Abstract:
An accumulator device for an electric or electronic apparatus includes an active element for charging and for producing electric power, and a casing for the active element. In order to counterbalance the pressure increase occurring during the charging operation of the active element, the casing for the active element is curved.

Description:
BACKGROUND OF THE INVENTION 
     FIELD OF THE INVENTION 
     The invention relates to an accumulator device for an electric and/or electronic apparatus comprising: 
     an active element for charging and for producing the electric power, 
     a casing for containing said active element. 
     The invention likewise relates to a type of portable radio telephone notably comprising such a device. 
     A problem often faced with accumulators is caused by the increase of pressure during the charging operation. This increase of pressure becomes formidable with accumulators which use active elements notably of the lithium-ion type. To avoid the unwanted effects of this pressure, a robust casing is known to be provided for packing this active element. Metallic casings are then used which are considered too heavy and too costly. This is considered disadvantageous. 
     It is suitable to note that certain accumulators need to have a certain pressure for operating properly. 
     The invention proposes a device of the type defined in the opening paragraph for which the problem of rising pressure is solved in a satisfactory manner without costing too much and which thus does not have the drawback mentioned earlier. 
     SUMMARY OF THE INVENTION 
     Therefore, such a device is characterized in that said casing is curved, so that the increase of pressure occurring during the charging operation is counterbalanced. 
     The invention is based on the recognition that a curved structure is used which is a robust structure and can thus easily withstand a growing pressure. 
     Thus, the advantage is obtained that the accumulator device can have a structure which is thin enough similar to bank cards. 
     These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 shows the various components forming the device according to the invention, 
     FIG. 2 shows an elevational view of the arrangement of the components of FIG. 1, 
     FIG. 3 shows the curvature of these components according to the invention, 
     FIG. 4 shows a first embodiment of the invention, 
     FIG. 5 shows a second embodiment of the invention, 
     FIG. 6 shows a third embodiment of the invention, 
     FIG. 7 shows an apparatus in accordance with the invention, on which an accumulator device has just been installed, 
     FIG. 8 shows a fourth embodiment of the invention, 
     FIG. 9 shows a fifth embodiment of the invention, 
     FIG. 10 shows a way of facilitating the curvature of the casing, 
     FIG. 11 shows a sixth embodiment of the device according to the invention, and 
     FIG. 12 shows a variant of the embodiment shown in FIG. 11. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, the active element 1 is an element which presents itself in the form of a plate. Elements of this type are mentioned in U.S. Pat. Nos. 5,047.300 and 5,198,313. Two electrodes 5 and 6 permit of charging and providing the energy. These electrodes may be bent according to the user&#39;s wishes. For protecting this active element 1 against the environment, a casing 9 is necessary. It is formed by a frame 10 and two caps 12 and 13. The active element 1 is placed inside the frame 10. The two caps 12 and 13 are flush-mounted with the walls of the frame 10, so that the active element 1 is inserted into the casing thus formed. The casing then has the form of a prism. FIG. 2 shows in an elevational view the casing with the active element inside it. The casing may be formed by plastic material of which well-known bank cards are formed. One may thus obtain a very flat aspect of the device according to the invention which is similar to bank cards or any other card of this type (telephone card etc.). 
     In accordance with the invention, said casing is curved as is shown in FIG. 3. The curvature of the casing is obtained either by curving means which control the resilience of the casing, or this curvature is final as a result of the initial concept of the casing. 
     For obtaining this curvature, the invention proposes a plurality of variants of embodiments. 
     A first variant is shown in FIG. 4. Two pins, or protrusions, 20 and 21, are provided on a side wall of the casing which is to be curved. A blocking part 25, which has two openings 27 and 28 for receiving the two pins in accordance with the curvature of the casing, maintains the curvature at the desired value. It will be evident that the invention also covers the fact that openings may also be made in the wall of the casing while pins are provided on said blocking part. Instead of the part 25, a part 25&#39; can be used whose form is such that it is aligned to the curvature it provides. 
     A second variant is shown in FIG. 5. A groove 30 is made in the wall of the casing intended to be curved. This groove may be obtained by having the caps 12 and 13 project from the frame 10 shown in a dashed line in FIG. 5. Another blocking part 35 which cooperates with this groove has a rim 37 intended to fit in said groove 30 thus imposing the desired curvature. There too, without leaving the scope of the invention, the role of the groove and the rim may be exchanged. 
     A third variant is shown in FIG. 6. In this variant is used at least a ring 40 which has an opening, so that, when the casing is slipped into it, the ring imposes the desired curvature. It is then possible to slip two rings on each one of the ends of the casing. 
     FIG. 7 shows an apparatus 48. This apparatus has a face 49 with a curvature. Thus the device according to the invention can profit from this curvature by conforming in shape thereto. Various fastening means can be provided in this case. 
     FIG. 8 shows a first one of these fastening means. A plate 52 maintains the device on the inside of the face 49. This plate 52 is fastened to this face 49 at two fastening points 54 and 55. 
     FIG. 9 shows a second one of these fastening means. Two fasteners 60 and 61, for example, around the device according to the invention, fasten the device on the outside to the face 49. In the latter two cases it is also possible to use magnetic attraction systems. 
     FIG. 10 shows a means for facilitating the curvature of the casing. Therefore, at least one of the caps 12 or 13 has grooves 70, 71, 72 . . . which may be obtained by removing material, so that small ribs arise. Thus, the rigidity/flexibility ratio is changed in one direction. 
     This ratio may also be changed if raised edges 80 and 81. which rigidify the casing without hindering its curvature as this is shown in FIG. 11, are provided on the caps 12 and 13. These raised edges may be separate parts 80&#39; and 81&#39; which are stuck or soldered onto the caps as is shown in FIG. 12.