EP3624270A1 - Terminal for connecting an electrical conductor to the connection pad of an electrical device, and electrical protection device including such a terminal - Google Patents

Abstract

The present invention relates to a connection terminal B of an electrical conductor to a connection pad belonging to an electrical appliance, such a terminal B comprising a cage C capable of being fixed inside the housing of the appliance and comprising a orifice (8) of substantially parallelepiped shape delimited by four walls (4,5,6,7), this orifice (8) being able to receive the aforementioned range, one (4) of the aforementioned walls of the cage, said wall upper, comprising an orifice capable of allowing the passage of a screw (10), said screw comprising at one (10a) of its ends (10a, 1 Oc) situated outside the cage C, means of actuation (10b) of said screw (10), and at its opposite end (10c), a clamping pad (11) adapted to allow the clamping of the conductor between the aforementioned range and said pad (11) during actuation of the screw (10) causing the relative translational movement between the screw (10) and the CC cage ette terminal B is characterized in that it comprises an intermediate stage created inside the cage C so as to allow the housing of a nut (22) with elastic branches (25,26) having a threaded orifice through which the clamping screw (10) is intended to be mounted screwed, said elastic branches (25,26) cooperating with shapes provided on the side walls (6,7) of the cage C so that the nut (22) disengages in rotation when screwing as soon as the correct tightening torque is reached, and engages from the start to the end of unscrewing.

Description

TECHNICAL AREA

The present invention relates to a terminal for connecting an electrical conductor to a connection pad of an electrical appliance, such a terminal comprising a cage capable of being fixed inside the housing of the appliance and comprising a shaped orifice substantially parallelepiped delimited by four walls, this orifice being able to receive the aforementioned range, one of the aforementioned walls of the cage comprising an orifice capable of allowing the passage of a screw, said screw having at one of its ends located outside the cage, means for actuating said screw, and at its opposite end, a clamping pad capable of allowing the conductor to be clamped between the aforementioned area and said pad during actuation of the screw in the tightening direction causing the relative translational movement between the screw and the cage.

The present invention also relates to an electrical protection device comprising such a terminal.

STATE OF THE PRIOR ART

A screw terminal of the kind previously mentioned, is described for example in the patent EP 0 555 157 .

The electrical connection of power cables to the circuit breaker connection areas is a recurring concern for questions of safety of people and goods.

In fact, the installers working on site do not have torque wrenches allowing tightening to the correct torque of the different connection points. These torque wrenches are expensive and must be calibrated approximately once a year.

In addition, these keys sometimes do not have the right range of torques corresponding to a particular range.

As a result, the devices are sometimes tightened intuitively by a less and less qualified workforce. As a result, it is necessary to carry out tightening campaigns intended to ensure compliance with the tightening torques recommended by the manufacturers.

The present invention solves this problem and proposes a connection terminal making it possible to carry out, in a simple and economical manner, tightening to the correct torque of the conductor in the terminal, as well as an electrical protection device comprising such a terminal.

STATEMENT OF THE INVENTION

To this end, the present invention relates to a connection terminal of the kind mentioned above, this terminal being characterized in that it comprises an intermediate stage created inside the cage so as to allow the housing of a nut. with elastic branches comprising a threaded orifice through which the clamping screw is intended to be mounted screwed, said elastic branches cooperating with shapes provided on the side walls of the cage so that the nut disengages in rotation when screwed from reaching the right tightening torque, and engaging from start to finish.

According to a particular characteristic, the two elastic branches are able to compress radially when screwed on slopes belonging to the cage, the torque resulting from the compression of the branches opposing the tightening torque of the screw, until these branches escape the slopes as soon as the desired tightening torque is reached.

According to a particular characteristic, this terminal includes means for producing a clicking noise from the aforementioned exhaust of the branches of the slopes.

According to another characteristic, the aforementioned nut comprises an annular part comprising the orifice for the passage of the aforementioned screw, and from which two elastic branches extend extending circumferentially around this annular part in respectively two opposite directions.

According to another characteristic, each branch has at its free end a hooking element capable of cooperating with two hollow shapes, respectively first and second, provided on each side wall of the cage, each hook element cooperating with a hollow shape said first during tightening, and with a hollow shape called second, during loosening.

According to another characteristic, the above-mentioned first and second hollow shapes are produced by striking inside the side walls of the cage.

According to another characteristic, in each side wall, the two hollow shapes extend in a direction substantially perpendicular to the axis of the cage, the two hollow shapes of one of the side walls being arranged opposite the two hollow shapes on the other side wall.

