Patent Abstract:
A low weight wheeled bag device having a bottom assembly having two crossed members with an upperside and an underside. The wheel members are coaxially mounted to a shaft journaled by two bushing members at the ends. Spacer leg members have cooperative dimensions to permit the bottom assembly to be at rest at a substantially parallel and spaced apart relationship with respect to a supporting surface. A bag member with flat bottom wall is mounted over the upperside and extends upwardly defining an internal compartment and an upper end opening. A reinforcement member can be optionally added to the bottom wall to enhance its structural integrity. A user tilts the bag assembly and pulls it from handles mounted adjacent to the opening causing the wheels to roll and the assembly to easily move with its contents.

Full Description:
OTHER RELATED APPLICATIONS 
     The present application is a continuation-in-part of pending U.S. patent application Ser. No. 11/873,614, filed on Mar. 4, 2008, which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wheeled shopping bag device, and more particularly, to a collapsible, lightweight, yet strong, low cost, recyclable and disposable-wheeled shopping bag device that is environmentally compatible with characteristics that readily allow for its compact stacking, easy deployment, quick opening, stability, and structural strength. 
     2. Description of the Related Art 
     Several designs for wheeled shopping bags have been designed in the past. None of them, however, includes the conveniences claimed herein. The present invention utilizes eco-friendly materials with greater resistance and capacity than conventional bags, achieving low cost and weight characteristics, while maintaining sufficient strength and being collapsible for compact stacking and storage as well as being easily deployed by a user. 
     Applicant believes that the closest related reference corresponds to U.S. Pat. No. 3,197,225 issued to Powell for a Collapsible Shopping Bag hereinafter “Powell Bag”. However, it differs from the present invention because, it relies on the use of hinges and supports made of sheet metal, fabric, or a combination thereof with the intent of being reused and does not rest on its roller system assembly when at rest due to the obtuse angle of attachment of the wheels. The present invention, on the other hand, is made of a disposable, lightweight material, yet with some rigidity, that sits on its roller system when at rest, aided by folds causing it to stand in a substantially upright position. Furthermore, the patented bag does not claim or demonstrate any stacking characteristics if collapsed. Nor does it disclose crossed-members for its base assembly to reduce weight and costs as claimed herein. 
     One of the disadvantages of the current designs for wheeled bags is that they rely on a multiplicity of parts, such as hinges, fasteners, and reinforcing members, to achieve stability and collapsibility. These parts result in high material and manufacturing cost. These designs must accommodate long term personal reuse, and thus focus on collapsing to the smallest possible dimensions to permit a person to carry them. Still another shortcoming of the current designs is that they are unsuitable for stacking due, among other factors, to lateral instability, protrusions of rigid supports, bulk, and lack of flat surfaces. 
     The present invention provides a low weight and volumetrically efficient solution for collapsible bags that permit its rapid folding and deployment by using a combination of folds and slots to permit the air to vent in and out of the bag. Trapped air prevents the rapid collapse of bags, especially if the bag&#39;s opening is closed. In folding a bag, the opening at the distal end of the bag is typically closed and then folded along a predetermined first folding line, then a second one, until different layers of the flattened bag are stacked over each other. In doing this, air is trapped inside the bag providing some resistance to the folding operation. By providing slots along the vertical walls of the bag, preferably along its diagonal folds, the air inside is allowed to exit. This facilitates the folding of the bag. The reverse operation is also helped. As a user unfolds the bag, air enters through the bag&#39;s opening as well as through the slots. 
