11  EP 3 800 012 A1 12  to release the adapter element 4 from the tool housing 2 and to extract the adapter element 4 from the recess 7. serted therein.The only visible difference isthe firstelec- triccable 5 ledoutoftheadapterhousing15 atthe visible part 10, in particular at the rear or a side of that part 10 ofthe adapterelement15 visible aftercomplete insertion into the recess 7. [0040] Preferably,the attachmentmembers are adapt- ed to automatically enter into mutual engagement with each other upon complete insertion of the part 8 of the adapter element 4 to be inserted into the recess 7. This has the advantage that the adapter element 4 does not have to be actively secured to the tool housing 2 after insertion. Rather, the adapter element 4 is automatically secured to the tool housing 2 upon complete insertion. This may be effected by a snap lock or a spring lock or by a magnetic lock. 5 10 [0045] Itispossible toreleasablyconnectthe firstcable 5to the adapterelement4 bymeans ofa plug-and-socket connection. However, in order to allow a flexible use of the power tool 1 with the adapter element 4 inserted therein withoutthe risk ofan unintentional disconnection of the power tool 1 from the power supply unit 40, it is suggested that the first cable 5 is fixedly attached to the adapter element4. The connection between the adapter element4and the firstcable 5 isthe one which isstressed most during an intense use ofthe power tool 1. Addition- ally, a kink protection element for the first cable 5 can be provided in the form of a grommet 50 attached to the adapter housing 15 (see Fig. 7). [0041] According to the embodiment of Fig. 6, the at- tachment members comprise at least one spring-loaded hook element 21 attached to the tool housing 2 within the recess 7. Of course the hook element 21 could also be attached to the tool housing 2 outside the recess 7. Alternatively,the hook element21 could also be provided on the adapter housing 15 ofthe adapter element4. The attachment members further comprise at least one cor- responding recess oropening 49 providedatthe adapter housing 15 of the adapter element 4 (see Fig. 7). The recess or opening 49 is provided in that part 8 of the adapter element 4 which is inserted into the recess 7. Of course, the recess or opening 49 could also be provided in another part 10 of the adapter element 4 which is not inserted into the recess 7. Alternatively, the recess or opening 49 could also be provided in the tool housing 2 of the power tool 1. The recess or opening 49 is adapted for receiving the hook element 21 upon complete inser- tion ofthe part8 of the adapter element 4 into the recess 7. The spring-effect of the hook element 21 may achieved by a separate spring element (not shown) or - as isthe case in Fig.6 -by means ofthematerialofwhich the hook element21 ismanufactured,the materialhaving elastic characteristics. For example, the hook element 21 could be manufactured from metal or synthetic mate- rial (e.g. plastic). 35 30 25 20 15 [0046] Furthermore,itissuggested thatthepowersup- ply unit 40 comprises a first electric socket 51 for releas- ably attaching the first cable 5 to the power supply unit 40 (see Fig. 9). The first cable 5 may be attached by means of a respective plug 52 which is connected to the first cable 5 and inserted into the socket 51. The socket 51 and the plug 52 may have any desired form. In par- ticular, they may have three contacts 53, 54 each, one for the positive pole, one for the negative pole and one for ground. Due to the fact that a reduced voltage (e.g. between 12 V and 48 V) is transmitted across the first cable 5 for operation of the power tool 1, rather large currents (up to 10 A) will have to be transmitted across the plug-and-socket-connection 51,52 and the firstcable 5 in order to achieve the desired output power at the powertool1.Therefore,the plug-and-socket-connection 51, 52 as well as the first cable 5 have to be adapted to transmit the relatively large currents. Furthermore, the first electric socket 51 of the powersupplyunit 40 should comprise mechanical protection means in order to pre- venta person fromreaching the contacts53 ofthe socket 51 with his/her fingers or an electric conductor and from getting an electric shock. Further, the plug-and-socket- connection 51, 52 should be water- and dustproof. Due to the fact that the power supply unit 40 is located in a distance to the power tool 1 and connected thereto by the flexiblefirstcable 5,there isno riskthattheplug-and- socket-connection 51, 52 will be unintentionally disen- gaged even during intense use of the power tool. How- ever, in order to provide for a water- and dustproof con- nection and for a safe connection of the plug 52 in the socket 51, the plug could be provided with a cylindrical retaining element 55 which may be freely rotated about its longitudinal axis in respect to the rest of the plug 52. The internal surface of the retaining element 55 is pro- vided with a thread. Similarly, the first electric socket 51 isprovided with a cylindricalprotruding element56which has a thread on its outer surface. Upon insertion of the plug 52 into the socket 51, the retaining element 55 can be screwed onto the protruding element 56 thereby se- 55 50 45 40 [0042] Thehousing 19 ofthebatterypack 6 comprises a respective recess or opening 49’ (see Fig. 4). Further, inside the batterypack 6 there are a numberofrecharge- able battery cells 20. [0043] Of course, many other embodiments of the at- tachment members for releasably attaching the adapter element 4 to the tool housing 2 after complete insertion into the recess 7 are conceivable, too. [0044] In order to provide for an appealing design of the power tool 1, it is suggested that at least that part 10 of the adapter housing 15 which is not inserted into the recess 7 upon complete insertion of the part 8 of adapter element 4 to be inserted into the recess 7 and stillvisible from outside(see Fig.7)has the same design as that part 11 of the battery pack 6 which is not inserted into the recess 7 upon complete insertion of the part 9 of the battery pack 6 to be inserted into the recess 7 and still visible from outside (see Fig. 5). Hence, the power tool 1 has almost the same look with the battery pack 6 inserted into the recess 7 or the adapter element 4 in- 7