According to another characteristic, each hollow shape called first comprises a surface portion forming a hooking slope located opposite the hollow shape called second of the same wall, the passage through this hooking slope for the element d 'hooking, to join the second hollow form, causing the aforementioned disengagement of the screw.

According to another characteristic, each hollow shape called second comprises, located opposite the hollow shape called first which is associated with it, a wall portion extending substantially perpendicular to the axis of the cage, and forming a stop d '' stop in rotation of the nut, during a unscrewing operation generating the clutch of the clamping screw from the start to the end of the unscrewing.

According to another characteristic, the aforementioned intermediate stage is formed by a mounted plate crimped inside the cage.

According to another characteristic, this plate has two pins said first able to be introduced respectively into two orifices belonging respectively to two edges respectively belonging to the two aforementioned side walls at the end of insertion of the plate in the cage, and two pins said second apt to be introduced by crimping the sheet of the plate into two orifices belonging respectively to the two edges of the side walls opposite to the previous ones.

The present invention also relates to an electrical protection device comprising at least one upstream terminal and / or at least one downstream terminal comprising the previously mentioned characteristics taken alone or in combination.

• La figure 1 est une vue en perspective d'une bague de friction appartenant à une borne selon une réalisation particulière de l'invention,
• La figure 2 est une vue en perspective d'un écrou appartenant à cette même borne, vu de dessus,
• La figure 3 est une vue en perspective illustrant la mise en place de cette bague sur cet écrou,
• La figure 4 est une vue en perspective de ce même écrou, vu de dessous,
• La figure 5 est une vue en perspective d'une cage appartenant à une borne selon l'invention,
• La figure 6 est une vue en perspective de cette même cage avant la mise en place de l'écrou précité à l'intérieur de la cage,
• La figure 7 est une vue en perspective de la plaque intermédiaire seule,
• La figure 8 est une vue en perspective de la cage précitée de la borne après la mise en place de l'écrou à l'intérieur de la borne, et avant l'introduction de la plaque intermédiaire,
• La figure 9 est une vue de face de la borne selon l'invention à l'état serré,
• La figure 10 est une vue en coupe axiale de la borne selon l'invention en position desserrée, sans le câble et sans la plaque,
• Les figures 11 et 12 sont des vues en perspective de cette même borne, vu du côté de l'insertion et du côté opposé à cette insertion,
• La figure 13 est une vue en coupe selon A-A de la figure 10, illustrant l'écrou en position d'accostage des pentes et autorisant le vissage,
• La figure 14 est une vue de dessus de l'écrou seul, dans la position de la figure précédente, illustrant l'effort de friction entre la cage et l'écrou, lié au couple de serrage,
• La figure 15 est une vue en coupe selon A-A de la figure 10, identique à la figure 13, mais illustrant la borne après le vissage, dans une position autorisant le dévissage, et
• La figure 16 est une vue en coupe selon A-A illustrant quatre positions différentes de l'écrou.

However, other advantages and characteristics of the invention will appear better in the detailed description which follows and which refers to the appended drawings given solely by way of example and in which:

• The figure 1 is a perspective view of a friction ring belonging to a terminal according to a particular embodiment of the invention,
• The figure 2 is a perspective view of a nut belonging to this same terminal, seen from above,
• The figure 3 is a perspective view illustrating the positioning of this ring on this nut,
• The figure 4 is a perspective view of the same nut, seen from below,
• The figure 5 is a perspective view of a cage belonging to a terminal according to the invention,
• The figure 6 is a perspective view of this same cage before the aforementioned nut is placed inside the cage,
• The figure 7 is a perspective view of the intermediate plate alone,
• The figure 8 is a perspective view of the above-mentioned cage of the terminal after the nut has been placed inside the terminal, and before the introduction of the intermediate plate,
• The figure 9 is a front view of the terminal according to the invention in the clamped state,
• The figure 10 is a view in axial section of the terminal according to the invention in the released position, without the cable and without the plate,
• The Figures 11 and 12 are perspective views of this same terminal, seen from the side of the insertion and from the side opposite to this insertion,
• The figure 13 is a sectional view along AA of the figure 10 , illustrating the nut in the docking position of the slopes and authorizing the screwing,
• The figure 14 is a top view of the nut alone, in the position of the previous figure, illustrating the friction force between the cage and the nut, linked to the tightening torque,
• The figure 15 is a sectional view along AA of the figure 10 , identical to the figure 13 , but illustrating the terminal after screwing, in a position allowing unscrewing, and
• The figure 16 is a sectional view along AA illustrating four different positions of the nut.

