Abstract:
A height-adjustable and collapsible seat for a child stroller. In the preferred embodiment, of the height-adjustable, collapsible seat is the second, or rear, seat of a tandem stroller, and is such that the child can sit in the seat either forward-facing or rearward-facing. Using the height-adjustable, collapsible rear seat, the pusher is able to adjust the seat height according to his/her preferences and needs (for instance, he/she can place the child at eye-level), or can even remove the seat entirely to provide for additional storage space or room for a second child to ride on the standing platform at the rear of the stroller, if such a platform is provided. In the preferred embodiment, the rear seat is also fitted out with the necessary attachments for an infant carrier, so that the stroller can accommodate any combination of child and infant, facing forward or rearward.

Description:
RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119(e) to U.S. provisional application Serial No. 60/234,644, filed Sep. 22, 2000. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to strollers or baby carriages. More specifically, the present invention relates to a tandem child stroller with a height-adjustable rear seat that is both collapsible and removable. 
     BACKGROUND OF THE FIELD 
     Child strollers are used by mothers and fathers every day. In the last several years, many different types of child strollers have been appearing on the market to accommodate the many different types of families who need strollers. There are double (tandem) strollers, triple strollers, and side-by-side strollers. There are strollers adapted to support infant carriers, which can then be detached from the stroller and carried away. 
     U.S. Pat. No. 5,622,375 to Fairclough discloses a stroller with front seat and rear standing platform, which is designed ideally to be used by a younger (first) child sitting in the front seat and an older (second) child standing facing forward on the platform and holding onto the rear frame of the stroller. Fairclough&#39;s stroller, has only a rear bench seat, however, for the second child to sit in if desirable or even necessary. 
     U.S. Pat. No. 5,664,795 to Haung discloses a double stroller with a rear-facing seat for a second child. However, Haung&#39;s rear bench seat is usable only by older children who do not need the structural support that younger toddlers and infants need. Alternatively, Haung&#39;s U.S. Design Pat. No. Des. 431,212 discloses a design for a double stroller with a rear seat for a second child that is more adapted for an infant or toddler. However, the tandem stroller has the rear seat directly behind the front seat, thereby providing the forward-facing second child with no appreciable view. 
     U.S. Pat. No. Des. 360,392 to Lewandowski discloses a design for a tandem double stroller with elevated rear seat, so that the second child has a forward view. Although the second child has a view, there is no capability in Lewandowski&#39;s design for adjusting the height of the rear seat. Also, the seats in Lewandowski&#39;s stroller are fixed to the frame such that the seats are only forward facing. 
     U.S. Pat. No. 6,099,022 to Pring discloses a stroller with height-adjustable seat. However, Pring&#39;s stroller is only a single stroller. Additionally, although in U.S. Pat. No. 4,728,112, Wynens discloses a double stroller with an elevated rear seat which is rear-facing, Wynens&#39; rear seat is not height-adjustable. There is no stroller currently in existence which has the versatility of a height-adjustable seat which can be forward-facing or rear-facing. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention comprises a child tandem stroller with a box-like wheeled frame supporting a fixed front seat and a height-adjustable rear seat. Whereas the frame, wheels, and front seat may be conventional elements, the innovative rear seat is novel in that not only is it height-adjustable, collapsible and removable, but also it provides the riding child with the choice of sitting forward-facing or rear-facing. In the preferred embodiment, the stroller also comprises a rear standing platform, so that the second child has the choice of riding while standing and gripping the frame (if the rear seat has been collapsed and removed). 
     In the preferred embodiment of the present invention, the height-adjustability of the rear seat is accomplished by making the back panel of the rear seat slidable along upwardly-extending frame members. Several detent holes in the upwardly-extending frame members pre-determine height settings. Once the pusher chooses a height setting, he/she locks the seat into position by fitting spring pins into the appropriate detent holes. 
     The rear seat completely collapses onto itself so that the stroller can be easily stored in a small space or so that the pusher can use the rear seat space for storage or other use. In the preferred embodiment, the rear seat is also completely removable by sliding it off the lower ends of the frame members. With the seat removed, the rear space is even more accessible. Being able to completely remove the rear seat greatly increases the versatility of the stroller, especially if the stroller is equipped with a rear standing platform (close to the rear wheels). In this case, the stroller can still accommodate two children: for instance, a younger child sitting in the front seat and an older child standing in the rear. 
