Backpack with removable wheels

Abstract

Rollers are fastened to a chassis which is removably held to a bottom of a backpack by hook and loop fasteners. The rollers are on legs which are rotatably mounted at one end so the rollers can be moved from a first, compact position to a second, expanded position to provide better stability to the backpack which rests on the rollers. Another hook and loop area on the backpack can be used to store the rollers and chassis when they are removed from the bottom of the backpack.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of provisional patent application No. 60/437,634 filed Jan. 31, 2002, the complete contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] This invention relates to a method and apparatus for selectively providing a backpack with wheels to facilitate movement of the backpack while removing the wheels when the wheels are not in use.

[0003] Students often use backpacks to carry school supplies and books. The backpacks often become very heavy, especially when many books are carried home or carrued between classes. Heavy backpacks can harm the students, especially by weakening or injuring the backs of the students carrying the heavy backpacks. Putting wheels on the backpacks allows the backpacks to be pulled, and reduces the amount of weight that must be carried. But the wheels present problems when the backpacks are put on a person's back, as the wheels may collect debris from the ground and the debris rub off on the student's backs when the backpacks are worn, or the wheels hit other students causing injury or transferring debris. There is thus a need for a backpack which can be pulled on wheels, +but which avoids the disadvantages of having exposed wheels when the backpack is worn on a person's back.

[0004] In some circumstances there may also be a social stigma or disincentive for using wheels on backpacks. Some people just don't want to be seen pulling a backpack on rollers or seen having a backpack with rollers. There is thus a need for a backpack with wheels that can be easily and quickly removed from the backpack.

SUMMARY OF THE INVENTION

[0005] One or more rollers are removably fastened to a backpack by use of hook and loop fasteners on the backpack and on a roller assembly. Advantageously there are four rollers fastened to a chassis, with the rollers being mounted to movable support legs which allow the rollers to separate and provide a larger and more stable support. The chassis is sufficiently large to provide enough area for the hook and loop fasteners to keep the rollers and chassis fastened to the backpack during use. A separate patch of hook or loop material can be fastened to the backpack to allow the rollers to be removed from the bottom of the backpack, and placed on the patch to be held in a storage or non-use location.

[0006] One embodiment of the invention thus comprises a wheeled back pack having at least one roller and means for removably fastening the at least one roller to the backpack. Advantageously the backpack has one of a hook or loop fastener on an exterior of a bottom of the back pack. A mounting chassis has the other of a hook or loop fastener fastened to the chassis so the chassis can be removably connected to the backpack. At least one roller is mounted to the chassis and preferably there are a plurality of rollers connected to the chassis.

[0007] Moreover, it is preferable that each roller is connected to a support which is mounted to and rotates relative to the chassis to allow the support to change position relative to the chassis. In a preferred embodiment there are four rollers each connected to a separate support. The support advantageously has a first end rotatably fastened to the chassis to rotate in a plane to allow positioning of the wheels relative to each other parallel to that plane.

[0008] In a further variation, the backpack has the one of the hook or loop fasteners at two locations, one location for holding the rollers during use, and one location for holding the rollers during non-use, with each of the fasteners being of sufficient size to hold the chassis to the backpack. In still further variations, the backpack has two shoulder straps for carrying the backpack and the chassis is removably fastened by the hook and loop fasteners to either a side or a bottom of the backpack.

[0009] This invention also includes a method of fastening wheels to a backpack, including placing one of a hook or loop fastener on a backpack at a first location on an exterior side, bottom or back of the backpack. The method further includes placing the other of a hook or loop fastener on a chassis. At least one roller is fastened to the chassis, with the hook and loop fasteners being of sufficient size to hold the chassis to the back pack when the backpack rests on the wheels and is rolled on a floor during use of the backpack.

[0010] In a further embodiment the method includes fastening each roller to a support that is movably relative to the chassis so the rollers can be positioned relative to each other. Advantageously, but optionally, the method includes fastening a mating hook or loop material to the backpack at a second location on a side, front or back of the backpack. Further, a pulling strap can also be fastened to the backpack. In the most preferred embodiment, the method includes fastening two shoulder straps to the backpack and located so a person's arms can fit through the straps and carry the backpack on a back of the person.

