EP3061114B1 - Electrical switch, in particular a switch for an electrical power tool - Google Patents

Description

The invention relates to an electrical switch according to the preamble of patent claim 1.

Such electrical switches are mainly used for a power tool use. These power tools may be angle grinders, drills, grinders, saws, planers, o. The like. Act.

From the DE 44 37 020 A1 An electrical switch is known which has a switchable between an off position and an on-contact system. The switch further has a movable actuator for switching the contact system. It has been found that a switched-on power tool, in which such a switch is used, can restart unintentionally and / or unattended in the event of failure and subsequent return of the power supply. This can cause dangerous situations for the user of the power tool. In particular, there is a risk of such a restart when the power tool is provided a locking device for the actuator in the on position of the contact system.

Such a switch with an additional restart protection after a power failure is out of the DE 26 26 003 A1 known. In this switch, the actuator comprises a plunger and a contact piece, wherein the contact piece for switching to the contact system acts. Furthermore, a coupling element is provided, such that the plunger can be brought into and / or out of cooperation with the switching piece. In this case, this interaction takes place such that the switching of the contact system in the on and off position by means of the plunger and the switching of the contact system in the off position allows independent of the plunger.

Other electrical switches that have a restart protection after a power failure are in the documents EP 0 174 382 A1 . DE 28 00 041 A1 and EP 0 458 190 A1 described.

The invention has for its object to further develop the switch so that a restart protection for the power tool is provided on the switch, in particular, the switch should be designed in a simple manner.

This object is achieved in a generic electrical switch by the characterizing features of claim 1.

In the switch according to the invention, the coupling element is arranged movably on the contact piece in a compact design. Next, an actuator for movement and / or for holding the coupling element is provided in a compact design, wherein in a first position of the coupling element (namely position coupled) of the plunger in cooperation with the switching piece and in a second position of the coupling element (namely position decoupled) of Tappet is out of cooperation with the contact piece. Characterized the switching of the contact system by means of the plunger and in the second position enables the switching of the contact system independently of the plunger in the first position. Further embodiments of the invention are the subject of the dependent claims.

In a further embodiment, at least one elastic element on the actuator to its provision in the off position of the contact system act. In a simple manner, it may be appropriate for this purpose that a compression spring acts on the contact piece.

It may be for the sake of simplicity offer that the coupling element is rotatably mounted on the contact piece. Furthermore, it may be that the coupling element is held in the first position by an elastic means, which may be a compression spring in a simple manner.

For simplicity, a transmission element may be provided between the coupling element and the actuator for movement and / or for holding the coupling element. In a compact manner, the transmission element in the manner of a slider, a Fork element o. The like. Be configured. Furthermore, it may be expedient that the transmission element moves by means of an elastic element, in particular by means of a compression spring, the coupling element in the second position.

The actuator may be an electromagnet, such a design being particularly reliable and reliable. In a compact design, the electromagnet can be designed as a holding magnet when the voltage is applied to the transmission element and / or as a solenoid releasing the transmission element upon application of electrical voltage.

In a particularly simple embodiment, the coupling element of a turntable, a pivot pin, a rotary lever o. The like. Exist. In a simple and compact way, a coupling region may be provided in the manner of a link on the plunger and / or on the coupling element. As a result, the coupling element can be moved to the second position upon return of the out of cooperation with the contact piece tappet.

At least one electrical connection for supplying the electrical voltage to the contact system can be provided on the electrical switch. This supplied electrical voltage can also apply the electromagnet to the simple functionality. Finally, at least one further electrical connection can be provided for discharging the electrical voltage connected by means of the contact system.

