Abstract:
A reel which is driven by a motor is disposed in a casing. First and second restraining mechanisms for restraining movement of a cable are located at first and second openings formed in the casing for insertion of the cable. The cable extends between said first and second openings and is wound around the reel. One end of the cable is secured by the first restraining mechanism, and the motor is activated to rotate the reel, thereby winding the cable around the reel. When a pressure sensor located on the surface of the reel detects that the pressure between the cable and the reel reaches a given value, the motor is stopped. The other end of the cable is secured by the second restraining mechanism.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a cable storage (retaining) apparatus and a cable processing method, which retain the surplus portions (surplus lengths) of cables at the time a plurality of electronic devices are connected by the cables.  
           [0003]    2. Description of the Related Art  
           [0004]    A plurality of electronic devices are normally connected by cables. In some cases, however, it is difficult to identify which connectors are connected by which cable. Without processing the surplus portion (surplus length) of a cable (surplus length processing), the cable hangs down loosely. further, the weight of the hung cable itself applies stress on the connectors or the like. As cables are likely to be laid disorderly, the layout looks poor and the working environment where electronic devices are to be handled is apt to become poor.  
           [0005]    Unexamined Japanese Patent Application KOKAI Publication No. H5-152770 discloses a cable apparatus which can overcome those problems. The disclosed cable apparatus can retain a part (surplus portion) of a cable in the casing. This cable apparatus however requires that a user should determine the length of the surplus portion of a cable and retain the surplus portion in the casing himself or herself. This work is troublesome and inconvenient.  
         SUMMARY OF THE INVENTION  
         [0006]    Accordingly, it is an object of the present invention to provide a cable storage apparatus and a cable processing method which can automatically adjust the length of the surplus portion of a cable.  
           [0007]    It is another object of the invention to provide a cable storage apparatus and a cable processing method which are easy to use.  
           [0008]    To achieve the above objects, according to the first aspect of the invention, there is provided a cable storage apparatus comprising:  
           [0009]    a casing;  
           [0010]    a cable having both ends respectively to be connected to connectors;  
           [0011]    a reel which is disposed in the casing and around which the cable is to be wound;  
           [0012]    a winding mechanism which winds the cable by rotating the reel;  
           [0013]    a pressure sensor which measures a pressure on the cable; and  
           [0014]    a control circuit which controls winding of the cable by the winding mechanism  
           [0015]    when the pressure measured by the pressure sensor becomes equal to or higher than a predetermined value.  
           [0016]    The pressure sensor is located on, for example, a cable winding surface of the reel and measures a pressure of the cable acting on the cable winding surface.  
           [0017]    For example, a first opening and a second opening are formed in the casing and a first and second restraining mechanisms which restrains movement of the cable are arranged in the casing near the first and second openings.  
           [0018]    A cable through hole may be formed in the reel, penetrating a circular side surface of the reel perpendicularly to a rotary shaft of the reel. In this case, the winding mechanism has a motor whose rotary shaft is coaxial to the rotary shaft of the reel, and the cable is led through the first opening of the casing, is put through the cable through hole of the reel, is wound on the circular side surface of the reel and is then led out from the second opening of the casing.  
           [0019]    With the cable secured by the first restraining mechanism and not by the second restraining mechanism, for example, the reel is rotated by the motor to wind the cable around the reel, and when the pressure sensor detects a predetermined pressure, the motor is stopped and the cable is secured by the second restraining mechanism.  
           [0020]    The cable storage apparatus may further comprise a sensor which detects that tension of the cable becomes equal to or lower than a predetermined value, and an alarm circuit which generates an alarm in response to detection of the sensor.  
           [0021]    To achieve the above objects, according to the second aspect of the invention, there is provided a cable storage apparatus comprising:  
           [0022]    a casing having two openings formed for insertion of a cable;  
           [0023]    a reel which is disposed in the casing and around which the cable extending between the two openings is to be wound;  
           [0024]    a winding mechanism which winds the cable by rotating the reel;  
           [0025]    a pressure sensor which measures a pressure on the cable; and  
           [0026]    a control circuit which controls winding of the cable by the winding mechanism when the pressure measured by the pressure sensor becomes equal to or higher than a predetermined value.  
