Abstract:
The present invention relates to a quick-change attachment means for a hole saw, which is directed to a tool for use with a hole saw for boring holes on a wooden plank, particularly a quick-change attachment means for quickly replacing a longitudinal body, which is a drill bit shank having a driving end, a tool end, and a limiting portion. The present invention is characterized by: it is a quick-change attachment means for assembling a longitudinal body and a hole saw, it has an axial hole for allowing a longitudinal body to move on a quick-change attachment means, a locking component for locking and releasing the longitudinal body on and from the quick-change attachment means. The locking component has a first component and a second component, which when used, the longitudinal body can be easily moved slidably and locked so the shreddings emerging from the hole saw can be cleaned.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Fields of the invention 
         [0002]    The present invention is directed to a quick-change attachment means for a hole saw, which is a tool used with a hole saw specifically used for wooden planks. The quick-change attachment means is particularly designed for coupling to a hole saw, in which the locking component and the positioning component in the quick-change attachment means can allow for faster reload of longitudinal body and detachment from the hole saw. 
         [0003]    2. Descriptions of Related Art 
         [0004]    As with the technology disclosed in Chinese Patent Application No. CN101076420A, entitled “Quick-change and Plug Eject Arbor for a Hole Saw,” the quick-change attachment means used for quickly replacing drill bit shank where the quick-change attachment means can be fitted to the hole saw is coupled to the longitudinal body (which is a drill bit shank), and is locked with respect to the longitudinal body and cannot be free to rotate, and also locked axially. Because of this setup, a plug of the sawn material can be pushed out of the hole saw after a material is sawn by slidably releasing the attachment means from the longitudinal body before passing the longitudinal body through the quick-change attachment means. 
         [0005]    The quick-change attachment means can be slidably released from the longitudinal body, and further apply a latch to slidably release the quick-change attachment means from the longitudinal body, before allowing the longitudinal body to further move into the holes. In this way, a slant terminal end of the longitudinal body can be used to push the plug out the hole saw, without needing any tool or disassembly tools. 
         [0006]    Disadvantageously, because the latch operates by pressing from top to bottom, and an end of the latch is used as a fulcrum, a problem with the invention is that the user using the tool would have to press down and hold down the latch on another end of the fulcrum. The applied force holding on these positions may not be necessarily well-distributed, and the disproportional pressing may consequently cause the user to exert more strength than necessary in order to suppress the latch down from becoming subject to axial release. As a result the adapter would be required to be threadably coupled first to the threaded hole. A problem implicated by this structure is that the actuating of the hole saw and the longitudinal body are both handled by radial rotation, and the adapter is also subject to radial rotation when coupling, therefore it is highly possible that during operation of the driving mechanism, the anti-vibrational force can cause the threaded spots of the quick-change attachment means and the hole saw to unscrew, thereby jeopardizing the cutting process. 
         [0007]    Accordingly, the inventor of the present invention, in an objective to resolve the above-identified shortcomings, has through improvement made in pursuit for innovative approach for problem solving, as well as relentless efforts to strive for technical progress, has for many accounts of trials, experiments with full and comprehensive conception, arrive at the present utility model invention and hereby files for a utility model patent protection. 
       SUMMARY OF THE INVENTION 
       [0008]    With the quick-change attachment means for a hole saw, it is an objective of the present invention to provide a locking switch capable of reducing required applied force and capable of locking and releasing a longitudinal body. Another advantage of the present invention is that it is possible to required less number of mechanical parts for assembly, thereby decreasing construction difficulty which also preserving use safety. 
         [0009]    A main feature of the quick-change attachment means of the present invention is that the quick-change attachment means includes a locking component that can allow the longitudinal body to be slidably released and locked, the quick-change attachment means also includes a positioning component that can keep the quick-change attachment means attached in a predetermined place on the hole saw and disconnect therefrom. 
         [0010]    The locking component of the longitudinal body according to the present invention has the advantage of being intuitive to use, and can release and allow the longitudinal body to slide freely on the quick-change attachment means. In more elaborate terms, the positioning component uses two pins for serving its positioning purpose. Also, the positioning component is installed in the quick-change attachment means to actuatingly fix the quick-change attachment means onto the closed surface of the hole saw. This is enabled because the working condition for the hole saw requires an assembly together with a longitudinal body, and the quick-change attachment means can provide support for coupling the longitudinal body to the hole saw to facilitate subsequent rotation for actuation. 
