DEVICE FOR INTERRUPTING AN ELECTRIC CURVE

Description

[0001] The present invention relates to a device for cutting off an electric current.

[0002] The invention relates in particular to the field of electrical switching devices intended to interrupt an electric current, such as circuit breakers or switches.

[0003] Separable contact switching devices include an energy-storing switching mechanism which has the function of moving the electrical contacts of the device between an open state and a closed state, for example in response to an action of a trigger or a user.

[0004] An example of such a mechanism is described in FR-2 985 600-B1.

[0005] For example, a movable, pivoting electrical contact is moved by a switching shaft mechanically coupled to a release hook via a linkage system. To close the contacts, a mechanical energy accumulator comprising one or more springs is actuated to set the linkage system in motion.

[0006] The switching mechanism is therefore subjected to numerous mechanical stresses, such as internal shocks, during each opening and closing of the contacts.

[0007] Such mechanisms have long been satisfactory. However, in some contemporary applications, the increase in electrical power associated with switching devices, as well as regulatory requirements, requires increasing the capacity of mechanical energy accumulators in order to increase the closing speed of contacts, which puts more stress on the switching mechanism and reduces the number of permissible opening and closing cycles during the product's lifetime.

[0008] To reduce stress on the switching mechanism, it is known to dampen or cushion the commutator shaft using a device external to the switching mechanism. For example, DE-10 2006 012125-B3 describes such an external device, using damped stops. However, such a solution results in additional bulk and has a limited effect on increasing the service life of the switching mechanisms.

[0009] It is also known to reinforce mechanical parts, notably by increasing their respective thicknesses, but such a solution reinforces inertial effects, which limits the actual benefits obtained in terms of lifespan.

[0010] It is desirable to have switching mechanisms with improved durability, for example to increase the number of permissible opening and closing cycles during the product's lifetime.

[0011] There is therefore a need for an electrical current interruption device whose switching mechanism has improved reliability, without resorting to adding parts outside the mechanism.

[0012] To this end, the invention relates to an electric current interruption device comprising separable fixed and movable electrical contacts and a mechanism for switching the contacts between a closed and an open state. The mechanism comprises: A switching shaft coupled to a movable electrical contact; a trip hook pivotally mounted on a fixed support of the mechanism and comprising a bore in which a stop is housed; and a linkage system coupling the switching shaft to the trip hook. The linkage system comprises a hinged connecting rod, which is rotationally linked to the trip hook and which includes a main bearing surface that bears against the stop when the switching mechanism is in the closed state. According to the invention, the stop is configured to deform elastically when the switching mechanism transitions from the open to the closed state and the connecting rod exerts a force on the stop, so as to dampen the impact of the connecting rod on the stop.

[0013] Thanks to the invention, the thrust bearing is elastically deformable and absorbs the kinetic energy of the connecting rod, thus extending the mechanism's lifespan. This effect is achieved without adding any external parts to the mechanism, which is advantageous in terms of size and cost.

[0014] Advantageously, elastomer damping elements, located at the thrust bearing, dampen the connecting rod before it rests on the thrust bearing, which further improves the absorption of kinetic energy each time the mechanism passes from the open state to the closed state.

