GB2265541A - Device for reducing the rotational speed of a seat belt take-up shaft - Google Patents

Device for reducing the rotational speed of a seat belt take-up shaft Download PDF

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Publication number
GB2265541A
GB2265541A GB9306261A GB9306261A GB2265541A GB 2265541 A GB2265541 A GB 2265541A GB 9306261 A GB9306261 A GB 9306261A GB 9306261 A GB9306261 A GB 9306261A GB 2265541 A GB2265541 A GB 2265541A
Authority
GB
United Kingdom
Prior art keywords
shaft
take
reduction device
seat belt
speed
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Withdrawn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
GB9306261A
Other versions
GB9306261D0 (en
Inventor
Jyoji Mishina
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.)
Takata Corp
Original Assignee
Takata Corp
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 Takata Corp filed Critical Takata Corp
Publication of GB9306261D0 publication Critical patent/GB9306261D0/en
Publication of GB2265541A publication Critical patent/GB2265541A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
    • F16F15/023—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using fluid means
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D57/00—Liquid-resistance brakes; Brakes using the internal friction of fluids or fluid-like media, e.g. powders
    • F16D57/02—Liquid-resistance brakes; Brakes using the internal friction of fluids or fluid-like media, e.g. powders with blades or like members braked by the fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D59/00—Self-acting brakes, e.g. coming into operation at a predetermined speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/02—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together
    • F16F7/023—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together and characterised by damping force adjustment means
    • 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
    • B60R2022/3419—Belt retractors, e.g. reels with end lock preventing means
    • 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
    • B60R22/44—Belt retractors, e.g. reels with means for reducing belt tension during use under normal conditions
    • B60R2022/4493—Belt retractors, e.g. reels with means for reducing belt tension during use under normal conditions for braking the belt reel using friction surfaces or the like

Abstract

In one embodiment the device comprises a liquid-filled confined chamber 28 having an impeller 30 disposed therein and fixed on the belt take-up shaft 15 or a shaft connected thereto. In another embodiment (Fig. 3) the device has a stationary cylindrical drum (40) containing a rotary disc (42) mounted on the take-up shaft, and the disc has four radial bores (46) each containing a respective brake pad (45) restrained by a tension spring (48) but moved radially into contact with the stationary drum by centrifugal force when the speed of the take-up shaft becomes excessive. <IMAGE>

