Patent Publication Number: US-2023159078-A1

Title: Foldable locking mechanism

Description:
FIELD OF THE INVENTION 
     The present invention relates to a foldable locking mechanism according to the pre-characterizing clause of claim  1 . 
     BACKGROUND OF THE INVENTION 
     A child carrier, such as a child stroller, usually has a foldable frame body to improve practicability and transportation convenience. When it is desired to use the child carrier, a user can unfold the child carrier to an unfolded state. When it is not required to use the child carrier, the user can fold the child carrier to a folded state to reduce an occupied space of the child carrier for easy storage and easy transportation. 
     The conventional foldable frame body usually includes a plurality of rods which can be categorized according to functions into a backrest, a seat, a rear leg, a front leg and a handle, and a locking device disposed between the plurality of rods for locking or unlocking the plurality of rods. However, the conventional locking device has complicated structure and is incapable of unlocking the plurality of rods at a same time. Furthermore, since the conventional locking device is actuated by a releasing button, a user has to bend down to operate the release button. Therefore, the conventional locking device is not convenient in use and needs improvement. 
     SUMMARY OF THE INVENTION 
     This is mind, the present invention aims at providing a foldable locking mechanism which is adapted for a frame body and has advantages of simple structure and easy operation. 
     This is achieved by a foldable locking mechanism according to claim  1 . The dependent claims pertain to corresponding further developments and improvements. 
     As will be seen more clearly from the detail description following below, the claimed foldable locking mechanism includes a first mounting seat, a second mounting seat, a third mounting seat, a first locking component and a driving component. The second mounting seat is pivotally connected to the first mounting seat. The third mounting seat is pivotally connected to the second mounting seat. The first locking component is at least partially and movably disposed between the second mounting seat and the third mounting seat. The first locking component is movable between a first releasing position and a first locking position. A relative pivotal movement of the second mounting seat and the third mounting seat is allowed when the first locking component is located at the first releasing position. The relative pivotal movement of the second mounting seat and the third mounting seat is restrained when the first locking component is located at the first locking position. The driving component is disposed on the first mounting seat and abuts against the first locking component. The driving component is configured to drive the first locking component to move from the first locking position to the first releasing position for allowing a folding operation of the foldable locking mechanism. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a fourth mounting seat and a second locking component. The fourth mounting seat is pivotally connected to the third mounting seat. The second locking component at least partially and movably disposed between third mounting seat and the fourth mounting seat. The second locking component is movable between a second releasing position and a second locking position. A relative pivotal movement of the third mounting seat and the fourth mounting seat is allowed when the second locking component is located at the second releasing position. The relative pivotal movement of the third mounting seat and the fourth mounting seat is restrained when the second locking component is located at the second locking position. The second locking component abuts against the first locking component, and the first locking component drives the second locking component to move from the second locking position to the second releasing position when the first locking component moves from the first locking position to the first releasing position. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a fifth mounting seat and a third locking component. The fifth mounting seat is pivotally connected to the fourth mounting seat. The third locking component is at least partially and movably disposed between the fourth mounting seat and the fifth mounting seat. The third locking component is movable between a third releasing position and a third locking position. A relative pivotal movement of the fourth mounting seat and the fifth mounting seat is allowed when the third locking component is located at the third releasing position. The relative pivotal movement of the fourth mounting seat and the fifth mounting seat is restrained when the third locking component is located at the third locking position. The third locking component abuts against the second locking component, and the second locking component drives the third locking component to move from the third locking position to the third releasing position when the second locking component moves from the second locking position to the second releasing position. 
     According to an embodiment of the present invention, the driving component includes a pushing portion disposed on the first mounting seat. The first locking component includes a pushed portion extending toward the pushing portion, and the pushing portion pushes the pushed portion to drive the first locking component to move from the first locking position to the first releasing position when the first mounting seat and the second mounting seat are pivotally folded relative to each other. 
     According to an embodiment of the present invention, the pushing portion is a pushing inclined surface disposed on the first mounting seat, and the pushed portion is a protrusion cooperating with the pushing inclined surface. 
     According to an embodiment of the present invention, the pushing inclined surface is helical. 
     According to an embodiment of the present invention, a through hole is formed on the second mounting seat and located a position corresponding to the pushed portion, and the pushed portion slidably passes through the through hole. 
     According to an embodiment of the present invention, the first locking component is movable along an axial direction of a pivoting axis of the second mounting seat and the third mounting seat. 
     According to an embodiment of the present invention, the first locking component includes a first engaging tooth. The second mounting seat includes a first left engaged tooth cooperating with the first engaging tooth. The third mounting seat includes a first right engaged tooth cooperating with the first engaging tooth. The first engaging tooth engages with the first left engaged tooth and the first right engaged tooth when the first locking component is located at the first locking position, and the first engaging tooth disengages from the first left engaged tooth when the first locking component is located at the first releasing position. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a first resilient component for driving the first locking component to move toward the first locking position. 
     According to an embodiment of the present invention, the first locking component includes a first abutting portion extending toward the second locking component, and the first abutting portion passes through the third mounting seat to abut against the second locking component. 
     According to an embodiment of the present invention, a penetrating hole is formed on the third mounting seat and located at a position corresponding to the first abutting portion. 
     According to an embodiment of the present invention, the second locking component is movable along an axial direction of a pivoting axis of the third mounting seat and the fourth mounting seat. 
