Patent Abstract:
A baby stroller for transporting an infant at speeds faster than normal walking is disclosed. This baby stroller can be folded to make it easier to stow and transport. The folding mechanism, a unique feature of the design is directed toward compactness, ease of use, reliability, and reduction in manufacturing costs.

Full Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation application of U.S. Ser. No. 10/430,688 filed May 5, 2003, now U.S. Pat. No. 6,991,248, where this application is incorporated herein by reference in their entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to baby strollers, and more particularly, to all-terrain baby strollers that can be folded. 
   2. Description of the Related Art 
   Traditionally, baby strollers have been used to push an infant slowly on a relatively hard, smooth floor or sidewalk. As a result, the strollers were made small and light. These strollers work well enough at slow speed, but are extremely unwieldy and even dangerous on rough surfaces or at higher speeds. 
   All-terrain baby strollers have been designed to overcome these problems. These strollers typically employ much larger wheels, often large bicycle tires. The stroller frame members are constructed of metal tubular stock and durable plastic frame connectors or other durable material to connect the frame members together to handle the heavy duty use they may receive. The frame connectors are used also to rotate or pivot one frame member relative to another, and are used to removably connect other frame members together. 
   Some advanced designs of all-terrain strollers have allowed for a certain degree of folding of the all-terrain baby strollers into less than a desirable amount of compactness. In addition, conventional folding mechanisms include complications that increase cost and reduce reliability and ease of use. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention resides in a folding baby stroller system and method. Embodiments include a front wheel and left and right side laterally spaced-apart front wheel supports. Each of the left and right side front wheel supports has a forward end portion and a rearward end portion. The front wheel is mounted to the forward end portion of at least one of the front wheel supports, the left and right side front wheel supports being rotatable as a unit. Further included are left and right rear wheels, and left and right side laterally spaced-apart rear wheel supports. Each of the left and right side rear wheel supports has a lower end portion and an upper end portion, the lower end portions being coupled to at least one of the left and right rear wheels. Further included are left and right side laterally spaced-apart handle members. Each of the left and right side handle members has a forward end portion and a rearward end portion with a handle portion, the left and right side handle members being rotatable as a unit. Further included are left and right side laterally spaced-apart folding assemblies. Each of the left and right side folding assemblies has a first rotatable member and second rotatable member rotatably coupled to a pivot member supported by the upper end portion of a corresponding one of the left and right side rear wheel supports for rotation about a common axis of rotation and independently rotatable relative to each other. The rearward end portion of a corresponding one of the left and right side front wheel supports is fixedly attached to the first rotatable member, and the forward end portion of a corresponding one of the left and right side handle members is fixedly attached to the second rotatable member. 
   Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is an isometric view of an exemplary implementation of a baby stroller embodying the present invention shown in a fully unfolded state ready for usage. 
       FIG. 2  is an isometric view of the stroller frame of  FIG. 1  without a seat and a leg guard. 
       FIG. 3  is a front elevational view of the stroller frame of  FIG. 2 . 
       FIG. 4  is a side elevational view of the stroller frame of  FIG. 2 . 
       FIG. 5  is a front elevational view of the stroller frame of  FIG. 2  shown in a partially folded state with left and right front supports being rotated about their respective side folding assemblies toward respective side rear wheel supports. 
       FIG. 6  is a side elevational view of the stroller frame of  FIG. 2  shown in the partially folded state of  FIG. 5 . 
       FIG. 7  is a side elevational view of the stroller frame of  FIG. 2  shown in a fully folded state with both left and right front supports and left and right side handle supports being rotated about their respective side folding assemblies toward respective side rear wheel supports. 
       FIG. 8  is an exploded isometric view of one of left and right side folding assemblies of the implementation shown in  FIG. 1 . 
       FIG. 9  is an enlarged, fragmentary, side elevational view of the stroller frame of  FIG. 2  in the fully unfolded state better illustrating one of the side folding assemblies. 
       FIG. 10  is a side elevational view of the stroller frame in the fully unfolded state of  FIG. 9  showing internal components of one of the side folding assemblies. 
       FIG. 11  is the side elevational view of the stroller frame in the fully unfolded state of  FIG. 9  with the internal components of the side folding assembly shown in broken line. 
       FIG. 12  is the side elevational view of the stroller frame of  FIG. 11  in the fully folded state with the internal components of the side folding assembly shown in broken line. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As shown in the drawings for purposes of illustration, the present invention is embodied in an all-terrain baby stroller  10 , as shown in  FIG. 1 , having a foldable, tubular metal frame  12  and a transversely extending rear axle assembly  14  with a transverse, non-rotating tubular rear axle  15 . Left and right side rear wheels  16  are rotatably mounted to the ends of the rear axle assembly  14 . The forward end of the frame  12  has a single front wheel  18  rotatably mounted thereto. 
