Abstract:
The invention relates to a charging device ( 10 ) for the batteries of a cellular telephone, whereby the same device can be used to charge batteries ( 15 ) with different external dimensions. The charging device ( 10 ) comprises width controllers ( 19   a   , 19   b ), the position of which controls the location and position of the actual battery guides ( 18   a   , 18   b ), which enable batteries of different sizes to get a reliable contact with the electrical connectors ( 17 ) of the charging device. Short batteries are locked to the charging device by means of a separate stopper ( 14 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     “The invention relates to a charging device for batteries, which comprises the body of the charging device, which body includes an upper part and a bottom part, electrical connectors for charging the batteries and battery guides for guiding the batteries to be charged to electrical connectors”. 
     2. Description of the Prior Art 
     There are already millions of mobile stations of different cellular networks in use. The use of mobile stations has increased in an explosive scale both in the number of users and the time used by each user. When the use increases, the duration of batteries is in a way critical. New applications are also coming into use, such as the GPRS (General Packet Radio Service) and UTMS (Universal Mobile Telecommunication System), in which the amount of information to be transferred increases substantially. In order to maintain the good quality of data transfer, the power of the transmitter of a cellular telephone must be increased in adverse conditions. The increase of power exhausts the battery of a cellular telephone rapidly. So the user may need at least one spare battery in addition to the battery in the cellular telephone for changing it to the telephone in a situation that the battery in the cellular telephone gives a notification that it is running out of charge. The exhausted battery should then be charged quickly and easily with a suitable device. 
     Because one device manufacturer may have tens of different telephone models with different batteries of different sizes, and several battery models may be suitable for the same cellular telephone, the users must acquire a separate charging device for each type of battery. The charging device of one battery type may in some cases be suitable for another type, too, but generally this is not possible with the prior art charging devices. In practice, the prior art operation is difficult and expensive for the user. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a new kind of a charging device for the batteries of cellular telephones, which charging device can be used for batteries of different width, length and thickness. 
     The objectives of the invention are achieved with a battery charging device, in which mechanical adjusters allow the attachment of batteries of different width, length and thickness on the electrical connectors of the charging device for performing the charging. 
     Preferred embodiments of the invention are described in the dependent claims. 
     The basic idea of the invention is the following: The electrical connectors needed for charging the batteries are at the first end of the charging device. The battery guides on the sides of the connectors of the charging device make sure that the connectors of the battery meet the right connectors in the device. The width of the battery to be placed in the charging device influences the width controllers on both sides of the charging device, and the mechanical solution in connection with the width controllers influences the width of the battery guides on the sides of the electrical connectors of the battery charger. With this method, batteries of different sizes are automatically guided in the right place in the charging device, when they are placed in it. In the longitudinal direction, a stopper has been arranged for batteries of different sizes close to the second end of the charging device to keep the battery in place during charging. After charging, the stopper can be pushed to the bottom of the charging device, whereby the battery can be removed from the device. The thickness of batteries to be charged in the charging device can vary, because the thickness of batteries is not restricted by the electric connectors, battery guides or width controllers of the charging device. 
     The invention provides the advantage that the same charging device can be used for batteries with different width, length and thickness. 
     In addition, the invention provides the advantage that the mechanism of the charging device guides the battery to be charged to the electrical contacts automatically and reliably. 
     Furthermore, the invention has the advantage that its manufacturing costs are low. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the following, the invention will be described in more detail with reference to the accompanying drawings, in which 
     FIG. 1 a  is an exemplary perspective drawing of a charging device according to the invention, 
     FIG. 1 b  shows a charging device according to the invention from above, when a short and narrow battery has been connected to it for charging, 
     FIG. 1 c  shows a charging device according to the invention from above, when a long and wide battery has been connected to it for charging, 
     FIG. 2 shows the structural parts of a charging device according to the invention as an exploded view, 
     FIG. 3 a  is an exemplary view of a charging device according to the invention from the bottom, when there i s no battery to be charged in the charging device, or the battery to be charged is narrow, and 
     FIG. 3 b  is an exemplary view of a charging device according to the invention from the bottom, when there is a wide battery to be charged in the charging device. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 a  shows an example of a charging device  10  according to the invention. The charging device preferably comprises a cover  1 , which is articulated to the device with two hinges  16  at the first end of the charging device. The second end of the charging device  10  is open in a way that the battery  15  to be charged can be easily placed in the device. The cover  11  can be closed for the duration of charging, and for its part it ensures that the battery  15  to be charged stays in the charging device  10 . The body of the charging device  10  consists of two parts: the bottom part  12   b  and the upper part  12   a , which are preferably made of plastic by injection moulding. The upper part  12   a  and the bottom part  12   b  can preferably be connected to each other with fast clips shaped for the parts, by gluing or by some mechanical connecting means. FIG. 1 a  also shows an example of the electrical connectors  17  of the charging device  10 , which connectors are of elastic construction so that they spring against the battery connectors and thus ensure a good contact. The number of connectors  17  is two or more, preferably four, and they are located close to the first end of the charging device  10 . FIG. 1 a  also shows a stopper  14 , which is needed when the charging device is used to charge a battery  15 , which is short as compared to the total length of the charging device  10 . 
