FR3035747A1 - CONNECTION ELEMENT OF A CYLINDRICAL FUSE WITH AN ELECTRICAL CONDUCTOR AND FUSE HOLDER EQUIPPED WITH SUCH A MEMBER - Google Patents

Abstract

This connection element (40) of a cylindrical fuse (24) to an electrical conductor comprises a one-piece piece (50) forming a receiving cage (52) for the electrical conductor and a jaw (54) for receiving one end ( 38A) of the fuse (24).

Description

The invention relates to a connection element of a cylindrical fuse to an electrical conductor and a fuse holder equipped with a fuse holder. such an element. In the field of protection of electrical installations, it is known to use a fuse system arranged between a power source and an electrical load to supply electrical energy, such as a motor. Such a fuse system makes it possible to disconnect the load from the power source, when too much current flows from the power source to the load, and thus to protect the circuit upstream of the load. Such a fuse system generally comprises a fuse holder, which includes a power source connection terminal and a load connection terminal which are electrically connected to each other by a fuse. The connection terminals are then equipped with means for holding the fuse, such as jaws and means for connecting the fuse respectively to an electrical conductor connected to the power supply and to an electrical conductor connected to the load. More specifically, it is known to use at the connection terminals a connection element composed of three distinct parts, namely, a receiving cage of an electrical conductor, a receiving jaw of an end of the fuse and a fuse holding spring in the jaw. The jaw is generally made of copper and includes a connecting wing to the receiving cage and two fuse holding tabs, which firmly hold the fuse with the spring. The manufacture and structure of such connection elements remain complex and their manufacturing cost is high. It is these disadvantages that the invention more particularly intends to remedy by proposing a connection element of a cylindrical fuse to an electrical conductor whose structure and manufacture are simplified. For this purpose, the invention relates to a connection element of a cylindrical fuse to an electrical conductor. According to the invention, the connection element comprises a one-piece piece forming a receiving cage of the electrical conductor and a receiving jaw of one end of the fuse. Thanks to the invention, a single piece allows both the reception of the electrical conductor and the maintenance of the fuse, and ensures electrical continuity between the fuse and the electrical conductor. The connection element is no longer in three parts but in one, which facilitates its manufacture and allows it to present a simplified structure. According to advantageous but non-obligatory aspects of the invention, such a connecting element comprises one or more of the following characteristics, taken singly or in any technically permissible combination: the single piece is formed from a steel strip cut and folded; the cage delimits a reception space of the electrical conductor and is provided with a contact flange with the electrical conductor and with a fastening wing of the electrical conductor, the fastening flange comprising a receiving orifice of an electrical conductor; holding the electrical conductor against the contact flange; the fixing wing comprises a first and a second wall superimposed on one another, the first and second walls comprising a first and a second recess facing each other, the first and second recesses forming the receiving orifice; The cage comprises first and second lateral wings facing one another and each connecting the contact wing to the attachment wing, the first and second lateral wings forming with the contact wing and the wing fastening a closed contour of the receiving space, while the second wall extends, opposite the second lateral wing, by a tongue, and the first lateral wing is provided with a notch receiving the tongue; the first wall extends, opposite the first lateral wing, by a stud, and the second lateral wing is provided with a housing for receiving the stud; the jaw comprises two lugs intended to define a housing for holding the end of the fuse, the lugs extending in the extension of the cage in a direction substantially parallel to a central axis of the cage, each lug comprising at least an electrical contact and mechanical support arm on a radial surface of the end of the fuse, and a connection zone extending between the tab and the cage; each leg comprises two electrical contact and mechanical support arms on the radial surface of the end of the fuse, the arms extending along a longitudinal axis substantially perpendicular to the central axis and separated by a slot; for each leg, the thickness of each arm, measured along a transverse axis perpendicular to the connection zone, decreases from the connection zone 35 towards a free end of the arm.

