Note: Descriptions are shown in the official language in which they were submitted.
3~
AUTOMATIC SEATBELT SYSTEM FOR VEHICLE
BACKGRO~ND OF THE INVENTION
1. Field of the Invention
The present invention;relates to a seatbelt system for
a vehicle designed to restrain the body of an occupant when
an emergency situation of the vehicle occurs. More
particularly, the present invention pertains to an automatic
seatbelt system for a vehicle which enables a webbing to be
automatically fastened to the body of an occupant after
seating himself in a seat provided on the vehicle.
2. Description of the Related Art
There are various types of automatic seatbelt system
for a vehicle which are adapted to enable a webbing to be
automatically fastened to the body of an occupant. As one
type of such automatic seatbelt system, a structure has
already been proposed wherein a slider is provided in such a
manner as to be movable along a guide rail laid on the body
of a vehicle, and this slider is activated by drive means so
as to move a webbing which is retained at one end thereof by
the slider.
The guide rail employed in this system is arranged such
that an end portion thereof which is closer to the rear end
of the vehicle is terminated after being bent so as to
extend downward in the substantially vertical direction
along a center pillar, thereby allowing the guide rail to
~3(~330
r
reliably carry the tension qenerated in the webbing by the
inertia which acts on the occupant's body when an emergency
situation of the vehicle occurs. The guide rail arran~ed as
described above needs retainer means for retaining the
slider in such a manner that the slider is inhibited from
moving toward the ceiling of the vehicle along the
vertically extended portion of the guide rail when the
vehicle overturns.
Seatbelt systems having such retainer means have
already been devised wherein a sensor such as a pendulum for
detecting overturn of the vehicle is provided, and the
movement of the slidex is inhibited when this sensor is
activated ~e.g., Japanese Patent Publication
No. 15716/1985). This type of retainer means suffers,
however, from the problem that, since a sensor such as a
pendulum projects from the guide rail, it is necessary to
form a bore in the center pillar for receiving such
projecting sensor structure or provide a raised portion on
the center pillar which protrudes into the compartment of
the vehicle.
SUMMA~y-oF THE INVENTION
In view of the above-described circumstances, it is a
primary object of the present invention to provide an
automatic seatbelt system which i6 50 designed that the
retainer means, which is adapted to inhibit the movement of
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the slider when the vehicle overturns, has a simplified
arrangement and a reduced size.
To this end, the present invention provides an
automatic seatbelt sy.stem for a vehicle which comprises: a
guide rail laid on the body of the vehicle; a slider
retaining a webbing and adapted to be movable along the
guide rail between a position at which the webbing is
fastened to the body of an occupant (hereinafter referred to
as the ~webbing fastening positionn) and a position at which
the webbing is unfastened therefrom (hereinafter referred to
as the "webbing unfastening positionn); dcive means adapted
to move along the guide rail in such a manner as to ~pply
driving force to the slider, the drive means being movable
relative to the slider by a predetermined amount along the
guide rail; and retainer means adapted such that, in
response to the movement of the ~lider to the webb$ng
fastening position, the retainer means is brought into a
f~rst state wherein it can inhibit the movement of the
slider toward the webbing unfastening position, and in
response to the above-described relative movement which
occurs when the drive means moves toward the webbing
unfastening position from the webbing fastening position,
the retainer means is brought into a second state wherein it
allows the slider to move toward the webbing unfastening
position.
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By virtue of the above-described arrangement, when the
slider is at the webbing fastening position, it is inhibited
from moving along the guide rail. Thus, the retainer means
need not be provided~with any special sensor means such as
an acceleration sensor, so that the arrangement of the
retainer means is simplified, and the size of the means is
reduced.
