EP2028721B1 - Installation device with a connection clamp assembly - Google Patents

Description

The invention relates to a service switching device having an insulating material housing and a terminal arrangement for clamping a connecting conductor with an annular clamping shoe, according to the preamble of claim 1.

The connection conductor is screwed in generic service switching devices on a screw hole having a stationary mounted inside the device connection plate with a clamping screw, which has a screw head and a screw shank. The terminal assembly is located in a terminal receiving space having an insertion opening for the terminal conductor and an access opening to the screw head for actuating the clamping screw with a tool, such as a screwdriver. When clamping the lead, the screw shaft penetrates the annular terminal shoe and is threadedly engaged with the screw hole.

In generic service switching devices are, for example, circuit breaker, motor protection switch or residual current circuit breaker, the terminal assembly is specially designed to connect a connecting conductor with a so-called annular clamping shoe, in particular with a clamping shoe with a closed ring. In the annular clamping shoe so there is a hole through which the clamping screw is guided during clamping. In previously known generic service switching devices clamping screws are used with a flat head and a long shaft, which are screwed into a connection plate in the interior of the switching device housing. Of the Clamping shoe is thereby clamped between the screw head and the connection plate, optionally with the interposition of an additional pressure piece. On the connection plate further, inside the leading conductors are attached, which carry the current path between an input and an output terminal through the installation switchgear.

A terminal conductor with an annular clamping shoe can not be clamped between the screw head and the terminal plate unless the terminal screw has been previously completely unscrewed and lifted from the terminal plate, thereby providing a passage for the closed terminal shoe at the insertion opening. The clamping screw can fall out through the access opening and be lost. The insertion of the clamping screw after inserting the terminal conductor with the annular terminal shoe requires some skill of the installer, because of the long shaft and the flat head of the commonly used clamping screws can easily tilt in the terminal receiving space between the access opening and the thread in the terminal plate, so that the screw shaft does not come into threaded engagement with the screw thread of the connection plate.

The DE 103 04 248 A1 shows a terminal device for an electrical device, which comprises a housing fixedly fixed to a connector, wherein the connector cooperates with a captive held clamping screw for making a Klemmkontaktierung an electrical conductor, and wherein the clamping screw has an elongated cylindrical guide head, which in a housing bore free of play and slidably guided in the axial direction.

The DE 20 2004 002 779 U1 shows a terminal block with a number of terminal spaces with terminals with clamping screws, the clamping screws are spring loaded by means of one spring element in the direction of the open position of the clamping screw, so that is released with relaxed spring element of the terminal space for the insertion of a cable lug.

It is therefore an object of the present invention to further develop a generic service switching device so that the clamping screw when connecting a connecting conductor with annular terminal shoe can not be lost, and that the screwing in of the clamping screw and the connection of the clamping shoe is simplified.

The object is achieved by a generic service switching device with the characterizing features of claim 1.

Thus, according to the invention, the restraint device is an undercut extending into the terminal receiving space in the region of the access opening, and the screw shank is chamfered at its free end to form a displacement member so that the clamping screw can be brought into the open position by pressing the clamping shoe onto the slope from the set-up position , By inventively provided retaining device a loss of the clamping screw is prevented. It may be sufficient in the embodiment according to the invention, the clamping shoe against the free end of the located in the Aufsetzposition Press the shaft of the clamping screw in order to push the clamping screw so far upwards over the bevel that the clamping shoe can slide on the connecting plate into its connection position. As a result, the assembly is further simplified, since the clamping screw does not have to be lifted separately by hand, it eliminates the need to bring them into a particular open position before the clamping shoe can be inserted, and due to the guide, it still remains centered in the direction aligned with the screw hole in the terminal plate.

According to a particularly advantageous embodiment of the invention comprises the screw head for the movable coupling first, head-side, in the direction of longitudinal movement of the screw extending guide means and the insulating housing comprises in the terminal receiving space second, receiving space-side guide means, which in inserted into the terminal receiving space screw for guiding the clamping screw interact in their longitudinal movement direction. The first, head-side guide means may be part of the screw head.