     According to an embodiment of the present invention, the second locking component includes a second engaging tooth. The third mounting seat includes a second left engaged tooth cooperating with the second engaging tooth. The fourth mounting seat includes a second right engaged tooth cooperating with the second engaging tooth. The second engaging tooth engages with the second left engaged tooth and the second right engaged tooth when the second locking component is located at the second locking position, and the second engaging tooth disengages from the second left engaged tooth when the second locking component is located at the second releasing position. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a second resilient component for driving the second locking component to move toward the second locking position. 
     According to an embodiment of the present invention, the second locking component includes a second abutting portion extending toward the third locking component, and the second abutting portion passes through the fourth mounting seat to abut against the third locking component. 
     According to an embodiment of the present invention, a penetrating hole is formed on the fourth mounting seat and located at a position corresponding to the second abutting portion. 
     According to an embodiment of the present invention, the third locking component is movable along an axial direction of a pivoting axis of the fourth mounting seat and the fifth mounting seat. 
     According to an embodiment of the present invention, the third locking component includes a third engaging tooth. The fourth mounting seat includes a third engaging tooth cooperating with the third engaging tooth. The fifth mounting seat includes a third right engaged tooth cooperating with the third engaging tooth. The third engaging tooth engages with the third engaging tooth and the third right engaged tooth when the third locking component is located at the third locking position, and the third engaging tooth disengages from the third engaging tooth when the third locking component is located at the third releasing position. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a third resilient component for driving the third locking component to move toward the third locking position. 
     According to an embodiment of the present invention, the foldable locking mechanism further includes a limiting assembly for limiting a relative pivotal angle of the first mounting seat and the second mounting seat. 
     According to an embodiment of the present invention, the limiting assembly includes a limiting component installed on the second mounting seat and protruding toward the first mounting seat. A limiting slot is formed on the first mounting seat and located at a position corresponding to the limiting component, and the limiting component slidably stretches into the limiting slot. 
     According to an embodiment of the present invention, the limiting assembly further includes a fourth resilient component. The limiting component is installed on the second mounting seat by the fourth resilient component, and the fourth resilient component is for driving the limiting component to resiliently abut against the limiting slot. 
     According to an embodiment of the present invention, the limiting component is a circular column. 
     According to an embodiment of the present invention, a passing hole is formed on the second mounting seat and located at a position corresponding to the limiting component, and the limiting component slidably passes through the passing hole. 
     According to an embodiment of the present invention, the driving component includes a pushing component and a driven component. The pushing component is pivotally connected to the first mounting seat. The driven component is movably disposed between the pushing component and the first locking component and movable between an extending position and a retracting position, and the pushing component pivots to drive the driven component to move from the retracting position to the extending position to push the first locking component from the first locking position to the first releasing position for allowing the folding operation of the foldable locking mechanism. 
     According to an embodiment of the present invention, the driving component further includes a linking component connected to the pushing component and for driving the pushing component to pivot. 
     According to an embodiment of the present invention, the pushing component includes an adjoining portion extending toward the driven component. The driven component includes an adjoined portion, and the adjoining portion is configured to push the adjoined portion to drive the driven component to move from the retracting position to the extending position. 
     According to an embodiment of the present invention, the adjoining portion is an adjoining protrusion. The adjoined portion is an adjoined protrusion. The adjoining protrusion and the adjoined protrusion are misaligned from each other when the driven component is located at the retracting position, and the adjoining protrusion and the adjoined protrusion are aligned with and abutted against each other when the driven component is located at the extending position. 
     According to an embodiment of the present invention, the driven component includes a pushing abutting portion. The first locking component includes a pushed portion extending toward the pushing abutting portion, and the pushing abutting portion pushes the pushed portion to drive the first locking component to move from the first locking position to the first releasing position when the driven component moves from the retracting position to the extending position. 
     According to an embodiment of the present invention, the driven component is movable along an axial direction of a pivoting axis of the first mounting seat and the second mounting seat. 