BRI E~ nE8fBIpTI ON~5E~ LDBA~1~15
Fig. 1 is a fraqmentary side view of a vehicle to which
a first embodiment of the automatic seatbelt system
according to the present invention is applied, as viewed
from the inside of the vehicle;
Fig. 2 is a sectional view taken along the line II-II
in Fig. 1, which shows the slider having moved to the
central portion of the guide rail;
Fig. 3 is a partially fiectioned side view of an
essential part of the first embodiment, which particularly
shows the retainer means;
Fig. 4 is an exploded perspective view of an essential
part of the arrangement shown in Fig. 3;
Fig. 5 is a sectional view taken along the line V-V in
Fig. 3, which particularly shows the retainer means with the
housing removed;
Fig. 6 is a partially cutaway perspective view of the
housing of the retainer means;
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Fig. 7 is a sectional view taken along the line VII-VII
in Fig. 3;
Fig. 8 is a view employed to explain the operation of
the essential part of. the first embodiment shown in Fig. 3;
Fig. 9 is a partially sectioned side view of an
essential part of a second embodiment of the present
invention, which particularly shows retainer means employed
in the second embodiment;
Fig. 10 is a view employed to explain the operation of
the retainer means shown in Fig. 9;
Fig. 11 is a partially cutaway perspective view of the
retainer means of the second embodiment;
Fig. 12 is a partially sectioned side view of an
essential part of a third embodiment of the present
invention, which particularly shows retainer means employed
in the third embodiment;
Fig. 13 is a partially sectioned side view of an
essential part of a fourth embodiment of the present
invention, which particularly shows retainer means employed
in the fourth embodiment;
Fig. 14 is a partially sectional side view of an
essential part of a fifth embodiment, which corresponds to
Fig . 3 of the first embodiment;
Fig. 15 is a view employed to explain the operation of
the essential part of the fifth embodiment shown in Fig. 14,
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which corresponds to Fig. 8;
Fig. 16 is an exploded perspective view of the
essential part of the fifth embodiment; and
Fig. 17 is a cutaway perspective view of a housing of
the fifth embodimet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described hereinunder in
detail with reference to the accompanying drawing~.
Fig. l is a fragmentary side view of a vehicle to which
a first embodiment of the seatbelt system according to the
present invention is applied, as viewed from the inside of
the vehicle.
~3C4;~30
The arrangement is such that, when an occupant 12 is
seated in a seat 10 ~hich is on the right-hand side of the
vehicle with respect to the forward direction, his body is
automatically fastened with a webbing 14. The webbing 14 is
wound up from one end thereof into a retractor 18 by means
of a predetermined biasing force, the retractor 18 being
secured to a floor member 16 in the substantially central
portion of the vehicle. The retractor 18 incorporates an
inertia type lock mechanism adapted to instantaneously stop
the webbing 14 from being unwound when an emergency
situation of the vehicle occurs.
The other end of the webbing 14 is retained by a slider
22 through an anchor plate 20. The slider 22 is adapted to
be movable in the longitudinal direction of the vehicle
along a quide rail 24. The guide rail 24 includes a guide
rail main body 28. The central portion of the main body 28
is disposed horizontally along a roof side member 26 which
constitutes a part of the side wall of the vehicle body.
The forward end portion of the guide rail main body 28 i8
slanted along a front pillar 30 and secured thereto.
The end portion of the gulde rail main body 28 on the
side thereof which is closer to the rear end of the vehicle
is bent at substantially right angles so as to extend toward
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the lower side of the vehicle, and secured to a center
pillar 32.
As shown in Fig. 2, the guide rail main body 28 has a
groove 34 which opens toward the lower side of the vehicle,
thus having a substantially U-shaped cross-section as a
whole. The intermediate portion of the groove 34 in the
depthwise direction thereof is enlarged in width so as to
receive an enlarged-width portion 36 which is formed on the
intermediate enlarged portion of the slider 22. This
enlarged-width portion 36 enables the slider 22 to move
smoothly within the guide rall main body 28 in the
longitudinal direction thereof, that is, in the longitudinal
direction of the vehicle. In addition, the enlarged-width
portion 36 is adapted to carry the tension applied to the
webbing 14 by the occupant when the vehicle is in a normal
state 80 that the slider 22 does not come off the guide rail
main body 28.
The bottom portion of the groove 34 in the main body 28
is also enlarged in width to define a tape accommodating
groove 38 which slidably guides a flexible tape 40, serving as
drive means, in the longitudinal direction of the guide rail
24.
The flexible tape 40 is, as also shown in Fig. 4, made
from a continuous thick-walled synthet~c res~n m~terial. A
plurality of openings 42 are formed in the tape 40 in such a
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manner that they are arranged in a row at a predetermined
regular spacinq alonq the longitudinal axis of the tape 40.
These openings 42 are adapted to engage with a sprocket
wheel (not shown) accommodated within a housing 44 which is
disposed on the lower part of the center pillar 32 as shown
in Fig. 1, so that the rotational force from a motor 46 is
transmitted to the tape 40 through the engagement between
the sprocket wheel and the openings 42, thus causing the
tape 40 to move along the longitudinal axis thereof.
Since the enlarged-width portion 36 which mainly
carries the load applied from the slider 22 is disposed
below the tape accommodating groove 38 within the guide rail
24 as described above, even when a relatively large load ~s
applied from the slider 22, there is no fear of-the flexible
tape 40 and the tape accommodating groove 38 being deformed
to a substantial degree, and it is therefore possible to
prevent the tape 40 from falling into an operation failure.
