EP2489100B1 - Clamping screw with cover and installation switching device - Google Patents

Description

The invention relates to a screw terminal for an electrical installation switching device for connecting an electrical connection conductor, comprising a terminal frame having a first and a second transverse leg, a first and second longitudinal leg, wherein the transverse and longitudinal legs frame a front and rear terminal insertion, wherein the first transverse leg a Having threaded bore for receiving a clamping screw, and wherein the second transverse leg is covered with a bottom plate comprehensive insulating cover, according to the preamble of claim 1. The invention further relates to an electrical service switching device according to claim 7.

Screw terminals are widely used, in particular, in domestic installation technology and serve to connect electrical connection conductors to an installation device, for example a circuit breaker or a fault current circuit breaker.

Such service switching devices have a Isolierstoffgehäuse with at least one front side, one of these opposite mounting side, may be provided on the fastening devices for snapping or otherwise attaching the installation switching device to a support rail or other fastening device, as well as with the front and the attachment side connecting narrow and broadsides.

The screw terminals for connecting the connection conductors are usually mounted in the region of the narrow sides in the service switching device. Inside the service switching device are the other required for the intended function of the installation switching device components or assemblies, such as triggers, shifter and contacts, arc quenching, alignment, etc

Known screw terminals are realized for example as so-called box terminals. They have a clamping frame with an approximately rectangular cross-section and a clamping screw, which projects through a threaded bore in a first transverse leg of the terminal frame in this. Turning the clamping screw moves the clamp frame along the axis of the clamping screw. Inside the terminal frame, a terminal space is formed for clamping a terminal conductor.

An inserted into the terminal frame connection conductor is thus clamped in the terminal space between the clamping screw and a second transverse leg opposite the first transverse leg of the terminal frame.

A variant of the box terminal additionally has a contact strip on which presses the clamping screw, so that the connection conductor between the contact strip and the second transverse leg is clamped.

In a further variant of box terminals while the contact strip in the installed position of the terminal in the housing is fixed and the clamping frame relative to the contact strip longitudinally displaceable parallel to a housing narrow side and parallel to the central axis of the clamping screw. The contact strip can be clamped about in grooves or between, formed in a corresponding position in the housing interior to the housing wall, protruding webs.

When the clamping screw is screwed in this latter type of box terminals, it first strikes the contact strip. Upon further rotation of the clamping screw in the screwing direction, the clamping screw is supported on the contact strip, and the clamping frame pushes thereby in the direction of the free end of the clamping screw to the top. As a result, the second transverse leg is moved upward in the direction of the contact strip. An inserted in the terminal space between the second transverse leg and the contact strip connecting conductor is thereby clamped between the contact strip and the second transverse leg.

The housing of the service switching device, in the interior of which such a screw terminal is arranged, has a Gehäuseinführöffnung, through which a connecting conductor in the housing and in the terminal space of the terminal frame is inserted. When the connection conductor is clamped, the second transverse leg of the terminal frame, against which the connection lead to be connected, can be visible and touchable through the insertion opening. Since the terminal frame is under tension during operation, avoid touching the terminal frame.

In the EP 1983541 A1 is in Fig. 5 a generic screw shown. The cover includes a bottom plate and a cover rib that covers the leading edge of the second transverse leg of the screw when the cover is attached to the screw. For attachment, the cover has on the Abdecksteg two snap hooks, which extends parallel to the bottom plate to the rear toward the rear edge of the second transverse leg. The snap hooks snap into two locking grooves in the longitudinal legs of the screw. To mount the cover, it must be pushed onto the clamping frame from the front. There is no guide for the cover, so this screw is not suitable for automated assembly. Because the snap hooks are attached to the cover bar, there is a lock on one side to the front side. At the rear side, the cover is not attached, the bottom plate could therefore stand out on one side of the second transverse leg and the insulating effect would no longer be given. If you wanted to prevent that, you would also need to attach more locking elements, which would further complicate the assembly.

The object of the invention is therefore to develop a screw of the type mentioned in such a way that the attachment of the cover improves on the clamping frame and is suitable for automated assembly.

Furthermore, it is an object of the present invention to provide a service switching device with such an improved screw terminal.

The task with respect to the screw is achieved by a Schraubklemme with the features of claim 1.

