Abstract:
A wheelbarrow includes a load carrying bin, a frame structure, a number of wheels, and a closed loop pivotal handle. The handle is attached near the rear of the wheelbarrow on a pivoting axis so that the user may adjust the height of the handle. The handle may be attached with two threaded pins having knobs at one end so a user may fix the handle at one particular height, may leave the handle entirely adjustable, or may remove the handle entirely for convenient storage of the device. The wheels are placed to provide complete support for the load and may include vertical swivel axes to make moving the wheelbarrow easier.

Description:
FILING HISTORY 
     This application is a continuation-in-part of application Ser. No. 09/259,449, filed on Mar. 1, 1999 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to load-carrying devices and in particular to wheelbarrows. 
     Wheelbarrows are well known in the art for use as load-carrying devices. Their popularity has derived from the usefulness and efficiency of this tool. Probably the most prevalent variety of wheelbarrows involves a carrying bin supported by a frame with a forwardly attached wheel and a two rearwardly attached handles. 
     The U.S. patent to Primeau, U.S. Pat. No. 4,471,996, discloses a wheelbarrow with handles which rotate between first and a second position. In the first position, the wheelbarrow bin is supported by frame supports, while in the second position the bin rests on the ground for convenient loading and unloading. In order to move the load, the user must lift the handles to a height so that the supports are off the ground. This invention does not incorporate the advantage of the present invention that the load may be moved without the user having to substantially support the weight of the load. 
     2. Description of the Prior Art 
     U.S. Pat. No. 3,552,760 to Sine teaches a Folding Wheelbarrow with the similar feature of the Primeau patent that the user must raise the handles and support a substantial portion of the load in order to move the wheelbarrow. 
     U.S. Pat. No. 3,552,762 to Garber, entitled Wheelbarrow Leg Assembly, relates to a leg assembly having a brace extending between a pair of supporting legs, presumably to assist in supporting the legs. Again, this device does not help the user to support the load while moving the wheelbarrow. 
     U.S. Pat. No. 3,826,511 to Frank, entitled Collapsible Beach Tote Barrow With Ball Combination, relates to a collapsible beach cart with a removable beach ball as a wheel. 
     Several other patents related to wheelbarrows exist in the prior art. These include U.S. Pat. No. 3,722,904 to Puckett, titled Foldable Wheelbarrow, U.S. Pat. No. 5,040,808 to Mentyre, titled Utility Cart, U.S. Pat. No. 5,087,061 to Wallace, titled Wheelbarrow-Trailer Implement and U.S. Pat. No. 5,087,062 to Chappell, titled Knock-Down Wheelbarrow and Fastening Devices Thereof. While not without merit, none of these devices provide the utility of the present invention. The aforementioned patents are aimed at convenient storage of wheelbarrows, improved structural rigidity, easy dumping of loads, or other multi-function purposes. These devices do not address any improvements from the standpoint of operational convenience to the person that operates or uses the wheelbarrow. 
     Both U.S. Pat. No. 1,901,878 to Schwenk, titled Portable Stand and Tilter for Barrels and the Like, and U.S. Pat. No. 4,861,110 to Rumpke, titled Tilt Truck Apparatus, disclose a load carrying device supported by wheels. These devices are suitable only for use on hard surfaces and certainly do not entertain the variety of functions of a wheelbarrow. The present device is intended to be used over a variety of surfaces and as such includes appropriate hardware and suitably-sized wheels to accomplish this task. Similarly, neither device teaches a conveniently adjustable handle intended for pushing or propelling the device as does the present invention. 
     SUMMARY OF THE INVENTION 
     The present invention accomplishes the above-stated objectives, as well as others, as may be determined by a fair reading and interpretation of the entire specification. 
     The present invention may have several embodiments. Generally the invention consists of a load-carrying bin supported by wheels having a pivotally adjustable handle for moving the device. 
     One object of the present invention is to provide a wheelbarrow that fully supports the weight of its load. 
     A second object of the present invention is to provide a wheelbarrow with an easily adjustable handle to so that it may be used at a variety of heights while the load carrying bin is fully supported. 
     Another object of the present invention is to provide a wheelbarrow with a removable handle for convenient storage. 
     Further objects of the present invention will become apparent from the following detailed description and accompanying drawings that form a part of the specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which: 
     FIG. 1 shows a lateral perspective view of one embodiment of the invention. 
     FIG. 2 shows a top perspective view of one embodiment of the closed loop handle. 
     FIG. 3 shows an elevated perspective view of another embodiment of the closed loop handle. 
     FIG. 4 shows a top perspective view of one embodiment of the invention with the load-carrying bin removed. 
     FIG. 5 shows a top perspective view of another embodiment of the invention with the load carrying bin removed. 
     FIG. 6 shows a top perspective view of yet another embodiment of the invention with the load carrying bin removed. 
     FIG. 7 shows a top perspective view of the closed loop handle, including the optional handle locking assembly. 
     FIG. 8 shows a lateral view of the present invention equipped with the handle locking assembly, the locking rod of which is shown in solid lines in its disengaged position and in broken lines in its engaged position. The closed loop handle is shown in partial cross-section. 
     FIG. 9 shows a lateral view as in FIG. 8 with the locking rod in its engaged position and the wheelbarrow pivoted upward on its forward wheel so that the contents of the load carrying bin are being dumped. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its application to the details of any particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. 
