Abstract:
A backpack having a front and back panel and side panels foldable one upon the other in which a strap for securing about the shoulders includes a strap guide which is fixed to the side and front panels to maintain the strap in position to enable the side panels to be folded and unfolded.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a backpack which is mounted about the back with straps that fit over the shoulders of the user. The backpack has a central section formed from foldable panels which are controlled by straps and secured by a strap guide assembly which enables the panels to fold one upon the other when the backpack is secured about the shoulders to provide greater safety and security of the contents contained in the backpack. The backpack provides flexibility yet can carry flat materials (e.g. paper) in an unfolded condition. 
     BACKGROUND OF THE INVENTION 
     Backpacks or knapsacks have been in use for many years. Such devices typically comprise a central storage compartment and optional secondary storage compartments. Attached to the central storage compartment is generally two straps which are worn about the shoulders of the user so that the backpack is partially supported by the shoulders and the back of the user. 
     Backpacks of the type disclosed in U.S. Pat. Nos. 432,607; 5,129,560; 5,431,317; and 5,577,652 are generally stiff shaped or non-flexible backpacks. Such backpacks typically have closures such as zippers. Such non-flexible backpacks are not comfortable because they have stiff edges which apply pressure to various portions of the user&#39;s back, and are awkward to carry. In addition, such backpacks can not be condensed so that they can be easily stored within a suitcase and transported during travel. 
     Another disadvantage of conventional backpacks whether having a zipper or drawstring closure is that entry to the central storage section is typically exposed to the public when the user is wearing the backpack. The closure is rather an easy target for someone who wishes to gain entry into the backpack even when the backpack is worn by the user. 
     It is therefore desirable in the backpack industry to provide a backpack assembly which is flexible, more comfortable to wear, allows for storage of materials in a flat condition and provides greater security than conventional backpacks described above. It would therefore be an advance in the art of developing backpacks to provide a backpack which provides a surface in contact with the back of the user which is generally flexible, conforms to the contour of the user&#39;s back, yet can carry flat materials in an unfolded condition. It would be a further advance in the backpack art to provide a backpack having a closure system which can not be readily tampered with when the user is wearing the backpack. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a backpack having a series of foldable panels which form the central storage section which panels can be folded one upon the other when the backpack is worn by the user. The backpack also provides for a strap assembly which facilitates the folding of the panels one upon the other and provides a secure closure of the central storage section when the backpack is operably carried by the user. 
     In one aspect of the present invention, the backpack comprises: 
     a) a central storage compartment comprising a bottom panel, a front panel, a back panel and plurality of opposed side panels foldable upon each other, said panels defining an upper opening for entry into the central storage compartment; 
     b) a strap secured to the backpack for releasably enabling the side panels to move from a folded condition thereby closing the upper opening to an unfolded condition whereby the upper opening allows access to the central storage compartment; 
     c) strap guide means operably fixed to the side and front panels to maintain the strap in position to enable the side panels to be folded and unfolded; and 
     d) strap attachment means for securing the strap to the front panel at a position to enable the strap to be placed about the shoulders of the user. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following drawings in which like reference characters indicate like parts are illustrative of embodiments of the invention and are not intended to limit the invention as encompassed by the claims forming part of the application. 
     FIG. 1 is a perspective view of the front of one embodiment of the present invention shown in the closed position employing upstanding loops as a strap guide; 
     FIG. 2 is a rear view of the embodiment shown in FIG. 1; 
     FIG. 3 is a side view of the embodiment shown in FIG. 1; 
     FIG. 4 is a perspective view of the embodiment shown in FIG. 1 with the backpack in position for receiving or removing articles from the central storage compartment; 
     FIG. 5 is a perspective front view of another embodiment of the backpack of the present invention; 
     FIG. 6 is a rear view of the embodiment shown in FIG. 5; 
     FIG. 7 is a side view of the embodiment shown in FIG. 5; and 
     FIG. 8 is a perspective view of the embodiment shown in FIG. 5 with the backpack in a position for receiving or removing articles in the central storage compartment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is generally directed to a backpack in which access to the backpack is substantially prevented when the backpack is worn by the user. In a first embodiment of the present invention, as represented by FIGS. 1-4, there is shown a backpack  2  having a topside  4  with an opening  6  therein providing access to a central storage compartment  10  as best shown in FIG.  4 . Opposite the topside  4  is a bottomside  8  which forms the base or floor of the central storage compartment  10 . 