         [0011]    An objective of the present invention is to offer a method in which the quick-change attachment means, one that can be quickly replaced in the longitudinal body, can be attached and fixed in place on the hole saw, can lock onto the drill bit shank after the longitudinal body passes through the hole of the quick-change attachment means. The longitudinal body can be free to rotate radially while it is axially locked in place. By way of the above mechanism, a longitudinal body can be dislodged from the quick-change attachment means and the hole saw, while shavings emerging from the working terminal of the longitudinal body can be removed at the same time when the longitudinal body is dislodged from the quick-change attachment means and the hole saw. Applicable situations benefiting the above solution include after the hole saw has performed cutting, after the longitudinal body has been unlocked from the quick-change attachment means. 
         [0012]    The quick-change attachment configuration for a hole saw is directed to a tool for use in drilling circular holes on wooden planks. Its constitution includes a hole saw, a longitudinal body and a quick-change attachment means, the hole saw herein includes a threaded aperture, a closed end, and coupling apertures. The longitudinal body is a shank that is capable of accommodating a drill bit, it includes a driving end, a tool end and a limiting portion, wherein the limiting portion cooperates with the quick-change attachment means to securely couple the locking component to the shank. 
         [0013]    An advantage of the present invention is that the quick-change attachment means used for assembling the longitudinal body and the hole saw together comprises a locking component and a positioning component. The locking component comprises a first component and a second component. The first component has an axial hole, an attachment means, a threaded portion, first attachment apertures and positioning apertures. The component has a first central hole, second attachment holes, and first through holes, where an outer diameter of an end of the first central hole is curvilinear. 
         [0014]    The positioning component has a second central hole, receiving holes, mortises and two pins. Each of the receiving holes includes first openings and second openings, wherein the inner diameter of each of the second opening is smaller than the inner diameter of each of the first opening, an end of the mortise is closed and another end of the mortise is open. An end of each of the pins whose outer diameter slightly diminishes is formed into a connecting portion. Regarding the mortises, the hole diameter of each of the mortise fits exactly with an outer diameter of the connecting portion of each of the pins and securely connected thereon. Each of the receiving holes of the positioning component is inserted with an actuating pin, which has an expanding portion on one end and of the actuating pin and a positioning portion on another end of the actuating pin. Further, the actuating pin is equipped with a spring and is inserted into each of the receiving holes at an end of each of the positioning portions, and out of the second openings, before passes through the first through holes of the second component and is securely connected to the positioning apertures of the first component by a tenon and mortise joint. The attachment portion of the first component passes through the first central hole of the second component. 
         [0015]    The axial hole is located on the attachment portion of the first component and traverses toward the threaded portion in a radial direction. The attachment portion has locking apertures located on the two ends of its radial axis, wherein each of the locking apertures is inserted with a retaining ball. Another aspect of the advantage of the current invention is that the outer diameter of the attachment means is slightly smaller than the first central hole and the second central hole, and the threaded portion is capable of being threadably connected to the threaded aperture of the hole saw. 
         [0016]    Additionally, the pins are designed to pass through the first attachment apertures of the first component and the second attachment apertures of the second component, and are allowed to pass through the second attachment holes before passing through the coupling apertures to prevent the quick-change attachment means from unscrewing off the safety-ensuring positioning configuration of the hole saw. 
         [0017]    In another aspect of the invention, the axial hole of the first component can provide the longitudinal body with room for axial movement through the quick-change attachment means. The retaining ball set in the locking aperture of the first component is used for locking the longitudinal body. More specifically, the subject invention involves using the upward and downward displacement of the retaining ball as a means to provide a mechanism dedicated to fasten the longitudinal body, in which the position of the retaining ball is switched between being pressed downward to be retained or released from the limiting portion of the longitudinal body at the command of the forward and backward movement of the second component. An inner diameter of one end of the second central hole of the positioning component includes an expanding receiving portion, which can provide for enveloping a biasing member. By way of operating the second component of the locking component with respect to switching between forward-moving and backward-moving displacement, the retaining ball can operate to be pressed downward to lock the connecting portions of the crank of the longitudinal body, or by the effect of switching to move the second component from its position, the retaining ball can be free from hold-up and detachable from the limiting portion of the longitudinal body, and can be raised upward, so that the shank for holding the drill bit can be detached from the quick-change attachment means and hole saw. 
