AU2013251019A1

AU2013251019A1 - Bridging device using different materials and method of manufacture

Info

Publication number: AU2013251019A1
Application number: AU2013251019A
Authority: AU
Inventors: Etienne Gancel
Original assignee: Hager Electro SAS
Current assignee: Hager Electro SAS
Priority date: 2012-04-17
Filing date: 2013-04-12
Publication date: 2014-11-06
Anticipated expiration: 2033-04-12
Also published as: EP2839550A1; FR2989526B1; FR2989526A1; WO2013156719A1; CN104247168A; BR112014025298A2; AU2013251019B2

Abstract

The subject of the present invention is a bridging device for electrically linking electrical apparatuses of a board such as circuit breakers, comprising an electrically conducting part (1) which exhibits, on the one hand, contact zones (2) for connecting electrically to said apparatuses, and, on the other hand, a core (3) for electrically interlinking said contact zones (2). This bridging device is characterized in that the constituent material of the contact zones (2), on the one hand, and the constituent material of the core (3), on the other hand, are different. The chosen shapes and principles of assembly associated with the choices of different materials allow economical execution. The subject of the invention is also a method of manufacturing such a device.

Description

1 Bridging device using different materials and method of manufacture The present invention relates to the field of electrical equipment for an 5 electrical installation of a building and its subject matter is a particular bridging device, as well as a method for manufacturing such a device. A bridging device generally makes it possible to set to the same electrical potential the connecting terminals of electrical devices, such as circuit 10 breakers, mounted adjacent to one another on an electrical panel. FR 2 190 319 discloses a bridging device comprising a flexible metal con ductor, on which plugs are fixed at predefined distances for the electrical connection of different devices. Said plugs can be fixed onto the conductor 15 by pinching, welding, brazing or the like. DE 26 00 795 discloses a similar bridging device in the form of a wire-like conductor to which lugs are fixed at regular intervals for the connection of devices. However, one of the dis advantages of this type of device is that it is necessary to make the connec tion of each device separately, taking into account the flexible nature of the 20 conductor. FR 2 693 318 discloses a bridging device in the form of teeth connected in twos, threes or more by a core. The components used to obtain a bridging device are therefore the same, regardless of the number of devices to be 25 connected. A bridging device of this type can however lack rigidity, and because of their arrangement in series the contact zones have to be dimen sioned to enable each one to transfer all of the current to the other devices.

-2 With the aim of reducing the cost of manufacturing a bridging bar, EP 1 930 986 discloses such a rigid bar made from a moulded aluminium alloy. The main disadvantage however is that the aluminium yields easily under restraint and tends to oxidize, making the electrical contacts less ef 5 fective over time. US 4 689 718 discloses a bridging device in the form of jumper links, mounted on an insulating base, the jumper links having two, three, even more free ends for contacting with the electrical device into which they are 10 fitted. One of the disadvantages of embodiments based on the principles de scribed above is that good electrical conduction, and the application of the required standards, requires the use of a material known for its electrical 15 conducting properties, for example a copper-based alloy, which is associ ated with significant costs for the bridging device, as this type of material is generally expensive. Furthermore, a bridging comb is generally obtained by cutting out from a larger strip of material, the amount of scrap material arising from defining the contours of the teeth of said comb can be very 20 significant, and the cost of manufacturing such an element can thus be high. The aim of the present invention is to overcome at least some and prefera bly all of these disadvantages, and in particular it proposes a bridging de 25 vice which ensures good electrical conduction and which is inexpensive to manufacture, which is achieved as described below, in particular by form ing the conducting part of the bridging device by way of an assembly.

