Abstract:
The invention relates to a device for transporting a child in a child seat including a first frame, a second frame, a linear guide, two first wheel arms and two second wheel arms, the wheel arms having at their wheel ends one or more wheels, whereby each wheel arm is coupled to both the first frame and the second frame and the first frame and the second frame are movable relative to one another along the linear guide for folding and unfolding the wheel arms. In accordance with the invention the first wheel arms are connected at their other ends by a first pivot to the first frame and move during folding or unfolding in a common plane whereby a slide that is connected by a second pivot to the second frame can move along the length of each first wheel arm.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority of European patent application No. 07 104 251 filed on Mar. 15, 2007 the content of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to a device for transporting a child in a child seat ( 2 ). The device includes a first frame ( 15 ), a second frame ( 8 ), a linear guide ( 17 ,  36 ), two first wheel arms ( 9 ) and two second wheel arms ( 12 ), the wheel arms having at their wheel ends one or more wheels ( 11 , 13 ), whereby each wheel arm is coupled to both the first frame and the second frame and the first frame and the second frame are movable relative to one another along the linear guide for folding and unfolding the wheel arms characterized in that the first wheel arms ( 9 ) are connected at their other ends by a first pivot ( 27 ) to the first frame ( 15 ) and move during folding or un-folding in a common plane whereby a slide ( 29 ) that is connected by a second pivot ( 29 ) to the second frame ( 8 ) can move along the length of each first wheel arm. 
       BACKGROUND OF THE INVENTION 
       [0003]    The disadvantage of the known device is that the first wheel arms have insufficient stabilisation perpendicular to the plane in which they fold, which means that during use the wheels have no constant distance, which makes moving the device especially over uneven pavement very uncomfortable. 
       SUMMARY OF THE INVENTION 
       [0004]    In order to avoid this disadvantage the device for transporting a child in a child seat ( 2 ) comprises a first frame ( 15 ), a second frame ( 8 ), a linear guide ( 17 ,  36 ), two first wheel arms ( 9 ) and two second wheel arms ( 12 ), the wheel arms having at their wheel ends one or more wheels ( 11 , 13 ), whereby each wheel arm is coupled to both the first frame and the second frame and the first frame and the second frame are movable relative to one another along the linear guide for folding and unfolding the wheel arms characterized in that the first wheel arms ( 9 ) are connected at their other ends by a first pivot ( 27 ) to the first frame ( 15 ) and move during folding or un-folding in a common plane whereby a slide ( 29 ) that is connected by a second pivot ( 29 ) to the second frame ( 8 ) can move along the length of each first wheel arm. In this way the first wheel arms swivel in a common plane and are supported in a stable way in this common plane and also in the swivel direction by the slide. This improved support of the first wheel arms makes moving the device more comfortable. 
         [0005]    In accordance with one embodiment, the distance between the first pivots ( 27 ) is shorter than the distance between the second pivots ( 29 ). This ensures that the wheels will move inwards when the distance between the first frame and the second frame increases during folding and so reduces the volume of the folded device. 
         [0006]    In accordance with an embodiment, ends of the second wheel arms ( 12 ) are coupled by a third pivot ( 26 ) to the second frame ( 8 ) and by a coupling bar ( 14 ) to the first frame ( 15 ). In this embodiment the second wheel arms can be near the plane of the first frame and second frame when folded, so providing a reduced volume and they can unfold in a direction away from the first and second frame for increasing the height of the device when unfolded. 
         [0007]    In accordance with an embodiment, the second wheel arms ( 12 ) are coupled such to the first frame ( 15 ) and the second frame ( 8 ) that they can pivot in two planes making a sharp angle. In this embodiment during folding the first and second frame move towards the ground until they are more or less parallel to the ground. Thereby the device remains standing with its wheels on the ground and the frames and the child seat do not come near the dirty street. In addition, the frames remain above the wheels so that the user does not need to bend too deep. 
