CIRCUIT BREAKER WITH MANUALLY CLOSING AND OPENING FUNCTIONALITY AND TRIPPING FUNCTIONALITY

Technical Field

The disclosure relates to a circuit breaker for manually closing and opening a current path by means of an actuation element and having a tripping functionality that allows to operate the circuit breaker in a tripped operation state in which a movable contact is moved in an open state without operating the actuation element. Background

A circuit breaker is an automatically operated electrical switch that is used to protect an electrical circuit from damage caused by the occurrence of a short-circuit or by a large current that is lower than the current in the case of the short-circuit but large enough to damage the electrical circuit. One requirement to the functionality of a circuit breaker is to operate the circuit breaker in a manually operating state that allows to move a movable contact between a closed and an open state. The circuit breaker may comprise an actuation element for example a rotatable knob that allows to switch the circuit breaker between the open and closed state by hand. In the closed state, the movable contact is in electrical contact with a fixed contact of the circuit breaker so that a current path is closed and a current can flow from an input terminal to an output terminal of the circuit breaker. In an open state of the circuit breaker, the movable contact is separated from the fixed contact so that the flow of current between the input and output terminal of the circuit breaker is interrupted.

In the case of a short-circuit in the electrical circuit connected to the circuit breaker, the circuit breaker has to be autonomously switched in a tripped operation state in which the moving contact is electrically isolated from the fixed contact so that the current path between the input and output terminal of the circuit breaker is interrupted. In the tripped operation state of the circuit breaker, it is required that the moving contact is separated from the fixed contact without moving the actuation element.

For this purpose, the circuit breaker usually comprises a solenoid and a solenoid tripping actuator. The solenoid tripping actuator may be configured as an anchor being arranged in the solenoid. A high current flowing through the solenoid excites a magnetic field by which the solenoid tripping actuator is moved out of the solenoid and hits against the moving contact to separate the moving contact from the fixed contact.

It is desirable to provide a circuit breaker with a manually closing and opening functionality and with a tripping functionality, wherein the circuit breaker allows to be switched from the manually operated state to the tripped operation state in an easy and reliable manner and the circuit breaker only comprises a low number of components. Summary

This object is achieved by a circuit breaker as specified in claims 1 and 14. According to the embodiment of the circuit breaker defined in claim 1, the circuit breaker comprises a fixed contact, a compliant element comprising a movable contact, a guiding slot and a guiding element being slidably arranged in the guiding slot. The compliant element is configured to move the movable contact between an open and closed state, wherein, in the open state, the movable contact is isolated from the fixed contact, and, in the closed state, the movable contact is electrically connected to the fixed contact. The guiding element is coupled to the compliant element. The compliant element has a first bending state in which the movable contact is in the open state, when the guiding element is arranged at a first position of the guiding slot. The

compliant element has a second bending state in which the movable contact is in the closed state, when the guiding element is arranged at a second position of the guiding slot being different from the first position of the guiding slot.

According to a possible embodiment of the circuit breaker, the guiding slot may be formed within a casing of the circuit breaker. The first end portion of the compliant element is movably arranged within the guiding slot by means of the guiding element that is coupled to a first end portion of the compliant element. The guiding element is slidably arranged within the guiding slot. The compliant element may be

configured as a compliant bow that is bent, when the guiding element slides in the guiding slot from the first position to the second position. The second end portion of the compliant element is coupled to a revolute joint.

The circuit breaker comprises a first actuation element that is configured to manually move the movable contact between the open and the closed state. The first actuation element is configured as a closing switch to move the movable contact from the open to the closed state. The first actuation element is coupled to the guiding element and thus to the first end portion of the compliant element. In particular, the first actuation element is configured to move the guiding element/the first end portion of the compliant element from the first position of the guiding slot, at which the movable contact is separated from the fixed contact, to the second position of the guiding slot, at which the movable contact is electrically connected to the fixed contact. The first position of the guiding slot may be located at the upper end of a vertical section of the guiding slot. The second position may be located at an end of a horizontal section of the guiding slot. In this configuration, the guiding slot may be configured as an L-shaped slot within the material of the casing of the circuit breaker.

