Electrical contact system for an auxiliary contactor block

Abstract

The invention relates to an electrical contact system (101) for an auxiliary contactor block (103). The system (101) comprises a stationary contact (105), a movable contact plate (107) and an actuator (109) for driving the movable contact plate (107) into a closed position or an open position. The movable contact plate (107) comprises, at one end, two separate contact plates (107a, 107b) which each comprise a movable contact (107aa, 107ba). Each movable contact (107aa, 107ba) has a planar section, in a plane parallel to a longitudinal axis in which extends the movable contact plate (107), which planar section is substantially U-shaped. During the tilting of the movable contact plate (107) from the open position to the closed position, and vice-versa, the point of contact between each movable contact (107aa, 107ba) and the first stationary contact (105) moves on the surface (105a) of the first stationary contact (105).

Description

[0001]Description TITLE: ELECTRICAL CONTACT SYSTEM FOR A CONTACTOR AUXILIARY BLOCK TECHNICAL FIELD The invention relates to the field of electrical contactors and relays. It concerns in particular an electrical contact system for a contactor auxiliary block. PRIOR TECHNIQUE The prior art includes, in particular, documents WO-A1-2024005842, EP-A1-0977220, DE202018103787U and US-B2-9275815. A contactor is a switching device that includes a moving part displaced by a mechanical actuator to allow or prevent the flow of an electric current. To provide information about the contactor's state (closed or open) to other devices or to control other actuators,An auxiliary block can be mechanically linked to the moving part of the mechanical actuator that supports the power contacts. The mechanical link is then ensured by an auxiliary blade attached to the moving part of the actuator, which drives a beam (i.e., the moving part of an auxiliary block), which in turn drives flexible blades on which the contacts are mounted. The main source of failure in these contactors is the appearance of discontinuity faults in the contacts of the auxiliary blocks. These discontinuity faults are due to the presence of insulating particles between the contacts. These insulating particles can originate from external pollution (for a fault early in the contactor's life) or from natural mechanical wear of the parts near the electrical contact (for a fault at the end of the contactor's life). Currently, there are,Solutions using bifurcated contacts in the construction of contactors exist; however, none of these solutions prevents the creation of a discontinuity fault at a contact. SUMMARY OF THE INVENTION The present invention proposes a solution to these drawbacks. Thus, an objective of the invention is to provide an electrical contact system that reduces the risk of failure by exhibiting both a self-cleaning capability and an arrangement that allows for doubling its contact means. To this end, the invention, according to a first aspect, relates to an electrical contact system for an auxiliary contactor block, said system comprising a first fixed contact, a movable blade having two movable contacts,said movable blade being movable relative to said first fixed contact between a closed position in which the two movable contacts are in contact with said first fixed contact and an open position in which the two movable contacts are separated from said first fixed contact, and an actuator for driving the movable blade towards one or the other of the closed and open positions, said system being characterized in that the movable blade comprises, at one end, two separate blades, each comprising one of the two movable contacts, each movable contact having a plane cross-section, along a plane parallel to a longitudinal axis of the movable blade, having substantially a U-shape, the lower end of which forms a point of contact with the first fixed contact when the movable blade is in the closed position, and, the system is configured so that, during the tilting of the movable blade, from the open position to the closed position, and vice versa,The point of contact between each moving contact and the first fixed contact moves on the surface of said first fixed contact, in that the default position of the moving blade is the open position and the actuator is configured to cause the moving blade to tilt into the closed position by pressure on said moving blade, and in that the moving blade is configured to deform elastically under the pressure of the actuator, and the tilting of said moving blade into the closed position causes each moving contact to rotate about itself by pressing on said moving contact. The system according to the invention may include one or more of the following features, taken individually or in combination with each other: - the shape of each moving contact is invariant with respect to the direction transverse to the longitudinal axis of the moving blade. - the moving blade has a thickness between 0.05 mm and 0.15 mm. - The system further includes a second contact in contact with the other end of the moving blade. - The two blades are separated by a slot, extending along the axis, with a length less than one-third of the length of the moving blade. - The slot has a width between 0.1 mm and 0.5 mm. - The moving blade is made of a metal alloy, preferably a copper / beryllium base alloy or a copper / zinc base alloy. - The moving contacts have, at the point of contact with the first fixed contact, a surface treatment of the gold and / or silver type. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood with the aid of the following description,given solely by way of example and made with reference to the accompanying drawings in which: Figure 1 is a side view of an auxiliary contactor block according to an embodiment of the invention; Figure 2 is a side view of an auxiliary contactor block according to an embodiment of the invention; Figure 3 is a schematic representation of an electrical contact system for an auxiliary contactor block according to an embodiment of the invention; Figure 4 is a schematic representation of an electrical contact system for an auxiliary contactor block according to an embodiment of the invention; Figure 5 is a top view of a moving blade of an electrical contact system for an auxiliary contactor block according to an embodiment of the invention; and,Figure 6 is an isometric view of a moving blade of an electrical contact system for a contactor auxiliary block according to one embodiment of the invention. DESCRIPTION OF EMBODIMENTS With reference to Figures 1 to 6, we will now describe embodiments of an electrical contact system 101 for a contactor auxiliary block according to the invention. The system 101 comprises a fixed contact 105, a moving blade 107 extending longitudinally along an X-axis (and substantially in the shape of an elongated ribbon), and an actuator 109. As can be seen in particular in Figures 5 and 6, the moving blade 107 has, at one end, two separate blades 107a and 107b, each comprising a moving contact, 107aa and 107ba respectively. Furthermore, in the embodiments shown in Figures 5 and 6, the two blades 107a and 107b are separated by a slot 111,which extends along the X-axis and whose length is less than one-third of the length of the moving blade 107. Furthermore, the slot 111 can have, for example, a width between 0.1 mm and 0.5 mm. In all cases, a person skilled in the art will be able to adapt the dimensions of the slot to guarantee the independence