           [0027]    To achieve the above objects, according to the third aspect of the invention, there is provided a cable processing method comprising:  
           [0028]    securing a cable, led into a casing through a first opening formed in the casing, put through a hole formed perpendicular to a rotary shaft of a reel, wound on a side surface of the reel and led out from a second opening formed in the casing, at one of the first and second openings;  
           [0029]    winding the cable around the reel by rotating the reel; and  
           [0030]    detecting force applied to the cable, and stopping rotating the reel and securing the cable at the second opening when the force applied to the cable reaches a predetermined value.  
           [0031]    Tension on the cable may be detected so that an alarm is generated when the tension becomes equal to or smaller than a predetermined value.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0032]    [0032]FIG. 1 is a perspective view illustrating how a cable storage apparatus embodying the present invention is used;  
         [0033]    [0033]FIG. 2 is a structural diagram of a cable storage apparatus according to a first embodiment of the invention;  
         [0034]    [0034]FIG. 3 is a diagram showing the detailed structure of a storage section of the cable storage apparatus shown in FIG. 2; and  
         [0035]    [0035]FIG. 4 is a diagram showing the detailed structure of a storage section of a cable storage apparatus according to a second embodiment of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    The present invention will now be described with reference to the accompanying drawings.  
         [0037]    [0037]FIG. 1 illustrates how a cable storage apparatus  100  according to the first embodiment of the invention is used.  
         [0038]    Electronic devices  200  and  300 , such as a computer and studio equipment, are to be connected together by cables C 1 , C 2  and C 3 .  
         [0039]    The cables C 1 -C 3  are, for example, multi-core cables with connectors CC attached to both sides of each cable. Each connector CC is connected to a connector CT located on the electronic device  200  or  300 . The cable storage (retaining) apparatus  100  automatically takes up the surplus portions (loose portions) of the cables C 1 , C 2  and C 3  so that the electronic devices  200  and  300  are connected together by the cables C 1 -C 3  which are hardly loose.  
         [0040]    [0040]FIG. 2 is a diagram showing the structure of the cable storage apparatus  100 . FIG. 2 shows the mechanical parts of the cable storage apparatus  100  in a cross-sectional view and an electric circuit in a block diagram.  
         [0041]    As shown in FIG. 2, the cable storage apparatus  100  has storage sections  101  to  103  for taking up and retaining the cables C 1 -C 3 , respectively.  
         [0042]    As the storage sections  101 - 103  have approximately the same structures, the structure and operation of the storage section  101  as a representative will be discussed below.  
         [0043]    Symbols having the same alphabets with different numerals are used to denote those components of the storage sections  102  and  103  which are the same as the corresponding components of the storage section  101 .  
         [0044]    As shown in enlargement in FIG. 3, the storage section  101  comprises a casing  10 , a converting circuit  11 , a control circuit  21 , a cable restraining mechanism  31  ( 31   a  and  31   b ), a cable restraining mechanism  41  ( 41   a  and  41   b ), constant torque motors  51  and  61 , a motor M 1 , a reel R 1  and a guide section G 1  (G 1   a  and G 1   b ).  
         [0045]    An opening E 1  for insertion of one end of the cable C 1  is formed in one side of the casing  10 , and an opening H 1  for insertion of the other end of the cable C 1  is formed in the opposite side of the casing  10  to the former side.  
         [0046]    The cable restraining mechanism  31  is located in the casing  10  near the opening E 1 . The cable restraining mechanism  31  comprises movable pieces  31   a  and  31   b  that are driven by the constant torque motor  51 .  
         [0047]    The cable restraining mechanism  41  is located in the casing  10  near the opening H 1 . The cable restraining mechanism  41  comprises movable pieces  41   a  and  41   b  that are driven by the constant torque motor  61 .  