The invention also relates to a fuse holder comprising a housing for receiving at least one cylindrical fuse inside which is positioned at least one connection element of the fuse to an electrical conductor. According to the invention, the connection element is as defined above.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the description which follows, given solely by way of nonlimiting example and with reference to the appended drawings in which: Figure 1 is a schematic representation of an electrical installation which comprises a fuse holder according to the invention; FIG. 2 is a three-dimensional representation, in a configuration of use, of a connection element, included in the fuse holder of FIG. 1 and in accordance with a first embodiment of the invention, and FIG. a cylindrical fuse portion; FIG. 3 is a representation, in an unfolded configuration, of the connection element of FIG. 2; and - Figure 4 is a representation similar to Figure 2 of a connection element according to a second embodiment of the invention and a cylindrical fuse. The electrical installation 10 visible in FIG. 1 comprises a power supply source 12, an electric load 14 and a fuse holder 16 positioned between the power supply source 12 and the electric load 14. The electrical installation 10 is a single-phase electrical installation, in which the fuse holder 16 is connected to the power supply 12 by a first phase electrical conductor 18 and to the electric load 14 by a second phase electrical conductor 20, while the power source 12 is connected to the electric load 14 by a third neutral electrical conductor 21. The power supply 12 is intended to supply electrical energy to the electric load 14. The power supply 12 corresponds to for example, to an electricity distribution network.

The electric load 14 is, for example, an industrial electrical receiver such as a motor. The fuse holder 16 comprises a housing 22 for receiving a cylindrical fuse 24 partially shown in FIG. 2. The housing 22 extends along an axis Z1, which is vertical in FIG. 1, and comprises, according to FIG. Z1 axis, a first end 26 of connection with the first electrical conductor 18 and a second end 28 of connection with the second electrical conductor 20. The housing 22 also comprises a notch 30 for fixing the fuse holder 16 on a rail an electrical panel not shown.

The housing 22 further comprises a front face 32 provided with a first port 34 for access to the first end 26 and a second port 36 for access to the second connection end 28. The fuse holder 16 also comprises a gripper 37 for receiving the fuse 24, which gripper 37 is pivotally mounted relative to the body 22 about an axis R perpendicular to the axis Zl. The cylindrical fuse 24 comprises an insulating body 38 such as a ceramic tube and two ends 38A, 38B, each forming a cylindrical fuse capsule, only one of which is shown in FIGS. 2 and 3. The insulating body 38 comprises within it a conductive element connecting the two ends 38A, 38B of the fuse 24. The first connection end 26 defines a zone 39 for receiving the first electrical conductor 18, at which is positioned a connection element 40 of the cylindrical fuse 24 to the first Electrical conductor 18. The connection element 40 is shown in FIGS. 2 and 3.

Similarly, the second connection end 28 defines a receiving zone 42 of the second electrical conductor 20, at which is positioned an additional connection element of the cylindrical fuse 24 to the second electrical conductor 20. The additional connection element is identical at connection element 40 and in the remainder of the description, only connection element 40 is described. As shown in FIGS. 2 and 3, the connection element 40 comprises a single piece 50, which forms a cage 52 for receiving the first electrical conductor 18 and a jaw 54 for receiving fuse 24 and in particular the end 38A of the fuse 24. In Figure 2, the electrical conductor 18 is represented by its central axis.

The integral piece 50 is made of steel and formed from a cut and folded steel strip, as can be seen from FIGS. 2 and 3, which respectively show the connection element 40 in the use configuration, c i.e., folded, and unfolded configuration. The cage 52 is parallelepipedic.

The cage 52 defines a space 56 for receiving the first electrical conductor 18 and defines a central axis Z2, which extends substantially parallel to the vertical axis Z1 3035747 when the connection element 40 is installed in the fuse holder 16. The conductor 18 is generally aligned on the central axis Z2 in the configuration of use, or at least parallel to this axis. The cage 52 is provided with a flange 60 for contact with the first electrical conductor 18 and a flange 62 for fixing the first electrical conductor 18 against the contact flange 60. The cage 52 also comprises a first 64 and a second 66 side wings, which each connect the contact wing 60 to the attachment wing 62 and which are positioned opposite one another.