     In contrast to the prior art, in the present invention, when the first mounting seat, the second mounting seat and the third mounting seat of the foldable locking mechanism are connected to different rods of a frame body, the foldable locking mechanism can use the driving component to move the first locking component to the first releasing position to allow a relative pivotal movement of the first mounting seat and the second mounting seat and the relative pivotal movement of the second mounting seat and the third mounting seat at a same time, so that relative movements of the different rods are allowed at a same time to achieve a folding operation of the entire frame body. Therefore, the present invention has advantages of simple structure and easy operation. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, the invention is further illustrated by way of example, taking reference to the accompanying drawings. Thereof 
         FIG.  1    is a schematic diagram of a child carrier in an unfolded state according to a first embodiment of the present invention, 
         FIG.  2    is a partial sectional diagram of the child carrier according to the first embodiment of the present invention, 
         FIG.  3    is an enlarged diagram of a C portion of the child carrier shown in  FIG.  2    according to the first embodiment of the present invention, 
         FIG.  4    and  FIG.  5    are partial diagrams of the child carrier at different views according to the first embodiment of the present invention, 
         FIG.  6    and  FIG.  7    are partial exploded diagrams of the child carrier at different views according to the first embodiment of the present invention, 
         FIG.  8    is a partial diagram of a first mounting seat according to the first embodiment of the present invention, 
         FIG.  9    is a partial internal structural diagram of the child carrier according to the first embodiment of the present invention, 
         FIG.  10    is an enlarged diagram of a D portion of the child carrier shown in  FIG.  9    according to the first embodiment of the present invention, 
         FIG.  11    is another partial internal structural diagram of the child carrier according to the first embodiment of the present invention, 
         FIG.  12    is an enlarged diagram of an E portion of the child carrier shown in  FIG.  11    according to the first embodiment of the present invention, 
         FIG.  13    is a partial diagram of the child carrier as a limiting component stretches into a limiting slot according to the first embodiment of the present invention, 
         FIG.  14    is an enlarged diagram of an F portion of the child carrier shown in  FIG.  13    according to the first embodiment of the present invention, 
         FIG.  15    is a schematic diagram of a child carrier in an unfolded state according to a second embodiment of the present invention, 
         FIG.  16    is a partial diagram of the child carrier according to the second embodiment of the present invention, 
         FIG.  17    is another partial diagram of the child carrier according to the second embodiment of the present invention, 
         FIG.  18    is an enlarged diagram of a G portion of the child carrier shown in  FIG.  17    according to the second embodiment of the present invention, 
         FIG.  19    is a partial internal structural diagram of the child carrier according to the second embodiment of the present invention, 
         FIG.  20    is an enlarged diagram of an H portion of the child carrier shown in  FIG.  19    according to the second embodiment of the present invention, 
         FIG.  21    is another partial internal structural diagram of the child carrier according to the second embodiment of the present invention, 
         FIG.  22    is an enlarged diagram of an I portion of the child carrier according to the second embodiment of the present invention, 
         FIG.  23    is a partial sectional diagram of the child carrier according to the second embodiment of the present invention, 
         FIG.  24    is an enlarged diagram of a J portion of the child carrier according to the second embodiment of the present invention, 
         FIG.  25    is a diagram of a driven component according to the second embodiment of the present invention, and 
         FIG.  26    is a diagram of a pushing component according to the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top”, “bottom”, “right”, “left”, “front”, “back”, etc., is used with reference to the orientation of the Figure(s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. Also, the term “connect” is intended to mean either an indirect or direct mechanical connection. Thus, if a first device is coupled to a second device, that connection may be through a direct mechanical connection, or through an indirect mechanical connection via other devices and connections. 
     Please refer to  FIG.  1    to  FIG.  5   .  FIG.  1    is a schematic diagram of a child carrier  100  in an unfolded state according to a first embodiment of the present invention.  FIG.  2    is a partial sectional diagram of the child carrier  100  according to the first embodiment of the present invention.  FIG.  3    is an enlarged diagram of a C portion of the child carrier  100  shown in  FIG.  2    according to the first embodiment of the present invention.  FIG.  4    and  FIG.  5    are partial diagrams of the child carrier  100  at different views according to the first embodiment of the present invention. As shown in  FIG.  1    to  FIG.  5   , in this embodiment, the child carrier  100  can be a child stroller and include a frame body  400  and two foldable locking mechanisms  200 . The two foldable locking mechanisms  200  are disposed on two lateral sides of the frame body  400  and symmetrical to each other for locking or unlocking different rods of the frame body  400  to allow or restrain pivotal movements of the different rods. However, the number of the foldable locking mechanism  200  is not limited to this embodiment. For example, in another embodiment, the child carrier  100  can be a child basket or a child safety seat and include only one foldable locking mechanism at one side of a frame body of the child basket or the child safety seat. 
     The foldable locking mechanism  200  includes a first mounting seat  1 , a second mounting seat  2 , a third mounting seat  4 , a first locking component  3 , a first resilient component  9  and a driving component  1   a . The first mounting seat  1 , the second mounting seat  2  and the third mounting seat  4  can be connected to three different rods of the frame body  400 . The second mounting seat  2  is pivotally connected to the first mounting seat  1 . The third mounting seat  4  is pivotally connected to the second mounting seat  2 . A chamber is formed between the second mounting seat  2  and the third mounting seat  4 . The first locking component  3  is at least partially and movably disposed inside the chamber between the second mounting seat  2  and the third mounting seat  4 . The first locking component  3  is movable between a first releasing position and a first locking position along an axial direction of a pivoting axis of the second mounting seat  2  and the third mounting seat  4 . The first locking component  3  which is located at the first locking position can lock a relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 , i.e., the first locking component  3  can restrain the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4  when the first locking component  3  is located at the first locking position. The first locking component  3  which is located at the first releasing position can unlock the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 , i.e., the first locking component  3  can allow the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4  when the first locking component  3  is located at the first releasing position. The first resilient component  9  can provide a resilient force to drive the first locking component  3  to move toward the first locking position. Preferably, in this embodiment, the first resilient component  9  can be a compression spring. However, the present invention is not limited to this embodiment. 
     Furthermore, the driving component  1   a  is disposed on the first mounting seat  1  and abuts against the first locking component  3  for driving the first locking component  3  to move from the first locking position to the first releasing position. In this embodiment, when the first mounting seat  1  and the second mounting seat  2  pivot relative to each other, the driving component  1   a  can be driven by a relative pivotal movement of the first mounting seat  1  and the second mounting seat  2  to push the first locking component  3  from the first locking position to the first releasing position. For example, when a rod connected to the first mounting seat  1  is operated to pivotally fold relative to a rod connected to the second mounting seat  2 , the first mounting seat  1  can be driven to pivotally fold relative to the second mounting seat  2 . When the first mounting seat  1  pivotally folds relative to the second mounting seat  2 , the driving component  1   a  can drive the first locking component  3  to move from the first locking position to the first releasing position for allowing a relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 , so that the rod connected to the second mounting seat  2  and a rod connected to the third mounting seat  4  can be pivotally folded relative to each other. In other words, the present invention can utilize the relative pivotal movement of the two rods connected to the first mounting seat  1  and the second mounting seat  2  to unlock a relative pivotal movement of other two rods. Therefore, the present invention has advantages of simple structure and easy operation. 