[0011] These and other advantages of the invention will become more apparent in connection with the following drawings in which like numbers refer to like or corresponding parts throughout the description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a perspective view of a roller assembly and strap for use with a backpack;

[0013] FIG. 2 is a perspective view of the bottom of the roller assembly of FIG. 1 in a retracted position;

[0014] FIG. 3 is a perspective view of the bottom of. the roller assembly of FIG. 1 in an expanded position;

[0015] FIG. 4 is an exploded perspective view of a roller assembly and fastening mechanism as partially shown in FIG. 1;

[0016] FIG. 5 is a perspective view of the bottom of the roller assembly of FIG. 1 before being fastened to a backpack;

[0017] FIG. 6 is a perspective view of the bottom of the roller assembly of FIG. 1 after being fastened to a backpack;

[0018] FIG. 7 is another perspective view of the backpack of FIG. 6;

[0019] FIG. 8 is a perspective view of the backpack of FIGS. 5-7 with the roller assembly stored on the backpack; and

[0020] FIG. 8 is a perspective view of the bottom of the roller assembly of FIG. 1 fastened to a container.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring to FIGS. 1, 5 and 6, a roller assembly 10 is provided which is removably fastened to a backpack 12 by hook or loop fasteners 14 having hooked portion14a and loop portion 14b. The roller assembly 10 has one or more rollers 16 with the illustrated embodiment having four rollers to provide a more stable support for the backpack 12. Advantageously, but optionally, each roller is mounted to a frame or chassis 18 rather than being separately mounted to the backpack, with the chassis 18 having one of the hook or loop fasteners 14a, 14b so the chassis can be mounted to the backpack 12 which contains the other of the hook or loop fasteners 14a, 14b. Further, the rollers 16 are preferably, but optionally mounted to supports 20 which are fastened to the chassis 18 and movable relative to the chassis so the rollers 16 can be spread apart to provide a wider support for the backpack 12. A pulling strap 22, preferably a removable strap, is fastened to the backpack 12 to allow the backpack to be pulled over the ground or other surfaces during use. When the backpack is not in use, the hook and loop fastener 14 allows removal of the roller assembly 10, which may then be stored inside the backpack, or alternatively fastened to a storage hook or loop area 24 which is located on the outside or inside of the backpack, or located elsewhere, as in a locker of the user.

[0022] Referring to FIGS. 1-4, the roller assembly 10 is further shown. In its simplest form the roller assembly 10 includes a roller 16 having a surface suitable for fastening to the hook and loop material 14. Referring especially to FIG. 4, the rollers 16 advantageously comprise commercially available casters which rotate about at least a first axis 26 which is typically parallel to the ground during use of the roller assembly. The rollers 16 preferably also advantageously also rotate about a second axis 28 which is orthogonal to the first axis 26, and which is typically vertical during use of the roller assembly 10. The casters 16 typically have a mounting plate 30 which accommodates a bushing or bearing and allows rotation about the second axis 28. In its simplest form the roller assembly fastens one of the hook or loop portions 14a, 14b to the mounting plate 30 for fastening to the backpack 12.

[0023] Preferably though, there are a plurality of rollers 16 each of which is fastened to the chassis 18. The mounting plates 30 of each roller 16 may be fastened directly to the chassis 18 by passing threaded fasteners through holes 32 in the mounting plate or otherwise securing the mounting plate to the chassis using various known fastening mechanisms including adhesives, welding, sewing, and other known means. But advantageously the rollers 16 are each mounted to a support 20 which is in turn fastened to chassis 18.

[0024] The supports 20 are shown as comprising flat, elongated metal plates with a roller 16 fastened to a distal end of the plate, and with the opposing end movably fastened to the chassis 18, which is also preferably a metal plate. Edges of each plate can be rolled to form stiffening ribs to strengthen the supports 20 or chassis 18. Other stiffening mechanisms can be used, such as internally located ribs. Because of the elongated nature the supports 20 will be referred to as support legs 20, but various shapes could be used. Passing an impact rivet 33 through a hole 34a (FIG. 4) in the movable end of the support leg 20 and a mating hole 34b in chassis 18, and forming an enlarged head on opposing ends of the rivet, allows the support leg to be rotably fastened to the chassis 18. Bearing assemblies, pin and clevis arrangements and other rotatable connections could be used, but the a rivet loose enough to allow rotation allows a low profile, inexpensive connection that is believed to be sufficiently durable for the intended use on a backpack with shoulder-carrying straps.