     FIG. 1 b  shows an example of a situation in which the charging device is used to charge a battery  15   a , which is short as compared to the length of the charging device and narrow as compared to the width of the charging device. The battery  15   a  to be charged is placed in the charging device by pushing it in the direction of the arrow A towards the first end of the charging device  10 . When the battery  15   a  is placed in the charging device, it meets two width controllers  19   a ,  19   b . The shape of these width controllers is preferably a triangle with a cut apex. The width controllers are partly located in the body of the charging device, in a space delimited by the upper part  12   a  and the bottom part  12   b  so that only the peaks of the width controllers are visible on the sides of the space reserved for the battery  15   a.    
     The location of the width controllers  19   a ,  19   b  in the transverse direction is determined by means of leaf springs  24   a ,  24   b  connected to them. The leaf springs, which are shown in FIG. 2, are entirely located in the body of the charging device in the space between the upper part  12   a  and the bottom part  12   b . The leaf springs are fastened at the first end to the upper part  12   a  and at the second end to the base of the width controllers. The wider the battery to be placed in the charging device is, the more the leaf springs  24   a ,  24   b  fastened to the width controllers  19   a ,  19   b  bend towards the outer edge of the charging device  10 . As a result of this, the distance between the width controllers  19   a ,  19   b  becomes large enough to allow the battery  15   a  to slip between them. 
     In the next step, the battery  15   a  presses against the battery guides  18   a ,  18   b , which are located near the first end of the charging device  10 , at both edges of the space reserved for the battery. The battery guides comprise, on the edges facing each other, guiding surfaces, which form a step-like pattern in the transverse direction of the charging device  10 . This enables placing batteries of different width at the right point against the electrical connectors  17  of the charging device. The battery guides  18   a ,  18   b  are fixed parts of the slide  21  shown in FIG.  2 . The slide is located in the body of the charging device, whereby only the battery guides  18   a ,  18   b  are outwardly visible. The slide is not fastened to the charging device as fixed, but it can move in the body in the direction of the longitudinal axis of the body within certain limits. The slide is connected with two coil springs  22  in the body, the coil springs are essentially V-shaped, and they impose a force on the slide pushing it away from the first end  21  of the charging device when there is no battery to be charged in the charging device. 
     The width controllers  19   a ,  19   b  function as locking devices, which determine how the slide  21  and the battery guides  18   a ,  18   b  on it can move towards the first end of the charging device  10 . When there is a narrow battery in the charging device, the sides of the battery do not reach to push the width controllers  19   a ,  19   b  sufficiently towards the outer edges of the charging device. Then the width controllers lock the slide  21  in place, whereby the slide and the battery guides  18   a ,  18   b  cannot move in the direction of arrow A towards the first end of the charging device. Thus the head of the battery to be charged is located in the narrowest gap formed by the closest guiding surfaces of the battery guides, whereby the gap guides the connectors at the end of the battery against the connectors of the charging device  17 . 
     If a wide battery is placed in the charging device, its sides pushing the width controllers  19   a ,  19   b  sufficiently far away from each other, the locking, which prevents the movement of the slide  21 , is released. Then the slide  21  can move the maximum distance in the direction of the arrow A towards the first end of the charging device  10 , which is the situation in the example of FIG. 1 c . Only the furthest guiding surfaces of the battery guides  18   a ,  18   b  are then visible, while the inner guiding surfaces are pushed into the body of the charging device. Now the head of the battery to be charged is located in the widest gap formed by the furthest guiding surfaces of the battery guides, and the connectors at the end of the battery are again placed accurately against the connectors  17  of the charging device. 
     A short battery  15   a  is locked in place by a stopper  14  moving up and down. When the battery  15   a  is pushed towards the electrical connectors  17  of the charging device  10 , the stopper  14  is pushed into the body of the charging device. When the battery  15   a  is in place, the spring  25  pushes the stopper  14  forth, whereby the battery remains pressed between the stopper and the battery guides  18   a ,  18   b . Thus the battery  15   a  has been locked in place to remain stationary. When the battery  15   a  is removed, the stopper  14  is pushed to the bottom, whereby the battery  15   a  can be removed from the device. 
