Abstract:
A child safety seat has a seat body with first and second side zones, a first abutment zone extending between the side zones for resting on a seat cushion of a vehicle seat and a second abutment zone extending between the side zones for abutting against a seat back of said vehicle seat. Each side zone carries a strap guide mounted in proximity to both the first abutment zone and the second abutment zone. A strap extends from a strap anchorage mounted on the side zone and located on the opposite side of the strap guide to the abutment zones. The strap extends through each strap guide to a releasable connector for engagement with an anchorage on the vehicle seat. The strap has an adjustment mechanism located on the opposite side of the strap guide to the releasable connector for adjusting the length of strap between such releasable connector and the corresponding strap guide.

Description:
This application claims benefit of Provisional No. 60/138,457 filed Jun. 10, 1999. 
    
    
     FIELD 
     This invention relates to a child safety seat for use in a vehicle. 
     RELATED ART 
     It is well known for a child safety seat to rest on a vehicle seat and to be secured thereon by the corresponding vehicle seat belt. The disadvantage of this arrangement is that, even if the vehicle seat belt is pulled very tight during installation, the resilience of the belt will permit undesirable movement of the child seat relative to the vehicle in the event of sudden deceleration, for example during an accident. In order to overcome this disadvantage, it has been proposed to provide vehicle seats with standard anchorage units at agreed locations near the rear edge of the vehicle seat cushion and the bottom of the vehicle seat back for engagement by releasable connectors which are attached to the child seat, either rigidly or by relatively short straps. Such anchorage units will be referred to hereinafter as “standard anchorage units”. 
     When flexible straps are used to attach a child safety seat to standard anchorage units, the length of the strap must be sufficient to accommodate a strap adjuster to enable the strap to be tightened after the releasable connector has engaged with the corresponding standard anchorage units. On the other hand, in order to minimise angular movement of the child safety seat relative to the standard anchorage unit, transverse movement of the releasable connector relative to the child seat must be minimised. 
     SUMMARY OF THE INVENTION 
     According to the invention, a child safety seat comprises a seat body having first and second side surfaces, a first abutment surface extending between the side surfaces and adapted to abut against a seat cushion of a vehicle seat and a second abutment surface extending between the side surfaces and adapted to abut against a seat back of said vehicle seat, first and second strap guides each mounted on a respective side surface in proximity to both the first abutment surface and the second abutment surface, first and second strap anchorages each mounted on a respective side surface on the opposite side of the corresponding strap guide to the abutment surfaces, first and second straps each having a releasable connector on one end and each extending through a respective strap guide to the corresponding anchorage, and a strap adjustment mechanism located on the opposite side of the strap guide to the releasable connector for adjusting the length of strap between such releasable connector and the corresponding strap guide. 
     In one form of the invention, the adjustment mechanism comprises a respective strap adjuster for each strap located in the portion of such strap extending between the strap guide and the strap anchorage. Alternatively, each strap anchorage may be mounted on the seat body by adjustable mounting means permitting variation of its distance from the corresponding strap guide. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a vehicle seat suitable for receiving a child safety seat in accordance with the invention; 
     FIG. 2 is a side view of a first embodiment of the invention, mounted on the seat shown in FIG. 1; 
     FIG. 3 is a cross-sectional view on the line  3 — 3  in FIG. 2; 
     FIG. 4 is a plan view of an assembly comprising a releasable connector and a strap for use with the child seat shown in FIGS. 2 and 3; 
     FIG. 5 is a longitudinal sectional view of the assembly shown in FIG. 4; 
     FIG. 6 is a sectional view of the releasable connector of the assembly shown in FIGS. 4 and 5 with the mechanism in the released condition; 
     FIG. 7 is a scrap cross-sectional view, similar to FIG. 6, but showing the releasable connector in its engaged condition; 
     FIG. 8 is a side view, similar to FIG. 2, of a second embodiment of the invention; 
     FIG. 9 is a side view, similar to FIG. 2, of a third embodiment of the invention; 
     FIG. 10 is a cross-sectional view taken on the line  10 — 10  in FIG. 9; 
     FIG. 11 is a side view, similar to FIG. 2, of a fourth embodiment of the invention, with the seat facing forwardly; and 
     FIG. 12 is a side view of the embodiment shown in FIG. 11 but with the seat facing rearwardly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a vehicle seat  10  comprising a seat cushion  12 , a backrest  14  and two standard anchorage units comprising transverse rods  16  and  18  which are accessible through openings  20  and  22  in the bottom of the backrest  14  and which are rigidly secured to the frame (not shown) of the seat  10 . 
