CA1050506A

CA1050506A - Seat belt assembly for a vehicle

Info

Publication number: CA1050506A
Application number: CA249,637A
Authority: CA
Inventors: Yutaka Kondo; Akira Yamanaka
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 1975-11-11
Filing date: 1976-04-06
Publication date: 1979-03-13
Also published as: AU1285776A; JPS5259423A; DE2618494A1; JPS5533350B2; AU499422B2; GB1512883A

Abstract

Abstract of the Disclosure A seat belt assembly wherein a shoulder belt and a lap belt which are continuously formed are taken upon a single take-up shaft of a retractor one over the other, so that the seat belt manipulation can be simply carried out and that the degree of freedom of a space for mounting the retractor can be enhanced.

Description

5~6 This invention relates to a seat belt retractor by which both a shoulder belt and a lap belt can be taken up simultaneously.
Objects of this invention are to make it possible to take up and draw out both a shoulder belt and a lap belt using a single retractor or a single belt take-up shaft, to perform the belt manipulation very easily, to draw out the shoulder belt and the lap belt freely in the optimum directions.
According to the invention there is provided a seat belt assembly including a continuous seat belt loop and a seat belt retractor adapted to be one of the anchor points of the assembly to the vehicle, said retractor comprising a housing, a rotary shaft mounted in said housing to receive a belt loop, spring means urging said shaft in a belt take-up direction, a take-up cylinder around said rotary shaft and connected thereto for rotation therewith, said take-up cylinder having an opening in the wall thereof for passage of the belt such that the belt loop enters the housing in lapped manner, ratchet wheel means connected with said shaft and said cylinder for rotation therewith and inertia-activated pawl means associated with said ratchet wheel means to prevent rotation of the latter in the event of a collision.
These and other objects and advantages of the invention may be :, :
ZO readily ascertained by referring to the following description and appended drawings.
Flgures 1 and 2 are front views of prior-art seat belt assemblies of the type which employs a single retractor, , ~ , .Figure 3 i5 a front vlew of a prior-art seat belt assembly of the type which employs two retractors, i~ Figure 4~ lS a front view of an assembly using a retractor of this invention, ~ ~ ... ....
Figure 5 is an enlarged vertical sectional front view of a first embodiment of this invention~
As shown in Figure;l or Figure 2, a prior-art seat belt assembly ;~
is so constructed that the belt take-up end of either one of a shoulder belt ;

8 and a lap belt 9 which are continuous to each other is wound on a retractor .
.1 ~ '.

)6 12a. In another prior-art seat belt assembly shown in Figure 3, a shoulder belt 8 and a lap belt 9 are respectively wound on individual retractors 12a and 12b.
With the former type, when the belt assembly is to be attached or when the occupant is to move during attachment both the belts 8 and 9 can be taken up or drawn out from one end only. Therefore, the belt length has to be adjusted by sliding the belt through a slot in tongue 11. This leads to the disadvantage of a high resistance and a difficult manipulation.
On the other hand, the latter type in which the shoulder belt 8 and the lap belt 9 are wound on the individual retractors 12a and 12b requires the two retractors and is disadvantageous in that the number of components, the weight, the mounting space and the cost increase as compared with those of the one-retractor type.
In the embodiment of the invention shown in Figures ~ and 5, a ¦ buckle 6 is anchored to a floor 1 by fitting 4 and coupling piece 5. An --apertured bracket joint 7 is mounted on a roof side rail 2, and a retractor 12 is mounted on a rocker panel 3. ~ -A shoulder belt 8 and a lap belt 9 which are formed continuously in i the shape of a loop are drawn out from the retractor 12.
The shoulder belt 8 extends upwards and through the apertured bracket 7, to extend down to the buckle 6 in front of a seat 100. On the other hand, the lap belt 9 is directly drawn out from the retractor 12 to the buckle 6 in front of the seat 100. ;~
The shoulder belt 8 and the lap belt 9 are inserted through a slotted tongue 11 to form a folded portion 10a. The shoulder belt 8 and the lap belt 9 can have their lengths partially interchanged and relatively adjusted.
The tongue ll can be engaged with the buckle 6.
The shoulder belt 8 and the lap belt 9 form a noose-like folded portion or loop 10b in the retractor 12, around a rotary shaft 16.
The rotary shaft 16 is arranged inside a hollow take-up cylinder 15 -concentric therewith. In addition, the shaft 16 and cylinder 15 are coupled . , .

~ -2-~L~50~i so as to rotate as one.
In the illustrated embodiment, the take-up cylinder 15 and the rotary shaft 16 constitute a single member.
The retractor 12 comprises a retractor body 13, the rotary shaft 16 which is rotatably supported on the retractor body 13, a spiral spring ~not shown) which is mounted on one end of the rotary shaft 16, ratchet wheels 14 which are mounted on the ends of the rotary shaft 16, and pawls ~not shown) which are so disposed that they can mesh with the ratchet wheels 14. The pawls are coupled with a vehicle inertia sensitive type emergency engagement device ~not shown).
The rotary shaft 16 is normally urged in the direction of belt take-up by means of the spiral spring. When the car is involved in a collisionj the vehicle inertia sensitive type emergency engagement device rotates the pawls in the direction in which they mesh with the ratchet wheels 14. Through the mesh between the pawls and 1,he ratchet wheels 14, the rotary ~, shaft 16 is locked so as to beprevented from .rotating in the direction of paying out of the belts.
The take-up ~ylinder 15 and the rotary shaft 16 are coupled through the ratchet wheels 14. '~
, , 20 ~ith the seat belt assembl~ of th~ foregoing construction, both 1 , : -the belts 8 and 9 are drawn out simultaneously and by equal lengths by !
~' pulIing out either the shoulder belt 8 OT the lap belt 9. : ' Since the shoulder belt 8 and the lap belt 9 are dra~n out or ',~ taken up simultaneously and by e~ual lengths, as the belts are slid through .1 : ..
j the bracket 7 and the tongue lll the relative sliding lengths of the belts ~;
are very small. Therefore, the resistance to sliding of the belts relatiYe to each other at the tongue 11 is low.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A seat belt assembly including a continuous seat belt loop and a seat belt retractor adapted to be one of the anchor points of the assembly to the vehicle, said retractor comprising a housing, a rotary shaft mounted in said housing to receive a belt loop, spring means urging said shaft in a belt take-up direction, a take-up cylinder around said rotary shaft and connected thereto for rotation therewith, said take-up cylinder having an opening in the wall thereof for passage of the belt such that the belt loop enters the housing in lapped manner, ratchet wheel means connected with said shaft and said cylinder for rotation therewith and inertia-activated pawl means associated with said ratchet wheel means to prevent rotation of the latter in the event of a collision.