Abstract
A fuse device comprising a housing, at least two connection lugs, a connecting element between the connection lugs, and an actuator. The actuator moves the connecting element from a closed position, in which it connects the connection lugs, to an open position, in which it is disconnected from at least one of the connection tabs. A particularly well-conducting connection between the connection lugs and the connecting element, which can nevertheless be easily disconnected by the actuator, is achieved by the connecting element being interference-fitted between the connection lugs.
Claims
1.-22. (canceled)
23. Electrical fuse device, in particular for a motor vehicle comprising; a housing; a first connection lug routed into the housing; a second connection lug routed into the housing, wherein the connection lugs are spaced from each other in the housing by a gap, wherein the gap spans between two end faces, respectively at the end of one of the connection lugs, facing one another; a connecting element electrically connecting the first and the second connection lug in the housing in a closed position, wherein the connection element is in mechanical contact with the two connection lugs respectively at a contact surface, wherein the end faces respectively at least partially form one of the contact surfaces; and an actuator arranged in the housing, moving the connecting element from the closed position to an open position, wherein in the open position the two connection lugs are electrically insulated from one another, wherein the connecting element is arranged in the gap between the two connection lugs and is pressed in an interference fit between the first and the second connection lug.
24. Fuse device according to claim 23, wherein the actuator is a pyrotechnic element, in particular an ignition pill.
25. Fuse device according to claim 23, wherein the gap has a constant cross-section along a spatial direction or the gap has a cross-section tapering along a spatial direction, in particular along a spatial direction the cross-sectional area of the gap is monotonically decreasing.
26. Fuse device according to claim 23, further comprising fastening means on the housing and/or on the connection lugs in order to fixate the connection lugs.
27. Fuse device according to claim 23, wherein the connection lugs have end faces, the end faces of the connection lugs are arranged facing one another and/or the end faces respectively at least partially form one of the contact surfaces.
28. Fuse device according to claim 23, wherein at least one of the contact surfaces between one of the connection lugs and the connecting element is larger than a cross-sectional surface of one of the connection lugs, in particular at least one of the contact surfaces is a surface running in the longitudinal direction of the connection lug, in particular is a wide surface running in the longitudinal direction of the connection lug.
29. Fuse device according to claim 23, wherein at least one of the connection lugs and/or the connecting element is metallically coated, in particular tin-plated, at least in the region of at least one of the contact surfaces.
30. Fuse device according to claim 29, wherein the metallic coating is formed from a softer material than the remainder of the connection lug, in particular has a lower Rockwell hardness, and consequently a plastic deformation, in particular an interlocking, of the two contact surfaces takes place when at least one of the connection lugs is pressed to the connecting element.
31. Fuse device according to claim 23, wherein at least one of the connection lugs and/or the connecting element is formed from an electrically conductive solid material, in particular from a metal material, in particular from copper or a copper alloy or from aluminum or an aluminum alloy.
32. Fuse device according to claim 23, wherein at least one of the connection lugs and/or the connecting element is at least partially formed as a flat element, in particular sheet metal, in particular as an H-element.
33. Fuse device according to claim 23, wherein the connecting element comprises a first conductive element made of an electrically conductive material and a second supporting element made of a second material, the first conductive element being in contact with the two connection lugs in the closed position and both the first and the second conductive element are arranged together between the two connection lugs in an interference fit.
34. Fuse device according to claim 33, wherein the conductive element comprises a flat part which embraces the support element in a U-shaped or pot-shaped manner, or the conductive element comprises a plurality of flat parts which are arranged in the region of the contact surfaces on the support element and a further electrically conductive element which establishes an electrical connection between the flat parts, or the conductive element is an H-element in which the two outer surfaces are the contact surfaces and the central strut connects the side surfaces, and the intermediate spaces are optionally filled by the support element.
35. Fuse device according to claim 23, wherein the connecting element in the open position in the direction of extension of the gap is longer than the width of the gap in this direction.