The first and second lateral wings 64 and 66 together with the contact flange 60 and the securing flange 62 form a closed contour of the receiving space 56 centered around the central axis Z2. The contact flange 60 advantageously comprises, and as shown in FIG. 3, grooves 70 for anchoring the first electrical conductor 18. The anchoring grooves 70 extend perpendicularly to the central axis Z2. The fastening flange 62 comprises an orifice 72 for receiving a screw 74 forming a holding member of the first electrical conductor 18 against the contact flange 60 and the anchoring striations 70. More specifically, and as shown in FIG. 3, the attachment flange 62 comprises a first 76 and a second 78 superimposed walls one on the other. The first 76 and second 78 walls each comprise a recess 80, 82 respectively. The recesses 80, 82 are positioned facing each other and form the receiving orifice 72 when the connection element 40 is in the configuration of use. The two recesses 80, 82 for receiving the holding member 74 are threaded. Alternatively, only one of these recesses is threaded. The first wall 76 extends the lateral wing 64 away from the contact wing 60, while the wall 78 extends the lateral wing 66 away from the contact wing 60. In the configuration of the 2, the wall 78 is located on the outside of the cage 52, while the wall 76 defines the space 56.

The second wall 78 extends, opposite to the lateral wing 66, by a tongue 90, while the wing 64 is provided, in the vicinity of the wall 76 of a notch 92 for receiving the tongue 90 The first wall 76 is extended, opposite the lateral wing 64, by a pin 96. The recess 82 is extended, on the side of the lateral wing 66, by a housing 100 for receiving the pin 96. .

Alternatively, the recess 82 and the housing 100 may be disjoint. The housing 100 then extends into the wing 66. The jaw 54 comprises two tabs 102, 104 which extend in the extension of the cage 52 along the central axis Z2.

More specifically, the tabs 102, 104 extend respectively in the extension of the first 64 and second 66 lateral wings. The tabs 102, 104 together define a housing 106 for holding the fuse 24. More specifically, the housing 106 is a housing for holding the end 38A of the fuse 24. Each lug 102, 104 comprises two arms 110, 112, respectively 114, 116 of electrical contact and mechanical support on a radial surface S1 of the end 38A of the fuse 24. Each lug 102, 104 also comprises a connecting zone 118, 120 which connects the arms 110, 112, 114, 116 and the cage 52. The tabs 102, 104 extend parallel to the lateral wings 64, 66. The arms 110, 112, 114, 116 extend parallel to a longitudinal axis X, extending substantially perpendicularly to the axis central Z2 and contact flanges 60 and attachment 62.

For each tab 102, 104, the arms 110, 112, 114, 116 are separated by a slot 122, 124 which extends parallel to the longitudinal axis X. The slots 122, 124 separating the arms 110, 112, 114 , 116 extend from a free end 125 of the arms and towards the connecting zone 118, 120. The width L1 of the connecting zone 118, 120 of each tab 102, 104, measured along the longitudinal axis X , is between 8 and 12 mm, preferably equal to about 10 mm. The thickness W1 of each arm 110, 112, 114, 116, measured along a transverse axis Y substantially perpendicular to the central axis Z2 and to the longitudinal axis X, that is to say perpendicular to the connection zones 118 , 120, is decreasing going from the connecting zone 118, 120 towards the free end 125 of the arm 110, 112, 114, 116. The thickness W1 of each arm 110, 112, 114, 116, is for example 1.5 mm, at the connection areas 118, 120 and between 0.3 mm and 0.6 mm at the free end 125 of the arms 110, 112, 114, 116. Each arm 110, 112 , 114, 116 comprises a face 126, 128, 130, 132 of contact 35 with the end 38A of the fuse 24.

