Patent EA-002857-B1 (EA)
Title: Electrical switchgear apparatus having a contact means equipped with a spark arrester
Inventor: SIPOLLI FRANCOIS
IPC: H01H9/46
Filed: 2000-06-30
Abstract: 1. An electrical switchgear apparatus, in particular an electrical switch, comprising at least one stationary contact means (20, 22) in the form of a long slender blade defining a longitudinal mid-plane (28) and a contact zone (32); - a movable contact means (24) in the form of a grip comprising at least two contact fingers (56, 58) facing one another on each side of the mid-plane (28) and both moving in a plane parallel to the mid-plane, each of the fingers comprising a contact zone (60, 62), - the movable contact means being able to take a closed position in which the two fingers (56, 58) grip the blade (20, 22) of the stationary contact means, the contact zones (60, 62) of the fingers (56, 58) then being in contact with the contact zone (32) of the blade, and an open position in which the two fingers (56, 58) are separated from the stationary contact means (20, 22), characterized in that - the apparatus further comprises a metallic spark arrester (40) securedly united to the stationary contact means (20,22) and in electrical contact with the latter, the spark arrester (40) having a curved top edge (48) with a middle part (50) situated at a small distance from the stationary contact means (20, 22) and at least one lateral part (52, 54) situated at a greater distance from the mid-plane and from the stationary contact means, at least one of the fingers (56, 58) of the movable contact means comprises a lateral arc transfer zone (64, 66) situated at a greater distance with respect to the mid-plane (28) than the contact zone (60, 62) of said finger, the spark arrester being shaped and arranged in such a way that when the movable contact means (24) is in its open position, the shortest distance between the spark arrester (40) and the movable contact means (24) is measured between the arc transfer zone (64, 66) and a corresponding zone of said lateral part (52, 54) of the top edge of the plate, and that this distance is smaller than the shortest distance between the movable contact means (24) in the open position and the stationary contact means (20,22). 2. The electrical switchgear apparatus according to Claim 1, characterized in that - the top edge (48) of the spark arrester is approximately U-shaped or V-shaped, with a middle part (50) situated a small distance from the stationary contact means (20,22) and two lateral parts (52, 54) appreciably symmetrical to one another with respect to the mid-plane (28), situated at a greater distance from the mid-plane (28) and from the stationary contact (20,22), - both of the fingers (56, 58) of the movable contact means comprise a lateral arc transfer zone (64, 66) situated at a greater distance with respect to the mid-plane than the zone of said finger coming into contact with the stationary contact means in the closed position, the two lateral arc stagnation zones being approximately symmetrical to one another on each side of the mid-plane, so that the shortest distance between the spark arrester (40) and the movable contact means is measured between one or the other of the arc transfer zones (64, 66) and a corresponding zone of said corresponding lateral part (52, 54) of the top edge of the plate, and that this distance is smaller than the shortest distance between the movable contact means in the open position and the stationary contact means. 3. The electrical switchgear apparatus according to either one of the Claims 1 or 2, characterized in that the spark arrester (40) is made of ferromagnetic material. 4. The electrical switchgear apparatus according to any one of the above Claims, characterized in that the stationary contact means comprise two longitudinal ends, the contact zone (32) being located on the side where one of the longitudinal ends is located and an electrical connection zone (34) being situated on the side where the other longitudinal end is located, and that the spark arrester (40) is fixed to the stationary contact means in a zone of the stationary contact means intermediate between the contact zone and the connection zone. 5. The electrical switchgear apparatus according to Claim 4, characterized in that the stationary contact means comprise a transverse slot (36) situated between the contact zone (32) and the connection zone (34), and that a bottom part (46) of the spark arrester is inserted in said slot. 6. The electrical switchgear apparatus according to any one of the above Claims, characterized in that it comprises an arc extinguishing chamber in which the spark arrester extends and which does not comprise separators. 7. The electrical switchgear apparatus according any one of the above Claims, characterized in that comprises a second stationary contact means (20, 22) with a long slender blade defining a longitudinal mid-plane and that the mid-plane of the first stationary contact means and a movable contact means (24) forming a bridge between the two stationary contact means.