On the figure 10 , we see a cage C belonging to a connection terminal B according to the invention, this terminal being intended to be mounted and fixed inside an electrical protection device such as a low voltage circuit breaker, in order to allow the electrical connection of a connection pad 1 of this device to an electrical conductor 2 such as a power cable.

In a manner known per se, this terminal B comprises a cage C of substantially parallelepiped shape formed by a metal part 3 comprising four parallel walls in pairs 4,5,6,7, respectively an upper wall 4, a lower wall 5, and two side walls 6,7, this assembly delimiting a through orifice 8 of substantially parallelepiped shape intended to receive the free end of the connection pad 1 of the device. The upper wall 4 of this cage C has a smooth orifice 9 intended to allow the passage of a clamping screw 10, said screw 10 comprising at one 10a of its free ends, a part 10b intended to allow its actuation by means of a tool provided for this purpose, while its opposite end portion 10c comprises a so-called clamping pad 11 capable of coming to bear on the conductor to be connected, when the screw 10 is actuated, causing it to move in translation relative to the cage C in the direction of the cable 2. It will be noted that advantageously, this clamping pad 11 is fixed to the free end 10c of the clamping screw 10 by crimping.

As illustrated on Figures 5 and 6 , the terminal B according to the particular embodiment of the invention illustrated, comprises on each of its side walls 6,7, and on each side of the cage C, notches or orifices 12,13,14,15 intended to cooperate with a so-called intermediate plate 16, as illustrated on the figure 7 , during the introduction of this plate 16 inside the cage C.

Thus, this intermediate plate 16, preferably made of metal, comprises two lugs 17,18 called first able to be introduced first respectively in two notches 12,13 of the cage at the end of the introduction of the plate 16 in the cage C, as well as two so-called second lugs 19.20 able to be introduced then respectively into the two other notches or orifices 14, 15 of the cage C by crimping the sheet forming the so-called second lugs, this crimping making it possible to secure the intermediate plate 16 to the cage C. This intermediate plate 16 also includes a smooth orifice 21 intended to be brought opposite the smooth orifice 9 of the upper wall 4 of the cage C when the plate 16 is fixed inside the cage C.

According to the invention, and as illustrated on the figures 3 to 6 , this terminal B also includes a piece called nut 22, made of an elastic material, and comprising an annular central portion 23 comprising a threaded orifice 24, this nut 22 being intended to be introduced into the cage C between the upper wall 4 of the cage C and the intermediate plate 16 so that the three orifices 9, 24, 21 respectively of the upper wall 4, of the nut 22 and of the intermediate plate 16 are aligned.

According to this particular embodiment of the invention, this nut 22 thus comprises an annular part 23 comprising the aforementioned threaded orifice 24, and two semi-circular branches 25, 26 each extending around the above-mentioned annular part 23 over approximately half of its outer circumference, these two branches 25, 26 extending from the outer surface of this annular part 23 while being connected to this surface at two points 23a, 23b ( fig. 2 ) radially opposite.

This nut 22 is mounted centered with respect to the cage C on the one hand, by the introduction of its annular part 23 into the orifice 9 of the upper wall 4 of the cage C, and on the other hand, by the compression exerted by the side walls 6,7 of the cage C on the branches 25,26. The clamping screw 10 passes through the three orifices 9, 24, 21 provided respectively in the upper wall 4 of the cage C, in the nut 22, and in the intermediate plate 16, while being screwed into the threaded orifice 24 of the nut 22.

As illustrated on Figures 1.3 and 10 , according to the illustrated embodiment, the terminal comprises a so-called friction ring 33 capable of being mounted around the annular part 23 of the nut 22 so as to be secured in rotation to this nut by means of recesses able to cooperate with portions of the nut. This ring is interposed between this annular part and the cage and is intended to manage the friction between the different parts. According to this particular embodiment illustrated in the drawings, the two branches 25, 26 have come integrally with the annular part 23. These two branches 25, 26 each have, at their free end, a hook element 27, 28 extending towards the exterior of the annular part 23, these elements being intended to cooperate with hollow shapes 29 to 32 or clearances of material provided for this purpose, formed on the inner face of the side walls 6, 7 as will be explained in the following. These material releases advantageously consist of strikes made on the internal face of the side walls 6,7 of the cage C.

So, as illustrated on figures 13 and 15 , each side wall 6,7 has two clearances of materials 29,30 and 31,32 each forming a notch intended to cooperate with the hook elements 27,28 of the branches 25,26.

