Note: Descriptions are shown in the official language in which they were submitted.
5 ~ ',.',' IOI~
FIELD OF ~HE INVE:NTION
The present invention relates to child safety seats
of the type used in vehicles to restrain small children from
being thrown from a safely seated position in the event of
~i a collision, upset or other emergency.
BACKGROUND OF THE IMVENTION
The occupant restraint belt systems which vehicles
are equipped with by the manufacturer are unsuited for use
by small children. Accordingly, a variety of special child
restraint systems are available and in widespread use. The
most common type of child restraint system is a special seat
which rests on the vehicle seat and is suitably fastened in
place by either the vehicle restraint belt or a special
belt. Conventional child safety seats usually consist of a
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small plastic shell-type seat having a padded cover and
fitted with a restraint belt system composed of a pair of
shoulder belts, a waist belt and a crotch belt. Because
children vary considerably in size as they grow from
infancy, the belts are usually adjustable. Many of the
known belt systems are relatively complicated because of
the number of belt sections involved and the adjustable
features incorporated in them. They are also frequently
cumbersome to put on the child. The child safety seats
described and shown in U. S. Patents Nos. 3,596,968,
3,606,453, and 3,794,379 are representative.
It is also been previously proposed to include an
abdominal pad in the restraint belt system of the child
seat. Such a pad enhances the protection of the child by
spreading the load over the child's pelvic area. Examples
of such systems are described and shown in U. S. Patents
Nos. 3,912,328, 4,025,111 and 4,040,664. Those systems
consist of a pair of shoulder straps joined to the abdomi-
nal pad by a metal anchor member which in turn joins the
shoulder straps to a crotch strap that is fastened to a
buckle under the front portion of the seat. Compared to
a number of other systems, which are somewhat more complex,
the last mentioned systems are comparatively convenient to
use, once relatively complicated adjustments have been made
so that the system fits the child. On the other hand, the
flexible crotch strap and the location of the buckle and
buckle tongue are somewhat inconvenient to fasten and
unfasten.
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The present inventor has heretofore made a desirable
improvement in child safety seats, and the seats embodying
such improvements have been marketed in Japan for some time.
One such improvement is the provision of an emergency lock-
ing retractor attached to the underside of the seat and
receiving a retractor belt which is joined to a pair of
shoulder belts. The provision of a retractor in the restraint
belt system of the child seat has the advantages of facili-
tating the proper fitting of the belt to children of various
sizes without requiring adjustment - the belt automatically
adjusts in length - and of being more comfortable to the
child by allowing him or her to move about in the seat,
particularly to lean forward. Nonetheless, the belt system
is highly effective in an emergency because the retractor
automatically locks when the belt is rapidly accelerated.
SUMMARY OF THE INVENTION
The present invention provides further improvements
in child safety seats of the general type described above.
Like conventional child safety seats, a seat embodying the
present invention includes a padded contoured seat having
a bottom, a back and sides and is constructed to rest on a
vehicle seat. The sides prevent the child for being thrown
sideways by restraining the head and shoulders of the child
and thereby supplement the belt system in protecting the
child in an emergency. Preferably, the seat is mounted on a
strong frame made of metal tubing. The seat is equipped with
a restraint belt system which includes an emergency locking
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retractor affixed to the underside of the seat. The
retractor maintains constant tension in the belt-winding
direction on a retractor belt but allows the belt to un-
wind relatively freely except when it locks in response to
a predetermined acceleration of the retractor belt in the
unwinding direction. The end of the retractor belt is
secured to a pair of shoulder straps which lead obliquely
up the back of the seat and pass through slots in the back
of the seat at a suitable height so that they lead down
over the shoulders of the child.
One aspect of the improved child safety seat, ac-
cording to the present invention, is an abdominal pad of -
polymeric foam which is united to the belt system by means
of embedding the portions of the shoulder belts in the
pelvic region and a portion of a buckle tongue within the
foam material of the abdominal pad. In particular,portions
of the shoulder straps adjacent the abdomen of the seat oc-
cupant and a portion of the buckle tongue to which the
shoulder straps are joined in a location corresponding to
the crotch of the child are embedded within and united to a
polymeric foam abdominal pad. In addition to cushioning
and spreading the strap loads over the occupant's abdomen,
the pad retains the parts of the strap above the abdomen in
laterally spaced apart relation. The lower parts of the
shoulder straps within the abdominal pad are affixed in
position within the foam material itself and converge down-
wardly to the upper end of the buckle tongue. The buckle
tongue fits into a buckle fastened under the front part of
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the seat. The abdominal pad preferably has a cover of
durable sheet material, such as a plastic leatherette,
which imparts stlffness to the pad, and the foam itself
is comparatively stiff. The composite stiffness consider-
ably facilitates applying the belt to the child because theperson applying lt can grasp the upper portion of the pad
and guide the tongue into the buckle much more conveniently
than presently known crotch straps which require the person
applying the belt to the child to grasp the upper portion of
the buckle tongue in order to secure the tongue to the buckle.
