Electrical contactor comprising a spring for rapidly driving contacts

Abstract

The invention relates to an electrical contactor (10) comprising stationary contacts (12) and movable contacts (14) which are movable relative to the stationary contacts (12) between a position of contact with the stationary contacts and a position of separation from the stationary contacts (12); an actuator (16) for driving the movable contacts (14) to move relative to the stationary contacts (12) towards either the position of contact with the stationary contacts (12) or the position of separation from the stationary contacts (12); a linkage (30) for driving the movable contacts (14) from the contact position to the separation position, independently of the actuator (16); the electrical contact being characterised in that the linkage (30) comprises a drive spring (32) and a system for disengageably locking the linkage.

Description

[0001] DESCRIPTION

[0002] TITLE: ELECTRIC CONTACTOR COMPRISING A FAST CONTACT DRIVE SPRING

[0003] TECHNICAL FIELD

[0004] The invention relates to an electrical contactor comprising an electromagnetic actuator for moving movable contacts towards fixed contacts and a system for quickly driving the movable contacts to quickly open the contactor.

[0005] The invention relates more particularly to an electrical contactor for which the rapid drive system comprises a drive spring.

[0006] STATE OF THE PRIOR ART

[0007] An electrical contactor has moving contacts, fixed contacts and means for driving the moving contacts.

[0008] These drive means include in particular an actuator which is designed to drive the moving contacts towards the fixed contacts to close the contactor, or away from the fixed contacts to open the contactor.

[0009] The contactor can also operate in circuit breaker mode when a short-circuit current occurs.

[0010] When the electrical contact is broken between the fixed contacts and the moving contacts, an electric arc forms between the fixed contacts and the moving contacts.

[0011] In the event of a short-circuit current occurring, the energy of the electric arc is particularly high, which means that the electric arc must be cut off as quickly as possible.

[0012] Thus, the electrical contactor also comprises means for driving the movable contacts allowing for a high contact separation speed, in order to have a rapid breaking of the electric arc. A first embodiment of the rapid speed drive means comprises a pyrotechnic device. An example of such a device is described in document US10388477. This pyrotechnic device comprises a charge which is ignited by a firing device and which acts on a piston driving the movable contacts.

[0013] This solution cannot be tested during product manufacturing.

[0014] A second embodiment comprises a compression spring, which releases the potential energy it stores to drive the moving contacts. Such a loaded spring is arranged in the axis of movement of the moving contacts.

[0015] According to this solution, in order to have a sufficient amplitude of displacement of the moving contacts as well as a sufficient speed, the dimensions of the spring are important in relation to the total dimensions of the electrical contactor, in particular for an electrical contactor which is intended to be mounted in an aircraft.

[0016] The aim of the invention is to propose an electrical contactor comprising means for driving the moving contacts at high speed which do not have the drawbacks presented previously.

[0017] STATEMENT OF THE INVENTION

[0018] The invention provides an electrical contactor comprising fixed contacts and movable contacts which are movable relative to the fixed contacts between a contact position with the fixed contacts and a position remote from the fixed contacts, an actuator for driving the movable contacts to move relative to the fixed contacts to one or other of the contact position with the fixed contacts and the position remote from the fixed contacts, a linkage for driving the movable contacts to move from the contact position to the remote position independently of the actuator, characterized in that the linkage comprises a drive spring and a system for locking the linkage which is disengageable. Preferably, the spring is a tension spring.

[0019] Preferably, the linkage comprises a crank pivotally mounted relative to a fixed axis which is capable of being driven in rotation by the spring and which is capable of driving a connecting rod for driving the movable contacts.

[0020] Preferably, a first end of the spring is connected to a fixed axle and a second end of the spring is connected to a movable end of the crank.

[0021] Preferably, the locking system comprises two articulated connecting rods which are interposed between a fixed axis and the movable end of the crank, and which are capable of locking the crank in motion, against the action of the spring.

[0022] Preferably, the locking system comprises a control lever against which a connecting rod bears when the locking system is in a locking position.

[0023] Preferably, the control lever is capable of being rotated by a pusher to drive the locking system towards a crank unlocking position.

[0024] Preferably, the electrical contactor comprises a beam to which the movable contacts are connected, and the beam is connected to an output shaft of the actuator and to the linkage via a shock blade.

