EP0893846B1 - Electrical apparatus having a fixed contact carrier and a connecting terminal - Google Patents

Description

The present invention relates generally to an apparatus electric carrying a connection terminal intended to be tightened around a fixed contact support of said device to perform the connection between external electrical conductors and the device electric.

Electrical devices, for example electrical contactors, have a fixed contact support protruding outwards from their housing and electrically connected to the circuit they contain, this support is intended to ensure the connection of external electrical cables with the internal circuit of the device.

A connection terminal implemented with the device ensures the electrical connection of at least one cable to the fixed contact support.

The connection terminals usually used allow making one or two electrical connections.

Such bollards include a cage intended to be placed around fixed contact support and a clamping screw passing through a wall of said cage to cause it to move axially in a direction parallel to said clamping screw. When screwing in the screw tightening of the terminal, the lower portion of the cage is brought closer to the lower end of the clamping screw so as to pinch the fixed contact support between the cage and the clamping screw. Space between the fixed contact support and the cage creates a zone of connection into which the stripped end can be inserted a cable.

Some terminals also include an axially driven stirrup relative to the cage when tightening the tightening screw. Such terminals are arranged on the contactor so as to pinch the fixed contact support between the underside of the stirrup and the face bottom of the cage.

Such clamp terminals can provide a single connection located in the connection area formed between the bracket and the support fixed contact.

They can also be set up in such a way that the spaces on either side of the fixed contact support, between this one and the cage on the one hand, between this one and the stirrup on the other hand, form connection zones in which can be inserted electrical cables. It is thus possible to connect electrically one or two cables, arranged in one and / or the other connection area, to the circuit connected to the fixed contact support.

In these connection terminals, the clamping screw does not pass through the or the connection areas which makes it impossible to work of mechanical means usually used to make the "captive" connection, closed terminal (eyelet) or semi-closed terminal (fork) mounted on the end of the cable to be connected.

Called captive connection, a connection made up of in such a way that the cable cannot extract itself from the area connection when it comes to be loose. We call lockable connection a connection for which it is necessary to use a tool to extract the cable after removing both sides of the connection area.

• câble raccordé à un circuit principal pour le contrôle de la présence de la tension électrique,
• dérivation d'un circuit principal pour l'auto-alimentation de la bobine d'un appareil,
• insertion momentanée, à la fermeture des pôles principaux, de résistances pour l'amortissement des pointes de courant pouvant apparaítre sur le circuit principal,
• livraison d'appareils précâblés avec bornes desserrées.

Such captive and / or lockable connections are used when the disconnection of a cable can endanger people and / or property, or cause the electrical installation in which it is mounted to malfunction. They are for example specially justified in the following provisions:

• cable connected to a main circuit for checking the presence of electrical voltage,
• derivation of a main circuit for the self-supply of the coil of a device,
• momentary insertion, at the closing of the main poles, of resistors for the damping of current peaks which may appear on the main circuit,
• delivery of pre-wired devices with loose terminals.

The object of the present invention is to provide an electrical device provided with a connection terminal allowing the realization of at minus a captive connection.

To this end, the invention provides an electrical device, such as a contactor, carrying a fixed contact support protruding outside of its housing and a connection terminal of the type comprising a cage through which a clamping screw passes, said fixed contact support and said terminal comprising contact surfaces intended to establish an electrical contact with one or more external cables, characterized in what he wears a piece to create a zone of additional connection located between a contact surface and the part, said connection zone having the form of a dihedral of which the closed side is of just sufficient height to allow the passage of the end of a cable so as to make a captive connection, the part being made up of a flat face, with two trapezoidal side faces, and returns folded in direction of each other, in a plane making an acute angle with said planar face, the part being attached to the contact surface by the establishment of returns on top of said surface of contact.

• la pièce est positionnée sous une des surfaces de contact,
• la face plane de la pièce et la surface de contact forment entre elles un dièdre dont l'ouverture est dirigée du côté destiné à l'insertion du câble,
• les faces latérales sont, du côté fermé du dièdre, de hauteur juste suffisante pour permettre le passage de l'extrémité du câble, de sorte que l'extrémité du câble est maintenue pincée dans la zone de raccordement même lorsque la borne est desserrée,
• la pièce est susceptible d'être maintenue dans une position pour laquelle sa face plane est disposée contre la surface de contact par des moyens d'accrochage,
• lorsque la borne de raccordement comporte un étrier dont l'extrémité supérieure est montée sur la tête de la vis de serrage et l'extrémité inférieure est à proximité de l'extrémité inférieure de la vis, à l'intérieur de la cage, la pièce est montée à l'intérieur de la cage, sous la face inférieure de l'étrier,
• la pièce est positionnée sous le support de contact fixe.

