Patent Publication Number: US-7581470-B1

Title: Universal screwdriver bit set

Description:
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS 
   Not applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT 
   Not applicable. 
   REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to a screwdriver bit set, and more particularly to an innovative bit set, which enables interpolation and assembly of at least four types of screwdriver bits. 
   2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98 
   The coupling position of common electric screwdriver bits can be adjusted for assembly and replacement of different screwdriver bits, however, it is possible that the adapter of an electronic screwdriver bit cannot be inserted into the screw in a narrow space due to the external diameter of the adapter being too large. 
   Therefore, a screwdriver bit set has been developed in timely response to the aforementioned issues. One end of a screwdriver bit set is generally a coupling rod for assembly onto the adapter, and the other end is extended to a preset length and provided with a slot for insertion of the screwdriver bit. However, it is found from actual application that the currently available screwdriver bits from different manufacturers have various insertion ends, e.g. at a minimum 4 dimensions of insertion ends in view of the spacing from the end surface to the lateral bead locating flange. Yet, only one or two models are considered in the structure of a typical screwdriver bit set, leading to lack of adaptability in the applications, possible failure of assembly of screwdriver bits and screwdriver bit set, as well as adverse impact on the applicability of the screwdriver bit set. 
   Thus, to overcome the aforementioned problems of the prior art, it would be advancement in the art to provide an improved structure that can significantly improve efficacy. 
   Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products. 
   BRIEF SUMMARY OF THE INVENTION 
   Based upon the unique structure of the present invention, the movable tube of the “universal screwdriver bit set” is externally provided with an abutting end and a recessing slot. The movable magnetic rod can be slidably and flexibly assembled into the movable tube recessing slot. The movable magnetic rod is provided with a magnetic head and drive rod. The magnetic head in a recessed state has a spacing fall with the abutting end of the movable tube, either single-ended or double-ended screwdriver bit, or the lateral bead locating flanges with some offsets, can be positioned securely, such that the universal screwdriver bit set allows for assembly of screwdriver bits with at least 4 currently available insertion ends, thereby improving the adaptability and applicability. 
   Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  shows an assembled perspective view of the preferred embodiment of the present invention. 
       FIG. 2  shows an exploded perspective view of the preferred embodiment of the present invention. 
       FIG. 3  shows an assembled sectional view of the preferred embodiment of the present invention. 
       FIG. 4  shows a sectional view of the present invention with the screwdriver bit being inserted. 
       FIG. 5  shows another sectional view of the present invention with the screwdriver bit being inserted. 
       FIG. 6  shows a sectional view of the present invention with the screwdriver bit being released. 
       FIG. 7  shows a schematic view of a comparison of different screwdriver bits of the present invention that can be inserted into the universal screwdriver bit set. 
       FIG. 8  shows a sectional view of the comparison of the present invention to different screwdriver bits assembled and inserted into the universal screwdriver bit set. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings. 
     FIGS. 1-3  depict preferred embodiments of universal screwdriver bit set of the present invention. The embodiments are provided only for explanatory purposes with respect to the patent claims. 
   The universal screwdriver bit set A comprises a hollow main rod  10 , containing a coupling end  11  and a screwdriver bit insertion end  12 . A recessed screwdriver bit slot  13  (with a hexagonal profile) is formed at the screwdriver bit insertion end  12 . A first bead hole  14  and a second bead hole  15  are arranged at interval onto the preset location on the wall of the screwdriver bit slot  13 . 
   The set A also includes a control bushing  20 , which is sleeved onto the periphery of the screwdriver bit insertion end  12  of the main rod  10 . A recessed circular trough  21  and a locked circular trough  22  are arranged alternatively on the inner wall of the control bushing  20 . 
   A first elastic spring  30  is assembled between the control bushing  20  and main rod  10 , used to support flexibly the control bushing  20  towards the screwdriver bit insertion end  12 . The first elastic spring  30  of the preferred embodiment is made of a helical spring. Circular shoulders  17 ,  23  are arranged correspondingly on the control bushing  20  and main rod  10 , so that the first elastic spring  30  is assembled between two circular shoulders  17 ,  23 . 
   There is also a movable tube  40 , which resembles a cylinder, assembled into the screwdriver bit slot  13  of the main rod  10  in a limited sliding state. An abutting end  41  and a recessing slot  42  are placed externally onto the movable tube  40 . A through-hole  43  is formed at the center of the recessing slot  42 . 
   A second elastic spring  50  is made of a helical spring, assembled between the inner end of movable tube  40  and the inner wall of screwdriver bit slot  13 , and used to support flexibly the movable tube  40  towards the screwdriver bit slot  13 . 
   A movable magnetic rod  60  is assembled into the recessing slot  42  of the movable tube  40  in a limited sliding expansion state. The movable magnetic rod  60  is provided with a magnetic head  61  and a drive rod  62 . When the magnetic head  61  is in a predefined recessing state, there is a spacing fall with the abutting end  41  of the movable tube  40 . The drive rod  62  then penetrates loosely the through-hole  43  of the recessing slot  42 . At the inner end of the drive rod  62 , an expanded limit portion  63  is formed by combining a fixed T-column or bolt. Additionally, a magnet  65  is embedded onto the magnetic head  61  provided a tank  64  is arranged on the surface. 
