U.S. patent application number 10/417814 was filed with the patent office on 2004-01-01 for child safety seat.
This patent application is currently assigned to XSCI, Inc.. Invention is credited to Arnott, Kris Alan, Clement, David F., Goor, Dan.
Application Number | 20040000802 10/417814 |
Document ID | / |
Family ID | 29783162 |
Filed Date | 2004-01-01 |
United States Patent
Application |
20040000802 |
Kind Code |
A1 |
Clement, David F. ; et
al. |
January 1, 2004 |
Child safety seat
Abstract
The infant safety seat of the present invention provides
improved occupant protection in all vehicles, especially in the
front seat of vehicles equipped with a passenger-side airbag. The
infant safety seat includes an air bag deflecting canopy, and
dampening mechanisms to protect against the shock of airbag
deployment and an impact. The safety seat comprises a base, adapted
to be secured to a seat of the vehicle by a seat belt passed
through an opening in the base and a cradle having a back portion
and seat portion having sides and a handle attached across said
sides. A latching mechanism incorporated in the base removably
secures the cradle to the base by grasping an attachment element
between the handle and sides. The cradle of the safety seat is
removable utilizing a single-handed release mechanism to unlock the
cradle from the base. In another aspect of the invention the infant
cradle has a curvature at the top head portion of the cradle to
captivate the infant's head to prevent extreme tensile loads to the
neck while under front deceleration loading.
Inventors: |
Clement, David F.; (Colorado
Springs, CO) ; Goor, Dan; (Colorado Springs, CO)
; Arnott, Kris Alan; (Colorado Springs, CO) |
Correspondence
Address: |
WEINGARTEN, SCHURGIN, GAGNEBIN & LEBOVICI LLP
TEN POST OFFICE SQUARE
BOSTON
MA
02109
US
|
Assignee: |
XSCI, Inc.
|
Family ID: |
29783162 |
Appl. No.: |
10/417814 |
Filed: |
April 17, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10417814 |
Apr 17, 2003 |
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10145384 |
May 14, 2002 |
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10145384 |
May 14, 2002 |
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09515434 |
Feb 29, 2000 |
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6386632 |
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09515434 |
Feb 29, 2000 |
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09170383 |
Oct 13, 1998 |
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6042181 |
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Current U.S.
Class: |
297/250.1 |
Current CPC
Class: |
B60R 2021/162 20130101;
B60N 2/2806 20130101; B60N 2/2839 20130101; B60N 2/2821 20130101;
B60N 2/2884 20130101; B60N 2/2863 20130101; B60N 2/2812 20130101;
B60N 2/286 20130101; B60N 2/2845 20130101 |
Class at
Publication: |
297/250.1 |
International
Class: |
A47C 001/08 |
Claims
We claim:
1. A rear-facing safety seat for a infant to be used in a vehicle,
the safety seat comprising: a base, adapted to be secured to a seat
of the vehicle by a seat belt passed through an opening in said
base; a cradle having a back portion, seat portion, sides to said
back and seat portions and a handle attached across said sides;
wherein a latching mechanism incorporated in said base removably
secures said cradle to said base by grasping a structural element
between said handle and said sides; the cradle having a curved top
head portion configured to captivate the head of an infant seated
in the cradle.
2. The rear-facing safety seat according to claim 1 wherein said
base further comprises a canopy and a foundation integrally joined
and a dissipating panel attached to said canopy.
3. The rear-facing safety seat according to claim 2 wherein said
dissipating panel comprises: a foam panel formed to conform to said
canopy in size and shape; and a fascia panel fastened to said
canopy with said foam panel sandwiched therebetween.
4. The rear-facing safety seat according to claim 2 wherein said
foundation comprises: a frame providing a set of sides and a bottom
for said base; and a suspension assembly comprising a set of shock
absorbers suspending a holder between said set of sides, said
holder supporting a set of paws of said latching mechanism.
5. The rear-facing safety seat according to claim 4 wherein said
latching mechanism further includes a pair of knobs each disposed
on one side of said base, each knob incorporating a releasing
mechanism to open said set of paws to release said cradle.
6. The rear-facing safety seat according to claim 1 wherein the
cradle has stiffening ribs on the back portion and an energy
absorbent layer on the back portion.
7. The rear-facing safety seat according to claim 6 wherein the
energy absorbent layer is composed of closed cell foam
material.
8. For use in a rear-facing safety seat for an infant to be used in
a vehicle and having a base adapted to be secured to a seat of the
vehicle by a seat belt, a cradle latchably attachable to the base,
said cradle comprising; a back portion having a curved top head
portion configured to captivate the head of an infant seated in the
cradle and having an energy absorbent layer; a seat portion; sides
to said back and seat portions; and a handle attached across the
sides.
9. The invention of claim 8 wherein the energy absorbent layer is a
closed cell foam material.
10. The invention of claim 9 wherein the back portion of the cradle
is stiffened by a plurality of ribs on the surface of the back
portion opposite to the energy absorbent layer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of patent
application Ser. No. 10/145,384 filed May 14, 2002, entitled CHILD
SAFETY SEAT, which is a continuation-in-part of patent application
Ser. No. 09/515,434 filed Feb. 29, 2000, entitled: CONVERTIBLE
CHILD SAFETY SEAT, now U.S. Pat. No. 6,386,632, which is a
continuation-in-part of patent application Ser. No. 09/170,383,
filed Oct. 13, 1998, entitled: CONVERTIBLE CHILD SAFETY SEAT, now
U.S. Pat. No. 6,042,181, the disclosures of all of which are
incorporated herein by reference.
[0002] This application also claims priority under 35 U.S.C.
.sctn.119(e) to U.S. provisional patent application serial
60/358,560 filed Feb. 21, 2002,
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] N/A
BACKGROUND OF THE INVENTION
[0004] Many states have passed laws that mandate the use of a child
safety seat for children up to the age of four years old. Since
1999 all new automobiles and light trucks produced in the United
States have been equipped with passenger-side airbags because of a
federal mandate.
[0005] Although child seat manufacturers routinely warn purchasers
to secure the child safety seat in the center of the rear-seat when
there is an airbag in the car, it is not uncommon for the safety
seat to be placed in the front, passenger-side seat. Rear-facing
infants in the back seat, when alone with the driver, often cause
distractions that contribute to, or cause, crashes. A distressed
infant alone in a safety seat in the back seat of a car is at least
as distracting to the driver as a cellphone, a well-established and
quantified distraction. In addition, recent Government data shows
that in numerous rear-end crashes, front seats break and hurt, or
even kill, children in the back seat. If not for passenger side
airbag, for the sake of safety, rearfacing infants should be placed
in the front seat to minimize distractions contributing to crashes
and to allow for infant/driver eye contact thus adding to the
infant's feeling of security. In recognition of this fact, the U.S.
Department of Transportation has recommended the installation of an
airbag on/off switch in cars carrying infants or small children in
the front seat. Still, there is risk to an infant in a rearfacing
safety seat positioned in front of a passenger side air bag.
[0006] A significant body of data has shown that the interaction
between a rear facing infant seat and a front passenger-side airbag
can result in excessive head and chest acceleration, causing
serious and perhaps fatal injury to the infant. For example, the
airbag/seat interaction produces accelerations of an infant's head
exceeding 100 G's at bag impact and Head Injury Criterion (HIC)
values ranging from up to 3000HIC. By contrast, rear facing seats
not experiencing airbag interaction produce head accelerations of
about 50 G's and HIC values less than 1000 and generally around 650
when crash tested at a standardized test speed of 48 km/hr. The
Child Restraint Air Bag Interaction (CRABI) task force recommends
390 HIC as the top acceptable number for infant safety. One reason
that it has not been possible to meet the HIC recommendations is
that current infant restraint systems use hard plastics.
[0007] Further research has shown that in some cases there is an
interaction between the rear facing infant seat installed in the
back seat and a front passenger seat back. In the case of a rear
collision, the impact causes the front passenger seat to collapse
and come in contact with the infant seat, transmitting forces that
need to be cushioned. Such forces can be greatly increased by the
presence of a passenger in the front passenger seat
[0008] Infants are usually transported in rear facing car seats and
in many cases, it is desired to transport the infant to other
locations such as a grocery cart, restaurant, etc. A handle is
usually incorporated in the cradle to facilitate removal of the
cradle from the car seat and to provide a convenient way to carry
the cradle. Current methods to transport the infant have required
removing the entire seat as one piece or have required that the
cradle first be released from the frame using releases on both
sides of the cradle and then the cradle be lifted from the frame.
These motions have been awkward for parents.
[0009] It would therefore be desirable to provide an infant child
safety seat that will protect the child when the safety seat is
installed facing rearward in any seat in a vehicle, whether or not
equipped with a passenger side airbag. The cradle should be easily
removed from the car seat base, have an ergonomically designed
handle and provide a infant safety seat that limits the shock
transmitted to a child in the case of an impact.
SUMMARY OF THE INVENTION
[0010] The present invention improves upon previous attempts to
overcome the disadvantages and dangers described above by providing
improved occupant protection in all vehicles, with particular
enhancement in vehicles equipped with a passenger-side airbag. The
infant safety seat base includes a canopy to deflect an expanding
air bag away from the infant and dissipate both the air bag and any
impact energy.
[0011] The canopy further incorporates a shock absorbent foam
barrier to absorb a significant portion of the deceleration and/or
shock energies that might harm the child. The canopy is integrated
with a base allowing the remaining energy to be dissipated by the
base components by both deforming and by moving the base. The base
includes a suspension system that suspends the cradle limiting the
transmission of force between the base and the cradle. The
suspension system includes a set of shock absorbers, where the
front shock absorbers are identical and the rear shock absorbers
are identical, but the front and rear absorbers differ in
stiffness. The difference in stiffness is chosen to allow the
installed cradle to rock toward the back canopy in response to an
impact on the canopy.
[0012] The infant cradle is held in the base suspension assembly by
a latching mechanism using gravity for engagement and using a
single-handed release mechanism. The mechanism uses jaws that grip
a structural element holding a handle to the cradle. The latching
mechanism opens when the cradle is placed on the paws of the jaws
and grips the structural element when the element has passed the
paws. The single-handed release allows a person to release and lift
the cradle without stretching across the seat to access the release
mechanism because the release is operated from either side of the
cradle and incorporates interlocks. The interlocks must be engaged
prior to the release.