         [0018]    Additionally, the connecting portion and mortise on one end of the pin of the positioning component are designed to be securely connected with a tenon and mortise joint, in such a sawy that the connecting portion can provide for the quick-change attachment means to prevent the hole saw from unscrewing off due to driving effectuated by rotational movement. This mechanism enables the component to assist the quick-change attachment means to be threadably connected to the threaded aperture, wherein the pins pass through the coupling apertures of the hole saw. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: 
           [0020]      FIG. 1  shows an exploded view of a possible embodiment of the hole saw, quick-change attachment means, and a longitudinal body for the current invention; 
           [0021]      FIG. 2  shows an exploded view of the quick-change attachment means for a first embodiment for the current invention; 
           [0022]      FIG. 3  shows an exploded view of the quick-change attachment means for a second embodiment for the current invention; 
           [0023]      FIG. 4  is a cross-sectional view of the first embodiment for the current invention; 
           [0024]      FIG. 5  is a cross-sectional view of the quick-change attachment means and the longitudinal body in a quick-change mode according to the first embodiment of the current invention; 
           [0025]      FIG. 6  is a cross-sectional view of the quick-change attachment means and the longitudinal body in a locked mode according to the first embodiment of the current invention; 
           [0026]      FIG. 7  is a cross-sectional view of the quick-change attachment means and the hole saw in a quick-change mode according to the first embodiment of the current invention; 
           [0027]      FIG. 8  is a cross-sectional view of the quick-change attachment means and the hole saw in a locked mode according to the first embodiment of the current invention; 
           [0028]      FIG. 9  is a cross-sectional view of the quick-change attachment means and the longitudinal body in a quick-change mode according to the second embodiment of the current invention; 
           [0029]      FIG. 10  is a cross-sectional view of the quick-change attachment means and the longitudinal body in a locked mode according to the second embodiment of the current invention; 
           [0030]      FIG. 11  is a cross-sectional view of the quick-change attachment means and the hole saw in a quick-change mode according to the third embodiment of the current invention; and 
           [0031]      FIG. 12  is a fourth view of the quick-change attachment means and the hole saw in a locked mode according to the fourth embodiment of the current invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    In order to enable a person skilled in the relevant technology to practice the invention described in the specification, the objectives, technical features and effects will be further understood in connection with the Preferred Embodiments and in conjunction with the Drawings below. 
         [0033]    Referring now to the first embodiment illustrated in  FIGS. 1 through 8 , the quick-change attachment configuration for a hole saw includes a hole saw  1 , a longitudinal body  2  and a quick-change attachment means a 3 . The hole saw  1  has a threaded aperture  111 , a closed surface  11 , and coupling apertures  12   a ,  12   b ,  12   c ,  12   d . The coupling apertures  12   a ,  12   b ,  12   c ,  12   d  are each separated with each pair aligned to form a cross on the closed end  11 . The threaded aperture  111  is located at he axial center of the closed end  11 ; further, the longitudinal body  2  is a drill bit shank, which includes a drilling end  23 , a tool end  22 , and a limiting portion  21 , wherein the limiting portion  21  can be used to help the quick-change attachment means  3  fasten the locking component  3 ′ and ultimately look the movement of the longitudinal body  2 . 
         [0034]    More particularly, the quick-change attachment means  3  used for assembling the longitudinal body  2  and the hole saw  1  comprises a locking component  3 ′ and a positioning component  31 . The locking component  3 ′ comprises a first component  33  and a second component  34 . The first component  33  has an axial hole  335 , an attachment portion  334 , a threaded portion  336 , first attachment apertures  332 ,  332   b  and positioning apertures  331   a ,  331   b . The second component  34  is a fastening component that is free to move forward and backward axially, which has a first central hole  343 , second attachment holes  342   a ,  342   b  and first through holes  341   a \,  341   b . A portion of the outer diameter of the first central hole  343  is disposed with a curvilinear position  344 . 