-3 For this purpose the subject matter of the invention is therefore a bridging device for electrically connecting electrical devices on a board, such as cir cuit breakers, comprising an electrically conducting part, which has on the one hand contact zones for electrical contact with said devices and on the 5 other hand a core making it possible to connect said contact zones between them electrically. Said bridging device is characterised in that the constituent material used for the contact zones on the one hand and the constituent material of the 10 core on the other hand are different. The subject matter of the invention is also a method for manufacturing such a connecting device, comprising a step of manufacturing the conduct ing part by assembly. 15 Said method is characterised in that the manufacture of the conducting part is performed by assembling with the core and by plastic deformation, the attached parts bearing the contact zones. 20 The invention is explained in more detail in the following description which relates to preferred embodiments, given as non-limiting examples, and explained with reference to the attached diagrammatic drawings, in which: 25 - figure 1 shows a portion of a particular embodiment of the invention, where the bridging device comprises a rigid metal core made from two plates between which bars are inserted to form the contacting parts; -4 - figure 2 shows a detail of a possible method of fixing the bars between two rigid plates forming the core of the bridging device. Therefore, firstly the subject matter of the invention is a bridging device for 5 electrically connecting the electrical devices of a board, such as circuit breakers, comprising an electrically conducting part 1 which has on the one hand contact zones 2 for electrical contact with said devices, and on the other hand a core 3 making it possible to electrically connect said contact zones 2 between them. 10 The bridging makes it possible to connect two electrical devices electri cally, such as circuit breakers, so as set the same potential at least at one of their terminals. Electrical devices are generally mounted on a board and aligned adjacent to one another. The provided terminals are therefore 15 aligned and generally spaced apart at regular intervals. The contact zones 2 are therefore also separated from one another on the bridging device at a distance which corresponds substantially to the possible distance of the contact terminals of the electrical devices. 20 Compatible electrical devices therefore have terminals where a bridging device can be connected so as to supply electrical potential thereto or take electrical potential therefrom to direct it to another device. The connection of the bridging device to different electrical devices is 25 preferably in the form of a rapid leaf spring connection, but can also be in the form of screws. The bridging device therefore has at least two contact zones 2, which as described below, can for example be supported by attachment parts 4 in the -5 form of bars, similar to teeth or forks, planar or not. Said contact zones 2 are connected electrically via the core 3, such that one of the latter, con nected electrically to a device, is connected electrically to another contact zone 2, connected to another device, so as to effectively provide the bridg 5 ing between these two devices. The contact zones 2 and the core 3 form all or part of the conducting part 1 of the bridging device. Furthermore, the core 3 can be common to two contact zones 2 or more. According to the invention the constituent material used for the contact 10 zones 2 on the one hand and the constituent material of the core 3 on the other hand are different, the core 3 being formed essentially in particular from a metal which is less conductive than the one used for the contact zones 2. The contact zones 2 can be obtained by galvanisation, directly on the core 3 or, as described below, on attachment parts 4 assembled with the 15 core 3. It is thus possible to adapt independently from one another, on the one hand, the constituent material of the core 3 to the function of the latter and, on the other hand, the constituent material of the contact zones 2 to their own function. In cases where the contact zones 2 are supported by attachment parts 4 the same material, suitable for their respective functions, 20 can be used for these two elements. Alternatively, the contact zones 2 and the attachment parts 4 can be made from a material suitable for their func tion: one material for the contact zones 2, one material for the attachment parts 4. Of course, the materials can be alloys that are specially formulated from several components. The difference in the constituent materials can 25 be interpreted as a difference in the proportions of the components, even in the components themselves. As described further below, one of the functions of the core 3 can also be to ensure the electrical connection between the contact zones 2, to give the -6 bridging device a certain amount of rigidity. The contact zones 2 them selves are preferably made from the same material as they are used for the same function, namely ensuring direct contact with the electrical device. The