Abstract:
The invention relates to a backpack with extendable wheels which extends to the ground, composed of a left and right shaft which contains the left and right shaft extension containing at one end a left and right pivoting wheel, which come in contact to the ground, therefore reducing the weight of the backpack and also contains a left and right shoulder strap and a waist belt, which also contribute to the load supporting features of the backpack wheel extension.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a backpack, particularly a backpack with wheel extensions. The invention relates to a backpack with a extendable left wheel and a extendable right wheel which can be extended from the backpack all the way to the ground, whereby transferring the load of the backpack to the ground surface therefore reducing the weight of the backpack. The backpack wheel extension also consists of shoulder straps and a waist belt, which also contribute to the load bearing functions of the backpack. 
       BACKGROUND OF THE INVENTION 
       [0002]    Backpacks have commonly been used in activities like hiking, climbing and military activities to carry various items such as clothing, equipments, weapons and various other items. Typical backpacks consists of a shoulder harness that extends over one or both of the wearer&#39;s shoulders in conjunction with a waist belt that wraps around the wearer&#39;s waist. The shoulder harness and the waist belt allow the load of the backpack and its contents to be distributed over both the wearer&#39;s shoulders and waist only, whereby the total weight of the backpack and its contents are still supported by the body of the wearer. Various backpack suspension systems have been developed to shift and redistribute the load from the shoulders to waists to make it feel like the weight of the backpack has been reduced, but in reality the weight has not been reduced but only redistributed and the wearer&#39;s body is still bearing the weight of the load. In addition there has been exoskeletons that bear the weight of the load placed on it, whereby transferring the weight to the ground. These exoskeletons are not incorporated into the backpack and are not supported by the backpack, they are independent exoskeletons wherein the load carrying backpack is placed onto the exoskeleton. These independent exoskeletons are bulky units. There is also an exoskeleton that is incorporated into the backpack and attached to the legs of the wearer. This type of exoskeleton, inhibit the free movements of the legs of the wearer. 
         [0003]    Therefore, there remains a need in the art for a backpack with extendable wheels incorporated into the construction of the backpack whereby the extendable wheels are carried by the backpack and utilized when needed by the wearer of the backpack while wearing the backpack and not hindering the normal movements of the wearer while the extendable wheels are extended to come in contact with the ground. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention relates to a backpack, particularly a backpack wheel extension, which is a backpack with extendable wheels. The invention relates to a backpack with built-in extendable wheels, which transfers most of the weight of the backpack to the ground surface. The wearer of the backpack wheel extension can engage and disengage the extendable wheels when desired while wearing the backpack. The backpack wheel extension contains two extendable wheels located on the end of, a right shaft extension and a left shaft extension, which can be extended from the backpack wheel extension to come in contact with the ground. The right shaft extension and the left shaft extension are located within the right shaft and left shaft respectively wherein the right and left shaft are fixed to the frame of the backpack and become a part of the frame. When the backpack wheels are extended all the way to the ground, the weight of the backpack is supported by the ground and wearer. There are three structures, which help support and transfer the weight of the backpack to the ground surface, which are the shoulder straps, a waist belt and the extendable wheels. The shoulder straps aid the wearer by holding the top weight of the backpack closer to the wearer&#39;s body and aligning the weight whereby allowing a more efficient transfer of weight to the ground surface. The waist belt aids in redistributing and aligning the weight over the waist of wearer. The extendable wheels transfers the majority of the weight of the backpack to the ground and the wheels give the wearer mobility to drag the backpack around instead of carrying the weight. The wheel extension for the backpack wheel extension can be utilized in an external or internal backpack frame as well as a center or sides frame structures. The wheel extension can also be an accessory for an existing backpack. 
         [0005]    The backpack wheel extension contains a right shaft, which holds a right shaft extension, which can be extended all the way to the ground or stored by retracting it all the way up the right shaft. At one end of the right shaft extension is a right pivoting wheel, which is able to move in all directions the wearer is able to move. The backpack wheel extension also contains a left shaft, which holds a left shaft extension, which can be extended all the way to the ground or stored by retracting it all the way up the left shaft. At one end of the left shaft extension is a left pivoting wheel, which is able to move in all directions the wearer is able to move. 
