Abstract:
An infant restraint for a motor vehicle comprising a base ( 10 ) located on and secured to the seat of a motor vehicle, an infant seat ( 12 ) releasably attached to the base ( 10 ) and a hook arrangement between the base ( 10 ) and the infant seat ( 12 ) that operatively engages the infant seat ( 12 ) to hold the infant seat with respect to the base ( 10 ) when the infant seat ( 12 ) is forced forward with respect to the base ( 10 ). The invention provides a means of holding the infant seat ( 12 ) to the base ( 10 ) that becomes active during a vehicle collision.

Description:
FIELD OF INVENTION 
   This invention relates to an infant restraint and particularly to a restraint of the type that comprises a base that releasably supports an infant seat. 
   BACKGROUND OF THE INVENTION 
   The most common form of restraint for infants under 6 months of age, is a child seat that locates within a motor vehicle so that the infant is rearward facing with respect to the vehicle. The restraint comprises a base that is secured with respect to the vehicle seat and an infant seat that locates within the base. The vehicle seat belts may be used to secure the base to the vehicle seat. The infant seat has restraining means such as a harness within the seat to hold an infant with respect to the seat. 
   Examples of such infant restraints are shown in Australian Patent No. 548416 and U.S. Pat. No. 4,943,113. Such infants seats as shown in the two patents use a latching mechanism to hold the infant seat with respect to the base. In both instances, the latching mechanism automatically engages upon an infant seat being placed with respect to the base and, has a manual release mechanism to allow the seat to be released from the base. This latching mechanism is relied upon to provide a sufficient holding force to hold the infant seat with respect to the base under collision loads. 
   An important requirement is to ensure that, during collision, the head end of the infant seat does not rotate downwardly to an extent that is greater than the prescribed limits. Such limits are generally prescribed by standards such as the United States Federal Motor Vehicle Standard FMVSS213 and other equivalent international standards. 
   Factors that contribute to downward rotation of the head end of the infant seat are compressibility of the vehicle seat and movement of the infant seat with respect to the base. 
   It is common for the base to be restrained with respect to the vehicle seat by the vehicle seat belts. The seat belts engage the base at a point that is close to the backrest of the vehicle seat. During collision, there is generally both forward force resolving from the rapid deceleration of the vehicle together with a downwards force causing rotation of the infant seat and base about the seat belt restraint so as to compress the vehicle seat. 
   In addition, there will be movement between the infant seat and the base. The base and infant seat are generally injection molded plastic components and so there will be some flexibility, particularly under high loads. Accordingly, the infant seat can move forward with respect to the base when impact forces are applied to the infant seat. 
   The combination of deflection resulting from deformation of the plastic components together with compression of the vehicle seat will often lead to an extent of rotation that is unacceptable. 
   Accordingly, it is an object of this invention to reduce the extent of rotation of the infant seat. 
   SUMMARY OF THE INVENTION 
   In one aspect, the invention comprises an infant restraint for a motor vehicle comprising; a base to be located on and secured to a seat of said motor vehicle, an infant seat releasably attachable to said base, and hook means between said base and infant seat that operatively engages said infant seat to hold the said infant seat with respect to said base when said infant seat is forced forward with respect to said base. 
   Prefrerably the hook means is mounted to said base. 
   It will be seen by this invention when the infant seat is forced forward with respect to said base due to collision of said motor vehicle the hook meeand on the base operatively engages with the infant seat to prevent rotation of the infant seat with respect to the base. 
   Preferably the infant seat is releasably attached to said base by a releasably engageable latch. 
   Preferably the hook means comprises at least one upstanding L-shaped post having a portion extending away from said post, said portion extending away from said post extending towards the rear of said vehicle when the infant restraint is mounted therein. 
   The portion extending away from said post preferably comprises a planar flange. 
   There may be at least one aperture in said infant seat which locates over said hook means, said hook means engagable on a edge of said aperture when said infant seat is forced forward with respect to said base. 
   Preferably the hook means aligns with said aperture so that said infant seat can be located on and removed from said base without interference by said hook means, said hook means relying upon differential movement between said infant seat and said base during a collision to operatively engage the edge of said aperture. 
   Preferably an outward edge of said flange does not overlap the edge of said aperture except upon relative movement between said infant seat and said base during a collision. 
   There may be two hook means on the base. 
   Preferably the hook means are located adjacent a foot end of said infant seat. 
   In an alternative form the invention comprises an infant restraint for a motor vehicle comprising; a base to be located on and secured to a seat of the motor vehicle, an infant seat releasably attachable to the base, a pair of hooks mounted on the base, each hook comprising an upstanding post and a flange portion extending away from the post, the flange portion extending towards the rear of the vehicle when the infant restraint is mounted therein, a pair of apertures in the infant seat, each aperture being aligned with a respective hook so that the infant seat can be located on and removed from the base without interference by the hooks and each aperture having a edge which engages with the flange portion when the infant seat is forced forward with respect to the base. 
   In an alternative form the invention comprises a base for use with an infant seat to comprise an infant restraint in a motor vehicle, said base including a pair of hooks mounted on the base, each hook comprising an upstanding post and a flange portion extending away from the post, the flange portion extending towards the rear of the vehicle when the infant restraint is mounted therein. 
