Hydraulic valve for preventing leakage in an actuator for activating a high- or medium-voltage circuit breaker

1. A hydraulic valve for connecting a first fluid-conducting pressure line to a second fluid-conducting pressure line in an actuator for activating a high- or medium-voltage circuit breaker, the hydraulic valve comprising:

a housing with a first channel inlet for attachment to the first pressure line, and a second channel inlet for attachment to the second pressure line, and a cavity situated between the first and the second channel inlets;

a sealing body configured to be moveable in the cavity and having a circumference which is greater, at least at one point, than a respective circumference of openings, adjoining the cavity, of the first and the second channel inlets, wherein the sealing body is geometrically matched to a cross-section of these openings such that it completely seals the openings when seated on the openings;

a first spring element, fastened in the first channel inlet opening, connected to the sealing body on a first side and projecting into the cavity in a relaxed state; and

a second spring element, fastened in the second channel inlet opening, connected to the sealing body on a second side and projecting into the cavity in a relaxed state.

2. The hydraulic valve according to claim 1 , wherein the first and the second channel inlet openings are configured to have a same size relative to each other, and the first and the second spring element are identical.

3. The hydraulic valve according to claim 1 , wherein the openings adjoining the cavity of the first channel inlet and the second channel inlet, in each case has a circular design, and wherein, on each side of the sealing body connected to the spring elements, the sealing body has at least one circular cross-sectional area which in each case corresponds to a cross-sectional area of the associated opening.

4. The hydraulic valve according to claim 3 , wherein the first and the second sides of the sealing body are spherical segments.

5. A two-stage valve arrangement for activating a piston of a hydraulic piston/cylinder arrangement in an actuator for activating a high- or medium-voltage circuit breaker, the valve arrangement comprising:

a pilot stage including at least one pilot valve; and

a main stage including at least one main valve,

wherein a first position of the at least one pilot valve is arranged such that a hydraulic connection will be established from a high-pressure tank to the piston/cylinder arrangement via the main stage so that a fluid at high pressure will be supplied to a space situated on one side of the piston, and

a second position of the at least one pilot valve is arranged such that a space situated on one side of the piston will be connected to a low-pressure tank via the main stage,

wherein a hydraulic valve according to claim 1 is arranged between an outlet side, connected to at least one control inlet of the main stage, and an outlet side, connected to the piston/cylinder arrangement, of the main stage.

6. The valve arrangement according to claim 5 , wherein the pilot stage contains two 2/2-port valves.

7. A hydraulic actuator for activating a high- or medium-voltage circuit breaker comprising:

a two-stage valve arrangement according to claim 5 .

8. The hydraulic actuator of claim 7 , which comprises:

a hydraulic piston/cylinder arrangement.

9. The hydraulic actuator of claim 8 , in combination with:

a high- or medium-voltage circuit breaker; and

a high-pressure tank arranged to be hydraulically connected to the piston/cylinder arrangement via the main stage.