Abstract:
A laser woodworking machine for cutting wood is disclosed. The machine includes a laser cutting head having two sections structurally configured to include sensors for measurements of depth and of reflected frequencies, a laser unit for supplying power to the laser cutting head, a cabinet enclosure for housing the laser unit and including a table surface, a radial arm supported by a column secured to the inside rear portion of the cabinet enclosure and including a pair of radial supports extending perpendicularly from opposite sides of the column and parallel to each other, and a glider carriage secured to the radial supports and including two substantially flat surfaces above and below the radial supports so that the glider carriage slides along the radial supports via sleeves, the glider carriage further comprising support for the laser cutting head so that the laser cutting head is moveable along the radial arm.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of prior application Ser. No. 11/501,333, filed Apr. 12, 2007, which is incorporated herein by reference as if set forth herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field of Invention 
         [0003]    This invention is generally related to woodworking and, more particularly, is related to an machine from which a laser beam is directed for making precise wood cuts. 
         [0004]    2. Description of the Related Art 
         [0005]    Traditional power tools for woodworking are very dangerous due to the amount and velocity of the moving parts. Due to size and power usage, laser cutting tools for woodworking and the like, if they can be found, are often cumbersome and not very easy or straightforward to use. Such tools are often large, non-portable assemblies that are not useful or affordable for hobbyists and do-it-yourself home maintenance types. 
         [0006]    What is needed is an affordable device that has reasonable space requirements. Such a device could be used for many types of woodworking and similar projects while also improving the safety environment for the user. 
       BRIEF SUMMARY 
       [0007]    According to one embodiment of the present invention, a laser woodworking machine for cutting wood is provided. The machine provides (1) a laser cutting head haivng two sections structurally configured to include sensors for measurements of depth and of reflected frequencies, and to combine a cutting beam and a light beam for monitoring a cut, (2) a variable power laser unit for supplying power to the laser cutting head, (3) a control panel for controlling the variable power output from the laser unit for variable depth of cut according to the power variation of the laser unit, (3) a cabinet enclosure for housing the laser unit, the cabinet enclosure including a table surface, (4) a radial arm supported by a column secured to the inside rear portion of the cabinet enclosure, wherein the radial arm includes a pair of steel pipes extending perpendicularly from opposite sides of the column and parallel to each other, and (5) a glider carriage secured to the radial supports having two substantially flat surfaces above and below the radial supports so that the glider carriage slides along the radial supports via nylon sleeves, the glider carriage further comprising support for the laser cutting head, wherein the laser cutting head is moveable along the radial arm. 
         [0008]    Another embodiment discloses a laser cutting head having two sections structurally configured to include sensors for measurements of depth and of reflected frequencies, a laser unit for supplying power to the laser cutting head, a cabinet enclosure for housing the laser unit and including a table surface, a radial arm supported by a column secured to the inside rear portion of the cabinet enclosure and including a pair of radial supports extending perpendicularly from opposite sides of the column and parallel to each other, and a glider carriage secured to the radial supports and including two substantially flat surfaces above and below the radial supports so that the glider carriage slides along the radial supports via sleeves, the glider carriage further comprising support for the laser cutting head so that the laser cutting head is moveable along the radial arm. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0009]    The above-mentioned features will become more clearly understood from the following detailed description read together with the drawings in which: 
           [0010]      FIG. 1  is a perspective view of a laser woodworking machine according to the present invention. 
           [0011]      FIG. 2  is a side view of the laser woodworking machine of  FIG. 1  and of the interior of a cabinet enclosure of the laser woodworking machine. 
           [0012]      FIG. 3  is a top view of a table surface of the laser woodworking machine. 
           [0013]      FIG. 4  is a front view of a support column within the cabinet enclosure of the laser woodworking machine of  FIG. 1 . 
           [0014]      FIG. 5  is a top view of the support column of  FIG. 4 . 
           [0015]      FIG. 6  is a front view of a cable slot of the support column of  FIG. 5 . 
           [0016]      FIG. 7  is a side view of a threaded rod within the support column for adjusting the height of a radial arm of the laser woodworking machine. 
           [0017]      FIG. 8  is a top view of a support yoke and glider carriage for a laser cutting head. 
           [0018]      FIG. 9-A  is a front view of the laser cutting head attached to the support yoke and glider carriage. 
           [0019]      FIG. 9-B  is a side view of the laser cutting head attached to the support yoke and glider carriage. 
           [0020]      FIG. 10-A  is an end view of one embodiment of an adjustable fence assembly with a spring attachment. 
           [0021]      FIG. 10-B  is an illustration of the fence assembly in an open position. 