One of these notches 29, 31, said to be first, has a hooking slope in cross section, said notch comprising three portions of successive walls 29a, 29b, 29c, 31a, 31b, 31c forming a certain angle with respect to to the other.

The other of these notches 30, 32, known as the second notch, has a L-shaped cross section, having a wall portion 30a, 32a substantially perpendicular to the side wall 6,7 of the cage C, and an elongated wall portion and curve 30c, 32c extending towards the inner part of the cage C.

The notches 29 to 32 of the two walls 6,7 are arranged in such a way that the notches called first 29 and second 30 of one 6 of the walls are arranged respectively opposite the notches 31,32 respectively said first and second of the other 7 of the walls 6.7.

The one 29c, 31c of the wall portions 29a, 29b, 29c and 31a, 31b, 31c of the so-called first notches 29, 31, located opposite the so-called second notch 30, 32, constitutes an attachment slope for the 'hook element 27,28 of the branches 25,26.

The operation of the terminal according to the invention will be described in the following with reference to Figures 9 to 16 .

The figure 9 illustrates the terminal B in the tight position of the power cable 2. In this position, the two elements forming a hook 27, 28 are located respectively in the two notches called seconds 30, 32, pressing against the face 30a, 32a of this notch forming stop which is perpendicular to the side wall 6,7.

On the figures 10, 11 and 12 , terminal B is in the released position, no cables have yet been inserted inside, position shown on the Figures 13 and 14 .

When the user wishes to tighten a power cable 2 in terminal B, he actuates the screw 10 in clockwise rotation. This actuation of the screw 10 causes said screw 10 to move in translation with respect to the cage C. This screwing of the screw into the nut 22 causes the nut to rotate clockwise against the torque of friction exerted by the elements forming hooks 27,28 of the branches 25,26 on the internal face of the side walls 6,7 of the cage and compressive forces exerted by these walls 6,7 on these elements forming hook 27,28. During this rotation of the branches during the screwing, these hook elements 27, 28 come into abutment on the portions 29c, 31c of the first notches 29, 31 situated on the side of the second notches 30, 32, called hooking slopes, then pass from the other side of these portions after bending of the branches 25, 26 by emitting a metallic click indicating the achievement of the correct tightening torque, position shown on the figure 15 . When the screwing is continued, a series of metallic clicks is heard. In this position, it is no longer possible to continue screwing because the nut 22 is no longer held firmly enough to constitute a screwing support.

In this position, the actuation of the screw 10 in the direction of loosening does not cause the rotation of the nut 22 because the hook elements 27, 28 of the branches 25, 26 are locked in rotation by the wall portions 30a , 32a forming a stop for the so-called second notches 30, 32, which extend perpendicular to the side walls 6, 7 of the cage.

The figure 16 represents all the possible angular positions of the nut 22 during its attachment or free release phases. In a), the screw is in the position of free rotation at the mid-point of the branches 25, 26, nothing which must protrude from the terminal. In b), the screw is in the docking position when the legs 25,26 are tightened clockwise. In c), the screw is in the docking position when the branches 25, 26 are unscrewed counterclockwise.

In d), the screw is in the release position after snapping when the legs 25,26 are tightened in the clockwise direction or in an approach position when unscrewing in the counterclockwise direction.

Thanks to the invention, a clamping terminal has therefore been produced in which an intermediate stage has been created by the insertion in the terminal of a sheet or plate and of a nut, this nut disengaging in rotation when screwed from the 'reaching the right tightening torque, and engaging when unscrewing, metal clicks can be heard when reaching the right tightening torque.

Note that the cage no longer has a tapped hole, but has a single smooth hole.

The friction torque exerted between the side walls of the cage and the hook-forming ends of the branches, to which is added the resulting torque corresponding to the compression of the branches by the walls during the cooperation between the elastic branches and the slopes of the particular shapes formed. by the clearances created in the side walls of the cage, oppose the screwing torque.

The user can tighten the terminal without a torque wrench, with any tool.

As the torque is under control, the terminal no longer needs normative mechanical oversizing. It is possible to size the terminal parts as accurately as possible.

The volume of the terminal is unchanged. The screw can be disengaged when unscrewed, for example with an electric screwdriver.

The shoe allows the tightening of two cables of different sections.

This terminal allows tightening to the correct torque using any 4mm hex tool in the user's toolbox.

It disengages and emits a series of mechanical clicks when the right torque is reached.

The invention advantageously applies to the field of low voltage power circuit breakers, in particular molded case circuit breakers.

The tightening torque limitation function is integrated into the terminal. It no longer comes in the form of a tool or an accessory.