[0013] In another aspect of the invention the infant cradle has a
curvature at the top head portion of the cradle to encapsulate or
captivate the infant's head to prevent extreme tensile loads to the
neck while under front deceleration loading. The cradle has a
stiffened back and an energy absorbent foam layer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] The invention will be more fully understood by reference to
the following detailed description when considered in conjunction
with the accompanying drawings, in which:
[0015] FIG. 1 is a view of the convertible child safety seat of the
present invention;
[0016] FIG. 2 is a front view of the frame and cradle of the child
safety seat of FIG. 1;
[0017] FIG. 3 is a diagrammatic side view of the child safety seat
of the present invention in a rearward position installed in the
front seat of a vehicle;
[0018] FIG. 4 is a partial cross-sectional view of the shock
absorbent crumple zone along line IV-IV of FIG. 5.
[0019] FIG. 5 is a diagram of the crumple zone of the
invention.
[0020] FIG. 6 is a further cutaway view of the shock absorbent
barrier as incorporated in the frame.
[0021] FIG. 7 is a diagrammatic side view of the child safety seat
of the present invention in a rearfacing position installed in the
rear seat of a vehicle.
[0022] FIG. 8 is a diagrammatic side view of the child safety seat
of FIG. 3 with the air bag fully inflated;
[0023] FIG. 9 is a view of a handle according to the invention;
[0024] FIG. 10 is a enlarged view of the handle of FIG. 12
illustrating the elbow carrying surface;
[0025] FIG. 11a is a front view of an alternate handle according to
the invention;
[0026] FIG. 11b is a side view of an alternate handle according to
the invention;
[0027] FIG. 12 is a detail side view of a release mechanism locked
to hold a child safety seat;
[0028] FIG. 13 is a detail side view of a release mechanism
released to allow removal of a child safety seat;
[0029] FIG. 14 is a side view of a mechanism for engaging the
safety release mechanism using a single hand;
[0030] FIG. 15 is a diagrammatic side view of the child safety seat
of the present invention in a forward position installed in the
front seat of a vehicle;
[0031] FIG. 16 is a diagrammatic side view of the child safety seat
of the present invention in a forward position installed in the
rear seat of a vehicle;
[0032] FIG. 17 is a diagrammatic side view of the child safety seat
of FIG. 15 with the air bag fully inflated;
[0033] FIG. 18 is a view of an embodiment of an airbag compliant
infant seat according to the invention;
[0034] FIG. 19 is a view of an embodiment of a cradle for the seat
of FIG. 18;
[0035] FIG. 20 is a diagram of a base for the seat of FIG. 18;
[0036] FIG. 21 is an exploded view of a suspension mechanism for
the base of FIG. 20;
[0037] FIG. 22 is an exploded view of a frame for the base of FIG.
20;
[0038] FIG. 23a is a front view of a shock absorber for the
suspension mechanism of FIG. 22.
[0039] FIG. 23b is a side view of a shock absorber for the
suspension mechanism of FIG. 22.
[0040] FIG. 24a is an view of a latching mechanism in the closed
position for the seat of FIG. 18;
[0041] FIG. 24b is an view of a latching mechanism in the open
position for the seat of FIG. 18;
[0042] FIG. 25 is an exploded view of a canopy for the base of FIG.
20;
[0043] FIG. 26 is a graph of the acceleration at the frame with and
without a foam insert in the canopy of FIG. 25;
[0044] FIG. 27 is a sectional side view of a cradle in accordance
with the invention; and
[0045] FIG. 28 is a cross sectional view along line V-V of FIG.
27.
DETAILED DESCRIPTION OF THE INVENTION
[0046] A removable infant/child safety seat that can be used with
the child facing forward or the infant facing backward incorporates
an advanced air bag deflector, improved handle and convenient
release mechanism. Referring to FIG. 1, the seat 10 includes a
frame 25 having a cradle 20 removably secured thereto. The seat 10
further comprises an airbag deflector 40, incorporating a crumple
zone 45 that surrounds and is a part of the frame 25. The air bag
deflector may be integrated as part of the frame or may be a
separate element, which attaches to and surrounds a portion of the
frame. The air bag deflector 40 is operative to deflect an
expanding air bag away from an infant seated within the cradle 20
of the seat 10. The crumple zone of the air bag deflector absorbs a
majority of the force imparted by the deploying air bag or by
contact between the safety seat and part of the car. The air bag
deflector/frame 40/25 both absorb and transfer the remainder of the
force imparted to the safety seat to the vehicle seat. The
removable cradle 20 can be installed within the frame 25 in a first
position in which an infant seated within the safety seat would be
facing rearward as shown in FIGS. 3, 7 and 8, or in a second
position in which the child (one to three years old) 30 seated
within the safety seat 10 would be facing forward as shown in FIGS.
14-16. The convertible car seat further includes a one-handed
safety release 32 to disengage the cradle from the frame as
illustrated in FIGS. 1, and 15-16. The cradle may further include a
removable handle 55 with ergonomic integral grips 57 for carrying
the cradle detached from the car seat frame as shown in FIGS.