         [0048]    The reel R 1  has a cylindrical or columnar outer shape with frames on upper and lower end faces as seen above the sheet of FIG. 3, and is formed of metal or plastics. A through hole R 11  for the cable C 1  is formed in the circular side surface of the reel R 1 , penetrating perpendicularly to the rotary shaft of the reel R 1 . The inside diameter of the hole R 11  is made large enough to freely pass the cable C 1  (less friction with the cable C 1 ).  
         [0049]    The motor M 1 , which drives the reel R 1 , is so arranged that its rotary shaft is coaxial to the rotary shaft of the reel R 1 .  
         [0050]    Further, a pressure sensor S 1  is attached to the side surface of the reel R 1 . The motor M 1  is provided with a fixed stand which has a ring-like conductor (ring conductor or slip ring). The output terminal of the pressure sensor S 1  comes in a movable contact with the ring-like conductor which provides the output of the pressure sensor S 1 .  
         [0051]    To make winding of the cable C 1  around the circular side surface of the reel R 1  easier, guides G 1   a  and G 1   b  have such walls as to be concentric to the reel R 1  and serve to guide the cable C 1 .  
         [0052]    The pressure sensor S 1  outputs a signal P 1  corresponding to the pressure applied to the sensor SI or the pressure that is applied to the side surface of the reel R 1  by the cable C 1  wound around the reel R 1 . The converting circuit  11  converts the signal level of the signal P 1  and sends the resultant signal to the control circuit  21 .  
         [0053]    The control circuit  21  compares the pressure that is indicated by the signal output from the converting circuit  11  with a preset reference pressure P 1 th. When the pressure detected by the pressure sensor S 1  (the pressure of the wound cable C 1  that presses the side surface of the reel R 1 ) becomes equal to or higher than the reference pressure P 1 th, the control circuit  21  sends a switch SW 1  with a control signal Cr 1  for stopping the rotation of the motor M 1 .  
         [0054]    A power source PW 1  supplies power to the switch SW 1  and the constant torque motor  51 . Upon reception of the power from the power source PW 1 , the constant torque motor  51  drives the movable pieces  31   a  and  31   b  of the cable restraining mechanism  31  to hold and stop the cable C 1 . The switch SW 1  starts supplying power to the motor M 1 .  
         [0055]    Upon reception of the control signal Cr 1 , the switch SW 1  stops supplying power to the motor M 1  and starts supplying power to the constant torque motor  61 . Then, the motor M 1  that winds the cable C 1  on the reel R 1  stops rotating and the movable pieces  41   a  and  41   b  of the cable restraining mechanism  41  hold and stop the cable C 1 . Note that the casing  10  is covered with a detachable lid. The lid is placed on the top side of the casing  10  as seen from above the sheets of FIGS. 2 and 3.  
         [0056]    The following will discuss how to use the cable storage apparatus  100  having the above-described structure.  
         [0057]    The electronic devices  200  and  300  and the cable storage apparatus  100  are so laid that the cables C 1 -C 3  can be laid in order as shown in FIG. 1. One end (connector CC 1 ) of the cable C 1  is connected to the connector CT of the electronic device  200 . Next, the lid of the casing  10  placed on the top side in FIG. 2) is opened and the other end of the cable C 1  whose one end (connector CC 1 ) is connected to the electronic device  200  is put through the opening H 1  of the storage section  101 . If there are cables C 2  and C 3  that should be connected to the electronic device  200 , the cables C 2  and C 3  are retained in the other storage sections  102  and  103  in the same procedures as mentioned above.  
         [0058]    The other end of the cable C 1  led into the casing  10  through the opening H 1  is put through the hole R 11  of the reel R 1  and is led out through the opening E 1  of the casing  10 . In this state, one end of the cable C 1  is stretched to the adequate length and the cable C 1  is wound on the circular side surface of the reel R 1  by about one turn. Then, the reel R 1  is manually turned clockwise a little so that the cable C 1  makes approximately one turn (see FIG. 3). At this time, the guide section G 1  serves to guide the cable C 1  so that the cable C 1  is easily taken up on the reel R 1 , and forms the winding of the cable C 1  on the reel R 1 .  