The apparatus according to the invention is also remarkable in that:

• the part is positioned under one of the contact surfaces,
• the flat face of the part and the contact surface form between them a dihedral, the opening of which is directed towards the side intended for the insertion of the cable,
• the side faces are, on the closed side of the dihedral, of a height just sufficient to allow the passage of the end of the cable, so that the end of the cable is kept pinched in the connection area even when the terminal is loose,
• the part is capable of being held in a position for which its planar face is disposed against the contact surface by attachment means,
• when the connection terminal includes a bracket, the upper end of which is mounted on the head of the clamping screw and the lower end is near the lower end of the screw, inside the cage, the part is mounted inside the cage, under the underside of the bracket,
• the part is positioned under the fixed contact support.

• la figure 1 montre une borne de raccordement sans étrier à une zone de raccordement imperdable selon l'invention,
• la figure 2 montre une borne de raccordement à étrier destinée à assurer un seul raccordement électrique, équipée suivant l'invention,
• la figure 3 montre une borne à double raccordement indépendant selon l'invention avec un câble disposé dans la zone de raccordement imperdable,
• la figure 4 montre la borne de la figure 3 assurant le raccordement de trois câbles,
• la figure 5 montre une variante de réalisation de la borne selon l'invention.

The invention will be better understood thanks to the description which follows given by way of nonlimiting example with reference to the appended drawings in which:

• FIG. 1 shows a connection terminal without stirrup to a captive connection zone according to the invention,
• FIG. 2 shows a clamp connection terminal intended to ensure a single electrical connection, equipped according to the invention,
• FIG. 3 shows a terminal with independent double connection according to the invention with a cable placed in the captive connection area,
• FIG. 4 shows the terminal of FIG. 3 ensuring the connection of three cables,
• Figure 5 shows an alternative embodiment of the terminal according to the invention.

In order not to unnecessarily overload the drawings, the housing of the electrical appliance, such as a contactor, is not shown, only the fixed contact support and the connection terminal are shown.

The connection terminal shown in Figure 1 is for the realization of a single connection, it consists of a screw clamping 1 and a cage 3.

The cage 3 has four walls arranged perpendicularly to the together to form a rectangular opening ring. It is usually manufactured by folding a metal strip, the flat upper wall 31 consisting of two portions of overlapping strip.

The clamping screw 1 is engaged with the internal thread of a tapped opening formed in the top wall of the cage so that said cage is driven axially in translation relative to the clamping screw during the rotation of said screw.

When implemented, this terminal is, as shown in drawing, arranged around the fixed contact support 4 in such a way that it is disposed between the lower end of the screw tightening 1 and the bottom wall of the cage 3. When the screw is screwed clamping 1, while its lower end bears against the fixed contact support 4, the cage 3 is moved axially towards the high until it is against the underside of the support fixed contact 4.

The space arranged between the fixed contact support 4 and the wall bottom of the cage 3 constitutes a connection zone 43 in which can be inserted an electric cable.

Figure 2 shows a connection terminal according to another embodiment, which comprises, in addition to the clamping screw 1 and the cage 3, a bracket 2 mounted by its upper end on the head of the screw clamp 1. In such a terminal, the cage 3 is mounted so fixed.

When a terminal according to this embodiment is mounted around a fixed contact support 4 exiting the housing (not shown in drawing) of a contactor, a connection zone 42 is formed between the lower end of the bracket 2 and the fixed contact support.

When tightening the tightening screw 1, the stirrup 2 moves axially until the fixed contact support 4 is pinched between the bracket 2 and cage 3.

The connection terminals shown in Figures 3 to 5 are terminals with independent double connection, they are also consisting of a clamping screw 1, a U-shaped bracket 2 and a cage 3.

As in the terminal shown in Figure 2, the bracket 2 is mounted on the clamping screw 1 by positioning the upper end of it on the head of the clamping screw 1 and its lower end at near the lower end of said screw 1, inside the cage 3. The stirrup 2 can thus slide axially with respect to said clamping screw for the amount of mounting clearance.

In Figures 3 to 5 appended to this application, only one half of cage 3 is drawn to better represent what is located inside said cage 3. Said cage 3 is to do this cut in half along its vertical plane of symmetry.

When the terminal is used to electrically connect one or more cable (s) to the electrical circuit of an electrical appliance (not shown in the drawing), for example an electrical contactor, terminated by a fixed contact support 4, it is positioned so that said fixed contact support 4 passes through the cage, and that the support of contact either inside the cage, between the lower end of the stirrup 2 and the lower end of the cage 3, being parallel to the ends opposite said stirrup and cage.

Bulges 41 arranged on either side of the contact zone 44 of the fixed contact support 4 are positioned against the edges external of the vertical sides 30 of the cage 3, only one of which is visible in the drawings. By this assembly, the double connection terminal is made integral with the fixed contact support 4, while being able slide vertically with respect to it, being guided by the side faces of the cage.

This arrangement creates two connection zones 42 and 43 arranged respectively between the fixed contact support 4 and the end bottom of the bracket 2 and between said fixed contact support 4 and the bottom wall of the cage 3. These two connection zones allow the positioning of cables intended to be connected electrically to the fixed contact support 4.

To make the electrical connection, the tightening screw is screwed 1.

