Vehicular infant safety seat with seat back safety stopper

An infant safety seat is provided on the rear side of an automobile seat back which is pivotable about a base hinge mechanism, between a position in which it leans to the rear so as to accommodate an adult passenger on the regular seat cushion, and a positon in which it leans forward so as to allow a removable infant safety seat cushion to be attached to the seat back. A seat back stopper is formed on the front edge of the removable infant safety seat. The seat back stopper projects between the bottom of the seat back frame and the relatively stationary seat cushion frame. With this arrangement if forces acting on the seat back in the rearward direction cause the dog clutch of a reclining mechanism of the seat back to fail, the seat back is prevented from rotating backwards and crushing the infant by means of the seat back stopper. Thus, it becomes unnecessary to provide a specially reinforced reclining mechanism on seats on which a rear mounted infant seat are to be mounted.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to an infant safety seat. More 
specifically, the present invention relates to an infant safety seat which 
is appropriate for use in an automotive vehicle. Still more specifically 
the present invention relates to an infant safety seat of the variety 
which is supported on the back of a seat which is pivotable between a 
rearwardly tilted position defining an adult mode and a forwardly tilted 
position defining an infant mode. 
2. Description of the Prior Art 
As is well known in the art of vehicular seats safety belts have been shown 
to reduce the hazard to the vehicular occupant in the event of accidents. 
Safety belts improve the safety of the occupant by preventing the occupant 
from being thrown from the vehicle in a crash and by preventing the 
occupant from being thrown against the interior walls of the vehicular 
cabin. Since adult safety belts are not effective for restraining infants 
in the same manner as adults due to the differences in both the size and 
the shape of the infant's body, it has been found that, in order to afford 
an infant the same protection which seat belts give to an adult, it is 
necessary to provide an infant safety seat which can be mounted on the 
seat of the vehicle and held securely in place. 
In view of the enhanced safety requirements, vehicle seats have been 
developed recently which can, when the seat back is tilted forward, 
accommodate an infant safety seat on the back thereof in such a manner 
that the child's seat faces in the rear direction. An example of such a 
prior art seat is shown in JM-A-62-37536. 
In the device mentioned above the main seat cushion is supported on a the 
vehicular floor by means of a rail in such a manner as to be slidable 
forwardly and backwardly. A seat back reclining device is provided by 
which the seat back is attached to the internal frame of the seat cushion. 
The seat back reclining device allows the angle of the seat back to be 
selected from among a number of predetermined angles. The reclining device 
is connected to the frame of the seat cushion by means of a pivotable base 
link which cooperates with the seat cushion frame and the seat back to 
allow free pivotal movement of the seat back between a position in which 
it leans rearwardly and a position in which it is tilted forward so as to 
accommodate an infant seat to be mounted on the rear side thereof. 
When the seat back is in either the rearwardly tilted position or the 
forwardly tilted position, the link plate can be locked by means of the 
latching mechanisms. 
When the seat back is in the forwardly tilted position the forward latch 
mechanism serves to maintain the seat back in a condition wherein force 
acting on the link cannot cause it to fall backwardly. Therefore, the 
infant safety seat, which comprises a safety harness for restraining the 
child within the seat so as to prevent an impact to the child in the event 
of an accident, can be safely supported on the back of the seat. When the 
seat back is in the rearwardly inclined or "reclining" position, the latch 
mechanism serves to prevent force exerted on the seat back in the forward 
direction from causing the seat back to fall forward. 
A release mechanism provided at the upper portion of the side edge of the 
seat serves to release the latching hooks from the stopper pins so that 
the position of the seat back can be selected from among the forward 
position and the reclining position. 
In the above described type of seat hinge mechanism, the latching mechanism 
of the base link is of the conventional type which is inherently very 
strong. Therefore, when strong force is applied to the seat back while it 
is in the forwardly tilted position the force is applied to the reclining 
mechanism which connects the seat back to the base link. In view of the 
safety aspect of the infant seat it is therefore imperative to provide a 
reclining mechanism which is much more strongly reinforced than those 
found in conventional types of seat back which do not accommodate the 
child safety seat. 