         [0006]    The shaft extension contains shaft extension holes, which are used to adjust for the different heights of the wearer. Located on the shaft are the top shaft pin, the bottom front shaft pin and the bottom back shaft pin. The bottom front shaft pin protrudes through the front shaft adjustment holes and the bottom back shaft pin protrudes through the back shaft adjustment holes and also protrudes through the corresponding shaft extension holes to fix the position of the shaft extension. The shaft pins are spring loaded and the wearer has only to press the bottom front shaft pin and the bottom back shaft pin at the same time to move out of one hole to the next hole and then release the shaft pins whereby adjusting the length of the right and left shaft extensions. The top shaft pin is used to store the shaft extension with the wheel in the up position, by pushing the shaft extension up through the shaft and engaging the top shaft pin. Once the top shaft pin is engaged, the pin protrudes through the shaft top hole and also protrudes through the shaft extension holes whereby locking the shaft extension in the up position. The wearer can release the shaft extension form its stored position by pressing down on the top shaft pin whereby extending the shaft extension to the ground. When the wearer is standing still and straight with the wheels in the down position, the wearer will feel as if there is no weight to the backpack. When the wearer is walking or running with the backpack wheel extension leaning on the wearer at an angle, the wearer will feel as if the wearer is only pulling a small fraction of the weight of the backpack. When the wheels are in the up position, the wearer is carrying all of the weight of the backpack wheel extension. There is another embodiment of the present invention where the wearer can carry any item on the wheel extension carrier. The only difference being that the wheel extension carrier has load platform where a load is placed on it and a load strap, which holds the load in place. 
         [0007]    These and other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustrations only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings, which are given by way of illustration only and are not limitative of the present invention, wherein: 
           [0009]      FIG. 1  is a side perspective view of the backpack wheel extension with the legs down; 
           [0010]      FIG. 2  is a side perspective view of the backpack wheel extension with the legs up; 
           [0011]      FIG. 3  is a front exploded view of the left shaft; 
           [0012]      FIG. 4  is a side perspective view of the left top shaft pin; 
           [0013]      FIG. 5  is a side perspective view of the left shaft extension; 
           [0014]      FIG. 6  is a side perspective view of the left shaft extension stored within the left shaft; 
           [0015]      FIG. 7  is a side perspective view of the left shaft extension extended within the left shaft; 
           [0016]      FIG. 8  is an illustrative view of the left side of the backpack wheel extension with the wheels up; 
           [0017]      FIG. 9  is an illustrative view of the left side of the backpack wheel extension with the wheels down; 
           [0018]      FIG. 10  is an illustrative view of the right side of the backpack wheel extension with the wheels down; 
           [0019]      FIG. 11  is an illustrative view of the front side of the backpack wheel extension with the wheels down; 
           [0020]      FIG. 12  is a perspective view of a wheel extension carrier; 
           [0021]      FIG. 13  is a illustrative view of the left side of the wheel extension carrier. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Referring now to the drawings wherein the depictions are for purposes of illustrating a preferred embodiment of the present invention only and not for the purpose of limiting the same.  FIG. 1  is a side perspective view of a backpack wheel extension  100  of the present invention. The backpack wheel extension  100 , has wheels which extends to the ground whereby transferring the weight of a backpack  12  to the ground. Attached to a backpack frame  10  are a left shaft  20  and a right shaft  40  and contained within the shafts are a left shaft extension  22  and a right shaft extension  42  respectively, which extends downwards to the ground. At one end of the left shaft extension  22  is a left pivoting wheel  30  and at one end of the right shaft extension  42  is a right pivoting wheel  50 .  FIG. 2  is a perspective view of the backpack wheel extension  100  with the left shaft extension  22  and the right shaft extension  42  stored with the wheels in the up position within the left shaft  20  and the right shaft  40  respectively.  FIG. 2  depicts a left shoulder strap  14  and a right shoulder strap  15 , which aids in supporting the weight of the backpack  12  by the shoulders of the wearer. A waist belt  16  goes around the wearer&#39;s waist and is held together by a waist strap  18 , which aids in redistributing the weight over the waist of user. 
         [0023]      FIG. 3  is a front exploded view of the left shaft  20 . The left shaft  20  consists of a left top shaft pin  26  located on the top of the left shaft  20  and aids in holding the left shaft extension  22  in the stored position on the backpack wheel extension  100 . The left top shaft pin  26  protrudes into a left shaft top hole  24 . Located on the bottom of left shaft  20  are a left bottom front shaft pin  27  and a left bottom back shaft pin  28  and these pins aid in the adjustment of the left shaft extension  22 . The left bottom front shaft pin  27  protrudes into a left front shaft adjustment hole  25  and the left bottom back shaft pin  28  protrudes into a left back shaft adjustment hole  21  located on the left shaft  20 . The shaft pins are fixed to the left shaft  20  and are spring loaded therefore the force of the spring is always pushing down on the shaft pin into the opening on the left shaft  20 . 
         [0024]      FIG. 4  is a perspective view of the left top shaft pin  26 . The left top shaft pin  26  is held by a pin holder  32 , which is fixed to the left shaft  20 . The pin holder  32  also holds a spring  34 , which pushes the top shaft pin  26  into the left shaft top hole  24 . 
         [0025]      FIG. 5  is a side perspective view of the left shaft extension  22 . At one end is a left shaft extension holes  23 , which are used for adjusting the height of the left shaft extension  22  and the other end contains the left pivoting wheel  30 . The left shaft extension holes  23  have corresponding holes on either sides of the left shaft extension  22 .  FIG. 6  is a side perspective view of the left shaft extension  22  stored with the wheels in the up position within the left shaft  20 .  FIG. 6  depicts the left top shaft pin  26  protruding through the left shaft top hole  24  and also through the left shaft extension holes  23  located on the left shaft extension  22  whereby holding the left shaft extension  22  in the stored position. The left bottom front shaft pin  27  and the left bottom back shaft pin  28  protrude partial through the left front shaft adjustment hole  25  and the left back shaft adjustment hole  21  respectively and rests on the left shaft extension  22 , since there are no holes at the bottom of the left shaft extension  22 . 
         [0026]      FIG. 7  is a side perspective view of the left shaft extension  22  extended with the wheels in the down position within the left shaft  20 .  FIG. 7  depicts the left top shaft pin  26  protruding through the left shaft top hole  24 . At the same time the left bottom front shaft pin  27  protrudes through the left front shaft adjustment hole  25  and through the left shaft extension holes  23 , and the left bottom back shaft pin  28  protrudes through the left back shaft adjustment hole  21  and through the corresponding left shaft extension holes  23  and locks the left shaft extension  22  in position. 
         [0027]      FIG. 8  is an illustrative view of the left side of the backpack wheel extension  100  with the wheels up.  FIG. 8  depicts the whole weight of backpack wheel extension  100  is supported by the wearer. This is like a typical backpack wherein the weight is supported by the left shoulder strap  14 , the right shoulder strap  15  and the waist belt  16 .  FIG. 9  is an illustrative view of the left side of the backpack wheel extension  100  with the left shaft extension  22  down, with the wheels in contact with the ground. The majority of the weight of the backpack wheel extension  100  is transferred to the ground and only a small portion is supported by the wearer.  FIG. 9  depicts the wearer as walking with backpack wheel extension  100 , wherein the backpack wheel extension  100  is in an angled position, leaning on the back of wearer, whereby the wearer is pulling the weight of the backpack wheel extension  100  instead of carrying the whole weight. The left pivoting wheels  30  allows the wearer to move in all direction by pulling the backpack wheel extension  100  to move forward and by pushing the backpack wheel extension  100  to move backward.  FIG. 10  is an illustrative view of the right side of the backpack wheel extension  100  with the right shaft extension  42  with the wheels in the down position, wherein the right pivoting wheel  50  is in contact with the ground. The right shaft extension  42  is inserted within the right shaft  40  and locked in position by a right bottom front shaft pin  47  protruding through a right shaft extension holes  43 , and a right bottom back shaft pin  48  protruding through the corresponding right shaft extension holes  43 . A right top shaft pin  46  located on top of the right shaft  40  protrudes through right shaft  40  and is utilized when the right shaft extension  42  is ready to be pulled up and stored with the wheels in the up position.  FIG. 10  depicts the wearer standing still and straight with the backpack wheel extension  100 . When the wearer stands straight the majority of the weight of the backpack wheel extension  100  is transferred to the ground and it will feel as if there is no weight, whereas when the wearer is walking with the backpack wheel extension  100  as in  FIG. 9 , the wearer is pulling the weight at an angle and it will feel as if the wearer is only pulling a small fraction of the weight and  FIG. 8  depicting the wearer carrying all of the weight with the wheels in the up position. 
         [0028]      FIG. 11  is an illustrative view of the front side of the backpack wheel extension  100 .  FIG. 11  depicts the left shaft extension  22  with the left pivoting wheel  30  and the right shaft extension  42  with the right pivoting wheel  50  in contact with the ground. The left shaft extension  22  and the right shaft extension  42  are positioned on the outside and behind the legs of wearer, therefore not hindering the movements of the wearer when the wearer is walking or running. 
         [0029]      FIG. 12  depicts another embodiment of the present invention where items can be placed on a wheel extension carrier  200 . The only difference with the wheel extension carrier  200  is that it contains a load platform  19  and a load strap  13  instead of the backpack  12 .  FIG. 13  is an illustration of a load  17  being placed on the load platform  19  and held in place with the load strap  13 .