Patent Publication Number: US-2009224509-A1

Title: Tow bar for wheelbarrows

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is related to Provisional Application Ser. No. 60/896,946 filed 26 Mar. 2007, and is a Continuation-in-Part of Non-Provisional application Ser. No. 11/810,676 filed Jun. 7, 2007. These prior applications are incorporated herein by these references and the benefit of their filing dates are claimed herein as well. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to wheelbarrows, and, in particular to the converting of wheelbarrows into garden or industrial type trailers. In general, wheelbarrows are designed to be manually lifted and moved. The present invention allows for any two-wheeled wheelbarrow to be attached to the rear of any ATV, riding lawn mower, or tractor thereby eliminating the manual labor. 
     2. Description of the Prior Art 
     The prior art has come up with various arrangements for utilizing a wheelbarrow as a garden or industrial trailer, for carrying such loads as the wheel barrow is designed to be pulled by a towing vehicle such as an ATV, riding lawn mower, or tractor. Thus, by way of example, in Lehman, U.S. Pat. No. 4,052,079, Lehman et al., U.S. Pat. No. 4,155,678, Lehman, et al. U.S. Pat. No.4,281,950 and Wannamaker, U.S. Pat. No. 5,031,926, the wheelbarrow is received and rested or fixed to a dolly, which, in turn, is coupled to a towing vehicle such as a conventional garden tractor. It can be seen that an additional piece of equipment is required, i.e. a dolly, there is no quick means of attachment/detachment to the towing vehicle and an additional hand operation is required to install/remove a pin for securement/detachment to/from the towing vehicle. Also, the wheelbarrow ends up being towed in a rearward direction. 
     Johnson, U.S. Pat. No. 4,740,008, and Porter, U.S. Pat. No. 4,789,171 disclose two-wheeled wheelbarrows that may be converted to a trailer and in which a tow bar is integrated into the wheelbarrow&#39;s handles. As with Lehman, there is no quick means of attachment/detachment to the towing vehicle, an additional hand operation is required to install/remove a pin for securement/detachment to/from the towing vehicle and the wheelbarrow ends up being towed in a rearward direction. 
     Wallace, U.S. Pat. No. 5,087,061 discloses a two-wheeled wheelbarrow that is convertible to a trailer via a tow bar extender detachably connected to a permanently affixed tow bar beneath the pan of the wheelbarrow. There is no quick means of attachment/detachment to the towing vehicle, an additional hand operation is required to install/remove a pin for securement/detachment to/from the towing vehicle and the wheelbarrow ends up being towed in a rearward direction. 
     Finally, Fedorko, U.S. Pat. No. 5,458,356 discloses a two-wheeled wheelbarrow that is convertible to a trailer via a tow bar that is attached to the bottom of the wheelbarrow&#39;s body or pan, attached to the legs by a cross piece and is coupled to a lawn tractor. There is no quick means of attachment/detachment to the towing vehicle, an additional hand operation is required to install/remove a pin for securement/detachment to/from the towing vehicle and the wheelbarrow ends up being towed in a rearward direction. 
     In reviewing the prior art, it will be appreciated that a need still exists for the means whereby a wheelbarrow may be quickly and simply converted to a garden or industrial type trailer and without modification of the wheelbarrow. 
     SUMMARY 
     An object of the invention is the conversion of a two-wheeled wheelbarrow into a garden or industrial type trailer. 
     Another object is the ability to perform such a conversion without any modification of the wheelbarrow itself 
     Still another object is a secure attachment/detachment of the wheelbarrow to a towing vehicle. 
     A further object is a quick attachment/detachment of the wheelbarrow to the towing vehicle. 
