Patent Publication Number: US-2010123298-A1

Title: Foldable Toy Stroller

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a foldable stroller and, more particularly, to a foldable toy stroller. 
     Toy strollers generally include two handles, a frame, and a plurality of wheels. The frame is generally foldable to allow easy carriage and storage. Furthermore, the frame generally includes movable and lockable joints so that the toy stroller can be retained in a folded state or an extended state. However, the frame may unfold due to accidental impact to the joints, such that a child playing the toy stroller may be injured due to falling or being impinged by the frame. U.S. Pat. No. 5,845,925 discloses a safety device mounted to the rear tubes of the stroller to avoid unintentional folding. However, the stroller has many parts and, thus, has high costs in manufacturing and assembly. Furthermore, the rear wheels of the stroller can not be detached, so that the package for the stroller occupies a large space, leading to increased costs for transport. 
     Thus, a need exists for a toy stroller that has fewer parts without sacrificing the structural strength while having a smaller volume for transport. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention solves this need and other problems in the field of toy strollers by providing, in a preferred form, a foldable toy stroller including a first bottom tube having a first longitudinal axis and first and second ends spaced from each other along the first longitudinal axis. The first bottom tube further includes a first arcuate intermediate portion between the first and second ends thereof. A second bottom tube includes a second longitudinal axis and first and second ends spaced from each other along the second longitudinal axis. The second longitudinal axis is coplanar with the first longitudinal axis. The second bottom tube further includes a second arcuate intermediate portion between the first and second ends thereof. The first and second bottom tubes being cross hinged at the first and second arcuate intermediate portions. A first rear tube includes a third longitudinal axis and first and second ends spaced from each other along the third longitudinal axis. The first rear tube further includes a third arcuate intermediate portion between the first and second ends thereof. A second rear tube includes a fourth longitudinal axis and first and second ends spaced from each other along the fourth longitudinal axis. The fourth longitudinal axis is coplanar with the third longitudinal axis. The second rear tube further includes a fourth arcuate intermediate portion between the first and second ends thereof. The first and second tubes are cross hinged at the third and fourth arcuate intermediate portions. Two linking members each have an end and a pivotal portion. The end of each linking member is pivotably connected to the first end of one of the first and second bottom tubes and to the second end of one of the first and second rear tubes. Two front legs each include an upper section, a lower section, and an intermediate section between the upper and lower sections. A front wheel unit is pivotably connected to the lower section of each front leg. The intermediate section of each front leg is pivotably connected to the pivotal portion of one of the linking members. A connecting member is mounted to a portion of each front leg adjacent to the upper section. The toy stroller further includes two handle tubes each having upper and lower ends. The upper end of each handle tube is pivotably connected to the first end of one of the first and second rear tubes. A handle is mounted to the upper end of each handle tube. The lower end of each handle tube is pivotably connected to one of the connecting members. A retaining member is slideably mounted on a portion of each handle tube adjacent to the lower end of the handle tube. Each retaining member has a positioning hole. The upper section of each front leg is received in the positioning hole of one of the retaining members when the handle tubes are generally parallel to the front legs, preventing rotation of the handle tubes relative to the front legs. A rear wheel unit is mounted to the second end of each of the first and second rear tubes. 
     When the retaining members are moved away from the front legs, so that the upper ends of the front legs are disengaged from the positioning holes of the retaining members, the front tubes are pivotable toward the front legs, the first and second bottom tubes are moveable toward each other, the first and second rear tubes are moveable toward each other, the handle tubes are moveable toward each other, and the front legs are movable toward each other, allowing folding of the toy stroller. 
     The present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The illustrative embodiment may best be described by reference to the accompanying drawings where: 
         FIG. 1  shows a perspective view of a toy stroller according to the preferred teachings of the present invention with the stroller in an assembled and extended state. 
         FIG. 1A  shows an enlarged view of a circled portion at a right portion of the toy stroller of  FIG. 1 . 
         FIG. 1B  shows an enlarged view of a circled portion at a left portion of the toy stroller of  FIG. 1 . 
         FIG. 2  shows a partly-exploded, perspective view of the toy stroller of  FIG. 1 . 
         FIG. 2A  shows an enlarged view of a circled portion at an upper portion of the toy stroller of  FIG. 2 . 
