Abstract:
A wheeled car seat sized to hold an infant or young toddler in the seat of an automobile that can also be converted to a wheeled stroller is disclosed herein. The wheeled car seat is made from materials to protect the occupant while at the same time keeping the weight of the wheeled car seat to a minimum. When removing the wheeled car seat from an automobile, the user need not remove the child passenger while the user converts the wheeled car to a stroller, but instead only need lift the car seat above the ground and allow a pivotal chassis to swing open and expose wheels to the ground. When the wheeled car seat is configured as a car seat, the wheels are enclosed to prevent dirt from getting on the upholstery of the automobile.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Design application Ser. No. 29/155,584, filed on Feb. 18, 2002 now U.S. Pat. No. D 471,727. This application also claims the benefit of U.S. Provisional Application No. 60/358,573, filed on Feb. 15, 2002. The above-identified applications are hereby incorporated by reference as if fully disclosed herein. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to car seats, and more specifically relates to portable car seats sized to hold an infant or young toddler in the seat of an automobile that can also be converted to a wheeled stroller. 
     BACKGROUND OF THE INVENTION 
     Portable seats sized to hold an infant or young toddler in the passenger seat of an automobile, otherwise known as car seats, are well-known in the art. The purposes of these car seats is to protect the child and to properly position the child in the car seat for such protection. Car seats may also raise the level of the child slightly to allow a parent or guardian can administer to the child&#39;s needs more easily and perhaps to allow the child to see out of a car window. However, some car seats are bulky, lack versatility, and may not provide all the protection needed for the infant or child traveler. 
     SUMMARY OF THE INVENTION 
     The instant invention provides a light weight, versatile wheeled car seat that provides adequate protection for the passenger and can also be easily be converted to a stroller. The wheeled car seat is made from materials to protect the occupant while at the same time keeping the weight of the wheeled car seat to a minimum. When removing the wheeled car seat from an automobile, the user need not remove the child passenger while the user converts the wheeled car to a stroller. The user only need lift the car seat above the ground and allow a pivotal chassis to swing open and expose wheels to the ground, which also allows the user to convert the wheeled car seat from a car seat to a stroller without repositioning his or her hand and without losing grip. This feature eliminates the need for an adult to transport a stroller and a separate car seat in his or her car, thus saving precious trunk space. Also, the adult no longer has to disturb a youngster secured in a car seat by picking him up out of the car seat and placing him in a stroller. The wheeled car seat also employs an extendable handle so the user can push the wheeled car seat along the ground when it is in the stroller configuration. When the wheeled car seat is configured as a car seat, the wheels are enclosed to prevent dirt from getting on the upholstery of the automobile. 
     In one particular aspect of the present invention, a car seat capable of being converted to a stroller includes, a shell having a seat portion, a back portion, a side portion, and a bottom portion, a gripping surface, at least one wheel connected with the shell, and a pivotal chassis rotatably connected with the shell. The car seat can also include a mechanism for releasably holding the pivotal chassis in at least one position. 
     In another scenario of the present invention, a car seat capable of being converted to a stroller includes, a seat portion, a back portion, a first side portion, a second side portion, a rear portion, and a bottom portion, a gripping surface, at least one first wheel connected under the bottom portion, a pivotal chassis connected with an axle cylinder, wherein the axle cylinder is pivotally connected with the first side portion and the second side portion under the bottom portion, and at least one second wheel connected with the pivotal chassis. The car seat can also include a mechanism releasably engaging the axle cylinder to hold the pivotal chassis in at least one position. 
     In a further representation of the instant invention, a car seat capable of being converted to a stroller includes, a shell having a seat portion, a back portion, a first side portion, a second side portion, a rear portion, and a bottom portion, a gripping surface mounted on the first side portion and the second portion, at least a first wheel connected with the shell below the bottom portion, a pivotal chassis having a first arm and a second arm connected with a cross member, wherein the first arm and the second arm are connected with an axle cylinder and wherein the axle cylinder is pivotally connected with the first side portion and the second side portion, at least a second wheel connected with a bottom surface of the cross member, and a mechanism releasably engaging the axle cylinder to hold the pivotal chassis in a closed position wherein the bottom surface faces upward, an open position wherein the bottom surface faces downward, or an intermediate position. 