     Besides, as shown in  FIG.  1    to  FIG.  3   , the foldable locking mechanism  200  further includes a fourth mounting seat  6 , a fifth mounting seat  8 , a second locking component  5 , a third locking component  7 , a second resilient component  10  and a third resilient component  11 . The fourth mounting seat  6 , the third locking component  7  and the fifth mounting seat  8  are sequentially disposed along a traverse direction of the foldable locking mechanism  200 . Taking  FIG.  3    as an example, the fourth mounting seat  6 , the third locking component  7  and the fifth mounting seat  8  are sequentially disposed along an arrow direction B shown in  FIG.  3   . The fourth mounting seat  6  is adjacent to a side of the third mounting seat  4  away from the second mounting seat  2 . The fourth mounting seat  6  is pivotally connected to the third mounting seat  4 . A chamber is formed between the third mounting seat  4  and the fourth mounting seat  6 . The second locking component  5  is at least partially and movably disposed inside the chamber between the third mounting seat  4  and the fourth mounting seat  6 . The second locking component  5  is movable between a second releasing position and a second locking position along an axial direction of a pivoting axis of the third mounting seat  4  and the fourth mounting seat  6 . The second locking component  5  which is located at the second locking position can lock a relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6 , i.e., the second locking component  5  can restrain the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6  when the second locking component  5  is located at the second locking position. The second locking component  5  which is located at the second releasing position can unlock the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6 , i.e., the second locking component  5  can allow the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6  when the second locking component  5  is located at the second releasing position. The second resilient component  10  can provide a resilient force to drive the second locking component  5  to move toward the second locking position. Preferably, in this embodiment, the second resilient component  10  can be a compression spring. However, the present invention is not limited to this embodiment. Moreover, the second locking component  5  abuts against the first locking component  3 . The first locking component  3  drives the second locking component  5  to move from the second locking position to the second releasing position when the first locking component  3  moves from the first locking position to the first releasing position. 
     In addition, the fifth mounting seat  8  is adjacent to a side of the fourth mounting seat  6  away from the third mounting seat  4 . The fifth mounting seat  8  is pivotally connected to the fourth mounting seat  6 . A chamber is formed between the fourth mounting seat  6  and the fifth mounting seat  8 . The third locking component  7  is at least partially and movably disposed inside the chamber between the fourth mounting seat  6  and the fifth mounting seat  8 . The third locking component  7  is movable between a third releasing position and a third locking position along an axial direction of a pivoting axis of the fourth mounting seat  6  and the fifth mounting seat  8 . The third locking component  7  which is located at the third locking position can lock a relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8 , i.e., the third locking component  7  can restrain the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8  when the third locking component  7  is located at the third locking position. The third locking component  7  which is located at the third releasing position can unlock the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8 , i.e., the third locking component  7  can allow the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8  when the third locking component  7  is located at the third releasing position. The third resilient component  11  can provide a resilient force to drive the third locking component  7  to move toward the third locking position. Preferably, in this embodiment, the third resilient component  11  can be a compression spring. However, the present invention is not limited to this embodiment. Moreover, the third locking component  7  abuts against the second locking component  5 . The second locking component  5  drives the third locking component  7  to move from the third locking position to the third releasing position when the second locking component  5  moves from the second locking position to the second releasing position. In other words, in this embodiment, the relative pivotal movement of the first mounting seat  1  and the second mounting seat  2  can unlock the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 , the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6 , and the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8 . Therefore, the present invention can provide operational convenience. 
     Specifically, as shown in  FIG.  1    to  FIG.  3   , the frame body  400  includes a backrest  12 , a seat  13 , a rear leg  14 , a front leg  15  and a handle  16  which are formed by different rods. The backrest  12  is connected to the first mounting seat  1 . The seat  13  is connected to the second mounting seat  2 . The rear leg  14  is connected to the third mounting seat  4 . The front leg  15  is connected to the fourth mounting seat  6 . The handle  16  is connected to the fifth mounting seat  8 . The backrest  12  and the seat  13  can be pivotally folded or unfolded relative to each other by the relative pivotal movement of the first mounting seat  1  and the second mounting seat  2 . The seat  13  and the rear leg  14  can be pivotally folded or unfolded relative to each other by the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 . The rear leg  14  and the front leg  15  can be pivotally folded or unfolded relative to each other by the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6 . The front leg  15  and the handle  16  can be pivotally folded or unfolded relative to each other by the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8 . During a folding operation of the frame body  400 , a relative pivotal movement of the backrest  12  and the seat  13  can unlock a relative pivotal movement of the seat  13  and the rear leg  14 , a relative pivotal movement of the rear leg  14  and the front leg  15 , and a relative pivotal movement of the front leg  15  and the handle  16  for allowing the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15 , and the relative pivotal movement of the front leg  15  and the handle  16  at a same time. On the other hand, during an unfolding operation of the frame body  400 , the relative pivotal movement of the backrest  12  and the seat  13  can lock the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15 , and the relative pivotal movement of the front leg  15  and the handle  16  for restraining the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15 , and the relative pivotal movement of the front leg  15  and the handle  16 . Therefore, the present invention has advantages of simple structure and easy operation. Moreover, preferably, the foldable locking mechanism  200  further includes a releasing operating component  17  disposed on a top portion of the backrest  12  and for unlocking the relative pivotal movement of the backrest  12  and the seat  13 . Therefore, a user can unlock all of the rods of the frame body  400  without bending down. 
