Abstract: A contact assembly and a vacuum circuit breaker for interrupting an electrical current are disclosed. The contact assembly includes an outer field generating element for generating a first axial magnetic field (AMF), and an inner field generating element for generating a second AMF opposite to the first AMF. The inner field generating element can be coaxial with the outer field generating element and can have a smaller diameter than the outer field generating element. The outer field generating element can be cup-shaped and slotted with non-radial slots to generate the first AMF. The contact assembly can include an innermost conducting element for nominal current conduction and coaxially adjusted with the inner field generating element.

Abstract: A vacuum switch has an elongated vacuum cartridge with a cylindrical enclosure blanked off by two end-plates, in which there are housed two arcing contacts respectively stationary and movable, and a coil designed to produce an axial magnetic field in the arc formation zone. The coil has one end arranged as a current conducting strip and an end electrically connected to one of the above-mentioned arcing contacts. The two ends of the coil are superposed and electrically connected, and a branch-off means, such as for example a magnetic circuit, is fitted between these two ends to branch off a part of the main current through the coil during breaking in order to create the axial magnetic field.

Abstract: A vacuum circuit interrupter has a coil for generating an axially oriented magnetic field to maintain an electric arc in a diffuse rather than columnar mode upon opening of the interrupter. At least one of two electrodes having abuttable disc shaped contacts is movable along an axis relative to the other and can be forced by an external mechanism to open. The electrodes are carried in a housing with an electrical insulator between opposite end mountings that support the electrodes with the contacts in an evacuated enclosure. One of the electrodes is an assembly including a rigid supporting member attached to one of the contacts and extending a length along the axis. A coil is wrapped circumferentially around the supporting member along this length, providing a conductive path to generate the axial magnetic field. The supporting member comprises a less-conductive path (e.g., a stainless steel sleeve) and the coil is more conductive (e.g., copper), providing a durable and inexpensive structure.