Abstract:
This invention relates to a folding mechanism for a playard, which comprises first and second joints substantially cylindrical in shape. The joints have arcuate plates and stops that cooperative with each other to effect the rotation between the joints, so that the changing table can be moved between an operation position and a storage position. This invention may avoid accidental collapse of the changing table, and enable the users to conveniently fold/unfold the changing table single handed.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a changing table for a playard which is simple and easy to operate, and may preclude the changing table from folding or pressing down unintentionally. 
     BACKGROUND OF THE INVENTION 
     Changing tables for playards are well known in the prior art. A parent or caretaker can change a child&#39;s diaper or perform other baby caretaking tasks on a changing table that can be mounted to the top of the playard. The changing table, which is generally rectangular in shape, can be supported on its sides by upper frame supports of the playard. After the child&#39;s diaper has been changed, the changing table can be removed from the playard, or in some applications, can be swung about an upper frame support of the playard to a storage position exterior of the playard. In this respect, the parent or caretaker can lift one side of the changing table and can swing the changing table about the upper frame support to its storage position at an exterior side of the playard. The changing table can then rest in its storage position exterior of the playard. 
     An exemplary apparatus in the prior art is described in U.S. Pat. No. 6,543,070 incorporated herein by reference. In this conventional changing table, the folding arms are designed to pivot about the pivot joint, and thus the changing table can be swung about the upper frame support of the playard to its storage position. However, this changing table has a disadvantage in that, when the baby is placed on the changing table, a rolling movement of the baby or the changing table is turned by the caretaker may result in the folding arms pivoting about the pivot joint accidently, and this may harm the baby. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide a changing table for a playard which tends to obviate the aforementioned problem. The changing table according to the present invention enables the child caretakers to conveniently move the changing table between an operation position and a storage position. The present invention may overcome the defects of the conventional changing tables, such as accidental collapse and harm to the child and caregiver. Furthermore, the present invention is low in manufacturing cost since the components thereof are relatively less than those of conventional ones. 
     This invention relates to a folding mechanism for a playard, which comprises first and second joints substantially cylindrical in shape. The joints have arcuate plates and stops that cooperative with each other to effect the rotation between the joints, so that the changing table can be moved between an operation position and a storage position. This invention may avoid accidental collapse of the changing table, and the users to conveniently fold/unfold the changing table by pulling or pressing the rail of the changing table with single hand. 
     Additional features and advantages of the present invention will be set forth in the description to follow. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims as well as the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described with reference to the accompanying drawings illustrating preferred embodiments, in which: 
         FIG. 1  is a schematic view showing a playard attached with a changing table in accordance with the present invention, in which the changing table is in an operation position. 
         FIG. 2  is an exploded view of the folding mechanism in accordance with a preferred embodiment of the present invention. 
         FIG. 3  is a perspective view showing the first and second joints are assembled. 
         FIG. 4  is a sectional view taken along line B-B of  FIG. 5 , illustrating the assembly of the first and second joints. 
         FIG. 5  is a sectional view taken along line A-A of  FIG. 4 , illustrating the assembly of the first and second joints.  FIG. 5  also shows the state in which the changing table is in the operation position. 
         FIGS. 6 to 8  illustrate the folding mechanism in accordance with the preferred embodiment of the present invention when the changing table is moved from a operation position to a storage position. 
         FIG. 9  is an exploded view of the folding mechanism in accordance with an alternate embodiment of the present invention. 
         FIG. 10  is a perspective view showing the assembly of the first and second joints. 
         FIG. 11  is a sectional view taken along line B-B of  FIG. 12 , illustrating the assembly of the first and second joints. 
         FIG. 12  is a sectional view taken along line A-A of  FIG. 11 , illustrating the assembly of the first and second joints.  FIG. 12  also shows the state in which the changing table is in the operation position. 
         FIGS. 13 to 15  illustrate the working of the joints when the changing table is moved from a operation position to a storage position. 
         FIG. 16  is a schematic view showing a playard attached with a changing table in accordance with the present invention, in which the changing table is in a storage position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the figures, wherein like numerals indicate like parts, and in particular to  FIG. 1 , a playard  20  is shown with a changing table  30  mounted thereto in accordance with the present invention. The playard  20  can be any conventional playard having at least one upper end rail member  21  and a pair of upper side rail members  23 . In general, the upper side rail members  23  are connected to the upper end rail member  21  directly or via other structural members, such as legs, corner pieces  22 ,  24  etc. 
     Each of the corner pieces  22 ,  24  is provided with a slot  25  to receive the rod-like supporting member  31  of the changing table  30  so as to secure the changing table  30  to the playard  20 . 
     Changing table  30  includes front and rear rails  32 ,  34  and a pair of side rails  36 ,  36 ′ respectively connected to the front and rear rails  32 ,  34  to form a platform  38  rectangular or elliptical in shape. 