   The frame  12  has no base frame members extending rearwardly from the front wheel  18  to the rear axle assembly  14  as do most conventional all-terrain strollers. Instead, the frame  12  includes left and right side, downwardly and forwardly sloping front wheels frame members or supports  20 , which each extend downward from a corresponding one of left and right side folding assemblies  22  in a converging configuration to the front wheel  18 . A forward free-end  20   a  of each of the left and right side front wheel supports  20  has a plastic front wheel connector (not shown) fixedly attached thereto and a corresponding one of the left and right ends of an axle  18   a  of the front wheel  18  removably attached thereto to mount the front wheel to the stroller frame  12 . 
   The front wheel supports  20  are interconnected by a foot rest  28  that spans between them toward but rearward of their forward free-ends  20   a  and that is fixedly attached to each at a position just above the front wheel  18  and just rearward of the axle  18   a  of the front wheel. As a result of the interconnection provided by the foot rest  28 , and also the front wheel  18  when attached to the left and right side front wheel connectors, the left and right side front wheel supports  20  form a stationary unit with respect to the left and right side folding assemblies  22  upon folding and unfolding of the stroller  10 , as will be described in greater detail below. 
   The frame  12  also includes left and right side, upwardly and rearwardly sloping handle frame members or supports  24 , which each extend upward from the corresponding one of the left and right side folding assemblies  22  in a generally parallel configuration to a handle  26  extending between the left and right side handle supports. The handle  26  is covered by a foam grip. The handle supports  24  are interconnected by the handle  26  that spans between them at their rearwardmost and uppermost extension and that is fixedly attached to each. 
   As a result of the interconnection provided by the handle  26 , the left and right side handle supports  24  move as a unit with respect to the left and right side folding assemblies  22  upon folding and unfolding of the stroller  10 , as will be described in greater detail below. It is noted that in lieu of the interconnecting handle  26 , the handle supports  24  may each be provided with a handle portion at the upper end thereof such as used with umbrella style strollers. 
   In the illustrated embodiment of the invention the left and right side handle supports  24  and the handle  26  are formed as an integral unit by bending a single length of aluminum tube. The left and right side handle supports  24  are movable relative to the left and right side front wheel supports  20  for folding of the stroller  10  and do not together form an integrated rigid upper frame. The left and right side handle supports  24  are also movable independent from movement of the left and right side front wheel supports  20 . 
   The frame  12  also includes left and right side, downwardly and rearwardly sloping rear wheel frame members or supports  30 , which each extend downward from the corresponding one of the left and right side folding assemblies  22  in a generally parallel configuration to the rear axle assembly  14 . A rearward free-end  30   a  of each of the left and right side rear wheel supports  30  is fixedly attached to a corresponding one of the left and right ends of the tubular rear axle  15 . The rear wheel supports  30  are interconnected by the rear axle assembly  14  that spans between them at the rearward free-ends  30   a  thereof. As a result of the interconnection provided by the rear axle assembly  14 , the left and right side rear wheel supports  30  move as a unit with respect to the left and right folding assemblies  22  for folding and unfolding of the stroller  10 , as will be described in greater detail below. The left and right side rear wheel supports  30  are also movable relative to the left and right side front wheel supports  20  and the left and right side handle supports  24  for folding of the stroller  10 . Further, the left and right side rear wheel supports  30  and the rear axle assembly  14  connected thereto do not form a part of a base frame extending between the rear and front wheels  16  and  18 . Much of the structural strength of the stroller  10  and the interconnection of the forward wheel supports  20 , the handle supports  24 , and the rearward wheel supports  30  are provided by the centrally positioned left and right side folding assemblies  22 , and not by a base frame. 
   In the illustrated embodiment of the stroller  10 , the left and right side front wheel supports  20 , the left and right side handle supports  24 , and the left and right side rear wheel supports  30  are made from aluminum tube. Suitable alternative materials may be used. 
   The left and right outward ends of the tubular rear axle  15  are open and internally threaded to receive a threaded stub axle  32  forming a part of the corresponding one of the left and right rear wheels  16 . A lock nut (not shown) when tightened against the face of the stub axle  32  locks the stub axle against loosening during usage of the stroller  10 . Alternative constructions may be used to fixedly or removably attach the rear wheels  16  to the tubular rear axle  15 , and any suitable alternative manner of mounting the rear wheels  16  to the real wheel supports  30  may be used with or without a park brake. 