[0025] Preferably, a disengageable connection is interposed between the output shaft and the beam.

[0026] Preferably, the electrical contactor comprises support rods supporting the movable contacts and a spring system interposed between each movable contact the support rod which is associated with the movable contact.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] [Fig. 1] is a schematic representation in front view of an electrical contactor comprising a linkage according to the invention.

[0029] [Fig. 2] is a top view of the electrical contactor shown in Figure 1. [Fig. 3] is a side view of the electrical contactor shown in Figures 1 and 2.

[0030] [Fig. 4] and

[0031] [Fig. 5] are views similar to that of Fig. 3, showing two other states of the linkage.

[0032] [Fig. 6] is a partial section detail showing the disengageable connection between the output shaft and the moving contact support beam.

[0033] DETAILED DESCRIPTION OF THE INVENTION

[0034] The figures show an electrical contactor 10 comprising a pair of fixed contacts 12 and a pair of movable contacts 14. Each fixed contact 12 is connected to a terminal of an electrical circuit.

[0035] The movable contacts 14 are electrically connected to each other and are capable of electrically connecting the fixed contacts 12 to each other to close the electrical circuit.

[0036] The movable contacts 14 are mounted to move in translation relative to the fixed contacts 12 along an axial direction A1 between a disconnection position corresponding to an open configuration of the electrical contactor 10, in which the movable contacts 14 are located at a predefined axial distance relative to the fixed contacts 12 and a connection position corresponding to a closed configuration of the electrical contactor 10, in which the movable contacts 14 are in electrical contact with the fixed contacts 12 and in which the movable contacts connect the fixed contacts 12 to each other.

[0037] The electrical contactor 10 also comprises an actuator 16 for driving the movable contacts 14 in translation along the axial direction A1 between their disconnection position and their connection position.

[0038] The actuator 16 preferably, but not limited to, an electromagnetic actuator comprising an output shaft 18 extending in the axial direction A1 and which is movable in translation along the axial direction A1. The output shaft 18 carries at its free axial end a beam 20 extending perpendicular to the output shaft 18. The free end of the output shaft is connected to a middle of the beam 20. As will be seen later, the connection between the end of the output shaft 18 and the beam 20 is disengageable, that is to say that the connection can be broken.

[0039] The beam 20 has two lateral ends 22, each of which carries a support rod 24 parallel to the axial direction A1.

[0040] The free end of each support rod 24 carries a movable contact 14.

[0041] Here, each movable contact 14 consists of a plate linked at its center to the free end of the support rod 24 associated with it.

[0042] Preferably, a spring system 26 is interposed between each movable contact 14 and the free end of the support rod 24 to exert a force to press the movable contact 14 against the fixed contact associated with it.

[0043] In normal operation, a closing phase of the contactor 10 consists, from a disconnection position of the movable contacts 14, in putting the actuator 16 into operation to cause an output of the output shaft 18.

[0044] The output shaft 18 drives the beam 20, the support rods 24 and consequently the movable contacts 14.

[0045] At an intermediate moment in this closing phase, the movable contacts 14 come into electrical contact with the fixed contacts 12.

[0046] After this intermediate moment, the output shaft 18 continues its axial translation, driving the beam 20 and the support rods 24 further. The assertion spring system 26 is then stressed to allow axial movement of the support rods 24 beyond the position corresponding to the intermediate moment.

[0047] At the end of the closing phase, the output shaft 18 is in an extreme extended position of the actuator 16, the movable contacts 14 are in contact with the fixed contacts 12 and the assertion spring system 26 is stressed, making it possible to maintain the movable contacts 14 in contact with the fixed contacts 12 whatever the operating conditions of the contactor 10. An opening phase of the contactor 10 consists, from the extreme closed position for which the movable contacts 14 are in contact with the fixed contacts 12 and the assertion spring system 26 is stressed, in putting the actuator 16 into operation to cause a retraction of the output shaft 18.

[0048] The output shaft 18 then performs a reverse movement, firstly allowing the assertion spring system 26 to no longer be stressed and then a separation of the movable contacts 14 from the fixed contacts 12.

[0049] The contactor 10 also has an operating mode called circuit breaker which consists, from the extreme closed position, of driving the moving contacts 14 to quickly separate them from the fixed contacts 12.

