EP0511111B1 - Electrical connection and a housing for electrical devices comprising such a connection - Google Patents

Description

The invention relates to electrical connections, of the screw type and to axial connection, and housings of electrical apparatus comprising at least one such connection.

French Patent 2,574,598 describes an electrical connection, in particular a miniature one, by means of which an electrically conductive wire is immobilized against a wire support wall of a conductive strip of an electrical appliance, such as for example a junction block, between this support wall and an internal wire support wall of a cage which surrounds the strip, under the action of a clamping screw which is screwed into the cage and which bears against the bar on the other side of the latter relative to the two wire support walls.

The clamping screw is arranged obliquely in the cage relative to the wire support wall of this cage and comes directly into pressure by its end on the bar, it is also laterally pressed against a lateral support element provided for this effect on the cage.

The insertion of a conductive wire between the bearing walls provided for him, on the bar and in the cage of a connection, is therefore provided in an oblique direction relative to the axis of the clamping screw.

In fact, when the connection is housed in a box, for example of a connector, a terminal block or any other electrical device, this box generally includes a wire introduction opening for connection and an opening for 'access to the clamping screw which are separate.

The connection mentioned above is more specifically intended for devices having housings where the introduction opening and the access opening for the same connection have respective oblique orientations, one with respect to the other, each opening opening for example onto a different face of the housing.

By cons it does not easily allow the realization of housings allowing an axial connection, that is to say where the introduction opening and the access opening relating to the same connection have parallel orientations, which allows them in particular lead in parallel on the same face of the housing. However, this may be important, since under certain conditions of use, access to a housing may only be possible at one of these faces, in particular a front face.

The invention therefore provides an electrical connection which, derived from that in the French patent mentioned above, for connecting a conductive wire with a conductive bar of an electrical device by immobilizing the wire against a support element provided on the bar, between this element and another support element, forming the bottom and at least approximately parallel, of a cage which surrounds the bar and this under the action of a clamping screw screwed into a cage element , located opposite the support element forming the bottom, and pressing at the end against the support element of the bar on the other side thereof relative to the support element of the cage, this screw being arranged obliquely with respect to these bar and cage support elements, against at least one lateral support structure opposing the transverse reaction of repulsion of the end of the screw by the bar when tightening, in the cage, the support elements of the bar rette and that of the cage delimiting between them a wire insertion conduit obliquely oriented relative to the screw.

According to a characteristic of the invention, the support element of the cage is extended by an extension serving as a wire guide which projects out of the cage on one of the sides where the wire insertion conduit opens.

The invention also provides an electrical appliance box internally comprising at least one connection as defined above, in a body of insulating material inside which the bar, the screw and the cage are housed, the bar being therein. immobilized, while the cage is susceptible to guided displacements, oriented along the axis of the screw and occasioned by the maneuver of the latter, between two positions respectively corresponding one to maximum approximation of the wire support elements of the bar and the bottom of the cage and the other at a maximum distance from these elements.

According to a characteristic of the invention, the housing comprises an arrangement for immobilizing in translation for a clamping screw allowing the operation of a screw via the head of this screw through an access opening of the housing. near which a wire introduction conduit having an orientation at least approximately parallel to the direction of cage movement defined by the screw axis opens, this introduction conduit being closed by the wire guide extension of the cage considered which penetrates there obliquely to the vicinity of a wall of this conduit with which it ensures relative continuity for guiding, in the insertion conduit of the cage, a wire pushed through said conduit d introduction since the opening of the latter.

The invention, its characteristics and its advantages are explained in the following description, in conjunction with the figures listed below.

Figure 1 shows an example of a screw cage for connection according to the invention.

FIG. 2 shows an example of a strip for connection according to the invention.

FIG. 3 shows a connection constituted using the screw cage and the bar according to FIGS. 1 and 2.

Figure 4 shows a section along IV-IV of an apparatus housing having connections as defined in connection with the previous figures.

FIG. 5 shows a partial section along V-V of a portion of the housing presented in FIG. 4.

The electrical connection, the essential constituent elements of which are shown in FIGS. 1 to 3, comprises a cage 1 provided with a clamping screw 2 which are shown in FIG. 1 and a conductive bar 3, an embodiment of which is given in FIG. 2.

