Title of Invention

A CASE FOR ELECTRICAL SWITCHGEAR AND AN ELECTRICAL SWITCHGEAR APPARATUS COMPRISING SUCH A CASE

Abstract

The present invention relates to a case for electrical apparatus. The case comprises a fIrst half shell (1) comprising a fIrst side wall (3) and circumferential walls (4), a second half shell (2) comprising a second side wall (5) and circumferential walls (6) and junction blocks (10, 11) arranged on an external part of the case to secure the first and second half shells. Said junction blocks comprise a first part (12) arranged outside the circumferential walls and two securing walls (13, 14) perpendicular to said first part and arranged on the external faces of the fIrst and second side walls. An electrical switchgear apparatus comprising such a case comprises connecting conductors (27) cooperating with terminals (26) situated in said junction blocks.

Full Text

The field of the present invention relates to a case for electrical apparatus and more particularly to a case for electrical switchgear and an electrical switchgear apparatus comprising such a case The invention relates to a case for electrical switchgear comprising: -a first half shell comprising a first side wall and first circumferential walls arranged appreciably perpendicularly to the edge of the first side wall, -a second half shell comprising a second side wall and second circumferential walls arranged appreciably perpendicularly to the edge of the second side wall, and -means for securing the first and second half shells face to face, the first and second circumferential walls being in contact. Cases for modular electrical switchgear comprise in known manner two half shells to be assembled. Generally, the two half shells are arranged one against the other and then assembled by screws or rivets. Each half shell generally comprises columns of cylindrical shape open onto the walls of said half shell so as to be able to insert the rivets or screws. When assembly takes place, complementary columns of each half shell are arranged in the extension of their respective axes in order to insert the rivets. After they have been inserted in each column, the rivets are crimped by means of a special tool. Assembly by screws is performed according to the same principle. The screws are inserted in the columns then screwed into nuts. It is also possible to screw the screws directly into the bulk of the case. In this case, the screws pass freely through a first column having an internal diameter larger than the diameter of the screws. The screws are then screwed into a second complementary columns having an internal diameter smaller than the diameter of the screws. Assembly by rivets or by screws requires special tools. This results in a large assembly time and a very high manufacturing cost of the switchgear. Moreover, these fixing modes do not provide cases that cannot be dismantled. It is in fact easy to dismantle a case fixed by screws or to remove a rivet and replace it by another one. The object of the invention is to achieve a case for electrical switchgear able to be assembled quickly without any special tools and also an electrical switchgear apparatus comprising such a case. Accordmg to the invention, the means for securing the case comprise at least one junction block arranged on an external part of the case to join an external face of the first side wall to an external face of the second side wall, said junction block comprising a first part arranged outside the circumferential walls and two securing walls perpendicular to said first part and arranged on the external faces of the first and second side walls. According to a preferred embodiment, the securing walls of the junction block comprise first latching means cooperating with suitable forms of the side walls to fix said junction block onto the case. Preferably, the first latchmg means of the securing walls of the junction block are tabs comprising latching splines designed to cooperate with notches situated in the side walls of the case. Advantageously, the first and second side walls comprise projections comprising second latching means to fix said side walls onto the first part of the junction block. In a particular embodiment, the half shells comprise third latching means arranged on the internal faces of the walls to hold the half shells in their respective positions. Preferably, the third latching means comprise flexible tabs provided with latching splines at their ends and arranged in the extension of circumferential walls, and notches situated in circumferential walls opposite the tabs to receive the latching Advantageously, the third latching means comprise at least three points for fixing to the circumferential walls, a first fixing point being situated towards the back plate of the case, a second fixing point being situated towards an output side of the case, and a third fixing point being situated towards a input side of the case. To make the case impossible to dismantle, the third latching means are arranged in a manner hardly accessible from the outside of the walls to prevent the case from being opened without the half shells being deformed. The case comprises a cover forming the front face of said case and fixed by means for fixing