Abstract:
A hole punch has a length in a first direction, a plurality of punch blocks each having a sinusoidal first guide surface, a slider movable along a frame in the first direction, and a roller connected to the slider at a position to engage the first guide surface of each punch block. Each punch block is fixed in the frame in the first direction and is moveable in the frame in a second direction perpendicular to the first direction. Each punch block also includes at least a punch head facing the second direction, and a retracting mechanism for urging the punch block in opposite the second direction to an initial position. When the slider moves in the first direction along the frame, the roller pushes the first guide surface near the middle of the punch block moving the punch block in the second direction to punch holes.

Description:
BACKGROUND OF INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a hole punch, and more specifically, to a punch for making a plurality of holes in a medium such as paper.  
         [0003]     2. Description of the Prior Art  
         [0004]     Hole punches are common devices found in offices, schools, and homes. Hole punches serve to punch or cut holes into one or more sheets of paper. The result is that the punched paper can then be stored in a binder or bound by some other means.  
         [0005]     The working principle of the common three hole punch is straightforward. A lever arm is hinged to a base, and three hole punch heads are connected to the lever arm. When a user presses down on the lever, the three hold punch heads are driven into receptacles in the base thereby cutting holes into paper placed on the base. Such a hole punch is suitable for light use; since the holes are punched simultaneously and by human effort, this type of punch is limited in the number of holes and in the number of sheets of paper that can be punched.  
         [0006]     One notable improvement in the basic hole punch is taught by Mori in U.S. Pat. No. 5,463,922, which is included herein by reference. Mori&#39;s punch is capable of cutting a large number of holes into several sheets of paper. Briefly, referring to  FIG. 1 , a slide rail  11  has a multiplicity of pairs of first slots  15 . Each pair of first slots  15  is provided for supporting an actuator pin  13  for actuating a cutting tool  17 . A slider  14  is fitted on the slide rail  11  and is slidable along it to engage the actuator pins  13  and thereby lower the cutting tools one after another to make a line of holes in paper. The slider  14  has an arch-shaped cross section to fit slidably over the slide rail  11  and has an inner surface provided with an upper guide surface  143  and a lower guide surface  144  which define a guide groove in which the actuator pins  13  are engageable to move the cutting tools  17  vertically. When the slider  14  is slid along the rail  11 , the guide surfaces  143 ,  144  move the actuator pins  13  driving the cutting tools down and up.  
         [0007]     While Mori&#39;s hole punch is one solution of how to cut a large number of holes into several sheets of paper, it suffers from several drawbacks. First, for each hole to be cut, there is one moving cutting tool  17 . Thus for 30 holes, at least 30 separate moving parts are required, and with each moving part comes the risk of malfunction. Second, the actuator pins  13  are required to be small diameter, and are thus prone to breakage or to damaging the guide surfaces  143 ,  144 . Given these two drawbacks, and more may be apparent to a skilled designer or user, there is a need for an improved hole punch.  
       SUMMARY OF INVENTION  
       [0008]     It is therefore a primary objective of the claimed invention to provide a punch for making a plurality of holes in a medium such as paper to solve the above-mentioned problems of the prior art.  
         [0009]     Briefly summarized, the claimed invention includes a frame having a length in a first direction, a plurality of punch blocks each having a first guide surface, a slider movable along the frame in the first direction, and a protrusion connected to the slider at a position to engage the first guide surface of each punch block. Each punch block is fixed in the frame in the first direction and is moveable in the frame in a second direction perpendicular to the first direction. The first guide surface faces opposite the second direction and spans from one end of the punch block to the other end along the first direction, being further in the second direction at the two ends of the punch block than at the middle of the punch block. Each punch block further comprises at least a punch head facing the second direction, and a retracting mechanism for urging the punch block in opposite the second direction to an initial position. When the slider moves in the first direction along the frame, the protrusion pushes the first guide surface near the middle of the punch block moving the punch block in the second direction.  
         [0010]     It is an advantage of the claimed invention that more than one punch can be driven by a punch block, reducing the number of mechanical parts and likelihood of malfunction.  
         [0011]     It is an advantage of the claimed invention that the first guide surface of the punch block and the protrusion can be made at a robust a scale to avoid damage to the punch.  
         [0012]     These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]      FIG. 1  is a schematic diagram of a prior art punch.  
         [0014]      FIG. 2  is a perspective diagram of a punch according to the present invention.  
         [0015]      FIG. 3  is a perspective diagram of the punch of  FIG. 2  with one side plate removed.  
         [0016]      FIG. 4  is an exploded perspective diagram of the punch of  FIG. 2 .  
         [0017]      FIG. 5  is a schematic diagram of the operation of the punch of  FIG. 2   
         [0018]      FIG. 6  is a perspective diagram of a second embodiment of the punch block of  FIG. 2 .  
         [0019]      FIG. 7  is a perspective diagram of a third embodiment of the punch block of  FIG. 2 .  
         [0020]      FIG. 8  is a perspective diagram of a fourth embodiment of the punch block and side plates of  FIG. 2 . 