• Schalter in kompakter Bauform mit indirekter Betätigung für kleine Winkelschleifer mit integriertem Wiederanlaufschutz. Die Wiederanlaufschutzfunktion wird künftig ab 2016 gemäß geänderter Gerätenorm EN 60745-2-3 auch für kleine Winkelschleifer gefordert.
• Der Wiederanlaufschutz verhindert, dass ein in der EIN-Stellung arretiertes Gerät nach Abfall und Wiederkehr der Netzversorgung ungewollt und/oder unbeaufsichtigt wieder anläuft und so für den Anwender gefährliche Situationen entstehen können.
• Die Funktion Wiederanlaufschutz wird bereits heute durch verschiedene separate Elektronikmodule in kleinen Winkelschleifern realisiert, bei denen noch weitere Elektronikfeatures integriert sind, wie ein Überlastschutz, eine Drehzahlvorwahl usw.. Die vorliegende Erfindung zielt jedoch auf solche Geräte ab, die heute keine Elektronik beinhalten, künftig aber auch die Normforderung erfüllen müssen. Im Idealfall muss dann hierfür lediglich der Schalter ausgetauscht werden, und schon erfüllt das Gerät die NormForderung nach Wiederanlaufschutz.
• Die Arretierung wird bei kleinen Winkelschleifern in der Regel am äußeren Betätigungselement des Gerätes realisiert. Man unterscheidet generell zwischen Schieber- und Paddle-Betätigung. Die vorliegende Lösung soll für beide gebräuchlichen Betätigungsarten geeignet sein. Bei Schieberbetätigung wird beispielsweise das Betätigungselement des Schiebers durch eine Kippbewegung in die Arretierstellung gebracht. Bei Paddlebetätigung geschieht dies beispielsweise durch einen separaten Arretierknopf. Um einen möglichst breiten Markt mit der erfindungsgemäßen Lösung zu erreichen, soll sie eingesetzt werden können, ohne dass der Elektrowerkzeughersteller sein Betätigungs- und/oder Arretiersystem ändern muss.
• Da eine im Schalter integrierte Lösung nur schwer auf das externe Betätigungs- und/oder Arretiersystem zugreifen kann, muss der Wiederanlaufschutz im Schalter nach Abfall und Wiederanlegen der Spannungsversorgung den Stromfluss unterbrechen bzw. verhindern, obwohl das äußere Betätigungssystem in der EIN-Stellung arretiert bleibt, und somit auch der Schalterstößel (Betätiger) in der EIN-Stellung verharrt.
• Die übrigen Funktionen des Schalters sollen erhalten bleiben.

For a particularly preferred embodiment is to be determined below. Created is a switch, especially for small angle grinders with integrated restart protection. The following should be ensured for this switch:

• Switch in compact design with indirect actuation for small angle grinders with integrated restart protection. Starting in 2016, the restart protection function will also be required for small angle grinders in accordance with the modified device standard EN 60745-2-3.
• The restart protection prevents a device locked in the ON position from restarting and restarting the power supply unintentionally and / or unattended restarting, resulting in dangerous situations for the user.
• The restart protection function is already implemented today by various separate electronic modules in small angle grinders, in which even more electronic features are integrated, such as overload protection, speed preselection, etc. However, the present invention aims at such devices that do not include electronics today, but in the future also have to meet the standard requirement. Ideally, then only the switch must be replaced, and already the device meets the standard requirement for restart protection.
• The locking is realized in small angle grinders usually on the outer actuator of the device. A distinction is generally between slide and paddle actuation. The present solution should be suitable for both common types of actuation. In slide operation, for example, the actuating element of the slider is brought by a tilting movement in the locked position. In paddle operation, this is done for example by a separate locking button. In order to achieve the widest possible market with the solution according to the invention, it should be able to be used without the power tool manufacturer having to change his actuating and / or locking system.
• Since a solution integrated in the switch is difficult to access the external actuation and / or locking system, the restart protection in the switch must interrupt or prevent the current flow after the power has dropped and re-applied, even though the external actuation system remains locked in the ON position, and thus also the switch plunger (actuator) remains in the ON position.
• The remaining functions of the switch should be retained.

• Ist die Scheibe in der Stellung "gekoppelt", kann durch Betätigung des Stößels normal ein- und/oder ausgeschaltet werden.
• Ist die Scheibe in der Stellung "entkoppelt", kann zwar der Stößel normal betätigt werden, das Schaltstück kommt aber nicht in die EIN-Stellung, es verharrt in der "AUS"-Stellung.
• Wird zunächst "gekoppelt" eingeschaltet und wird dann die Scheibe in die Stellung "entkoppelt" gebracht, springt das Schaltstück in die AUS-Stellung. Eine erneute Kopplung zwischen Stößel und Schaltstück erfolgt nur, wenn beide Teile, und zwar der Stößel und das Schaltstück, sich in der AUS-Stellung befinden und die Scheibe in der Stellung "gekoppelt" ist.

