Abstract:
An improved infant car seat can be attached to and detached from a car seat base and a stroller. The stroller can be used with or without the infant car seat. The infant car seat connects to the stroller frame through a bar that supports a tray at the front of the stroller. The tray slides out of the way for car seat attachment.

Description:
REFERENCE TO RELATED APPLICATION 
   This application is a divisional of U.S. patent application Ser. No. 10/152,921, filed on May 21, 2002, now U.S. Pat. No. 6,834,915, which claims priority to U.S. provisional application Ser. No. 60/361,922, filed Mar. 4, 2002, the entire disclosures of which are hereby incorporated by reference herein. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to infant car seats for seating and transporting infants and small children. 
   2. Description of the Related Art 
   Infant car seats are commonly used to conveniently and safely seat and transport infants and small children. Such car seats generally comprise a molded plastic seat shell having a seat back for supporting the infant and a U-shaped handle that extends across the seat shell for carrying the seat shell. 
   Infant car seat systems include various other elements that can be used in connection with the car seat, such as strollers and car seat bases for supporting the car seat on the seat of a vehicle. The interconnection mechanisms between the car seat and the other elements, however, can often be difficult or confusing to operate. 
   Attachment of the car seat base to the vehicle seat is typically accomplished by routing the vehicle seat belt through various slots in the base, which can often be difficult and time consuming. In addition, the slots in the base are typically linear, and do not very well accommodate the range of seat belt entry angles that results from the differing locations of the seat belt buckles in various vehicle makes and models. Accordingly, the seat belt can become twisted and caught in the slots. 
   Some existing car seat bases include adjustment mechanisms to allow adjustment of the angular orientation of the car seat when the car seat is situated on the base. Such adjustment mechanisms, however, are typically located at the end of the base positioned against the vehicle seat back, making them difficult to reach and operate. In addition, the adjustment mechanisms typically operate by raising or lowering the end of the base adjacent the seat back, which can interfere with, and require readjustment of, the connection between the base and the vehicle seat. 
   Some car seat systems include strollers to which the car seat can be connected. Such strollers typically include a bar that extends across the frame of the stroller to support the car seat. In some systems, a detachable tray can be connected to the bar when the car seat is disconnected from the stroller to allow a larger child to be seated in the stroller seat. The tray can be used to support items such as drink cups, food and toys. Because the tray is detachable from the bar, however, the tray can easily be misplaced. 
   SUMMARY OF THE INVENTION 
   Accordingly, an infant carrier system is provided wherein the interconnection mechanisms between the carrier and the other elements of the system are convenient and simple to operate. 
   In accordance with one aspect of the present invention, a base is provided for supporting an infant car seat on a vehicle seat. The base comprises a main body, a foot portion beneath the main body, a lifter between the main body and the foot portion, the lifter having a threaded recess, and a screw extending into the recess. Rotation of the screw moves the lifter along the foot portion to extend or retract the foot portion relative to the main body. 
   In accordance with another aspect of the present invention, a base for supporting an infant car seat on a seat of a vehicle is provided. The base comprises a main body, a first rail slideably connected to the main body, the first rail having a latch at an end thereof for connection to the vehicle, and a second rail slideably connected to the main body, the second rail having a latch at an end thereof for connection to the vehicle. A first lock is associated with the first rail to selectively engage the first rail to lock the first rail in position relative to the main body. A second lock is associated with the second rail to selectively engage the second rail to lock the second rail in position relative to the main body. 
   In accordance with another aspect of the present invention, an apparatus is provided, comprising a base and an infant car seat. The base includes a main body and a connection bracket extending from the main body. The connection bracket includes a first side wall having a first slot therein, a first pawl pivotably connected adjacent the first side wall, a biasing member biasing the first pawl towards the first slot, a second side wall spaced apart from the first side wall and having a second slot therein, a second pawl pivotably connected adjacent the second side wall, and a second biasing member biasing the second pawl towards the second slot. The infant car seat includes a seat shell and a rod extending through the seat shell. The rod extends into the first and second slots when the car seat is situated on the base. The first and second pawls extend over the rod to lock the car seat to the base. 
   In accordance with another aspect of the present invention, an apparatus is provided, comprising an infant car seat and a stroller. The infant car seat includes a first support having a first recess therein, a second support having a second recess therein, a first mounting hook, a second mounting hook, a first release strap and a second release strap. The first mounting hook includes a first leg and a second leg connected to the first leg. The first leg has a barb extending therefrom. The barb extends into the first recess. The second mounting hook includes a first leg and a second leg connected to the first leg. The first leg has a barb extending therefrom. The barb extends into the second recess. The first strap connects the release handle to the first leg of the first mounting hook. The second strap connects the release handle to the first leg of the second mounting hook. The stroller includes a stroller frame and a bar connected to a bar connected to the stroller frame. The bar includes a first opening, a first engagement surface, a second opening, and a second engagement surface. The first and second supports extend into the first and second openings when the car seat is situated on the bar. The barbs engage the first and second engagement surfaces to lock the car seat to the stroller. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of one embodiment of an infant car seat having certain features and advantages in accordance with the present invention; 
       FIG. 2  is a front perspective view of the infant car seat illustrating the movable seat back and adjustment mechanism in exploded view; 
       FIG. 3  is a rear perspective view of the infant car seat illustrating the movable seat back and adjustment mechanism in exploded view; 
       FIG. 4  is a rear perspective view of the movable seat back; 
       FIG. 5  is a front perspective view of the inner member of the adjuster of the adjustment mechanism; 
       FIG. 6  is a side elevational view of the inner member; 
       FIG. 7  is side elevational view of the inner member rotated 90 degrees from the orientation of  FIG. 6 ; 
       FIG. 8  is a front perspective view of the biasing member of the adjustment mechanism; 
       FIG. 9  is a front perspective view of the infant car seat with a portion of the movable seatback cut away to illustrate the adjustment mechanism; 
       FIG. 10  is an enlarged cutaway view of the adjustment mechanism with the adjuster in a first rotational orientation; 
       FIG. 11  is an enlarged cutaway view with the adjustment mechanism with the adjuster rotated 90 degrees from the first rotational orientation of  FIG. 10 ; 
       FIG. 12  is a left side view of the infant car seat with the left sides of the car seat and the movable seat back cut away to illustrate the routing of one of the safety belts of the car seat; 
