Abstract:
An attachment which is readily installed on a conventional hand truck, providing additional load bearing area and restraining points, thereby increasing the utility of the hand truck, and making the hand truck safer to operate.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention is directed to hand trucks and particularly to a hand truck attachment which readily attaches to a hand truck thereby allowing different types, shapes and sizes of items to be transported by the hand truck.  
           [0002]    Conventional hand trucks are manually propelled and generally comprise a frame with a handle on the upper end of the frame, wheels at the lower end of the frame, and a toe plate attached at the lower end of the frame, where the toe plate is generally perpendicular to the frame. Items carried on the hand truck are stacked on the toe plate, and the frame is rocked backwards, tilting on the wheels so that the items rest against the frame as the hand truck is wheeled to the desired location. However, the types, shapes and sizes of items which may be transported on a conventional hand truck are limited. Typically, a conventional hand truck works best for moving boxes, bags, and barrels. Items which are not placed directly on the toe plate may not be stable during transporting the hand truck, and those items may fall off through the frame members, to the side, or the front of the hand truck because the only points of support provided by a conventional hand truck are at the toe plate and at the frame supports. Small items and items which are not readily stackable are even more difficult to transport by a conventional hand truck, because of the lack of support points.  
           [0003]    Various ideas have been proposed for modifying a conventional hand truck to provide greater utility in transporting different items. For example, U.S. Pat. No. 4,726,602 (Sanders) discloses a hand truck for handling bulky freight. This hand truck has a large cage or freight supporting surface with three walls, which may be used to support and carry bulky freight such as loaf bread, plastic foam objects and the like. However, the front of this hand truck is open. When this hand truck is not being used, the side members and the toe plate extension can be folded to permit the hand truck to be carried by a supply truck or stored without occupying an undue amount of space. The side members and toe plate extension are not readily detachable from the hand truck.  
           [0004]    U.S. Pat. No. 5,465,987 discloses an attachment to a conventional hand truck which readily attaches to increase the ease of carrying small articles. This attachment comprises a foldable panel system which provides lateral support for articles loaded on the hand truck. The three panels include a back plate and two side plates. However the only support provided at the front of the hand truck are straps which extend across the two side plates. The attachment provides no additional load-bearing area to the toe plate.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention is directed to an apparatus which readily attaches to a conventional hand truck, and is easily removed once use of the hand truck has been completed. As a further advantage the present invention provides additional load-bearing area to the toe plate thereby increasing the capacity of a conventional hand truck.  
           [0006]    The conventional hand truck is comprised of a vertical ladder-back frame which includes a plurality of horizontal cross-braces extending between vertical side rails from an upper end of the frame to a lower end of the frame. The frame typically has a handle at the top and a pair of axle-mounted wheels at a bottom. The frame has a toe plate affixed to the bottom, which extends substantially horizontally from the front of the frame. The present invention comprises a plurality of cage members, each cage member comprising a lower load bearing section, a front restraining section and an upper enclosing section. The lower load bearing section rests on the toe plate and extends forward. The front restraining section comprises the vertical portion of the cage member, and the upper enclosing section comprises the portion of the cage member continuing backwardly to the upper end of the frame. A first attachment means connects the lower load bearing section of each cage member to a horizontal cross-brace at the lower end of the frame and a second attachment means connects the upper enclosing section of each cage member to a horizontal cross-brace at the upper end of the frame. A plurality of cross-supports connecting adjacent cage members. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is an isometric view of one embodiment of the disclosed invention attached to a conventional hand truck.  
         [0008]    [0008]FIG. 2 is an isometric view of one embodiment of the disclosed invention, detached from a hand truck.  
         [0009]    [0009]FIG. 3 shows a top view of an alternative means of attaching the upper end of the disclosed invention to a conventional hand truck.  
         [0010]    [0010]FIG. 4 shows a side view of an alternative means of attaching the lower end of the disclosed invention to a conventional hand truck.  
         [0011]    [0011]FIG. 5 shows an isometric view of an alternative embodiment of the disclosed invention attached to a conventional hand truck. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0012]    As shown in FIG. 1, a conventional hand truck comprises a ladder-back frame  10 , two vertical side rails,  12 , a handle  14 , horizontal cross-braces  16 , a toe plate  18 , and wheels  22 . The present invention comprises a plurality of cage members  24 , each cage member comprising a lower load bearing section  26 , a front restraining section  28 , and an upper enclosing section  30 . The cage members  24  may be constructed of a malleable, moldable or weldable material, such as thin wall mild steel tubing. If smaller items are to be carried on the hand truck, it may be desirable to have more than two cage members  24  so that there will be less space between the cage members. The embodiment shown in FIG. 1 has two cage members  24 , which reduces the cost and weight of the invention.  
