Patent Publication Number: US-7895756-B1

Title: Punch pliers having lower costs of fabrication

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pair of punch pliers and, more particularly, to a pair of punch pliers for punching holes. 
     2. Description of the Related Art 
     A pair of conventional punch pliers in accordance with the prior art shown in  FIG. 9  comprise a handle  50 , a control shank  60  pivotally connected with the handle  50 , a punching member  64  rotatably mounted on the control shank  60  and movable relative to the handle  50 , and a connecting device  70  mounted between the handle  50  and the control shank  60  to connect the handle  50  and the control shank  60 . The handle  50  has an upper end provided with a punching seat  53 , a mediate portion provided with two first pivot holes  51  and two first toothed portions  52  and a forked lower end provided with two grip portions  54 . A sleeve  55  is mounted on the two grip portions  54  of the handle  50 . The control shank  60  has a forked upper end provided with two second pivot holes  61  corresponding to the first pivot holes  51  of the handle  50  and two second toothed portions  62  each meshing with a respective one of the two first toothed portions  52  of the handle  50 . The forked upper end of the control shank  60  has an end portion provided with a mounting hole  63  for mounting the punching member  64 . The connecting device  70  includes two connecting pieces  71  each having a first end abutting the handle  50  and a second end abutting the control shank  60 , a first pivot pin  73  each extending through each of the two connecting pieces  71  and each of the first pivot holes  51  of the handle  50  so that the handle  50  is pivotable between the two connecting pieces  71  about the first pivot pin  73 , a second pivot pin  74  each extending through each of the two connecting pieces  71  and each of the two second pivot holes  61  of the control shank  60  so that the control shank  60  is pivotable between the two connecting pieces  71  about the second pivot pin  74 , and an elastic member  72  mounted on the first pivot pin  73  or the second pivot pin  74  and biased between the handle  50  and the control shank  60 . 
     In operation, when the two grip portions  54  of the handle  50  and the lower end of the control shank  60  are pressed to move toward each other, the handle  50  and the control shank  60  are pivotable between the two connecting pieces  71  about the first pivot pin  73  and the second pivot pin  74  respectively so that the punching member  64  is movable toward the punching seat  53  of the handle  50  so as to perform a punching action. 
     As shown in  FIGS. 10-12 , the handle  50  is made by a punch press. In fabrication of the handle  50 , the punch press has an upper die and a lower die which are designed to have a planar profile of the handle  50 . Then, the upper die and the lower die of the punch press provide a shear force on a raw material  1  by the impact force applied by the punch press to shear and squeeze the raw material  1  to form the planar profile of the handle  50  on the raw material  1  so as to form the product of the handle  50 . 
     As shown in  FIGS. 13-15 , the control shank  60  is made by a punch press. In fabrication of the control shank  60 , the punch press has an upper die and a lower die which are designed to have a planar profile of the control shank  60 . Then, the upper die and the lower die of the punch press provide a shear force on a raw material  1   a  by the impact force applied by the punch press to shear and squeeze the raw material  1   a  to form the planar profile of the control shank  60  on the raw material  1   a  so as to form the product of the control shank  60 . 
     However, the handle  50  has a forked lower end, and the control shank  60  has a forked upper end so that the handle  50  and the control shank  60  produce many wasted materials as show in  FIGS. 10 and 13 , thereby increasing the costs of fabrication. In addition, the two grip portions  54  of the handle  50  have to be inserted into the forked upper end of the control shank  60 , so that the punch pliers are not assembled easily and quickly. Further, the handle  50  has a forked lower end, and the control shank  60  has a forked upper end so that the handle  50  and the control shank  60  have a larger volume, thereby causing inconvenience in packaging, transportation and storage of the punch pliers. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a pair of punch pliers, comprising a handle, a control shank assembly pivotally connected with the handle, a punching member mounted on the control shank assembly and movable relative to the handle, and a connecting device mounted between the handle and the control shank assembly to connect the handle and the control shank assembly. The handle has a first end provided with a grip portion, a second end provided with a punching seat and a mediate portion provided with a hollow receiving base located between the grip portion and the punching seat. The control shank assembly includes two press members each pivotally mounted on the receiving base of the handle, and a press block mounted between the two press members. 
     The primary objective of the present invention is to provide a pair of punch pliers having lower costs of fabrication. 
     Another objective of the present invention is to provide a pair of punch pliers, wherein the blanks of the handle are juxtaposed to each other on the raw material, and the blanks of each of the two press members of the control shank assembly are juxtaposed to each other on the raw material, so that the wasted materials of the handle and each of the two press members of the control shank assembly are reduced largely, thereby greatly decreasing the costs of fabrication of the punch pliers. 
     A further objective of the present invention is to provide a pair of punch pliers, wherein each of the two press members of the control shank assembly is mounted on the receiving base of the handle easily and quickly, so that the punch pliers are assembled easily and quickly. 
