EP4027461A1

EP4027461A1 - Insulated terminal for fork type or eyelet cable lugs

Info

Publication number: EP4027461A1
Application number: EP21215309.2A
Authority: EP
Inventors: Anand CHIMAN; Thomas Gattringer; David Muellner
Original assignee: Eaton Intelligent Power Ltd
Current assignee: Eaton Intelligent Power Ltd
Priority date: 2021-01-12
Filing date: 2021-12-16
Publication date: 2022-07-13
Anticipated expiration: 2041-12-16
Also published as: CN114765322A; PL4027461T3; CN114765322B; EP4027461B1

Abstract

A terminal (1) for fixing a plurality of cable lugs (2) at the end of cables (3) is disclosed. The terminal (1) comprises at least one base body (4) and a plurality of terminal screws (5) screwed thereto, wherein each terminal screw (5) can clamp an eyelet end or a fork type end of a cable lug (2) between the base body (4) and said terminal screw (5). The terminal (1) also comprises a case (6) with a fixed part (7) and a plurality of movable case parts (10) individually movably arranged in the fixed case part (7). The case (6) encloses the base body (4), the terminal screws (5) and the cable lugs (2). Each movable case part (10) is associated each with a terminal screw (5), and each movable case part (10) comprises a recess (A) forming a feed through for a cable (3) mounted to the cable lug (2).

Description

TECHNICAL FIELD

The invention relates to a terminal for fixing a plurality of cable lugs each being mounted to an end of a cable, wherein the terminal comprises at least one base body and a plurality of terminal screws screwed into the at least one base body and wherein each terminal screw is designed to clamp an eyelet end or a fork type end of a cable lug of the cable lugs between the at least one base body and said terminal screw. Moreover, the invention relates to a cable connection, with a terminal of the above kind and a plurality of cable lugs mounted to the terminal.

BACKGROUND ART

Terminals and cable connections of the above kind are known in prior art. An eyelet end or a fork type end of a cable lug simply is screwed to at least one base body. Besides of problems resulting from different embodiments of a cable lug from different suppliers and besides of problems resulting from tolerances, a drawback of this kind of terminal and cable connection is that a predetermined rotation angle of a cable lug around a rotation axis of the terminal screw, by which the cable lug is fixed, cannot be ensured. Instead, said rotation angles can widely vary depending on the torque, which the terminal screw applies to the cable lug, on the friction coefficient between the cable lug and the at least one base body and between the cable lug and the terminal screw and on the torque by which the cable lug is held in position by the cable mounted thereto.
In some prior art embodiments, side stoppers in the at least one base body are provided to define a particular rotation angle of the cable lugs. However, this just works for a defined pair of a terminal and a cable lug. If different (and unknown) cable lugs shall be mounted to the terminal, again the problem of unpredictable angles of cable lugs arises.
Moreover, a particular rotation angle often is defined by exterior conditions. In particular, thick cables are often led to the terminal at a particular angle, which mainly is defined by the situation within the device (e.g. the switchgear), which the terminal is built into. Especially, those thick cables cannot be bent in any arbitrary shape.
In the end, the angle, at which a cable lug finally is mounted to the terminal, is unpredictable. Accordingly, it is also complicated to provide a case, which provides a particular protection class for the terminal and which in particular allows to attach cables of different cross section to the terminal.

DISCLOSURE OF INVENTION

Accordingly, an object of the invention is the provision of an improved terminal for cable lugs and an improved cable connection with such a terminal. In particular, a case shall be provided for the terminal, which provides a particular protection class for the terminal irrespective of a particular type of a cable lug, irrespective of tolerances and irrespective of a rotation angle of a cable lug and which allows to attach cables of different cross section to the terminal.
The object of the invention is solved by a terminal as disclosed in the opening paragraph, which additionally comprises:

a case with a fixed case part and a plurality of movable case parts individually movably arranged in the fixed case part,
wherein the case encloses the at least one base body and the terminal screws and wherein space is left for the cable lugs within the case,
wherein the fixed case part is fixedly arranged relative to the at least one base body and
wherein each movable case part is associated each with a terminal screw of the terminal screws and wherein each movable case part comprises a (center) recess forming a feed through for a cable mounted to the cable lug associated with said movable case part.

