Abstract:
A tool head structure is used to screw a regular screw or a damaged screw and comprises two cutting portions located at the center of the front portion thereof. Between the two cutting portions is formed a ridge line, and behind the two cutting portions are formed two concave flank portions, and the respective flank portions are correspondingly linked up with scraping grooves. By such arrangements, the tool head structure can solve the problems of easy slipping and being unable to remove the damaged screw.

Description:
[0001]    This application is a continuation of part of U.S. patent application Ser. No. 11/770,723, which claims the benefit of the earlier filing date of Jun. 28, 2007. Claim  1  of this application is added with more new limitations than the previous claim 1 of the U.S. patent application Ser. No. 11/770,723, claim  2  of this application is new, and claim  3  of this application is the previous claim 3 of the U.S. patent application Ser. No. 11/770,723. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a tool head structure which is used to screw a regular screw or a damaged screw and further can directly drill a hole in the working surface. 
         [0004]    2. Description of the Prior Art 
         [0005]    Conventionally, when using the tool heads (such as: slot screwdrivers, cross screwdrivers or star screwdrivers) to screw various screws, it often causes the following problems: 
         [0006]    1. The screw was often screwed in an embedded manner to obtain a smooth and nice looking working surface, but the corresponding embedding working procedure of the screw head is troublesome, the operator must replace the tool head with drill bit to machine an embedding recess, and then replace the tool head again to screw the screws, thus greatly increasing the cost. 
         [0007]    2. The head portion of the screw is often damaged by a damaged screwdriver head, and the damaged head of the screw will cause the screw unable to continue the screwing operation, so the operator must remove the damaged screw as soon as possible, thus reducing the whole work efficiency. 
         [0008]    3. During a general screwing operation, the unbalanced force applied by the operator and the poor contact angle between the screwing tool and the screw often cause the screw head to be damaged, or a slippage during operation causes the unexpected injuries, thus not only causing the screw unable to continue the screwing operation, but also causing the severe problem of injury. 
         [0009]    In order to solve a part of the abovementioned problems, as shown in  FIG. 1 , the tool head  10  disclosed by U.S. Pat. No. 6,868,572 B1 is mounted with a drill cone  11  at the center thereof, and the protruding driving portion of the tool head  10  is formed with a blade  101 . Moreover, four claw portions  12  are extended from one end of the drill cone  11 , and on the front edge of each claw portion  12  is formed a cutting portion  121 . By such arrangements, this conventional structure can perform both the drilling operation and the screw driving operation. The damaged screw can be removed by engaging the claw portions  12  of the drill cone  11  in the screwing recess of the screw. However, the abovementioned structure still has the following problems: 
         [0010]    1. The end portion of the drill cone  11  is extended to form four claw portions  12 , so there is not a key ridge line of a general drill, but the four angle points or four equally divided cross bevel edge. Hence, this drill cone  11  has a poor grasping ability, thus often skidding on the surface of the machining object during an electric drive operation. 
         [0011]    2. The engagement of the claw portions  12  of the drill cone  11  with the screwing recess of the damaged screw makes the claw portions  12  grasp the inner of the screwing recess of the screw, but the four claw portion  12  with cutting portions  121  doesn&#39;t have the chisel point which is the most important during the drilling operation, so the hole drilling ability of this drill cone  11  is relatively poor. 
         [0012]    3. The end portion of the drill cone  11  is extended to form four claw portions  12 , and a special machining method is required to form the four cutting portions  121  of different directions and angles, hence the working procedure is complicated and the machining difficult is relatively high. 
         [0013]    In order to solve the abovementioned relevant problems, based on the accumulative research technology and experience in the field of the screwdriver and the screw tool, from the angle of improving the effect of making a hole and simplifying the working procedure, the applicant of the present invention has developed a tool head structure for screwing the damaged screw. 
         [0014]    The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
       SUMMARY OF THE INVENTION 
       [0015]    The primary objective of the present invention is to provide a tool head structure which can easily engage with the screw and is unlikely to skid. 
         [0016]    The secondary objective of the present invention is to provide a tool head structure which can directly drill a hole in a working surface. 
