Abstract:
This invention relates to a driving head of rotary wrenching tools, the driving head can be a sleeve or directly implemented on the wrench, the driving head has an opening with grooves, forefront surfaces and concavities implemented inside the opening, the forefront surfaces are implemented individually in-between the grooves, and one concavity is implemented on each forefront surface, with which varieties of work pieces in different shapes can be tightly fitted into.

Description:
FIELD OF THE INVENTION 
   This invention relates to a driving head of rotary wrenching tools, specifically the one which has an opening with grooves, forefront surfaces and concavities implemented inside, which is capable for varieties of work pieces in different shapes to be tightly fitted into. 
   BACKGROUND OF THE INVENTION 
   As what have been acknowledged, the current patent of driving head of rotary wrenching tools structured for fitting varieties of work pieces in different shapes such as U.S. Pat. No. 3,354,757, U.S. Pat No. 3,657,516 and U.S. Pat. No. 5,388,486 is having a sleeve on the driving head, twelve equally spaced convexities are angularly implemented inside the sleeve, with which varieties of work pieces in different shapes such as gear type or hexagonal type work pieces can be fit into the sleeve and rotated. In spite of the advantages of the three patents mentioned above, there are shortcomings for the three patents on the action of rotating as following: although there are twelve convexities inside the sleeve to accommodate varieties of bolt in different shapes, but the possibility for the sleeve to work on hexagonal bolts is very high because hexagonal bolts is the most prevalent bolts in the market; when the sleeve rotates the hexagon bolt, the two of the twelve convexities contact with the side of the six hexagon bolt, which will produce a gap in-between, then instability and damage are to be created. 
   SUMMARY OF THE INVENTION 
   This invention is about a driving head of rotary wrenching tools, which is capable for varieties of work pieces in different shapes to be tightly fitted into with improvement on tight fitness. The structure of this invention is that the driving head has an opening with grooves, forefront surfaces and concavities implemented inside; more specifically, the forefront surfaces are implemented individually in-between the grooves, and one concavity is implemented on the center of each forefront surface, the concavities is parallel to the central axis, which is deep enough to accommodate varieties of work pieces in different shapes for tight fitness. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a 3-dimensional view of the sleeve of the present invention. 
     FIG.  1 - a  is a front plan view of  FIG. 1 . 
       FIG. 2  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 3  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 4  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 5  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 6  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 7  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 8  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 9  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 10  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 11  is a partial enlarged view of another embodiment of the invention. 
       FIG. 12  is a partial enlarged view of another embodiment of the invention. 
       FIG. 13  is a partial enlarged view of another embodiment of the invention. 
       FIG. 14  is a partial enlarged view of another embodiment of the invention. 
       FIG. 15  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 16  is a partial enlarged view of another embodiment of the invention. 
       FIG. 17  is a partial enlarged view of another embodiment of the invention. 
       FIG. 18  is a partial enlarged view of another embodiment of the invention. 
       FIG. 19  is a partial enlarged view of another embodiment of the invention. 
       FIG. 20  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 21  is a partial enlarged view of another embodiment of the invention. 
       FIG. 22  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 23  is a partial enlarged view of another embodiment of the invention. 
       FIG. 24  is a partial enlarged view of another embodiment of the invention. 
       FIG. 25  is a 3-dimensional view of another embodiment of the invention. 
       FIG. 26  is a front plan view shows the driving head with a handle. 
       FIG. 27  shows the combination status of the work piece and the driving head of the invention. 
       FIG. 28  shows the combination status of the work piece and the driving head of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As shown on  FIG. 1 , this invention is about a driving head of rotary wrenching tools, the driving head  10  has two opposite ends and a central axis which connects the two ends, at least one end of the driving head  10  has an opening  100  extending along the central axis, the opening  100  is for fitting work pieces. The opening  100  has plurality grooves  12  that are distributed equidistant along the inner surface of the opening, the grooves  12  extend along the central axis. Every two adjacent grooves  12  forms a forefront surface  11 , the forefront surface  11  is closer to the central axis than the groove  12 . At least a concavity  13  is implemented on the center of each forefront surface  11 , the extending direction of the concavity  13  is also parallel to the central axis and is deep enough to accommodate the extrusion parts of work pieces. In the embodiment shown on  FIGS. 1 and 1   a , the driving head  10  is a sleeve, one end of the sleeve has an opening  100  for purpose of fitting work pieces, the other end of the sleeve has a square hole  14  for fitting other tools, every forefront surface  11  has one concavity  13 , the forefront surface  11  can be a flat surface or a curved surface. On  FIG. 1 , the forefront surface  11  is an arc surface tangent to the arc surface of the groove  12 . 
