EP1782443B1 - Contact assembly - Google Patents

Abstract

A contact arrangement for use on an insulating rod having an upper fastening bore and a lower fastening bore has a U-shaped contact having a pair of limbs each formed with an upper bore and a lower bore. The contact is fittable around the rod with the limbs flanking the rod and the upper and lower bores of the limbs aligned with the respective upper and lower bores of the rod. Respective upper and lower contact holders each have a pair of mounts flanking the rod and respectively downwardly and upwardly engaging the limbs of the contact. The mounts of the contact holders are formed with bores aligned with the bores of the rod and with the bores of the respective limbs. Dielectric upper and lower pins extend through the bores of the mounts of the holders, the bores of the limbs, and the bores of the rod.

Description

The invention relates to a contact arrangement with a fixed electrical contact, which is attached to a lsolierstab, for a tap changer or diverter.

Tap changer and diverter are known devices for switching between different winding taps of a control transformer for voltage regulation. They have fixed contacts that are electrically connected to the individual winding taps of a control transformer and are usually arranged in phases on superimposed circular paths. In each horizontal plane, the fixed contacts are connectable by a movable contact, usually a contact bridge, which is connected to the electrical load dissipation. The fixed contacts are attached to vertical Isolierstäben made of hard paper or glass fiber reinforced plastic or in the wall of Isolierzylindern.

The attachment to insulating rods is hitherto usually characterized in that both the corresponding insulating rod itself and a fixing part of the fixed contact is provided in each case with holes and this contact arrangement is clamped together by screws and nuts. Such a contact arrangement with a screw is off FIG. 1 of the AT-PS 187991 known. The disadvantage of this simple per se attachment, however, is that the dielectric strength of the entire tap changer or diverter is deteriorated by the insulating rods penetrating metallic fasteners.

To remedy this problem, numerous proposals have already become known. The named AT-PS 187991 itself describes a further contact arrangement in which clamping pieces are provided which comprise the respective insulating bars and which are screwed outside of these insulating bars, so that no metallic fastening means penetrate the insulating bars themselves. A very similar solution is later in the AT-PS 315302 been proposed. Although the holes through the insulating bars can be avoided, metallic fasteners are nevertheless present, even if outside the insulating bars; their unfavorable influence on the dielectric strength thus persists.

From the AT-PS 382476 another contact arrangement is known, wherein on the contact to be fixed a sleeve is provided, which has on one side a collar whose diameter is larger than the bore diameter of the respective insulating rod. On the other side of the insulating rod, the sleeve of the contact to be fastened on an annular groove, in which a slotted ring made of plastic is inserted. However, this arrangement has not been successful in practice. Insulating rods generally shrink during the required drying of the respective on-load tap-changer or diverter before commissioning; in this known contact arrangement loosen, due to the purely positive attachment, the individual contacts, which is undesirable.

From the DE-PS 3801151 and 3801152 are known a contact arrangement and an associated fastening method, wherein the contact by permanent deformation of its shaft on the outer side, more precisely by expansion of specially provided holes, is held. This is relatively expensive and requires a special tool for expanding the holes described, also allows only a positive fastening. Finally, no destructive disassembly of this contact arrangement is possible.

The DE-GM 9010730 suggests a similar contact arrangement; Here, the shank of the contact in a defined area is weakened in its cross section, and by upsetting from the outside a bead-like thickening of the shaft is reached at this point, whereby a fixing takes place. Although no special tool is required for the compression described from the outside - a hammer is sufficient - but also here in addition to the turn only positive connection has the disadvantage that disassembly is also possible only by destruction of the contact.

The DE-PS 4236528 describes a further possibility of attaching a contact by a contact bolt penetrating the transverse bolt and cooperating locking means. This connection is non-destructive solvable, can also be performed non-positively and is also suitable for the simultaneous attachment of shield rings. However, it could not prevail because it is relatively complicated and requires a large number of highly accurate parts manufactured to each other. document DE-A-2 705 772 discloses a contact arrangement according to the preamble of claim 1.

The object of the invention is therefore to provide a contact arrangement of the aforementioned type, in which a solid electrical contact to a lsolierstab can be fastened, without affecting the dielectric strength by metallic fasteners, wherein the contact assembly further constructed simple and inexpensive, against loosening of secured solid contact and also destructible again disassembled.