As ~hown in Fig. 4, an elongated opening 50 which has a
longer longitudinal dimenslon than that of the openings 42
is formed in an end portion of the flex$ble tape 40 on the
slde thereof which is clo~er to the front end of the
vehicle. The elongated opening 50 receiveR a portion of the
slider 22 which is lntermedlate between the head portion 52
and the enlarged-width portion 36. In consequence, when the
flexible tape 40 moves in the longitudinal direction of the
13~4330
vehicle along the guide rail 24, the slider 22 is driven by
the tape 40 and can move in the longitudinal direction of
the vehicle along the guide rail 24 together with the tape
40. As shown in Fig~ 1, when the slider 22 is moved to the
forward end of the guide rail 24, the slider 22 brings the
webbing 14 to a position at which the webbing 14 is
unfastened from the occupant's body as shown by the
imaginary line (this position being hereinafter referred to
as a "webbing unfastening positionn), whereby a space for
the occupant 12 to enter and leave the vehicle can be
deined betwen the webbing 14 and the seat 10. When the
slider 22 is moved to the rear end of the guide ra~l 24 as
shown by the solid line in Fig. 1, the webbing 14 is brought
to a position at which it is fastened to the occupant's body
(this position being hereinafter referred to as a ~webbing
fastening position~), whereby the occupant 12 can
automatically be fastened with the webbing 14.
As shown in Fig. 4, the longitudinal dimension L of the
elongated opening 50 is made larger than the longitudinal
dimension R of the head portion 52, so that, when the head
portion 52 abuts against either the longitudinal edge 50A or
50B of the elongated opening 50 on the side thereof which is
closer to the front or rear end of the vehicle,
respectively, a space or play S is defined between the head
portion 52 and the other of the two longitudinal edges of
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the opening 50. Accordingly, the flexible tape 40 and the
slider 22 are movable relative to each other by an amount
corresponding to the length of the space S, so that, even
when the tape 40 is s.tarted to move, the slider 22 is not
moved until the space or play S has disappeared.
Referring to Figs~ 3 to 6, a retainer means 54 is
disposed on the vertically extended portion of the guide
rail 24 which is defines the rear end portion thereof. The
retainer.means 54 includes a hollow housing 56 which is
disposed adjacent to the lower end of the guide rall ma~n
body 28 and rigidly secured to the center pillar 32 through
a reinforcing bracket 58. This bracket 58 has a
substantially U-~haped cross-section so that it cover6 the
forward end surface and two lateral side surfaces of the
housing 56. The bracket 58 has mounting bores 60 provided
in the end portion of each of the side walls theeeof, and
mounting bolts are respectlvely received through the~e bore~
60 to rigidly secure the bracket 58 to the center pillar 32.
It should be noted that the housings 56 and 44 are
connected together by a guide tube 61 which tightly
accommodates the flexible tape 40.
As shown in Figs. 3 and 4, an anchor pin 62 is secured
at both end portions thereof to the bracket 58 in such
manner that the anchor pln 62 opposes the lntermedlate
enlarged portion of the slider 22 having the enl~rged-width
1 1
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portion 36 formed thereon when the slider 22 is stopped at
the webbing fastening position. Thus, when a relatively
large tension acts on the webbing 14 at the webbing
fastening position so. as to force the slider 22 to come out
of the groove 34 in the guide rail main body 28, the anchor
pin 62, which is located on the side of the intermediate
enlar~ed portion of the slider 22 which is closer to the
front end of the vehicle, engages with the enlarged-width
portion 36, thereby preventing the slider 22 from coming off
the guide rail main body 28.
A latch pawl 64 which is used as a locking apparatus
is disposed within the housing 56 in such a manner that the
pawl 64 opposes the enlarged-width portion 36 of the slider
22 when stopped at the webbing fastening position. This
pawl 64 is received in a support bore 66 with a triangular
cross-section which extends through the housing 56 in the
lateral direction of the vehicle, and adapted to be pivotal
in the direction of the arrow A about one vertex of the
triangular support bore 66.
More specifically, when the pawl 64 pivots maxlmumly
within the triangular support bore 66 counterclockwise as
viewed in Fig. 3, the distal end of the pawl 64 is
interposed in the locus of movement of a hook portion 68
provided at the distal end portion of the enlarged-width
portion 36, theceby making it possible to inhibit the slider
22 f rom moving toward the upper side of the vehicle. When
13~4~30
the pawl 64 moves maximumly clockwise as shown in ~ig. 8,
the distal end of the pawl 64 is withdrawn from the locus of
movement of the hook portion 68, thereby allowing the slider
22 to move upward. For this purpose, the pawl 64 is baised
by a torsion coil spring 70 so as to be brought into the
state shown in Fig. 3, that is, in the state wherein the
pawl 64 is interposed in the locus of movement of the hook
portion 68. Thus, the pawl 64 and the torsion coil spring
70 constitute in combination an engagement section for
engagement with the hook portion 68.
