GB2522335A - Load limiting device for a seat belt of a vehicle - Google Patents

Load limiting device for a seat belt of a vehicle Download PDF

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Publication number
GB2522335A
GB2522335A GB1422388.7A GB201422388A GB2522335A GB 2522335 A GB2522335 A GB 2522335A GB 201422388 A GB201422388 A GB 201422388A GB 2522335 A GB2522335 A GB 2522335A
Authority
GB
United Kingdom
Prior art keywords
spool
torsion bar
limiting device
seat belt
load limiting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB1422388.7A
Inventor
Kalyan Cheruvu
Gopal Krishnan Chinnaswamy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mercedes Benz Group AG
Original Assignee
Daimler AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daimler AG filed Critical Daimler AG
Priority to GB1422388.7A priority Critical patent/GB2522335A/en
Publication of GB2522335A publication Critical patent/GB2522335A/en
Withdrawn legal-status Critical Current

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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
    • B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
    • 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
    • B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
    • B60R2022/286—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices using deformation of material
    • B60R2022/287—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices using deformation of material of torsion rods or tubes
    • 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
    • B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
    • B60R2022/288—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices with means to adjust or regulate the amount of energy to be absorbed
    • 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
    • B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
    • B60R2022/289—Energy-absorption curves

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Automotive Seat Belt Assembly (AREA)

Abstract

A load limiting device 10 for a seat belt 12 of a vehicle, having first and second torsion bars 24, 34 arranged in respective first and second spools 26, 36, the torsion bars 24, 34 being configured to twist due to loads exerted on the respective spools 26, 36 by the seat belt. Load may be transferred from the seat belt 12 to the load limiting device 10 by respective first and second cables 42, 44, with at least one of the torsion bars 24, 34 being attached to a structure of the vehicle. The provision of multiple torsion bars and spools may allow for variable load limiting based on the physical and mechanical properties of the components.

