# US 11,772,596 B2 · Gas generator for vehicle safety system, airbag module and vehicle safety system as well as method for operating a gas generator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,772,596 B2 - Document ID: US11772596B2 - Status: Granted - Kind: B2 - Application number: 17/944,695 - Filed: 2022-09-14 - Published: 2023-03-16 - Granted: 2023-10-03 - Earliest claimed: 2021-09-14 - Assignees: Zf Airbag Germany GmbH - Applicants: ZF Airbag Germany GmbH - Inventors: Karl Engibrecht; Johannes Ebner; Benedikt Peters - Web page: https://patentgrep.com/patent/US11772596B2 ## CPC - B60R 21/262: Elongated tubular diffusers, e.g. curtain-type - B60R 21/264: using instantaneous generation of gas, e.g. pyrotechnic (B60R21/268 takes precedence) - B60R 21/2644: {using only solid reacting substances, e.g. pellets, powder} - B60R 2021/2642: {comprising a plurality of combustion chambers or sub-chambers} - B60R 2021/2648: {comprising a plurality of combustion chambers or sub-chambers} - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract The disclosure relates to a gas generator for a vehicle safety system, comprising an ignition unit, a propellant configured in a combustion chamber in a form of a propellant bed extending along a longitudinal axis of the gas generator. A sleeve having an axial opening protrudes into the propellant bed such that it surrounds the ignition unit at least partially and portions of the propellant are stored inside and outside the sleeve. ## Claims ### Claim 1 A gas generator for a vehicle safety system, comprising an ignition unit, a propellant which is configured in a combustion chamber in a form of a propellant bed extending along a longitudinal axis of the gas generator, wherein a sleeve having an axial opening protrudes into the propellant bed such that the sleeve surrounds the ignition unit at least partially and portions of the propellant are stored inside and outside the sleeve. ### Claim 2 (depends on 1) The gas generator according to claim 1, wherein the sleeve surrounds the ignition unit at least partially at a radial distance and the ignition unit in the combustion chamber. ### Claim 3 (depends on 2) The gas generator according to claim 2, wherein no further propellant is stored next to the propellant and the ignition unit in the combustion chamber. ### Claim 4 (depends on 2) The gas generator according to claim 2, wherein the ignition unit protrudes at least partially into the propellant bed in such a way that a portion of the propellant is located between the ignition unit and the sleeve. ### Claim 5 (depends on 2) The gas generator according to claim 2, wherein the gas generator additionally has a second ignition unit associated with a combustion compartment separate from the combustion chamber, wherein the combustion compartment includes a propellant and/or a stored compressed gas and a diffuser is axially interposed between the ignition unit and the second ignition unit. ### Claim 6 (depends on 5) The gas generator according to claim 5, wherein by activating the ignition unit a moderate combustion of the propellant and/or a lower pressure level can be generated inside the combustion chamber, as compared to a gas generator which includes no sleeve as it is installed in the gas generator. ### Claim 7 (depends on 1) The gas generator according to claim 1, wherein the ignition unit protrudes at least partially into the propellant bed in such a way that a portion of the propellant is located between the ignition unit and the sleeve. ### Claim 8 (depends on 1) A vehicle safety system to protect a vehicle occupant or pedestrian, comprising a gas generator, an airbag inflatable by the generator, as part of an airbag module, and an electronic control unit by which the gas generator can be activated when a trigger situation is given, wherein, the gas generator is configured according to claim 1. ### Claim 9 (depends on 1) The gas generator according to claim 1, wherein no further propellant is stored next to the propellant and sleeve surrounds the ignition unit in the combustion chamber. ### Claim 10 (depends on 1) The gas generator according to claim 1, wherein when the gas generator is not activated, the axial opening of the sleeve is unclosed and is surrounded substantially by the propellant only and/or the sleeve is stationarily secured to a housing of the gas generator or the ignition unit. ### Claim 11 (depends on 1) The gas generator according to claim 1, wherein the combustion chamber extends in its axial longitudinal extension starting from the ignition unit along a housing of the gas generator to a volume compensation arrangement or a terminating housing part of the gas generator. ### Claim 12 (depends on 1) The gas generator according to claim 1, wherein the sleeve extends relative to its longitudinal extension in a range from 20% to 80% of the longitudinal extension of the combustion chamber into the propellant bed. ### Claim 13 (depends on 1) The gas generator according to claim 1, wherein the sleeve has, relative to its longitudinal extension, 1.5 to 4 times a value of a longitudinal extension of the ignition unit and/or is designed as a hollow body open to both end faces. ### Claim 14 (depends on 1) The gas generator according to claim 1, wherein a housing to which the sleeve is secured is an outer housing of the gas generator, and/or the propellant is formed of single molded bodies. ### Claim 15 (depends on 1) The gas generator according to claim 1, wherein the gas generator additionally has a second ignition unit associated with a combustion compartment separate from the combustion chamber, wherein the combustion compartment includes a propellant and/or a stored compressed gas and a diffuser is axially interposed between the ignition unit and the second ignition unit. ### Claim 16 (depends on 1) The gas generator according to claim 1, wherein by activating the ignition unit, a moderate combustion of the propellant and/or a lower pressure level can be generated inside the combustion chamber, as compared to a gas generator, which includes no sleeve as the ignition unit is installed in the gas generator. ### Claim 17 (depends on 1) An airbag module comprising a gas generator, an airbag inflatable by a gas generator according to claim 1. ### Claim 18 A method for operating a gas generator comprising the following steps of: a. providing a gas generator comprising an ignition unit, a propellant configured in a combustion chamber in a form of a propellant bed extending along a longitudinal axis of the gas generator, wherein a sleeve having an axial opening protrudes into the propellant bed such that it surrounds the ignition unit at least partially and portions of the propellant are stored inside and outside the sleeve; b. activating the ignition unit and igniting the portion of the propellant that is located inside the sleeve, wherein a part of the portion of the propellant is broken by a pressure surge of the ignition unit, thereby forming a larger combustion surface for more rapid combustion, then: c. igniting and burning the remaining propellant of the propellant bed at a combustion rate lower compared to step b.