       FIG. 13  is a rear view of the splitter plate of the infant car seat; 
       FIG. 14  is a rear view of the splitter plate with the safety belts of the car seat connected thereto; 
       FIG. 15  is a perspective view of the splitter plate illustrating a first step in the connection of one of the safety belts; 
       FIG. 16  is a perspective view of the splitter plate illustrating a second step in the connection of the safety belt of  FIG. 15 ; 
       FIG. 17  is a left side view of the infant car seat with both viewing areas of the angle indicator of the car seat indicating a proper angular orientation of the car seat; 
       FIG. 18  is a left side view of the infant car seat illustrating the pendulum of the angle indicator in phantom; 
       FIG. 19  is a side elevational view of the pendulum; 
       FIG. 20  is a top plan view of the pendulum; 
       FIG. 21  is a left side view of the infant car seat with one of the viewing areas of the angle indicator of the car seat indicating an improper angular orientation of the car seat; 
       FIG. 22  is a perspective view of the top of a car seat base for use in connection with the infant car seat; 
       FIG. 23  is a perspective view of the bottom of the base with the foot portion of the base removed; 
       FIG. 24  is a perspective view of the one of the rails, rail guides and lock mechanisms of the base; 
       FIG. 25  is a cross-sectional view of the rail, rail guide and lock mechanism taken through the rail guide and lock mechanism; 
       FIG. 26  is a perspective view of one of the lock stampings of the lock mechanism; 
       FIG. 27  is a cross-sectional view of the base taken through one of the rails; 
       FIG. 28  is a perspective view of the bottom of the car seat; 
       FIG. 29  is a perspective view of the bottom of the release handle of the car seat; 
       FIG. 30  is a left side view of the car seat with a portion of the left side cut away to illustrate the manner of operation of the release handle; 
       FIG. 31  is a perspective view of the connection bracket of the base; 
       FIG. 32  is a left side view of the connection bracket; 
       FIG. 33  is a perspective view of the car seat and base; 
       FIG. 34  is a left side view of the car seat and base with the car seat connected to the base; 
       FIG. 35  is a perspective view of the lifter of the base; 
       FIG. 36  is a left side view of the lifter; 
       FIG. 37  is a perspective view of the bottom of the base; 
       FIG. 38  is a perspective view of the foot portion of the base; 
       FIG. 39  is a left side view of the foot portion; 
       FIG. 40  is a cross-sectional view of the base taken alongside one of the side walls of the connection bracket; 
       FIG. 41  is a perspective view of a stroller for use in connection with the car seat; 
       FIG. 42  is a perspective view of the bottom of the tray of the stroller; 
       FIG. 43  is a top plan view of the tray bar of the stroller; 
       FIG. 44  is a rear elevational view of the tray bar; 
       FIG. 45  is a cross-sectional view of the tray and tray bar taken along one of the runners of the tray, with the tray cradled in the tray bar; 
       FIG. 46  is a cross-sectional view of the tray and tray bar taken along one of the runners of the tray, with the tray rotated away from the tray bar; 
       FIG. 47  is a perspective view of the tray bar and tray, with the tray rotated away from the tray bar; 
       FIG. 48  is a perspective view of the car seat and the stroller, with the car seat connected to the stroller; 
       FIG. 49  is a perspective view of the bottom of the car seat and tray bar, with the car seat connected to the tray bar; and 
       FIG. 50  is a perspective view of one of the supports connected to the stroller, with the support deployed to support the car seat. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference initially to  FIG. 1 , an infant car seat  20  is illustrated having certain features and advantages in accordance with the present invention. In the illustrated embodiment, the infant car seat  20  includes a molded plastic seat shell  22  having a head end  24  and a foot end  26 . The seat shell  22  includes a seating surface  28  and a pair of side walls  30  that extend upwardly from the sides of the seating surface  28 . The seating surface  28  and the side walls  30  are preferably covered with a removable padding material (not shown) to comfortably support an infant in the seat shell  22 . 
   As illustrated in  FIG. 1 , a handle assembly  38  extends transversely across the seat shell  22  and is connected to the side walls  30 . In the illustrated embodiment, the handle assembly  38  includes a generally triangular central grip portion  40  and a pair of handle arms  42  that extend towards the side walls  30  from the grip portion  40 . The ends of the handle arms  42  opposite the grip portion  40  preferably are rotatably connected to the seat shell by rivets  44  or other suitable fasteners that extend through openings  46  in the ends of the handle arms  42 . The rivets  44  preferably extend through brackets (not shown) which, in turn, are connected to the side walls  30  of the seat shell. 
   A lock mechanism  50  preferably is provided at the end of each of the handle arms  42  to lock the handle assembly  38  in a desired rotational position relative to the seat shell  22 . In the illustrated embodiment, the lock mechanisms  50  are operated by actuators  54  that extend from pockets in the handle arms  42 . When both of the actuators  54  are manually pressed into the pockets, the handle assembly  38  can be rotated relative to the seat shell  22 . In  FIG. 1 , the handle assembly  38  is illustrated in a typical carrying orientation, wherein the handle assembly  38  extends above the seat shell  22 . By pressing the actuators  54 , the handle assembly  38  can be rotated and locked behind the head end  24  of the seat shell, for example, to more conveniently allow an infant to be placed in or removed from the car seat  20 . 
   It is to be understood that the particular configurations of the handle assembly  38  and handle lock mechanisms  50  illustrated are merely exemplary. Those skilled in the art will recognize that other suitable handle assemblies and handle lock mechanisms can alternatively be used. 
   Movable Seat Back 
   With reference now to  FIGS. 2 and 3 , in the illustrated embodiment, the infant car seat  20  includes a movable seat back  60 . The seat back  60  has an elongated center portion  64  and a head rest portion  66  that extends outwardly from the sides of the center portion  64 . A head rest insert  68 , preferably comprising an expanded polystyrene (EPS) foam, fits over the head rest portion  66  to support the head of an infant occupying the car seat  20 . 
   As best illustrated in  FIG. 4 , a shoulder belt channel  70  is formed along each side of the center portion  64  of the seat back  60  by ribs  74  that extend from the center portion  64 . A transversely extending slot  76  is provided at an end of each of the channels  70  for passage of a first safety belt  80  and a second safety belt  82  (see  FIG. 14 ). A number of hooks  84  extend from the sides of the center portion  64  to connect the seat back  60  to the seat shell  22  in a manner to be described in greater detail below. 
   In the illustrated embodiment, the car seat  20  includes an adjustment mechanism  88  to adjust the longitudinal position of the seat back  60  relative to the seat shell  22 . With reference still to  FIG. 4 , the adjustment mechanism  88  includes a plurality of adjustment teeth  90 , which are provided along the center portion  64  of the seat back  60 . In the illustrated embodiment, the adjustment teeth  90  are arranged in a line extending longitudinally along the center portion  64 . The individual adjustment teeth  90  extend laterally towards a side of the center portion  64  and define a number of generally U-shaped valleys  94  therebetween. 
