Patent ID: 12224610

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

InFIG.1a, a first exemplary embodiment of the present invention is shown on the basis of a battery-operated device10that is designed as a cordless vacuum cleaner12and that is connected to an interchangeable drive unit14in the form of a motor-driven suction nozzle16. The connection between cordless vacuum cleaner12and suction nozzle16takes place via a telescopic extension tube18. Telescopic extension tube18has locking devices20at its two ends for detachably connecting to an electromechanical interface22(cf.FIG.1b) of cordless vacuum cleaner12and a corresponding counter-interface (not shown) of drive unit14. In this way, a user is able to operate locking device20by simply applying finger pressure for the purpose of establishing or releasing the connection. Telescopic extension tube18thereby serves almost like an electromechanical extension between electromechanical interface22of cordless vacuum cleaner12and the counter-interface of drive unit14. The counter-interface of drive unit14may likewise be detachably connected directly without a telescopic extension tube to electromechanical interface22of cordless vacuum cleaner12via an appropriate locking device.

A battery24that is designed as an interchangeable battery pack26and that is detachably connected to cordless vacuum cleaner12via a further electromechanical interface27is used to supply cordless vacuum cleaner12with power. Since the mechanical implementation of further electromechanical interface27is not important for the present invention, it is not to be discussed in greater detail at this point. However, further electromechanical interface27must be designed, just as electromechanical interface22, in such a way that it allows for a bidirectional energy flow, so that on the one hand, electrical power may flow from interchangeable battery pack26to cordless vacuum cleaner12for the purpose of operating same and on the other hand, electrical energy may flow from cordless vacuum cleaner12into interchangeable battery pack26for the purpose of charging same.

FIG.1bshows cordless vacuum cleaner12in a further perspective view without an interchangeable drive unit14. As already mentioned above, the latter may be detached and reattached by a user by manually actuating locking device20. Electromechanical interface22for detachably connecting motor-driven suction nozzle16or other suction accessories to telescopic extension tube18is located at a tube extension28of cordless vacuum cleaner12, which itself may be used directly as a suction nozzle. The motor-driven suction nozzle in turn includes a rotation brush (not shown) that is set into rotation by an electric motor (also not shown) that is situated in the suction nozzle. For this purpose, the electric motor of suction nozzle16is supplied with power via electromechanical interface22of cordless vacuum cleaner12and the counter-interface of suction nozzle16as a function of the actuation of a master switch30of cordless vacuum cleaner12. If master switch30is actuated by a user, this results in a start of a suction motor32of cordless vacuum cleaner12and—in the case that removable suction nozzle16is mounted at tube extension28or at telescopic extension tube18—also in the start of the electric motor of suction nozzle16. In this case, cordless vacuum cleaner12may be designed in such a way that master switch30serves as an acceleration switch, with the aid of whose pressure travel the rotational speed of the electric motors may be controlled. Further embodiments to this extent follow in the context ofFIG.2.

To charge interchangeable battery pack26quickly and easily, tube extension28of cordless vacuum cleaner12may now be plugged into a correspondingly designed receptacle34of a charging device36according toFIG.1c. Charging device36must merely be adjusted to the specifications of interchangeable battery pack26, in particular to its voltage, capacity, charging current and the like. In its simplest implementation, charging device36includes a power supply38and an operation display, a charge level indicator and/or an error display40, so that the charging process starts automatically when cordless vacuum cleaner12is plugged into receptacle34and ends automatically when interchangeable battery pack26is fully charged. It is likewise possible that a charging device that is designed for interchangeable battery pack26may be provided with a plug-on adapter having a receptacle corresponding to receptacle36for electromechanical interface22of cordless vacuum cleaner12. In this way, already present interchangeable battery pack charging devices may be retrofitted subsequently in an easy and reversible manner to directly charge the interchangeable battery pack via battery-operated device10.

FIG.2ashows a block diagram of a circuit42of battery-operated device10for activating interchangeable drive unit14designed as electric motor44via electromechanical interface22of battery-operated device10. Battery-operated device10may be designed as a cordless vacuum cleaner12and interchangeable drive unit14as a suction nozzle16with reference to the first exemplary embodiment according toFIG.1.

Electromechanical interface22has a first contact44and at least one second contact46for the purpose of supplying electric motor44of suction nozzle16with power. First contact44is connected to a drain terminal D of a first semiconductor switch48and second contact46is connected to a source terminal S of first semiconductor switch48. In the present case, the semiconductor switch is designed as a MOSFET that is activated via a gate terminal G by a control unit50of cordless vacuum cleaner12. First semiconductor switch48is part of a power output stage52having at least one second semiconductor switch54that is connected in series to first semiconductor switch48for the purpose of implementing a so-called two-quadrant actuator.

