EP0570265B1 - Earthing switch with perpendicular contact opening - Google Patents

Abstract

Perpendicular-opening earthing isolator comprising a female contact (3) and a male contact (6) which is arranged at the end of an operating arm (7), characterised in that it comprises two parallel metal horns (13, 14) arranged so as to grip, when the isolator is in the closed position, the end of the arm in the vicinity of the male contact, and a flexible metal rod (16) termed a whip, constrained to slide, when the arm effects an opening movement, over a fixed point of a guide piece (17), the respective lengths of the horns (13, 14) and of the whip (16) being chosen such that, during opening, the current switches firstly onto the horns, and then onto the whip. <IMAGE>

Description

The present invention relates to an earthing switch perpendicular opening with a mechanism allowing a sudden breakdown of the residual current during an operation opening according to the preamble of claim 1.

We know that high voltage earthing switches must be endowed with a certain breaking capacity to allow the breaking of inductive and capacitive currents induced by the proximity of another parallel line under charge.

An object of the present invention is to define a disconnector with a breaking mechanism to give it a certain breaking capacity.

Another object of the invention is to provide a disconnector capable, during operation both opening than closing, breaking the ice that may have train on his contacts.

Another object of the invention is to provide a disconnector provided with a robust mechanism allowing a large number of cuts, with safe and repetitive operation, and economic achievement.

The closest prior art is the document DE-A-1964363, which describes a disconnector provided with a arcing contact formed by a whip; the implementation of this whip requires a complex mechanism including several moving parts, as well as a brake for brake the whip movement at the end of the maneuver opening hours. Such a complex mechanism is expensive, costly maintenance, and cannot operate when the disconnector is covered with ice.

An object of the invention is to provide a disconnector with whip operating safely, even when the disconnector is covered with ice.

The subject of the invention is an earthing switch with perpendicular opening, including female contact arranged at the end of a metal support connected to a power outlet and attached to the top of an insulating column and a male contact arranged at the end of an operating arm actuated by an operating mechanism, said arm being connected to earth, the operating mechanism allowing, when an opening operation of the disconnector, first a translational movement of the arm along its axis, then a rotational movement with an amplitude close to 90 degrees angle, and a flexible metal rod called a whip, fixed by a end at a point on the arm, said whip being subject to sliding, when the arm performs an opening movement, along a fixed point a guide piece, characterized in that it comprises two horns metallic, fixed to said support and in electrical connection with it, said horns being parallel and arranged in so as to clamp, when the disconnector is in position closed, the end of the arm near the male contact, the rod extends, when the disconnector is in the closed position, along said arm, the respective lengths of the horns and whip being chosen so that, during a opening operation, current switches, after separation male and female contacts, first on the horns, then on the whip, so that it has a curvature ensuring good electrical contact when the arm leaves the horns.

Advantageously, the fixed guide piece is a metal rod fixed to said support and arranged perpendicular to said arm when the disconnector is in closed position, said rod being provided with a pin, said fixed point being at the junction between said rod and said barb.

• la figure 1 est une vue en élévation d'un sectionneur de terre à ouverture perpendiculaire,
• la figure 2 est une vue en élévation et en coupe partielle de la partie supérieure du sectionneur de terre, représenté en posistion enclenchée,
• la figure 3 est une vue de dessus du sectionneur lorsqu'il est dans la position de la figure 2,
• la figure 4 est une vue partielle en coupe selon la ligne IV-IV de la figure 2,
• la figure 5 est une agrandie d'une partie de la figure 2,
• la figure 6 est une vue en élévation partiellement en coupe de la partie supérieure du sectionneur, représenté au début d'une opération d'ouverture,
• la figure 7 est une vue de dessus du sectionneur dans la position de la figure 6,
• la figure 8 est une vue en coupe selon la ligne VIII-VIII de la figure 6,
• la figure 9 est une vue agrandie d'une partie de la figure 6,
• la figure 10 est une vue en élévation de la partie supérieure du sectionneur précédent, à environ la moitié de la phase d'ouverture,
• la figure 11 est une vue de dessus du sectionneur dans la position de la figure 10,
• la figure 12 est une en coupe selon la ligne XII-XII de la figure 10,
• la figure 13 est une vue agrandie d'une partie de la figure 10.

