UNLOADING

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 61/878,767, WHEEL BARROW WITH IMPROVED STRUCTURE FOR LOADING AND UNLOADFNG, filed on September 17, 2013, which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention disclosed herein generally relates to an improved structure for a wheel barrow to provide efficient loading and unloading.

BACKGROUND

[0003] A modern wheel barrow generally has a single wheel mounted on an axle attached to a linear member on each side of the wheel which extends slightly in front of the wheel and extends significantly back from the wheel with a tub mounted and set back from the wheel, and located on the two linear members, and a leg connected to each linear member extending to the ground.

[0004] This design is generally used in modern wheel barrows to give the required functionality of being loadable/unloadable and mobile/stationary. To achieve loading, the unit is made stationary by locating it on its wheel and two legs and then the tub is loaded. To achieve unloading the handles of the unit are raised which initially causes the section of the frame in front of the wheel to make contact with the ground to stop the wheel from turning; then as the handles are raised further the wheel is raised off the ground allowing the handles to be moved forward as they are raised until they are in a substantially upright position.

SUMMARY OF THE INVENTION

[0005] The present invention relates to a wheel barrow that can include a tub, frame (which can include handles, hinges, legs and wheel mounting), single wheel, and linkages between the tub and frame that can be capable of movement in a parallel manner or approximately parallel which can raise and lower the tub relative to the ground. [0006] In some embodiments the movement can be controlled by at least one gearbox and/or the movement can be controlled by an electric motor.

[0007] In some embodiments, the gearbox can be a reduction gearbox so that rotating the input to the gearbox rotates the output at a slower rate. In some embodiments, the gearbox can include a brake, can be self-locking, and/or can have a handle for manual operation.

[0008] In some embodiments, the handle can each include two elements which can be folded together and/or the handles can be removed. In some embodiments, the handles can be hinged, need not be straight, can be semi-permanently locked in at least one position, and/or can hinge down toward the ground.

[0009] In some embodiments, the hinges can be non-perpendicular with respect to the line of the handles.

[0010] In some embodiments, the legs can be adjustable in length.

[0011] In some embodiments, the movement of the linkages can allow the tub to be moved in such a way that the base of the tub remains in the same orientation throughout the movement, to be raised to such a position that an evenly distributed load in the tub can be distributed with more than a quarter of the weight or more on the front wheel when the legs and wheel are on the ground, and/or to be raised to such a position that an evenly distributed load in the tub can be distributed with more than half the weight or more on the front wheel when the legs and wheel are on the ground. In some embodiments, at least two linkages can be connected to allow a single rotational input to be applied to both. In some embodiments, at least one linkage can be non-planar. In some embodiments, at least one linkage can be non-coplanar with another.

[0012] In some embodiments, the tub can remain approximately horizontal. In some embodiments, the back of the tub can be removable and/or rotatable with respect to any of its edges in contact with another edge of the tub. In some embodiments, the front of the tub can be removable and/or rotatable with respect to any of its edges in contact with another edge of the tub. In some embodiments, the front and/or back of the tub can be substantially perpendicular to the base of the tub. In some embodiments, the front and/or back of the tub can be angled in a manner other than perpendicular to the base of the tub. In some embodiments, the sides of the tub can be substantially perpendicular to the base of the tub. In some embodiments, the sides of the tub can be angled in a manner other than perpendicular to the base of the tub. In some embodiments, the tub can be supported directly on the frame in at least one position.

[0013] In some embodiments, the wheel can have a brake applied.

[0014] In some embodiments, a pallet can be used to load the tub.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Those of skill in the art will understand that the drawings, described below, are for illustrative purposes only. The drawings are not intended to limit the scope of the present teachings in any way.

[0016] Figure 1 is a simple sketch of the overall invention.

[0017] Figure 2 depicts the various positions of the tub of the wheel barrow

[0018] Figure 3 depicts the wheel barrow in a raised position

[0019] Figure 4 depicts the movement of the wheel barrow from a raised position to a lowered position.

[0020] Figure 5 depicts the various components of the wheel barrow.

[0021] Figure 6 depicts the various components of the wheel barrow.

[0022] Figure 7 depicts the wheel barrow in a lowered position with the frame handles folded down at the handle hinges.

[0023] Figure 8 depicts the wheel barrow in an upended position.

