Abstract:
This invention involves a set of exclusive methods of folding mechanisms for means of collapsing and opening a baby stroller. The methods aims for the compact ability, ease of use, versatility and easy manufacturing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 61/662,930, filed on Jun. 22, 2012. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates methods of folding mechanism on a baby stroller to conveniently collapse a baby stroller and more particularly, is directed to baby strollers which fold with single hand operation. 
         [0004]    2. Discussion of Related Art 
         [0005]    In recent years, several inventions have been developed in attempt to produce an easy method of collapsing the stroller. One particular prior art worth mentioning is a collapsible baby stroller by Sutherland et al. (U.S. Pat. No. 6,102,431) involving a folding, mechanism that uses a two knife blade followers to engage the spring loaded piston in an unfolded position. With this present invention, followers are not necessary, thus, reduces extra parts to be made. This will reduce the manufacturing cost and time. Mechanism such as stoppers—gear locking slots, protrusion tab—latch and plug—hole positioned in strategic places described in first, second and third embodiments provides a strong locking system to maximize the rigidity of the entire frame structure. 
         [0006]    In the fourth, fifth and sixth embodiments, the gears are placed in face-to-face juxtaposition. In comparison with the collapsible baby stroller by Chili-Ching Cheng (U.S. Pat. No. 7,632,035B2), the embodiments of this present invention providing a solution for better fixation of the pinion gears on folding mechanism by eliminating the need of using rotatable members with apertures. Therefore, this reduces not only manufacturing cost and time; it also allows increases the durability of the gear component as one solid component instead of having apertures on its surface. In addition, two of the embodiments of the present invention eliminates the need of installing the spring locking system on rear wheel support bar. 
       SUMMARY OF THE INVENTION 
       [0007]    The present of this invention is series of methods of folding baby stroller, which improve the ease of folding a baby stroller and lessen the bulkiness of the stroller for storage. Embodiments of the folding mechanism involve two gears moving simultaneously in the opposite direction to guide the movement of folding mechanism. The two gears are further connected to the two main parts of the stroller—the front wheel(s) and the handle bar(s), by means of extensions. One gear is connected to the extension to front wheel(s), the other is connected the extension to the handle bar. The embodiments further include a locking mechanism to halt the movement of the two gears indefinitely until the locking mechanism is disengaged. The locking mechanism, in a few embodiments is further connected to the extension of the rear wheels. In other embodiments, the locking system is an independent mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an isometric view of an exemplary implementation of baby stroller embodying the present invention shown in unfolded state. 
           [0009]      FIG. 2  is an isometric view of the stroller frame of  FIG. 1 . 
           [0010]      FIG. 3  is a side elevation view of the stroller frame of  FIG. 2 . 
           [0011]      FIG. 4  is a side elevation view of the stroller frame with a folding mechanism shown in fully folded state. 
           [0012]      FIG. 5  is an enlarged fragmentary view of the folding mechanism according to an embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0013]      FIG. 6  is exploded view corresponding to  FIG. 5  of the folding mechanism. 
           [0014]      FIG. 7  is an enlarged fragmentary view of the folding mechanism according to the second embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0015]      FIG. 8  is exploded view corresponding to  FIG. 7  of the folding mechanism. 
           [0016]      FIG. 9  is an enlarged fragmentary view of the folding mechanism according to the third embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0017]      FIG. 10  is exploded view corresponding to  FIG. 9  of the folding mechanism. 
           [0018]      FIG. 11  is an enlarged fragmentary view of the folding mechanism according to the fourth embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0019]      FIG. 12  is exploded view corresponding to  FIG. 11  of the folding mechanism. 
           [0020]      FIG. 13  is an enlarged fragmentary view of the folding mechanism according to the fifth embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0021]      FIG. 14  is exploded view corresponding to  FIG. 13  of the folding mechanism. 
           [0022]      FIG. 15  is an enlarged fragmentary view of the folding mechanism according to the sixth embodiment of present invention with its outer housing removed and in fully unfolded state. 