     The central storage compartment  10  is formed by the interconnection of a front panel  12 , a back panel  14 , and a plurality of opposed side panels  16  which, as explained hereinafter, fold upon each other in accordance with the present invention. In the embodiments specifically shown in FIGS. 1-4, the backpack  2  is provided with two side panels  16 A and  16 B. 
     It will be understood that the aforementioned panels  12 ,  14 , and  16  are described herein for convenience as separate panels which are connected together by stitching or the like. It will be understood that the present invention also provides for the panels to be integral with each other (ie. formed from a single piece of material). 
     The backpack  2  includes a pair of strap arms  18  which are secured to both the front panel  12  and the back panel  14 . As shown in FIGS. 1-4, there is a single strap piece having a pair of strap arms  18  each of which is adapted to fit over a respective shoulder of the user. In the embodiment illustrated in FIGS. 1-4, the attachment of the strap arms  18  to the front and back panels is best illustrated in FIG.  4 . As shown in FIG. 4, the strap arms  18  are secured to the back panel  14  by a back strap securing device  20 . The securing device  20  secures the strap arms to the backpack  2  at the back panel  14 , but does not otherwise assist in the closing of the backpack  2  as hereinafter described. The securing device  20  includes a loop  70  secured to a substrate  72  which itself is secured to the back panel  14 . The strap arms  18  are provided with loops  74  which interact with the loops  70  to provide attachment of the strap arms  18  to the back panel  14 . The substrate  72  can be any support material which can be attached to the back panel  14  and to which can be attached a loop  70  to secure the strap arms  18 . The support material can be made from plastic, fabric, leather, and the like. Most typically, the support material will be selected from the same type of material that is used to construct the backpack. 
     The strap arms  18  are secured to the front panel  12  through a front strap securing device  22  which may be in the form of an upstanding strap support as best shown in FIG.  4 . It is desirable to provide an elongated strap support for the front strap securing devices  22  so as to enable the strap arms  18  to more easily extend along the opposed sides of the backpack as explained hereinafter. The front strap securing device  22 , unlike the back strap securing device  20 , does assist in the closing of the backpack  2  and the securing of the contents therein when the backpack  2  is operatively situated on the user&#39;s back. 
     In accordance with one aspect of the present invention, the strap arms  18  are provided with a strap guide means  26  that preforms at least two functions. The first function is to position the strap arms  18  along opposed sides of the backpack from the back strap securing device  20  to the front strap securing device  22 . The strap guide means  26  also serves to enable the side panels  16  to fold upon themselves when the straps are secured about the shoulders of the user. 
     In the embodiment shown in FIGS. 1-4, the strap guide means  26  includes back panel upstanding loops  28  and side panel upstanding loops  30 . The upstanding loops  28  and  30  are secured to the upper edge portion  76  of the back panel  14  and the upper edge portion  78  of the side panels  16 . The loops  28  and  30  extend above the topside  4  of the backpack when the backpack is in the closed position as illustrated in FIG.  1  and in the open position as illustrated in FIG.  4 . 
     In operation, the user places the backpack  2  in the open position as illustrated in FIG. 4 to gain access to the central storage compartment  10 . Articles may be placed into the central storage compartment or removed therefrom when the backpack  2  is in the position shown in FIG.  4 . When the user places the backpack in the carrying position by placing the strap arms  18  around the shoulders so that the back panel  14  rests against the users back, the straps automatically are pulled forward towards the user so that pressure is exerted on the front strap securing device  22  forcing the front panel  12  to move towards the back panel  14 . This exerts a force on the junction between the respective side panels  16 A and  16 B so that they begin to fold one upon the other. At the same time, the side panel upstanding loops  30  are so positioned that the interaction of the strap arms  18  and the upstanding loops  30  creates a further pressure on the respective side panels  16  to fold one upon the other so that the backpack moves from the position shown in FIG. 4 to the position shown in FIG.  1 . When the backpack is in the position shown in FIG. 1, it is difficult for a person to gain access to the opening  6  of the backpack because the interaction between the strap arms  18  and the strap guide means  26  maintains the backpack  2  in the closed position shown in FIG. 1 denying access to the central storage compartment  10 . This provides the user with greater security against those who seek to obtain unlawful entry to the backpack while it is being worn by the user. 