[0050] This circuit breaker mode is implemented when a short-circuit current flows between the fixed contacts 12 and the moving contacts 14. This short-circuit current has the particularity of having a high intensity compared to normal operating conditions.

[0051] In the presence of this short-circuit current, when the moving contacts 14 separate from the fixed contacts 12, an electric arc is formed. Rapid separation of the contacts 12, 14 makes it possible to quickly cut off the electric arc thus formed.

[0052] To implement this circuit breaker mode, the contactor 10 includes a linkage 30 for driving the movable contacts 14 independently of the actuator 16.

[0053] The linkage 30 comprises a spring 32 storing a quantity of potential energy and a plurality of connecting rods and cranks which are connected and / or articulated to each other and to the spring 32.

[0054] The linkage 30 is further connected to the beam 20 via a shock blade 34 to transmit the potential energy from the spring 32 to the beam 20 and therefore to the movable contacts 14.

[0055] Preferably, the spring 32 is a tension spring whose stiffness and the length by which the spring 32 is extended are predefined to produce a force which will be transmitted by the rest of the linkage 30 and the shock blade 34 to the beam 20 for driving the moving contacts.

[0056] The assembly of connecting rods and cranks is designed to obtain, from the action of the spring 32, a sufficiently high speed of movement of the moving contacts 14.

[0057] As can be seen in Figures 1 and 2, the linkage 30 comprises two support plates 36 between which the spring 32, the connecting rods and the cranks are arranged. The support plates 36 are fixed relative to the actuator 16 and are connected to each other by fixed pins 38.

[0058] Furthermore, preferably, the connecting rods and the cranks are distributed in pairs arranged substantially symmetrically on either side of the spring 32.

[0059] According to another variant embodiment, the linkage 30 is also doubled, that is to say that it comprises two sets of connecting rods and cranks as well as two springs 32, which are distributed on either side of the actuator 16. This doubling of the linkage 30 makes it possible to balance the mechanical forces coming into play in the contactor 10.

[0060] In the following description of the linkage, reference will be made to only one connecting rod or crank of each pair; the description of the other connecting rod or crank will be deduced by similarity.

[0061] As can be seen in more detail in Figure 3, the spring 32 has a first end 40 which is connected to a first fixed axis 38 and a second end 42 which is connected to a first movable axis 44.

[0062] The linkage 30 comprises a first crank 46, a first end 48 of which is articulated relative to the second fixed axis 38 and a second end of which is articulated to the first movable axis 44. The first crank 46 carries a second movable axis 50 located along the first crank 46 between the second fixed axis 38 and the first movable axis 44.

[0063] The linkage 30 comprises a first connecting rod 52, a first end 54 of which is connected to the second movable axis 50, and consequently to the first crank 46, and a second end 56 of which is connected to the shock blade 34 via a third movable axis 58.

[0064] The fixed and movable axes are arranged in the linkage so that when the linkage 30 is in a loaded position, i.e. before operation in circuit breaker mode, the first movable axis 44 is offset relative to a straight line passing through the two fixed axes. Also, in this loaded position of the linkage, the spring 32 is prestressed in tension. The spring 32 exerts on the first movable axis 44 a force driving the first movable axis 44 towards the first fixed axis 38, so that the first movable axis 44 comes into alignment with the two fixed axes 38, which would result in a rotation of the first crank 46 around the second fixed axis 38.

[0065] As a result of this rotation of the first crank 46, the second movable axis 50 also moves, driving the first connecting rod 52, which in turn drives the shock blade 34 towards the actuator 16.

[0066] The fixed axes and the movable axes are also arranged in the linkage 30 to have a reduction in the displacement of the first movable axis 44 relative to the first fixed axis 38 and thus have a significant displacement speed of the third movable axis 58.

[0067] The linkage 30 also includes a system for locking the first crank 46 and the first connecting rod 52 in the loaded position. This locking system can be disengaged to achieve the circuit breaker mode of the contactor 10.

[0068] The locking system comprises a first connecting rod 60, a first end 62 of which is connected to a third fixed axis 64 and a second end 66 of which is connected to a fourth mobile axis 68. The locking system comprises a second connecting rod 70, a first end 72 of which is connected to the fourth mobile axis 68 and a second end 74 of which is connected to the first mobile axis 44.