[0025] Advantageously each support leg 20 has a detent mechanism to hold the support legs 20 in a desired orientation relative to the chassis 18. One way to form the detent mechanism is to have one or more projections 36 or one or more recesses 38 which removably receive a mating projection 36 or recess 38 on the adjacent side of the chassis 18. The recess 38 could be on either, or both of the support leg 20 and chassis 18, with the mating projection 36 located on the other of the support leg 20 and chassis 18. Other types of detent mechanisms could be used, and other position retention mechanisms could be used, including frictional position mechanisms.

[0026] Still referring to FIG. 4, a clamp plate 40 is adjustably urged against one or more of the rotatable ends of the support legs 20 to hold the legs 20 in a desired position. This can be achieved several ways, but the illustrated embodiment uses a threaded post 42 extending from the chassis 18. Advantageously, but optionally, the threaded post 42 is formed by a flat headed screw which extends through a countersunk hole in the chassis 18 and through a corresponding hole in clamp plate 40. A nut or preferably a manually grippable knob 44 fastens onto the distal end of the post 42. By tightening the knob 44 the clamp plate 40 can force a portion of the support legs 20 against the chassis and restrain movement of the legs 20. Other clamping mechanisms known to those skilled in the art could be used given the present disclosure.

[0027] Referring to FIGS. 2-4, the projections and recesses 36, 38 are located on a longitudinal axis of each support leg 20, but they could be located elsewhere. In the depicted location, the projections and recesses 36, 38 engage to maintain the support legs 20 along two parallel lines, and keep the rollers 16 in pairs in which two rollers are adjacent each other. This provides a compact storage configuration. The rotatable connection of the support legs 20 to the chassis 18 allows the support legs to rotate so the rollers 16 move away from each other into an expanded position as shown in FIG. 3. The rollers 16 and support legs 20 can be maintained in this expanded position by providing a detent mechanism as previously described. But preferably the knob 44 is tightened to releasably clamp the legs 20 into position. In the expanded position the support legs 20 are advantageously aligned along two intersecting lines, generally forming a cross or X.

[0028] One or more of the detent mechanism, the tightening knob and the other releasable fastening mechanisms thus provide means for releasably fastening the support legs 20 in position, either in the storage position, or in the expanded position which is believed preferable for use of the roller assembly, as described later.

[0029] Referring to FIGS. 4 and 5, the side of the chassis 18 opposite the rollers 16 has a surface to which is fastened one of a hook or loop fastener 14a, 14b. For illustration a hook material 14a is shown, but it could be the loop material 14b. Adhesives can fasten the hook material 14a to the chassis. A hook material with a self-adhesive backing is believed suitable. Advantageously the hook material 14a has holes cut through it so that various fasteners, such as rivets 33 can pass through and do not impede the use of the hook material adjacent the fasteners and holes. A corresponding amount of loop material 14b is fastened to the backpack 12. Preferably the loop material 14b is fastened by adhesives, but it could be fastened by other known mechanisms, such as sewing, rivets, etc. In use, hook and loop materials 14a, 14b abut and engage in order to releasably fasten the roller assembly 10 to the backpack 12.

[0030] The strap 22 is fastened to the backpack 12 and used to pull the backpack so it rolls along the ground or other surface on rollers 16. Depending on the size and shape of the backpack, and the contents of the backpack, the size of the roller assembly may vary. In the compact configuration shown in FIG. 5, the rollers 16 are aligned in a narrow rectangle with the four rollers in two pairs, and the rollers in each pair being next to each other. That configuration will work for light loads and smaller backpacks when the backpack towed along the ground. For larger or heavier backpacks 12, the rollers 16 may be spread apart and held in place by the detent mechanism. Preferably though the clamp plate 40 and knob 44 are used as shown in FIG. 6. The knob 44 is loosened to move the rollers 16 into a spread apart position, and then the knob is tightened to hold the rollers in position. The spread apart rollers 16 provide a wider base and a more stable rolling support for the backpack 12. The spread.apart rollers 16 are also useful on those backpacks 12 which have a flexible bottom. Advantageously, the backpack 12 has a stiffener in the bottom of the backpack, such as a piece of plastic or cardboard as are typically used. That helps prevent the edges of the backpack 12 from hanging over the rollers 16 and rubbing on the ground. The spread apart configuration of FIG. 6 helps distribute the weight on the bottom of the backpack over the chassis and support legs 20, and provides a better and more stable support for the backpack.