         [0008]    In accordance with an embodiment, the device includes spring means ( 35 ) that push the first frame ( 15 ) towards the second frame ( 8 ). In this embodiment folding or preferably unfolding of the device is assisted by the spring means so that for the user folding or unfolding is eased. 
         [0009]    In accordance with an embodiment, the first frame ( 15 ) or the second frame ( 8 ) is coupled to a foot support ( 34 ) for pushing with a foot against the spring force and the other frame has a handle ( 18 ) for holding it during pushing on the foot support. In this embodiment folding or unfolding is further eased by making it possible to use the leg muscles. 
         [0010]    In accordance with an embodiment, the child seat ( 2 ) is coupled to a support bracket ( 5 ) which is connected by a first support bar ( 16 ) to the first frame ( 15 ) and by a second support bar ( 6 ) to the second frame ( 8 ). In this embodiment the child seat moves during folding towards the main frame so that in folded position the device takes less room. 
         [0011]    In accordance with an embodiment, the support bracket ( 5 ) comprises an arc shaped guide in which a slide ( 32 ) can move and whereby the first support bar ( 16 ) and/or the second support bar ( 6 ) are connected to the slide. In this embodiment it is possible to have a stable and tiltable connection between the device and the child seat. 
         [0012]    The invention further concerns a child seat suitable for use with support brackets whereby the largest distance between the connecting and/or supporting points ( 40 ) on the support bracket ( 5 ) is at least one third of the distance between the two brackets. In this way, the child seat is fastened in a way that limits its wobbling in the longitudinal direction, which improves its stability. 
         [0013]    In accordance with an embodiment, the child seat has at least four connecting and/or supporting points ( 40 ) connectable to the two support brackets ( 5 ). By having the child seat connected in four points to the device a child can be transported in a safe and stable way. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The invention is explained below with reference to one or more exemplary embodiments with the aid of a drawing, in which: 
           [0015]      FIG. 1  shows a perspective view of a stroller with an infant carrier, 
           [0016]      FIG. 2  shows a perspective view of a stroller with a child seat for elder children, 
           [0017]      FIG. 3  shows a perspective view of the stroller of  FIG. 2  with the support bar for the child seat, 
           [0018]      FIG. 4  shows the stroller of  FIG. 3  in side view, 
           [0019]      FIG. 5  shows the stroller of  FIG. 4  whereby the support bar is tilted, 
           [0020]      FIG. 6  shows the stroller of  FIG. 4  whereby the stroller is partly folded, 
           [0021]      FIG. 7  shows the stroller of  FIG. 4  whereby the stroller is completely folded and the push bar is upright, 
           [0022]      FIG. 8  shows the stroller of  FIG. 4  whereby the stroller is completely folded and the push bar is flat, 
           [0023]      FIG. 9  shows a side view of the stroller of  FIG. 1  without the infant carrier, 
           [0024]      FIG. 10  shows a top view perpendicular to the plane of the first wheel arms and the upper and lower frames, and 
           [0025]      FIG. 11  shows a side view and section perpendicular to the plane of the first wheel arms and the upper and lower frames. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]      FIG. 1  shows a stroller  1  with an infant carrier  2 , which infant carrier  2  has a carrier frame  3  that is mounted on a support bracket  5  of the stroller  1 . The stroller  1  has two first wheel sets  11  and two second wheel sets  13 . Each wheel set can pivot around a vertical axis in a wheel pivot  10 . In the illustrated embodiment, the stroller  1  has wheel sets  11 ,  13  with two wheels that rotate around a common axis. In other embodiments instead of the two wheels a single wheel can be used. The wheel sets  11 ,  13  support an upper frame  15  and a lower frame  8  which frames  8 ,  15  can move relative one another and are connected by a rail  17  which is fastened to the lower frame  8  and can slide in a rail guide  36  of the upper frame  15  (see  FIG. 10 ). The first wheel set  11  is mounted at one end of a first wheel arm  9 , the other end of the first wheel arm  9  is coupled to the upper frame  15 . For support and stabilizing the first wheel arm  9  is supported in and can slide through a bearing bush  29  (see  FIGS. 4-11 ) which is mounted in the lower frame  8 . The second wheel set  13  is mounted at one end of the second wheel arm  12 ; the other end of the second wheel arm  12  is fastened to the lower frame  8 . For support and stabilizing the second wheel arm  12  a bar  14  connects the second wheel arm  12  approximately in the middle to the upper frame  15 . 