Support bores 72 are formed in the houslng 56 as shown
in Fig. 6, and support shafts 76 of a ratchet member 74
shown in Fig. 4 are respectively received in the support
bores 72. This ratchet member 74 is provided for the
purpose of controlling the pawl 64. Two lateral end
portions of ~he ratchet member 74 are bent at right angles
so as to extend parallel with each other, thereby defining a
pair of leg plate portions 78. The support shafts 76 are
coaxially formed on the leg plate portions 78, respectively,
so as to project in opposite directions. Accordingly, in
assembly, the ratchet member 74 is lnserted lnto the housing
56 while the leg plate portlons 78 are being elastically
deformed toward each other, whereby the support shafts 76
enter the corresponding support bores 72 by virtue of the
restoring force of the leg plate portions 78, and the
~3C}4~30
ratchet member 74 is thereby pivotally supported within the
housing 56.
The ratchet member 74 has a pawl portion 80 projecting
from the central portion thereof in such a manner that the
pawl portion 80 is able to enter the elongated opening 50 in
the flexible tape 40. When the pawl portion 80 of the
ratchet member 74 is within the elongated opening 50, the
pawl 64 is interposed in the locus of movement of the hook
portion 68 as shown in Fig. 3. However, when the pawl
portion 80 is out of the elongated opening 50 as shown in
Fig. 8, the ratchet member 74 causes the pawl 64 to move
against the biasing force from the torsion coil spring 70 so
as to be withdrawn from the locus of movement of the hook
portion 68.
The pawl portion 80 of the ratchet member 74 is
disposed in such a manner that it is able to enter the
elonqated opening 50 when the flexible tape 40 moves to the
position shown in Fig. 3 and the slider 22 consequently
reaches the webbing fastening position. Accordlngly, when
the tape 40 moves toward the webbing unfastening posltlon,
the pawl portion 80 is caused by the rear edge 50B of the
elongated opening 50 to pivot counterclockwise as viewed in
Fig. 3 about the support shafts 76, thus causing the pawl 64
to move the retraction position shown in Fig. 8 before the
tape 40, which is moving toward the webbing unfastening
14
13C~4;~30
position, makes the space or play S disappear and causes the
~lider 22 to be started to move.
Guide bores 82 are respectively provided in the leg
plate portions 78 of-the ratchet member 74. The guide
bores 82 respectively receive pins 86 projecting from both
sldes of a slide block 84 which is received in slide grooves
83 formed inside the housing 56 and which is movable only in
directions parallel to the direction of movement of the
flexible tape 40. More sp2cifically, the 61ide block 84 is
disposed between the pair of leg plate portions 78, and the
pins 86 which coaxially pro~ect in opposite directions are
respectively received in the guide bores 82 from the inside
of the leg plate portions 78.
The slide block 84 is arranged such that, when the
slider 22 reaches the webbing fastening posit~on, the sl~de
block 84 i5 pressed and moved by the hook portion 68 as
shown in Fig. 3, thus cau~ing the pins 86 to enter larger-
width portions 82A (see Fig. 4) of the gulde bores 82,
respectively. In this state, the pins 86 allow the ratchet
member 74 to pivot from the posltion shown in Fig. 3 to the
position shown in Fig. 8.
When the slider 22 is moved to the webbing unfastening
position, the slide block 84 i8, as shown in Fig. 8,
released from the contact with the hook portion 68 and
therefore pushed out toward the slider 22 by the action of a
13(~4;~30
projecting detector element 90 of a limit switch 88 which is
secured to the housing 56. This projecting detector element
90 is constantly biased so as to project from the limit
switch 88 by the force from a resilient member (not shown)
which is mounted inside the limit switch 88. Thus, when the
detector element 90 is in its projecting position, the fact
that the slider 22 is not at the webbing fastening position
can be detected, whereas, when the detector element 90 is
withdrawn into the limit switch 88 as shown ln Fig. 3, it is
possible to detect the fact that the slider 22 is at the
webbing fastening position.
Accordingly, when the slide block 84 is in the state
shown in Fig. 8, it is pushed out by the projecting detector
element 90, causing the pins 86 to enter smaller-width
portions 82B of the guide bores 82, respectively. In
consequence, the ratchet member 74 is pivoted about the
support shafts 76 and held in the state shown in Flg. 8.