     A further objective of the present invention is to provide a pair of punch pliers, wherein the handle and each of the two press members of the control shank assembly have a smaller volume, thereby saving the storage space, and thereby facilitating packaging, transportation and storage of the punch pliers. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a perspective view of a pair of punch pliers in accordance with the preferred embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the punch pliers as shown in  FIG. 1 . 
         FIG. 3  is a planar view showing fabrication of a handle of the punch pliers as shown in  FIG. 1 . 
         FIG. 4  is a planar view of the handle of the punch pliers as shown in 
         FIG. 3 . 
         FIG. 5  is a perspective view of the handle of the punch pliers as shown in  FIG. 4 . 
         FIG. 6  is a planar view showing fabrication of a press member of the punch pliers as shown in  FIG. 1 . 
         FIG. 7  is a planar view of two press members of the punch pliers as shown in  FIG. 6 . 
         FIG. 8  is a perspective view of the two press members of the punch pliers as shown in  FIG. 7 . 
         FIG. 9  is an exploded perspective view of a pair of conventional punch pliers in accordance with the prior art. 
         FIG. 10  is a planar view showing fabrication of a handle of the conventional punch pliers as shown in  FIG. 9 . 
         FIG. 11  is a planar view of the handle of the conventional punch pliers as shown in  FIG. 10 . 
         FIG. 12  is a perspective view of the handle of the conventional punch pliers as shown in  FIG. 11 . 
         FIG. 13  is a planar view showing fabrication of a control shank of the conventional punch pliers as shown in  FIG. 9 . 
         FIG. 14  is a planar view of the control shank of the conventional punch pliers as shown in  FIG. 13 . 
         FIG. 15  is a perspective view of the control shank of the conventional punch pliers as shown in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to  FIGS. 1 and 2 , a pair of punch pliers in accordance with the preferred embodiment of the present invention comprise a handle  10 , a control shank assembly  20  pivotally connected with the handle  10 , a punching member  30  mounted on the control shank assembly  20  and movable relative to the handle  10 , and a connecting device  40  mounted between the handle  10  and the control shank assembly  20  to connect the handle  10  and the control shank assembly  20 . 
     The handle  10  is a bent sheet plate and has a first end provided with a grip portion  11 , a second end provided with a punching seat  13  and a mediate portion provided with a hollow receiving base  12  located between the grip portion  11  and the punching seat  13 . The receiving base  12  of the handle  10  has two opposite sidewalls  120 . Each of the two sidewalls  120  of the receiving base  12  of the handle  10  is provided with a first pivot hole  121  and a first toothed portion  122 . The punching seat  13  of the handle  10  is provided with a circular punching block  131 . 
     The control shank assembly  20  includes two press members  21  each pivotally mounted on the receiving base  12  of the handle  10 , and a press block  22  mounted between the two press members  21 . 
     The two press members  21  of the control shank assembly  20  are separated from each other. Each of the two press members  21  of the control shank assembly  20  is an elongate sheet plate, wherein one of the two press members  21  of the control shank assembly  20  is received in the receiving base  12  of the handle  10 , and the other one of the two press members  21  of the control shank assembly  20  is located outside of the receiving base  12  of the handle  10 . Each of the two press members  21  of the control shank assembly  20  abuts a respective one of the two sidewalls  120  of the receiving base  12  of the handle  10 . Each of the two press members  21  of the control shank assembly  20  has a first end movable relative to the grip portion  11  of the handle  10 , a second end movable relative to the punching seat  13  of the handle  10 , and a bent mediate portion provided with a recessed limit portion  214  that is movable to press a respective one of the two sidewalls  120  of the receiving base  12  of the handle  10  to limit a further movement of each of the two press members  21  of the control shank assembly  20  relative to the handle  10 . The first end of each of the two press members  21  of the control shank assembly  20  is provided with a positioning hole  211  and has an end face provided with a positioning breach  212 . The second end of each of the two press members  21  of the control shank assembly  20  is provided with a second pivot hole  215  corresponding to the first pivot hole  121  and a second toothed portion  216  meshing with the first toothed portion  122  of a respective one of the two sidewalls  120  of the receiving base  12  of the handle  10 . The second end of each of the two press members  21  of the control shank assembly  20  has an end portion provided with a circular limit hole  213 . 
     The press block  22  of the control shank assembly  20  is a solid body made of plastic material. The press block  22  of the control shank assembly  20  is mounted between the first ends of the two press members  21  and has two opposite sides each provided with an elongate positioning channel  221  to receive the first end of a respective one of the two press members  21 . Each of the two opposite sides of the press block  22  of the control shank assembly  20  is provided with a positioning stub  223  inserted into the positioning hole  211  of the respective press member  21  and a positioning rib  224  inserted into the positioning breach  212  of the respective press member  21 . The press block  22  of the control shank assembly  20  has a periphery provided with a retaining groove  222 . 
     The punching member  30  is rotatably mounted between the second ends of the two press members  21  of the control shank assembly  20  and has a periphery provided with a plurality of punching posts  31  having different diameters and each movable to press the punching block  131  of the punching seat  13  of the handle  10 . The punching member  30  has two opposite sides each provided with a circular limit protrusion  32  rotatably mounted in the limit hole  213  of a respective one of the two press members  21  of the control shank assembly  20 . 