In the case of the switch, the switch's operator is divided into two parts: "plunger" and "contact piece". The plunger transfers the movement of the external actuator of the power tool, namely the paddle or the slider, into the interior of the switch. The contact piece transmits this movement to the mechanical contact system and causes the closing and / or opening of the contacts. Both elements, namely the plunger and the contact piece are urged by compression springs in the OFF position. These two elements are mechanically coupled by a turntable. The turntable has two rotary positions "coupled" and "decoupled". The coupling takes place for example via a corresponding link on the outer wall of the plunger and the inner wall of the disc. In the "coupled" position, the contact piece is taken along by the plunger when the plunger is pressed from the outside into the ON position. In the position "decoupled" the switching piece is not taken from the plunger or, if the switch is in the ON position and then the turntable is brought into the "decoupled" position, the contact moves to the OFF position, while the plunger can remain in the ON position. This means:

• If the disc is "coupled" in the position, can be switched on and / or off normally by pressing the plunger.
• If the disc in the position "decoupled", although the plunger can be operated normally, but the switching piece does not come in the ON position, it remains in the "OFF" position.
• If "coupled" is first switched on and then the disc is brought into the "decoupled" position, the switching element jumps to the OFF position. A renewed coupling between plunger and switching piece takes place only if both parts, namely the plunger and the contact piece, are in the OFF position and the disc is in the "coupled" position.

The articulation of the turntable takes place via an electromagnet. In the event that the solenoid is designed as a solenoid, the solenoid pulls on application of a voltage its armature against the force of a return spring and brings over a mechanical coupling of the armature with the hub this "coupled" in the position. Disconnect the power supply of the solenoid, the armature returns by the force of the armature return spring to its original position, and the disc returns to the position "decoupled" back.

The electromagnet is preferably electrically connected so that it is energized when mains voltage is applied to the mains inputs of the switch, i. as soon as the mains plug of the device is plugged in. Alternatively, this can also be done via an auxiliary contact, which only closes when the switch plunger is moved out of its "OFF" position.

1. a) Stößel und Schaltstück in der AUS-Stellung, danach wird die Scheibe in die Stellung "gekoppelt" gebracht.
2. b) Stößel in EIN-Stellung, Schaltstück in AUS-Stellung sowie Drehscheibe in Stellung "gekoppelt", danach wird der Stößel in die AUS-Stellung gebracht, die Scheibe wird kurz ausgelenkt und schnappt wieder ein.

The coupling between armature and turntable should be provided with an additional spring element for the following reason. When the switch was in the ON position, and by dropping the mains voltage, the disc was placed in the "decoupled" position, the contact has jumped to the OFF position while the plunger has remained in the ON position. Since the contact is in the OFF position, the contacts are open. Now when the voltage is restored, which is the classic restart protection case, the power tool will not start because the main contacts are open. Nevertheless, the electromagnet brings the disc back into the position "coupled". To deactivate the restart protection, the external lock must now be unlocked by pressing the slider or paddle. When the external actuator returns to its "OFF" position, it also allows the switch plunger to return to the OFF position, however, since the turntable is already in the "coupled" position, it is necessary to use the abovementioned spring element and a suitable link between When the plunger is raised, the gate temporarily forces the disc against the spring force into the "decoupled" position and then snaps into the "coupled" position when the end position is reached two ways possible, namely:

1. a) plunger and switching piece in the OFF position, then the disc is brought into the "coupled" position.
2. b) Plunger in ON position, switching piece in OFF position and turntable in position "coupled", then the plunger is brought into the OFF position, the disc is deflected briefly and snaps back on.

Above all, this mechanism described above is necessary in order to allow an electromagnet designed as a lifting magnet to permanently reach the maximum tightening position while energizing in each switching case. In this position, current consumption and heating of the coil are lowest, but the armature force is highest. This condition ensures that the magnet can be optimally designed for 100% duty cycle with minimum size. The minimum size of the magnet is in turn crucial to the size of the switch. The switch size is important because of the limited space available in the power tool.

Instead of a solenoid designed as a solenoid and a holding magnet for the switch can be used. The advantage here is that such a holding magnet has a lower power consumption, that the holding magnet must perform no lifting work, and that the holding magnet has a smaller size. The function of the holding magnet is as follows.

The position "coupled" of the coupling element is held as long as the holding magnet is energized. The required lifting work to bring the coupling element from the position "decoupled" in the position "coupled" is effected by the return spring of the contact piece via an oblique gate between the contact piece and the example formed as a slide transmission element during the turn-off. That is, when the contact moves upwards, by regular off or by decoupling in case of power failure, is stretched over the oblique backdrop of the slide against its return spring. As a result, the coupling element can be rotated by its return spring in the "coupled" position. The return spring of the turntable is now placed differently, but still acts in the direction of "coupled". The yoke of the holding magnet should be pressed by a light spring against the holding magnet, since only the full holding force is unfolded without air gap.

Furthermore, of course, the coupling element can be configured not only as a hub but in different ways. Thus, as a further embodiment of the coupling element, for example, a pivot pin, a rotary lever o. The like. Use find.

In summary, the following can be established for the functional principle of the switch according to the invention.

