Patent Publication Number: US-2018054076-A1

Title: Mains-operable battery charging device and charging system

Description:
The present invention relates to a mains-operable battery charging device including a charger housing which includes a main charging interface designed for exchangeably accommodating a main rechargeable tool battery of a hand-held power tool, for example a hammer drill or a combi-hammer. The battery charging device further includes a charging electronics system which is situated within the charger housing and is designed for charging a main rechargeable tool battery accommodated in the main charging interface with a main charging voltage. The present invention also relates to a charging system including a mains-operable battery charging device and a main rechargeable tool battery. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a mains-operable battery charging device and a charging system which are usable in diverse ways. With respect to the battery charging device, the object is achieved in that the battery charging device includes at least one auxiliary charging interface via which an auxiliary rechargeable tool battery is connectable to the battery charging device and is chargeable with an auxiliary charging voltage which differs from the main charging voltage. 
     The main rechargeable tool battery and the auxiliary rechargeable tool battery may be of different types, in particular the main rechargeable tool battery and the auxiliary rechargeable tool battery may be designed and/or intended for operating different types of hand-held power tools. 
     The present invention incorporates the finding that main rechargeable tool batteries and auxiliary rechargeable tool batteries previously could not be charged using one and the same battery charging device, in particular when they are of different types. In this way, it is not possible, for example, with the aid of battery charging devices from the prior art, to charge an auxiliary rechargeable tool battery with a nominal voltage of 14 volts or 22 volts while simultaneously charging a main rechargeable tool battery with a nominal voltage of 36 volts. 
     In contrast to the prior art, by way of the mains-operable battery charging device according to the present invention, a main rechargeable tool battery accommodated in a main charging interface may now be advantageously charged with a main charging voltage and, simultaneously, an auxiliary rechargeable tool battery may be charged with an auxiliary charging voltage which differs from the main charging voltage. 
     In one preferred embodiment, the main charging interface designed for accommodating the main rechargeable tool battery and the auxiliary charging interface which is connectable to an auxiliary rechargeable tool battery are mechanically encoded differently, the main rechargeable tool battery and the auxiliary rechargeable tool battery being of different types, in particular. In other words, the main charging interface is therefore designed, in particular, only for accommodating the main rechargeable tool battery and, in particular, not for accommodating a different type of auxiliary rechargeable tool battery. 
     In one particularly preferred embodiment, the auxiliary charging interface is designed as a plug to be plugged into an auxiliary rechargeable tool battery. The present invention incorporates the finding, in this regard, that previously only one main rechargeable tool battery and no auxiliary rechargeable tool batteries of a different type could be charged on battery charging devices from the prior art. In this way, it was previously not possible, for example, to simultaneously charge a main rechargeable tool battery with a nominal voltage of 36 volts and having a first hardware encoding, and an auxiliary rechargeable tool battery with a nominal voltage of 14 volts or 22 volts and having a hardware encoding which differs from the hardware encoding of the main rechargeable tool battery. 
     Due to the fact that the auxiliary charging interface is preferably designed as a plug to be plugged into an auxiliary rechargeable tool battery, the auxiliary rechargeable tool battery may now be charged simultaneously with a main rechargeable tool battery, even though it is encoded, in particular mechanically, differently. An embodiment of the battery charging device including differently hardware-encoded main charging interfaces is now no longer required. In other words, a mains-operable battery charging device may be designed only for accommodating precisely one mechanically encoded main tool, and a charging of a differently encoded auxiliary rechargeable tool battery may take place with the aid of a corresponding plug. 
     The battery charging device may include one, two or three or more auxiliary charging interfaces. The battery charging device preferably includes precisely two auxiliary charging interfaces. The battery charging device may include precisely one auxiliary charging interface. 
     The main charging voltage for charging a main rechargeable tool battery is preferably configured with a nominal voltage of 36 volts. The auxiliary charging voltage is also preferably configured for charging a rechargeable tool battery with a nominal voltage of 14 volts or 22 volts. A first auxiliary charging voltage may be configured for charging a rechargeable tool battery with a nominal voltage of 14 volts. A second auxiliary charging voltage may be configured for charging a rechargeable tool battery with a nominal voltage of 22 volts. Conversely, a first auxiliary charging voltage may be configured for charging a rechargeable tool battery with a nominal voltage of 22 volts. A second auxiliary charging voltage may be configured for charging a tool with a nominal voltage of 14 volts. 
