WO2001094164A1 - Pretensioner drive - Google Patents
Pretensioner drive Download PDFInfo
- Publication number
- WO2001094164A1 WO2001094164A1 PCT/US2001/018074 US0118074W WO0194164A1 WO 2001094164 A1 WO2001094164 A1 WO 2001094164A1 US 0118074 W US0118074 W US 0118074W WO 0194164 A1 WO0194164 A1 WO 0194164A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pretensioner
- activation
- pulley
- clutch
- strap
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/34—Belt retractors, e.g. reels
- B60R22/46—Reels with means to tension the belt in an emergency by forced winding up
- B60R22/4628—Reels with means to tension the belt in an emergency by forced winding up characterised by fluid actuators, e.g. pyrotechnic gas generators
- B60R22/4633—Linear actuators, e.g. comprising a piston moving along reel axis and rotating along its own axis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/34—Belt retractors, e.g. reels
- B60R22/46—Reels with means to tension the belt in an emergency by forced winding up
- B60R2022/468—Reels with means to tension the belt in an emergency by forced winding up characterised by clutching means between actuator and belt reel
Definitions
- the present invention relates to seat belt pretensioners and, more specifically, to a seat belt pretensioner that incorporates a plurality of simplified motion multipliers thereby reducing the actuator stroke requirement.
- Seat belt pretensioners remove slack from a seat belt in the event of a collision in order to minimize forward movement of the passenger.
- pyrotechnic gas generators While it is known to use pyrotechnic gas generators to operate mechanisms which wind up or otherwise pull in slack of the seat belt during a collision, such known pyrotechnic gas generators are generally disposed internally of a seat belt retractor.
- the vehicle owner is faced with a significant cost penalty in that the entire pretensioner and retractor assembly must be replaced after activation because of the inability to prevent degradation of the retractor.
- German Patent No. DE 10010379 A1 herein incorporated by reference, describes a pretensioner having an arcuate path for a multi-piece actuator (a plurality of cylinders) that drives a steel cord wrapped around a webbing reel hub and thereby effects pretensioning of an associated seat belt.
- the manufacturing of the pretensioner is more complex given the multi-piece actuator and given the arcuate channel that the actuator must traverse. Uniformity in channel width and effective sealing becomes more difficult with the use of an arcuate channel.
- a noise reduction means is employed to prevent rattling during normal vehicle operation, thereby increasing manufacturing costs.
- a seat belt pretensioner that utilizes a plurality of motion multipliers within an essentially sealed housing thereby preventing retractor exposure to combustion gases and clinkers. More specifically, the present invention utilizes a drive gear that is meshed or engaged with a geared clutch sleeve. A pair of clutch segments is fixed radially inward of the clutch sleeve and radially outward of a webbing reel shaft of a seat belt retractor for gripping the shaft upon pretensioner activation. The webbing reel shaft axially extends through the circumferentially opposed clutch segments and rotates freely during normal operation of the vehicle.
- the webbing reel shaft also extends through the house and axially through a webbing reel of the seat belt retractor thereby establishing coaxial communication between the activated clutch and the webbing reel.
- Inclusion of the clutch (clutch sleeve and clutch segments) within the pretensioner eliminates the need for a clutch operable within the retractor.
- the present design also prevents occupant exposure to the gases and solids formed upon combustion of a pyrotechnic composition contained within the pretensioner.
- the pretensioner contains a housing, a geared pulley or drive gear engaged with a geared clutch sleeve, a retractor shaft axially and longitudinally disposed within the geared clutch, a strap that rotates the drive gear upon pretensioner activation, a piston that tensions and impels the strap upon pretensioner activation, a gas generant or pyrotechnic that propels the piston, and an initiator that ignites the gas generant upon a signal from an accelerometer, for example.
- the piston Upon ignition of the gas producing pyrotechnic, the piston is driven forward in an essentially linear path thereby tightening the strap and rotating the drive gear, and simultaneously rotating the geared clutch to facilitate a torque about the webbing reel shaft. Rotation of the geared clutch sleeve fixed over a first end of the webbing reel shaft thus effects pretensioning of a seat belt spooled about the webbing reel.
