Abstract:
A punch tool is provided that is adapted to create a pair of spaced apart apertures through a thin-walled work piece when clamped. The device comprises a hand tool having a pair of handles and a tool head comprising a first head portion and a second head portion. The head portions pivot away from each other and bear against one another based on movement of the handles to compress a sheet of material therebetween. The head portions are T-shaped members, in which the first head portion supports a pair of dies and the second head portion supports a pair of punches adapted to be received by the dies. The head portions are clamped together, whereby the dies are punched through the work piece sheet material to form spaced apart apertures. An embodiment of the head portions contemplates an adjustable width for varying the spacing of the punches.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a punch tool for creating a pair of spaced apart apertures into sheet metal using a pair of manually operated handles for input. More specifically, the present invention provides a punch tool that comprises a pair of head portions that are pressed together to punch a pair of holes through a sheet material work piece, which is particularly useful when creating new connection points in cable tray material to connect adjacent lengths of cable trays together. 
     In commercial electrical construction, cable trays are used to support bundles of cable and other electrical wiring from ceilings and wall structures. These include elongated trays that support the cable along long lengths for cable management purposes. Typical materials for these trays are steel sheet metal, aluminum, and plastics. 
     When fitting adjoining trays together, a common connection method involves a pair of factory stamped, square holes and complimentary flanges that engage the square holes. This connection prevents the trays from pulling apart once connected and supported by the adjacent structure. The connection points are generally positioned at the distal ends of precut tray lengths. When installing cable trays intermediate length with regard to their precut length, modification of the trays and fabrication of new connector holes is necessary to join the adjacent lengths. 
     Common methods of modifying the cable trays to fit shorter spaces include cutting the precut lengths and then creating new square hole connection points. The fabrication during installation often falls short of precise while in the field. As a result, the connections can be haphazard and result in improper fitment when the trays are aligned and connected. The present invention provides a punch tool for punching spaced apart holes through sheet material that is well adapted for modification of cable trays. 
     While the application of creating square apertures in cable trays is described above and is a useful application of the present invention, this singular application should not be construed as the sole use or only application of the present invention. The tool of the present invention is a general purpose punch tool that can create a pair of apertures through sheet metal using a pair of head portions and elongated handles that press the head portions together to punch holes through the material between the head portions. Along with providing a general purpose punching tool, it should furthermore be understood that the punch protrusions and complementary punch dies may be formed having any desired shape. 
     SUMMARY OF THE INVENTION 
     The following summary is intended solely for the benefit of the reader and is not intended to be limiting in any way. The present invention provides a new hand tool for punching sheet material using a pair of handles and a pair of head portions that clamp the sheet material. 
     It is therefore an object of the present invention to provide a new and improved punch tool device that has all of the advantages of the prior art and none of the disadvantages. 
     It is another object of the present invention to provide a hand tool that is suited for punching spaced apart holes through sheet material. 
     Another object of the present invention is to provide a hand tool that comprises a pair of handles that control a pair of head portions, whereby the head portions clamp a sheet material work piece and press a pair of punches through a pair of dies to create defined apertures in the sheet material. 
     Yet another object of the present invention is to provide a hand tool that is particularly suited for punching apertures in cable trays when fabricating connections between adjacent lengths. 
     Another object of the present invention is to provide a hand tool that comprises head portions that are adjustable, whereby the spaced apart apertures created by the tool can be controlled and set for the given application. 
     Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout. 
         FIG. 1  shows a view of the first and second tool head portions along the working end of the tool. 
         FIG. 2  shows another perspective view of the first and second tool head portions along the working end of the tool. 
         FIG. 3  shows a view of the tool in its entirety, including the elongated handles. 
         FIG. 4  shows a side view of the first head portion and the punch-receiving dies thereof. 
         FIG. 5  shows a close-up view of one of the head portions, and a contemplated adjustment assembly for adjusting the separation between the outer ends of each head portion. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the punch tool of the present invention. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for punching spaced apart apertures through sheet material using a clamping tool and manual user input through the elongated handles of the tool. The figures are intended for representative purposes only and should not be considered to be limiting in any respect. 
     Referring now to  FIG. 1 , there is shown a perspective view of the punch tool of the present invention, and particularly of the head of the tool. The tool comprises a hand tool having a first handle  42  and a second handle  41  that are used to operate the tool head. The tool head performs a punching operation, whereby a pair of spaced apart apertures can be punched through sheet material when the first head portion  20  and the second head portion  10  are pressed together and clamp the sheet material therebetween. The head portions are hinged relative to one another and actuated by way of the handles, whereby the user can operate the handles to apply pressure to the sheet material work piece between the head portions. 
     The tool is used to create spaced apart apertures, whereby the apertures a clean hole through the material that take on a defined shape. The shape of the apertures is defined by the head portions, which comprise a pair of punches  11  and a pair of complimentary punch-receiving dies  21 . The dies  21  are disposed opposite of the punches  11 , whereby the second head portion supports the punches  11  and the first head portion supports the dies  21 , respectively. When the head portions are pressed together, the punches  11  enter the dies  21 . The punches are pressed through the material work piece placed between the head portions, whereby the user applies force to the handles to supply sufficient energy for the punching operation. 
     Referring to  FIGS. 1-3 , the first  20  and second  10  head portions each comprise a substantially T-shaped structure with a first and second outer end. Specifically, the first head portion  20  comprises a T-shaped structure with a first and second outer end  22 , while the second head portion  10  comprises also comprises a T-shaped structure with its own first and second outer end  12 . The first head portion includes a first and second punch-receiving die  21  disposed within the outer ends  22  thereof. The dies  21  are adapted to receive the complimentary punch  11  extending from the second head portion. The second head portion includes a first and second punch  11  extending therefrom and disposed along the outer ends  12  thereof. The punches  11  are protruding members extending from the inner surface of the second head portion  10 , which are aligned with the dies  21  of the first head portion such that the punches are received by the dies when the head portions are pressed tighter. The inner surfaces of the head portions abut against each other when the two are pressed together by way of the handles. 