[0031] Referring to FIGS. 7-8, when the roller assembly 10 is not in use or not being used to roll the backpack on the ground, the assembly 10 may be removed at the option of the user. Preferably, but optionally, a storage patch 46 of hook or loop material is placed on the backpack 12 so the roller assembly 10 may be held by the storage patch of material. Whether the patch 46 is formed of a hook material 14a or loop material 14b depends on what material is fastened to the chassis 18, as the patch 46 must be the opposite so it will cooperate to form a hook and loop connection. The storage patch 46 is shown located on one side of the backpack 12, but it could be on the top, or the front of the backpack, or it could be on the inside of the backpack. The roller assembly 10 could also be simply placed inside the backpack, or in a pocket on the backpack 12, with or without a storage patch 46 of hook and loop material to hold the roller assembly 10 in position. Similarly, a storage patch 46 could be fastened to the inside of a school locker or a user's closet or wall in order to store the roller assembly 10 when not in use.

[0032] The roller assembly 10 can be made of various materials. A 16 gauge galvanized plate is believed suitable for the support legs 20, especially with rolled edges on the plate to form stiffeners. Legs 20 formed of molded polymer are also believed suitable. Various shapes of supports 20 and chassis 18 can be used, but the flat plates allow a low profile for the roller assembly and that keeps the center of gravity of the rollers and backpack closer to the ground, and thus provides a more stable assembly.

[0033] The roller assembly 10 can be used with ordinary, commercially available backpacks 12 which are not specifically designed for use with the roller assembly. Advantageously the backpacks 12 have a stiffened bottom, with a stiffening plate (not shown) in the bottom of the backpack so the edges of the backpack do not sag over the rollers 16 and rub on the ground. But such stiffening plates are not required. As used here, the backpack 12 is preferably of the type that has at least one flexible side with two shoulder straps 48 fastened to the backpack so a user can place a strap over each of the user's arm to carry the backpack on the back of the user. But the use of the roller assembly 10 is not limited to this type of container, and the term “backpack” is to be construed broadly to include any type of container, especially containers having one or more flexible sides, unless specifically described otherwise. The use of backpacks with arm straps 48 is advantageous, because the arm straps can be grabbed to pull the backpack 12 on the roller assembly 10 so the separate pulling strap 22 is not needed.

[0034] Alternatively, the pulling strap 22 can encircle one or both of the arm straps 48 to allow the user to pull the backpack 12 on the roller assembly 10. The pulling strap 22 advantageously, but optionally has hook and loop material along a length of the strap adjacent the end fastened to the backpack, in order to allow flexibility in fastening the pulling strap 22 to the backpack 12. The pulling strap 22 can fasten to a mating piece of hook and loop material, or it can encircle a D ring fastened to the backpack 12, or it can fasten to other suitable portions of the backpack by means known to one skilled in the art.

[0035] The roller assembly 10 can be releasably fastened to the backpack 12 by using releasable attachments other than hook and loop fasteners 14. Snap-lock fasteners could be used but are not as desirable as they are more difficult to engage and disengage. The hook and loop material 14 allows easy removal and reattachment of the roller assembly and is thus preferable. The hook and loop material 14 must be large enough to prevent the roller assembly from disengaging from the backpack during use when the backpack is being pulled across the ground, down the sidewalk, over curbs, and during other uses of the backpack when the rollers 16 are attached. An area of about 12 square inches of hook and loop material 14 is believed suitable for Nylon hook and loop fasteners. The hook and loop material 14 is advantageously made of Nylon or other polymer, but they could be made of metal such as aluminum or steel, in order to allow larger forces to be transmitted. Depending on the type and construction of the hook and loop fasteners, different areas of material may be needed for the hook and loop material 14.

[0036] Referring to FIG. 9, the roller assembly 10 can be fastened to a container 50 having any of a variety of shapes. The roller assembly 10 in FIG. 9 can have the hook and loop material 14 mating with a corresponding material 14 on the container. But alternatively, the hook and loop material 14 can be omitted from the container 50, or the roller assembly 10, and the roller assembly fastened to the container 50 by other mechanisms, such as strap 52. The straps 52 can go through apertures or slots 54 (FIG. 4) on opposing sides of the chassis 18 to fasten the straps 52 directly to the chassis. Alternatively, the straps 52 can go on the exterior side of the support legs 20 and chassis and urge those parts against the container 50, but that is less desirable. The pulling strap 22 can be fastened to one of the straps 52 which fasten the container 50 to the roller assembly 10.

