# US 11,077,820 B2 · Propellant cage for an inflator, inflator comprising such propellant cage operating method and method of guiding a shock wave of an inflator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,820 B2 - Document ID: US11077820B2 - Status: Granted - Kind: B2 - Application number: 16/409,971 - Filed: 2019-05-13 - Published: 2019-11-21 - Granted: 2021-08-03 - Earliest claimed: 2018-05-18 - Assignees: TRW Airbag Systems GmbH - Applicants: TRW Airbag Systems GmbH - Inventors: Daniel Hillmann; Christian Jung; Lorenz Seidl; Georg Tautschnig; Wolfgang Tengler - Web page: https://patentgrep.com/patent/US11077820B2 ## CPC - B60R 21/272: with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators - B60R 21/274: characterised by means to rupture or open the fluid source - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract The invention relates to a propellant cage (10) for an inflator, especially for a tubular inflator of an airbag module, comprising a substantially tubular base (11) which forms, on the one hand, a gas inlet opening (12a) and, on the other hand, a gas outlet opening (12b) along its longitudinal axis (L), wherein at least one lateral gas flow opening (13) is configured in a circumferential wall (12) of the base (11), wherein the base (11) includes a radially outwardly extending collar (11c) having at least one frontal gas flow opening (14) in the area of the gas flow opening (12c). ## Claims ### Claim 1 A propellant cage (10) for an inflator of an airbag module, comprising a substantially tubular base (11) which along its longitudinal axis (L) forms a gas inlet opening (12a) and a gas outlet opening (12c), the base (11) defining a passageway that longitudinally extends through the propellant cage (10) from the gas inlet opening (12a) to the gas outlet opening (12c), at least one lateral gas flow opening (13) being formed in a circumferential wall (12) of the base (11), wherein the base (11) includes a radially outwardly extending collar (11c) which has at least one frontal gas flow opening (14) in the area of the gas outlet opening (12c). ### Claim 2 (depends on 1) The propellant cage (10) according to claim 1, wherein the base (11) includes a substantially funnel-shaped portion (11b) widening toward the gas outlet opening (12c), and wherein the at least one lateral gas flow opening (13) is arranged in the funnel-shaped portion (11b) or is disposed in a hollow-cylindrical portion (11a) of the base (11) comprising the gas inlet opening (12a). ### Claim 3 (depends on 1) The propellant cage (10) according to claim 1, wherein at least one of the at least one lateral gas flow opening (13) and the at least one frontal gas flow opening (14) is designed to be at least one of circular, slotted, and gill-type. ### Claim 4 (depends on 3) The propellant cage (10) according to claim 3, wherein the at least one lateral gas flow opening (13) is formed by a radially inwardly shaped part (15) of the circumferential wall (12) of the base (11). ### Claim 5 (depends on 4) The propellant cage (10) according to claim 4, wherein the shaped part (15) of the circumferential wall (12) forms a flow guiding element by which part of an axial ignition gas flow can be deflected to the outside. ### Claim 6 (depends on 2) The propellant cage (10) according to claim 2, wherein at least one of the circumferential wall (12), the funnel-shaped portion (11b), and the hollow-cylindrical portion (11a) comprises plural lateral gas flow openings (13) which jointly form a hole pattern. ### Claim 7 (depends on 6) The propellant cage (10) according to claim 6, wherein the lateral gas flow openings (13) of the hole pattern are configured to be geometrically different, wherein the lateral gas flow openings (13) are arranged to be regularly or irregularly distributed in the circumferential direction and/or in the longitudinal direction of the base (11). ### Claim 8 (depends on 2) The propellant cage (10) according to claim 2, wherein the base (11) is integrally formed and the hollow-cylindrical portion (11a) merges into the funnel-shaped portion (11b), wherein the lateral gas flow openings (13) and/or the hole pattern extend(s) into the hollow-cylindrical portion (11a) and/or into the funnel-shaped portion (11b). ### Claim 9 (depends on 1) An inflator for an airbag module comprising a tubular housing (31) and a propellant cage (10) according to claim 1, wherein the propellant cage (10) is arranged inside the tubular housing (31), and wherein the tubular housing (31) delimits a propellant chamber (17) which includes gas-generating propellant bodies. ### Claim 10 (depends on 9) The inflator according to claim 9, wherein the at least one lateral gas flow opening (13) forms a gas inlet of the propellant chamber (17) and the at least one frontal gas flow opening (14) forms a gas outlet of the propellant chamber (17). ### Claim 11 (depends on 9) The inflator according to claim 9, wherein an igniter unit (20) is arranged in the tubular housing (42), the igniter unit (20) being in fluid communication with the gas inlet opening (12a) of the propellant cage (10), wherein the igniter unit (20) is inserted into the gas inlet opening (12a) and includes an inlet-side bursting diaphragm (24) that closes the gas inlet opening (12a). ### Claim 12 (depends on 9) The inflator according to claim 9, wherein the housing (31) forms a compressed gas tank (30) which is filled with biased compressed gas, with the collar (11c) of the propellant cage (10) being adjacent to a circumferential taper (32) of the housing (31). ### Claim 13 (depends on 9) An airbag module comprising an inflator, an airbag inflatable by the inflator and a securing unit for attaching the airbag module to a vehicle, wherein the inflator is configured according to claim 9. ### Claim 14 (depends on 9) A vehicle safety system comprising the inflator of claim 9, an airbag inflatable by inflator as part of an airbag module, and an electronic control unit for activating the inflator when a trigger situation is given. ### Claim 15 (depends on 9) A method of operating an inflator according to claim 9, comprising the following steps of: triggering an igniter unit (20) for generating ignition gas inside an ignition chamber (23); axially introducing the ignition gas into a flow passage (12b) tubularly encompassed by a propellant cage (10); discharging part of the ignition gas via lateral gas flow openings (13) of the propellant cage (10) into a propellant chamber (17) radially inwardly delimited by the propellant cage (10); igniting propellant bodies, especially propellant pellets, within the propellant chamber (14) by the discharged part of the ignition gas, wherein propellant gas is generated; and passing the propellant gas out of the propellant chamber (17) through frontal gas flow openings (14) of the propellant cage (10). ### Claim 16 (depends on 9) A method of guiding a shock wave within an inflator claim 9, comprising the following steps of: triggering an igniter unit (20) for generating excess pressure inside an ignition chamber (23); generating a shock wave by bursting an inlet-side bursting diaphragm (24) by means of the excess pressure, the bursting diaphragm being disposed in the area of a gas inlet opening (12a) of a tubular base (11) of a propellant cage (10); guiding the shock wave along the base (11); and radially widening the shock wave along a funnel-shaped widening portion (11b) of the base (11). ### Claim 17 (depends on 6) The propellant cage (10) according to claim 6, wherein the lateral gas flow openings (13) of the hole pattern are configured to be at least one of circular, slotted, and gill-type, and wherein the lateral gas flow openings (13) are arranged to be regularly or irregularly distributed in the circumferential direction and/or in the longitudinal direction of the base (11). ### Claim 18 (depends on 1) The propellant cage (10) according to claim 1, wherein the propellant cage (10) is formed as a single piece.