This reinforced reclining mechanism is problematic in that it is heavier 
and more expensive to produce than other conventional seat back reclining 
mechanisms. Therefore, in view of cost and weight factors, it is 
preferable not to provide such a reinforced seat back reclining mechanism 
in all vehicle seats, and accordingly, a second production line must be 
established for the reclining mechanisms of vehicles in which it is 
anticipated that the infant safety seat will be installed. 
In view of the above problems there is a need that is felt in the prior art 
to provide a method of reinforcing conventional seat backs in such a 
manner that a single inexpensive production line of seat back reclining 
mechanisms can be safely employed, both in seats that are intended to 
accommodate the infant seat and in those which are not. 
SUMMARY OF THE INVENTION 
In view of the above problems encountered in the infant safety seats 
according to the prior art, it is an object of the present invention to 
provide a strong, inexpensive means for reinforcing a seat back reclining 
mechanism so as to render it appropriate for use in both conventional seat 
backs and those on which it is intended to provide the infant safety seat 
of the type which is supported by the seat back. 
It is a further object of the invention to provide a seat back reclining 
mechanism whose strength and safety are superior to the prior art devices. 
In brief, the above objects are achieved by an arrangement wherein an 
infant safety seat is provided on the rear side of an automobile seat back 
wherein the seat back is pivotable about a base hinge mechanism, between a 
position in which it leans to the rear so as to accommodate an adult 
passenger on the regular seat cushion, and a position in which it leans 
forward so as to allow a removable infant safety seat cushion to be 
attached to the seat back. A seat back stopper is formed on the front edge 
of the removable infant safety seat. The seat back stopper projects 
between the bottom of the seat back frame and the relatively stationary 
seat cushion frame. With this arrangement, if forces acting on the seat 
back in the rearward direction cause the dog clutch of a reclining 
mechanism of the seat back to fail, the seat back is prevented from 
rotating backwards and crushing the infant by means of the seat back 
stopper. Thus, it becomes unnecessary to provide a specially reinforced 
reclining mechanism on seats on which a rear mounted infant seat are to be 
mounted. 
More specifically, a first aspect of the present invention is deemed to 
take the form of a child safety seat arrangement which is provided on a 
vehiclular seat and which features: a seat cushion; a seat back support 
mechanism, which is movable relative to the seat cushion between a first 
position and a second position; a seat back, which is movably supported by 
the seat back support mechanism so as to be movable between a first 
position and a second position; an infant back support means defined on 
the back side of said seat back for supporting the back of an infant 
seated in the infant safety seat; an infant seat cushion means, detachably 
provided at the back side of the seat back for supporting the buttocks of 
the infant; an infant restraining means operable for restraining the body 
of the infant within said infant safety seat; a seat back stopper means 
provided on the infant seat cushion at a position between the seat cushion 
and the seat back for restricting rotation of the seat back relative to 
the seat cushion while the infant seat cushion is disposed on the seat 
back. 
According to another aspect of the invention, an infant safety seat 
arrangement for a vehicular seat comprises: a seat back reclining means 
operable for defining the reclining angle of a vehicular seat back; a 
vehicular seat back pivotally mounted so as to pivot relative to a first 
vehicular seat cushion about an axis defined by the reclining means; a 
first vehicular seat cushion; a second vehicular seat cushion detachably 
disposed on the back of the seat back for defining an infant seat cushion; 
and a seat back stopper means formed integrally with said second vehicular 
seat cushion for being disposed between a lower edge of the vehicular seat 
back and a rear frame portion of the vehicular seat cushion for blocking 
rotation of the seat back relative to the first seat cushion in the 
rearward direction while the infant seat cushion is disposed on the seat 
back. 