     The features, utilities, and advantages of various embodiments of the invention will be apparent from the following more particular description of embodiments of the invention as illustrated in the accompanying drawings and defined in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front left-side perspective view of a wheeled car seat. 
         FIG. 2  is a rear left-side perspective view of the wheeled car seat in  FIG. 1 . 
         FIG. 3  is a right-side view the wheeled car seat depicted in  FIGS. 1 and 2  in an automobile with a seatbelt holding the wheeled car seat in a position such that a child passenger would be facing the rear of the automobile. 
         FIG. 4  is a left-side view the wheeled car seat depicted in  FIGS. 1 and 2  in an automobile with a seatbelt holding the wheeled car seat in a position such that a child passenger would be facing the front of the automobile. 
         FIG. 5A  is a bottom left-side perspective sectional view of the wheeled car seat configured as a car seat. 
         FIG. 5B  is a front view of a lower surface of a cross member of a pivotal chassis when the wheeled car seat is configured as a car seat. 
         FIG. 5C  is a sectional bottom view of the wheeled car seat configured as a stroller detailing a detent. 
         FIG. 6A  is a bottom right-side perspective sectional view of the wheeled car seat showing how a user actuates the detent. 
         FIG. 6B  a front left-side perspective sectional view of the wheeled car seat showing a user&#39;s hand reaching through a detent hand slot. 
         FIGS. 7A–7C  show the wheeled car seat being transformed from a car seat configuration to a stroller configuration. 
         FIG. 8  is a bottom view of the wheeled car seat in the stroller configuration. 
         FIG. 9A  is a front left-side perspective view of a second embodiment of the wheeled car seat in the car seat configuration. 
         FIG. 9B  is a front left-side perspective view of the second embodiment of the wheeled car seat in the stroller configuration. 
         FIG. 10  is a rear right-side perspective view of the wheeled car seat in the stroller configuration with a removable tote. 
         FIG. 11A  is a front left-side perspective view of the wheeled car seat in a booster seat configuration. 
         FIG. 11B  is a bottom view of the wheeled car seat showing an intermediate slot located in the axle cylinder. 
         FIG. 12  is a front right-side perspective view of a third embodiment of the wheeled car seat in the stroller configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a front left-side perspective view a wheeled car seat  30 , and  FIG. 2  shows a rear left-side perspective view of the wheeled car seat  30  in  FIG. 1 . The wheeled car seat depicted in  FIGS. 1 and 2  is shown in a car seat configuration. As discussed in more detail below, the wheeled car seat  30  may be reconfigured to function as a stroller. The shape of the wheeled car seat  30  is defined by a shell  32 . As shown in  FIGS. 1 and 2 , the shell includes a seat portion  34 , a back portion  36 , a right side portion  38 , a left side portion  40 , a rear portion  42 , and a bottom portion  44 . The right side portion  38  and the left side portion  40  are mirror images of each other. Typically, a child seated in the wheeled car seat  30  rests his or her bottom on the seat portion  34  and his or her back against the back portion  36 . The right side portion  38  and the left side portion  40  of the shell provide side impact protection to a child passenger. When the child is seated in the wheeled car seat, the right side portion  38  and the left side portion  40  of the shell  32  will oftentimes be positioned adjacent the child&#39;s head, shoulder, and torso. In some instances, the side portions could absorb the impact from an exploding side door air bag or block flying glass and debris from striking the child passenger during an automobile accident. 
     As shown in  FIGS. 1 and 2 , the right side portion  38  and left side portion  40  each have an interior surface  46  and exterior surface  48  and are defined by a bottom edge  50 , an arcuate front edge  52 , a rounded rear corner  54 , and a rear edge  56 . The rounded rear corner  54  is defined by the intersection of the right side portion  38  or left side portion  40  and the rear portion  42  of the shell. The bottom edge  50  extends between the rear edge  56  and the arcuate front edge  52 . The rear edge  56  extends upwardly from the bottom edge  50  to the rounded rear corner  54 . The arcuate front edge  52  extends upwardly from the bottom edge  50  and curves toward the rear portion  42  of the shell  32  until it intersects with the rounded rear corner  54 . 