When voltage is applied to the switch, the armature is held by the electromagnet. As a result, the transmission element designed, for example, as a slide is also held in its position. The coupling element, for example, the hub, the pivot pin, the rotary lever o. The like., Is held coupled by a compression spring in the position. The coupling element is rotatably mounted on the contact piece. The coupling takes place between the coupling element and the example designed as a pusher plunger.

Coupled in the position of the pusher hits a certain area of the coupling element and thereby takes this and the switching piece with. Decoupled in the position of the pusher does not hit this particular area of the coupling element and can not take this with the contact piece.

The decoupling is initiated by the slider. If there is no voltage left on the switch, the electromagnet no longer holds the armature. As a result, the slider is no longer held in position. In this situation, the slider is moved by one or more compression springs. With this movement, the coupling element is rotated decoupled in the position.

The advantages achieved by the invention are, in particular, that the switch meets the requirement of the changed device standard after a restart protection. By integrating the restart protection in the switch nothing or only very little has to be changed on the device design and / or the device wiring. The switch with restart protection according to the invention is against a conventional switch without Restart protection easily replaceable. The device manufacturers can thus use the same device platform for countries in which the restart protection is prescribed and for those in which it is not required. The proposed solution is equally suitable for paddle as well as slide operation of the device. Furthermore, the added value increases compared to a simple switch without restart protection. Compared to a solution with a separate electronic module for restart protection, the wiring and mounting of the device with a switch according to the invention is much easier and less expensive. This eliminates additional lines and / or connections.

• Fig. 1 einen elektrischen Schalter in perspektivischer Ansicht,
• Fig. 2 den kompletten elektrischen Schalter aus Fig. 1 in Draufsicht, wobei der Deckel am Gehäuse entfernt ist,
• Fig. 3 den Schalter wie in Fig. 2 in perspektivischer Ansicht,
• Fig. 4 den Schalter wie in Fig. 3, jedoch von der anderen Seite,
• Fig. 5 das Kontaktsystem des Schalters, wobei das Gehäuse entfernt ist,
• Fig. 6 einen Ausschnitt aus Fig. 5 in perspektivischer Ansicht,
• Fig. 7 den Stößel aus Fig. 6 als Einzelteil in einer Detailansicht,
• Fig. 8 die Drehscheibe aus Fig. 6 als Einzelteil in einer Detailansicht,
• Fig. 9 Teile für die Betätigung des Kontaktsystems mitsamt dem Aktor in perspektivischer Ansicht, wobei das Gehäuse entfernt ist,
• Fig. 10
  bis
• Fig. 20 das Kontaktsystem mitsamt Aktor wie in Fig. 9, jedoch in entsprechend deren Funktionsweise unterschiedlichen Stellungen,
• Fig. 21 ein Elektrogerät mit elektrischem Schalter in einer schematischen Prinzipdarstellung,
• Fig. 22 den kompletten elektrischen Schalter gemäß einer weiteren Ausführung in Draufsicht, wobei der Deckel am Gehäuse entfernt ist,
• Fig. 23
  bis
• Fig. 27 das Kontaktsystem des Schalters aus Fig. 22 mit den zugehörigen Elementen zur Betätigung, jedoch in entsprechend deren Funktionsweise unterschiedlichen Stellungen,
• Fig. 28 den kompletten elektrischen Schalter gemäß einer wiederum weiteren Ausführung in Draufsicht, wobei der Deckel am Gehäuse entfernt ist,
• Fig. 29 das Kontaktsystem des Schalters aus Fig. 28 mit den zugehörigen Elementen zur Betätigung,
• Fig. 30 den kompletten elektrischen Schalter gemäß einer nochmals weiteren Ausführung in Draufsicht, wobei der Deckel am Gehäuse entfernt ist, und
• Fig. 31 das Kontaktsystem des Schalters aus Fig. 30 mit den zugehörigen Elementen zur Betätigung.

An embodiment of the invention with various developments and refinements is shown in the drawings and will be described in more detail below. Show it