     
    
     DETAILED DESCRIPTION  
       [0021]     Please refer to  FIG. 2  illustrating a punch  10  according to the first embodiment of the present invention. The punch  10  includes a frame  20  inside which several punch blocks  30  are situated. The frame  30  is fastened to a base  70  so the punch blocks  30  are restricted from moving along the length of the frame  20 . Attached to each side of the frame  20  are two side plates  40  for keeping the punch blocks  30  inside the frame  20  among other things (described later). Also provided is a slider  50  slidable along the frame  20 , the slider  50  being held to the frame  20  and/or to the side plates  40  as necessary by straight guide grooves (not shown) or a similar well-know mechanism.  
         [0022]      FIG. 3  illustrates the punch  10  with one side plate  40  removed. In  FIG. 3 , the punch blocks  30  are more visible.  
         [0023]     Referring to  FIG. 4 , an exploded view of the punch  10 , the frame  20  includes a rail  202  and two ends  204 . The rail  202  provides a surface for the slider  50  to slide upon. The ends  204  serve to anchor the frame  20  to the base  70 . The ends  204  need not be exactly as depicted, alternative structures are also suitable. The dimensions and precise shape of the frame  20  can be selected according to suitable mechanical properties of the materials used among other considerations, however, the length of the rail  202  should be selected considering the size of the medium to be punched, and the height of the ends  204  should be selected considering the height of the punch blocks  30  and the maximum thickness and quantity of the medium to be punched. The frame  20  could be metal or hard plastic.  
         [0024]     Each punch block  30  comprises a block body  302  and a first guide surface  304  formed in the block body  302 . The first guide surface  304  has a sinusoidal or hill-valley-like shape. Offset above the first guide surface  306  and having a corresponding shape is a second guide surface  306 . First and second guide surfaces  304 ,  306  can have continuous curvature or be a made of a series of adjacent flat planes. The punch block  30  further includes four pins  308  (two on the reverse side not visible) protruding laterally from the block body  302 , and four punch heads  310  protruding downward from the block body  302 . The punch heads  310  are cutting tools, hole punch heads, or the like and are for cutting holes in the medium. In other embodiments, the quantities of the pins  308  and punch heads  310  can be changed (these quantities are independent), with minimum or maximum numbers being a design choice. The block body  302  can be made of any shape and material, and can be optimized for weight, material use, and manufacturing concerns. As one example, the entire punch block  30  could be hard plastic with the exception of the punch heads  310  being wear-resistant steel.  
         [0025]     Each side plate  40  includes a plate  402  in which a plurality of slots  404  and a window  406  are punched, cut, or otherwise formed. The plate  402  can be made of metal or hard plastic. The slots  404  correspond to the pins  308  of the punch blocks  30 . Each slot  404  has a slight constriction, or narrowed part, near the top which holds the pin  308  against the weight of the punch block  30 . An external force is required to move the pin  308  (and thus the block  30 ) past the constriction into the remaining part of the slot  404  in which the pin  308  can freely move. The slots  404  of the slide plates  40  serve to hold each punch block  30  at the topmost part of its range—the initial position of the punch block  30  (described later).  
         [0026]     The slider  50  includes a slider frame  502 , a pair of rollers  504 , and a handle  506 . The frame  506  is formed in an overall U-shape to straddle and slide along the rail  202 , although other shapes that accomplish this are also suitable. Each roller  504  is installed on an inside wall of the frame  502  and is positioned to engage with the first and second guide surfaces  304 ,  306  of each punch block  30  through the window  406  of the side plate  40 . Though the roller  504  need not actually rotate, this helps in reducing wear to the guide surfaces  304 ,  306 . The frame  502  is held to the rail  202  and/or side plates  40  by straight guide grooves (not shown for clarity) or similar well-know mechanism such that vertical movement of the rollers  504  is prevented. The height at which the roller  504  is located is selected so that the roller  504  applies substantially no force to either the first or second guide surface  304 ,  306  when the roller  504  is near the end of a punch block  30  (i.e. between two punch blocks  30 ) when the punch block  30  is in the initial position. The handle  506  of the slider  50  is located at the top of the frame  502  and is for a user to comfortably manually move the slider along the frame  20 . The slider  50  may be made of metal or hard plastic.  
         [0027]     The base  70  includes a base plate  72  and a plurality of holes  74 . The plate  72  connects to the ends  204  of the frame  20  by preferably a removable fastening mechanisms such as bolting or clipping. The holes  74  line up with the punch heads  310  of the punch blocks  30  and are important to the cutting action of the particular type of punch head  310  described. Since other types of punch heads or cutting heads are suitable for use in the invention, the holes  74  in the base  70  may be omitted or changed to a suitable form, the base plate  72  serving essentially to provide a location for the stationary part of whatever cutting tools used. The base  70  is preferably made of metal, however hard plastic is also suitable.  
         [0028]     In addition, a hole plate  60  is provided as shown in  FIG. 4 . The hole plate  60  includes a plate  62  punched with a plurality of holes  64 . The holes  64  engage with the punch heads  310  regardless of the position of the punch block  30 , so that the hole plate  60  serves to keep the punch blocks  30  properly aligned. The hole plate  60  is optional and is simply provided to improve the performance of the invention, and other types of cutting tools may preclude its use. The hole plate  60  can be made of metal or hard plastic.  
         [0029]     Regarding the operation of the punch  10 , please refer to  FIG. 5 .  FIG. 5  illustrates a schematic of key parts of the invention. Also illustrated are arrows indicating a first direction  102  and a second direction  104 , and paper  80  to be punched. The symmetry of the invention described above allows the first direction  102  to be bi-directional, meaning that either left or right on the page of  FIG. 5  can be considered the first direction  102 . When the user pushes the slider  50 , the roller  504  is constrained to move along the dashed line in the first direction  102 . The roller  504  enters the punch block  30  and contacts the first guide surface  304  thereby pushing the block  30  in the second direction  104 . As the block  30  leaves the initial position, the pin  308  passes through the constriction of the slot  404  and enters the free-moving range of the slot  404 . As the roller  30  leaves the punch block  30 , it contacts the second guide surface  306  and pulls the block  30  back up to the initial position. As the block  30  returns to the initial position, the pin  308  passes through the constriction of the slot  404  causing the block  30  to be held in place. Thus, as the roller  30  traverses through all the blocks  30 , it causes sets of holes (the size of a set determined by the number of punch heads  310  per block) to be punched into the paper  80 .  
         [0030]     The second guide surface  306  and the pins  308  and slots  404  act as a retracting mechanism for the block  30 . Other embodiments of the retracting mechanism are illustrated in  FIG. 6-9 .  FIG. 6  shows a block  32  without an upper guide surface or pins, the absence of pins allowing the slots  404  on the plate  402  to be omitted. The block  32  includes a block body  322 , a lower first guide surface  324  formed in the block body  322 , a coil spring  326 , and three punch heads  328 . The coil spring  326  is connected to the underside of the rail  202  (or similar structure) and provides the retracting action to the block  32 . That is, the coil spring  326  tends to pull the block  32  opposite the second direction  104  (i.e. up). The coil spring can also be located below the block  32  as indicated by  326 ′ so as to push the block  32  opposite the second direction  104 . The coil spring  326  has the other end connected to the hole plate  60  or base  70 . In other aspects, operation of a present invention punch including blocks  32  is the same as that of the punch  10 .  
         [0031]      FIG. 7  illustrates another block  34  for use in the present invention punch. Like the block  32 , the block  34  is without an upper guide surface or pins, the absence of pins allowing the slots  404  on the plate  402  to be omitted. The block  34  includes a block body  342 , a lower first guide surface  344  formed in the block body  342 , a flat spring  346 , and two punch heads  348 . The flat spring  346  is connected to the underside of the rail  202  (or similar structure) and provides the retracting action to the block  34 . Specifically, the flat spring  346  tends to pull the block  34  opposite the second direction  104  (i.e. up). The flat spring can also be located below the block  34  as indicated by  346 ′, having the other end connected to the hole plate  60  or base  70 , so as to push the block  34  opposite the second direction  104 . In other aspects, operation of a present invention punch including blocks  34  is the same as that of the punch  10 .  
         [0032]      FIG. 8  illustrates another block  36  according to the present invention. The block  36  includes a block body  362 , a first guide surface  364 , a second guide surface  366 , a single punch head  368 , and slots  370 . The slots  370  are for mating with pins  464  of a side plate  46 , which is made of a plate  462  that includes a window  466 . The block  36  and side plate  46  are similar to the block  30  and side plate  40  except that the locations of the pins and slots are reversed. Operation of a present invention punch including blocks  36  is the same as that of the punch  10 .  
         [0033]     As illustrated in the other embodiments of the block, the block used in the present invention can have any number of punch heads. In addition, the punch can be designed to punch any number of holes, which need not be uniform in spacing nor style/shape. The punch heads can also be designed to punch or cut appurtenances other than round holes. Moreover, the punch can be used to punch holes into any material, paper merely being an example. Other materials for which the punch is suited include textiles, plastic, thin metal, and cardboard. Additionally, the construction materials of the punch described above can be altered to suit manufacturing needs. For instance, the entire punch can be made of metal if desired. The shape of block  30  can be optimized as it depends on the manufacturing process and material used (i.e. the block shape can be made hollow or can be made with material-saving cavities). It should also be noted that any combination of one or more than one spring (coil, flat, or other) at any position relative to a punch block can be used to provide retracting action to the punch block, in lieu of the upper guide surface and associated pins and slots. Finally, although depicted as a cross-section-symmetrical device, the entire punch can be made in a half-section (as if split down the length about the axis of symmetry) with only trivial modifications apparent to anyone skilled in the art.  
         [0034]     In contrast to the prior art, the present invention provides a punch block by which one or more punches can be driven, reducing the number of mechanical parts and the likelihood of malfunction. In addition, the first guide surface of the punch block and the protrusion (i.e. the roller) can be made at a robust a scale to avoid damage to the moving parts.  
         [0035]     Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.