     The shell  32  includes various openings or windows to allow a person to more easily grasp the wheeled car seat  30  when picking it up or maneuvering it into a desired position. Some of the openings or windows may also allow a child seated in the wheeled car seat to have a better view of his or her surroundings. For example, as shown in  FIGS. 1 and 2 , a front upper opening  58  and a front lower opening  60  are located in the right side portion  38  and left side portion  40  of the shell. A first gripping area  62  is defined where the perimeter of the front upper opening  58  is nearest the arcuate front edge  52 . A second gripping area  64  is defined where the perimeter of the front lower opening  60  is nearest the arcuate front edge  52 . A third gripping area  66  is defined where the perimeter of the front upper opening  58  is nearest the perimeter of the front lower opening  60 . A person desiring to lift or maneuver the wheeled car seat  30  in an awkward environment, such as the back seat of an automobile, may find these numerous gripping areas useful. 
     Other openings may be located in the right side portion  38  and left side portion  40  to create additional gripping areas. For example, as shown in  FIG. 2 , a rear upper opening  68  and a rear lower opening  70  are located in the ride side portion  38  and left side portion  40  of the shell  32 . A fourth gripping area  72  is defined where the perimeter of the rear lower opening  70  is nearest the rear edge  56 . A fifth gripping area  74  is defined where the perimeter of the rear upper opening  68  is nearest the rear edge  56 . It should be understood that the present invention may include more or less openings in the shell  32  with different shapes and sizes, and is not limited to what is depicted herein. However, the windows or openings should be located near one another or to the edges of the shell, so that the structural integrity of the of wheeled car seat  30  is sufficient to support being grasped. The stronger the shell material, the closer the openings can be to one another and to the edges. 
     As shown in  FIGS. 1 and 2 , the wheeled car seat also includes an extendable handle mechanism  76 . The extendable handle mechanism  76  can be configured in a retracted position when the wheeled car seat is in the car seat configuration. The handle mechanism can also help to reinforce the structure of the wheeled car seat when the extendable handle mechanism  76  is in the retracted position.  FIGS. 1 and 2  show the extendable handle mechanism in the retracted position. Alternatively, the extendable handle mechanism can be configured in an extended position when the wheeled car seat is in the stroller configuration, as is discussed in more detail below. 
     As shown in  FIGS. 1 and 2 , the back portion  36  of the shell is generally defined by a surface area between an upper arcuate edge  78  and a rounded seat corner  80 . The upper arcuate edge  78  extends between the arcuate front edges  52  of the left side portion  40  and right side portion  38 . The rounded seat corner  80  extends between the interior surfaces  46  of the right side portion  38  and the left side portion  40  and is defined by the intersection of the back portion  36  and the seat portion  34  of the shell  32 . The seat portion  34  is defined by a rear seat portion  82  of the shell  32  between right side portion  38  and the left side portion  40  extending forward from the back portion  36  and sloping upward to a bend area  84 . From the bend area  84 , the seat portion  34  is further defined by a front seat portion  86  as the seat portion  34  extends forward and curves downward to an intersection of the front arcuate edges  52  and bottom edges  50  of the right side portion  38  and left side portion  40 . A front bottom edge  88  extends between the bottom edges  50  of the right side portion  38  and the left side portion  40  adjacent the front seat portion  86 . A detent hand slot  90  may also be located in the front seat portion  86 , as shown in  FIG. 1 . The detent hand slot  90  serves as an additional gripping area as well as access to a detent  92  (not shown in  FIGS. 1–2 ) discussed in more detail below. 
