DE716967C

DE716967C - Electric switch with arc extinguishing and movement of the nozzle contact by a flowing pressure medium

Info

Publication number: DE716967C
Application number: DEM146563D
Authority: DE
Inventors: Henri Puppikofer
Original assignee: Werkzeugmaschinenfabrik Oerlikon Buhrle AG
Current assignee: Rheinmetall Air Defence AG
Priority date: 1939-11-01
Filing date: 1939-11-28
Publication date: 1942-02-02
Also published as: FR876219A; GB542601A; CH214012A

Description

Bei Schaltern mit Lichtbogenlöschung und Kontaktbewegung durch ein Druckmittel, wie z. B. Druckluft, gibt es bekanntlich zwei Ausführungsarten, die in der Schweizer Patentschrift 190816 einander gegenübergestellt worden sind. Bei der einen Bauart (Fig. 1 der erwähnten Patentschrift) sind zwei Öffnungsstrecken vorhanden: die eine zur Stromunterbrechung mit einem festen und. einem druckmittelbewegten Kontakt, die andere zur Isolation, auch, ohne Vorhandensein des Druckmittels, mit einem festen und einem mechanisch angetriebenen Kontakt. Bei der andern Bauart (Fig. 2) ist nur eine Öffnungsstrecke vorhanden. Der eine Kontakt wird durch einen Antrieb mechanisch bewegt, während der andere unmittelbar durch das Druckmittel bewegt \vird. Beiden Lösungen ist die Benutzung eines druckmittelbewegten Kontaktes gemeinsam. Bei diesen Kontakten ist es nun sehr wichtig, daß die Bewegung erst dann beginnt, wenn der Druck in der Schaltkammer vor der Löschdüse auf einen für die Löschung notwendigen Wert angestiegen ist. Ist dieser Druck vorhanden, so muß die Kontaktbewegung möglichst rasch erfolgen; der Kontakt muß in der für die Löschung notwendigen Distanz anhalten und ohne Prellungen dort verbleiben, bis der S ehalt Vorgang· beendet ist. Man versuchte dieses Ziel da- 3p durch zu erreichen, daß man auf dem Wege des Kolbens, der den druckmittelbewegtenFor switches with arc quenching and contact movement by a pressure medium, such as z. B. compressed air, there are known to be two types of execution, which in the Swiss patent Juxtaposed in 190816 have been. In one type (Fig. 1 of the aforementioned patent) there are two opening sections available: the one for power interruption with a fixed and. one contact moved by pressure medium, the other for isolation, even without the pressure medium being present, with one fixed and one mechanically driven contact. In the other design (Fig. 2) there is only one opening section available. One contact is moved mechanically by a drive while the other is moved directly by the pressure medium. Both solutions are the usage of a contact moved by pressure medium. With these contacts it is now very important that the movement only then begins when the pressure in the switching chamber in front of the extinguishing nozzle has risen to a value necessary for extinguishing. If this pressure is present, the contact movement must take place as quickly as possible; contact must be maintained at the distance necessary for deletion and without bruises remain there until the hold process is finished. This goal was tried 3p to achieve that one is on the way of the piston that moves the pressure medium

Claims

Contact carries and during the off switching process is acted upon on both sides by the pressure medium, the piston area can grow (z. B. in Fig. 3 of Swiss Patent 190 816). In particular with the switches for higher voltages, which have large piston surfaces and in which the contact has to travel a relatively long distance, the function is not precise enough and the counter springs that have to return the piston to the initial position become too large.

These disadvantages can be eliminated if, according to the present invention, the pressure medium when the pressure required for extinguishing is reached through an adjustable maximum pressure relay on one side of the piston is drained without pressure, whereby the adjustability of the maximum pressure relay enables to determine the occurrence of the differential action in advance. This starts the movement of the differential piston and thus of the contact only and is quickly brought to an end when the pressure in the switching chamber in front of the extinguishing nozzle has risen to a value necessary to extinguish the arc. To achieve this, would the known design of the movable nozzle contact as a differential piston alone not enough yet.

The drawing shows schematically and in section an exemplary embodiment of the subject matter of the invention. In the switching chamber 1, the wall 2 of which is made of insulating material, the pressure medium enters at arrow D. When switching off, the contact 3 is moved downwards in the direction of the arrow U by a mechanical drive (not shown). The mating contact 4 is moved by the pressure medium itself in the direction of arrow O upwards; it is designed as a nozzle and forms part of a piston I \ with a piston disk 5. This runs in a cylinder 6 which is part of a metallic housing 7. 10 indicates the upper power connection. The lower power connection and the transfer to contact 3 are not shown for the sake of simplicity. The current transfer from the metal nozzle of the contact 4 5i> to the housing 7 takes place through springs 9. When the switch is closed, a spring S- 'is generated. the contact pressure between the contacts 3. rind 4. A maximum pressure relay 11 is connected to the holding chamber 1.

As long as the limit pressure is not reached. Lets pressure medium through the cavity 14 of the Sicuerkolbens 12 and through the tube 15 into the space 16 above the piston disk 5. Since the expression df-d _s - is greater than the expression d { ² -d, r, the piston disk 5 is on the The bottom of the cylinder 6 is pressed. In order to obtain a reliable effect of the differential piston / v, the gap 19 between the piston disk 5 and the bottom of the cylinder 6 is connected to the outside air by a pipe 18, an annular space 17 of the control piston 12 and an opening 21. As soon as the pressure in the holding chamber 1 has reached the value necessary for the extinction, the control piston 12 is pressed upwards against an adjustable spring 13. The vent pipe 18 is closed. The guide tube 15 is connected to the annular space 17 and thus to the vent opening 21. The pressure medium is drained V5 from the space 16 above the piston disk 5 and penetrates into the rapidly expanding space 19. The piston / ( with which contact 4 is thrown upwards and, due to the large piston area with approximately the ring width cl.jd _n, remains in the end position on the ceiling] 20 until the switching process is ended and the pressure medium inflow is blocked.

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Electrical switch with arc quenching and movement of the nozzle contact by a flowing pressure medium, wherein the fluid-moving contact sits on a differential piston which during of the switch-on process is acted upon by the pressure medium on both sides, characterized in that the pressure medium b? i Reaching the pressure required for extinguishing by means of an adjustable maximum pressure relay (11) is drained pressure-free on one side of the piston, whereby the adjustability of the maximum pressure relay enables the occurrence of the differential action to be determined in advance.

For this purpose ι sheet of drawings