This object is achieved by a contact arrangement with the features of the first claim. The subclaims relate to particularly advantageous developments of the invention.

According to the invention, the contact arrangement of the type mentioned except the actual contact, which is to be attached to an insulating rod, nor a two-part contact holder made of insulating material and bolts for mounting, also made of insulating material. According to the invention, the actual contact is U-shaped. The contact arrangement according to the invention has a number of advantages: There are no metallic parts required for attachment, the entire arrangement consists of only a few, easy to produce parts, yet a secure attachment without special tools is possible. The attachment according to the invention also ensures a reliable secure attachment in case of eventual shrinkage of the insulating rod or during subsequent vibrations during operation; Finally, again without special tools - at any time an easy and non-destructive disassembly possible.

According to an advantageous development of the invention, additional shielding caps, which surround the contact on both sides in the longitudinal direction of the insulating rod, can be fastened in a simple manner.

Figur 1

eine erfindungsgemäße Kontaktanordnung in seitlicher Darstellung

Figur 2

diese Kontaktanordnung, horizontal um 90° gedreht

Figur 3

einen Schnitt in der Ebene A-A durch diese Kontaktanordnung

Figur 4

einen Schnitt in der Ebene B-B durch diese Kontaktanordnung

Figur 5

einen Schnitt in der Ebenen C-C durch diese Kontaktanordnung

Figur 6

eine perspektivische Darstellung der Kontaktanordnung

Figur 7

eine ebensolche Darstellung wiederum horizontal um 90° gedreht

Figur 8

einen Kontakt allein in perspektivischer Darstellung

Figur 9

diesen Kontakt um 180° gedreht

Figur 10

einen oberen Kontakthalter allein in perspektivischer Darstellung

Figur 11

einen unteren Kontakthalter allein in perspektivischer Darstellung

Figur 12

einen Bolzen zur Befestigung

Figur 13

einen oberen Schirmring allein in perspektivischer Darstellung

Figur 14

einen unteren Schirmring allein in perspektivischer Darstellung.

The invention will be explained in more detail by way of example with reference to drawings. Show it:

FIG. 1

a contact arrangement according to the invention in a lateral view

FIG. 2

this contact arrangement, rotated horizontally by 90 °

FIG. 3

a section in the plane AA through this contact arrangement

FIG. 4

a section in the plane BB through this contact arrangement

FIG. 5

a section in the plane CC through this contact arrangement

FIG. 6

a perspective view of the contact arrangement

FIG. 7

a similar representation in turn rotated horizontally by 90 °

FIG. 8

a contact alone in perspective view

FIG. 9

rotated this contact by 180 °

FIG. 10

an upper contact holder alone in perspective view

FIG. 11

a lower contact holder alone in perspective view

FIG. 12

a bolt for attachment

FIG. 13

an upper shield ring alone in perspective view

FIG. 14

a lower shield ring alone in perspective view.

In the FIGS. 1-7 , which show the entire contact arrangement according to the invention in the mounted state, not all reference numerals are listed for reasons of clarity.

In the FIGS. 1-7 showing the entire contact arrangement, first an insulating rod 1 is shown, to which the contact arrangement according to the invention is to be attached. The individual parts of the contact arrangement according to the invention are in the FIGS. 8 to 14 shown separately.

The insulating rod 1 has, for each contact arrangement to be fastened, in each case an upper fastening bore 11 and a lower fastening bore 12. On the insulating rod 1, the contact 2 is arranged, which is U-shaped. It has a contact area 21; this is the area in which it can be connected at the top and bottom by a movable contact (not shown). He also has a long leg 22 and a short leg 23, in the long leg 22 is a connection bore 24, to which the electrical connection line, not shown here, can be connected to the respective winding tap of the control transformer. The long leg 22 also has an upper mounting hole 25 and a lower mounting hole 26. The short leg 23 extends on the opposite side of the insulating rod 1 parallel to the long leg 22 and also has an upper mounting hole 27 and a lower mounting hole 28. The mounting holes 25 and 27 and 26 and 28 correspond to the mounting holes 11 and 12, the insulating rod. 1 penetrate. Above, the contact 2 is fixed by an upper contact holder 3. The contact holder 3 has a guide shaft 31 whose inner dimensions correspond to the outer dimensions of the insulating rod 1; he is pushed onto this insulating rod 1. He further has a circumferential collar 32, on the side, opposite each other, molded contact receptacles 33 and 34 are provided. In the contact 33 rests in the assembled state, the upper portion of the long leg 22 of the contact 2, in the contact 34 corresponding to the upper portion of the short leg 23. In the contact receiving 33, 34 are also opposite, abutment 35, 36 for a bolt 5, which will be explained later, provided. Finally, there is a bore 37 and on the opposite side a further bore 38 through the guide shaft 31st