- Fig. 1 is a diagrammatic elevational view of a replaceable seat belt pretensioner prior to activation, in accordance with the present invention.
- Fig. 2 is a diagrammatic elevational view of the replaceable seat belt pretensioner after activation, in accordance with the present invention.
- Fig. 3 is an elevational view of an embodiment containing a cover.
- Fig. 4 is a cross-sectional view of the embodiment in Fig. 3 taken along the line A-A, and illustrates the mechanical cooperation between a pretensioner clutch of the present invention and a state-of-the-art seat belt retractor.
- Fig. 5 is a cross-sectional view of the embodiment in Fig. 3 taken along the line B-B, and illustrates the mechanical cooperation between the strap and the geared pulley of a pretensioner of the present invention.
- Fig. 6 is a plan view of the clutch assembly spaced radially outwardly of the retractor shaft prior to pretensioner activation.
- Fig. 7 is a plan view of the clutch assembly compressed radially inwardly about the retractor shaft upon pretensioner activation.
- Fig. 8 is an elevational view of a preferred actuator.
- Fig. 9 is an elevational view of an embodiment containing a gas generator.
- a pretensioner 10 in accordance with a preferred embodiment of the invention, comprises a gas generating composition 1 6 employed to pretension a seat belt 1 2 of a conventional seat belt retractor 1 4.
- Typical seat belt retractors to which the pretensioner of the present invention has application, are taught in U.S. Patent Nos. 5,743,480, 5,553,803, 5,667,1 61 , 5,451 ,008, 4,558,832 and 4,597,546, herein incorporated by reference. It should be emphasized, however, that although many known retractors employ clutch mechanisms upon pretensioner activation, the present invention obviates the need for clutch assemblies within the retractor used to pretension the seat belt. Pretensioners of the present invention contain a clutch assembly to improve and simplify the pretensioner drive as compared to other known pretensioners. Manufacturing of retractors associated with a pretensioner of the present invention may therefore be simplified.
- Housing 1 8 contains the gas generant 1 6. Upon combustion, the gas generant 1 6 drives a piston 20.
- the piston 20 is made from steel, brass, aluminum, plastic, or other sufficiently rigid material.
- a gas generator 22 may be contained within the housing 1 8 and employ the pyrotechnic material 1 6 for generating gas upon ignition thereof.
- the gas generant composition 1 6 may be any known pretensioner gas generant compound or alternatively, it may be any known gas generant useful in airbags, for example. To illustrate, see U.S. Patent 5,035,757 herein incorporated by reference. Additionally, as shown in Fig. 1 , the gas generant 1 6 may be contained within the piston 20 thereby eliminating the need for a separate generator 22.
- an initiator 26 communicates with a crash event sensor (not shown) that signals actuation of the pretensioner 10 upon a vehicle collision.
- a crash event sensor not shown
- the initiator 26 receives a signal, from an accelerometer for example, it ignites the pyrotechnic gas generant 1 6.
- An initiator retainer 28 is threadedly or otherwise received within the housing 1 8 and houses the initiator 26.
- a means for activating the pretensioner 10 and driving the actuator 20 upon a crash event includes the gas generant 1 6 contained within the piston 20 (or provided in a separate gas generator 22), the electrical contacts 24, and the initiator 26.
- the strap 30 is spooled and anchored at a first end 32 around a drive gear or geared pulley 34.
- a second end 36 of the strap 30 is preferably secured to the exterior of housing 1 8 at a point adjacent or proximate to the piston 20.
- Drive gear 34 engages a geared clutch sleeve 38 during normal operation of the vehicle.
- a first end 42 of a webbing reel shaft 40 is axially disposed within a clutch assembly 37 and rotates independently of the clutch assembly 37 prior to pretensioner 10 activation.
- a second end 44 of retractor axle 40 extends through the housing 1 8 and into the retractor 14.
