Abstract:
A power tool comprises a spindle, a slide, and an alignment guide. The spindle is attached to the power tool and operably supported relative to a work piece wherein the spindle defines an axis of operation for the power tool. The slide is moveably attached to the power tool. The alignment guide is secured to the slide and has a first laser and a second laser. The first laser projects a first laser beam in a first plane and the second laser projects a second laser in a second plane. The first plane and the second plane intersect along the axis of operation.

Description:
[0001]     The present invention relates to a guide for a power tool, and more particularly to an alignment guide for a drill press.  
         [0002]     A typical drill press has a table attached to a support arm, which, in turn, is supported by a vertical post on a base. A head is supported at the top of the post, and a motor-driven drill chuck extends downwardly from the head. The chuck holds a drill bit and is raised and lowered towards the table to drill a hole in the work piece.  
         [0003]     In order to accurately position a hole on a work piece with such a drill press, an operator must perform a time-consuming process of raising and lowering the head while test drilling holes and readjusting the position of the work piece. Optical alignment systems have been developed to address this problem. These alignment systems are mounted to the drill press and project intersecting lines onto the work piece. The alignment systems are calibrated so that the intersection point of the two projected lines corresponds with the axis of the drill bit. For example, U.S. Patent Application 2003/0095840 to Wang discloses a laser positioning system for an aperture-processing machine where the lasers are fixed within the head. When larger drill bits or hole saws are used in the drill press, however, the projected laser beams may be partially obstructed so that the lines projected on the work piece do not intersect. This increases the setup time for an operator, forcing him or her to align the projected laser lines with some other mark, temporarily remove the drill bit, or extrapolate the intersection point of the projected laser lines, for example.  
         [0004]     U.S. Patent Application 2004/0032587 to Garcia discloses an optical alignment system for a power tool having a horizontal spacing connector that allows the distance between a first and second laser generator to be adjusted. The use of such a spacing connector, however, requires an operator to realign the lasers to project laser lines that intersect at the drill bit axis, increasing the set up time. In addition, because the alignment system is mounted on the drill bit quill, it may interfere with the work piece or other parts as the drill bit is lowered. The present invention addresses these and other needs.  
       SUMMARY  
       [0005]     Accordingly, embodiments of the present invention provide a new and improved alignment guide for a power tool. The alignment guide may be secured to a slide that may be integrally mounted to the power tool or attached as an accessory. A rotary handle is mounted to the power tool, and coupled with a transmission. The transmission engages a rack located on the slide. The slide allows the alignment guide to be adjustably positioned relative to the work piece. Provided the slide moves parallel to the drill bit axis, the alignment guide does not need to be realigned. In addition, the alignment guide may be equipped with at least one lamp, such as a light emitting diode, to provide light onto the work piece.  
         [0006]     According to one aspect of the invention, a power tool includes a spindle, a slide, and an alignment guide. The spindle is attached to the power tool and operably supported relative to a work piece wherein the spindle defines an axis of operation for the power tool. The slide is moveably attached to the power tool. The alignment guide is secured to the slide and has a first laser and a second laser. The first laser projects a first laser beam in a first plane and the second laser projects a second laser in a second plane. The first plane and the second plane intersect along the axis of operation.  
         [0007]     According to another aspect of the invention, a drill press comprises a vertical support post, a head, a slide, and an alignment guide. The head is mounted to the support post and has a rotatable chuck, wherein the rotatable chuck defines an axis of operation. The slide is attached to the drill press and the alignment guide is secured to the slide. The alignment guide has a first laser projecting a first laser beam in a first plane and a second laser projecting a second laser beam in a second plane. The first plane and the second plane intersect along the axis of operation.  