Although the pad can be made by joining two pieces
of foam material to each other and to the belt by an adhesive
and thereafter fitting a cover, a further aspect of the inven-
tion involves the formation of the foam in situ within the
cover with the strap portions and tongue portion in place
within the cover.
Among the desirable characteristics of a preferred
embodiment of the present invention are the following:
(1) The abdominal pad is generally "T" shaped in
that it includes a relatively narrow lower portion which is
received between the seat occupant's legs and a relatively
wider upper portion that extends across the occupant's abdomen.
(2) The cover consists of a front panel and a rear
panel stitched to each other around their perimeters to define
a cavity between the two panels, and the shoulder straps are
bound in the stitching at laterally spaced apart locations
along the top edge of the cover.
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3) The shoulder straps pass through the seat
back and include portions that extend downwardly behind
the seat back. The seat is fastened to a rigid frame which
includes a frame member adjacent the locations from which
the straps extend through the seat backs so that the frame
carries at least part of the strap loads in an emergency
situation.
4) There are at least two pairs of slots in the
back, each pair being at a different height from any other
pair, so that straps can be adjusted to suit the size of the
seat occupant by passing them through a selected pair of
slots.
5) The length of belt that can be wound and unwound
from the emergency locking retractor should be relatively
short so that the child cannot remove the belt by loosening
it and then climb out of the seat. Accordingly, for adjust-
ment of the belt system to fit children of various sizes,
say from age 7 months to 4 years, an adjustable detachable
buckle is fitted on each shoulder strap, preferably adjacent
the retractor belt, so that each strap can be detached from
the retractor belt and the effective length of each strap
can be altered. This feature, in conjunction with multiple
pairs of slots in the back ensures proper fitting of the
belt system to children of various sizes.
In addition to the advantages already mentioned of
allowing the child to move freely and yet protecting the
child in an emergency and the ease of fastening and unfasten-
ing the belt system from the buckle, the abdominal pad,
particular insorar as it includes a portion that extends down
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between the child's legs, provides good protection for
the pelvic region of the child, particularly the crotch.
The lower portion of the abdominal pad is more comfortable
to the child and safer as well, as compared to a crotch
strap which can rub on the inside of the child's thighs
and which can be abrasive to the legs and crotch in an
emergency and cause injury to the skin and flesh. The
above-described adjustment features are convenient to use
and increase the versatility of the seat so that it can be
used for children of a wide range of sizes. The affixation
of the lower ends of the shoulder belts to the abdominal pad
ensures good fit of the shoulder belts to the occupant and
maintains the lateral separation between them without the
metal anchor and other relatively complicated components of
previously known abdominal pads.
For a better understanding of the invention, refer-
ence may be made to the following description of exemplary
embodiments taken in conjunction with the figures of the
accompanying drawings.
DESCRIPTION OF THE DRAWINGS
Fig. is a front elevational view of a child safety
seat embodying the present invention;
Fig. 2 is a side elevational view of the seat shown
in Fig. l;
Fig. 3 is a rear view of the seat shown in Figs.
1 and 2;
Fig. 4 is a fragmentary side view in cross section
taken along the front portion of the seat bottom of the seat
shown in Figs. 1 to 3;
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Eig. 5 is a fragmentary front elevational view of
the abdominal pad with the lower portion broken out in
cross section;
Fig. 6 is a side elevational view of the abdominal
pad with the lower portion broken out in cross section;
Fig. 7 is a rear elevational view of another embo-
diment of the invention;
Fig. 8 is also a rear elevational view of the embo-
diment shown in Fig. 7, but shows the belt system adjusted to
fit a small child;
Fig. 9 is a rear elevational view of a third embo-
diment;
Fig. 10 is a pictorial view of an adjustable,
releasable buckle useful in the embodiments of Figs. 7 to 9;
and
Fig. 11 is a edge view of the buckle of Fig. 10
showing portions of the components in cross section.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
The child seat s-hown in Figs. 1 to 3 comprises a
molded plastic seat 10 having a bottom 12, a back 14 and
a pair of sides 16 and 18. The upper portion of each of
the sides 16 and 18 has a forwardly extending projection
16A, for protection of the head of the occupant, and both
sides 16 and 18 are shaped in profile to lie laterally
adjacent the shoulders, arms and hips of the child to re-
strain him laterally and supplement the restraint belt
system of the seat (which is described in detail below). The
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seat 10 is fitted with a padded cover 20, the perimeter
of which is pocketed to receive peripheral flanges of the
seat 10. Removable snap type buttons 22 fasten the lower
rear portions of the cover 20 to the seat 10.