     The front rail  32  and the pair of side rails  36 - 36 ′ may be separate components or integral formed. The changing table  30  is movable between an operation position and a storage position by the operation of a folding mechanism, which will be described in detail hereinafter. 
       FIG. 2  is an exploded view of the folding mechanism  50  in accordance with a preferred embodiment of the present invention. The folding mechanism  50  primarily comprises a first joint  51  connected to a side rail  36  at one end of the side rail  36 , and a second joint  52  connected to the rear rail  34  at the rear end thereof (refer to  FIG. 1 ). 
     Referring to  FIG. 2 , the first joint  51  is a substantially hollow cylindrical body with a closed end  511 , and has an opening through which a fastener  59  may pass to connect the first joint  51  to the second joint  52 . A pair of opposed arcuate plates  512 ,  514  extend upwardly (outwardly and toward the left as seen in  FIG. 2 ) from the bottom wall of the closed end  511  of the first joint  51  and positioned opposite to each other. 
     The pair of arcuate plate  512 - 514  extend beyond the cylindrical body of the first joint  51 , and the upper arcuate plate  512  bends downwardly, the lower arcuate plate  514  bends upwardly. A stop  513  extends from the upper side wall of the arcuate plate  512 , and is cooperative with and corresponds to the stop  523  to be mentioned hereinafter. The second joint  52  is also a substantially hollow cylindrical body with a closed end. A fastener receiving portion  525  in a form of cylindrical post protrudes from the center of the second joint  52  for receiving the fastener  59 . By inserting the fastener  59  through the opening (not shown) of the first joint  51 , and then into the fastener receiving portion  525  of the second joint  52 , the first joint  51  can be pivotally connected with the second joint  52 . 
     Furthermore, the first joint  51  includes a receiving portion  515  at one side thereof to receive a portion of the side rail  36 . The receiving portion  515  extends laterally from the one side of the first joint  51  and is formed of substantially hollow, cylindrical body, so that one end of the side rail  36  can be inserted and received therein. The side rail  36  is formed of a substantially hollow, and elongated cylindrical tube and includes a pair of opposed, horizontally extending and rectangular-shaped slots  361  near one end. Furthermore, an aperture  362  is provided at a predetermined distance from the slots  361  at the same level with the slots  361 , for the insertion of a pin  53  therethrough and received therein. The slots  361  are configured to receive the fastener  59 . It is appreciated that the elongate slots  361  can also be formed of a channel having an open end and a close end, so that a passage is provided to allow the side rail  36  to move to and fro when a force is applied to the side rails  36 . 
     In assembly, a spring  54  is mounted on the side rail  36 , and inserted along with the side rail  36  into the first joint  51  and received therein.  FIG. 3  is a perspective view showing the first joint  51  and second joint  52  are assembled and  FIG. 4  is a sectional-view thereof. The fastener  59  is passed through the opening (not shown) of the first joint  51 , and then into the fastener receiving portion  525  of the second joint  52 , so that the first joint  51  is pivotally connected to the second joint  52 . When the folding mechanism  50  is assembled, the side rail  36  is accommodated in the side rail receiving portion  515  of the first joint  51 , the pin  53  is abutted against the side wall of the first joint  51  and the second joint  52 , and the spring  54  located between the fastener  59  and the pin  53 . 
     With reference to  FIG. 4 , the second joint  52  includes a cavity wall  521  at about half the axial length of the cylindrical body. An arcuate plate  522  substantially in the shape of a semi-circle extends upwardly (laterally as seen in  FIG. 2 ) from the cavity wall  521 , and is spaced from the peripheral wall  526  of the second joint  52  at a predetermined distance. The arcuate plate  522  of the second joint  52  corresponds to the arcuate plates  512 ,  514  of the first joint  51 , and thus the arcuate plates may contact with each other. 
     Therefore, arcuate plates  512 ,  514  may cooperate with arcuate plate  522 , and serve the purpose of guiding when the first joint  51  rotates relative to the second joint  52 . In other words, when the two joints rotate relative to each other, arcuate plates  512 ,  514  will rotate along the inner wall of arcuate plate  522 , so that the two joints are in alignment with each other. 
       FIG. 5  is a sectional view taken along line A-A of  FIG. 4 , which illustrates the assembly of the first and second joints  51 ,  52 . 
     Referring to  FIGS. 4 and 5 , the arcuate plate  522  of the second joint  52  is formed of a stop  523  at one end thereof (at the upper right corner in  FIG. 5 ), while the other end is formed of a stop  524  (at the lower position in  FIG. 5 ). As mentioned above, the fastener receiving portion  525  formed of a substantially hollow, cylindrical body protrudes from the center of the second joint  52  for receiving the fastener  59 . 