12-14. The convertible car seat may further include an anti-kick
bar 50 at the end of the frame 40 furthest from the airbag
deflector shown in FIGS. 3, 7, 9, 10 and 11. The seat 10 also
includes a front orifice 12 for allowing a seat belt to pass
therethrough for securing the safety seat to the automobile
passenger seat when the safety seat 10 is used in a rearward facing
position, and a rear orifice 13 for allowing a seat belt to pass
therethrough for securing the safety seat 10 to the automobile
passenger seat when the safety seat 10 is used in a forward facing
position.
[0047] Referring now to FIG. 2, a view of the frame and cradle only
are presented. The frame 25 in this embodiment is comprised of
sidepieces 26 that are generally parallel to each other, a top
piece 28 and a bottom piece 27. The top piece 28 and bottom piece
27 mechanically interconnect the sidepieces 26 to each other. While
a four piece frame is shown, it should be understood that a unitary
frame or a frame comprising any number of pieces could also be
utilized. The cradle 20 is mounted to the frame 25. Additionally,
while the cradle is shown mounted to the frame, the cradle can be
detached from the frame by any mechanisms known in the art. The
mounting mechanism can include shock mounting components. It should
be understood that any number of shock mounts, absorbent materials
or shock mounting configurations including but not directly limited
to mounts molded directly to the frame or cradle may be used to
mount the cradle to the frame.
[0048] A rear facing convertible child seat installed for normal
operation of the vehicle is shown in FIGS. 3. The convertible child
safety seat 10 with handle removed is shown installed in the
passenger side front seat 60 of a motor vehicle. A seat belt 70
aids in securing the safety seat 10 to the front seat 60 of the
vehicle. In this configuration, the airbag deflector 40 with
crumple zone 45 faces the dashboard where airbags 80 are
installed.
[0049] The airbag deflector, illustrated in FIGS. 4-6, is formed as
a composite panel having a compound curved back surface to deflect
the air bag and absorb air bag and impact energy. The deflector
includes a crumple zone construction that accomplishes the
absorption. The composite panel of the deflector has an outer shell
46 and an inner shell 47. The interior region between the shells is
filled with a collapsible ribbing reinforcement forming a cellular
structure and a fill material, such as polystyrene. The cellular
structure is preferably formed of orthogonal ribs or walls that
define square or rectangular chambers and provide reinforcement.
Cylindrical or hexagonal tubular members are disposed in abutting
relationship within each chamber. FIG. 4 provides a cross section
of the composite panel of the crumple zone. During a collision, the
outer shell 46 deflects the airbag energy until the force causes
the outer shell to deform and start to compress the expanded
polystyrene foam fill 48. As the foam fill 48 compresses, it
contacts the tubular members 49 which provide more resistance than
the fill to the compression force. The force is blunted by the
compression of the foam and the gradual resistance of the tubular
members. In addition, orthogonal ribbing further spreads out shock
waves.
[0050] FIG. 5. schematically illustrates further detail of the
composite panel. The polystyrene fill has been omitted for clarity.
The orthogonal walls 42 form cells 43 on the edge that have less
volume than the interior cells 44 and are substantially filled only
with the expanded polystyrene foam fill. The inner cells 44 support
clusters of the honeycombed tubular members 49. The composite panel
45 buffers the infant away from any airbag or other impacting
object such as the dashboard or a seat back. FIG. 6 illustrates how
the airbag deflector 45, incorporating the crumple zone 48, is
separated from the cradle providing even more buffering.
[0051] As shown in FIG. 7, during the largest motion of the frame
and deflector 40 due to an impact, the deflector 40 has tensioned
the seat belt 70. The seat 10 translates approximately four to five
inches towards the front of the vehicle. The air bag 80 is at its
maximum inflation. Further, the air bag 80 has been deflected above
and over the infant 30 by air bag deflector 40 and thus air bag 80
does not come into contact with the infant 30 or infant cradle 20.
In addition, the crumple zone 45 has absorbed and spread out the
force of the airbag expansion protecting the child further. Any
rebound from the impact will be dampened by the anti-kick bar 50
disposed at the front of the safety seat 10.
[0052] When the infant is placed in the rear seat facing rearward
as illustrated in FIG. 7, the airbag deflector 40 with crumple zone
45 faces the seat back 60 of the unoccupied front passenger seat.
If an impact flings the seat back 60 to the rear, the airbag
deflector 40 with crumple zone 45 will absorb the force protecting
the infant.
[0053] In a further embodiment, the cradle 20 accepts a removable
handle 55. This handle, as shown in FIG. 9, incorporates three
gripping locations 90, 92, 94. The center grip 92 is positioned to
facilitate straight lifting motions of the cradle. The right grip
94 is positioned to facilitate lifting the cradle with the right
hand when the person lifting is on the left or carrying the cradle
with the left hand. Similarly, the left grip 90 is positioned to
facilitate lifting the cradle with the left hand when the person is
on the right or carrying the cradle with the right hand.
[0054] The angle and placement of the grips allow the deadweight
forces of the infant in the cradle 20 to be ergonomically
translated through the hand and arm of the adult carrying the
infant and cradle. When held by the right 94 or left grip 90, the
cradle naturally pivots to swing close to the carrier's body. The
bend 96 in the handle 55, FIG. 10, is adapted to facilitate
carrying the cradle with the handle 55 tucked into the elbow. When
the handle 55 is in the vertical position, the handle 55 angles
downwardly inward so that the arm can be held against the body.