     The rear portion  42  of the shell  32  is generally defined by an area surrounded by a rear bottom edge  94 , the rounded rear corners  54 , the rear edges  56  of the right side portion  38  and the left side portion  40 , and the upper arcuate edge  78 . As shown in  FIG. 2 , the rounded rear corners  54  extend downward from the upper arcuate edge  78  to the rear edges  56  of the right side portion  38  and the left side portion  40 . The rear edges  56  of the right side portion  38  and the left side portion  40  extend downward from the rounded rear corners  54  to the bottom edges  50  of the right and left side portions. The rear bottom edge  94  extends between the bottom edges  50  of the right side portion  38  and the left side portion  40  adjacent the rear portion  42  of the shell  32 . The rear portion  42  also defines an upper rear portion  96  and a lower rear portion  98 . As shown in  FIG. 2 , a rear gripping slot  100  is located in the upper rear portion  96 . The lower rear portion  98  can also form a storage compartment  102  that can be closed by any suitable means such as a flap or an elastic cord net stretched across the lower rear portion  98  and secured to the right side portion  38  and the left side portion  40 . 
     The bottom portion  44  of the shell  32  is generally defined by a surface area underneath the seat portion  34 . As shown in  FIGS. 1 and 2 , a pivotal chassis  104  is mounted to the shell  32  by an axle cylinder  106  extending between the right side portion  38  and the left side portion  40  and the bottom portion  44 . The pivotal chassis  104  is discussed in greater detail below. 
       FIGS. 3 and 4  show the wheeled car seat  30  configured as a car seat and secured in an automobile. In particular,  FIG. 3  shows the wheeled car seat  30  secured to a rear seat  108  of the automobile by passing a seat belt  110  through the middle of the axle cylinder  106  such that a child seated in the wheeled car seat  30  would be facing the rear of the automobile.  FIG. 4  shows the wheeled car seat  30  secured to the rear seat  108  of the automobile by passing the seat belt  110  through the lower rear opening  70  on the right side portion  38  of the shell  32  along the rear potion and exiting the lower rear opening  70  on the left side portion  40  of the shell such that a child seated in the wheeled car seat  30  would be facing the front of the automobile. Depending on the configuration of a particular seat belt, the shoulder harness of the seat belt could also pass through the upper rear opening  68  on one side of the wheeled car seat  30  and the lower rear opening  70  on the opposite side of the wheeled car seat  30 . 
     The wheeled car seat  30  may be constructed utilizing available technology to enhance the strength of the seat in order to protect the child passenger while at the same time providing a comfortable riding environment. For example, the wheeled car seat may be manufactured by utilizing similar techniques used in the manufacture of lightweight sports helmets, such as bicycle helmets. As is well known, bicycle helmets are made with essentially three layers. An outer most layer is a thin vacuum formed shell usually made from a high strength and lightweight plastic material such as polycarbonate or PET vacuum formable materials. A center layer or core of these materials typically comprises expanded polystyrene or other rigid but crushable cushioning materials. The core is usually attached to the shell using adhesives or hook and loop fasteners. A third layer, the inner most portion of bicycle helmets, comprises isolated textile pads which are held in strategic positions on the inside of the expanded polystyrene core with hook and loop fasteners. 
     Similarly, the present invention may employ many of these known helmet technologies by constructing the wheeled car seat using a strong, flexible, crushable, resilient layered approach. The shell  32 , as shown in  FIGS. 1 and 2 , would comprise one or more vacuumed formed shell portions, which are assembled together using adhesives. In an alternative configuration, the axle cylinder  106  could hold two half-shelled portions together. The shell can be made utilizing various manufacturing techniques known in the art, such as injection-molding, blow-molding with a foam filled hollow core, and rotational molding. Immediately within the shell  32  would be a rigidifying and impact absorbing expanded plastic layer or core. While not shown, textile upholstery sections and cushioning sections for the seat portion and back portion of the wheeled car seat would be releasably attached using adhesives or hook and loop fasteners, and the like to the wheeled car seat. Because the cushioning sections would be releasably attached, they could be removed for cleaning or replaced when worn out without the having to replace the entire wheeled car seat. The strength of the shell material would help protect a child passenger in the event of an automobile accident, while at the same time providing a light weight design that can more easily be lifted or maneuvered. 