       FIG. 5  also shows the state of the folding mechanism  50  in which the changing table  30  is in the operation position. In this state, the pin  53  is blocked by the stop  523  of the second joint  52  to prevent the side rails  36  (and hence the changing table  30 ) from being lifting, so that the changing table  30  is kept in the operation position. Besides, the stop  513  of the first joint  51  and the stop  523  of the second joint  52  engage with each other, and thus the first joint  51  cannot rotate with respect to the second joint  52 , thereby preventing the changing table  30  from being pressed downwards, and this is the bearing point for the load of the changing table  30 . At this state, the user or caretaker can change a child&#39;s diaper or perform other baby caretaking tasks on the changing table  30  at ease. 
     Referring to  FIG. 6 , after the user or caretaker has finished changing a child&#39;s diaper or performing baby caretaking tasks, to move the changing table  30  to its storage position, the user only has to press the front rail  32  by one hand. As the side rail  36  is forced, to move inwards (leftwards in  FIG. 5 ) in the folding mechanism  50 , so that the spring  54  is compressed. As the side rail  36  has a horizontally extending slot  361  at one end, the side rail  36  may move with respect to the first joint  51 . The pin  53  secured in the opening  362  of the side rail  36  also moves inwards (leftwards) simultaneously, causing the pin  53  to remove away from the stop  523  of the second joint  52 . Subsequently, the side rails  36  can be lifted along in the direction as shown by the arrow in  FIG. 7  and the changing table is further to be in the folding/storage position. 
     Referring to  FIG. 8 , when the changing table  30  is swung to move to the storage position by the rotation movement of the side rail  36 , one end of the side rail  36  will move outwardly (substantially downwards as seen in  FIG. 8 ) in the folding mechanism  50  to restore to its original position due to the restoring force of the compression spring  45 . The pin  53  mounted within the opening  362  of the side rail  36  moves outwards (downwards) simultaneously, resulting in the engagement of the pin  53  with the stop  524  of the second joint  52 , to thereby locking the changing table  30  in the storage position. 
     When it is desired to swing the changing table  30  back to its operation position, the user only has to press the front rail  32  by one hand to subject a force on the side rail  36 , causing the pin  53  to disengage from the stop  524  of the second joint  52 . In this manner, the changing table  30  can be raised along with the side rails  36  and rotated to return to its operation position. 
       FIG. 9  is an exploded view of the folding mechanism  60  in accordance with an alternate embodiment of the present invention. This folding mechanism  60  is somewhat similar to the folding mechanism  50  of the first embodiment, and primarily comprises a first joint  61  and a second joint  62 . 
     The first joint  61  is similar to the first joint  51  of the folding mechanism  50  in the aforementioned embodiment in structure, and is formed of a substantially hollow and cylindrical body, and is attached to a second joint  62  by a fastener  69 . The first joint  61  also has a pair of opposed arcuate plates  612 ,  614 , in which the upper arcuate plate  612  curves downwardly, and the lower arcuate plate  614  curves upwardly. A stop  613  extends from the upper side wall of the arcuate plate  612 , and abutted against a stop  623  to be mentioned hereinafter. 
     The second joint  62  is also formed of a substantially cylindrical body closed at one end and opened at the other end. The second joint  62  includes a cavity wall  621  at about half the axial length of the cylindrical body. An arcuate plate  622  substantially in the shape of a circle extends upwardly from the cavity wall  621 , and is spaced from the peripheral wall  626  of the second joint  62  at a predetermined distance. The arcuate plate  622  of the second joint  62  corresponds to the arcuate plates  612 ,  614  of the first joint  61 . Therefore, arcuate plates  612 ,  614  may cooperate with arcuate plate  622 , and serve the purpose of guiding when the first joint  61  rotates relative to the second joint  62 . In other words, when the two joints rotate relative to each other, arcuate plates  612 ,  614  will rotate along the inner wall of arcuate plate  622 , so that the two joints are in alignment with each other. 
     A stop  623  extends from the upper side wall of the arcuate plate  622 , and is abutted against the stop  613  to be mentioned hereinafter. 
     A fastener receiving portion  625  protrudes from the center of the cavity wall  621  of the second joint  62 . The fastener receiving portion  625  includes an opening  6253  in the center thereof to receive a fastener  69 . The fastener  69  is passed through the opening (not shown) of the first joint  61 , and then into the opening  6253  of the fastener receiving portion  625  of the second joint  62 , so that the first joint  61  is pivotally connected to the second joint  62 . The fastener receiving portion  625  is formed of a substantially cylindrical body, but chamfered at the right lower corner. Referring to  FIGS. 9 and 11 , it can be seen that the fastener receiving portion  625  includes a horizontally face  6251  and a vertically face  6252 , which may serve as stops (to be described hereinafter). 
