Electric push button switches are used to switch electrical devices on and/or off and have a contact system in the switch housing for this purpose. By means of a manual actuating element, namely the push button, a switching operation can be effected.

Documents DE 93 05 556 U1 and EP 2 141 717 Al, describe a push button switch where an electrically controlled actuator is used to move the push button from the on position to the off position and to release the electrical contacts from each other. A push button retention device in the form of a sliding piece with actuating member guidance (shaped like a heart) is provided for a push button pin to hold the push button in the switch-on position. However, such controlled switching of the contact system is only possible in the on position. Remotely controlled switching on and closing of the contacts is not possible.

To integrate electrical devices into a global infrastructure (Internet of Things), it is necessary to network devices with each other. For such a system (IOT), it is a prerequisite that a switch can be controlled by an actuator in both switching positions of the actuating element. Such remotely controllable switches are described in documents DE 10 2016 101 016 and DE 10 2016 101 017, but only in the form of rocker switches.

The object of the present invention is to provide a push button switch that can be operated manually and remotely in both switching positions, whereby both switching operations are effected equally, namely with the same switching force and the same switching haptic.

This task is solved with a push button switch with the characteristics of claim 1. Advantageous design solutions describe the subclaims.

A new electric push button switch of a first embodiment has a push button for manual actuation, which is mounted axially movable on the switch housing, and can assume at least two different actuation positions. This push button is under the action of at least one return spring, whose spring force loads the push button in the direction of the switch-off position. A contact system with at least one moving contact and at least one fixed contact is arranged in the housing. From these contacts, electric connections lead out of the housing. The push button is not directly connected to the moving contact. A transmission mechanism is provided for transmitting manual actuation of the push button to the contact element fitted with the movable contact, which on the one hand works with the push button and on the other hand with the contact element in order to close a load circuit in one actuation position of the push button, which corresponds to a switch position, for example the on position, and to interrupt the load circuit in the other actuation position of the push button, which corresponds to the other switch position, namely the off position. Here, switching from one to the other switching position is possible by remote control in addition to the manual operation of the push button as described above. This remotely controlled switching is effected in an inventive manner by means of a bistable electromechanical actuator arranged in the housing of the push button switch and acting on the transmission mechanism. The actuator has an e-shaped magnetic core consisting of two yoke halves, which are fitted with a permanent magnet in the middle.

The transmission mechanism is a pivotable control lever that engages with its driving element in a slot guide arranged on the push button. In one design, for example, such a slot guide is a heart-shaped guide into which a hook-shaped driving element of the control lever is guided. The control lever is also directly or indirectly connected to a contact spring fitted with the moving contact. In a preferred way, the pivoting control lever has two arms. Depending on the pivoting position of the control lever, one arm touches the bistable actuator and forms a closed magnetic circuit through the contact. The permanent magnet generates a permanent magnetic flux and thus provides a self- retaining switching position of the control lever. This switching position can be cancelled by generating a further magnetic field. For this purpose, an excitation winding is arranged on both sides of the actuator. An electromagnetic flux can be generated by energising the excitation windings. The excitation windings are wound in such a way that an electromagnetic flux is generated during this energisation, which is oriented in the opposite direction to the permanent magnetic flux, so that this closed magnetic circuit is extinguished in one half of the yoke and the arm of the control lever is no longer attracted. The magnetic flux always present in the other half of the yoke exerts an attraction on the other arm of the control lever, causing the pivoting control lever to pivot. This is advantageously supported by the contact spring coupled to the control lever, which is designed in such a way that it generates forces in the respective contact position that support the switching.

Instead of this direct coupling, indirect coupling is also possible. The control lever is also connected directly or indirectly to the contact spring.

The heart of the new electric push button switch is the bistable actuator with the two yoke halves and the permanent magnet. In the passive states of the excitation coils, i.e. when these coils are not activated, the permanent magnetic flux holds an arm of the control lever on the actuator and pulls it stably onto the respective yoke. Depending on which arm is held on the actuator, the switch is in the on or off position.

The control lever, on the other hand, acts on the contact spring with the moving contact. In particular, in one embodiment of the invention, it is provided that one arm of the control lever is extended beyond its point of contact with the actuator and is coupled at this end to a transmission element which is connected to the contact spring. In this way, the contact spring with the moving contact is pressed against the fixed contact in one pivoted position of the control lever and pulled away from this fixed contact in the other pivoted position of the control lever. The contact spring is designed in such a way that a spring tongue is exposed as the carrier of the moving contact. By releasing the spring tongue, this contact spring can continue to move even after the contact has closed and generates a so-called overstroke. This generates a suitable contact force when the contact is closed.

To switch the contact system, manual operation by means of the push button switch is possible on the one hand, which, via its active connection with the control lever, causes a pivoting movement of the control lever and thus a switching of the contact system. On the other hand, for remote control of the push button switch, one or both coils are activated depending on the circuitry, whereby the respective closed permanent magnetic circuit is extinguished and at the other yoke a permanent magnetic bypass attracts the arm of the control lever, which means that the control lever is pivoted. After the coil is disconnected from its control voltage, this now fully closed permanent magnetic circuit also causes the attracted control lever to be held and thus the new switching position to be maintained.

The new electric push button switch allows both the integration of an electrical device into an "Internet of Things" system and can be switched remotely. The new electric push button switch can be operated simultaneously in the usual manual manner. Equivalent switching functions are performed both remotely and manually, which provide a pleasant haptic when the push button is pressed manually. This is effected by the equivalent movement behaviour of the bistable actuator during both switching operations, both when switching off and when switching on. In particular, a precise switching point can be generated in both directions of actuation, and sensed during manual actuation. A bistable actuator and its mode of operation is known from the document DE 10 2010 017 874 B4. It depicts a high energy spectrum and high holding forces, so that the entire electric push button switch can be highly miniaturised.

All movable components of the push button switch, namely the push button, control lever, contact spring, are positively coupled to switch the contact system, and movement of one of these components results in movement of the other components. The bistable electromechanical actuator ensures that the system can only assume two defined states.

A new electric switch of a second embodiment comprises a housing, a manual actuating element, and at least two electric contacts in the interior of the housing, wherein the actuating element is movably mounted and configured to have two different actuating positions which correspond to two different switching positions, each electric contact led out of the housing as electric connections, one contact being designed as a fixed contact and the other as a moving contact. The new electric switch further comprises a bistable actuator for remote control is integrated in the housing of the switch, wherein the actuating element interacts directly or indirectly with a control lever or member of the bistable actuator, the actuating element, the control lever or member of the bistable actuator and the movable electric contact are forcibly coupled to one another such that the actuating element can be moved from one switching position to the other in a manually or remotely controlled way.

A new electric switch of a third embodiment comprises a housing, and at least two electric contacts in the interior of the housing, each electric contact led out of the housing as electric connections, one contact being designed as a fixed contact and the other as a moving contact. The new electrical switch comprises an actuating assembly having two different actuating positions which correspond to two different switching positions, and further comprises a bistable actuator for remote control is integrated in the housing of the switch, wherein the actuating assembly interacts directly or indirectly with a control member of the bistable actuator, the actuating assembly, the control member of the bistable actuator and the movable electric contact are forcibly coupled to one another such that the new electric switch can be remotely switched from one switching position to the other.

The invention is explained in the following by means of an example of execution.

Fig. 1 shows a perspective view of the electric push button switch;

Fig. 2 shows a side view of the push button switch without housing in the off position;

Fig. 3 shows a perspective view of the push button switch without housing and rocker;

Fig. 4 shows a side view of the push button switch without housing in the on position;

Fig. 5a-5d shows a perspective view of positions of a control lever and a hook when the push button switch is driven from the on position to the off position.

Fig. 1 shows the electric push button switch 10 with its housing 11. The manual actuating element, namely the push button 20, is mounted on the housing 11 so that it can move axially. This is ensured by a guide slot 21 on the push button 20 and pins 12, 13 on the housing side. Push button 20 has different actuation positions, which will be explained later. Four electric connections 15, 16, 17, 18 protrude from the housing 11. The electric connections 17, 18 are control connections for the bistable actuator 30. The electrical connection 15 is connected to the contact spring 40 via the printed circuit board 19, as can be seen better from Fig. 2, where the push button switch 10 is shown without housing. The contact spring 40 holds the moving contact 41 at the end of a spring tongue 42. The electric connection 16 is connected to the fixed contact 61.

The electric push button switch 10 is shown in Fig. 2 in the off position and can be moved to the on position by manually pressing the push button 20. The push button 20 is not directly connected to the contact spring holding the movable contact 41, but a transmission mechanism is provided to transmit the movement of push button 20. This includes a control lever or member 50, which has a hook 51 as a driving element to interact with the push button 20. For this purpose, push button 20 has a slot guide 23 on bearing body 22. The hook 51 of the control lever 50 engages in this slot guide 23 and is guided when the control lever or member 50 is moved or when the push button 20 is moved. In this design example, the slot guide 23 is designed as a heart curve. In the starting position of push button 20 in Fig. 2 or Fig. 5a, hook 51 is in the lower position of the heart curve of the slot guide 23. If the push button 20 is actuated, namely in this example pressed down, the hook 51 is forced to the right in the heart curve, thus creating a torque on the control lever 50, which causes the control lever 50 to pivot. In this design example, this control lever 50 is pivotably mounted on the bistable actuator 30. The control lever 50 has two arms 53, 54. The extended arm 54 is coupled with a transmission element 52. An angled arm 43 of the contact spring 40 engages in this transmission element 52, so that the operation of the push button 20 causes the control lever 50 to pivot and the contact spring 40 to be lowered. This results in contacting as the moving contact 41 is pressed onto the fixed contact 61. The achieved position of control lever 50 and its hook 51 is shown in Fig. 4 and Fig. 5b. The push button switch 10 is switched on. If button 20 is now briefly released, hook 51 can jump to the maximum right position as shown in Fig. 5c. The push button 20 is moved to its raised initial position by the return springs 14. This allows the push button 20 to be pressed in further. When pressing the push button 20 again, the hook 51 is forced to the left again over the heart curve, shown in Fig. 5d, and the control lever 50 pivots, opening the contact. The push button switch 10 is switched off. When the pressure button 20 is released again, it is moved into its raised initial position by the return springs 14 and the hook 51 jumps to the lower position of the heart curve, shown in Fig. 5a.

The manual switching operation described above can be effected in the same way by remote control, as the control lever 50 is not only actively connected with the push button 20, but also with a bistable electromechanical actuator 30. This actuator 30 is arranged in the housing 11 and has a permanent magnet 32 in the middle between two yoke halves 34, 35 holding a centre leg 36. In this way, an e-shaped magnetic core is created. On both sides of the actuator 30, there is an excitation winding 31. In the passive states, i.e. when the excitation windings 31 are not activated and thus do not generate an additional magnetic field, the permanent magnet 32 holds an arm 53, 54 of the control lever 50. In Fig. 2 this is the arm 53. In the shown left half of the actuator 30, a closed permanent magnetic circuit A is present by touching the arm 53 of the control lever 50, whereby a permanent magnetic flux flows via the permanent magnet 32, the centre leg 36, the yoke 34 and the arm 53. This permanent magnetic flux, fed by the permanent magnet 32, pulls the arm 53 on the actuator 30 steadily onto the yoke 34. In this position of the control lever 50, shown in Fig. 2, the contact spring 40 is pulled upwards via the transmission element 52 and the contact 41 is at a distance from the fixed contact 61. In this manually or remotely controlled switch-off position, the control lever 50 is tilted to the left as shown in Fig. 2.