The seat 10 is affixed to a frame 24 which includes
a one piece bottom and back frame member 26 consisting of
an upper back portion 28, a pair of generally vertical side
portions 30 and 32, each of which curves downwardly from
the upper back portion 28, and a pair of generally parallel
horizontal bottom portions 34 and 36 which curve forwardly
from the lower ends of the respective side portions and
along the sides of the seat bottom 12. The back 14 of
the seat 10 is fastened to the upper back portion 28 of the
frame member 26 by rivets 38. The other member 40 of the
frame is assembled from three pieces. First, there is a
generally U-shaped front piece 42 having a horizontal trans-
verse portion 44 located generally under the front of the
seat and a pair of generally vertical side leg portions 46,
~ the upper ends of which curve rearwardly and extend under
a flange 48 along the front edges of the respective side
portions 16 and 18 of the seat 10. The rearward upper end
of each side leg portion abuts the forward end of respec-
tive second and third pieces, rear leg members 50 which are
generally Z-shaped when viewed from the side and have a
turned-in rearward end portion 52. The rear leg pieces 50
are, preferably, welded to the front piece 42, but other
modes of connection can also be used. A front cross bar 54
located under the front of the seat is welded to the front
0
leg portions 46 of the frame piece 42, and a rear cross bar
56 is welded to the rear leg members 50. The frame members
26 and 40 are connected to each other where they cross at
each side by rivets 58 and 60. The sides 16 and 18 of the
seat 10 are fastened to the frame member 40 by rivets 62.
The restraint belt system of the child safety seat
shown in Figs. 1 to 3 includes an emergency locking retractor
70 which is housed in a casing 72 and is fastened under the
seat bottom 12 by a nut and bolt 74 (see Fig. 4). The
retractor is, preferably, of the type which locks in response
to a predetermined acceleration of the retractor belt 76
that is wound onto it. The belt is continuously kept under
tension by winding spring but is otherwise free to be pulled
from the retractor except when it locks. The retractor 70
can also be of the type which responds to an inertia sensi-
tive device which detects a predetermined acceleration of
the vehicle in any direction. Emergency locking retractors
have the advantage of permitting the person who is restrained
by the belt to move relatively freely except when the retrac-
tor is locked in an emergency.
The relationship between the length of the retractor
belt and the lengths of the shoulder belts are such that only
a short length of the retractor belt 76 can be unwound from
the retractor 70 so that the child sitting in the seat,though
he or she can lean forward on the seat, is not apt to get
out of the belt by loosening it too far by pulling it off
the retractor.
The retractor belt 76 leads from the retractor a
short distance rearwardly and upwardly to the rear portion
of the seat and is sewn to one end of each of a pair of
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shoulder belts 78. Each shoulder belt 78 extends upwardly
along the back of the seat and then turns forward and
passes through one of a pair of transversely spaced-apart
slots 80 located at a suitable height along the back 14 of
the seat for proper fitting of the shoulder belts 78 to the
seat occupant. Each belt 78 then extends downwardly,
forwardly and slightly inwardly to an abdominal pad 81. As
shown in Figs. 5 and 6, and as particularly apparent from
the broken-away portions of those figures, the abdominal pad
81 comprises an outer cover 82 made from a front panel 84
and a rear panel 86 sewn together around the perimeter. The
shoulder belts 78 are bound into the stitching at trans-
versely-spaced locations along the upper edge of the cover.