According to the invention, the bottom plate carries on a first and second opposite narrow side each have a first and second Abdecksteg, which Abdeckstege are oriented perpendicular to the broad side of the bottom plate, and the bottom plate further carries on a third and fourth, opposite narrow side depending on a first and second snap hook. Thus covers when plugging the cover to the terminal frame of the first and second cover web from the narrow sides of the second transverse leg at the front and rear terminal insertion, and the snap hooks can engage in locking grooves on the longitudinal legs and thereby reliably hold the cover to the clamping frame. The cover is in the screw according to the invention from below, so perpendicular to the second transverse leg plugged. This is very beneficial for automated assembly. The two front and rear cover webs created a kind of receiving pocket for the second transverse leg of the screw. The cover is thereby guided when plugging. In the attached state, the cover webs are well fixed to the clamping frame. The fact that according to the invention engage the snap hooks from below, so that the snap hooks engage around the longitudinal limbs from below and engage in the corresponding locking grooves reliably prevents the bottom plate unintentionally stand out again from the second transverse leg. This is further prevented by the combination effect of the two cover webs, which ensure by means of a clamping effect that the bottom plate, once it is plugged, can not be bent on one side. In the known Schraubklemme according to the prior art, this advantageous combination effect is not achievable. There it prohibits namely, to attach a second Abdecksteg on the back of the bottom plate. Because the Ansteckrichtung is given from the front there by the design and arrangement of the latching hooks, a bottom plate can only be infected easily if the back carries no further Abdecksteg.

As a result, unintentional contact with live parts of the terminal frame through the housing insertion opening is no longer possible. If, for example, the clamping screw is tightened and the movably guided clamping frame is displaced upward in the housing in the direction of the clamping screw opening, so that the clamping screw facing away, lower side of the second transverse leg through the insertion opening is visible and touchable, so is in an inventive Screw terminal only touched the cover, but no longer the bare metal of the terminal or the terminal frame. As a result, a reliable protection against personal injury is given by the action of electricity.

According to an advantageous embodiment of the invention, the clamping screw protrudes through the threaded hole in the terminal frame, and the terminal frame is slidably guided in its installed position in the housing of the service switching device parallel to the central axis of the clamping screw, so that the connection conductor is clamped in the terminal frame

According to a further advantageous embodiment of the invention, the surface contour of the bottom plate of the surface contour of the second transverse leg is adjusted. For example, the second transverse leg may have a slightly V-shaped cross-sectional contour, so that the surface contour of the second transverse leg is channel-shaped with a longitudinal direction of extension of the channel from the front to the rear terminal insertion opening. As a result, a connecting conductor to be connected is better guided and held with its connection end in the second transverse limb. Accordingly, then also the bottom plate has a corresponding channel shape, so that the bottom plate fits like a key to the lock on the second transverse leg when the cover is plugged.

According to a further advantageous embodiment of the invention, the latching grooves are mounted near the front terminal insertion opening. As a result, a free surface in the rear part of the longitudinal leg is available for the installation of the screw in the housing.

According to a further advantageous embodiment of the invention, the locking grooves are mounted in the middle between the front and rear insertion opening. Due to the central locking provided thereby lifting the bottom plate of the second transverse leg is further difficult.

According to a further advantageous embodiment of the invention, a contact strip is provided within the terminal frame, on which presses the clamping screw, and the connection conductor is clamped between the second transverse leg and the contact strip.

Further advantageous embodiments and improvements of the invention and further advantages can be taken from the subclaims.

Reference to the drawings, in which 2 embodiments of the invention are shown, the invention, advantageous embodiments and improvements of the invention, and further advantages are explained and described in detail.

Fig. 1

eine Ausführungsform einer erfindungsgemäßen Schraubklemme, gesehen von der hinteren Klemmeneinführöffnung her,

Fig. 2

die Schraubklemme nach Fig. 1, gesehen von der vorderen Klemmeneinführöffnung her,

Fig. 3

eine Ausführungsform einer Abdeckung passend zu der Schraubklemme nach Fig. 1,

Fig. 4

ein elektrisches Installationsschaltgerät, in der Ansicht der Klemmeneinfuhröffnung,

Fig. 5

eine Einsicht in ein geöffnetes Gehäuse eines erfindungsgemäßen Installationsschaltgerätes, sowie

Show it:

Fig. 1

an embodiment of a screw according to the invention, as seen from the rear terminal insertion opening,

Fig. 2

the screw terminal after Fig. 1 seen from the front terminal insertion opening,

Fig. 3

an embodiment of a cover according to the screw after Fig. 1 .