     The first joint  61  is similar to the first joint  51  of the previous embodiment in that it also has a side rail receiving portion  615  to accommodate one end of the side rail  36 ′. The side rail  36 ′ is also formed of a substantially hollow tube, and includes a pair of opposed, horizontally extending slots  365 . Furthermore, an aperture  362  is provided at a predetermined distance from the slots  365  at the same level with the slots  365 , for the insertion of a pin  63  therethrough and received therein. The slots  365  are configured to receive the fastener  69 . It is appreciated that the slots  365  can also be formed of a channel having an open end and a close end, so that a passage is provided to allow the side rail  36 ′ to move to and fro when a force is applied to the side rails  36 ′. In assembly, the spring  64  is mounted on the side rail  36 ′, and inserted along with the side rail  36 ′ into the first joint  61  and received therein. Besides, the spring  64  is located between the pin  63  and the peripheral wall of the first joint  61 . 
       FIGS. 10 and 11  illustrate respectively the perspective view and sectional-view of the first joint  61  and second joint  62  after assembly. The assembly is achieved by inserting the fastener  69  through an opening (not shown) of the first joint  61 , and then into opening  6253  of the fastener receiving portion  625  of the second joint  62 , so that the first joint  61  is pivotally connected to the second joint  62 . In the assembled state, the side rail  36 ′ is accommodated in the side rail receiving portion  615  of the first joint  61 , in which the slot  365  thereof receives the fastener  69  which is then secured in the fastener receiving portion  625  of the second joint  62 . 
       FIG. 12  is a sectional view taken along line A-A of  FIG. 11 , which illustrates in detail the assembly of the first and second joints  61 ,  62 . 
       FIG. 12  also shows the state of the folding mechanism  60  for rotatably folding/unfolding the changing table in which the changing table  30  is in the operation position. In this state, the pin  63  is blocked by the horizontally face  6251  of the fastener receiving portion  625  of the second joint  62  to prevent the side rails  36 ′ (and hence the changing table  30 ) from being lifting, so that the changing table  30  is kept in the operation position. Besides, the stop  613  of the first joint  61  and the stop  623  of the second joint  62  engage with each other, and thus prevents the changing table  30  from being pressed downwards. At this state, the user or caretaker can change a child&#39;s diaper or perform other baby caretaking tasks on the changing table  30  at ease. 
     Referring to  FIG. 13 , after the user or caretaker has finished changing a child&#39;s diaper or performing baby caretaking tasks, to move the changing table  30  to its storage position (as shown in  FIG. 16 ), the user only has to pull the front rail  32  by one hand. As the side rail  36 ′ is forced to move outwards (rightwards in  FIG. 13 ) in the folding mechanism  60 , so that the spring  64  is compressed. As the side rail  36 ′ has a slot  365  at one end, the side rail  36 ′ may move with respect to the fastener  69  outwards (rightwards) until the left side wall of the slot  365  urges against the fastener  69 . The pin  63  secured in the opening  366  of the side rail  36 ′ also moves outwards (rightwards) simultaneously, causing the pin  63  to remove away from the horizontally face  6151  of the fastening receiving portion  625  of the second joint  62 . Subsequently, the side rails  36 ′ can be lifted along the direction as shown by the arrow in  FIG. 14  and the changing table  30  is further to be in the folding/storage position. 
     Referring to  FIG. 15 , when the changing table  30  is swung to move to the storage position by the rotation movement of the side rail  36 ,  36 ′, one end of the side rail will move inwardly (substantially upwards as seen in  FIG. 15 ) in the folding mechanism  60  to restore to its original position due to the restoring force of the spring  64 . The pin  63  secured in the opening  366  of the side rail moves inwards (upwards) simultaneously, resulting in the engagement of the pin  63  with the vertically face  6252  of the fastening receiving portion  625  of the second joint  62 , to thereby locking the changing table  30  even when it is in the storage position. 
     When it is desired to swing the changing table  30  back to its operation position, the user only has to pull the front rail  32  by one hand to subject a force on the side rails  36 ,  36 ′ causing the pin  63  to disengage from the vertically face  6252  of the fastening receiving portion  625  of the second joint  62 . In this manner, the changing table  30  can be raised along with the side rails  36 ,  36 ′ and rotated to return to its operation position. 
     Furthermore, the above embodiments can be modified in a number of ways. For example, the front end of the rail  36  does not necessarily to have a slot or opening, nor have to connect to the fastener  69 , and the spring  64  does not necessarily have to be located between the pin  63  and the peripheral wall. Such modified embodiment includes a spring to connect the pin  63  and fastener  69  instead. In the general state, the rail  36  moves inwardly due to the spring, and when it is intended to fold the changing table, it is only necessary to pull the rail  36  outwards. 
     Although the foregoing has been described in terms of presently preferred and alternate embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described. The apparatus of the present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting the present invention.