According to still another aspect of the present invention, a vehicular 
seat features a seat back which is pivotable about an axis defined by 
pivotable base link journal, between a first position and a second 
position defined with respect to a main seat cushion, a seat back base 
link locking mechanism for locking the seat back base link in a forward 
position, and a seat back reclining mechanism for defining a pivoting axis 
at an upper portion of the seat back base link, about which the seat back 
may be rotated relative to the seat back base link, the seat back 
reclining mechanism having an incremental stopper means for defining 
angular positions with respect to the seat back base link, at which the 
seat back is rigidly maintained on the seat back base link for defining 
the reclining angle of the seat back, and a seat back stopper means 
comprising: an infant seat cushion mounting member defined on a rigid 
frame member of said seat back; an infant seat cushion; an infant seat 
cushion stay received on said rigid seat cushion mounting member for 
rigidly maintaining the infant seat cushion on the seat back; a rigid main 
seat cushion frame member defined at a rear portion of the main seat 
cushion; and a seat back stopper rigidly formed on said infant seat 
cushion stay so as to projected toward said rigid main seat cushion frame 
member, the seat back back stopper coming into rigid contact with the 
rigid main seat cushion frame member for arresting rearward rotational 
movement of the seat back when rearward rotational forces acting on the 
seat back overcome said incremental stopper means of the seat back 
reclining mechanism causing rearward rotational movement of the seat back.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In order to provide a clearer understanding of the principles of the 
present invention and in order to clarify the difference between the 
infant safety seat manufactured according to the principles of the present 
invention with those of the prior art, a detailed description shall 
hereinafter be given of an infant safety seat according to the instant 
invention using a brief disclosure of a prior art infant safety seat as a 
point of departure. 
In FIG. 1 a vehicular seat is shown on which an infant safety seat 
according to the prior art is disposed. In this device a seat cushion 103 
is slidably supported on a support structure 105 by means of an upper rail 
107 in such a manner as to be slidable forwardly and backwardly so as to 
be adjusted to the position which best suits the occupant of the seat. The 
seat back 101 comprises an inner frame which is connected to a seat back 
reclining device 111 at the end thereof. The seat back reclining device 
111 is provided for allowing the angle of the seat back to be adjusted to 
the angle which the seat occupant prefers. 
The reclining device 111 is connected to a frame 117 of the seat cushion 
103 by means of a base link 113 which cooperates with the frame 117 which 
extends upwardly along the lateral side of the seat cushion 103 and toward 
the seat back 109. This arrangement allows free pivotal movement of the 
seat back 109 between a position in which it leans rearwardly and a 
position in which it is tilted forward. It also accommodates the mounting 
of an infant seat cushion 137 on the rear side thereof and/or in the case 
of a two door automobile, to allow the occupant of the rear seat to get in 
or out of the vehicle. 
When the seat back 109 carried on the link plate 113 is in the rearwardly 
tilted position or it is in the forwardly tilted position, the link plate 
113 can be locked by means of one of either the rear latching mechanism 
122 or the front latching mechanism 121. 
When the seat back is in the rearwardly inclined or "reclining" position, 
the latch mechanism 122 which is comprised of the hook 118 and the pin 
119, serves to prevent force exerted on the seat back 109 in the forward 
direction, from causing the link plate 113 which carries the seat back 
109, from moving forward. 
When the seat back 109 is in the forwardly tilted position the engagement 
between the front latching hook 118 of the front latch mechanism 121, and 
the front latching pin of the front latching mechanism 121, serves to 
maintain the base link 113 in a condition wherein force acting on the link 
113 cannot cause it to fall backwardly. 
The release mechanism 125 provided at the upper portion of the side edge of 
the seat serves to release the hooks 118 from the pins 119 so that the 
position of the seat back can be selected from among the forward position 
and the reclining positions. 
In the prior art device shown in FIG. 1 the front latch mechanism 121, if 
constructed in accordance with the general standard, is robust enough to 
prevent the seat pivot plate 113 from falling rearwardly, even under the 
rearward stresses thereon which would occur in a rear end type accident 
wherein the vehicle in which the safety seat is provided is struck from 
the rear. Therefore the rearward stresses, which are imposed on the seat 
back 109 by the mass of an infants body acting on the the safety harness 
123, trying to cause the seat back 101 to collapse to the rear, are 
concentrated in the reclining mechanism 111. 
Since it is imperative to the infant's safety that the reclining mechanism 
does not collapse and allow the seat back to fall backwardly, it is 
necessary in the prior art seat, whereon an infant seat is to be 
accommodated, to provide a specially reinforced reclining mechanism 111 
which is heavier and stronger than the type which would otherwise 
conventionally be provided on a seat not intended to accommodate the rear 
mounted infant seat. This reinforced reclining mechanism is heavier than 
the normal type and is more expensive to produce. 
