Seat belt pretensioner
US6679446B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2002 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Dec 18, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R2022/468
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A seat belt pretensioner has a piston; a tube housing the piston; a force reservoir, activatable when a crash is sensed, to drive the piston along the tube; a resilient steel band connected to the piston; and means for selectively connecting the steel band to a retractor spool. Preferably the force reservoir is a gas generator which may be pyrotechnically activated and has an output in the tube on one side of the piston to drive the piston along the tube pulling the steel band and engaging the connecting means to turn the retractor spool and shorten the belt webbing. The steel band has indexing features, such as indexing holes or slots to engage teeth on the outer periphery of a drive wheel attached to the retractor spool. As the steel band is pulled by the piston it tightens around the drive wheel and the indexing holes engage the teeth, turning the drive wheel and thus the spool and pulling in the webbing to secure the vehicle occupant. The piston may have two piston members connected by a connecting assembly including a resilient member such as a coil spring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.