Gas-blast load-break middle and high voltage switch.

摘要

The invention relates to a gas-blast circuit breaker comprising a cylindrical metallic or insulating envelope (1) filled with pressurised dielectric gas, a fixed arc contact (3) and a movable rig connected to an operating member comprising a blast cylinder (4) associated with a blast nozzle (6) and cooperating with at least one piston (7), and a moving arc contact (9) carried by a tubular part (8) inside the blast cylinder (4).
<??>According to the invention, the internal wall of the said tubular part (8) includes a neck restriction of smaller cross-section than the inner cross-section of the tubular part (8) and coaxial with the latter.
<??>Thus cutoff is improved by increasing the gas pressure in proximity to the moving arc contact through a particularly simple and inexpensive arrangement.
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