   As shown on  FIG. 2 , the inside of the concavities  13  are arc surfaces that will fit the round extrusions  31  of the work piece  30 . As shown on  FIGS. 3 and 4 , the inside of the grooves  12  are arc surfaces that will fit not only the round extrusions  31  of the work piece  30  but also polygonal work piece  20 . When the grooves  12  and the concavities  13  are both implemented, that a work piece  40  with plurality of extruded teeth  41  can be fitted into as shown on  FIG. 5 ; or an octagonal work piece  50  can be fitted into as shown on  FIG. 6 ; or a quadrangular work piece  52  can be fitted into as shown on  FIG. 7 ; or an asteroid shape of work piece  53  can be fitted into as shown on  FIG. 8 ; or a nine sides polygonal work piece  54  can be fitted into as shown on  FIG. 9 ; or a trigonal work piece  55  can be fitted into as shown on  FIG. 10 . 
   As shown on  FIG. 11 , the surface connecting the forefront surface  11  and the concavities  13  is shaped as a round corner  131 . 
   As shown on  FIG. 12 , the driving head  10  is a sleeve, one end of the sleeve has an opening  100  for purpose of fitting work pieces, and the other end of the sleeve is shaped polygonal  15  for fitting other tools. 
   As shown on  FIG. 13 , the inside of the concavity  13  is an oval-shaped arc surface. 
   As shown on  FIG. 14 , the inside of the concavity  13  is a paraboloid. 
   As shown on  FIG. 15 , the concavity  13  still can fit the round extrusions  31  of the work piece  30   
   As shown on  FIG. 16 , the concavity  13  is composed by the two interconnected arc surface  131  and  132 , which are round surfaces. 
   As shown on  FIG. 17 , a secondary concavity  130  is implemented inside the concavity  13 , the secondary concavity  130  extends along the central axis, the inside of the concavity  13  and the secondary concavity  130  are both round, the radius of the concavity  13  is longer than that of the concavity  130 . 
   As shown on  FIG. 18 , the wall of the concavity  13  is formed by at least three surfaces  133 ,  134  and  135 . The three surfaces can be arc surfaces in an embodiment, or can be flat surfaces as shown on  FIG. 18 , the angles formed by each two adjacent flat surfaces are all 120 degree. 
   As shown on  FIGS. 19 and 20 , the wall of the concavity  13  is formed by four surfaces  133   a ,  134   a ,  135   a  and  136   a , each of the surfaces is flat and at least one of the angles formed by each two adjacent flat surfaces is 120 degree, which will fit the round extrusions  31  of the work piece  30  as shown on  FIG. 20 . 
   As shown on  FIGS. 21 and 22 , the wall of the concavity  13  is formed by four surfaces  133   b ,  134   b    135   b  and  136   b , each of the surfaces is flat and the angles formed by each two flat surfaces are all 120 degree, which will fit the round extrusions  31  of the work piece  30  as shown on  FIG. 22 . 
   As shown on  FIG. 23 , the wall of the concavity  13  is formed by four surfaces  133   c ,  134   c ,  135   c  and  136   c , each of the surfaces is flat and the angles formed by each two adjacent flat surfaces are all 135 degree. 
   As shown on  FIG. 24 , the wall of the concavity  13  is formed by five surfaces  133   d ,  134   d ,  135   d ,  136   d  and  137   d , each of the surfaces is flat and the angles formed by each two adjacent flat surfaces are all 135 degree. 
   As shown on  FIG. 25 , the driving head  10  is a sleeve with an opening  100  at one end, plurality ratchets  16  are implemented on the peripheral of outside of the sleeve. 
   As shown on  FIG. 26 , a handle  17  is implemented on one side of the driving head  10 , which is to be used as an usual wrenching tool. 
   As shown on  FIG. 27 , the two ends of the concavity  13  are connecting their neighboring forefront surfaces  11  to form continuous curves, the forefront surfaces  11  are formed by multiple curves for varieties of work pieces to fit. 
   As shown on  FIG. 28 , the forefront surfaces  11  are flat and there are six of them, with six forefront surfaces  11 , which a hexagonal shape of work piece  20  can be fitted into.