     The present invention could also utilize its own harness or seat belt restraint to better secure the child passenger to the wheeled car seat. For example, a car seat restraint could be equipped with a releasable buckle, similar to a standard automobile seat belt buckle as is known in the art, attached to a lower belt that is connectable to an upper harness. The lower belt could be affixed to the seat portion of the shell. The upper harness could be affixed to the back portion of the shell and includes a left strap and a right strap. The child passenger is secured to the wheeled car seat using the car seat restraint by passing the lower belt upward between the child passenger&#39;s legs and then buckling it to the upper harness after the left strap and right strap have been lowered across the child passenger&#39;s shoulders. Other car seat restraint configurations could include a waist strap secured to the back portion or seat portion of the shell that buckles across the child passenger&#39;s waist. 
       FIG. 5A  is a bottom left-side perspective sectional view of the wheeled car seat  30  configured as a car seat. The pivotal chassis  104  includes a right pivot arm  112 , a left pivot arm  114 , and a cross member  116 . As previously discussed, the pivotal chassis  104  is connected to the shell  32  by an axle cylinder  106  extending between the right side portion  38  and the left side portion  40  under the bottom portion  44 . In particular, a first end  118  of the axle cylinder  106  penetrates the right side portion  38  and connects with a pivot area  120  of the right pivot arm  112 . Similarly, a second end  122  of the axle cylinder  106  penetrates the left side portion  40  and connects with the pivot area  120  of the left pivot arm  114 . Therefore, the axle cylinder rotates  106  with the pivotal chassis  104 . The cross member  116  extends between and is connected with the left pivot arm  114  and the right pivot arm  112  at a swing area  124  located on each pivot arm. As shown in  FIG. 5A , the cross member  116  also has an upper surface  126  and a lower surface  128 . In an alternative configuration, the pivotal chassis could be secured to holes on the right side portion and the left side portion with a separate brace passing between the right and left side portions under the bottom portion of the shell. 
       FIG. 5B  shows a front view of the lower surface  128  of the cross member  116  of the pivotal chassis  104  when the wheeled car seat  30  is configured as a car seat. As show in  FIG. 5B , two cross member wheels  130  are mounted on the lower surface  128  of the cross member  116  of the pivotal chassis  104 . Two seat wheels  132  are mounted on a wheel axle  134  extending between the right side portion  38  and the left side portion  40  under the rear portion  44  of the shell  32 . When the wheeled car seat  30  is configured as a car seat, the cross member wheels  130  extend upwardly toward the bottom portion  44  of the wheeled car seat such that the cross member wheels  130  and seat wheels  132  are enclosed between the bottom portion  44  of the wheeled car seat and the lower surface  128  of the cross member  116 . This helps to prevent dirt from rubbing off the wheels and onto the upholstery of the automobile. As shown in  FIG. 5B , the cross member wheels  130  are caster wheels, and the seat wheels  132  are fixed axis wheels with larger diameters. It should be understood that alternative wheel configurations may be used with different numbers, designs, and diameters, and the invention is not limited to what is depicted herein. For example, the wheels may be fixed axis or caster design, and a single wide roller or wheel could be used instead of a plurality of wheels. The cross member wheels  130  are mounted on the cross member  116  and spaced apart such that they do not interfere with the seat wheels  132  when the wheeled car seat  30  is configured as a car seat. 
       FIG. 5C  is a detailed sectional bottom view of the wheeled car seat  30  configured as a stroller detailing the detent  92  used to hold the pivotal chassis  104  in closed and open positions. The detent  92  is comprised of a housing  136  attached to the bottom portion  44  of the shell  32 . The housing  136  maintains a sliding plate  138  with an engaging portion  140  and a handle portion  142 . As shown in  FIG. 5C , springs  143  are attached to plate tabs  144  extending from the sliding plate  138  and to housing tabs  146  attached to the housing  136  such that a force exerted by the springs  143  operates to continuously pull the sliding plate  138  in a rearward direction toward the axle cylinder  106 . Therefore, the engaging portion  140  of the sliding plate  138  is continuously forced against the axle cylinder  106  by the springs  143 . 