     In the case shown in FIG. 1 c  as an example, a battery with external dimensions as large as the charging device  10  can hold has been placed in the charging device  10 . The width controllers  19   a ,  19   b  are now entirely sunk into the shell parts  12   a ,  12   b , whereby the slide  21  and its battery guides  18   a ,  18   b  have been able to move to the extreme position towards the first end of the charging device as pushed by the battery to be placed in the charging device. The stopper  14  has been pushed by the battery  15   b  into the inner space formed by the shell parts  12   a ,  12   b . At the second end of the charging device  10 , the battery  15   b  to be charged is supported at the side by the auxiliary guides  13   a ,  13   b . Because the battery thus fills up the space reserved for the battery, it cannot move in the charging device but stays in place reliably. The battery is removed from the charging device  10  by lifting it at first up with fingers from the second end of the charging device. After this, the battery  15   b  can be lifted off the charging device. The stopper  14  comes up again and the battery guides  18   a ,  18   b  return from the force of the springs  22  to the starting position as far from the first end of the charging device  10  as possible. 
     FIG. 2 shows the parts of a charging device according to the invention as an exploded view. The largest single parts that are outwardly visible are the cover  11 , the bottom part  12   b  and the upper part  12   a . The rest of the parts of the charging device remain either entirely or partly invisible in the space between the bottom part and the upper part. The charging device  10  comprises a circuit board  29 , which resembles a letter T upside down in FIG. 2, to which connectors  17  for the batteries, a connector  23  of the electrical connector of the charging device and the charging light indicator  35  are connected. The slide  21  is arranged to move on the narrow part of the circuit board  29 . The slide  21  is connected with two V-shaped coil springs  22 , which tend to return the slide to a position, which is as far as possible from the first end of the charging device  10 . The charging device comprises two leaf springs  24   a ,  24   b , which are fastened from their first end to the opposite sides of the outer edges of the upper part  12   a , and to the second end of which width controllers  19   a ,  19   b  are fastened. A coil spring  24  is placed inside the stopper  14 . The stopper  14  and the circuit board  29  are preferably fastened by means of a board  26  and a screw  27  connected to it to the upper part  12   a . The board  26  is preferably made of heavy material, such as metal, so as to balance and stabilize the charging device  10 . The bottom part  12   b  is connected to the upper part  12   a  preferably with screws. Four screws are used in the example shown in the drawing. 
     FIGS. 3 a  and  3   b  show an example of a charging device according to the invention as seen from the bottom, when the bottom part has been removed. FIGS. 3 a  and  3   b  thus show the inner part of the body of the charging device, which is normally hidden. The purpose of the drawings is to illustrate how the movement of the slide  21  is adjusted by means of the width controllers  19   a ,  19   b.    
     FIG. 3 a  shows a situation in which there is either no battery in the charging device or the battery in the device is so narrow that its sides do not push the width controllers sufficiently to the direction of the outer edges of the charging device. In this situation, the leaf springs  24   a ,  24   b  push the width controllers  19   a ,  19   b  towards each other, whereby the claws  30   a ,  30   b  in the width controllers are pushed into the dents  32   a ,  32   b  on the sides of the slide and thus prevent the movement of the slide towards the first end of the charging device. 
     FIG. 3 b  shows a situation in which there is a wide battery in the charging device, pushing the width controllers  19   a ,  19   b  away from each other. Then the claws  30   a ,  30   b  move off the dents  32   a ,  32   b  and the slide can move towards the first end of the charging device as pushed by the battery. FIG. 3 b  shows a situation in which the slide has moved to its extreme position at the first end of the charging device. FIGS. 3 a  and  3   b  also show the coil springs  22 , the force of which pushes the slide continuously away from the first end of the charging device. When the battery has been removed, the slide  21  and the width controllers  19   a ,  19   b  are moved back to the position shown in FIG. 3 a , as forced by the coil springs  22  and the leaf springs  24   a ,  24   b.    
     Due to the invention, the same charging device according to the invention can conveniently be used to charge batteries with the following external dimensions: the width of the battery is preferably between 33 and 29 mm, and the length can be between 53 and 72 mm. 
     Some preferred embodiments of the invention have been described above. However, the invention is not limited to the solutions described above. For example, one stopper was mentioned in the preferred embodiment, but more stoppers can be provided to prevent the longitudinal movement of the batteries, whereby it is possible to charge batteries of very different lengths with the same device. In addition, the inventive idea can be applied in many different ways within the scope defined by the attached claims.