Description

Load Limiting Device for a Seat Belt of a Vehicle The invention relates to a load limiting device for a seat belt of a vehicle.
US 6012667 shows an energy absorbing retractor having a spool and torsion means for generating selected levels of reaction torque on the spool permitting the spool to rotate in a controlled manner in a bolt protracting direction including a middle portion and a first portion member extending therefrom, the middle portion fixedly coupled to the spool to prevent relative rotation there between. The energy absorbing retractor further comprises a frame, wherein the spool is rotationally supported relative to the frame. A locking mechanism is provided, the locking mechanism comprising a primary mechanical first locking mechanism adapted to initially stop the spool from rotating in a belt protraction direction, said torsion means permitting the spool to rotate thereafter in the direction of belt protraction. Moreover, a seat belt is wound about the spool. The energy absorbing retractor also comprises bias means to retract the seat belt onto the spool, the first torsion member including a first end operatively coupled to the primary mechanical first locking mechanism, the first locking mechanism when in a locked condition prevents the first end from rotating, whereby when the spool is loaded, the first torsion member twists and deforms torsionally to generate a controlled reaction force having a first level. The torsion means includes a second torsion member extending from the middle portion opposite to the first portion member, the second torsion member including a second end operatively coupled to a second locking mechanism to prevent the second end from rotating when the second locking mechanism is in a locked condition, whereby when the spool is loaded, the second torsion member twists and deforms torsionally to create a controlled reaction force which supplements the first level of reaction force.
Moreover, the second locking mechanism includes a pawl movable into a locking relationship with a toothed wheel and wherein the pawl is moved by pyrotechnically activated mechanism.
It is an object of the present invention to provide a load limiting device by means of which loads acting upon an occupant via a seat belt due to an accident can be limited in a particularly advantageous and need-based manner.
This object is solved by a load limiting device having the features of patent claim 1.
Advantageous embodiments with expedient developments of the invention are indicated in the other patent claims.
According to the present invention the load limiting device for a seat belt of a vehicle, in particular a passenger vehicle, comprises a first torsion bar and a first spool in which the first torsion bar is arranged at least partially. The first torsion bar is connected to the first spool and configured to be twisted due to loads exerted on the first spool by the seat belt.
Moreover, the load limiting device comprises a second torsion bar and a second spool in which the second torsion bar is arranged at least partially, the second torsion bar being connected to the second spool and configured to be twisted due to loads exerted on the second spool by the seat belt. Since the load limiting device according to the present invention comprises the separate spools as well as the separate torsion bars loads acting upon an occupant via the seat belt during an accident, in particular a frontal impact can be kept particularly low and controlled in a need-based manner. In other words, the load limiting device according to the present invention serves for realizing a variable load limiting on the basis of the design of the load limiting device, in particular the torsion bars.
For example, it is possible to limit and control the loads acting upon the occupant in at least two stages since the load limiting device comprises at least the two torsion bars configured to control and limit the loads acting upon the occupant by twisting.
Further advantages, features, and details of the invention derive from the following description of preferred embodiments as well as from the drawing. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respective indicated combination but also in any other combination or taken alone without leaving the scope of the invention.
The drawing shows in: Fig. 1 a schematic side view of a first embodiment of a load limiting device for a seat belt of a vehicle, the load limiting device comprising two separate torsion bars and two separate spools, the torsion bars being configured to limit loads acting upon an occupant via the seat belt in such a way that the torsion bars can twist due to loads exerted on the torsion bars by the seat belt at least indirectly; Fig. 2 a schematic perspective view of the first embodiment of the load limiting device; Fig. 3 a schematic sectional view of the first embodiment of the load limiting device; Fig. 4 a schematic sectional view of a second embodiment of the load limiting device; Fig. 5 a further schematic sectional view of the second embodiment of the load limiting device; and Fig. 6a-f respective diagrams illustrating loads acting upon the occupant via the seat belt during an accident.
In the figures the same element or elements having the same functions are indicated by the same reference signs.
Figs. ito 3 show a first embodiment of a load limiting device 10 for a seat belt 12 of a vehicle, in particular a passenger vehicle. As can be seen from Figs. 1 and 2 the seat belt 12 comprises a webbing 14 attached to a belt tongue 16. The belt tongue iSis connected to a belt buckle lBso that the seat belt 12 is fastened. Thereby, an occupant of the vehicle can be restrained by the seat belt 12 in case of an accident, in particular a frontal impact of the vehicle. The webbing 14 forms a shoulder belt 15 for restraining the upper body of the occupant. Moreover, the webbing 14 forms a lap belt 17 for restraining the waist of the occupant. During such an accident the occupant will typically move forwards thereby exerting a force on the seat belt 12. In other words, loads or forces are exerted on the seat belt 12 by! the occupant. The consequence of these forces or loads are reaction forces which are loads exerted on the occupant by the set belt 12. These reaction forces or loads are also referred to as belt loads. The load limiting device 10 serves to keep the belt loads particularly low and control the belt loads during an accident.
For this purpose the load limiting device 10 comprises an upper assembly 20 and a lower assembly 22 which can be seen particularly well from Fig. 3. The upper assembly 20 comprises a first torsion bar 24 as well as a first drum or spool 26. As can be seen from Fig. 3 the first torsion bar 24 is arranged at least partially in the first spool 26, wherein the first spooi 26 is connected to the first torsion bar 24 in a first connection area 28. The first spool 26 is connected to the first torsion bar 24 in a rotationally fixed manner, wherein the first torsion bar 24 is configured to be twisted due to loads exerted on the first spool 26 by the seat belt 12 and a rotational movement of the first spool 26 in relation to the first torsion bar 24. As can be seen particularly well from a magnified area B. the first spool 26 can rotate over the first torsion bar 24. The first torsion bar 24 is attached to a structure of the vehicle in a rotationally fixed manner. Thus, when the first spool 26 is rotated in relation to the first torsion bar 24 about a first rotation axis 32, the first torsion bar 24 is twisted. Thereby, the rotational movement about the first rotation axis 32 is influenced or constrained by the first torsion bar 24.
