Abstract: A circuit breaker with a first contact sleeve (3, 14), a second contact sleeve (4, 16), an insulating sleeve (5, 18) disposed between the first contact sleeve (3, 14) and the second contact sleeve (4, 16) has a switching piston (6, 20) with at least one contact section (8) and an isolating section (7, 19), which is disposed at the side of the contact section (8), whereby the switching piston (6, 20) is movable between a closed position in which the contact section (8) of switching piston (6, 20) connects the first contact sleeve (3, 14) with the second contact sleeve (4, 16) so as to be electrically conductive, and an open position in which the contact section (8) of the switching piston (6, 20) does not connect the first contact sleeve (3, 14) with the second contact sleeve (4, 16), in which the first contact sleeve (3, 14), second contact sleeve (4, 16) and insulating sleeve (5, 18) is movable.

Abstract: An electric fan having an electric motor and a fan wheel connected to the electric motor. The fan wheel has a hub and fan blades extending from the hub. The fan blades include a proximal section at the hub, a distal section and a middle section. The proximal section has a flat surface at a trailing edge of the blade. The trailing edge at the distal section is curved with an angle of curvature of about 10°. The trailing edge at the middle section is curved with an angle of curvature of about 36°. When the fan wheel is rotated by the electric motor at a constant speed, air pushed by each of the fan blades is propelled at a substantially same velocity and direction from the blade measured across a radial length of the blade.

Abstract: An electric fan having an electric motor and a fan wheel connected to the electric motor. The fan wheel has a hub and fan blades extending from the hub. The fan blades include a proximal section at the hub, a distal section and a middle section. The proximal section has a flat surface at a trailing edge of the blade. The trailing edge at the distal section is curved with an angle of curvature of about 10°. The trailing edge at the middle section is curved with an angle of curvature of about 36°. When the fan wheel is rotated by the electric motor at a constant speed, air pushed by each of the fan blades is propelled at a substantially same velocity and direction from the blade measured across a radial length of the blade.