use of different materials also makes it possible to make the contact 5 zones 2 and the core 3 separately 2, which makes it possible to reduce the cost of primary materials. If the contact zones 2 are possibly supported by the attachment parts 4 as sembled with the core 3, the attachment part 4 can be made from a ho 10 mogenous material and therefore identical to that of the contact zone 2, different from the material used for the core 3. According to one possible feature the attachment parts 4 on the one hand as well as the core 3 on the other hand have essentially the form of a section 15 of linear profile, which can of course be used even if the constituent mate rial used for the contact zones 2 on the one hand and the constituent mate rial of the core 3 on the other hand are identical. The advantage of such a feature is in particular that the amount of discarded material produced dur ing manufacturing is reduced significantly, as it is not necessary to produce 20 a comb by removing material around the contact zones 2. Thus, the amount of waste produced is reduced significantly compared to embodiments in which the conducting part 1 is obtained by removing material from raw material. Holes 8 required for crimping attachment parts 4 assembled with the core 3 may for example constitute most of the discarded material. 25 In particular embodiments, which do not necessarily require the material used for the contact zones 2 on the one hand and the constituent material of the core on the other hand to be different, the bridging device is in the form of a rigid bar in the form of a rake, the contact zones 2 being supported by -7 metal attachment parts 4 fixed to the core 3, in particular in the form of bars, said core 3 being made of metal and rigid so as to give said bridging device its rigidity, the attachment parts 4 having in particular the form of teeth or forks. The advantage of supporting the contact zones 2 with at 5 tachment parts 4, and therefore making the conducting part 1 in the form of an assembly, is in particular to limit the quantity of discarded material pro duced during manufacture. As the bridging device is then rigid, it is possi ble to obtain at the same time at least the good positioning of the contact zones 2 relative to the electrical contact surfaces of the devices against 10 which they have to bear. If the electrical devices are provided with a rapid connection, generally by means of a leaf spring, the simple positioning of the bridging device is sufficient to ensure the electrical connection with and between the different electrical devices. 15 Thus, the core 3 is preferably sufficiently rigid to give the bridging device resistance so that it does not at least deform under its own weight, and re sistance which enables it not to deform when mounted in different electri cal devices. 20 The attachment parts 4 can each be in the form of a bar similar to a rectan gle of a material with a metal base, that is preferably a good conductor, and bears the contact zones 2, and is therefore designed to fit into the electrical device. The attachment part 4 can have another form compatible with its connecting function: a fork, angular piece in the form of an obtuse V, etc. 25 According to a further possible feature, which does not necessarily require the material used for the contact zones 2 on the one hand and the constitu ent material of the core 3 on the other hand to be different, the core 3 is in the form of two electrically conducting plates 5 placed against one another, -8 each having concave projections 6 arranged such that when a concave pro jection 6 of a plate 5 is placed opposite a concave projection 6 of the other plate 5, they together define an opening 7, at the centre of the core 3, where an attachment part 4 bearing a contact zone 2 can be placed. 5 The core 3 can be made advantageously from a material that is less electri cally conductive than the contact zones 2, see attachment parts 4 which bear them, which makes it possible to reduce the cost of the device. It is then necessary to use a greater amount of material which can be obtained 10 by using a thicker core 3, or, as described above, a core made from two plates 5 positioned against one another, between which the attachment parts 4, bearing the contact zones 2, are mounted in contact with each of the two plates 5. 15 By placing the attachment piece 4 in the centre of the core 3 it is possible to double the contact surface between the attachment part 4 and the core 3, and therefore the surface through which electricity circulates, thus reducing the local temperature. The opening 7 into which the attachment part 4 is placed is obtained by the simple presence opposite one another of a con 20 cave projection 6 in at least one of the plates 5. Arranging concave projec tions 6 on each plate 5 makes it possible in particular to reduce the number of different parts, as then both plates 5 have the same shape. Of course, in alternative embodiments, the positioning of the attachment 25 part 4 in the centre of the core 3 can be achieved in a similar manner but with a monobloc core 3, and the opening 7 can be made by removing mate rial in a conventional way, by piercing or the like.