         [0008]     Yet another aspect of the invention includes a drill press that includes a base, a vertical support post, a head, a slide, and an alignment guide. The vertical support post is attached to the base. The head is mounted to the support post and has a rotatable chuck, wherein the rotatable chuck defines an axis of operation. The slide is moveably attached to the drill press, and the alignment guide is secured to the slide. The alignment guide has a first laser projecting a first laser beam in a first plane and a second laser projecting a second laser beam in a second plane, wherein the second laser is positioned at a fixed distance from the first laser. The first plane and the second plane intersect along the axis of operation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  shows a perspective view of the alignment guide of the present invention, shown mounted to a drill press.  
         [0010]      FIG. 2  is a side view of the alignment guide of the present invention, shown mounted to a drill press.  
         [0011]      FIG. 3  is a front view of the alignment guide of the present invention, shown mounted to a drill press.  
         [0012]      FIG. 4  is a perspective view of the alignment guide of the present invention.  
         [0013]      FIG. 5  is a side view of the alignment guide of the present invention.  
         [0014]      FIG. 6  is a top view of the alignment guide of the present invention.  
         [0015]      FIG. 7  is a side view of the alignment guide of the present invention showing a partial cross-section view taken along section B-B of  FIG. 6 , showing the battery compartment and the laser generator.  
         [0016]      FIG. 8  is a perspective view of one embodiment of the slide of the present invention.  
         [0017]      FIG. 9  is a side view of the alignment guide of the present invention shown mounted to the slide shown in  FIG. 8 .  
         [0018]      FIG. 10  is a perspective view of another embodiment of the slide of the present invention.  
         [0019]      FIG. 11  is a perspective view showing the alignment guide of the present invention mounted to the slide shown in  FIG. 10 .  
         [0020]      FIG. 12  is a perspective view showing a geometric relationship of the laser generators and projected laser beams of the alignment guide of the present invention to the drill bit.  
         [0021]      FIG. 13  is another perspective view showing a geometric relationship of the laser generators and projected laser beams of the alignment guide of the present invention to a hole saw.  
         [0022]      FIG. 14  is a perspective view of the slide of the present invention shown mounted to a drill press behind the drill chuck.  
         [0023]      FIG. 15  is a perspective view of the slide of the present invention shown mounted to a drill press in front of the drill chuck.  
         [0024]      FIG. 16  is a perspective view of the slide of the present invention shown mounted to the support post of a drill press. 
     
    
     DETAILED DESCRIPTION  
       [0025]     Referring now to  FIGS. 1-3 , an alignment guide  30  according to the present invention is shown mounted to a drill press  10 . The drill press  10  includes a support post  14 , a base  15 , and a head  12 . The support post  14  may have a hollow cylindrical shape to fit within an opening formed in the base  15 . Generally, the base  15  supports the support post  14  and it extends generally vertically from the base  15 . The head  12  includes an opening that receives a post  14  and is supported thereon. A conventional spindle  13  extends from head  12 , with a chuck  16  coupled to spindle  13 . A rotatable handle  28  for raising or lowering the chuck  16  extends from head  12 . A conventional drive mechanism (not shown) for the spindle  13  and chuck  16  is also disposed within head  12 . A drill bit  18  or a hole saw  19  may be mounted in chuck  16  to rotate about an axis of operation  20 . A table support  24  is mounted to post  14  to support a table  25  positioned under chuck  16 . A work piece  26  may be placed onto the table  25  so that the drill bit  18  or the hole saw  19  may perform various machining operations upon it.  
         [0026]     Referring to  FIGS. 4-7 , the alignment guide  30  includes a housing  32  and a cover  34 . As seen in  FIG. 6 , the cover  34  may be secured to a housing  32  by screws  35 , although other means of joining the two parts may be used, such as an adhesive, a snap or interference fit, etc. The housing  32  and the cover  34  may be injection molded from a suitable plastic such as polycarbonate, acetal, or ABS (acrylonitrile-butadiene-styrene). The housing  32  includes a first receptacle  36  and a second receptacle  37 . The first and second receptacles  36 ,  37  may be integrally formed as cylindrical bores in housing  32 . Alternatively, the first and second receptacles  36 ,  37  may be configured so that they are movable with respect to the housing  32 . In this regard, the entire receptacle  36 ,  37  or portions of it may be movable with respect to the housing  32 .  