From below, the contact 2 in the assembled state is surrounded by a lower contact holder 4. The lower contact holder 4 is constructed identically as the already described upper contact holder 3; he is pushed from below onto the insulating rod 1. In a completely analogous manner, it again has a guide shaft 41 to which a circumferential collar 42 is integrally formed, which in turn has laterally formed contact receptacles 43 and 44. In the contact 43, the lower portion of the long leg 22 rests in the contact 44, the lower portion of the short leg 23. In the area are in turn abutment 45 and 46 and holes 47 and - 48 opposite.

For attachment are now only an upper bolt 5 and a lower bolt 6, both made of insulating material, for. As GFK, required. The upper pin 5 is horizontally from the outside through the upper mounting hole 25 of the long leg 22 of the contact 2, further through the bore 37 of the upper contact holder 3, further through the upper mounting hole 11 of the insulating rod 1, further through the bore 38 of the upper contact holder. 3 on the opposite side, finally guided by the upper mounting hole 27 of the opposite short leg 23 of the contact 2 and then points on the opposite side again to the outside.

Accordingly, the lower pin 6 is first through the lower mounting hole 26 of the long leg 22 of the contact 2, further through the bore 47 of the lower contact holder 4, further through the lower mounting hole 12 of the insulating rod 1, then through the bore 48 on the opposite side of the bottom contact holder 4 and finally passed through the lower mounting hole 28 in the short leg 23 of the contact 2, before he also steps on the opposite side again to the outside.

For a reliable attachment of the contact 2 on the insulating rod 1 is given. By the contact holders 3 and 4 arranged on both sides above and below the contact 2 is reliably fixed and fixed under all operating conditions. The bolts 5 and 6 are dimensioned in their length such that they rest laterally on the corresponding abutment 35, 36 for the upper bolt 5 and 45, 46 for the lower bolt 6.

According to an advantageous embodiment of the invention, the outer regions of the abutments 35, 36 relative to the upper mounting hole 11 and the abutment 45, 46 relative to the lower mounting hole 12 vertically displaced by a small amount, so that, due to the existing within certain limits elasticity the components, the inserted bolts 5 and 6 are pressed during assembly in the axial direction against the outer regions of the abutments 35, 36 and 45, 46, to final assembly position "abut" these abutment in its outer region and the respective bolt thereby is secured axially. This prevents unintentional slipping out.

According to a development of the invention, an upper shielding cap 7 and a lower shielding cap 8 are additionally provided. The open sides of these shielding caps 7 and 8 are respectively facing the contact piece 2. The upper shielding cap 7 has a first fastening tab 71 and, opposite this, a second fastening tab 72; each bore holes 73 and 74 are located therein. The upper shielding cap 7 is pushed from above onto the insulating rod 1 so that the fastening tabs 71, 72 point downwards. Analogously, the shield cap 8 constructed identically has a first fastening tab 81 pointing upwards in the pushed-on state and, opposite, a second fastening tab 82, in each of which there is a bore 83 or 84 again. The fastening tabs 71, 72 and 81, 82 and the holes therein 73, 74 and 83, 84 are dimensioned such that the fastening bolts 5 and 6 are also guided in the mounted state through these holes, whereby the shielding caps 7 and 8 together with the contact 2 and upper contact holder 3 and lower contact holder 4 are attached to the insulating rod 1 with, without the need for additional fasteners. The electrical contact between the respective shielding cap 7 or 8 and the contact 2 is achieved by means of the respective pre-bent fastening tabs 71, 72 and 81, 82. Furthermore, the lateral edges of the fastening tabs 71, 72 and 81, 82, which are guided in a form-fitting manner in pockets 39, 49 of the respective contact holder 3, 4, prevent lateral twisting.