         [0027]    Each support bracket  5  is connected by a lower support bar  6  to the lower frame  8  and by an upper support bar  16  to the upper frame  15 . For pushing the stroller  1  a push bar  18  is connected by a push bar axis  7  to the upper frame  15 . For uncoupling the infant carrier  2  from the stroller  1  the support bracket  5  has a release button (not shown). For setting the tilting angle of the support bracket  5  the support bracket  5  has a setting button  4 . 
         [0028]      FIG. 2  shows the stroller  1  with a child seat  21  with a seat frame  20  mounted on the support bracket  5 . The seat frame  20  is part of the child seat  21  which includes a hood  19  and a leg support  22  that might be swivable in order to adjust the child seat  21 . The  FIGS. 3-8  show how the stroller  1  is folded and the movements of the support bracket  5  with the seat frame  20  that represents the frame of the child seat  21 . 
         [0029]      FIG. 3  and  FIG. 4  show the stroller  1  in the same position as shown in  FIG. 2  whereby only the seat frame  20  is visible and whereby the other parts of the child seat  21  are not shown.  FIG. 3  shows that the U-shaped upper support bar  16  can rotate in an upper support bar bearing  25  and the U-shaped lower support bar  6  can rotate in a lower support bar bearing  23 . The upper support bar bearing  25  is part of the upper frame  15  and the lower support bar bearing  23  is part of the lower frame  8 .  FIG. 4  shows in interrupted lines that the lower support bar  6  and in the shown embodiment the upper support bar  16  are coupled to the support bracket  5  with slides which give this connection stability so that the support bracket  5  is firmly supported on the stroller  1 . In another embodiment, see  FIGS. 6-8 , only the lower support bar  6  has at its end a slide that slides in the support bracket  5  and the upper support bar  16  is connected with a pivot to the slide that is part of the lower support bar  6 . 
         [0030]    Each first wheel arm  9  is coupled to the upper frame  15  by a wheel arm pivot  27  that has a rotation axis that is perpendicular to the rail  17 . The first wheel arm  9  slides through a bearing bush  29  which can rotate around an axis parallel to the rotation axis of wheel arm pivot  27 . As these rotation axes are both perpendicular to the rail  17 , both first wheel arms  9  move in a plane parallel to the rail  17  when the distance between the rotation axes changes during folding or unfolding of the stroller  1 . When folding or unfolding the stroller  1  the rail  17 , which is connected to the lower frame  8 , moves along a rail guide  36  (see  FIG. 10 ) in the upper frame  15  and the distance between the upper frame  15  and the lower frame  8  changes. During this movement, the first wheel arm  9  makes a changing angle with the direction of movement along rail  17 , which angle increases as the upper frame  15  moves towards the lower frame  8 . The distance between the two first wheel sets  11  increases thereby from approximately the width of the lower frame  8 , for instance from 0.30-0.40 m, to the distance suitable for use of the stroller  1 , for instance approximately 0.60 m. The wheel arm pivot  27  and the bearing  29  rotate respectively in the upper frame  15  and the lower frame  8  around a single axis which can be effected in a construction in a stable way with little backlash and the first wheel arm  9  is guided in a stable way. 
         [0031]    In the shown embodiment, there is a single rail  17 , which is oval and enclosed by the oval rail guide  36  so that the upper frame  15  and the lower frame  8  cannot rotate relative one another. Instead of one rail  17  the same effect can be obtained in a design for instance with two rails  17  that can be a round shaft whereby the rail guide  36  is formed by two round bearings. 