         [0013]    Each cage member  24  is comprised of three different sections, the lower load bearing section  26 , the front restraining section  28  and the upper enclosing section  30 . The lower load bearing section  26  is generally horizontal, extending from the front edge of the toe plate  18 . The front restraining section  28  is the generally vertical section of each cage member which restrains cargo loaded on the hand truck from sliding forward. From the generally vertical front restraining section  28 , each cage member  24  curves back at the top to connect the cage member to the ladder back frame  10 , the horizontal section forming the upper enclosing section  30  of the cage member.  
         [0014]    The lower load bearing section  26  of each cage member  24  rests upon the toe plate  18 . The lower load bearing section  26  extends out beyond the front edge of the toe plate  18 , following a plane parallel to the plane of the toe plate, thus providing a load bearing area which extends beyond the edge of the toe plate. Attachment means, such as a lower hanger assembly  32 , terminating in a hanger  34 , connect each cage member  24  to a horizontal cross-brace  16  of the hand cart. As shown in FIGS. 1 and 4, the lower hanger assembly  32  and hanger  34  may be constructed of flat metal stock or of flattened tubing. The hanger  34  is formed at the upper end of the hanger assembly in a U-shaped configuration, as shown in FIG. 1. Alternatively, the hanger  34 ′ may be formed in a V-shaped configuration as shown in FIG. 4. For either configuration, the lower hanger assembly  34  or  34 ′ is hung on the horizontal cross-brace  16 .  
         [0015]    The front restraining section  28  of each cage member  24  is substantially vertical, extending from the end of the lower load bearing section  26  at the lower end of the hand truck to the end of the upper enclosing section  30  of the cage member. As shown in FIG. 1, the front restraining sections  28  of each cage member  24  define a plane generally parallel to the plane formed by the ladder-back frame  10  of the hand truck. The front restraining sections  28  provide rigid support points for cargo transported by the hand truck. For example, when transporting items such as cinder blocks, the front restraining sections  28  provide front support to prevent the blocks from tumbling from the front of the hand truck. The front restraining sections  28  further provide support to items which do not readily stack. For example, firewood is not easily transported by a conventional hand truck because the rounded pieces tend to roll. However, the present invention provides additional support points to firewood so that it may be stacked and easily transported with the hand truck.  
         [0016]    The upper enclosing section  30  provides horizontal containment and support for cargo transported by the hand truck. The upper enclosing section  30  extends from the top of the front restraining section  28  backward to the ladder-back frame  10  of the hand truck. As shown in FIG. 1, the upper enclosing section  30  may be attached to a horizontal cross-brace  16  of the ladder-back frame  10  by means of an attachment bracket  36 , where the attachment bracket is generally U-shaped as depicted in FIG. 1. Alternatively, the attachment bracket  36  may be generally V-Shaped and formed by connecting two plates together at the top. As depicted in FIGS. 2 and 3, the upper enclosing section  30  may also be attached to a vertical side rail  12  of the ladder-back frame  10 , using a universal mount  36 ′. The universal mount is formed by terminating the upper enclosing section  30  in the shape of a “U,” configured to fit around each vertical side rail  12 . The universal mount  36 ′ is further secured by a retaining pin  40 .  
         [0017]    Adjacent cage members  24  are attached to one another with horizontal cross-supports  38 . The cross-supports provide further contact points for cargo carried on the hand truck. Side panels constructed of metal screening, plastic, or other light weight materials may be attached to the front or sides of the cage members  24  to provide additional support or to enable transporting smaller items with the hand truck without the items falling through the space between the cage members.  
         [0018]    An alternative embodiment of the invention is disclosed in FIG. 5. In this embodiment, each cage member  24  is comprised of two different sections, the lower load bearing section  26  and the front restraining section  28 . The lower load bearing section  26  is generally horizontal, extending from the front edge of the toe plate  18 . The front restraining section  28  is the generally vertical section of each cage member which restrains cargo loaded on the hand truck from sliding forward. Adjacent cage members  24  are attached to one another with horizontal cross-supports  38 . In this embodiment, because there is only one connection of each cage member  24  to the ladder-back frame  10  of the hand truck, the cage members may be constructed of a more rigid material than the embodiment disclosed in FIG. 1.  
         [0019]    In addition to use of the disclosed invention for transporting various items, such as cinder blocks, fire wood, and boxes, the disclosed invention, when attached to a hand truck, provides a portable storage rack for these items. This use may be accomplished by simply lowering the handle  14  of the hand truck to the ground, so that the ladder back frame  10  is parallel to the ground and resting on the ground.  
         [0020]    While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims.