Patent Application
20100116118
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.
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 '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 '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.
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.
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.
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.
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
Shown by hidden lines in
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
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
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
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
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'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.
Referring now to
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.
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'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.