More specifically, the ratchet member 74 allows the
pawl 64 to be held in a state wherein it is withdrawn from
the locus of movement of the hook portion 68 with a margin
and the pawl portion 80 to be held in a state wherein it is
withdrawn from the locus of movement of the flexible tape 40
with a margin. Therefore, in the state shown in Fig. 8,
when the flexible tape 40 moves along the longitud~nal axis
thereof, it is prevented from contacting the pawl portion
16
~3(~4~30
80, and when the slider 22 moves toward the webbing
unfastening position, it is prevented from contacting the
pawl 64. Thus, the ratchet member 74, the slide block 84
and the projecting detector element 90 con~titute in
combination a release section which allows the pawl 64 to be
separated from the hook portion 68.
In order to ensure the required movement of each of the
associated portions, the larger-width portion 82a of each of
the guide bores 82 in the ratchet member 74 has a dimens~on
which allows the pin 86 to move therein with a margin.
In addition, the slider 22 is arranged such that the
enlarsed-width portion 36 is stopped by abuttinq against the
inner ends 83A of the guide grooves 83 formed inside the
housing 56. A cu~hioning material such as rubber may be
interposed between the enlarged-width portion 36 and the end
portions 83A.
The followinq is a description of the operation of the
above-described embodiment.
After seating himself in the seat 10, the occupant 12
actuates a manually-operated switch. Alternatively, the
fact that the occupant 12 enters the vehicle and seats
himself in the seat 10 is detected by swltch means such as a
switch adapted to detect whether the door i8 open or closed
and a switch provided in the seat 10. In consequence, the
motor 46 is activated to move the flexible tape 40 toward
~3a4;~30
the rear end of the vehicle. This movement of the tape 40
causes the webbing 14 to n~ove from the webbing unfastening
position shown by the imaginary line in Fig. 1 to the
webbing fastening position shown by the solid line so as to
be automatically fastened to the body of the occupant 12.
The slider 22 is driven to move toward the rear end of
the vehicle while abutting against the forward edge SOA of
the elongated opening 50 formed in the tape 40 with a space
or play S defined between the head portion 52 and the rear
edge 50B of the opening S0.
Near the stroke end of the slider 22, it moves downward
from the position shown in Fig. 8. In consequence, the hook
portion 68 of the slider 22 forces the projecting detector
element 90 into the limit switch 88 through the sllde block
84 as shown in Fig. 3. Thus, the limit switch 88 detects
the fact that the slider 22 has reached the webbing
fastening position, and control means (not shown) suspends
the rotation of the motor 46.
The slide block 84 thus moved by the hook portion 68
causes the pins 86 to move to the larger-width portions 82A
from the smaller-width portions 82B, respectively, thus
allowing the ratchet member 74 to pivot. In consequence,
the pawl 64, which has been moved to and held at the
retraction position by the ratchet member 74, causes the
ratchet member 74 to pivot clockwise by virtue of the
~3~P4;~30
biasing force from the torsion coil spring 70, thereby
bringing the ratchet member 74 into the state shown in
Fig. 3. At the same time, the pawl 64 is interposed in the
locus of movement of the hook portion 68 and enters the
recess on the side of the hook portion 68 which is closer to
the upper side of the vehicle as shown in Flg. 3.
Accordingly, the slider 22 is inhibited from moving toward
the upper side of the vehicle. In addition, the ratchet
member 74 pivots clockwise as viewed in Fig. 3, and the pawl
portion 80 enters the space S defined in the elongated
opening 50.
When the vehicle is in a normal state, the webbing 14
can be unwound from the retractor 18; therefore, the occupant
12 can assume any desired driving posture.
When the vehicle runs into an emergency situat$on, the
retractor 18 stops the webbinq 14 from being unwound, so
that the body of the occupant 12 is restrained by the
webbing 14.
In an emergency situation of the vehicle, a relatively
large tension is generated in the webbing 14 by the inertia
which acts on the occupant's body, and transmitted to the
slider 22 through the anchor plate 20. However, since the
anchor pin 62 is diposed in opposing relation to the slider
22, the slider 22 is reliably supported by the vehicle body
through the bracket 58.
19
~3~4;~30
When the vehicle overturns, the hook portion 68 of the
slider 22 is also inhibited by the pawl 64 from moving
toward the upper side of the vehicle. There is therefore no
fear of the slider 22 moving toward the ceiling of the
vehicle.
In the case where the occupant 12 leaves the vehicle
upon the completion of a normal drive, when he opens the
door, the control means activates the motor 46 to rotate in
reverse.
Accordinqly, the flexible tape 40 is moved toward the
front end of the vehicle within the guide rail main body 28.