     As shown in  FIG. 5C , a first slot  148  and a second slot  149  are located on the axle cylinder  106  and are spaced approximately 180° apart. When the wheeled car seat  30  is configured as a car seat, the pivotal chassis  104  is in the closed position. Conversely, when the wheeled car seat  30  is configured as a stroller, the pivotal chassis  104  is in the open position. Therefore, when the engaging portion  140  of the sliding plate  138  engages the second slot  149 , the pivotal chassis  104  is held in the closed position, as shown in  FIG. 5A . When the engaging portion  140  of the sliding plate  138  engages the first slot  148 , the pivotal chassis  104  is held in the open position, as shown in  FIG. 5C . When the engaging portion  140  of the sliding plate  138  is not engaged in either slot, the pivotal chassis  104  is free to pivot, and the axle cylinder  106  is the center of rotation about which the pivotal chassis  104  rotates. Because the pivotal chassis  104  is connected with the axle cylinder  106 , the axle cylinder rotates together with the pivotal chassis  104 . As the pivotal chassis  104  and axle cylinder  106  rotate from one position to another, the engaging portion  140  of the sliding plate  138  is continuously pulled against the axle cylinder until the engaging portion  140  is aligned with either the first slot  148  or the second slot  149 . Once the engaging portion  140  of the sliding plate  138  is aligned with either the first slot  148  or the second slot  149 , the force exerted on the sliding plate  138  by the springs  143  pulls the engaging portion  140  into the slot, thus locking the axle cylinder  106  and pivotal chassis  104  into either the open position or closed position. It should be understood that the present invention is not limited to the detent design depicted and described herein. Other mechanisms could be employed to hold the pivotal chassis  104  in the open and closed positions without the need for the axle cylinder, while allowing rotation between these positions, such as a ratchet mechanism or releasable clasps that directly engage the right pivot arm  112  and the left pivot arm  114 , a rotating detent, and the like. In alternative embodiments of the present invention, no mechanism is utilized to hold the pivotal chassis in various positions. Instead, the pivotal chassis is allowed to pivot freely. 
     When a user wishes to convert the wheel car seat  30  from the car seat configuration to the stroller configuration, the user grasps the handle portion  142  of the sliding plate  138  of the detent  92  and pulls it in a forward direction until the engaging portion  140  of the sliding plate  138  is disengaged from the second slot  149  in the axle cylinder  106 , as shown in  FIG. 6A . As shown in  FIG. 6B , a user&#39;s hand  150  reaches the handle portion  142  of the sliding plate  138  of the detent  92  from outside of the wheeled car seat  30  through the detent hand slot  90  located in the front seat portion  86 . 
       FIGS. 7A–7C  show one method of how a user can transform the wheeled car seat  30  from the car seat configuration to the stroller configuration. In  FIG. 7A , a user is holding the wheeled car seat  30  above the ground by grasping the rear gripping slot  42  with her right hand and gripping the detent hand slot  90  with her left hand. Once the user grasps the handle portion  142  of the sliding plate  138  and pulls it forward until the engaging portion  140  of the sliding plate  138  is disengaged from the second slot  149 , the pivotal chassis  104  is free to rotate with the axle cylinder  106  in a counter-clockwise direction, as shown in  FIG. 7B . The user then places the wheeled car seat  30  on the ground, forcing the pivotal chassis  104  to rotate further until the engaging portion  140  of the sliding plate  138  engages the first slot  148  in the axle cylinder  106 , as shown in  FIG. 7C . The user then places the extendable handle mechanism  76  in the extended position, thus completing the reconfiguration of the wheeled car seat  30  to the stroller configuration. 
     As shown in  FIG. 7C , the extendable handle mechanism  76  comprises a handle  152  attached to extendable handle support posts  154 . The handle support posts  154  can be configured to telescopically extend and retract.  FIG. 7C  shows the extendable handle mechanism  76  in an extended position, and  FIGS. 7A and 7B  show the extendable handle mechanism  76  in a retracted position. When the extendable handle mechanism  76  is in the retracted position, the handle support posts  154  are stored within the right side portion  38  and the left side portion  40  of the shell  32 . The extendable handle mechanism  76  may be locked in the retracted position by a handle latching mechanism as is common in the art. Locking the extendable handle mechanism  76  in retracted position allows a user to grasp the handle  152  when lifting the wheeled car seat  30 . When a user configures the wheeled car seat  30  to the stroller configuration, the user grasps the handle  152  and pulls the extendable handle mechanism  76  from its retracted position to its extended position. In an another embodiment, the handle support posts can be configured to pivot around the wheeled car seat such that the user can push the wheeled car seat either from behind or in front of the wheeled car seat. 