         [0032]    Each second wheel arm  12  is coupled with its end to the lower frame  8  by a wheel arm pivot  26 . Along its length, for instance approximately in its middle the second wheel arm  12  is connected with the bar  14  by a pivot  28  and by a pivot  30  to the upper frame  15 . The rotation axes of the wheel arm pivot  26  and the pivots  28  and  30  are parallel and during folding or unfolding. The second wheel arms  12  move in planes that makes an angle of approximately 30 degrees with each other. The pivots  26 ,  28  and  30  each have only one rotation axis so that these pivots can rotate in a stable way with little backlash. 
         [0033]    When the stroller  1  is in folded condition whereby the distance between the upper frame  15  and the lower frame  8  is maximal a second wheel arm  12  is more or less in the plane of the first wheel arms  9 . The distance between the second wheel sets  13  is then approximately the same as the distance between the first wheel sets  11  for instance between 0.30 m and 0.40 m. As the plane in which the second wheel arm  12  moves makes an angle with the plane in which the lower frame  8  and the upper frame  15  move, the distance between the second wheel sets  13  increases as the stroller  1  unfolds. In unfolded condition, this distance is more or less the same as the distance between the first wheel sets  11 , for instance 0.60 m. 
         [0034]    The plane in which the lower frame  8  and the upper frame  15  move makes in the unfolded condition, which is the condition of use, an angle of approximately 30-40 degrees with the plane on which the first wheel sets  11  and the second wheel sets  13  are placed. During folding, this angle reduces to approximately zero. The support bracket  5  is coupled to both the upper frame  15  and the lower frame  8  respectively by the upper support bar  16  and the lower support bar  6 . As the stroller  1  folds the distance between the upper frame  15  and the lower frame  8  increases. By this movement the distance between the support bracket  5  and the plane of the upper frame  15  and the lower frame  8  decreases so that in folded condition (see  FIGS. 7 and 8 ) the height of the support bracket  5  above the wheels is reduced, which makes the folded stroller  1  easier to store. Also the orientation of the support bracket  5  in the folded situation is such that the seat frame  20  is approximately parallel to the plane of the upper frame  15  and lower frame  8  and the floor on which the folded stroller  1  is standing. The hood  19  can be folded in the plane of the seat frame  20 , which reduces the volume of the folded stroller  1  so there is no need to remove the child seat  21  from the stroller  1 . 
         [0035]      FIG. 5  shows the stroller  1  of  FIG. 4  whereby the seat frame  20  has been tilted. As can be seen the support bracket  5  has been rotated along the slide connected to the lower support bar  6 . 
         [0036]      FIG. 6  shows the stroller  1  of  FIG. 4  whereby the upper support bar  16  is pivotable connected to the slide of the lower support bar  6  mounted in the support bracket  5 . The  FIG. 6  shows the rail  17  halfway in the upper frame  15 , so that there is a distance between the upper frame  15  and the lower frame  8 . The bearing bush  29  is approximately halfway the first wheel arm  9  and the bar  14  has moved the second wheel arm  12  towards the upper frame  15 . The support bracket  5  is low and near the upper frame  15 . 
         [0037]      FIG. 7  and  FIG. 8  show the stroller  1  of  FIG. 6  completely folded and the first wheel arm  9  and the second wheel arm  12  (together with the bar  14 ) are more or less in the same plane as the upper frame  15  and the second frame  8 . The push bar can be positioned above the upper frame  15 , see  FIG. 7 , or in the same plane as the wheel arms  9 ,  12  and the upper frame  15 , see  FIG. 8 . 
