Abstract:
A punch device for punching parallel slots in sheets to facilitate the mounting of card-like objects on sheets. The device comprises a male plate on which at least one pair of cutting projections are mounted. The device also comprises a female plate moveably hinged to the male plate through which rectangular slots are formed, each slot being so positioned as to correspondingly face one of the cutting projections in the male plate. The hinge assembly comprises an axle part and a swivel part. The axle part comprises cams and the swivel part comprises grooves. The cams are positioned to penetrate the grooves and wrap around over an angle less than the whole circumference of the axle part.

Description:
FIELD OF THE INVENTION 
   This invention claims the benefit of US Provisional Application No. 60/600479 with the title, “Card Slot Punch Device” filed on Aug. 11, 2004 and which is hereby incorporated by reference. Applicant claims priority pursuant to 35 U.S.C. Par 119(e)(i). The present invention is an office stationary device paper punch. More specifically it relates to a light and portable paper punch used to cut precision slots into a letter to hold diagonally opposite corners of a card such as a business card. 

   BACKGROUND 
   To appreciate the innovative attributes of this invention, it is important to distinguish between paper-punch devices that produce slits and those that produce slots. In a slit, the paper is simply cut along a line segment, and no paper material is removed from the sheet. The edges of a slit touch each other. In a slot, the paper is cut according to an approximate rectangular shape. Paper material is removed and the edges of the slot do not touch each other. Because of their greater opening, a slot is significantly more convenient to use when inserting a business card than a slit. In addition, a slot is less likely to tear since its ends are rounded. While this particular “slit/slot” nomenclature is used in this patent application to distinguish between slits and slots, the prior art does not always make this distinction clearly. 
   In addition, it is also important to distinguish in the prior art those devices equipped with easily assembled/disassembled hinges from those with fixed hinges. Paper punches equipped with easily assembled/disassembled hinges have the potential of being significantly less expensive to manufacture and to assemble. 
   None of the devices described in the prior art achieves the combination of economy with functionality that this invention provides. 
   For example, the invention described in U.S. Pat. No. 914,613 by Storlie benefits from an economical design that consists of a simple rectangular sheet metal plate approximately folded in a springy V-shape and stamped to display sharp edges. When the device is pressed, the sharp edges cut slits in paper. 
   Another invention by Scalise, in U.S. Pat. No. 4,879,932 describes a paper punching device that produces slits. These slits are produced by “slitting blades” mounted on a first platen, that face “complementary slots formed in a second platen” In addition, the device cannot be easily assembled or disassembled. 
   The invention described in U.S. Pat. No. 4,893,535 by Bentrim produces slits: the punching element as described in all of its independent claims and in its  FIG. 18  is a blade. The hinge used by that device cannot be easily disassembled. 
   U.S. Pat. No. 4,941,381 by Garner describes a paper punching device that produces slits. This is evidenced by the fact that the cutting element is a blade as described in its claim and in its  FIG. 7A . 
   U.S. Pat. No. 5,611,254 by Rail describes a paper punch capable of making holes in a diversity of shapes including circular, semicircular, triangular and rectangular holes. This device, however, is complex: its hinges are fixed; the punching elements are metal rods as evidenced in that patent  FIG. 5 . The complexity of the device, together with its form factor which includes a large vertical dimensions gives the device a poor portability. 
   Hence, there is a need for a device capable of making slots, with a hinge mechanism that can be easily disassembled, and with a high portability. 
   It is therefore an object of this invention to provide greater safety by replacing tile sharp blade used in most other prior art by a blunt approximately squared-edged male projection that reciprocatingly engages into a female “slot.” 
   It is an additional object of this invention to punch paper slots rather than paper slits to facilitate mounting of business cards or the like, and to increase the resistance to tears. 
   It is yet another advantage of this device to be cheaply assembled because of its hinged structure. 
   Further features, aspects, and advantages of the present invention will be more fully understood when considered with respect to the following detailed description, claims and accompanying drawings. 
   SUMMARY OF THE INVENTION 
   This invention is a paper punch device specially designed to punch slots to hold business cards or the like. It comprises two plates, a male plate comprising a number of projections and a female plate comprising an equal number of slots. The two plates are hinged together such that, in the closed position, the male projections fit exactly into the female slots. In addition, the edges of the projections and of the slots are sharp enough to punch slots into paper. Several embodiments are described such as a four punch device, a two punch device, a punch mechanism generating rectangular slots in paper, a punch mechanism generating slots with rounded edges, a male punch with a flat top, and a male punch with a concave top. The hinge of the device designed to facilitate the manufacturing process allows the device to be assembled or disassembled when it is open at an angle of approximately 270 degrees. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a three dimensional view of a two-punch device. 
