The present invention relates to a device for detecting the three states, “On”, “Off” and “Trip” of an electric circuit breaker.
Through document U.S. Pat. No. 4,969,063, a device for detecting and signalling the three states “On”, “Off” and “Trip” of an electric circuit breaker is known. This device comprises a three-position switch mechanically coupled with the member for actuating the circuit breaker. The three-position switch is materialized by three electric tracks each allocated to one of the positions of the actuation member and interacting with a moveable electric contact secured to the actuation member. Depending on the position of the actuation member, the switch switches on a first LED of a first colour, a second LED of a second colour or both LEDs at the same time to mix their colours.
This type of device operates by mechanical contact between the actuation member and the electric tracks. These tracks may become worn gradually with the switchings of the actuation member, eventually affecting the quality of the electric connections. Also, if, in one of its positions, the actuation member has some clearance, the electric connection between the moveable contact and the corresponding magnetic track may be deficient.
The object of the invention is to propose a device for detecting the three states of a circuit breaker that is reliable, precise, requires little space and whose electric connections do not risk wear that is too premature.
This object is achieved by a device for detecting the three states of an electric circuit breaker, characterized in that it comprises:
According to a particular feature, the magnetic device is mechanically coupled to an actuation member of the circuit breaker capable of taking three positions corresponding to the three states of the circuit breaker.
According to a first variant embodiment of the invention, the magnetic device is actuated in translation.
According to one particular feature, the magnetic device comprises a symmetrical part made of ferromagnetic material. In a first configuration, the ferromagnetic part has for example two U-shaped branches and the permanent magnet is mounted symmetrically on the ferromagnetic part, between the two branches. In a second configuration, the ferromagnetic part may also have three branches in order to form an E, a permanent magnet occupying each one of the two hollows formed by the three branches of the ferromagnetic part.
According to a second variant embodiment, the magnetic device is actuated in rotation. The permanent magnet of the magnetic device is for example mounted on a frame actuated pivotingly by a rail mechanically coupled to the actuation member.
According to the invention, the moveable element is for example a ferromagnetic membrane capable of pivoting under the magnetic effect.
According to the invention, the detection device comprises a signalling device responsible for indicating each of the three states of the circuit breaker depending on the position of the microswitches. The signalling device is for example mounted on the casing of the circuit breaker or is remote relative to the circuit breaker.
The invention also relates to an electric circuit breaker comprising a detection device as defined above and a system for monitoring a plurality of circuit breakers of this type. The monitoring system comprises for example a communication bus to which the circuit breaker detection devices are connected. This communication bus is connected to a central terminal responsible for processing and centralizing the signals received and displaying the state of each of the circuit breakers connected to the bus according to these signals. The display may be produced on an illuminated board or on a screen of the terminal.
Other features and advantages will appear in the following detailed description with reference to an embodiment given as an example and represented by the appended drawings in which:
The detection device according to the invention is designed to be installed in a three-position electric circuit breaker 1. In a known manner, a circuit breaker 1 comprises a casing 10 on which is mounted an actuation member consisting for example of an operating device 11 that pivots or rotates. In
The operating device 11 may be set in motion between three positions, an “On” (M) position, an “Off” (A) position and a “Trip” (D) position situated halfway between the “On” (M) position and the “Off” (A) position. The movement of the operating device from the “On” (M) position to the “Trip” (D) position is carried out automatically when an electric fault such as a short circuit is detected. In each of the three positions (M, A, D) of the operating device 11, the circuit breaker is therefore respectively in the “On”, “Off” or “Trip” position.
The detection device comprises at least two adjacent microswitches 2a, 2b (both referenced 2) mounted on an electric signalling circuit C and designed to detect the state of the circuit breaker 1.
Each of these microswitches 2a, 2b may be switched by an actuator between two positions, an open position (
According to the invention, between their two positions, these microswitches 2a, 2b are controlled by magnetic effect. Each of these microswitches 2a, 2b is sensitive to the orientation of the field lines L of a magnetic field generated by a magnetic actuator. This type of microswitch 2 is for example manufactured in MEMS (for “Micro-Electro-Mechanical System”) technology.
An exemplary configuration of a microswitch 2 sensitive to the orientation of the field lines L is represented in
A microswitch 2 sensitive to the orientation of the field lines L comprises a deformable ferromagnetic moveable membrane 20 that is able to be actuated in rotation about an axis of rotation (R) by the magnetic actuator. The membrane 20 is for example made of iron-nickel.
The membrane 20 has a longitudinal axis (A) and is connected, at one of its ends, by means of connecting arms 22a, 22b, to one or more anchoring blocks 23 secured to a substrate 3. The membrane 20 is capable of pivoting relative to the substrate 3 on its axis (R) of rotation perpendicular to its longitudinal axis (A). The connecting arms 22a, 22b form an elastic connection between the membrane 20 and the anchoring block 23 and are flexed when the membrane 20 pivots. The two microswitches 2a, 2b are for example made on one and the same substrate 3.
At its distal end relative to its axis of rotation, the membrane 20 supports a moveable contact 21. By pivoting, the membrane 20 may take at least two determined positions, an open position (
One of the methods of actuating the membrane 20 consists in applying a magnetic field created by a permanent magnet 4. The ferromagnetic membrane 20 moves between its two positions aligning itself on the field lines L of the magnetic field generated by the permanent magnet 4. With reference to
This principle of actuation is employed in the detection device according to the invention.
The detection device comprises a plate 5 that can move in translation, for example made of plastic, mechanically coupled to the operating device 11 and capable of taking three positions corresponding to the three states of the circuit breaker 1. With reference to
The moveable plate 5 supports a magnetic device 40, 41 with one or two permanent magnets, designed to actuate the microswitches 2a, 2b between their two positions.
On its top face, the magnetic device 40 has successively a first end ferromagnetic portion, a first magnetic portion consisting of the first permanent magnet 400, a second central ferromagnetic portion, a second magnetic portion consisting of the second permanent magnet 401 and a third end ferromagnetic portion. The arrangement of the permanent magnets 400, 401 in the ferromagnetic part 402 makes it possible to confine the field lines of the magnetic fields generated by the two permanent magnets 400, 401 around the magnetic device 40 (
On its top face, the magnetic device 41 according to this second embodiment has successively a first end ferromagnetic portion, a hollow, a central magnetic portion consisting of the permanent magnet 410, a second hollow and a second end ferromagnetic portion.
According to the invention, the microswitches 2a, 2b enclosed in a casing 24 are mounted on a printed circuit 25 fixed opposite the moveable plate 5 (
The microswitches 2a, 2b are positioned so that their axes of rotation (R) are parallel to the plane of translation of the moveable plate 5 and perpendicular to the direction of translation of the moveable plate 5.
In a first configuration, the moveable plate 5 supports the magnetic device 40 with two permanent magnets 400, 401.
In this first configuration, the two microswitches 2a, 2b are for example oriented in the same direction.
In the bottom position of the moveable plate 5 (
In the top position of the moveable plate 5 (
In the middle position of the moveable plate 5 (
In a second configuration, the moveable plate 5 supports the magnetic device 41 with a single permanent magnet 410. In this configuration, the two microswitches 2a, 2b are for example oriented in a different direction, for example back-to-back along their axis of rotation (R).
In the bottom position of the moveable plate 5 (
In the top position of the moveable plate 5 (
In the middle position of the moveable plate 5, the two microswitches 2a, 2b are positioned symmetrically on either side of the axis of symmetry of the magnetic device 41 so that their membranes 20 are each aligned in the two different directions of the field lines of the permanent magnet 410. The two back-to-back microswitches 2a, 2b are therefore in an open position.
In the two configurations, the two microswitches 2a, 2b are controlled to form, in each position of the plate 5, a different open and/or closed combination of their membranes 20 and therefore generate on each occasion a different signal representative of the position of the moveable plate 5 and therefore of the position of the operating device 11 and of the state of the circuit breaker 1.
According to a variant embodiment, the magnetic device consists of a single permanent magnet 43 mounted fixedly on a frame 60 actuated in rotation about an axis by a rail 61 mechanically coupled with the operating device 11 directly or indirectly by means of a mechanism interacting on the one hand with the operating device 11 and on the other hand with a trigger (not shown). In a known manner, this rail 61 can be moved in translation to take three positions: an “On” position, an “Off” position and a “Trip” position, depending on the state of the mechanism, in order to represent respectively the “On” state of the circuit breaker, its “Off” state and its “Trip” state. This type of device is described more fully in patents FR 2 834 379 and FR 2 827 703.
In this variant, the magnetic device is not actuated in translation but in rotation about an axis. A combination of a translation and rotary movement of the magnetic device may also be envisaged.
In rotation, the permanent magnet 43 subjects the two microswitches 2a, 2b, for example enclosed in their casing 24, to a magnetic field having field lines L of different orientations in order to force them into their open or closed position.
With reference to
In
In
Depending on the state of the two microswitches 2a, 2b, a different signal may be transmitted by a signalling device 7 (
The signalling device represented in
This electric circuit C comprises for example four branches C1, C2, C3, C4 in parallel. Two branches C1, C2 are each controlled by one of the microswitches 2a, 2b. A diode D1, D2 is mounted in series with each of the microswitches, one being oriented on-state and the other off-state. The other two parallel branches C3, C4 of the circuit C each support an LED (for “Light Emitting Diode”) L1, L2, one being oriented on-state and the other off-state.
When the first microswitch 2a is closed and the second microswitch 2b is open, the first LED L1 is on and the second LED L2 is off. This combination corresponds for example to the “Off” state of the circuit breaker 1.
When the first microswitch 2a is open and the second microswitch 2b is closed, the first LED L1 is off and the second LED L2 is on. This combination corresponds for example to the “On” state of the circuit breaker 1.
When both microswitches 2a, 2b are open, both LEDs L1, L2 are on. This combination corresponds for example to the “Trip” state of the circuit breaker 1.
According to the invention, based on the two microswitches 2a, 2b, the issue therefore is to draw up a truth table representing the states of each of the microswitches 2a, 2b depending on the position of the moveable plate 5 and the state resulting from the LEDs of the signalling device. This truth table differs depending on the initial configuration of the microswitches 2a, 2b.
The signalling device 7 may be remote and may be incorporated into a monitoring system designed to monitor the state of several circuit breakers mounted on one and the same board or dispersed in different locations. Advantageously, in this system, the electric signals obtained at the output of the detection device of a circuit breaker 1 are for example sent to a communication bus connected for example to a central computer terminal responsible for processing the signals received and displaying the states of all the circuit breakers thus connected to the bus. The display may be achieved by means of an illuminated board with LEDs or the screen of the terminal.
According to the invention, it is possible to detect more than three mechanical states by employing more than two microswitches arranged in an appropriate manner.
It is well understood that, depending on the position of the magnetic device, the states of the microswitches are dependent on their orientation, on the geometry of the permanent magnet(s) employed or the method of actuating the magnetic device. The various combinations obtained, described above, are not limiting and other configurations may be envisaged.
It is well understood that it is possible, without departing from the context of the invention, to imagine other variants and enhancements of detail and even to envisage the use of equivalent means.
Number | Date | Country | Kind |
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06/51970 | May 2006 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP07/54675 | 5/15/2007 | WO | 00 | 12/24/2008 |