US 12,296,786 B2
Seatbelt system and method for determining the extension length of a seatbelt system belt strap which is wound on a rotatable belt coil
Wolfgang Holbein, Alfdorf (DE); Frederic Michel, Schwäbisch Gmünd (DE); and Patrizia Lang, Waldstetten (DE)
Assigned to ZF AUTOMOTIVE GERMANY GMBH, Alfdorf (DE)
Appl. No. 17/916,092
Filed by ZF AUTOMOTIVE GERMANY GMBH, Alfdorf (DE)
PCT Filed Mar. 30, 2021, PCT No. PCT/EP2021/058233
§ 371(c)(1), (2) Date Sep. 30, 2022,
PCT Pub. No. WO2021/198219, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 10 2020 109 041.2 (DE), filed on Apr. 1, 2020.
Prior Publication US 2023/0158996 A1, May 25, 2023
Int. Cl. B60R 22/48 (2006.01); B60R 22/34 (2006.01)
CPC B60R 22/48 (2013.01) [B60R 22/34 (2013.01); B60R 2022/4816 (2013.01); B60R 2022/4825 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A seat belt system comprising a control unit (14) and a seat belt (16) which includes a webbing (18) and a belt retractor (20),
the belt retractor (20) including a belt reel (28) for the webbing (18), a rotation angle sensor (30) with a sensor unit (32) and a rotatable measuring element (34), and a gear unit (36) coupling the belt reel (28) to the measuring element (34) and comprising at least one gear element (42, 44),
the belt reel (28) having a fully extended position and a ghost position,
wherein the gear unit (36) is designed such that the gear unit (36) reduces the rotation of the belt reel (28), when the belt reel (28) is adjusted from the ghost position to the fully extended position, to a maximum of 1.0 revolutions of the measuring element (34), the rotation angle sensor being the only sensor used to determine an extension length of the webbing from the belt retractor.