         [0038]    In a further embodiment (not shown) it is possible to design the upper support bar bearing  25  and/or the lower support bar bearing  23  in such a way that when the stroller  1  is in folded condition respectively the upper support bar  16  and/or the lower support bar  6  can be uncoupled from the bearing  25 , 23 . By uncoupling either the upper support bar  16  or the lower support bar  6  the support brackets  5  can be moved away from the upper frame  15 . If for instance the upper support bar  16  can be moved out of the upper support bar bearing  25  by removing a cover, the support bracket  5  can swivel in the lower support bar bearing  23  and can be located between the push bar  18  (see  FIG. 8 ) so that the height of the folded stroller  1  is further reduced. 
         [0039]    According to another embodiment (not shown) the upper frame  15  and the lower frame  8  are designed such that in folded condition the support bracket  5  fits between the frames  8 , 18  and the wheel arms  9 , 12 . In such a design, the upper support bar bearing  25  and/or the lower support bar bearing  23  can be located at the underside of the upper frame  15  and the lower frame  8  respectively. 
         [0040]      FIG. 9  shows the stroller  1  of  FIG. 1  without the infant carrier  2 . The infant carrier  2  can be supported on a support surface  40  of the support bracket  5 . In the support bracket  5  a first arcuate slide  32  which is connected to the lower support bar  6  can slide along an arcuate path. A second arcuate slide  33 , which is connected to the upper support bar  16 , can slide in the first arcuate slide  32 . The support bracket  5  can rotate over a considerable angle relative to the stroller  1 , which is suitable for the use with child seats for older children. For use with an infant carrier  2  such as shown in  FIG. 1  this is undesirable and therefore the support bracket  5  includes a signal pin  31 , that extends above the support surface  40  and that is activated by those child seats for which the rotation of the support bracket  5  must be limited. When activated, the signal pin  31  blocks the path of the first arcuate slide  32  and thereby prevents rotation of the support bracket  5  to undesirable angles. 
         [0041]    At the end of rail  17 , a fold button  34  is placed. Activation of the fold button  34  makes it possible that rail  17  slides in the rail guide  36  that is part of the upper frame  15  (see  FIG. 10 ). It might be sufficient for folding the stroller  1  to push the fold button  34 . It is however preferred that the user takes two separate actions. In this embodiment, the user first unlocks the swivelling of the push bar  18  by pressing a push bar release button  39  (see  FIG. 11 ) and brings the push bar  18  approximately in the plane of the rail  17 . The user then places his or her foot on the fold button  34  and pushes the rail  17  into the upper housing  15  while pulling on the push bar  18 . The stroller  1  now folds and the fold button  34  lowers towards the ground while the push bar  18  slightly rotates in the push bar bearing  24 . When the stroller  1  is completely folded, the rail  17  locks in the upper frame  15  (not shown). 
         [0042]      FIG. 10  shows the stroller  1  in unfolded position in the view perpendicular to the plane of the first wheel arms  9 , the upper frame  15  and rail  17 .  FIG. 11  shows the front view and partially a section perpendicular to this plane. A gas spring  35  is mounted in rail  17  whereby its one end is coupled to the rail  17  and via the rail  17  to the lower frame  8  and its other end via a bracket  37  to the upper frame  15 . During folding of the stroller  1  the rail  17  is pressed into the upper frame  15  and slides along the rail guide  36  and the gas in the gas spring  35  is compressed. As the rail  17  is moved by a foot of the user the additional force of the gas spring  35  is hardly noticed. For unfolding the stroller  1  the rail  17  is unlocked in the upper frame  15  (not shown) and the gas spring  35  pushes the rail  17  out of the upper frame  15  and the lower frame  8  and the upper frame  15  move towards each other. This movement pushes the second wheel arms  12  downwards and the upper frame  15  upwards and the second wheel sets  13  move outwards. The first wheel arms slide through the bearing bushes  29  and fold outwards until the stroller is completely unfolded and the rail  17  is locked in its unfolded position. Now the push bar  18  is brought in its position of use and locked in that position and the stroller  1  is ready for use.