Patent Publication Number: US-2010116118-A1

Title: Multi-Plane Hole Punch

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to industrial hole punches, and more particularly relates to an improved punch-head featuring multiple punch surfaces that, together, significantly reduce the blunt driving force necessary for forming apertures in metallic objects. 
     BACKGROUND OF THE INVENTION 
     In use, a punch and die are axially aligned with a metallic work piece located therebetween. The punch and die are brought closer and closer together until the punch is recessed into the die cavity. In the process, metal from the work piece is sheared by the cutting edges of the punch moving relative to a correspondingly shaped aperture of the die cavity. 
     Each punch has a punch face, which is the portion of the punch that actually makes contact with and pushes the metal out of the aperture in the work piece. Most industrial punch faces are simply flat surfaces having the necessary outer shape to create the desired aperture in the punched object. In terms of physics, with a flat-faced punch head, the hole is formed simply by a brute force pushing of the metal into the die. The force that is needed to push the metal out of the aperture increases exponentially as the thickness and area of the metal being punched increases. In industrial applications, punching metal with thicknesses on the magnitude of ½ of an inch and greater results in large power requirements, intense audible noise, and shaking that has detrimental effects on the lifespan of equipment and structures. 
     A few punch manufacturers have used punch-head designs that vary from the standard flat-faced punches. One such head, invented in 1883, is described in U.S. Pat. No. 294,991. The punch head described therein provides cutting faces inclined in mirror-opposing directions, with a “center pin” formed directly in the center. The supposed purpose of the inclined faces on the punch head is to distribute pressure and create a shearing force as the punch is forced into the metal. However, the extended leading edges of each of the inclined surfaces of the head described in the &#39;991 patent are not supported and cannot be used on significant thicknesses of metal because they are easily distorted or dulled. Sharpening the edges is difficult or impossible to perform because the center pin does not allow the head to be moved across a sharpening blade. In addition, the punch head described in the &#39;991 patent has a tendency to twist as it is inserted into the metal. 
     Therefore, a need exists to overcome the problems with the prior art as discussed above. 
     SUMMARY OF THE INVENTION 
     Briefly, in accordance with the present invention, disclosed is a hole punch with a body having a punching end and a longitudinal extent defining a longitudinal axis, where the punching end defines a punching face that has a first surface substantially perpendicular to the longitudinal axis, the first surface having a length substantially bisecting the punching face and a non-zero width, a second sloping surface with a slope starting substantially near an extent of and substantially near a plane of the first surface, sloping away from the first surface at a slope angle, and running in a direction of the length of the first surface, and a third sloping surface on a side of the first sloping surface opposite the second sloping surface and having a slope angle opposite the slope angle of the second sloping surface. 
     In accordance with another feature of the present invention, the slope of the third sloping surface starts substantially near an extent of and substantially near the plane of the first surface, slopes away from the first surface at the slope angle, and runs in a direction of the length of the first surface. 
     In accordance with a further feature of the present invention, the slope of the second sloping surface intersects the slope of the third sloping surface at an intersection point. 
     In accordance with yet another feature of the present invention, an imaginary line parallel to the plane of the first surface and perpendicularly intersecting the length of the first surface is parallel to an imaginary line connecting the second sloping surface to the third sloping surface at the intersection point. 
     In accordance with an additional feature of the present invention, the imaginary line connecting the second sloping surface to the third sloping surface at the intersection point is substantially directly below a center line of the first surface. 
     In accordance with another feature, an embodiment of the present invention also includes a punch body of a metallic material sufficient to withstand at least 60 pounds of compressive force, the body having a longitudinal extent defining a longitudinal axis, a base end at which the compressive force is applied to the body, the base end having a securing device shaped to releasably attach the body at least to the punch press, and a punch end opposite the base end with respect to the longitudinal axis, the punch end having a distal end surface with at least three surface portions. A first of the surface portions extends in a plane substantially orthogonal to the longitudinal axis, a second of the surface portions extends in a plane at an angle to the longitudinal axis, and a third of the surface portions extends in a plane at an angle to the longitudinal axis reverse-mirror opposite the second surface portion. 
     The present invention, according to various embodiments, provides several advantages over the prior art, such as, requiring less punching force, requiring less electricity to drive the machine using the punch, reducing wear on all parts, reducing the cost of maintenance, reducing noise, reducing shockwaves, and many more. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which, together with the detailed description below, are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
         FIG. 1  is a plan view of a hole punch in accordance with the present invention; 
         FIG. 2  is a side elevational and hidden view of the hole punch of  FIG. 1  in accordance with the present invention; 
         FIG. 3  is a fragmentary side elevational and hidden view of the hole punch of  FIG. 2  in accordance with the present invention; 
         FIG. 4  is a perspective view of the hole punch of  FIG. 2  in accordance with the present invention; 
         FIG. 5  is a partially cross-sectional and fragmentary side elevational view of the hole punch of  FIG. 2  axially aligned with a die in accordance with the present invention; 
         FIG. 6  is a partially cross-sectional, partially hidden, and side elevational view of the hole punch of  FIG. 2  held in a sharpening fixture in accordance with the present invention; and 
         FIGS. 7-10  are plan views of different punch face shapes in accordance with the present invention. 