Description

2265541 S P E C I F I C A T 1 0 N TITLE OF THE INVENTION Take-up Shaft
Rotation Reduction Devic Belt Retractor e for Seat
BACKGROUND OF THE INVENTION Field of the Invention
The present invention relates to a seat belt retractor mounted on a vehicle for protecting a passenger in an emergency such as a collision. More particularly, the present invention relates to a take-up shaft rotation reduction device for the seat belt retractor for preventing the belt take-up shaft of the seat belt retractor from rotating at an excessively high speed by applying a decelerating force to the belt takeup shaft when the rotating speed of the belt take-tip shaft exceeds a predetermined value.
Description of the Related Art
A take-up shaft for taking up the seat belt of the seat belt retractor is driven by a return spring. As a result, the rotating speed of the take-up shaft is high, if the return spring is given a large spring constant, and low if a low spring constant.
1 The takeup force for the seat belt retractor to take up the seat belt is convenient, if considerably high, when using the seat belt retractor. In order to increase the take-up force, it is sufficient to increase the spring constant of the return spring biasing the take-up shaft in the takingup direction. With the enlarged spring constant of the return spring, however, there arises a problem that the taking-up speed of the seat belt is excessively high.
OBJECT AND SUNLMARY OF THE INVENTION An object of the present invention is to provide a take-up shaft rotation reduction device for the seat belt retractor for preventing the belt take- up shaft of the seat belt retractor from rotating at an excessively high speed by applying a decelerating force to the belt take-up shaft when the rotating speed of the belt take-up shaft exceeds a predetermined value.
According to a first aspect of the present invention, there is provided a reduction device for reducing the speed of rotation of a belt take-up shaf t of a seat belt retractor, comprising: a confined chamber at either one end of the belt take-up shaf t or a shaft member leading to the belt take-up shaft end; an impeller disposed in the confined chamber and fixed on the shaft 2 member; and a liquid in the confined chamber.
According to a second aspect of the present in vention, there is provided a reduction device for reducing the speed of rotation o f a belt take-up shaft of a seat belt retractor, comprising: a cylindrical sta tionary drum having an inner circumference and ccaxial with the axis of either one end of the belt take-up shaft or a shaft member leading to the belt take-up shaft end; at least one sliding member arranged to slide along the inner circumference of the stationary drLn; and at least one elastic member cc=cting the sliding member and the sna-r-t:-,-mber for spacing the sliding member from the inner circumference of the stationary drum when a centrifugal force applied to the sliding member is lower than a predetermined level, and to allow the sliding member into abutment a gainst the inner circumference of the stationary drum when the centrifugal force exceeds the predetermined level.
In the take-up shaft rotation reduction device for a seat belt retractor according to the first as pect, the resistance the impeller receives from the liquid in the confined chamber gradually increases as the rotating speed of the take-up shaft increases.
When the rotating speed of the take-up shaft exceeds a 3 certain value, the resistance rises considerably to prevent rotation of the take-up shaft at any higher speed.
In the take-up shaft rotation reduction device for a seat belt retractor according to the second aspect, the sliding member is pushed onto the inner circumference of the drum by the centrifugal force when the rotating speed of the take-up shaft exceeds a certain,.;,alue. Then, the take-up shaft is prevented from rotating at anyhigher speed by the frictional resistance te-tween the sliding member and the drum inner circumference.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a section showing a seat belt retractor equipped with a reduction device according to an embodiment; Fig. 2 is a section taken along line II - II of Fig. 1; and T_ -- -12.
IE7. 'i is a sectilan showing a reduction device according to another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in the following in connection with its embodiments with reference to the accompanying drawings. Fig. 1 is a sec- 4 tion showing a rotation reducing device for a take-up shaft of a seat belt according to an embodiment of the present invention, and Fig. 2 is a section taken along line II - II of Fig. 1. section taken along the of a seat belt.
In Fig. 1, a seat belt retractor has its frame 10 constructed to include a back plate 12, and a pair of side plates 14 and 16 raised from the two sides of the back plate 12. Between the side plates 14 and 16, there is rotatably borne a seat belt take-up shaft 18. This seat belt take-up shaft 18 has its end portion at the lefthand side of Fig. 1 extended through the side plate 14 such that it has a return spring 20 wound thereon outside of the side plate 14. Numeral 22 designates a cover for the return spring 20.
The end portion 24 of the seat belt take-up shaft 18, as located at the righthand side of Fig. 1, is inserted into the casing 28 of a take-up shaft rotation reduction device 26. On the take-up shaft end portion 24, there is fixed an impeller 30 which can rotate in the casing 28. In the present embodiment, the impeller 30 has four blades. The casing 28 has its inside filled up with a liquid 32. Numeral 34 designates a seal mounted between the outer circumference of the Fig. 1 is a axis of the take-up shaft take-up shaft end portion 24 and the casing 28.
In the seat belt retractor thus constructed, the seat belt is wound on its take-up shaft 18 and can be taken up thereon by the action of the return spring 20. While the take-up shaft 18 is rotating at a low speed, it receives a low resistance from the liquid 32 so that it can easilY rotate. As the rotating speed of the take-up shaft 18 increases the resis the impeller 30 receives from the liquid When the rotating speed of the take-up shaft 18 exceeds a predetermined value, the impeller 30 receives a high resistance from the liquid 32. This prevents the take-up shaft 18 from rotating at an excessively high speed.
Fig. 3 is a section showing a reduction device according to another embodiment of the present inven tion. Fig. 3 presents a section of a portion similar to that of Fig. 2.
Reference numeral 40 designates a stationary drum having a cylindrical shape, which is fixed on the side plate 16 (although omitted from Fig. 3) of the seat belt retractor. Coaxial with the drum 40, there is inserted the end portion 24 of the take-up shaft.
This end portion 24 is arranged on its outer circum ference with a disc 42. The shaft end portion 24 is tance 32 also increases.
6 inserted into the center hole of the disc 42 and is keyed at 44 to the same so that the disc 42 and the take-up shaft 18 (although omitted from Fig. 3) can rotate together.
The disc 42 is formed with a plurality of (four in the present embodiment) guide holes 46 which extend radially to carry brake pads 48 acting as sliding members at their radial end portions. Between an axial member 50 of the disc 42 and the individual brake pads 48, there are sandwiched tension coil springs 52 for urging the brake pads 48 toward the take-up shaft end portion 24.
In the reduction device of Fig. 3 described above, the brake pacb 48 are spaced from the inner circumference of the drum 40, while the take-up shaft 18 has a low rotating speed, so that the take-up shaft 18 is allowed to freely rotate. As the rotating speed of the take-up shaft 18 gradually rises, the springs 115.21 are eXtended to brjnff the brake pads 48 into sliding contact with the flat inner circumference of the drum 40. Then, the take-up shaft 18 is braked andprevented from reaching a far higher speed of rotation.
Thus, according to the embodiment described above, the seat belt take-up shaft 18 isprevented from rotating at an excessively high speed so that an upper 7 limit is given to the take-up speed of the seat belt.
In the embodiment of Figs. 1 and 2, the impeller 30 is fixed directly on the end portion 24 of the take-up shaft, but a suitable shaft member may be connected to the shaft end portion 24 so that the impeller may be fixed on the shaft member. In the embodiment of Fig. 3, on the other hand, the shaft end portion 24 is fitted in the disc 42, and the springs 52 are connected to the center member 50 of the disc 42. However, the springs 52 may be connected directly to the shaft end portion 24.
According to the reduction device of the present invention, as described above, the seat belt take-up shaft can be prevented from rotating at an excessively high speed to suppress the seat belt take-up speed within a predetermined range. Incidentally, the let-off speed of the seat belt is also suppressed within the predetermined range, but the let-off speed of the seat belt for the seat b-c-It to be applied to a passenger -i-- --P-lower than the take-up speed within the predetermined range so that operating feeling of the reduction device is kept good.
In this specification, the term 'passenger' also includes a driver.
8