         [0035]    Note that the positioning component  31  has a first end surface  311   a  and a second end surface  311   b , and a second central hole  313  receiving holes  312   a ,  312   b  and mortises  314   a ,  314   b  are interposed between the first end surface  311   a  and the second end surface  311   b . Moreover,  314   a ,  314   b  are disposed on the second end surface  311   b , for providing the connecting portions  321   a ,  321   b  of the pins  32   a ,  32   b  to be riveted to the mortises  314   a ,  314   b . The receiving holes have first openings  3121   a ,  3121   b , and second openings  3122   a ,  3122   b . The inner diameter of each first openings  21211 ,  3121   b  traverses axially for a predetermined distance from one end of each second openings  3122   a ,  3122   b . As will be understood by the illustration of  FIG. 7 , an end of each of the mortises  314   a ,  314   b  is an opening, the diameter of an end of each of the pins  32   a ,  32   b  slightly decreases to form connecting portions  312   a ,  321   b . The diameter of each of the mortises  314   a ,  314   b  fits exactly with the diameters of the connecting portions  321   a ,  321   b . By the above, the connecting portions  321   a ,  321   b  of the pins  32   a ,  32   b  are connected to the mortises  314   a ,  314   b  by a tenon and mortise joint. 
         [0036]    As will be seen, the receiving holes  312   a ,  312   b  of the positioning component  31  can receive the actuating pins  5   a ,  5   b . Ends of each of the actuating pins  5   a ,  5   b  are expanding portions  51   a ,  51   b , and the other ends of each of the actuating pins are disposed with positioning portions  52   a ,  52   b . After each of the actuating pins  5   a ,  5   b  pass through a spring  61   a ,  61   b , the positioning portions  52   a ,  52   b  are inserted through the receiving holes  312   a ,  312   b  of the first openings  3121   a ,  3121   b , pass through the second openings  3122   a ,  3122   b , before being passed through the first through holes  341   a ,  341   b  of the second components, where they are fastened by a tenon and mortise joint to the positioning apertures  331   a ,  331   b . The expanding portions  51   a ,  51   b  are anchored on the inclined plane of the inner diameters of the second openings  3122   a ,  3122   b . Meanwhile, the attachment means  334  of the first component  33  pass through the first central hole  343  of the second component, and the second central hole  313  of the positioning component. 
         [0037]    The axial hole  335  of the first component  33  is installed in the axial direction of the attachment portion  334  and extends through the threaded portion  336 , the axial hole  335  has a hexagonal shape. The two ends on the radial axis of the attachment portion  334  are disposed with locking apertures  333   a ,  333   b . The locking apertures  333   a ,  333   b  are receivable for certain retaining balls  8   a ,  8   b . The outer-diameters of the attachment portions are slightly smaller than the outer diameters of the first central hole  3434  and the second central hole  313 . Additionally, the attachment portion  334  is jacketed by a biasing member  7  and passes through the second central hole  313  of the positioning component  31  after the attachment portion  334  passes through the first central hole of the second component  34 . The jacket attachment portion is also restricted for movement by means of the blocking portion  3131  pre-established in the space defined by the inner diameter of the second central hole  313 . 
         [0038]    The threaded portion  336  is used to threadably attach and be secured to the threaded aperture  111  of the hole saw  1 . The pins  32   a ,  32   b  pass through the first attachment holes  332   a ,  332   b  of the first component  33  and the second attachment holes  342   a ,  342   b  of the second component  34 . After they are set up to pass through the second attachment holes  342   a ,  342   b , they can be asserted into any pair of the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the hole saw  1  in order to prevent the quick-change attachment means from unscrewing off from the hole saw  1  due to the radial rotation as effected by the hole saw  1 . 
