Abstract:
In this patent, mechanically simple and inexpensive to produce platforms for modification of a stroller such that an additional child or a pet or a package may be transported are taught.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from U.S. provisional patent application No. Ser. No.: 60/941,598, filed Jun. 1, 2007, and from U.S. provisional patent application No. 60/974,661, filed Sep. 24, 2007, which are incorporated herein by reference in their entirety and for all their teachings and disclosures. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     Single child strollers are built and sold with the intention of conveying a single child in a seated position. Families or childcare givers that start with a stroller for one child only and then have a second child are faced with a problem of only being able to seat one of the children should they need to transport both. Similarly for families and childcare givers with multiple children, they face the dilemma of how to transport an additional child should it arrive. 
     Solutions available to the parents and childcare givers include: obtaining a second stroller; obtaining a larger stroller to seat the extra child (a double or triple stroller); having one child walk or be carried; or obtain a wheeled device that attaches to the back of the stroller upon which the additional child can stand. Examples of the wheeled devices include the Bugaboo Wheeled Board and the Lascal Buggy Board. 
     The mentioned solutions are not ideal. Obtaining a second stroller is expensive and excessive in terms of new materials required. As well, a second adult is now required whenever the additional child needs to be transported. Double and triple strollers are also expensive and excessive, and furthermore have reduced maneuverability. The size of the stroller can prevent access to various locations: reduced turning radius can limit steering and turning about in cramped places such as shopping aisles; increased width can prevent traversing doorways. Having the additional child walk and/or be carried can be tiring for the additional child and/or parent and can limit the distance that the family or group can travel. Finally, wheeled devices for attachment to the stroller to allow a standing child can be obtrusive for the parent pushing the stroller by disrupting their natural stride, and can limit vision for the child standing as the child may not be able to see over the stroller if the child is not tall. Although not as expensive as a new stroller, these devices involve specialized parts including linkages, casters and bearings, the wheeled devices can be relatively expensive compared to what could be spent to build a similar performing device such as the device of this invention. 
     It is the objective of this invention to provide transportation for an additional child with the original stroller (single stroller for two children, double stroller for three, and so on) that solves the above-mentioned problems of inconvenience, excess and expense. For strollers in which there is an under-riding basket (for storage of toys, clothes, groceries and other things) or another similar structure capable of supporting a platform structure and a standing child, a platform is disclosed that allows the modification of a stroller for carrying an additional child in a standing position. 
     PATENT DOCUMENTS 
     See U.S. Pat. Nos. 6,827,356, 6,698,772, 6,422,634, 6,371,498, 5,882,022, 5,361,454, 5,312,122, D428367, and applications 2003/0025304 and 2006/0290081. 
     OTHER PRIOR ART 
     Bugaboo Wheeled Board and Lascal Buggy Board product literature. 
     BRIEF SUMMARY OF THE INVENTION 
     Devices to modify a baby carriage, pram or child&#39;s stroller (herein ‘stroller’) for the conveyance of an additional child are described. Although the application is written with the outlook of transporting a child, it could also be used to transport a pet, a package or other such object. 
     This invention comprises a main body and constraining mechanism. The main body can act as a platform for standing on by a child. The constraining mechanism couples the invention to the stroller and can limit motion of the invention relative to the stroller. The platform gains support for the weight of the child from positioning the main body in such a way that it the child&#39;s weight is transferred to one or more members of the stroller&#39;s frame. The platform is intended to support the weight of the child and provide safe transportation for that child. 
     The invention is intended to be of simple construction and thereby easily manufactured and inexpensive to produce and sell. The invention can comprise as few parts as a single piece that can be CNC machined; cast; injection, spin or blow molded; vacuum formed; or manufactured in another inexpensive, mass production fashion. The few parts can allow for ease of removal when the platform is not required. 
     In use, the child can stand on the platform and hold onto the back of the stroller and/or the handles of the stroller used for pushing the stroller. This places the child in a position from where they can see without viewing obscured by the stroller, increasing the child&#39;s acceptance and enjoyment of this mode of transport. The length of the stroller footprint is not changed; i.e. the size of the stroller&#39;s footprint is not lengthened by the placement of the child between the stroller pusher and the stroller. Thereby, pushing the stroller is not interfered with and not made inconvenient to the stroller pusher or otherwise user; the stroller is not kicked or tripped on by users. 
     The invention further comprises adaptive mechanisms to provide universal adaptation to most stroller types. These adaptive mechanisms include hinges and sliders to permit reach over distances and adjustment for angles of different stroller types. Furthermore these hinges can permit freer access to contents of containers associated with the stroller, without having to remove the stroller platform. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the invention in an exploded top-view. 
         FIG. 2  shows the invention integrated with a stroller. 
         FIG. 3  is a simplified view to better display the invention in relationship to the stroller. 
         FIG. 4  shows the invention in an exploded top-view where the crosspiece has been replaced by a tubular member that mounts into the thickness of the main body of the platform. 
         FIG. 5  shows the invention in an exploded top-view where the invention has been made adjustable to fit varying sizes of strollers. 
         FIG. 6  shows the invention in an exploded top-view where the platform further comprises an internal reinforcement bar. 
         FIG. 7  shows top views of the stroller platform with integrated attachment mechanism, (A) as a single piece construction; (B) with additional bolts for additional safety; (C) with hinges for adjustment to the angle of the vertical frame members; and (D) with hinges for adjustment to the angle of the vertical frame members and to the spacing of the vertical frame members. 
         FIG. 8  shows a close-up view of a bent clip arm with hinge. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to a platform for a stroller to allow a child to be conveyed such that they can stand. Again, the invention could also convey a pet, package or other such object, not necessarily standing. This platform is comprised of a main body upon which the child can stand and a mechanism for removably attaching the main body to the stroller. Support for the child, pet or package&#39;s weight is provided by members of the stroller&#39;s frame, in a preferred instance by elements of an underbasket. 
     As drawn in  FIG. 1 , the attaching mechanism can be a crosspiece  13  with one or more joints  14  between crosspiece  13  and main body  16  to allow engagement with main body  16 . As drawn in  FIG. 1 , crosspiece can be a flat material such as wood or plastic. Crosspiece  13  can also be a simple bar with a suitable joining means such as brackets or loops fixed to main body  16 . The platform main body  16  is positioned over and rests on a cross member of the stroller as a cantilever extending towards the person pushing the stroller. There are at least three points of contact between the stroller and the platform to reduce unwanted motion of the platform relative to the stroller. The area of contact is preferably a flat line or rectangle to prevent roll of the platform relative to the stroller. To prevent pitch rotation of the main body  16 , crosspiece  13  engages the stroller below structural members running lengthwise along the stroller and joins main body  16  at joint  14 . Yaw rotation is limited by engagement of the platform with descending pieces of the stroller frame (stroller frame  11  in  FIG. 2 ), passing through platform slot  15 . 
     Crosspiece  13  and/or main body  16  can have one or more posts and the other can have one or more mating holes to connect at joint  14  and to temporarily or permanently fix main body  16  and crosspiece  13  together. Exemplary mechanisms for implementing joint  14  include a pin joint, where one or both of main body  16  and crosspiece  13  have a post and the other has a mating hole; a screw or bolt joint where one or more screws or bolts penetrate through either or both of main body  16  and crosspiece  13 , and receiving nuts are located either integral to main body  16  using an overmolding process for example or external to main body  16 ; and an adhesive joint. 
       FIG. 2  shows the invention integrated with a stroller. The stroller is composed of a frame  11 , mounted to which are front wheels  8  and rear wheels  9 , underbasket  3  supported by underbasket frame  2 , child seat  4  with restraining bar  5  and entertainment toy  6 , wind and rain screen  7 , pushing handle  10  and breaking mechanism  12 . Platform  1  is seen at the back of the stroller above rear wheel  9 , being held in place by its arrangement with underbasket frame  2  and stroller frame  11 . 
       FIG. 3  is a simplified rear view of the stroller and platform combination, to better display the invention in relationship to the stroller. The stroller is represented in a cutaway view showing the rear wheels  22 , frame  21 , underbasket frame  23  and braking mechanism  24 . The platform is composed of main body  25  and crosspiece  26 , connected by joint  27 . In a preferred instantiation of the invention, the platform engages with the stroller by resting on underbasket frame  23  and by encircling surrounding members of frame  21  forming the rear of the stroller and possibly descending from the pushing handle (pushing handle  10  in  FIG. 2 ) towards rear wheels  22 . Surrounding frame  21  prevents lateral motion of the platform. In the design of  FIG. 3 , platform slot  28  can be made optional. 
     A somewhat loose fit of the platform to the members of the stroller will allow better access to the contents of the underbasket (underbasket  3  in  FIG. 2 ) and give one platform the ability to fit many different models of strollers, ie. strollers of differing dimensions, particularly in the spacing of the members of the frame captured by the stroller platform. 