     In one particularly preferred embodiment, the main charging voltage is configured for charging a main rechargeable tool battery with a nominal voltage of 36 volts, and the main charging interface is designed or mechanically encoded for accommodating a main rechargeable tool battery with 36 volts. Alternatively, the main charging voltage may be designed for charging a main rechargeable tool battery with a nominal voltage of 14 volts or 22 volts, and the main charging interface may be designed for accommodating a main rechargeable tool battery with a nominal voltage of 14 volts or 22 volts. 
     The auxiliary charging interface may be electrically connected to the same charging electronics system as the main charging interface. Preferably, precisely one charging electronics system is provided both for the main charging interface and for the auxiliary charging interface/the auxiliary charging interfaces. 
     Preferably, the auxiliary charging interface is connected via an auxiliary charging cable to the battery charging device, in particular to its charging electronics system. A first auxiliary charging interface may be connected via a first auxiliary charging cable to the battery charging device, in particular to its charging electronics system. A second auxiliary charging interface may be connected via a second auxiliary charging cable to the battery charging device, in particular to its charging electronics system. 
     It has proven advantageous that the battery charging device include a cooling fan situated within the charger housing for cooling the charging electronics system. 
     The main charging interface may include at least one ventilation channel via which a main rechargeable tool battery accommodated in the main charging interface is coolable with the aid of air drawn in by the cooling fan. The main rechargeable tool battery itself may include a rechargeable battery ventilation channel via which air may flow through the main rechargeable tool battery. 
     With respect to the charging system, the object is achieved by an above-described, mains-operable battery charging device and a main rechargeable tool battery; the main charging interface of the mains-operable battery charging device is designed for accommodating the main rechargeable tool battery. Preferably, the main charging interface is encoded exclusively mechanically for the main rechargeable tool battery; in particular, the main rechargeable tool battery has a nominal voltage of 36 volts. 
     Further advantages result from the following description of the figures. The figures illustrate different exemplary embodiments of the present invention. The figures, the description and the claims contain numerous features in combination. Those skilled in the art will advantageously also consider the features individually and combine them to form other meaningful combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the figures, identical and equivalent components are provided with identical reference numerals. 
         FIG. 1  shows a schematic representation of a first exemplary embodiment of a mains-operable battery charging device according to the present invention; 
         FIG. 2  shows a schematic representation of a second exemplary embodiment of a mains-operable battery charging device according to the present invention; and    
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a mains-operable battery charging device  100  including a charger housing  90  which includes a main charging interface  80  designed for exchangeably accommodating a main rechargeable tool battery  10  of a hand-held power tool. Main rechargeable tool battery  10  accommodated in main charging interface  80  in the present case has a nominal voltage of 36 volts. Correspondingly, main charging interface  80  is designed and mechanically encoded for accommodating the main rechargeable tool battery having 36 volts. Mains-operable battery charging device  100  may be connected via a mains plug  101  to a 230-volt AC-voltage network, for example. 
     Battery charging device  100  includes a charging electronics system  70  which is situated within charger housing  90 . Charging electronics system  70  is designed for charging main rechargeable tool battery  10 , which is accommodated in main charging interface  80  and has a nominal voltage of 36 volts, with a main charging voltage U 10 . 
     Mains-operable battery charging device  100  from  FIG. 1  includes a first auxiliary charging interface  21  and a second auxiliary charging interface  31  in the present case. First auxiliary charging interface  21  is connected to charging electronics system  70  via a first auxiliary charging cable  22 . Second auxiliary charging interface  31  is connected to charging electronics system  70  via a second auxiliary charging cable  32 . First auxiliary rechargeable tool battery  20  shown in  FIG. 1  is connected to first auxiliary charging interface  21  in the present case and is chargeable with a first auxiliary charging voltage U 20  via the first auxiliary charging interface. Second auxiliary rechargeable tool battery  30 , which is connected to battery charging device  100  via second auxiliary charging interface  31 , is chargeable with a second auxiliary charging voltage U 30  via battery charging device  100 . Main charging voltage U 10  differs from auxiliary charging voltages U 20 , U 30 . 