In an infant safety seat assembly manufactured in accordance with the 
principles of the instant invention, a stopper mechanism is provided for 
retaining the seat in the forwardly tilted position even when forces 
acting on the seat in the rearward direction exceed those which can be 
withstood by the restriction means of the seat back reclining mechanism, 
thus allowing a conventional seat back reclining mechanism to be employed 
on a seat back on which a rear mounted infant safety seat is to be 
supported. 
Referring now to FIG. 2, the details of an infant safety seat assembly 
according to a first embodiment of the present invention shall be set 
forth. 
FIG. 2 is a side elevational view showing an automobile seat 1 according to 
the invention, in a state in which an infant safety seat is supported on 
the rear side of the seat back 3, of the seat 1. 
The automobile seat 1 according to the invention comprises the seat back 3 
and the seat cushion 5. By means of a reclining angle adjuster mechanism 
7, the angle of the seat back can be selected and the desired orientation 
obtained. 
The reclining angle adjuster 7 is provided on the upper end of a base 
connector link plate 11. The base connector link plate 11 is pivotably 
connected at its lower and to the frame 13 of the seat cushion 5 by means 
of a journal pin 15. The journal pin 15 serves to establish a pivoting 
axis about which the set back connector link plate 11 may freely pivot 
relative to the frame 13 of the seat cushion 5. These elements in 
cooperation define a seat pivot mechanism 17 by which pivotal movement of 
the seat can be established. 
Through the pivoting action of the base connector plate 11 in relation to 
the internal frame 13 of the seat cushion 5, about the axis defined by the 
journal pin 15, the seat back 3 can be moved from the rearwardly tilted 
position, wherein the vehicular seat 1 is in a mode appropriate to 
comfortably accommodate an adult or large child, to the forward tilted 
position indicated in the solid lines of FIG. 1 wherein the vehicular seat 
is in an "infant" mode suitable for accommodating an infant safety seat 
provided at the rear side thereof. 
As the seat back 3 is moved forward, the above mentioned elements forming 
the seat pivoting mechanism 17 cooperate so as to pivotally support the 
seat back as it is moved into the infant mode position for accommodating 
the infant safety seat. Once the seat back is in this position the forward 
seat latching mechanism 19a serves to lock the seat back in the forwardly 
tilted infant mode position. 
The forward seat latching mechanism 19a comprises a hook 21 which is 
pivotally connected to the side of the base connector link plate 11 by 
means of a journal pin 29 which serves to define a pivoting axis about 
which the hook 21 may pivot relative to the base link plate 11. The 
forward seat latching mechanism 19a also comprises a rigid stopper pin 25 
which is formed so as protrude from the side of the seat cushion frame 13. 
When the seat back 3 is tilted into the position defining the infant mode 
as set forth above, the latching hook 21 becomes engaged with the stopper 
pin 25 so as to lock the base connector link plate 11 in its forwardmost 
position. 
The rearward seat latching mechanism 19b comprises a hook 23 which is 
pivotally connected to the side of the base connector link plate 11 by 
means of a journal pin 31 which serves to define a pivoting axis about 
which the hook 23 may pivot relative to the base link plate 11. The 
rearward seat latching mechanism 19b also comprises a rigid pin 27 which 
is formed so as protrude from the side of the seat cushion frame 13. When 
the seat back 3 is tilted into the position defining the adult mode as set 
forth above, the latching hook 23 becomes engaged with the stopper pin 27 
so as to lock the base connector link plate 11 in its rearwardmost 
position. 
Thus, the base connector link plate is firmly maintained in the selected 
operating mode by means of the seat pivot locking mechanisms 19a and 19b. 
As mentioned above, the front latching hook 21 is pivotally mounted at the 
front edge of the base plate 11 at the approximate vertical center thereof 
and is supported so as to be freely pivotable about the journal pin 29. A 
return spring (not shown) is provided for biasing the the front latching 
hook in the engaging direction (clockwise in the figures) so as to keep it 
in locking engagement with the stopper pin 25. 
