Patent Publication Number: US-2007095185-A1

Title: Quickly detachable protective cover unit of a table sawing machine

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a quickly detachable protective cover unit of a table-sawing machine, particularly to one able to be assembled and disassembled easily and quickly, needless to employ any tool for carrying out disassembling work.  
      2. Description of the Prior Art  
      Generally, a table-sawing machine is provided with a protective cover unit covered around its saw blade for the sake of protection of a user. The conventional protective cover unit of a table&#39;s sawing machine, as shown in  FIG. 1 , includes an extending rod  1 , a combining plate  2  and a protective cover  3 , which are firmly combined together by bolts to prevent them from loosening or falling off.  
      However, to detach the conventional protective cover unit from the table sawing machine, the locking bolts of the components have to be unscrewed one by one by means of special hand tools, thus wasting much time and resulting in much trouble.  
     SUMMARY OF THE INVENTION  
      The objective of the invention is to offer the quickly detachable protective cover unit of a table sawing machine, including an extending plate connected with the saw base of a table sawing machine. A quickly detachable handle unit is fixed at the inner end of the extending plate for quickly positioning a combining plate that is cut with two positioning notches at preset locations. A protective plate is inserted through the combining plate and then firmly positioned on the worktable of the table-sawing machine. A non-return plate and a protective cover are respectively assembled with the two positioning notches of the combining plate respectively by a quickly detachable device. By so designing, the protective cover unit can be detached from the table sawing machine with convenience and with less time as well, unnecessary to use any tool for carrying out assembling and disassembling work. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      This invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a partial side sectional view of the protective cover unit of a conventional table-sawing machine;  
       FIG. 2  is a perspective view of a table sawing machine in the present invention;  
       FIG. 3  is an exploded perspective view of the quickly detachable protective cover unit of the table-sawing machine in the present invention;  
       FIG. 4  is a cross-sectional view of the quickly detachable device of a protective cover in the present invention;  
       FIG. 5  is a cross-sectional view of the protective cover in a quickly detached condition in the present invention;  
       FIG. 6  is a cross-sectional view of the quickly detachable device of a non-return plate in the present invention;  
       FIG. 7  is a cross-sectional view of the quickly-detachable handle unit of an extending plate in a locked condition in the present invention; and  
       FIG. 8  is a cross-sectional view of the quickly-detachable handle unit of the extending plate in an unlocked condition in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A preferred embodiment of the quickly detachable protective cover unit of a table-sawing machine in the present invention, as shown in  FIGS. 2 and 3 , includes a worktable  10  and a quickly detachable protective cover unit  20 .  
      The worktable  10  of the table-sawing machine is formed at a preset location with an oval groove  11  having its lower periphery provided with protruding lugs  111  preset in number. The worktable  10  has a saw base  12  installed in the interior.  
      The quickly detachable protective cover unit  20  assembled at the outer side of the saw base  12  is composed of an extending plate  21 , a combining plate  22 , a protective plate  23 , a non-return plate  24  and a protective cover  25 .  
      The extending plate  21  secured at one side of the. saw base  12  has its inner end fixed with a quickly-detachable handle unit  30  composed of a fixing base  31 , an elastic member  32 , a position-limiting plate  33  and a quickly detachable pivot  34 . The fixing base  31  is fixed on the extending plate  21  and cut with a recessed groove  311  bored with a through receiving slot  312  for receiving the elastic member  32  therein. The position-limiting plate  33  is to be positioned at one side of the fixing base  31 , having one side provided with a projecting block  331  to fit in the recessed groove  311  of the fixing base  31 , with an insert space  301  adjustably formed in its width between the position-limiting plate  33  and the fixing base  31 . Further, the position-limiting plate  33  is bored with a through hole  332  with a comparatively small diameter at a location aligned to the receiving slot  312  of the fixing base  31 . The quickly detachable pivot  34  is inserted through both the through hole  332  of the position-limiting plate  33  and the receiving slot  312  of the fixing base  31 , and has its front end pivotally connected with a rotary handle  35 , which is bored with eccentric holes  351  to be pivotally combined with the quickly detachable pivot  34 , and its rear end screwed with a locking nut  341 .  
      The combining plate  22  has its lower end cut with an elongate notch  221  to be fitted on the projecting block  331  of the position-limiting plate  33  of the quickly-detachable handle unit  30  and its upper end cut at preset locations with two positioning notches  222 ,  223  having their lower ends respectively bored with a positioning hole  224 ,  225 .  
      The protective plate  23  is an oval plate having the same shape as the oval groove  11  of the worktable  10  and has its peripheral edge pivotally provided with plural elastic positioning projections  231  at preset locations. The protective plate  23  has an elongate slot  232  lengthwise bored in the center for matching with the saw base  12  and a round hole  233  bored in one side.  