     The base or bottom assembly in the present invention includes a pair of coaxially disposed wheels mounted to its underside, opposite to each other at the end of a shaft. The other end includes a spacer leg assembly, opposite to the shaft supporting the coaxially disposed wheels. The dimensions of the spacer leg assembly cooperate with those of the wheels to permit the bag assembly to be at an upright position when at rest. In one of the embodiments, the bottom assembly is implemented using moldable material technology. Minimization of the material used is achieved with two crossed, elongated, and rigid members using molding technology. In one of the embodiments, the crossed members include through openings for permitting the glue to go through and achieve better engagement of the base assembly with the bottom of the bag member. Reinforcement angular members further strengthen the attachment to bushing members that journal the shaft supporting the wheels. Another way of attaching the bottom of the bag members to the base is through the use of ultrasound welding. For this, the paper used for the bag member is covered with a thin film of plastic material that is welded with the plastic material used for the cross members. None of these features are disclosed in the prior art. 
     The present invention also solves the prior art problems by using a bottom or base assembly with simple parts and paper bags that can be glued and do not require hinges or similar hardware. Strength of the wheeled base is enhanced through the use of reinforced cross-members with a substantially flat upperside. As a result of the design, multiple units may be stacked stably in their collapsed states. The folding characteristics of paper bags achieve collapsibility when integral hinges or folds are created along cooperative locations. The folds are positioned so that the folded portions of the bag member leave a clearance for the spacer leg members to fit in the collapsed disposition. 
     Other documents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention. 
     SUMMARY OF THE INVENTION 
     It is one of the main objects of the present invention to provide a collapsible wheeled bag device of sufficient strength and rigidity to carry goods normally carried by the shopper in a non-wheeled bag. 
     It is another object of this invention to provide a bag with a wheeled mechanism that allows a shopper to pull it when tilted at an angle that varies in accordance with the height of the user&#39;s body. 
     It is also an objective of the present invention to provide a wheeled bag device that is easily and readily deployed and opened by a user as well as collapsed when ready for storage with minimum resistance from the air inside the bag member. 
     It is still another object of the present invention to provide a device that stacks compactly so that a single device can be removed from the top of the stack without disruption to the rest. 
     It is also an object of the present invention that the device rests in a substantially upright position when not being pulled by the shopper. 
     It is yet another object of this invention to provide such a bag device that is inexpensive to manufacture and maintain while retaining its effectiveness. 
     An objective of the present invention is that the bag has characteristics similar to that of other paper shopping bags, such as its low weight and low cost with enhanced strength. 
     Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which: 
         FIG. 1  represents an isometric view of one the embodiments of the present invention with the wheeled assembly mounted on the longer end of the bottom assembly having a rectangular shape. The folds of the bag assembly and the venting slots  65  along the diagonal folds are shown, as well as venting holes  65 ′. 
         FIG. 2A  shows an isometric view of bag assembly  60  in a partly collapsed condition. 
         FIG. 2B  is another isometric view of bag assembly  60  in a substantially collapsed condition, similar to  FIG. 2A . 
         FIG. 2C  shows an isometric view of bag assembly  60  in its fully collapsed state. 
         FIG. 3A  shows a partial isometric enlarged view of the shaft  144 , stopper  50 , and wheel  42 . 
         FIG. 3B  shows an elevational cross-sectional view of shaft  144  inside bushing  28 ′. 
         FIG. 4  illustrates a top plan view of collapsed bag assembly  60  and handle  62  slid inside. 
         FIG. 5  illustrates the stackable characteristics of one embodiment of the present invention shown in the previous figures. 
         FIG. 5A  is a partial side elevational representation of the bag folds (without the handles) showing how a clearance space for the contiguously positioned spacer leg member is provided by shortening the length of the folds. 
         FIG. 5B  is similar to the previous figure except that two folds are shortened. 
         FIG. 6  is a top view of the base or bottom assembly  20  showing two crossed elongated members and the two wheels. 
         FIG. 7  is a bottom view of what is shown in the previous figure with bushing assembly  28  supporting shaft  44 . 
         FIG. 7A  is an isometric view of bushing assembly  28  used in the previous figure. 
         FIG. 7B  is an alternate embodiment for a bushing assembly referenced with numeral  28 ′. 
