Abstract:
A quickly detachable spreader mounting structure used in a table saw is disclosed to include a spreader holder, a spreader detachably clamped in the spreader holder, a positioning member inserted through the spreader holder and the spreader and having a positioning portion, and a handle coupled to the positioning member and having a protruding portion and biasable between an unlocking position where the protruding portion is moved away from the positioning portion to release the spreader from the spreader holder and a locking position where the protruding portion is abutted against the positioning portion to lock the spreader to the spreader holder.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to table saws and more specifically, to a quickly detachable spreader mounting structure for table saw, which allows quick mounting/dismounting of the spreader. 
         [0003]    2. Description of the Related Art 
         [0004]    When a workpiece is placed on the table and pushed toward the saw blade for cutting by the saw blade, the cut part of the workpiece may impart a clamping force to the saw blade subject to the applied push force and the material return spring power of the workpiece itself, enhancing friction between the workpiece and the saw blade and hindering feeding of the workpiece. To avoid this problem, a table saw is usually equipped with a spreader for cutting into the cut gap in the workpiece being cut by the saw blade to stretch open the cut part of the workpiece, facilitating cutting operation and workpiece feeding and assuring cutting safety. 
         [0005]    Further, the saw blade of the table saw is vertically adjustable to facilitate cutting of different workpieces. Further, the spreader of the table saw is made detachable to facilitate installation. It is always the way people in the sawing machine industry to design a table saw that facilitates quick mounting and dismounting of the spreader. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a quickly detachable spreader mounting structure for table saw, which allows quick mounting and dismounting of the spreader. 
         [0007]    To achieve this and other objects of the present invention, a quickly detachable spreader mounting structure for table saw comprises a spreader holder, which comprises two clamping plates each having a through hole, a spreader, which is set in between the two clamping plates and comprises a sliding slot kept in alignment between the through holes of the clamping plates, a positioning member, which is inserted through the through holes of the clamping plates and the sliding slot of the spreader and comprises a head disposed outside the spreader holder and a positioning portion perpendicularly radially protruded from the periphery of the head, a handle, which is coupled to the positioning member and movable along the positioning member and biasable relative to the spreader between a locking position and an unlocking position and comprises a protruding portion, which is abutted against the positioning portion of the positioning member such that the handle is moved along the positioning member to push one clamping plate and the spreader toward the other clamping plate when the handle is in the locking position and which is disengaged from the positioning portion of the positioning member such that the handle is released from the clamping plates when the handle is in the unlocking position, and a first spring member stopped between the head of the positioning member and the handle and adapted to push the handle apart from the clamping plates when the handle is in the unlocking position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an elevational assembly view of a quickly detachable spreader mounting structure for table saw in accordance with the present invention. 
           [0009]      FIG. 2  is an exploded view of the quickly detachable spreader mounting structure in accordance with the present invention. 
           [0010]      FIG. 3  is a sectional side view of a part of the present invention, showing the handle in the locking position. 
           [0011]      FIG. 4  is a sectional view of  FIG. 3 , showing the protruding portions of the handle forced into engagement with the positioning portions of the positioning member. 
           [0012]      FIG. 5  is another sectional side view of a part of the present invention, showing the handle in the locking position. 
           [0013]      FIG. 6  is a sectional view of  FIG. 5 , showing the positioning portions of the positioning member received in the recessed portions of the handle. 
           [0014]      FIG. 7  is a side view of the present invention, showing the positioning rods of the fixed clamping plate engaged into the third positioning holes of the spreader. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Referring to  FIGS. 1 and 2 , a quickly detachable spreader mounting structure  10  in accordance with the present invention is shown comprising a spreader holder  20 , a spreader  30 , a positioning member  40 , a second spring member  50 , a handle  60  and a first spring member  70 . 
         [0016]    The spreader holder  20  comprises a fixed clamping plate  22  and a movable clamping plate  24 . The fixed clamping plate  22  has a rectangular first through hole  221  at the center, two connection rods  223  perpendicularly extended from its one side and respectively disposed at the top and bottom sides relative to the first through hole  221 , two chamfered positioning rods  225  perpendicularly extended from the same side and respectively disposed at the left and right sides relative to the first through hole  221 , and a locating rod  227  perpendicularly extended from the same side in the lower right corner. The movable clamping plate  24  has a rectangular second through hole  242  corresponding to the rectangular first through hole  221  of the fixed clamping plate  22 , two connection holes  244  respectively disposed at the top and bottom sides relative to the rectangular second through hole  242  for receiving the connection rods  223  of the fixed clamping plate  22  respectively, two first positioning holes  246  respectively disposed at the left and right sides relative to the rectangular second through hole  242  for receiving the positioning rods  225  of the fixed clamping plate  22 , and a locating hole  24  disposed in the lower right corner for receiving the locating rod  227  of the fixed clamping plate  22 . 
         [0017]    The spreader  30  has a sliding slot  32  longitudinally extending to the bottom side and terminating in an opening  34  through which the connection rods  223  of the fixed clamping plate  22  is inserted into the sliding slot  32  of the spreader  30  to have the spreader  30  set in between the fixed clamping plate  22  and the movable clamping plate  24  without biasing, two second positioning holes  36  disposed near the bottom end of the sliding slot  30  and at two opposite lateral sides relative to the sliding slot  32 , two third positioning holes  38  disposed near the top end of the sliding slot  30  and at two opposite lateral sides relative to the sliding slot  32 , and a beveled stop edge  39  disposed at the right bottom side. The two second positioning holes  36  and the two third positioning holes  38  are adapted to selectively receive the positioning rods  225  of the fixed clamping plate  22  to let the spreader  30  be selectively positioned in two different elevations. 