         [0039]    Next, the locking and quick disassembly of the longitudinal body  2  and the quick-attachment means  3  are depicted in  FIGS. 5 and 6 . The longitudinal body  2  can move radially in the axial hole  335  of the first component  3  of the quick-change attachment means  3 . The components for locking the longitudinal body  2  are the set in the retaining balls disposed in the locking apertures  333   a ,  333   b . By way of displacing the second component  34  backward in a radial direction, the longitudinal body  2  can pass through the axial hole  335  until the limiting portion  21  reach the locking apertures  333   a ,  333   b . At this point, the second component  34  is released to allow the springs  61   a ,  61   b  housing the actuating pins  5   a ,  5   b  to return the second component  34  back to its original position, and at the same time the curvilinear portion  344  is used to push against the retaining balls  8   a ,  8   b , which are pressed downward from the locking apertures  333   a ,  333   b  onto the limiting portion  21  of the longitudinal body  2 . By way of the force applied as resulting from the springs compressed by the actuating pins  5   a ,  5   b , the second component  34  is held to be closely attached to the first component. This leads the bottom end of the curvilinear portion  344  of the second component  34  to be tightly pressed to the retaining balls  8   a ,  8   b . In this situation there are some areas of the retaining balls  8   a ,  8   b  that protrude out of the bottom ends the locking apertures  333   a ,  333   b  and can be held up on the limiting portion of the longitudinal body  21 . This means that the longitudinal body can be securely locked on the quick-change attachment means  3 . 
         [0040]    According to an embodiment of the invention, a method for disassembling the longitudinal body  2  from the quick-change attachment means  3  are the following. One is to start by displacing the second component  34  backward in order to disattach the second component embedded into the retaining balls  8   a ,  8   b  of the limiting portion  21  of the longitudinal body  2  from the compression of the second component  34 . By this approach, the retaining balls  8   a ,  8   b  would, in an opposite fashion, be pushed out of the limiting portion  21  by the surface of the outer axial handle of the limiting portion  21  of the longitudinal body  2 , and pushed upward to finally return to the locking apertures. In this configuration, some areas of the retaining balls  8   a ,  8   b  protrude out of the bottom ends of the locking apertures  333   a ,  333   b , thereby forcing the retaining balls  8   a ,  8   b  to exit out of the limiting portion  21  in order to allow the longitudinal body  2  to disattach from the quick-change attachment means  3 . 
         [0041]    The function of the actuating pins  5   a ,  5   b  is to assist in returning the second component  34  and the positioning component  31  back to its original position during their axial displacement. Because ends of the springs  61   a ,  61   b  are limited by the enlarged portions  51   a ,  51   b  after the actuating pins are housed by the springs  61   a ,  61   b , which is meant to prevent the springs from unscrewing off the actuating pins  5   a ,  5   b . Then the actuating pins  5   a ,  5   b  that are housed with springs  61   a ,  61   b  are inserted into receiving holes  312   a ,  312   b . The positioning component  31  is pushed backward at the same time when the second component  34  used for operating the locking component  3 ′ is switched between a forward and backward movement. In other more elaborated words, the actuating pins  5   a ,  5   b  located inside the receiving holes  312   a ,  312   b  can recede or return to their original position at the same time. Under the effect created by the enlarged portions  51   a ,  51   b  of the actuating pins  5   a ,  5   b  being held up in the second openings  3122   a ,  3122   b  of the receiving hole  312   a ,  312   b , the actuating pins  5   a ,  5   b  will not be completely removed from the receiving holes  312   a ,  312   b . Also, the actuating pins  5   a ,  5   b  and the attachment portions  334  are disposed in respective positions relative to the locking apertures  333   a ,  333   b  of the attachment portion in a parallel fashion, the upper and lower pitch length of the actuating pins  5   a ,  5   b  and the attachment portion  34  are smaller than the outer diameter of the retaining balls  8   a ,  8   b . This arrangement is set up to block the retaining balls  8   a ,  8   b  form excessive movement, disabling the retaining balls  8   a ,  8   b  from complete detachment from the locking apertures  333   a ,  333   b . This means the retaining balls  8   a ,  8   b  can be limited inside the locking apertures  333   a ,  333   b . Notably, the maximum outer diameters of the retaining balls are required to be larger than the inner diameters of the lower ends of the locking apertures  333   a ,  333   b  such that the retaining balls would not break away from the lower ends of the locking apertures  333   a ,  333   b.    
         [0042]    Reference is now turned to  FIGS. 7 and 8  for the positioning and quick-change operation of the quick-change attachment means  3  and the hole saw  1 . 