           [0023]      FIG. 16  is exploded view corresponding to  FIG. 15  of the folding mechanism. 
           [0024]      FIG. 17  is an enlarged fragmentary view of the folding mechanism according to the seventh embodiment of present invention in fully unfolded state. 
           [0025]      FIG. 18  is exploded view corresponding to  FIG. 17  of the folding mechanism. 
           [0026]      FIG. 19  is side view, corresponding to  FIG. 17  of the folding mechanism. 
       
    
    
     DETAILED DESCRIPTION OF INVENTION 
       [0027]    The stroller frame is made up of three sections; front wheel support  2 , push handle support  4 , rear wheel support  3  (See  FIG. 2 ). The left and right front wheels are mounted to the end of the front wheel supports  2 . The stroller push handle  5  is mounted to the left and right of the push handle support  4  and the left and right of rear wheels are mounted to end of the rear wheel supports  3 . These sections are hinged by a folding mechanism  6  (See  FIG. 1 ) placed on both side of the stroller. The stroller, in the unfolded position depicted in  FIG. 3 , has the from wheel support  2  and push handle support  4  aligned in a straight line. Conversely, the stroller, in the folded position, is depicted in  FIG. 4 . 
         [0028]    The folding mechanism  6  consists of two outer casing  10   a ,  10   b , two gear components  15 ,  16  and a locking system  80  (See  FIG. 5  and  FIG. 6 ). The gear components each consists of a mesh gear with a bar that extends to become the front wheel support  4  or the push handle support  2 . The gear components can be made as an entire piece to include all its parts or be made separately. Both gear components  15 ,  16  are mounted on pivots of the folding mechanism  6 . The gears constrain the movement between the front wheel support  2  and push handle support  4 , so either one is rotates toward the rear wheel support, the other one will rotate toward rear wheel support as well. The mesh gear is partially toothed or can be of any type of gear as long as it achieves the same result as above. At the end of the sequence of gear teeth is a gear locking slot  17 . The gear locking slot  17  is slightly different from the tooth spaces as its main function is to provide a fit for the stopper  14  from the locking system  80 . 
         [0029]    The locking system  80  consists of a spring loaded piston  12 , connected to a central bar  13  with stoppers  14  at the ends of the bar. The stoppers  14 , can be made of lug, bar, tab; are positioned with means to constrain the movements of both gear components  15 ,  16  by insertions into the gear locking slot  17  of each gear component  15 ,  16 . The locking system  80  can also be designed with spring loaded piston connects to only one stopper engaging on one gear locking slot  17  on either side of the gear component instead of both sides since locking one gear component will prevent another gear component to move. 
         [0030]    When folding, the stoppers  14  on the locking system  80  are retracted from the gear locking slots  17 , thereby freeing both gear components  15 ,  16  to rotate with the influence of force gravity pulling and hence the collapsing of the front wheel support  2  and push handle support  4 . In the case, depicted in  FIG. 2  the push handle  5  of stroller that is connected to the left and right push handle supports  4  at one end rotates anti-clockwise, while the front wheels that are connected to the left and right front wheel supports  2  at the other end rotates clockwise. Thus, the final result is a folded stroller depicted in  FIG. 4 . 
         [0031]    The stroller, in the unfolded position depicted in  FIG. 3 , has the front wheel support  2  and push handle support  4  aligned in a straight line. During the unfolding process, each gear component  15 ,  16  moves upwardly, with sequence of teeth on the mesh gear rotates in the opposite direction, until the stoppers  14  falls into the gear locking slot  17  with the release of the loaded tension in the locking system  80  (See  FIG. 5 ). The rotation of the gear components is further constrained by lack of gear teeth on the other end of the teeth sequence. The remaining tension from in the locking system  80  maintains the stoppers  14  in contact with the gear locking slots  17  prevent the front wheel support  2  and push handle support  4  from folding. 