While one embodiment is based on the posture of the average person,
the removable nature of the handle allows special handles that
accommodate individual needs to be provided.
[0055] FIG. 11a illustrates two alternate configurations of grips
(90, 92, 94 or 90', 92, 94') on a handle that maintains the
ergonomic placement. The side view, FIG. 11b illustrates the
displacement of the gripping surfaces from the sidebar portion of
the handle allowing for the natural lie of the cradle. Either
embodiment can accommodate the use of an elbow in the bend of
handle.
[0056] While the handle accommodates lifting the cradle with one
hand, the single-handed release mechanism 32 makes it practical to
use this capability in removing the cradle and infant from a car. A
locking mechanism must be configured so that very little alignment
is required in order to position and lock the cradle within the
frame. FIG. 12 illustrates one such lock mechanism. In this lock,
The cradle 20 has integral to it a set of protuberances 120 facing
the frame 10. The frame is fitted with a corresponding set of
locking paws 122, which in FIG. 12 are engaged, and holding the
cradle 20 securely. The paws 122 have a hook end 144, a ball end
146, and a pivot point 142. Paws are interconnected in pairs by
springs 148 to assure synchronized action. In order to disengage
the paws, a mechanism moves the ball end 142 to the position shown
in FIG. 13.
[0057] Any number of locking mechanisms may be employed for
releasably securing the cradle to the frame, as long as, once the
cradle is inserted within the frame, the seat is locked in place
and the lock cannot be released accidentally. In conventional car
seats, the release is implemented by for instance, depressing two
levers, one on each side of the seat.
[0058] A duplicated single-handed release mechanism provides the
convenience of being able to release the cradle from either side
with one hand while providing the safety interlock and release
needed to assure that the cradle does not unlock accidentally. In
the child safety seat of the invention, the release mechanism is
replicated on each side of the frame and either side can complete
the action. To prevent accidental release of the locking mechanism,
the release mechanism requires two actions to disengage the cradle
from the frame.
[0059] FIGS. 12 and 13 illustrate one side of a symmetric lock and
release mechanism utilized in a preferred embodiment. In FIG. 12
the mechanism is locked. In FIG. 13 the mechanism is released. To
unlock the mechanism, the central button 128 of the release handle
140 is pushed in. This button is connected to the child lock shaft
130 that is concentrically mounted within the main shaft 126.
Connected to the inward end of the child lock shaft 130 is a
crossbar 132. The crossbar extends through the main shaft via a
slit 134 in the main shaft. The crossbar 132 normally rests against
lock bar 136, which prevents the main shaft 126 and the child lock
shaft 130 from turning. When the child lock button 128 is pushed
in, the crossbar 132 is pushed to the position in FIG. 13,
displaced from the lock bar 136. Now handle 140 can be turned.
[0060] The handle coupler 150 to the main shaft 126, turns the main
shaft 126 rotating the asymmetrically mounted wing 124. As the wing
124 moves from the position shown in FIG. 12, to that in FIG. 13,
the ball end 146 of the paw 122 is displaced. The paw 122 rotates
around the pivot point 142 releasing the protuberances 120 on the
cradle 20. The crossbar 132 and the main shaft 126 are fitted with
torsional springs 138 and not shown, so that the system returns to
locking position (FIG. 12) as soon as the handle is released.
[0061] FIG. 14 illustrates an alternate push and swing release
mechanism 32. With one hand, the operator pushes in on handle 110
to unlock the mechanism and then swings the pushed-in handle until
it engages detent 112 to release it. Once the cradle 20 is
released, it may be lifted from the frame. In one embodiment, the
release handle 110 remains in the detent 112 indicating whether the
cradle is locked in the frame. It will be understood that the push
and swing release is illustrative of many stepped motions that can
accomplish the "unlock and release" sequence.
[0062] The convertible child seat 10 can also be used in a forward
facing orientation. As shown in FIG. 15, in this embodiment 10' the
cradle 20 is disposed at the second end of the frame/deflector
25/40. The seat is mounted in the vehicle in a manner similar to
the embodiment 10, with the difference that the occupant 30 is now
forward facing. Since the child is usually larger, a larger cradle
will typically be substituted for the original cradle used in the
rearward facing embodiment. This larger cradle will usually not
incorporate the handle since a child of this size is carried
independent of the cradle. The forward facing orientation is also
applicable in the rear seat as shown in FIG. 16. In both of these
placements, the airbag deflector and crumple zone continue to
spread and absorb the shock of an impact.
[0063] As shown in FIG. 17, at a time of maximum force on the car
seat, the child 30 and seat 10' start to translate towards the
front of the vehicle. The seat belt 70 is at its elastic limit and
the inflating air bag 80 expands over the top of the deflector 40
and encounters the head of the infant 30 thus preventing and
cushioning further forward movement of the infant 30 relative to
the vehicle. The crumple zone reduces the effects of the impact by
deforming as needed.
[0064] The convertible child safety seat provides protection for an
occupant in either a forward facing or rearward facing orientation.