   As illustrated in  FIGS. 2 and 3 , the adjustment mechanism  88  further includes an adjuster  98  and a biasing member  100 . In the illustrated embodiment, the adjuster  98  includes an inner member  104  and an outer member  106 . The inner member  104 , illustrated in  FIGS. 5–7 , includes a main body  108  having a larger diameter portion  110  and a smaller diameter portion  112 . A first cylindrical projection  120  and a second cylindrical projection  122  extend from the larger diameter portion  110 . Each of the projections  120 ,  122  has a central axis offset from a central axis of the main body  108 . Preferably, the projections  120 ,  122  are aligned on opposite sides of the central axis of the main body  108 . As best illustrated in  FIG. 7 , a pair of tabs  126  extends from the smaller diameter portion  112  of the main body  108 . 
   As best illustrated in  FIG. 8 , the biasing member  100  comprises a generally K-shaped member having a contact segment  136  and a pair of cantilever legs  138 . Each of the legs  138  is attached at one end to a side of the contact segment  136 . A rib  140  extends along the side of the contact segment  136  to reinforce the contact segment  136 . 
   With reference again to  FIG. 3 , in the illustrated embodiment, a recessed area  146  is provided in the seating surface  28  of the seat shell  22  near the head end  24  of the seat shell  22 . A transversely extending slot  150  is provided in the recessed area  146 . Preferably, the height of the slot  150  in the longitudinal direction of the seat shell  22  is slightly greater than the diameter of the smaller diameter portion  112  of the main body  108  of the inner member  104 , and less than the diameters of the larger diameter portion  110  and the outer member  106  of the adjuster  98 . 
   The inner member  104  of the adjuster  98  is positioned on the inside of the seat shell  22  so that the larger portion  110  of the main body  108  abuts the seat shell  22  and the smaller portion  112  extends through the slot  150 . The outer member  106  of the adjuster  98  is positioned on the outside of the seat shell  22  and is aligned with the inner member  104 . The tabs  126  of the inner member  104  extend into openings  154  (see  FIG. 2 ) formed in the outer member  106 . One or more screws (not shown) extend through the inner member  104  into the outer member  106  to connect the inner member  104  to the outer member  106 , thereby retaining the adjuster  98  in the slot  150 . 
   With reference now to  FIG. 9 , the seat back  60  is positioned at the inside of the seat shell  22  so that the ribs  74  defining the shoulder belt channels  70  extend into the recessed area  146  of the seat shell  22 . The hooks  84  at the sides of the seat back  60  extend into longitudinal slots  156  that extend along the seating surface  28  below the recessed area  146 . A fastener, such as a rivet (not shown), extends through an opening  152  provided in the seat back  60  above the adjustment teeth  90 , and through a longitudinally extending slot  154  provided in the seat shell  22 . The seat back  60  is thereby slideably connected to the seat shell  22 . Additional fasteners (not shown) may be provided through various openings (not shown) in the seat back  60  and slots (not shown) in the seat shell  22 , as necessary, to retain the seat back  60  in parallel to the recessed area  146  of the seat shell  22 . 
   The biasing member  100  is positioned between the seat back  60  and the seat shell  22 . As best illustrated in  FIG. 10 , a first rib  160  extends longitudinally along the recessed portion  146  of the seat shell  22 . A second rib  162  and a third rib  164  extend laterally along the recessed portion  146  from the first rib  160  towards the adjuster  98 . The legs  138  of the biasing member  100  contact the first rib  160 . The contact segment  136  of the biasing member  100  contacts the adjustment teeth  90  provided along the seat back  60 . 
   When the adjuster  98  is oriented as shown in  FIGS. 9 and 10 , each of the projections  120 ,  122  resides in one of the valleys  94  between the adjustment teeth  90 . The second projection  122  is above the first projection  120 . The first and second projections  120 ,  122  cooperate with the adjustment teeth  90  to fix the longitudinal position of the seat back  60  relative to the seat shell  22 . 
   When the adjuster  98  is rotated as illustrated in  FIG. 11 , the first projection  120  abuts the bottom of one of the valleys  94  between the adjustment teeth  90 . The second projection  122  contacts and slides along the contact segment  136  of the biasing member  100 . The contact segment  136  is moved towards the first rib  160 , causing the legs  138  of the biasing member  100  to flex. The second and third ribs  162 ,  164  help to retain the biasing member  100  in place as the second projection  122  slides along the contact segment  136 . 
   As the adjuster  98  is rotated, the axis of rotation of the main body  108  is moved laterally in the slot  150  away from the adjustment teeth  90 . As a result, the first projection  120  is moved generally linearly along the longitudinal axis of the seat shell  22 . When the adjuster  98  is rotated from the orientation of  FIGS. 9 and 10  to the orientation of  FIG. 11 , the first projection  120  is moved longitudinally towards the head end  24  of the seat shell  22 . The second projection  122  is rotated around the first projection  120  towards the foot end  26  of the seat shell  22 . 
   As the adjuster  98  is rotated beyond the orientation illustrated in  FIG. 11 , the axis of rotation of the main body  108  is moved laterally in the slot  150  back towards the adjustment teeth  90 . The biasing member  100  urges the second projection  122  towards the adjustment teeth  90  and into the valley  94  below the first projection  120 . Thus, as adjuster  98  is rotated counterclockwise (from a perspective inside the seat shell) 180 degrees from the orientation of  FIGS. 9 and 10 , the second projection  120  is rotated from the valley  94  above the first projection  120  to the valley  94  below the first projection  120 , thereby extending the seat back  60  relative to the seat shell  22 . 
   Accordingly, by rotating the adjuster  98 , the longitudinal position of the seat back  60  can be adjusted to accommodate infants of various sizes. The first and second projections  120 ,  122  mate with the adjustment teeth  90  to extend or retract the seat back  60  relative to the seat shell  22 . Preferably, as illustrated in  FIG. 11 , a stop surface  172  is provided at each end of the adjustment teeth  90  so that, when the seat back  60  is fully extended or retracted, one of the projections  120 ,  122  abuts the stop surface  172  to prevent the adjuster  98  from being further rotated. 
   Advantageously, the movable seat back  60  allows the car seat  20  to be better fitted to the size of the infant occupying it. The seat back  60  can be extended as the infant grows. By adjusting the position of the seat back  60  relative to the seat shell  22 , the head rest portion  66  can be moved into place behind the infant&#39;s head, increasing the comfort and safety of the infant. 