Cage 1 and bar 3 are intended to cooperate with each other to on the one hand immobilize one end of the conductive wire between them and on the other hand ensure the electrical connection of this conductive wire with an electrical appliance by the 'Intermediate of a connection member 4 capable of being carried by the bar as shown in Figures 2 to 5, or possibly by the cage, this connection member 4 being for example of clamp type, as shown here.

The cage 1 and the assembly formed by the bar 3 and by the connection member 4, are here assumed to be produced by cutting and folding from metal blanks according to techniques well known in the field, such a cage can also be obtained by other techniques and for example by molding.

The bar 3 proper is here assumed to consist of a strip, of resilient metal which is a good conductor, of rectangular shape, extending a common part uniting the two jaws of the clamp which here constitutes the connection member 4; this band of rectangular appearance comprises an element, called a support element, 5 against a wall from which it is intended to apply the conductive wire to be connected.

This support element 5 is here connected to the common part connecting the clamp jaws by an element, called a wire stop, 6 against which the end of a conductive wire to be connected should normally come up against.

This stop element 6 is here composed of two successive portions which are obliquely positioned by transverse folding each with respect to the other and with respect to the element which it extends, that is to say one with respect to the element d 'support 5 and the other relative to the connection member 4.

The support element 5 is also continued on the other side of the stop element by an element 7, called a wire guide, also here assumed to consist of two successive portions obliquely positioned by transverse folding one relative to the other and relative to the support element 5 that one of them extends.

A relief 8 is provided to serve as a support at the end of the screw 2, on the support element 5.

This relief 8 is here produced in the form of a tongue partially cut from the strip forming the bar and then folded.

The cage 1 is intended to surround the bar 3 at the level of the support element 5.

This cage 1 is produced by folding around a central element 9 intended to serve as an internal support at the bottom of the cage for the wire to be connected.

The support element 9 is provided arranged obliquely to the rest of the cage and at least approximately parallel to the support element 5 of the bar 3, when the connection which comprises them is assembled, so as to delimit a wire insertion conduit with this support element 5 and at possibly come to press against him under the action of screw 2.

The support element 9 is identically extended on two of its parallel edges by two strip elements 10 and 10 'folded in opposite directions so as to be perpendicular to it and parallel to each other, when the cage is made.

The support element 9 is also extended by an extension 11, called the wire guide, projecting out of the cage, here in the same plane as the element 9 itself, or possibly with a slightly different angulation.

The two strip elements 10, 10 ′ are interconnected by at least one and here two elements 13, 13 ′ which are perpendicularly folded towards each other and each with respect to the strip element 10 or 10 ′ from which it comes to form with the other a single connecting element, having a double thickness, where is provided a tapped bore for the screw 2.

The latter enters the cage by this tapped bore to come to bear against the relief 8 on the bar 3, it also bears against a support structure composed of two projections 14, 14 ′ each carried laterally by one of the elements of strip 10 or 10 ′ with respect to which it is perpendicularly folded down so as to serve as a lateral stop for the screw 2, the body of which is preferably made smooth at this level, ie here towards the conical end of support of this screw on the bar 3 .

The bar 3 is mounted in the cage 1 so that the support element 5 comes between the elements 10, 10 ′ parallel to the support element 9 with which it determines the wire insertion conduit .

The guide element 7 is positioned along the screw 2 on the side of the end of the wire insertion conduit where the wire guide extension 11 is located, the element wire stop 6 placed at the other end of the insertion duct which it closes, in the vicinity of the projections 14, 14 ′.

An example of use of an electrical connection according to the invention in an apparatus is shown in FIGS. 4 and 5, it relates to a connector comprising a double row of such connections in a housing made of insulating material, here produced in two nested parts 15A, 15B. The two connections shown in Figure 4 each include a cage 1 or 1 ′, a screw 2 or 2 ′ and a bar 3 or 3 ′ housed in the housing 15A, 15B so that the screws 2 and 2 ′ are parallel and each the along one of the edges of the case.

It is the same for the connection formed by the cage 1˝, the screw 2˝ and the bar 2˝ which can be seen in FIG. 5 with the cage 1, the screw 2 and the bar 3.

