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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to a holder for tools, fasteners and supplies that is intended to be mounted on the top of a conventional folding stepladder having a four-legged, top-hinged frame.  
           [0003]    2. Prior Art  
           [0004]    Various stepladder-mounted pocketed holders for tools, fasteners and the like have been proposed heretofore for the convenience of a person standing on the ladder.  
           [0005]    For example, U.S. Pat. No. 4,356,854 to McGee discloses a pocketed holder for tools and supplies that is shaped to fit snugly over the top of a conventional folding stepladder. Other shaped tool holders of the same general type are disclosed in Weller U.S. Pat. No. 5,749,437, Kornblatt U.S. Pat. No. 5,813,530, and Armstrong U.S. Pat. No. 5,988,383.  
           [0006]    Cook U.S. Pat. No. 4,773,535 (FIG. 3) discloses an open-bottomed, non-folding, vertical sided, box-like tool holder that seats on top of a folding stepladder.  
           [0007]    Hardy U.S. Pat. No. 5,638,915 discloses a foldable tool holder with a rectangular central top panel that rests on top of a stepladder and four pocketed rectangular side panels or “skirtings” that hang down from the respective edges of the top panel and are attached to it by various means, including sewn stitching, a zipper, buttonable or clippable straps, and rivets. Straps are provided on the lower ends of the side panels or skirtings for tying them to the ladder&#39;s support rails.  
           [0008]    Cassells U.S. Pat. No. 5,647,453 discloses a foldable tool holder with a rectangular, central top panel that fits on top of a stepladder and four pocketed trapezoidal side panels that hang down from the respective edges of the top panel. The side panels are attachable to each other at their lower ends by hook and loop tapes on straps that respectively wrap around the legs, one front step and one back rung of the ladder.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention is directed to a novel tool holder for snug, substantially form-fitting attachment to the top of a conventional stepladder to make tools, fasteners, supplies and the like readily accessible to a person standing on the ladder.  
           [0010]    A principal object of this invention is to provide a novel and advantageous stepladder-mounted tool holder that can be readily applied to the top of the ladder with a snug fit that keeps it securely in place on the ladder.  
           [0011]    Another object of this invention is to provide such a tool holder having a manually attachable and detachable front panel that enables the remainder of the tool holder to be positioned on the ladder before the front panel is attached, and when detached enables the ladder user to stand on upper steps of the ladder without interference from the tool holder.  
           [0012]    Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment thereof, with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a perspective view taken from the rear side of a folding stepladder with the present tool holder in place thereon;  
         [0014]    [0014]FIG. 2 is a top plan view of the present tool holder unfolded;  
         [0015]    [0015]FIG. 3 is a bottom plan view of this tool holder unfolded;  
         [0016]    [0016]FIG. 4 is a front perspective view of this tool holder with its front (step side) panel partly attached;  
         [0017]    [0017]FIG. 5 is a front perspective view of this tool holder in place on the top of a stepladder; and  
         [0018]    [0018]FIG. 6 is a perspective view looking up at the front side of the stepladder with the present tool holder in place but with its front panel removed. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Before explaining the present invention in detail it is to be understood that the invention is not limited in its application to the particular arrangement shown and described since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.  
         [0020]    The present tool holder is for use with a conventional top-hinged, four-legged stepladder  10  as shown in FIG. 1. When erected, the ladder&#39;s front legs  11  and  12  extend down from a flat rectangular top piece T (FIG. 6) near its opposite ends and carry steps  13  at different levels below the top piece. The ladder&#39;s back legs  14  and  15  extend down from the top piece T near its opposite ends and they carry cross pieces  16  at different levels. When erected, viewed from the front or back the stepladder has a rectangular outline, and viewed from either end it has a trapezoidal outline.  
         [0021]    As shown in FIGS. 2 and 3, the present tool holder has a central top panel  20  of rectangular configuration that substantially matches that of the top piece T of the ladder, presenting a substantially straight front edge  21  that overlies the front edge of the ladder top piece, a substantially straight back edge  22  that overlies the back edge of the ladder top piece, and substantially straight opposite end edges  23  and  24  that overlie corresponding end edges of the ladder top piece.  
         [0022]    The top panel  20  of this tool holder preferably is constructed with a foam layer sandwiched between top and bottom sheets of leather or leather-like material. A flexible carrying handle  25  (FIGS. 1, 2 and  4 ) of suitable fabric has its opposite ends affixed to the top of panel  20  and extends parallel to the front and back edges  21  and  22  of panel  20  midway between them.  
