Patent Publication Number: US-2011061247-A1

Title: Quick-release structure for outer cover of a handheld circular saw

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a quick-release structure, and more particularly to a quick-release structure for outer cover of a handheld circular saw. 
     A conventional handheld circular saw mainly includes a main body, an outer cover, a circular saw blade and a motor. The circular saw blade is disposed between the main body and the outer cover. The motor is disposed in the main body for driving the circular saw blade. The outer cover is assembled and locked with the main body generally by means of one or two threaded rods. When it is necessary to maintain or service the handheld circular saw, the threaded rods are detached with a tool so as to separate the outer cover from the main body. However, in some cases, a suitable tool for detaching the threaded rods can be hardly readily found. 
     Furthermore, after detached, the threaded rods are separated from the outer cover. In this case, the threaded rods are apt to roll away or be covered by some other articles. Therefore, after the maintenance or service of the handheld circular saw is completed, the threaded rods are often hard to retrieve. Under such circumstance, a user may have to operate the handheld circular saw without the outer cover. This is extremely dangerous to the user. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a quick-release structure for outer cover of a handheld circular saw, which enables a user to readily and conveniently disassemble and assemble the outer cover of the handheld circular saw. 
     It is a further object of the present invention to provide the above quick-release structure for outer cover of the handheld circular saw, which can ensure safety in use of the handheld circular saw. 
     To achieve the above and other objects, the quick-release structure for outer cover of the handheld circular saw of the present invention includes a main body, an outer cover, a circular saw blade disposed between the main body and the outer cover, a motor disposed in the main body for driving the circular saw blade and a first, a second, a third and a fourth connection sections. The first connection section is disposed at a first end of the main body. The second connection section is disposed at a second end of the main body. The third connection section is disposed at a first end of the outer cover corresponding to the first connection section for connecting with the same. The fourth connection section is disposed at a second end of the outer cover corresponding to the second connection section for connecting with the same. The third connection section is angularly and linearly displaceable relative to the outer cover and the first connection section without detaching from the outer cover. 
     The present invention can be best understood through the following description and accompanying drawings wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective assembled view of a first embodiment of the present invention; 
         FIG. 2  is a perspective exploded view of the first embodiment of the present invention, showing the main body, the outer cover, the first connection section, the second connection section, the third connection section and the fourth connection section thereof; 
         FIG. 3  is a sectional assembled view of the first embodiment of the present invention, showing that the third connection section is assembled with the outer cover corresponding to the first connection section; 
         FIG. 4  is a perspective exploded view of a second embodiment of the present invention, showing the main body, the outer cover, the first connection section, the second connection section, the third connection section and the fourth connection section thereof; and 
         FIG. 5  is a sectional assembled view of the second embodiment of the present invention, showing that the third connection section is assembled with the outer cover corresponding to the first connection section. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 1 ,  2  and  3 . According to a first embodiment, the quick-release structure for outer cover of the handheld circular saw of the present invention includes a main body  12 , an outer cover  13 , a first connection section  14 , a second connection section  15 , a third connection section  16  and a fourth connection section  17 . 
     A motor  22  is disposed in the main body  12  and connected to a circular saw blade  24  for driving the same. The circular saw blade  24  is disposed between the main body  12  and the outer cover  13 . 
     The first connection section  14  is disposed at a first end of the main body  12 . The first connection section  14  can be a column body or a cylindrical body. Two ends of the first connection section  14  are fixedly connected to the main body  12 . 
     The second connection section  15  is disposed at a second end of the main body  12 . The second connection section  15  can be a waved plate body. One end of the second connection section  15  is fixedly connected to the main body  12 . 
     The third connection section  16  is disposed at a first end of the outer cover  13  corresponding to the first connection section  14  for connecting with the same. 
     The third connection section  16  includes a first rod body  62 , a second rod body  64  and a resilient member  66 . 
     The first rod body  62  is fitted through a through hole  32  formed on the outer cover  13 . A first end of the first rod body  62  is positioned on outer side of the outer cover  13  and has a force application section  621 . The outer periphery of the first end of the first rod body  62  is formed with a polygonal shape such as hexagonal shape. The force application section  621  is a shift member. One end of the shift member is formed with a through hole  621 ′. The inner periphery of the through hole  621 ′ has a shape corresponding to that of the outer periphery of the first end of the first rod body  621 . Accordingly, the shift member can be engaged with or connected with the first rod body  62  by means of a screw. Alternatively, the first end of the first rod body  62  with the hexagonal shape itself serves as the force application section  621 . In this case, the first rod body  62  can be wrenched with a tool such as a wrench. 
     The second rod body  64  is positioned on inner side of the outer cover  13 . A first end of the second rod body  64  has a cross-sectional area larger than that of the through hole  32  on the inner side of the outer cover  13 . The first end of the second rod body  64  is formed with a threaded hole  641  for connecting with an outer thread  622  of the second end of the first rod body  62 . The second end of the second rod body  64  has a hook section  642  outward extending from the second end for hooking the column body or cylindrical body of the first connection section  14 . A guide slope  642 ′ is formed on outer side of the hook section  642 . 
     The resilient member  66  is disposed between the outer cover  13  and the first rod body  62 . When the first rod body  62  is rotated and the second rod body  64  is drivingly angularly displaced, the guide slope  642 ′ of the hook section  642  slides over the column body or cylindrical body of the first connection section  14 . Therefore, the second rod body  64  is also driven and vertically displaced. The resilient member  66  can be a wave washer. Two ends of the resilient member  66  respectively abut against the outer cover  13  and the first rod body  62 . 
     The fourth connection section  17  is disposed at a second end of the outer cover  13  corresponding to the second connection section  15  for connecting with the same. 
     The fourth connection section  17  can be a column body or cylindrical body fixedly disposed on the outer cover  13  for engaging with the waved plate body of the second connection section  15 . Alternatively, the second connection section  15  can be a C-shaped plate body (not shown). In this case, the column body or cylindrical body can be also engaged with the C-shaped plate body. 
     According to the above arrangement, after using the circular saw and when it is necessary to detach the outer cover  13  for maintaining or servicing the circular saw, a user only needs to rotate the first rod body  62  to separate the first and second connection sections  14 ,  16  from each other. Then the second and fourth connection sections  15 ,  17  are separated from each other. After serviced, a user can perform an operation reverse to the above operation to easily assemble the outer cover  13  with the main body  12 . 
     After the outer cover  13  is disassembled, the assembling components will not detach from the outer cover  13  so that the user can immediately reassemble the outer cover  13  with the main body  12 . Accordingly, the problem existing in the prior art that the assembling components are often hard to find is eliminated. Therefore, the user is protected from holding the circular saw without the outer cover so that the safety can be ensured. 
     Please refer to  FIGS. 4 and 5 , which show a second embodiment of the quick-release structure for outer cover of the handheld circular saw of the present invention. In this embodiment, the through hole  32  of the outer cover  13  is stepped hole and the resilient member  66  is a coiled spring. 
     The coiled spring is positioned in the through hole  32  of the outer cover  13 . The first rod body  62  is fitted through the coiled spring. 
     The hole  641  of the second rod body  64  extends through the second rod body  64 . The first rod body  62  is formed with a threaded hole  623 . A screw  643  is screwed through the hole  641  into the threaded hole  623  of the first rod body  62  to connect the first and second rod bodies  62 ,  64 . 
     The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.