   The movable seat back  60  of the illustrated embodiment is simple and convenient to adjust. It can be extended or retracted simply by rotating the adjuster  98 . In contrast to some prior art car seats, the first and second safety belts  80 ,  82  need not be re-threaded through the seat back  60  and/or the seat shell  22  to fit the infant after the seat back  60  has been adjusted. As the seat back  60  is adjusted, the safety belt harness is also adjusted. As a result, the potential for misuse of the car seat  20  is reduced. 
   Splitter Plate 
   With reference again to  FIG. 3 , in the illustrated embodiment, a safety belt slot  180  is provided in the recessed area  146  of the seat shell  22  on each side of the adjuster slot  150 . Preferably, the safety belt slots  180  in the seat shell  22  are located so that they are generally in registration with the safety belt slots  76  in the seat back  60  when the seat back  60  is fully extended relative to said seat shell  22 . 
   With reference now to  FIG. 12 , the first safety belt  80  extends from the inside of the seat shell  22  through one of the safety belt slots  76  in the seat back  60 . The second safety belt  82  (not shown in  FIG. 12 ) extends from the inside of the seat shell  22  through the other safety belt slot  76  in the seat back  60 . The first and second safety belts  80 ,  82  extend through the channels  70  in the seat back  60  and through the safety belt slots  180  in the seat shell  22 . 
   As the position of the seat back  60  is adjusted to fit the size of the infant occupying the car seat  20 , the safety belt slots  76  in the seat back  60  are moved to position them directly above the shoulders of the infant. The first and second safety belts  80 ,  82  preferably are connected to a buckle (not shown) positioned in front of the infant. The buckle preferably is connected to various other belts (not shown) that extend between or around the legs of the infant, as is well known in the art, to restrain the infant in the car seat  20 . In the illustrated embodiment, the buckle is connected to a crotch belt (not shown) that extends from a crotch belt pocket  184  (see  FIG. 28 ) near the foot end  26  of the seat shell  22 . 
   With reference to  FIG. 13 , the first and second safety belts  80 ,  82  preferably are connected behind the seat shell  22  to a splitter plate  188 . In the illustrated embodiment, the splitter plate  188  includes a lower portion  190  and an upper portion  192  extending over the lower portion  190  from a first side of the lower portion  190  towards a second side of the lower portion  190 . A gap  196  is provided between an end of the upper portion  192  and the second side of the lower portion  190 . 
   The upper portion  192  preferably has a curved interior surface  200  and includes a retainer  202  that extends inwardly from the end of the upper portion  192 . The lower portion  190  preferably includes a first retainer  204  that extends inwardly from the first side of the lower portion  190  and a second retainer  206  that extends inwardly from the second side of the lower portion  190 . 
   As illustrated in  FIG. 14 , the first and second safety belts  80 ,  82  preferably each have an end that is folded over and sewn to form a loop  210 . A third safety belt  216 , preferably also having a looped end  210 , is connected to the splitter plate  188  by sliding the looped end  210  over the lower portion  190  of the splitter plate  188 . A first side of the looped end  210  is first slid beneath the first retainer  204  of the lower portion, as illustrated in  FIG. 15 . The looped end  210  is then bunched together, as illustrated in  FIG. 16 , to allow a second side of the looped end  210  to slide beneath the second retainer  206 , thereby preventing the looped end  210  of the third safety belt  216  from sliding off of the lower portion  190  of the splitter plate  188 . 
   With reference again to  FIG. 14 , the first and second safety belts  80 ,  82  are connected to the splitter plate  188  by sliding the looped ends  210  over the upper portion  192  of the splitter plate  188 . The retainer  202  prevents the looped ends  210  from sliding off of the upper portion  192 . Advantageously, because the looped ends  210  of the first, second and third safety belts  80 ,  82 ,  216  can be slid through the gap  196 , the sewing of the looped ends  210  can be performed prior to connecting the belts  80 ,  82 ,  216  to the splitter plate  188 . 
   The curved interior surface  200  of the upper portion  192  of the splitter plate  188  accommodates the converging arrangement of the first and second safety belts  80 ,  82  and allows a greater width of the looped ends  210  to contact the upper portion  192  of the splitter plate  188 . The curved surface  200  further prevents bunching of the looped ends  210  of the first and second safety belts  80 ,  82  at the ends of the upper portion  192 . 
   With reference again to  FIG. 1 , the end of the third safety belt  216  opposite the splitter plate  188  preferably is routed through an opening  220  of a tensioning device  222  provided near the foot end  26  of the seat shell  22 , as is well known in the art. When the tensioning device  222  is actuated, the third safety belt  216  can be drawn through the opening  220 . When the device  222  is released, the belt  216  is constrained in the opening  220 . Accordingly, by operating the tensioning device  222 , the length of the third safety belt  216  extending behind the seat shell  22  can be varied. By reducing the effective length of the third safety belt  216 , the splitter plate  188 , and thus the ends  210  of the first and second safety belts  80 ,  82 , can be drawn towards the foot end  26  of the seat shell  22  to remove any excess slack in the first and second safety belts  80 ,  82  and secure the infant in the car seat  20 . 
   Multiple-Range Angle Indicator 
   With reference now to  FIG. 17 , in the illustrated embodiment, the infant car seat  60  includes a multiple-range angle indicator  230 . As discussed above, it is important for the safety of the infant that the infant not be too inclined or too reclined in the car seat  20  when the car seat  20  is being transported in an automobile. Generally, the seat shell  22  should be more inclined or upright when transporting larger infants, and more reclined when transporting smaller infants. The multiple-range angle indicator  230  of the illustrated embodiment allows the proper angular orientation of the seat shell  22  to be determined based on the weight of the infant occupying the car seat  20 . 
   With reference again to  FIG. 9 , in the illustrated embodiment, a large pocket  234  is provided in the seat shell  22  on each side of the seating surface  28 . As illustrated in  FIG. 3 , each of the pockets  234  is defined by an inner side wall  236  and an outer side wall  238  that extend generally vertically beneath the seating surface  28 . The inner and outer side walls  236 ,  238  of each pocket  234  form a support  242  for supporting the car seat  20 . Preferably, each of the supports  242  has a curved bottom surface  246  to allow the car seat  20  to rock back and forth on the supports  242  when the car seat  20  is placed on a floor or other surface. 