Each bar is individually immobilized in the housing, for example after the part 15A is pressed onto the part 15B by virtue of the complementary shapes of these bars and of the housings of the housing where they are positioned, as is usual in the field.

Each cage encircles the corresponding bar as indicated above and is capable of moving relative to it in a translational movement along the axis of the corresponding tightening screw inside a rectilinear guide formed in the example proposed by the external wall of the housing, such as 16 - FIG. 4 -, which adjoins the associated screw, ie here 2, and by parallel guide walls, such as 17 and 18 - FIG. 5 -, which are perpendicular to this external wall in the housing and which separate the connections from each other.

Each screw is immobilized in translation on the one hand because of the support of its end against a relief provided for this purpose on the support element of each bar, such that the relief 8 on the support element 5 for the screw, and on the other hand due to the partial imprisonment of its head in an arrangement, such as 17 for the screw 2, and here molded in the part 15A of the housing.

This arrangement here comprises an individual housing for each screw head which is preferably cylindrical, each housing opens on the one hand by a conduit, such as 19, for the passage of the screw body towards the rectilinear guide where the associated cage moves. to the screw considered, on the other hand by an access opening, which, such as 20, in an outer wall of the housing and here in part 15A, initially allows the insertion of a screw, then later its operation from the outside of this case.

The imprisonment of a screw head in an arrangement housing 17 is obtained for example by means of a peripheral bead, such as 21, formed at the edge of the opening 20. The operation of a screw, such as 2 alternately allows the support walls 5 and 9 of the bar and the cage associated with this screw to be moved apart then brought closer between a position of maximum approximation and a position of maximum separation.

The latter shown in connection with the screw 2 in Figure 4 allows the insertion of a conductive wire, shown in dashed lines, the jamming of a connected conductive wire 22 being shown in connection with the screw 2 ′ in this same figure 4 .

The introduction of a wire to be connected to a connection in the housing 15A, 15B, is carried out via an introduction conduit, such as 23 - Figure 4 -, which opens near the opening 20 for access to the screw assigned to this connection, this introduction conduit here being parallel to the direction of movement of the cage of this connection.

Each introduction conduit 23 is for example bordered on two sides by parallel walls such as 17 and 18 between which the associated cage moves and on a third side by a wall 24 integral with one of the constituent parts of the housing, here Part 15A.

In the example presented this wall is common to two parallel connections transversely disposed in the housing, a fourth wall of the introduction conduit is here formed by an element, such as 7, of bar which, projecting out of the wire insertion conduit formed between support walls 5 and 9 of bar and cage, is pressed against the screw and the cage portion where this screw is positioned.

In a preferred embodiment, the element 7 is obliquely folded towards the screw body, in the direction of the head of this screw, and it pushes the cage, on which it presses, against the wall 16 of the housing along which it slides and towards the support element 5 of the bar, when the distance between the support elements 5 and 9 of this bar and of the cage differs from their maximum distance, to preposition the cage in its housing before connecting a wire.

The introduction conduit associated with a connection communicates with the insertion conduit provided for this connection and it is closed by the extension 11 which comprises the corresponding wall 9 of cage support.

The insertion of a wire into an introduction conduit, such as 23, from outside the housing brings the end of this wire against the extension 11 situated at the bottom of this conduit, here bearing against a stop, such as 25, when the cage is at the bottom of its housing and the support walls are in the position of maximum separation.

The inclination of the extension 11 directs the end of the conductor, then pushed, towards the inside of the insertion conduit and until it stops against the wire stop element, such as 6, which terminates this conduit. 'insertion.

The screwing of the screw ensures the rise of the cage, the support wall of which approaches that of the associated bar and wedges the wire, as seen on the right-hand part of FIG. 4.