   A first group of locating beads  71  is assembled into the first bead hole  14  on the wall of screwdriver bit slot  13 . The first group of locating beads  71  can be pressed by the inner wall of the control bushing  20  for snapping and locating inwards the screwdriver bit  81 . When the recessed circular trough  21  on the inner wall of the control bushing  20  is aligned with the first group of locating beads  71 , the first group of locating beads  71  are protruded to release the screwdriver bit  81 . 
   A second group of locating beads  72  are assembled into the second bead hole  15  on the wall of the screwdriver bit slot  13 . The second group of locating beads  72  can be supported by the movable tube  40  and snapped into the locked circular trough  22  on the inner wall of the control bushing  20 . 
   An inner tube limitation member  73  limits the movable tube  40  sliding towards the screwdriver bit slot  13 . The inner tube limitation member  73  of the preferred embodiment is made of a locating bead  731 , so that a bead accommodating hole  732  on the wall of the screwdriver bit slot  13  could accommodate the locating bead  731 . The locating bead  731  can be pressed by the inner wall of the control bushing  20  for snapping inwards onto the abutting end  41  of the movable tube  40 . 
   Referring to  FIG. 3 , at one side of the locked circular trough  22  of the control bushing  20 , a recessed limitation slot  221  is arranged to lock the second group of locating beads  72  so as to prevent the maximum sliding and disengagement of the control bushing  20  (shown in  FIG. 5 ). 
   Based on above-specified structures, the present invention is operated as follows: 
   Referring first to  FIG. 3 , the universal screwdriver bit set A isn&#39;t yet inserted into the screwdriver bit  81 . In such a case, the movable tube  40  is supported outwards by the second elastic spring  50 , then the second group of locating beads  72  are supported and snapped into the locked circular trough  22  on the inner wall of the control bushing  20 , realizing the positioning of the control bushing  20 . In such a case, the first elastic spring  30  is slightly squeezed by two circular shoulders  17 ,  23  to accumulate its elastic force. On the other hand, the first group of locating beads  71  are aligned with the recessed circular trough  21  on the inner wall of the control bushing  20 , thus achieving a protruding or recessing state. 
   Referring also to  FIGS. 4 and 5 , when the screwdriver bit  81  is inserted into predefined depth of screwdriver bit slot  13  on the screwdriver bit insertion end  12  of the main rod  10 , the abutting end  41  is pushed to make the movable tube  40  slide inwards. Meanwhile, the second elastic spring  50  is squeezed to accumulate elastic force, so that the second group of locating beads  72  is recessed slightly and disengaged from the locked circular trough  22  of the control bushing  20 . In such a case, the control bushing  20  will slide forwards to a predefined distance under the elastic release of first elastic spring  30  (shown by L 1  in  FIG. 5 ). With the forward shift of the control bushing  20  and insertion of the screwdriver bit  81 , the first group of locating beads  71  can be properly snapped onto the bead locating flange  810  at one side of the screwdriver bit  81 . Moreover, with the forward shift of the control bushing  20 , the recessing state of the first group of locating beads  71  will be pressed by the inner wall of the control bushing  20 , thus positioning robustly the screwdriver bit  81 . 
   Referring also to  FIG. 6 , when the screwdriver bit  81  is to be released, it is only required to push backwards the control bushing  20  (indicated by L 2 ), thus realizing the state disclosed in  FIG. 4 . Namely, the first group of locating beads  71  can be protruded into the recessed circular trough  21  of the control bushing  20  so as to release the screwdriver bit  81 . In such a case, with the elastic release of the second elastic spring  50 , the movable tube  40  will be pushed outwards to allow for protruding of the screwdriver bit  81 . The insertion end of the screwdriver bit  81  will be adsorbed by the magnetic head  61  of the movable magnetic rod  60  without disengagement. 
   As for the universal screwdriver bit set A of the present invention, the screwdriver bits with at least 4 available insertion ends can be assembled as shown in  FIG. 7 . The difference of 4 screwdriver bits  81 ,  82 ,  83 ,  84  lies in varying spaces (W 1 , W 2 , W 3 , W 4 ) from the insertion ends to the lateral bead locating flange  810 ,  820 ,  830 ,  840 . 
   As mentioned above, these 4 screwdriver bits  81 ,  82 ,  83 ,  84  are assembled onto the universal screwdriver bit set A of the present invention as shown in  FIG. 8 . There exist varying spaces W 1 , W 2 , W 3  from the insertion end of three single-ended screwdriver bits  81 ,  82 ,  83  to the lateral bead locating flanges  810 ,  820 ,  830 , enabling automatic adjustment with the sliding characteristics of the movable tube  40 . The space W 4  from the conical insertion end of a double-ended screwdriver bit  84  to its lateral bead locating flange  840  is much bigger than the other three ones. So, the magnetic head  61  of the movable magnetic rod  60  can be recessed into the abutting end  41  of the movable tube  40 , such that the conical insertion end of the screwdriver bit  84  can be further extended into the movable tube  40 , thereby locating securely and accurately the bead locating flange  840 .