Patent Publication Number: US-6902093-B1

Title: Centering punch

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a centering punch, and more particularly to a centering punch that can be centered and aligned easily and exactly. 
   2. Description of the Related Art 
   A conventional centering punch in accordance with the prior art shown in  FIGS. 15–18  comprises a first body  80  having an inner wall having a first end formed with a receiving recess  803 , a mediate portion formed with a tapered face  802  and a second end formed with a receiving chamber  801 , a fixing member  83  mounted on the first end of the first body  80 , a second body  87  having a first end mounted on the second end of the first body  80  and a second end formed with a passage  872  and having an inside formed with a receiving space  871 , a punching head  81  movably mounted in the receiving recess  803  of the first body  80  and having a first end formed with a control hole  811 , an elastic member  82  mounted in the receiving recess  803  of the first body  80  and urged between a second end of the punching head  81  and the fixing member  83 , a first push member  86  movably mounted in the passage  872  of the second body  87  and having an enlarged first end  860  rested on a shoulder  875  formed between the receiving space  871  and the passage  872  of the second body  87  and a second end protruded outward from the passage  872  of the second body  87 , a second push member  84  movably mounted in the receiving space  871  of the second body  87  and having a first end rested on the first end of the punching head  81  and located adjacent to the control hole  811  of the punching head  81  and an enlarged second end  840  rested on the enlarged first end  860  of the first push member  86 , and a spring  85  mounted on the second push member  84  and urged between the enlarged second end  840  of the second push member  84  and the first end of the punching head  81 . 
   As shown in  FIG. 16 , the second push member  84  is rested on the first end of the punching head  81  eccentrically by an elastic force of the spring  85 , so that the first end of the second push member  84  is rested on the first end of the punching head  81  and is not in alignment with the control hole  811  of the punching head  81 . 
   As shown in  FIG. 17 , the second end of the first push member  86  is provided with a socket (not shown) which is mounted on a tool (not shown), such as a nail or the like, which is moved to press a working face (not shown). When the first body  80  is held and driven by a user&#39;s one hand to move toward the working face, the first push member  86  is pushed by the reaction of the working face to move toward the punching head  81 , so that the second push member  84  is driven to press and move the punching head  81  and to compress the elastic member  82 . At this time, the spring  85  is compressed and guided by the tapered face  802  of the first body  80 , so that the second push member  84  is moved radially in the receiving space  871  of the second body  87  by guidance of the tapered face  802  of the first body  80  until the first end of the second push member  84  is in alignment with the control hole  811  of the punching head  81 . 
   As shown in  FIG. 18 , after the first end of the second push member  84  is in alignment with the control hole  811  of the punching head  81 , the punching head  81  is driven by the restoring force of the elastic member  82  to hit the second push member  84  which hits the first push member  86 , so that the first push member  86  is pushed outward to drive the tool to pierce the working face, thereby forming a hole (not shown) in the working face. At this time, the first end of the second push member  84  is inserted into the control hole  811  of the punching head  81 . 
   However, the first end of the second push member  84  is not easily in alignment with the control hole  811  of the punching head  81 , so that the conventional centering punch cannot be centered and aligned exactly, thereby limiting operation of the conventional centering punch. 
   SUMMARY OF THE INVENTION 
   The primary objective of the present invention is to provide a centering punch that can be centered and aligned easily and exactly. 
   Another objective of the present invention is to provide a centering punch, wherein the tapered portion of the punching head is moved along the tapered face of the first body, and the punching head is moved radially in the receiving chamber of the first body by guidance of the tapered face of the first body, so that the push portion of the push member is in alignment with the control hole of the punching head easily and exactly. 
   A further objective of the present invention is to provide a centering punch, wherein the punching head is located eccentrically in the receiving chamber of the first body by the elastic force of the elastic body, thereby simplifying the construction of the centering punch. 
   A further objective of the present invention is to provide a centering punch, wherein the push member is rotated by the second body, so that the socket of the push member is rotated to function as a screwdriver head. 