The convertible child safety seat also protects the occupant from
an inflating air bag when the seat is installed in the front
passenger-side seat of a vehicle equipped with a passenger-side air
bag and from a collapsing front seat when installed in the rear
seat. The cradle is removable from the frame of the seat using a
single-handed safety release mechanism. A handle, adapted to be
gripped by either hand facilitates removal and carrying of the
cradle.
[0065] An airbag compliant rear-facing infant seat (ACIS)
embodiment that incorporates these principles is illustrated in
FIG. 18. The cradle 184 of this ACIS 1810 is narrower and has
higher sides than other models and comes with guidelines, based on
height and weight, that transition an infant out of the ACIS 1810
earlier than one would be transitioned from other infant seats. The
narrowness and guidelines permit greater protection for the infant
from the shocks generated by impacts. The ACIS 1810 may be
manufactured of tubular aluminum, thermoformed plastic, machined
plastic or injectable plastics, with injection molding of most of
the parts as a preferred practical and cost effective manufacturing
method.
[0066] The ACIS 1810 is composed of 2 major components: the base
186 and the cradle 184. The base 186 is adapted to be
semi-permanently mounted to the seat of a vehicle, while the cradle
184 is removable, but may be easily and securely mounted to the
base 186. It is intended that the base 186 remain in the vehicle,
while the infant is transported between the vehicle and other
destinations securely held by the cradle 184.
[0067] A cradle with padding 191, as shown in FIG. 19, is an infant
carrier type cradle 184 adapted to fit in the base 186. It is
narrower than the generally available cradle used in similar infant
seats. This narrowness limits the extent of movement of an infant
during an impact. Further, it is suggested that an infant
transition to a larger seat when the infant's head extends past the
top 193 of the cradle 191. A high quality harnessing system 195
incorporating shoulder straps 194 and a crotch strap 198, as
illustrated in FIG. 19, installed correctly and used consistently
will assure maximum benefit from the safety features of the ACIS
1810. The handle 185 is normally in the position shown in FIG. 1
while the cradle 184 is in the base 186. The handle 185 in this
position can act as a rebound limiter for the most extreme of
impacts. The cradle 184 is held to the base 186 by a clamping
mechanism that grips a structural connection between the cradle
body 184 and the handle 185 as detailed below.
[0068] The base 186 is composed of a foundation 181 and a canopy
182 integrally connected together. This base 186 works with the
installed seat(not shown)in the car to disperse the shock wave
created by the interaction with the airbag or barrier contact,
isolate the shock away from the child's head, neck, and thorax, and
at the same time prevent the front seat back from crushing the
child. The canopy 182 receives the first impact from either
striking a part of the vehicle or from an airbag. The foundation
181 receives any part of the shock not handled by the canopy 182
and dissipates it to protect the infant.
[0069] The foundation 181, as shown in FIG. 20, is composed of a
frame 203 and a suspension assembly 205. The frame 203, as
illustrated in FIG. 22 comprises two side panels 221, 2211 each
including a crossbar brace 225, 2215. The crossbar braces 225, 2215
are joined by the crossbar retainer 222 to form the frame 203. The
side panels 221, 2211 incorporate openings 227, 229 to allow seat
belts to secure the base 186 to the vehicle seat. The side panels
221, 2211 are formed of structurally rigid polypropylene (PP) or
similar material that is reinforced by extensive ribbing 2220 as
shown to allow energy to propagate across the panels to the vehicle
seat. The need for ribbing is inversely proportional to the modulus
of the PP used.
[0070] The suspension assembly 205 comprises a set of shock
absorbers 183, suspending a holder 209 between the side panels 221,
2211 of the frame 203, and a latching mechanism, detailed below, to
fasten the cradle 184 to the holder 209. The shock absorbers 183
mount high enough on the side panels 221, 2211 that the bottom of
the holder 209 is a distance above the bottom of the side panels.
This placement allows room for downward deflection of the holder
209 and cradle 184 during an impact.
[0071] As seen in FIG. 21, the holder 209 incorporates a scooped
basin 212 for receiving the cradle 184 and a pair of side arms 214,
2114. The scooped basin 212 is reinforced by ribbing to be as
strong as the cradle 184. The side arms 214, 2114 provide mounting
surfaces 218, 219 for connecting the shock absorbers 183 to the
holder 209. In addition, the side arms 214, 2114 incorporate
latching mechanism backstops 216, 2116 and access passages (not
shown) for the latching mechanism paws 242 described below.
[0072] One implementation utilizing the shock absorbers 183 is
shown in more detail in FIG. 21. Here, two pairs of shock absorbers
183, termed the front absorbers 2120, 2130 and rear absorbers 2122,
2132 span between the holder 209 and the side panels (not shown).
When the front and rear absorbers are identical and exhibit the
same stiffness, the front and back of the holder 209 move together.
When the characteristics differ among the absorbers, movements that
are more complex are possible. In particular, where the front
shocks 2120, 2130 are stiffer than the rear shocks 2122, 2132, the
more pliable absorbers 2122, 2132 will pivot around the firmer
absorbers 2120, 2130. The pivoting allows the holder 209, and
attached cradle 184, to rotate as well as translate while the shock
pulse to the ACIS 1810 is being dampened.