When the first actuator is pressed downwards, it exerts a force to the guiding element. As a result, the first end portion of the compliant element and the guiding element is moved downwards in the vertical section to a third position at which the vertical and the horizontal section of the guiding slot intersect. The guiding element is then moved in the vertical section of the guiding slot towards the third position .

The circuit breaker comprises a second actuation element being configured as an opening switch to move the movable contact from the closed to the open state. The second

actuation element is coupled to a supporting element. The supporting element is arranged at an end of a coupling element that couples the supporting element with the first end portion of the compliant element and the guiding element. The supporting element bears on a spring element. When the second actuation element is moved from a first actuation state to a second actuation state, for example is pressed downwards in the casing, the second actuation elements comes in contact with the supporting element and moves the supporting element. The supporting element moves the coupling element and thus the first end section of the compliant element and the guiding pin in the guiding slot from the second position in the vertical section of the guiding slot to the third position at the interconnection of the vertical and the horizontal section of the guiding slot and from the third position to the first position of the guiding slot at which the movable contact is again

electrically separated from the fixed contact. In order to realize a tripping functionality of the circuit breaker, a solenoid pin may exert a force on the supporting element in the case of a short circuit so that the first end portion of the compliant element and the guiding pin is moved from the second position of the guiding slot to the third position of the guiding slot at which the movable contact is electrically isolated from the fixed contact.

According to another possible embodiment, the circuit breaker may comprise a rotatable element that is rotatably arranged at the casing of the circuit breaker. The guiding slot may be arranged at the rotatable element. The circuit breaker may comprise a latching element to lock the rotatable element in a first rotatable state. In the first rotatable state of the rotatable element the movable contact may be moved between the open and the closed position by an actuation element of the circuit breaker.

In order to operate the circuit breaker in a tripped

operation state the latching element may be actuated by a solenoid pin to unlock the rotatable element so that the rotatable element is freely movable. In the unlocked state of the rotatable element the bending force stored in the

compliant element releases so that the guiding element and thus the first end portion of the compliant element is moved in the guiding slot from the second position at which the movable contact is in a closed state to a position of the guiding slot at which the movable contact is electrically separated from the fixed contact. According to an embodiment of the circuit breaker specified in claim 14, the circuit breaker comprises a fixed contact, and a compliant element comprising a movable contact. The compliant element is configured to move the movable contact between an open and closed state. In the open state, the movable contact is isolated from the fixed contact, and, in the closed state, the movable contact is electrically

connected to the fixed contact. The circuit breaker comprises a rotatable actuation element to move the movable contact from the open state to the closed state. The compliant element has a first end being coupled to the rotatable actuation element and a second end coupled to a revolute joint. In a first rotatable state of the rotatable actuation element, the compliant element has a first bending state, in which the movable contact is in the open state. In a second rotatable state of the rotatable actuation element, the compliant element has a second bending state, in which the movable contact is in the closed state.

The circuit breaker may comprise a latching element to lock the rotatable actuation element at the second rotatable state so that the movable contact is secured in the closed state of the circuit breaker. In the case of the occurrence of a short circuit a solenoid pin may exert a force on the latching element so that the rotatable actuation element is unlocked and the movable contact snaps back by a release of the compliant element to the open state.

The accompanying drawings are included to provide a further understanding and are incorporated in and constitute a part of this specification. The drawings illustrate several embodiments of the circuit breaker, and together with the description serve to explain principles and the operation of the various embodiments.

Brief Description of the Drawings

Figure 1 shows a first embodiment of a circuit breaker in a manually operation state with a movable contact in an open position;

Figure 2 shows the first embodiment of the circuit breaker in a manually operation state with a movable contact in the closed position;

Figure 3 shows the first embodiment of the circuit breaker in a tripped operation state with a movable contact in an open position; Figure 4 shows a second embodiment of a circuit breaker in a manually operation state with a movable contact in an open position;

Figure 5 shows the second embodiment of the circuit breaker in a manually operation state with a movable contact in a closed position;

Figure 6 shows the second embodiment of the circuit breaker in a tripped operation state with a movable contact in an open position; Figure 7 shows a third embodiment of a circuit breaker in an open state; and Figure 8 shows the third embodiment of the circuit breaker in a closed state.

