Abstract:
An adjustable stop plank for a power tool includes a drive mechanism connected to the stop plank for continuous adjustment of the angle of the stop plank with respect to the work surface and has a display for indicating the current angle of the stop plank. In one form, the micro-adjusting device for the stop plank of a power tool includes a hand wheel unit provided on the holding frame operable to continuously adjust the angle of the stop plank. The power tool may include indicia to indicate a plurality of angles for the stop plank and an index for indicating on the indicia the current angle of the stop plank.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a micro-adjustment device for the angle stop plank of a planer, particularly to one able to micro-adjust the slanting angles of the angle stop plank of a planer accurately and quickly. 
   2. Description of the Prior Art 
   A conventional planer has a stop plank positioned stationary on its wood conveying table, always maintaining a single angle between the stop plank and the wood conveying table; therefore after a wood material is positioned to lean on the stop plank for planing, it can be planed only at a single angle, making it impossible to be planed at a specific angle. To carry out planing at a specific angle, it is necessary to draw a line on the wood material in advance and then perform planing with the help of certain auxiliary tools, and is impossible to plane the wood material with great accuracy, making it inconvenient in performing planing work. 
   In view of the above-mentioned drawback, another conventional planer is provided with an adjustable stop plank which can be adjusted and positioned at frequently employed angles, such as an interior angle of 45 degrees, a right angle or an exterior angle of 45 degrees, which is able to carry out planing at a specific angle safely and conveniently. However, although the stop plank of the conventional planer can be adjusted and positioned at certain specific angles, yet such a design cannot fully meet the needs in planing work because many wood materials may be required to be planed at other different angles rather than at the aforesaid specific angles. 
   SUMMARY OF THE INVENTION 
   A main objective of the invention is to offer a micro-adjustment device for the angle stop plank of a planer, able to accurately micro-adjust the stop plank of a planer at any angle from an interior angle of 45 degrees to an exterior angle of 45 degrees by turning around a hand wheel. 
   Another objective of the invention is to offer a micro-adjustment device for the angle stop plank of a planer, able to have the angle stop plank accurately and quickly adjusted at one of frequently employed specific angles, such as an interior angle of 45 degrees, a right angle and an exterior angle of 45 degrees without help of a graduation ruler. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     This invention will be better understood by referring to the accompanying drawings, wherein: 
       FIG. 1  is a partial perspective view of a micro-adjustment device for the angle stop plank of a planer in the present invention; 
       FIG. 2  is an exploded perspective view of the micro-adjustment device for the angle stop plank of a planer in the present invention; 
       FIG. 3  is a top view of the micro-adjustment device for the angle stop plank of a planer in the present invention; 
       FIG. 4  is a bottom view of the micro-adjustment device for the angle stop plank of a planer in the present invention; 
       FIG. 5  is a perspective view of the upper connecting rod of the micro-adjustment device for the angle stop plank of a planer in the present invention; 
       FIG. 6  is a cross-sectional view of the micro-adjustment device for the angle stop plank of a planer in the present invention, showing the angle stop plank adjusted and positioned at a right angle; 
       FIG. 7  is a cross-sectional view of the micro-adjustment device for the angle stop plank of a planer in the present invention, showing the angle stop plank adjusted and positioned at an exterior angle of 45-degrees; and 
       FIG. 8  is a cross-sectional view of the micro-adjustment device for the angle stop plank of a planer in the present invention, showing the angle stop plank adjusted and positioned at an interior angle of 45-degrees. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A preferred embodiment of a micro-adjustment device for the angle stop plank of a planer  1  in the present invention, as shown in  FIGS. 1 to 4 , includes a wood-conveying table  10 , a holding frame  20 , a stop plank  30 , a hand wheel unit  40 , a transmission rod  50 , an upper connecting rod  60 , a lower connecting rod  70  and a locking handle  80  combined together. 
   The wood-conveying table  10  has one side combined with the upper holding frame  20  connected with the stop plank  30 , which is located at one side on the top side of the wood-conveying table  10  for a wood material to be leaned thereon during planing. 