       FIG. 1A  provides a three-dimensional exploded view of the two punch device. 
       FIG. 2  illustrates an exploded view of the top view of a two-punch device. 
       FIG. 3  shows a three dimensional view of a four-punch device. 
       FIG. 4  provides an exploded view of the top view of a four-punch device. 
       FIG. 5  illustrates a top view of the male projection equipped with a rectangular slot cutter. 
       FIG. 6  illustrates a top view of the rectangular female slot. 
       FIG. 7  shows a top view of the male projection equipped with a smooth-angled slot cutter. 
       FIG. 8  provides a top view of a female slot with smooth angles. 
       FIG. 9  shows a male punch projection equipped with a flat top. 
       FIG. 10  illustrates a male punch projection equipped with a concave top. 
       FIG. 11  shows an exploded side view of the device. 
       FIG. 12  illustrates the angular state for the device to be assembled or disassembled. 
       FIG. 13  shows the device open at 180 degrees. 
       FIG. 14  shows the device in a closed position. 
       FIG. 15  illustrates the device in an open perspective view. It shows a paper stop as a rectangular block abutting the hinge. 
       FIG. 16  illustrates the device in an disassembled state. It shows a paper stop as a rectangular block abutting the hinge. 
   

   DETAILED DESCRIPTION 
   As shown in  FIG. 1  this device is made in two separate plates  1  and  2  that can easily be joined together by means of a hinge  3  to form a paper punch specially designed to cut diagonally placed slots.  FIG. 1A  provides an exploded view of the device. The purpose of the device is to cut slots for mounting cards such as business cards on a sheet of paper, Bristol board or the like. 
     FIG. 2  shows the two plates  1  and  2  disassembled. These plates are typically made of hard plastic material or the like and can be manufactured by an injection molding process, for example. They are hinged together at the shorter side of the rectangle. The male hinged plate  1  carries a set of protrusions  4  that form the male part of the punch, and the female plate  2  has a set of slots  5  that form the corresponding female part of the punch. In addition, each hinged plate carries either the male part  6  of the hinge  3  or the corresponding female part  7  of the hinge  3  or vice versa. (Assigning male hinge to male plate and female hinge to female plate is not necessary, and the assignment can be reversed.) Further, the punching device includes projecting portions  11 . 
   Punch and Slot Mechanism. 
   The female plate  2  of the device comprises a hinged rectangle penetrated by small slots  5  at its corners. The slots  5  are approximately diagonal, being placed at about a 45 degree angle to the edge of the rectangle. The slots  5  are approximately 3 mm wide and 18.5 mm long. They penetrate the female hinged plate  2  completely forming a see-through rectangular hole. 
   The male plate  1  of the punch is hinged to the female plate  2  and carries punch projections  4 . These male projections  4  are so placed that they insert themselves exactly into the slots  5  found on the female hinged plate  2  when the two hinged plates are brought together. 
   Several versions of this invention are described. The first version shown in  FIG. 1  incorporates only two punches. Two projections are located at opposite corners of the male plate and two slots are located at corresponding corners of the female plate. 
   In another version shown in  FIG. 3 and 4 , the invention comprises four punches consisting of one projection  4  at each corner of the male plate  1  and one slot  5  at each corner of the female plate  2 . 
   The punches themselves can be made in different ways. As shown in  FIGS. 5 and 6  the projections  4  and the slots  5  can be rectangular. In yet another version the punches and slots can be rectangular with rounded corners as shown in  FIGS. 7 and 8 . This design has the advantage of producing slots in paper with rounded corners to minimize stress and tearing. 
   These male punch projections  4  differ from simple blades in that they are shaped with their top approximately flat as shown in  FIG. 9  or slightly concave as shown in  FIG. 10 , defining a cutting edge with angles between the top and the sides slightly less than or equal to 90 degrees. It is important to note that the angle is “sharp” in the sense that it is not rounded and is so designed to enable the projections to cut slots instead of slits in paper. The cutting surface of the punch is achieved by maintaining a sharp angle of 90 degree or slightly smaller at the edge where the vertical sides of the rectangular punch meet the concave surface face. The projections  4  are slightly smaller than the slots, that is, they are about 2.5 mm wide and 18 mm long. They are positioned exactly facing their corresponding slot  5  on the female hinged plate  2  when the punch mechanism is depressed. They have a height of about 2.5 mm sufficient to allow them to penetrate their slot  5 . 
   It is important to note that, even though the absolute dimensions of the male projection and the slot are not critical, their relative dimensions are important and must conform to a “slip-fit.” The term “slip-fit” applies to cases involving a tight tolerance. 
   The projection design of  FIG. 10  showing a concave curve of the cutting edge allows the projection  4  to engage the corresponding slot  5  first from the outside edge and then work inward towards the center of the slot, cutting the paper as it penetrates into the slot. 