Fig. 4

an electrical service switching device, in the view of the terminal insertion opening,

Fig. 5

an insight into an open housing of a service switching device according to the invention, as well as

The same or similar components or elements bear the same reference numerals in different figures.

In Fig. 1 and Fig. 2 a screw terminal 10 according to the invention is shown, once seen from the rear and once from the front terminal insertion 64, 34 ago. The screw terminal 10 comprises a terminal frame 14, a clamping screw, not shown here, and a cover 80. The terminal frame 14 and the clamping screw each consist of an electrically conductive material, usually of metal, such as stainless steel or a copper alloy. The cover 80 is made of an insulating material. It can be produced particularly economically as an injection-molded part on a thermoplastic.

The terminal frame 14 in this example is for receiving a lead with a relatively large cross-section of 50 mm ^{2 is} provided. But on other types of terminal frame, for example, for a conductor cross section of 35 mm ² , the invention is applicable.

The terminal frame 14 is approximately cuboidal and has an approximately rectangular cross-section with a first longitudinal leg 20, a second longitudinal leg 22 extending parallel thereto, a first transverse leg 24 running perpendicular to the longitudinal legs 20, 22 and a second transverse leg 26 extending parallel to the first transverse leg 24 ,

The clamping frame 14 is usually used as a stamped bent part of a metal strip produced. The first transverse leg 24 is formed by overlapping stacking of the two end pieces 241, 242 of the sheet metal strip after the cuboid box shape has been bent. The second transverse leg 26 has a channel-shaped contour, which facilitates the insertion and holding of a terminal end to be clamped.

The transverse legs 24, 26 and the longitudinal legs 20, 22 respectively frame a front and rear terminal insertion opening 34, 64 for insertion of a terminal conductor end.

The first transverse leg 24 has a threaded bore 28 into which a clamping screw (not shown in FIG Fig. 1 and 2 , see reference 64 in Fig. 5 ) can be used. A connecting conductor inserted into the front terminal connection opening 34 can thus be clamped by tightening the clamping screw between the clamping screw and the second transverse leg 26.

At the second transverse leg 26 is from below, so from outside the terminal insertion openings 34, 64, mounted a cover 80 and secured there latching. The cover 80 is in Fig. 3 shown alone. It comprises a bottom plate 81, which is formed substantially rectangular. The bottom plate 81 has a contour adapted to the contour of the second transverse leg 26 contour, so it is also formed channel-shaped. When the cover 80 is attached to the second transverse leg 26, see Fig. 1 and Fig. 2 in that the bottom plate 81 fits snugly against the second transverse leg 26, both fit into each other like a key, creating a virtually gap-free cover.

At a first and a second narrow side 82, 83 of the bottom plate 81 are each a Abdecksteg 84, 85 formed, which webs perpendicular to the broad side of the bottom plate 81 rise. The first and second narrow sides 82, 83 are those that would abut the second transverse leg 26 at the front and rear terminal insertion openings 34, 64, respectively, when the cover 80 is engaged. When the cover 80 is attached to the second transverse leg 26, so cover the two Abdeckstege 84, 85 at the front and at the rear terminal insertion opening 34, 64 each of the narrow side of the second transverse leg 26 from. The Abdeckstege 84, 85 also have a V-shaped contour, this is adapted to the V-shaped cross-sectional contour of the channel-shaped bottom plate 81. The two Abdeckstege 84, 85 together with the bottom plate 81 a box-shaped receptacle for the terminal frame 14 with its second transverse leg 26. When the cover 80 is fitted onto the clamping frame 14 from the side of the second transverse leg 26, the clamping frame 14 is guided between the two cover webs 84, 85, and the two cover webs 84, 85 are then fixed well to the clamping frame 14.

At the two other narrow sides 86, 87 of the bottom plate, that is the third and fourth narrow side 86, 87, which extend perpendicular to the front and rear terminal insertion openings 34, 64, a first and a second snap hook 90, 91 are attached. Each snap hook 90, 91 has an L-shaped holding part 95, 96, and a latching nose 97, 98. A first leg of each holding part 95, 96 is perpendicular to the third and fourth narrow side 86, 87 from a second leg points perpendicular to the bottom plate upwards, so that it runs approximately parallel to the first and second longitudinal legs 20, 22, when the cover is attached to the clamping frame. In this respect, the second legs of the holding parts 95, 96 form additional guide aids when attaching the cover 80 to the clamping frame 14.