At this time, even when the tape 40 moves from the position
shown in Fig. 3, the slider 22 is not moved until the rear
edge 50B of the elongated opening 50 abuts against the
slider 22. Before the rear edge 50B abuts against the
slider 22, the relative movement between the tape 40 and the
slider 22 causes, through the opening 50, the ratchet member
74 to pivot counterclockwise as viewed in Fig. 3 about the
support shafts 76. This movement of the ratchet member 74
causes the pawl 68 to pivot from the position shown in
Fiq. 3 to the position shown in ~ig. 8 so as to be withdrawn
from the locus of movement of the hook portion 68.
Accordingly, the slider 22 is released and allowed to move
toward the front end of the vehicle together with the
flexible tape 40 when the rear edge 50B of the e~ongated
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opening 50 abuts against the slider 22 and thereby causes
the latter to be started to move.
When the slider 22 which is driven by the tape 40
reaches the front end of the vehicle as shown in Fig. 1, a
limit switch (not shown) is activated so as to suspend the
rotation of the motor 46, thereby allowing the webbing 14 to
be automatically unfastened from the body of the occupant
12.
During such movement of the flexible tape 40, the slide
block 84,~which has been released from the contact with the
slider 22, is pushed up by the projecting detector element
90 of the limit switch 88 as shown in Fig. 8. Consequently,
the pawl portion 80 of the ratchet member 74 is separated
from the tape 40, and there is therefore no fear of the pawl
portion 80 contacting the edges of the openings 42 to
generate noise when the tape 40 is moved.
In addition, the ratchet member 74 holds the pawl 64 ~n
a state wherein it is withdrawn from the locus of movement
of the hook portion 68 with a margin. There is therefore no
risk of the pawl 64 interfering with the hook portion 68
when the slider 22 is moved.
When the occupant 12 opens the door thereafter in order
to re-enter the vehicle, the same operation as that which
has already been described takes place. Namely, after the
occupant 12 has been seated, the slider 22 i6 moved toward
13~4~30
the rear end of the vehicle again, thereby allowing the
webbing 14 to be automatically fastened to the occupant'
body.
Referring next to Figs. 9 to 11, there is ~hown a
second embodiment of the present invention. In this
embodiment, the slide block 84 and the pawl 64 which are
employed in the above-described embodiment are omitted, and
a pin 92 is stretched between the leg plate portions 78 of
the ratchet member 74 so as to serve as a member similar to
the pawl 64 in the first embodiment. Both ends of the pin
92 project from the leg plate portions 78 and are
respectively received in Elots 93 formed ln the housing 56,
thereby limiting the angle of rotation of the ratchet member
74.
In addition, a spr~ng retainer pin 94 project~ from the
inner slde of each of the leg plate portions 78 of the
ratchet member 74, and a tenslon coil spring 98 i8 stretched
be~ween the pin 94 and a spring retainer pin 96 which
projects from each of the opposing inner sides of the
housing 56. Thi6 tension coil spring 98 i8 a turnover
spring which causes the ratchet member 74 to perform snap
action. More fipecifically, when the axis of the ten~ion
coil spring 98 is positioned closer to the flexible tape 40
than the prolongation of the axes of the support shaft6 76,
the spring 98 biasefi the ratchet member 74 80 as to pivot
~3~4;~30
clockwise as viewed in Fig. 9, whereas, when the axi~ of the
spring 98 is shifted passing the prolongation of the axes of
the support shafts 76 in a direction in which it is
separated from the tape 40, the spring 98 biases the ratchet
member 74 so as to pivot counterclockwise as viewed in
Fig. 9, thereby allowing the ratchet member 74 to pivot to
the position shown in Fig. 10.
In addition, when the pawl portion 80 of the ratchet
member 74 which is within the elongated opening 50 as shown
in Fig. 9 is caused to pivot counterclockwise as viewed in
Fig. 8 by the front edge 50A of the opening S0 when the
flexible tape 40 is moved, the ratchet member 74 causes the
axis of the tension coil spring 98 to pass its neutral point
defined by the prolongation of the axes of the support
shafts 76 and move to the other side, thereby allowing the
ratchet member 74 to move to the position shown in Fig. 10
by the action of the spring 98.
In the case where the ratchet member 74 is maximumly
pivoted counterclockwise by the biasing force from the
tension coil spring 98 as shown in Fig. 10, when the slider
22 is moved to the webbing fastening position, the enlarged-
width portion 36 of the slider 22 abuts againt the ratchet
member 74 and causes the latter to pivot clockwi6e as viewed
in Fig. 10. In consequence, the axis of the tension coil
spring 98 passes the prolongation of the axes of the support
13G~;~30
shafts 76, and this also forces the ratchet member 74 to
pivot clockwise, thus allowing the pawl portion 80 to enter
the elongated opening 50.