         FIG. 2B  shows an enlarged view of a circled portion at a lower portion of the toy stroller of  FIG. 2 . 
         FIG. 3  shows a side view of the toy stroller of  FIG. 1 . 
         FIG. 4  shows a partial, cross sectional view of the toy stroller of  FIG. 1  according to section line  4 - 4  of  FIG. 3 . 
         FIG. 5  shows a partial, cross sectional view of the toy stroller of  FIG. 1  according to section line  5 - 5  of  FIG. 1 . 
         FIG. 6  is a view similar to  FIG. 5 , illustrating folding of the toy stroller. 
         FIG. 7  shows a side view of the toy stroller of  FIG. 1  with the toy stroller being folded. 
         FIG. 8  shows a side view of the toy stroller of  FIG. 1  with the toy stroller completely folded. 
         FIG. 9  shows a perspective view of the toy stroller of  FIG. 1  with the toy stroller completely folded and with rear wheel units of the toy stroller detached. 
     
    
    
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood. 
     Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “third”, “fourth”, “lower”, “upper”, “inner”, “outer”, “side”, “end”, “portion”, “section”, “longitudinal”, “lateral”, and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A toy stroller according to the preferred teachings of the present invention is shown in the drawings and includes cross-hinged first and second bottom tubes  10 . Specifically, first bottom tube  10  includes a first longitudinal axis  112  and first and second ends  100  and  102  spaced from each other along first longitudinal axis  112 . First bottom tube  10  further includes an arcuate intermediate portion  104  between first and second ends  100  and  102 . Arcuate intermediate portion  104  of first bottom tube  10  defines a groove that faces upward when the toy stroller is in an extended state. Second bottom tube  10  includes a second longitudinal axis  114  coplanar and at an angle A with first longitudinal axis  112  and first and second ends  100  and  102  spaced from each other along second longitudinal axis  114 . Arcuate intermediate portion  104  of second bottom tube  10  defines a groove that faces downward when the toy stroller is in the extended state. According to the most preferred form shown, a middle of arcuate intermediate portion  104  of first bottom tube  10  is pivotably connected by a pivot  106  to a middle of arcuate intermediate portion  104  of second bottom tube  10 . Furthermore, first and second ends  100  and  102  of first and second bottom tubes  10  are at the same level and on the same plane. Specifically, first and second longitudinal axes  112  and  114  of first and second bottom tubes  10  are located at the same level and on the same plane. This allows reduction in an overall volume of the toy stroller in a folded state. 
     According to the preferred form shown, the toy stroller further includes two substantially L-shaped first pivotal members  28  each having a first section  280  and a second section  282  perpendicular to first section  280 . First section  280  of each first pivotal member  28  is pivotably connected to first end  100  of one of first and second bottom tubes  10 . 
     According to the preferred form shown, the toy stroller further includes two substantially L-shaped second pivotal members  30  each having a first section  300  and a second section  302  perpendicular to second section  300 . First section  300  of each second pivotal member  30  is pivotably connected by a pin  304  to second section  282  of one of first pivotal members  28 . 
     According to the preferred form shown, the toy stroller further includes two substantially L-shaped third pivotal members  32  each having a first section  320  and a second section  322  perpendicular to first section  320 . First section  320  of each third pivotal member  32  is pivotably connected by a pin  324  to second end  102  of one of first and second bottom tubes  10 . 
     According to the preferred form shown, the toy stroller further includes two tubular linking members  19  each having an end  190  pivotably connected by pin  304  to second section  282  of one of first pivotal members  28 . Each linking member  19  further includes a pivotal portion  192  between end  190  and the other end of linking member  19 . 
     According to the preferred form shown, the toy stroller further includes two tubular front legs  16  each having an upper section  160 , a lower section  162 , and an intermediate section  164  between upper and lower sections  160  and  162 . Each front leg  16  is pivotably connected by a pin  326  to second section  322  of one of third pivotal members  32  at a portion intermediate lower section  162  and intermediate section  164 . Pivotal portion  192  of each linking member  19  is pivotably connected to intermediate section  164  of one of front legs  16 . Each linking member  19  is at an angle B with one of front legs  16 . A front wheel unit  20  is coupled to lower section  162  of each front leg  16 . 