   In order to fully understand the invention, a preferred embodiment will now be described. However, it should be realized that the scope of the invention is not to be restricted to the features of this embodiment. Modifications and variations such as would be apparent to a skilled addressee are to be deemed within the scope of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This embodiment is illustrated in the accompanying drawings and photographs wherein; 
       FIG. 1  shows a perspective view of a base according to one embodiment of the invention; 
       FIG. 2  shows a perspective view of an infant seat according to one embodiment of the invention; 
       FIG. 3  shows a perspective view of the base as shown in  FIG. 1  assembled with an infant seat as shown in  FIG. 2 ; 
       FIG. 4  shows a closer view of the hook means on the base according to one embodiment of the invention; 
       FIG. 5  shows a closer view of the hook means on the base engaged in an aperture in the infant seat; 
       FIG. 6  shows a detailed cross sectional view of a portion of the base and infant seat as shown in  FIGS. 1 and 2  with the hook means received in the aperture; and 
       FIG. 7  shows the view of  FIG. 6  but with the hook means engaged onto the edge of the aperture as would occur in the event of a collision. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   One embodiment of infant seat and base is shown in  FIGS. 1 to 4 . In this embodiment, the base  10  is provided with a seat belt locating means  11  that allows a seat belt (not shown) to secure the base  10  to a vehicle seat  12 . The base  10  has longitudinal recesses  13  that are engaged by projections  14  on the infant seat  15 . The infant seat  15  has a seat portion  16  and a back portion  17 . When the infant seat  15  is located within the base, the backrest portion  17  positions so that it is at an angle with respect to the horizontal. 
   Within the recesses  13 , there are latching posts  20  and there are spring loaded hooks (not shown) on the infant seat  15  that automatically engage apertures within the latching posts  20 . By placing the infant seat  15  into the base  10  so that the projections  14  locate within the recess  13 , the infant seat  15  will automatically latch to the base  10 . The infant seat  15  has a manual release (not shown) which enables it to be disconnected from the base  10 . 
   As a result of a single latch between the base  10  and the infant seat  15 , and also due to the resilient nature of the material from which both components are molded, then there tends to be some displacement of the infant seat  15  with respect to the base  10  under impact loads. In addition, the single two latches between the base  10  and infant seat  15 , are transversely aligned so there is minimal resistance to rotation of the infant seat  15  with respect to the base. 
   In order to restrain this excessive movement of the infant seat  15  with respect to the base  10 , a pair of hooks  21  are attached to base  10  and they locate through corresponding apertures  22  in the infant seat  15 . The hooks  21  and corresponding apertures  22  engage during a collision to hold the infant seat  15  with respect to the base  10 . 
   Each of the hook means  21  comprises an upwardly extending post  23  that is secured to the base  10 . The end of the post  23  has a hook comprising a flange  24  that extends from the post  23  in a direction that is towards the foot end of the infant seat  15 . 
   With respect to each aperture  22  in the infant seat  15 , there is a hook engaging edge which in this embodiment comprises a surface  25  which is the portion of the infant seat  15  immediately adjacent the aperture  22 . 
   In normal use, the aperture  22  aligns with the post  23  and flange  24  so that, as the infant seat  15  is attached to the base  10 , the flange  24  and post  23  locate through the aperture  22 . The projections  14  on the infant seat  15  have surfaces which engage with the corresponding surfaces in the recess  13  that ensure alignment of the post and flange  24  with the aperture  22  at the point where the flange  24  is immediately adjacent in the aperture  22 . 
   The projections  14  locating within the recesses  13  also accurately position the edge  26  of the surface  25  so that it is substantially directly below the forward edge  27  of the flange  24 . In this position, any forward movement of the infant seat  15  with respect to the base  10  will result in the edge  26  locating beneath flange  24 . Accordingly, any tendency for rotation of the infant seat  15  with respect to the base  10  will be arrested by the surface  25  engaging the flange  24 . 
   The location of the post  23  towards the forward edge of the base  10  positions the latching means adjacent to the seat belt locating means  11  and therefore provides maximum resistance to movement of the infant seat  15  with respect to the vehicle seat belt. Accordingly, as seen in  FIG. 5 , there should be a reduction in rotation of the head end of the infant seat  15  as any rotation should be largely limited to that which is due to compression of the vehicle seat  12 . 
     FIG. 6  shows a detailed cross sectional view of a portion of the base and infant seat as shown in  FIGS. 1 and 2  with the hook means received in the aperture and  FIG. 7  shows the view of  FIG. 6  but with the hook means engaged onto the edge of the aperture as would occur in the event of a collision. 
   In the position with the infant seat  15  normally mounted onto the base  10  the flange  24  on the hook means  21  on the base  10  enters the aperture  22  in the infant seat  15  but does not engage with the edges of the aperture  22 . This position is shown in  FIG. 6 . In the event of a collision, however, the seat  15  moves with respect to the base  10  in the direction shown by the arrow  28  in  FIG. 7  so that the flange  24  on the hook means  21  overlies the surface  25  extending back from the edge  26  of the aperture  22 . 
   Hence any tendency for the infant seat to rotate with respect to the base about the latching arrangement (not shown in  FIGS. 6 and 7 ) will be prevented. 
   In addition to the use of a hook means  21  in relation to an aperture  22 , the hook means may comprise other arrangements. For example, the hook means may incorporate elements that rotate into a hooking position using the inertia of the element under impact conditions. Other variations will be possible and are considered to be within the scope of this invention. 
   Throughout this specification various indications have been given as to the scope of this invention but the invention is not limited to any one of these but may reside in two or more of these combined together. The examples are given for illustration only and not for limitation. 
   Throughout this specification and the claims that follow unless the context requires otherwise, the words ‘comprise’ and ‘include’ and variations such as ‘comprising’ and ‘including’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.