[0015] According to advantageous but not mandatory aspects of the invention, such a support may incorporate one or more of the following features in any technically permissible combination: the stop is made of high-elasticity steel; the stop is made of a hardened steel grade 420-545 HV or of a stainless steel grade 1.4310; the stop includes a spiral pin; the stop is held in the bore of the release hook by elastic return of the stop; the switching device includes elastically deformable damping elements, the damping elements being in a relaxed configuration when the switching mechanism is in the open state, while, when the switching mechanism is in the closed state, secondary bearing surfaces of the connecting rod are bearing on respective bearing portions of the damping elements and the damping elements are in a deformed configuration;the damping elements are each located at a respective end of the stop and each includes a retaining orifice on the stop, each damping element also including a passage light, so that in the closed state of the cutting device, the main bearing surface of the connecting rod is in direct contact with the stop; each damping element includes a front portion and a rear portion, the front and rear portions being located on either side of the passage light and being configured so that, when the tripping mechanism passes from the open state to the closed state, they come into contact with the secondary bearing surfaces of the connecting rod before the main bearing surface of the connecting rod is in direct contact with the stop;the damping elements include deformable cavities formed within the front portion, the cavities being open when the damping elements are in the relaxed configuration, while when the cutting device is in the closed state, the cavities are closed; the damping elements are configured such that the cavities of the front portion each have a respective thickness measured parallel to a mean support direction, the sum of the thicknesses being between 30% and 70% of a dimension of the front portion measured parallel to the mean support direction, preferably between 40% and 60%, the mean support direction being defined by the direction of the contact force between the connecting rod and the front portion as the cutting device moves from the open state to the closed state;the shock-absorbing elements are made of an elastomer material having a Shore A hardness between 50° and 90°, preferably between 60° and 80°, preferably still substantially equal to 70°;The switching mechanism comprises two spacers, which are integral with the release hook and are each located at the level of a respective damping element, each spacer having support faces configured to cooperate by complementary shape with the lower faces of the damping elements, the lower faces being located opposite the front and rear portions along the mean support direction of the connecting rod, so that, in deformed configuration, the damping elements are deformed in compression, and the front portions of the damping elements partially protrude from the support faces, so that when the switching device is in the closed state, the front portion of each damping element also includes a zone of deformation in tension.

[0016] The invention will be better understood, and other advantages thereof will become more apparent, in the light of the following description of an embodiment of an electric current-interrupting device conforming to its principle, given solely by way of example and with reference to the accompanying drawings, in which: [ Fig 1 ] there figure 1 schematically illustrates a switching device with separable contacts, shown in cross-section along a median plane, comprising a switching mechanism with a connecting rod according to the invention, the mechanism and the connecting rod being shown in a simplified manner in a first configuration; Fig 2 ] there figure 2 is a partially exploded perspective view of the connecting rod assembly of the figure 1 , the crankshaft being in a second configuration; Fig 3 ] there figure 3 is a perspective view of certain parts of the connecting rod assembly of the figure 2 in assembled configuration, observed along arrow III of the figure 2 , And [ Fig 4 ] there figure 4 is a cross-sectional view, along a cutting plane parallel to the median plane, of the connecting rod assembly of the figure 2 shown assembled in a third configuration.

[0017] There figure 1 represents a part of an electrical switching device 2 for interrupting an electric current, such as a circuit breaker or contactor. The interruption of the electric current is achieved in air and by means of separable electrical contacts.

[0018] According to examples, device 2 is a low-voltage, high-current, multi-pole circuit breaker.

[0019] Device 2 includes a fixed electrical contact 4 and a movable pole 6 which, in some examples, carries pivotally mounted contact fingers 8 arranged opposite the fixed contact 4. The contacts 4 and 8 are connected to opposite electrical connection terminals of device 2.

[0020] The movable pole 6 is reversibly movable, for example by pivoting relative to a fixed frame of the device 2, between an open position and a closed position of the contacts, corresponding respectively to an electrically open state and an electrically closed state of the device 2. The axis of rotation of the movable pole 6 is here noted by the reference X6.

[0021] Device 2 also includes a switching mechanism 10 adapted to switch contacts 4 and 8 between the open and closed state by moving the movable pole 6 between the open and closed positions.

[0022] The contact finger 8, carried by the moving pole 6, is by extension a moving electrical contact, which is movable in rotation relative to the frame of the device 2 around the axis of rotation X6, in particular during the switching movements of the device 2 between the electrically open and closed states.

[0023] For convenience, we define a median plane P1 as a plane orthogonal to the X6 axis. The median plane P1 is also the plane of the image of the figure 1 . In the illustrated embodiments, the pivoting and rotation movements of the elements of the mechanism 10 take place around axes of rotation which are fixed relative to the frame and which extend parallel to each other, here in directions perpendicular to the plane P1.

[0024] For example, the mechanism 10 can be controlled by means of a trigger 12 of the device 2 and / or by a manual control device, such as a lever or a push button.

[0025] In some embodiments, device 2 is a multipole device adapted for interrupting a polyphase electric current. Device 2 then comprises several poles, each of which is associated with an electrical phase and has a pair of contacts 4 and 8. In non-limiting examples, device 2 has three, four, six, or eight poles.

[0026] Depending on the implementation, the mechanism 10 is a mechanical energy storage switching mechanism. The operating principle of a switching mechanism using this technology is described, for example, in FR-2 985 600-B1.

[0027] The mechanism 10 includes in particular a switching shaft 20 coupled to the moving pole 6, here by means of a crank 24 and a connecting rod 25. The shaft 20 is mobile in rotation around its longitudinal axis relative to a fixed frame, or fixed support, of the switching device 2. In other words, the switching shaft 20 is coupled to the contact finger 8, which is a movable contact.

[0028] In the case where the device 2 has several poles, the shaft 20 is common to all the poles and is mechanically coupled with each moving pole 6.

[0029] The mechanism 10 also includes a release hook 40 and a linkage system 22 coupling the switching shaft to the release hook.

[0030] For example, the linkage system 22 is articulated by a pivot link with an arm of the crank 24 carried by the shaft 20, as described below.

[0031] The mechanism 10 also includes an opening ratchet 26 associated with a lock 28, also called a "half-moon".

[0032] The opening ratchet 26 is mounted pivotally relative to the frame and cooperates with the release hook 40. A spring 29 is hooked between, on the one hand, the shaft 20 and, on the other hand, an axis fixed to the frame of the device 2.

[0033] A locking latch 30, also called a "half-moon" latch, and an intermediate lever 31 cooperate mechanically with an actuator driven by the trigger 12, such as an electromechanical coil actuator, and / or with the manual control member. On the figure 1 The association between the trigger and the lever 31 is schematically represented by rods, although in practice this mechanical cooperation can be achieved in a completely different way.

[0034] The lock 30 is also mechanically associated with a closing ratchet 32 ​​mounted pivotally relative to the frame.

[0035] The mechanism 10 further includes a mechanical energy storage device 34, comprising at least one spring. For example, the device 34 stores mechanical energy when the spring is compressed and releases this mechanical energy when the spring is released.

[0036] A drive mechanism 36, comprising one or more articulated and / or pivotally mounted connecting parts relative to the fixed frame, is mechanically coupled to the device 34. The drive mechanism 36 acts on the connecting system 22 to strike it and move it to a closed position. As it moves, the connecting system 22 in turn drives the release hook 40.

[0037] In the illustrated example, the trigger hook 40 also has an opening 46 for receiving a pivot connection with the frame and is articulated by a pivot connection with the linking system 22.

[0038] The linking system 22 and the hook 40 are also shown in more detail on the figure 2 .

[0039] The linkage system 22 comprises a first pair of connecting rods 42 and a second pair of connecting rods 44 articulated with each other and on which are formed the pivot links of articulation with the trigger hook 40 and the shaft 20. The two pairs of connecting rods 42 and 44 together form an articulated "crankshaft" 45.

[0040] In the illustrated example, the trigger hook 40 also has an orifice 46, used to receive a pivot connection with the frame, and a stop 48, housed in a bore of the hook 40 and protruding here on either side of the hook 40. For example, the trigger hook 40 has an essentially flat shape, parallel to the median plane P1.

[0041] In accordance with embodiments, as will be understood from reading the examples given below, the stop 48 is more generally configured to deform elastically when the switching mechanism 10 passes from the open state to the closed state and the connecting rod 45 exerts a force on the stop, so as to dampen the shock of the connecting rod 45 on the stop 48.

[0042] The first pair 42 of connecting rods comprises two similar or identical connecting rods 50 and 52 arranged parallel to each other. In some examples, the connecting rods 50 and 52 have a flat shape.

[0043] The connecting rods 50 and 52 are, on a first end, here a lower end, each mounted pivotally on the release hook 40, and more precisely, on a distal end 54 of the release hook 40.

[0044] This pivot joint is formed here by means of a rigid axis 56, such as a trunnion, which extends perpendicularly to the connecting rods 50 and 52. The reference X56 designates the axis of rotation associated with this pivot joint. The axis X56 is parallel to the axis X6.

[0045] According to examples, the linkage system 22 also includes a ring 58 mounted between the connecting rods 50 and 52 on a spacer 59 which secures the connecting rods 50 and 52 to each other. The spacer 59 extends parallel to the axis X56.

[0046] For example, the spacer 59 and the ring 58 are struck by the drive mechanism 36 when energy is released by the device 34.

[0047] The second pair 44 of connecting rods comprises two similar or identical connecting rods 60 and 62 arranged parallel to each other. In some examples, connecting rods 60 and 62 have a flat shape.

[0048] According to optional but nevertheless advantageous embodiments, each of the second connecting rods 60 and 62 has a curved arc shape, which reduces bulk, improves the distribution of mechanical stresses and increases the mechanical endurance of the system 22.

[0049] The connecting rods 60 and 62 are, on a first end, here an upper end, adapted to be mounted pivotally on the shaft 20, and more precisely, on an arm of the crank 24, here in an orifice formed in this arm of the crank 24.

[0050] This pivot joint is formed by means of a rigid shaft 64, which extends perpendicularly to the connecting rods 60 and 62, preferably projecting beyond the outer lateral faces of the connecting rods 60 and 62. The reference numeral X64 designates the axis of rotation associated with this pivot joint. The axis X64 is parallel to the axis X56. The rigid shaft 64 is located on the first end of the connecting rods 60 and 62.

[0051] According to examples, the rigid shaft 64 is mounted and linked in translation with the connecting rods 60 and 62. In other words, the rigid shaft 64 is mobile in rotation, but remains immobile in translation relative to the connecting rods 60 and 62.

[0052] The connecting rods 60 and 62 forming the second pair of connecting rods 44 are kept apart from each other along the direction X64 so as to allow the passage of one end 66 of the release hook 40 between the connecting rods 60 and 62.

[0053] This end 66 has a V-shaped hooking portion 67, which cooperates with the opening ratchet 26, for example by bearing against a stop linked to an axis 27 of the opening ratchet 26 in the closed position.

[0054] The connecting rods 50 and 52 are connected with the connecting rods 60 and 62 by means of a single pivot axis 68 which forms a pivot joint between the connecting rods 50 and 52 of the first pair 42 and the connecting rods 60 and 62 of the second pair 44. The reference X68 designates a line giving the axis of rotation associated with this pivot joint.

[0055] The articulation axis 68 extends along this axis X68, which is referred to as the "X68 direction" hereafter to avoid confusion with the articulation axis 68.

[0056] In the examples, connecting rods 60 and 62 are positioned on either side of connecting rods 50 and 52 and are in contact with them along part of their length. Connecting rod 50 is adjacent to connecting rod 60, and connecting rod 52 is adjacent to connecting rod 62.

[0057] The pivot joint formed by the articulation axis 68 is formed on the other end of each of the connecting rods 50, 52, 60 and 62, that is to say formed on the second end of the connecting rods 50 and 52 and on the second end of the connecting rods 60 and 62. In practice, the second end of each connecting rod is located opposite the first end of said connecting rod.

[0058] Thus, in the illustrated examples, the pivot joint formed by the articulation axis 68 is located on the lower end of the connecting rods 60 and 62 and on the upper end of the connecting rods 50 and 52. In these examples, the joint is therefore formed essentially in the middle of the connection system 22.

[0059] Examples of the operation of mechanism 10 are now briefly described.

[0060] In a stable open position, illustrated by the figure 1 The accumulation device 34 is armed, i.e., the spring is compressed and stores energy. The lock 30 holds the closing pawl 32 in a first position.

[0061] To close contacts 4 and 8, the closing lock 30 is flipped, for example by action of the trigger 12 or the push button, which releases the closing ratchet 32.

[0062] The movement of the closing pawl 32 actuates the device 34 and the energy accumulated in the device 34 is released by a release movement of the spring, which, via the drive mechanism 36, actuates the linkage system 22, for example by striking the ring 58, so as to move the movable pole 6 via the shaft 20, until the contact finger 8 comes into contact with the fixed contact 4.

[0063] The linkage system 22 continues to move towards its closed position until it passes in front of a predefined alignment position, called "dead point", causing the release hook 40 and the opening ratchet 26 to move towards a stop position, in which the return of the linkage system 22 is prevented.

[0064] The connecting rod assembly 45, and more specifically the first pair of connecting rods 42, then comes into contact with the stop 48, so as to lock the position of the linkage system 22.

[0065] The mechanism 10 is then in a stable closed position.

[0066] To reopen the device 2, the lock between the opening ratchet 26 and the lock 28 is broken, for example by moving the lever 31 by means of the actuator 12 or by a manual action directly on the lock 28. The opening ratchet 26 pivots, which releases the stop of the release hook 40.

[0067] The linkage system 22 is no longer held against the stop by the hook 40, while the stop 48 forces the first pair of connecting rods 42 to move away under the action of the restoring force exerted by the spring 29, so as to return the linkage system 22 to the open position. Once the linkage system 22 has returned behind the dead center position, the moving pole 6 is driven to its open position. The mechanism 10 has returned to the stable open position.

[0068] As illustrated here on the figures 2 , 3 And 4 The stop 48, visible on a larger scale, includes a spiral pin. Spiral pins, which are described for example in ISO 8748 or ISO 8750 standards, are formed by winding a sheet of metal, for example high-elasticity steel.

[0069] High-tensile steel refers to a grade of steel designed to be resistant to impact and bending. Many grades of steel exist, and a skilled professional will be able to select the most suitable grade based on the geometry of the stop 48 and the required performance, particularly in terms of durability and kinetic energy absorption. For example, but not limited to, hardened steel grades 420-545 HV or stainless steel grade 1.4310 provide good results.

[0070] The stop 48 has a generally cylindrical shape with a circular cross-section, the generatrix of which extends along an axis X48, the axis X48 being parallel to the axis X56, and has an external surface 70 with two opposite ends 72 and 74, which are here of frustoconical shape.

[0071] The stop 48 is press-fitted into the bore of the hook 40 in which the stop 48 is housed, the stop 48 being held in said bore by elastic return. In particular, the stop 48 is not welded to the hook 40 and remains free to deform elastically under the effect of an external stress; specifically, the stop 48 remains free to deform in bending when the connecting rod pair 42 comes to rest against the stop 48 during the closing of the mechanism 10.

[0072] Such a spiral pin, used as a stop 48, is particularly resistant to shock and material fatigue, especially compared to prior art stops, which are generally solid cylinders made of hard but inflexible steel, or to split pins. Of course, the stop 48 can have other shapes than a spiral pin as long as equivalent shock resistance performance is achieved.

[0073] The cutting device 2 further includes two shock-absorbing elements 76 and 78.

[0074] Each shock-absorbing element 76 or 78 is located at one end 72 or 74 respectively of the stop 48, the shock-absorbing elements 76 and 78 being arranged symmetrically on either side of the hook 40. Advantageously, the shock-absorbing elements 76 and 78 have a symmetrical structure with respect to the median plane P1.

[0075] The dampers 76 and 78 are configured to dampen, by elastic deformation, the movement of the connecting rod 45, when the device 2 passes from the open state to the closed state.

[0076] The shock absorbers 76 and 78 are in a so-called "relaxed" configuration when the switching mechanism 10 is in the open state, and are in a so-called "deformed" configuration when the switching mechanism 10 is in the closed state, parts of the connecting rod 45 being in contact with the shock absorbers 76 and 78.

[0077] On the figure 3 , only shock absorber 78 is visible, while on the figure 4 Only connecting rod 52 and damper element 78 are visible. The following description relates solely to connecting rod 52 and damper element 78, given that connecting rod 50 and damper element 76 have a symmetrical structure and function in the same way.

[0078] Shock absorber 78, visible in the illustration of the figure 3 , includes a central portion 79 in the shape of a ring or cylinder, in which an orifice 80 is provided, the orifice 80 cooperating with the stop 48 so as to maintain the shock-absorbing element 78 on the stop 48. The shock-absorbing element 78 has a front portion 82 and a rear portion 84, which are integral with the central portion 79 and extend on either side of the central portion 79, the rear portion 84 being closer to the distal end 54 of the hook 40 than the front portion 82.

[0079] A passage 90 is provided in the central portion 79 between the front and rear portions 82 and 84, radially to the axis X48. The passage 90 allows the connecting rod 52 to pass through, so that when the cutting device 2 is in the closed state, the connecting rod 52 bears directly against the stop 48. More precisely, a main bearing surface 85 of the connecting rod 52 bears directly against the external surface 70 of the stop 48.

[0080] The passage light 90 prevents the shock absorber element 78, made here of elastomer material, from being sheared between the connecting rod 52 and the stop 48, which would lead to rapid deterioration of the shock absorber element 78.

[0081] On the figure 4 The device 2 is shown in an intermediate configuration between the open and closed states during a closing movement of the mechanism 10. In particular, the linkage system 22 is not yet in contact with the stop 48. In the intermediate configuration of the figure 4 The connecting rod 45 comes into contact with the damper element 78, which is still in its relaxed position. More precisely, the front and rear portions 82 and 84 are respectively in contact with secondary bearing surfaces 86 and 88 of the connecting rod 52, the secondary bearing surfaces 86 and 88 being located on either side of the main bearing surface 85.

[0082] For illustrative purposes, a mean support direction F86 of the secondary support surface 86 on the front portion 82 is defined as the direction of movement of the secondary support surface 86 when contact with the front portion 82 occurs, i.e., in the configuration shown on the figure 4 The average support direction F86 is represented by an arrow on the figure 4 , the arrow F86 being orthonormal to the axis X56 around which the connecting rod 52 pivots.

[0083] In particular, the secondary bearing surface 86 is provided at the end of a protrusion 92 of the connecting rod 52, the protrusion 92 extending outward from the end of the connecting rod 52 having the axis X68 towards the front portion 82 of the shock absorber 78, in a direction substantially orthoradial to the axis X56 of rotation of the connecting rod 52. The protrusion 92 allows the contact between the bearing surface 86 and the front portion 82 to occur jointly with the contact between the bearing surface 88 and the rear portion 84, so as to stabilize the shock absorber 78 around the stop 48.

[0084] In the intermediate configuration shown on the figure 4 , it is understood that the front and rear portions 82 and 84 of the shock absorber 78 come into contact with the secondary bearing surfaces 86 and 88 of the connecting rod 45 before the main bearing surface 85 of the connecting rod 45 is in direct contact with the stop 48, which allows the shock absorber elements 76 and 78 to absorb, by elastic deformation, part of the kinetic energy of the connecting rod 45 before the impact on the stop 48.

[0085] The energy dissipated by damping is generally equal to the work done by the contact force between the damper 78 and the connecting rod 52, that is to say equal to the intensity of the contact force multiplied by the amplitude of the displacement of the point of contact between the damper 78 and the connecting rod 52.

[0086] It is understood that the damping effect is greater if the contact of the damper 78 with the connecting rod 45 occurs as early as possible before the connecting rod 45 is in direct contact with the thrust bearing 48. Similarly, for the same elastic deformation, a hard, or rigid, elastomer generates a greater force compared to a soft elastomer and the damping effect is greater.

[0087] However, if the internal stress within the elastomer exceeds a certain limit, the material risks being damaged by crushing. It is understood that the harder an elastomer is, the lower its capacity for elastic deformation.

[0088] Deformable alveoli 101, 102 and 103 are thus provided within the front portion 82 of the shock absorber 78, so that the shock absorber 78 can deform over a large spatial amplitude while being made of a relatively hard elastomeric material.

[0089] The hardness of elastomers can be evaluated by a standardized test known as the "Shore hardness test," the results of which are expressed on a scale called "Shore A" ranging from 0° to 100°. "Relatively hard" means that the damping element 78 is made of an elastomeric material with a hardness, measured on the Shore A scale, between 50° and 95°. Preferably, the hardness of the elastomer is between 60° and 80°, and preferably approximately 70°.

[0090] In the illustrated example, the alveoli 101 to 103 each have an elongated oval shape, each of the ovals being arranged lengthwise perpendicular to the mean support direction F86 of the connecting rod 52.

[0091] Similarly, a cavity 104, which here has a circular section, is provided within the rear portion 84 of the shock-absorbing elements 76 and 78.

[0092] When the damper 78 is in the relaxed configuration, the cells 101 to 104 are open, that is to say, internal surfaces of each of the cells 101 to 104, located opposite each other along the mean support direction F86, do not touch, while when the cut-off device 2 is in the closed state, the cells 101 to 104 are closed, that is to say, the internal surfaces of each cell 101 to 104 are in contact with each other.

[0093] Thus, the combination of a relatively hard elastomeric material with cells 101 to 104 formed in the damping elements 76 and 78 makes it possible to generate a greater damping force over a longer spatial amplitude compared to damping elements 76 or 78 without cells. On the figure 4We define dimension D1 as the dimension of cell 101, measured parallel to the mean support direction F86, when the damper 78 is in its relaxed configuration. Similarly, we define dimension D2 associated with cell 102 and dimension D3 associated with cell 103.

[0094] A dimension D82 of the front portion 82 is also defined as the dimension of the front portion 82, measured parallel to the mean support direction F86, when the damper 78 is in its relaxed configuration. The cells 101 to 103 of the front portion 82 represent a total thickness, equal to the sum of dimensions D1, D2, and D3, between 30% and 70% of the dimension D82 of the front portion 82. Preferably, the total thickness of the cells 101, 102, and 103 is between 40% and 60% of the dimension D82 of the front portion 82 of the damper element 78.

[0095] Of course, the number and shapes of the cells 101 to 104 are not limiting, and cells with shapes other than cells 101 to 104 may be provided in the damper 78, as long as similar effects in terms of damping and durability are obtained.

[0096] The cutting device 2 further comprises two spacers 106 and 108, which are located on either side of the hook 40 symmetrically with respect to the median plane P1. The spacers 106 and 108 advantageously have a symmetrical structure with respect to the median plane P1.

[0097] Each of the spacers 106 and 108 is located at the level of a respective shock-absorbing element 76 or 78, and has a housing 109 and a support face 110.

[0098] The spacers 106 and 108 cooperate on one side with a shaft passing through the orifice 46 and, on the other side, the housing 109 cooperates with one of the ends 72 or 74 of the stop 48, so as to secure the spacers 106 and 108 with the hook 40.

[0099] In the illustrated example, the support face 110 has, in cross-section in the median plane P1, an L-shape which cooperates by complementary shape with a lower face 112 of the damping elements 76 or 78. The lower faces 112 of each of the damping elements 76 or 78 are located opposite the front and rear portions 82 and 84 along the support direction F86 of the connecting rod 45, so that, in the deformed configuration of the damping elements 76 and 78, the damping elements 76 and 78 are primarily deformed in compression. The support face 110 also prevents rotational movement of the dampers 76 and 78 around the axis X48 of the thrust bearing 48.

[0100] For each of the damping elements 76 and 78, the lower face 112 is aligned, along the mean support direction F86, with a first portion of the front sections 82, located near the passage opening 90. A second portion of the front sections 82, further from the passage opening 90, is not aligned with the lower face 112 along the mean support direction F86. In other words, the front sections 82 partially extend beyond the support faces 112. When the shut-off device 2 is in the closed state, the front portion 82 of each damping element 76 or 78 thus includes a tensile deformation zone, which contributes more to damping the connecting rod 45 over a greater spatial amplitude when the shut-off device 2 transitions from the open to the closed state.

[0101] Of course, the support face 110 can have other shapes than the L-shape illustrated in the figures, as long as the support face 110 allows the support of the dampers 76 and 78, while allowing the dampers 76 and 78 to deform over a greater spatial amplitude.