     FIG. 2 shows a forward-facing child seat in accordance with the invention comprising a seat body  24  having a seat portion  26  resting on the seat cushion  12  of the vehicle seat  10 , and a backrest  28  abutting against the backrest  14  of the vehicle seat  10 . The seat body  12  also has a side wall  30  together with another side wall which is not visible in the drawing. 
     A releasable connector  32  engages with the standard anchorage unit  18 . The connector  32  is attached by a first strap  34  to a strap adjuster  36 . A second strap  38  has one end secured to the side wall  30  of the child seat  24  by a strap anchorage  40 . The other end  42  of the second strap  38  is threaded through the strap adjuster  36 , as will be explained in more detail hereinafter. The first strap  34  is threaded through a strap guide  44  which is secured to the side wall  30  by rivets  46  and  48 . As can be seen from FIG. 3, the strap guide  44  comprises two mutually confronting hook formations  50  and  52  with a central opening  54  therebetween through which the strap can be inserted. The strap guide  44  prevents lateral movement of the strap  34 . Consequently, any possibility of angular or upward movement of the child seat body  22  relative to the vehicle seat  10  is severely restricted, provided that the straps  34  and  38  are tightened by pulling on the free end  40 . 
     The other side wall (not shown) on the other side of the child seat body  24  is a mirror image of the side wall  26  and has a similar strap arrangement with a releasable connector for engagement with the other standard anchorage unit  20 . 
     FIGS. 4 and 5 show more detail of the connection of the straps  34  and  38  to the strap adjuster  36 . The strap adjuster  36  comprises a U-shaped frame  56  with first and second fixed transverse bars  58  and  60  extending between its limbs. A third bar  62  is slidably mounted in slots in the limbs of the U-shaped frame  56  so as to be movable in a direction perpendicular to the fixed transverse bars  58  and  60  (i.e. parallel to the straps  34  and  38 ). The first strap  34  is permanently attached to the first transverse bar  58 . The second strap  38  is wrapped round the third bar  62  and then passes between this bar  62  and the second fixed bar  60  so that the third movable bar  62  moves towards the second fixed bar  60  so as to lock the strap  38  when tension is applied to the end attached to the anchorage unit  40 . Strap adjusters of this type are well known. 
     FIGS. 6 and 7 show the releasable connector  32  in more detail. The connector  32  has a body  66  with a ring  68  secured to one end, the first strap  34  being secured to the ring  68 . Two mutually parallel side flanges  70  (only one of which is visible in the drawing) project from the other end of the body  36  and have a V-shaped opening  72  therein for receiving the bar of the standard anchorage unit  18 . Inwardly of the flanges  70 , the body  66  has a transverse end wall  74  and a transverse intermediate wall  76  parallel to the wall  74  but spaced therefrom. An ejector rod  78  is slidably mounted through these two walls  74  and  76  and is urged outwardly across the inner ends of the notches  72  by a compression spring  80 . A generally L-shaped latch plate  82  is pivotally mounted on a pin  84  extending between the flanges  70  and biassed in the clockwise direction (as viewed in FIGS. 6 and 7) to the position illustrated in FIG. 6 by a spring  86 . When the connector  32  is pushed against the anchorage unit  18 , the latter engages with the shorter limb of the latch plate  82 , causing it to rotate to the position shown in FIG.  7 . The anchorage unit  18  now engages with the ejector rod  78 , displacing it inwardly and compressing the spring  80 . The latch plate  82  is held in this position by a catch plate  88 , which is pivotally mounted on a pin  90  extending between the two flanges  82  and engages round the end of the longer limb of the latch plate  82 . The catch plate  88  is pivotally coupled to one end of a connecting rod  92  which also extends through the walls  74  and  76  and which is biassed outwardly by a second compression spring  94 , thus tending to rotate the catch plate  88  in the clockwise direction into a position in which it engages with the latch plate  82 . 