[0024] Figure 9 depicts an embodiment of the wheel barrow with the tub moved further over the front wheel.

[0025] Figure 10 depicts embodiments of the wheel barrow with bent handles and a non-perpendicular hinge which causes the handles to swing away from the tub when in their down position.

[0026] Figure 11 depicts an embodiment of the wheel barrow with variable leg lengths and pivot point positions.

[0027] Figure 12 depicts an embodiment of the wheel barrow with supports for the tub and/or load arms when the wheel barrow is in the raised position.

[0028] Figure 13 depicts an embodiment of the wheel barrow with a swing arm rotating around a brake pivot shaft constructed so that when the tub at its maximum height the frame brake is applied to the wheel. [0029] Figure 14 depicts an embodiment of the wheel barrow with a swing arm rotating around a brake pivot shaft constructed so that when the tub is at its standard raised position, the brake releases and when the tub is at its maximum height the brake is applied.

[0030] Figure 15 depicts an embodiment of the wheel barrow with the rear load arms shortened by an amount compared to the front load arms so that the base of the tub is horizontal relative to the ground when the wheel barrow is in motion.

[0031] Figure 16 depicts embodiments of the wheel barrow using pallets.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Embodiments of this invention maintain the existing functionality of loading/unloading and mobile/stationary but add an extra method to load the unit with less effort.

[0033] Embodiments of the invention relate to an improved design for a wheel barrow to provide an additional method of loading and unloading. The additional method of loading that separates it from existing designs is the ability to load the wheel barrow tub at ground level and then raise the tub to the standard position while maintaining the base of the tub largely horizontal. The movement of the tub is made possible by a parallel linkage to the frame consisting of 2 arms on each side of the tub. Through geometrical constraints, the arms keep the tub substantially horizontal throughout the entire movement. The ability to remove or rotate the back panel of the tub allows the tub to be loaded at ground level without having to raise the load over the sides of the tub.

[0034] Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art.

Basic Operation

[0035] The operation of the invention can be understood with reference to Figure 3. As shown in Figure 3, the wheelbarrow can include a tub 10, frame 20 (which can include legs 30), single wheel 40, and linkages 11 between the tub and frame that can be capable of movement in a parallel manner or approximately parallel which can raise and lower the tub relative to the ground.

[0036] Figure 3 shows the wheel barrow in the raised position which is the traditional configuration of a modern wheel barrow; however, the tub 10 is not mounted directly to the frame; instead it is connected to the frame via four load arms 11 (only 2 can be seen in Figure 3) which are connected by rotational joints to the frame and tub. The geometry of the connections is such that the load arms 11 and points of connection to the tub and frame form a parallelogram with the sides formed by the tub (from pivot point 12A to pivot point 12B) and frame (from pivot point 12C to pivot point 12D) largely horizontal.

[0037] A manual gearbox causes the load arms to rotate which in turn moves the tub along a circular path while maintaining the base of the tub in a largely horizontal orientation until the tub reaches the ground (see Figure 4A). The plane formed by the front and rear load arm connections to the frame need not be on a horizontal plane. In order to achieve this, the connections to the tub are also preferably located on a parallel plane (see Figure 4B). This simplifies manufacture by allowing the pivots on the frame to be attached directly to the frame rather than to an extra frame element.

Detailed operation of preferred embodiments

[0038] In order to rotate the load arms as mentioned above a reduction gearbox 23 is preferred to reduce the load a user has to rotate, another preferred feature of the gearbox is that it also has a self-locking feature so that the tub can be held at any point in its movement (Figure 5).

[0039] The gearbox can be operated at its position near the front load arm 11 A; however, it will be more convenient to operate the gearbox closer to the handles where the user generally operates the unit so a transfer shaft 25 is run along the frame 20 to the direction change gearbox 24 which connects to a handle 27. Running the transfer shaft 25 along the frame has the added benefit of raising the gearbox to be operated further from the ground as the frame angles away from the ground toward the handles. The self-locking feature and the load reduction provided by the gearboxes can be distributed between the two or in any combination (Figure 5).

[0040] The operation handle 26 of the direction change gearbox 24 preferably folds flat against the transfer handle 27 when not in use as to prevent it from making the wheel barrow wider overall. The handle can also be removable (Figure 5).