• Fig. 1 an electric switch in perspective view,
• Fig. 2 the complete electrical switch off Fig. 1 in plan view, with the lid removed from the housing,
• Fig. 3 the switch as in Fig. 2 in perspective view,
• Fig. 4 the switch as in Fig. 3 but from the other side,
• Fig. 5 the contact system of the switch, with the housing removed,
• Fig. 6 a section from Fig. 5 in perspective view,
• Fig. 7 the plunger off Fig. 6 as a single part in a detailed view,
• Fig. 8 turn the turntable off Fig. 6 as a single part in a detailed view,
• Fig. 9 Parts for the actuation of the contact system together with the actuator in perspective View with the housing removed,
• Fig. 10
  to
• Fig. 20 the contact system including actuator as in Fig. 9 , but according to their mode of operation different positions,
• Fig. 21 an electrical device with electrical switch in a schematic schematic diagram,
• Fig. 22 the complete electrical switch according to another embodiment in plan view, wherein the cover is removed from the housing,
• Fig. 23
  to
• Fig. 27 the contact system of the switch Fig. 22 with the associated elements for actuation, but in accordance with their operation different positions,
• Fig. 28 the complete electrical switch according to yet another embodiment in plan view, wherein the cover is removed from the housing,
• Fig. 29 the contact system of the switch Fig. 28 with the associated elements for actuation,
• Fig. 30 the complete electrical switch according to yet another embodiment in plan view, wherein the cover is removed from the housing, and
• Fig. 31 the contact system of the switch Fig. 30 with the associated elements for actuation.

In Fig. 1 is an electrical switch 1 for a powered by mains voltage power tool to see. The switch 1 has a contact system 6 and serves as an on / off switch for the electric motor 22 of the power tool 21, how to continue the Fig. 21 extracts. At least one electrical connection 4 for supplying the electrical voltage, namely the mains voltage, to the contact system 6 is provided. Furthermore, at least one further electrical connection 5 is provided for discharging the electrical voltage connected by means of the contact system 6, this voltage then being supplied to the electric motor 22. Finally, the switch 1 has a movable actuator 7 for switching the contact system 6.

The actuator 7 is in turn moved by a power tool 21 located on the user by the double arrow 24 movable actuator 23, i. the switch 1 is operated indirectly. In the corresponding actuating position of the actuating element 23, in which the switch 1 is turned on, the actuating element 23 can be locked by the user by means of a locking element 25 located on the electric tool 21. For this purpose, upon appropriate movement according to the pivoting arrow 26, a hook 27 on the locking element 25 engages in a corresponding groove 28 on the actuating element 23. The locked actuator 23 therefore does not need to be held by the user during operation of the power tool 21, which is particularly advantageous in continuous operation of the power tool 21.

However, if the mains voltage fails and then returns again, then the electric motor 22 starts again in an uncontrolled manner when the switch 1 is switched on, which is the case in particular in the case of the locked actuating element 23. It is immediately apparent that this results in a high risk of accidents due to the power tool 21. To avert this danger, the switch 1 is designed such that a restart protection for the electric motor 22 is effected by the switch 1 in these cases.

How the turn Fig. 1 can be seen, the switch 1 has a housing 2, which comprises a cover 3. On the housing 2 are the electrical connections 4 (see Fig. 3 ) for the supply of the mains voltage and the electrical connections 5 for the leads to the electric motor 22. In the housing 2 is in accordance with Fig. 2 . Fig. 3 or Fig. 4 the switchable between an off position and an on position contact system 6 for switching on / off of the power tool 21. From the housing 2 protrudes the movable Actuator 7 for switching the contact system 6 out, how to Fig. 1 extracts. The actuator 7 is sealed on the cover 3 by means of an elastic bellows 8.

How to continue in Fig. 5 sees, the actuator 7 comprises a plunger 9 and a contact piece 10. The contact piece 10 acts to switch to the contact system 6 a. A coupling element 11 is provided such that the plunger 9 can be brought into and / or out of cooperation with the contact piece 10. As a result, the switching of the contact system 6 in at least one position by means of the plunger 9 and the switching of the contact system 6 in at least one position independently of the plunger 9 allows. More specifically, the switching of the contact system 6 in the on and off position by means of the plunger 9 and the switching of the contact system 6 in the off position regardless of the plunger 9 allows. The coupling element 11 consists in a first embodiment according to Fig. 6 from a turntable, which is arranged movably on the contact piece 10, and that is rotatably mounted on the contact piece 10.

In Fig. 5 are a closer view of the contact system 6 with movable switching contacts 12, the plunger 9, which provided with a return spring 13 switching piece 10 and the hub 11 are shown. The fixed contacts of the contact system 6, with which the movable switching contacts 12 interact to make contact, are not shown. The coupling of the plunger 9 and the contact piece 10 by means of the hub 11 is in Fig. 6 shown closer. It is in Fig. 6 in which the compression spring 13 is omitted on the contact piece 10 to see the position "decoupled". The coupling between the plunger 9 and the hub 11 by means of a located on the plunger 9, in Fig. 7 visible backdrop 14 and by means of a arranged on the hub 11, corresponding thereto and in Fig. 8 visible backdrop 15.