Of course, the invention is not limited to the embodiment described and illustrated which has been given only by way of example.

On the contrary, the invention includes all the technical equivalents of the means described as well as their combinations if they are carried out according to the spirit.

Claims (12)

Terminal for connecting an electrical conductor to a connection pad belonging to an electrical appliance, such a terminal comprising a cage capable of being fixed inside the housing of the appliance and comprising an orifice of substantially parallelepipedal shape delimited by four walls, this orifice being able to receive the aforementioned area, one of the aforementioned walls of the cage, called the upper wall, comprising an orifice capable of allowing the passage of a screw, said screw comprising at one of its ends situated outside the cage, means for actuating said screw, and at its opposite end, a clamping pad capable of allowing the conductor to be clamped between the aforementioned area and said pad during actuation of the screw in the tightening direction causing the relative translational movement between the screw and the cage,
characterized in that it comprises an intermediate stage created inside the cage C so as to allow the housing of a nut (22) with elastic branches (25, 26) comprising a threaded orifice (24) through which the clamping screw (10) is intended to be mounted screwed, said elastic branches (25,26) cooperating with shapes (29 to 32) provided on the side walls (6,7) of the cage C so that the nut (22) disengages in rotation when screwed upon reaching the correct tightening torque, and engages from the start to the end of unscrewing. Connection terminal according to claim 1, characterized in that the two aforementioned elastic branches (25,26) are able to compress radially when screwed on slopes (29c, 31c) belonging to the cage C, the torque resulting from the compression branches (25,26) opposing the tightening torque of the screw (10), until these branches (25,26) escape the slopes (29c, 31c) as soon as the desired tightening torque is reached. Connection terminal according to claim 1 or 2, characterized in that it includes means for producing a clicking noise from the aforementioned exhaust of the branches (25,26) of the slopes (29c, 31c). Connection terminal according to any one of the preceding claims, characterized in that the aforementioned nut (22) comprises an annular part (23) comprising the orifice (24) for passage of the aforementioned screw (10), and from from which two elastic branches (25, 26) extend circumferentially around this annular part (23) in respectively two opposite directions. Connection terminal according to claim 4, characterized in that each branch (25,26) has at its free end a hooking element (27,28) able to cooperate with two hollow shapes (29 to 32), respectively first and second, provided on each side wall (6,7) of the cage C, each hook element (27,28) cooperating with a hollow shape called first (29,31) during tightening, and with a hollow shape said second (30.32), during the loosening. Connection terminal according to claim 5, characterized in that the abovementioned first (29,31) and second (30,32) hollow shapes are produced by striking inside the side walls (6,7) of the cage vs. Connection terminal according to claim 5 or 6, characterized in that in each side wall (6,7), the two hollow shapes (29,30 and 31,32) extend in a direction substantially perpendicular to the axis X of the cage C, the two hollow shapes (29,30) of one (6) of the side walls (6,7) being arranged opposite to the two hollow shapes (31,32) of the other side wall (7). Connection terminal according to any one of claims 5 to 7, characterized in that each hollow shape called first (29,31) comprises a surface portion (29c, 31c) forming a hooking slope, located opposite the hollow shape called second (30,32) of the same wall, the passage through this hooking slope (29c, 31c) for the hooking element (27,28), to join the second hollow shape ( 30.32), causing the aforementioned disengagement of the screw (10). Connection terminal according to any one of claims 5 to 8, characterized in that each so-called second hollow shape (30,32) comprises, located opposite the so-called first hollow shape (29,31) which is associated with it , a wall portion (30a, 32a) extending substantially perpendicular to the axis X of the cage C, and forming a rotation stop for the nut (22), during a unscrewing operation generating the clutch of the clamping screw (10) from the start to the end of unscrewing. Connection terminal according to any one of claims 1 to 9, characterized in that the aforementioned intermediate stage is formed by means of a plate (16) mounted crimped inside the cage C. Connection terminal according to claim 10, characterized in that this plate (16) comprises two so-called first lugs (17,18) capable of being introduced respectively into two orifices (12,13) belonging respectively to two edges belonging respectively to the two walls aforementioned lateral (6,7), at the end of insertion of the plate (16) in the cage C, and two so-called second lugs (19,20) able to be introduced by crimping the sheet of the plate (16) into two orifices (14,15) belonging respectively to the two edges of the side walls (6,7), these edges being opposite to the previous ones. Electrical protection device comprising at least one upstream terminal and / or at least one downstream terminal according to any one of the preceding claims.

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