      The non-return plate  24  is composed of a fundamental base  241 , a front position-limiting member  242 , a rear position-limiting member  243  and two ratchet plates  244  respectively having their lower convex edges formed with many small teeth. The two ratchet plates  244  are respectively assembled on opposite sides of the fundamental base  241  by the front and the rear position-limiting member  242 ,  243 . Further, the non-return plate  24  has a quickly detachable device  40  pivotally assembled thereon. The quickly detachable device  40  includes a stepped bolt  41  to be fitted in the positioning notch  222  of the combining plate  22 . The stepped bolt  41  has its front end fitted with an elastic member  42  and its rear end fastened on the non-return plate  24  by means of an E-shaped clasp  43 .  
      The protective cover  25  is composed of a basic body  251 , two connecting rod units  252  and two protective plates  253 . The two connecting rod units  252  are respectively and pivotally positioned at a preset location on the opposite sides of the basic body  251 , and the two protective plates  253  are respectively and pivotally combined with an upper end of the two connecting rod units  252  (seen as in  FIG. 4 ). A quickly detachable device  50  is pivotally assembled at the end of basic body  251 , including a stepped bolt  51  to be fitted in the positioning notch  223  of the combining plate  22 . The stepped bolt  51  has its front end fitted with an elastic member  52  and its rear end fastened by an E-shaped clasp  53  for positioning the quickly detachable device  50  on the basic body  251 . Furthermore, the basic body  251  of the protective cover  25  is disposed at the inner side with two positioning blocks  254  corresponding to the quickly detachable device  50 .  
      To assemble the protective cover unit on the table sawing machine, as shown in  FIGS. 3 and 7 , firstly, the combining plate  22  has its elongate notch  221  inserted in the insert space  301  between the fixing base  31  and the position-limiting plate  33  of the quickly-detachable handle unit  30  at the inner end of the extending plate  21  and mounted on the projecting block  331  of the position-limiting plate  33 , and then the rotary handle  35  is turned and pressed downward. At this time, by the eccentric action of the eccentric holes  351  of the rotary handle  35 , the position-limiting plate  33  is pressed by the rotary handle  35  to move close to the fixing base  31  to diminish the insert space  301  between the position-limiting plate  33  and the fixing base  31  for firmly clamping the combining plate  22  therebetween. Subsequently, hook the round hole  233  of the protective plate  23  with a finger to lift up the protective plate  23  and have its central elongate slot  232  passing through the saw base  12  and the combining plate  22  and then position the protective plate  23  on the lugs  111  of the oval groove  11  of the work table  10 . Simultaneously, the elastic positioning projections  231  at the peripheral edge of the protective plate  23  will function to push against the inner peripheral edge of the oval groove  11  and fix the protective plate  23  on the oval groove  11 .  
      To assemble the non-return plate  24  on the combining plate  22 , as shown in  FIG. 6 , firstly, the quickly detachable device  40  is pressed to let the smaller-diameter column of the stepped bolt  41  inserted through the positioning notch  222  of the combining plate  22 . After the quickly detachable device  40  is moved in the positioning hole  224  at the lower end of the positioning slot  222 , release the quickly detachable device  40  to let the quickly detachable device  40  moved back by the recovering elasticity of the elastic member  42  and make the larger-diameter column of the stepped bolt  41  inserted and positioned in the positioning hole  224  to fix the non-return plate  24  on the combining plate  22 .  
      To assemble the protective cover  25  on the combining plate  22 , as shown in  FIG. 4 , the quickly detachable device  50  of the protective cover  25  has its stepped bolt  51  fitted in the positioning hole  225  at the bottom of the positioning notch  223  of the combining plate  22  in the same way as that for assembling the non-return plate  24  on the combining plate  22 .  
      To detach the quickly-detachable protective cover unit  20  from the table sawing machine, as shown in  FIG. 5 , firstly, the quickly detachable device  50  of the protective cover  25  is pressed to let the smaller-diameter column of the stepped bolt  51  not positioned restricted in the positioning hole  225 . At this time, the stepped bolt  51  can be removed out of the positioning notch  223  of the combining plate  22 . Next, the non-return plate  24  has the stepped bolt  41  of its quickly detachable device  40  removed out of the positioning notch  222  of the combining plate  22  in the same way as described above. Subsequently, hook the round hole  233  of the protective plate  23  with a finger to lift up the protective plate  23  and remove it from the saw base  12  and the combining plate  22 .  
      To remove the combining plate  22  from the quickly-detachable handle unit  30 , as shown in  FIGS. 7 and 8 , the rotary handle  35  is turned upward to let the elastic member  32  recover its elasticity to push the position-limiting plate  33  away from the fixing base  31  to enlarge the insert space  301  between the position-limiting plate  33  and the fixing base  31 . Thus, the combining plate  22  can easily be separated from the quickly detachable handle unit  30 .  
      As can be understood from the above description, the components of the quickly-detachable protective cover unit are fixed in position respectively by the quickly detachable device; therefore, the components of the quickly-detachable protective cover unit can be respectively disassembled or assembled with convenience and with less time as well, needless to employ any tool for carrying out disassembling or assembling work.  
      While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.