# US 2021/0241981 A1 · Arc chamber for a low-voltage switching device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0241981 A1 - Document ID: US20210241981A1 - Status: Published application - Kind: A1 - Application number: 17/048,699 - Filed: 2018-04-19 - Published: 2021-08-05 - Earliest claimed: 2018-04-19 - Assignees: ABB AB - Applicants: ABB S.p.A. - Inventors: Pierantonio Arrighetti; Antonello Antoniazzi; Alessandro Adami; Daniele Torresin; Francesco Agostini - Web page: https://patentgrep.com/patent/US20210241981A1 ## CPC - H01H 9/342: {Venting arrangements for arc chutes} - H01H 73/18: Means for extinguishing or suppressing arc {(magnet coil acting as blow-out device H01H71/38)} - H01H 2009/347: {using lids for closing the arc chamber after assembly} - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) ## Abstract An arc chamber 10, 20, 30, 40, 50 for a low voltage switching device comprising an insulating casing 1, having a first and a second lateral walls 2,3, a rear and a front wall 4,5, that defines an internal space housing a number of arc-breaking plates, a top wall 6 of said casing having a discharge opening 101 for venting off the gases from said internal space, said discharge opening 101 being covered by a top cover 7, 37, 47, 57. The arc chamber for a low voltage switching device comprises a filter 11, 21, 31, 41, 51 made of an open cell metal foam is positioned at said discharge opening 101. ## Claims ### Claim 1 An arc chamber for a low voltage switching device comprising an insulating casing (1), having a first and a second lateral walls a rear and a front wall, that defines an internal space housing a number of arc-breaking plates, a top wall of said casing having a discharge opening for venting off the gases from said internal space, said discharge opening being covered by a top cover, and a filter made of an open cell metal foam is positioned at said discharge opening. ### Claim 2 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said filter made of an open cell metal foam covers entirely said discharge opening. ### Claim 3 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said open cell metal foam of said filter has a porosity of greater than 70%, preferably greater than 80%, more preferably greater than 85%. ### Claim 4 (depends on 3) The arc chamber for a low voltage switching device, according to claim 3, wherein said open cell metal foam of said filter has a thermal conductivity of lower than 15 W·m−1·K−1. ### Claim 5 (depends on 4) The arc chamber for a low voltage switching device, according to claim 4, wherein said open cell metal foam of said filter has a tensile strength of greater than 5 MPa. ### Claim 6 (depends on 5) The arc chamber for a low voltage switching device, according to claim 5, wherein said open cell metal foam of said filter is provided with a structure having randomly distributed channels. ### Claim 7 (depends on 6) The arc chamber for a low voltage switching device, according to claim 6, wherein said filter made of an open cell metal foam is interposed between said discharge opening and said top cover. ### Claim 8 (depends on 7) The arc chamber for a low voltage switching device, according to claim 7, further comprising a perforated sheets positioned between said filter made of an open cell metal foam and said discharge opening, a spacer interposed between said perforated sheets and said filter made of an open cell metal foam, said top cover being superimposed onto said filter made of an open cell metal foam. ### Claim 9 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1 wherein said filter made of an open cell metal foam is inserted into said top cover. ### Claim 10 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said filter made of an open cell metal foam is integrally made within said top cover. ### Claim 11 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said top cover is entirely made with said filter made of said open cell metal foam. ### Claim 12 (depends on 1) A low voltage switching device comprising an arc chamber according to claim 1. ### Claim 13 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said open cell metal foam of said filter has a thermal conductivity of lower than 15 W·m−1·K−1. ### Claim 14 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said open cell metal foam of said filter has a tensile strength of greater than 5 MPa. cm 15. The arc chamber for a low voltage switching device, according to claim 1, wherein said open cell metal foam of said filter is provided with a structure having randomly distributed channels. ### Claim 16 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, wherein said filter made of an open cell metal foam is interposed between said discharge opening and said top cover. ### Claim 17 (depends on 1) The arc chamber for a low voltage switching device, according to claim 1, further comprising a perforated sheets positioned between said filter made of an open cell metal foam and said discharge opening a spacer interposed between said perforated sheets and said filter made of an open cell metal foam, said top cover being superimposed onto said filter made of an open cell metal foam. ### Claim 18 (depends on 13) The arc chamber for a low voltage switching device, according to claim 13, wherein said open cell metal foam of said filter has a thermal conductivity of lower than 12 W·m−1·K−1. ### Claim 19 (depends on 14) The arc chamber for a low voltage switching device, according to claim 14, wherein said open cell metal foam of said filter has a tensile strength of greater than 10 MPa. ### Claim 20 (depends on 3) The arc chamber for a low voltage switching device, according to claim 3, wherein said open cell metal foam of said filter is provided with a structure having randomly distributed channels.