[0041] The front load arms 11A need not be connected by the connecting shaft 21; however, it is advantageous as it reduces the flexing of the tub when loaded by distributing the load across the tub. If a tub is particularly prone to flexing either due to its construction or an excessive load, then all four load arms can be connected via gearboxes and shafts such that the single input from the direction change gearbox can apply force to all load arms to more evenly distribute the load to the tub. In some embodiments at least one front load arm 11A and one back load arm 11B are driven by the gearbox; in preferred embodiments, all four arms are driven with the front arms driven by a common shaft 21 with belts attached to the rear two arms (Figure 6).

[0042] In a preferred embodiment the tub end of the front load arms rotate directly past the frame end of the rear load arm. This means the front load arms can be offset from the rear load arms or the front load arms can be bent.

[0043] The gearbox can be electrically powered or replaced with an electric motor to make the wheel barrow easier to use.

[0044] The handles 50 can be folded down at the handle hinges 51 to allow closer access to the tub when in the lowered position (Figures 5 and 7). The handles can be temporarily locked in the raised position such that they do not fall down under their own weight but can be easily moved from one position to the other by the user. In this way, repeated moving of the wheel barrow does not require continual bending down to near the ground by the user to access the handles, and when emptying in the upended position the wheel barrow can be swung from side to side using the handles. This locking can be performed by catches or detent systems or any other method known in the art.

[0045] Having described the invention in detail, it will be apparent that modifications, variations, and equivalent embodiments are possible without departing from the scope of the invention defined in the appended claims. Furthermore, it should be appreciated that all examples in the present disclosure are provided as non-limiting examples.

EXAMPLES

[0046] The following non-limiting examples are provided to further illustrate embodiments of the invention disclosed herein. It should be appreciated by those of skill in the art that the techniques disclosed in the examples that follow represent approaches that have been found to function well in the practice of the invention, and thus can be considered to constitute examples of modes for its practice. However, those of skill in the art will, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention. EXAMPLE 1

ALTERNATIVE EMBODIMENT TO REDUCE WEIGHT ON HANDLES

[0047] The requirement for the wheel barrow to empty when upended (Figure 8) on the frame requires that the tub have an angled front which affects the location of the center of mass of the tub.

[0048] If this method of unloading is not required then the invention also allows a further embodiment where the tub is moved further over the front wheel (Figure 9), which can greatly lower the load on the handles when moving the wheel barrow by changing the length of the load arms and where they attach to the frame and tub. Further, if upended emptying is required the preferred embodiment can achieve this by having a removable or hinged front tub panel.

EXAMPLE 2

ALTERNATIVE EMBODIMENT TO PROVIDE NARROWER HANDLES

[0049] Another embodiment provides handles for the user at a spacing less than the width of the tub. This can be an advantage if a wide tub or a small user is contemplated. As shown in Figure 10, the handles 50 are no longer straight but bend in towards each other. In order to prevent them from hitting the tub when in the lowered position the handle hinges 51 can be other than perpendicular to the line of the frame. This will cause the handles to swing away from the tub when in their down position and swing in towards each other when in their up position (Figure 10).

EXAMPLE 3

ALTERNATIVE EMBODIMENT TO PROVIDE HANDLE HEIGHT ADJUSTMENT

[0050] To accommodate different sized users, another embodiment allows the legs' 30 lengths and pivot point 12 position to be adjusted such that in the lowered position the handles are at a convenient height so as not to require excessive bending by the user to grasp the handles (Figure 11). Without adjustable leg lengths, the height of the handles when in the raised position is fixed and is the most common position in which to grasp the handles, however as operators are different sizes it is advantageous to have the handles at a height that is directly proportional to the height of the operator. EXAMPLE 4

ALTERNATIVE EMBODIMENT TO PROVIDE A SUPPORT TO THE TUB

[0051] When in the raised position the load of the tub is held by the locking mechanism of the gearbox. In some instances this may not be sufficient to support excessive loads or shock loads; in this case there exists an embodiment that has supports 60 from the frame for the tub and/or the load arms to locate on when in the raised position (Figure 12). As shown in Figure 12, there can be support for the tub 60A, support for the front load arm 60B, and support for the rear load arm 60C.