     In another instantiation of the invention, other mechanisms are available to adapt the platform to fit to the stroller.  FIG. 4  shows an instantiation where u-shaped crosspiece  40  mates with joining holes  41  on the edge of main body  42 . Joining holes  41  are indicated by broken lines in the diagram, because the joining holes  41  have been made internal to main body  42  in this depiction. Other means of removably attaching u-shaped crosspiece  40  external to main body  42  including use of loops or hooks are also possible. In the design of  FIG. 4 , platform slot  43  can be made optional. An exemplary instantiation of u-shaped crosspiece  40  includes bent tubular bars that interface with joining holes in the vertical edge of main body  42 . U-shaped crosspiece  40  can be maintained in the joining holes  41  through mechanisms including use of a friction fit, o-rings gripping u-shaped crosspiece  40  internal to main body  42 , a ball and socket joint, and a key and lock locking mechanism. 
     Crosspiece  40  in  FIG. 4  and crosspiece  13  in  FIG. 1  can also be substituted for by the use of suitably tensioned chains, belts, straps or ropes. 
     Another instantiation of the invention where the invention includes a mechanism for to allow adaptation to different types of strollers with variation in spacing distances of the members of the stroller frame is shown in  FIG. 5 . The main body can be constructed as main body left side  50  and main body right side  51 , where main body left side  50  and main body right side  51  can join as a peg and hole fit with one or more pegs  52  inserted a varying depth into one or more holes  53  (indicated with broken lines denoting holes hidden from the view penetrating main body left side  50  and right side  51 ). The depth of the penetration of the pegs  52  into holes  53  depends on the spacing of members of the stroller frame. To prevent motion of main body left side  50  and main body right side  51  while in use, the peg and hold fit can further comprise mechanisms of resisting motion including friction fits, quick-release clamps and locking mechanisms. Either or both of main body left side  50  and main body right side  51  can have overlapping material, to close any gap that may occur if main body left side  50  and right side  51  are sufficiently spaced apart, to provide a complete and continuous platform. 
     Similarly, to adapt to different sized strollers, the crosspiece for capturing the members of the stroller frame is made expandable for the instantiation of  FIG. 5 . The crosspiece can be made up of crosspiece left half  54 , crosspiece right half  56  and an optional crosspiece joining piece  55 . To allow reduction in overall width and to tighten the crosspiece assembly ( 54 ,  55  and  56 ), crosspiece right half  56  can slide interiorly into or exteriorly over crosspiece left half  54 . Without crosspiece joining piece  55 , the fit of crosspiece left half  54  and crosspiece right half  56  can be made tight to reduce sliding tendency. With crosspiece joining piece  55 , the fit of crosspiece left half  54  and crosspiece right half  56  can comprise a means of reducing motion of the two pieces relative to each other partially such as by a frictional fit due to light gripping, light contact or by a small clearance between the inner and outer diameters of the interconnecting pieces, or by use of rubber seals and/or o-rings. Crosspiece joining piece  55  can otherwise comprise a locking feature where crosspiece joining piece is a collar rotatably fixed on one of crosspiece left half  54  or crosspiece right half  56 , and the other of crosspiece left half  54  or crosspiece right half  56  further comprises threading to receive crosspiece joining piece  55 . 
       FIG. 6  shows another instantiation where, to reinforce the platform, structural members including bars and/or pipe of stronger material than that of the main body  60  are incorporated into main body  60 . In the figure, reinforcement member  61  (drawn in dotted line to indicate its incorporation into main body  60 ) has been incorporated into main body  60  and is used to receive crosspiece  62  at the top of its “u” shape. Adhesives, press fitting, fasteners, overmolding or a similar process are exemplary ways in which the reinforcement material can be added. 
     In the figures, the platforms and crosspieces have been depicted with square corners. In another instantiation the corners can be rounded as a safety feature. 
     The invention can further comprise one or more slip resistant surfaces. These surfaces can be patterns (e.g. grooves) formed (by molding or a secondary process such as cutting, for example) into the surface of the platform&#39;s component parts and can also comprise another material bonded, molded into or otherwise attached to the platform. 
     In another preferred instantiation of the invention, the platform of the invention can be made with a mechanism for attaching the main body to the stroller integrated into the design so as to attach the stroller platform to the members of the stroller frame, as a one-piece construction without the use of a crosspiece.  FIG. 7A  shows an exemplary embodiment of the invention as a single molded piece comprised of main body  70 , clip necks  71  and clips  72 . Necks  71  can function to join main body  70  and clips  72 . Necks  71  can be made optional if clips  72  are integrated into main body  70 . Necks  71  can be made with length to accommodate the stroller geometry if it is desirable or necessary to separate main body  70  from the vertical members of the stroller frame. 