During this tightening, the cage 3 is driven upwards, in the direction of the fixed contact support 4 and of the stirrup 2. This displacement of the cage 3 initially plates the cable placed in the area 43 against the fixed contact support 4, and in a second time the cable introduced into connection area 42 against caliper 2. Continued screwing tightens the assembly and ensure the electrical connection of the cables to the contact support fixed 4.

According to the invention, the device comprising the fixed contact support 4 and a connection terminal is provided with a part 6, which can be called a waterproofing piece, mounted in one of the zones of connection of the terminal so as to create a additional and captive connection.

In the example of implementation shown in Figure 1, said part 6 is positioned on the fixed contact support 4.

In the example of implementation shown in Figures 2 to 5, said part 6 is positioned on the lower end of the bracket 2.

In general, said part 6 is arranged under a surface of contact.

As visible in the drawing, the part 6 consists of a flat face 60, rectangular in the example shown, connected to two faces side 61 finished, on their edge opposite the flat face 60, by returns 62 folded in the direction of one another.

The lateral faces 61 are such that their edges are connected to the flat face 60 and returns 62 are not parallel to each other. By this arrangement, the flat face 60 forms an acute angle with the plane containing the returns 62. These lateral faces 61 are by trapezoidal example.

If we refer to Figures 2 to 5, we see that the part 6 is mounted inside the cage 3, under the underside of the stirrup being attached to it by the installation of returns 62 on the top of the underside of said stirrup 2. The dihedral formed between the face rectangular 60 of part 6 and the underside of stirrup 2 is open from the side for cable insertion.

This dihedral thus formed allows the user to easily insert the end of the cable, provided in a manner known per se with a ferrule 51, between part 6 and the stirrup 2. In the embodiment shown in the drawing the tip 51 is a flat tip.

Preferably and as shown in the drawing, the cable is inserted until the free end of the flat tip 51 protrudes the end of part 6 opposite the cable insertion side.

The lateral faces 61 of the part 6 are, on the closed side of the dihedral, of just high enough to allow the end of the cable with cable end 51.

The end of the cable, provided with the flat end piece 51, is thus maintained pinched in the connection area, between part 6 and bracket 2, even when the terminal is loose as shown in figure 1.

When the terminal is tightened, the part 6 pivots while being pushed by the fixed contact support 4 during the approximation of the stirrup 2 and of the fixed contact support 4, while being held laterally at the during this movement through the side walls of the cage 3. The part 6 is, at the end of tightening, positioned with its flat face 60 parallel to the surfaces facing the stirrup and the fixed contact support. Said flat face 60 is then supported by its entire surface with the flat end 51 of the cable while the returns 62 extend to distance from the lower end of the stirrup 2, obliquely by compared to it.

This position of the part 6 is shown in FIG. 4.

In this figure 4, the other two cables have also been shown. 52 and 53 that can be electrically connected to the support fixed contact 4 when the bollard is fitted with the waterproofing part 6.

Indeed, the establishment of the piece of impermeability 6 creates a zone additional captive connection while retaining the or the connection areas initially contained in the terminal.

When the terminal is loosened, the cage 3 and the bracket 2 move away from the contact support 4 and cables 52 and 53 are free to fall from their connection area. Exhibit 6 comes back in its position shown in Figure 1 and holds the cable 50 in place this which prevents him from disconnecting.

The assembly and use of part 6 are of course similar when the part 6 is mounted on the fixed contact support 4 as in Figure 1.

We then create an additional connection area and captive between the fixed contact support 4 and the cage 3 by adapting a leakproof part 6 to the contact support 4.

In the embodiment shown in Figure 5, means are used to maintain the part 6 in its position for which its flat face 60 bears against the lower end of stirrup 2.

These means consist of lugs 26 carried by the stirrup 2 and cutouts made in the border of part 6.

According to another embodiment of the non-leakage part shown in the drawing, said part is elastic and deforms during tightening of the terminal to secure the cable.

Claims (4)

1. Electrical apparatus, such as a contactor, bearing a fixed contact support (4) externally protruding from its case and a connection terminal of the type comprising a cage (3) with a tightening screw (1) going through, said fixed contact support (4) and said terminal comprising contact surfaces designed for making electrical contact with one or more external cables, characterised in that it bears a part (6) which makes it possible to create an additional contact area located between a contact surface and the part (6), said connection area having the shape of a dihedral, the closed side of which has a height just sufficient to allow the passage of the end of a cable in order to make a captive connection, part (6) being made up of a flat side (60), two trapezoidal lateral sides (61) and of returns (62) folded in each other's direction, in a plane forming an acute angle with said flat side (60), part (6) being suspended on the contact surface through the positioning of the returns (62) on the top of said contact surface.
2. Apparatus according to claim 1, characterised in that the part is capable of being held in a position for which its flat side is placed against the contact surface by hanging means.
3. Apparatus according to any one of the preceding claims in which the connection terminal comprises a calliper (2), the upper end of which is fitted on the head of the tightening screw and the lower end is close to the lower end of the screw inside the cage, characterised in that part (6) is fitted inside cage (3) under the lower side of the calliper.
4. Apparatus according to any one of the preceding claims, characterised in that part (6) is positioned under the fixed contact support (4).

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