36. Fuse device according to claim 23, further comprising at least one insulator made of electrically non-conductive material arranged in the housing on at least one of the connection lugs on the side facing away from the actuator, which terminates flush with the contact surface and/or projects beyond the contact surface towards the center of the gap.
37. Fuse device according to claim 36, wherein the insulator is formed from an elastic material, in particular plastic, and/or is formed as snap elements and/or the insulator is part of a conductor insulation and/or the insulator is part of the housing, in particular projections on inner walls of the housing.
38. Fuse device according to claim 23, wherein a cavity of the housing, into which the connecting element is moved by the actuator, encloses the connecting element at least in one spatial direction.
39. Fuse device according to claim 23, wherein the connecting element is configured to move along a guide, in particular along rails arranged on the inner wall of the housing and/or along rails penetrating the connecting element and/or along the contact surfaces of the connection lugs.
40. Fuse device according to claim 23, wherein a plurality of pairs of connection lugs, each with a connecting element, are arranged in the housing and at least one group of connecting elements is driven by a single actuator from a respective closed to a respective open position and/or a connecting element is driven individually by an actuator from a respective closed to a respective open position.
41. Fuse device according to claim 23, further comprising venting means in the housing, via which a gas located in the housing escapes when the actuator is triggered and/or seals are provided between the connecting element and/or connection lugs and the inner wall of the housing.
42. Method of manufacturing a fuse device according to claim 23, wherein the connection lugs are mechanically pressed with the connecting element and then installed together with the actuator in a housing and/or the connection lugs and the connecting element are first introduced into the housing and then pressed with the connecting element.
Description
[0062] In the following, the subject matter is explained in more detail with reference to a drawing showing embodiment examples. In the drawing show:
[0063] FIG. 1 an embodiment of a fuse device according to the subject matter with connection lugs and connecting element made of solid material;
[0064] FIG. 2 an embodiment of a fuse device with connection lugs and a connecting element made of sheet metal;
[0065] FIG. 3 an embodiment of a fuse device according to the subject matter with a cylindrical structure with concave gap surfaces of the connection lugs;
[0066] FIG. 4 an embodiment of a fuse device according to the subject matter with a cylindrical structure with convex gap surfaces of the connection lugs;
[0067] FIG. 5 an embodiment of a fuse device according to the subject matter with contacting of the longitudinal surfaces of the connection lugs;
[0068] FIG. 6 an embodiment of a fuse device according to the subject matter with contacting of the longitudinal surfaces of the connection lugs;
[0069] FIG. 7 embodiments of the fastening means between the connection lug and the housing of the fuse device according to the subject matter;
[0070] FIG. 8 embodiments of the connecting element of the fuse device according to the subject matter;
[0071] FIG. 9 embodiments of tapering connecting elements of the fuse device according to the subject matter;
[0072] FIG. 10 embodiments of the surfaces of the connecting element and connection lugs of the fuse device according to the subject matter;
[0073] FIG. 11 embodiments of the fuse device according to the subject matter with multiple fuse conductors;
[0074] FIG. 12 embodiments of the fuse device according to the subject matter with venting means;
[0075] FIG. 13 embodiments of the insulators of the fuse device according to the subject matter.
[0076] FIG. 1 shows a fuse device 1, which comprises a housing 10, a first connection lug 11 and a second connection lug 12. The housing 10 protects the fuse device 1 from external influences. The housing 10 can further serve as a holder for the connection lugs 11 and 12, as well as other elements of the fuse device 1.
[0077] The two connection lugs 11, 12 are connected by a connecting element 13. For this purpose, the connecting element 13 is arranged between the two connection lugs 11, 12 in the gap 26 and is in mechanical and electrical contact with the connection lugs 11, 12 at contact surfaces 21b and 22b. The connection lugs 11, 12 in turn contact connecting element 13 at contact surfaces 21a, 22a. In the configuration shown in FIG. 1, connecting element 13 is arranged between the end faces of connection lugs 11, 12.