Similarly, as mentioned above, the rear latching hook 23 is pivotally 
mounted at the rear edge of the base plate 11 at the approximate vertical 
center thereof and is supported so as to be freely pivotable about the 
journal pin 31. A second return spring (not shown) is provided for biasing 
the the rear latching hook in the engaging direction (clockwise in the 
figures) so as to keep it in locking engagement with the stopper pin 27. 
The latching hooks 21 and 23 are connected to a release mechanism or 
disengaging mechanism (not shown) which is operable to rotate the hooks in 
the counterclockwise direction so as to release them from the locking 
engagement with the stopper pins 25 and 27. 
The reclining mechanism 7 of the seat 1 comprises an annular locking 
mechanism by which the angular relationship between the seat back 
connector plate 7 and the base connector link 11 is maintained. By the 
disengagement of a pawl or dog member (not shown) with the teeth (not 
shown) of the annular gear member (not shown) of the reclining mechanism 
7, the locking engagement between the plate 9 and the base link plate 11 
can be released and relative rotational movement between the seat back 3 
and the base connector link 11 about a pivoting axis defined by the 
reclining mechanism 7 rendered possible. In this manner the reclining 
angle of the seat back may be selected. 
When the engagement of the pawl (not shown) with the teeth of the annular 
gear (not shown) of the reclining mechanism 7 is re-established, the angle 
of the seat 3 relative to the base connector link 11 once again becomes 
fixed. Thus the seat back becomes locked at the selected reclining angle. 
It will be noted that the above method of adjusting the reclining angle of 
the seat may be employed in both the mode where the seat is acting as an 
infant seat and in the mode wherein it is suited to accommodate an adult. 
Hereinafter the construction and operation of the structure for supporting 
the body of an infant at the back side of the seat 3, which includes the 
shoulder members 33, so as to define the side restraints of the infant 
safety seat and the infant restraining harness 35, shall be described in 
detail. 
At the lower side of the seat back 3 immediately beneath the infant 
restraining shoulder flanges 33, the infant seat cushion 37 which is 
designed to support the infant is detachably supported on the seat 3. 
As can be appreciated from FIGS. 2 and 3, a substantially rigid inner 
member 39 is provided for defining the support structure and general shape 
of the seat cushion member 37. A generally U-shaped stay 41 is welded to 
the front end of the inner support member 39 of the seat cushion member 
37. As shown most clearly in FIG. 8 the stay 41, has arms which project 
upwardly at either side of a horizontal central section so as to engage 
holder 43 which is fixedly mounted on the bottom edge frame 10 of the seat 
back 3. The arms of the stay 41 are received in the holder in such a 
manner as to be freely detachably therefrom. 
Thus the mechanism for detachably accommodating the infant safety seat on 
the seat back 3 of the vehicular seat 1 is defined by the stay 41 and the 
holder 43. Thus the infant seat cushion may be easily and quickly 
installed on or removed from the seat. 
An infant safety harness assembly is provided for restraining the infant to 
the seat. 
The infant safety harness assembly comprises shoulder straps 35 which are 
attached at one end thereof to an anchoring member 45 defined on the seat 
back frame 10 in the internal portion of the seat back 3. The infant 
safety harness mechanism's shoulder straps 35 are attached at their other 
ends to the top end of a breast cushioning member 47 which engages the 
chest of the infant seated in the infant seat defined at the rear of the 
seat back 3. The lower end of the breast cushioning member 47 is attached 
to an engaging tongue 49 by means of a crotch strap 49a which passed over 
the edge seat cushion member 37. The engaging tongue 49 is attached to the 
bottom end of the crotch strap 49a so as to be located at the bottom side 
of the infant safety seat cushion member 37 in the vicinity of the 
rearmost portion thereof. The engaging tongue 49 is provided so as to be 
detachably received in a safety buckle 55 which is attached at its lower 
end, via a lower strap member 55a, to the rear edge 51 of the internal 
frame 13 of the vehicular seat cushion 5 by means of a lower seat belt 
anchoring member 53 which projects downwardly at the lower side of the 
rear edge 51. Thus the infant safety harness comprises the infant shoulder 
straps 35, the breast cushioning member 47, the crotch strap 49a, the 
tongue 49, the safety buckle 55, and the lower strap 55a, which are 
connected in series so as to form a restraining mechanism for retaining 
the body of the infant of the infant seat defined by the back 3 of the 
vehicular seat, the infant restraining flanges 33 and the infant seat 
cushion member 37. 