Claims (14)

WHAT iS CLAI1LIED IS:
1. A reduction device for reducing the speed of rotation of a seat belt take-up shaft of a seat belt retractor, the device comprising means to apply a frictional restraining force to said take-up shaft to prevent an excessive speed of ration.
2. A reduction device according to claim 1 for reducing the speed of rotation of a belt take-up shaft of a seat belt retractor, wherein said means comprises: a confined chamber having fitted therein a shaft member made rotatable with said belt take-up shaft; at least an impeller disposed in said confined chamber and driveably connected with one of said belt take-up shaft and said shaft member; and a liquid in said confined chamber.
3. A reduction device according to claim 2, wherein said confined chamber is attached to one side plate of a frame of said seat belt retractor.
-1 1
4. A red-,.--c t -Lon device according to claim 9 wherei-n- said impeller includes a plurality of blades.
5. A reduction device according to claim 2, wherein said shaft member forms one end of said take-up shaft.
9
6. A reduction device according to claim 21, wherein sa-1 shaft member leads to said take-up shaft.
7. A reduction device according to claim 1 for reducing the speed of rotation of a belt take-up shaf t of a seat belt retractort comprising; a cylindrical stationary drum having an inner circumf erence and f itted coaxially with the axis of a shaf t member made rotatable with said belt take-up shaft; at least one sliding member arranged to slide along the inner circumference of said stationary drum; and at least one elastic member connecting said sliding member and said shaft member for spacing said sliding member from the inner circumference of said stationary drum when a centrifugal force applied to said sliding member is lower than a predetermined level, and to allow said sliding member into abutment against the inner circumference of said stationary drum when said centrifugal force exceeds said predetermined level.
8. A redi:ic±------n dlevice according to claim 7, wherein sa-ir-3 stationary drum is attached to one side plate of a f rame of said seat belt retractor.
9. A reduction device according to cla. m 7, further comprising a disc fixed on said shaft member and having at least one guide hole extending radially thereof and carrying said sliding member at its leading end and said elastic member therein.
10. A reduction device according to claim 9, wherein there are a plurality of said guide holes.
11. A reduction device according to claim 7, wherein said shaft member forms one end of said take-up shaft.
12. A reduction device according to claim 7,, wherein said shaft member leads to said take-up shaft.
13. A reduction device according to claim 7 wherein said inner circumference of said drum is flat in the axial direction.
14. A reduction device substantially as hereinbef ore described with reference to the accompanying description and Figures 1 and 2; or Figure 3 of the tl
GB9306261A 1992-03-30 1993-03-26 Device for reducing the rotational speed of a seat belt take-up shaft Withdrawn GB2265541A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4074098A JPH05270357A (en) 1992-03-30 1992-03-30 Winding shaft rotation decelerating device for seat belt retractor

Publications (2)

Publication Number Publication Date
GB9306261D0 GB9306261D0 (en) 1993-05-19
GB2265541A true GB2265541A (en) 1993-10-06

Family

ID=13537375

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9306261A Withdrawn GB2265541A (en) 1992-03-30 1993-03-26 Device for reducing the rotational speed of a seat belt take-up shaft

Country Status (4)