     More specifically, please refer to  FIG.  6    to  FIG.  8   .  FIG.  6    and  FIG.  7    are partial exploded diagrams of the child carrier  100  at different views according to the first embodiment of the present invention.  FIG.  8    is a partial diagram of the first mounting seat  1  according to the first embodiment of the present invention. As shown in  FIG.  6    to  FIG.  8   , the driving component  1   a  includes two pushing portions disposed on the first mounting seat  1 . The two pushing portions are symmetrical to each other relative to a pivoting axis of the first mounting seat  1  and the second mounting seat  2 . Each of the two pushing portions protrudes from the first mounting seat  1  toward the second mounting seat  2 . The first locking component  3  includes two pushed portions  31  extending toward the two pushing portions. When the first mounting seat  1  and the second mounting seat  2  are pivotally folded relative to each other, each of the two pushing portions pushes the corresponding pushed portion  31  to drive the first locking component  3  to move from the first locking position to the first releasing position. Preferably, each of the two pushing portions can be a pushing inclined surface, and each of the two pushed portions  31  can be a protrusion cooperating with the corresponding pushing inclined surface. Each of the two pushing inclined surfaces can push the corresponding protrusion by height difference. More preferably, each of the two pushing inclined surfaces can be helical, and a central axis of each of the two pushing inclined surfaces can be coincided with the pivoting axis of the first mounting seat  1  and the second mounting seat  2 . Furthermore, each of the two protrusions can be formed in a shape of a circular column. However, the structures of the driving component and the first locking component are not limited to this embodiment. Besides, two through holes  21  are formed on the second mounting seat  4  and located at positions corresponding to the two pushed portions  31  respectively. Each of the two pushed portions  31  slidably passes through the corresponding through hole  21  to allow the first locking component  3  to stretch into a chamber between the first mounting seat  1  and the second mounting seat  2  to achieve a purpose of driving the first locking component  3  by the driving component  1   a  when the first mounting seat  1  and the second mounting seat  2  pivot relative to each other. In this embodiment, the driving component  1   a  includes the two pushing portions symmetrical to each other relative to the pivoting axis of the first mounting seat  1  and the second mounting seat  2 , and the first locking component  3  includes the two pushed portions  31 . Therefore, the driving component  1   a  can push the first locking component  3  stably for ensuring a smooth movement of the first locking component  3 . However, the numbers of the pushing portion and the pushed portion are not limited to this embodiment. For example, in another embodiment, the driving component can include only one pushing portion, and the first locking component can include only one pushed portion. 
     Besides, as shown in  FIG.  6    to  FIG.  8   , the first locking component  3  further includes a first engaging tooth  32 . The second mounting seat  2  includes a first left engaged tooth  22  cooperating with the first engaging tooth  32 . The third mounting seat  4  includes a first right engaged tooth  41  cooperating with the first engaging tooth  32 . When the first locking component  3  is located at the first locking position, the first engaging tooth  32  engages with the first left engaged tooth  22  and the first right engaged tooth  41 , so that the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4  is restrained. At this moment, since the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4  is restrained, the relative pivotal movement of the seat  13  and the rear leg  14  is also restrained. When the first locking component  3  is located at the first releasing position, the first engaging tooth  32  engages with the first right engaged tooth  41  but disengages from the first left engaged tooth  22 , so as to allow the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4 . At this moment, since the relative pivotal movement of the second mounting seat  2  and the third mounting seat  4  is allowed, the relative pivotal movement of the seat  13  and the rear leg  14  is also allowed. 
     As shown in  FIG.  3    and  FIG.  6    to  FIG.  8   , the first locking component  3  includes a first abutting portion  33  extending toward the second locking component  5 . The first abutting portion  33  passes through the third mounting seat  4  to abut against the second locking component  5 . Specifically, the first abutting portion  33  can be a protruding block extending toward the second locking component  5 . Preferably, in this embodiment, a cross section of the first locking component  3  can be formed in a shape of two L-shaped structures back to back. However, the present invention is not limited to this embodiment. A penetrating hole  42  is formed on the third mounting seat  4  and located at a position corresponding to the first abutting portion  33 . The first abutting portion  33  slidably passes through the penetrating hole  42  to resiliently abut against the second locking component  5 . 
     As shown in  FIG.  3    and  FIG.  6    to  FIG.  8   , the second locking component  5  includes a second engaging tooth  51 . The third mounting seat  4  includes a second left engaged tooth  43  cooperating with the second engaging tooth  51 . The fourth mounting seat  6  includes a second right engaged tooth  61  cooperating with the second engaging tooth  51 . When the second locking component  5  is located at the second locking position, the second engaging tooth  51  engages with the second left engaged tooth  43  and the second right engaged tooth  61 , so that the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6  is restrained. At this moment, since the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6  is restrained, the relative pivotal movement of the rear leg  14  and the front leg  15  is also restrained. When the second locking component  5  is located at the second releasing position, the second engaging tooth  51  engages with the second right engaged tooth  61  but disengages from the second left engaged tooth  43 , so as to allow the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6 . At this moment, since the relative pivotal movement of the third mounting seat  4  and the fourth mounting seat  6  is allowed, the relative pivotal movement of the rear leg  14  and the front leg  15  is also allowed. 