   A pendulum  250  preferably is pivotably suspended in one of the pockets  234  of the car seat  20 , as illustrated in  FIG. 18 . As best illustrated in  FIGS. 19 and 20 , in the illustrated embodiment, the pendulum  250  is generally triangular in shape, having a first side  252 , a second side  254 , a bottom  256 , and a face  258 . An axle  260  having cylindrical ends is provided at the apex of the first and second sides  252 ,  254 . Preferably, the pendulum  250  is molded from a plastic material having a bright color that contrasts with the color of the seat shell  22 . 
   As illustrated in  FIG. 19 , an opening  280  is provided through the face  258  of the pendulum  250 . The opening  280  generally includes a first region  282  at a first radial distance from the center of the axle  260  of the pendulum  250 , and a second region  284  at a second radial distance from the center of the axle  260  greater than the first distance. The first region  282  is bounded by a first line L 1  extending through the center of the axle  260 , and a second line L 2  extending through the center of the axle  260  at an angle α with respect to the first line L 1 . In the illustrated embodiment, the angle α is approximately 9 degrees. The second region  284  is bounded by a third line L 3  extending through the center of the axle  260 , and a fourth line L 4  extending through the center of the axle  260  at an angle β with respect to the third line L 3 . In the illustrated embodiment, the angle β is approximately 16 degrees. 
   With reference again to  FIG. 18 , a rib  262  having generally U-shaped cutout  264  preferably extends upwardly into one of the pockets  234 . An opening  266  is provided in one of the side walls  236 ,  238  across from the cutout  264 . The pendulum  250  is pivotably supported in the cutout  264  and the opening  266 . 
   As the car seat  20  is inclined or reclined, gravity causes the pendulum  250  to pivot within the pocket  234 . In the illustrated embodiment, a first viewing area  290  and a second viewing area  292  are provided in the outer side wall  238  of the pocket  234 . Preferably, the first and second viewing areas  290 ,  292  comprise openings in the outer side wall  238 . The location of the first viewing area  290  is selected so that, when the angular orientation of the seat shell  22  is proper for an infant having a weight within a first weight range, the first region  282  of the opening  280  in the pendulum  250  is in registration with the first viewing area  290 . As a result, the face  258  of the pendulum  250  is not visible in the first viewing area  290 . 
   When the seat shell  22  is too inclined or too reclined for an infant having a weight within the first weight range, the pendulum  250  pivots in the pocket  234  so that at least a portion of the face  258  of the pendulum  250  is visible in the first viewing area  290 , as illustrated in  FIG. 21 . Thus, by looking to see whether the face  258  of the pendulum  250  is visible in the first viewing area  290 , it can be determined whether the angular orientation of the seat shell  22  is proper for transporting an infant having a weight within the first weight range. 
   Similarly, the location of the second viewing area  292  is selected so that, when the angular orientation of the seat shell  22  is proper for an infant having a weight within a second weight range, the second region  284  of the opening  280  in the pendulum  250  is in registration with the second viewing area  292 . When the seat shell  22  is too inclined or too reclined for an infant having a weight within the second weight range, the pendulum  250  pivots in the pocket  234  so that at least a portion of the face  258  of the pendulum  250  is visible in the second viewing area  292 . Accordingly, by looking to see whether the face  258  of the pendulum  250  is visible in the second viewing area  292 , it can be determined whether the angular orientation of the seat shell  22  is proper for transporting an infant having a weight within the second weight range. 
   With reference still to  FIG. 21 , in the illustrated embodiment, a label  298  having instructions concerning the proper use of the angle indicator  230  is applied to the outer side wall  238 . In illustrated embodiment, the label  298  indicates that the first viewing area  290  is to be used if the infant occupying the car seat  20  weighs less than 20 pounds, and the second viewing area  292  is to be used if the infant weighs more than 20 pounds. 
   Those of ordinary skill in the art will recognize that, by increasing or decreasing the angle α, the range of angular orientations of the seat shell  22  that the angle indicator  230  indicates as “proper” for a child having a weight within the first weight range (i.e., less than 20 pounds in the illustrated embodiment) can be increased or decreased, respectively. Similarly, by increasing or decreasing the angle β, the range of angular orientations of the seat shell  22  that the angle indicator  230  indicates as “proper” for a child having a weight within the second weight range (i.e., more than 20 pounds in the illustrated embodiment) can be increased or decreased, respectively. 
   It will be further recognized that the particular range of angular orientations of the seat shell  22  that the angle indicator  230  indicates as “proper” for a child having a weight within the first weight range depends on the particular sizes, shapes, and relative locations of the first viewing area  290  and the first region  282  of the opening  280  in the pendulum  250 . Similarly, the particular range of angular orientations of the seat shell  22  that the angle indicator  230  indicates as “proper” for a child having a weight within the second weight range depends on the particular sizes, shapes, and relative locations of the second viewing area  292  and the second region  284  of the opening  280  in the pendulum  250 . 
   It is to be understood that various modifications may be made to the angle indicator  230  of the illustrated embodiment. For example, in alternative embodiments, the angle indicator may include more than two viewing areas, and the opening in face of the pendulum may include more than two regions, to indicate the proper angular orientation of the seat shell for more than two different infant weight ranges. Instead of providing an opening in the face of the pendulum, a label may be affixed to the face of the pendulum. Preferably, the label would have a color that contrasts with the color of the surrounding face of the pendulum, so that the proper angular orientation of the seat shell could be determined based on the color that is visible through the appropriate viewing area. 
   Connection of Car Seat Base to Vehicle 
   The infant car seat  20  can be positioned directly on the seat of a vehicle and secured to the vehicle seat by passing the vehicle seat belt through curved slots  304  (see  FIG. 21 ) provided in the sides of the seat shell  22 . Preferably, however, with reference to  FIG. 22 , a base  320  is provided for supporting the car seat  20  on the vehicle seat to allow the car seat  20  to be quickly installed and removed from the vehicle. In the illustrated embodiment, the base  320  includes a main body  324 , preferably having a rigid, double-walled blow-molded construction. The base  320  can be secured to the vehicle seat by routing the vehicle seat belt (not shown) over the main body  324  and through a pair of curved slots  328  formed in a connection bracket  330  that extends upwardly from the main body  324 . The curvature of the slots  328  serves to accommodate multiple entry angles of the seat belt resulting from the differing locations of the seat belt buckles in various vehicle makes and models. 
   If the vehicle in which the base  320  is situated is provided with universal anchors (not shown), the base is preferably connected to the anchors. The universal anchors comprise 6 mm pins, which typically are located near the junction of the vehicle seat bottom and the vehicle seat back. In the illustrated embodiment, latches  332  extend from an end of the main body  324  of the base for connection to the anchors. The latches  332  can be of any known type suitable for use in universal anchoring systems. 
