Abstract:
A container box for use in a communication apparatus. The container box has a container case defining an internal space; partitions connected to the container case for partitioning the internal space to have at least two accommodating chambers; and a container cover corresponding to each of the at least two accommodating chambers. Each cover is connected to the container case for independently closing and opening the at least two accommodating chambers. Wherein the at least two accommodating chambers each have differing degrees of waterproof level.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 08/977,423 filed Nov. 24, 1997, now abandoned. 
    
    
     BACKGROUND OF INVENTION 
     This invention relates to a communication apparatus used in an open-air environment and, in particular, to a container box for use in the communication apparatus. 
     Typically, communication apparatus are attached to an open-wire or aerial communication cable extended between utility poles in a power network. For the purpose of protection against various influences from an open-air environment, the communication apparatus is accommodated in a container box. 
     Referring to FIG. 1, a typical conventional container box for a communication apparatus comprises a container case  1  having an open end, a single container cover  2  for closing the open end of the container case  1 , and a waterproof packing or stuffing  3  interposed between a marginal surface of the container case  1  at its open end and a confronting surface of the container cover  2  to seal an internal space of the container case  1  in a watertight condition. 
     In the conventional container box in FIG. 1, a plurality of internal elements are accommodated in the single internal space. These internal elements are different in material, structure, and function and therefore require different waterproof levels. Thus, a whole of the single internal space must be sealed watertight so as to assure a sufficient waterproof level corresponding to a highest one of the different waterproof levels of the internal elements. Practically, it is difficult and uneconomical to assure such a highest waterproof level over the whole of the single internal space. 
     Referring to FIG. 2, another conventional container box comprises a container case  4  and a partition wall  5  partitioning an internal space of the container case  4  to form an electronic apparatus accommodating chamber  6  and a cable connection accommodating chamber  7 . The electronic apparatus accommodating chamber  6  is for accommodating an electronic apparatus while the cable connection accommodating chamber  7  is for accommodating a cable connection. In this case also, an open end of the container case  4  is closed by a single container cover (not shown). 
     In the conventional container box in FIG. 2, the electronic apparatus accommodating chamber  6  and the cable connection accommodating chamber  7  are isolated from each other by the partition wall  5 . Following variation in ambient temperature, a pressure difference is produced between the electronic apparatus accommodating chamber  6  and the external environment or atmosphere. This results in easy condensation of dewdrops in the electronic apparatus accommodating chamber  5 . Like the first-mentioned conventional container box, the open end of the container case  4  is closed by the single container cover. Again, it is therefore difficult and uneconomical to assure a sufficient waterproof level as described above. 
     In both of the conventional container boxes, it is impossible to expose a particular one of the internal elements alone which is to be subjected to some operation such as maintenance work. In other words, all of the internal elements are inevitably exposed because the single container cover must be opened to gain access to the particular internal element. This results in decrease in operability. In addition, the other internal elements requiring no operation may often be deteriorated in reliability because they are exposed to the external environment during operation of the particular internal element. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide a container box for use in a communication apparatus, having a plurality of independent chambers which are different from one another in waterproof level. 
     It is another object of this invention to provide a container box of the type described, which is capable of achieving an improvement in reliability of the communication apparatus because a particular internal element can be operated without affecting other internal elements. 
     It is still another object of this invention to provide a communication apparatus improved in operability and reliability by the use of a container box of the type mentioned above. 
     Other objects of this invention will become clear as the description proceeds. 
     According to a first embodiment of the present invention, there is provided a container box for use in a communication apparatus. The container box comprises: a container case defining an internal space; partitioning means connected to said container case for partitioning said internal space to have at least two accommodating chambers; and a container cover corresponding to each of said at least two accommodating chambers. Each cover is connected to said container case for independently closing and opening said at least two accommodating chambers, wherein said at least two accommodating chambers each have differing degrees of waterproof level. 
     In a second embodiment of the present invention, a communication apparatus is provided. The communication apparatus comprises an electronic apparatus and a container box accommodating said electronic apparatus. The container box comprises: a container case defining an internal space; partitioning means connected to said container case for partitioning said internal space to have at least two accommodating chambers, one of which accommodates said electronic apparatus; and a container cover corresponding to each of said at least two accommodating chambers, each cover being connected to said container case for independently closing and opening said at least two accommodating chambers, wherein said at least two accommodating chambers each have differing degrees of waterproof level. 
     In a variation of the first and second embodiments of the present invention, the at least two accommodating chambers comprises first, second, and third accommodating chambers. Furthermore, said partitioning means comprises a first partition wall connected to said container case and placed between said first and said second accommodating chambers and a second partition wall connected to said container case and placed between said second and said third accommodating chambers. 
     In another variation of the first and second embodiments of the present invention, at least one of said first and second partition walls has a pressure regulating hole for regulating a pressure between adjoining accommodating chambers. The pressure regulating hole is preferably provided with an air-permeable film through which gas is permeable and which liquid is not permeable. 
     In yet another variation of the container box of the present invention, the first accommodating chamber has waterproofness, the second accommodating chamber has drip-proofness and ventilability, and the third accommodating chamber has water permeability and ventilability. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional container box for a communication apparatus; 
     FIG. 2 is a front view of another conventional container box for a communication apparatus; 
     FIG. 3 is a perspective view of a container box for a communication apparatus according to the present invention; and 
     FIG. 4 is a cross-sectional view of the container box for a communication apparatus of FIG.  3 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Now, description will be made about preferred embodiments of this invention with reference to the drawings. 
     At first referring to FIG. 3, the description will be directed to a container box according to a first embodiment of this invention. The container box is for use in a communication apparatus and comprises a container case  11 . The container case  11  has an internal space partitioned by first and second partition walls  12  and  13  to form first, second, and third accommodating chambers  14 ,  15 , and  16  adjacent to one another in a horizontal direction, respectively. 