of the moving contacts 107aa and 107ba while exhibiting the desired mechanical properties (stress, elasticity, etc.). Advantageously,The blade's split design ensures electrical contact is maintained even if one of the moving contacts is faulty. The moving blade 107 is movable relative to the fixed contact 105 between a closed position, in which both moving contacts 107aa and 107ba are in contact with the fixed contact 105, and an open position, in which both moving contacts 107aa and 107ba are separated from the fixed contact 105. The actuator 109 drives the moving blade 107 to either the closed or open position. Furthermore, as illustrated in particular by Figures 1 and 2, which show an auxiliary contactor block 103 comprising a system 101 according to the invention, the actuator 109 can be, for example, a beam of the auxiliary block 103. In this case, the beam can itself be driven by a moving part of another contactor actuator. In addition to the elements described above,In the non-limiting examples shown in Figures 1, 2, and 5, the system 101 includes a second fixed contact 113 that is in contact with the other end (i.e., the end without the two separate blades 107a and 107b) of the movable blade 107. Thus, when the movable blade 107 is in the closed position, an electrical contact is established between the first fixed contact 105 and the second fixed contact 113, via the movable blade 107. In all embodiments of the invention, the two movable contacts 101aa and 101ba have a planar cross-section, respectively along a plane P1 and a plane P2, which are parallel to an axis X extending longitudinally along the movable blade 107, and which is substantially U-shaped. In other words, each movable contact has a shape such that its cross-section in a plane parallel to the X-axis is substantially U-shaped. In different embodiments, the U-shape may correspond, for example,to the shape of a parabola or to the shape of an arc of a circle. In all cases, the lower end (in the curved area of ​​the U) forms a point of contact with the fixed contact 105 when the movable blade 107 is in the closed position. The term "lower" is defined here with respect to the U and therefore refers to the end of the U located opposite the terminations of the two arms of the U. Thus, as shown in particular in Figures 1 and 2, when the movable blade 107 is in the closed position, this lower end of the U for each movable contact 107aa and 107ba is in contact with the surface 105a of the first fixed contact 105 at an area called the point of contact (shown in particular by the arrow 115 in Figures 3 and 4). Furthermore, in the embodiments shown in the figures, the shape of each movable contact 107aa and 107ba is invariant (in translation) along the direction transverse to the X-axis with longitudinal extent of the movable blade 107. In other words,For each moving contact 107aa and 107ba, regardless of the position of the section planes P1 and P2 parallel to the X-axis, the section has essentially a U-shape. Finally, the system 101 is configured so that, during the tilting of the moving blade 107 from the open position to the closed position, and vice versa, the point of contact between each moving contact 107aa and 107ba and the first fixed contact 105 moves to the surface 105a of the fixed contact 105. Figure 3 illustrates in more detail the steps of the tilting of the moving blade 107 from the open position to the closed position. In this non-limiting example, the default position of the movable blade 107 is the open position (in the upper part of the figure), and the actuator 109 is configured to cause the movable blade 107 to tilt to the closed position by applying pressure to the movable blade 107. The vertical arrows 117 show the direction of movement of the actuator 109 and, consequently,the direction of the force exerted on the moving blade 107 by the actuator 109. In this example, the moving blade 107 is configured to deform elastically under the pressure of the actuator 109 (i.e., the force exerted by the actuator 109 on the moving blade 107), and the tilting of the moving blade 107 into the closed position causes each moving contact 107aa and 107ba to rotate about its own axis by bearing on the surface 105a of the first fixed contact 105 and by deformation of the moving blade 107. In other words, Figure 3 shows the elastic deformation of the blade at rest (without pressure exerted by the actuator) and during operation (with pressure exerted by the actuator), and this deformation allows the establishment of a contact pressure force necessary for good electrical contact. In other words,The movable blade 107 is flexible and exhibits elasticity, allowing it to return to its initial shape and default position as soon as the actuator no longer exerts pressure on it (i.e., at rest). Furthermore, under pressure from the actuator 109 (for example, at a flat area of ​​the movable blade 107 (at rest) and distant from the movable contacts 107aa and 107ab), the movable blade 107 deforms until the lower end of the U formed by the movable contacts 107aa and 107ba comes into contact with the surface 105a of the first contact 105 at the point of contact. Furthermore, in the example shown, the actuator 109 performs an overtravel such that the moving blade 107 continues to deform after the moving contacts 107aa and 107ba have come into contact with the first fixed contact 105. The deformation of the moving blade 107, under the effect of the pressure from the actuator 109,and the bearing of movable contacts 107aa and 107ba on the surface 105a of the first fixed contact 105, causes the contact point to move (slide) on the surface 105a of the first fixed contact 105 by rotation (around an axis orthogonal to the X-axis) of the movable contacts 107aa and 107ba about themselves. The rotation is made possible by the curvature of the movable contacts 107aa and 107bb at the point of contact (i.e., the lower end of the U) due to their U-shaped cross-section. In the example shown in Figure 3,The contact point shown by arrow 115 moves from right to left on the surface 105a of the first fixed contact 105 as pressure is applied to the moving blade 107 by the actuator 109. Conversely, during the tilting (not shown) of the moving blade 107 from the closed position to the open position when pressure is released by the actuator 109 (and under the effect of the elasticity of the moving blade 107), the contact point moves from left to right on the surface 105a of the first fixed contact 105. Figure 4 illustrates in more detail how this movement of the moving contacts 107aa and 107bb allows for the removal of dust 119 positioned at the contact point and potentially preventing electrical contact. The flexibility and elasticity of the movable blade 107 can be related, for example, to its dimensions and / or the material from which it is made. In a particular embodiment,The moving blade has a thickness between 0.05 mm and 0.15 mm. In another particular embodiment of the invention, the moving blade 107 is made of a metal alloy, preferably a copper / beryllium alloy or a copper / zinc alloy. Advantageously, these materials offer good mechanical strength, fatigue resistance, conductivity, and corrosion resistance. Finally, in yet another particular embodiment, the moving contacts 107aa and 107ba have, at the point of contact with the first fixed contact 105, a gold and / or silver plating surface treatment. Advantageously, this type of coating makes it possible to create contacts suitable for both low and high electrical currents.