   Government safety regulations dictate certain dimensional ranges for the locations of the anchors relative to one another and relative to the vehicle seat. Accordingly, the latches  332  preferably are movable relative to the main body  324  of the base  320  in order to accommodate the full dimensional ranges allowed under the regulations. With reference to  FIG. 23 , in the illustrated embodiment, each of the latches  332  is attached to an end of an elongated rail  340 . The rails  340  reside in channels  344  formed along the sides of the base  320 . 
   In the illustrated embodiment, a first cross-member  350  and a second cross-member  352  extend laterally between the rails  340 . A rail guide  358  is connected to each end of each of the cross-members  350 ,  352 . The rail guides  358  reside in recesses  360  formed in the underside of the main body  324 . As best illustrated in  FIGS. 24 and 25 , each of the rail guides  358  preferably has a generally U-shaped cross-section and includes a top wall  364  and two generally parallel side walls  366 . The rails  340  extend through slots  368  provided in the side walls  366  of the rail guides  358 . 
   In the illustrated embodiment, a lock mechanism  380  is provided at each of the rail guides  358  of the first cross-member  350  to selectively lock the rails  340  in place relative to the rail guides  358 . Each of the lock mechanisms  380  preferably includes a lock arm  384  comprising a pair of elongated stampings  386 . As illustrated in  FIG. 26 , each of the stampings  386  has a longitudinally extending slot  388  in an end thereof. The height of the slot  388  preferably is slightly greater than the cross-sectional height of the rails  340 . 
   The lock arms  384  preferably extend through openings  390  provided in the top walls  364  of the rail guides  358 , as illustrated in  FIG. 25 . The rails  340  extend through the slots  388  at the ends of the lock arms  384 . A coil spring  396  preferably is provided around each of the rails  340  between the lock arms  384  and the side walls  366  of the rail guides  358  opposite the latch  332  ends of the rails  340 , forcing the ends of the lock arms  384  towards the side walls  366  adjacent the latches  332 . 
   When the rails  340  are pulled away from the main body  324  of the base  320 , the lock arms  384  tend to pivot against the top walls  364  of the rail guides  358  so that the lock arms  384  are more parallel to the rails  340 . As a result, the lock arms  384  contact and “bite” into the top and bottom surfaces of the rails  340 , thereby preventing the rails  340  from being further extended relative to the main body  324 . When the rails  340  are pushed towards the main body  324 , however, the lock arms  384  tend to pivot so that the lock arms  384  are more perpendicular to the rails  340 , thereby better aligning the slots  388  at the ends of the lock arms  384  with the rails  340  passing through the slots  388 . As a result, the lock arms  384  do not “bite” into the upper and lower surfaces of the rails  340  as the rails  340  are retracted towards the main body  324  of the base  320 . Accordingly, in the illustrated embodiment, the lock mechanisms  380  lock the rails  340  in place to prevent the rails  340  from being extended relative to the main body  324  of the base, but allow the rails  340  to be retracted relative to the main body  324 . 
   With reference again to  FIG. 22 , in the illustrated embodiment, an actuator  410  is provided above each of the lock arms  384 . The actuators  410  preferably are connected to the main body  324  of the base  320  by threaded fasteners (not shown) that extend into the main body  324  through openings  412  in the actuators  410 . As best illustrated in  FIGS. 25 and 27 , the ends of the actuators  410  opposite the openings  412  contact the upper ends of the lock arms  384 . When the ends of the actuators  410  are deflected towards the lock arms  384 , the lock arms  384  pivot against the top walls  364  of the rail guides  358  so that the lock arms  384  are more perpendicular to the rails  340 , thereby better aligning the slots  388  at the ends of the lock arms  384  with the rails  340  passing through the slots  388 . As a result, the lock arms  384  do not “bite” into the upper and lower surfaces of the rails  340  when the actuators  410  are deflected, allowing the rails  340  to be extended from the channels  344 . When the actuators  410  are released, the coil springs  396  force the ends of the lock arms  384  back towards the opposite side walls  366  of the rail guides  358  again to prevent the rails  340  from being further extended relative to the main body  324 . 
   To install the base  320  in a vehicle, the actuators  410  preferably are actuated to allow the rails  340  to be extended from the main body  324  of the base  320 . The actuators  410  are then released and the latches  332  are connected to the anchors of the vehicle. The main body  324  of the base  320  is then pressed towards the vehicle seat back, thereby retracting the rails  340  and preferably compressing the vehicle seat bottom beneath the main body  324 . The lock mechanisms  380  and the vehicle seat back prevent movement of the main body  324  in the forward/aft directions. 
   Connection of Car Seat to Car Seat Base 
   With the base  320  secured to the vehicle seat by means of the vehicle seat belt or the latches  332 , the car seat  20  can conveniently be connected to the base  320  to safely transport an infant. With reference to  FIG. 28 , in the illustrated embodiment, a connection rod  400  is installed in the seat shell  22  by inserting the rod  400  through openings  402  in the inner and outer side walls  236 ,  238  of one of the supports  242 . The rod  400  is then passed through the bottom of the crotch belt pocket  184  and through an opening  406  in the inner wall  236  of the other support  242 . Preferably, the crotch belt (not shown) is passed around the connection rod  400  to securely anchor the crotch belt to the seat shell  22 . 
   A release handle  412 , illustrated in  FIG. 29 , preferably is slideably connected to the seat shell  22  near the foot end  26  thereof by a pair of hooks  416  that extend into slots (not shown) in the seat shell  22 . As illustrated in  FIG. 29 , the release handle  412  preferably includes a pair of arms  420  and a pair of contact surfaces  422  located inwardly of the arms  420 . In the illustrated embodiment, each of the arms  420  includes two generally parallel walls  426  and a web portion  428  that extends between the walls  426 . A biasing member, such as a coil spring (not shown), biases the release handle  412  towards the head end  24  of the seat shell  22 . 
   With reference to  FIG. 30 , a release strap  430  preferably is connected to each of the arms  420  of the release handle  412 . The release straps  430  preferably have hooked ends  432  that extend around the web portions  428  of the arms  420 . Each of the straps  430  extends through an opening  436  in one of the supports  242  and beneath a guide surface  438  towards the head end  24  of the seat shell  22 . 