   The holding frame  20  has an inverted U-shaped body, having an accommodating space  21  formed in the center, and an index hand  22  provided at a preset location of the top side and pointing to one side of the accommodating space  21 . 
   The stop plank  30  has its front side formed with a leaning surface  31  for a wood material to lean thereon and its rear lower side locked with two connecting bolts  32  separately positioned at preset locations and respectively having a lateral insert hole  321 . The stop plank  30  further has a rod-connecting base  33  with a lateral shaft hole  331  secured near the upper edge of its rear central wall. 
   The hand wheel unit  40  consists of a hand wheel  41  and a worm  42  actuated to rotate by the hand wheel  41 . The worm  42  is vertically inserted in a through hole  26  in the top side of the holding frame  20 . 
   The transmission rod  50  to be transversely inserted in the holding frame  20  and positioned at the lower end of the worm  42  of the hand wheel unit  40 . The transmission rod  50  has one end provided with a worm wheel  51  to be meshed with the worm  42  and the other end formed with a transmission gear  52 . 
   The upper connecting rod  60 , as shown in  FIG. 5 , to be positioned in the accommodating space  21  of the holding frame  20 , is provided with a bolt  61  at the front end to be inserted in the shaft hole  331  of rod-connecting base  33  fixed at the rear wall of the stop plank  30 , and a rack  62  at the rear upper side, with a guiding groove  63  formed beneath the rack  62 , which is formed with multiple row teeth  621  to be meshed with the transmission gear  52  of the transmission rod  50 . Further, the upper connecting rod  60  has the top side above the guiding groove  63  provided with a graduated ruler  64  having angle graduations marked thereon. Thus, the graduated ruler  64  on the upper connecting rod  60  in cooperation with the index hand  22  on the holding frame  20  can indicate the positioning angle of the stop plank  30  after it is adjusted. 
   The lower connecting rod  70  is shaped like a plate and has two bolts  71  respectively provided at the opposite ends of its rear side to be respectively and pivotally inserted in two insert holes  23  at the opposite lower front sides of the holding frame  20 , and another two bolts  71  respectively provided at the opposite ends of its front side to be respectively and pivotally inserted in the two insert holes  321  of the two connecting bolts  32  of the stop plank  30 . Thus, the pivotal joints of the lower connecting rod  70  with the holding frame  20  and the stop plank  30  respectively make up a turning fulcrum. 
   The locking handle  80  is transversely and pivotally inserted in the left side of the holding frame  20  and positioned opposite to the worm  42 . The locking handle  80  has its end screwed with a locking block  81  to be fitted in the opposite side of the guiding groove  63  of the upper connecting rod  60  and limited to rotate therein. Thus, when the locking handle  80  is turned and locked tightly, its locking block  81  will be actuated to push tightly against or release the upper connecting rod  60 . 
   In addition, the micro-adjustment device of this invention is also provided with three positioning methods able to quickly position the stop plank at three specific angles: 
   1. A positioning method of a right angle: Referring to  FIG. 6 , the holding frame  20  is formed integral with a stop base  24  protruding upward on one side abutting the upper connecting rod  60 . The stop base  24  has a pivotal stop block  25  able to be rotated and positioned on the top side of the upper connecting rod  60  at times. The upper connecting rod  60  is provided with a bolt base  65  protruding upward at a preset location on the top side thereof and having a stop bolt  66  screwed therein. Thus, when the stop plank  30  is turned and adjusted, the stop bolt  66  of the upper connecting rod  60  and the stop block  25  of the holding frame  20  will push against each other and quickly position the stop plank  30  at the angle of 90 degrees. 
   2. A positioning method of an exterior angle of 45 degrees: Referring to  FIG. 7 , the lower connecting rod  70  is provided with a stop bolt  72  at a preset location on the top side thereof. Thus, when the stop plank  30  is turned and adjusted, the stop bolt  72  of the lower connecting rod  70  will push against a preset part on the rear wall of the stop plank  30  and quickly position the stop plank  30  at the exterior angle of 45 degrees. 