       FIG. 8  shows a bottom left-side perspective view of the wheeled car seat  30  in the stroller configuration. When the wheeled car seat  30  is in the stroller configuration, the wheeled car seat  30  is supported on the ground by the cross member wheels  130  and the seat wheels  132 . As shown in  FIG. 8 , the cross member wheels  130  are caster wheels that add to the maneuverability of the wheeled car seat  30 . A user is able to push on the handle  152  of the wheeled car seat and steer by manipulating the direction of the cross member wheels  130  as the wheeled car seat  30  rolls along the ground. Other embodiments of the present invention can utilize seat wheels  132  that are caster wheels and cross member wheels  130  that are fixed axis designs. As previously discussed, a single wide roller or wheel could also be used instead of a plurality of wheels. Embodiments of the present invention may also employ a design where the rear portion  42  of the wheeled car seat presents a rounded, prow like configuration, as shown in  FIG. 2 . This prow like configuration enhances the ability of a user to aim the wheeled car seat through crowded urban walkways when the wheeled car seat  30  is configured as a stroller. 
     Reconfiguring the wheeled car seat  30  to the car seat configuration from the stroller configuration works in an opposite manner as previously described with reference to  FIGS. 7A–7C . The user places the extendable handle mechanism  76  in the retracted position, and holds the wheeled car seat  30  above the ground by grasping the rear gripping slot  42  with her right hand and gripping the detent hand slot  90  with her left hand. The user then grasps the handle portion  142  of the sliding plate  138  and pulls it forward until the engaging portion  140  of the sliding plate  138  is disengaged from the first slot  148 , allowing the pivotal chassis  104  to rotate in a clockwise direction, opposite of  FIG. 7B . The user then places the wheeled car seat  30  on a surface, such as a seat in an automobile, so that the pivotal chassis  104  is forced to rotate until the engaging portion  140  of the sliding plate  138  engages the second slot  149  in the axle cylinder  106 , completing the reconfiguration of the wheeled car seat  30  to the car seat configuration. As shown in  FIGS. 5A and 5B , the wheels are encased between the bottom portion  44  of the shell  32  and the lower surface  128  of the cross member  116  when the wheeled car seat  30  is in the car seat configuration. This helps to keep automobile seats relatively clean, because it is difficult for dirt accumulated on the wheels to rub off on the upholstery. 
       FIGS. 9A and 9B  show a second embodiment of the present invention describing an alternative shell configuration and cross member design. Conversion of the wheeled car seat  30  depicted in  FIGS. 9A and 9B  from the car seat configuration to the stroller configuration works in substantially the same way as has been previously described. As shown in  FIGS. 9A and 9B , the shell  32  of the wheeled car seat  30  has a single large opening  156  located in the left side portion  40  and one located in the right side portion  38 . A long gripping area  158  is defined where the perimeter of the large opening  156  is nearest the arcuate front edge  52  of the right side portion  38  and the left side portion  40 . A small opening  160  is located in the right side portion  38  and the left side portion  40  in a location near the intersection of the seat portion  34  and the back portion  36 . As shown in  FIG. 9B , a foot rest  162  is located on upper surface  126  of the cross member  116  of the pivotal chassis  104 . When the wheeled car seat  30  is in the stroller configuration, a child passenger can rest his or her feet on the foot rest which can help prevent the child&#39;s feet from dragging on the ground. 
     As shown in  FIG. 10 , the wheeled car seat  30  can be equipped with a removable tote  162 . The removable tote  162  is configured to be removably attached to the handle support posts  154  of the extendable handle mechanism  76 . The removable tote  162  depicted in  FIG. 10  is sized to fit between the handle support posts  154 . The removable tote  162  can be attached to and hang below the handle support posts  154  by any known means. In  FIG. 10 , the removable tote  162  is attached to the wheeled car seat  30  by spring loaded pins  164  that protrude from the removable tote  162  through pin holes  166  located in the handle supports  154 . The removable tote  162  shown in  FIG. 10  is conveniently positioned between the user and child passenger at a comfortable access level, and can be used for carrying baby accessories and the like when the wheeled car seat  30  is in the stroller configuration. It should be understood that the removable tote could be secured in different ways and in other locations on the wheeled car seat, and is not limited to what is depicted herein. For example, the removable tote could be attached to the rear portion of the wheeled car seat using hook and loop fasteners. The removability of the tote allows the user to separate the weight of any bagged accessories from the wheeled car seat when lifting or maneuvering the wheeled car seat. 