     According to the preferred form shown, the toy stroller further includes cross-hinged first and second rear tubes  12 . First rear tube  12  includes a third longitudinal axis  126  and first and second ends  120  spaced from each other along third longitudinal axis  126 . First rear tube  12  further includes an arcuate intermediate portion  124  between first and second ends  120  and  122 . Arcuate intermediate portion  124  of first rear tube  12  defines a groove that faces forward when the toy stroller is in the extended state. Second rear tube  12  includes a fourth longitudinal axis  128  coplanar and at an angle C with third longitudinal axis  126 . Second rear rube  12  further includes first and second ends  120  and  122  spaced from each other along fourth longitudinal axis  128 . Arcuate intermediate portion  124  of second rear tube  12  defines a groove that faces rearward when the toy stroller is in the extended state. According to the most preferred form shown, a middle of arcuate intermediate portion  124  of first rear tube  12  is pivotably connected by a pivot  130  to a middle of arcuate intermediate portion  124  of second rear tube  12 . Furthermore, first and second ends  120  and  122  of first and second rear tubes  12  are on the same plane. Specifically, third and fourth longitudinal axes  126  and  128  of first and second rear tubes  12  are located on the same plane. This allows reduction in the overall volume of the toy stroller in the folded state. 
     According to the preferred form shown, the toy stroller further includes two substantially L-shaped fourth pivotal members  34  each having a first section  340  and a second section  342  perpendicular to first section  340 . First section  340  of each fourth pivotal member  34  is pivotably connected by a pin  348  to first end  120  of one of first and second rear tubes  12 . 
     According to the preferred form shown, the toy stroller further includes two rear wheel units  22 , two connecting tubes  24 , and two coupling members  26 . Each rear wheel unit  22  includes an axle  220 . Each connecting tube  24  has a lower end  242  rotatably receiving axle  220  of one of rear wheel units  22  and an upper end  240  located at a level higher than rear wheel unit  22  when the toy stroller is in the extended state. Each coupling member  26  includes a first end  260  having an outer diameter corresponding to an inner diameter of rear tubes  12 . Each coupling member  26  further includes a second end  262  fixed in upper end  240  of one of connecting tubes  24  by a rivet. First end  260  of each coupling member  26  includes a longitudinal groove  266 , forming two resilient tab  264  spaced by longitudinal groove  266 . Resilient tabs  264  in the original position have a maximum width lager than the inner diameter of rear tubes  12 . The width of longitudinal groove  266  can be changed by pressing resilient tabs  264  toward each other, so that first end  260  of each coupling member  26  can be inserted into second end  122  of one of first and second rear tubes  12 . When the pressing force is released, resilient tabs  264  of first end  260  of each coupling member  26  tend to return to their original position and, thus, press against and in friction contact with an inner periphery of second end  122  of one of first and second rear tubes  12 . In this way, rear wheel units  22  can be easily attached to second ends  122  of first and second rear tubes  12 . 
     According to the preferred form shown, the toy stroller further includes two handle tubes  14  each having an upper and  140  and a lower end  142 . Each handle tube  14  is pivotably connected by a pin  346  to second section  342  of one of fourth pivotal members  34  at a portion adjacent to upper end  140 . A handle  145  is fixed to upper end  140  of each handle tube  14 . A user can grip handles  145  and move the toy stroller. 
     According to the preferred form shown, the toy stroller further includes two connecting members  166  each of which is mounted to a portion of one of front tubes  16  adjacent to upper section  160  of front tube  16 . Each connecting member  166  is substantially L-shaped in cross section and includes a through-hole  168  and a compartment  170  in an end thereof. Lower end  142  of each handle tube  14  is pivotably received in compartment  170  of one of connecting members  166  and pivotable about a pivot axis defined a pin  174 . Upper section  166  of each front leg  16  is extended through through-hole  168  of one of connecting members  166  and beyond connecting member  166 . A retaining member  18  is slideably mounted on each handle tube  14  at a location above connecting member  166 . Each retaining member  18  includes upper and lower ends  180  and  182  and a through-hole  186  extending from upper end  180  through lower end  182 . A protrusion  181  is formed on an outer periphery of upper end  180  of each retaining member  18 . Upper end  180  of each retaining member  18  further includes a compartment  184  in communication with through-hole  186 . Lower end  182  of each retaining member  18  includes a positioning hole  188  aligned with through-hole  168  of one of connecting members  166 . Each handle tube  14  is extended through through-hole  186  of one of retaining members  18 . A peg  144  is extended through a section of each handle tube  14  received in compartment  184  of one of retaining members  18  and has an end extending into compartment  184 , and a spring  185  is mounted between a bottom wall of compartment  184  and the end of peg  144 , biasing retaining member  18  to a position so that positioning hole  188  receives one of front legs  16  when the toy stroller is in the extended state, preventing rotation of front leg  16  relative to handle tube  14 . 
