Abstract:
An improved backpack which includes a pack and a single shoulder strap. The single shoulder strap extends from a top corner of the pack to the lower corner on an opposite side from the top corner. The single shoulder strap allows the backpack wearer greater freedom of movement than conventional two shoulder strap backpacks.

Description:
FIELD OF THE INVENTION 
     The invention relates to a backpack. 
     BACKGROUND OF THE INVENTION 
     Conventional backpacks have two shoulder straps extending from the top to the bottom on the relevant side of the backpack. In numerous sport and leisure-time activities there are more or less pronounced movements of the arms at an angle to the direction of locomotion, frequently in the form of a pendulum movement, for example in inline skating or roller skating. The two shoulder straps of known backpacks greatly impair these arm movements. 
     SUMMARY OF THE INVENTION 
     The problem addressed by the invention is therefore to provide a backpack which ensures the greatest possible arm movement in such sport and leisure-time activities. 
     This is obtained according to the invention by providing the backpack with a main shoulder strap extending diagonally from one side at the upper end area of the backpack across the wearer&#39;s chest to the other side at the lower end area of the backpack. 
     Advantageous embodiments of the invention are characterized hereafter. 
     Due to the main shoulder strap extending over the shoulder and then downward diagonally across the chest in the inventive backpack, the upper area of the backpack is not fixed by a strap on the side where the lower end of the main shoulder strap is fastened, in contrast to known backpacks. This area of the backpack can thus move away from the wearer&#39;s back in uncontrolled fashion and thereby disturb the wearer in his movements. 
     In order to prevent this, the inventive backpack is preferably &#34;cut off&#34; diagonally in this area, so to speak. That is, the upper end area of the backpack slants downward in accordance with the diagonally extending main shoulder strap. The inventive backpack thus at the same time has a &#34;racy&#34; slanted look. 
     Movement of the arms at an angle to the direction of locomotion is usually accompanied by a lateral rotational movement of the wearer&#39;s upper body. 
     In order to be fixed securely on the back in the case of strong upper-body movements, the inventive backpack is therefore preferably provided with a stabilizing strap which extends from the lower end area on the side of the backpack where the main shoulder strap is fastened with its upper end, diagonally upward to the middle area of the main shoulder strap, and/or with an auxiliary shoulder strap which extends from the upper slanted end area of the backpack to the middle area of the main shoulder strap. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     In the following descriptions, an embodiment of the inventive backpack will be explained more closely by way of example with reference to the drawings, in which 
     FIGS. 1 and 2 show front and rear views of the backpack, however the auxiliary shoulder strap is stowed in FIG. 2. 
    
    
     DETAILED DESCRIPTION 
     Backpack 1 accordingly has main shoulder strap 2 which extends in FIG. 1 from the right upper end area of backpack 1 at 3 to the left side at 4 at the lower end area across the chest of the wearer (not shown). 
     Main shoulder strap 2 consists of upper portion 5 and lower portion 6 which are interconnected via buckle 7 such that the length of main shoulder strap 2 is adjustable. 
     In the area of its attachment points 3 and 4 to backpack 1 strap portions 5 and 6 are of broader design. This prevents main shoulder strap 2 from twisting. In addition it stabilizes backpack 1 on the back. The greater contact surface also prevents strap 2 from cutting into the shoulder. 
     On the left side of backpack 1, i.e. the side where the lower end of main shoulder strap 2 is fastened at 4, backpack 1 has upper end area 8 which slants in the same direction as main shoulder strap 2, i.e. from the right top to the left bottom in FIG. 1, and extends above main shoulder strap 2. Backpack 1 is thus diagonally cut off in this area, so to speak see also FIG. 2). 
     Upper slanted end area 8 has the opening (not shown) in backpack 1, which is covered by cover part 9 fastened to slanted end area 8 and adapted to be fastened to the back of backpack 1 with fastener 10 (FIG. 2). 
     Main shoulder strap 2 has in its middle area, i.e. in the area of upper portion 5, a plate-shaped slide 11 which is displaceable along main shoulder strap 2 in accordance with double arrow A in FIG. 1. 
     From the lower end area on the right side of backpack 1 (FIG. 1), i.e. the side where main shoulder strap 2 is fastened with its upper end, stabilizing strap 13 extends from 12 to slide 11 to which it is detachably fastened. For this purpose, the upper end of stabilizing strap 13 is drawn for example through clip or slot 14 on slide 11 and fixed thereto, e.g. by a Velcro (hook and loop fastener) closure 15. 
     A further stabilizing or auxiliary shoulder strap 16 extends from slanted upper end area 8 of backpack 1 to slide 11 to which it is detachably fastened. For this purpose the lower end of auxiliary shoulder strap 16 is for example, like stabilizing strap 13, drawn through clip or slot 17 on slide 11 and fixed with a Velcro closure 18. 
     Stabilizing strap 13 can also be used as a hip or belly strap. For this purpose the upper end of stabilizing strap 13, detached from slide 11, can be placed about the belly and fastened to the left side in the lower end area of backpack 1, for example by drawing this end through clip 19 fastened to backpack 1 at this place, and then fixing this end of stabilizing strap 13 with Velcro closure 15. 
     If stabilizing strap 13 is not required as a hip or belly strap it can be fastened to clip 19, while extending between backpack 1 and the wearer&#39;s back. 
     Auxiliary shoulder strap 16 is fastened with wide portion 20 to slanted upper end area 8 of the backpack. This causes it to lie, like main shoulder strap 2, on the wearer&#39;s left shoulder, safe from twisting with a wide contact surface on the wearer&#39;s other, i.e. right, shoulder. 
     The auxiliary shoulder strap can, in its state of nonuse detached from slide 11, be stowed in a pocket extending diagonally from the top to the bottom in upper slanted end area 8 of backpack 1 behind cover part 9, said pocket having opening 21 to be closed for example by a zipper. Portion 20 of auxiliary shoulder strap 16 can be made for example of a netlike material which is not only breathable but can also be stowed with little volume in the pocket in cover part 9. 
     If backpack 1 has little weight, it generally suffices to wear it only with main shoulder strap 2. In addition stabilizing strap 13 can be used as a belly or hip strap in this case. 
     If backpack 1 has greater weight and/or the wearer makes strong lateral movements of his upper body, stabilizing strap 13 can be fixed and tightened on slide 11, and/or auxiliary shoulder strap 16 stowed in the pocket in cover part 9 can be taken out and fixed and tightened on slide 11. 
     Slide 11 is thereby shifted along the middle area of main shoulder strap 2 into the optimal position along double arrow A, depending on whether only one of straps 13, 16 is fixed on slide 11 or both straps 13, 16, as shown in FIG. 1, i.e. if straps 13 and 16 cross main strap 2. 
     Case 22 can further be fastened to main shoulder strap 2. In addition whistle 23 can be provided in a corresponding receiving means in the upper area of main shoulder strap 2 on backpack 1, being fastened to backpack 1 with cord 24 or the like. 
     Backpack 1 can further have pocket 25 on its back with rearward openings 26 in which one can put for example a flashing light which shines through openings 26. 
     In cover part 9 there is a pocket with an opening to be closed by zipper 27 and extending diagonally downward in accordance with upper end area 8, which is accessible from outside. 
     The inventive backpack is intended in particular for in-line skaters and mountain bikers. However it can be used in general as a sport backpack, in particular for sports involving strong lateral upper-body movements, i.e. along with inline skaters, skateboarders and snakeboarders, roller skaters and ice skaters, for example also for skiers and snowboarders.