Claims

1. A device (2) for interrupting an electric current, the device comprising separable fixed (4) and movable (8) electrical contacts and a mechanism (10) suitable for switching the contacts between a closed state and an open state, the mechanism comprising: - a switching shaft (20) coupled to the movable electrical contact (8); - a release hook (40) pivotably mounted on a fixed support of the mechanism and comprising a bore in which a stop (48) is housed, - a connecting system (22) coupling the switching shaft (20) to the release hook, the connecting system comprising an articulated linkage (45), which is rotationally connected to the release hook (40) and which comprises a main bearing surface (85), which bears on the stop (48) when the switching mechanism is in the closed state, characterised in that the stop (48) is configured to resiliently deform when the switching mechanism changes from the open state to the closed state and the linkage exerts a force on the stop, so as to absorb the impact of the linkage on the stop.

2. The interrupting device (2) according to the preceding claim, characterised in that the stop (48) is made of high-yield-strength steel.

3. The interrupting device (2) according to any one of the preceding claims 1 or 2, wherein the stop (48) is made from a hardened steel grade 420-545 HV or from a stainless steel grade 1.4310.

4. The interrupting device (2) according to any one of claims 2 or 3, characterised in that the stop (48) comprises a spiral pin.

5. The interrupting device (2) according to any one of the preceding claims, characterised in that the stop (48) is held in the bore of the release hook (40) by resilient return of the stop.

6. The interrupting device (2) according to any one of the preceding claims, characterised in that the switching device comprises resiliently deformable damping elements (76, 78), the damping elements being in a relaxed configuration when the switching mechanism (10) is in the open state, whereas, when the switching mechanism is in the closed state, secondary bearing surfaces (86, 88) of the linkage (45) bear on respective bearing portions (82, 84) of the damping elements and the damping elements are in a deformed configuration.

7. The device (2) for interrupting an electric current according to the preceding claim, characterised in that the damping elements (76, 78) are each situated at a respective end (72, 74) of the stop (48) and each comprise an orifice (80) for holding on the stop, each damping element also comprising a through aperture (90), so that in the closed state of the interrupting device (2), the main bearing surface (85) of the linkage bears directly on the stop.

8. The interrupting device (2) according to the preceding claim, characterised in that each damping element comprises a front portion (82) and a rear portion (84), the front and rear portions being situated on either side of the through aperture (90) and being configured in order to, when the release mechanism (10) changes from the open state to the closed state, come into contact with the secondary bearing surfaces (86, 88) of the linkage (45) before the main bearing surface (85) of the linkage bears directly on the stop (48).

9. The interrupting device (2) according to the preceding claim, characterised in that the damping elements (76, 78) comprise deformable cells (101, 102, 103) provided within the front portion (82), the cells being open when the damping elements (76, 78) are in the relaxed configuration, whereas when the interrupting device (2) is in the closed state, the cells are closed.

10. The interrupting device (2) according to the preceding claim, characterized in that the damping elements (76, 78) are configured such that the cells (101, 102, 103) of the front portion (82) each have a respective thickness (D1, D2, D3) measured parallel to a mean bearing direction (F86), the sum of the thicknesses being between 30% and 70% of a dimension (D82) of the front portion (82) measured parallel to the mean bearing direction, preferably between 40% and 60%, the mean bearing direction (F86) being defined by the direction of the contact force between the linkage (45) and the front portion (82) as the switching device goes from the open state to the closed state.

11. The interrupting device (2) according to any one of claims 6 to 10, characterised in that the damping elements (76, 78) are made of an elastomer material having a Shore A hardness of between 50° and 90°, preferably between 60° and 80°, even more preferably substantially equal to 70°.

12. The interrupting device (2) according to any one of claims 6 to 11, characterised in that the switching mechanism (10) comprises two spacers (106, 108), which are integral with the release hook (40) and are each located at the level of a respective damping element (76, 78), each spacer having bearing faces (110) configured to cooperate by complementarity of shape with lower faces (112) of the damping elements, the lower faces being situated opposite the front and rear portions (82, 84) in the mean bearing direction (F86) of the linkage (45), so that, in the deformed configuration, the damping elements are deformed in compression.

13. The interrupting device (2) according to the preceding claim, characterised in that the front portions (82) of the damping elements (76, 78) partially project beyond the bearing faces (110), so that when the interrupting device is in the closed state, the front portion (82) of each damping element further comprises a tension deformation zone.