Patent ID: 6872907

Claim:
A circuit-breaker, which has at least one arcing chamber which is filled with an isolating gas, extends along a longitudinal axis ( 1 ), is designed to be essentially radially symmetrical, contains an arc area and has at least two power contact pieces, with at least one of the power contact pieces being in the form of a moving or stationary tubular hollow contact, which is provided for dissipating hot gases from the arc area into an exhaust volume, having a deflection device, which is arranged on the side of the hollow contact facing away from the arc area, interacts with at least one first opening in the hollow contact and is connected to a connecting piece, for the radial deflection of the hot gases into the exhaust volume, which is connected through at least one second opening to an arcing chamber volume, with at least one first intermediate volume being provided between the hollow contact and the exhaust volume, wherein the following ratios are complied with: V 1 /A 1 =(0.1 to 0.5) m, V 2 /A 2 =(0.1 to 0.5) m, V 3 /A 3 =(1.0 to 2.5) m, where: V 1 is the volume within the hollow contact and A 1 is the cross section of the first opening, V 2 is the volume of the first intermediate volume and A 2 is the cross section of the third opening, V 3 is the volume of the exhaust volume and A 3 is the cross section of the second opening.