Accordingly, in this embodiment also, when the slider
22 is at the webbing fastening position as shown in Fig. 9,
the pawl portion 80 of the ratchet member 74 is within the
elongated opening 50, and the pin 92 is disposed on the side
of the the hook portion 68 which is closer to the upper side
of the vehicle, whereby it is possible to prevent the slider
22 from moving accidentally or undesirably. When the
flexible tape 40 is moved toward the webbing unfastening
position, the pawl portion 80 is pushed down by the rear
edge 50B of the elongated opening 50 to the position shown
in Fig. lO. Therefore, the pin 92 is withdrawn from the
locus of movement of the hook portion 68 before the space or
place S defined ~n the elongated opening 50 of the tape 40
disappears and the tape 40 consequently causes the slider 22
to be started to mobe, thereby allowing the slider 22 to
move. Since, in this sate, the pawl portion 80 ha~ already
been separated from the tape 40 at an adequate spacing,
there is no fear of the pawl portion 80 abutting againt the
edges of the openings 42 in the take 40.
It should be noted that the tension coil spring 98 in
this embodiment may be disposed in such a manner that it
constantly biases the ratchet member 74 so as to pivot
24
13(~4;~30
clockwi~e as viewed in Figs. 9 and 10. In such case, the
width A of the pawl portion 80 1R made larger than the width
B of the openings 42 in the tape 40 80 that there iB no fear
of the pawl portion 80 entering the openings 42 to generate
noi~e when the flexible tape 40 i6 moved.
Referring next to Fig. 12, there i8 shown a third
embodiment of the present invention. The ratchet member 74
in this embodiment has an arrangement substantlally similar
to that in the second embodiment. In this embodiment,
however, the ratchet member 74 ha~ an arm 102 which
projects from a position in the vicinity of the support
shaft~ 76 ~o as to oppose a leaf spring 104 which ls secured
at one end thereof to the housing 56. A pair of recesses
106 and 108 are formed in the intermediate portlon of the
leaf ~pring 104 in such a manner tha~ each of the rece~ses
106 and 108 is able to accommodate the distal end of the arm
102, thereby controlling the pivoting motion of the ratchet
member 74.
Thus, when the ratchet member 74 abuts against the
enlarged-width portion 36 of the slider 22 which is moved
downward, the ratchet member 74 is able to move from the
position shown by the solid line in Fig. 12 in which the pin
92 is withdrawn from the locus of movement of the hook
portion 68 to the position shown by the phantom line in
which the pawl portion 80 is within the elongated opening 50
13~4;~3~
in the flexible ~ape 40. ~rhus the ratchet member 74 in thi~
embodiment performs an action similar to that in the above-
described embodiments.
In this embodiment, when the ratchet member 74 which i6
in the position shown by ~he imaginary line is pivoted
counterclockwise to come close to the position shown by the
solid line, the arm 102 of the ratchet member 74 i8 biased
by the leaf spring 104 so as to turn and enter the recess
106 thanks to the configuration of the recess 106. In
consequence, the arm 102 is moved into the recess 106.
Thus, when the ratchet member 74 is in the position shown by
the solid line, the pawl portion 80 can be held in a state
wherein it is separated from the flexible tape 40.
Fig. 13 shows a fourth embodiment of the present
invention.
In this embodiment, a torsion coil sping 110 serves as
both the ratchet member 74 and the pawl 64 in the fir~t
embodiment.
More specifically, a coil portion 110A formed on the
intermediate portion of the spring 110 i8 rotatably
supported on a spring retainer pro~ection 114 which i8
rigidly secured to the housinq 56. One end portion of the
~pring 110 is retained by a retainer pro~ection 116. A coil
portion 110B which is adjacent to the coil portion 110A i8
dispo~ed in such a manner a~ to hold the pin 92. The other
26
13~ 3~
end portion of the spring 110 ~s bent to define a ratchet
portion llOC which serves as a member similar to the ratchet
member 74 in the above-described embodiments.
Therefore, in this embodiment, when the slider 22 is in
the position shown in Fig. 13, the ratchet portion llOC i8
within the elongated opening 50, and the pin 92 i5
interposed in the locus of movement of the hook portion 68.
When, in this state, the slider 22 is moved toward the
webbing unfastening position, the ratchet portion llOC is
expelled from the elongated opening 50. In confiequence, the
torsion coil spring llO is forced to pivot counterclockwise
as viewed in Fig. 13 about the coil portlon llOA so as to be
elastically deformed, thereby causing the coil portion llOB
and the pin 92 to be withdrawn from the locu~ of movement of
the hook portion 68, and thus allowing the movement of the
slider 22.