[0073] The front face 232 of shock absorbers 183 is illustrated in
FIG. 23a, showing a pattern of mounting holes 234 sized to allow
passage of mounting bolts 2210. Each front face 232 slides into a
mounting pocket 2212 on the inside of a side panel of the frame
203. The sides of the mounting pockets 2212 are tapped to capture
the mounting bolts 2210. The side view of shock absorbers 183 in
FIG. 23b illustrates the front face tab 2312.
[0074] The rear side panel 236 of the shock absorbers 183 similarly
fits within a reinforced channel 2110 in the front 218 and rear 219
of the side arms 214, 2114. These fastening mechanisms securely
fasten shock absorbers 183 to holder 209 while allowing the flexure
of the shock absorbers 183. Other fastening mechanisms, as are
known in the art, may be employed to connect the shock absorbers
183 with similar effect. The remainder of the body 2310 of shock
absorbers 183 dampens the dynamic loading on the infant while
spreading the shock pulse out over time. The shocks absorbers 183
allow the cradle 184 to move within the physical constraints of the
base 186, and specifically the canopy 182, without colliding with
the canopy 182.
[0075] The cradle 184 locks into the suspension mechanism 205 using
a latching mechanism 243 as shown in FIG. 24. Alternate locking
mechanisms may be employed for releasably securing the cradle to
the frame, as long as, once the cradle is inserted within the
frame, the seat is locked in place and the lock cannot be released
accidentally. The cradle latching mechanism 243 consists of a set
of paws 242, 2412 that latch onto a structural member (not shown)
that connects the handle 185 to the cradle 184. Either of the knobs
244, 2414 on the sides of the base 181 can actuate the set of paws
242, 2412. Linkages 246, 2416, implemented utilizing rods, cables
or the like, connect the paws 242, 2412 to the translation bar 248
to open the normally closed paws 242, 2412. The mechanism 243 is
preset to automatically return to a state in which the paws 242,
2412 are closed as shown in FIG. 24a. Positive stops 245, 2415
built into the mechanism 243, constrain the release knobs 244, 2414
to rotate in one direction and only to the point where the
mechanism 243 is fully open as shown in FIG. 24b.
[0076] The automatic return allows for hands free insertion of the
cradle 184 in the mechanism 243 because the mechanism 243 opens
under the weight of the cradle 184 and then closes automatically. A
slot (not shown), incorporated in the stem of each of the knobs
244, 2414, frees the moving linkage from rotating the knob not
being turned externally. This independent operation reduces the
rotational force that needs to be applied to the active knob to
release the cradle 184. To activate the release mechanism, one of
the knobs 244, 2414 is pushed in engaging with the positive stops
245, 2415. Once engaged, the turning knob 244, 2414 can turn the
translation bar 248 that in turn draws the paws 242, 2412 open.
[0077] In FIG. 24b, the cradle latching mechanism 243 is shown in
an open position. Knob 2414 has turned to activate the linkages
246, 2416 opening the paws 242, 2412. The open paws allow the
cradle 185 to be removed from the base 207. Knob 244 remains in the
same position as shown in FIG. 24a illustrating the effect of the
independent operation of the linkages.
[0078] The canopy 182 is composed of three primary parts as shown
in FIG. 25. The fascia panel 251 forms the outside of the canopy
182 facing the automobile dash panel and is typically made of a
thin-walled polypropylene (PP) or other plastic with a high
rubber-like content that is highly deformable. In one embodiment,
the fascia panel is made of 0.08" thickness polystyrene. Although
the fascia panel 251 is the first part of the ACIS 1810 to feel an
impact during a collision, its primary purpose is to hold the
remaining parts of the canopy 182 together. The exterior surface of
the fascia panel 251 is detailed primarily to provide purchase for
handling and for aesthetics rather than to reinforce the panel.
[0079] The foam panel 252 is sandwiched between the fascia panel
251 and the back canopy 253. The foam panel 252 reduces the impact
load to the infant significantly and transfers energy uniformly to
the back canopy 253. The foam has surface ribs 256 across its
surface to improve shock absorption and stretch out the shock wave.
The foam panel 252is shaped to assure that the alignment with the
back canopy 253 is uniform and precise. Different types of foam may
be used in the panel including Expanded Polystyrene (EPP), EPP
closed cell foam, urethanes etc.
[0080] The back canopy 253 encompasses the rearmost portion of the
base. It is structurally rigid relative to the EPS foam panel 252
and the fascia panel 251. In one embodiment, the back canopy 253 is
formed of polypropylene. It is physically attached to the side
panels 224, 2214 via an integrating joint such as a welded joint.
This integrating joint allows the force transferred to the back
canopy to be transmitted to the rest of the base homogeneously. The
foam panel 252 is formed to conform to the shape of the back canopy
253, thereby improving the transmission of force. The fascia 251
and back canopy, with the foam panel 252 compressed inside, are
fastened together across the top 254 and sides 255 of the canopy
253.