Very advantageous is an embodiment in which the screw head is a longitudinally extending direction of the screw elongated cylinder, wherein the first guide means are formed by the shell of this cylinder. Also advantageous is an embodiment in which the terminal receiving space comprises a wall extending in the longitudinal direction of movement of the clamping screw and leading the screw head. In the case of a clamping screw with a screw head designed as an elongate cylinder, it is encompassed by the wall along its cylinder jacket and guided thereby. A tilting of the clamping screw is avoided by the fact that the lateral surface of the cylindrical screw head slidably bears against the leading wall.

Particularly advantageous is an embodiment in which the leading wall is formed by the inner wall of a cylindrical guide channel in the terminal receiving space, which comprises the screw head.

Advantageously, the restraint device is an undercut extending into the terminal receiving space in the region of the access opening. Such an undercut can easily be used in injection molding of the housing together with the housing shells to be made with. The clamping screw should then be inserted into the terminal compartment before closing the housing.

A further alternative embodiment which is not part of the invention provides that the screw head and the wall in the open position of the clamping screw are in threaded engagement, so that the clamping screw is held in the open position thereby movable. As a result, the clamping screw can be held in the open position in a defined position. The threaded engagement between the clamping screw and the wall additionally prevents loss of the screw.

Advantageously, the threaded engagement between the screw head and the wall begins where the threaded engagement between the screw shaft and the screw hole ends. When the clamping screw is then unscrewed from its clamping position, in which it is screwed into the connecting thread on the connection plate, by actuation with a tool, it moves with the screw head in its longitudinal displacement direction upwards in the direction of the access opening. Upon reaching the placement position, the threaded engagement between the shank of the clamping screw and the screw thread of the connection plate ends. In a design of the screw head with an external thread and an arrangement of the corresponding internal thread in the wall then the thread engagement between the screw head and the wall begins in the placement, so that upon further actuation of the screwdriver, the clamping screw now unscrewed so to speak on the internal thread in the wall becomes. It can thus no longer be lost and it is held by the thread in the open position, without the fitter would have to hold them from the outside somehow, which facilitates insertion of the annular clamp shoe.

When tightening the clamping screw from the open position out via the thread in the wall a secure guidance of the screw shaft on the screw thread in the connection plate out. In the set position, the threaded engagement of the screw head ends with the wall, and the threaded engagement between the screw shaft and the screw thread in the connection plate begins. From now the clamping screw is screwed with the screw thread in the connecting plate until it has reached the clamping position with continued operation of the tool.

Particularly advantageous wearing the screw head an outer and the wall has an internal thread.

With regard to the connection plate, an advantageous embodiment of the invention provides that the connection plate is a leg of a U-shaped conductor rail, which is stationarily mounted in the housing of the service switching device and whose second, the terminal plate opposite leg is connected via a web with this.

At the free end of the connection plate can advantageously be formed a discharge for connecting further current conductors inside the service switching device.

In a very advantageous embodiment, the web can be contacted for testing and calibration purposes from outside the housing. The contacting for testing purposes is required, for example, in the so-called hot test of the thermal release of a Leifungsschutzschalters. In this case, in a corresponding test apparatus by means of a test terminal via the bridge a defined overcurrent, which may be about 1.5 times the rated current, connected to the device and checks whether the thermal release inside actually triggers within the required shutdown ,

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

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

Figur 1

eine erste Ausführungsform die nicht Teil der Erfindung ist, bei der die Klemmschraube sich in der Aufsetzposition befindet,

Figur 2

die Ausführungsform nach Figur 1, wobei die Klemmschraube sich in der offenen Stellung befindet,

Figur 3

die Ausführungsform nach Figur 1, wobei die Klemmschraube sich in der Klemmposition befindet, sowie

Figur 4

eine zweite Ausführungsform gemäß der Erfindung, bei der Schraubenkopf der Klemmschraube kein Gewinde trägt.

Show it:

FIG. 1

a first embodiment which is not part of the invention, in which the clamping screw is in the touchdown position,

FIG. 2

the embodiment according to FIG. 1 with the clamping screw in the open position,

FIG. 3

the embodiment according to FIG. 1 , wherein the clamping screw is in the clamping position, as well

FIG. 4

a second embodiment according to the invention, in which the screw head of the clamping screw carries no thread.

The FIG. 1 shows schematically and as a partial section of an installation switching device 1, which has an insulating material 2. The service switching device 1 is for example a circuit breaker. Its insulating housing comprises a front and rear front 3,4, a front and rear narrow side 5,6 and a mounting side 7. On the mounting side 7, a fixed lug 8 is attached, which with another, not shown, generally movable nose when clamping of the circuit breaker 1 cooperates on a mounting rail.