     
    
    
     In the following, the invention will be described in more detail by exemplary embodiments and the corresponding figures. The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. These schematic illustrations are not true to scale. 
     DETAILED DESCRIPTION 
     While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. It is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention. 
     The terms “a” or “an,” as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. 
     The present invention provides a hole punch with a multi-faceted punch face that distributes shearing forces across a punch load, thereby drastically reducing the force needed to remove material from an aperture in a work piece. 
     Referring now to  FIG. 1 , the inventive hole punch  100  is shown in a top planar view. In this view, the face  102  of the punch  100  is easily seen and includes three main sections: a central flat planar section  104 , a first sloping surface  106  immediately adjacent the flat surface  104 , and a second sloping surface  108 , also immediately adjacent the flat surface  104 , but on a side opposite the first sloping surface  106  and with a slope angle mirror-opposite the slope angle of first sloping surface  106  as viewed in  FIG. 3 . When viewed from the face  102  (i.e., a plan view), the orientation of the opposing surfaces  106  and  108  can be referred to as reverse-mirror opposite, in that one of these surfaces is 180-degrees opposite to an expected orientation of the surface when a mirror is disposed therebetween. The opposing slope angles are better seen in the following figures. 
       FIGS. 2 and 3  are side elevational views of the hole punch  100  and provide a clear illustration of the slopes of the three surfaces  104 ,  106 , and  108 , as well as their relationship to each other. In the particular embodiment shown, the flat planar section  104  is elevated slightly above the two sloped surfaces  106  and  108 . This elevation, however, is not required and is not present in other embodiments.  FIG. 3 , in particular, shows a dimension  300 , which corresponds to a difference in height between the flat planar section  104  and a leading edge  302  of the second sloping surface  108 . When the dimension  300  is non-zero, the flat planar section  104  makes contact with the work piece before the leading edge  302  of the second sloping surface  108 . The downward slope of the second sloping surface  108  results in an angle  306  between a plane of the flat planar section  104  and a plane of the second sloping surface  108 . The load then transfers along the length of the second sloping surface  108 , pushing the material out of the way a little at a time. 
     Shown by hidden lines in  FIGS. 2 and 3  is the first sloping surface  106  on a side of the flat planar section  104  opposite the second sloping surface  108  and sloping in a direction mirror-opposite to the slope direction of the second sloping surface  108 . A leading edge  304  of the first sloping surface  106 , according to the embodiment shown in  FIGS. 2 and 3 , is also at a distance  300  below the surface of the flat planar section  104 . The distance  300  is not necessary, however, and can be zero in certain embodiments. 
     Additionally, as with the second sloping surface  108 , the downward slope of the first sloping surface  106  results in an angle substantially the same as angle  306 , between a plane of the flat planar section  104  and a plane of the first sloping surface  106 . The term “substantially,” as used herein, is intended to indicate something that is largely but not necessarily wholly that which is specified. When the slope angles are the same, the slope of the first sloping surface intersects the slope of the second sloping surface at an intersection point  308  when viewed from the elevational view of  FIG. 3 . The intersection point  308 , when viewed in the perspective view of  FIG. 4 , becomes an imaginary line  410  that connects the first sloping surface  106  to the second sloping surface  108 . The imaginary line  410  is parallel to a second imaginary centerline  412  that runs through the plane of the first surface  104  and perpendicularly intersects the length L of the first surface  104 . 
     In some embodiments, the slopes of surfaces  106  and  108  angle slightly outward and away from each other. In these embodiments, the imaginary line  410  will only make contact With the surfaces  106 ,  108  at a single point on the inside edge of each (the edges touching the sidewalls of the first surface  104 ) and will not rest on the entire plane of the surfaces  106 ,  108 , as does line  410 . 
     Continuing to focus on  FIG. 4 , a perspective view of the hole punch  100  is shown, where the inventive features can be seen with specificity. In particular, the view of  FIG. 4  shows a body  402  that has a punching end  406  and a longitudinal extent defining a longitudinal axis  404 . The punching end  406  defines the punching face  102 , with the first surface  104  substantially perpendicular to the longitudinal axis  404 . The first surface  104  has a length L that substantially bisects the punching face  102 . The first surface also has a non-zero width W, giving it a rectangular shape in the embodiments shown. 
     The first sloping surface  106  has a slope starting at an extent  408  of and substantially near the plane of the first surface  104 . The sloping surface  106  slopes away from the first surface  104  at a slope angle mirror-opposite to  306  (shown in  FIG. 3 ) and runs in a general direction D-D′ of the length L of the first surface  104 , although not in the same plane. The general direction D-D′ is shown in  FIG. 4  as a double headed arrow. The arrow indicates that D is one direction and D′ is a opposite to D, but in the same plane. Put in another way, the term “runs in a general direction D of the length L of the first surface  104 ,” as used herein, is intended to mean that if the angle of the slope of the sloped surfaces  106  and  108  was reduced to zero, the planes of all three surfaces would be parallel with each other. The second sloping surface  108  is shows on a side of the first surface  104  mirror-opposite the first sloping surface  106  and has a slope angle  306  (shown in  FIG. 3 ) mirror-opposite to the slope angle of the first sloping surface  106 . 