Advantageously, each contact face 126, 128, 130, 132 comprises a silver-plated copper strip 134, 136, 138, 140 deposited locally. Advantageously, the distance Y1, measured along the transverse axis Y in the absence of a fuse in the housing 106, between the tabs 102, 104 is smaller than the diameter D1 of the end 38A of the fuse 24. The empty distance between the two tabs 102, 104 is for example 8 mm, while the diameter D1 of the end 38A is for example equal to 10 mm. Thus, once the end 38A of the fuse 24 is positioned in the jaw 54, between the tabs 102, 104, the fuse 24 is held firmly in contact with the connection element 40, thanks to the elasticity of the tabs 102. and 104 and arms 110, 112, 114 and 116. The silver-plated copper strips provide a good quality of contact between the fuse 24 and the arms 110, 112, 114, 116. Specifically, the copper strips promote electrical contact between the arms 110, 112, 114, 116 and the fuse 24, since the current density to pass through a silver-plated copper strip is much greater than that through a steel strip, in practice about seven times higher. The steel strip shown in Figure 3 is cut flat in a steel plate. It is then folded to obtain the connection element illustrated in Figure 2. More specifically, the band is folded on itself along fold lines L1 to L5 parallel to the axis Z2.

The fold line L1 separates the contact flange 60 and the lateral flange 64. The fold line L2 separates the contact flange 60 and the lateral flange 66. The fold line L3 separates the lateral flange 64 and the first wall 76. The fold line L4 separates the lateral flange 66 and the second wall 78. The fold line L5 separates the second wall 78 and the tongue 90. This makes it possible to form the cage 52, with a covering, at the level of the attachment wing 62, the first wall 76 by the second wall 78. The position of the first 76 and second 78 walls relative to each other is maintained thanks to the tongue 90 which is then engaged in the notch 92 and the pin 96 which cooperates with the housing 100. The anchoring grooves 70 can promote electrical contact between the contact flange 60 and the first electrical conductor 18. The screw 74 is accessible at by means of a screwdriver through the orifice 34 formed on the front face 32 of the housing 22. Avan tageusement, a U-shaped stirrup, not shown, is associated with the screw 74 and held by the screw 74 against the first electrical conductor 18, in order to keep it in contact with the contact flange 60. This is not not required and the screw 74 can bear directly against the electrical conductor 18.

In FIG. 4, a connection element 140, according to the second embodiment of the invention is illustrated. The connection element 140 is generally similar to the connection element 40 according to the first embodiment. The parts of the connection element 140 similar to those of the connection element 40 have the same references. Thereafter, only the differences between the first and second embodiments will be presented. The connecting member 140 differs from the connecting member 40, in that the walls 76 and 78 do not include a tongue and tab, and the lateral wings 64, 66 do not include a tongue receiving notch. and receiving housing of the nipple. In other words, the lateral wings 64, 66 each comprise a wall 142, 144 solid, which connects the contact flange 60 to the fastening flange 62, while the walls 76 and 78 are of rectangular shape. In addition, the connecting member 140 differs from the connecting member 40 in that the arms 110, 112, 114, 116 have a different shape compared to the first embodiment. In this second embodiment, the arms 110, 112, 114, 116 have a V-shaped localized deformation, at the contact faces 128, 130, 132, 134, in a plane perpendicular to the central axis Z2 and extending along the longitudinal axis X and the transverse axis Y. More specifically, the shape of the arms 110, 112, 114, 116 at the contact areas 128, 130, 132, 134 is, for example, such that as presented in EP 1 194 943 B1 in paragraphs [0015] to [0029]. In both embodiments, the fact that the connecting member 40, 140 is formed of a single piece 50 facilitates the manufacture of the connection member 40, 140 while reducing its cost. In addition, the fact that the one-piece piece 50 is made of steel gives it a high rigidity and allows a firm hold of the fuse 24 in the jaw 54. Such a connection element 40, 140 makes it possible in particular to get rid of the use of a spring in order to firmly hold the end 38A of the fuse 24 between the tabs 102, 104. Moreover, the fact that the thickness of the arms 110, 112, 114, 116 decreases along the longitudinal axis X makes it possible to provide flexibility to the jaw 54 and facilitates the integration of the fuse 24 between the arms 110, 112, 114, 116.