EXAMPLE 5

ALTERNATIVE EMBODIMENT TO PROVIDE A BRAKE

[0052] In some instances of operation the user may consider moving the wheel barrow while the tub is at its maximum height. Depending on the load this may cause some instability in the wheel barrow once the legs are raised off the ground. To prevent this issue another embodiment includes an automatic brake which makes it significantly difficult to move the wheel barrow while not in the standard raised position (Figure 13).

[0053] The wheel is mounted on a separate swing arm 71 rather than the frame. This swing arm rotates around a brake pivot 72 shaft. The frame has a brake section 70 which goes over the top of the wheel. When in a position other than the standard raised position the swing arm 71 rotates due to the weight of the wheel barrow, resulting in the wheel 40 contacting the frame brake section 70, preventing the wheel from turning (Figures 13 and 14).

[0054] The swing arm also has a section which goes over the top of the wheel. When the tub is in the standard raised position the tub bears down on the section over the swing arm, which raises the front of the frame and prevents contact between the wheel and frame brake section. In a preferred embodiment, the motion of the swing arm is limited such that if the wheel barrow is lifted off the ground the swing arm does not swing significantly from its normal operating position.

[0055] The brake is preferably automatic but can be manual. The implementation of the brake can be achieved via numerous other methods known in the art. [0056] In some other instances, however, it may be advantageous not to have a brake as the wheel barrow can then be used with the tub only slightly off the ground which significantly increases its stability.

EXAMPLE 6

ALTERNATIVE EMBODIMENT TO MAINTAIN THE TUB HORIZONTAL WHILE IN

MOTION

[0057] In some instances of use it is important to maintain the base of the tub horizontal while in motion rather than during loading. To achieve this there exists an alternative embodiment where the lengths forming the parallelogram are approximate.

[0058] If the rear load arms are shortened by an amount compared to the front load arms, and the distance between the pivots along the side of the frame is increased by the same amount as compared to the distance between the pivot points on the tub and the rear pivot point on the frame lowered, then the base of the tub will slope toward the handles when the legs are on the ground (Figure 15). However, when the legs are raised by a different amount by the operator, the base of the tub will then become horizontal, and when the legs are in contact with the ground and the base is rotated into the lowered position, it will be horizontal when in contact with the ground.

[0059] It should be noted that the top of the tub can be at any angle to the bottom of the tub and this does not influence the movement of the bottom of the tub.

EXAMPLE 7

ALTERNATIVE EMBODIMENT UTILIZING PALLET LOADING

[0060] The functionality of ground-level loading can provide a non-traditional method of loading and unloading. When the tub is on the ground, loading can be simplified if the load is previously mounted on a wheeled pallet such that it can be simply rolled forward onto the tub base (Figure 16). This can be considered advantageous when assembling the load takes longer than transporting the load.

[0061] Another palletizing embodiment removes the center and back section of the base of the tub leaving an edge around the sides and front (Figure 16). This allows the wheel barrow to be backed or rocked sideways onto a pallet with a raised lip, again decreasing loading time. EXAMPLE 8

ALTERNATIVE EMBODIMENT TO PROVIDE OVERLOAD PROTECTION

[0062] There exists a likely scenario when an operator may attempt to raise a weight in the tub that is in excess of the design capacity of the wheelbarrow unit. In order to prevent the load from raising and thereby potentially overloading, the structure a feature can be added to the gearbox—specifically a torque limiting mechanism of which there are many known in the art. The feature operates such that when a torque is applied to the gearbox, an input shaft in excess of the design capacity the handle no longer acts as a rigid body with the gearbox input shaft and instead allows the handle to turn without turning the gearbox input shaft. While there are many known mechanisms for this feature, an added requirement for the feature is that when the torque transitions from the below to above the design capacity the handle requires substantially the same torque to rotate even when not turning the gearbox input shaft as otherwise the operator may become injured if they are applying excessive force against the largely resisting handle which suddenly becomes easy to rotate.

[0063] The preferred design for this feature is called a friction plate where two plates are held against each other with one plate attached to the handle and the other to the input shaft. While the torque required to force the two plates to rotate against each other is below the friction force between the plates they act as a rigid body however as the torque exceeds the friction force the two plates "slip" past each other.

EXAMPLE 9

ALTERNATIVE EMBODIMENT OF DIFFERENT COLORS OF THE TUB

[0064] There exists an opportunity to make the tubs in different colors including a clear option.