[0078] On one side of the connecting element 13, an actuator 17 is located in the housing 10. The actuator 17 can be arranged in a recess of the housing 10 and/ or attached to the inner wall of the housing 10, for example glued, screwed, riveted, or otherwise fastened.
[0079] On the side of the housing 10 in which the actuator 17 is located, a cavity is provided, the drive chamber 23. On the side of the housing 10 facing away from the actuator 17, a second cavity 24 is provided.
[0080] On the side of the second cavity 24 of the housing 10, i.e. facing away from the actuator 17, insulators 16 (16a and 16b in FIG. 1) are provided at the connection lugs 11, 12. The insulators 16 can be part of an insulation applied to the connection lugs 11, 12 and/or can be part of the housing 10 in the form of, for example, projections.
[0081] FIG. 1b shows an exemplary actuation of the fuse device 1. The actuator 17 moves the connecting element 13 out of its closed position in the gap 26 between the two connection lugs 11, 12 and into the open position outside the connection lugs 11, 12. Due to the elastic expansion of the connecting element 13, it is wider after the movement out of the press fit between the two connection lugs 11, 12 than before. It remains in the cavity 24.
[0082] The insulators 16a, 16b ensure the insulation of the connecting element 13 in the open position from at least one of the two connection lugs 11, 12.
[0083] As can be seen in FIG. 1c, the housing 10 is preferably arranged tightly around the connecting element 13 and/ or at least one of the connection lugs 11, 12. Thus, the drive chamber 23 and the cavity 24 are separated from each other, preferably at least almost airtight, which is particularly advantageous for pyrotechnic and gas-operated actuators 17, as this allows a pressure to build up in the drive chamber 23, which leads to the movement of the connecting element 13.
[0084] In the embodiment shown in FIG. 1, it can further be seen that the cross-section of the connecting element 13 is substantially constant along the direction of movement of the actuator 17, spatial direction z. Thus, the connecting element 13 can slide along the connection lugs 11 ,12 when moving out of the gap 26.
[0085] FIG. 2 shows an embodiment example with connection lugs 11, 12 made of sheet metal. In this embodiment, the connection lugs are arranged on opposite sides of the housing 10 and have been bent downward to increase the contact surfaces 21a, 22a (consequently also contact surfaces 21b, 22b) with the connecting element 13. Furthermore, the connection lugs 11, 12 rest against and are supported by the inner wall of the housing.
[0086] The connecting element 13 according to FIG. 2 is also partially formed from a sheet metal piece 15. In addition, the sheet metal piece 15 is arranged on a support element 14. The sheet metal piece (contact piece) 15 serves the purpose of electrically connecting the two connection lugs 11, 12. The sheet metal of the contact piece 15 can be turned over the support element 14, for example, in a U-shaped or pot-shaped manner and wrap around it on three sides.
[0087] As shown in FIG. 2, the support element 14 can have a cavity pointing downward toward the actuator. This can absorb forces during pressing of the connecting element 13 and be pressed slightly inwards in the process, so that its width in the x-direction is reduced in the press fit. When the connecting element 13 is released from the gap 26, a further spreading of the contact piece 14 can thus be achieved in comparison with a connecting element 13 and/or support element 14. In this way, the fixation of the connecting element 13 after release from the gap 26 in the upper area 24 is achieved with increased security.
[0088] It is also possible for the contact piece 15 to comprise a plurality of electrically conductive flat elements, such as metal sheets or strips, one or more of which are arranged respectively at the contact surfaces 21b, 22b to the two connection lugs 11, 12 and their contact surfaces 21a, 22a. The sheets at the contact surfaces 21b, 22b are in this case still connected by a further conductive element, which may be a sheet, a solid material component and/or a cable or other conductive element.