The infant seat cushion member 37 according to the invention further 
comprises a seat back stopper member 57 which is provided for the purpose 
of restricting the possible range of rotation of the seat back 3 about the 
axis defined by the internal pivot mechanism of the reclining device 7 for 
preventing rotation of the seat back 3 in the rearward direction 
(clockwise in FIGS. 1 and 2) beyond a defined limit. 
The safety stopper mechanism of the infant safety seat according to the 
instant invention is essentially comprised of a Y-stopper member 59 which 
is generally an inverted Y shape in cross section and which has downwardly 
projecting arm sections 59a and 59b, and a Y-stopper arm receiving slot 61 
which is formed at the rear upper edge of cross stay member 51 the seat 
cushion frame 13 and the seat cushion 5. 
The Y-shaped seat back safety stopper functions, via the direct engagement 
of the downwardly projecting arms of the stopper mechanism with the 
lateral seat cushion frame member 51 of the inner frame 13 of the seat 
cushion 5. This engagement serves to arrest the rearward rotation on the 
seat back 3 while the infant safety seat cushion 37 is installed at the 
rear portion of the seat cushion 5 and the seat back 3 so as to prevent 
injury to the infant in the event of a rear end accident. 
Specifically, the above functions are achieved by the Y-shaped safety 
stopper member 59 according to the instant invention via the engagement 
between the arm 59a and the front edge of the lateral frame member 51 of 
the internal frame 13 of the seat cushion 5, which engagement is enabled 
by the seat back safety stopper member slot 61 formed at the upper side of 
the seat cushion 5, and the engagement of the seat back safety stopper arm 
59b with the upper surface of the rear edge of the seat cushion 5. This 
engagement serves to restrict the range of rotation of the seat back 3 
about the axis defined by the seat back reclining mechanism 7 when force 
in the rearward direction on the seat back 3 exceeds that degree of force 
which the seat back reclining mechanism 7 can resist. 
Thus, by employing a stopper mechanism, having the above described 
construction, at the rear edge of a seat cushion, it becomes possible to 
provide an infant safety seat at the rear side of an automobile seat 
having a conventional unreinforced pivoting and reclining mechanism 
without the danger of the seat back falling from the forwardly tilted 
infant mode position into the rearwardly tilting adult mode position while 
the infant safety seat is in use. 
Hereinafter, operation of the infant safety seat mechanism according to the 
invention shall be described. When the seat back 3 is in the rearwardly 
tilted position defining the adult mode, the seat back 3 is tilted 
forwardly to the position defining the infant mode by means of the 
pivoting mechanism 17. In this case the latch release lever (not shown) 
generally provided at the side of the seat back 3 is operated so as to 
release the latch hook 23 from the pin 27 so as to allow the seat back to 
pivot forward about the journal pin 15. Thereafter, when the pivot 
mechanism 17 reaches the forward position the front latch hook 21 becomes 
engaged with the front latch pin 25 so as to lock the pivot mechanism 17, 
which carries the seat back 3, in the forwardly tilted position defining 
the infant mode. 
In the above manner the seat back 3 becomes fixed in forwardly tilted 
position defining the infant mode. Thereafter the arms of the stay 41 
which project upwardly at the front edge of the inner support member 39 of 
the infant seat cushion member 37 as can best be seen from FIG. 3, are 
inserted into the stay holder 43 provided at the lower rear edge of the 
seat back 3. 
When the arms of the stay 41 projecting at the front edge of the seat 
cushion member 37 of the infant safety seat have been inserted into the 
holder 43 at the rear of the seat back 3, the infant may then be placed in 
the seat. 
Once the infant is seated in the safety seat, thereafter the infant safety 
harness is attached so as to restrain the body of the infant within the 
seat. 
