Patent Publication Number: US-6219925-B1

Title: Punch having changeable punching member

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a punch, and more particularly to a punch having one or more punching members that may be replaced with each other. 
     2. Description of the Prior Art 
     Typical punches comprise a punch rod slidably received in a housing, a knob secured on top of the punch rod for forcing the punch rod downward to cut or to punch the sheet members. A spring is engaged with the punch rod for biasing the punch rod away from the sheet members before the punch rod is depressed against the sheet members. The punch rod has a predetermined shape which may be used to punch or to form a predetermine-shaped pattern on the sheet members. The patterns may not be changed. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional punches. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a punch including one or more punching members that may be replaced and changed with each other according to the user&#39;s need. 
     In accordance with one aspect of the invention, there is provided a punch comprising a plate, a mold piece disposed on the plate and including a cavity formed therein, an arm including a first end having a barrel secured thereon, and including a second end secured to the plate, a shaft slidably received in the barrel and including a bottom end extended downward and outward of the barrel, a punch rod secured to the bottom end of the shaft and moved in concert with the shaft, means for moving the shaft and the punch rod downward to actuate on the mold piece. 
     The shaft includes a middle portion, the moving means includes a lever having a first end pivotally secured to the barrel at a pivot axle and having a middle portion, and a pin engaged through the middle portions of the lever and of the shaft for allowing the lever to move the shaft and the punch rod to actuate on the mold piece. The barrel includes an oblong hole formed therein for slidably receiving the pin and for allowing the pin to be moved up and down relative to the barrel. A spring biasing device is further provided for biasing the shaft and the punch rod away from the mold piece. 
     A securing device is further provided for securing the punch rod to the shaft and includes a catch secured to the shaft and having one or more ribs detachably engaged into one or more engaging channels of the punch rod for detachably securing the punch rod to the shaft. A gasket is further engaged between the punch rod and the catch for securing the punch rod to the catch. 
     A device is further provided for aligning the punch rod with the mold piece and includes a housing having a bottom portion, a board secured to the bottom portion of the housing and having a hub provided thereon for slidably receiving the punch rod, and means for guiding the punch rod to move relative to the housing and the board. The guiding means includes at least one guide rail formed on the hub of the board, and at least one slot formed in the punch rod for slidably receiving the guide rail and for guiding the punch rod to move relative to the housing and the board and for preventing the punch rod from being rotated relative to the housing and the board. 
     The housing includes at least one depression formed therein, the board includes at least one projection extended therefrom and engaged into the depression of the housing for further securing the board to the housing. A panel includes a hole formed therein for receiving the mold piece, and means for detachably securing the panel to the plate. The plate includes a retaining member secured thereon, the panel includes a peripheral flange extended laterally outward therefrom for engaging with the retaining member and for detachably securing the panel to the plate. 
    
