Abstract:
A collapsible stroller for children and the like includes front and rear struts interconnected by at least one transverse strut and a pair of longitudinal struts. Ground-engaging wheels are mounted at the lower ends of the front and rear struts. A push handle adapted for grasping includes lateral extensions having lower ends pivotally connected with a pair of slides, which are in turn slidingly connected with the upper portions of the rear struts to permit the push handle to be shifted between unfolded and folded configurations. A pair of support levers have opposite ends pivotally connected with the lower portions of the handle extensions and the upper portions of the front struts to permit shifting the stroller between the folded and unfolded configurations.

Description:
CLAIM OF PRIORITY  
       [0001]     Applicant hereby claims the priority benefits under the provisions of 35 U.S.C. § 119, basing said claim of priority on European Patent Application Serial No. 05 006 496.3, filed Mar. 24, 2005. In accordance with the provisions of 35 U.S.C. § 119 and Rule 55(b), a certified copy of the above-listed European patent application will be filed before the grant of a patent.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to strollers for children and the like, and in particular to a folding or collapsible stroller.  
         [0003]     A folding stroller is disclosed in DE 40 04 536 A1. In it, a compact folding dimension is achieved since the kinematic requirements allow a parallel position of front and rear struts and the lateral extensions of the pushing handle. However in this stroller, it is disadvantageous that the rear struts are connected by brackets fastened to them with only connection by force to the front struts and otherwise are only connected to the longitudinal struts and swivel-mounted by way of strut extensions connected to the rear struts with an extension of the pushing handle. Because of this, a stable and thus form-fitting connection of front and rear struts does not exist. Besides that, when the stroller is lifted, the rear struts release from the front struts, namely in the area of the brackets. This, along with laterally acting forces experienced during maneuvering, causes a situation in which the front struts shift with respect to the rear struts. In the prior art stroller, it is also disadvantageous that, with the given kinematic requirements, a maximum compact folding dimension is not achieved because the handle grip of the pushing handle extends beyond the lower end of the front struts when the stroller is in folded position. Finally, it is disadvantageous that, with the given kinematic requirements, the use of wheels with a diameter of more than 250 millimeters is impossible since, during the folding process, larger wheels bump against each other before the parallel position of front struts, rear struts and lateral pushing handle extensions is reached and prevent complete folding.  
         [0004]     A folding stroller is also disclosed in GB 1 419 799. There the lateral extensions of the pushing handle are swivel-mounted directly on the rear struts so that, because of the resulting kinematic specifications, the stroller cannot be folded together in a way such that both the front and rear struts, as well as the pushing handle, come to rest so that they are parallel. It is much more the case that the arrangement of the parts causes the pushing handle to run at a sharp angle to the front and rear struts when the stroller is folded together. Apart from this, the direct mounting of the pushing handle in the rear struts leads to a situation in which the respective rear wheels are arranged at a distance from the front wheels when the stroller is folded, while the pushing handle pulls the rear struts almost parallel to the front struts shortly before the folded position of the stroller is reached. The arrangement of the rear wheels at a distance from the front wheels when the stroller is folded causes increased storage space in this position.  
       SUMMARY OF THE INVENTION  
       [0005]     One objective of the present invention is to further develop a stroller of the type mentioned above in such a way that it eliminates the disadvantages described in the state of the art, and also has a stable connection of front and rear struts, as well as the most compact possible folding dimension even with the use of wheels with relatively large diameters, especially with diameters of more than 250 millimeters.  
         [0006]     Another objective is achieved with a folding stroller of the type mentioned at the beginning with the following characteristics: 
        the front struts each hold slides that can slide freely in their longitudinal direction;     the lateral extensions of the pushing handle are swivel-mounted in the slides in the area of their ends turned toward the front struts;     the rear struts are swivel-mounted in the slides in the area of their ends turned toward the front struts; and     on both sides of the stroller, support levers are arranged, each of which engages so they can swivel on the front struts between the slides and the front wheels and on the lateral extensions of the pushing handle.        
 
         [0011]     Thus according to at least one embodiment of the present invention, it is provided that a slide is provided on each side of the stroller, in which the front strut and rear strut assigned to the respective side are mounted. The support lever assigned to this side controls the sliding movement of the slide with respect to the front strut since on one side, it engages on the front strut and the assigned lateral extension of the pushing handle, by way of the pushing handle extension, which is also mounted in the slide. Because of this mounting of the parts and their arrangement, a very stable design results, particularly in the area of the front strut, rear strut and extension of the pushing handle.  
         [0012]     In one embodiment of the present invention, the lateral extensions of the pushing handle are swivel-mounted in the slides above the front struts. In addition, preferably the rear struts are swivel-mounted in the slides below the front struts. In addition, advantageously the support levers that are arranged on both sides each engage below the slides on the front struts and above the slides on the lateral extensions of the pushing handle. The front struts advantageously run from the lower front to the upper top and especially define an angle of 35 degrees to 65 degrees with the resting surface of the stroller on the base on which the stroller rolls. The rear struts accordingly run from the bottom rear to the top front and especially define an angle of 40 degrees to 80 degrees with the resting surface of the stroller.  