Moreover, the object of the invention is solved by a set of terminals as disclosed above, wherein the movable parts of different terminals have recesses of different size.
Finally, the object of the invention is solved by a cable connection as disclosed in the opening paragraph,

wherein one eyelet end or a fork type end of each cable lug is clamped each between the at least one base body and a terminal screw of the terminal screws and
wherein said cable lugs are enclosed by the case of the terminal and
wherein cables mounted to the cable lugs are guided through the recesses of the movable case parts.

By the above measures, different types of cable lugs can easily mounted to the terminal and tolerances of the cable lugs can easily be compensated. In particular, also a varying rotation angle of the cable lugs around the terminal screw axis can be compensated without foiling the protection of the interior of the case. By the above measures, advantageously, the case can provide a protection according to IP3XD or IP4X according to standard ISO 20653, irrespective of whether the cable lug is mounted at a zero angle or not. In addition, the terminal can be adapted to different requirements, i.e. to different cable sizes, just by changing the movable case parts. By choosing a movable case part, whose recess fits to the cross section of a cable (i.e. by choosing a movable case part with a recess having a size which corresponds to the cross section of a cable), the above protection class can easily be achieved for different cross sections of cables. Generally, it is of advantage if an area of the recess forming the feed through in a movable case part is in a range between 1.25 mm² and 70 mm². In turn, cables of different cross sectional areas can be guided through the recesses of the movable case parts, in particular cables having a cross section in a range of 1.25 mm² and 70 mm². Generally, the recesses in the movable case parts can have the same size or different sizes. Accordingly, cables having the same cross sectional area or different cross sectional areas can be connected to the terminal. The benefit of the proposed case particularly becomes visible if cables and thus cable lugs of different size shall be mounted to a terminal because it is hard to impossible then to define a zero rotation angle of the cable lugs by side stoppers in the at least one base body. In addition, the benefit of the proposed case particularly becomes visible if inflexible cables, which cannot be bent in any arbitrary shape, are led to the terminal at a particular angle, which mainly is defined by the situation within the device (e.g. the switchgear), which the terminal is built into.
So, concluding a case is provided for the terminal, which provides a particular protection class for the terminal irrespective of a particular type of a cable lug, irrespective of tolerances and irrespective of a rotation angle of a cable lug and which allows to attach cables of different cross sections to the terminal in a modular way, i.e. just by choosing appropriate movable case parts.
It should be noted that each terminal screw can have its own base body, or some or all terminal screws can be screwed into a common base body. The first case applies to applications where the different cables shall have independent voltage potentials. The second case applies to applications where different cables shall electrically be connected.
Further advantageous embodiments are disclosed in the claims and in the description as well as in the figures.
Beneficially, the fixed case part comprises a first case subpart and a second case subpart mounted thereto. In this way, the fixed case part can easily be mounted to the terminal, for example by means of case screws. However, the fixed case part may also be built of just one part or may comprise more than two case subparts.
Beneficially, the first case subpart and the second case subpart can be cup-shaped. Accordingly, they can easily enclose the at least one base body, the terminal screws and the cable lugs. Nevertheless, different shapes are possible as well for the first case subpart and the second case subpart.
Beneficially, the movable case parts are plate shaped. In that way, the movable case parts can easily be produced by cutting or stamping a plate like material. However, one skilled in the art will easily understand that other shapes can be used for the movable case parts as well. In that way, the movable case parts can easily be produced by cutting, too.
It is advantageous, if the fixed case part comprises a first case subpart and a second case subpart mounted thereto, and the first case subpart and the second case subpart are cup-shaped, and the movable case parts are plate shaped. In that way, the above advantages can be combined.
Beneficially, the movable case parts are movably arranged in grooves of the fixed case part. Accordingly, a particular protection class can be achieved irrespective of the position of the movable case parts.
Advantageously, the movable case parts are each movable transverse to an axis of the associated terminal screw, in particular movable perpendicular to said axis. More particularly, the movable case parts can each be movable in one linear direction of a Cartesian coordinate system. In this way, a rotation of the cable lug around the terminal screw axis can be compensated.
It is also of advantage if the movable case parts are each movable in a plane in two orthogonal directions of a Cartesian coordinate system. In this way, a deformation of the cable lugs in vertical direction, i.e. a bending around an axis transverse to the terminal screw axis can be compensated as well.
Beneficially, a center axis of the recess forming the feed through in the movable case part in one position of the movable case part crosses the axis of the associated terminal screw. Accordingly, the cable lug can be mounted at a zero rotation angle easily.
Advantageously, the movable case parts are each movable in a moving range of ± 2 mm. Accordingly, common tolerances and rotation angles of the cable lugs can be compensated. In particular, axes of at least two cable lugs or cables can include an angle in a range of ± 10° within the case.
Advantageously, the movable case parts are made of rigid plastic, in particular of fiber reinforced plastic. Accordingly, the case withstands very unfavorable environmental conditions like short circuits, high energy arc flashes and so on. In particular, the movable case parts are superior to conventional grommets or rubber materials not only in terms of mechanical strength, but also in terms of temperature, especially when the cables lead through the movable case parts get glowing.