[0089] The support element 14 serves to absorb mechanical pressure generated during the pressing of the connecting element 13. It is located together with the contact piece 15 between the connection lugs 11, 12 and may contact them in addition to the contact piece 15. Preferably, only parts of the contact piece 15 contact the contact surfaces 21a, 22a of the connection lugs 11, 12 in order to maximize the conductive contact area as much as possible. By combining a support element 14 made of a possibly non-conductive or also conductive material with a conductive contact piece 15 made of several individual parts of sheet metal and/or solid material, the weight and costs are reduced compared to a connecting element 13 made of solid material. The mechanical and electrical functions of the connecting element 13 are separated: the supporting element 14 takes over the mechanical absorption of pressure and the contact piece 15 establishes the electrical connection between the connection lugs 11, 12.
[0090] FIG. 2b shows the open position of the connecting element 13 and thus the electrical separation of the two connection lugs 11, 12 from each other. Also in this embodiment, the connecting element 13 expands after leaving the gap 26 and cannot slide back into the gap 26. The insulators 16a, 16b permanently interrupt the electrical contact between at least one connection lug 111, 12 and the connecting element 13. The sheet metal elements in the region of the contact surfaces 21b, 22b can be dimensioned such that they can slip over the insulators 16a, 16b, but a downwardly projecting part of the support element 14 remains in the gap 26. In particular, the support element 14 can be dimensioned so that the part projecting downwards over the contact piece 15 fits at least almost exactly into the gap 26 in the open position and the connecting element 13 is thus stabilized in the open position.
[0091] FIG. 2c shows a top view of the fuse device 1. A seal 18 is arranged on both sides of the string of connection lugs 11, 12 and connecting element 13. Its purpose is to isolate the two cavities 23 and 24 of the housing 10 from each other and to allow a pressure to be built up in the drive chamber 23 without a relevant amount of gas being able to penetrate from cavity 23 into cavity 24 and the pressure in cavity 23 thus being lost. In particular, the two cavities are separated from each other in a gas-tight manner.
[0092] As a further embodiment, an essentially cylindrical structure of the fuse device 1 is shown in FIGS. 3a-c. As can be seen in the top view in FIG. 3c, the cross-section of the connecting element 13 is round and it is enclosed by the connection lugs 11, 12 in the closed position. For this purpose, the connection lugs 11, 12 are widened in the area of the contact surfaces 21a, 22a, and in particular their shape is essentially that of half tubes. In this design, the contact area is increased. Also, the connecting element 13 is moved along a channel when moved by the actuator 17, so the connection lugs 11, 12 act as a guide.
[0093] In the top view in FIG. 3c, it can further be seen how a seal 18 isolates the two cavities 23 and 24 from each other.
[0094] A similar design is disclosed in the embodiment of FIG. 4a, b. Instead of the connection lugs 11, 12 engaging around the connecting element 13, the connecting element 13 here has recesses in the region of the contact surfaces 21b, 22b, in which corresponding convex formations of the connection lugs 11, 12 engage.
[0095] FIG. 5 shows an alternative embodiment in which the two connection lugs 11 and 12 are not guided into the housing 10 from opposite sides with their end faces facing each other, but are aligned essentially parallel to each other coming from the same side.
[0096] In FIG. 5c, it can be seen that the connection lugs 11 and 12 and the connecting element 13 can bear against the inner wall of the housing essentially without any gap, so that the regions 23 and 24 are essentially insulated from one another, in particular insulated in a gas-tight manner. This has a similar effect to the insulation 18 in FIG. 2c, for example.
[0097] It is also possible that the connection lugs 11, 12 are arranged substantially parallel to each other from opposite sides, see FIGS. 6a-c, or that a first connection lug is aligned substantially perpendicular to the second connection lug. In the embodiment shown, the contact surface 21a, 22a (consequently also contact surfaces 21b, 22b) between connecting element 13 and connection lug 11, 12 is a longitudinal surface in both connection lugs 11, 12. This may be a narrow or a wide longitudinal surface. By contacting the connection lug 11, 12 and the connecting element 13 at a longitudinal surface, the contact area can be increased compared to contacting at the end surface (see FIG. 1).
[0098] In FIGS. 5 and 6, the insulators 16a, 16b are again arranged on the conductors on the side facing away from the actuator 17, in the embodiment in FIG. 5 on the end faces of the connection lugs 11,'12 and in the embodiment from FIG. 6 on the narrow longitudinal surfaces of the connection lugs 11, 12. The insulators 16 also prevent electrical contact between connection lugs 11, 12 and the connecting element 13 in the open position here.
[0099] Fasteners may be provided to secure the connection lugs to the housing 10. FIG. 7a-c shows some embodiments of such fastening means.
[0100] In the embodiment of FIG. 7a, projections are provided on the walls of the housing 10 and fastening means 20a, 20b, in this case projections, are provided on the edges of the recess through which the connection lug is guided, which projections embrace the connection lug 11, 12. An extended projection is provided towards the interior, which extends to the edge of the contact surface 21b, 22b of the connection lug 11, 12 and can act as an insulator 16. The connection lug 11, 12 has fastening elements 19a, 19b, in this case recesses. The projections of the housing 10 can engage in these recesses and thus fix the connection lug 11, 12. Fixing the connection lug 11, 12 is particularly important when the connecting element 13 is detached from the gap 26, since this ensures that force is transmitted between the actuator 17 and the connecting element 13. If the connection lugs 11, 12 and the connecting element 13 were able to move jointly, disengagement and thus electrical separation of the connection lugs 11, 12 from each other would not occur.
[0101] Similar to FIG. 7a, FIG. 7b shows fastening means having a plurality of recesses 19 per side in the connection lug 11, 12 in which a plurality of projections 20 of the housing 10 engage. In this embodiment, the insulator 16 is applied to the conductor 11 and is not part of the housing 10. The fact that the fastening means (protrusions) 20 are each attached to protrusions projecting from the housing wall allows them to yield during assembly of the connection lug 11, 12 and facilitates insertion of the connection lug 11, 12.
[0102] FIG. 7c shows a simpler embodiment in which the entire housing wall engages in a recess 19 in the connection lug.
[0103] In FIG. 7d, an embodiment is given in which the conductor has projections and engages in recesses of the housing 10.
[0104] All of the connecting elements of FIGS. 1, and 3-6 may be formed from a solid material or may be formed from a composite of a support element 14 and a contact piece 15, as illustrated in FIGS. 8a-f.
[0105] As shown in FIG. 8a, b, the connecting element 13 may be formed of solid material, for example a metal material.
[0106] It is also possible for the connecting element 13 to be formed from a support element 14 and a contact piece 15, as shown in FIGS. 8c-g. FIGS. 8c, d show an H-shaped contact piece 15 made of two flat elements or elements of solid material in the area of the contact surfaces 21b, 22b and a third contacting element between the flat elements. The contacting element can be a sheet with a surface normal substantially parallel to the spatial direction z or to the spatial direction y or in another spatial direction, or a conductor made of solid material, for example a round conductor or a flat conductor, which is either located in the volume between the contact surfaces 21a, 22a (consequently also contact surfaces 21b, 22b) and/or is enclosed by the support element. The support element fills the spaces between the flat elements at the contact surfaces.
[0107] FIGS. 8e, f show a cylindrical connecting element comprising contact piece 15 and support element 14, and FIGS. 8g, h show a cylindrical connecting element with troughs provided for connection lugs 11, 12, which also comprises support element 14 and contact piece 15. Support element 14 and contact piece 15 can each be composed of several elements.
[0108] The support element 14 can also project beyond the parts of the contact piece 15 at the contact surfaces 21b, 22b, see FIG. 8f for details, and the contacting element for electrically connecting the contact surfaces 21b, 22b of the connecting element 13 can also describe any paths outside the volume enclosed by the contact surfaces 21a, 22a.