   As illustrated in  FIG. 30 , each of the straps  430  is connected at an end opposite the release handle  412  to a mounting hook  450 . The mounting hooks  450  are preferably formed of acetyl or a similarly resilient material. In the illustrated embodiment, the mounting hooks  450  generally have an inverted “V” shape and include a number of ribs  454  and a central gusset  456  for reinforcement. Each of the mounting hooks  450  includes a first leg  460 , to which the release strap  430  is connected, and a second leg  462 . The first leg  460  includes an upper barb  466  and a lower barb  468  that extend towards the second leg  462 . The second leg  462  is retained in place by ribs  474  extending from the support  242 . 
   With reference again to  FIG. 28 , a slot  490 , also having an inverted “V” shape, extends upwardly from the bottom surface  246  of each of the supports  242 . In  FIG. 28 , the upper and lower barbs  466 ,  468  of the mounting hooks  450  protrude into the slot  490 . When the release handle  412  is moved towards the foot end  26  of the seat shell  22 , the release straps  430  pull the first legs  460  of mounting hooks  450  away from second legs  462 , so that the upper and lower barbs  466 ,  468  no longer protrude into slots  490 . When the handle  412  is released, the mounting hooks  450  resiliently return to their original positions. 
   With reference now to  FIGS. 31 and 32 , in the illustrated embodiment, the connection bracket  330  includes a central portion  496  and two side walls  498  that extend in a direction generally perpendicular to the central portion  496 . A slot  500  is provided in each of the side walls  498  near the curved seat belt slots  328 . A tab  502  extends upwardly from the central portion  496  adjacent each of the side walls  498 . A pawl  504  is pivotably connected between each tab  502  and the adjacent side wall  498 . A biasing spring  512  biases a hooked end portion  516  of each pawl  504  away from the central portion  498  so that, when viewed from the perspective of  FIG. 32 , the hooked portion  516  extends across the slot  500 . 
   With reference now to  FIG. 33 , the side walls  498  and the pawls  504  of the connection bracket  330  extend upwardly through the main body  324  of the base  320  near a foot end  518  of the base  320 . As the foot end  26  of the infant car seat  20  is lowered onto the base  320 , the connection rod  400  is aligned with and lowered into the slots  500  in the connection bracket  330 . The connection rod  400  contacts and deflects the pawls  504  away from the slots  500  as it passes downwardly into the slots  500 . When the connection rod  400  reaches the bottom of the slots  500 , the biasing springs  512  bias the pawls  504  back towards the slots  500  so that the hooked portions  516  of the pawls  504  extend over the rod  400 , thereby retaining the rod  400  in the slots  500 . 
   With reference still to  FIG. 33 , in the illustrated embodiment, a mount  520  having a rounded top and a notch  522  in a side thereof is located on each side of the base  320  near a head end  530  of the base  320 . As the head end  24  of the car seat  20  is lowered onto the base  320 , the slots  490  in the supports  424  of the car seat  20  are aligned with the mounts  520 . The mounts  520  contact the lower barbs  468  of the mounting hooks  450  (not visible in  FIG. 33 ), thereby deflecting the first legs  460  of the mounting hooks  450  away from the second legs  462 . When the car seat  20  is fully lowered onto the base  320 , as illustrated in  FIG. 34 , the lower barbs  468  are aligned with the notches  522  in the sides of the mounts  520 . The first legs  460  of the mounting hooks  450  resiliently return towards the second legs  462  so that the lower barbs  468  extend into the notches  522 . The lower barbs  468  abut the tops of the notches  522 , thereby locking the head end  24  of the car seat  20  to the base  320 . 
   To release the car seat  20  from the base  320 , the release handle  412  is moved towards the foot end  26  of the seat shell  20 . As the handle  412  is moved towards the foot end  26 , the contact surfaces  422  (see  FIG. 29 ) of the handle  412  contact the pawls  504  of the connection bracket  330  (see  FIG. 31 ). The pawls  504  are rotated away from the slots  500  in the bracket  330  so that hooked portions  516  of the pawls  504  do not extend over connection rod  400 . At the same time, the movement of the release handle  412  pulls the release straps  430  (see  FIG. 30 ) towards the foot end  26  of the seat shell  20 , thereby pulling the first legs  460  of mounting hooks  450  away from second legs  462  so that the lower barbs  468  do not extend into the notches  522  in the mounts  520 . The car seat  20  can then be lifted off of the base  320 . 
   Angular Adjustment of Car Seat Base and Car Seat 
   With reference again to  FIG. 23 , in the illustrated embodiment, the base  320  has an angular adjustment mechanism  550  including a lifter  552 . The lifter  552 , illustrated in  FIGS. 35 and 36 , includes a generally planar portion  556  and projections  558  that extend upwardly from a first end  562  of the planar portion  556 . A threaded recess  566  extends between the projections  558 . A bearing surface  570 , preferably comprising a generally convex surface, slopes downwardly away from the planar portion  556  from the first end  562  thereof. Slots  574  are provided in the planar portion  556  near a second end  578  thereof. 
   As illustrated in  FIG. 23 , the lifter  552  preferably is slideably connected to the underside of the main body  324  of the base  320  by fasteners (not shown) that extend through the slots  574  in the planar portion  556 . The projections (not visible in  FIG. 23 ) extend into channels  584  formed in the underside of the main body  324 . An adjustment screw  588  extends into the threaded recess  566  of the lifter  552  from the head end  530  of the base. The screw  588  is rotatably connected to the main body  324  by a retainer  590  that extends over the screw  588  and is connected to the main body  324  by a pair of fasteners  592 . An adjustment knob  596  is connected to an end of the screw  588 . The screw  588  mates with the threaded recess  566  of the lifter  552  so that, by turning the adjustment knob  596 , the lifter  552  can be drawn towards or away from the head  530  end of the base  320 . 
   With reference now to  FIG. 37 , in the illustrated embodiment, the base  320  includes a foot portion  600  at the underside thereof. The foot portion  600 , illustrated in  FIGS. 38 and 39 , has an extension  602  that overhangs a first end  606  of the foot portion  600 , and a cantilever spring  610  that extends from the first end  606  towards a second end  612  of the foot portion  600 . In the illustrated embodiment, projections  616  extend upwardly from the second end  612  of the foot portion  600 . Each of the projections  616  defines a bearing surface  620 , preferably comprising a generally concave surface corresponding to the generally convex bearing surface  570  of the lifter  552 , that slopes upwardly towards the second end  612 . A recess  624  preferably is formed between the projections  616  for passage of the adjustment screw  588 . 
   As illustrated in  FIG. 37 , the extension  602  at the first end  606  of the foot portion  600  is retained under the first cross-member  350  between first cross-member  350  and the main body  324  of the base  320 . The cantilever spring  610  extends under the second cross-member  352  between the second cross-member  352  and the main body  324 . 