Country Link
JP (1) JPH05270357A (en)
KR (1) KR930019482A (en)
DE (1) DE4310174A1 (en)
GB (1) GB2265541A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5794878A (en) * 1997-05-20 1998-08-18 Am-Safe, Inc. Device for prevention of slap-back lock of inertia reel
EP2682313A1 (en) * 2012-07-06 2014-01-08 Volvo Car Corporation Belt reel for a vehicle safety restraint arrangement and method for limiting the retraction speed of a belt during retraction onto a belt reel
GB2523093A (en) * 2014-02-13 2015-08-19 Daimler Ag Load limiting device for a seat belt of a vehicle
GB2525154A (en) * 2014-02-12 2015-10-21 Daimler Ag Load Limiting device for a seat belt of a vehicle

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10232308C1 (en) * 2002-07-17 2003-12-24 Autoliv Dev Seat belt retractor with a rotary damper having a windowed piston
DE10251057B4 (en) * 2002-11-02 2006-06-22 Julius Cronenberg Offene Handelsgesellschaft Retractor for straps or the like
DE102005036199A1 (en) * 2005-08-02 2007-02-08 Trw Automotive Gmbh Seat belt retractor for vehicle, has rotatably supported belt reel, rotor unit arranged inside workspace, and rotation damper arranged inside belt reel, where workspace is fillable with damping medium
JP6433685B2 (en) * 2014-05-30 2018-12-05 株式会社東海理化電機製作所 Webbing take-up device
CN104047976B (en) * 2014-06-04 2017-02-22 郑州磨料磨具磨削研究所有限公司 Revolution machine as well as deceleration method and deceleration device thereof
CN105927681B (en) * 2016-06-29 2018-01-02 湘潭电机股份有限公司 A kind of fluid vortex brake
CN111306241B (en) * 2020-02-05 2021-06-25 武汉理工大学 Self-adaptive friction energy dissipation and vibration reduction device for bridge structure
WO2023220953A1 (en) * 2022-05-18 2023-11-23 浙江吉利控股集团有限公司 Retractor, seat belt device, and apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB611271A (en) * 1946-04-26 1948-10-27 Vitoux Ets Centrifugal governor principally for machines for repairing stockings or like hosiery articles
GB685591A (en) * 1950-01-30 1953-01-07 Robert Strahm Improvements in and relating to brakes using a liquid energy absorbing medium
GB1003162A (en) * 1962-07-06 1965-09-02 Minden Vaughan Blake Improvements in or relating to apparatus for resisting a sudden pull
GB1354804A (en) * 1971-12-03 1974-06-05 Ford Motor Co Reel for a seat belt assembly
GB1440232A (en) * 1972-06-24 1976-06-23 Kangol Teka Sicherheitsgurt Gm Safety belt winding drums

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB611271A (en) * 1946-04-26 1948-10-27 Vitoux Ets Centrifugal governor principally for machines for repairing stockings or like hosiery articles
GB685591A (en) * 1950-01-30 1953-01-07 Robert Strahm Improvements in and relating to brakes using a liquid energy absorbing medium
GB1003162A (en) * 1962-07-06 1965-09-02 Minden Vaughan Blake Improvements in or relating to apparatus for resisting a sudden pull
GB1354804A (en) * 1971-12-03 1974-06-05 Ford Motor Co Reel for a seat belt assembly
GB1440232A (en) * 1972-06-24 1976-06-23 Kangol Teka Sicherheitsgurt Gm Safety belt winding drums

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5794878A (en) * 1997-05-20 1998-08-18 Am-Safe, Inc. Device for prevention of slap-back lock of inertia reel
WO1998052798A1 (en) * 1997-05-20 1998-11-26 Am-Safe, Inc. Device for prevention of slap-back lock of inertia reel
EP2682313A1 (en) * 2012-07-06 2014-01-08 Volvo Car Corporation Belt reel for a vehicle safety restraint arrangement and method for limiting the retraction speed of a belt during retraction onto a belt reel
US9862351B2 (en) 2012-07-06 2018-01-09 Volvo Car Corporation Belt reel for a vehicle safety restraint arrangement and method for limiting the retraction speed of a belt during retraction onto a belt reel
GB2525154A (en) * 2014-02-12 2015-10-21 Daimler Ag Load Limiting device for a seat belt of a vehicle
GB2523093A (en) * 2014-02-13 2015-08-19 Daimler Ag Load limiting device for a seat belt of a vehicle

Also Published As

Publication number Publication date
JPH05270357A (en) 1993-10-19
GB9306261D0 (en) 1993-05-19
DE4310174A1 (en) 1993-10-07
KR930019482A (en) 1993-10-18

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