     As shown in  FIG.  1    to  FIG.  3   , the third locking component  7  includes a second abutting portion  52  extending toward the third locking component  7 . The second abutting portion  52  passes through the fourth mounting seat  6  to abut against the third locking component  7 . Specifically, the second abutting portion  52  can be a protruding block extending toward the third locking component  7 . Preferably, in this embodiment, a cross section of the third locking component  7  can be formed in a shape of two L-shaped structures back to back. However, the present invention is not limited to this embodiment. A penetrating hole  62  is formed on the fourth mounting seat  6  and located at a position corresponding to the second abutting portion  52 . The second abutting portion  52  slidably passes through the penetrating hole  62  to resiliently abut against the third locking component  7 . 
     As shown in  FIG.  3    and  FIG.  6    to  FIG.  8   , the third locking component  7  includes a third engaging tooth  71 . The fourth mounting seat  6  includes a third left engaged tooth  63  cooperating with the third engaging tooth  71 . The fifth mounting seat  8  includes a third right engaged tooth  81  cooperating with the third engaging tooth  71 . When the third locking component  7  is located at the first locking position, the third engaging tooth  71  engages with the third left engaged tooth  63  and the third right engaged tooth  81 , so that the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8  is restrained. At this moment, since the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8  is restrained, the relative pivotal movement of the front leg  15  and the handle  16  is also restrained. When the third locking component  7  is located at the first releasing position, the third engaging tooth  71  engages with the third right engaged tooth  81  but disengages from the third left engaged tooth  63 , so as to allow the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8 . At this moment, since the relative pivotal movement of the fourth mounting seat  6  and the fifth mounting seat  8  is allowed, the relative pivotal movement of the front leg  15  and the handle  16  is also allowed. 
     Please refer to  FIG.  6    and  FIG.  9    to  FIG.  14   .  FIG.  9    is a partial internal structural diagram of the child carrier  100  according to the first embodiment of the present invention.  FIG.  10    is an enlarged diagram of a D portion of the child carrier  100  shown in  FIG.  9    according to the first embodiment of the present invention.  FIG.  11    is another partial internal structural diagram of the child carrier  100  according to the first embodiment of the present invention.  FIG.  12    is an enlarged diagram of an E portion of the child carrier  100  shown in  FIG.  11    according to the first embodiment of the present invention.  FIG.  13    is a partial diagram of the child carrier  100  as a limiting component  181  stretches into a limiting slot  1   b  according to the first embodiment of the present invention.  FIG.  14    is an enlarged diagram of an F portion of the child carrier  100  shown in FIG.  13  according to the first embodiment of the present invention. As shown in  FIG.  6    and  FIG.  9    to  FIG.  14   , the foldable locking mechanism  200  further includes a limiting assembly  18  configured to limit a relative pivotal angle of the first mounting seat  1  and the second mounting seat  2 . The limiting assembly  18  includes the limiting component  181 , a fourth resilient component  182  and a limiting connecting component  183 . The limiting component  181  is installed on the second mounting seat  2  and protrudes toward the first mounting seat  1 . The limiting slot  1   b  is formed on the first mounting seat  1  and located at a position corresponding to the limiting component  181 . The limiting component  181  slidably stretches into the limiting slot  1   b . By a cooperation of the limiting component  181  and the limiting slot  1   b , the limiting assembly  18  can limit the relative pivotal angle of the first mounting seat  1  and the second mounting seat  2  for preventing an excessive relative pivotal angle of the first mounting seat  1  and the second mounting seat  2 . For example, the limiting component  181  can be configured to slidably stretch into the limiting slot  1   b  when the child carrier  100  is in the folded state, so as to prevent an excessive folding operation of the child carrier  100 . Specifically, the limiting connecting component  183  is fixed on the second mounting seat  2 . Two ends of the fourth resilient component  182  can be connected to the limiting connecting component  183  and the limiting component  181  respectively. The limiting component  181  is installed on the second mounting seat  2  by the fourth resilient component  182  and the limiting connecting component  183 , so that the limiting component  181  can resiliently abut against the limiting slot  1   b  for preventing wear or damage of components due to collision. Preferably, in this embodiment, the limiting component  181  can be a circular column, so as to achieve a smoother sliding movement of the limiting component  181 . However, the present invention is not limited to this embodiment. Besides, a passing hole  23  is formed on the second mounting seat  2  and located at a position corresponding to the limiting component  181 . The limiting component  181  slidably passes through the passing hole  23  to resiliently abut against the limiting slot  1   b.    
     As shown in  FIG.  1    to  FIG.  14   , operational principle of the foldable locking mechanism  200  is provided as follows. When it is desired to fold the frame body  400  of the child carrier  100 , the user can press the releasing operating component  17  to unlock the relative pivotal movement of the backrest  12  and the seat  13 , and then operate the backrest  12  to drive the backrest  12  to pivotally fold relative to the seat  13  along an arrow direction A shown in  FIG.  1    to drive the first mounting seat  1  to pivotally fold relative to the second mounting seat  2  along the arrow direction A. When the first mounting seat  1  pivotally folds relative to the second mounting seat  2  along the arrow direction A, the pushing portions of the driving component  1   a  can push the pushed portions  31  of the first locking component  3  to drive the first locking component  3  to move from the first locking position to the first releasing position along the arrow direction B shown in  FIG.  3    by overcoming the resilient force generated by the first resilient component  9 . Since, the first locking component  3  abuts against the second locking component  5 , and the second locking component  5  abuts against the third locking component  7 , the second locking component  5  and the third locking component  7  can be driven to move from the second locking position and the third locking position to the second releasing position and the third releasing position respectively, to unlock the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15  and the relative pivotal movement of the front leg  15  and the handle  16  when the first locking component  3  moves from the first locking position to the first releasing position. Afterwards, the user can operate the seat  13 , the rear leg  14 , the front leg  15  and the handle  16  to complete the folding operation of the frame body  400  of the child carrier  100  by the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15  and the relative pivotal movement of the front leg  15  and the handle  16 . 
     On the other hand, when it is desired to unfold the frame body  400  of the child carrier  100 , the user can operate the backrest  12  to drive the backrest  12  to pivotally unfold relative to the seat  13  along a direction opposite to the arrow direction A to drive the first mounting seat  1  to pivotally unfold relative to the second mounting seat  2  along the direction opposite to the arrow direction A. When the first mounting seat  1  pivotally unfolds relative to the second mounting seat  2  along the direction opposite to the arrow direction A, the pushing portions of the driving component  1   a  do not push the pushed portions  31  of the first locking component  3  along the arrow direction B. Therefore, the resiliently deformed first resilient component  9  can drive the first locking component  3  to move from the first releasing position to the first locking position along a direction opposite to the arrow direction B. When the first locking component  3  moves from the first releasing position to the first locking position, the first locking component  3  does not push the second locking component  5  along the arrow direction B. Therefore, the resiliently deformed second resilient component  10  can drive the second locking component  5  to move from the second releasing position to the second locking position along the direction opposite to the arrow direction B. When the second locking component  5  moves from the second releasing position to the second locking position, the second locking component  5  does not push the third locking component  7  along the arrow direction B. Therefore, the resiliently deformed third resilient component  11  can drive the third locking component  7  to move from the third releasing position to the third locking position along the direction opposite to the arrow direction B. The first locking component  3  located at the first locking position, the second locking component  5  located at the second locking position, and the third locking component  7  located at the third locking position can respectively lock the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15  and the relative pivotal movement of the front leg  15  and the handle  16 , so that the frame body  400  can be locked in the unfolded state. 
     Please further refer to  FIG.  15    to  FIG.  26   .  FIG.  15    is a schematic diagram of a child carrier  500  in an unfolded state according to a second embodiment of the present invention.  FIG.  16    is a partial diagram of the child carrier  500  according to the second embodiment of the present invention.  FIG.  17    is another partial diagram of the child carrier  500  according to the second embodiment of the present invention.  FIG.  18    is an enlarged diagram of a G portion of the child carrier  500  shown in  FIG.  17    according to the second embodiment of the present invention.  FIG.  19    is a partial internal structural diagram of the child carrier  500  according to the second embodiment of the present invention.  FIG.  20    is an enlarged diagram of an H portion of the child carrier  500  shown in  FIG.  19    according to the second embodiment of the present invention.  FIG.  21    is another partial internal structural diagram of the child carrier  500  according to the second embodiment of the present invention.  FIG.  22    is an enlarged diagram of an I portion of the child carrier  500  according to the second embodiment of the present invention.  FIG.  23    is a partial sectional diagram of the child carrier  500  according to the second embodiment of the present invention.  FIG.  24    is an enlarged diagram of a J portion of the child carrier  500  according to the second embodiment of the present invention.  FIG.  25    is a diagram of a driven component  20  according to the second embodiment of the present invention.  FIG.  26    is a diagram of a pushing component  19  according to the second embodiment of the present invention. As shown in  FIG.  15    to  FIG.  26   , the child carrier  500  includes two foldable locking mechanisms  300  and the frame body  400 . Structure of the foldable locking mechanism  300  of this embodiment is similar to structure of the foldable locking mechanism  200  of the first embodiment. Different from the first embodiment, the foldable locking mechanism  300  of this embodiment further includes a shell  202  configured to accommodate the fourth mounting seat, the fifth mounting seat and the third locking component. The third mounting seat  4  can be detached from the fourth mounting seat.  FIG.  15    to  FIG.  26    only illustrate a part of the structure of the foldable locking mechanism  300  without illustrating the fourth mounting seat, the fifth mounting seat, the second locking component, the third locking component and the limiting assembly. Structures of the fourth mounting seat, the fifth mounting seat, the second locking component, the third locking component and the limiting assembly of this embodiment are similar to the ones of the fourth mounting seat  6 , the fifth mounting seat  8 , the second locking component  5 , the third locking component  7  and the limiting assembly  18  of the first embodiment. Detailed description is omitted herein for simplicity. 
     Besides, each of the two foldable locking mechanisms  300  of this embodiment includes a driving component  2   a . The driving component  2   a  includes the pushing component  19 , the driven component  20  and a linking component  201 . The pushing component  19  is pivotally connected to the first mounting seat  1 . A pivoting axis of the pushing component  19  is coincided with the pivoting axis of the first mounting seat  1  and the second mounting seat  2 . 