     Main charging voltage U 10  for charging the main rechargeable tool battery is configured with a nominal voltage of 36 volts in the present case. First auxiliary charging voltage U 20  is configured for charging the first auxiliary rechargeable tool battery with a nominal voltage of 22 volts. Second auxiliary charging voltage U 30  is configured for charging second auxiliary rechargeable tool battery  30  with a nominal voltage of 14 volts. 
     As is also apparent from  FIG. 1 , main charging interface  80  is connected to charging electronics system  70  via an internal charging cable  71 . Both first auxiliary charging interface  21  and second auxiliary charging interface  31  are electrically connected to one and the same charging electronics system  70  as main charging interface  80 . 
     Main charging interface  80  of battery charging device  100  is situated directly on charger housing  90 , as is apparent. The main rechargeable tool battery, which has a nominal voltage of 36 volts, is chargeable via this main charging interface  80 . The main rechargeable tool battery may be plugged into main charging interface  80  for this purpose. First auxiliary charging interface  21  and second auxiliary charging interface  31  are situatable remotely from battery charging device  100  via first auxiliary charging cable  22  and second auxiliary charging cable  32 , respectively. In the present case, first auxiliary rechargeable tool battery  20 , which has a nominal voltage of 22 volts, is charged remotely by battery charging device  100 . Second auxiliary rechargeable tool battery  30 , which has a nominal voltage of 14 volts, is also charged remotely by battery charging device  100 . Further auxiliary charging interfaces including additional auxiliary charging cables are possible. 
     Mains-operable battery charging device  100  and main rechargeable tool battery  10 , for the accommodation of which main charging interface  80  of mains-operable battery charging device  100  is designed, form a charging system  500  according to the present invention in this case. First auxiliary rechargeable tool battery  20  and/or second auxiliary rechargeable tool battery  30  may be included in charging system  500 . 
     The exemplary embodiment shown in  FIG. 2  includes, in addition to the exemplary embodiment described with reference to  FIG. 1 , a cooling fan  60  situated within charger housing  90 , which is situated to cool charging electronics system  70  of battery charging device  100 . Main charging interface  80  of battery charging device  100  includes two ventilation channels  81  via which the main rechargeable tool battery accommodated in main charging interface  80  is coolable with the aid of air L drawn in via cooling fan  60 . Main rechargeable tool battery  10  includes internal rechargeable battery ventilation channels  12 . 
     During the charging operation, cooling fan  60  of battery charging device  100  rotates in a direction of rotation R. As a result, air L is drawn into main rechargeable tool battery  10  through inner rechargeable battery ventilation channels  12  and, in charger housing  90 , is guided further in the direction of charging electronics system  70  and, on its further course, is guided past the charging electronics system, and is finally discharged into the surroundings through outlet openings  91  in the bottom of charger housing  90 . Both main rechargeable tool battery  10  to be charged and charging electronics system  70 , which is charging main rechargeable tool battery  10  and connected auxiliary rechargeable tool batteries  20  and  30 , are cooled with the aid of air L. Cooling fan  60  is operated in such a way that required waste heat may be carried away from main rechargeable tool battery  10  and away from charging electronics system  70  via the air. 
     With the embodiment of  FIG. 1 , main charging interface  80  is mechanically encoded only for accommodating main rechargeable tool battery  10 . First auxiliary charging interface  21  and second auxiliary charging interface  31  can be mechanically encoded differently from main charging interface  80 , since these are designed as plugs to be plugged into an auxiliary rechargeable tool battery. 
     LIST OF REFERENCE NUMERALS 
     
         
         U 10  main charging voltage 
         U 20  first auxiliary charging voltage 
         U 30  second auxiliary charging voltage 
         L air 
         R direction of rotation 
           10  main rechargeable tool battery 
           12  rechargeable-battery ventilation channels 
           20  first auxiliary rechargeable tool battery 
           21  first auxiliary charging interface 
           22  first auxiliary charging cable 
           30  second auxiliary rechargeable tool battery 
           31  second auxiliary charging interface 
           32  second auxiliary charging cable 
           60  cooling fan 
           70  charging electronics system 
           71  internal charging cable 
           80  main charging interface 
           81  ventilation channel 
           90  charger housing 
           91  outlet openings 
           100  battery charging device 
           101  mains plug 
           500  charging system