         [0032]    The retraction of locking system  80  can be achieved by lifting up the pull bar or lever  19 . The lever  19  is connected to the locking system via pin  18  (See  FIG. 6 ). The position of the lever can be extended away from the locking system  80  to be in closer proximity to the stroller user by using means such as cable wires on locking system  80  and levers  19  to control the locking operation. The stroller will fold only when both levers  19  on each side of the stroller, are lifted up simultaneously. This can be achieved by connecting both levers  19  on each side of the stroller with a handle strap. 
         [0033]    Instead of using the stoppers  14  and gear locking slots  17  for means of initiating and halting the movement of the gear components  15 ,  16 , in the folding mechanism  6   a , a modification can be made to one of the gear components where a protrusion tab  21  is positioned at the end of the sequence of gear teeth of the gear component  26  (See  FIG. 7  and  FIG. 8 ). The protrusion tab  21  acts as stopper for a complimentary latch  22 , which is connected to the locking system  81 . The locking system  81  consists of a spring loaded piston  12 , connected to a latch  22 . 
         [0034]    When folding, latch  22  retracted away from the protrusion tab  21 , allowing the movement of the gear components  25 ,  26 . The bar of the gear components will move downwardly with influence of gravity force. When unfolding, the gear components  25 ,  26 , rotate in the opposition direction with the gear teeth surface sliding along the surface of latch  22  as tension from the loaded spring keeps a light contact between the gear teeth and the surface. When the protrusion tab  21  passes the tip  22   a  of latch  22 , the tension from the spring loaded piston  12  will cause latch  22  to anchor onto the protrusion tab  21 , thereby halting the movement of the gear components  25 ,  26 . The latch  22  and protrusion tab  21  can be of any size and shape as long as it able to engage to each other. 
         [0035]    In another embodiment, instead of having gear locking slots  17  or protrusions  21 , a locking hole  37  on the surface of one of the gear components of the folding mechanism  6   b  and a spring loaded plug  34  is being used (See  FIG. 9  and  FIG. 10 ). A lever  29  is attached to the spring loaded plug  34  by cable wire  11  to control the movement of the plug. 
         [0036]    When the front wheel support  2  and push handle support  4  are in the process of unfolding, the plug  34  of the locking mechanism slides along the surface of the gear component  35  until it finally meets with hole  37  and engages with the hole  37  due to the tension release of spring, thereby locking the rotator movement of the gear components  35 ,  36 . To fold, the lever  29  is lifted up to retract the spring of the plug  34 , thereby removing the plug  34  from the hole  37 . Both gear components  35 ,  36  begin to rotate freely with the influence of gravity force on the front wheel support  2  and push handle support  4  to fold the stroller. One of the benefits of this embodiment is that the locking system is no longer attached to the rear wheel support  3 . In this design, the locking system can be placed on lateral side or any position of the folding mechanism  6   b  instead on rear wheel support  3 . 
         [0037]    The fourth embodiment is a folding mechanism  6   c  consisting of two outer casing  20   a ,  20   b , two gear components  45 ,  46 ; two pinion gears  41 ,  42 ; and a locking, system  82  (See  FIG. 11  and  FIG. 12 ). The two gear components  45 ,  46  are placed in face-to-face juxtaposition. Each gear component has a set of gear teeth in a partial hollow cut from the surface. In  FIG. 12 , the series of gear teeth is along the bottom lip of the hollow cut  45   a  (radially inward gear) of the first gear component  45 , while a second series of gear teeth is along the top lip of the hollow cut  46   a  (radially outward gear) of second gear component  46 . The hollow cut  45   a ,  46   a  can be part of the gear component itself (by stamping or molding) or can part of made as individual piece attached to each of the bar connected to front wheel support  2  and push handle bar  4 . 