Claims

CLAIMS 1. An electrical contact system (101) for an auxiliary contactor block (103), said system (101) comprising a first fixed contact (105), a movable blade (107) having two movable contacts (107aa, 107ba), said movable blade (107) being movable relative to said first fixed contact (105) between a closed position in which the two movable contacts (107aa, 107ba) are in contact with said first fixed contact (105) and an open position in which the two movable contacts (107aa, 107ba) are separated from said first fixed contact (105), and an actuator (109) for driving the movable blade (107) to either the closed or open position, said system (101) being characterized in that the movable blade (107) has, at one end, two separate blades (107a, 107b) having each one of the two moving contacts (107aa, 107ba), each moving contact (107aa, 107ba) has a planar section, along a plane (P1,P2) parallel to an axis (X) of longitudinal extent of the movable blade (107), having substantially a U-shape, the lower end of which forms a point of contact with the first fixed contact (105) when the movable blade (107) is in the closed position, and, the system (101) is configured such that, during the tilting of the movable blade (107) from the open position to the closed position, and vice versa, the point of contact between each movable contact (107aa, 107ba) and the first fixed contact (105) moves on the surface (105a) of said first fixed contact (105), in that the default position of the movable blade (107) is the open position and the actuator (109) is configured to cause the movable blade (107) to tilt into the closed position by pressure on said movable blade (107), and in that the movable blade (107) is configured to deform elastically under the pressure of the actuator (109),and the tilting of said movable blade (107) into the closed position causes each movable contact (107aa, 107ba) to rotate about itself by pressing said movable contact (107aa, 107ba) on the, surface (105a) of the first fixed contact (105) and by deformation of said movable blade (107).

2. System (101) according to claim 1, wherein the shape of each movable contact (107aa, 107ba) is invariant along the transverse direction to the longitudinal extent axis (X) of the movable blade (107).

3. System (101) according to claim 1 or claim 2, wherein the movable blade (107) has a thickness between 0.05 mm and 0.15 mm.

4. System (101) according to any one of the preceding claims, further comprising a second fixed contact (113) in contact with the other end of the movable blade (107).

5. System (101) according to any one of the preceding claims, wherein the two blades (107a, 107b) are separated by a slot (111) extending along the axis (X), with a length less than one-third of the length of the movable blade (107).

6. System (101) according to claim 5, wherein the slot (111) has a width between 0.1 mm and 0.5 mm. 7.System (101) according to any one of the preceding claims, wherein the movable blade (107) is made of a metal alloy, preferably a copper / beryllium base alloy or a copper / zinc base alloy.

8. System (101) according to any one of the preceding claims, wherein the movable contacts (107aa, 107ba) have, at the point of contact with the first fixed contact (105), a gold and / or silver plating surface treatment.

Images