     The driven component  20  is movably disposed between the pushing component  19  and the third locking component  3  and movable between an extending position and a retracting position. Preferably, the pivoting axis of the pushing component  19  passes through a center of the driven component  20 . The driven component  20  is movable along an axial direction of the pivoting axis of the first mounting seat  1  and the second mounting seat  2 . The linking component  201  is connected to the pushing component  19 , so that the pushing component  19  can be driven by the linking component  201  to pivot relative to the first mounting seat  1  to drive the driven component  20  to move from the retracting position to the extending position for driving the first locking component  3  to move from the first locking position to the first releasing position. Understandably, in this embodiment, the two foldable locking mechanisms  300  are symmetrically disposed on the two lateral sides of the frame body  400 . The two linking components  201  connected to the two pushing components  19  can be connected to each other to form a one-piece linking structure connected to the two pushing components  19 . 
     As shown in  FIG.  17    to  FIG.  26   , the pushing component  19  includes three adjoining portions  191  adjacently disposed and extending toward the driven component  20 . The driven component  20  includes two adjoined portions  20   a  adjacently disposed and cooperating with the three adjoining portions  191 . Each of the three adjoining portions  191  is for pushing the corresponding adjoined portion  20   a  to drive the driven component  20  to move from the retracting position to the extending position for achieving a purpose of driving the driven component  20  to move by the pushing component  19 . Each of the three adjoining portions  191  can be an adjoining protrusion. Each of the two adjoined portions  20   a  can be an adjoined protrusion. When the driven component  20  is located at the retracting position, the two adjoined protrusions and the three adjoining protrusions are misaligned from each other, i.e., each of the two adjoined protrusions is located in a recess between the two corresponding adjoining portions  191 . When the driven component  20  is located at the extending position, the two adjoined protrusions and the two corresponding adjoining protrusions are aligned with and abutted against each other. In other words, when the pushing component  19  pivots relative to the first mounting seat  1  to drive the two adjoined protrusions and the two corresponding adjoining protrusions to be aligned with and abutted against each other, the driven component  20  can be driven by the pushing component  19  to move from the retracting position to the extending position. When the pushing component  19  pivots relative to the first mounting seat  1  to drive each of the two adjoined protrusions to move in the recess between the two corresponding adjoining portions  191 , the pushing component  19  does not push the driven component  20 , so that the driven component  20  can be driven by the first locking component  3  to move from the extending position to the retracting position. Preferably, each of the three adjoining protrusions and each of the two adjoined protrusions can be arc-shaped structures. However, the numbers of the adjoining portion and the adjoined portion are not limited to this embodiment. For example, in another embodiment, the pushing component can include only one adjoining portion, and the driven component can include only one adjoined portion. 
     As shown in  FIG.  17    to  FIG.  26   , the driven component  20  includes two pushing abutting portions  20   b  oppositely disposed and extending toward the first locking component  3 . The first locking component  3  includes two pushed portions  31  extending toward the two pushing abutting portions  20   b  respectively. The two pushing abutting portions  20   b  can push the two pushed portions  31  to drive the first locking component  3  to move from the first locking position to the first releasing position when the driven component  20  moves from the retracting position to the extending position. However, the numbers of the pushing abutting portion and the pushed portion are not limited to this embodiment. In another embodiment, the driven component can include only one pushing abutting portion, and the first locking component can include only one pushed portion. 
     As shown in  FIG.  15    to  FIG.  26   , operational principle of the foldable locking mechanism  300  is provided as follows. When it is desired to fold the frame body  400  of the child carrier  500 , the user can press the releasing operating component  17  to unlock the relative pivotal movement of the backrest  12  and the seat  13 , and then operate the linking component  20  to drive the pushing component  19  to pivot relative to the first mounting seat  1  to drive the adjoining portion  191  of the pushing component  19  to push the adjoined portion  20   a  of the driven component  20 , so that the driven component  20  is driven to move from the retracting position to the extending position for driving the first locking component  3  to move from the first locking position to the first releasing position. Similar to the first embodiment, since the first locking component  3  abuts against the second locking component, and the second locking component abuts against the third locking component, the second locking component and the third locking component can be driven to move to the second releasing position and the third releasing position respectively for unlocking the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15 , and the relative pivotal movement of the front leg  15  and the handle  16  when the first locking component  3  moves from the first locking position to the first releasing position. Afterwards, the user can operate the seat  13 , the rear leg  14 , the front leg  15  and the handle  16  to complete the folding operation of the frame body  400  of the child carrier  500  by the relative pivotal movement of the seat  13  and the rear leg  14 , the relative pivotal movement of the rear leg  14  and the front leg  15  and the relative pivotal movement of the front leg  15  and the handle  16 . When it is desired to unfold the frame body  400  of the child carrier  500 , the unfolding operation of the frame body  400  can be completed by reversing the folding operation. 
     In summary, in the present invention, when the first mounting seat, the second mounting seat and the third mounting seat of the foldable locking mechanism are connected to the different rods of the frame body, the foldable locking mechanism can use the driving component to move the first locking component to the first releasing position to allow the relative pivotal movement of the first mounting seat and the second mounting seat and the relative pivotal movement of the second mounting seat and the third mounting seat at the same time, so that relative movements of the different rods are allowed at the same time to achieve the folding operation of the entire frame body. Therefore, the present invention has advantages of simple structure and easy operation. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.