     The other end of the connecting rod  92  is connected to a lever  96  which is mounted on a pivot pin  98  within the body of the connector  32 . The free end of the lever  96  projects outwardly through a slot  100  in the side wall of the body of the connector  32  so as to engage in a recess  102  in a finger grip  104  which is integrally formed with a sleeve  106 . The sleeve  106  is slidably mounted on the outside of the body  32  so that displacement of the finger grip  104  to the right as viewed in the drawing causes the connecting rod  92  to rotate the catch plate  88  in the counter-clockwise direction so as to cause it disengage from the latch plate  82 . The spring  86  then rotates the latch plate  82  in the clockwise direction back to the position illustrated in FIG. 6 as the ejector rod  78  pushes the connector  32  clear of the anchorage unit  18 . 
     FIG. 8 shows a second embodiment of the invention comprising a rearward facing seat having a seat body  110  having a first abutment surface  112  near the bottom of its backrest, resting on the vehicle seat cushion and a second abutment surface  114  at the front edge of its seat portion  118  adapted to abut against the backrest  14  of the vehicle seat. The seat body  110  has a strap assembly including a strap anchorage  120  and a strap guide  122  on its side wall  124  which are identical to the strap anchorage  40  and the strap guide  44  of FIG. 2 but which are positioned at somewhat different locations. Associated with the strap anchorage  120  and strap guide  122  are a strap assembly comprising first and second straps  34  and  38 , a strap adjuster  36  and a releasable connector  32  which engages with the anchorage unit  18 . These components are identical with the correspondingly numbered components in FIGS. 2 and 3 and will not be described in detail. A similar strap assembly is mounted on the opposite side wall of the child seat body  110  for engagement with the other anchorage unit  20 . 
     FIGS. 9 and 10 show a third embodiment of the invention comprising a forward facing seat having a seat body  130  which is identical with the seat body  24  of FIG.  2 . The only difference is that the strap guide  44  of FIG. 2 is replaced by an alternative strap guide  132  which is shown in more detail in FIG.  10 . The strap guide  132  comprises a static base part  134  which is secured to the side  130  of the seat by the rivets  44  and  46 . On one side of the strap  34 , the base part  134  has an upstanding projection  136  carrying a pivot pin  138  which engages in one end of a clamp bar  140 . The other end of the clamp bar  140  comprises an integrally formed hand-grip portion  142 . Adjacent to the hand-grip portion  142  is a hook formation  144  which engages with a complimentary formation on a projection  146  on the static base  134 . When so engaged, the first strap  34  is clamped between the base part  134  and the clamp bar  140 . The clamp bar  140  is formed of a material which is sufficiently resilient to allow bending of a reduced thickness portion  148  thereof so as to permit disengagement of the hook formation  144  from the projection  146 . A similar strap guide is provided on the other side of the seat body  130 . 
     FIG. 11 shows a fourth embodiment of the invention comprising a forward facing seat having a seat body  150  which is similar to the seat body  24  of FIG. 2 but shaped so that it can also be used facing rearwardly, as shown in FIG.  12 . The seat body  150  has a strap assembly including a strap anchorage  152  and a strap guide  154  on its side wall  156  which are identical to the strap anchorage  40  and the strap guide  44  of FIGS. 2 and 3. Associated with the strap anchorage  152  and strap guide  154  are a strap assembly comprising first and second straps  34  and  38 , a strap adjuster  36  and a releasable connector  32  which engages with the anchorage unit  18 . These components are identical with the correspondingly numbered components in FIGS. 2 and 3 and will not be described in detail. A second strap guide  158 , identical to the strap guide  154 , is positioned on the side wall  156  for use when the seat body  150  is facing rearwardly, as shown in FIG. 12. A similar strap assembly is mounted on the opposite side wall of the child seat body  150  for engagement with the other anchorage unit  20 . 
     The strap guides  154  and  158  may be replaced by strap guides of the type shown in FIG.  10 . 
     For the avoidance of doubt, it is hereby confirmed that the term “comprising” is used herein to mean both “including” and “consisting of”. The terms “comprise” and “comprises” have equivalent meanings.