After the slider 22 has moved, the ratchet portion llOC
which ~s pressed by the flexible tape 40 holds the pin 92
out of the locus of movement of the hook portion 68.
However, when the slider 22 returns to the webbing fastening
posit$on shown in Fig. 12, the ratchet port$on llOC enters
the elongated opening 50, so that the pin 92 is interposed
in the locus of movement of the hook portion 68 aga~n.
In this case, the length A of the ratchet portion llOC
is preferably made so large that it cannot enter the
openings 42 in the flexible tape 40.
27
~3(~4~30
A fifth em~odiment ol ~he present invention is silowrl
in Figs~ 14 through 17. In this embodiment, the slide block
~4 and the latch pawl ~ use(~in the first embodiment are
omitted, but a lock pin 570 is provided between leg plates
78 of a ratchet member 74A, and the lock pin 570 is able to
be made of metal or the like. The lock pin 570 is
engageable with the hook portion 68 as the same manner in
the second embodiment shown in Figs. 3 through Fig. 11.
A control pin 580 provided to a detector element 578
of a limit switch 576 is inserted in a guide bore 82 of the
ratchet member 74A. The detector element 578 is
longitudinally slidably disposed to the limit switch 576
through a hole formed in a housing 56A, and the control pin
580 is transversely extended from the detector element 578.
In this embodiment, as shown in Figs. 14 and 15, a
compressed coil spring 575 urges a pawl 80 of the ratchet
member 74A to a direction of the flexible tape 40.
Accordingly, in the embodiment, as the slider 22 pushes
in the detector element 578 to the limit switch 576 at a
stroke end portion resistant to a spring member which is not
shown in the drawings, but provided in the limit switch 576,
a driving motor for the flexible tape is stopped by the
limit switch, and the control pin 580 is inserted in a
larger width portion 82A of the guide bore 82 of the
ratchet member 74A, and then a pawl portion 80 of the
ratchet member 74A is gotten into the longitudinal opening
50 of the flexible tape ~y the urginq force of the coil
; 2~
~3(~4;~30
spring 575.
At this condition, even though external force is
upward added to the slider 22 from the webbing 14 in Fig.
14, the external force is received by the body of the
vehicle through the housing 56A and projected portions 559
of a bracket 58A.
At the time of automatically setting the webbing to an
occupant, referring Fig. 14, when the flexible tape 40 is
upward driven, the pawl portion 80 is withdrawn by the
flexible tape 40 from the locus of movement thereof, and
the pin 570 is disengaged from the hook portion of the slider
22, then the slider 22 is delayingly moved in accordance
with the relative movement with the flexible tape 40. At
this stage, the control pin 580 of the detector element 578
is slidingly received in a smaller width portion 82B of the
guide bore 82, and the ratchet member 74A is prevented from
pivotal movement.
The pin 570 is not limited to around shape in a
cross-sectional view, and can be formed to any shape.
Moreover, the pin 570 can integrally formed with the ratchet
member 74A by diecasting. The compressed coil spring 575
can be replaced with any other leaf spring or the like.
The anchor pin 62 used in each embodiments can be
omitted, and substitutionally the bracket 58 is able to be
constituted so as to receive by itself the large force of
the webbing 14 which may occur in the emergency of
the vehicle.
29
13~330
It should be noted that the drive means employed in the
present invention is not necessarily limitative to a
continuous member su~h as a flexible tape, and any other
type of drive means may be employed.
As has been described above, the automatic seatbelt
system for a vehicle according to the present invention
comprises: a guide rail laid on the body of the vehicle; a
slider retaining a webbing and adapted to be movable along
the guide rail between a position at which the webbing is
fastened to the body of an occupant (hereinafter referred to
as a "webbing fastening position~) and a position at which
the webbing is unfastened therefrom (hereinafter re~erred to
as a "webbing unfastening position~); drive means adapted to
move along the guide rail in such a manner as to apply
driving force to the slider, the drive means being movable
relative to the slider by a predetermined amount along the
guide rail; and retainer means adapted such that, in
response to the movement of the slider to the webbing
fastening position, the retainer means is brought into a
first state wherein it can inhibit the movement of the
slider toward the webbing unfastening position, and in
response to the above-described relative movement which
occurs when the drive means moves toward the webbing
unfastening position from the webbing fastening position,
~3G~3~
the retainer means is brought into a second state wherein it
allows the slider to move toward the webbing unfastening
position. Accordingly, the retainer means for preventing
the slider from moving when the occupant has the webbing
fastened can be simplified in arrangement and reduced in
size, advantageously.
