Patent EA-003757-B1 (EA)
Title: Electrical switchgear apparatus comprising a vacuum cartridge and a flexible electrical connector
Inventor: ALLARD HERVE
IPC: H01H33/664
Filed: 2001-03-30
Abstract: 1. An electrical switchgear apparatus designed to be electrically connected to a busbar and comprising: a vacuum cartridge (10) comprising a body (17) forming an enclosure (18) housing a pair of separable contacts (22, 24), one of said contacts (24) being fixedly secured to a metal rod (32) movable in translation, a part of the rod (32) protruding out from the enclosure (18) of the cartridge; a flexible metallic electrical connector (50) designed to electrically connect the rod (32) to the busbar, the flexible connector being formed by a stack of metal blades (52) and comprising a first rigid end part (58) defining a bored hole (64) in which the protruding part of the rod (32) is inserted; wherein: the metal blades (52) are assembled to one another by welding at the level of said first rigid end part (58) so as to form a monoblock assembly at this level, the flexible electrical connector (50) is fixed to the protruding part of the rod (32) by means of a braze (72) between the protruding part of the rod (32) and the first rigid end part (58). 2. The switchgear apparatus according to claim 1, comprising a sealing bellows (40) brazed on the one hand onto a wall of the body (17) of the cartridge and on the other hand onto the rod (32), the joining braze (72) fixing the flexible electrical connector and the protruding part of the rod implementing a metallic filler compound having a melting temperature lower than the melting temperature of the braze fixing the rod to the sealing bellows. 3. The switchgear apparatus according to any one of claims 1 to 2, wherein the metallic filler compound has a melting temperature appreciably lower than 900 degree C, and preferably lower than 700 degree C. 4. The switchgear apparatus according to claim 3, wherein the metallic filler compound is a silver-based compound in proportions of more than 30%, with a tin content in proportions of less than 10%. 5. The switchgear apparatus according to claim 4, wherein the metallic filler compound is a silver-based compound in proportions of more than 50%, with a tin content in proportions of less than 6%. 6. The switchgear apparatus according to claim 5, wherein the metallic filler compound is a quaternary silver-copper-zinc-tin compound. 7. The switchgear apparatus according to any one of claims 1 to 6, wherein the protruding part of the rod (32) comprises a spindle (36), limited on the cartridge side by a shoulder (38), a part of the filler compound forming an interface joint (76) interposed axially between the shoulder and an axial edge of the bored hole, and another part of the filler compound forming a radial interface joint (74) between the bored hole (64) and the spindle (36). 8. The switchgear apparatus according to claim 7, wherein the spindle (36) is of circular cross-section, as is the bored hole (64), so that the radial interface joint (74) between the bored hole (64) and the spindle (36) takes a cylindrical shape. 9. The switchgear apparatus according to any one of claims 1 to 8, wherein the metal blades (52) are assembled to one another by electron bombardment welding or by electron scattering welding, without any filler material. 10. The switchgear apparatus according to any one of claims 1 to 9, wherein the flexible connector (50) comprises a second rigid end part (56), forming a connecting strip (16) equipped with means (60) for connection to the busbar, the first (58) and second (56) rigid end parts being joined by a flexible part (54) of the flexible connector (50). 11. The switchgear apparatus according to claim 10, wherein the metal blades (52) are assembled to one another by welding at the level of said second rigid end part (56) and remain independent from one another in the flexible part (54) of the connector (50).