The lower assembly 22 comprises a second torsion bar 34 as well as a second drum or spool 36, wherein the second torsion bar 34 is arranged at least partially in the second spool 36. The second spool 36 is connected to the second torsion bar 34 in a second connection area 38, wherein the second spool 36 is connected to the second torsion bar 34 in a rotationally fixed manner. The second torsion bar 34 is configured to be twisted due to loads exerted on the second spool 36 by the seat belt 12. In other words, when the second spool 36 is rotated in relation to the second torsion bar 34 about a second rotation axis 40 the second torsion bar 34 is twisted thereby influencing or constraining the rotational movement of the second spool 36 about the rotation axis 40.
In the first embodiment the second torsion bar 34 is attached to the structure 30 in a rotationally fixed manner. In order to transmit loads from the seat belt 12 to the load limiting device 10 the load limiting device 10 comprises a first cable 42 wound about the first spool 26 and connected to the first spool 26. Moreover, the first cable 42 is connected to the belt buckle 18. Moreover, the load limiting device 10 comprises a second cable 44 wound about the second spool 36 and connected to the second spool 36. Moreover, the second cable 44 is connected to the belt buckle 18. Moreover, a roller 46 for guiding the cables 42 and 44 is provided. For example, the roller 46 is configured as a pulley.
During a frontal impact and a forward movement of the occupant, the forward movement resulting from the frontal impact, the seat belt 12 pulls the cables 42 and 44. Thus, the cables 42 and 44 are unwound from the respective spools 26 and 36 which results in respective rotational movements of the spools 26 and 36 about the rotation axes 32 and 34. Thereby, the torsion bars 24 and 34 are twisted thereby protracting the rotational movements of the spools 26 and 36. Thereby, the occupant can be restrained by the seat belt 12 and loads exerted on the occupant by the seat belt 12 can be kept particularly low since the load limiting device 10 allows the forward movement of the occupant in a controlled manner. For example, the cables 42 and 44 which can be configured as wires can be wound about the spools 26 and 36 in different patterns to achieve various or different types of load limiting effects. In other words, dynamically variable load limiting effects can be realized by winding the cables 42 and 42 about the respective spools 26 and 36. Fig. 3 shows respective ends 47 of the cables 42 and 44, wherein the respective ends 47 are connected to the respective spools 26 and 36.
In the figures the load limiting device 10 is shown in regard to the belt buckle 18.
However, the load limiting device 10 can be additionally or alternatively used in conjunction with an anchor or in a shoulder region of the occupant.
Figs. 4 and 5 show a second embodiment of the load limiting device 10. In the second embodiment, the first torsion bar 24 is attached to the structure 30 in a rotationally fixed manner. However, in the second embodiment the second torsion bar 34 is rotatably mounted on a supporting element 48 which is attached to the structure 30 in a rotationally fixed manner. For example, the second torsion bar 34 is rotatably supported on the supporting element 48 by a bearing 50 which is, for example, a roller bearing. Thus, the second spool 36 and the second torsion bar 34 can be rotated about the rotation axis 40 in relation to the supporting element 48 and, thus, the structure 30. As can be seen from Fig. 5, the load limiting device 10 comprises a stopping device 52 comprising a first stopping element 54 and a second stopping element 56. The stopping element 54 is mounted on the bearing element 50 which in turn connected to the torsion bar 34 in a rotationally fixed manner so that the first stopping element 54 can rotate together with the second torsion bar 34 about the rotation axis 40.
However, the second stopping element 56 is attached to the structure 30 in a rotationally fixed manner at least indirectly. The stopping device 52 and, thus, the stopping elements 54 and 56 are configured to stop the second torsion bar 34 in a stopping position S shown in Fig. 5. In other words, when loads are transferred from the seat belt 12 via the belt buckle 18 and the second cable 44 to the second spool 36 and, thus, the second torsion bar 34 the second torsion bar 34 can rotate from a first position F into the stopping position S. This means the second torsion bar 34 can rotate until the first stopping element 54 comes upon the second stopping element 56. Then, the second torsion bar 34 has reached its stopping position S from which it cannot rotate any further about the rotation axis 40. When the loads continue to act upon the second spool 36 and, thus, the second torsion bar 34 a rotational movement of the second spool 36 in relation to the second torsion bar 34 about the rotation axis 40 is effected. Thereby, the second torsion bar 34 is twisted thereby limiting and controlling the loads acting upon the occupant via the seat belt 12. The respective rotational movements of the spools 26 and 36 are illustrated by directional arrows 58 and 60 in Fig. 5.
Figs. 6a-f show respective diagrams 62, the respective diagrams 62 showing the belt loads on the ordinate 64 versus the time on the abscissa 66. This means a respective graph 68 shows the belt loads over the time, the belt loads being exerted on the occupant by the seat belt 12. As can be seen from Figs. 6a-f the belt loads can be variably limited and controlled by, for example, varying the design of the torsion bars 24 and 34 and/or by winding the cables 42 and 44 about the respective spools 26 and 36 in different ways. As can be seen particularly well from Figs. 6b, Sd and 6f the belt loads can be limited and controlled particularly advantageously and in a need-based manner by employing the stopping device 52. Thereby, for example, the loads acting upon the occupant can be limited and controlled in at least two stages over the time.
List of reference signs load limiting device 12 seat belt 14 webbing shoulder belt 16 belttongue 17 lap belt 18 belt buckle upper assembly 22 lower assembly 24 first torsion bar 26 first spool 28 first connection area structure 32 first rotation axis 34 second torsion bar 36 second spool 38 second connection area second rotation axis 42 first cable 44 second cable 46 roller 47 end 48 supporting element bearing 52 stopping device 54 first stopping element 56 second stopping element 58 directional arrow directional arrow 62 diagram 64 ordinate 66 abscissa 68 graph
S
F first postition S stopping position

