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 fig1 - 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 fig4 . 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 fig1 - 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 fig1 - 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 fig1 - 4 , the attachment of the strap arms 18 to the front and back panels is best illustrated in fig4 . as shown in fig4 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 fig4 . 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 fig1 - 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 fig1 and in the open position as illustrated in fig4 . in operation , the user places the backpack 2 in the open position as illustrated in fig4 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 fig4 . 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 fig4 to the position shown in fig1 . when the backpack is in the position shown in fig1 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 fig1 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 fig1 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 fig1 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 fig4 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 . fig4 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 fig1 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 fig5 - 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 fig4 . 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 fig5 - 8 is essentially the same as that of the embodiment of fig1 - 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 fig5 . as previously described in connection with the embodiments of fig1 - 4 , the backpack 2 shown in fig5 - 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 fig1 - 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 .
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 .