         [0018]    The positioning member  40  is a stepped rod member having a head  42  of circular cross section, an endpiece  46  of circular cross section, a shank  44  of rectangular cross section connected between the head  42  and the endpiece  46 . As shown in  FIG. 4 , the shank  44  and the endpiece  46  are inserted through the rectangular second through hole  242  of the movable clamping plate  24 , the sliding slot  32  of the spreader  30  and the rectangular first through hole  221  of the fixed clamping plate  22 . By means of engagement between the rectangular shank  44  and the rectangular first through hole  221  of the fixed clamping plate  22  and the rectangular second through hole  242  of the movable clamping plate  24 , the positioning member  40  is prohibited from rotation relative to the spreader holder  20  and the spreader  30 . The positioning member  40  further has two positioning portions  48  radially extending out of the head  42  at two opposite sides. According to this embodiment, a pin is transversely inserted through the head  42  of the positioning member  40 , thereby forming the two positioning portions  48 . 
         [0019]    The second spring member  50  is sleeved onto the shank  44  of the positioning member  40  and stopped between the head  42  of the positioning member  40  and the movable clamping plate  24  to impart a pressure to the movable clamping plate  24  toward the spreader  30 . 
         [0020]    The handle  60  has a coupling unit  62  and a grip  69 . The coupling unit  62  includes a coupling hole  64  coupled to the head  42  of the positioning member  40  so that a user can operate the grip  69  to bias the handle  60  between a locking position P 1  shown in  FIG. 3  and an unlocking position P 2  shown in  FIG. 5 . The handle  60  further has a plurality of protruding portions  66  and recessed portions  68  alternatively arranged around the coupling hole  64  to provide a cam effect. When the handle  60  is in the locking position P 1  shown in  FIGS. 3 and 4 , the protruding portions  66  are abutted against the positioning portions  48  of the positioning member  40  to prohibit rotation of the handle  60  relative to the spreader  30 , enabling the handle  60  to be moved axially along the positioning member  40  toward the movable clamping plate  24  to push the movable clamping plate  24  toward the fixed clamping plate  22  and to have the spreader  30  be firmly secured between the movable clamping plate  24  and the fixed clamping plate  22 . When the handle  60  is in the unlocking position P 2  shown in FIGS.  5  and  6 , the protruding portions  66  are disengaged from the positioning portions  48  of the positioning member  40 , and the recessed portions  68  are shifted to the positioning portions  48  of the positioning member  40 . At this time, the second spring member  70  that is received in the coupling unit  62  of the handle  60  and stopped the head  42  of the positioning member  40  and a cap  65  that is fastened to the coupling unit  62  of the handle  60  impart a pressure to push the handle  60  away from the movable clamping plate  24 , thereby unlocking the spreader  30 . 
         [0021]    The mounting and dismounting operations of the spreader  30  are described hereinafter. 
         [0022]    When mounting the spreader  30 , make sure that the handle  60  is in the unlocking position P 2 , and then insert the bottom end of the spreader  30  into the gap between the fixed clamping plate  22  and the movable clamping plate  24  to aim the opening  34  of the spreader  30  at the connection rods  223  of the fixed clamping plate  22 , and then lower the spreader  30  to force the movable clamping plate  24  apart from the fixed clamping plate  22  to the position where the first positioning holes  246  of the movable clamping plate  24  are respectively disengaged from the positioning rods  225  of the fixed clamping plate  22 . When the beveled stop edge  39  of the spreader  30  touches the locating rod  227  of the fixed clamping plate  22 , the positioning rods  225  of the fixed clamping plate  22  are respectively forced into the second positioning holes  36  of the spreader  30 . Thereafter, bias the handle  40  to the locking position P 1  shown in  FIGS. 3 and 4  to force the protruding portions  66  into engagement with the positioning portions  48  of the positioning member  40  and to further force the movable clamping plate  24  against the spreader  30  toward the fixed clamping plate  22 , thereby locking the spreader  30  in position. 
         [0023]    On the contrary, when wishing to dismount the spreader  30 , bias the spreader  60  to the unlocking position P 2  shown in  FIGS. 5 and 6  to release the second spring member  70 , enabling the second spring member  70  to push the cap  65  and the handle  60  apart from the movable clamping plate  24 . At this time, the handle  60  is prohibited from vibration, and the user can pull the spreader  30  directly away from the spreader holder  20 . 
         [0024]    When the second positioning holes  36  of the spreader  30  are respectively coupled to the positioning rods  225  of the fixed clamping plate  22 , the spreader  30  is set for a relatively thicker workpiece cutting operation, and an eye-protection guard can be mounted on the top side of the spreader  30 . When an eye-protection guard is not used, the third positioning holes  38  of the spreader  30  are respectively coupled to the positioning rods  225  of the movable clamping plate  22 , and the locating rod  227  of the movable clamping plate  22  is engaged into a locating hole  37  on the spreader  30  (see  FIG. 7 ). At this time, the spreader  30  is set for a relatively thinner workpiece cutting operation. 
         [0025]    Thus, by means of the cam design of the protruding portions and recessed portions of the handle, the spreader can be conveniently and rapidly mounted in or detached from the spreader holder. 
         [0026]    Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims