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(11) | EP 2 947 673 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A trip mechanism for a low and medium voltage switching device |
| (57) A trip mechanism (1) for a LV or MV switching device (100) characterised in that
it is operatively coupleable with a first operating element (401) of said switching
device, which is reversibly movable between a first actuation position (A0) and a
second actuation position (B0), and with second operating element (402) of said switching
device, which is reversibly movable between a third actuation position (A5) and a
fourth actuation position (B5). The trip mechanism comprises: - a supporting frame (2); - a first trip lever (3), which is operatively connected to said supporting frame and is capable to rotate with respect to said supporting frame between a first engage position (A1) and a first trip position (B1), said first trip lever being operatively coupleable to said first operating element (401), so that said first operating element moves said first trip lever from said first engage position (A1) to said first trip position (B1), when said first operating element moves from said first actuation position (A0) to said second actuation position (B0); - a second trip lever (6), which is operatively connected to said supporting frame and is capable to rotate with respect to said supporting frame between a second engage position (A2) and a second trip position (B2), said second trip lever being operatively engageable with said first trip lever, so that said second trip lever is blocked by said first trip lever in said second engage position (A2) when said first trip lever is in said first engage position (A1), said second trip lever moving from said second engage position (A2) to said second trip position (B2) when said first trip lever moves from said first engage position (A1) to said first trip position (B1); - a third trip lever (8), which is operatively connected to said supporting frame is capable to rotate with respect to said supporting frame between a third engage position (A3) and a third trip position (B3), said third trip lever being operatively engageable with said second trip lever, so that said third trip lever is blocked by said second trip lever in said third engage position (A3) when said second trip lever is in said second engage position (A2), said third trip lever moving from said third engage position (A3) to said third trip position (B3) when said second trip lever moves from said second engage position (A2) to said second trip position (B2); - a trip pin (9), which is operatively connected to said supporting frame and is capable to translate with respect to said supporting frame between a fourth engage position (A4) and a fourth trip position (B4) and is operatively engageable with said third trip lever, so that said trip pin is blocked by said third trip lever in said fourth engage position (A4) when said third trip lever is in said third engage position (A3), said trip pin moving from said fourth engage position (A4) to said fourth trip position (B4) when said third trip lever moves from said third engage position (A3) to said third trip position (B3), said trip pin being operatively coupleable with said second operating element (402), so that said trip pin moves said second operating element from said third actuation position (A5) to said fourth actuation position (B5), when said trip pin moves from said fourth engage position (A4) to said fourth trip position (B4). |
[0001] The present invention relates to a trip mechanism for low and medium voltage switching devices, such as circuit breakers, disconnectors, contactors, reclosers or the like.
[0002] Within the framework of the present invention, the term "low voltage" relates to voltages lower than 1 kV AC and 1.5 kV DC whereas the term "medium voltage" relates to voltages lower than 72 kV AC and 100 kV DC.
[0003] As is known, low and medium voltage switching devices are used in electric circuits or grids to allow the correct operation of specific parts or sections of these latter.
[0004] For instance, they may be installed to ensure the availability of a nominal current necessary for several utilities, enable the proper insertion and disconnection of electric loads, protect (especially circuit breakers) the electric grid and the electric loads installed therein against fault events such as overloads and short circuits.
[0005] A conventional switching device generally comprises one or more electric poles, each of which comprises a movable contact and a fixed contact that can be mutually coupled/separated to allow/prevent the circulation of an electric current.
[0006] More specifically, the mobile contacts of the electric poles can be reversibly moved between a closing position and an opening position, in which they are respectively coupled with and separated from the corresponding fixed contacts.
[0007] In a switching device, the movable contacts of the electric poles are normally moved from the closing position to the opening position by main actuation means, which may include, for example, actuation springs.
[0008] Such actuation means are operatively connected to a kinematic chain, which is conveniently arranged to allow/prevent the main actuation means to intervene and cause the opening of the electric contacts of the electric poles.
[0009] In some switching devices of the state of the art, an actuation coil is used for snap actuating the kinematic chain from a blocking position to a release position, in which the kinematic chain respectively prevents and allows the main actuation means to intervene.
[0010] The actuation coil, which is normally fed by a power and control unit, has to provide a given mechanical energy to properly actuate the kinematic chain.
[0011] In some applications, the level of mechanical energy to be provided is relatively high. Commonly available actuation coils capable of providing such a high level of mechanical energy are characterised by high power consumption and a huge size, which is unacceptable in most cases.
[0012] Further, such actuation coils are prevented to operate in some operating conditions of the switching device, particularly when the electric power available to drive the actuation coil is relatively low.
[0013] In the market, it is quite felt the need of providing technical solutions to solve or mitigate the above technical issues.
[0014] In particular, it is quite felt the need of technical solutions that allow adopting actuation coils, which have a relatively small size and low power consumption even when a relatively high level of mechanical energy is required to actuate the kinematic chain driving the opening operation of the mobile contacts of the switching device.
[0015] In order to respond to such a need, the present invention provides a trip mechanism for a LV or MV switching device, according to the following claim 1 and the related dependent claims. In a further aspect, the present invention relates to a LV or MV switching device, according to claim 15.
[0016] Characteristics and advantages of the trip mechanism according to the invention will emerge from the description and from the attached drawings, in which:
- Figures 1-9 are partial views of the trip mechanism, according to the invention, in different operating conditions;
- Figure 10 is a partial view of a switching device comprising the trip mechanism, according to the invention.
[0017] With reference to the mentioned figures, the present invention relates to a trip mechanism 1 for a LV or MV switching device 100.
[0018] The switching device 100 may be a circuit breaker (as shown in figure 10), a disconnector, a contactor, a recloser or the like.
[0020] Each electric pole corresponds to an electric phase and comprises a fixed contact and a corresponding movable contact (not shown), which can be positioned between an opening position and closing position.
[0021] The switching device 100 comprises actuation means 500 to move the movable contacts of the electric poles from the closing position to the opening position.
[0022] The actuation means 500 are operatively connected to a kinematic chain 600, which is conveniently arranged to allow/prevent the actuation means 500 to intervene and cause the opening of the electric contacts.
[0023] The switching device 100 comprises an actuation coil 700, which is operatively connected to the kinematic chain 600.
[0024] The actuation coil 700 is adapted to cause the actuation of the kinematic chain 600 from a blocking position to a release position, in which the kinematic chain 600 respectively prevents and allows the actuation means 500 to intervene.
[0025] The actuation coil 700 comprises an electric winding (not shown) that is operatively associated with a movable plunger 401.
[0026] Depending on the type of the actuation coil 700, the movable plunger 401 moves when the electric winding is suitably fed by an excitation current provided by a power and control unit (not shown) of the switching device 100.
[0027] The trip mechanism 1 is operatively coupleable with a first operating element 401 of the switching device 100, which is reversibly movable between a first actuation position A0 and a second actuation position B0, and with a second operating element 402 of the switching device 100, which is reversibly movable between a third actuation position A5 and a fourth actuation position B5.
[0028] In the following, the trip mechanism 1 will be described with reference to its usage in the opening actuation chain 500, 600, 700 of the mobile contacts of the switching device 100, as illustrated in the cited figures.
[0029] In this case, the first operating element 401 is the movable plunger of the actuation coil 700, which is reversibly movable between the actuation positions A0 and B0, whereas the second operating element 402 is the release lever of the kinematic chain 600, which is reversibly movable between the actuation positions A5 and B5.
[0030] The trip mechanism 1 may be however used in other actuation mechanisms of the switching device 100.
[0031] In general, the first operating elements 401, 402 may be any interacting operating components of the switching device 100, wherein the first operating element 401 is configured to actuate the second operating component 402 but it is capable to provide a level of mechanical energy that is lower with respect to that one required by the second operating element 402 for being operated.
[0032] The trip mechanism 1 comprises a supporting frame 2, which is preferably configured to form a substantially U-shaped supporting structure having first and second plates 21, 22 arranged mutually parallel and spaced one from another to define an internal volume.
[0033] Even if they may be differently contoured according to the needs, the plates 21, 22 have preferably a substantially rectangular shape and comprise first and second opposite end sides 21A, 22B, 22A, 22B and first and second opposite lateral sides 21C, 22C, 21D, 22D.
[0034] At the respective end sides 21A, 22A, the plates 21, 22 are joined by a third transversal wall 23 that is oriented substantially perpendicular to them.
[0035] At the respective end sides 21B, 22B, the plates 21, 22 are joined by one or more transversal pins as it will be illustrated in the following.
[0036] In an intermediate position between the respective end sides, the plates 21, 22 are further joined by an internal supporting element 24 positioned in the internal volume delimited by the plates 21, 22.
[0037] Conveniently, the supporting frame 2 is solidly fixable to the main casing 900 of the switching device 1. To this aim, the switching device 1 preferably comprises one or more connection brackets 200 that are solidly fixable to the plate 22 and to the casing 900b. Preferably, the actuation coil 700 is solidly fixed to the first plate 21, so that the movable plunger 401 moves in a direction that is parallel to the external surface of the plate 21. Preferably, the movable plunger 401 is capable to reversibly move between the actuation positions A0 and B0, which correspond to the closing and opening positions of the electric contacts of the switching device 100.
[0038] Preferably, the release lever 402 of the kinematic chain 600 is rotatably coupled to the supporting frame 2 by means of a supporting bracket 201 that is fixed to the transversal wall 23.
[0039] Preferably, the release lever 402 can rotate about a fourth rotation axis 410 that is conveniently oriented along a direction parallel to the transversal wall 23 and perpendicular to the plates 21, 22.
[0040] Preferably, fifth elastic means 411 (e.g. a torsional spring coaxial with the rotation axis 410) are operatively coupled to the supporting frame 2 and the release lever 402.
[0041] Preferably, the release lever 402 is capable to reversibly rotate with respect to the supporting frame 2 between the actuation positions A5 and B5, which correspond to the closing and opening positions of the electric contacts of the switching device 100.
[0042] The trip mechanism 1 comprises a first trip lever 3 that is operatively connected to the supporting frame 2.
[0043] Preferably, the trip lever 3 can rotate about a first rotation axis 310 that is substantially perpendicular to the plates 21, 22.
[0044] The trip lever 3 is capable to reversibly rotate with respect to the supporting frame 2 between a first engage position A1 and a first trip position B 1.
[0045] The trip lever 3 is coupleable to the movable plunger 401 of the actuation coil 700 (first operating element).
[0046] In particular, when it is in the engage position A1, the trip lever 3 is positioned with respect to the movable plunger 401 (not necessarily in contact), so that the movable plunger 401 can exert a force on the trip lever 3 to rotatably move this latter from the engage position A1 to the trip position B1, when it moves from the actuation position A0 to the actuation position B0 (trip event).
[0047] The trip mechanism 1 comprises a second trip lever 6 that is operatively connected to the supporting frame 2.
[0048] Preferably, the trip lever 6 can rotate about a second rotation axis 610 that is substantially perpendicular to the plates 21, 22 (and parallel to the axis 310).
[0049] The trip lever 6 is capable to reversibly rotate with respect to the supporting frame 2 between a second engage position A2 and a second trip position B2.
[0051] More specifically, the second trip lever 6 is operatively engageable with the trip lever 3, so that it is blocked by the trip lever 3 in the engage position A2, when the trip lever 3 is in the engage position A1.
[0052] Further, the trip lever 6 rotatably moves from the engage position A2 to the trip position B2 when the trip lever 3 rotatably moves from the engage position A1 to the trip position B1. The trip mechanism 1 comprises a third trip lever 8 that is operatively connected to the supporting frame 2.
[0053] Preferably, the trip lever 8 can rotate about a third rotation axis 810 that is substantially perpendicular to the plates 21, 22 (and parallel to the axes 310, 610).
[0054] The trip lever 8 is capable to reversibly rotate with respect to the supporting frame 2 between a third engage position A3 and a third trip position B3.
[0056] More specifically, the trip lever 8 is operatively engageable with the trip lever 6, so that it is blocked by the trip lever 6 in the engage position A3, when the trip lever 6 is in the engage position A2.
[0057] Further, the trip lever 8 rotatably moves from the engage position A3 to the trip position B3 when the trip lever 6 rotatably moves from the engage position A2 to the trip position B2. The trip mechanism 1 comprises a trip pin 9, which is operatively connected to the supporting frame 2.
[0058] The trip pin 9 is capable to reversibly translate with respect to the supporting frame 2 between a fourth engage position A4 and a fourth trip position B4.
[0060] More specifically, the trip pin 9 is engageable with the trip lever 8, so that it is blocked by the trip lever 8 in the engage position A4 when the trip lever 8 is in the engage position A3. Further, the trip pin 9 translationally moves from the engage position A4 to the trip position B4 when the trip lever 8 rotatably moves from the engage position A3 to the trip position B3. The trip pin 9 is also operatively coupleable with the release lever 402 (second operating element) of the switching device 100.
[0061] In particular, the trip pin 9 is operatively coupleable with the release lever 402, so that said it exerts a force to move the release lever 402 from the actuation position A5 to the actuation position B5, when it translationally moves from the engage position A4 to the trip position B4.
[0062] Preferably, the trip pin 9 is operatively coupleable with the release lever 402, so that the release lever 402 moves the trip pin 9 from the trip position B4 to the engage position A4, when it moves from the actuation position B5 to the actuation position A5.
[0063] Preferably, the coupling between the trip pin 9 and the release lever 402 is constantly kept by the elastic means 411 that are arranged to contrast the movement of the release lever 402 from the actuation position A5 to the actuation position B5.
[0064] Preferably, the trip mechanism 1 comprises first elastic means 11, which are operatively coupled to the trip pin 9 and the supporting frame 2.
[0065] The elastic means 11 are arranged so as to store elastic energy and contrast the movement of the trip pin 9, when this latter translationally moves from the trip position B4 to the engage position A4.
[0066] The elastic means 11 thus constantly exerts a force on the trip pin 9 to move this latter from the engage position A4 to the trip position B4.
[0067] Conveniently, the elastic means 11 are designed to provide the trip pin 9 with a sufficient mechanical energy for properly operating the release lever 402.
[0068] The mechanical characteristics of the elastic means 11 may thus vary depending on the mechanical energy required for operating the release lever 402 and independently from the mechanical energy provided by the movable plunger 401.
[0069] Preferably, the elastic means 11 are formed by a compression spring that is coaxial with the trip pin 9 and is positioned between a coupling surface 93 of this latter and the supporting element 24.
[0070] Preferably, the rotation axis 310 of the trip lever 3 is positioned in the proximity of the end sides 21B, 22B and of the lateral sides 21C, 22C of the plates 21, 22.
[0071] Preferably, the trip lever 3 comprises a first portion 3A and a second portion 3B, which are integral or solidly connected one to another.
[0072] The portion 3A of the trip lever 3 is partially accommodated in the internal volume defined by the plates 21, 22 and is configured as a transversal connection pin, which passes through and joins the plates 21, 22 and externally protrudes from the plate 21.
[0073] The portion 3B of the trip lever 3 is positioned externally to the supporting frame 2 and is configured as a shaped wing extending perpendicularly with respect to the rotation axis 310 and the plate 21.
[0074] The portion 3B advantageously comprises a first coupling surface 311 configured to be coupled (not necessarily in contact) with the movable plunger 401 of the actuation coil 700, when the trip lever 3 is in the engage position A1.
[0075] The coupling surface 311 is pushed by the movable plunger 401 when this latter moves from the actuation position A0 to the actuation position B0 (trip event).
[0076] The portion 3A advantageously comprises a second coupling surface 312 configured to be coupled with the second trip lever 6, when the trip levers 3, 6 are in the engage positions A1, A2, respectively.
[0077] The portion 3A advantageously comprises a third coupling surface 313 configured to be coupled with the second trip lever 6, when the trip levers 3, 6 are in the trip positions B1, B2, respectively.
[0078] Preferably, the trip mechanism 1 comprises second elastic means 5, which are operatively coupled to the trip lever 3 and the supporting frame 2.
[0079] The elastic means 5 are arranged so that they contrast the rotational movement of this latter from the first engage position A1 to the first trip position B1.
[0080] The elastic means 5 thus store elastic energy when the first trip lever 3 moves from the first engage position A1 to the first trip position B1 and constantly exert a force on the trip lever 3 to move it from the first trip position B1 to the first engage position A1.
[0081] Preferably, the elastic means 5 are formed by a torsional spring, which is coaxial with the rotation axis 310 and has arms respectively coupled to the plate 21 (at its end side 21B) and to the portion 3B of the trip lever 3.
[0082] Preferably, the rotation axis 610 of the trip lever 6 is positioned in the proximity of the end sides 21B, 22B and the lateral sides 21D, 22D of the plates 21, 22.
[0083] Preferably, the trip lever 6 is accommodated in the internal volume defined by the plates 21, 22 and extends along a direction that is substantially parallel to the surface of the plates 21, 22 and transversal to the lateral sides 21C, 22C, 21D, 22D of these latter.
[0084] Preferably, the trip lever 6 comprises an elongated body having a first and second opposite ends 611, 612.
[0085] Preferably, the body of the trip lever 6 is formed by two parallel arms 613 that are joined by a plurality transversal connection pins 614, 615, 616.
[0087] At the end 611, the trip lever 6 rotates about the rotation axis 610 and is operatively coupled to the plates 21, 22 by means of a first connection pin 614 that passes through and joins the plates 21, 22.
[0088] Preferably, the trip lever 6 comprises a fourth coupling surface 617 and a fifth coupling surface 618 that are coupleable with the trip lever 3.
[0089] Conveniently, the coupling surfaces 617, 618 are positioned at the end 612 of the trip lever 6. The coupling surface 617 is configured to couple with the coupling surface 312 of the trip lever 3, when the trip levers 3, 6 are in the engage positions A1, A2.
[0090] In this way, the trip lever 3 is capable to block the trip lever 6 in the engage position A2, when it is in the engage position A1.
[0091] The coupling surface 618 is configured to couple with the coupling surface 313 of the trip lever 3, when the trip levers 3, 6 are in the trip positions B1, B2.
[0092] In this way, the trip lever 6 is capable to prevent the rotational movement of the trip lever 3 from the trip position B1 to the engage position A1 (such movement would occur due to the action of the elastic means 5).
[0093] Preferably, the trip lever 6 comprises a fifth coupling surface 619 that is coupleable with the third trip lever 8, when the trip levers 6, 8 are in the engage positions A2, A3 respectively. Preferably, the coupling surface 619 is a portion of the external surface of a second connection pin 616, which connects the parallel arms 613 in an intermediate position between the opposite ends 611, 612 of the lever 6.
[0094] Preferably, the trip lever 6 comprises a third connection pin 615 that connects the parallel arms 613 in an intermediate position between the end 612 and the connection pin 616 of the lever 6.
[0095] Preferably, the trip mechanism 1 comprises third elastic means 7, which are operatively coupled to the trip lever 6 and the supporting frame 2.
[0096] The elastic means 7 are arranged so that they contrast the rotational movement of this latter from the engage position A2 to the trip position B2.
[0097] The elastic means 7 store elastic energy when the trip lever 6 moves from the engage position A2 to the trip position B2 and constantly exert a force on the lever 6 to move it from the trip position B2 to the engage position A2.
[0098] Preferably, the elastic means 7 are formed by a torsional spring, which is coaxial with the rotation axis 610 and has arms respectively coupled to the plate 21 (at its end side 21B) and to one of the arms 613.
[0099] Preferably, the rotation axis 810 of the trip lever 8 is located in the proximity of the lateral sides 21C, 22C of the plates 21, 22 in an intermediate position between the opposite end sides of these latter.
[0100] Preferably, the trip lever 8 is accommodated in the internal volume defined by the plates 21, 22 and extends along a direction that is substantially parallel to the lateral sides of the plates 21,22.
[0101] Preferably, the trip lever 8 is partially accommodated in a throat cavity 241 obtained in the supporting element 24.
[0102] Preferably, the trip lever 8 comprises an elongated body having a third and fourth opposite ends 811, 812.
[0103] Preferably, the trip lever 8 is formed by a single arm operatively connected to the plates 21, 22 by a fourth connection pin 813, which is positioned at the rotation axis 810 and passes through and joins the plates 21, 22.
[0104] Preferably, the trip lever 8 comprises a sixth coupling surface 814 that is coupleable with the trip lever 6, when the trip levers 6, 8 are in the engage positions A2, A3 respectively. Conveniently, the coupling surface 814 is positioned at the end 811 of the trip lever 8.
[0105] The coupling surface 814 is configured to couple with the coupling surface 619 of the trip lever 6, when the trip levers 6, 8 are in the engage positions A2, A3 respectively.
[0106] In this way, the trip lever 6 is capable to block the trip lever 8 in the engage position A3, when it is in the engage position A2.
[0107] On the other hand, the trip lever 8 constantly exerts a force on the trip lever 6 to move this latter from the engage position A2 to the trip position B2, when it is in the engage position A3.
[0108] Preferably, the trip lever 8 comprises a seventh coupling surface 814A that is coupleable with the trip lever 6, when the trip levers 6, 8 are in the trip positions B2, B3 respectively. Conveniently, also the coupling surface 814A is positioned at the end 811 of the trip lever 8. The coupling surface 814A is configured to couple with the coupling surface 619 of the trip lever 6, when the trip levers 6, 8 are in the trip positions B2, B3 respectively.
[0109] The trip lever 8 is thus capable to prevent the rotational movement of the trip lever 6 from the trip position B2 to the engage position A2 (such movement would occur due to the action of the third elastic means 7).
[0110] Preferably, the trip lever 8 comprises a eighth coupling surface 815 that is coupleable with the trip pin 9, when the lever 8 and the trip pin 9 are in the engage positions A3, A4, respectively. Preferably, the trip lever 8 comprises a ninth coupling surface 816 that is coupleable with the trip pin 9, when the lever 8 and the trip pin 9 are in the trip positions B3, B4, respectively. Conveniently, the coupling surfaces 815, 816 are positioned at the fourth end 812 of the trip lever 8.
[0111] Preferably, the trip mechanism 1 comprises fourth elastic means 10, which are operatively coupled to the trip lever 8 and the supporting frame 2.
[0112] The elastic means 10 are arranged so that they contrast the rotational movement of this latter from the engage position A3 to the trip position B3.
[0113] The elastic means 10 store elastic energy when the trip lever 8 moves from the engage position A3 to the trip position B3 and constantly exert a force on the lever 8 to move it from the trip position B3 to the engage position A3.
[0114] Preferably, the elastic means 10 are formed by a torsional spring, which is coaxial with the rotation axis 810 and has arms respectively coupled to the supporting element 24 (or to one of the plates 21, 22) and to one of the edges of the lever 8.
[0115] Preferably, the trip pin 9 is arranged so as to move along a translation axis 90 that is substantially perpendicular and parallel respectively to the end sides and lateral sides of the plates 21, 22.
[0116] Preferably, the trip pin 9 is partially accommodated in the internal volume defined by the plates 21, 22 and protrudes from the supporting frame 2 at the transversal wall 23.
[0117] Preferably, the trip pin 9 comprises an elongated body having fifth and sixth opposite ends 91, 92.
[0118] Preferably, the trip pin 9 comprises a third portion 93, which includes the end 91 and passes through a first hole 231 obtained in the transversal wall 23, so as to protrude externally with respect to the supporting frame 2.
[0119] Preferably, the trip pin 9 comprises a fourth portion 94, which includes the end 92 and passes through a second hole 242 obtained in the supporting element 24.
[0120] Preferably, the trip pin 9 comprises a fifth portion 95, which is positioned between the portions 93, 94.
[0121] Preferably, the portions 93, 94 of the trip pin 9 have substantially cylindrical shapes extending along the axis 90.
[0123] Preferably, the portion 95 of the trip pin 9 comprises sub-portions 95A, 95B having substantially cylindrical shapes extending along the axis 90 (figure 7).
[0124] The sub-portion 95B, at a proximal position with respect to the end 92 of the trip pin 9, has a larger radius with respect to the sub-portion 95A, at a proximal position with respect to the end 91 of the trip pin 9.
[0125] Preferably, the mentioned sub-portions of the portion 95 are joined by a further intermediate sub-portion 95C having a preferably frusto-conical shape oriented towards the end 91 of the trip pin 9.
[0126] Preferably, the trip pin 9 comprises a tenth coupling surface 911 that is operatively coupled with the elastic means 11.
[0127] Conveniently, the portion 95 of the trip pin 9 comprises the coupling surface 911 at a proximal position with respect to the end 92 of the trip pin 9 (i.e. at the sub-portion 95B). Preferably, the trip pin 9 comprises an eleventh coupling surface 912 that are operatively coupleable with the transversal wall 23.
[0128] Conveniently, the portion 95 of the trip pin 9 comprises the coupling surface 912 at a distal position with respect to the end 92 of the trip pin 9 (i.e. at the sub-portion 95A).
[0129] The coupling surface 912 is configured to couple with the transversal wall 23, when the trip pin 9 is in the trip position B4.
[0130] The coupling surface 912 thus defines the end-of-run of the trip pin 9 along the axis 90 during its movement from the engage position A4 to the trip position B4.
[0131] Preferably, both the coupling surfaces 911, 912 are planar, substantially perpendicular to the axis 90 and coaxially centred with this latter.
[0132] Preferably, the trip pin 9 comprises a twelfth coupling surface 913 and a thirteenth coupling surface 914 that are coupleable with the trip lever 8.
[0133] Conveniently, the portion 95 of the trip pin 9 comprises the coupling surfaces 913, 914 in an intermediate position between the coupling surfaces 911, 912.
[0134] The coupling surface 913 is configured to couple with the coupling surface 815 of the trip lever 8, when the trip lever 8 and the trip pin 9 are respectively in the engage positions A3, A4.
[0135] In this way, the trip lever 8 is capable to block the trip pin 9 in the engage position A4, when it is in the engage position A3.
[0136] The engagement force that the trip lever 8 has to exert on the trip pin 9 basically depends on the force exerted by the elastic means 11 on the trip pin 9.
[0137] The coupling surfaces 815, 913 are arranged so that it is possible to modulate the engagement force that is exerted by the trip lever 8 by varying the shape of the coupling surfaces 815, 913. Preferably, the coupling surfaces 815, 913 are matching along a contact plane that is incident with respect to the axis 90 and perpendicular to the plates 21, 22.
[0138] By varying the inclination of such a contact plane, it is possible to modulate the engagement force that is exerted by the trip lever 8 (when it is in the engage position A3), as a function of on the force exerted by the elastic means 11.
[0139] The coupling surface 914 is configured to couple with the coupling surface 816 of the trip lever 8, when the trip lever 8 and the trip pin 9 are respectively in trip positions B3, B4.
[0140] In this way, the trip pin 9 is capable to prevent the rotational movement of the trip lever 8 from the trip position B3 to the engage position A3 (such movement would occur due to the action of the elastic means 10), when it is in the trip position B4.
[0141] Preferably, the coupling surface 913 has a frusto-conical shape that is oriented towards the end 91 of the trip pin 9 whereas the coupling surface 914 has a cylindrical shape with a larger radius with respect to the coupling surface 913.
[0142] In this way, the trip pin 9 exerts a force to move the trip lever 8 from the engage position A3 to the trip position B3, when it moves from the engage position A4 to the trip position B4. Preferably, the trip mechanism 1 comprises a stop pin 4 that is solidly connected to the supporting frame 2.
[0144] The stop pin 4 is operatively coupleable with the second trip lever 6 to stop the movement of this latter at the trip position B2 when the trip lever 6 moves away from the engage position A2.
[0145] In this way, the stop pin 6 operates as an end-of-run element, which limits the run of the trip lever 6 during its movement from the engage position A2 to the trip position B2.
[0148] The trip lever 3 is coupled with the movable plunger 401, which is in the actuation position A0.
[0149] The trip lever 3 is maintained in the engage position A1 due to the action of the elastic means 5.
[0150] The coupling surfaces 312, 617 of the trip lever 3, 6 are mutually coupled and the trip lever 6 is blocked in the engage position A2.
[0151] The coupling surfaces 619, 814 of the trip levers 6, 8 are mutually coupled and the trip lever 8 is blocked in the engage position A3.
[0152] The coupling surfaces 815, 913 of the trip lever 8 and of the trip pin 9 are mutually coupled and the trip pin 9 is blocked in the engage position A4.
[0153] The trip pin 9 is coupled with the release lever 402, which is in the actuation position A5. When a trip event occurs, the movable plunger 401 moves from the actuation position A0 to the actuation position B0.
[0154] The movable plunger 401 pushes the trip lever 3, which moves from the engage position A1 to the trip position B1.
[0155] As a consequence of the movement of the trip lever 3, the coupling surfaces 312, 617 of the trip levers 3, 6 mutually decouple.
[0156] Being pushed by the trip lever 8, the trip lever 6 moves from the engage position A2 to the trip position B2, at which it is stopped by the stop pin 4.
[0157] As a consequence of the movement of the trip lever 6, the coupling surfaces 619, 814 of the trip levers 6, 8 mutually decouple.
[0158] Being pushed by the trip pin 9, the trip lever 8 moves from the engage position A3 to the trip position B3.
[0159] As a consequence of the movement of the trip lever 8, the coupling surfaces 815, 913 of the trip lever 8 and of the trip pin 9 mutually decouple.
[0160] Being pushed by the elastic means 11, the trip pin 9 moves from the engage position A4 to the trip position B4.
[0161] The trip pin 9 pushes the release lever 402 and this latter moves from the actuation position A5 to the actuation position B5.
[0162] The movement of the release lever 402 causes a corresponding snap movement of the kinematic chain 600 towards the mentioned release position, at which the kinematic chain allows the actuation means 500 to intervene and cause the opening of the movable contacts of the switching device 100.
[0164] The coupling surfaces 816, 914 of the trip lever 8 and of the trip pin 9 are coupled, so that trip pin 9 prevents the movement of the trip lever 8 from the trip position B3 to the engage position A3.
[0165] The coupling surfaces 619, 814A of the trip levers 6, 9 are coupled, so that trip lever 8 prevents the movement of the trip lever 6 from the trip position B2 to the engage position A2. The coupling surfaces 313, 618 of the trip levers 3, 6 are coupled, so that trip lever 6 prevents the movement of the trip lever 3 from the trip position B1 to the engage position A1.
[0166] In order to return the trip mechanism 1 in an engage condition, the release lever 402 is moved from the actuation position B5 to the actuation position A5 by a suitable actuation mechanism (not shown).
[0167] Being pushed by the release lever 402, the trip pin 9 moves from the trip position B4 to the engage position A4.
[0168] This movement of the trip pin 9 is contrasted by the elastic means 11, which store elastic energy during the translation of the trip pin 9 towards the engage position A4.
[0169] As a consequence of the movement of the trip pin 9, the coupling surfaces 816, 914 of the trip lever 8 and of the trip pin 9 mutually decouple.
[0170] Due to the action of the elastic means 10, the trip lever 8 moves to the engage position A3. The coupling surfaces 815, 913 of the trip lever 8 and of the trip pin 9 mutually couple.
[0172] As a consequence of the movement of the trip lever 8, the coupling surfaces 619, 814A of the trip levers 6, 8 mutually decouple.
[0173] Due to the action of the elastic means 7, the trip lever 6 moves to the engage position A2. The coupling surfaces 619, 814 of the trip levers 6, 8 mutually couple.
[0175] As a consequence of the movement of the trip lever 6, the coupling surfaces 313, 618 of the trip levers 3, 6 mutually decouple.
[0177] As a consequence of the movement of the trip levers 3 and 6, the coupling surfaces 312 and 617 of the trip lever 3, 6 mutually couple.
[0179] As mentioned above, the trip lever 3 is maintained in the engage position A1 due to the action of the elastic means 5.
[0180] In the engage position A1, the trip lever 3 is coupled with the movable plunger 401, which is immediately returned in the actuation position A0 after the trip event, independently from the operating conditions of the trip mechanism 1.
[0181] The trip mechanism 1 advantageously maintains such an engage condition until the next trip events occurs.
[0183] The trip mechanism 1 can be operatively associated to the actuation coil 700 to advantageously increase in a controlled manner the mechanical actuation force to be provided to the kinematic chain 600 driving the opening of the movable contacts of the electric poles of the switching device 100.
[0184] By properly designing the elastic means 11, it is possible to regulate the actuation force for operating the kinematic chain 600 independently from the actuation force that is actually provided by the movable plunger 401.
[0185] In this way, it is possible to adopt small size and low power consumption actuation coils even when a relatively high mechanical energy is required to actuate the kinematic chain.
[0187] Further, the opening of the electric contacts of the electric poles can still be achieved even when low electric power levels are available to feed the actuation coil 700.