- a webbing spool or reel 46 in coaxial communication with the clutch assembly 37 rotates about the second end 44 for winding and unwinding of the seat belt 1 2.
- a clutch 37 contains the geared clutch sleeve 38 compressively biased against a pair of fixed clutch segments 52 and 58, wherein a rotary torque exerted upon clutch sleeve 38 in turn exerts a compressive and rotary torque upon segments 52 and 58 as they grip the shaft 40 upon pretensioner activation 10.
- a first shear pin 50 fixes the corresponding first clutch segment 52 to the housing 18 and to a cover 56.
- a second shear pin 54 fixes the corresponding second clutch segment 58 to the housing 1 8 and to the cover 56.
- the geared clutch segments 52 and 58 are fixed apart and radially outwardly of the retractor axle 40 wherein each segment is circumferentially opposed to the other relative to the circumference of the shaft 40. Stated another way, an inner surface 53 of arcuate segment 52 faces the inner surface 55 of arcuate segment 58 wherein the cylindrical shaft 40 lies therebetween. Conversely, clutch segments 52 and 58 are fixed radially inwardly of and in flush peripheral communication with an inner surface 39 of the geared clutch sleeve 38.
- An axial cylinder or cylindrical portion 60 of pulley 34 accepts coiled or circumferential disposition of the strap 30 fixed thereto.
- the tensioned strap 30 exerts a torque about the cylinder 60 of the pulley 34.
- the geared pulley 34 exerts a rotary torque upon the geared clutch sleeve 38 in geared communication therewith.
- the geared clutch sleeve 38 in turn initially exerts a compressive torque upon segments 52 and 58.
- the clutch sleeve 38 fractures respective shear pins 50 and 54, thereby simultaneously imparting a rotary and compressive torque to the segments and rotatably driving the clutch segments 52 and 58 about the shaft 40.
- the webbing reel 46 correspondingly rotates and the seat belt 1 2 wound about the reel 46 is thereby pretensioned.
- a first rectangular channel 72 has a first end 74 and a second end 76, and is formed longitudinally and substantially coextensive with the housing 18.
- the actuator 20 is housed within the first end 74 prior to ignition of the propellant 22 and pretensioner 1 0 activation.
- a spring 77 may be employed to bias a leading edge of the actuator 20 against the flat portion 31 of the strap 30 that crosses the passage 72. Noise due to vibration is thereby inhibited.
- the first end 32 of the strap 30 extends from portion 31 and is spooled about the cylindrical portion 60 of the pulley 34.
- the second end 36 of strap 30 is fixed to the exterior of the housing 18 adjacent the piston 20.
- the strap 30 When arranged in this manner, the strap 30 provides a motion multiplier effect comparable to that afforded by the use of geared motion multipliers such as planetary gears, but at a much lower cost.
- linear motion of the actuator 20 translates to rotary motions of the drive gear 34 and the geared clutch sleeve 38, and rotary motion of the spool 46 in co-axial relation with the geared clutch sleeve 38.
- the seat belt 1 2 is thus tightened.
- the present invention incorporates several motion multiplying features: 1 ) the piston 20/strap 30 arrangement; 2) the two diameter geared pulley 34 (a smaller input diameter of cylinder 60 vs. a larger relative output diameter of geared portions meshed with sleeve 38, wherein the input diameter or cylinder 60 has the strap 30 coiled and fixed about it); and 3) larger drive gear 34 output diameter vs. a relatively smaller clutch sleeve 38 diameter. Additionally, the present invention simplifies the design and manufacturing of known motion multipliers incorporating clutch mechanisms. Finally, an essentially sealed housing 18 prevents the release of relatively large quantities of gas, noise, and flame.
- Pretensioning is generally defined to mean to take up slack in the seat belt.
- the gas produced by the gas generant propels the piston 20 into the strap 30 and thus affects rotary advancement of the hub 38 thereby tightening the slack in the seat belt 12. 2.
- a preferred actuator as shown in Fig. 8 results in a substantial increase in strap integrity during pretensioner activation.