         [0023]    On the bottom (FIG. 3), the top panel  20  carries a pair of pads  26  and  27 , each of which is elongated perpendicular to the front and back edges  21  and  22 . Elongated straps  28  and  29  of suitable fabric are each affixed at one end to the bottom of panel  20  near its back edge  22 . Metal D-rings  30  and  31  are pivotally mounted on the bottom of panel  20  near its front edge  21 . The free ends of straps  28  and  29  can be passed through these D-rings and folded over on themselves (FIG. 6). Complementary hook or loop fastener strips of Velcro® are provided on the confronting faces of the straps where they are folded over so that they can be manually attached to and separated from each other. In use, each strap  28  or  29  is passed under the top piece T of the ladder and through the respective D-ring  30  or  31  and pulled tight before the hook and loop fastener strips are brought into interlocking engagement with each other to hold the top panel  20  of the tool firmly in place on the top piece T of the ladder.  
         [0024]    A left panel  32  of this tool holder of suitable material is joined to the top panel  20  along its left edge  23 , such as by sewn stitching, and hangs down from it to the left of the ladder when the tool holder is in place on the ladder, as shown in FIG. 1. Panel  32  has a trapezoidal shape (narrower at the top) substantially matching the trapezoidal outline of the left end of the ladder in its erected state. On the outside, the left panel carries a large pouch  33  that provides a plurality of open-topped pockets for receiving and holding various tools, screws, nails, and other supplies. A tool holder loop  34  also is affixed to the outside of pouch  33  near its lower end. A metal D-ring  35  is pivotally affixed to the left panel  32  near its bottom edge.  
         [0025]    A similar trapezoidal right panel  36  of the tool holder is joined in the same manner to its top panel  20  along its right edge  24 . On the outside, panel  36  carries a pouch  37  providing several open-topped pockets for holding different tools, fasteners, or other supplies. A tool holder loop  38  is affixed to the outside of pouch  37  near its lower end.  
         [0026]    The tool holder of this invention has a back panel  39  of rectangular shape substantially matching the rectangular configuration of the back side of the ladder. Panel  39  carries a compartmentalized pouch  40  extending across substantially its full width up from its lower edge and providing three large open-topped pockets  40 . Inside these large pockets are a plurality of open-topped inner pockets  41  of smaller cross-sectional size for holding individual tools, such as screw drivers. The back panel  39  is joined to the top panel  20  along the latter&#39;s back edge  22  in the same manner as the left and right panels  32  and  36  are joined to top panel  20 .  
         [0027]    The material of each end panel  32  and  36  and the back panel  39  is sufficiently flexible that this panel hangs down from the top panel  20  next to the corresponding side of the ladder when the tool holder is in place on the ladder. Panels  32 ,  39  and  36  carry hook and loop fastener strips along their neighboring downwardly extending edges so that they may be wrapped snugly against the ladder.  
         [0028]    As thus far described, the present tool holder has a top panel, a back panel, and opposite end panels. As thus constituted, it may be readily applied to the upper end of the step ladder, with the top panel  20  strapped to the top piece T of the ladder, and the back panels  39 , the left panel  32  and the right panel  36  extending down next to the corresponding sides of the ladder, leaving the front side of the ladder (where its steps  13  are located) open from the top down. For certain jobs the user may choose to leave the tool holder this way on the ladder so that he or she can stand on upper steps of the ladder without interference from the tool holder.  
         [0029]    However, in most situations the user will attach a front panel of the tool holder to its top panel  20  so as to provide additional storage capacity at the front for tools and supplies. This front panel of the present tool holder is shown at  50  in FIGS. 2, 3,  4  and  5 . It carries a plurality of open-topped pockets  51  extending side-by-side up from the lower edge of the panel. At the top the front panel  50  carries a pair of laterally spaced latch plates  52  and  53 , each with two projecting prongs P (FIG. 4). A pair of buckles  54  and  55  extend from the front of top panel  20  for slide-in reception and locking engagement therein of the respective latch plates  52  and  53 , which snap into locking engagement with the buckles in essentially the same manner as a passenger car seat belt. Each buckle  54  and  55  preferably has a push-button release enabling the separation of the corresponding latch plate from locking engagement with the buckle when the user decides to detach the front panel  50  from the rest of the tool holder. Preferably, the front panel  50  has hook or loop fastener strips along the sides for manually attachable and detachable interlocking engagement with complementary loop or hook fastener strips on the adjacent sides of the neighboring end panels so that the complete tool holder (including the front panel  50 ) has a snug fit on the upper part of the stepladder.  
         [0030]    From the foregoing, it will be evident that the illustrated embodiment of this invention can be conveniently and readily applied with substantially form-fitting engagement to the top of the stepladder absent the front panel, which may be attached afterward or left off depending on the user&#39;s preference.

Summary:
A tool holder for mounting on the top of a conventional stepladder. The holder has trapezoidal pocketed end panels and a rectangular pocketed back panel each flexibly connected to a top panel that can be strapped to the top piece of the ladder. The end and back panels conform closely to the outlines of corresponding sides of the ladder at its upper end and are attachable to each other at adjoining side edges to fit snugly around the ladder. A pocketed front panel is manually attachable to and detachable from the top panel.