Chairs and seats – Body or occupant restraint or confinement – Safety belt or harness; e.g. – lap belt or shoulder harness
Reexamination Certificate
1998-11-30
2001-03-06
Barfield, Anthony D. (Department: 3624)
Chairs and seats
Body or occupant restraint or confinement
Safety belt or harness; e.g., lap belt or shoulder harness
C297S475000, C297S480000
Reexamination Certificate
active
06196633
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a retractor for a seatbelt and, in particular, to an improved retractor for a seat belt which is mounted in the interior portion of a seat back of a seat of a reclining type for use in a vehicle or the like.
Conventionally, a retractor of a seat belt device for holding an occupant of a vehicle in a seat of the vehicle in safety is well known. The retractor is a device which, when a seat belt is not in use, pulls in a webbing automatically and also, when the seat belt is in use, allows the webbing to vary freely in length.
Recently, for example, Japanese Patent Unexamined Publication No. Hei. 8-80807 and the like teaches a seat belt device comprising a retractor of the above-mentioned type in which the retractor is mounted in the interior portion of a seat back of a reclining type seat in a vehicle or the like. In addition, the seat belt device further comprises a vehicle body acceleration sensor which can be operated even when the seat back (a support of the back of the seat) is inclined at any different positions.
Referring in particular to the conventional seat belt device
70
, as shown in
FIG. 25
, one end of a webbing
90
is held by a seat-built-in type retractor
80
disposed in the upper portion of a seat back
73
of a seat
71
of a reclining type in such a manner that it can be taken up and drawn out, whereas the other end of the webbing
90
is supported by an anchor plate
74
fixed to a vehicle body or to a seat base portion.
In addition, a through tongue
75
disposed in the middle portion of the webbing between the retractor
80
and anchor plate
74
is engaged with a buckle
76
erected almost in the central portion of the vehicle body, thereby being able to hold an occupant in the seat
71
of a reclining type.
The seat back
73
of the seat
71
, which is supported by a reclining device
78
so as to be inclinable back and forth with respect to the back-and-forth slidable seat sitting portion
72
, s adjusted to inclined positions which vary in angles according to the physiques of occupants. On the other hand, in the structure of the vehicle body acceleration sensor of the retractor
80
, for example, such acceleration sensor is supported so as to be pivotable about a rotation axis extending in parallel to the adjusting axis D of the seat back
73
. Accordingly, the vehicle body acceleration sensor can be operated even when the seat back
73
is adjusted in the angle and is thus held at different inclined positions.
However, there are still left some problems which should be solved in the above-mentioned conventional seat belt device
70
. In the seat belt device
70
, one end portion of the webbing
90
is disposed on the swing end side
73
a
of the seat back
73
of the reclining type, but the other end portion
73
b
is supported by the anchor plate
74
fixed to the vehicle body or seat base portion. Due to this structure, if the seat back
73
is inclined back and forth, the webbing
90
can be taken up or drawn out with respect to the retractor
80
.
In the seat-built-in type retractor
80
which incorporates therein at least the vehicle body acceleration sensor, if the seat back is inclined further beyond the allowable angle of the vehicle body acceleration sensor, there is possibly actuated an emergency lock mechanism which prevents the webbing
90
from being drawn out.
Thus, in the above seat belt device
70
, as shown by imaginary lines
FIG. 25
, when the seat back
73
is inclined forwardly, the webbing
90
, the other end portion of which is fixed to the vehicle body or seat sitting portion, is wound into the retractor
80
. Moreover, if the seat back
73
is inclined forwardly further beyond the allowable angle of the vehicle body acceleration sensor, then the emergency lock mechanism is actuated to thereby prevent the webbing
90
from being drawn out.
And, even if the occupant tries to raise the seat back
73
again, because the emergency lock mechanism is in operation at the position where most of the webbing
90
is wound into the retractor
80
, it becomes impossible to draw out the webbing
90
from the retractor
80
. That is, there is a possibility that the webbing
90
is subjected to the tension and then the seat back
73
can not be raised.
In addition to this, when the seat
71
is slid forward from the state shown in
FIG. 25
, the anchor plate
74
, as shown by imaginary lines in
FIG. 25
, is moved to a position behind the seat sitting portion
72
. In this case, there is a possibility that, if the seat back
73
is inclined backwardly, then the emergency lock mechanism is actuated, so that, similarly to the above case, the seat back
73
cannot be raised.
SUMMARY OF THE INVENTION
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional seat belt device.
Accordingly, it is an object of the invention to provide a retractor for a seat belt which is mounted in the interior portion of a seat back of a reclining type seat and also which allows the seat back to be raised, even if the seat back is inclined beyond the allowable angle of a vehicle body acceleration sensor under a state that the seat belt is stored in the retractor.
In attaining the above object, according to the invention, there is provided a retractor for a seat belt for use in a seat back of a reclining seat, the retractor comprising:
a retractor base;
a winding shaft rotatably supported on the retractor base for winding a webbing thereon;
a lock element interposed between the winding shaft and the retractor base for locking the rotation of the winding shaft in a webbing drawn-out direction thereof;
a vehicle body acceleration sensor for detecting a predetermined vehicle body acceleration to thereby actuate the lock element; and
a restrict mechanism for preventing the lock element from actuating in accordance with an inclined angle of the seat back when a predetermined length of the seat belt is wound on the winding shaft while the seat belt is not use.
Further above-mentioned object can be attained by a retractor for a seat belt for use in a seat back of a reclining seat, the retractor comprising:
a retractor base;
a winding shaft rotatably supported on the retractor base for winding a webbing thereon;
a lock element interposed between the winding shaft and the retractor base for locking the rotation of the winding shaft in a webbing drawn-out direction thereof;
a vehicle body acceleration sensor movably disposed on the retractor base for detecting a given vehicle body acceleration to thereby actuate the lock element, the vehicle body acceleration sensor including a sensor case and an inertia body, the inertia body being capable of taking a first position when the acceleration sensor is set in a predetermined state and a second position when the acceleration sensor is shifted from the predetermined state;
transmission mechanism interposed between the seat back and the vehicle body acceleration sensor for linking the movement of the sensor case with the movement of the seat back in accordance with the inclination angle of the seat back in order to be able to set the vehicle body acceleration sensor at the predetermined state regardless of the inclined state of the seat back; and
a restrict mechanism for preventing the lock element from actuating in accordance with an inclination angle of the seat back when a predetermined length of the seat belt is wound on the winding shaft while the seat belt is not use.
In the above-mentioned retractor for a seat belt, preferably, the predetermined length of the webbing wound on the winding shaft is in the range from a first length given when the seat back is inclined at the most forwardly inclined position while the seat belt is not use and a second length given when the seat back is inclined at the most backwardly inclined position thereof while the seat belt is not use.
In the above-mentioned retractor for a seat belt, preferably, the predetermined length of the webbing wound on the winding shaft is in the range from the shor
Fukunaga Masanao
Yamamoto Kazuo
Barfield Anthony D.
Evenson, McKeown, Edwards & Lenahan P.L.L.C.
NSK Ltd.
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