BRIEF DESCRIPTION OF DRAWINGS

The invention now is described in more detail hereinafter with reference to particular embodiments, which the invention however is not limited to.

Fig. 1: shows an exemplary embodiment of a terminal in exploded view;
Fig. 2: shows a top view of a cable connection with the terminal of Fig. 1 with a part of the case being detached;
Fig. 3: shows an angled view of the cable connection of Fig. 2 at a first viewing angle and
Fig. 4: shows an angled view of the cable connection of Fig. 2 at a second viewing angle.

DETAILED DESCRIPTION

Generally, same parts or similar parts are denoted with the same/similar names and reference signs. The features disclosed in the description apply to parts with the same/similar names respectively reference signs. Indicating the orientation and relative position (up, down, sideward, etc) is related to the associated figure, and indication of the orientation and/or relative position has to be amended in different figures accordingly as the case may be.
Fig. 1 shows an exemplary embodiment of a terminal 1 in exploded view. The terminal 1 is designed to fix a plurality of cable lugs 2 each being mounted to an end of a cable 3. Note that Fig. 1 shows the cable lugs 2 without the cables 3 mounted thereto, but Figs. 2 to 4 show cables 3 as well. Do also note that mounting cable lugs 2 without cables 3 to the terminal 1 in reality is not useful, and usually a cable 3 is connected to a cable lug 2, for example by crimping or soldering.
The terminal 1 comprises at least one base body 4 and a plurality of terminal screws 5 screwed into the at least one base body 4. Each terminal screw 5 is designed to clamp an eyelet end or a fork type end of a cable lug 2 between the at least one base body 4 and said terminal screw 5. In Fig. 1, just eyelet ends of eyelet cable lugs 2 are shown, but fork type ends of fork cable lugs work as well. Moreover, the terminal 1 comprises a case 6 with a fixed case part 7, which comprises a first subpart 8a and a second subpart 8b mounted thereto by means of case screws 9 in this example and which is fixedly arranged relative to the at least one base body 4. In addition, the case 6 comprises a plurality of movable case parts 10 individually movably arranged in the fixed case part 7. The case 6 encloses the at least one base body 4 and the terminal screws 5. In addition, space is left for the cable lugs 2 within the case 6. Each movable case part 10 is associated each with a terminal screw 5 and comprises a (center) recess A forming a feed through for a cable 3 mounted to the cable lug 2 associated with said movable case part 10.
In this example, the terminal 1 is mounted to a base plate 11, which could be part of a switchgear of example. However, said application is not mandatory, and the terminal 1 can be used in other applications as well.
Figs. 2 to 4 now show a cable connection 12, i.e. a terminal 1 with cable lugs 2 and cables 3 connected thereto in different views. Fig. 2 shows a top view of a cable connection 12 with the first subpart 8a of the fixed case part 7 being detached, and Figs. 3 and 4 show the complete cable connection 12 in different view angles. In Figs. 2 to 4, the cables 3 are guided through the recesses A of the movable case parts 10.
In the example shown in the Figs. 1 to 4, the movable case parts 10 are movably arranged in grooves B of the fixed case part 7 what is beneficial but not mandatory. Preferably, the movable case parts 10 are each movable transverse to an axis C of the associated terminal screw 5, in particular movable perpendicular to said axis C, as this is the case in the example shown in the Figs. 1 to 4 and what is indicated by arrows. In this example, the movable case parts 10 are each movable in one linear direction y of a Cartesian coordinate system. However, it is also possible that the movable case parts 10 are each movable in a plane in two orthogonal directions y, z of a Cartesian coordinate system. Beneficially, the movable case parts 10 are each movable in a moving range of ± 2 mm. However, another moving range is possible as well. Advantageously, a center axis D of the recess A forming the feed through in the movable case part 10 in one position of the movable case part 10 crosses the axis C of the associated terminal screw 5 as this is the case in the example shown in the Figs. 1 to 4.
