DE1221353B - Contact piece for transformer tap selector - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

HOIf

HOIh

German class: 21 d2- 53/03

Number: 1221353

File number: L 42626 VIII b / 21 d2

Filing date: August 3, 1962

Opening day: July 21, 1966

In the case of transformer tap changers, which are usually designed with multiple phases, the tap lines end at fixed contact pieces. Most of time are the contact pieces corresponding to the same voltage level on a common vertical one Fastened insulation element and work together with horizontally movable contact bridges. There are z. B. Voters known, in which vertical Isoherstoffst rods arranged in a circle and above and are connected at the bottom with a plate, so that a drum cage results. Inside the cage runs the drive shaft with the movable contact bridges held on it. The ones on the insulating rods The contact pieces attached to the cage are arranged in several levels depending on the number of phases, and each level is assigned a double contact bridge, which is the conductive connection between each two adjacent contact pieces or between a contact piece and a central one Slip ring forms.

The known form of a fixed contact piece for such voters is the so-called knife contact piece. The name comes from the shape of the contact-making part, a horizontal one Plate with edges bevelled on both sides in the manner of a cutting edge, which facilitate the pushing on the contact bridges should facilitate. These contact pieces have the disadvantage that they relate to the relative large flat contact surfaces can form deposits of carbon and metal debris and that they represent a large accumulation of material that is difficult to cool.

The invention characterized in the claim avoids these disadvantages.

It is true that contact pieces that have an annular bead are already known in step load switches for transformers have a strongly rounded cross-section. This training of the known arrangement however, serves a different purpose. A plunger is provided there within an annular contact part, which carries a further contact part serving as a pre-contact. This pre-contact part fills in closed contact the interior of the annular contact part almost completely or even covers it. The passage of a cooling insulating agent is neither intended nor possible here.

On the basis of FIG. 1 and 2 is intended in the following to be an exemplary embodiment shown in a side view and a plan view of the subject matter of the invention are explained in more detail. The same parts are in both figures provided with the same reference numerals.

Contact piece for transformer tap selector

Applicant:

Licentia Patent-Verwaltungs-G. mb H.,
Frankfurt / M., Theodor-Stern-Kai 1

Named as inventor:

Klaus Ziegler, Esslingen / Neckar

The insulating rod 1 of rectangular cross-section is used to attach the contact piece according to the invention. It rests with the surface 2 on the broad side of the insulating rod, with a not shown, The screw inserted through the insulating rod is tightened in the thread 3. For screwing the feed line to the extension 11 of the contact piece is used by the thread 8. The contact-making Part is designed as an annular bead 4. Its cross-section is approximately circular, with the exception of one to the Ring inside pointing, the stiffening approach 15. In the middle of the annular bead leaves the Opening 5 free. The bridges 9 and 10 acting as double contact bridges are only shown schematically. They are under spring pressure, indicated by arrows 12 and 13, and are turned off in a F i g. 2 apparent movement pushed onto the bead. The arrow 14 points to the direction of the slide-on movement there.

The inclined cut of the annular bulge creates a very slight slope, which should be considered on the torque to be expended is very desirable and otherwise only through a wide and low angled bevel could be achieved. Deposits can arise due to the lack of horizontal surfaces no longer educate. The cooling is made considerably easier because the annular bead is protected from the flow of isolating medium is washed around on all sides, while in the known contact pieces there are flow-free storage spaces could form. Furthermore, the contact piece according to the invention offers the possibility of the same Tension smaller distances to be observed, since the field lines at the annular bead are not in the same way as before Concentrate the knife contacts in the usual way. This applies to a contact piece formed circle both in the radial as well as in the tangential direction and in the direction of the insulating rods. In order to avoid sliding discharges along the bars, the beads 6 and 7 are so-called advanced electrodes provided.

609 590/164

Claims (1)

Claim: Contact piece for transformer tap selector, for attachment to vertical Insulating elements, in particular on the insulating rods of a selector drum cage is suitable, has a horizontal plane of symmetry and for making contact between two for same level symmetrical contact bridges can be clamped, whereby the electrical Contact causing part of an annular bead with a strongly rounded, preferably circular cross-section, characterized in that the ring opening (5) enclosed by the annular bead (4) to the Passage of the insulating agent, which rises upwards as a result of heating, remains free. Considered publications:
French patent specification No. 1271 885. 1 sheet of drawings 609 590/164 7.66 © Bundesdruckerei Berlin