         FIG. 8  is an isometric view of the alternate embodiment shown in the previous four figures using the alternate bushing assembly  28 ′. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, where the present invention is generally referred to with numeral  10 , it can be observed that it basically includes base or bottom assembly  20 , wheel assembly  40  and bag assembly  60 . A user typically tilts wheeled bag device  10  about the end having the wheels and pulls from handles  62 .  FIG. 1  shows the end with wheel assembly  40  as the wider side of a bag assembly  60  with a rectangular projection. The shopping bag device  10  stands in a substantially upright position. 
     Bottom or base assembly  20  is shown in  FIGS. 6 through 8  where a molded plastic material is used with sufficient degree of rigidity. This option is compatible with mass production molding techniques and permits the minimization of material usage, as well as its weight, yet maintaining its functionality. This embodiment includes integrally built crossed members  21  and  23  that are angularly disposed with respect to each other. The angle varies depending on the dimensions intended for the bag&#39;s footprint. If members  21  and  23  are perpendicular to each other, the footprint will be a square. It is preferred to have a rectangular bag footprint that resembles those of commercially available bags. It has been found that with the angle between members  21  and  23  of approximately 120 degrees, the resulting bag assembly  60  works well. This angle, however, can vary from 60 degrees to 150 degrees and still result in a practical projection for device  10 . 
     In  FIG. 6 , upperside  22  can be observed with the front wheel ends  21 ′ and 23′ connected by wheel assembly  40 . Assembly  40  includes shaft  44  and wheel members  42  and  42 ′ mounted to the ends. Cross members  21  and  23  are connected by shaft  44 . Shaft  44  includes wheel members  42  and  42 ′ rigidly mounted to the ends of shaft  44 . Shaft  44  is rotatably mounted to the underside  24  of base assembly  20 , as explained below. In  FIGS. 3A and 3B , the shaft has a star cross-section with four legs (stars with three legs or five or more can also be used) to minimize its weight. 
       FIG. 7  shows underside  24  where members  21  and  23  include a perpendicularly mounted reinforcement rib member  29  with sub-ends  29 ′ reinforcing spacer leg member  25 . Adjacent to front ends  21 ′ and  23 ′, bushing assemblies  28  (or equivalent structure such as bushing assembly  28 ′ showing in  FIG. 7B ) are mounted. The through openings  27  are aligned to permit shaft  44  to go through and be rotatably journaled. The same applies for alternate bushing assemblies  28 ′ where through openings  27 ′ are also aligned. With assembly  28 ′, shaft  44  is pressed in through cut  26 ′ with a predetermined force magnitude and that cammingly enlarges cut  26 ′ as shaft  44  passes through. Assembly  28 ′ has the advantage of not requiring the disassembly of wheels  42  for its removal.  FIG. 8  shows bottom assembly  20  using bushing assemblies  28 ′. 
     In  FIG. 8 , it can also be observed that spacer leg members  25  extend perpendicularly from the ends  21 ″ and  23 ″ of members  21  and  23 , respectively. The dimensions of spacer leg members  25  are selected to cooperate with the dimensions of wheels  42  to approximate a plane that is parallel to a supporting surface, typically horizontal. Reinforcement end  29 ′ keeps member  25  in a perpendicular disposition with respect to members  21  and  23 . 
     Bag assembly  60  has a bottom wall  64  that is mounted to upperside  22  directly. Bag assembly  60  is thus mounted over upperside  22  directly. Bag assembly  60  extends upright defining a compartment and has an opening at its distal upper end. 
     Bag assembly  60  has overall dimensions that cooperate with the dimensions of bottom assembly  20  on which it is mounted. The height of bag assembly  60  is ergonomically compatible with the height of most users to permit the user to comfortably pull bag device  10  when tilted. Bag assembly  60  is made out of a paper base material, in one of the embodiments, with a thickness range between 100 and 800 grams per square meter. It has been found that paper material with this thickness provides sufficient rigidity to keep bag assembly  20  open, aided with cooperatively positioned transversal folds along integral hinges. At the same time, several cooperatively designed integral hinges or folds permit the ready deployment and collapse of bag assembly  20 . To permit the entry and exit of air inside bag assembly  20 , slots  65  are inconspicuously perforated through diagonal bag folds  63 . Optionally, through holes  65 ′ can also be used outside of folds  63 . If holes  65 ′ are used instead of slots  65 , then the resistance of diagonal bag fold  63  is increased. Through openings  26  are designed to receive an adhesive therethrough to improve the engagement with upperside  22 . 
     Bag assembly  60  includes four longitudinal corner bag folds  67  defining longitudinal walls  71 ;  71 ′;  72 ; and  72 ′. Walls  71  and  71 ′ each include one longitudinal bag fold  61 . 
     To facilitate the collapse or folding of bag assembly  60 , diagonal bag folds  63  and longitudinal bag folds  61  cooperate with longitudinal walls  71  and  71 ′, as best seen in  FIGS. 1 and 2A . When bag opening  69  is being closed, air exits also through slots  65  (and, optionally, holes  65 ′). The first fold of the lowermost section of bag assembly  60  results in walls  71  and  71 ′ defining triangular portions  171 , and the lowermost portions of walls  72  and  72 ′ defining rectangular portions  172  and  172 ′. Portions  171 ;  172 ; and  172 ′ are brought towards upperside  22  of bottom assembly  20 . Then, portions  272  and  272 ′ of walls  72  and  72 ′, respectively, are folded, as best seen in  FIG. 2B . Portion  272 ′ is longer than potion  272 . This is followed by portions  372  and  372 ′. Portions  472  and  472 ′ are the last ones, in this embodiment, resulting in a footprint confined within the dimensions of upperside  22  of bottom assembly  20 . 
     In one of the embodiments, portions  372 ;  372 ′;  472 ; and  472 ′ have smaller dimensions than what they would otherwise have to fit the entire footprint or plan projection of upperside  22 , as seen in  FIGS. 5A and 5B . This is desirable in order to provide clearance for spacer leg members  25  of adjacent bag device  10  stacked up above, when storing it. This option will minimize the spaces between stacked bag devices, shown in  FIG. 5 , reducing somewhat the overall height of the stack. 
     Wheel assembly  40  includes shaft  44  that is slidably passed through through opening  27  (or  27 ′) allowing shaft  44  to rotate. Wheel members  42  and  42 ′ are rigidly mounted to the ends of shaft  44 . An adhesive can be used to secure wheel members  42  and  42 ′ to the ends of shaft  44 . The ends of shaft  44  protrude a sufficient distance to permit the mounting of wheels  42  and  42 ′ to the former. As shown in  FIG. 3A , an equivalent embodiment for shaft  44  is represented as shaft  144  with a star cross-section. This provides additional savings in cost and weight. Stopper  50  is positioned a predetermined distance from wheel  42  to prevent shaft  144  (or  44 ) to limit its transversal movement. In  FIG. 3B , shaft  144  is shown in cross-section inside of bushing  28 ′. 
     For storage, device  10  is volumetrically efficient requiring minimum footprint, as shown in  FIG. 4 .  FIG. 5  shows one of the preferred manners for stacking up devices  10 , which results in a stable stacked structure. In  FIGS. 5A and 5B , the elevational representation of two versions of folded bag  60  is shown to accommodate spacer leg members  25  of different dimensions to permit the adjacent device  10  (shown in broken lines) to fit and this resting in a substantially horizontal position. Optionally, a flat reinforcement member  70  (a sheet of plastic or cardboard) is added either inside of bag assembly  60  ( FIG. 5A ) or outside adjacent to bottom wall  64  ( FIG. 5B ). Member  70  in  FIG. 5B  can be glued to bottom wall  64  and upperside  22 . This will prevent the rupture of bottom wall  64 . 
     The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.

Technology Classification (CPC): 1