A further semiconductor switch56is connected in series to power output stage52, control unit50activating the at least two semiconductor switches48,54of power output stage52and further semiconductor switch56in such a way that upon connecting suction nozzle16to electromechanical interface22and as a function of master switch30, a power supply of suction nozzle16takes place with the aid of interchangeable battery pack26. For this purpose, interchangeable battery pack26supplies circuit42via a first contact58and at least one second contact60of further electromechanical interface27of cordless vacuum cleaner12with a d.c. voltage U. Control unit50detects the state of master switch30(not illustrated inFIG.2afor the sake of clarity) in such a way that when master switch30is actuated by a user, it activates the two semiconductor switches48,54of power output stage52with the aid of correspondingly pulse-width modulated (PWM) signals in the sense of a two-quadrant actuator. It is possible in this way to implement a speed control of electric motor44as a function of the pressure travel of master switch30. The charging process of interchangeable battery pack26may be interrupted completely with the aid of further semiconductor switch56. In addition, a capacitor62is used to suppress any electromagnetic interferences due to the PWM. It should also be noted that all semiconductor switches illustrated inFIGS.2aand2bare designed as MOSFETs having corresponding intrinsic diodes, the intrinsic diode of semiconductor switch48being used in particular as a freewheeling diode for electric motor44. Bipolar transistors, IGBTs, etc., may, however, also be used as semiconductor switches instead of MOSFETs, without restricting the present invention. Furthermore, control unit50may be implemented with the aid of a microprocessor, a DSP, a FPGA or the like, but also with the aid of a discrete design. Instead of an electric motor44, interchangeable drive unit14may ultimately also include other electric drives and actuators, such as piezoelectric drives, sound generators, vibration actuators, electromagnets, light emitting elements, etc., for example.

If battery-operated device10or cordless vacuum cleaner12are now connected to charging device36according toFIG.1cvia electrical contacts44,46of its electromechanical interface22, then this is detected by control unit50according toFIG.2bwith the aid of a corresponding voltage drop via first semiconductor switch48. It is important in this case that control unit50permanently opens first semiconductor switch48immediately after separating interchangeable drive unit14from electromechanical interface22, in order to avoid a short-circuit of charging device36. After recognizing charging device36, control unit50permanently closes second semiconductor switch54and further semiconductor switch56until the charging process of battery26is completed. With the aid of second and further semiconductor switch54,56, control unit50may also intentionally control the charging process, for example for maintaining a charging state or charging to a maximal charging limit that was previously set at battery-operated device10. However, this control generally takes place directly in charging device36. It is possible, however, that charging device36and control unit50of battery-operated device10communicate with one another via electromechanical interface22, in order to control the charging process accordingly. The communication may take place per modulated data signal via the two contacts44and46of electromechanical interface22or alternatively or additionally via further, not shown electrical contacts of electromechanical interface22.

Moreover, it should be noted that electromechanical interface22of battery-operated device10as well as the counter-interface of interchangeable drive unit14and of charging device36may also include coils instead of electrical contacts for inductive energy and/or data transfer, for example per NFC or the like.

FIGS.3aand3bshow a second exemplary embodiment of the present invention on the basis of a battery-operated device10designed as a percussion drill62. As already shown in the case of cordless vacuum cleaner12according toFIGS.1athrough1c, percussion drill62may also be detachably connected to an interchangeable drive unit14in the form of a suction device64via an electromechanical interface22(cf.FIG.3b). A locking device20of suction device64is used among other things to detachably connect suction device64. Suction device64moreover includes an electric motor (not shown) as a suction motor for drilling debris, drilling dust, or the like, which is supplied with the power of an interchangeable battery pack26via electromechanical interface22. A detailed description of percussion drill62as well as suction device64is to be dispensed with in this case, since these are conventional. If a master switch30of percussion drill62is actuated, the electric motor of suction device64is also activated via electromechanical interface22in addition to a drilling tool66being driven. Electromechanical interface22is configured in such a way that it continues to run for a few seconds after master switch30has been released in order to reliably suction further drilling dust. Analogously toFIGS.1cand2b, interchangeable battery pack26may now be charged via electromechanical interface22, without having to remove it from percussion drill62. For this purpose, a charging adapter (not shown) that is connected via a cable to charging device36may be attached at percussion drill62. Directly attaching an appropriately designed charging device36is naturally also possible.

Finally, it should be noted that the present invention is not limited to the shown exemplary embodiments according toFIGS.1through3. The present invention may, for example, also be applied to a battery-operated measuring device in the form of a laser rangefinder or a cross-line laser that includes an electromechanical interface for activating a motor-driven swivel base. The present invention may also be applied to other battery-operated devices including a corresponding electromechanical interface, such as household appliances or gardening tools. In addition, it should be mentioned again that the present invention is not limited to removable batteries and interchangeable battery packs, but is also applicable to battery-operated devices having fixedly integrated rechargeable batteries.