In addition, the fact that each lug 102, 104 comprises two arms 110, 112, 114, 116 separated by a slot 122, 124 gives the arms 110, 112, 114, 116, which adapt better to the circularity defect of the end 38A of the fuse 24. Moreover, the arms 110, 112, 114, 116 make it possible to provide several points of contact with the end 38A of the fuse 24 and thus to guarantee the electrical contact between the connection element 40, 140 and fuse 24. In addition, in the second embodiment, the fact that the arms 110, 112, 114, 116 have a V-shaped localized deformation improves the maintenance of the fuse 24 between the arms 110, 112, 114, 116.

Alternatively, each tab 102, 104 comprises a single arm or more than two arms. Alternatively, the fuse holder 16 is a three-phase fuse holder and comprises three cylindrical fuses each connected via two different connection elements with two different electrical conductors. In this variant, the fuse holder 16 is positioned in a three-phase electrical installation and is a three-pole fuse holder which comprises three grippers 37 interconnected. The embodiments and variants envisaged above are suitable for being combined with one another to give rise to other embodiments of the invention. 20

Claims (10)

1. A connecting element (40; 140) of a cylindrical fuse (24) to an electrical conductor (18, 20), characterized in that it comprises a single piece (50) forming a receiving cage (52). an electrical conductor (18, 20) and a jaw (54) for receiving an end (38A, 38B) of the fuse (24). 2. Element according to claim 1, characterized in that the one-piece piece (50) is formed from a cut steel strip and folded. 3.- Element according to claim 1 or 2, characterized in that the cage (52) defines a space (56) for receiving the electrical conductor (18, 20) and is provided with a flange (60) for contact with the electrical conductor (18, 20) and a flange (62) for securing the electrical conductor (18, 20), the fastening flange (62) comprising an orifice (72) for receiving a member (74) of holding the electrical conductor (18, 20) against the contact flange (60). 4. Element according to claim 3, characterized in that the fixing flange (62) comprises a first (76) and a second (78) walls superimposed on one another, the first (76) and second (78) walls comprising a first recess (80) and a second recess (82) facing each other, the first (80) and second (82) recesses forming the receiving port (72). 5. Element according to claim 4, characterized in that the cage (52) comprises a first (64) and a second (66) lateral wings facing one another and each connecting the contact flange ( 60) to the fastening flange (62), the first (64) and second (66) lateral wings forming with the contact flange (60) and the fastening flange (62) a closed outline of the space receiving device (56), in that the second wall (78) extends, opposite the second lateral wing (66), by a tongue (90), and in that the first lateral wing (64) is provided with a notch (92) for receiving the tongue (90). 6. Element according to claim 5, characterized in that the first wall (76) extends, opposite the first lateral wing (64), by a pin (96), and in that the second lateral wing (66) is provided with a housing (100) for receiving the pin (96). 3035747 11 7.- element according to any one of the preceding claims, characterized in that the jaw (54) comprises two lugs (102, 104) for defining a housing (106) for holding the end (38A, 38B) of the fuse (24), the tabs (102, 104) extending in the extension of the cage (52) in a direction substantially parallel to a central axis (Z2) of the cage (52), each leg (102, 104 ) comprising at least one arm (110, 112, 114, 116) of electrical contact and mechanical support on a radial surface (S1) of the end (38A, 38B) of the fuse (24), and a connection zone (118, 120) extending between the tab (102, 104) and the cage (52). 10 8.- Element according to claim 7, characterized in that each lug (102, 104) comprises two arms (110, 112, 114, 116) of electrical contact and mechanical support on the radial surface (S1) of the end (38A, 38B) of the fuse (24), the arms (110, 112, 114, 116) extending along a longitudinal axis (X) substantially perpendicular to the central axis (Z2) and separated by a slot ( 122, 124). 15 9.- element according to claim 7 or 8, characterized in that for each lug (102, 104), the thickness (W1) of each arm (110, 112, 114, 116), measured along a transverse axis (Y ) perpendicular to the connection zone (118, 120), decreases from the connecting zone (118, 120) towards a free end (125) of the arm (110, 112, 114, 116). 10. Fuse holder (16) comprising a housing (22) for receiving at least one cylindrical fuse (24) inside which is positioned at least one connection element (40; 140) of the fuse (24) to an electrical conductor (18, 20), characterized in that the connection element (40; 140) is according to any one of the preceding claims.