Portions of the shoulder belts extend convergently down
within the cavity defined between the panels 84 and 86 of
the cover 82 and are joined at the lower end of the pad to
a buckle tongue 88, the upper portion of which extends up
into the lower end of the cavity. The cavity within the
cover 82 is filled with a polymeric foam, such as thermally-
blown polyurethene. The pad 81 is made by sewing the cover
82 with the belt portions and buckle portion inserted into
it, and charging the cavity with the uncured polymeric mate-
rial which is then thermally blown in situ. Accordingly, the
belt portions and the buckle tongue portion that are located
within the cavity are imbedded within and united to the poly-
meric foam mass 90 contained within the cover 82. The polymeric
foam is sufficiently soft and compressible to provide a cush-
ioning and load-spreading effect against the body of the child
to which the belt system is fitted. On the other hand, the
composite structure of the pad 81 is such as to render it
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quite stiff, partly because of the relative non-extensibility
of the covering and the sandwich effect of uniting the
covering with the foam material within it and partly because
of the inherent relative stiffness of the foam. The stiff-
ness of the pad 80 also maintains a desired separation between
the lower ends of the shoulder belt 78 at the points where
they enter the pad and are stitched to the cover. The abdo-
minal pad is generally T-shaped as viewed from the front and
includes a narrow,elongated generally vertical lower portion
92 that fits between the legs of the child sitting in the
seat and a comparatively wide top portion 94 which extends
across the abdomen of the child.
The lower end of the buckle tongue 88 is releasably
received within a buckle 96 which is fastened to a bracket
98 affixed by a nut and bolt 100 to the underside of the
front portion of the seat 10. A portion of the bracket is
also fastened to the base of the retractor 70 by the nut
and bolt 74, thereby enhancing the strength of the belt
system. The buckle tongue enters the buckle 96 through a
slot 102 in the bottom portion 12 of the seat 10. The releas-
ing button 96a of the buckle 96 is located under the seat
in a location where it is very unlikely that a child could
reach down and release the buckle. Nonetheless, it is con-
veniently accessible to the person who places the child in
the seat and does up the belt system. The upper portion of
the buckle tongue (the part which is received within the
lower portion 92 of the abdominal pad 80) is bent rearwardly
so that when the buckle tongue is locked in the buckle 96,
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the abdominal pad 81 lies obliquely to the seat bottom 12
in a position favorable for comfortable and safe fitting
of the upper portion 94 to the abdomen of the child. The
lower portion 92 of the pad 80 is sufficiently flexible
to allow the pad to bend slightly forward when the child
leans forward, and there is also some play between the
buckle tongue and the buckle mechanism which affords pivot-
ing of the pad forward and backward so that the child is
relatively free to move in the seat and yet is somewhat
retrained against moving forward and in any event is held
in the seat for restraint upon locking of the retractor in
an emergency.
It will be observed, especially from Fig. 2, that
the shoulder belts 78 pass over the transverse top portion
28 of the frame member 26. Accordingly, when the belts 78
are under relatively high tension in an emergency, the frame
carries a large part of the load that would otherwise be
imposed upon the back of the plastic seat lO. Accordingly,
the seat need not be as strongly constructed as it would have
to be in order to carry the entire load in an emergency. The
upper back portion of the seat lO has molded into it a trans-
verse box-like stiffener portion 104 which strengthens the
region of the back 14 of the seat 10 around the slots 80
through which the belt passes.
An important advantage of the child seat and the
components thereof described above and shown in Figs. 1-6
is the ease of hooking up the restraint belt. When the
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child is buckled into the seat, the person who releases
him or her can conveniently grasp any part of the abdominal
pad 81; usually, it is most convenient to grasp some part
of the upper portion 94 rather than reaching down between
the child's legs and grasping the lower portion. The per-
son then pushes on the release button 96a of the buckle 96
and lifts up on the abdominal pad, and once the buckle
tongue 88 is moved just a slight distance up to release the
locking pin from the receiving hole in the buckle tongue, the
hand used to release the buckle is available for use, if neces-
sary, in repositioning or otherwise tending to the child. It
is then very easy to swing the abdominal pad 81 up over the
child's heat and lay it over the back of the seat or onto the
back of the vehicle seat, thereby completely freeing the child
from restraint by the belt system. A young child can then
easily be lifted out of the seat, and an older child can get
out of the seat himself. When the child is put into an
empty seat, the process is reversed. The user need only
grasp some part of the abdominal pad and with only one hand,
because of the relative stiffness of the abdominal pad, can
easily guide the buckle tongue 88 through the slot 102 in
the seat and push it down to lock it to the buckle 96. Mean-
while, the shoulder straps will easily follow the pad over
the child's head and become properly positioned over his
shoulders. The retractor 70 readily permits the desired
lengths of shoulder belts to be pulled out to facilitate
positioning of the shoulder straps 78 and reception of the
buckle 88 in the buckle 96. Once the child is installed and
buckled into the seat, the retractor allows the belts to
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pull out when the child leans forward, but in an emergency
the retractor 70 will lock in response to rapid accelera-
tion of the retractor belt 76 and prevent the shoulder
belts 78 and the pad 81 from being pushed forward, thereby
restraining the infant. The abdominal pad spreads the
load of the child's body when it is thrown forward in an
emergency over his abdomen and cushions the child against
injury. The laterally-extending portions of the upper part
94 of the abdominal pad, acting in conjunction with the
shoulder belt, keep the child from being thrown upwardly by
engaging the tops of his thighs and holding him down.