Claims (9)

1. An electrical terminal for putting a conductor wire into connection with a conducting strip (3) of electrical equipment by holding the wire against a clamping element (5) of the strip between said element and another clamping element (9) which constitutes the at least approximately parallel bottom of a cage (1) which surrounds the strip, clamping being obtained under drive from a clamping screw (2) screwed into an element (13, 13′) of the cage and situated opposite to the bottom, the end of the screw pressing against the face of the clamping element of the strip which faces away from the clamping element of the cage, said screw being disposed obliquely relative to the clamping elements of the strip and of the cage, and pressing against at least one lateral thrust structure (14, 14′) opposing the transverse repulsion reaction of the end of the screw on the clamping elements on the strip on clamping, the clamping elements of the strip and of the cage delimiting between them an insertion duct for the wire, which duct extends obliquely relative to the screw, the terminal being characterized in that the clamping element (9) of the cage is extended by an extension (11) constituting a wire-guide which projects beyond the cage from one of the sides into which the wire insertion duct opens out.
2. An electrical terminal according to claim 1, characterized in that the wire-guide extension is situated at the end of the insertion duct which is on the side opposite to the side where the structure for pressing the screw laterally against the cage is to be found.
3. An electrical terminal according to claim 1 or 2, characterized in that the cage is made from a strip of cutout and folded sheet metal to form two parallel elements (10, 10′) each connected firstly at one end to a common central clamping element (9) disposed obliquely and serving to clamp against the wire, and secondly at its opposite end by at least one link element (13 and/or 13′) extending perpendicularly thereto and including a tapped bore for positioning the clamping screw (2) parallel to said parallel elements so as to press against a lateral thrust structure for the screw constituted by two projections (14, 14′) carried laterally by respective ones of the parallel elements, and includes a clamping element (9) which, extending obliquely, is provided with an extension (11) extending beyond the parallel element to one side of the cage where the wire-insertion duct opens out to form a wire-guide.
4. An electrical terminal according to any one of claims 1 to 3, characterized in that the clamping element (5) of the strip extends in the form of an element (7) which is disposed to project beyond the cage in a direction at least approximately parallel to the axis of the clamping screw (2) through the opening of the wire-insertion duct on the same side of the cage as the wire-guide extension (11) and on the other side of the duct opening from said wire-guide extension.
5. An electrical terminal according to any one of claims 1 to 4, characterized in that the clamping element of the strip is extended by a second element (6) which closes the wire-insertion duct of the cage on the other side of said duct in the cage relative to the wire-guide extension (11) and optionally relative to the first extension of the strip (7).
6. An electrical equipment box including internally at least one terminal according to any one of claims 1 to 5, in a body (15A, 15B) of insulating material within which the cage (1), the screw (2), and the strip (3) are housed, the strip being held stationary therein while the cage is capable of guided displacement therein along the screw axis under drive from the screw, between two positions corresponding respectively to the wire-clamping elements (5 and 9) of the strip and of the bottom of the cage being at a minimum separation and to said elements being at a maximum separation, the box being further characterized in that it includes an arrangement (8, 17) for preventing the screw (2) moving in translation, enabling said screw to be rotated via its head through an access opening (20) of the box next to which there opens out a wire insertion duct (23) extending at least approximately parallel to the cage displacement direction defined by the screw axis, said insertion duct being closed by an extension (9) of the cage in question which penetrates obliquely into the duct to constitute an end wall extending to the vicinity of a wall of said duct with which it provides relative continuity for guidance of a wire within the insertion duct of the cage when the wire is pushed along said insertion duct from the opening thereof.
7. An electrical equipment box according to claim 6, characterized in that the arrangement for retaining the clamping screw in translation comprises an element for partially holding captive the head of the screw and cooperating with the thrust projection of the strip on which the screw presses, said element being constituted by a portion of the box (17) which includes a housing (20, 21) for holding captive a cylindrical screw head, said housing opening out firstly into a duct (19) for passing the shank of the screw and in the opposite direction opening out into an access opening enabling the head of the screw to be rotated.
8. An electrical equipment box according to claim 6, characterized in that it includes an abutment element (25) for the wire-guide extension against which said wire bears when the clamping elements (5 and 9) of the strip and of the cage are in their maximum separation position.
9. An electrical equipment box according to any one of claims 6 to 8, characterized in that the wire insertion duct (23) of a terminal is at least partially delimited by an element (10) included in the strip (3) of said terminal adjacent to said duct and close to the clamping screw (2), said first element being folded back obliquely towards the shank of the screw (7) and towards the head of said screw, bearing against the cage (1) of the screw to push the cage against the wall (16) of the box along which it slides and towards the clamping element (5) of the strip whenever the distance between the clamping elements (5 to 9) of the strip and of the cage is different from the maximum separation distance therebetween.

Images