     A flange  110  is provided at a point along the body  402  of the hole punch  100  a distance away from the punching end  406 . The flange  110  is used to apply force to the punch  100  and move it toward the work piece with sufficient pressure to form an aperture in the work piece. Any force applied to the flange  110  is transferred through the punch body  402  to the punch face  102 . 
     Referring now to  FIG. 5 , a die  500  is shown. The die  500  has a cavity  502  with a shape that substantially corresponds to a shape of the punch  100 , but is slightly larger than an outer dimension OD of the shape of the punch  100 . The die cavity  502  is positioned under a work piece axially aligned with the punch  100  prior to punching. Once the work piece is in place, i.e., placed between the punch  100  and the die  500 , the punch  100  is pressed toward the die cavity  502 , through the work piece, and ultimately into the die cavity  502 . In the process, a portion of the work piece is sheared by the punch  100 . 
     Through use of the punch head shape, and slight variations thereof, in accordance with embodiments of the present invention, the force needed to punch apertures in metallic work pieces, e.g. ¼ to 1″ thick, is reduced by approximately half of that needed to punch apertures in the same thickness material using prior-art flat punch heads. In addition, the noise factor is reduced by as much as 90%, providing significant improvements to the working environment around the punch machines and reducing or even eliminating the risk of damage to worker&#39;s hearing. 
     Advantageously, the present invention is easily maintained for continued effective aperture punching. Due to the large forces that the punch face  102  is exposed to, some degradation of the surfaces  104 ,  106 ,  108  will naturally result over time. As a result, the surfaces  104 ,  106 ,  108  may require some regular sharpening or maintenance to place them back into proper condition.  FIGS. 4 and 5  show an opposing set of exemplary indentions  504  and  506  provided on a location along the body  402 . The indentions  504 ,  506 , as shown in  FIG. 6 , can be used for holding the punch  100  when sharpening the edges  104 ,  106 , and  108  of the punching face  102 , as will now be described. 
     Referring now to  FIG. 6 , the punch  100  is held in a sharpening fixture  600  by a pair of opposing members  602  and  604  that clamp onto the punch  100  by making securing contact with the opposing indentions  504  and  506 , respectively. Once secured to the fixture  600 , a sharpening blade  606  (diagrammatically shown with a double-dot-dashed line) is brought into contact with the edges  104 ,  106 ,  108 . The sharpening blade  606  can be a sharpening stone or any other material that is suitable for grinding the material of the punch, e.g., metal. 
     In the embodiment shown, the fixture  600  secures the punch  100  at an angle  608 , which is the same angle as the slope angle  306  of the first and second sloped faces  106  and  108 . When the fixture  600  is moved relative to the fixed sharpening blade  606 , the surfaces are sharpened and retain the same slope. When utilizing a fixture such as fixture  600 , the punch  100  is sharpened in one direction and then turned and sharpened in another direction. More specifically, the punch  100 , after passing under the sharpening blade  606  (or the blade being passed over the punch  100 ), the punch  100  can be released from between the opposing member  602  and  604  and turned 180 degrees so that member  602  makes contact with indention  506  and opposing member  604  makes contact with indention  504 . The fixture can then again be moved relative to the fixed sharpening blade  606  to sharpen the surfaces. 
     Punches sharpened with the sharpening fixture  600  stay sharp longer and are less prone to damage since the load forces at the punch edges are significantly reduced due to the shearing action that takes place during a typical punch. The punch displaces the material a little at a time rather than all at once, which significantly reduces the trauma inflicted by the prior-art flat-faced punches to both the machinery and the punch assembly. 
     As an additional feature, the shape of the punch head  102  can be provided in a plurality of different shapes, each of which can be used to create corresponding aperture shapes in work pieces.  FIGS. 7-10  provide some exemplary punch head shapes. For instance, punch head  702  in  FIG. 7  is square, punch head  802  in  FIG. 8  is hexagonal, punch head  902  in  FIG. 9  is octagonal, and punch head  1002  in  FIG. 10  is ovular. These exemplary shapes are in no way exhaustive of the possible punch-head shapes provided with embodiments of the present invention. 
     An improved hole punch has been disclosed that features multiple surfaces with varying slopes, which serve to drastically reduce the force needed to create apertures in metallic and other work pieces, as well as reduce the sound made at the time of impact between the punch and the work piece. Less force results in an ability to use smaller sized equipment, which eliminates the need to purchase expensive larger machinery for the facility. In short, the present invention&#39;s dramatic improvement over prior-art punches results in a dramatic reduction in trauma to the work piece, the punch, and to all other equipment driving the punch.