It will be noted that in addition to holding the infant in place on the 
infant seat the infant safety harness also serves to hold the infant seat 
cushion member 37 on the rear side of the seat 1. 
By means of the infant seat's safety harness assembly the infant seated in 
the infant safety seat is restricted from coming out of the infant safety 
seat as for example would otherwise occur in the event of a rear end 
accident wherein the vehicle in which the infant safety seat is provided 
would be struck from the rear by another automobile. In the case of such a 
rear end accident the force of the vehicle striking the rear of the 
vehicle in which the infant safety seat according to the invention in 
disposed causes the vehicle to jump forward and the inertia of the child 
in the safety seat effectively carries the infant's body backwards 
relative to the body of the automobile. 
This backwards force of the infant's body is exerted mainly on the infants 
breast cushioning member 47, which is linked at its upper end to the 
shoulder harness 35. The force of the infant's body is exerted on the 
breast cushioning member is therefore exerted in the direction indicated 
by arrow (a) in FIG. 5. The force on the breast cushioning member 47 is 
therefore transmitted through the shoulder harness 35 to the seat back 3 
as a tensile force in the direction indicated by the arrow denoted (b) in 
FIG. 5. 
This tensile force is also exerted on the anchor member 53 as well as the 
anchor member 45 which is formed in connection with the frame 10 of the 
seat back 3. The force of the infant's body in the rearward direction 
which is exerted on the seat back 3 through the child's safety harness 35 
urges the seat back in the rearward direction as indicated by the arrow 
(d) shown in FIG. 5. 
This rearward force on the seat back 3 translates into an extremely strong 
clockwise rotational force which is exerted on the link plate 11 of the 
pivoting mechanism 17 through the reclining mechanism 7 as indicated by 
the arrow (c) in FIG. 5. 
At this time, since the forward latching hook 21 is firmly engaged with the 
forward latch stopper pin 25, the lower link plate 11 is, in effect, 
rigidly maintained in the forward position. Therefore, since the pivoting 
link 11 cannot be rotated in the direction shown by the arrow (c) by the 
force exerted on the seat back 3 by the infant's body, the rotational 
force exerted on the seat back 3 in the rearward direction is effectively 
concentrated on the reclining mechanism 7 of the seat back 3. 
In the situation set forth above the engagement between the teeth of the 
annular gear (not shown) and the dog (not shown) of the reclining 
mechanism 7 is overcome by the rotational force exerted thereon by the 
seat 3, thus the seat back 3 is caused to rotate in the direction 
indicated by the arrow (d) in FIG. 5 so as to move toward the position 
defining the adult mode. 
This rotation of the seat back 3 in the rearward direction exerts a 
rotational force on the seat cushion member 37 of the infant seat which 
causes it to rotate downwardly in the direction indicated by the arrow (e) 
in FIG. 5 about a pivoting axis defined by the reclining mechanism 7. This 
downward rotation of the infant seat cushion member 37 has the effect of 
urging the front arm of the inverted Y-shaped stopper member 59 into the 
stopper receiving slot 61 defined in the upper rear edge of the seat 
cushion member 5 so that the inner surface of the arm 59a engages the 
front inner edge of the lateral frame member 51 of the seat cushion frame 
13. 
The rear arm of the inverted Y-shaped stopper member on the other hand is 
driven into forceful engagement with the upper surface of the lateral 
frame member 51 of the seat cushion frame 13 thus preventing the further 
insertion of the inverted Y-shaped member into the receiving slot 61 
beyond the stopping engaging position indicated by the solid lines in FIG. 
5. 
In FIG. 6 the view of the stopper member is enlarged and the seat stopper 
59 is indicated by the solid lines in the state wherein it has been forced 
into engagement with the lateral frame member 51. 
In this manner the stopper member becomes engaged with the lateral frame 
member 51 of the inner frame 13 of the seat cushion member for preventing 
the further rearward rotation of the seat back member 3. Thus it becomes 
impossible for the seat back to fall rearwardly while the infant safety 
seat is disposed on the rear side of the seat back 3. 
In FIG. 7 a second embodiment of an infant safety seat according to the 
instant invention is explanatorily depicted. The parts of the second 
embodiment whose functions are essentially identical to those of the first 
embodiment will not be described in detail so as to avoid redundant 
disclosure. 