     Supporting the first and second head portions and controlling their position relative to each other are the handles  41 ,  42 , which may connect directly to the head portions or may connect thereto using a pair of intermediate members  51 ,  52 . In one embodiment, the handle member  41 ,  42  are hinged to each other and directly connect to the head portions. The handles  41 ,  42  may overlap each other at the hinge joint and comprise a defined curve or bend. This direct connection affords one of two methods of pressing the head portions together. That is, the handles may be pressed together to draw the head portions together, or alternatively the handle portions may be pulled apart to press the head portions together. 
     In the embodiment shown in the drawing views, a levered configuration is provided. This configuration is similar to bolt cutter tools. This structure amplifies the mechanical advantage by providing intermediate members  51 ,  52  that are driven by the handles  41 ,  42 , whereby the handles act as levers and the intermediate members are supported by cross members  61  that act as a fulcrum points. As the handles  41 ,  42  are pressed together, the lower end of the intermediate members  51 ,  52  separate, while the upper ends of the intermediate members  51 ,  52  are drawn together. The upper ends of the intermediate members  51 ,  52  are connected to the first and second head portions  20 ,  10 . In this configuration, the handles are pivotably connected at a pivot point  45 . The upper ends of the handles are pivotably connected to the lower ends of the intermediate members  51 ,  52  and pivot the intermediate members about the cross members  61 . The cross members  61  are likewise pivotably connected at a fulcrum point  53 ,  54  along the intermediate members. This fulcrum point  53 ,  54  allows the intermediate members to pivot the head portions  10 ,  20  together and to separate the same based on the position of the handles  41 ,  42 . 
     Thus, the first handle  42  and second handle  41  are connected at a pivot point  45 . The first tool head portion  20  comprises an elongated intermediate portion  52  disposed above the pivot point  45  and pivotably connected  43  to the first handle  42 . The second tool head portion  10  further comprises an elongated intermediate portion  51  disposed above the pivot point  45  and pivotably connected  44  to the second handle  41 . Cross members  61  pivotably connect to the intermediate members  51 ,  52  at the ends thereof to form fulcrum points  53 ,  54  for the first intermediate member  52  and the second intermediate member  51 . When the handles  41 ,  42  are pressed together, the upper end of the handles separates the lower ends of the intermediate members  51 ,  52 , causing the head portions  10 ,  20  to come together along the opposite end of the fulcrum points  54 ,  53 . The handles are preferably elongated to improve the mechanical advantage of the tool when pressing the punches  11  through the material work piece and into the punch-receiving dies  21 . 
     Referring now to  FIG. 4 , there is shown a view of the first head portion  20  from a side view. The head portions comprise a substantially T-shaped construction with a first and second outer end  22 . The outer ends  22  may include an upstanding portion within which the die  21  or punch is located, however the punch and dies are separated from one another by the length  28  of the outer ends  22 . The separation allows the punched holes to be a given distance from one another. The head portions are driven by the intermediate member  51 , which is secured to the outer surface  29  of the head portions and drives the head portions together. 
     Referring finally to  FIG. 5 , there is shown an assembly  70  that is adapted to be disposed within the length  28  of the head portion outer ends for separating the punch and dies a desired distance. Therefore, the outer ends of the head portions are length adjustable, whereby the separation of the punches created in the work piece can be varied depending on the application. In one embodiment, and as shown in  FIG. 5 , the outer ends may comprise an adjustable length  28  that is separable and controlled by way of a threaded member  75  within the interior of the outer ends. The threaded member  75  is captive and rotated in place, which drives the outboard segment of the outer portion from an inboard section. In this way, the user can rotate the threaded member to change the distance between the punches and between the dies as required. 
     Specifically, the outer ends  28  of each head portion comprise an inboard segment  25  and an outboard segment  26  that are separable. The threaded member  75  is captively disposed within the inboard segment  25 , whereby the outer surface  72  of the threaded member is exposed along the inboard segment  25 . The user can rotate the threaded member  75  by physically rolling the member, whereby outer surface is pressed upon and rolled during this operation. A pair of notches  73  holds the threaded member  75  in place within the inboard segment  25  while still accommodating axial rotation thereof. The opposite end of the threaded member  75  is threadably engaged with an elongated channel  77  within the outboard segment  26 . The elongated channel  77  comprises complimentary threads  76 , whereby rotation of the threaded member  75  drives the outboard segment  26  away or towards the inboard segment  25 , depending on the rotation thereof. To prevent the outboard segment  26  from rotating, a pair of dowels  74  extends from the outboard segment  26  and into the inboard segment  25 . This in turn allows rotation of the threaded member  75  to translate the outboard member  26  relative to the inboard member  25  of the head portion when the threaded member  75  is rotated. 
     Overall, the present invention provides a manually operated punch tool that can be used to create defined apertures in sheet material. The punches and the punch-receiving dies can be shaped and sized in a desired configuration, including rectangularly shaped, rounded shaped, or the like. The tool clamps the material work piece and the handles are used to force the punch through the work piece and into the punch-receiving dies. The user can quickly and efficiently create apertures in sheet material without resorting to other, less attractive fabrication methods. The punches can be statically disposed and at a premeasured distance from one another, or alternatively the tool may include an adjustment assembly for altering the distance between the pair of punches and the pair of dies. 
     It is submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.