   The frame  12  of the stroller  10  is shown in  FIG. 1  in the fully unfolded state with a fabric seat  2 , fabric leg support and guard  3 . For purposes of illustration, the frame  12  is shown in  FIG. 2  without the seat  2  and the leg guard  3 . The seat  2  is suspended from the left and right side handle supports  24 , and the leg guard  3  spans between and is supported by the left and right side front wheel supports  20 . 
   For the depicted implementation, user operation of the left and right side folding assemblies  22  will now be described. The left and right side folding assemblies  22  have the same construction, and the description below while in the singular is applicable to both. Each of the left and right rear wheel supports  30  supports an inwardly extending lever  34 , which has a predominantly vertical orientation, as shown in  FIG. 3 , when the frame  12  of the stroller  10  is locked in the fully unfolded position. To begin the procedure to fold the frame  12 , each of the levers  34  are pulled upward and inward as depicted by arrows R 1  to thereby put the folding assemblies  22  in an unlocked state as further explained below. 
   With each of the left and right folding assemblies  22  in an unlocked state, the left and right handle supports  24 , along with the handle  26 , and the left and right forward wheel support  20 , along with the forward wheel  18 , can be rotated about the left and right folding assemblies, respectively, toward the left and right rear wheel supports  30 , respectively, as depicted by arrows R 2  shown in  FIG. 4 . As stated, the forward wheel supports  20  can be moved independently from movement of the handle supports  24 . In the process of folding the frame  12 , if the forward wheel supports  20  were to be rotated about the folding assemblies  22  before rotation of the handle supports  24  about the folding assemblies, then the frame  12  would appear in a partially folded state as shown in the front elevational view of  FIG. 5  and the side elevational view of  FIG. 6 . In a fully folded state, both the forward wheel supports  20  and the handle supports  24  have been rotated about the folding assemblies  22  to be positioned in close proximity to the rear wheel supports  30  as shown in the side elevational view of  FIG. 7 . 
   As shown in  FIG. 8 , each of the folding assemblies  22  includes a forward rotatable member  35 ′ having a disk  36 ′ with a notch  38 ′ and an arm  40 ′, and a rearward rotatable member  35 ″ having a disk  36 ″ with a notch  38 ″ and an arm  40 ″. The disks  36 ′ and  36 ″ and the arms  40 ′ and  40 ″ are depicted in  FIG. 8  as being part of a single formed piece; however, in other implementations the disks and arms are individual pieces that are fixedly attached together. The rotatable members  35 ′ and  35 ″, along with a corresponding one of the rear wheel supports  30 , are contained between left and right slotted halves of a housing  42  that allow the arms  40 ′ and  40 ″ to protrude outside of the housing. The inside wall of each half of the housing  42  has recess  42   a  sized and shaped such that when the two halves of the housing are positioned together, the recesses form a cavity to securely receive the upper free-end portion of the rear wheel support  30  therein. The disks  36 ′ and  36 ″ each have a central aperture  41 ′ and  41 ″, respectively, sized to receive a bushing  43  therethrough having a length longer than the cumulative thickness of the two disks. When the folding assembly  22  is assembled, the disks  36 ′ and  36 ″ are arranged facing each other with the bushing  43  extending through the aligned apertures  41 ′ and  41 ″ of the disks, and this subassembly is positioned in a slot  30   b  in the enlarged, upper free-end portion of the real wheel support  30 . The slot  30   b  has a forward to rearward orientation. A central aperture  43   a  of the bushing  43  is aligned with a pair of opposing inward and outward side apertures  30   c  of the rear wheel support  30 , transverse to the orientation of the slot  30   b , and the left and right slotted halves of the housing  42  clamp around the slotted upper free-end portion of the rear wheel support  30 . The left and right slotted halves of the housing  42  have opposing apertures  42   b , which align with the central aperture  43   a  of the bushing  43 , such that a bolt  44  extends fully through the apertures  42   b  of the halves of the housing  42 , through the aperture  30   c  of the rear wheel support  30 , and through the central aperture  43   a  of the bushing  43 . A nut  44   a  is threaded onto the threaded end of the bolt  44  to hold the assembly together with the disks  36 ′ and  36 ″ freely rotatable on the bushing  43 . With this assembly, the bolt  44  and nut  44   a  hold the left and right slotted halves of the housing  42  securely clamped together with the slots of the housing having the arms  40 ′ and  40 ″ extending therethrough. The arm  40 ′ extends forwardly through the forward opening of the slot  30   b  and the other arm  40 ″ extends rearwardly through the rearward opening of the slot  30   b  in the rear wheel support  30 . 