The construction of the second embodiment of the instant invention differs 
from that of the first embodiment of the invention in that an additional 
connector link member 63 comprised of members 67 and 65 is provided at 
lower side of the infant seat cushion member 37. The connector link member 
63 forms a link between the infant seat cushion member 37 and the anchor 
member 51 formed at the bottom of the seat cushion frame 13 of the seat 
cushion 5. At one end of the connector link 63 the tongue member 65 is 
connected to the inner frame member 39 of the infant seat cushion member 
39 and at the other end of the connector link member 63 the buckle member 
67 is connected to the anchor member defined on the bottom of the lateral 
frame member 51 of the seat cushion 5. Thus the internal frame member 39 
of the infant seat cushion 37 is fixed directly to the lateral frame 
member 51 of the internal frame member 13 of the seat cushion 5 by means 
of the engagement of the tongue 65 with the buckle 67. 
The provision of the positive connection between the internal frame 39 of 
the infant seat cushion member 37 serves to provide an additional safety 
feature to those provided by the construction according to the first 
embodiment in that it prevents the rotation of the seat back 3 in the 
forward direction. 
The explanation of the manner in which the infant seat cushion according to 
the second embodiment of the invention restricts the forward rotation of 
the seat back 3 is set out hereinafter. 
When force acting on the seat back 3 in the forward direction becomes great 
enough to overcome the reclining mechanism, the seat back tilts forward 
slightly, rotating about the axis of the reclining mechanism in the 
counterclockwise direction of FIG. 7. This counter clockwise rotation of 
the seat back causes the infant seat cushion 37, which is rigidly attached 
to the bottom of the seat back 3 by means of the engagement of the stay 41 
with the holder 43, to also rotate in the counterclockwise direction of 
FIG. 7. 
Since the rear edge of the infant seat cushion 37 is attached to the 
lateral member 51 of the inner frame 13 of the seat cushion 5 by means of 
the connector belt member 63, once the connector belt member 63 becomes 
taunt it becomes impossible for the infant seat cushion to rotate about 
the axis of the reclining mechanism. Therefore, since the infant seat 
cushion is rigidly retained on the bottom of the seat back 3 by means of 
the holder 43, it also becomes impossible for the seat back 3 to rotate 
further in the counterclockwise direction. 
As set forth above, by providing a vehicular infant safety seat constructed 
in accordance with the principles of the instant invention, it is possible 
to provide an infant safety seat. Thus a superior infant safety seat is 
provided at a greatly reduced manufacturing cost because a special 
reinforced reclining mechanism does not need to be provided in the 
automobile in which the infant safety seat is to be employed thus allowing 
use of a single standard production line of reclining device. 
It will be appreciated by those skilled in the art that although the safety 
stopper set forth in the above embodiments is provided on an infant seat 
cushion which is attached to the lower edge of the seat back's interior 
frame, embodiments are also conceivable wherein the infant seat cushion 
comprising the stopper is rigidly attached to the rear end portion of the 
main seat cushion. In such an embodiment the stopper would be rigidly 
affixed to the main seat cushion frame along with the infant seat cushion. 
Thus the safety stopper would have an upper portion which would come into 
engagement with the lower portion of the seat back frame in the event that 
the seat back reclining mechanism's dog clutch was overcome by rearward 
rotational forces imposed on the seat back. 
It will also be appreciated by those skilled in the art that embodiments of 
the seat stopper are conceivable wherein the infant seat cushion is 
rigidly attached to neither the seat back frame or the main seat cushion 
frame but "floats" therebetween maintained in position by the infant 
safety strap or other restraining means. In such an embodiment the seat 
back safety stopper would only come into contact with the frames of the 
seat back and seat cushion when the dog clutch of the seat back was 
overcome by rearward rotational forces acting on the seat back. 
It will be appreciated that the embodiment set forth above in the detailed 
disclosure represents but one of a large number of possible modes by which 
a safety stopper device might be carried out and that it is not intended 
to imply limitation to the scope of the invention beyond that set forth in 
the appended claims.