Figs. 7 through 9 of the drawings shows two
variations of a child seat that is similar in most respects
to the one shown in Figs. 1 through 6, but which includes
provision in the restraint belt system~for adjustment ~f
the lengths, and positions of the shoulder belts for better
fitting to very small children and relatively large children.
The seat and frame of the two embodiments are almost iden-
tical to those of the embodiment of Figs. 1 through 6. The
only differences are the addition of a tubular crosspiece
200 welded to the side portions 30 and 32 of the frame
member 24 a short distance below the upper portion 28 and
the provision of another pair of shoulder belt slots 202
adjacent the bar 200 and some distance below the slots 80.
Both embodiments, (that of Figs. 7 and 8 and that
of Fig. 9) also include a modified belt system, the modifica-
tion involving the addition of an adjustable and detachable
buckle in each shoulder strap. In the form shown in Figs.
7 and 8, there is a separate buckle 204 in each shoulder
strap 206. Two short pieces 208 of belt material are
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stitched to the end of the retractor belt 76 and, as shown
in detail in Figs. 10 and 11, the end of each piece is
inserted through a connection slot 210 in a buckle frame
212, folded back on itself a short distance and then stitched
by stitching 214. The lower back end of each shoulder belt
206 is passed outwardly through a locking slot 216 in the
buckle frame, passes around a lock bar 218, passes back
down through the locking slot 216 and leads back on the in-
coming portion of the belt 206 through a retainer ring 220
which keeps the incoming and outgoing sections of the belt
against each other. The lock bar 218 is urged by a spring
222 affixed to the frame in a direction to clamp the out-
going segment 206a of the end of the belt 206 against the
edge of the locking slot 216. When each shoulder strap
206 is pulled on, such as in an emergency, the belt force
is transmitted to the locking bar 218 and clamps it more
tightly against the buckle frame 212 with a force propor-
tional to the tension on the belt. Accordingly, the buckle
securely locks the belt 206 to an adjusted length. The
length of the belt is adjusted by pushing the lock bar 218
in a direction opposite that of the force of the spring 222
and taking up or paying out the desired amount of shoulder
belt 206. Such adjustment need be made only occasionally
as a particular child who uses the chair grows.
When the child who uses the seat is very small,
the belts 206 are installed,as shown in Fig. 8, through
the lower pair of slots 202 in the back of the seat 10, and
the belts are shorted accordingly by means of the respective
buckles 204. As shown in Fig. 8, each shoulder belt 206
passes over the cross bar 200 of the frame, which carries
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the major portion of the belt loads. For a larger child,
the belts 206 are installed, as shown in Fig. 7, through
the upper slots 80 in the seat 10, again, with suitable
adjustment of the belt lengths by means of the respective
buckles 204.
The embodiment of Fig. 9 is the same in all
respects as the embodiment of Figs. 7 and 8 except for the
substitution for the belt pieces 208 and separate buckles
204 of a single tandem buckle 230 having a frame 232 that
is attached directly to the retractor belt 76. The frame
232 of the buckle 230 has a pair of locking slots, spring-
loaded locking bars and retainer rings that correspond in
all respects to the buckle components shown in Figs. 10
and 11 and described above.
There is, therefore, provided, in accordance
with the present invention, an improved child safety seat
characterized by various aspects of construction that con-
tribute to safe restraint of the child by means of a belt
system which allows the child some freedom of movement and
yet responds to emergency situations by automatic locking
of a highly effective belt system coupled to an abdominal
pad of unique construction. The seat is easy to use and
is well suited to the inclusion of adjustable features that
allow it to be used for several years of the child's early
period of growth, say from about 7 months to about 4 years
of age.
The above-described embodiments are intended to
be merely exemplary, and numerous variations and modifica-
tions of them will be apparent to those skilled in the art
without departing from the spirit and scope of the invention.
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All such variations and modificat:ions are intended to be
included within the scope of the invention, as defined
in the appended claims.
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