     The connecting device  40  includes two connecting pieces  42  each having a first end abutting the handle  10  and a second end abutting a respective one of the two press members  21  of the control shank assembly  20 , a first pivot pin  43  each extending through each of the two connecting pieces  42  and the first pivot hole  121  of each of the two sidewalls  120  of the receiving base  12  of the handle  10  so that the handle  10  is pivotable between the two connecting pieces  42  about the first pivot pin  43 , a second pivot pin  44  each extending through each of the two connecting pieces  42  and the second pivot hole  215  of each of the two press members  21  of the control shank assembly  20  so that each of the two press members  21  of the control shank assembly  20  is pivotable between the two connecting pieces  42  about the second pivot pin  44 , and an elastic member  41  mounted on the first pivot pin  43  and biased between the grip portion  11  of the handle  10  and the press block  22  of the control shank assembly  20  to open the punching member  30  relative to the punching seat  13  of the handle  10 . The first end of each of the two connecting pieces  42  of the connecting device  40  is provided with a first through hole  420  aligning with the first pivot hole  121  of each of the two sidewalls  120  of the receiving base  12  of the handle  10  to allow passage of the first pivot pin  43 , and the second end of each of the two connecting pieces  42  is provided with a second through hole  421  aligning with the second pivot hole  215  of each of the two press members  21  of the control shank assembly  20  to allow passage of the second pivot pin  44 . The elastic member  41  of the connecting device  40  has a first end  410  secured in the retaining groove  222  of the press block  22  of the control shank assembly  20  and a second end  411  abutting an inner side of the grip portion  11  of the handle  10 . 
     In operation, when the grip portion  11  of the handle  10  and the press block  22  of the control shank assembly  20  are pressed to move toward each other, the handle  10  and the control shank assembly  20  are pivotable between the two connecting pieces  42  about the first pivot pin  43  and the second pivot pin  44  respectively so that the punching member  30  is movable toward the punching seat  13  of the handle  10  until one of the punching posts  31 , of the punching member  30  presses the punching block  131  of the punching seat  13  of the handle  10  so as to perform a punching action. At this time, the second toothed portion  216  of each of the two press members  21  of the control shank assembly  20  meshes with the first toothed portion  122  of a respective one of the two sidewalls  120  of the receiving base  12  of the handle  10  so that the handle  10  and the control shank assembly  20  are pivoted in concert with each other. After the force applied on the grip portion  11  of the handle  10  and the press block  22  of the control shank assembly  20  disappears, the grip portion  11  of the handle  10  and the press block  22  of the control shank assembly  20  are pushed to space from each other by the restoring force of the elastic member  41  of the connecting device  40  so as to open the punching member  30  relative to the punching seat  13  of the handle  10 . 
     As shown in  FIGS. 3-5 , the handle  10  is made by a punch press. In fabrication of the handle  10 , the punch press has an upper die and a lower die which are designed to have a planar profile of the handle  10 . Then, the upper die and the lower die of the punch press provide a shear force on a raw material  1  by the impact force applied by the punch press so as to form the planar profile of the handle  10  on the raw material  1 . Then, the punch press bends the handle  10  downward, presses and squeezes the blank of the handle  10  to form a substantially inverted U-shaped cap at the punching seat  13  of the handle  10  and to form a mounting hole in the punching seat  13  of the handle  10 . Then, the blank of the handle  10  is placed on a die of a small-size punch press, and the punching block  131  is punched into the hole in the punching seat  13  of the handle  10  so as to form a product of the handle  10 . 
     As shown in  FIGS. 6-8 , each of the two press members  21  of the control shank assembly  20  is made by a punch press. In fabrication of each of the two press members  21  of the control shank assembly  20 , the punch press has an upper die and a lower die which are designed to have a planar profile of each of the two press members  21  of the control shank assembly  20 . Then, the upper die and the lower die of the punch press provide a shear force on a raw material  1   a  by the impact force applied by the punch press to shear and squeeze the raw material  1   a  to form the planar profile of each of the two press members  21  of the control shank assembly  20  on the raw material  1   a  so as to form the product of each of the two press members  21  of the control shank assembly  20 . 
     Accordingly, the blanks of the handle  10  are juxtaposed to each other on the raw material  1  as shown in  FIG. 3 , and the blanks of each of the two press members  21  of the control shank assembly  20  are juxtaposed to each other on the raw material  1   a  as shown in  FIG. 6 , so that the wasted materials of the handle  10  and each of the two press members  21  of the control shank assembly  20  are reduced largely, thereby greatly decreasing the costs of fabrication of the punch pliers. In addition, each of the two press members  21  of the control shank assembly  20  is mounted on the receiving base  12  of the handle  10  easily and quickly, so that the punch pliers are assembled easily and quickly. Further, the handle  10  and each of the two press members  21  of the control shank assembly  20  have a smaller volume, thereby saving the storage space, and thereby facilitating packaging, transportation and storage of the punch pliers. 
     Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.