         [0059]    The other end (connector CC 2 ) of the cable C 1  that is led out through the opening E 1  is connected to the connector CT of the electronic device  300 . The length of the cable C 1  whose other end (connector CC 2 ) is connected to the electronic device  300 , between the electronic device  300  and the opening E 1 , is manually adjusted to the adequate length. After the adjustment, the power source PW 1  is turned on. As a result, the power from the power source PW 1  is supplied to the constant torque motor  51 . This activates the constant torque motor  51  to cause the cable restraining mechanism  31  (comprising the two pieces  31   a  and  31   b ) to hold the cable C 1  with a constant torque. The constant torque of the cable restraining mechanism  31  prevents the cable C 1  from being damaged and from moving inside and outside the casing  10 .  
         [0060]    Further, the power is supplied to the motor M 1  via the switch SW 1 . The motor M 1  rotates the reel R 1  counterclockwise. The rotation of the reel R 1  causes the cable C 1  to be wound on the circular side surface of the reel R 1  with the proper forming by the guide section G 1 .  
         [0061]    At the beginning of the winding of the cable C 1 , the cable C 1  is not taken up on the reel R 1  even when the reel R 1  rotates, and the cable C 1  between the reel R 1  and the cable restraining mechanism  31  and the cable C 1  between the reel R 1  and the cable restraining mechanism  41  become loose slightly. As the rotation of the reel R 1  continues, however, the winding of the cable C 1  on the reel R 1  starts. In this case, the other end of the cable C 1  is held securely by the cable restraining mechanism  31 , so that the cable C 1  slides between the reel R 1  and the guides G 1   a  and G 1   b  while being wound on the reel R 1 . When the reel R 1  takes up one end side of the cable C 1  by a certain amount, the cable C 1  starts applying a pressure on the circular side surface of the reel R 1 . When the length of the cable C 1  between the electronic device  200  on one end side of the cable C 1  and the opening H 1  becomes an adequate length, the predetermined pressure P 1 th is applied to the pressure sensor S 1 .  
         [0062]    The pressure sensor S 1  sends the converting circuit  11  with the signal P 1  that indicates the pressure applied to the circular side surface of the reel R 1 . The converting circuit  11  converts the signal level of the signal P 1  and sends the resultant signal to the control circuit  21 . Upon reception of the electric signal indicative of the pressure corresponding to the pressure P 1 th, the control circuit  21  sends the control signal Cr 1  to the switch SW 1 . In response to the control signal Cr 1 , the switch SW 1  stops supplying power to the motor M 1  to stop rotating the motor M 1  and starts supplying power to the constant torque motor  61 . The constant torque motor  61  drives the movable pieces  41   a  and  41   b  of the cable restraining mechanism  41  to hold the cable C 1  and restrains the further movement of the cable C 1  into the casing  10 .  
         [0063]    The above-described sequence of operations causes the surplus portion of the cable C 1  to be retained in the storage section  101 . Therefore, the lengths of the cable C 1  between the electronic device  200  and the storage section  100  and between the electronic device  300  and the storage section  100  are adjusted to the adequate lengths. The storage sections  102  and  103  have the same capabilities as that of the storage section  101 , so that the cable storage apparatus  100  promotes the automation of orderly surplus length processing with respect to diverse cable connections of information devices and AV (Audio and Visual) devices.  
         [0064]    It is to be noted that the sizes and strengths of reels R 2  and R 3 , sensors S 2  and S 3  and two kinds of cable restraining mechanisms  32 ,  33  and  42 ,  43 , and predetermined pressures to be detected are designed in accordance with the types of cables to be wound around the reels.  