By the movable case parts 10, different types of cable lugs 2 can easily mounted to the terminal 1 and tolerances of the cable lugs 2 can easily be compensated. Further on, varying rotation angles of the cable lugs 2 around the screw axes C are possible without foiling the protection of the interior of the case 6. Especially, Fig. 2 shows what is meant. As is visible there, all three cable lugs 2 are mounted to the terminal 1 at different rotation angles around the screw axes C of the terminal screws 5. The movable case parts 10 compensate these different rotation angles. The moving range of ± 2 mm beneficially allows to compensate common tolerances and rotation angles. In particular, the axes E of at least two cable lugs 2 or cables 3 can include an angle in a range of ± 10° within the case 6. When the center axis D of the recess A forming the feed through in the movable case part 10 crosses the axis C of the associated terminal screw 5, the cable 3 is mounted to the terminal 1 at a zero angle.
By the above measures, advantageously, the case 6 can provide a protection according to IP3XD or IP4X according to standard ISO 20653, irrespective of whether the cable lug 2 is mounted at a zero angle or not. Note that there may also be movable case parts 10, which have no recess A like this is the case for the very left movable case part 10 in the Figs. 1 to 4. This is useful, if not all possible positions of the terminal 1 are seized by a cable lug 2.
The above measures are particularly useful for thick cables 3, which cannot easily bent in small radii. Generally, an area of the recess A forming the feed through in a movable case part 10 beneficially can be in a range between 1.25 mm² and 70 mm². In turn, cables 3 of different cross sectional areas can be led through the recesses A of the movable case parts 10, in particular cables 3 having a cross section in a range between 1.25 mm² and 70 mm². By choosing a movable case part 10, whose recess A fits to the cross section of a cable 3 (i.e. by choosing a movable case part 10 with a recess A having a size which corresponds to the cross section of a cable 3), the above protection class can easily be achieved for different cross sections of cables 3.
The recesses A in the movable case parts A all can have the same size or different sizes so that cables 3 having the same cross sectional area or having different cross sectional areas can be mounted to the terminal 1.
Generally, it is also of advantage if a set of terminals 1 provided, wherein the movable parts 10 of different terminals 1 have recesses A of different size. In this way, the terminal 1 can be adapted to different requirements, i.e. to different cable sizes.
If the movable case parts 10 are each movable in a plane in two orthogonal directions y, z of a Cartesian coordinate system, not only a rotation of the cable lugs 2 around the screw axis C can be compensated, but a deformation of the cable lugs 2 in vertical z-direction, too.
In the example shown in the Figs. 1 to 4, the first case subpart 8a and the second case subpart 8b are cup-shaped and the movable case parts 10 are plate shaped. In that way, the movable case parts 10 can easily be produced by cutting or stamping a plate like material. However, one skilled in the art will easily understand that other shapes can be used for the case 6 as well.
Generally, it is of advantage if the movable case parts 10 are made of rigid plastic, in particular of fiber reinforced plastic. Accordingly, the case 6 withstands very unfavorable environmental conditions like short circuits, high energy arc flashes. In particular, the movable case parts 10 are superior to conventional grommets or rubber materials not only in terms of mechanical strength, but also in terms of temperature, especially when the cables 3 lead through the movable case parts 10 get glowing.
It is noted that the invention is not limited to the embodiments disclosed hereinbefore, but combinations of the different variants are possible. In reality, the terminal 1 and the cable connection 12 may have more or less parts than shown in the figures. Moreover, the description may comprise subject matter of further independent inventions.
It should also be noted that the term "comprising" does not exclude other elements and the use of articles "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

LIST OF REFERENCE NUMERALS

1: terminal
2: cable lug
3: cable
4: base body
5: terminal screw
6: case

7: fixed case part
8a, 8ab: case subpart
9: case screw
10: movable case part
11: base plate
12: cable connection

A: recess
B: groove
C: axis of terminal screw
D: axis of recess / feed through
E: axis of cable lug
x, y, z: coordinate directions

Claims

Terminal (1) for fixing a plurality of cable lugs (2) each being mounted to an end of a cable (3), wherein the terminal (1) comprises
- at least one base body (4) and a plurality of terminal screws (5) screwed into the at least one base body (4), wherein each terminal screw (5) is designed to clamp an eyelet end or a fork type end of a cable lug (2) of the cable lugs (2) between the at least one base body (4) and said terminal screw (5),
characterized in

- a case (6) with a fixed case part (7) and a plurality of movable case parts (10) individually movably arranged in the fixed case part (7),

- wherein the case (6) encloses the at least one base body (4) and the terminal screws (5) and wherein space is left for the cable lugs (2) within the case (6),

- wherein the fixed case part (7) is fixedly arranged relative to the at least one base body (4) and

- wherein each movable case part (10) is associated each with a terminal screw (5) of the terminal screws (5) and wherein each movable case part (10) comprises a recess (A) forming a feed through for a cable (3) mounted to the cable lug (2) associated with said movable case part (10).
Terminal (1) as claimed in claim 1, characterized in that the fixed case part (7) comprises a first case subpart (8a) and a second case subpart (8b) mounted thereto, and the first case subpart (8a) and the second case subpart (8b) are cup-shaped, and the movable case parts (10) are plate shaped.
Terminal (1) as claimed in claim 1 or 2, characterized in that the movable case parts (10) are movably arranged in grooves (B) of the fixed case part (7).
Terminal (1) as claimed in any one of claims 1 to 3, characterized in that the movable case parts (10) are each movable transverse to an axis (C) of the associated terminal screw (5).
Terminal (1) as claimed in claim 4, characterized in that a center axis (D) of the recess (A) forming the feed through in the movable case part (10) in one position of the movable case part (10) crosses the axis (C) of the associated terminal screw (5).
Terminal (1) as claimed in any one of claims 1 to 5, characterized in that the movable case parts (10) are each movable in a moving range of ± 2 mm.
Terminal (1) as claimed in any one of claims 1 to 6, characterized in that the movable case parts (10) are each movable in
a) one linear direction (y) of a Cartesian coordinate system or

b) in a plane in two orthogonal directions (y, z) of a Cartesian coordinate system.
Terminal (1) as claimed in any one of claims 1 to 3, characterized in that an area of the recess (A) forming the feed through in a movable case part (10) of the movable case part (10) is in a range between 1.25 mm² and 70 mm².
Terminal (1) as claimed in any one of claims 1 to 8, characterized in that the recesses (A) in the movable case parts (A) have
i) the same size or

ii) different sizes.
Terminal (1) as claimed in any one of claims 1 to 9, characterized in that the movable case parts (10) are made of rigid plastic.
Set of terminals (1) as claimed in any one of claims 1 to 10, characterized in that the movable parts (10) of different terminals (1) have recesses (A) of different size.
Cable connection (12), characterized in a terminal (1) according to any one of claims 1 to 10 and a plurality of cable lugs (2) mounted to the terminal (1),
- wherein one eyelet end or a fork type end of each cable lug (2) is clamped each between the at least one base body (4) and a terminal screw (5) of the terminal screws (5) and

- wherein said cable lugs (2) are enclosed by the case (6) of the terminal (1) and

- wherein cables (3) mounted to the cable lugs (2) are guided through the recesses (A) of the movable case parts (10).
Cable connection (12) as claimed in claim 12, characterized in that the case (6) provides protection according to IP3XD or IP4X according to standard ISO 20653.
Cable connection as claimed in claim 12 or 13, characterized in that axes (E) of at least two cable lugs (2) or cables (3) include an angle in a range of ± 10° within the case (6).