Abstract:
A saw blade adjustment structure used in a table saw for correcting the position of a saw blade of a saw unit includes a supporting member provided below the bottom side of the table of the table saw to support the saw unit of the table saw, and an adjustment device, which includes a driven member connected to the supporting member and a rotating member that has an eccentric portion for moving the driven member to correct the position of the saw blade upon rotation of the rotating member by an external rotary driving force.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a table saw and more particularly, to a position-adjusting apparatus for a saw blade of a table saw.  
         [0003]     2. Description of the Related Art  
         [0004]     Referring to  FIG. 1 , a conventional table saw  1  comprises a table  2  and a saw unit  3 . The table  2  has an elongated slot  2   a . The saw unit  3  is fastened to a support bar  4 , which is locked to the bottom side of the table  2 . The saw unit  3  comprises a saw blade  3   a  suspending in the elongated slot  2   a . The cutting direction of the saw blade  3   a  is kept perpendicular to the front edge  2   b  of the table  2  for cutting the workpiece conveniently.  
         [0005]     However, the saw blade  3   a  may be deviated from the position and not kept perpendicular to the front edge  2   b  of the table  2  due to impact of an external object accidentally during delivery of the table saw  1 , inaccurate installation, or other unexpected reasons. For example, the imaginary line in  FIG. 1  shows a deviated status of the saw blade  3   a . This position deviation will cause an error in size of the cut workpiece.  
         [0006]     Therefore, it is desirable to provide a table saw that eliminates the aforesaid problem.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a saw blade adjustment structure for table saw, which enables the user to adjust the position of the saw blade conveniently.  
         [0008]     To achieve this object of the present invention, the saw blade adjustment structure is used in a table saw having a table, an elongated opening formed in the table, and a saw unit installed in the bottom side of the table. The saw unit has a saw blade suspending in the elongated opening for cutting. The saw blade adjustment structure comprises a supporting structure, and at least one adjustment device. The supporting structure comprises a supporting member provided below the bottom side of the table. The supporting member has at least one connection portion and defines a first axis. The at least one adjustment device is set between the table and the supporting structure. Each adjustment device comprises a driven member coupled to one of the at least one connection portion of the supporting member and movable along a second axis that is not in parallel to the first axis, and a rotating member. The rotating member has an eccentric portion for moving the driven member along the second axis upon rotation of the rotating member by an external rotary driving force. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a schematic top view of a part of a table saw according to the prior art.  
         [0010]      FIG. 2  is an exploded view of a saw blade adjustment structure for table saw according to a preferred embodiment of the present invention.  
         [0011]      FIG. 3  is a schematic bottom view of the present invention.  
         [0012]      FIG. 4  is a schematic top view in section of a part of the preferred embodiment of the present invention.  
         [0013]      FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 4 .  
         [0014]      FIG. 6  is a top view of a part of the present invention before rotation of the rotating member.  
         [0015]      FIG. 7  is a side view in section of  FIG. 6 .  
         [0016]      FIG. 8  is a perspective view of the rotating member according to the present invention.  
         [0017]      FIG. 9  is a sectional view of the rotating member according to the present invention.  
         [0018]      FIG. 10  is similar to  FIG. 6  but showing the rotating member rotated, the driven member moved rightwards.  
         [0019]      FIG. 11  is similar to  FIG. 7 , but showing the rotating member rotated, the driven member moved rightwards.  
         [0020]      FIG. 12  is similar to  FIG. 6  but showing the rotating member rotated, the driven member moved leftwards.  
         [0021]      FIG. 13  is similar to  FIG. 7 , but showing the rotating member rotated, the driven member moved leftwards.  
         [0022]      FIG. 14  is an exploded view of another preferred embodiment of the present invention.  
         [0023]      FIG. 15  is a top view in section of a part of the embodiment shown in  FIG. 14 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Referring to  FIGS. 2-5 , a saw blade adjustment structure is shown used in a table saw  100 . The table saw  100  comprises a table  10  and saw unit  14 . The table  10  is has a front edge  11 , and an elongated opening  12 . The saw unit  14  is installed in the bottom side of the table  10  adjacent to the elongated opening  12 , comprising a motor  15 , a circular saw blade  16 , and a linking mechanism  17 . The motor  15  is adapted to rotate the circular saw blade  16 . The linking mechanism  17  is adapted to move the circular saw blade  16  vertically upwards and downwards and to tilt the circular saw blade  16 . When the circular saw blade  16  is lifted and protruding over the top surface of the table  10 , it is in the working position for cutting the workpiece. Because the saw unit  14  is of the known design, no further detailed description in this regards is necessary.  
         [0025]     The saw blade adjustment structure of the present invention is adapted to correct the deviated saw blade to the accurate position, comprising a first connection means, which is comprised of two screw holes  18  provided at the bottom side of the table  10  near the front edge  11  of the table  10 , two second connection means formed in the bottom side of the table  10  and symmetrically disposed near the two distal ends of the elongated opening  12  and each comprised of two screw holes  19  and a recess  20  between the screw holes  19 , and a circular locating hole  21  formed in the bottom side of the table  10  near the screw holes  18  of the first connection means, a supporting structure  22 , and an adjustment unit  26 .  
         [0026]     The supporting structure  22  comprises a supporting member  23 , two locating plates  24 , and four fastening members  25 . The supporting member  23  is round rod extending along a first axis L 1  and a connection portion  231  at one end (the action end). The two locating plates  24  each have two through holes  241 . The fastening members  25  are screw members each having a head  251  and a threaded shank  252 . The threaded shanks  252  of the fastening members  25  are respectively inserted through the through holes  241  of the locating plates  24  and respectively threaded into the screw holes  19 , and the heads  251  of the fastening members  25  are respectively stopped at the locating plates  24  against the bottom side of the table  10  to affix the locating plates  24  to the bottom side of the table  10  over the respective recesses  20 , keeping the supporting member  23  in the recesses  20 .  