[0109] FIGS. 9a-f show further embodiments of the solution according to the subject-matter, in which the connecting element 13 is tapered in one direction. In particular, the connecting element 13 tapers in a direction substantially antiparallel to the direction of movement of the actuator, here negative spatial direction z, hereinafter taper direction. The connection lugs 11, 12 are substantially shaped so that the connecting element 13 fits precisely into the gap 26 spanned between them.
[0110] FIG. 9a, b shows a substantially tapered design of the connecting element 13 in which the cross-section of the connecting element 13 decreases substantially continuously along the taper direction. Due to the taper, a separation from the connection lugs 11, 12 is already achieved after small distances of movement of the connecting element 13, and no frictional resistance between connection lugs 11, 12 and connecting element 13 has to be overcome over long displacement distances. In particular, it is possible to dimension the cavity 24 and the insulators 16 such that the freedom of movement of the connecting element 13 in the open position is restricted and the latter cannot tilt in the direction of the connection lugs 11, 12.
[0111] The cross-sectional area of the connecting element 13 does not need not fall uniformly per length in the taper direction. Thus, FIG. 9c, d shows a design of the connecting element 13 of the solution according to the subject matter in which the cross-section is at least almost constant along the taper direction in sections and then decreases again at least almost abruptly. It is advantageous if the cross-sectional area tapers monotonically, i.e. does not substantially increase with the taper direction. Sections with substantially constant cross-sectional area are possible.
[0112] FIGS. 9e, f show another embodiment in which the cross-section of the connecting element 13 is substantially semi-circular in the spatial direction y. The connecting element 13 may be formed as a half cylinder, a half sphere, or a similar shape with a semicircular cross-section. Again, the cross-section slopes monotonically, though not continuously, in the direction of taper. The circular cross-sectional shape ensures that the connecting element does not come into contact with either of the connection lugs, even when twisted about the spatial direction y.
[0113] FIGS. 10a-d show embodiments of the surfaces of connecting element 13 and/or connection lugs 11, 12. Since the electrical contact resistance between connection lugs 11, 12 and connecting element 13 decreases as the contact area increases, it can be advantageous not to keep the contact surfaces 21a, 22a (consequently also contact surfaces 21b, 22b) smooth but to structure them in a targeted manner.
[0114] This can be done, for example, as shown in FIG. 10a, via a substantially serrated surface structure. The serrations of the connecting element 13 and those of the connection lugs 11, 12 interlock and the contact area is thus increased. The interlocking individual projections and recesses (serrations in FIG. 10a) can also be rounded, for example wave-shaped, as shown in FIG. 10b. Also, parts of the contact surfaces 21a, 22a (consequently also contact surfaces 21b, 22b) may be smooth and other parts may be structured, see FIG. 10c. It is advantageous if the cross-section along spatial direction z is further either constant or monotonically tapers in negative z-direction.
[0115] In a further embodiment, FIG. 10d shows the at least partial coating of at least one of the contact surfaces 21a, 22a (consequently also contact surfaces 21b, 22b) of connecting element 13 and/or connection lugs 11, 12. In particular, it is useful for improving the electrical contact between connecting element 13 and connection lugs 11, 12 if the coating is formed from a softer material than the at least one of the connection lugs 11, 12 and/or the connecting element 13. Thus, when the connecting element 13 and the connection lugs 11, 12 are pressed together, a high contact quality and, if necessary, interlocking of the contact surfaces 21b, 22b of the connecting element 13 and contact surfaces 21a, 22a of the connection lugs 11, 12 can be achieved by plastic deformation of the coating.
[0116] In another embodiment, FIG. 11a, b shows a fuse device 1 according to the subject matter with several fuse conductors, each comprising two connection lugs 11, 12 and a connecting element 13. The fuse conductors can be located in a common chamber of the housing, see the insulation conductors of the pairs of connection lugs 11b-12b and 11c-12c in FIG. 11b.