         [0065]    Motors M 2  and M 3 , switches SW 2  and SW 3  and openings E 2 , E 3 , H 2  and H 3  in the storage sections  102  and  103  are likewise designed in accordance with the types of cables to be wound around the reels.  
         [0066]    [0066]FIG. 4 presents a structural diagram of a storage section  101 A of a cable storage apparatus  100 A according to another embodiment of the invention. The cable storage apparatus  100 A has a capability of detecting detachment (coming off) of the connectors that are connected to the electronic devices  200  and  300  in FIG. 1 and generating an alarm when such detection is made. The storage section  101 A will be discussed below with reference to FIG. 4. Same symbols are given to those components in FIG. 4 which are the same as the corresponding components in FIG. 3.  
         [0067]    The movable piece  41   b  of the cable restraining mechanism  41  in the storage section  101 A has a tension sensor S 21  provided at its distal end portion which holds the cable C 1 . The movable piece  31   b  of the cable restraining mechanism  31  has a tension sensor S 22  provided at its distal end portion which holds the cable C 1 .  
         [0068]    The tension sensors S 21  and S 22  respectively measure tension T 1  of that portion of the cable C 1  which lies on that side of the electronic device  200  and tension T 2  of that portion of the cable C 1  which lies on that side of the electronic device  300 . When the connector CC 1  or CC 2  of the cable C 1  comes off the connector CT of the electronic device  200  or  300 , the tensions T 1  and T 2  of the cable C 1  fall. The output signals of the tension sensors S 21  and S 22  are sent to an alarm buzzer circuit  51 . The alarm buzzer circuit  51  discriminates the amount of reduction in tension that is indicated by the signal supplied from the tension sensor S 21  or S 22  and determines whether or not the reduction amount is equal to or greater than a predetermined reference value T 1 th. If the reduction amount of tension is equal to or greater than the reference value T 1 th, a buzzer generates an alarm.  
         [0069]    Suppose the connector that is connected to one end of the cable C 1  comes off the electronic device  200  in the state shown in FIG. 4. Then, the tension of one end of the cable C 1  drops rapidly, so that the tension detected by the tension sensor S 22  falls sharply. If the tension drops from T 10  to T 11 , the amount of reduction ΔT becomes T 10 -T 11  The alarm buzzer circuit  51  compares this reduction amount ΔT with the reference value T 1 th. When the reduction amount ΔT is equal to or greater than the reference value T 1 th, the alarm buzzer circuit  51  drives the buzzer B 1 , warning a user of the disconnection of the cable C 1 .  
         [0070]    The invention is not limited to the above-described embodiments, but may be modified and adapted in various other forms.  
         [0071]    For example, the structures of the cable restraining mechanisms  31  and  41  are not limited to the above-described structures, and may be so designed that the movable pieces take the form of an elastic member, such as a spring, to press a cable with the force of the elastic member and the pressing is released by an actuator. The cable restraining mechanisms may be so designed as not to use movable pieces. The position where the pressure sensor S 1  is attached is not limited to the side surface of the reel R 1  but can be set arbitrarily.  
         [0072]    The motor for driving the reel may be controlled based on the tension of a cable. For instance, the motor M 1  may be driven to wind the cable on the reel until the tension reaches a given value. When the tension drops sharply, an alarm is buzzed.  
         [0073]    The number of cables that are processed by the cable storage apparatus is not limited to three, but may be set to any number.  
         [0074]    Various embodiments and changes may be made thereunto without departing from the broad spirit and scope of the invention. The above-described embodiments are intended to illustrate the present invention, not to limit the scope of the present invention. The scope of the present invention is shown by the attached claims rather than the embodiments. Various modifications made within the meaning of an equivalent of the claims of the invention and within the claims are to be regarded to be in the scope of the resent invention.  
         [0075]    This application is based on Japanese Patent Application No. 2000-042561 filed on Feb. 21, 2000 and including specification, claims, drawings and summary. The disclosure of the above Japanese Patent Application is incorporated herein by reference in its entirety.