by latching onto walls of the half shells, said means for fixing by latching not being able to be plied with from the outside of the case, and the circumferential walls having an opening situated towards the front face of the case. For connection of the case, the junction block comprises recesses designed to receive means for electrical connection cooperating with conductors arranged between the inside and the outside of the case. An electrical switchgear apparatus according to an embodiment of the invention comprises a case according to embodiments described above, an electrical circuit arranged inside said case, and electrical conductors connected to said circuit and passing through the circumferential walls to cooperate with terminals of the means for electrical connection of a junction block. In a particular embodiment of a switchgear apparatus, the electrical conductors are made of preformed flat copper connected to a electrical circuit arranged in the case, the form of the conductors having a first part connected perpendicularly to the plane of the electrical circuit, a second part folded with respect to the first part and a third part extending outside the circumferential wall. Preferably the first part of the conductors comprises two ends able to be connected to the circuit, the second part of the connector being closer to a first end to make the connecting conductor reversible. Other advantages and features will become more clearly apparent from the following description of particular embodiments of the invention given as non-restrictive examples only and represented in the accompanying drawings in which: -Figure 1 represents a first embodiment of a half shell for a case according to the invention, -Figure 2 represents an embodiment of a second half shell complementary to the first half shell of figure 1, -Figures 3 and 4 represent embodiments of junction blocks for a case according to the invention, -Figure 5 represents a front face cover for a case according to figures 1 and 2, -Figure 6 represents the assembly of an electrical switchgear apparatus comprising a case according to figures 1 to 5, -Figure 7 represents an assembled case comprising elements according to figures 1 to 5, -Figures 8 and 9 represent embodiments of connecting conductors for switchgear apparatuses comprising a case according to the invention, -Figure 10 shows the layout of a connecting conductor between a electrical circuit and a terminal. A modular case for electrical switchgear according to an embodiment comprises a first half shell 1 and a second half shell 2 represented respectively in figures 1 and 2. The first half shell 1 comprises a first side wall 3 and first circumferential walls 4. The second half shell 2 also comprises a second side wall 5 and second circumferential walls 6. To assemble the case, the half shells are arranged side by side and the first and second circumferential walls are positioned in contact so as to form the outline of said case. Thus formed, the case comprises a back plate 7 designed to be fixed onto a support, and a first output side 8 and a second input side 9 perpendicular to the back plate and to the side walls. The support is preferably a symmetrical rail. According to an embodiment of the invention, the half shells 1 and 2 are secured by junction blocks 10 and 11 represented in figures 3 and 4. Each junction block comprises a first part 12 designed to be in contact with an output or input side of the circumferential walls, and two securing walls 13 and 14 perpendicular to said first part. Each securing wall of the junction blocks is in contact with an external face of each side wall to keep the half shells side by side in their respective positions. The securing walls comprise a first latching device to fix the junction blocks onto the walls of the half shells. This device preferably comprises tabs 15 extending the securing walls and comprising latching splines 16 designed to cooperate with notches 17 situated in the side walls of the case. To achieve a more efficient fixing of the junction block, the side walls of the half shells comprise projections 18 comprising a second latching device to fix said side walls to the first part 12 of the junction blocks. This second latching device comprises for example flexible tabs 19 cut out from the bulk of the projections and openings 20 situated in the first part of the junction blocks. When the junction blocks are fitted, to secure the half shells, the projections 18 are slid onto the first part 12 of the block and the securing walls 14 are slid onto the external faces of the side walls 3 and 5. Then, at the end of travel, when the block is in place, the tabs 15 latch onto the notches 17 and the tabs 19 penetrate into the openings 20 to secure the junction block on the half shells. When the two junction blocks are fitted respectively on the output and input sides, the two half shells are securedly united. It is then possible to fit a cover 21 onto the front part of the case, opposite the back plate. This cover 21 is preferably fixed by a latching device. Said device comprises for example latching splines on the edge of the cover and notches on the edge of the circumferential walls of the half shells. Assembly of such a case is very easy and does not require any special tools. Assembly in fact consists in holding the half shells against one another and then fitting the output and input side junction blocks until the tabs latch, and in fixing the cover by simply pressing it into place. The half shells can also be secured in their respective positions by a third fixing device with latching. In the particular embodiment of figures 1 and 2, these devices notably comprise flexible tabs 22a to 22d arranged on the internal faces of the side walls in the extension of the circumferential walls. Said tabs comprise at their ends latching splines respectively 23a and 23d. Opposite the tabs, the circumferential walls comprise notches 24a and 24d or shoulders to receive the latching splines and lock the case closed. The case preferably comprises at least three fixing points, a first fixing point corresponding to a first tab 22a arranged on the input side and cooperating with a first notch 24a, a second fixing point corresponding to a second tab 22b arranged on the output side and cooperating with a second notch 24b, and a third fixing point corresponding to a third tab 22c or 22d arranged on the back plate of the case and cooperating with a third notch respectively 24c or 24d. To guarantee operation of certain electrical switchgear, it has to be made impossible or difficult to dismantle the cases without damaging the latter. In cases according to this particular embodiment of the invention, the tabs are disposed in such a way that they are no longer plied with to separate the half shells, any attempt at opening being liable to deform the case. Figure 6 shows an exploded view of a case according to the particular embodiment of the invention and figure 7 shows a view of the same case assembled. In an electrical switchgear apparatus according to an embodiment of the invention comprising a case as described above, an electrical circuit 25 is arranged between the two half shells 1 and 2. According to a preferred embodiment, the junction blocks comprise recesses designed to receive electrical connection terminals 26. Said terminals are designed to be associated to connecting conductors 27 arranged inside and outside the case. The terminals are preferably tunnel terminals comprising a stirrup and a clamping screw to secure a connecting conductor and a line conductor. The circumferential walls comprise openings 28 to enable the connecting conductors to pass between the inside and the outside of the case. The junction blocks preferably comprise insulating partitions 29 arranged between the terminals. These insulating partitions advantageously comprise an edge 30 of a larger width than that of the partition so as to increase the isolation distance between the terminals. When the junction block is fitted onto the case, the edge 30 comes into contact with the output and input circumferential walls so as to ensure continuity of electrical isolation and a high isolation distance outside said circumferential walls of the case. The connecting conductors 27 can be connected inside the case to electrical circuits 25 comprising electrical circuits and possibly electronic components. The plane of the electrical circuits being generally parallel to the side walls, said connecting conductors must have particular forms to be able to connect the output terminals and said circuits. In preferred embodiments, the electrical conductors are made of preformed flat copper and connected to the electrical circuit by soldering or crimping of a first end. Said conductors represented in figures 8 and 9 preferably have a first part 31 arranged perpendicularly to the plane of the electrical circuit, a second part 32 folded with respect to the first part and a third part 33 extending outside the circumferential walls. The first part comprises cutouts 34 so as to be able to be soldered onto a electrical circuit by one or more soldering points 35. Said first part preferably comprises two opposite-ends so as to make the connecting conductors reversible, the second part being closer to a first end than to a second end. This type of preferred connecting conductors enables two connecting conductors to be connected in the same output plane and two terminals to be used side by side, said conductors being arranged head-to-tail as in figures 8 and 9. Each end of the first part comprises cutouts 34 to be able to be soldered onto the electrical circuit. Figure 10 shows connecting conductors 27 connected to the circuit 25 and associated to terminals 26. The components constituting the case described above are preferably made of moulded plastic material. The shapes of the half shells and junction blocks may be different while performing the same functions. In particular, the shapes of the latching means may be different from those of the flexible tabs provided with splines. The cover represented in figures 5 and 7 is closed, but in other embodiments a cover can have openings or comprise setting, operating or display means. The width of the cases can be variable, for modular cases it is generally equal to multiples of 9mm, for example 18mm, 27mm, 36mm or 54mm. In this case, the junction blocks can have a large number of terminals arranged side by side WE CLAIM: 1. A case for electrical apparatus comprising: a first flange (1) comprising a first side wall (3) and first circumferential walls (4) arranged appreciably perpendicularly to the edge of the first side wall, a second flange (2) comprising a second side wall (5) and second circumferential walls (6) arranged appreciably perpendicularly to the edge of the second side wall, and means for securing the first and second flanges face to face, the first and second circumferential walls being in contact, and at least one electrical junction block arranged on an external parts of the case, the case characterized in that at least one of said means for securing the flanges is formed by one of said electrical junction blocks (10, 11), joining an external face of the first side wall (3) to an external face of the second side wall (5), said electrical junction block comprising a first part (12) arranged outside the circumferential walls and two securing walls (13, 14) perpendicular to said first part and arranged on the external faces of the first and second side walls. 2. The case as claimed in claim 1 wherein the securing walls (13,14) of the electrical junction block comprise first latching means (15, 16) operating in conjunction with notches (17) of the side walls to fix an electrical junction block onto the case. 3. The case as claimed in claim 2 wherein the first latching means of the securing walls of the electrical junction block are tabs (15) comprising latching splines (16) designed to operate with notches (17) situated in the side walls of the case. 4. The case as claimed in claim 2 or 3 wherein the first and second side walls (2,3) comprise projections (18) comprising second latching means (19) to fix said side walls onto the first part (12) of the electrical junction block (10,11). 5. The case as claimed in any one of the claims 1 to 4 wherein the flanges comprise third latching means (22a-22d, 23a-23d, 24a-24d) arranged on the internal faces of the circumferential walls (4,6) to hold the flanges in their respective positions. 6. The case as claimed in claim 5 wherein the third latching means comprise flexible tabs (22a-22d) provided with latching splines (23a-23d) at their ends and arranged in the extension circumferential walls, and notches (24a-24d) situated in circumferential walls opposite the tabs to receive the latching splines. 7. The case as claimed in one of the claims 5 or 6 wherein the third latching means comprise at least three fixing points for fixing to the circumferential walls, a first fixing point (22c, 22d, 23c, 23d, 24c, 24d) being situated towards the back plate (7)of the case, a second fixing point (22b, 23b, 24b) being situated towards an output side of the case, and a third fixing point (22a, 23a, 24a) being situated towards a input side of the case. 8. The case as claimed in any one of the claims 1 to 7 comprises a cover (21) forming the front face of said case and fixed by means for fixing by latching onto walls of the flanges, said means for fixing by latching not being able to be touched from the outside of the case, and the circumferential walls having an opening situated towards the front face of the case. 9. The case as claimed in any one of the claims 1 to 8 wherein the electrical junction block comprises recesses designed to receive means for electrical connection (26) operating in conjunction with conductors (27) arranged between the inside and the outside of the case. 10. The case as claimed in claim 9 wherein the electrical junction block comprises means for insulating separation (29) comprising an edge (30) so as to increase an isolation distance between two terminals (26) of the means for electrical connection, the insulating separations (29)being in contact with the circumferential walls of the case. 11. An electrical apparatus comprising a case as claimed in any one of the claims 1 to 10, an electrical circuit (25) arranged inside said case, and electrical conductors (27) connected to said circuit and passing through the circumferential walls to operate in conjunction with terminals of the means for electrical connection of said electrical junction blocks. 12. The electrical apparatus as claimed in claim 11 wherein the electrical conductors (27) are made of pre-formed flat copper connected to electrical circuit (25) arranged in the case, the form of the conductors having a first part (31) connected perpendicularly to the plane of the electrical circuit, a second part (32) (32) folded with respect to the first part and a third part (33) extending outside of the circumferential wall. 13. The electrical apparatus as claimed in claim 12 wherein the first part of the conductors comprises two ends able to be connected to the circuit, the second part of the connector being closer to a first end to make the connecting conductor reversible.

Documents:

228-mas-1998-abstract.pdf

228-mas-1998-claims duplicate.pdf

228-mas-1998-claims original.pdf

228-mas-1998-correspondence others.pdf

228-mas-1998-correspondence po.pdf

228-mas-1998-description complete duplicate.pdf

228-mas-1998-description complete original.pdf

228-mas-1998-drawings.pdf

228-mas-1998-form 1.pdf

228-mas-1998-form 26.pdf

228-mas-1998-form 3.pdf

228-mas-1998-other documents.pdf

abs-228-mas-1998.jpg