Land vehicles – Wheeled – Tiltable vehicles – stabilized by attendant or article
Reexamination Certificate
2001-07-12
2003-04-29
Johnson, Brian L. (Department: 3618)
Land vehicles
Wheeled
Tiltable vehicles, stabilized by attendant or article
C280S047120, C298S003000
Reexamination Certificate
active
06554301
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a device to pivot a material handler. In particular, the invention relates to methods and other accommodations to pivot a wheelbarrow to efficiently support and empty the wheelbarrow.
A wheelbarrow is a device that is used to transport heavy loads by hand. A wheelbarrow consists of a tray mounted on a wheel and two legs with handles that extend to the rear of the tray. A wheelbarrow is moved by lifting its handles to raise the legs off the ground, pivoting and balancing the loaded wheelbarrow on its wheel, and walking the wheelbarrow to the location for the load to be emptied. A wheelbarrow is typically unloaded by emptying the contents wherein the worker lifts the handles to pivot the tray into a vertical position in order for the load to slide or pour out of the forward portion of the tray.
Wheelbarrows are especially useful in moving loads across soft or uneven ground because the single wheel provides high maneuverability and also because the user can easily keep the load balanced by raising or lowering one or both of the handles. Wheelbarrows are also especially useful because of their ability to easily empty the load. However, as the weight of the load increases, it becomes more difficult to balance the wheelbarrow during movement and emptying.
Emptying a heavy load is particularly difficult because the user must change from lifting the handles with an underhanded grip to pushing the handles with an overhanded grip while simultaneously balancing the wheelbarrow on a single wheel as the load rapidly shifts position. Further, to completely empty the load in the tray, the worker is often required to shake and vibrate or rock the wheelbarrow back and forth with the wheelbarrow in the vertical position.
Additionally, during such a forward emptying operation, the wheelbarrow often loses its balance, especially when the load is heavy or the worker is not strong enough or skilled enough. It is not only inefficient but also dangerous if a wheelbarrow accidentally topples with its heavy load in the vertical position.
Thus, efficiently emptying a load is crucial to maintaining an organized and safe work area. As such, pivoting the tray of the wheelbarrow in a tight and smooth manner is extremely important. Typical wheelbarrows, in use, present different mechanisms to pivot and empty the load from the tray. Commonly, the wheelbarrow will utilize a wheel guard or front guard which includes a horizontal bar in front of the wheel. These typical wheelbarrows further use two tray braces connected between the front guard and a support plate which is mounted on the front portion of the wheelbarrow. The worker will pivot the wheelbarrow via the tray braces. Typically, the tray brace comprises a flat piece of steel extending from the tray to the undercarriage of the wheelbarrow. Alternatively, existing wheelbarrows will use one piece tubular members which act as the pivot point in front of the wheel. Further, these one-piece tubular members also act as the handles.
A problem with emptying the load with these mechanisms, however, is being to conveniently and efficiently pivot the tray as the front guards do not provide a smooth pivot motion while the worker is lifting the handles resulting in a difficult and unsafe discharge of the load. Accordingly, the operator often loses control and dumps the load. Additionally, with the front guard, current wheelbarrows must be pivoted almost completely upside down or another worker must clean the wheelbarrow with a hoe or shovel to completely discharge the wheelbarrow. Additionally, the front guard, the two tray braces and the support plate typically used are separate pieces adding to the components which comprise the wheelbarrow assembly. Thus, the added components increase the assembly required to make the wheelbarrow resulting in higher manufacturing costs. Further, the added components increase the chance for the component to fail resulting in costly repairs and lost work time. Further, one-piece tubular members commonly do not provide enough pivot force required by heavier loads resulting in the tubular members becoming bent. As the one-piece tubular members become bent from the load, the worker is required to remove and replace the entire tubular member resulting in work downtime and costly repairs.
A need, therefore, exists to safely and efficiently support the wheelbarrow and transport the wheelbarrow. A need also exists to efficiently and conveniently discharge a load from the tray. The solution, however, must be capable of pivoting the tray holding a heavy load without failing. Additionally, the solution must not add extra elements to the wheelbarrow assembly to limit assembly and repair costs.
Because of the difficulty in balancing a conventional wheelbarrow while emptying the load, many different modifications have been suggested which fail to meet the current need. U.S. Pat. No. 5,601,298 issued to Watanabe discloses a wheelbarrow having a front guard positioned in front of the wheel. The front guard comprises a bar portion or a curved plate which acts as the pivot point while the wheelbarrow is in the vertical position. This front guard does not solve the current need, though, as the front guard does not provide enough of a pivot point. Because the front guard is a bar portion or small curved plate, the front guard does not provide a larger curvature required for a pivot in a smooth manner. Accordingly, tipping the wheelbarrow in the vertical position will result in an abrupt stop by the front guard leading to an unbalanced and unsafe condition. Further, the wheelbarrow requires two tray braces in addition to the separate front guard. Thus, the front guard is an extra element which requires increased assembly time of the wheelbarrow.
Another device, U.S. Pat. No. 5,884,924 issued to Fairchild et al. discloses another wheelbarrow having two spaced apart roll bars which are one piece tubular members which extend from the bottom of the tray to a point in front of the wheel. The roll bars then extend up vertically for at least six inches to connect to the top of the tray. This wheelbarrow does not solve the current need either, as the roll bars are tubular members which cannot support heavier loads resulting in the tubular members becoming bent. Further, the roll bars are continuations of the handles so that when the roll bar becomes bent, the entire assembly needs to be replaced resulting in a longer downtime for repairs. Additionally, the upward curve of the roll bar is located below the wheel axle resulting in a sharp curve which prevents any pivoting movement of the wheelbarrow in a smooth manner.
SUMMARY OF THE INVENTION
The present invention relates to a brace for a material handler, in particular, a rollbar support unit that supports and pivots a wheelbarrow in a safe and smooth manner.
In an embodiment, the rollbar support unit connects to a tray of a wheelbarrow wherein the rollbar support unit comprises a mount removably fastened to a front portion of the tray. The rollbar support unit further comprises a first leg connected to the mount wherein the first leg extends down from the front portion. Additionally, the first leg has a first curvilinear portion positioned to curve outwardly from the front portion.
The rollbar support unit further comprises a second leg connected to the mount wherein the second leg also extends down from the front portion. The second leg also has a second curvilinear portion positioned to curve outwardly from the front portion. Both the first curvilinear portion and the second curvilinear portion are positioned above a wheel axle at the wheelbarrow.
A first leg support connects to the first leg opposite the mount while a second leg support connects to the second leg opposite the mount wherein the first leg support and the second leg support connect to the first leg and the second leg at an angle greater than ninety degrees.
In an embodiment, the first leg support further connects at the bottom of a first handle end of the wheelbarrow while the seco
Maio Kenneth
Scott James
Scott Marilyn
Sturm Mark
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