   With reference now to  FIG. 40 , in the illustrated embodiment, the foot portion  600  is pivotable about the first cross-member  350  relative to the main body  324 . When the screw  588  is turned in a first direction, the lifter  552  is drawn towards the head end  530  of the base  320 . The bearing surface  570  of the lifter  552  rides over the bearing surfaces  620  of the projections  616 . If the foot portion  600  is supported on a surface, such as a vehicle seat, the head end  530  of the main body  324  is lifted relative to the foot portion  600 , thus changing the angular orientation of the main body  324 . The cantilever spring  610  is deflected as the head end  530  of the main body  324  is lifted relative to the foot portion  600 . 
   When the screw  558  is turned in the opposite direction, the lifter  552  is moved away from the head end  530  of the base  320 . The bearing surface  570  of the lifter  552  slides down the bearing surfaces  620  of the projections  616 . The cantilever spring  610  assists gravity to force the head end  530  of the main body  324  downwardly towards the foot portion  600 . 
   Accordingly, by rotating the adjustment knob  596 , it is possible to adjust the angular orientation of the main body  324  of base  320 , and therefore the angular orientation of the car seat  20  when the car seat  20  is connected to the base  320 . In contrast to some existing systems, the angular adjustment mechanism  550  is provided at the head end  530  of the base  320 , opposite the vehicle seat back, making it more convenient to reach and operate. The adjustment knob  596  preferably is turned until the angle indicator  230  of the car seat  20  indicates that the orientation of the seat shell  22  is proper for the weight of the infant occupying it. 
   Connection of Car Seat to Stroller 
   With reference now to  FIG. 41 , the car seat  20  preferably can be connected to a stroller  700  which, in the illustrated embodiment, includes a stroller frame  702  and a stroller tray  704  that traverses the stroller frame  702 . The stroller tray  704  preferably includes recessed areas  708  for supporting items such as drink cups, food and toys. As illustrated in  FIG. 42 , the underside of the tray  704  preferably includes runners  712  that extend from a front  714  of the tray  704  to a rear  716  of the tray  704 . Each of the runners  712  defines an elongated slot  718 . A lock  720  is provided at the rear of the tray  704  between the runners  712 . 
   The stroller tray  704  preferably is supported by a tray bar  730 . As illustrated in  FIG. 43 , the tray bar  730  preferably includes recesses  732  that correspond to the recessed areas  708  in the tray  704 . Channels  736  extend from a front  738  of the tray bar  730  to a rear  740  of the tray bar  730  to accommodate the runners  712  of the tray  704 . An opening  748  is provided through the tray bar  730  on each side of the channels  736 . A lock opening  750  is provided at the rear  740  of the tray bar  730  between the channels  736 . 
   The tray bar  730  may be adapted to be connected to the stroller frame  702  in any suitable manner. In the illustrated embodiment, the tray bar  730  includes an arm portion  756  at each side thereof. A vertical slot  758  is provided at the end of each arm portion  756 , as illustrated in  FIG. 44 . The arm portions  756  slide over fingers (not shown) extending from the arms  762  (see  FIG. 41 ) of the stroller. The fingers extend through the slots  758  in the arm portions  756  and cooperate with the arm portions  756  to lock the tray bar  730  to the stroller  700 . 
   With reference now to  FIG. 45 , in the illustrated embodiment, the tray  704  is connected to the tray bar  730  by a pivot rod  770  that extends along the front  738  of the tray bar  730  through the slots  718  in the runners  712 . When the tray  704  is in its use position, as illustrated in  FIG. 45 , the tray  704  is cradled by the tray bar  730 . The tray lock  720  extends into the lock opening  750  of the tray bar  730  to lock the tray  704  in place. 
   Prior to connecting the infant car seat  20  to the stroller  700 , the lock  720  is released and the rear  716  of the tray  704  is pivoted upwardly about the pivot rod  770  away from the tray bar  730 . The tray  704  is then lowered by allowing the pivot rod  770  to slide through the slots  718  in the runners  712  until it reaches the rear ends of the slots  718 , as illustrated in  FIGS. 46 and 47 . Accordingly, the tray  704  remains connected to the tray bar  730  even when it is not in use, thereby reducing the likelihood of misplacing the tray  704 . 
   With reference again to  FIG. 43 , in the illustrated embodiment, each of the openings  748  in the tray bar  730  has a stepped outer side wall  780 . An attachment bar  784  is defined behind each of the openings  748 . Each of the attachment bars  784  preferably has an inverted “V” shaped cross section that corresponds to the shape of the upper ends of the slots  490  in the supports  242  of the car seat  20  (see  FIG. 28 ). 
   With reference now to  FIG. 48 , to connect the infant car seat  20  to the stroller  700 , the car seat  20  is lowered onto the stroller  700  so that the supports  242  extend into the openings  748  in the tray bar  730 . The attachment bars  784  are guided upwardly through the slots  490  in the supports  242 . As the car seat  20  is lowered, the attachment bars  784  deflect the first legs  460  of the attachment hooks  450 . When the attachment bars  784  reach the upper ends of the slots  490 , the first legs  460  of the attachment hooks  450  spring back so that the upper barbs  466  abut the bottom of the tray bar  730 , as illustrated in  FIG. 49 . The stepped outer side walls  780  of the openings  748  cooperate with the stepped outer side walls  238  of the supports  242  to prevent rotation of the car seat  20  relative to the tray bar  730 . 
   The stroller frame  702  preferably is provided with integral supports for supporting the foot end  26  of the seat shell  22 . Alternatively, however, as illustrated in  FIGS. 48 and 50 , add-on supports  790  can be provided. In the illustrated embodiment, the add-on supports  790  are retractable. As illustrated in  FIG. 50 , each of the supports  790  preferably includes a ring portion  792  that clasps the stroller frame  702  and a finger portion  794  pivotably connected to the ring portion  792 . To deploy the supports  790 , the finger portions  794  are pivoted inwardly away from the frame  702 . The foot end  26  of the seat shell  22  can then be lowered onto the finger portions  794 . 
   To release the car seat  20  from the stroller  700 , the release handle  420  is moved towards the foot end  26  of seat shell  20 . As the handle  412  is moved towards the foot end  26 , the release straps  430  (see  FIG. 30 ) pull the first legs  460  of the mounting hooks  450  away from the second legs  462  so that the upper barbs  466  do not abut the bottom of the tray bar  730 . The car seat  20  can then be lifted off of the stroller  70 . 
   Although the invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.