         [0043]    The drawings here show the on and off position for an assembly of a quick-change attachment means  3  and a hole saw  1 . In the current embodiment, the positioning component  31  of the quick-change attachment means  3  is pulled backward to be temporarily held in a particular position, causing the pins  32   a ,  32   b  to simultaneously move backward. At this time the biasing member  7  disposed between the positioning component  31  and the second component  34  can be set to push against the second component  34 , so as to prevent the second component  34  and the positioning component  31  from moving backward. Next, the threaded portion  336  is threadably coupled to the threaded aperture  111  of the hole saw  1  until the pins  32   a ,  32   b  of the quick-change attachment means  3  are aligned with the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the closed end  11  of the hole saw  1 . After the pins  32   a ,  32   b  are aligned with the two apertures corresponding to the coupling apertures  12   a ,  12   b ,  12   c ,  12   d , the positioning component  31  is released in order for itself to return to its original position. At this point, by way of the pins  32   a ,  32   b  returning to their positions, the pins  32   a ,  32   b  protrude and pass through the corresponding two apertures of the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  so that the hole saw  1  can be prevented from unscrewing after the quick-change attachment means  3  is set to pass through the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the hole saw  1 . 
         [0044]    Next, a walkthrough of how to operate quick-change mechanism with the quick-change attachment means  3  and the hole saw  1  will be discussed. The positioning component  31  of the quick-change attachment means  3  is pulled backward and held down in a locked position by hand, and the pins  32   a ,  32   b  are permitted to move backward such that after the pins  32   a ,  32   b  are detached from the two apertures corresponding to the coupling apertures  12   a ,  12   b ,  12   c ,  12   d , the threaded portion  336  is rotated to be unscrewed from the threaded aperture  111  of the hole saw  1 , before the held-down positioning component  31  is released in order to return to its original position, meanwhile, the corresponding pins  32   a ,  32   b  can return to their original position, the quick-change attachment means  3  is uncoupled from the hole saw  1 . 
         [0045]    Next, as shown in  FIGS. 9 through 12  which depict the second embodiment of the present invention, the quick-change attachment means  3  includes a locking component  3 ′ and a positioning component  31 , wherein the locking component  3 ′ is the first component  33 , the first component  33  has an axial hole  335 , an attachment portion  334 , a threaded portion  336 , a first attachment holes  332   a ,  332   b  and positioning apertures  331   a ,  331   b . The positioning component  31  has a second central hole  313 , receiving holes  312   a ,  312   b , mortises  314   a ,  314   b , and two pins  32   a ,  32   b . The receiving holes  312   a ,  312   b  have first openings  3121   a ,  3121   b  and second openings  3122   a ,  3122   b . The inner diameters of the second openings  3122   a ,  3122   b  are smaller than the inner diameter of the first openings  3121   a ,  3121   b . The width of diameters of the first openings  3121   a ,  3121   b  spans from a distance away from ends of the receiving holes  312   a ,  312   b  to terminal ends and gradually shrink to form the second openings  3122   a ,  3122   b  whose inner diameter define an inclined surface. An end of each of the mortises  314   a ,  314   b  is designed to be closed, while another end of them is designed to be open. The diameter of an end of each of the pins  32   a ,  32   b  gets slightly smaller to become connecting portion  321   a ,  321   b . The aperture diameters of the mortises  314   a ,  314   b  fit exactly with the outer diameter of the connecting portions  321   a ,  321   b  of the pins  32   a ,  32   b . In this way, the connecting portions  321   a ,  321   b  of the pins  32   a ,  32   b  and the mortises  314   a ,  314   b  are connected together by way of a tenon and mortise joint. The receiving holes  312   a ,  312   b  of the positioning component can be used to house actuating pins  5   a ,  5   b , which have ends that are formed to be enlarged portions  51   a ,  51   b . Other ends have positioning portions  52   a ,  52   b . After the actuating pins  5   a ,  5   b  are set to house springs  61   a ,  61   b , the positioning portions  52   a ,  52   b  are introduced through the first openings  3121   a ,  3121   b  of the receiving holes, before passed through the second openings  3122   a ,  3122   b  and secured to the positioning apertures  331   a ,  331   b  of the first component  33  by way of a tenon and mortise joint. The enlarged portions  51   a ,  51   b  are set to be held against the inclined surface defined by the inner diameter of the second openings  3122   a ,  3122   b . The attachment portion  334  of the first component  33  passes through the second central hole  313  of the positioning component  31 . The axial hole  335  of the first component  33  is disposed on the attachment portion  334  in the axial direction and extends toward the threaded portion  336 . The hole of the axial hole  335  has a hexagonal shape. The attachment portion  334  has locking apertures  333   a ,  333   b  on the two ends in the radial direction. The locking apertures  333   a ,  333   b  provide for insertion of retaining balls  8   a ,  8   b . Further, the outer diameter of the attachment portion  334  is slightly smaller than the first central hole  343  and second central hole  313 , and the threaded portion  336  is threadably attached to the threaded aperture  111  of the hole saw  1 . 