Next is according to Fig. 4 an electromagnet 16, which is designed here as a solenoid, provided with a lifting rod 17 as an actuator and a fork element 18 as a transmission element for moving the coupling element 11. The electromagnet 16 is according to Fig. 21 to its power supply also connected to the mains voltage via the terminals 4. The coupling between the solenoid 16 and the hub 11 is in Detail in Fig. 9 to see, wherein the compression spring 19 is tensioned between the contact piece 10 and the hub 11. As a result, in a first position of the coupling element 11 of the plunger 9 in cooperation with the contact piece 10 and in a second position of the coupling member 11 of the plunger 9 in cooperation with the contact piece 10, as will be explained in more detail below.

The sequence of operation of the electrical switch 1 is now closer to the basis of 10 to FIG. 20 shown.

In Fig. 10 is the contact system 6 in the OFF position, wherein the switching contacts 12 are opened. The electromagnet 16 is not energized. The hub 11 is "decoupled" in the position.

In Fig. 11 the switch 1 and the plunger 9 are actuated. The switching contacts 12 of the contact system 6 are open. The electromagnet 16 is not energized. The hub 11 is in the "decoupled" position. The plunger 9 can pass through the hub 11 and the contact piece 10, since the scenes 14, 15 (see FIGS. 7 and 8 ) are aligned with each other. As a result, the plunger 9 does not take this.

In Fig. 12 is the contact system 6 in the OFF position, wherein the switching contacts 12 are opened. The electromagnet 16 is not energized. The hub 11 is "decoupled" in the position.

In Fig. 13 the switching contacts 12 are open. The electromagnet 16 is energized and thus the fork element 18 is tightened. The hub 11 rotates by the force of the compression spring 19 between the contact piece 10 and the hub 11, so that the scenes 14, 15 (see FIGS. 7 and 8 ) are no longer aligned with each other. The hub 11 is thus "coupled" in the position.

In Fig. 14 the switch 1 and the plunger 9 are actuated. The switching contacts 12 are closed. The electromagnet 16 is energized. The hub 11 is in the "coupled" position.

In Fig. 15 the switch 1 and the plunger 9 are actuated. The switching contacts 12 are still closed. The mains voltage at the switch 1 drops, so that therefore the electromagnet 16 is no longer energized. The hub 11 is rotated by the force of the return spring 20 of the electromagnet 16 via the fork element 18 in the "decoupled" position.

In Fig. 16 the switch 1 and the plunger 9 are still actuated. The switching contacts 12 are open. The electromagnet 16 is not energized because the mains voltage has dropped. Now when the mains voltage returns, what happens after plugging in the power plug of the power tool 21 or at the end of the mains voltage failure, what happens in Fig. 17 you can see. The switch 1 and the plunger 9 are actuated and the switching contacts 12 are opened because the contact piece 10 is located in the OFF position. The electromagnet 16 is energized. The turntable 11 is brought into the position "coupled". Upon recurrence of the mains voltage, the solenoid 16 can leave the hub 11 in the "coupled" position, but the switching contacts 12 remain open. The same applies to the situation when the switch 1 of the power tool 21 is locked in the ON position without mains voltage and then the mains voltage returns. For this case, the switch 1 or the plunger 9 must be unlocked in order to turn on the power tool 21 again. The switch 1 and the plunger 9 are according to Fig. 18 , in which an intermediate position is shown, let go. The switching contacts 12 remain open. The electromagnet 16 is energized. The hub 11 is "coupled" from the position by the according to Fig. 7 wedge-shaped backdrop 14 on the plunger 9 and by the according Fig. 8 Correspondingly designed gate 15 on the hub 11 in the direction of "decoupled" rotated.

In Fig. 19 now the switch 1 and the plunger 9 are completely released. In particular, the switch 1 or the plunger 9 is thus not locked. The switching contacts 12 are open. The electromagnet 16 is energized. The turntable 11 has been rotated to the "decoupled" position and can now snap back to the "coupled" position.

In Fig. 20 Finally, the switch 1 and the plunger 9 are completely released. The switching contacts 12 are open. The electromagnet 16 is energized. The hub 11 is snapped back into the position "coupled" by the force of the compression spring 19 between the contact piece 10 and turntable 11. Now the power tool 21 can be turned on again.

In Fig. 22 the electric switch 1 can be seen in a further embodiment, in which a holding magnet serves as an actuator 16. The switch 1 in turn has at least one elastic element 13, which acts on the actuator 7 to its provision in the off position of the contact system 6. How to be especially based on the Fig. 24 sees, this is a force acting on the contact piece 10 compression spring 13. The coupling element 11, which is a turntable, is arranged movably on the contact piece 10, in accordance with Fig. 23 rotatably mounted on the contact piece 10.