         [0027]     A first laser generator  40  is mounted in the first receptacle  36 , and a second laser generator  41  is mounted in the second receptacle  37 . Set screws  52  are positioned in a transverse bore  51  in each of the first and the second receptacles  36 ,  37  to secure the laser generators  40 ,  41 . Of course, other known securing apparatus can be used to more easily facilitate the securing of the laser generators  40 ,  41 . For example, a rotatable handle or a cam having a lever or other apparatus suitable for securing the laser generators  40 ,  41  can be used.  
         [0028]     The laser generators  40 ,  41  may be commercially available laser generators that produce a planar, fan shaped beam of light. A first adjustment ring  54  is rotatably positioned on the first receptacle  36  to adjust the laser beam generated by the first laser generator  40 . A second adjustment ring  55  is rotatably positioned on the second receptacle  37  to adjust the laser beam generated by the second laser generator  41 . The adjustment will be explained in further detail below.  
         [0029]     As seen in  FIGS. 5 and 7 , at least one lamp  66  may be associated with the alignment guide  30  to illuminate the work piece  26 . The lamp  66  may be integrally mounted in the alignment guide  30  or may be attached to the alignment guide  30  in any known or suitable manner. The lamp  66  is preferably a light emitting diode (LED); however, other types of lights may be used, such as incandescent or halogen bulbs, lasers, etc.  
         [0030]     A battery  60  housed in a battery receptacle  62  in the alignment guide  30  may power the laser generators  40 ,  41  and the lamp  66 . A battery cover  64  is secured to the alignment guide  30  to cover and secure the battery  60  within the battery receptacle  62 . The battery cover  64  provides easy replacement of the battery  60 . Alternatively, the laser generators  40  and  41  and the lamp  66  may be powered by AC power, either directly from the AC line current or through electrical cables connected to the electrical system of the drill press  10 . An AC to DC converter and voltage reducers may be required if AC line current is used, as is known.  
         [0031]     A power switch  65  allows power from the battery  60  or other power source to actuate the laser generators  40 ,  41  and the lamp  66 . Alternatively, the switch  65  may be configured to separately allow power to the laser generators  40 ,  41  or the lamp  66 , or an additional switch may be used.  
         [0032]     The alignment guide  30  is coupled to the drill press  10  through a slide  70 . The slide  70  comprises a bracket  72 , a first guide shaft  74  that extends from bracket  72 , and a first locking knob  86 . As best seen in  FIGS. 1-3  and  14 - 15 , the slide  70  may be mounted to the head  12 , with the bracket  72  positioned in the head  12 . Alternatively, the slide  70  may be integrally formed as part of the head  12 . In yet another alternative, as seen in  FIG. 16 , the bracket  72  may be mounted to the support post  14  through a clamp  90 . The bracket  72  may also have a second guide shaft  75 .  
         [0033]     The first locking knob  86  extends transversely from the first guide shaft  74  and secures the position of the alignment guide  30  with respect to the drill press  10 , clamping to the head  12  or to the clamp  90 . A second locking knob  88  may also extend transversely from the second guide shaft  75  to provide additional clamping. One skilled in the art will understand that an alternative locking apparatus can be used. For example, a locking handle or a cam can be used to provide locking engagement. Guide shafts  74 ,  75  are inserted into the shaft receptacles  58  formed in the alignment guide  30 . Inserts, such as bearings, may be placed within the shaft receptacles  58  to aid in aligning the guide shafts  74 ,  75  with the alignment guide  30 .  
         [0034]     As seen in  FIGS. 10-11 , a transmission may couple the slide  70  with the head  12 . The transmission includes a rack  81 , a pinion  82 , a pinion shaft  83 , and a rotating knob  84 . The rack  81  may be integrally formed along the first guide shaft  74 , with the pinion  82  coupled with the rack  81 . A pinion shaft  83  extends from the pinion  82  through the head  12 . A rotating knob  84  and a C-ring  85  are positioned at opposite ends of the pinion shaft  83  to axially secure the pinion shaft  83  to the head  12 . By rotating the knob  84 , the pinion shaft  83  rotates, which in turn rotates the pinion  82 . The pinion  82  engages the rack  81 , causing the first guide shaft  74  and the alignment guide  30  to move up or down.  
         [0035]     Various parameters of the pinion  82  and the rotating knob  84 , such as the outer diameters or the radii, may be selected so that a desired mechanical advantage is achieved, where the displacement or movement of the slide  70  and the alignment guide  30  relative to the head  12  is a particular ratio to the rotational movement of the rotating knob  84 . A gear ratio of approximately 1:2 is illustrated in  FIGS. 10-11 . However, the sizes of the pinion  82  and the knob  84  can be selected so that other mechanical advantages are achieved, such as 1:4, 2:1, or 4:1, providing for increased or reduced adjustment sensitivity, as desired.  
         [0036]     In operation, the switch  65  actuates the laser generators  40 ,  41  and the lamp  66 . The first adjustment ring  54  is rotated until the fan-shaped first laser beam  44  projected by the first laser generator  40  is coplanar with the drill bit axis of operation  20 . Similarly, the second adjustment ring  55  is rotated until the fan-shaped second laser beam  45  projected by the second laser generator  41  is also coplanar with the drill bit axis  20 . The set screws  52  are then tightened to secure this orientation. The alignment guide  30  is preferably designed to have the first laser beam  44  oriented perpendicular to the second laser beam  45 , although the alignment guide  30  may be designed to permit other angles of intersection.  
         [0037]     Once the alignment guide  30  has been aligned with respect to the drill bit axis  20 , the alignment guide  30  projects a first laser line  48  and a second laser line  49  with an intersection point  50  that coincides with the projection of the drill bit axis  20  onto the work piece, as best seen in  FIG. 12 . By aligning this intersection point  50  and the laser lines  48 ,  49  with a reference mark  51  on the work piece, an operator can accurately locate a hole.  
         [0038]     As seen in  FIGS. 12-13 , when large diameter drill bits  18  or hole saws  19  are placed into the chuck  16 , the drill bit  18  or hole saw  19  may obstruct a portion of the projected laser beams  44 ,  45 , which blocks the intersection of the laser lines  48 ,  49  projected on the work piece. By using the slide  70  to move the alignment guide  30  closer to the work piece  20 , the length of the projected laser lines  48 ,  49  on the work piece increases. This increase in the length of the projected laser lines  48 ,  49  reduces the inaccuracies associated with an operator extrapolating the location of intersection point  50 . With the embodiments shown in  FIGS. 1-3  and  14 - 15 , the distance between the axes of the laser generators  40 ,  41  and the drill bit axis  20  remains fixed as the alignment guide  30  and the slide  70  move with respect to the head  12 . This maintains the alignment of the laser beams  44 ,  45  with the drill bit axis  20 . Further, as machining operations are conducted on larger work pieces  20  that may interfere with the alignment guide  30 , the alignment guide  30  may be repositioned through the slide  70 .  
         [0039]     The present invention is applicable to power tools having an axis of operation such as drill presses, gang drills, turret drills, multiple-spindle drills, boring machines, band saws, lathes, milling machines, etc. While the invention has been described with reference to details of the illustrated embodiment, these details are not intended to limit the scope of the invention as defined in the appended claims. For example, while the guide shafts have been illustrated as having straight shafts, shafts with other shapes may also be used, such as curved or angled shafts. In addition, other cross-sectional shapes and sizes for the guide shafts may also be used, such as polygonal shapes, including hexagons, octagons, etc., or rounded shapes such as ellipses. Further, in place of a rack and pinion transmission, the slide may use another type of transmission to create a mechanical advantage. A transmission made up of levers in a linkage system, pulleys, or a hydraulic or pneumatic actuator may also be used to transfer a mechanical advantage from the rotating knob to the slide. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.