         [0013]     It is to be understood that the lateral strut and/or lateral struts can be not only a rod or rods that connect the front and rear struts to each other, whereby the stroller maintains its width dimension during folding. These terms are to be understood inclusively, e.g., with the meaning of cross strut or cross struts. If the front and rear struts are each connected by one or more cross struts, the stroller can also fold together with respect to its width as known from the state of the art. Preferably the cross struts are controlled in such a way that during folding of the stroller by moving the front and rear struts toward each other while swiveling the pushing handle, the front and rear struts of one side of the stroller are also moved toward the front and rear struts of the other side of the stroller.  
         [0014]     It is to be understood that the longitudinal struts can be attached on the front and rear struts in different ways. For example, the longitudinal struts can be connected directly with the front and rear struts. However, an indirect connection is also conceivable, for example in that the longitudinal strut is connected to the front and/or rear strut by way of a spring housing fastened on the respective strut. Because of this, there is increased riding comfort when the stroller is pushed due to the suspension.  
         [0015]     The front wheels, especially, of the stroller can be designed so that they can be steered, i.e., the respective front wheel is held in a bearing so that it can rotate, it being possible for this bearing in turn to rotate around a vertical axle in the front strut or an extension piece connected to it.  
         [0016]     If four rigid wheels are used in the stroller, these especially have a large size, e.g., a diameter of 300 millimeters. If the stroller is provided with steered wheels on the front, these have a diameter of 190 millimeters; the rigid rear wheels have a diameter of 300 millimeters.  
         [0017]     Other characteristics of the invention are described in the sub-claims, the description of the figures and the figures themselves, whereby it will be noted that all the individual characteristics and all combinations of individual characteristics represent further inventive designs.  
         [0018]     These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     In the figures, the invention is explained using two embodiment examples, without being restricted to these.  
         [0020]     They show:  
         [0021]      FIG. 1  shows a first embodiment of a folding stroller in a perspective view, shown unfolded, without a seat part and with front wheels that cannot be steered;  
         [0022]      FIG. 2  shows a first embodiment of a folding stroller in a perspective view, shown unfolded, without the seat part and with front wheels that can be steered;  
         [0023]      FIG. 3  shows a side view of the stroller shown in  FIG. 2 ;  
         [0024]      FIGS. 4 and 5  show the stroller shown in  FIGS. 2 and 3  in intermediate positions while the stroller is being folded; and  
         [0025]      FIG. 6  shows the stroller according to FIGS.  2  to  5 , in the completely folded position, but shown without the rear wheel that covers the stroller for better view of the individual parts. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     For purposes of description herein, the terms “upper”, “lower”, “right”, “left”, “rear” “front”, “vertical”, “horizontal” and derivatives thereof shall relate to the invention as oriented in  FIGS. 1 and 2 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It s also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.  
         [0027]      FIG. 1  shows the unfolded stroller  1  for children and youth. It has front struts  2  and rear struts  3  arranged on both sides of the stroller  1  to hold front wheels  4  and rear wheels  5 . The front and rear struts  2 ,  3  are each connected by transverse struts  6  and  21 . On both sides, longitudinal struts  7  are arranged, each of which engages on the front and rear struts  2 ,  3 . In this case, the respective longitudinal struts  7  engage indirectly on the front struts  2 , in that a pair spring housings  8  are connected to the front struts  2 , on which the longitudinal struts  7  engage. The swivel axles  9 , in the area of the respective longitudinal struts  7 , are mounted in the rear struts  3  and the spring housings  8 .  
         [0028]     Each of the illustrated front struts  2  holds a slide  10  that can be slid freely in its longitudinal direction. In longitudinal direction of the extensions  11 , the lateral extensions  11  of pushing handle  12  hold sliding locking sleeves  14 , which in the unfolded position of stroller  1  that is shown, can be lowered to the upper free ends of the front struts  2  and engage under them with a form fit, because of which the lateral extensions  11  of the pushing handle  12  that contact the front struts  2  cannot be pivoted away from the front struts  2 .  
         [0029]     The rear struts  3  are mounted below the front struts in slides  10  so they can pivot around swivel axles  15 . Support levers  18  are mounted on both sides of the stroller  1  on the outside, each of which engages so that it can swivel around swivel axles  17  below the slides  10  on the front struts  2  and around swivel axles  18  above the slides  10  on the lateral extensions  11  of pushing handle  12 .  
         [0030]     Each of the illustrated front struts  2  holds a slide  10  that can be slid freely in its longitudinal direction. In the slides  10 , the lateral extensions  11  of the pushing handle  12  are swivel-mounted in the area of their ends turned toward the front struts  2 . Support levers  16  are arranged on both sides of the stroller  1 , and engage the front struts  2  between slides  10  and front wheels  4 , as well as the lateral extensions  11  of the pushing handle  12 .  