         [0038]    The pinion gears  41 ,  42  are positioned in the hollow cut on gear components  45 ,  46  for driving engagement of folding mechanism  6   c . The gear teeth of first pinion gear  41  is positioned to engage on the gear teeth of the first gear component  45  while the gear teeth of second pinion gear  42  is positioned to engage with the gear teeth of the second gear component  46 . Both pinion gears are coupled to rotate simultaneously about a common axis fixed by the pin  43  connected to an arm  40 . The arm  40  is further connected to the bolt  47  at the center of the gear components to secure the common axis in place. Hence if one of the gear components is rotated, the rotational force is transferred to the pinion gears to cause the other gear component to rotate. For example, when the push handle support  4  is rotated towards to the rear wheel support  3 , the front wheel support  2  is rotated simultaneously towards the rear wheel support  3  as well. The two pinion gears can be manufactured as a single unit or by two separate units attached as one entity. Each gear component  45 ,  46  further consist of a near locking slot  49   a ,  49   b  on the edge to engage with a stopper  48  connected to the locking system  82 . The locking system  82  consists of a spring loaded piston  12  which is attached to the end of outer casing  20   a ,  29   b . The end of the outer casing further connected to a rear support wheel  3 . A lever  19  is connected to the locking system  82  via pin  18  for retracting the stopper  48 . 
         [0039]    To fold the stroller, the lever  19  is lifted up to retract the stopper  48 . The stopper  48  detaches from the gear locking slots  49   a ,  49   b  and frees the two gear components  45 ,  46  to rotate. Since the gear components  45 ,  46  are further attached to front wheel support  2  and push handle support  4  respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly. The position of the lever  19  can be extended away from the locking system  82  to be in closer proximity to the stroller user by using means such as cable wires on locking system  82  and levers  19  to control the locking operation. 
         [0040]    It is worth mentioning that as an alternative embodiment of the locking mechanism  82 , a receptor block  52  is connected the locking system  83  to engage with the protrusion tabs  51   a ,  51   b  at the gear component (See  FIG. 14 ). The receptor block  52  has a hollow section or it can be a hole or a slot to engage with the protrusion tabs  51   a ,  51   b  of gear components. The folding mechanism  6   d  is able to operate in a similar fashion. This is depicted in  FIG. 13  and  FIG. 14 . 
         [0041]    To fold the stroller, the lever  19  is lifted up to retract the spring loaded receptor block  52 . The receptor block  52  detaches from the protrusion tabs  51   a ,  51   b  and frees the two gear components  55 ,  56  to rotate. Since the gear components  55 ,  56  are further attached to the front wheel support  2  and push handle support  4  respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly. 
         [0042]    When unfolding, the gear components  55 ,  56 , rotate in the opposition direction with the edge of both gear components sliding along the surface of receptor block  52  as tension from the loaded spring keeps a light contact between the gear components and the receptor block  52 . When the protrusion tabs  51   a ,  51   b  reach the tip of the receptor block  52 , the tension released will cause the receptor block  52  to rise, thereby fitting the protrusion tabs  51   a ,  51   b  into the hollow slot  52   a , halting the movement of the gear components  55 ,  56 . The receptor block  52  and protrusion tabs  51   a ,  51   b  can be of any size and shape as long as they able to engage to each other. 
         [0043]    In another embodiment of the folding mechanism  6   e , is a hole  67  on the of the gear surface of one or both of the gear components  65 ,  66 . This is depicted in  FIG. 15  and  FIG. 16 . The hole  67  is positioned on the surface of a gear component  65  adjacent to the outer casing  61   a  of the folding mechanism compartment  6   e . A plug  64  is attached to the outer casing  61   a . The movement of the plug  64  is guided by tension created with either cable tension or spring loaded. The purpose of the plug  64  is to initiate and stop the movement of the gear component  65  since locking one gear component will prevent another gear component to move. To initiate the process of folding, as tension is applied from the cable, the plug  64  is being pulled away from the hole  67  of the gear component  65 , allowing initiation of movements of the gear components. With the guidance of the pinion gears  41 ,  42 , all rotatable gears move in accordance as stated in previous embodiment until the push handle support  4  and front wheel support  2  are parallel with each other. When the front wheel support  2  and push handle support  4  are in the process to be unfolded, the gear components  65 ,  66  to move in accordance with the pinion gears  41 ,  42  in the folding mechanism in the opposite direction. The tensioned plug  64  slides along the surface of the gear component  65  until it drops into the hole  67  of the gear component  65  to halt the movement of the gears, thereby, keeps the stroller in fully unfolded position. The locking mechanism can also be achieved with a hole position on gear component  66  with tensioned plug engaging on gear component  66  to prevent another gear component to move. 