-9 The attachment part 4 can also be fixed for example on the outside of the core 3 by clinching. 5 According to a further possible feature which makes it possible to avoid using additional parts to fix them to one another and ensure the rigidity of the assembly, the two metal plates 5 are fixed to one another by plastic de formation, in particular by clinching in a clinching zone 10, even crimping. This also makes it possible to limit the size of the core 3 formed by these 10 two plates 5. The clinching zone 10 contributes to the good electrical communication between the two plates 5. According to a further possible feature, in particular in order to reduce the cost of manufacture by assembling the device, and also complete the 15 clamping between the two plates 5 when the core 3 is made from the latter, the contact zones 2 are supported by attachment parts 4 fixed by plastic deformation to the core 3, in particular the attachment parts are in the form of bars and connected for example by riveting, even crimping, punching, clinching or the like. This feature can also be implemented even if the con 20 stituent material used for the contact zones 2 on the one hand and the con stituent material of the core 3 on the other hand are identical. As already outlined above, good contact between the bar 4 and the core 3 is necessary to ensure the good circulation of electrical energy without exces 25 sive heating. Thus preferably, the attachment parts 4 are fixed by crimping to the core 3, by deforming a tongue 9 such that it terminates in a hole 8, for example a tongue 9 extending from the core 3 and a hole 8 formed in the attachment part 4. Furthermore, according to a further possible feature, the tongue 9 extends from a concave projection 6, the hole 8 being ar- -10 ranged in the attachment part 4 and having a rectangular form, the tongues 9 terminating in pairs head-to-tail relative to one another in the same hole 8, so as to each terminate close to an end of said hole 8 in the form of a rectangle. This assembly is illustrated in figure 2. 5 By using parts in the form of a section of linear profile and assembly by plastic deformation of the attachment parts 4 bearing the contact zones 2, the amount of primary material used can be significantly reduced, as the discarded material is essentially that which is generated from making the 10 hole 8. The cost of manufacturing the device is therefore reduced. Preferably, the core 3 is made essentially from a metal which is less con ductive than the one used for the contact zones 2, or for the bar or bars 4, the contact zones 2 being made in particular essentially of copper, and the 15 core 3 being made essentially of zinc. The contact zones 2 can be made by a coating of different material on the attachment parts 4 or can be a portion of the attachment part 4, the contact zones 2 being thus of the same mate rial as the attachment part 4. The contact zones 2 are therefore made from a highly conductive material, and can therefore have small dimensions, 20 which is particularly compatible with connecting solutions by rapid fitting into the centre of the electrical devices. The core 3 itself is made essentially of zinc, possibly combined with copper, which has satisfactory electrical conductivity and which is less expensive. Pure zinc can be obtained for example from strips. 25 Lastly, to avoid any electrical hazards, it is possible for the bridging device to have a coating of insulating material around the conducting part 1, in particular a plastic material overmoulded onto the conducting part 1 or an extruded profile, which makes it possible to insulate the conducting part 1 - 11 electrically from the exterior. The selected forms and principles of assembly combined with the selection of different materials therefore enable an economic method. 5 The subject matter of the invention is also a method for manufacturing a bridging device as described above, comprising a step of manufacturing the conducting part 1 by assembly. According to the invention the manufacture of the conducting part 1 is performed by assembling with the core 3, by 10 plastic deformation, attachment parts 4 bearing the contact zones 2. This method of assembly is particularly economical, as it limits the amount of discarded material and components used for this assembly. In advanta geous embodiments for assembling the metal part 1, the assembly of at tachment parts 4 to the core 3 is performed by crimping, by deforming a 15 tongue 9 so that the latter terminates in a hole 8, each hole 8 being for ex ample arranged to receive two tongues 9, the tongue 9 extending in particu lar from the core 3 and the hole 8 being in particular arranged in the at tachment part 4. Technical details relating to securing by crimping have already been described above. 20 According to a further possible feature, the method also comprises a step consisting of cutting sections of profile to the required length for the pur pose of forming attachment parts 4 and/or the core 3, which makes it pos sible to reduce the amount of primary material required to form assembled 25 components designed for forming the conducting part 1. In fact, it is suffi cient to cut the components to have the desired cross section, then cut them to the desired length.