     Embodiments of the wheeled car seat may also utilize other various shell and pivotal chassis designs so that the wheeled car seat could be employed for additional uses. For example, the wheeled car seat could be designed such that it could be used as a child&#39;s booster seat, as shown in  FIG. 11A . When the wheeled car seat  30  is in the booster seat configuration, the pivotal chassis  104  is positioned in an intermediate position such that the rear portion  42  of the wheeled car seat  30  is elevated from the surface upon which it is resting. As shown in  FIG. 11A , the wheeled car seat is supported by the front bottom edge  88  and the pivotal chassis  104 . In particular, support from the pivotal chassis  104  comes from the swing areas  124  of the right pivot arm  112  and the left pivot arm  114  along with the cross member  116 . As shown in  FIG. 11B , an intermediate slot  168  is located in the axle cylinder  106 . When the engaging portion  140  of the sliding plate  138  engages the intermediate slot  168 , the pivotal chassis  104  is held in position such that the wheeled car seat  30  is secured in the booster seat configuration. 
     The bottom view of the embodiment of the wheeled car seat shown in  FIG. 11B  illustrates only one intermediate slot  168  located in the axle cylinder  106 . In addition, the detent  92  depicted in  FIG. 11B  is not spring loaded. Therefore, a user need not manipulate the detent  92  when converting the wheeled car seat from the car seat configuration to the stroller configuration and back again. In this configuration, the pivotal chassis  104  is free to rotate as previously discussed with reference to  FIGS. 7A to 7C  when the user lifts the wheeled car seat  30  above the ground. In another embodiments, the present invention could be configured with the first slot  148 , the second slot  149 , and the intermediate slot  168  located in the axle cylinder  106 . Depending on the desired functionality, the detent may or may not be spring loaded. In other embodiments, a plurality of intermediate slots could be located in the axle cylinder at various locations around its circumference, giving the user several choices of positions and elevations in which to place the wheeled car seat. 
     As shown in  FIG. 11A , the right pivot arm  112  and left pivot arm  114  of the pivotal chassis  104  could also define a curved rocking surface  170 . This feature would allow the wheeled car seat  30  to rock back and forth on the curved rocking surface  170  when the wheeled car seat  30  is placed in the car seat configuration. Therefore, a person could rock a child seated in the wheeled car seat or the child seated in the wheeled car seat could rock the seat. 
       FIG. 12  shows yet another alternative wheeled car seat conforming to aspects of the present invention. This wheeled car seat is shown configured as a stroller. As shown in  FIG. 12 , the wheeled car seat  30  includes seat wheels  132  and no cross member wheels. Because there are no cross member wheels, the cross member  116  could be supported by glides  172 . The glides  172  should be oriented on the cross member  116  such that they will not interfere with the seat wheels  132  when the wheeled car seat  30  is placed in the car seat configuration. The extendable handle mechanism  76  is also connected with the rear portion  42  of the wheeled car seat  30 . When a user desires to roll the wheeled car seat  30 , he or she grasps the handle  152  and tips the wheeled car seat  30  back until the pivotal chassis  104  is suspended above the ground, and then pushes or pulls the wheeled car seat  30  in the desired direction as it rolls on the seat wheels  132 . The wheeled car seat could also be configured with a gripping surface integral with the shell at a point where the user could push or pull the wheeled car seat. In an alternative configuration, the wheeled car seat could be configured with cross member wheels and no seat wheels. As previously discussed, the wheels may be fixed axis or caster design, and a single roller or wheel could be used instead of a plurality of wheels. 
     Although various embodiments of this invention have been described above with a certain degree of particularity or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to those disclosed embodiments without departing from the spirit or scope of this invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments, and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.