         [0044]    In another embodiment, the folding mechanism  6   f  now consist of two gear components  75 ,  76 , a bevel gear controller  71 , housing  90   a ,  90   b  and a locking system  70  (See  FIG. 17  and  FIG. 18 ). The locking system  70  consists of blocker support  74  and spring loaded piston  12  positioned inside the spring support holder  74   a  (See  FIG. 18 ). The spring support holder  74   a  further connects to rear wheel supports  3  (not shown). The two gear components  75 ,  76  are placed in face-to-face juxtaposition. The bolt  91  inserted to gear hub  92  to clamp the housing  90   b  of the folding mechanism secure the two gear components  75 ,  76 . The gear controller  71  can be of a bevel gear or any shape gear as long as it achieves the same result. The gear components  75  further contains a stopping pin  72  fixed on its disk surface while another gear component  76  consists of a stopping groove  73 . As usual, the gear component  75  is connected to the front wheel support  2  and the gear component  76  is connected to the push handle support  4  of the stroller. The gear controller  71  initiates the simultaneous movement of the two gear components  75 ,  76 , by rotating on a vertical axis. The gear controller  71  initiates the gliding of the stopping pin  72  along the stopping groove  73 , as both gear components rotates simultaneously, in  FIG. 19 , the gear controller  71  further consists of a locking slit  77  (female connector) on its edge. The blocker support  74  has a protruded blocker  78  act as a male connector to lock the female connector of gear controller  71  when the spring is released. The locking slit  77  has right-angled shaped  77   a  on one end and a slope  77   b  on other end. The protruded blocker  78  has right-angled shaped apex  78   a  on one end and a slope  78   b  on other end. The gear controller  71  is rotatable but the blocker support  74  is non-rotatable and only move vertically alone with the spring. 
         [0045]    When folding the stroller, the lever  19  is engaged to retract blocker support  74 , thereby removing protruded blocker  78  from the locking slit  77 , allowing the gear controller  71  to rotate. The stopping pin  72  guides the gear controller  71  to rotate one direction until stopping pin  72  reaches the end of the stopping groove  73 . Since the gear components  75 ,  76  are further attached to front wheel support  2  and push handle support  4  respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly. The stopping pin  72  glides in the direction from one end of the stopping groove  73  to the other end. 
         [0046]    At the end of folded position, the protruded blocker  78  rest on the surface of the gear controller  71  with tension from the loaded spring holding it in place. 
         [0047]    When unfolding the stroller, the initial upward pulling of the push handle  4  which is connected to gear component  76  will starts the rotation of the gear controller  71  in a clockwise direction (from the top view). The rotation in the clockwise direction will continue with the locking slit  77  slide out of the slope  78   b  of the protruded blocker  78  effortlessly, until the stopping pin  72  glides from one end of the groove  73  to the other. At the end of the unfolding process, the stopping pin  72  will prevent the gear components from further unfolding. The locking slit  77  will rest in the protruded blocker  78  with angled shaped apex  78   a  of protruded blocker  78  engage with the right-angled shaped  77   a  of the locking slit  77 , thereby prevent the folding movement (anti-clockwise direction) of the gear components  75 ,  76 . The combination of groove  73 , stopping pin  72 , protruded blocker  78  and locking slit  77  result in an locking system on gear components  75 ,  76 . The locking slit  77  and protruded blocker  78  can be of any size shape as long as it able to engage to each other.