The invention is explained in detail by the description of an exemplary implementation, with reference to the attached drawing in which:

• FIG. 1 is an elevation view of an earthing switch with perpendicular opening,
• FIG. 2 is a view in elevation and in partial section of the upper part of the earthing switch, shown in the engaged position,
• FIG. 3 is a top view of the disconnector when it is in the position of FIG. 2,
• FIG. 4 is a partial sectional view along the line IV-IV of FIG. 2,
• FIG. 5 is an enlarged view of part of FIG. 2,
• FIG. 6 is an elevational view partially in section of the upper part of the disconnector, shown at the start of an opening operation,
• FIG. 7 is a top view of the disconnector in the position of FIG. 6,
• FIG. 8 is a sectional view along line VIII-VIII of FIG. 6,
• FIG. 9 is an enlarged view of part of FIG. 6,
• FIG. 10 is an elevation view of the upper part of the previous disconnector, about halfway through the opening phase,
• FIG. 11 is a top view of the disconnector in the position of FIG. 10,
• FIG. 12 is a section along line XII-XII of FIG. 10,
• FIG. 13 is an enlarged view of part of FIG. 10.

Reference is made to FIGS. 1 to 4 which illustrate a opening type earthing switch perpendicular, shown in the closed position, and comprising an insulating column 1 placed at the top of a frame metallic 2 and carrying a female contact 3 at the end of a support 4 placed at the top of the insulating column. The support 4, metallic, carries a socket 5.

Reference 6 designates a male contact, placed at the end of an operating arm 7, moved by means of a mechanism 8 driven by a motor enclosed in a housing 9 and by a motion transmission shaft 10.

The female contact 3 is of the tulip type, that is to say comprising a plurality of parallel fingers arranged along a cylindrical surface; the female contact is fixed to the support by a bolted plate 12; male contact 6 has at its end intended to come to cooperate with the female contact, a bulged part 6A, ensuring good contact pressure. The other end of arm 7 is connected to the frame with the potential of the earth by a metallic braid 11.

The disconnector operating mechanism ensures that the arm 7, during an opening maneuver, first a vertical movement allowing the separation of the contacts male and female, then a rotational movement in a plane vertical, until the arm reaches a position horizontal, as shown in dotted lines in Figure 1.

As shown in Figures 2 to 5, the disconnector carries two metal horns 14 and 13, fixed to the support 4 by a bolt 15, and extending parallel and horizontally. The spacing of the horns is such that they enclose the male contact with sufficient pressure to ensure the flow of current, as will be seen below. The horns are curved at their ends to facilitate engagement of the male contact during an operation of disconnector closing.

To the arm 7 is fixed a flexible metal rod 16, called whip, extending, when the disconnector is in closed position, along the arm 7; its length is such it exceeds the support 4. This whip is guided by a piece guide 17, fixed to the support 4, and consisting of a rod metal arranged perpendicular to the arm 7 when the disconnector is in the closed position; the rod 17 has a portion 17A inclined upwards and has a barb 17B. The whip is fixed to the arm 7 by a bolt 18 which carries also a part 19 limiting the inclination of the whip 16 relative to the arm 7. The bolt 18 ensures the contact electric between arm 7 and whip 16. The piece of guidance forces the whip to slide along a fixed point, the junction between the guide piece and the barb, at during a disconnector opening operation, which causes more and more bending of the whip.

The operation of the disconnector is as follows:

OPENING THE DISCONNECTOR

Before opening (Figure 2) the male contact 6 is in contact by its swollen part with the contact fingers 3. Current flows through socket 5, support 4, fingers 3, the male contact 6, the arm 7, the braid 11, the frame 2 and Earth.