         [0031]     The front struts  2  extend from the lower front to the upper rear, and in the illustrated example, define an angle of 35 degrees to 65 degrees with the resting or support surface of stroller  1 . The rear struts  3  extend from bottom rear to top front, and in the illustrated example, define an angle of 40 degrees to 80 degrees with the resting or support surface of stroller  1 .  
         [0032]     On the respective front strut  2 , a sleeve-shaped element  19  is fastened by means of a screw nut connection  20  that passes through it and the front strut  2 . The swivel axle  17  passes through the sleeve-shaped element  19  and the front strut  2  in the area of the end of the sleeve-shaped element  19  turned toward the slide  10 . In the area of the other end of the same sleeve-shaped element  19 , a U-shaped angled pipe  21  is connected to it, whereby the “U” is oriented perpendicular to the two front struts  2  in the direction of the longitudinal struts  7 . A seat bracket  22  is swivel-mounted in the two swivel axles  17  and is used to hold and connect a seat (not shown) for the child or the youth. This seat bracket  22  is provided on the bottom with a slot  23  that is circular and runs concentrically to the swivel axis  17 . The slot  23 , which has the function of a bracket, passes through a device  24  that is connected to pipe  21  and is used for variable positioning of the seat bracket  22  in the different swivel positions relative to the swivel axle  17 .  
         [0033]     In the embodiment shown in  FIG. 1 , four rigid wheels  4 ,  5  are provided, and in fact they are of the same size, e.g., having a diameter of 300 millimeters each.  
         [0034]     The embodiments shown in FIGS.  2  to  6  differ from the one according to  FIG. 1  in that the stroller  1  is provided with front steered wheels  4 , which have a diameter of 190 millimeters each. The rear wheels  5  are rigid, as before, and have a diameter of 300 millimeters each.  
         [0035]     In this second embodiment ( FIGS. 2-6 ), the lower free ends of front struts  2  are connected by an essentially U-shaped hoop  25 , which in the area of the two free ends of the respective swivel axle  28 , holds a U-shaped bearing part  27  that can swivel, and that is used for mounting the assigned front wheel  4 , so that it can rotate around a swivel axle  28  of bearing part  27 .  
         [0036]     The process for folding or unfolding the stroller  1  is the same in both embodiments shown in  FIGS. 1 and 2 - 6 . It is shown in various intermediate steps and in the folded position for the second embodiment according to FIGS.  2  to  6 , to which the following description will make reference.  
         [0037]     In the illustrated stroller  1 , the slides  10  and support levers  16  are mounted on both sides. The slides  10  are pushed from the top onto the front struts  2  and can slide freely on them. In the sections of slides  10  positioned above the front struts  2 , the lateral extensions  11  of the pushing handle  12  are swivel-mounted in axle  13 . In the sections of slides  10  that are. positioned below the top struts  2 , the rear struts  3  are swivel-mounted in axle  15 . This creates a form-fitting connection between front struts  2  and rear struts  3 .  
         [0038]     The support levers  16  control the folding process, as can be seen from the illustrations of the intermediate positions of the stroller during folding according to  FIGS. 4 and 5 . In this case, the support levers  16  are mounted so that they can swivel with the lateral extensions  11  of pushing handle  12  in axle  18 , and with the front struts  2  in the axle  17 . When the pushing handle  12  is swiveled from below, for the purpose of folding the stroller  1 , the support levers  16  are first also pivoted in the direction from below, while the slides  10  are slid upward on the front struts  2  by the pivoting movement of the lower sections of the lateral extensions  11  of pushing handle  12 , and thus pull the rear struts  3  upward with them. During this folding process, as soon as axles  13 ,  15  and  18  lie on one plane, the swivel movement of the support levers  16  reverses toward the back again, so that at the end of the folding process they come into the compact initial position, while the lateral extensions  11  of the pushing handle  12  swivel further toward the bottom front, and the slides  10  are slid again in the direction of the upper end of the front struts. The longitudinal struts  7  are connected to axle  9  of the rear struts  3  and the axle  9  of the front struts  2 , in each case so they can swivel and, during the folding process, guide the rear struts  3  in such a way that at the end of the folding process, they come as close as possible to the front struts  2 . In the version shown, since the rear struts  3  are curved for design reasons, naturally it is impossible to reach a position parallel to the front struts  2 .  
         [0039]     The dimensions and positioning of the support levers  16  determine the position of the slides  10  and thus that of the pushing handle  12  in the unfolded or folded state. Optimum dimensions and positioning result from the wheel base, wheel size and the requirement of the shortest possible folding dimensions. This means that, with the given wheel base and given wheel size, the front struts  2  should be selected as short as possible, and both the position (axles  17  and  18 ) and the length (distance between axles  17  and  18 ) of the support levers  16  are to be determined such that the upper ends of each of the front struts  2  and slides  10  lie basically in one plane (matching) at the end of the folding process. The length and position of the longitudinal struts  7  (axles  8  and  9 ) are to be determined in such a way that the required wheel base is achieved in unfolded position, and the rear struts  3  come to rest as close as possible to the front struts  2  in folded position.  
         [0040]     In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.