   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 DRAWINGS 
       FIG. 1  is an exploded perspective view of a centering punch in accordance with the preferred embodiment of the present invention; 
       FIG. 2  is a partially cross-sectional perspective assembly view of the centering punch in accordance with the preferred embodiment of the present invention; 
       FIG. 3  is a plan cross-sectional view of the centering punch as shown in  FIG. 2 ; 
       FIG. 4  is a schematic operational view of the centering punch as shown in  FIG. 3 ; 
       FIG. 5  is a schematic operational view of the centering punch as shown in  FIG. 4 ; 
       FIG. 6  is a schematic operational view of the centering punch as shown in  FIG. 5 ; 
       FIG. 7  is an exploded perspective view of a centering punch in accordance with another embodiment of the present invention; 
       FIG. 8  is an exploded perspective view of a centering punch in accordance with another embodiment of the present invention; 
       FIG. 9  is a plan cross-sectional view of the centering punch as shown in  FIG. 8 ; 
       FIG. 10  is an exploded perspective view of a centering punch in accordance with another embodiment of the present invention; 
       FIG. 11  is a perspective assembly view of the centering punch as shown in  FIG. 10 ; 
       FIG. 12  is a plan cross-sectional view of the centering punch as shown in  FIG. 11 ; 
       FIG. 13  is a schematic operational view of the centering punch as shown in  FIG. 11 ; 
       FIG. 14  is an exploded perspective view of a centering punch in accordance with another embodiment of the present invention; 
       FIG. 15  is an exploded perspective view of a conventional centering punch in accordance with the prior art; 
       FIG. 16  is a plan cross-sectional assembly view of the conventional centering punch as shown in  FIG. 15 ; 
       FIG. 17  is a schematic operational view of the conventional centering punch as shown in  FIG. 16 ; and 
       FIG. 18  is a schematic operational view of the conventional centering punch as shown in  FIG. 17 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings and initially to  FIGS. 1–3 , a centering punch in accordance with the preferred embodiment of the present invention comprises a first body  10 , a second body  70 , a punching head  20 , an elastic body  30 , an elastic member  40 , a push member  50 , and a spring  60 . 
   The first body  10  has an inner wall having a first end formed with a receiving recess  13 , a mediate portion formed with a tapered face  12  and a second end formed with a receiving chamber  11 . The receiving chamber  11  of the first body  10  has a diameter greater than that of the receiving recess  13  of the first body  10 . The second end of the inner wall of the first body  10  has a distal portion formed with an inner thread  14 . 
   The second body  70  is mounted on the first body  10  and has an inside formed with a receiving space  71  communicating with the receiving chamber  11  of the first body  10 . The second body  70  has a first end formed with an outer thread  73  screwed into the inner thread  14  of the first body  10  and a second end formed with a non-circular (hexagonal) passage  72 . 
   The punching head  20  is movably mounted in the receiving chamber  11  of the first body  10  and has a first end formed with a tapered portion  23  aligning with the tapered face  12  of the first body  10  and a second end formed with a control hole  21 . The punching head  20  has a diameter smaller than that of the receiving chamber  11  of the first body  10 . 
   The elastic body  30  is urged between the receiving chamber  11  of the first body  10  and a periphery of the punching head  20  so that the punching head  20  is located eccentrically in the receiving chamber  11  of the first body  10  by an elastic force of the elastic body  30 . Preferably, the periphery of the punching head  20  is formed with a mounting recess  22  for mounting the elastic body  30 . 
   The elastic member  40  is mounted in the receiving recess  13  of the first body  10  and urged between the first body  10  and the tapered portion  23  of the punching head  20 . 
   The push member  50  having a non-circular (hexagonal) shape is movably mounted in the receiving space  71  and the passage  72  of the second body  70  and has a first end provided with a push portion  52  rested on the second end of the punching head  20  and located adjacent to the control hole  21  of the punching head  20  and a second end protruded outward from the passage  72  of the second body  70 . The second end of the push member  50  is provided with a socket  53 . Preferably, the socket  53  is detachably mounted on the push member  50  to facilitate assembly of the push member  50  in the second body  70 . The push member  50  has a mediate portion provided with a catch portion  51  rested on a shoulder  75  formed between the receiving space  71  and the passage  72  of the second body  70 . 
   The spring  60  is mounted on the push portion  52  of the push member  50  and urged between the push member  50  and the punching head  20 . The spring  60  has a first end urged on the second end of the punching head  20  and a second end urged on the catch portion  51  of the push member  50 . 
   As shown in  FIG. 3 , the punching head  20  is located eccentrically in the receiving chamber  11  of the first body  10  by the elastic force of the elastic body  30 , so that the push portion  52  of the push member  50  is rested on the second end of the punching head  20  and is not in alignment with the control hole  21  of the punching head  20 . 