In the region of the rear narrow side 6, a terminal receiving space 10 is provided in the housing 2, in which a terminal assembly 11 is housed. The terminal receiving space 10 is accessible at the rear narrow side 6 through an insertion opening 27 for a terminal conductor 12 and at the rear front side 4 through an access opening 28 for an actuating tool, such as a screwdriver 22.

With the terminal assembly 11, the terminal conductor 12, which carries an annular clamping shoe 14 with a central opening 13, screwed by a clamping screw 15 to a connection plate 16.

The clamping screw 15 has a screw head 17 designed in the form of an elongate cylinder and a shaft 18. The shaft 18 is approximately as long as the screw head 17. The shaft 18 carries an external thread 19. At the free end face 20 of the screw head 17 is a slot 21 for receiving the operating tool, such as a screwdriver 22, is provided.

The connection plate 16 carries a screw hole 23 with an internal thread 25. It is aligned approximately parallel to the rear front side 4. The connection plate 16 forms a Leg of a U-shaped busbar 30, which is supported by web-like housing projections 32 fixed in the housing 2 of the service switching device 1.

The second leg 33 of the U-shaped busbar 30 is connected by means of a web 35 to the connection plate 16. It has an opening 34 which faces the screw hole 23 and also has a diameter at least as large as this.

The busbar 30 is arranged in the housing so that the web 35 comes to lie in the vicinity of the rear narrow side 6 and is accessible by a test opening 36 from the outside for contacting for testing or calibration purposes by means of a probe.

At the free end of the connection plate 16, a discharge bar 37 is formed, to which further, in the interior of the service switching device 1 outgoing conductor can be connected. However, these are not shown here, as well as all other required for operating a service switching device other components and assemblies, such as a thermal and electromagnetic release, a derailleur, a lever with a contact point, an arc extinguishing system, etc.

The clamping screw 15 is guided in an approximately cylindrical guide channel 24 in the terminal receiving space 10. The guide channel 24 extends approximately parallel to the rear narrow side 6, so that the clamping screw 15 is guided by him perpendicular to the screw hole 23 in the connection plate 16 out. The inner diameter of the guide channel 24 corresponds to the outer diameter of the screw head 17, so that the screw head 17 slidably guided in the guide channel 24 and is coupled in a manner movable with the insulating material inside the terminal receiving space 10.

In the FIG. 1 the clamping screw 15 is shown in a Aufsetzstellung, that is, the free end of the screw shaft 18 is straight on the internal thread 25 of the screw hole 23. In this position, the annular clamping shoe 14 can not be inserted into the terminal receiving space 10 because it would be blocked by the screw shaft 18. Before inserting the clamping shoe, the clamping screw 15 must be lifted so far in the direction of arrow P upwards from the connection plate 16 be that a at least the thickness of the clamping shoe 14 corresponding space between the free end of the shaft 18 and the connection plate 16 is opened, so that then the clamping shoe 14 can be inserted through the insertion opening 27 until it abuts the discharge rail 37 and its opening 13 just above the screw hole 23 comes to rest. This position is in the FIG. 2 shown.

The discharge bar 37 thus still comes here as the second function of the Einführstops for the clamping shoe 14, thereby avoiding too far insertion of the clamping shoe and thus the assembly of the connection conductor 12 is further facilitated.

The screw head 17 carries in its upper part an external thread 38. On the inner wall of the guide channel 24, an internal thread 39 is introduced. This starts where in the Aufsetzstellung according to FIG. 1 the external thread 38 on the screw head 17 ends. If now in the in the FIG. 1 shown Aufsetzstellung the clamping screw 15 is further rotated by means of the screwdriver 22 in the direction of arrow R, the screw head 17 and the inner wall of the guide channel 24 come into threaded engagement and further rotation of the clamping screw 15 it is moved over the internal thread 39 upwards in the open position and held there at the termination of the rotational movement.

After insertion of the connecting conductor 12 with the clamping shoe 14, see FIG. 2 , then the clamping screw 15 can be moved by turning in the internal thread 39 back down. It covers the opening 13 of the clamping shoe 14 and holds it firmly.