Claims (5)

  1. Claims A load limiting device (10) for a seat belt (12) of a vehicle, the load limiting device (10) comprising: -a first torsion bar (24); -a first spool (26) in which the first torsion bar (24) is arranged at least partially, the first torsion bar (24) being connected to the first spool (26) and configured to be twisted due to loads exerted on the first spool (26) by the seat belt (12); -a second torsion bar (34); and -a second spool (36) in which the second torsion bar (34) is arranged at least partially, the second torsion bar (34) being connected to the second spool (36) and configured to be twisted due to loads exerted on the second spool (36) by the seat belt (12).
  2. 2. The load limiting device (10) according to claim 1, wherein the load limiting device (10) comprises: -at least one supporting element (48) on which the second torsion (34) bar is rotatably mounted about a rotation axis (40), the second spool (36) and the second torsion bar (34) being rotatable about the rotation axis (40) due to loads exerted on the second spool (36) by the seat belt (12); and -at least one stopping element (54) configured to stop the second torsion bar (34) after its rotation in a stopping position (S) in which the second torsion bar (34) is capable of being twisted due to loads exerted on the second spool (36) by the seat belt (12).
  3. 3. The load limiting device (10) according to any one of claims 1 or 2.wherein the load limiting device (10) comprises: -a first cable (42) wound about the first spool (26); and -a second cable (44) wound about the second spool (36), wherein the cables (42, 44) are configured to be attached to the seat belt (12) at least indirectly respectively.
  4. 4. The load limiting device (10) according to claim 3, wherein the cables (42, 44) are connected to a belt buckle (18) configured to be connected to the seat belt (12).
  5. 5. The load limiting device (10) according to any one of the preceding claims, wherein the first torsion bar (24) is attached to a structure (30) of the vehicle at least indirectly in a rotationally fixed manner.
GB1422388.7A 2014-12-16 2014-12-16 Load limiting device for a seat belt of a vehicle Withdrawn GB2522335A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1422388.7A GB2522335A (en) 2014-12-16 2014-12-16 Load limiting device for a seat belt of a vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1422388.7A GB2522335A (en) 2014-12-16 2014-12-16 Load limiting device for a seat belt of a vehicle

Publications (1)

Publication Number Publication Date
GB2522335A true GB2522335A (en) 2015-07-22

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB1422388.7A Withdrawn GB2522335A (en) 2014-12-16 2014-12-16 Load limiting device for a seat belt of a vehicle

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GB (1) GB2522335A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3450262A1 (en) * 2017-09-05 2019-03-06 Toyota Jidosha Kabushiki Kaisha Three-point seatbelt device
CN116001723A (en) * 2022-12-09 2023-04-25 上海卜瑞科技有限公司 Miniature waist energy absorbing device and safety belt lock catch
WO2024102822A1 (en) * 2022-11-10 2024-05-16 Joyson Safety Systems Acquisition Llc Energy absorbing seatbelt assembly

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6302346B1 (en) * 2000-01-14 2001-10-16 Trw Vehicle Safety Systems Inc. Seat belt webbing energy management device
EP1449725A1 (en) * 2003-02-20 2004-08-25 TAKATA-PETRI (Ulm) GmbH Fixing device for a safety belt
DE102012024898A1 (en) * 2012-12-20 2014-06-26 Autoliv Development Ab Seat harness release force reduction device for use in vehicle, has unwinding or winding force reduction element for reducing force acting on buckle and coupled with connecting element that is formed with elongated hole
DE102013001375A1 (en) * 2013-01-28 2014-07-31 Autoliv Development Ab Seat belt lock force reducing device for reducing force operating on seat belt lock in load condition, has two damping elements provided in load condition, where damping elements are movable with each other depending on relative positions

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6302346B1 (en) * 2000-01-14 2001-10-16 Trw Vehicle Safety Systems Inc. Seat belt webbing energy management device
EP1449725A1 (en) * 2003-02-20 2004-08-25 TAKATA-PETRI (Ulm) GmbH Fixing device for a safety belt
DE102012024898A1 (en) * 2012-12-20 2014-06-26 Autoliv Development Ab Seat harness release force reduction device for use in vehicle, has unwinding or winding force reduction element for reducing force acting on buckle and coupled with connecting element that is formed with elongated hole
DE102013001375A1 (en) * 2013-01-28 2014-07-31 Autoliv Development Ab Seat belt lock force reducing device for reducing force operating on seat belt lock in load condition, has two damping elements provided in load condition, where damping elements are movable with each other depending on relative positions

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3450262A1 (en) * 2017-09-05 2019-03-06 Toyota Jidosha Kabushiki Kaisha Three-point seatbelt device
RU2699167C1 (en) * 2017-09-05 2019-09-03 Тойота Дзидося Кабусики Кайся Device of three-point safety belt
US10703332B2 (en) 2017-09-05 2020-07-07 Toyota Jidosha Kabushiki Kaisha Three-point seatbelt device
WO2024102822A1 (en) * 2022-11-10 2024-05-16 Joyson Safety Systems Acquisition Llc Energy absorbing seatbelt assembly
CN116001723A (en) * 2022-12-09 2023-04-25 上海卜瑞科技有限公司 Miniature waist energy absorbing device and safety belt lock catch

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)