   As shown in  FIGS. 4 and 5 , the socket  53  of the push member  50  is mounted on a tool (not shown), such as a nail or the like, which is moved to press a working face (not shown). When the first body  10  is held and driven by a user&#39;s one hand to move toward the working face, the push member  50  is pushed by the reaction of the working face to move toward the punching head  20 , so that the push portion  52  of the push member  50  is driven to move the punching head  20  which drives the tapered portion  23  to move along the tapered face  12  of the first body  10  and to compress the elastic member  40 . At this time, the punching head  20  is moved radially in the receiving chamber  11  of the first body  10  by guidance of the tapered face  12  of the first body  10 , so that the push portion  52  of the push member  50  is in alignment with the control hole  21  of the punching head  20  as shown in  FIG. 5 . 
   As shown in  FIG. 6 , after the push portion  52  of the push member  50  is in alignment with the control hole  21  of the punching head  20 , the punching head  20  is driven by the restoring force of the elastic member  40  to hit the push member  50 , so that the push member  50  is pushed outward to drive the tool to pierce the working face, thereby forming a hole (not shown) in the working face. At this time, the push portion  52  of the push member  50  is inserted into the control hole  21  of the punching head  20 , and the spring  60  is compressed by the punching head  20 . 
   After the force applied on the first body  10  is removed, the push member  50  and the punching head  20  are separated from each other by the restoring force of the spring  60 , thereby detaching the push portion  52  of the push member  50  from the control hole  21  of the punching head- 20 , so that the centering punch is returned to the original position as shown in  FIG. 3 . 
   Accordingly, the tapered portion  23  of the punching head  20  is moved along the tapered face  12  of the first body  10 , and the punching head  20  is moved radially in the receiving chamber  11  of the first body  10  by guidance of the tapered face  12  of the first body  10 , so that the push portion  52  of the push member  50  is in alignment with the control hole  21  of the punching head  20  easily and exactly. In addition, the punching head  20  is located eccentrically in the receiving chamber  11  of the first body  10  by the elastic force of the elastic body  30 , thereby simplifying the construction of the centering punch. Further, the push member  50  is rotated by the second body  70 , so that the socket  53  of the push member  50  is rotated to function as a screwdriver head. 
   Referring to  FIG. 7 , the centering punch further comprises a ball  31  urged between the receiving chamber  11  of the first body  10  and the elastic body  30 . In addition, the first end of the inner wall of the-first body  10 A has a distal portion formed with a plurality of insertion recesses  14 A, and the second body  70 A has a first end formed with a plurality of inserts  73 A each inserted into a respective one of the insertion recesses  14 A of the first body  10 A. In addition, the push member  50 A has a square shape, and the second body  70 A has a second end formed with a square passage  72 A. 
   Referring to  FIGS. 8 and 9 , the first end of the inner wall of the first body  10  has a distal portion formed with an inner thread  15 , and the centering punch further comprises an adjusting knob  16  rotatably mounted on the first body  10  and having a threaded rod  161  screwed into the inner thread  15  of the first body  10  and urged on the elastic member  40  to adjust the tension of the elastic member  40 . In addition, the push member SOB is separated from the catch portion  51  and the push portion  52  and has a first end rested on the catch portion  51  and formed with a retaining groove  55 B, and the centering punch further comprises a snap ring  54 B snapped into the retaining groove  55 B of the push member SOB and rested on the shoulder  75  formed between the receiving space  71  and the passage  72  of the second body  70 . 
   Referring to  FIGS. 10–13 , the periphery of the punching head  20 C is formed with a flattened face  24 C rested on the elastic body  30 C. In addition, the socket  53  is detachably mounted on the push member  50 . In addition, the second body  70 C has a peripheral wall formed with a substantially L-shaped guide slot  74 C communicating with the receiving space  71  and having a transverse section  740 C and an axial section  742 C, and the centering punch further comprises a tubular control member  56  rotatably mounted on the push portion  52  of the push member  50  and having an end rested on the catch portion  51  of the push member  50  and provided with a control block  561  slidably mounted in the guide slot  74 C of the second body  70 C and located between the transverse section  740 C and the axial section  742 C of the guide slot  74 C. Preferably, the control block  561  is detachably mounted on the control member  56 . 
   As shown in  FIGS. 11 and 12 , the control block  561  of the control member  56  is located in the transverse section  740 C of the guide slot  742 C, so that the control member  56  is fixed on the second body  70 C and the push member  5  is fixed by the control member  0 . 56  without movement. 
   As shown in  FIG. 13 , the control block  561  of the control member  56  is located in the axial section  742 C of the guide slot  74 C, so that the control member  56  is movable relative to the second body  70 C and the push member  50  is movable freely. 
   As shown in  FIG. 14 , the centering punch is mounted in a receiving portion  171  of a hammer  17  and covered by a tap  172 . 
   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.