Motor vehicles – With belt or harness for restraining occupant – and means... – System comprises transmission or element thereof
Reexamination Certificate
2002-08-22
2004-03-09
Dickson, Paul N. (Department: 3616)
Motor vehicles
With belt or harness for restraining occupant, and means...
System comprises transmission or element thereof
C280S806000, C280S807000
Reexamination Certificate
active
06702056
ABSTRACT:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a seatbelt retractor that is equipped in a vehicle such as an automobile for controlling extraction and retraction of a seatbelt and for restraining and protecting an occupant. More specifically, the present invention relates to a seatbelt retractor in which an occupant is more securely restrained and protected by retracting a seatbelt with a motor based on a situation outside a vehicle and operational conditions of the seatbelt so as to control belt tension, while when the seatbelt is not in use, the seatbelt is mechanically retracted with a spring.
Conventionally, in a seatbelt apparatus equipped in a vehicle such as an automobile, upon an emergency such as a vehicle collision in which large deceleration is applied to the vehicle, a seatbelt restrains an occupant to keep from jumping out of a seat and protects the occupant.
Such a seatbelt apparatus is provided with a seatbelt retractor for retracting the seatbelt. The seatbelt retractor comprises a spring such as a power spring for constantly urging a spool for winding the seatbelt in a winding direction. By virtue of the urging force of the spring, the seatbelt is wound about the spool when the seatbelt is not worn. When wearing the seatbelt, the seatbelt is extracted against the spring urging force for the occupant to wear. Upon the emergency as mentioned above, the seatbelt retractor blocks the extraction of the seatbelt by blocking the rotation of the spool in an extraction or withdrawing direction because of an operation of locking means. The occupant is thereby restrained and protected securely with the seatbelt upon the emergency.
In such a conventional seatbelt apparatus, while wearing the seatbelt, a substantially constant belt tension due to the spring urging force is applied to the seatbelt. Therefore, the seatbelt retractor is set to operate in substantially the same manner regardless of situations between the vehicle and surrounding objects. Although the conventional seatbelt apparatus can securely restrain and protect the occupant upon an emergency, as described above, it is difficult for the apparatus to control the occupant comfortably during a normal state other than the emergency. Moreover, upon the emergency, it is preferable to protect the occupant more securely by firmly restraining the occupant.
From the above point of view, the inventor has filed a patent application on a seatbelt retractor. The seatbelt retractor can restrain and protect an occupant more efficiently and more comfortably by controlling a rotation of a spool so as to adjust a belt tension with a motor depending on situations between the vehicle and surrounding objects. Moreover, the seatbelt retractor can simply and securely adjust the belt tension with a simple structure for adjusting the belt tension (U.S. patent application Ser. No. 09/631,728 corresponding to Japanese Patent Publication No. 2000-238735).
The seatbelt retractor according to the invention in the patent publication can be easily understood in detail with reference to a specification and drawings of the publication. Here, parts relating to the present invention will be described.
FIGS. 1
to
3
is drawings showing the seatbelt retractor according to the invention in the patent publication.
As shown in
FIGS. 1 and 2
, a seatbelt retractor
1
according to the patent publication comprises at least a power-transmission gear mechanism
11
for transmitting power of a motor
10
; a reducer mechanism
12
comprising a planetary gear mechanism for reducing the rotation of the motor
10
transmitted from the power-transmission gear mechanism
11
to a spool
4
; a power-transmission route switching mechanism
13
for selectively switching between states that the power of the motor
10
is transmitted to the spool
4
and the rotation of the spool
4
is not transmitted to the motor
10
; and spring means
14
for urging the spool
4
in a winding direction, i.e. a counter-clockwise (CCW) direction, of a seatbelt
3
. An operation of this seatbelt retractor
1
will be described next.
(1) Non-Operational State of Seatbelt Retractor
1
(Total Amount Seatbelt Stored State)
In the non-operational state of the seatbelt retractor
1
, the total amount of seatbelt webbing
3
is wound around the spool
4
by the spring means
14
, while the motor
10
is not in operation. In the non-operational state, as shown in
FIG. 2
, a motor gear
36
, connecting gears
37
, and a switching gear
46
, which are attached to a rotational shaft
10
a
of the motor
10
, are not rotated, so that the switching gear
46
is set at a limited position (a right limited position shown in
FIG. 1
) perpendicular to the plane of
FIG. 2
on the other side across the drawing. A plunger
47
protrudes at most from a cylinder housing
51
so that a front inclined surface (not shown) of an abutting part
47
c
abuts against a front inclined surface
46
b
of the switching gear
46
. In this state, a retainer lever
49
is set at a position that a retainer claw
49
c
does not engage a ratchet gear
44
b
of an internal gear
44
so as to set a power-transmission route off. Therefore, the internal gear
44
is rotatable in any one of the belt extracting or withdrawing directions, i.e. the clockwise (CW) direction, and the belt winding direction, i.e. the CCW direction.
(2) Seatbelt Extracting Operation
When the seatbelt webbing
3
is extracted from the seatbelt extractor
1
in the non-operational state mentioned above, the spool
4
rotates in the belt extracting CW direction. Then, the second torque-transmission part
26
d
of a torsion bar
26
and the second carrier
56
shown in
FIG. 1
simultaneously rotate in the belt extracting CW direction. Since the first carrier
38
is thereby rotated in the same CW direction, planetary gears
39
and
40
move around a sun gear
43
in the same CW direction. Therefore, respective large planetary gears
39
a
and
40
a
of the planetary gears
39
and
40
rotate in the belt extracting CW direction so as to rotate the sun gear
43
in the belt winding CCW direction. On the other hand, respective small planetary gears
39
b
and
40
b
rotate in the belt winding CCW direction so as to rotate the internal gear
44
in the belt winding CCW direction. At this time, a reducer gear
45
is constantly meshed with the sun gear
43
; a small-diameter connecting gear
37
b
of the connecting gears
37
is constantly meshed with an outer tooth
45
b
of the reducer gear
45
; and the motor gear
36
and the switching gear
46
are constantly meshed with a large-diameter connecting gear
37
a
integrated with the small-diameter connecting gear
37
b
, so that the sun gear
43
does not rotate because a predetermined rotational resistance is applied to the sun gear
43
, whereas the internal gear
44
is freely rotatable as mentioned above. At this time, the small planetary gears
39
b
and
40
b
also rotate in the belt extracting CW direction together with the respective large planetary gears
39
a
and
40
a
, while the internal gear
44
rotates in the same CW direction.
Since the sun gear
43
does not rotate, the rotation of the spool
4
during the extraction of the seatbelt webbing
3
in the belt extracting CW direction is not transmitted to the switching gear
46
, so that the power-transmission route switching mechanism
13
does not operate and the power-transmission route between the spool
4
and the motor
10
is kept off. Thus, the rotation of the spool
4
is not transmitted to the motor
10
, which is not affected by the rotation of the spool
4
.
In addition, when extracting or withdrawing the belt, the second torque-transmission part
26
d
is rotated by the rotation of the spool
4
, so that a return spring
54
of the spring means
14
is wound up through a first shaft
26
f
and a bushing
53
fitted to spline grooves
26
e
of the first shaft
26
f
so as to gradually increase the spring force corresponding to the amount of the belt extraction.
(3) Seatbelt Windin
Matsui Tomoji
Tanaka Koji
Tanji Hiromasa
Dickson Paul N.
Kanesaka & Takeuchi
Takata Corporation
To Toan C
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