RETRACTOR WITH ROTARY RACK PRETENSIONER
First Claim
1. A seat belt retractor (100) having a rotationally mounted spool (120) with a seat belt wound or windable thereon and a pretensioner (300) for selectively winding the spool in a belt winding direction to rewind the seat belt upon the spool;
- the pretensioner comprising;
a power transfer mechanism (350) activated by a pyrotechnic element (400) for causing a clutch assembly (200) to change state from a disengaged mode to an engaged mode in which the clutch assembly drivingly engages the spool;
the clutch assembly (200) comprising a clutch housing (210) having provision to support a plurality of rotationally mounted clutch pawls (240, 240a-c), the clutch housing received within a recess (202) of the spool (120), such recess including a plurality of engagement teeth (204) thereon, each of the clutch pawls configured to be column loaded between the spool and the clutch housing when in the engaged mode.
10 Assignments
0 Petitions
Accused Products
Abstract
A seat belt retractor (100) having a rotationally mounted spool (120) with a seat belt windable thereon and a pretensioner (300) for winding the spool in a belt winding direction to rewind the seat belt upon the spool; the pretensioner comprising a rack and pinion mechanism (350) activated by a pyrotechnic element (400) for causing a clutch assembly (200) to change state from a disengaged mode to an engaged mode in which the clutch assembly drivingly engages the spool.
26 Citations
18 Claims
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1. A seat belt retractor (100) having a rotationally mounted spool (120) with a seat belt wound or windable thereon and a pretensioner (300) for selectively winding the spool in a belt winding direction to rewind the seat belt upon the spool;
- the pretensioner comprising;
a power transfer mechanism (350) activated by a pyrotechnic element (400) for causing a clutch assembly (200) to change state from a disengaged mode to an engaged mode in which the clutch assembly drivingly engages the spool; the clutch assembly (200) comprising a clutch housing (210) having provision to support a plurality of rotationally mounted clutch pawls (240, 240a-c), the clutch housing received within a recess (202) of the spool (120), such recess including a plurality of engagement teeth (204) thereon, each of the clutch pawls configured to be column loaded between the spool and the clutch housing when in the engaged mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- the pretensioner comprising;
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12. The apparatus of claim 12 wherein the main body includes grooved segments (230a-c) lying on a same radius effectively forming a circular groove (230) for receiving a resilient member including an O-ring (232).
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13. The apparatus of claim 13 wherein each groove segment (230a-c), proximate each curved end wall (226), includes a partial-cylindrical slot (231 a), which deepens each groove segment (230a-c) toward a corresponding one of the curved end walls (226), the main body (212) includes a center bore (234), received about a portion of the shaft (126), further, a clutch pawl (240) is pivotably received in each cavity (214).
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14. The apparatus of claim 14 wherein each clutch pawl is configured to be relatively short, thereby reducing the overall size of the assembly (200), each clutch pawl has a narrow shaft portion (241) and considerably wider head portion (250) which is configured to locate the center-of-gravity of the clutch pawl within the head portion to increase an effective radius between the center of gravity and a pivot end of the pawl, thereby enhancing the speed of outward rotation of the pawl at any given level of speed of the clutch housing.
- 15. The apparatus of claim 15 wherein each clutch pawl has a hardness greater than that of the spool, and the clutch housing and clutch pawls are configured to enable the clutch pawls to be column loaded to the clutch housing when a toothed end of the pawl has engaged the peripheral surface of the spool.
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18. A seat belt retractor (100) having a rotationally mounted spool (120) with a seat belt wound or windable thereon and a pretensioner (300) for selectively winding the spool in a belt winding direction to rewind the seat belt upon the spool;
- the pretensioner comprising;
a rack and pinion mechanism (350) activated by a pyrotechnic element (400) for causing a clutch assembly (200) to change state from a disengaged mode to an engaged mode in which the clutch assembly drivingly engages the spool; the clutch assembly (200) comprising a clutch housing (210) having provision to support a plurality of rotationally mounted clutch pawls (240, 240a-c), the clutch housing received within a recess (202) of the spool (120), such recess including a plurality of engagement teeth (204) thereon, each of the clutch pawls configured to be column loaded between the spool and the clutch housing when in the engaged mode.
- the pretensioner comprising;
Specification