In the first longitudinal leg 20 and in the second longitudinal leg 22, a first and a second locking groove 92, 93 are introduced, in which the locking lugs 96, 97 can latch when plugging the cover 80. The locking grooves 92, 93 may also be formed as latching openings. In the in the FIGS. 1 and 2 In the embodiment shown, the latching grooves 92, 93 are mounted near the front terminal insertion opening 34, respectively, and the snap hooks 90, 91 are mounted near the first narrow side 82 of the cover plate 81. The latching of the cover 80 on the terminal frame 14 takes place in the front part. This is beneficial if, when installing the screw in a service switching device only space in the front region of the clamping frame 14 for the side surfaces of the screw 10 projecting snap hook is present. If the spatial conditions allow it during installation, the locking grooves 92, 93 may also be mounted centrally between the front and the rear terminal insertion opening. The locking of the cover 80 would then be done centrally.

In Fig. 4 an electrical installation device 60 is shown, for example, a circuit breaker, a residual current circuit breaker or the like. The installation switching device device 60 comprises a first housing part 52 and a second housing part 54, which surround the live parts of the service switching device 60.

The side facing away from the second housing part 54 of the first housing part 52 is referred to as the first broad side 53 and is hidden in this representation. The side facing away from the first housing part 52 of the second housing part 54 is referred to as the second broad side 55.

An attachment side 66 of the installation device 60 is perpendicular to the broad sides 53, 55. The attachment side 66 is configured such that the installation device 60 can be fixed by means of this attachment side 66 to a support rail, not shown here, for example, a DIN rail.

The fastening side 66 opposite side of the installation device 60 is referred to as the front 68. The front side 68 comprises a central area, which is referred to as the front front 70, and two adjacent areas, which are set back relative to the front front 70 and are referred to as the rear front 72.

Perpendicular to the broad sides 53, 55 and perpendicular to the mounting side 66 and the front 68 extend the narrow sides, of which only the first narrow side 74 is visible in the illustration shown.

The housing parts 52, 54 are designed such that they form a housing insertion opening 62 in the region of the first narrow side 74, through which an electrical connection conductor 58 can be inserted into the interior of the housing of the installation device 60. In the interior of the housing of the installation device 60 and the housing insertion opening 62 immediately adjacent, there is only partially visible in this illustration screw. The terminal conductor 58 is inserted through the housing insertion opening 62 into the front terminal insertion opening 34 of the terminal frame 14 of the screw 10 and clamped there in a known manner.

At the screw 10, in the illustration shown here below the connecting conductor 58, a cover 80 is attached. The cover 80 obscures the portion of the end face of the clamp frame formed by the second transverse leg and extends away from the clamp frame, downwardly in the illustration shown.

The remaining parts of the energized terminal frame 14 are of the Housing parts 52, 54 hidden. Thus, no live part of the installation device 60 is visible and touchable from the outside.

Im in the Fig. 4 As shown, the terminal frame is provided for a conductor cross-section of 50 mm ² . However, the connected terminal conductor 58 has a relatively small cross section of only 6 mm ² . In order to firmly clamp this connection conductor 58, the second transverse leg must therefore be positioned relatively close to the clamping screw of the screw terminal. In the illustration shown, the terminal frame and thus the cover 80 is thus relatively high up.

The remaining insertion opening 62 has a maximum size. Without additional measures such as the attachment of a cover 80 according to the invention, it would be easily possible to touch the finger with the finger through the insertion opening 62 through the terminal frame. The cover 80 in the illustration shown prevents contact via the plate 81 and the first cover web 84.

In Fig. 5 is that off Fig. 4 known installation device 60 shown with the housing open. A first housing part 52 receives a screw 10 and a contact strip 56, wherein the screw 10 is arranged on the edge of the first housing part 52. The flat contact strip 56 is positioned so that one end is within the terminal frame 14 of the screw terminal 10, from where the contact strip 56 protrudes into the interior of the housing. The contact strip is mounted fixed relative to the housing halves 52, 54, for example, by being clamped in corresponding grooves which are formed by webs integrally formed on the inside of the housing. The clamping frame 14 is longitudinally displaceably guided in the housing interior parallel to the longitudinal direction of the first narrow side 74 of the housing.

At the screw terminal 10 opposite edge of the first housing part 52 is another screw with another contact strip, which have the same structure and which will not be discussed here. The electrically active parts, such as a triggering device, are not shown here.

A connection conductor 58 is connected to the screw terminal 10. In this case, a clamping screw 64 presses on the contact strip 56. As a result, the clamping frame 14 is moved upward in the direction of the rear front side 72, so that the connecting conductor 58 between the contact strip 56 and the second transverse leg 26th the clamping frame 14 is clamped. Through a bore, which is located in the closed housing in the rear front 72 of the installation device 60, the clamping screw 64 for an operating tool, such as a screwdriver, accessible.

In the region of the second transverse leg 26 of the terminal frame 14, an insulating cover 80 is attached, which, as in Fig. 4 already clarified, prevents contact with live parts.

LIST OF REFERENCE NUMBERS

10 screw 83 second narrow side 14 clamping frame 84 first cover web 20 first longitudinal leg 85 second cover web 22 second longitudinal leg 86 third narrow side 24 first transverse leg 87 fourth narrow side 26 second transverse leg 90 first snap hook 28 threaded hole 91 second snap hook 34 front insertion opening 92 locking groove 52 first housing part 93 locking groove 53 first broadside 94 holding part 54 second housing part 95 holding part 55 second broadside 96 locking lug 56 Contact strips 97 locking lug 58 connecting conductors 241 tail 60 installation device 242 tail 62 Gehäuseeinführöffnung 64 rear insertion opening 66 mounting side 68 Front of the installation device 70 front front 72 rear front 74 first narrow side 80 cover 81 baseplate 82 rear first narrow side

Claims (7)

1. Screw terminal (10) for an electrical installation device (60) for connecting an electrical connecting conductor (58), comprising a terminal frame (14) with a first and a second transverse limb (24, 26), a first and second longitudinal limb (20, 22), wherein the transverse and longitudinal limbs frame a front and rear terminal insertion opening (34, 64), wherein the first transverse limb (24) has a threaded bore (28) for accommodating a clamping screw (64), and wherein the second transverse limb (26) is covered by an insulating cover (80) surrounding a base plate (81), characterized in that the base plate (81) bears on each of a first and second mutually opposite narrow side (82, 83) a first and second covering web (84, 85), and in that the base plate (81) bears on each of a third and fourth mutually opposite narrow side (86, 87) a first and second snap-action hook (90, 91), which covering webs and snap-action hooks are oriented perpendicularly to the broad side of the base plate, with the result that, when the cover (80) is plugged onto the terminal frame (14), the first and second covering web (84, 85) covers the narrow sides of the second transverse limb (26) at the front and rear terminal insertion opening (34, 64), and the snap-action hooks (90, 91) latch into latching grooves (92, 93) in the longitudinal limbs (20, 22), and the cover (80) is thereby held on the terminal frame (14).
2. Screw terminal (10) according to Claim 1, characterized in that the clamping screw (64) protrudes through the threaded bore (28) into the terminal frame (14), and in that the terminal frame (14) is guided moveably, in its installed position, in the housing of the installation switching device parallel to the mid-axis of the clamping screw (64), with the result that the connecting conductor (58) can be clamped fixedly in the terminal frame (14).
3. Screw terminal (10) according to Claim 1, characterized in that the surface contour of the base plate (81) is matched to the surface contour of the second transverse limb (26).
4. Screw terminal (10) according to Claim 1, characterized in that the latching grooves (92, 93) are fitted close to the front insertion opening (34).
5. Screw terminal (10) according to Claim 1, characterized in that the latching grooves (92, 93) are fitted in the centre between the front and rear insertion openings (34, 64).
6. Screw terminal (10) according to Claim 1, characterized in that a contact strip (56) is provided within the terminal frame (14), with the clamping screw (64) pressing on the contact strip, and in that the connecting conductor (58) can be clamped fixedly between the second transverse limb (26) and the contact strip (56).
7. Installation switching device (60), comprising at least one screw terminal (10) according to one of the preceding claims.

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