     The first accommodating chamber  14  preferably has waterproofness. The second accommodating chamber  15  preferably has drip-proofness and ventilability. The third accommodating chamber  16  preferably has water permeability and ventilability. The waterproofness and the drip-proofness are discussed below with reference to FIG.  3  and also defined by Japanese Industrial Standard JIS-C0920. Thus, the first through the third accommodating chambers  14  through  16  are formed as independent spaces having different waterproof levels. In this event, a combination of the first and the second partition walls  12  and  13  is referred to as a partitioning arrangement. 
     The container case  11  comprises first through third container covers  17  through  19  corresponding to the first through the third accommodating chambers  14  through  16 , respectively. The first through the third container covers  17  through  19  are rotatably attached to the container case  11  by the use of hinges  21  to independently open and close the first through the third accommodating chambers  14  through  16 . Each of the first through the third accommodating chambers  14  through  16  has an open end. When each accommodating chamber is closed by each corresponding container cover, a marginal surface of each accommodating chamber at the open end of the container case  11  is brought into tight contact with a confronting surface of each container cover. 
     As illustrated in FIG. 4, the communication apparatus comprises an electronic apparatus  22 , a cable connection  23 , and a battery  24 . The first accommodating chamber  14  serves as an electronic apparatus accommodating chamber for accommodating the electronic apparatus  22 . The second accommodating chamber  15  serves as a cable connection accommodating chamber for accommodating the cable connection  23 . The third accommodating chamber  16  serves as a battery accommodating chamber for accommodating the battery  24 . Throughout the specification, the electronic apparatus  22 , the cable connection  23 , and the battery  24  may collectively be called internal elements. 
     In practical use, the electronic apparatus  22 , the cable connection  24 , and the battery  25  are accommodated in the first through the third accommodating chambers  14  through  16 , respectively. The communication apparatus with its internal elements accommodated in the container box is attached to an open-air communication cable extended between utility poles in a power network. 
     In the above-mentioned communication apparatus, a desired one of the first through the third container covers  17  through  19  can be independently opened to operate a particular one of the internal elements. Thus, operability is improved. In addition, the particular internal element can be operated without affecting the other internal elements. Therefore, a high reliability is maintained after the operation of the particular internal element. 
     Referring to FIGS. 3 and 4, the container case preferably  11  has a side wall  25  which is formed with a cable introducing hole  26 , a plurality of gas escaping holes  27 , and two drain holes  28  and  29 . As is known in the art, suitable packing can be provided between the container case  11  and each of the first, the second, and the third container covers  17 ,  18 , and  19 . Thus, there is achieved a different desired degree of waterproofness in each of the accommodating chambers. 
     The cable introducing hole  26  is communicated with the second accommodating chamber  15  and is used for introducing a cable  30  into the second accommodating chamber  15 . In this preferred structure, it is assumed that a small gap exists around the cable  30  inserted in the cable introducing hole  26 . Therefore, water can invade the second accommodating chamber  15  through the small gap. Thus, the second accommodating chamber  15  is lower than the first accommodating chamber  14  in degree of waterproofness. Any water which enters the second accommodating chamber  15  is drained therefrom through the drain hole  28 . 
     As is known in the art, the battery  24  generates gas in the third accommodating chamber  16 . Thus, gas escaping holes  27  are provided in the third accommodating chamber  16 . The gas escaping holes  27  are opened at all times and serve to vent the gas from the third accommodating chamber  16  to the outside. Inasmuch as the gas escaping holes  27  are opened at all times, water freely invades into the third accommodating chamber  16  through the gas escaping holes  27 . This means that the third accommodating chamber  16  is lower than the second accommodating chamber  15  in degree of waterproofness. Any water entering the third accommodating chamber  16  is drained therefrom through the drain hole  29 . Thus, the internal elements of the chambers are protected from water invasion by differing degrees of waterproofness according to the sensitivity of the particular internal element to water. In the preferred implementation discussed above, the electronic apparatus  22  receives the highest degree of waterproof protection, followed by the cable connection  23  and the battery  24 . 
     The cable introducing hole  26  may alternatively be formed at the rear face of the container case  11 . Similarly, each of the gas escaping holes  27  can be formed at the rear face or the upper face of the container case  11 . 
     Referring again to FIG. 4, the description will be directed to a container box according to a variation of the embodiments of the present invention. The container box of FIG. 4 is also for use in the communication apparatus and comprises similar parts designated by like reference numerals. 
     In the container box of FIG. 4, a pressure regulating hole  12   a  is formed in the first partition wall  12  partitioning the first and the second accommodating chambers  14  and  15 . The pressure regulating hole  12   a  serves to alleviate or suppress a pressure difference between the inside and the outside of the container box and to prevent condensation of dewdrops in the first accommodating chamber  14 . The pressure regulating hole  12   a  is preferably provided with an air-permeable film  12   b  through which gas is permeable and which a liquid is not permeable. Thus, pressure is regulated between the first and second accommodating chambers  14 ,  15  without permitting entry of water into the first accommodating chamber  14  from the second accommodating chamber  15 . 
     Although the air-permeable film  12   b  is placed in the pressure regulating hole  12   a  in the example illustrated, it may alternatively be attached to at least one surface of the first partition wall  12  to close the pressure regulating hole  12   a.    
     While the present invention has thus far been described in conjunction with a few embodiments thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, the internal space may be partitioned into four or more accommodating chambers. The container covers may be attached to the container case in any appropriate manner different from suspension by the hinges. In addition, the container covers may be removable from the container case.