   3. A positioning method of an interior angle of 45 degrees: Referring to  FIG. 8 , the upper connecting rod  60  is provided with a stop bolt  67 , in front of the bolt base  65 , on the top side thereof. Thus, when the stop plank  30  is turned and adjusted, the stop bolt  67  will push against a preset part on the top side of the lower connecting rod  70  and quickly position the stop plank  30  at the interior angle of 45 degrees. 
   In operating and using the micro-adjustment device, as shown in  FIGS. 6 ,  7  and  8 , before the stop plank  30  is adjusted, the stop bolt  66  on the upper connecting rod  60  for positioning an angle of 90 degrees and the stop bolt  67  for positioning an exterior angle of 45 degrees and the stop bolt  72  on the lower connecting rod  70  for positioning an interior angle of 45 degrees are respectively screwed and adjusted to an accurate position. Thus, when the hand wheel  41  is turned around, the upper connecting rod  60  will be actuated by the worm  42  and the transmission rod  50  to pull or push the stop plank  30 , and simultaneously the stop plank  30  will be turned in a specific direction by means of the turning fulcrums respectively formed at the pivotal joints at the front and the rear end of the lower connecting rod  70 . 
   Specifically, to position the stop plank  30  at the interior angle of 45 degrees, the hand wheel  41  is turned in a proper direction to let its worm  42  actuate the worm wheel  51  of the transmission rod  50  to rotate. In the meantime, the transmission rod  50  rotates, having its transmission gear  52  actuate the row of teeth  621  together with the upper connecting rod  60  to move forward and push the stop plank  30  to force the upper portion of the stop plank  30  to slant outward until the stop bolt  67  adjusted in advance on the upper connecting rod  60  exactly pushes against the top side of the lower connecting rod  70 , thus able to position the stop plank  30  at the interior angle of 45 degrees. 
   To position the stop plank  30  at the right angle, the stop block  25  on the holding frame  20  is pulled toward the upper connecting rod  60  and lies on the top side of the upper connecting rod  60 . Then, the hand wheel  41  is turned counter-clockwise to let the row of teeth  621  of the upper connecting rod  60  actuated by the transmission gear  52  of the transmission rod  50  to move backward and pull the stop plank  30  until the stop bolt  66  adjusted in advance on the upper connecting rod  60  exactly pushes against the stop block  25 , thus able to position the stop plank  30  at the right angle. 
   To position the stop plank  30  at the exterior angle of 45 degrees, the stop block  25  of the holding frame  20  is pulled outward to enable the upper connecting rod  60  to move backward smoothly. Then, the hand wheel  41  is turned around to let the row of teeth  621  together with the upper connecting rod  60  actuated by the transmission gear  52  of the transmission rod  50  to move backward and pull the stop plank  30  until a preset part on the rear wall of the stop plank  30  exactly pushes against the stop bolt  72  on the top side of the lower connecting rod  70 , thus able to position the stop plank  30  at an exterior angle of 45 degrees. The scope of the adjustable angle of the stop plank  30  is 90 degrees from the interior 45 degrees to the exterior 45 degrees. 
   Apart from being quickly positioned at the above-mentioned specific angles, the stop plank  30  can also be precisely micro-adjusted at any angle, as shown in  FIG. 3 . To micro-adjust the stop plank  30 , the hand wheel  41  is turned around to actuate the upper connecting rod  60  to move back or forth and push or pull the stop plank  30  to control its slanting angle. As mentioned above, the holding frame  20  is provided thereon with the index hand  22  pointing to the graduated ruler  64  on the upper connecting rod  60 ; therefore when the hand wheel  41  is turned to micro-adjust the stop plank, the upper connecting rod  60  is moved back or forth according to the angle graduations indicated on the angle graduation ruler  64  by the index hand  22  so as to micro-adjust and position the stop plank  30  at an expected angle precisely and quickly. 
   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.