     FIG. 1 shows a lateral perspective view of one embodiment of the invention. A load carrying bin  1  is shown and it includes a bin bottom wall  3  and a bin side wall  5 . A forward wheel assembly  7  primarily consists of elongated tubular members in addition to a wheel hub structure  9  and a wheel  11 , which freely rotates about a horizontal axis. The forward wheel assembly  7  is attached to the bin bottom wall  3  and extends toward the rear of the wheelbarrow. A single rearward wheel assembly  13  is visible from this drawing. The rearward wheel assembly  13  includes a wheel hub structure  15  and a wheel  17 , which freely rotates about a horizontal axis. A closed loop handle  19  is pivotally attached to the wheelbarrow and provides a way to move the wheelbarrow by pushing or pulling. This drawing displays an important feature of the closed loop handle  19  in that the pivotal attachment allows the handle to reach varying heights H o , H 1 , H 2 , and H 3 . Another feature of the pivotal attachment is that the tubes of the wheel assembly  7  interfere with part of the closed loop handle  19  and provide a lower limit on the closed loop handle&#39;s movement. Similarly, the rearward portion of the bin side wall  5  provides an upper limit on the closed loop handle&#39;s movement. 
     FIG. 2 shows a top perspective view of one embodiment of the closed loop handle  21 . The closed loop handle is made up of several interconnected longitudinal members. The lagging traverse member  23  provides the actual handle portion which is meant to be gripped by the user. Two parallel side members  25  extend from either end of the lagging traverse member  23  and are attached to a leading traverse member  27 . The parallel side members  25  interfere with the rearward portion of the bin side wall  5  to provide an upper limit on the closed loop handle&#39;s movement, while the leading traverse member  27  interferes with the forward wheel assembly  7  to provide a lower limit on the closed loop handle&#39;s movement. Two holes  29  are drilled, one in each of the parallel side members  25  to provide a pivotal mounting point for the closed loop handle  21 . 
     FIG. 3 shows an elevated perspective view of another embodiment of the closed loop handle. In this embodiment the parallel side members  25  each incorporate a downward bend  31  near the mounting hole  29 . Also visible in this drawing are adjustable mounting knobs  33  which enable the user to adjust the closed loop handle to different heights, or to fix the handle at one height, or to remove the handle entirely for convenient storage. The mounting knobs  33  have a handle end fixed to a pin with a threaded end opposite the handle. 
     FIG. 4 shows a top perspective view of an embodiment of the invention similar to that shown in FIG. 1, with the load-carrying bin removed. This drawing depicts the relationship between the leading traverse member  27  and the forward wheel assembly  7 , specifically how the leading traverse member  27  interferes with the tubes on the forward wheel assembly  7  to provide a lower limit on the closed loop handle&#39;s pivotal movement. Also presented here is the fulcrum structure  35  which is laterally connected to the forward wheel assembly  7 . The closed loop handle is attached to the fulcrum structure  35  at two pivotal mounting points  37 . The threaded ends of the mounting knobs  33  (see FIG. 3) engage these mounting points  37  which include threaded portions complimentary to the threads found on the mounting knobs. The wheels shown here  17  and  11  may be installed so that they have only a horizontal axis of rotation or they may also be mounted with a swivel so that the wheel has a vertical swivel axis. 
     FIG. 5 shows a top perspective view of another embodiment of the invention with the load carrying bin removed. This embodiment includes two forward wheels  39 , which are mounted to have a horizontal axis of rotation and may also include a swivel so that they have a vertical swivel axis. 
     FIG. 6 shows a top perspective view of yet another embodiment of the invention with the load carrying bin removed. This embodiment includes a singular rearward wheel  41  which is mounted to the fulcrum structure  35 . This wheel may include not only a horizontal axis of rotation but may also a swivel so that it has a vertical swivel axis. The inclusion of vertical swivel axis on a wheelbarrow wheel makes the movement of the load easier and more convenient for the user. 
     FIG. 7 shows a top view of the closed loop handle  21 , equipped with an optional handle locking assembly  50  for releasibly locking the loop handle  21  against pivoting relative to the load carrying bin  1 . When locking assembly  50  is engaged, lifting the lagging traverse member  23  of the closed loop handle  21  in turn lifts and pivots the forward wheel assembly  7  and bin  1  about the wheel hub structure  15 , rather than causing the closed loop handle  21  to simply pivot on the wheel hub structure  15 . The handle locking assembly  50  includes a U-shaped locking rod  52  for bridging the space between the loop handle  21  and bin  1 . Locking rod  52  includes two generally parallel U-side segments  54  and  56  and an interconnecting U-middle segment  58  interconnecting U-side segments  54  and  56  and sized to fit closely within the loop handle  21 . The U-side segments  54  and  56  extend generally along parallel side members  25  of the loop handle  21 , and each U-side segment  54  and  56  is pivotally secured to its corresponding and adjacent side member  25  with a fastener  62  such as a rivet or a nut and bolt so that the locking rod  52  pivots within loop handle  21 . At least one of the U-side segments  54  and  56  includes a locking rod lateral stop segment  64  extending laterally outward to interfere with and abut the adjacent side member  54  when the locking rod  52  is pivoted to a disengaged, downward position relative to the bin  1 . See FIGS. 7 and 8. For engagement, the locking rod  52  is pivoted so that U-middle segment  58  is swung upwardly, over and against the rear wall of the bin  1 , where U-middle segment  58  abuts and wedges against bin  1 , thereby obstructing upward pivoting of loop handle  21 . See FIG.  9 . Then lifting lagging member  23  of loop handle  21  lifts the rear end segments of side members  25  and bin  1  and causes them to rotate around wheel hub structure  9 , so that the contents of bin  1  are dumped forwardly, as shown in FIG.  9 . Bin  1  preferably includes an outwardly protruding peripheral lip  66  of conventional design for catching and abutting U-middle segment  58 . 
     While the invention has been described, disclosed, illustrated, and shown in various terms and certain embodiments, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.