In a first position of the coupling element 11, which in Fig. 23 can be seen, the plunger 9 in cooperation with the contact piece 10. It is therefore in the first position to the position "coupled". In a second position of the coupling element 11, which in Fig. 26 can be seen, the plunger 9 is out of cooperation with the contact piece 10. It is in the second position to the position "decoupled". The coupling element 11 is held in the first position by an elastic means 30, for example by a compression spring.

A transmission element 18, which in the present case is designed in the manner of a slide, is provided between the coupling element 11 and the actuator 16 for moving and / or holding the coupling element 11. The transmission element 18 in turn moves by means of an elastic element 31, in this case a compression spring, the coupling element 11 in the second position.

In the case of the actuator 16 provided for moving and / or holding the coupling element 11, in this case, as already mentioned, there is an electromagnet acting as a holding magnet, which is acted on simultaneously with the electrical voltage supplied via the terminals 4 at the switch 1 ( please refer Fig. 21 ). The yoke 32 located at the armature of the holding magnet 16 thus holds the transmission element 18 by means of the yoke 32 when subjected to the electrical voltage. Otherwise, however, in the Embodiment after Fig. 2 in which the electromagnet is a lifting magnet 16 releasing the transmission element 18 when exposed to electrical voltage.

For closer operation of this embodiment of the switch 1 is still on the FIGS. 23 to 27 referenced, in which the housing, the terminals and the fixed contacts are omitted for clarity.

In Fig. 23 the switch 1 can be seen in the OFF position of the contact system 6, while the coupling element 11 is coupled in the position. When power is applied to the switch 1, the holding magnet 16 holds the turntable 11 in position coupled. The switch 1 can then be switched on electrically by means of the plunger 9.

In Fig. 24 and Fig. 25 , in which in addition the movable contact carrier are omitted, the electrical voltage is applied. As a result, the holding magnet 16 is energized, so that it holds the hub 11 coupled in the position. The switch 1 is turned on, with which the plunger 9 has taken over the turntable 11, the contact piece 10.

In Fig. 26 the switch 1 is turned on. The plunger 9 is about the external locking by the locking element 25 (see Fig. 21 ) held in the ON position. If the power fails, the holding magnet 16 releases. The slider 18 is moved via the return spring 31 to the right. As a result, hub 11 is rotated decoupled in the position. From this position, the contact piece 10 is pushed by its return spring 13 upwards in the OFF position. During this upward movement, the slider 18 and the yoke 32 on the holding magnet 16 are pushed back into the holding position via the slotted links 14, 15, which form the coupling region 34 between the rotary disk 11 and the plunger 9. The turntable 11 is coupled back into the position. However, since the contactor 10 is in the OFF position, the contacts of the contact system 6 remain open.

In Fig. 27 the plunger 9 remains in the ON position. But due to the decoupling the contact piece 10 has jumped upwards in the OFF position. The contacts of the contact system 6 are open. The slider 18 is shifted to the left. If now voltage is applied to the switch 1, holding the holding magnet 16 its yoke 32 and thus the slider 18 again. The turntable 11 is coupled in position. However, the coupling with the plunger 9 can take place only when the plunger 9 by unlocking the external locking means of the locking element 25 (see Fig. 21 ) is brought to the OFF position. Then the switch 1 can be turned on again. The coupling region 34 thus causes the coupling element 11 to be moved to the second position upon return of the tappet 9, which is out of cooperation with the contact piece 10.

Yet another embodiment for the electrical switch 1 is in Fig. 28 and Fig. 29 to see. Again, a holding magnet is provided as the actuator 16. However, the coupling element is not designed as a turntable but as a pivot pin 11, in particular in Fig. 29 you can see. Next is in Fig. 29 to see that in addition to the return spring 13 for the contact piece 10, a further return spring 33 is provided on the plunger 9 to its provision. Thus, the two return springs 13, 33 serve overall as an elastic element for returning the actuator 7. In Fig. 29 is the coupling region 34 between the pivot pin 11 and the plunger 9 clearly visible.

Finally, in Fig. 30 and Fig. 31 to see the electrical switch 1 in yet another embodiment. Again, a holding magnet is provided as an actuator 16. The coupling element is designed here as a rotary lever 11 which can cooperate with the plunger 9 by means of the one lever arm with the transmission element configured as a slide 18 and by means of the other lever arm. In Fig. 31 is the coupling region 34 between the rotary lever 11 and the plunger 9 clearly visible.