   When the folding assemblies  22  are in a fully unfolded state, as shown in  FIG. 9 , the disks  36 ′ and  36 ″ of the folding assembly are locked in place by components positioned internal to the rear wheel supports  30  including a slidably mounted head  50  with a tip  52  inserted into the notches  38 ′ and  38 ″ as shown in  FIG. 10 . In  FIG. 10 , a cover portion  30   d  of the upper free-end portion of the rear wheel support  30  is shown removed in order to better illustrate the components of the folding assembly  22  contained therein. The cover portion  30   d  is attached to the other portion of the free-end portion of the rear wheel support  30  by a bolt  30   e , as seen in  FIG. 9 . The lever  34  is pivotally mounted to the rear wheel support  30  and the head  50  is mechanically linked to the lever  34  so that when the lever  34  is pulled upward and inward as depicted by the arrows R 1  in  FIG. 5 , the head  50  is moved away from the disks  36 ′ and  36 ″, thereby causing the tip  52  to be retracted and disengaged from the notches  38 ′ and  38 ″. The disks  36 ′ and  36 ″ are then free to rotate on the bolt  44  and hence allow folding of the front wheel support  20  and the handle support  24  about the rear wheel support  30  in a clam shell movement, as will be explained in greater detail below. 
   The head  50  further includes a base  54 , which rests against one end of a spring  56 . The other end of the spring  56  rests against an internal support  58  inside the rear wheel support  30  such that the spring provides a force adequate to bias the tip  52  into an engaged state within the notches  38 ′ and  38 ″ of the disks  36 ′ and  36 ″ when the folding assembly  22  is in the fully unfolded state. While supplying a force to the head  50  to keep the tip  52  in the notches  38 ′ and  38 ″, the force is not so great as to require undue force to be applied to the lever  34  by the user to retract and disengage the tip from the notches when the folding assembly is to be folded. 
   The internal support  58  is coupled to or may be an integral part of the rearward free-end  30   a  of the rear wheel support  30  to couple the folding assembly  22  to the rear axle assembly  14 . As shown in  FIGS. 11 and 12 , for each of the folding assemblies  22  on the left and right sides of the stroller  12 , the front wheel support  20  is bolted onto the arm  40 ′ of the forward rotatable member  35 ′ using a pair of bolts  60 , and the handle support  24  is bolted onto the arm  40 ″ of the rearward rotatable member  35 ″ using a pair of bolts  62 . 
   In the fully folded state of the stroller  12 , both the front wheel support  20  and the handle support  24  are moved into close proximity to the rear wheel support  30 . As shown in  FIG. 12 , in the fully folded state, the tip  52  of the head  50  is retracted and disengaged from the notch  38 ′ of the forward rotatable member  35 ′ and the notch  38 ″ of the rearward rotatable member  35 ″. In the fully folded state, both the front wheel support  20  and the handle support  24  are free to rotate independently of the other about the bolt  44  of the folding assembly  22  so that the notches  38 ′ and  38 ″ can be brought back into alignment with the tip  52  of the head  50  to consequently secure the stroller  12  into the fully folded state. 
   From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. For instance, the depicted implementation used the bolt  44  and nut  44   a  assembly to rotatably couple the forward rotatable member  35 ′ and the rearward rotatable member  35 ″ together with a corresponding one of the rear wheel supports  30 . In other implementations, pivot members other than the bolt-nut assembly may be used, including pin assemblies. As another example, in the depicted implementation, the rear wheel supports  30  supported the bolt  44  on which the rotatable members  35 ′ and  35 ″ where rotably mounted. In other implementations, either the front wheel support  20  can support the bolt  44  and have the rotatable members  35 ′ and  35 ″ rotatably mounted thereon with the arms  40 ′ and  40 ″ each fixedly attached to one of the handle support  24  and the rear wheel support  30  such that the handle support and the rear wheel support fold about the front wheel support, or the handle support  24  can support the bolt  44  and have the rotatable members  35 ′ and  35 ″ rotatably mounted thereon with the arms  40 ′ and  40 ″ each fixedly attached to one of the front wheel supports  20  and the rear wheel support  30  such that the front wheel support and the real wheel support fold about the handle support. As a further example, the rotatable members  35 ′ and  35 ″ were depicted as including the disks  36 ′ and  36 ″, however, in other implementations the rotatable members  35 ′ and  35 ″ may have other shapes. As an additional example, the depicted implementation aligned the tip  52  of the spring loaded head  50  of each folding assembly  22  with the notches  38 ′ and  38 ″ of the disks  36 ′ and  36 ″ to secure the stroller  12  into the fully folded state. In other implementations, each folding assemblies  22  can use a pin or other member that is inserted into holes in each of the disks  36 ′ and  36 ″ to hold the front wheel supports  20 , the handle supports  24 , and the rear wheel supports  30  in the unfolded state. Accordingly, the invention is not limited except as by the appended claims.

Technology Classification (CPC): 1