[0037] The invention also includes a kit, comprising the roller assembly 10 with chassis 18 and rollers 16, and a suitable piece of hook and loop material 14a, 14b to mount the roller assembly 10 to the backpack 12. In the kit, the piece 14b of hook or loop material 14 advantageously has a self adhesive on the back of the piece 14b of hook or loop material so it may be fastened to the back pack 12. Alternatively, a vial of adhesive can be provided to fasten the hook or loop material 14 to the backpack. If the roller assembly does not have any hook and loop material on the chassis 18, then the kit advantageously includes a piece of hook and loop material. The kit also advantageously, but optionally, includes the pulling strap 22.

[0038] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

[0039] The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention, including various ways of forming the roller assembly of one or more rollers, and various ways of removably fastening the roller assembly to the backpack. Further, the various features of this invention can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the invention is not to be limited by the illustrated embodiments but is to be defined by the following claims when read in the broadest reasonable manner to preserve the validity of the claims.

Claims

1. A wheeled back pack, comprising:

a backpack;

at least one roller;

means for removably fastening the at least one roller to an exterior surface of a bottom the backpack.

2. The back pack of claim 1, wherein the means comprise hook and loop fasteners.

3. A wheeled backpack, comprising:

a backpack having a bottom and a side, with one of a hook or loop fastener fastened to the backpack using the hook or loop fastener;

a mounting chassis having the other of a hook and loop fastener fastened to the chassis so the chassis can be removably connected to the backpack;

at least one roller mounted to the chassis.

4. The backpack of claim 3, wherein the at least one of the hook and loop fastener if fastened to an exterior surface of the bottom of the backpack.

5. The backpack of claim 3, wherein the chassis comprises a plate with the other of the hook or loop fastener fastened to a first side of the plate.

6. The backpack of claim 5, wherein there are a plurality of rollers connected to the chassis.

7. The backpack of claim 3, wherein there are a plurality of rollers at least some of which are connected to at least one support which moves relative to the chassis to allow the support to change a position of the roller connected to that support.

8. The backpack of claim 3, wherein there are four rollers each connected to a support having a first end rotatably fastened to the chassis.

9. The backpack of claim 3, wherein there are four rollers each connected to a support having a first end rotatably fastened to the chassis to rotate in a plane to allow positioning of the wheels relative to each other parallel to that plane.

10. The backpack of claim 3, wherein there are four rollers each connected to a support having a first end rotatably fastened to the chassis to rotate in a plane, the rollers and supports having a first position in which the supports are substantially parallel and a second position in which the supports are aligned along intersecting lines.

11. The backpack of claim 3, wherein there are four rollers each connected to a support having a first end rotatably fastened to the chassis to rotate in a plane, the rollers and supports having a first position in which the rollers are adjacent each other, and a second position in which the rollers are spaced further apart than in the first position.

12. The backpack of claim 3, wherein the backpack further has the at least one of the hook or loop fasteners at two locations, and each of sufficient size at each location to hold the chassis and rollers to the back pack.

13. The backpack of claim 3, wherein the backpack has two shoulder straps for carrying the backpack and the chassis is removably fastened by the hook and loop fasteners to either a side or a bottom of the backpack.

14. A method of fastening wheels to a backpack, comprising:

placing one of a hook or loop fastener on a backpack at a first location on a side, bottom or back of the backpack;

placing the other of a hook or loop fastener on a chassis;

fastening at least one roller to the chassis, the hook and loop fasteners being of sufficient size to hold the chassis to the back pack when the backpack rests on the rollers and is rolled during use of the backpack.

15. The method of claim 14, further comprising the step of fastening each roller to a support movably extending from the chassis.

16. The method of claim 14, further comprising fastening each roller to a support having one end movably fastened to the chassis so the rollers can be positioned relative to each other.

17. The method of claim 14, further comprising, fastening a patch of the other of a hook or loop fastener to the backpack at a second location on a side, front or back of the backpack, and sizing the patch to hold the chassis and rollers.

18. The method of claim 14, further comprising fastening a pulling strap to the backpack.

19. The method of claim 14, further comprising fastening two shoulder straps to the backpack and located so a person's arms can fit through the arm straps and carry the backpack on a back of the person.