         [0017]    In order to achieve the above objectives, the tool head structure of the present invention comprises two scraping grooves longitudinally located on a periphery of a front portion of the tool head structure, each of the two scraping grooves including a scraping surface in a counterclockwise direction and a bounding surface in a clockwise direction, the scraping surfaces each including a scraping edge; two spacing grooves longitudinally located on the periphery of the front portion of the tool head structure and staggered with the scraping grooves, the respective spacing grooves including a first groove surface in the counterclockwise direction and a second groove surface in the clockwise direction; two protruding driving portions defined by the scraping surfaces of the scraping grooves and the second groove surfaces of the neighboring spacing grooves in the clockwise direction; two spacing protrusions defined by the bounding surfaces of the scraping grooves and the first groove surfaces of the neighboring spacing grooves in the counterclockwise direction; two ridge surfaces each including a first ridge edge and a second ridge edge that connects to each other at a chisel point, the ridge surfaces being located on boundaries of the scraping surfaces and top ends of the neighboring second groove surfaces in the counterclockwise direction, the first ridge edges being connected with the scraping edges, the second ridge edges being located between the scraping surfaces and the neighboring second groove surfaces in the clockwise direction; two cutting portions each including a first cutting portion edge and a second cutting portion edge that are oppositely arranged and further including a cutting portion line between the first and second cutting portion edges, the respective cutting portions being located on top ends of the protruding driving portions, the first cutting portion edge of each of the cutting portions coinciding in position with the first ridge edge of one of the ridge surfaces, and the second cutting portion edge of the each of the cutting portions coinciding in position with the second ridge edge of the other of the ridge surfaces, the cutting portion lines of the two cutting portions coinciding in position with each other, and two end points of the respective cutting portion lines coinciding in position with the chisel points; and two flank portions each including a first flank portion edge and a second flank portion edge, the respective flank portions being located on top ends of the spacing protrusions and between the bounding surfaces and the neighboring first groove surfaces in the counterclockwise direction, the first flank portion edges being located closer to the respective chisel points than the respective second flank portion edges. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of a conventional tool head structure; 
           [0019]      FIG. 2  is a perspective view of a tool head structure in accordance with the present invention; 
           [0020]      FIG. 3  shows one end of the tool head structure in accordance with the present invention; 
           [0021]      FIG. 4  is a side view of the tool head structure in accordance with the present invention; 
           [0022]      FIG. 5  is a side view of the tool head structure in accordance with the present invention of  FIG. 4  that rotates 90 degrees counterclockwise; 
           [0023]      FIG. 6  is a side view of the tool head structure in accordance with the present invention of  FIG. 5  that rotates 90 degrees counterclockwise; 
           [0024]      FIG. 7  is a cross-sectional view illustrating how the tool head structure in accordance with the present invention shovels into a damaged screw; 
           [0025]      FIG. 8  is another cross-sectional view illustrating how the tool head structure in accordance with the present invention shovels into the damaged screw; and 
           [0026]      FIG. 9  is schematic view illustrating how the tool head structure in accordance with the present invention drills a hole. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention. 
         [0028]    Referring to  FIGS. 2-6 , a tool head structure  20  in accordance with the present invention is integrally formed. The rear portion of the tool head structure  20  is in the form of a hexagonal column for assembling with relevant tools, and the front portion of the tool head structure  20  includes two scraping grooves  30 , two spacing grooves  40 , two protruding driving portions  51 , two spacing protrusions  52 , two ridge surfaces  60 , two cutting portions  70  and two flank portions  80 . 
         [0029]    The two scraping grooves  30  are longitudinally located on the periphery of the front portion of the tool head structure  20  and each include a scraping surface  31  in the counterclockwise direction and a bounding surface  32  in the clockwise direction. Each of the scraping surfaces  31  includes a scraping edge  311 . 
         [0030]    The two spacing grooves  40  are longitudinally located on the periphery of the front portion of the tool head structure  20  and staggered with the respective scraping grooves  30 . The respective spacing grooves  40  include a first groove surface  41  in the counterclockwise direction and a second groove surface  42  in the clockwise direction. 
         [0031]    The two protruding driving portions  51  are defined by the scraping surfaces  31  of the scraping grooves  30  and the second groove surfaces  42  of the neighboring spacing grooves  40  in the clockwise direction, respectively. 
         [0032]    The two spacing protrusions  52  are defined by the bounding surfaces  32  of the scraping grooves  30  and the first groove surfaces  41  of the neighboring spacing grooves  40  in the counterclockwise direction, respectively. 
         [0033]    The two ridge surfaces  60  each include a first ridge edge  61  and a second ridge edge  62 . The first and second ridge edges  61 ,  62  of each of the two ridge surfaces  60  connect to each other at a chisel point  63 . The ridge surfaces  60  are located on the boundaries of the scraping surfaces  31  of the scraping grooves  30  and the top ends of the second groove surfaces  42  of the neighboring spacing grooves  40  in the counterclockwise direction, respectively. The respective chisel points  63  are located on the tip end of the front portion of the tool head structure  20 . The two chisel points  63  define a ridge line  64  therebetween. The first ridge edges  61  connect with the scraping edges  311 , and the second ridge edges  62  are located between the scraping surfaces  31  and the neighboring second groove surfaces  42  in the clockwise direction, respectively. 
