GB2242347A

GB2242347A - Cover for seat belt reel mechanism

Info

Publication number: GB2242347A
Application number: GB9104967A
Authority: GB
Inventors: Yoshiichi Fujimura; Shizutaka Matsuura
Original assignee: Takata Corp
Current assignee: Takata Corp
Priority date: 1990-03-29
Filing date: 1991-03-08
Publication date: 1991-10-02
Also published as: KR910016552A; DE4108497A1; FR2660265A1; FR2660265B1; JPH03279058A; CA2037871A1; GB9104967D0

Abstract

A seatbelt retractor comprises a frame having a pair of opposite side plates, a reel shaft extending between the side plates, an operating mechanism connected to the reel shaft and attached to the outer surface of the side plate, and a cap-like cover 52 surrounding the operating mechanism. A flexible member 62 is received in and extends along an open end of the cap-like cover and is in close contact with the outer surface of the side plate. The flexible member helps to reduce the transmission of noise from the operating mechanism. <IMAGE>

Description

SEATBELT RETRACTOR

FIELD OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a seatbelt retractor adapted to protect vehicle occupants in case of emergency and in particular, to an improved. retractor mounted to a vehicle in an attempt to reduce transmission of noise due to vibration or the like.

A motor vehicle conventionally includes a seatbelt system mounted to a passenger's seat to protect a vehicle occupant in case of collision or other accidents. In such.a seatbelt system, each seatbelt is taken up by a lockable retractor which is, in turn, attached to a rigid member of the vehicle. Normally, the seatbelt is freely extracted from the retractor so as not to inhibit movement of the occupant.

When vehicle collision or other accidents occur, the resultant impact or sudden acceleration is sensed. A reel shaft locking means is then operable to lock a reel shaft around which the seatbelt is wound. Grip means may sometimes be used to sandwich the seatbelt per se. In either way, the seatbelt serves to restrain the occupant in order for him not to suddenly move away from the seat and to protect the vehicle occupant.

One example of a conventional seatbelt retractor will be described with reference to Fig. 4. 1 With reference to Fig. 4, a frame 10 is substantially C-shaped as viewed in plan. The frame 10 includes a pair of opposite side plates 12 and 14, and a conndcting portion 16 extending between the side plates 12 and 14. A reel shaft 18 extends between the side plates 12 and 14. A seatbelt 20 is wound around the reel shaft 18.

A coil spring (not shown) is disposed on the outer surface of the side plate 12 so as to urge the reel shaft 18 in such a direction as to take up the seatbelt 20. A cover 22 surrounds the coil spring.

A lock mechanism 24 is attached to the outer surface of the side plate 14 so as to lock the reel shaft 18. The coil spring and the lock mechanism 24 together form an operating mechanism. The lock mechanism 24 includes, among others, a ratchet wheel 26 secured to the reel shaft 18, a lock ring 28 fit around the reel shaft 18, a flywheel 30, a lever 32 adapted to effect forced locking of the ratchet wheel 26, and an operating unit 36 including an operating lever 34 engageable with the flywheel 30.

The operating unit 36 generally includes a casing 38 secured to the side plate 14, an operating element 40 loosely fit within the casing 38, the operating lever 34 having a projection 34a in contact with the upper surface of the operating element 40 and a support 42 configured to pivotably support the operating lever 34. 2 i i The lock ring 28 includes an integral arm 44 which in turn has an elongated hole 46. the lever 32 has a lower end pivotably mounted to the side plate 14 by a pivot-pin 48 and an angularly movable upper end. The lever 32 has a pin 50 in engagement with the elongated hole 46.

Although not shown, a frictional engagement member is mounted within the flywheel 30. A hook, a hook retainer or other components are assembled into the lock ring 28.

A cover 52 is substantially in the form of a cap and surrounds the lock mechanism 24 and has an open end 52a in contact with the outer surface of the side plate 14. The cover 52 has a hook portion 52b fit in a circular opening 54 so that the cover 52 is detachably mounted to the outer surface of the side plate 14.

With the seatbelt retractor thus constructed, when the operating lever 34 is disengaged from the flywheel 30, the reel shaft 18 is freely rotated so that the vehicle occupant can pull out the seatbelt 20. When the occupant releases the seatbelt 20, then the reel shaft 18 is urged by a spring in the cover 22 so as to take up the seatbelt 20.

When large acceleration is applied to the vehicle due, for example, to collision, the operating unit 36 is operable to inhibit extraction of the seatbelt 20. Specifically, when large acceleration is applied to the operating unit 36, the operating element 40 is inclined to cause the projection 34a 3 to push up the operating lever 34. -The front end of the operating lever then comes into engagement with one of pawls which are, in turn, formed on the outer periphery of the flywheel 30. This results in stoppage of the flywheel 30. The lock ring 28 is, ther, rotated in a counterclockwise direction in Fig. 4 by a mechanism not shown. This causes the arm 44 to shift the upper end of the lever 32 to the right in Fig. 4. Then, the front end of the lever 32 is brought into enaaaement with the ratchet wheel 26 so as to positively lock the reel shaft 18.

In such a seatbelt retractor, small noise occurs in the lock unit 36, the flywheel 30, the lock ring 28 and the related parts due to mechanical vibrations even under a normal circumstance. Also, the coil spring makes noise upon extraction and retraction of the seatbelt. The cover serves to reduce transmission of such noise to the outside to some extent. However, a substantial amount of noise is transmitted to the outside. This may bother the vehicle occupant. And besides, the occupant may erroneously consider it to be due to mechanical failure.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a seatbelt retractor which can reduce transmission of noise from locking or other operating mechanisms to the outside of the 4 i unit so as to improve occupant's comfort in a vehicle.

It is another object of the present invention to provide a seatbelt'retractor which prevents a vehicle occupant from misunderstanding that noise is due to mechanical failure which may be generated within the retractor.

In accordance with the present invention, a seatbelt retractor comprises flexible members fit in the covers 22 and 52 to seal between the covers 22 and 52 and the side plates 12 and 14.

With the seatbelt retractor of the present invention, noise is less transmitted from the operating mechanism to the outside of the covers. This results in a substantial decreas in noise that a vehicle occupant may hear.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a cover for use in a seatbelt retractor according to one embodiment of the present invention; Fig. 2 is a sectional view taken along the line II-II of Fig. 1; Fig. 3 is a sectional view showing the principal part of another embodiment; and Fig. 4 is a perspective view of a conventional seatbelt retractor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described by way of example with reference to the drawings.

Fig. 1 is a perspective view of a cover for use in one embodiment of the present invention. Fig. 2 is a sectional view taken along the line II-II of Fig. 1. Reference will be made only to the cover since the remainder of the seatbelt retractor is identical in structure to the prior art seatbelt retractor.

In the illustrated embodiment, the cover 52 has an open end 52a. A groove 60 is formed in and extends along the open end 52a of the cover 52. A flexible member (e.g. rubber or synthetic resin) 62 is received in the groove 60 so as to partly project from the open end 52a. This causes the flexible member 62 to closely contact the side plate 14 so as to substantially reduce transmission of noise from the lock mechanism 24 to the outside of the cover 52.

The flexible member 62 may have an adhesive property so as to closely contact the frame 10 and the cover 52. This provides an improvement in sound insulation. Also, such a flexible member makes it difficult to remove the cover 52 from the side plate 14. This prevents inadvertent disassemblage or repair of the lock mechanism 24 and consequently, machanical failure due to incomplete repair or the like.

In this embodiment, the cover 52 has projections 64 6 t 1 in which openings 66 are formed. Bolts extend through the openings 66 and corresponding openings of the side plate 14 so as to secure the cover 52 to the side.plate 14. The flexible member 62 is then pressed by and between the cover 52 and the side plate 14 so as to provide an excellent seal. This results in a substantiai decrease in noise transmitted from the cover 52.

In the foregoing embodiment, the flexible member 62 is fit in the groove 60. As shown in Fig. 3, synthetic resin may be used to integrally form the cover and the flexible member 62 by means of two-color molding. It is preferable that the flexible member 62 partly projects from the open end 52a of the cover 52 as in the embodiment shown in Fig. 2 to provide a seal between the cover 52 and the side plate 14.

In the illustrated embodiments, the lock mechanism is attached to the outer surface of the side plate 14 to lock the reel shaft 18 so as to prevent extraction of the seatbelt 20 in case of emergency. However, the present invention is not limited thereto. A mechanism may be mounted within the frame 10 to sandwich the seatbelt 20 so as to prevent extraction of the seatbelt 20 in case of emergency. In this case, an additional mechanism, covered by the cover 52, is provided to operate such mechanim.

Illustratively, no particular means is included in the cover 22 to effect sound insulation. As shown in Figs. 7 2 and 3, flexible members may be attached to the end surface of the cover 22 to prevent transmission of noise from the cover 22 to the outside of the cover. - 8

Claims

What is claimed is:

1. A seatbelt retractor comprising:

frame having a pair of opposite side plates; reel shaft extending between said side plates; mechanism connected to said reel shaft and attached to the outer surface of said side plate, said mechanism being operable to lock said reel shaft; a cap-like cover surrounding said mechanism; and a flexible member received in and extending along an open end of said caplike cover, said flexible member being in close contact with the outer surface of said side plate so as to inhibit transmission of noise from said mechanism to the outside of the cover.

2. A seatbelt retractor according to claim 1, wherein said cover includes a groove in its open end, and said flexible member is received in said groove and partly project from the open end of said cover.

3. A seatbelt retractor according to claim 1, wherein said cover and said flexible member are made of synthetic resin and integrally formed together by means of two-color molding.

4. A seatbelt retractor according to claim 2, wherein 9 i said flexible member has an adhesive property so that said flexible member may be adhered to said frame and said cover.

5. A seatbelt retractor according to claim 3, wherein said flexible member has an adhesive property so that said flexible member may be adhered to said frame.

1 i i 1 1 0 Published J991 at The Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 I RH, Further copies may. be obtained from Sales Branch. Unit

6. Nine Mile Point. Cumifelinfach. Cross Keys. Newport. NPI 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.