[0081] The force transmitted to a ACIS 1810 when the vehicle is in
a front-end collision can be deflected from the occupant by energy
absorbing measures. The energy absorbing methods available to a
safety seat are the movement of the seat in various directions and
friction forces. In terms of movement, the infant seat can move
horizontally within the limits of the automobile seat and
seatbelts, vertically down depending on the stiffness of the
automobile seat cushion, vertically up within the limits of the
seatbelts, and rotationally about a point. Friction forces that can
absorb energy include the crush force on padding between components
of the seats, deformation of components of the seat, and heating of
components because of the other friction forces. In the any one
embodiment, energy dissipation is accomplished using a variety of
these methods.
[0082] When the canopy receives a force on the fascia panel 251,
the panel 251 deforms absorbing some of the energy and transfers
the majority of the force to the foam panel 252. The foam panel 252
compresses, absorbing a significant portion of the energy to dampen
the force pulse, and transfers the remaining force uniformly to the
back canopy 253.
[0083] FIG. 26 illustrates the shape of the force pulses
transmitted to the ACIS 1810 and in particular, the difference in
force to the foundation 181 based on the presence or absence of the
foam. Trace 261 illustrates the acceleration force felt at the
foundation 181 when a foam panel 251 is deleted from the canopy 182
structure. A narrow extreme pulse 261a is experienced approximately
400 ms after the impact, with a wider secondary pulse 261b of much
diminished intensity occurring between 500 and 700 ms after the
impact. The effect of the impact is essentially dissipated 261c
within 1300 ms. In contrast, with the foam panel 251 installed, the
sharpest pulse 262a, measured at the same place, is less than one
quarter the undamped pulse 261a. The secondary pulse 262 is larger
than in the undamped case, but is still less that the primary
damped pulse 262a. The effect of the impact is essentially
dissipated 262c by 1150 ms, more quickly than in the undamped
case.
[0084] The back canopy 253, being integrally coupled to the
foundation 181 and more structurally rigid that the other
components of the canopy 182, bends and deforms under the forces
received, transmitting some of the energy to the rest of the base,
including the side walls 204.
[0085] In impact dynamics terms, the shocks produce a combined
stress state, with normal, shear and bending moments. The specific
material selection afforded by plastics allows the ACIS 1810 to
utilize varying stiffness of shocks 183 from baby front to baby
back. This difference in stiffness converts the direct
straight-line energy of airbag impact and infant deceleration into
both straight-line and rotational motion. Since the infant is held
securely to the cradle within the base, the full benefit of the
shock absorptive capabilities of the canopy, side panels, and shock
absorbers are afforded to the infant in the cradle.
[0086] When an automobile in which the ACIS 1810 is mounted in the
front seat suffers a frontal collision, there are three sources of
force on the seat, the deceleration from the collision, the force
from the impact of seat on the dashboard and the force from the
airbag's explosive inflation. When the ACIS contacts the dash or
the airbag, the impact energy is transferred through the canopy and
foundation into the automobile seat cushions. The most likely dash
impact point is on the fascia panel 251 and direct horizontally
backward. The most likely airbag impact point is higher on the
fascia panel 251 and directed both horizontally backward and
downward.
[0087] In both cases, the fascia panel deforms transferring most of
the energy to the foam panel 252. The foam panel 252 compresses
both vertically and horizontally, spreading the energy out across
the back canopy and decreasing the transmitted force. The result of
these compensating actions is that the child in the cradle is
shielded from the most extreme aspects of the impacts before the
suspension mechanism is used. The force causes the frame of the
safety seat to be significantly pushed down into the car seat
cushion, but the shock absorbers buffer the cradle from much of
this motion further dissipating energy in the process. The result
of these compensating actions is that the child in the cradle is
displaced minimally and never leaves the protective confines of the
base.
[0088] It has been determined by tests on a 12 month CRABI test
dummy that the factor Nij should be less than unity in order to
maintain an acceptable safety margin to minimize the chance for
neck injury during a deceleration event. The objective is to reduce
loads in the rear facing mode in an automobile experiencing a
frontal collision.
[0089] An embodiment of the cradle is shown in FIGS. 27-28 which
further reduces the load to the neck of an infant in the event of a
collision and which meets the objective of an Nij value of less
than 1.0. In this embodiment, the top 300 of the cradle has a
curvature in the head region to encapsulate or captivate the
infant's head. This curvature prevents extreme tensile loads to the
neck in the event of a frontal deceleration force. The cradle
includes a stiffened back 302 having an energy absorbent closed
cell foam layer 304. The back is stiffened by ribs 306. The
stiffened cradle back reduces the neck shear component Fx. The
curved cradle back reduces the tension component Fz and the neck
extension component My. The combined reduction in loads achieves
reduction of the Nij value to less than 1.0.
[0090] The construction of the cradle and the base in which it is
mounted are otherwise as shown and described in the previous
embodiments. Stiff shocks are employed and are desirable to reduce
the G loads to the head and chest during the dynamic vehicle
conditions described above. The shocks allow the cradle and its
occupant to be isolated from direct impact loads to the head, neck
and thorax.
[0091] Having described preferred embodiments of the invention it
will now become apparent to those of ordinary skill in the art that
other embodiments incorporating these concepts may be used.
Accordingly, it is submitted that the invention should not be
limited by the described embodiments but rather should only be
limited by the spirit and scope of the appended claims.
* * * * *