         [0027]     The adjustment unit  26  is set in the bottom side of the table  10  adjacent to the front edge  11  of the table  10 , comprised of a driven member  27 , two locating members  28 , and a rotating member  29 .  
         [0028]     Referring to  FIGS. 6 and 7 , the driven member  27  has a vertical wall  271  and a horizontal wall  272  arranged at right angles, a circular hole  273  formed in the vertical wall  271  for receiving the connection portion  231  of the supporting member  23 , two first oblong holes  274  formed in the horizontal wall  272  and aligned in line along a second axis L 2 , and one second oblong hole  2775  formed in the horizontal wall  272  and extending along a third axis L 3 . The aforesaid first axis L 1  is parallel to the circular saw blade  16 . The second axis L 2  and the third axis L 3  are perpendicularly intersected with each other.  
         [0029]     The two locating members  28  are screw members each having a head  281  and a threaded shank  282 . The threaded shanks  282  of the locating members  28  are respectively inserted through the first oblong holes  274  of the driven member  27  and threaded into the screw holes  18  at the bottom side of the table  10 , and the heads  281  of the locating members  28  are respectively stopped at the horizontal wall  272  of the driven member  27  to secure the driven member  27  to the bottom side of the table  10 , allowing the driven member  27  to be moved along the second axis L 2  within the constraint of the first oblong holes  274 .  
         [0030]     Referring to  FIGS. 8 and 9 , the rotating member  29  comprises a first round rod  291 , a second round rod  292 , a collar  293  extending around the connection portion between the first round rod  291  and the second round rod  292 , and a receiving portion, for example, a hexagonal countersunk hole  294  formed in one end of the second round rod  292  remote from the first round rod  291  and axially extending inwards from the end of the second round rod  292  for receiving a driving tool, for example, a hexagonal wrench to be operated to rotate the rotating member  29 . According to this embodiment, the longitudinal center axis L 4  of the first round rod  291  and the longitudinal center axis L 5  of the second round rod  292  are arranged in parallel, and the longitudinal center axis L 5  of the second round rod  292  is deviated from the longitudinal center axis L 4  of the first round rod  291 , therefore the first round rod  291  and the second round rod  292  are in an eccentric relationship. During installation, as shown in  FIG. 7 , the first round rod  291  is inserted into the locating hole  21  at the table  10 , the second round rod  292  is inserted into the second oblong hole  275  of the driven member  27 , and the collar  293  is disposed in contact with the horizontal wall  272  of the driven member  27 .  
         [0031]     Referring to  FIGS. 2 and 3  again, the saw unit  14  is fastened to the supporting member  23  through two lugs  171  of the linking mechanism  17 , and disposed near the adjustment unit  26 . If the circular saw blade  16  is deviated from the correct position by external factors, the operator can use a hand tool, for example, a hexagonal wrench to rotate the rotating member  29  clockwise/counter-clockwise. When rotating the rotating member  29 , the second round rod  292  will be forced to move the driven member  27  rightwards (see  FIGS. 10 and 11 ) or leftwards (see  FIGS. 12 and 13 ). During rightward or leftward displacement of the driven member  27 , the supporting member  23  and the saw unit  14  are moved synchronously, thereby correcting the position of the saw blade  16  for accurate cutting. By means of the saw blade adjustment structure, the operator can correct the position of the saw blade  16  conveniently.  
         [0032]      FIGS. 14 and 15  show an alternate form of the present invention. According to this embodiment, the saw blade adjustment structure comprises two first connection means each comprised of two screw holes  32  and respectively formed in the bottom side of the table  30  of the table saw  200 , two circular locating holes  34  respectively formed in the bottom side of the table  30  of the table saw  200  and spaced between the two screw holes  32  of each of the two connection means, a supporting structure  36 , and two adjustment devices  40 .  
         [0033]     The supporting structure  36  according to this second embodiment is comprised of one supporting member  37  and two guide members  38 . The supporting member  37  has a flat base  371  and two sidewalls  372  perpendicularly downwardly extending from the two distal ends of the flat base  371 . The two guide members  38  are arched blocks respectively affixed to the sidewalls  372  of the supporting member  37  at an outer side. Further, the arched track of the two guide members  38  extends across a first axis L 6 .  
         [0034]     The two adjustment devices  40  each comprise a driven member  41 , two locating members  42 , and a rotating member  43 . The driven member  41  comprises two first oblong holes  411 , a second oblong hole  412 , and an arched guide slot  413 . The arched guide slot  413  of the driven member  41  of each of the two adjustment devices  40  are respectively coupled to the guide members  38  of the supporting structure  36 , for enabling the supporting member  37  to be turned about the first axis L 6 . The two locating members  42  are screw members respectively inserted through the first oblong holes  411  of the respective driven member  41  and the corresponding two screw holes  32  at the table  30  to secure the respective driven member  41  to the table  30 , allowing the respective driven member  41  to be moved along the second axis L 7  within the constraint of the first oblong holes  411 . The rotating member  43  comprises a first round rod  431  and a second round rod  432  arranged in an eccentric relationship. The first round rod  431  is inserted into one locating hole  34 . The second round rod  432  is inserted into the second oblong hole  412  of the respective driven member  41  and extending in direction perpendicular to the first oblong holes  411 . By means of rotating the rotating member  43 , the respective driven member  41  is moved to correct the position of the saw blade.  
         [0035]     Further, because the table saw  200  comprises two adjustment devices  40 , the user can selectively operate one of the adjustment devices  40  to correct the position of the saw blade.  
         [0036]     Although particular embodiments of the invention have 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.