Detailed Description Figures 1 to 3 illustrate a first embodiment of a circuit breaker 1 to realize the manually opening and closing functionality as well as the tripping functionality of the circuit breaker. Figures 1 and 2 illustrate the functionality of the first embodiment of the circuit breaker in the manual operation state in which the circuit breaker may be switched by hand between the open and closed state. Figure 3

illustrates the tripping state of the circuit breaker of the first embodiment in which the circuit breaker is switched in the open state in the case of the occurrence of a short circuit.

The circuit breaker 1 comprises a fixed contact 10 and a compliant element 20 comprising a movable contact 24. The circuit breaker further comprises a guiding slot 30 and a guiding element 40 that is slidably arranged in the guiding slot 30. According to the first embodiment of the circuit breaker shown in Figures 1 to 3, the guiding slot 30 is arranged in a casing 140 of the circuit breaker, for example the guiding slot 30 is provided in a wall of the casing 140. The guiding element 40 is coupled to the compliant element 20. In particular, the guiding element 40 is coupled to a first end portion 21 of the compliant element 20. The guiding element 40 may be configured as a guiding pin that is slidably/movably arranged within the guiding slot 30. A second end portion 22 of the compliant element 20 may be supported at an abutment element 150. The abutment element 150 may be configured as a revolute joint.

The compliant element 20 is configured to move the movable contact 24 between an open and closed state. In the open state shown in Figure 1, the movable contact 24 is isolated from the fixed contact 10. In the closed state shown in

Figure 2, the movable contact 24 is electrically connected to the fixed contact 10.

The compliant element 20 has a first bending state shown in Figure 1 in which the movable contact 24 is in an open state, when the guiding element 40 is arranged at a first position PI of the guiding slot 30. Referring to Figure 2, the

compliant element 20 is shown in a second bending state in which the movable contact 24 is in the closed state, when the guiding element 40 is arranged at a second position P2 of the guiding slot 30 being different from the first position PI of the guiding slot 30.

The guiding slot 30 has a first section 31 and a second section 32 that are directed in different directions. The first section 31 of the guiding slot 30 extends from the first position PI of the guiding slot to a third position P3 of the guiding slot. The second section 32 of the guiding slot extends from the third position P3 to the second

position P2.

According to the first embodiment of the circuit breaker the first section 31 of the guiding slot may be configured as a vertical section, and the second section 32 of the guiding slot may be configured as a horizontal section. In

particular, the guiding slot may be L-shaped, as shown in Figures 1 to 3. In order to manually move the movable contact 24 from the open to the closed state when the circuit breaker is operated in the manual operation state, the circuit breaker 1

comprises a first actuation element 50 that is configured as a closing switch. The first actuation element 50 protrudes out of the casing 140 and is coupled to the compliant element 20 to bend the compliant element from the first bending state (Figure 1) to the second bending state (Figure 2) . In

particular the first actuation element 50 is coupled to the guiding element 40 to move the guiding element 40 in the guiding slot 30 from the first position PI to the second position P2. As a consequence, the compliant element 20 and thus the movable contact 24 is bent towards the fixed contact 10.

The first actuation element 50 may comprise a first portion 51 that may be configured as a knob to be manually pushed by an operator from a first actuation state to a second

actuation state. In the first actuation state of the first actuation element 50, the movable contact 24 is in the open state. In the second actuation state of the first actuation element 50 the movable contact 24 is in the closed state.

The first actuation element 50 comprises a second portion 52, wherein an end section of the second portion 52 of the first actuation element 50 is supported at a spring element 160. The spring element 160 bears on an abutment element 60. The second portion 52 of the first actuation element 50 has a cavity 53. The first actuation element 50 is arranged such that in the first actuation state of the first actuation element 50 in which the movable contact is in the open state, the second portion 52 and, in particular, the cavity 53 extends along the guiding slot 30, as illustrated in Figures 1 and 2. In the first actuation state of the first actuation element 50, the second portion 52 and, in particular, the cavity 53 of the first actuation element 50 is arranged above the guiding slot 30.

The first section 31 of the guiding slot 30 is directed so that the guiding element 40 is vertically moved in the guiding slot 30 from the first position PI to the third position P3 of the guiding slot, when the first actuation element 50 is pressed downwards from the first actuation state to the second actuation state. The second section 32 of the guiding slot 30 is directed so that the guiding element 40 is horizontally moved in the second portion 32 of the guiding slot 30 from the third position P3 of the guiding slot 30 to the second position P2 of the guiding slot, when the guiding element 40 is moved prior to that in the first section 31 from the first position PI to the third position P3.

The guiding slot 30 may be formed such that the guiding element 40 is locked at the second position P2 of the guiding slot 30 so that the compliant element 20 is locked in the second bending state of the compliant element 20 and the movable contact 24 is locked in the closed state.

The circuit breaker 1 further comprises a spring element 70 and a coupling element 80. The spring element 70 bears on an abutment element 60. The coupling element 80 has a first end section 81 coupled to the compliant element 20 by a joint 90. The compliant element 80 further has a second end section 82 coupled to the spring element 70. The spring element 70 is configured to exert a force on the compliant element 20 by means of the coupling element 80 so that the guiding element 40 is moved in the second section 32 of the guiding slot 30 from the third position P3 of the guiding slot 30 to the second position P2 of the guiding slot, when the guiding element 40 is moved prior to that by the first actuation element 50 from the first position PI of the guiding slot 30 to the third position P3 of the guiding slot.

In order to move the movable contact 24 from the closed state shown in Figure 2 to the open state shown in Figure 1, the circuit breaker comprises a second actuation element 100 that is configured as an opening switch. The second actuation element 100 is coupled to the coupling element 80 to move the coupling element 80 in a direction so that the guiding element 40 is moved in the second section 32 of the guiding slot 30 from the second position P2 to the third position P3. In order to open the movable contact 24, the second actuation element 100 is moved from a first actuation state to a second actuation state by pressing the second actuation element 100 downwards. As a consequence, the second actuation element 100 moves/pulls the coupling element 80 towards the spring element 70.

The circuit breaker 1 may comprise a supporting element 130 that is coupled to the coupling element 80 and is arranged between the second end section 82 of the coupling element 80 and the spring element 70. The second end section 82 of the compliant element 80 is coupled to the spring element 70 by the supporting element 130. When the second actuation element 100 is moved from the first actuation state to the second actuation state to open the movable contact 20, the second actuation element 100 exerts a force on the supporting element 130. As a consequence, the coupling element 80 is moved by the supporting element 130 towards the spring element 70, and the guiding element 40 is moved in the second section 32 of the guiding slot 30 from the second position P2 to the third position P3.

The second actuation element 100 has a first end section 101 to be pushed by an operator and a second end section 102 having a slanted surface 103. The supporting element 130 has a slanted surface 131 being in contact with the slanted surface 103 of the second actuation element 100. When the second actuation element 100 is moved from the first

actuation state to the second actuation state, for example is pushed down, the slanted surface 103 of the second end section 102 of the second actuation element 100 slides on the slanted surface 131 of the supporting element 130. As a result, the supporting element 130 pulls the coupling element 80 in a direction to the left so that the guiding element 40 is moved in the second section 32 of the guiding slot 30 from the second position P2 to the third position P3. In particular, the supporting element 130 is moved by the second actuation element 100 towards the spring element 70 and pushes the guiding element 40 in the second section 32 of the guiding slot from the second position P2 to the third position P3. As shown in Figure 2, the coupling element 80 is arranged and moved in a direction parallel to the second section 32 of the guiding slot 30.

When the guiding element 40 is moved in the guiding slot 30 from the second position P2 to the third position P3, the bending force stored in the compliant element 20 effects that the compliant element 20 releases and the guiding element 40 is moved in the first section 31 of the guiding slot 30 from the third position P3 to the first position PI of the guiding slot 30 so that the movable contact 24 returns in the open state shown in Figure 1.

The functioning of the first embodiment of the circuit breaker 1 in the manual operation state can be summarized as follows . In order to manually switch the circuit breaker 1 from the open to the closed state, a vertical force is applied on the first actuation element 50 against the spring element 160. The guiding element 40 is moved by the first actuation element 50 within the guiding slot 30 in the vertical downward direction. As a consequence, the compliant element 20 bends which in turn translates the movable contact 24 towards the fixed contact 10 until the contact is closed. The spring element 70 always tries to keep the joint 90/guiding element 40 within the horizontal arm 32 of the guiding slot 30 at the second position P2, i.e. in the extreme left position. This spring force along with the compliance of the mechanism provides the necessary contact force. The guiding element 40 may be held at the second position P2 by some latching mechanism. Figure 2 shows the mechanism in the closed position.

In order to manually open the movable contact 24, a vertical force is applied on the second actuation element 100 so that the guiding element 40/the joint 90 is pushed from the second position P2 to the third position P3 against the spring force of the spring element 70 until the guiding element 40 comes to the third position P3 in the extreme right position of the horizontal arm 32 of the guiding slot 30. The guiding element 40 then freely moves upwards in the vertical arm 31 of the guiding slot 30 unloading the compliant element 20, which in turn opens the movable contact 24 by a snapping action. The spring element 160 will bring back the first actuation element 50 to its original position once the contacts are open.

In order to operate the circuit breaker 1 of the first embodiment in the tripped operation state, the circuit breaker 1 comprises a solenoid 110 and a solenoid pin 120. The solenoid pin 120 is arranged so that in the case of a short circuit, an electromagnetic field is generated in the solenoid 110 that moves the solenoid pin 120 towards the supporting element 130. As a consequence, the coupling element 80 moves in a direction that causes the guiding element 40 to be moved in the second section 32 of the guiding slot 30 from the second position P2 to the third position P3.

Figure 3 shows the circuit breaker 1 in the tripped

configuration when the guiding element 40 is moved by the tripping force applied to the supporting element 30 from the second position P2 to the third position P3 in the horizontal arm 32 of the guiding slot 30. The guiding element 40 then moves freely upwards in the vertical arm 31 of the guiding slot unloading the compliant element 20 which opens the contacts by a snapping action. Thus irrespective of the first and the second actuation elements 50 and 100, the contacts 10, 24 will open when the tripping force is applied. The spring element 160 will bring back the first actuation element 50 to its original position once the contacts are open .

Figures 4 to 6 show a second embodiment of the circuit breaker 2 to realize the manual opening and closing

functionality and to realize a tripping operation of the circuit breaker. The circuit breaker 2 comprises a fixed contact 10 and a compliant element 20 comprising a movable contact 24. The circuit breaker 2 further comprises a guiding slot 30 and a guiding element 40 being slidably arranged in the guiding slot 30. The compliant element 20 is configured to move the movable contact 24 between an open and closed state. The guiding element 40 is coupled to the compliant element 20 at a first end portion 21 of the compliant element 20. A second end portion 22 of the compliant element is coupled to an abutment element 150 that may be configured as a revolute joint.

The guiding element 40 may be configured as a guiding pin that is slidably or movably arranged within the guiding slot 30. The guiding element 40 is fixed to the first end portion 21 of the compliant element 20. An opposite second end portion 22 of the compliant element 20 may be supported at an abutment element 150. The abutment element 150 may be

configured as a revolute joint.

The compliant element 20 has a first bending state shown in Figure 4 in which the movable contact 24 is in the open state, when the guiding element 40 is arranged at a first position PI of the guiding slot 30. The compliant element 20 has a second bending state shown in Figure 5 in which the movable contact 24 is in the closed state when the guiding element 40 is arranged at a second position P2 of the guiding slot 30. The compliant element 20 may be configured as a compliant bow.

The circuit breaker 2 comprises a rotatable element 170 being rotatably arranged at the casing 140. The rotatable element 170 may be configured as a rotating disk. The guiding slot 30 is arranged within the rotatable element 170. The guiding slot 30 has a first section 31 and a second section 32 that are directed in different directions. The first section 31 of the guiding slot 30 extends from the first position PI of the guiding slot 30 to a third position P3 of the guiding slot 30. The second section 32 of the guiding slot 30 extends from the third position P3 of the guiding slot to the second position P2 of the guiding slot. The first and the second sections 31, 32 of the guiding slot may be orthogonally arranged and intersect at the third position P3. The guiding slot 30 may be formed such that the guiding element 40 is locked at the second position P2 of the guiding slot 30 so that the compliant element 20 is locked in the second bending state of the compliant element 20 and the movable contact 24 is locked in the closed state.

The circuit breaker 2 comprises an actuation element 180 to move the movable contact 24 from the open state to the closed state. The circuit breaker 2 further comprises a coupling element 80 having a first end section 81 coupled to the compliant element 50 by a joint 90 and having a second section 82 coupled to the actuation element 180. The

actuation element 180 may be configured as a push button having a first end section 181 to apply a force by an operator to the actuation element 180 to close the movable contact 24. A second end section 182 of the actuation element 180 rests on a spring element 200.

The actuation element 180 is configured to exert a force on the compliant element 20 by the coupling element 80 so that the compliant element 20 is bent from the first bending state shown in Figure 4 to the second bending state shown in Figure 5, when the actuation element 180 is moved from a first actuation state in which the movable contact 24 is in the open state to a second actuation state in which the movable contact is in the closed state. When pushing the actuation element 180 from the first actuation state to the second actuation state, the guiding element 40 is moved in the guiding slot 30 from the first position PI (Figure 4) to the second position P2 (Figure 5) .

The circuit breaker 2 comprises a latching element 190 to lock the rotatable element 170 in a first rotatable state so that the guiding slot 30 is firmly positioned. In the first rotatable state of the rotatable element 170, the actuation element 180 is configured to manually move the movable contact 24 between the open and closed state by means of the actuation element 180. The rotatable element 170 is locked during the manual operating state of the circuit breaker when the guiding pin 40 is moved from the first position PI to the second position P2 of the guiding slot 30.

Referring to Figure 4 showing the mechanism of the circuit breaker 2 in an open position, a force is applied in the negative "x" direction on the actuation element 180 that pushes the guiding element 40 in the guiding slot 30 from the first position PI to the second position P2. As the guiding element 40 is moved in the guiding slot 30, the compliant element 20 gets translated in the negative "x" direction as well as getting bent. Thus, the movable contact 24 is electrically connected to the fixed contact 10. The actuation element 180 may be arrested in this position with some spring mechanism. Slot angled orientation helps in arresting the mechanism in a closed position. The latching element 190 is in the latched condition during the manual operating state of the circuit breaker. The latching element 190 along with the compliance of the mechanism provides necessary contact force in the closed state of the movable contact 24.

Figure 5 shows the mechanism in the closed state. When the actuation element 180 is released, it pulls the coupling element 80 in the positive "x" direction. This pulling force along with the compliance of the mechanism results in

opening of the contacts. The angled orientation of the guiding slot 40 helps in contact opening. The latching element 190 is in the latched condition during the manual opening of the movable contact 24.

In order to realize the tripping functionality the circuit breaker 2 comprises a solenoid 110 and a solenoid pin 120. The solenoid pin 120 is arranged so that, in the case of a short circuit, an electromagnetic field is generated in the solenoid 110 that move the solenoid pin 120 towards the latching element 190. The latching element 190 releases the rotatable element 170 so that the fixed state of the

rotatable element 170 is changed in an unlocked state in which the rotatable element is freely rotatable.

The rotatable element 170 is configured to move in a stable rotatable state, when the rotatable element 170 is unlocked during the tripping operation. To this purpose, the rotatable element 170 may be configured as a spring loaded device. As shown in Figure 6, the rotatable element rotates in the anticlockwise direction, when the latching element 190 releases the locking element 171 of the rotatable element 170. The rotational movement of the rotatable element 170 is stopped when the locking element 171 abuts on a connecting link/abutment 210. In the stable rotatable state of the rotatable element 170, the guiding slot 30 is positioned such that the bending force stored in the compliant element 20 effects that the compliant element 20 releases and the guiding element 40 is moved in the second section 32 of the guiding slot 30 from the second position P2 to the third position P3 so that the movable contact 20 is moved in the open state, as shown in Figure 6.

During the tripped operation state, the tripping force from the solenoid pin 120 is applied on the latching element 190 which unlatches the mechanism allowing the rotatable element 170 to rotate in the anticlockwise direction. The rotatable element stops until the locking element 171 abuts on the connecting link/abutment 210. During the rotation of the rotatable element 170 the guiding element 40 moves in the guiding slot from the position P2 to the position P3 which results in span opening of the contacts. The compliant element 20 bends as the guiding element 40 moves in the guiding slot 30, making sure that the contacts will open irrespective of the actuation state of the actuation element 180. Figures 7 and 8 show a third embodiment of a circuit breaker 3 to realize an opening and closing functionality in a manual operation state and a tripping operation state, when a short circuit occurs. The circuit breaker 3 comprises a fixed contact 10 and a compliant element 20 comprising a movable contact 24. The compliant element 20 is configured to move the movable contact 24 between an open and closed state. In the open state, the movable contact 24 is isolated from the fixed contact 10, and in the closed state the movable contact 24 is electrically connected to the fixed contact 10.

The circuit breaker 3 further comprises a rotatable actuation element 220 to move the movable contact 24 from the open state to the closed state. The compliant element 20 has a first end 21 being coupled to the rotatable actuation element 220 and a second end 22 coupled to a revolute joint 150. The revolute joint 150 is attached to the ground/casing of the circuit breaker.

The proposed mechanism makes use of the compliant element being configured as a flexible bow-like structure to store energy as well as to transfer motion of the movable contact 24. In a first rotatable state of the rotatable actuation element 220 shown in Figure 7, the compliant element 20 has a first bending state, in which the movable contact 24 is in the open state. In a second rotatable state of the rotatable actuation element 200 shown in Figure 8, the compliant element 20 has a second bending state, in which the movable contact 24 is in the closed state. In order to move the movable contact 24 in the closed state, the actuation element 220 is rotated in the anticlockwise direction. The contact is established and also the mechanism is latched.

To realize the latching action, the circuit breaker 2 comprises a latching element 230 being configured to lock the rotatable actuation element 220, when the rotatable actuation element 220 is manually moved by means of the rotatable actuation element 220 in the second rotatable state, as shown in Figure 8.

The rotatable actuation element 220 comprises a locking element 221. The latching element 230 is configured to engage in the locking element 221 so that the rotatable actuation element 220 is locked in the second rotatable state in which the movable contact 24 is electrically connected to the fixed contact 10. The latching element 230 is configured as a spring-loaded latching element comprising a pre-loaded torsional spring 233. In order to realize the tripping functionality, the circuit breaker 3 comprises a solenoid 110 and a solenoid tripping actuator 120. The latching element 230 has a first section 231 to engage in the locking element 221 and a second section 232. The solenoid tripping actuator 120 is arranged so that, in the case of a short circuit, an electromagnetic field is generated in the solenoid 110 that moves the solenoid

tripping actuator 120 towards the second section 232 of the latching element 230. As a result, the first section 231 of the latching element 230 disengages from the locking element 221. The rotatable actuation element 220 is unlocked and the bending force stored in the compliant element 20 effects that the compliant element 20 releases and the movable contact 24 is moved in the open/tripped state. List of Reference Signs

1, 2, 3 embodiments of a circuit breaker

10 fixed contact

20 compliant element

30 guiding slot

40 guiding element

50 first actuation element

60 abutment element

70 spring element

80 coupling element

90 j oint

100 second actuation element

110 solenoid

120 solenoid tripping actuator

130 supporting element

140 casing

150 revolute joint

160 spring element

170 rotatable element

180 actuation element

190 latching element

200 spring element

210 connecting link

220 rotatable actuation element

230 latching element