     Clips  72  can function as the attachment mechanism of main body  70  to the stroller. Clips  72  can be made of a flexible material such as a plastic or can be made thin to allow spreading about, and then closing around and capture of members of the stroller frame. Through selection of appropriate materials and geometry of clips  72 , the opening force can be designed to be sufficient to withstand accidental disengagement of the platform in regular use. Thus, this version of the invention can be easy to assemble and disassemble. 
     Clips  72  can be made of sufficient size and material to hold the weight of the child, or can be sized smaller if the invention can rely on the stroller&#39;s underbasket or other members of the stroller&#39;s frame to support the weight of the child. 
     Clips  72  can be sized to fit standard vertical bar sizes. Clips  72  can be sized slightly smaller than standard sizes to provide a tighter fit. Clips  72  can be oversized relative to standard sizes of stroller frame members and shims can be used to ensure a good fit. Making available shims of various thicknesses can allow for use with different sized stroller frame members. Suitable materials can include flexible materials such as rubbers, foams and neoprene. 
       FIG. 7B  shows the top left corner of  FIG. 7A  modified by the addition of safety bolt  75  to modified clips  74 . Safety bolt  75  comprises a safety mechanism to further ensure that there is no accidental disengagement of the platform in regular use. Safety bolt  75  can serve to provide adjustment for frames of varying thicknesses. 
     Further adaptation of the invention to universally fit many different models of strollers can be done by adding hinges.  FIG. 7C  shows the top left corner of  FIG. 7A  modified by the addition of hinge  76  to allow rotation of modified clip piece  78  relative to modified neck  77  permitting adjustment to the angle of the stroller frame member. If there is an underbasket or similar method of containing and transporting items with the stroller, hinges can also permit access to the contents of these containers without having to remove the stroller platform. In another instantiation modified neck  77  can be rotated by 90 degrees to allow better adjustment of the spacing of the clips to allow capture of frame members with different spacings. In another instantiation modified neck  77  can be rotated by an angle between 0 and 90 degrees to provide for some adjustment to both angle and spacing of the stroller frame members. 
     In another instantiation of the invention, the modified neck  77  is as it was in  FIG. 7C  and the invention can further comprise hinges to accommodate different sized spacing between the vertical members of the stroller. In  FIG. 7D , the invention disclosed in  FIG. 7C  is further modified by the addition of hinge joint  79  to modified neck  77  of  FIG. 7C . This additional joint adds an additional degree of freedom allowing for better reach and better capture of the stroller&#39;s frame. Hinge joint  79  can be a pin joint allowing for yaw rotation of clips to rotationally change the distance between the clips  72  or clips  74  or clips  78 , whichever is being used. 
     To allow adjustment to angle and to spacing of the members of the stroller to which the platform connects, the hinges can be incorporated into one piece. This can be accomplished by making the hinge a ball joint. This can also be accomplished by having neck  73  or neck  77  of  FIG. 7  constructed with an angle as bent piece  81  of  FIG. 8 . In  FIG. 8 , a side view of the stroller platform presents main body  80  with bent arm  81  connecting to clip  84 , and further comprising hinge  82 . 
     To adapt to specific brands of strollers and in particular to accommodate different configurations and relationships of the members in the frames of the stroller, neck  71 , neck  73  and neck  77  of  FIG. 7  and bent arm  81  of  FIG. 8 , can be made with horizontal and/or vertical bends to allow connection to members of the stroller that cannot be directly attached to in a straight line. The jog can take the form of one or more bends in one or more links. The bends will allow the clips to reach and attach to stroller members that are partially obscured, by fabric for example. The bends can be made to allow grips above and below the plane of the stroller platform main body. 
     The neck pieces and other modifications from  FIG. 7  can further comprise a sliding mechanism to adjust the length of the neck and other modified pieces to allow attaching to many different stroller varieties. 
     Furthermore, a general stroller platform main body can be made for use with many types of strollers and specific neck and arm pieces made and used to attach and adapt to individual stroller types. 
     The invention is intended to be of simple construction and thereby easily manufactured and inexpensive to produce and sell. The crosspieces, and main bodies and sides of main bodies can be made using inexpensive, mass production processes including injection molding and vacuum forming. These parts are preferably shells with support structures including vertical ribs and honeycombing to save weight and material without sacrificing strength, but can also be solid parts. In another exemplary method of reducing weight for a solid body, the main body, cross-section and other such parts could consist of hollow shells with or without foam, cork or other lightweight cores. Preferably these materials are made from an injection moldable plastic such as one of the polyethylenes, polyamides or another engineered material with appropriate mechanical properties so as to resist breakage under the weight of the child.