     These and other objects, features and advantages are accomplished in accordance with the teachings of the present invention, one illustrative embodiment of which comprises a tow-bar assembly for converting a two-wheeled wheelbarrow into a garden or industrial type trailer that includes a bar of metal box or round tubing with horizontal holes at the wheelbarrow end and vertical holes at the tractor end. The wheelbarrow end is slid onto the axle of the wheelbarrow, keeping the bar between the tub of the wheelbarrow and its toe plate. Grommets positioned on the axle on either side of the bar center the tow bar assembly on the axle. A threaded post is inserted into the holes in the tractor end of the bar and locked into place by nuts. In use, the handles of the wheelbarrow are raised and the post inserted into the aperture of the tractor&#39;s draw bar from the underside of the aperture. The cantilevered weight of the wheelbarrow keeps the wheelbarrow from becoming disengaged from the garden tractor or towing vehicle. The legs of the wheelbarrow are kept off the ground and the trailer-barrow is now ready for use. Where the wheelbarrow conversion to a trailer is intended for heavy loads, a piece of flat iron is attached to the top-side of the rails of the wheelbarrow close to its dumping end. In this way, when in use, the tow bar will rest on the flat iron instead of the wheelbarrow&#39;s toe bracket. In a preferred embodiment the bar is PVC piping and a piece of flat iron is riveted to the bar, parallel to same so that in use the flat iron rests on the toe plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Other objects, features and advantages of the present invention will be apparent from the following detailed description and accompany drawing, wherein: 
         FIG. 1  is a partial side elevation view of a wheelbarrow being towed by garden tractor utilizing the novel tow bar assembly of the present invention; 
         FIG. 1A  is a partial side view, partly in phantom, of the tow bar assembly where joined to the garden tractor; 
         FIG. 2  is a bottom view of the wheelbarrow; 
         FIG. 3  is a side view, partially cut away, of the bar of the tow bar assembly; 
         FIG. 4  is a side view of a threaded post, with nuts, used in securing the tow bar assembly to the draw bar of the tractor; 
         FIG. 5  is a top view of a flat iron piece for attachment to the front of the wheelbarrow above its toe plate and used when hauling heavy loads; 
         FIG. 6  is a side view, partially cut away, of a grommet to be mounted on the axle of the wheelbarrow on either side of the tow bar for centering the tow bar on the axle; 
         FIG. 7  is a partial perspective view of the tow bar assembly where attached to the tractor draw bar; 
         FIG. 8  is a partial perspective view of the tow bar assembly where joined to the axle of the wheelbarrow; 
         FIG. 9  is a top view of the tow-bar used in an alternate, preferred embodiment of the present invention; 
         FIG. 9A  is a partial perspective view of an alternate, preferred embodiment of the tow-bar assembly and shown where joined to the tractor; 
         FIG. 9B  is a partial perspective view of the alternate, preferred embodiment of the tow-bar assembly and shown where joined to the wheelbarrow; 
         FIG. 10  is a side view, partially cut away of the tow-bar of  FIG. 9 ; 
         FIG. 10A  is a cross-sectional view taken along the line  10 A- 10 A of  FIG. 9 ; and, 
         FIG. 10B  is a cross-sectional view taken along the lines  10 B- 10 B of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION  
     Referring now to  FIG. 1  of the drawing, a two-wheeled wheel barrow  11  is shown being used as a trailer attached to a typical garden tractor  12  by means of the novel tow bar assembly  13  of the present invention. Only so much of the wheelbarrow  11  and garden tractor  12  are shown as is necessary for an understanding of the present invention. The wheelbarrow  11  is shown ( FIGS. 1 and 2 ) as having a body or tub  14  with workman&#39;s end  15  and dumping end  16  and sidewalls  17 ,  18 . 
     The frame  21  of the wheelbarrow upon which the body  14  is supported includes a pair of wooden lower rails  22 ,  23  with lifting/supporting handles  24 ,  25  forward of the workman&#39;s end  15 . The wooden rails  22 ,  23  extend and converge from forward of the workman&#39;s end  15 , beneath the body  14  to the dumping end  16 . The wooden rails  22 ,  23  are connected at their dumping end  16  by a toe plate  26 . A pair of tired wheels  27 ,  28  is placed on an axle  29  supported on the rails  22 ,  23  towards the dumping end  16 . Also attached to the rails is a pair of legs  30 ,  31 . 
     The tractor  12  is seen as having a draw bar  41  at its rear ( FIGS. 1 ,  1 A and  7 ) with a standard one half to five eights inch hole specifically for the attachment of accessories. In accordance with the teachings of the present invention, one starts with a bar  51 , for example, a two foot long piece of inch and a quarter by inch and a quarter by 16 gauge box tubing ( FIGS. 1 ,  1 A,  2 ,  3 ,  7  and  8 ). Holes  52 ,  53 , typically five eighths of an inch in diameter are drilled through the bar, horizontally at the wheelbarrow end of the bar and vertically through the tractor end of the bar. 
     The tow bar assembly  13  is installed on the wheelbarrow by turning the wheelbarrow upside down, removing one of the wheels  27 ,  28  by removing a cotter pin using ordinary pliers. The axle  29  is slid halfway out. A grommet  54  ( FIG. 6 ) is then slid onto the axle  29 . The wheelbarrow end of the bar  51  is then slid onto the axle  29 , but keeping the tow bar  51  between the toe plate  26  and the body  14  of the wheelbarrow  11 . 
     A second grommet  54  is then slid onto the axle. The grommets  54  perform the function of centering the tow bar  51  on the axle  29 . The axle  29  is then slid back in place, the removed wheel  27  or  28 , is re-attached and the wheelbarrow  11  righted. 
     A threaded post  55  ( FIGS. 1A ,  4  and  7 ) is then inserted in the hole  53  at the tractor end of the bar and securely and permanently locked in place to the bar by a pair of one half inch nuts  56 ,  57 . This post&#39;s height will be sufficient to keep the wheelbarrow attached to its towing vehicle, as it bounces along during towing. 
     In use, the handles  24 ,  25  of the wheelbarrow are raised and the post  55  is inserted into the aperture of the draw bar  41  from the underside of the aperture. The cantilevered weight of the wheelbarrow keeps the wheelbarrow  11  from becoming disengaged from the garden tractor or towing vehicle  12 . The legs  30 ,  31  of the wheelbarrow  11  are kept off the ground, approximately four inches. The trailer-barrow  11  is now ready for use. Where the wheelbarrow conversion to a trailer is intended for heavy loads a piece of flat iron  58  is attached to the top-side of the rails  22 ,  23  close to the dumping end  16  of the wheelbarrow  11 . In this way, when in use, the tow bar will rest on the flat iron  58  instead of the wheelbarrow&#39;s toe bracket. 
     An alternate, preferred tow bar assembly  60  of the present invention is shown in  FIGS. 9 through 10B . The assembly includes a bar  61 , in this case a piece of PVC piping. Holes are drilled through the bar, vertically at the forward end and towards the back end, and horizontally at the back end. A piece of flat iron  62  is riveted to the bottom of the bar  61  at  63 , 64  and positioned parallel to the bar  61 . 
     As with the prior embodiment, tow bar assembly  60  is installed on the wheelbarrow by turning the wheelbarrow upside down, removing one of the wheels  27 ,  28  by removing a cotter pin using ordinary pliers. The axle  29  is slid halfway out. No grommets are needed. The wheelbarrow end of the bar  61  is then slid onto the axle  29 , but keeping the tow bar  61  between the toe plate  26  and the body  14  of the wheelbarrow  11 . The axle  29  is then slid back in place, the removed wheel  27  or  28  is re-attached and the wheelbarrow  11  righted. 
     A threaded post  66  is then inserted in the hole at the tractor end of the bar and securely and permanently locked in place to the bar by a pair of one half-inch nuts  67 , 68 . The post&#39;s height will be sufficient to keep the wheelbarrow attached to its towing vehicle, as it bounces along during towing. 
     In use, the handles  24 ,  25  of the wheelbarrow are raised and the post  66  is inserted into the aperture of the draw bar (not shown) from the underside of the aperture. The cantilevered weight of the wheelbarrow keeps the wheelbarrow  11  from becoming disengaged from the garden tractor or towing vehicle. The legs  30 ,  31  of the wheelbarrow  11  are kept off the ground, approximately four inches. The flat iron piece  64  rests against the toe plate  26 , keeping the bar  61  from rubbing against the toe plate  26 . It also adds rigidity to the bar  61 . The trailer-barrow  11  is now ready for use. 
     The present invention is of simple design, uses minimal material and can be used with any two-wheeled wheelbarrow. 
     Its cantilevered feature lessens weight at the point of attachment on the towing vehicle. Unlike prior art assemblies the instant tow bar assembly attaches to or coordinates with the most durable portions of the wheelbarrow, i.e. the axle and rails. 
     With the present invention a quick attachment/detachment can be made to any towing vehicle. There is no additional hand operation required to install/remove a securing pin. Since the wheelbarrow is towed in a forward direction, it allows the user to simply grab the handles to attach/disconnect the wheelbarrow from the towing vehicle. 
     It should be obvious that changes, additions and omissions may be made in the details and arrangement of parts without departing from the spirit and scope of the invention as hereinafter claimed.