     According to the preferred form shown, the toy stroller further includes two safety rings  172  each having a first end pivotably connected to a section of one of handle tubes  14  between one of connecting members  166  and one of retaining members  18 . Each safety ring  172  further includes two lateral sides and a bottom side interconnected between the lateral sides. Each safety ring  172  falls and rests on one of retaining members  18  due to gravitational force such that retaining member  18  is received between the lateral sides. 
     When the toy stroller is in a fully extended state, handle tubes  14  are generally parallel to front legs  16 . Lower end  142  of each handle tube  14  is completely received in compartment  170  of one of connecting members  166 . Positioning hole  188  of each retaining member  18  is aligned with upper section  160  of one of front legs  16 . Each retaining member  18  is biased by one of springs  185  to a position, so that positioning hole  188  receives one of front legs  16  to prevent rotation of front leg  16  relative to handle tube  14  ( FIG. 5 ). In this state, first and second ends  100  and  102  of first and second bottom tubes  10  are on the same plane and at the same level above the ground on which the toy stroller is placed. Furthermore, angle A between first and second longitudinal axes  112  and  114  of first and second bottom tubes  10  is in the order of 69°, angle B between each linking member  19  and one of front legs  16  is 110°, and angle C between third and fourth longitudinal axes  126  and  128  of first and second rear tubes  12  is in the order of 59°. 
     When folding of the toy stroller is desired, the user grips protrusion  181  of each retaining member  18  and moves retaining member  18  upward along one of handle tubes  14  to overcome one of springs  185  until upper section  160  of front leg  16  is no longer received in positioning hole  188  ( FIG. 6 ). Each handle tube  14  can be pivoted relative to one of front legs  16 . However, further pivotal movement of handle tubes  14  relative to front legs  16  is limited by safety rings  172  when the bottom side of each safety ring  172  presses against one of front leg  16 . Thus, injury to the user due to unintentional folding of the toy stroller can be avoided even if retaining members  18  are inadvertently moved. 
     Safety ring  172  can be manually moved away from front legs  16  ( FIG. 7 ), so that handle tubes  14  can be pivoted toward front legs  16 . First and second rear tubes  12  are also pivoted toward front legs  16  together with handle tubes  14 . Second pivotal members  30  allow pivotal movement of linking members  19  toward first and second bottom tubes  10 , which in turn, causes pivotal movement of front legs  16  toward first and second bottom tubes  10 . Thus, first and second bottom tubes  10  are moveable toward each other, first and second rear tubes  12  are moveable toward each other, handle tubes  14  are moveable toward each other, and front legs  16  are movable toward each other, allowing folding of the toy stroller. When the toy stroller is in the completely folded state ( FIGS. 8 and 9 ), angle A between first and second longitudinal axes  112  and  114  of first and second bottom tubes  10  is in the order of 13°, angle B between each linking member  19  and one of front legs  16  is 180°, and angle C between third and fourth longitudinal axes  126  and  128  of first and second rear tubes  12  is in the order of 13°. 
     It can be appreciated that rear wheel units  22  do not have to be assembled during transport. Specifically, rear wheel units  22  can be placed in spaces between the toy stroller and the package receiving the toy stroller, reducing the overall volume of the package. Thus, the costs of packaging and transport can be cut. Furthermore, since rear wheel units  22  are not coupled with the portions of the toy stroller to which safety rings  172  are mounted, the number of parts of the toy stroller according to the preferred teachings of the present invention is smaller than that of conventional toy strollers. However, according to tests, the structural strength of the toy stroller according to the preferred teachings still meets the safety requirements for toy strollers. 
     Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. For example, second end  122  of each rear tube  12  can include notches or protrusions, and resilient tabs  264  of connecting members  26  can include protrusions or notches for engaging with the notches or protrusions of rear tube  12 . Pegs  114  can be directly fixed on outer peripheries of handle tubes  14 . 
     Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.