- 12 According to another possible feature, the method also comprises a step consisting of assembling the core 3 using at least two plates 5. It is thus possible to arrange the contact zones 2 on attachment parts 4 placed in the centre of the core 3 between the two plates 5. 5 In possible embodiments the assembly of the core 3 is performed by plastic deformation, in particular by clinching the plates 5 in a punching zone. It is thus possible to limit the components necessary to obtain the assembly. 10 Lastly, according to a further possible feature of the method it also includes a step consisting of forming contact zones 2 by galvanisation. Of course, the invention is not limited to the embodiments described. It is in particular completely possible to combine the features described above 15 in a different way. Therefore, modifications are still possible, particularly from the point of view of the composition of the various elements, with a different combination of the above features, or by the substitution of equivalent techniques, without departing as such from the scope of protec tion of the invention. 20

Claims

1. Bridging device for electrically connecting electrical devices of a board, such as circuit breakers, comprising an electrically conducting part 5 (1) which has on the one hand contact zones (2) for electrical contact with said devices and on the other hand a core (3), making it possible to connect said contact zones (2) between them electrically, the bridging device being characterised in that the constituent material used for the contact zones (2) on the one hand and the constituent material of the 10 core (3) on the other hand are different.

2. Bridging device according to claim 1, characterised in that it has the shape of a rigid bar in the form of a rake, the contact zones (2) being sup ported by metal attachment parts (4) fixed to the core (3), in particular in 15 the form of bars, said core (3) being made of metal and being rigid so as to give said bridging device its rigidity.

3. Bridging device according to claim 2, characterised in that the at tachment parts (4) on the one hand and the core (3) on the other hand have 20 essentially the form of a section with a linear profile.

4. Bridging device according to any one of claims 2 or 3, characterised in that the contact zones (2) are supported by attachment parts (4) fixed by plastic deformation to the core (3). 25

5. Bridging device according to claim 4, characterised in that the at tachment parts (4) are fixed by crimping to the core (3), by deforming a tongue (9) such that it terminates in a hole (8). -14

6. Bridging device according to any one of claims 1 to 5, characterised in that the core (3) is in the form of two electrically conducting plates (5) placed against one another, each having concave projections (6) arranged such that when a concave projection (6) of a plate (5) is placed opposite a 5 concave projection (6) of the other plate (5) they define between them in the centre of the core (3) an opening (7) in which an attachment part (4) bearing a contact zone (2) can be placed.

7. Bridging device according to claim 6, characterised in that the two 10 metal plates (5) are fixed to one another by plastic deformation.

8. Bridging device according to claims 5 and 7, characterised in that the tongue (9) extends from a concave projection (6), the hole (8) being arranged in the attachment part (4) and having a rectangular shape, the 15 tongues (9) terminating in pairs arranged head-to-tail pair relative to one another in the same hole (8), such that each tongue (9) terminates close to an end of said hole (8) in the form of a rectangle.

9. Method of manufacture of a bridging device according to any one of 20 claims 1 to 8, comprising a step of making the conducting part (1) by as sembly, characterised in that the manufacture of the conducting part (1) is per formed by assembling with the core (3), by plastic deformation, the at tachment parts (4) bearing the contact zones (2). 25

10. Method of manufacture according to claim 9, characterised in that it also comprises a step consisting of cutting to the required length sections of the profile for the purpose of forming the attachment parts (4) and/or the core (3). - 15

11. Method of manufacture according to any one of claims 9 or 10, characterised in that it also comprises a step consisting of assembling the core (3) from at least two plates (5). 5

12. Method of manufacture according to claim 11, characterised in that the assembly of the core (3) is performed by plastic deformation.

13. Method of manufacture according to any one of claims 9 to 12, 10 characterised in that the assembly of attachment parts (4) with the core (3) is performed by crimping, by deforming a tongue (9) such that it terminates in a hole (8), each hole (8) being set up for example to receive two tongues (9). 15

14. Method of manufacture according to any one of claims 9 to 13, characterised in that it also comprises a step consisting of forming the con tact zones (2) by galvanisation.