[0117] Here it may be advantageous to arrange a seal 18 between the conductors. All or a subset of the fuse conductors can also be separated from each other by additional housing walls extending between the fuse conductors, see the separated connection lug pair 11a-12a in FIG. 11b.
[0118] The connecting elements 13 of the respective fuse conductors can be released together from the respective gaps 26 between the respective connection lugs 11, 12 by a single actuator 17. It is also possible for the connecting elements 13 of the fuse conductors to each be released from the connection lugs 11, 12 by a different actuator 17. It is also possible for subsets of the fuse conductors to be disconnected from respective individual actuators 17 and/ or for subsets to be driven together by a common actuator 17.
[0119] Separation of the housing 10 into a plurality of chambers containing individual ones or more of the fuse conductors, as shown in FIG. 11c, has the advantage that a separation operation in a first chamber does not affect the contents of another chamber. For example, the distribution of waste products generated during the separation such as dust, soot, splinters or the like from already separated fuse conductors into the area of other fuse conductors that may still be separated can be prevented.
[0120] Since gas can accumulate in the cavity 24 when the connecting element is abruptly disconnected from the connection lugs 11, 12 and a pressure can build up which impedes the movement of the connecting element 13, it may be advantageous to provide venting means 25 in this area of the housing 10. As shown in FIG. 12a, b, for example, a valve, hole, by breakable seal, or similar device is possible through which gas can escape into the cavity 24 when the fuse device 1 is triggered and the connecting element 13 moves. The venting means may be located on the top wall of the housing 10 as shown in FIG. 12, but may also be located on side surfaces or other surfaces.
[0121] FIGS. 13a-d show embodiments of the insulators 16 of the fuse device 1 according to the subject matter. The insulator 16 as shown in FIG. 13a is flush with the contact surface 21a, 22a of the connection lug 11, 12. It can also project beyond the contact surface 21a, 22a towards the center of the gap as shown in FIG. 13b. In FIG. 13b, various designs of insulators 16 projecting beyond the contact surface 21a, 22a are shown, an insulator with a constant cross-section at the top and two tapered designs below. By tapering the insulator 16, increased flexibility can be achieved, and one of the lower two insulators 16 of FIG. 13b offers less resistance when the connecting element 13 is detached from the gap 26 than the upper design, in which the insulator's area moment of inertia is higher due to the unchanged cross section.
[0122] FIG. 13c shows the sequence of deformation of an insulator overhanging the contact area 21a, 22a of the connection lug 11, 12 when the connecting element 13 is separated from the connection lugs 11, 12. The connecting element 13 causes bending of the insulator 16 as it moves out of the gap 26. Once it has passed the insulator 16, the latter, driven by its elasticity, moves back to its original position and prevents the connecting element 13 from sliding back into the gap 26, together with the expansion of the connecting element 13. If the insulator 16 protrudes into the gap 26, it is impossible for the connecting element 13 to slide back into the gap 26, even without expansion of the latter.
[0123] In particular, in the embodiment examples FIG. 13 b, the insulator 16 may be formed of an elastic non-conductive material such as plastic, rubber, silicone. In FIG. 13a, in addition to these materials, a solid material such as glass, ceramic, coated metal, or the like may be used.
[0124] FIG. 13d discloses a mechanical snap element that, like the elastic insulator 16 of FIG. 13c, is displaced and opened by the connecting element 13 when the connector 13 is moved. After the connecting element 13 has left the gap 26 and left the insulator 16 behind, the latter snaps back into the starting position driven by its mechanical mechanism and blocks the return path of the connecting element 13. The snap element may be formed of elastic non-conductive materials such as plastic, rubber, silicone, etc., but also of non-conductive solids such as glass, ceramic, coated metal, or the like. The elasticity is achieved by a spring mechanism.