In practice, the contact 2 is brought to the appropriate location of the insulating rod 1, to which it is to be attached, for mounting. Subsequently, the upper contact holder 3 and from below the lower contact holder 4 is pushed onto the insulator 1 from above. Both contact holders 3 and 4 fix the contact 2. Subsequently upper shielding cap 7 can be slid from above and lower shielding cap 8 from below onto the insulating rod.

• Obere Befestigungsbohrung 25 des Kontaktes 2, Bohrung 37 des oberen Kontakthalters 3, Bohrung 73 der oberen Abschirmkappe 7, obere Befestigungsbohrung 11 des Isolierstabes 1, Bohrung 74 der oberen Abschirmkappe 7, Bohrung 38 des oberen Kontakthalters 3, obere Befestigungsbohrung 27 des Kontaktes 2.
• Durch diese fluchtenden Bohrungen wird horizontal der obere Bolzen 5 eingeschoben. Im eingeschobenen Zustand ruht der obere Bolzen 5 seitlich mit seinen freien Enden auf dem inneren Widerlager 35 bzw. - auf der anderen Seite - dem inneren Widerlager 36.

In the position provided for fixing, the following bores are aligned in an upper horizontal plane:

• Upper mounting hole 25 of the contact 2, bore 37 of the upper contact holder 3, bore 73 of the upper shield 7, upper mounting hole 11 of the insulating rod 1, bore 74 of the upper shield 7, bore 38 of the upper contact holder 3, upper mounting hole 27 of the contact. 2
• Through these aligned holes, the upper pin 5 is inserted horizontally. In the retracted state, the upper pin 5 rests laterally with its free ends on the inner abutment 35 or - on the other side - the inner abutment 36th

• Untere Befestigungsbohrung 26 des Kontaktes 2, Bohrung 47 des unteren Kontakthalters 4, Bohrung 83 der unteren Abschirmkappe 8, untere Befestigungsbohrung 12 des Isolierstabes 1, Bohrung 84 der unteren Abschirmkappe 8, Bohrung 48 des unteren Kontakthalters 4, untere Befestigungsbohrung 28 des Kontaktes 2.
• Durch diese fluchtenden Bohrungen wird horizontal der untere Bolzen 6 eingeschoben. Im eingeschobenen Zustand ruht der untere Bolzen 6 seitlich mit seinen freien Enden auf dem inneren Widerlager 45 bzw. - auf der anderen Seite - dem inneren Widerlager 46.

Accordingly, in a lower horizontal position, the following holes are aligned:

• Lower mounting hole 26 of the contact 2, bore 47 of the lower contact holder 4, bore 83 of the lower shield 8, lower mounting hole 12 of the insulating rod 1, bore 84 of the lower shield 8, bore 48 of the lower contact holder 4, lower mounting hole 28 of the contact second
• Through these aligned holes of the lower bolt 6 is inserted horizontally. In the retracted state, the lower bolt 6 rests laterally with its free ends on the inner abutment 45 and, on the other side, the inner abutment 46.

• einen Kontakthalter, z. B. kostengünstig als Spritzgussteil aus Kunststoff herstellbar, der sowohl als oberer Kontakthalter 3 als auch - um 180 Grad gedreht - als identischer unterer Kontakthalter 4 auf den Isolierstab 1 aufgeschoben wird
• eine Abschirmkappe, leicht aus Blech herstellbar, die sowohl als obere Abschirmkappe 7 als auch - um 180 Grad gedreht - als identische untere Abschirmkappe 8 auf den Isolierstab 1 aufgeschoben wird
• einen einfachen Bolzen aus Isolierstoff, der sowohl als oberer Befestigungsbolzen 5 als auch als unterer Befestigungsbolzen 6 dient.

Overall, the-explained inventive contact arrangement in addition to the actual conductive contact 2, which is attached to the insulating rod 1, thus only three different further components:

• a contact holder, z. As cost-effective as an injection molded plastic part produced both as the upper contact holder 3 and - rotated by 180 degrees - is pushed as an identical lower contact holder 4 on the insulating rod 1
• a shield, easily made of sheet metal, which is pushed both as the upper shield 7 and - rotated by 180 degrees - as an identical lower shield 8 on the insulating rod 1
• a simple bolt of insulating material, which serves both as the upper fastening bolt 5 and 6 as a lower mounting bolt.