   The projections could have a width between 2 and 2.5 mm, a length of about 18 mm, and a height of about between 6 mm and 8 mm above said male plate. The slots should be slightly larger than the Cutting projection by a clearance ranging from 0.2 mm to 0.05 mm. Preferably the slots Should have a clearance ranging from 0.1 mm to 0.05 mm. 
   The male punch projections nearest the hinge can be altered to be approximately 1 mm shorter than the male punch projections farthest away from the hinge to compensate for the different lengths in the arc of the two plates as they swing to a close, thereby allowing the slots to be cut simultaneously. 
   Stop Mechanism. 
   As shown hi  FIGS. 5 ,  7 ,  9  and  10  each hinged plate includes a stop system  10  to prevent “over-closure” in which the punch projections traverse the slot in its entirety thus becoming exposed and presenting a danger to the user. 
   The stop  10  could be incorporated into the base of the punch area and made approximately the same shape as, but slightly larger than, the slot  5 . For example the stop  5  could have a length of about 18 mm in length, a width ranging from 5.0 mm to 7.0 mm and a height above the male plate ranging from 3.5 mm to 4 mm. Preferably, the width could be about 6.0 mm and the height about 4 mm above the above the base plate. Being larger than the slot, the stop  5  prevents the Cutting punch projection  4  from penetrating the slot  5  more than 2.5 mm. 
   Alternatively, the stop  10  could be located on the slot side, essentially creating a rim around the slot area. The slot would then become elevated in relation to the rest of the female hinged plate of the punch system. 
   In yet another variation, a combination of the two alternatives described above could be used, in which a first part of the stop would be provided by a thickening at the base of the punch projection and a second part, by an elevation of the slot above it, substrate. 
   Hinge Assembly 
   The hinge assembly  3  includes on one side the male part  6  or axle part  6  and on the other the female part  7  or swivel part  7 . The assembly allows the male plate  1  and the female plate  2  of the punch to rotate with respect to each other until the plates abut each other. The hinge also ensures that the male punch projections  4  fit exactly into the female slots  5  as the device is closed. As shown in  FIG. 2 ,  4  and  11  the hinge includes on one side, cam guides  9  that fit grooves  8  located on the other side. In the assembled position, the cam  9  and groove  8  combination prevents the two sides of the hinge from sliding along its axis and coming apart. However, as shown in  FIG. 11 , the cams  9  do not extend all around the circumference of the hinge  3 , thus permitting the hinge  3  to be taken apart when the angle between the male plate  1  and the female plate  2  approaches 270 degrees as shown in  FIG. 12 . In this manner the punch mechanism can easily be assembled or disassembled. This feature simplifies assembly of the device during manufacturing. It should be noted that the hinge mechanism can be reversed, that is the grooves can be placed in the male plate and the cam in the female plate or vice versa. 
   To assemble the device, the male plate  2  and the female plate  1  must be joined together at an angle of approximately 270 degrees. The plates are then slid with respect to each other to engage the hinge. In the 180 degree position shown in  FIG. 13  or in the closed position, shown in  FIG. 14  the cam and groove are fully engaged and prevent the hinge from sliding, keeping the device securely assembled during normal operation. To perform the disassembly, the reverse operation is performed. 
   Paper Stop or Card Stop Feature 
   As shown in  FIGS. 1 ,  2 ,  3 ,  4 ,  11 ,  12 ,  13  and  14 , guides  12  can be located in the card punch device to facilitate the positioning of the paper inside the device. This guide or paper stop is incorporated on the female plate. It allows the paper inserted into the punch to be placed at an exact and repeatable position. This paper stop should be approximately 1.5 mm wide, 2.5 mm high, and 40 mm long. The edge of the paper stop should be located approximately 1.5 mm from the edge of the hinge assembly. This paper stop should protrude from the female plate and make a 90 degree angle with the surface of the plate on the side presented to the paper. 
   Optionally the paper stop could be constructed as shown in  FIGS. 15 and 16 . The paper stop  14  would be formed as a rectangular block of plastic abutting the hinge assembly  3 . This paper stop  14  would be 1.5 mm wide, 2.5 mm high and 2.5 mm long. Two such paper stops would be fabricated, one for each side of the hinge assembly  3 . 
   As shown in  FIGS. 1 ,  1 A,  2 ,  3 ,  4 , a logo  13  can be inserted on the device. Such a logo  13  can be used to publicize the name of a company for marketing or business purposes. 
   While the above description contains many specificities, the reader should not construe these as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possible variations within its scope. Accordingly, the reader is requested to determine the scope of the invention by the appended claims and their legal equivalents, and not by the examples which have been given.