[0069] When the linkage 30 is in the loaded position shown in Figure 3, the third fixed axis 64 is substantially aligned with the first fixed axis 38 and the first movable axis 44. Also, the fourth movable axis 68 is offset from the straight line passing through the third fixed axis 64 and the first movable axis 44.

[0070] As previously stated, the first movable axis 44 is driven to move towards the first fixed axis 38 by the spring 32. Due to the position of the fourth movable axis 68, the action of the spring also tends to bring the first movable axis 44 closer to the third fixed axis 64. The locking system is maintained in the position just described by the cooperation of a control lever 76 with a stop bar 78 which is fixed to the second link 70.

[0071] The control lever 76 here has the shape of an L, it comprises a first branch 80 of vertical orientation in Figure 3, a free end of which is articulated relative to a support bar 36 around a fourth fixed axis 82 and it comprises a second branch 84 of horizontal orientation in Figure 3, a first end of which is connected to the second end of the first branch 80 and the second end is free and is connected to a pusher 86.

[0072] The control lever 76 further comprises a tab 88 located at the level of the connecting angle of the two branches 80, 84 and the free end of which cooperates with the free end of the stop bar 78.

[0073] The stop bar 78 is connected to the second connecting rod 70 at the level of the first movable axis 44 and it bears against the tongue of the control lever 76 in a direction corresponding to a movement of the first movable axis 44 towards the first fixed axis and the third fixed axis 64.

[0074] Thus, the locking system maintains the first movable axis 44 in its position furthest from the first fixed axis 38 and therefore in a loaded position of the linkage 30.

[0075] When the circuit breaker operating mode of the electrical contactor 10 is triggered, to unlock the first crank 46 and the first connecting rod 52 in order to drive the impact blade 34, the pusher 86 is activated to rotate the control lever 76 around the fourth fixed axis 82. In this rotation of the control lever 76, the tab 88 presses on the free end of the stop bar 78. The circuit breaker operating mode of the electrical contactor 10 will be described subsequently based on Figures 3 to 5.

[0076] In Figure 3, the electrical contactor 10 is shown in the closed position in which the movable contacts 14 are in electrical contact with the fixed contacts. An electric current can then flow through it. The output shaft 18 is in the extreme extended position.

[0077] The linkage 30 is in the loaded position, that is to say that the spring 32 is extended and the locking system is in the locking position of the first movable axis 44.

[0078] In the event of the occurrence of a short-circuit current, the pusher 86 is activated, then driving the control lever 76 in rotation around the fourth fixed axis 82. The control lever 76 in turn drives the second connecting rod 70 by the cooperation of the tongue 88 on the free end of the stop bar 78.

[0079] The second connecting rod 70 is then driven in pivoting so that the fourth movable axis 68 crosses the straight line passing through the third fixed axis 64 and the first movable axis 44. When the fourth movable axis 68 passes to the other side of this straight line, the locking system is then deactivated, thus releasing the first crank 46 and the first connecting rod 52.

[0080] Under the action of the spring 32, the first movable axis 44 is driven in the direction of the first fixed axis 38, the crank 46 pivots around the second fixed axis 38, driving the first connecting rod 52 which in turn drives the beam 20 and the movable contacts.

[0081] In a first intermediate step shown in Figure 4, the fourth movable axis 68 has passed to the other side of the straight line passing through the third fixed axis 64 and the first movable axis 44, that is to say the locking system is deactivated.

[0082] The crank 46 has begun its pivoting about the second fixed axis 38 driving the beam 20. At the intermediate instant shown in Figure 4, the beam 20 has moved a certain distance corresponding to the displacement of the beam 20 and the support rods 24 relative to the movable contacts permitted by the assertion spring systems 26.

[0083] After this intermediate instant, that is to say between the intermediate instant shown in Figure 4 and the instant shown in Figure 5, the electrical contact between the movable contacts 14 and the fixed contacts 12 is broken, an electric arc is formed between the fixed contacts and the movable contacts.

[0084] However, the first crank 46 is still driven in pivoting by the spring 32, thus driving the first connecting rod 52 and the beam 20. Its pivoting speed makes it possible to have a speed of movement of the beam 20, the support rods 24 and the movable contacts 14 thanks to the linkage 30 sufficiently high so that the electric arc is quickly cut.

[0085] At the end of the movement of the beam 20, the support rods 24 and the movable contacts 14, as can be seen in Figure 5, the movable contacts 14 are at a sufficiently large separation distance from the fixed contacts 12, the electrical contactor 10 is fully open.

[0086] When implementing the circuit breaker operating mode of the electrical contactor 10, the actuator 16 is in an activated configuration for which the output shaft 18 is fully extended.

[0087] To allow the beam 20 to move independently of the position of the output shaft 18, a disengageable connection 90 shown in FIG. 6 is interposed between the output shaft 18 and the beam 20. This disengageable connection 90 here consists of a spring-loaded ball connection.

[0088] The output shaft 18 comprises a peripheral groove 92 and the beam 20 comprises two housings 94 oriented radially relative to the output shaft 18 and which open into a central orifice of the beam 20 which is crossed by the output shaft 18. A ball 96 and a thrust spring 98 are arranged in each housing

[0089] 94. Each ball 96 is intended to be partially received in the groove 92 of the output shaft and the thrust spring 98 associated with this ball 96 exerts on the ball 96 a force for holding the ball 96 in the groove 92.

[0090] The depth of the groove 92 as well as the stiffness of the thrust spring 98 are defined to keep the beam 20 stationary relative to the output axis 18 under normal operating conditions of the electrical contactor 10.

[0091] When implementing the circuit breaker operating mode of the electrical contactor 10, the force driving the beam 20 by the linkage 30 causes the balls 96 to exit the groove 92. Once the balls 96 have exited the groove 92, the balls 96 are in contact with the outer cylindrical surface of the output shaft, the resistance to the relative movement of the beam 20 relative to the output shaft 18 is then negligible.

Claims

Claims 1. Electrical contactor (10) comprising fixed contacts (12) and movable contacts (14) which are movable relative to the fixed contacts (12) between a position of contact with the fixed contacts and a position remote from the fixed contacts (12), an actuator (16) for driving the movable contacts (14) in movement relative to the fixed contacts (12) towards one or other of the position of contact with the fixed contacts (12) and the position remote from the fixed contacts (12), a linkage (30) for driving the movable contacts (14) in movement from the contact position towards the remote position independently of the actuator (16), characterized in that the linkage (30) comprises a drive spring (32) and a system for locking the linkage which is disengageable.

2. Electrical contactor according to the preceding claim, characterized in that the spring (32) is a traction spring.

3. Electrical contactor (10) according to claim 1 or 2, characterized in that the linkage comprises a crank (46) pivotally mounted relative to a fixed axis (38) which is capable of being driven in rotation by the spring (32) and which is capable of driving a connecting rod (52) for driving the movable contacts (14).

4. Electrical contactor (10) according to the preceding claim characterized in that a first end of the spring (32) is connected to a fixed axis (38) and a second end of the spring (32) is connected to a movable end of the crank (46).

5. Electrical contactor (10) according to the preceding claim, characterized in that the locking system comprises two articulated connecting rods (60, 70) which are interposed between a fixed axis and the movable end of the crank, and which are capable of locking the crank (46) in movement, against the action of the spring (32).

6. Electrical contactor (10) according to the preceding claim, characterized in that the locking system comprises a control lever (76) against which a connecting rod (70) bears when the locking system is in a locking position.

7. Electrical contactor (10) according to the preceding claim, characterized in that the control lever (76) is capable of being rotated by a pusher (86) to drive the locking system towards a position for unlocking the crank (46).

8. Electrical contactor (10) according to any one of the preceding claims, which comprises a beam (20) to which the movable contacts (14) are connected, characterized in that the beam is connected to an output shaft (18) of the actuator (16) and to the linkage (30) via a shock blade (34).

9. Electrical contactor (10) according to the preceding claim, characterized in that a disengageable connection (90) is interposed between the output shaft (18) and the beam (20).

10. Electrical contactor (10) according to any one of the preceding claims, characterized in that it comprises support rods (24) supporting the movable contacts (14) and a spring system (26) interposed between each movable contact (14) the support rod (24) which is associated with the movable contact (14).

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