     The present invention of the rear seat includes leg holes in both the front and the back panels. Further, both panels are otherwise stiff enough and high enough to provide structural back support to an infant or toddler. With these features, the second child can sit forward-facing or rear-facing in the rear seat. This option allows the pusher to position the child forward-facing so that the child can have a view, or rear-facing so that the pusher can observe the child&#39;s face. With the height-adjustability feature, the pusher can even position the child at or near eye level so that he/she can keep in close contact with the child. 
     The rear seat design of the preferred embodiment also comprises folding sidearms which, when locked into the extended position, provide arm rests for the child. To eliminate the possibility of a child getting pinched in the sidearm hinge, the hinges are covered with comfortable sleeves. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the preferred embodiment of the tandem child stroller with the height-adjustable rear seat; 
     FIG. 2A is a side view of the stroller with the rear seat in the fully extended position; 
     FIG. 2B is a detail view of the rear seat in an intermediate stage between the fully extended and fully collapsed positions; 
     FIG. 2C is a detail view of the rear seat in the fully collapsed position; 
     FIG. 2D is a detail view of the sleeve covering the sidearm in the locked position; 
     FIG. 3A is a section view showing the preferred method of height adjustability of the rear seat; and 
     FIG. 3B is a section view showing an alternate method of height-adjustability of the rear seat. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a tandem child stroller  10  with conventional frame  12  and forward-facing front seat  14 . It has been chosen to use this type of tandem stroller for the preferred embodiment of the present invention although it is understood that the present invention could be embodied in a triple stroller, a side by side stroller, or even a single stroller with the invention of the height-adjustable seat being the only seat in the stroller. Furthermore there could be a standing platform  26 , such as that described in U.S. Pat. No. 5,622,375 to Fairclough, mounted on the frame of the stroller and used in conjunction with the present invention. 
     For clarity, the front seat  14  in the drawing of FIG. 1 has been simplified. However, it is understood that the front seat of the tandem stroller contemplated for the preferred embodiment is a standard front seat such as the ones shown in the Haung patents or the ones in current use on most tandem strollers on the market today. 
     The preferred embodiment includes two front wheels  16   a  and  16   b  and two rear wheels  18   a  and  18   b  arranged in a generally rectangular pattern below the frame. It is important for the present invention, whether or not the rear wheels  18   a  and  18   b  share a common axle, that the axis of rotation of the rear wheels  18  be located far enough rearward to stabilize the stroller when the rear seat  24  is in the highest position. In the design of the preferred embodiment of the present invention, the regulations of the Juveniles Products Manufacturers Association have been heeded, and the rear axis may be positioned far enough rearward on the frame so that the center of gravity of the child or children seated in the stroller will fall within the wheel base. 
     The frame  12  typically is constructed of tubular aluminum members having circular cross-sections. Other materials, such as plastics, could be used, and certainly the cross-section could be ovate or rectangular. Frame  12  includes two upwardly and rearwardly extending frame members, or rails,  20   a  and  20   b  (collectively  20 ), which in the preferred embodiment reach to a height of between approximately 2.5 and approximately 3 feet, a height about even with the waist of the average adult, and are connected to each other at their extreme upper ends by a lateral pushbar  22 . If the frame members  20  are to support a second, height-adjustable seat  24  as in the present invention, the angle of the frame members  20  to the ground becomes rather important. For the preferred embodiment, an angle of approximately 70 degrees was chosen. This angle allows a large range of height adjustment choices for the rear seat  24  along the rails  20  without undue changes in the overall length of the stroller  10 . A flatter angle may result in a greater number of adjustment settings; however, it would also necessitate a longer wheelbase of the stroller  10  so that the center of gravity of the children would fall within that wheelbase and the stroller  10  would maintain stability when loaded. 
     The preferred embodiment comprises a rear standing platform  26 , which increases the versatility of the stroller  10 . With the rear seat collapsed and removed, a child can stand on the standing platform  26  and grip the handles  28 , thereby riding in a forward-facing mode. 
     FIG. 1 shows the rear seat  24  in the fully extended position. It is seen that a child can be placed in the seat  24  in a forward-facing or a rearward-facing position, depending only on the preferences of the child and the pusher. In the preferred embodiment, legholes are provided, which will be discussed in more detail later, in both front and rear panels; and at least the seat bottom, if not all the panels, is cushioned for the child&#39;s comfort. In the preferred embodiment, there is provided a removable cushioned back support panel which is of approximately the same size as the front and back panels and can be used to cover the unused legholes and provide a cushioned back rest for the child. In alternate embodiments, the rear seat  24  as well as the front seat  14  has attachments for infant carriers, so that any child-infant combination can be accommodated. 
     The height-adjustable rear seat  24  in the preferred embodiment comprises three major panels, which are shown in the side view of FIG.  2 A. (For clarity, the handles  28  are not shown.) Front panel  30  is attached to the seat bottom panel  32  with two double-leaf hinges  36 . (Different types or numbers of hinges could be used, as long as they will perform the necessary function.) The hinges  36  allow that the front panel  30  can collapse completely against the bottom panel  32  in the direction of the arrow shown in FIG.  2 B. Likewise the seat bottom panel  32  is attached to the rear panel  34  by a lateral hinge  38  which allows the seat bottom panel  32  to rotate in the direction shown by the arrow in FIG. 2C to collapse completely against the rear panel  34 . (In alternate embodiments, of course, two or more hinges  38  could be used.) The hinge  38  is of the type, however, that prevents overrotation in the opposite direction, so that the seat bottom panel  32  can never extend further than a horizontal (with respect to the ground) position. A fully collapsed rear seat  24  may provide additional storage space behind the front seat  14 . 
     The two links  40   a  and  40   b  of the sidearm  40  are also shown in FIG.  2 B. (For clarity, only one sidearm will be discussed; it is understood that the two sidearms, one on each side of the seat  24  are symmetrical.) The links  40  are connected by a swivel hinge  42 , which allows the links  40  to collapse upon each other when the seat  24  is folded. When the seat  24  is fully extended, the links  40  will be aligned such that the hinge  42  can be locked into position using the sleeve  44  as shown in FIG.  2 D. The sleeve  44  not only locks the sidearm  40  for safety, but also provides comfort for the child rider and prevents any potential pinching of the child&#39;s arms and fingers. A further benefit of the locking sidearms is that the front and back panels are locked into the extended position so that the child rider cannot push or pull the seat panels out of position. 
     Further, the front panel  30  and the rear panel  34  (best seen in FIG. 1) define legholes, so that the child can sit forward-facing or rearward-facing in the rear seat  24 . The panel opposite the legholes used obviously becomes a backrest for the child, and so the height of the panel becomes important, in order to prevent the child from toppling over the panel. It has been discovered through experimentation based on the size of a normal child/toddler that the panels  30  and  34  should each be at least 7 inches high as measured from the seat bottom panel  32 . 
     In the preferred embodiment, the rear panel  34  of the rear seat  24  slides up and down along the rails  20 , thereby providing height-adjustability of the rear seat  24 . The pusher can therefore choose the desired configuration based on the size of the child and the pusher&#39;s preferences. FIG. 3A shows the preferred arrangement of channels  50   a  and  50   b , which are mounted on the backside of rear panel  34 , riding on the rails  20   a  and  20   b  respectively. (For clarity, only one channel of the seat  24  is shown; it is understood that the two channels, one on each side of the seat  24  are symmetrical.) The pusher can choose any point along the rails  20 , and then simply tighten the hand screws  52 , which extend through the channels  50 , against the rails  20 . Alternatively, as is shown in FIG. 3B, the pusher adjusts the height of the rear seat  24  by choosing a set of detent holes (not shown) along the rails  20  and releasing the spring pins  52   a  and  52   b  into those holes. These alternate embodiments include means by which the pusher can easily actuate, i.e., disengage and engage, the spring pins  52 . For instance, bias box  54   a  can be attached to channel  50   a  to provide the spring bias. A trigger or button mechanism can easily be mechanically linked to the spring pin  52 , depression of which would cause the spring pin  52  to disengage so that the rear seat  24  could be slid along the rails  20 . In another alternate embodiment, the adjustment is not made by pins at all but sheathed cables which run up and down within the rails  20  and are attached to the rear seat  24 . 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation, so as to encompass all such modifications and equivalent arrangements. 
     While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the exemplified embodiment set forth herein. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to.