1. A trip mechanism (1) for a LV or MV switching device (100) characterised in that it is operatively coupleable with a first operating element (401) of said switching
device, which is reversibly movable between a first actuation position (A0) and a
second actuation position (B0), and with second operating element (402) of said switching
device, which is reversibly movable between a third actuation position (A5) and a
fourth actuation position (B5), said trip mechanism comprising:
- a supporting frame (2);
- a first trip lever (3), which is operatively connected to said supporting frame and is capable to rotate with respect to said supporting frame between a first engage position (A1) and a first trip position (B1), said first operating element moving said first trip lever from said first engage position (A1) to said first trip position (B1), when said first operating element moves from said first actuation position (A0) to said second actuation position (B0);
- a second trip lever (6), which is operatively connected to said supporting frame and is capable to rotate with respect to said supporting frame between a second engage position (A2) and a second trip position (B2), said second trip lever being blocked by said first trip lever in said second engage position (A2) when said first trip lever is in said first engage position (A1), said second trip lever moving from said second engage position (A2) to said second trip position (B2) when said first trip lever moves from said first engage position (A1) to said first trip position (B1);
- a third trip lever (8), which is operatively connected to said supporting frame and is capable to rotate with respect to said supporting frame between a third engage position (A3) and a third trip position (B3), said third trip lever being blocked by said second trip lever in said third engage position (A3) when said second trip lever is in said second engage position (A2), said third trip lever moving from said third engage position (A3) to said third trip position (B3) when said second trip lever moves from said second engage position (A2) to said second trip position (B2);
- a trip pin (9), which is operatively connected to said supporting frame and is capable to translate with respect to said supporting frame between a fourth engage position (A4) and a fourth trip position (B4), said trip pin being operatively engageable with said third trip lever, so that said trip pin is blocked by said third trip lever in said fourth engage position (A4) when said third trip lever is in said third engage position (A3), said trip pin moving from said fourth engage position (A4) to said fourth trip position (B4) when said third trip lever moves from said third engage position (A3) to said third trip position (B3), said trip pin moving said second operating element from said third actuation position (A5) to said fourth actuation position (B5), when said trip pin moves from said fourth engage position (A4) to said fourth trip position (B4).
2. A trip mechanism, according to claim 1, characterised in that it comprises first elastic means (11), which are operatively coupled to said trip
pin and said supporting frame, said first elastic means moving said trip pin from
said fourth engage position (A4) to said fourth trip position (B4).
3. A trip mechanism, according to one or more of the previous claims, characterised in that it comprises second elastic means (5), which are operatively coupled to said first
trip lever and said supporting frame, said second elastic means contrasting the movement
of said first trip lever from said first engage position (A1) to said first trip position
(B1).
4. A trip mechanism, according to one or more of the previous claims, characterised in that it comprises third elastic means (7), which are operatively coupled to said second
trip lever and said supporting frame, said third elastic means contrasting the movement
of said second trip lever from said second engage position (A2) to said second trip
position (B2).
5. A trip mechanism, according to one or more of the previous claims, characterised in that it comprises fourth elastic means (10), which are operatively coupled to said third
trip lever and said supporting frame, said fourth elastic means contrasting the movement
of said third trip lever from said third engage position (A3) to said third trip position
(B3).
6. A trip mechanism, according to one or more of the previous claims, characterised in that said second trip lever (6) prevents the movement of said first trip lever (3) from
said first trip position (B1) to said first engage position (A1), when said second
trip lever is in said second trip position (B2).
7. A trip mechanism, according to one or more of the previous claims, characterised in that said third trip lever (8) exerts a force on said second trip lever (6) to move said
second trip lever from said second engage position (A2) to said second trip position
(B2), when said third trip lever is in said third engage position (A3).
8. A trip mechanism, according to one or more of the previous claims, characterised in that said third trip lever (8) prevents the movement of said second trip lever (6) from
said second trip position (B2) to said second engage position (A2), when said third
trip lever is in said third trip position (B3).
9. A trip mechanism, according to one or more of the previous claims, characterised in that said trip pin (9) exerts a force on said third trip lever (8) to move said third
trip lever from said third engage position (A3) to said third trip position (B3),
when said trip pin moves from said fourth engage position (A4) to said fourth trip
position (B4).
10. A trip mechanism, according to one or more of the previous claims, characterised in that said trip pin (9) prevents the rotational movement of said third trip lever (8) from
said third trip position (B3) to said third engage position (A3), when said trip pin
is in said fourth trip position (B4).
11. A trip mechanism, according to one or more of the previous claims, characterised in that trip pin (9) moves said trip pin from said fourth trip position (B4) to said fourth
engage position (A4), when said second operating element moves from said fourth actuation
position (B5) to said third actuation position (A5).
12. A trip mechanism, according to one or more of the previous claims, characterised in that it comprises a stop pin (4) that is solidly connected to said supporting frame, said
stop pin stopping the movement of said second trip lever (6) at said second trip position
(B2), when said second trip lever moves away from said second engage position (A2).
13. A trip mechanism, according to one or more of the previous claims, characterised in that said first operating element (401) is a movable plunger of an actuation coil (700)
of said switching device.
14. A trip mechanism, according to one or more of the previous claims, characterised in that said second operating element (402) is a release lever of a kinematic chain (600)
to drive the opening of one or more electric contacts of said switching device.
15. A LV or MV switching device (100) characterised in that it comprises a trip mechanism (1), according to one or more of the previous claims.