The invention is not limited to the described and illustrated embodiment. Rather, it also encompasses all expert developments within the scope of the invention defined by the claims. Thus, such an electrical switch 1 not only in power tools, such as angle grinder, for example in all small angle grinders, which in the future must meet the requirement for a restart protection, drills, grinders, saws, planer o. The like., But also in other electrical equipment use. In particular, these may be those electrical appliances that require indirectly actuated switches in conjunction with a lock and / or with a restart protection.

Reference numeral list:

1:

(electrical) switch

2:

casing

3:

Cover (of housing)

4:

(electrical) connection (for the mains voltage)

5:

(electrical) connection (for the electric motor)

6:

Contact system

7:

actuator

8th:

(elastic) bellows

9:

tappet

10:

switching piece

11:

Coupling element / turntable / pivot pin / rotary lever

12:

(movable) switching contact

13:

elastic element / return spring / compression spring (on the contact piece)

14:

Scenery (on the plunger)

15:

Scenery (at the turntable)

16:

Actuator / electromagnet / lifting magnet / holding magnet

17:

Lifting rod (from electromagnet)

18:

Transmission element / fork element / slider

19:

Compression spring (between contact piece and turntable)

20:

Return spring (on the electromagnet)

21:

power tool

22:

electric motor

23:

jig

24:

double arrow

25:

locking

26:

Panning arrow

27:

hook

28:

groove

30:

elastic means (on coupling element)

31:

elastic element (on transmission element) / return spring

32:

Yoke (from holding magnet)

33:

Return spring (on ram)

34:

coupling region

Claims (15)

1. An electrical switch for a power tool, such as for an angle grinder, a drill, a grinder, a saw or a plane, having a contact system (6) switchable between an off position and an on position, and having a mobile actuating member (7) for switching the contact system (6), the actuating member (7) comprising a plunger (9) and a contact piece (10), the contact piece (10) acting on the contact system (6) for switching purposes, and a coupling element (11) being provided, enabling switching of the contact system (6) into the on and off positions by means of the plunger (9) and switching of the contact system (6) into the off position independently of the plunger (9), characterised in that the coupling element (11) is arranged movably on the contact piece (10), and in that an actuator (16) is provided for moving and/or holding the coupling element (11), wherein in a first position of the coupling element (11) the plunger (9) interacts with the contact piece (10) and in a second position of the coupling element (11) the plunger (9) is decoupled from the contact piece (10), enabling switching of the contact system (6) by means of the plunger (9) in the first position and switching of the contact system (6) independently of the plunger (9) in the second position.
2. The electrical switch according to claim 1, characterised in that at least one resilient element (13) acts on the actuating member (7) to reset it to the off position of the contact system (6).
3. The electrical switch according to claim 2, characterised in that the resilient element (13) is a compression spring acting on the contact piece (10).
4. The electrical switch according to claim 1, 2 or 3, characterised in that the coupling element (11) is mounted rotatably on the contact piece (10).
5. The electrical switch according to one of claims 1 to 4, characterised in that the coupling element (11) is held in the first position by a resilient means (30).
6. The electrical switch according to claim 5, characterised in that the resilient means (30) is a compression spring.
7. The electrical switch according to one of claims 1 to 6, characterised in that a transmission element (18) of the slide or fork element type is provided between the coupling element (11) and the actuator (16) for moving and/or holding the coupling element (11).
8. The electrical switch according to claim 7, characterised in that the transmission element (18) moves the coupling element (11) into the second position by means of a resilient element (31).
9. The electrical switch according to one of claims 1 to 8, characterised in that the actuator (16) is an electromagnet.
10. The electrical switch according to claim 9, characterised in that the electromagnet (16) takes the form of a holding magnet retaining the transmission element (18) on application of electrical voltage and/or of a solenoid releasing the transmission element (18) on application of electrical voltage.
11. The electrical switch according to one of claims 1 to 10, characterised in that the coupling element (11) consists of a rotary disc, a rotary pin or a rotary lever.
12. The electrical switch according to one of claims 1 to 11, characterised in that a coupling region (34) is provided in the manner of a slideway (14, 15) on the plunger (9) and/or on the coupling element (11), such that, on resetting of the plunger (9) decoupled from the contact piece (10), the coupling element (11) is moved into the second position.
13. The electrical switch according to one of claims 1 to 12, characterised in that at least one electrical connection (4) is provided for supplying electrical voltage to the contact system (6).
14. The electrical switch according to claim 13, characterised in that the supplied electrical voltage is applied to the electromagnet (16).
15. The electrical switch according to one of claims 1 to 14, characterised in that at least one further electrical connection (5) is provided for dissipating the electrical voltage switched by means of the contact system (6).

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