         [0034]    The two cutting portions  70  each include a first cutting portion edge  71  and a second cutting portion edge  72  that are oppositely located and further include a cutting portion line  73  between the first and second cutting portion edges  71 ,  72 . The respective cutting portions  70  are located on the top ends of the protruding driving portions  51 . The first cutting portion edge  71  of each of the cutting portions  70  coincides in position with the first ridge edge  61  of one of the ridge surfaces  60 , and the second cutting portion edge  72  of the each of the cutting portions  70  coincides in position with the second ridge edge  62  of the other of the ridge surfaces  60 . The cutting portion lines  73  of the two cutting portions  70  coincide in position with each other and further coincide in position with the ridge line  64  in such a manner that the two end points of the cutting portion line  64  coincide in position with the chisel points  63 . 
         [0035]    The flank portions  80  each include a first flank portion edge  81  and a second flank portion edge  82 . The respective flank portions  80  are located on the top ends of the spacing protrusions  52  and between the bounding surfaces  32  and the neighboring first groove surfaces  41  in the counterclockwise direction. The first flank portion edges  81  are located closer to the respective chisel points  63  than the respective second flank portion edges  82 . 
         [0036]    The aforementioned is the summary of the positional and structural relationship of the respective components of the preferred embodiment in accordance with the present invention. 
         [0037]    For a better understanding of the present invention, its operation and function, reference should be made to  FIGS. 7-8 . When the screw  91  with a damaged screwing recess  911  is screwed, the tool head structure  20  of the same size is employed in such a manner that the scraping grooves  30 , the spacing grooves  40 , the protruding driving portions  51  and the spacing protrusions  52  are engaged in the damaged screwing recess  911 . Since the cutting direction of the scraping surfaces  31  of the scraping grooves  30  is the same as the screwing direction of the screw  91 , when the tool head structure  20  rotates, the scraping surfaces  31  utilize the scraping edges  311  to engage the protruding driving portions  51  to the undamaged part of the screwing recess  911  adequately. 
         [0038]    The key point is that, at the convergence center of the scraping grooves  30 , the spacing grooves  40 , the protruding driving portions  51  and the spacing protrusions  52  are formed two symmetrically-arranged cutting portions  70 , and between the two cutting portions  70  is formed a ridge line  64 , so that when the screw  91  with the damaged screwing recess  911  is screwed, the two cutting portions  70  of the present invention can utilize the ridge line  64  and the first ridge edges  61  to quickly bite the bottom surface of the screwing recess  911 , thus effectively offering the functions of preventing slippage, increasing the engaging effect and screwing the damaged screw. 
         [0039]    It is to be noted that, referring to  FIG. 8 , the present invention will produce cutting powder during the process of using. In order to solve the cutting powder problem, the present invention is formed with two flank portions  80  that are respectively located at the top ends of the spacing protrusions  52  and linked up with the scraping grooves  30 . By such arrangements, when the two cutting portions  70  of the present invention shovel into the bottom of the screwing recess  911  of the screw  91 , the powder caused by shoveling can be quickly discharged along the scraping grooves  30  from the flank portions  80 . Hence, the powder caused by shoveling of the present invention can be smoothly discharged. 
         [0040]    Referring to  FIG. 9 , because at the convergence center of the scraping grooves  30 , the spacing grooves  40 , the protruding driving portions  51 , the spacing protrusions  52  of the tool head structure  20  are formed two symmetrically-arranged cutting portions  70 , between the two cutting portions  70  is formed a ridge line  64 , and the two flank portions  80  are concave and formed behind the two cutting portions  70  for performing the powder discharging operation, the tool head structure of the present invention can drill into a regular machining surface  92  (such as: a board). By cooperating with the scraping surfaces  31  of the scraping grooves  30  and the first ridge edges  61  of the ridge surfaces  60  (i.e. the first cutting portion edges  71  of the cutting portions  70 ), since the cutting direction of the scraping surfaces  31  and the ridge surfaces  60  is the same as the screwing direction of the screw, with the abovementioned design, the tool head structure of the present invention can effectively perform the drilling operation, thus solving the problem of being unable to drill a hole. 
         [0041]    While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.