On opening, the male contact gradually leaves the contact fingers 3, the current is gradually switched on the horns 13 and 14 (Fig. 5). The whip remains the along the arm 7.

After leaving fingers 3, male contact 6 moves away from the female contact, the arm 7 performing a rotational movement (Figure 6). The current is shared between the horns 13 and 14 on the one hand and the whip 16 on the other go; the latter is in good electrical contact with the part 17, thanks to the pressure exerted by the curvature of the whip; the barb 17B guides the whip which slides inside the barb 17B.

When the male contact leaves the horns 13 and 14, the current is fully switched in the whip whose more and more curvature (Fig. 10 and 13). Finally stroke of arm 7, the distance between the male contact and the female contact being maximum and ensuring impossibility resetting, the whip escapes the barb 17B; due of its elasticity, the whip makes a sudden movement which brings him back to arm 7; the power goes out and none risk of re-ignition is to be feared since the distance isolation is reached.

Note that at the start of the opening maneuver, the current is switched on the horns; during this phase the whip bends; when the current is switched, first partially, then totally, on the whip, the pressure of contact between the whip and the support piece 17 is strong: this contributes to a significant reduction in wear electric whip and thus ensures an increase the number of cuts allowed before replacing the whip and support piece.

CLOSING OF THE DISCONNECTOR

The same movements take place in reverse; male contact first finds its place between the horns 13 and 14 before the last movement comes to oblige it to engage between the fingers 3. The whip, which remains stuck to the arm 7 during the rotational movement, engages automatically in the barb 17B. The separation of the horns 13 and 14 facilitate the engagement of the arm.

We note that at the start of an opening maneuver disconnector, the current, which passed through the contacts main 3 and 6, switches on arm 7 and horns 13 and 14. During this maneuver, the whip bends, like the shows figure 6, and is therefore under tension before the separation; contact 6 is very far from horns 13 and 14 when the whip leaves the rod 17; so we see that the whip plays its role of protecting the active parts of the disconnector vis-à-vis the burning effects of the arc. The strong pressure exerted between the whip 16 and the rod 17 breaks the ice that could have formed before the opening maneuver, and thus ensuring perfect switching the current on the whip.

Furthermore, the horns 13 and 14 constitute a pliers which exerts sufficient pressure on arm 7 to break any ice that may have formed and this, too both at opening and closing.

In addition the clamp 13,14 keeps the arm 17 well centered both during an opening maneuver and during a closing maneuver.

The invention applies to earthing switches with high voltage with perpendicular opening, that these are vertical, as described above, or horizontal.

Claims (2)

1. A perpendicularly-opening grounding section switch comprising a female contact (3) disposed at the end of a metal support (4) that is connected to a current terminal (5) and that is fixed to the top of an insulating column (1), a male contact (6) disposed at the end of a drive arm (7) actuated by a drive mechanism (8), said arm being connected to ground, the drive mechanism serving during a section switch opening operation initially to move the arm in translation along its own axis, and then to swing the arm through an angle of amplitude close to 90°, and a flexible metal rod (16) referred to as a "whip" having one end fixed to a point (18) of the arm (7), said whip being constrained to slide along a fixed point of a guide piece (17) while the arm is performing an opening operation, the section switch being characterized in that it includes two metal horns (13, 14) fixed to said support and in electrical contact therewith, said horns being parallel and being disposed in such a manner as to clamp against the end of the arm in the vicinity of the male contact when the section switch is in its closed position, the rod extending along said arm when the section switch is in its closed position, the respective lengths of the horns (13, 14) and of the whip (16) being chosen in such a manner that after the male and female contacts (6, 3) have separated during a switching operation, current is diverted firstly to the horns and subsequently to the whip, such that the whip is then sufficiently curved to provide good electrical contact when the arm looses contact with the horns.
2. A section switch according to claim 1, characterized in that the stationary guide piece is a metal rod (17) fixed to said support and disposed perpendicularly to said arm when the section switch is in its closed position, said rod (17) being provided with a barb (17B), said fixed point being at the junction between said rod (17) and said barb (17B).

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