         [0046]    Also, after the pins  32   a ,  32   b  pass through the first component  33  and the first attachment holes  332   a ,  332   b  pass through the second attachment holes  342   a ,  342   b , the pins  32   a ,  32   b  can be inserted into any set of mutually corresponding apertures of the coupling apertures  12   a ,  12   b ,  12   c ,  12   d , such that the quick-change attachment means  3  can be prevented from unscrewing from the hole saw  1  when the hole saw  1  is rotating radially. 
         [0047]    The mode of operation for the locking and quick-change mechanism with the longitudinal body and quick-change attachment means  3  in the second embodiment of the present invention will be discussed below. The longitudinal body  2  can move radially in the axial hole  335  of the first component  33  of the quick-change attachment means  3 . The component for locking the longitudinal body  2  are the retaining balls  8   a ,  8   b  disposed in the locking apertures  333   a ,  333   b  of the first component  33 , which, by way of the backward-moving radial displacement of the positioning component  31  as shown in  FIGS. 9 and 10 , the longitudinal body  2  is inserted through the axial hole  335  and extends until the limiting portion reaches the locking apertures  333   a ,  333   b . At this point the positioning component  31  is released to let the actuating pins  5   a ,  5   b  to be housed by springs  61   a ,  61   b  in order to return the positioning component  31  back to its original position. In the meantime the curvilinear portion  344  is used to push against the retaining balls  8   a ,  8   b . The locking apertures  333   a ,  333   b  are pressed downward into the limiting portion  21  of the longitudinal body  2 , and, by the account of the forward-pushing force applied by the springs  61   a ,  61   b  on the actuating pins  5   a ,  5   b , the positioning component  31  is closely held together with the first component  33 , thereby causing the curvilinear portion  344  of the positioning component  31  to be closely held against the retaining balls  8   a ,  8   b . At this point about half of the area of the retaining balls  8   a ,  8   b  are closely held against the limiting portion  21 , so this means the longitudinal body  2  is securely fixed in the quick-change attachment means  3 . The mode of operation for detaching the longitudinal body  2  from the quick-change attachment means  3  will now be described below. The positioning component  31  is pulled backward in order to detach the downwardly embedded retaining balls  8   a ,  8   b  in the limiting portion  21  of the longitudinal body  2 . The retaining balls, in this configuration however, are pushed out by the outer axial handle surface of the limiting portion  21  of the longitudinal body  2  and move upward to return to the locking apertures  333   a ,  333   b . At this point the retaining balls  8   a ,  8   b  have some areas that protrude out of the locking apertures  333   a ,  333   b , causing the retaining balls  8   a ,  8   b  to exit the limiting portion  21  and therefore the quick-change attachment means  3 . 