    
     Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a punch in accordance with the present invention; 
     FIG. 2 is a partial exploded view of the punch; 
     FIG. 3 is a partial cross sectional view of the punch; 
     FIG. 4 is a partial exploded view of the punch; 
     FIG. 5 is a partial cross sectional view of the a punch; and 
     FIG. 6 is a cross sectional view illustrating the operation of the punch. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and initially to FIGS. 1-3, a punch in accordance with the present invention comprises an arm  1  secured on a plate  11  which includes an opening  13  formed therein for allowing the punched material to be moved out of the plate  11  and which includes a substantially V-shaped retaining member  12  provided thereon and having an open end facing toward the opening  13  of the plate  11 . It is preferable that the arm  1  includes a bent portion formed in the middle portion thereof. A barrel  14  is secured to the upper end of the arm  1  for receiving a shaft  15  and a spring  151  therein and includes a peripheral shoulder  18  formed therein for engaging with the spring  151  and for retaining the spring  151  in the barrel  14 . The shaft  15  includes a head  154  provided on top thereof and engaged with the spring  151  such that the spring  151  may bias the shaft  15  upward relative to the barrel  14  or may bias the shaft  15  upward away from the plate  11 . The shaft  15  includes a catch  155  provided on the bottom thereof and extended downward and outward of the barrel  14  and having a pair of ribs  157  extended inward therefrom. The barrel  14  includes one or a pair of oblong holes  153  (FIG. 1) formed therein for slidably receiving a pin  4  which is engaged through a middle hole  152  of the shaft  15  (FIGS. 3,  5 ,  6 ), such that the pin  4  moves up and down in concert with the shaft  15 . 
     A lever  2  includes one end  22  pivotally secured to the hub  141  of the barrel  14  at a pivot axle  23  that is formed by the fasteners  23  and includes one or more holes  21  formed in the middle portion thereof for receiving the end portions of the pin  4  such that the lever  2  may move the shaft  15  downward against the spring  151 . The lever  2  includes a handle  27  formed on the other end opposite to the pivot axle  23 . The distance between the handle  27  and the pin  4  is greater than that between the pin  4  and the pivot axle  23 , such that the moving distance or the moving stroke of the pin  4  is limited, and such that the handle  27  may apply a great torque to the shaft  15  via the pin  4 . 
     Referring next to FIGS. 4-6, and again to FIGS. 1 and  2 , the punch includes a housing  31  having an orifice  311  formed in the upper portion thereof and having one or more depressions  312  formed in the bottom portion thereof. A board  33  is secured to the bottom of the housing  31  by such as the adhesive materials or by welding processes, and includes one or more projections  333  engaged into the depressions  312  of the housing  31 , and includes a hub  331  extended upward therefrom and extended inward of the housing  31 , and includes one or more guide rails  332  extended inward of the hub  331 . A punch rod  32  includes a pole  321  extended upward from the base  324  thereof and slidably engaged through the orifice  311  of the housing  31 , and includes one or more engaging channels  323  formed therein for slidably receiving the ribs  157  of the catch  155  and for detachably securing the punch rod  32  to the shaft  15  by such as a force-fitting engagement. A gasket  37  or the like is secured on the upper surface  322  of the punch rod  32  and is engaged with the catch  155  (FIGS. 5,  6 ) for increasing the frictional force between the punch rod  32  and the catch  155  and for further detachably securing the punch rod  32  to the shaft  15  by the force-fitted engagement. The base  324  of the punch rod  32  includes one or more slots  325  formed therein for slidably receiving the guide rails  332  of the board  33  and for guiding the punch rod  32  to move up and down relative to the hub  331  of the board  33  and for preventing the punch rod  32  from rotating relative to the board  33 . 
     A panel  34  includes a peripheral flange  342  laterally extended outward therefrom for engaging with the retaining member  12  and for being secured to the plate  11 . The panel  34  includes a hole  341  aligned with the hub  331  of the board  33  and with the punch rod  32 . A mold piece  35  includes a peripheral shoulder  352  formed therein for engaging with the corresponding peripheral shoulder  344  of the panel  34  (FIG. 5) and for securing the mold piece  35  in the panel  34 . The mold piece  35  may be secured to the panel  34  with a detachable and force-fitted engagement or by an adhesive material or by a welding process. The mold piece  35  includes a cavity  351  formed therein and having a shape corresponding to the pattern or the letter or the word to be punched and formed. The punch rod  32  includes a mold element  327  (FIGS. 5,  6 ) extended downward therefrom and having a shape corresponding to that of the pattern cavity  351  of the mold piece  35  for engaging into the pattern cavity  351  of the mold piece  35  and for punching the pattern on the sheet members that are engaged on the panel  34 . The panel  34  preferably includes a spacer  343  provided thereon and extended upward from one end thereof for engaging with the board  33  and for determining the greatest size of the sheet members to be punched, for example. 
     It is to be noted that the housing  31  and/or the panel  34  and/or the retaining member  12  preferably include a non-circular or a non-symmetric shape, such that the direction of the pattern cavity  351  of the mold piece  35  and/or of the mold element  327  of the punch rod  32  may be determined and aligned. It is further to be noted that, alternatively, the punch rod  32  may also be directly secured to the catch  155  of the shaft  15  without the housing  31  and the board  33 . The mold piece  35  may also be directly secured or disposed on the plate  11  without the panel  34 . 
     In operation, as shown in FIGS. 5 and 6, the shaft  15  and thus the punch rod  32  may be moved downward toward and to engage with the mold piece  35  by depressing the handle  27  of the lever  2  against the spring  151 . The lever  2  may apply a great torque against the punch rod  32  such that the punch rod  32  may be actuated to cut the sheet members that have a greater thickness. The provision of the housing  31  and the panel  34  and the retaining member  12  is for aligning the mold piece  35  and the mold element  327  of the punch rod  32 . 
     Accordingly, the punch in accordance with the present invention includes one or more punching members that may be replaced and changed with each other according to the user&#39;s need. 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.