Operating device for a contact device for a pre-insertion resistor in a high-voltage circuit breaker

Claim 1

An operating device for rapid On-Off operation of a contact device having a movable contact for a pre-insertion resistor in a high-voltage compressed gas circuit breaker, which operating device comprises a high pressure chamber, a cylinder, a piston (1) movable in the cylinder (3) and connected to the movable contact of said contact device, one side of said piston limiting a first cylinder space (4), a quick-operating control valve (11) for connecting said first cylinder space alternatively to said high-pressure chamber for closing the contact device and to a low-pressure space for opening the contact device, the other side of the piston (1) limiting a second cylinder space (5), a delay space, at least one opening which, at least during the latter stage of the contact operation, connects the delay space (8) with the second cylinder space, said control valve including means to connect said delay space (8) to the high-pressure chamber to be supplied with high-pressure gas substantially simultaneously with pressurizing said first cylinder space (4), and a non-return valve in the connection between the delay space (8) and the control valve (11).