         [0048]    The actuating pins  5   a ,  5   b  are used for returning the displaced positioning component  31 . Because after the actuating pins  5   a ,  5   b  are housed by springs  61   a ,  61   b , the enlarged portions  51   a ,  51   b  are set to limit particular ends of the springs  61   a ,  61   b , thereby preventing the springs  61   a ,  61   b  from unsleeving the actuating pins  5   a ,  5   b , inserting the actuating pins  5   a ,  5   b  housed with springs  61   a ,  61   b  into receiving holes  312   a ,  312   b , and moving the positioning component  31  of the locking component  3 ′ backward in a radial direction. In other words, the actuating pins  5   a ,  5   b  can simultaneously contract and return to their original position in the receiving holes  312   a ,  312   b  of the positioning component  31  at this point. Because the enlarged portions  51   a ,  51   b  of the actuating pins  5   a ,  5   b  are stuck inside the second openings  3122   a ,  3122   b  of the receiving holes  312   a ,  312   b . Therefore the actuating pins  5   a ,  5   b  will not completely detach from the receiving holes  312   a ,  312   b . Further, the actuating pins  5   a ,  5   b  and the attachment portion  334  are disposed in parallel with respect to each other in the locking apertures  333   a ,  333   b  of the attachment portion  334 . As a result the pitch above and below the space between the actuating pins  5   a ,  5   b  and the attachment portion  334  is smaller than the width of the outer diameter of the retaining balls  8   a ,  8   b . By way of the above, the actuating pins  5   a ,  5   b  can exactly block the retaining balls  8   a ,  8   b . The retaining balls  8   a ,  8   b  would not completely detach from the locking apertures  333   a ,  333   b , which means that the retaining balls  8   a ,  8   b  can be limited in the locking apertures  333   a ,  333   b.    
         [0049]    The positioning and quick-change operation with the quick-change attachment means  3  and the hole saw  1  for the second embodiment of the present invention will now be discussed with reference to  FIG. 11 . The drawing therein shows a positioned status for the quick-change attachment means  3  and the hole saw  1 . Firstly shown is the quick-change attachment means  3  and the hole saw  1  set up in an assembled status. The positioning component  31  of the quick-change attachment means  3  is pulled back to be temporarily retained in a given position, causing the pins  32   a ,  32   b  to be permitted to simultaneously move backward. Next, the threaded portion  336  is threadably attached to the threaded aperture  111  on the hole saw  1 , until the pins  32   a ,  32   b  of the quick-change attachment means  3  are aligned with the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the closed end  11  of the hole saw  1 . After two corresponding apertures are aligned with, the positioning component  31  is released to return to its original position, and the mutually corresponding pins  32   a ,  32   b  are set to return to their original position. By way of returning the pins  32   a ,  32   b  back to their original positions to protrude through the mutually corresponding two apertures of the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the hole saw  1 , the quick-change attachment means  3  uses the pins  32   a ,  32   b  to pass through the coupling apertures  12   a ,  12   b ,  12   c ,  12   d  of the hole saw  1 , such arrangement can stabilize positioning and prevent unscrewing as a result of driving rotation. 
         [0050]    The quick-change operation with the quick-change attachment means  3  and the hole saw  1  is now described. The first step begins with pulling the positioning component  31  of the quick-change attachment means  3  backward and holding the it down by hand to temporarily stabilize the position. At the same time, the pins  32   a ,  32   b  are pulled backward. After the pins  32   a ,  32   b  detach from the mutually corresponding tow apertures of the coupling apertures  12   a ,  12   b ,  12   c ,  12   d , the threaded portion  336  is unscrewed by way of rotation to come off from the threaded aperture  111  of the hole saw. Then the held-down positioning component  31  is released to return to their original position, at the same time, the corresponding pins  32   a ,  32   b  are relieved to their original position. The quick-change attachment means  3  is detached from the hole saw  1 , as shown in  FIG. 12  which shows the quick-change operation with the quick-change attachment means  3  and the hole saw  1 . 
         [0051]    By way of the above, the cross-sectional area and the corresponding outer shape of the quick-change attachment means  3  can be circular, elliptical or polygonal (examples include hexagonal or quadrilateral). 
         [0052]    The longitudinal body  2  that may be used to assemble with the quick-change attachment means  3  can be a drill bit shank, and other tools. Examples include razors, hole saws, diamonds, polishing discs, or polishing films, brushes, tools for boring a hole, tools for grinding, or other similar tools. Such design can help create a multi-purpose tool replacement system. 
         [0053]    The above is only for the description of the preferred embodiments of the utility model, not for limiting the scope of this utility model. Any modifications, equivalent changes and improvements that are within the spirit and principles in the utility model should be included in the scope of protection of the utility model.