Upon reaching the Aufsetzstellung the threaded engagement between the outer thread 38 of the screw head 17 ends with the internal thread 39 of the inner wall of the guide channel 24, and it starts on further rotation with simultaneous slight downward pressure on the clamping screw 15, the threaded engagement between the external thread 19 on the shaft 18 and the internal thread 25 of the screw hole 23. By this threaded engagement, the clamping screw 15 is further pulled further rotation down into the screw hole 23, until the clamping shoe 14 is clamped between the screw head 17 and the terminal plate 16. This position is in the FIG. 3 shown. In this way, a solid screw with a good surface contact can be produced.

If the stem 18 were slightly longer, it could be received in the opening 34 of the second leg 33. In one, not shown, variant, the opening 33 could also carry an internal thread and thus possibly also in threaded engagement with the shaft 18 and thus contribute to the clamping action of the screw.

The FIG. 4 shows a further embodiment of the invention. All identical or equivalent components or assemblies carry in the FIG. 4 the same reference numerals as in the FIGS. 1 to 3 , preceded by a "10".

In this embodiment, there is no external thread on the screw head and no internal thread on the inner surface of the guide channel 1024. The slidable coupling between the screw head and the guide channel 1024 is effected by sliding the lateral surface of the cylindrical screw head along the lateral surface of the likewise cylindrical guide channel 1024. This tilting of the clamping screw 1015 is securely prevented in the guide channel 1024 and it is ensured that the axis of the Clamping screw 1015 always aligned with the axis of the screw hole 1023, so that when lowering the clamping screw 1015 in the guide channel 1024 from the open position to the set position of the shaft 1018 safely slides into such a position in which it is in threaded engagement with the internal thread in the screw hole 1023 can come.

Losing the clamping screw 1015 is avoided by an undercut 1040 in the guide channel 1024. The undercut 1040 may be formed as an annular bead or a cross-sectional constriction of the guide channel 1024 upwards. The reduced by the undercut 1040 cross-sectional area of the guide channel 1024 is still so large that a screwdriver 1022 can be performed to actuate the clamping screw 1015, but it is smaller than the cross section of the screw head, so that this somewhat captive in the guide channel 1024th is caught.

The lifting of the clamping screw 1015 from the touchdown position to the open position can be done here for example by magnetic holding force of the clamping screw 1025 on a magnetic screwdriver 1022.

In an advantageous further embodiment, the shaft 1018 is tapered slightly conically at its free end, indicated by the bevel 1042. On the other hand, annular clamping shoes 1014 are usually very thin, the thickness of the ring of such a clamping shoe 1014 is often less than 1 mm. It may therefore be sufficient to press such a thin clamping shoe 1014 strongly against the free end of the in-put position shaft 1018 to push the clamping screw 1015 so far above the slope 1042 that the clamping shoe 1014 on the connection plate 1016 can slide into its connection position. In this case, the assembly is further simplified because the clamping screw 1015 does not need to be lifted separately by hand, eliminating the need to bring them into a particular open position before the clamping shoe 1014 can be inserted.

The undercut and the slope are also in the embodiment according to the FIGS. 1 to 3 However, their special functional advantages such as the "captivation" of the clamping screw and the automatic pushing up of the clamping screw during insertion of the lead there are less relevant because both functions essentially by the internal thread in the Inside the guide channel in cooperation with the external thread on the outer surface of the screw head are realized. LIST OF REFERENCE NUMBERS 1, 101 Service switching device 35 web 2, 102 Insulated 36, 1036 test opening 3, 103 Front front 37, 1037 discharge bar 4, 104 Rear front 38 External thread on the screw head 5, 105 Front narrow side 39 Internal thread in the guide channel 6, 106 Rear narrow side 40, 1040 undercut 7, 107 mounting side 42, 1042 Schräqe at the shaft end 8, 108 Fixed nose 10, 1010 Terminal accommodation area 11, 1011 Terminal arrangement 12, 1012 terminal block 13, 1013 Opening in the clamping shoe 14, 1014 Annular clamping shoe 15, 1015 clamping screw 16, 1016 connecting plate 17 screw head 18, 1018 shaft 19, 1019 External thread on the shaft 20 Face of the screw head 21 slot 22, 1022 screwdriver 23, 1023 Screw hole in the connection plate 24, 1024 Guide channel in the terminal receiving space 25 Internal thread of the screw hole 27, 1027 insertion 28, 1028 access opening 30, 1030 conductor rail 32, 1032 Web-like projections 33, 1033 Second thigh 34, 1034 Opening in the second leg

Claims (9)

1. Service switching device (1, 101) having an insulating-material housing (2, 102) and a connection terminal arrangement (11, 1011) for the terminal connection of a connection conductor (12, 1012) having an annular terminal lug (14, 1014) to a connection plate (16, 1016) which has a screw hole (23, 1023) and is mounted in the device interior in a stationary manner, having a clamping screw (15, 1015) which has a screw head (17) and a screw shaft (18, 1018), wherein the screw shaft (18, 1018) passes through the annular terminal lug (14, 1014) and is in threaded engagement with the screw hole (23, 1023) during the terminal connection of the connection conductor (12, 1012), comprising a terminal accommodation space (10, 1010) having a guide channel (24, 1024) with an inner surface, having an insertion opening (27, 1027) for the connection conductor (12, 1012) and having an access opening (28, 1028) to the screw head (17) for the purpose of operating the said screw head, wherein the screw head (17) has an outer guide face which is in sliding contact with the inner surface of the guide channel (24, 1024) and as a result is movably coupled to the insulating-material housing (2, 102) in the interior of the guide channel (24, 1024) in the longitudinal movement direction of the clamping screw (15, 1015), so that, when the clamping screw (15, 1015) moves between an open position of the screw, in which there is space for inserting the terminal lug (14, 1014) of the connection conductor (12, 1012) between the free end of the screw shaft (18, 1018) and the connection plate (16, 1016), and a mounting position of the screw, in which the threaded engagement between the screw shaft (18, 1018) and the screw hole (23, 1023) just begins, the movement axis of the screw shaft (18, 1018) remains oriented toward the axis of the screw hole (23, 1023), and wherein the guide channel (24, 1024) comprises a retaining apparatus (40, 1040) for the clamping screw (15, 1015), the said retaining apparatus, in the open position, preventing the clamping screw (15, 1015) from being removed from the terminal accommodation space (10, 1010), characterized in that the retaining apparatus is formed by a section of the guide channel with a cross-sectional constriction, which is narrower than the diameter of the screw head, in the region of the access opening, and in that the screw shaft (1018) is conically bevelled at its free end in order to form a displacement element, so that the clamping screw can be moved from the mounting position to the open position due to pressure of the terminal lug on the bevel.
2. Service switching device according to Claim 1, characterized in that the terminal lug (1014) can be firmly clamped directly between the screw head and the connection plate (1016) in a clamping position of the clamping screw (1015).
3. Service switching device according to Claim 2, characterized in that the screw head, for being movably coupled, comprises first guide means on the head, which first guide means extend in the direction of the longitudinal movement of the screw, and the insulating-material housing, in the region of the terminal accommodation space (1010), comprises second guide means (1024) in the accommodation space, the said first and second guide means, in the case of the screw being inserted into the terminal accommodation space (1010), interacting in order to guide the clamping screw (1015) in its longitudinal movement direction.
4. Service switching device according to Claim 3, characterized in that the screw head is a cylinder which is elongated in the longitudinal movement direction of the screw, wherein the first guide means (1024) are formed by the casing of this cylinder.
5. Service switching device according to Claim 4, characterized in that the terminal accommodation space (1010) comprises a wall which extends in the longitudinal movement direction of the clamping screw (1015) and surrounds the screw head in a guiding manner.
6. Service switching device according to Claim 5, characterized in that the wall is formed by the inner wall of a cylindrical guide channel in the terminal accommodation space (1010) which comprises the screw head.
7. Service switching device according to one of the preceding claims, characterized in that the connection plate (1016) is a limb of a U-shaped busbar which is mounted in a stationary manner in the housing of the service switching device and of which the second limb, which is situated opposite the connection plate (1016), is connected to the said connection plate by means of a web (1035).
8. Service switching device according to Claim 7, characterized in that a discharge rail (1037) for the connection of further busbars in the interior of the service switching device is integrally formed at the free end of the connection plate (1016).
9. Service switching device according to one of Claims 7 to 8, characterized in that contact can be made with the web (1035) from outside the housing for testing and calibration purposes.

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