to an external main electric device 104 without requiring the use of slip ring contacts or the like..

The lead cable 106 is wound on a reel 110 which is coaxially connected to one end of the drum 1 01. The lead cable 106 is connected to the cable 102 which is wound in and played out from the drum 101. When the lead cable 106 is being wound in or played out from the reel 110, the number of revolutions or the number of turns of the lead cable 106 is equal to that of the cable 102 on the drum 101. Therefore, if the diameter of the winding barrel of the reel 110 is made smaller than that of the winding barrel of the drum 101, then the wound-in or played-out length of the lead cable 106 can be made much shorter than that of the cable 102. That is, it can be reduced in proportion to the winding barrel diameter ratio.

When the main cable 102 is played out, the lead cable 106 is wound in and when the main cable 101 is wound in, the lead cable 106 is played out. In this connection, the length of the lead cable 106 which is played out must be received by a suitable device. For this purpose, a cable storing device 211 is provided. The cable storing device 211 is constituted by stationary pulleys 212 and a movable pulley 213. When the lead cable 106 is wound on the reel 110, the movable pulley 213 is moved toward the stationary pulley 212 in the direction of the arrow A to feed the lead cable to the reel 110. On the other hand, when the lead cable is played out from the reel 110, the movable pulley 213 is moved away from the stationary pulley 212 in the direction of the arrow B so that the length of the lead cable 106 which is played out is received by the cable storing device 211.The movable pulley 213 may be moved by using, for instance, a weight 214 to give predetermined tension to the movable pulley 213 or by pulling the movable pulley 213 with a torque motor. The cable storing device 211 may be extended either horizontally or vertically.

Alternatively, a number of movable guide wheels 213 may be arranged along the circumference of the reel 110 as shown in Fig. 14 in such a manner that they move in the directions of the arrows A or B as the lead cable is wound in or played out from the reel 101. In other words, in this case, the movable guide wheels 213 are moved radially inwardly in the directions of arrows A when the lead cable 106 is wound on the reel 110 and the movable guide wheels are moved radially outwardly in the direction of arrows B when the lead cable 106 is played out from the reel 110 so that the lead cable 106 is effectively stored.

As is clear from the above description, with the device according to the invention, the lead cable can be completely connected to an electric wire or cable wound on the drum without using a rotary slide contactor. Therefore, the device of the invention is quite suitable for high frequency signal transmission or optical transmission.

Claims

1. A device for transmitting signals between a movable unit, connected to one end of a multicore cable which is wound on a rotor, and stationary terminal units which are connected through dummy cables to the other end of said multi-core cable, comprising, dummy bobbins provided coaxially with and integrally rotatable with said rotor, said dummy cables being wound on said dummy bobbins, and cable storing devices arranged, in use, between said dummy bobbins and said stationary terminal units for storing said dummy cable.

2. A device as claimed in claim 1, wherein said cable is a multi-core optical fiber cable and in which a first end of said optical cable wound on said rotor is connected to said movable unit, the second end of said optical cable is introduced into said rotor, optical fibers of said optical cable introduced into said rotor are connected to second ends of said dummy cable which are wound on said dummy bobbins, first ends of said dummy cables are introduced to said cable storing devices which comprise coupling bobbins which are mounted on shafts provided separately from the shaft of said rotor, said dummy fibers introduced to said coupling bobbins are positioned on the axes of bearings provided on the ends of said shafts of said coupling bobbins, and first ends of optical fibers whose second ends are connected to said stationary terminal units are positioned on said axes of said bearings.

3. A device as claimed in claim 1, wherein said cable storing device comprise bundle receiving devices and further comprising pinch rollers interposed between said bundle receiving devices and said dummy bobbins to impart tension on said dummy cables to pull said dummy cables away from said dummy bobbins.

4. A device for transmitting signals between a multi-core optical cable and stationary terminal units corresponding to each core of said multicore optical cable, comprising a rotatable drum rotatably mounted upon rotary shafts, a multicore optical cable adapted to be wound upon said drum, one end of said optical cable being disposed through a through hole in said drum, at least one of said rotary shafts being hollow, at least one rotary joint coupled to at least one of said rotary shafts, one core of said multi-core cable being operationally coupled through said rotary joint to a first stationary terminal unit, a plurality of dummy bobbins mounted upon and rotating with at least one of said rotary shafts, a plurality of coupling bobbins, one of said coupling bobbins being provided for each of said dummy bobbins, each of said coupling bobbins being mounted upon a corresponding rotary shaft, a plurality of dummy fibers, one of said dummy fibers being provided for each pair of said dummy bobbins and said coupling bobbins, each of said dummy fibers having a first end disposed through a through hole in its corresponding dummy bobbin and being coupled to a corresponding core of said multi-core cable, and being adapted to be wound upon a corresponding dummy bobbin and coupling bobbin, means for rotating said coupling bobbins in response to rotation of said rotary said coupling bobbins in response to rotation of said rotary shafts, a plurality of second rotary joints, one of said second rotary joints being provided at the end of each of said shafts upon which said coupling bobbins are mounted, each of said dummy fibers having a second end disposed through a through hole in its corresponding coupling bobbin and being coupled to the corresponding rotary joint, each of said rotary joints being coupled at the end thereof away from said coupling bobbins to a corresponding one of said stationary units.

5. A device as claimed in claim 4, wherein a rotary joint is provided at an end of each of said rotary shafts upon which said drum is mounted, with a corresponding core of said multi-core cable being coupled thereto.

6. A device as claimed in claim 5, wherein said means for rotating said shafts upon which said coupling bobbins are mounted comprises a first set of pulleys, one pulley of said first set of pulleys being provided for each of said dummy bobbins, a second set of pulleys one pulley of said second set of pulleys being provided for each of said coupling bobbins and being mounted to rotate a corresponding rotary shaft upon which the corresponding coupling bobbin is mounted, and a plurality of belt means, one of said belt means extending between each pulley of said first set of pulleys and a corresponding pulley of said second set of pulleys.

7. A device as claimed in claim 4, wherein the rotary shaft upon which said dummy bobbins are mounted is bent in a crank shape.

8. A device as claimed in any one of claims 1 to 7, wherein said dummy fibers are extensions of cores of said multi-core cable.

9. A device for transmitting signals between a multi-core optical cable and stationary terminal units corresponding to each core of said multicore optical cable, comprising a drum, a rotary shaft, said drum being mounted on said rotary shaft to rotate therewith, a multi-core cable adapted to be wound upon said drum, said multicore cable having one end thereof extending through a through hole in said drum, a plurality of dummy bobbins mounted upon said rotary shaft and rotatable therewith, a plurality of dummy fibers, one of said dummy fibers being provided for and wound upon corresponding ones of said dummy bobbins, each of said dummy fibers being coupled to a corresponding core of said multicore cable, a plurality of tensioning devices, one of said tensioning devices being provided for each of said dummy fibers, a plurality of bundle receiving units, each of said bundle receiving units being provided to receive one of said fibers unwound from a corresponding dummy bobbin, said tensioning devices providing tension to the corresponding fibers between said dummy bobbins and said bundle receiving units.

10. A device as claimed in claim 9, wherein said tensioning devices each comprise a pinch roller to contact a corresponding dummy fiber and a motor unit for driving said pinch roller.

11. A device as claimed in claim 9, further comprising at least one rotary joint operationally coupled to said rotary shaft, at least one core of said multi-core cable being operationally coupled through said rotary joint to a corresponding stationary unit.

1 2. A device for transmitting energy between a cable wound on a drum and a unit provided separately from said drum, comprising said drum, a rotary reel connected directly to and coaxially with said drum to rotate with said drum, a cable connected to said unit provided separately from said drum and wound on said rotary reel, and cable storing means disposed between said reel and said unit for storing a length of said cable unwound from said reel.

1 3. A device as claimed in claim 12, in which said cable storing means comprises a stationary pulley and a movable pulley provided at positions outside said reel.

14. A device as claimed in claim 13, wherein said pulleys comprise multi-wheel pulleys.

1 5. A device as claimed in claim 12, in which said cable storing means comprises a plurality of movable guide wheels arranged along the circumference of said reel in such a manner that said movable guide wheels move radially as said cable is wound in or played out from said reel.

1 6. A device as claimed in claim 12, wherein said cable storing means comprises a stationary reel provided coaxially with said movable reel, and an intermediate guide interposed between flanges of said rotary and stationary reels, said intermediate guide being rotated and driven along said flanges of said rotary and stationary reels, said intermediate guide being rotated and driven along said flanges of said rotary and stationary reels so that a cable connected between said cable on said drum and said unit provided separately from said drum is wound on said rotary reel in one direction while said cable is wound on said stationary reel in the opposite direction.

1 7. A device substantially as hereinbefore described with reference to and as shown in Figures 4 and 5, or Figures 4 and 5 as modified by Figure 6, or Figure 7, or Figures 8 and 9, or Figures 8 and 9 as modified by Figure 10, or Figures 11, 1 2a and 12b, or Figure 13 or Figure 14 of the accompanying drawings.