- an actuator 20 as shown in Fig. 8 includes a first cylindrical component 21 interlocked with a second component 23, the second component forming a leading or rounded edge 29 of the actuator 20 and having a first flat side 25 and a second flat side 27 wherein the sides are joined by the rounded edge 29, the rounded edge 29 in flush communication with the strap 30.
- the housing 18, the piston 20, the drive gear 34, the 1 geared clutch sleeve 38, the clutch segments 52 and 58, and the initiator retainer 28 are preferably injection-molded, die cast, impacted, and/or machined from plastics, composites, and/or one or more metals such as steel, a steel alloy, zinc, or aluminum.
- the gas generating composition 1 6, the gas generator 22, the initiator 26 and the strap 30 are all manufactured or obtained by methods known to those of ordinary skill.
- Strap 30, for example may be formed from steel or aluminum strip, steel or aluminum cable, or fabric (cloth or rubber) strip. Companies such as Takata, Inc. of Japan may supply the gas generator 22.
- the initiator 26 may be supplied by the original equipment manufacturer or from companies such as Special Devices Incorporated of Moorpark, California, for example.
- the aforementioned references are incorporated by reference and cited by way of example.
- Resultant benefits include simplified manufacturing and retractor preservation.
- U.S. Patent No. 5,899,399 to Brown et al. also see U.S. Patent No. 5,397,075 to Behr, herein incorporated by reference, wherein relatively complex gear driving mechanisms used to actuate the retractor axle can be replaced by the present invention.
- gas ventilation ports as described in the cited references are not required (but may be provided if desired) and therefore manufacturing is even further simplified.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Automotive Seat Belt Assembly (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002501698A JP3792649B2 (en) | 2000-06-05 | 2001-06-05 | Pretensioner drive device |
EP01941902A EP1286868A4 (en) | 2000-06-05 | 2001-06-05 | Pretensioner drive |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US20937600P | 2000-06-05 | 2000-06-05 | |
US60/209,376 | 2000-06-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2001094164A1 true WO2001094164A1 (en) | 2001-12-13 |
WO2001094164A9 WO2001094164A9 (en) | 2002-10-10 |
Family
ID=22778519
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2001/018074 WO2001094164A1 (en) | 2000-06-05 | 2001-06-05 | Pretensioner drive |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1286868A4 (en) |
JP (1) | JP3792649B2 (en) |
WO (1) | WO2001094164A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5734889B2 (en) * | 2012-02-10 | 2015-06-17 | 株式会社東海理化電機製作所 | Pretensioner mechanism |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231509A1 (en) * | 1982-08-25 | 1984-03-08 | Daimler-Benz Ag, 7000 Stuttgart | Tension device for a belt end windable on to a belt reel and belonging to a safety-belt system |
US4750759A (en) * | 1986-09-18 | 1988-06-14 | Aciers Et Outillage Peugeot | Return tightener for a safety belt strap winder, in particular for a motor vehicle |
US4932603A (en) * | 1987-12-23 | 1990-06-12 | Nissan Motor Company, Limited | Safety belt arrangement with pretensioning mechanism |
US5222994A (en) * | 1991-03-12 | 1993-06-29 | Takata Corporation | Retractor shaft-rotating pretensioner |
US5397075A (en) * | 1993-09-10 | 1995-03-14 | Automotive Systems Laboratory, Inc. | Seat belt pretensioner |
US5588608A (en) * | 1993-08-30 | 1996-12-31 | Kabushiki Kaisha Tokai-Rika-Denki Seisakusho | Pretensioner |
US5641131A (en) * | 1993-10-25 | 1997-06-24 | Trw Repa Gmbh | Combined seat belt retractor and tensioner unit |
US5899399A (en) * | 1997-06-12 | 1999-05-04 | Trw Vehicle Safety Systems Inc. | Seat belt pretensioner |
US5906328A (en) * | 1998-03-12 | 1999-05-25 | Takata Corporation | Pre-tensioner for seat belt device |
US5944350A (en) * | 1997-11-14 | 1999-08-31 | Takata Inc. | Buckle pretensioner |
US5967440A (en) * | 1996-08-13 | 1999-10-19 | Breed Automotive Technology, Inc. | Pretensioner for a seatbelt retractor |
US6036274A (en) * | 1997-11-13 | 2000-03-14 | Breed Automotive Technology, Inc. | Drive pulley, compact buckle pretensioner |
DE10010379A1 (en) * | 1999-03-04 | 2000-09-14 | Nsk Ltd | Safety belt system for motor vehicles has belt winder with winder shaft, gas generator, shaft drive, and simple coupling mechanism |
US6139058A (en) * | 1997-06-12 | 2000-10-31 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt tensioner for an occupant restraint system |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2222510B (en) * | 1988-09-07 | 1992-10-07 | Autoliv Dev | Improvements in or relating to a safety belt arrangement |
DE4222993A1 (en) * | 1992-07-13 | 1994-01-20 | Trw Repa Gmbh | Belt retractor with a belt tensioner acting on the belt reel |
-
2001
- 2001-06-05 WO PCT/US2001/018074 patent/WO2001094164A1/en not_active Application Discontinuation
- 2001-06-05 EP EP01941902A patent/EP1286868A4/en not_active Withdrawn
- 2001-06-05 JP JP2002501698A patent/JP3792649B2/en not_active Expired - Fee Related
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231509A1 (en) * | 1982-08-25 | 1984-03-08 | Daimler-Benz Ag, 7000 Stuttgart | Tension device for a belt end windable on to a belt reel and belonging to a safety-belt system |
US4750759A (en) * | 1986-09-18 | 1988-06-14 | Aciers Et Outillage Peugeot | Return tightener for a safety belt strap winder, in particular for a motor vehicle |
US4932603A (en) * | 1987-12-23 | 1990-06-12 | Nissan Motor Company, Limited | Safety belt arrangement with pretensioning mechanism |
US5222994A (en) * | 1991-03-12 | 1993-06-29 | Takata Corporation | Retractor shaft-rotating pretensioner |
US5588608A (en) * | 1993-08-30 | 1996-12-31 | Kabushiki Kaisha Tokai-Rika-Denki Seisakusho | Pretensioner |
US5397075A (en) * | 1993-09-10 | 1995-03-14 | Automotive Systems Laboratory, Inc. | Seat belt pretensioner |
US5641131A (en) * | 1993-10-25 | 1997-06-24 | Trw Repa Gmbh | Combined seat belt retractor and tensioner unit |
US5967440A (en) * | 1996-08-13 | 1999-10-19 | Breed Automotive Technology, Inc. | Pretensioner for a seatbelt retractor |
US5899399A (en) * | 1997-06-12 | 1999-05-04 | Trw Vehicle Safety Systems Inc. | Seat belt pretensioner |
US6139058A (en) * | 1997-06-12 | 2000-10-31 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt tensioner for an occupant restraint system |
US6036274A (en) * | 1997-11-13 | 2000-03-14 | Breed Automotive Technology, Inc. | Drive pulley, compact buckle pretensioner |
US5944350A (en) * | 1997-11-14 | 1999-08-31 | Takata Inc. | Buckle pretensioner |
US5906328A (en) * | 1998-03-12 | 1999-05-25 | Takata Corporation | Pre-tensioner for seat belt device |
DE10010379A1 (en) * | 1999-03-04 | 2000-09-14 | Nsk Ltd | Safety belt system for motor vehicles has belt winder with winder shaft, gas generator, shaft drive, and simple coupling mechanism |
Non-Patent Citations (1)
Title |
---|
See also references of EP1286868A4 * |
Also Published As
Publication number | Publication date |
---|---|
EP1286868A4 (en) | 2005-03-02 |
WO2001094164A9 (en) | 2002-10-10 |
JP3792649B2 (en) | 2006-07-05 |
EP1286868A1 (en) | 2003-03-05 |
JP2003535751A (en) | 2003-12-02 |
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