REFERENCE NUMBERS

1

Insulating

11

Upper mounting hole

12

Lower mounting hole

2

Contact

21

contact area

22

Long thigh

23

Short thigh

24

Connection hole in 22

25

Upper mounting hole in 22

26

Lower mounting hole in 22

27

Upper mounting hole in 23

28

Lower mounting hole in 23

3

Upper contact holder

31

guide shaft

32

Circumferential collar

33

Shaped contact for 22

34

Shaped contact for 23

35

abutment

36

abutment

37

drilling

38

drilling

39

bag

4

Lower contact holder

41

guide shaft

42

Circumferential collar

43

Shaped contact for 22

44

Shaped contact for 22

45

abutment

46

abutment

47

drilling

48

drilling

49

bag

5

Upper bolt

6

Lower bolt

7

Upper shielding cap

71

mounting tab

72

mounting tab

73

drilling

74

drilling

8th

Lower shielding cap

81

mounting tab

82

mounting tab

83

drilling

84

drilling

Claims (8)

1. Contact arrangement with a fixed electrical contact (12) which is fastened to an insulating rod (1) and has a contact region at which electrical connection can be made, wherein the insulating rod (1) has an upper fastening bore (11) and wherein the fixed contact (2) is of U-shaped construction in such a manner that it has the contact region (21) in the middle and a respective limb (22, 23) on each side thereof, characterised in that the insulating rod (1) has a lower fastening bore (12), the two limbs (22, 23) each have two fastening bores (25, 26; 27, 28) corresponding with the fastening bores (11, 12) in the insulating rod (1), the contact (2) is fixed at both sides at the top and bottom respectively by an upper and a lower contact holder (3, 4) each pushed onto the insulating rod (1), each of the two contact holders (3, 4) has, at both sides, contact mounts (33, 34; 43, 44) each with a respective bore (37, 38; 47, 48), a respective limb (22, 23) of the contact (2) being received in each mount, and not only the contact (2), but also the two contact holders (3, 4) fixing it at both sides are fastened to the insulating rod (1) in common by two pins (5, 6) which horizontally penetrate the respective mutually corresponding fastening bores (11, 12) of the insulating rod (1), the fastening bores (25, 26; 27, 28) of the contact (2) and the bores (37, 38; 47, 48) of the respective contact holders (3, 4).
2. Contact arrangement according to claim 1, characterised in that each contact holder (3, 4) has a guide shank (31, 41) which surrounds the insulating rod (2) and at which is integrally formed an encircling collar (32, 42), at which the contact mounts (33, 34; 43, 44) are arranged opposite one another.
3. Contact arrangement according to claim 1 or 2, characterised in that respective counter-bearings (35, 36; 45, 46) for the pins (5, 6) are provided in the region of the contact mounts (33, 34; 43, 44).
4. Contact arrangement according to claim 3, characterised in that the outer regions of the counter-bearings (35, 36; 45, 46) are vertically displaced by a small amount relative to the respective corresponding fastening bore (11, 12) at the insulating rod (1) in such a manner that the respective inserted pin (5, 6) is axially fixed.
5. Contact arrangement according to one of claims 1 to 4, characterised in that upper contact holder (2) and lower contact holder (4) are identical components.
6. Contact arrangement according to one of claims 1 to 5, characterised in that in addition an upper and a lower screening cap (7, 8) are provided, the open sides of which each face the contact (2), each screening cap (7, 8) has lateral fastening straps (71, 72; 81, 82) with a respective bore (73, 74; 83, 84) and each screening cap (7, 8) is fastened to the insulating rod (1) in such a manner that each of the pins (6, 7) is additionally also guided through the respective corresponding bore (73, 74; 83, 84).
7. Contact arrangement according to claim 6, characterised in that the side edge of the fastening straps (71, 72; 81, 82) is held in lateral pockets (39, 49) of the respective contact holders (3, 4) by mechanically positive coupling.
8. Contact arrangement according to claim 6 or 7, characterised in that upper screening cap (7) and lower screening cap (8) are identical components.

Images