EXAMPLE 10

ALTERNATIVE EMBODIMENT OF WHEREIN THE TUB AND BACK OF TUB ARE COMPRISED OF DIFFERENT MATERIALS

[0065] While the tub and back are generally considered to be manufactured as a pair, the requirements for the tub and back differ and hence different materials may be selected for each. In particular, the tub can be formed from a polymer such as High Density Polyethylene which is cheap and strong when made thick enough and/or with enough shape features. However the back needs to be stiff and relatively flat which leads to a material preference of a metal such as steel or aluminum.

EXAMPLE 11

ALTERNATIVE EMBODIMENT WHEREIN THE BACK OF THE TUB IS NOT

REMOVABLE, JUST HINGEABLE

[0066] When the tub is lowered to the ground level the back of the tub is required to move away from its initial position at the back of the tub, this can be achieved simply by making the back removable as a separate item from the tub. However, this can complicate some embodiments as when the wheelbarrow is rotated into the upright position (see Figure 8) the back of the tub may fall from its position if not held in place by various mechanisms which in turn may complicate its removal when at ground level. An alternative to this design is to have the back of the tub hinge along one of its common sides with the tub. If the bottom side is selected the back of the tub can also act as protection from damage to the bottom back edge of the tub during loading, this is particularly useful as any damage to the back edge of the tub will compromise the seal formed by the tub's back edge and the back's bottoms edge.

EXAMPLE 12

ALTERNATIVE EMBODIMENT WHEREIN THE BACK OF THE TUB DOES NOT

FALL OUT WHEN UPENDED

[0067] Similar to the feature mentioned in Example 11 , it is preferred that the back of the tub does not fall out when rotated into the upright position (see Figure 8). Example 11 explains one possible embodiment to achieve this, however there are numerous others such as using fasteners to attach the back to the tub, having a sliding arrangement between the back and the tub, and having a rotating arrangement between the back and the tub.

[0068] The various methods and techniques described above provide a number of ways to carry out the application. Of course, it is to be understood that not necessarily all objectives or advantages described can be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that the methods can be performed in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objectives or advantages as taught or suggested herein. A variety of alternatives are mentioned herein. It is to be understood that some preferred embodiments specifically include one, another, or several features, while others specifically exclude one, another, or several features, while still others mitigate a particular feature by inclusion of one, another, or several advantageous features.

[0069] Furthermore, the skilled artisan will recognize the applicability of various features from different embodiments. Similarly, the various elements, features and steps discussed above, as well as other known equivalents for each such element, feature or step, can be employed in various combinations by one of ordinary skill in this art to perform methods in accordance with the principles described herein. Among the various elements, features, and steps some will be specifically included and others specifically excluded in diverse embodiments.

[0070] Although the application has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the embodiments of the application extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and modifications and equivalents thereof.

[0071] In some embodiments, the terms "a" and "an" and "the" and similar references used in the context of describing a particular embodiment of the application (especially in the context of certain of the following claims) can be construed to cover both the singular and the plural. The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (for example, "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the application and does not pose a limitation on the scope of the application otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the application.

[0072] Preferred embodiments of this application are described herein. Variations on those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. It is contemplated that skilled artisans can employ such variations as appropriate, and the application can be practiced otherwise than specifically described herein. Accordingly, many embodiments of this application include all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the application unless otherwise indicated herein or otherwise clearly contradicted by context.

[0073] All patents, patent applications, publications of patent applications, and other material, such as articles, books, specifications, publications, documents, things, and/or the like, referenced herein are hereby incorporated herein by this reference in their entirety for all purposes, excepting any prosecution file history associated with same, any of same that is inconsistent with or in conflict with the present document, or any of same that may have a limiting affect as to the broadest scope of the claims now or later associated with the present document. By way of example, should there be any inconsistency or conflict between the description, definition, and/or the use of a term associated with any of the incorporated material and that associated with the present document, the description, definition, and/or the use of the term in the present document shall prevail.

[0074] In closing, it is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the application. Other modifications that can be employed can be within the scope of the application. Thus, by way of example, but not of limitation, alternative configurations of the embodiments of the application can be utilized in accordance with the teachings herein. Accordingly, embodiments of the present application are not limited to that precisely as shown and described.