     Further security can be provided to the backpack  2  through the employment of a flap  24 . The flap is secured to the inside surface of the back panel  14 . When the backpack  2  is in the closed position as shown in FIG. 1, the flap  24  passes over the opening  6  and is secured to the outside surface of the front panel  12 . The flap  24  may be secured to the inside surface of the back panel  14  by stitching, adhesive or the like and is preferably secured to the outside surface of the front panel  12  through a releaseable attachment means (not shown) such as a hook and eye attachment assembly sold under the trademark Velcro. As best shown in FIG. 1, the flap  24  when secured about the backpack  2  provides an additional measure of security against unlawful entry into the opening  6  leading to the central storage compartment  10 . 
     In a further optional and preferred embodiment of the invention as best illustrated in FIG. 4, the inside surfaces of the front panel  12 , back panel  14  and side panels  16  can be provided with a releasable attachment means  34  preferably comprised of hook and eye strips  36  sold under the trademark Velcro. 
     It will be understood that the outside surface of the respective panels may be provided with the releasable attachment means  34 . It is preferred, however, to provide the inside surfaces with the releasable attachment means  34 . FIG. 4 shows the strips  36  lining the upper portion of the inside surfaces of the front panel  12 , back panel  14  and side panels  16 . In operation as previously described, as the front panel  12  is pulled forward towards the back panel  14 , the side panels  16 A and  16 B fold upon each other so that the strip  36  attached to the side panel  16 A releasably secures to the strip  36  attached to the inside front panel  12 . The strips  36  of the side panels  16 B engage the strip  36  attached to the inner surface of the back panel  14 . When the backpack  2  is in the closed position as shown in FIG. 1, the panels  12 ,  14  and  16  are releasably secured to each other as described above by the releasable attachment means  34 . This provides an added measure of security when the backpack  2  is worn by the user. 
     In another embodiment of the invention, the strap guide means  26  is comprised, not of upstanding loops  28  and  30  but of back panel openings  52  and double side panel openings  54  as hereinafter described. In addition, the front strap securing device  22  is secured to the inside surface of the front panel  12  so that the strap may be aligned with the openings  52 ,  54  as described hereinafter. 
     Referring specifically to FIGS. 5-8, the strap guide means  26  includes back panel openings  52  and double side panel openings  54 . The openings  52  in the back panel appear in the relatively same position as the upstanding loops  28  shown in FIG.  4 . The openings, however, are within the back panel  14  and enable the strap arms  18  to extend from the back strap securing device  20  to the front strap securing device  22 . 
     Each of the side panels  16 A and  16 B are provided with openings  54  near the fold line separating the panels  16 A and  16 B from each other. The operation of the embodiment of FIGS. 5-8 is essentially the same as that of the embodiment of FIGS. 1-4. As the user puts the strap arms  18  around the shoulder, the strap arms  18  together apply a force on the front strap securing device  22  pulling the front panel  12  towards the back panel  14 . The position of the double openings  54  in the side panels  16  causes the side panels  16 A and  16 B to fold one upon the other until the backpack  2  assumes the closed position as shown in FIG.  5 . 
     As previously described in connection with the embodiments of FIGS. 1-4, the backpack  2  shown in FIGS. 5-8 may be provided with a flap  24  and a releasable attachment means  34  which may be comprised of releasably securable strips  36  (e.g. hook and eye strips sold under the trademark Velcro) to provide a further means of securing the backpack  2  in the closed position. 
     The embodiments shown in FIGS. 1-8 are illustrative of the structure and operation of the present invention. It will be understood that modifications to the present invention can be made within the spirit and the scope of the invention as covered by the claims presented herein.