If a coil 31 is now activated, in this case the excitation winding 31 at the yoke 34, then the magnetic circuit A in the yoke 34 is cancelled, since the magnetic field of the coil 31 is opposed to the magnetic flux A. The magnetic flux A generated by the permanent magnet is displaced from the left parallel circuit into the right parallel circuit B. This exerts a magnetic attraction on the arm 54 of the control lever 50, which causes the control lever 50 to pivot to the right, closing the gap at the yoke 35. If the control voltage is disconnected from the coil 31 at yoke 34, the arm 54 remains at actuator 30. Due to its permanent magnetic field B, the permanent magnet 32 produces a magnetic force that holds the arm 54. This position is shown in Fig.4. With the lowered arm 54, the transmission element 52 is also lowered, which moves the arm 43 of the contact spring 40. By lowering the contact spring 40, a contact between the moving contact 41 and the fixed contact 61 is established. In this manually or remotely controlled switch-on position, control lever 50 in this example is tilted to the right. The push button 20 can be pressed in to open the contact. In the same way, the excitation winding 31 adjacent to the yoke 35 can be excited to cause this switching process by generating a magnetic field.

The moving contact 41 is provided from a contact spring 40, as shown in Figures 2 to 4. The shape of contact spring 40 is best shown in the perspective view of Fig. 3. It is designed in such a way that a spring tongue 42 as the carrier of the moving contact 41 is exposed. One end of the contact spring 40 is connected to the electrical connection 15 via the printed circuit board 19 and is firmly clamped at this end. The other end of the contact spring 40 is angled to an arm 43, which has an engagement end 44 that engages in the transmission element 52. This transmission element 52 is coupled to the control lever 50, so that a pivoting movement of the control lever 50 causes the contact spring 40 to be lowered or raised. Due to the release of the spring tongue 42, when the contact spring 40 is lowered, this contact spring 40 can also move further downwards after the contact has closed and generates a so-called overstroke, see Fig. 4. This generates a suitable contact force when the contact is closed. In the off position, shown in Fig. 2, the end of the spring tongue 42 rests against a stop 33; here too the movement of the contact spring 40 is not blocked. The shown contact spring 40 has the advantage that due to the release of the spring tongue 42, the contact 41 safely contacts the fixed contact 61, even if the end position of the contact spring 40 varies due to manufacturing and assembly tolerances. In addition, undesirable contact bounce is suppressed. It should be noted that the control lever 50 can be substituted for a control member with any other shapes in other embodiments. The contact spring 40 can have several exposed spring tongues 42 with contacts 41, which interact accordingly with several counter contacts 61, i.e. the contact system comprises several pairs of contacts (41, 61). In this way, contact bounce can be additionally minimised and the current carrying capacity or switching capacity can be increased for the same installation space of switch 10.

In addition, a defined spring force can be provided to the bistable actuator 30 in the on position as well as in the off position, so that the start of the switching movement is supported and a faster and safer switching takes place.

With a further version of a push button switch 10, another contact can be provided instead of the previously described stop 33 to form a changeover switch.

The invention is not limited to the design example shown. Push button switches 10 may contain further electronic elements that provide illumination, communication, time control or acoustic signals.

List of reference symbols

10 Push button switch

11 Housing

12, 13 Pin

15 Connection for 4

16 Connection for 61

17, 18 Connection for 3

19 Printed circuit board

20 Push button

21 Slot guide

23 Slot guide, heart curve

30 Bistable actuator

31 Excitation winding, coil

32 Permanent magnet

33 Stop

34, 35 Yoke

36 Centre leg

40 Contact spring

41 Contact

42 Spring tongue

43 Arm

44 Engagement end

50 Control lever

51 Driving element, hook

52 Transmission element, coupler

53, 54 Arm

61 Fixed contact

A, B Magnetic circuit