           [0022]      FIG. 10-C  is an illustration of the fence assembly in a closed position. 
           [0023]      FIG. 11  is one embodiment of a control panel for use with the laser woodworking machine. 
           [0024]      FIG. 12-A  and  FIG. 12-B  are respective views of the inside of a laser cutting head. 
           [0025]      FIG. 13  is one embodiment of an aiming bracket for the laser cutting head. 
           [0026]      FIG. 14  is an illustration of a fiber cable connector. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    A machine for laser woodworking is disclosed. The machine provides precise woodcuts via a directed laser beam. 
         [0028]      FIG. 1  is a perspective view of one embodiment of a laser woodworking machine  100 . The laser woodworking machine  100  includes a cabinet enclosure  110 , a cabinet base  112 , a support column  120 , a radial arm  130 , a laser head  140 , and a control panel  150 . The cabinet enclosure  110  typically also includes doors (not shown) or the like for enclosing the front of the cabinet enclosure  110  as well as providing access to the inside of the cabinet. In some embodiments, the cabinet enclosure  110  includes an openable and/or detachable panel to cover the front access opening.  FIG. 2  is a side view of one embodiment of the laser woodworking machine  100  and also shows the interior of the cabinet enclosure  110 . 
         [0029]    The machine  100  is quiet and simple to use while also providing for precise and sanding free woodworking. The laser beam cuts to an exact depth with fine cuts that are smooth and ready for joining or finishing. Energy use is small in comparison to conventional woodworking tools. Since, there are no powered moving parts, the machine  100  provides improved safety. Frequency adjustable sensors react only to the detection of flesh to provide instant disconnection of power from the device to reduce or eliminate risk to users, whether they are skilled or unskilled. 
         [0030]    The cabinet enclosure  110  is free standing upon the cabinet base  112  and is self-ventilated. In one embodiment, the cabinet enclosure  110  is a NEMA Type I steel enclosure and includes doors attached via hinges. In such a cabinet enclosure  110 , at least one fan is typically included within the enclosure. Vent openings are typically located on both sides and on the rear. In one embodiment, the vent openings are louvered as necessary for air circulation around the laser and the power supply. The number of vent openings in the cabinet enclosure  110  may be increased or decreased according to the specific cooling requirements. 
         [0031]    In another embodiment, the cabinet enclosure is small enough to rest upon a counter-top or workbench. In one embodiment, power is provided to the cabinet enclosure  110  from the rear. In various embodiments, the cabinet enclosure  110  is mounted on casters, legs, and the like. 
         [0032]    In one embodiment the cabinet enclosure  110  is of conventional welded steel construction. Those of skill in the art will readily appreciate that multiple types of framing may be used to ensure a rigid assembly of the cabinet enclosure  110 . In various embodiments access to the interior of the cabinet enclosure  110  is provided via a door located on either or both sides of the front of the cabinet enclosure  110  wherein the door(s) are attached via hinges of sufficient strength to support the weight of the door(s). 
         [0033]    The laser woodworking machine  100  includes a table surface  114  above the cabinet enclosure  110 . The table surface  114  typically covers the entirety of the area immediately above the cabinet enclosure  110 . The table surface  114  is made from any material that is suitable as a woodworking surface. In one embodiment, the table surface  114  is made of welded steel secured via welding to the cabinet enclosure  110 . Those of skill in the art will readily appreciate that other materials may also serve as a suitable table surface  114 . An adjustable fence  116  is located at the rear of the table surface  114 . The fence  116  is used as a guide or to position the wood or other material that is being cut by the laser woodworking machine  100 . The fence  116  can also be lowered so that the cutting surface is substantially smooth. 
         [0034]    Turning again to  FIG. 2 , the interior of the cabinet enclosure  110  includes an enclosure shelf  220  resting upon support channels (or struts)  210 . In the illustrated embodiment, there are four (4) support channels  210  (see  FIG. 4 ). Other embodiments may include more or less than four support channels  210  to support an enclosure shelf  220 . A laser (and power) unit  240  is situated on the enclosure shelf  220  and receives power from a power input  230 . The power input  230  is typically supplied through the rear (not shown) of the cabinet enclosure  110 . An emergency shutoff  250  is located at the front of the cabinet enclosure  110  just below the table surface  114 . The emergency shutoff  250  provides capability for the user to instantly disconnect the power from the machine  100 . In one embodiment the emergency shutoff  250  is a pushbutton for ease of activation (to remove power). 
         [0035]    The laser unit  240  includes a standard Nd:YAG flash pumped solid state type laser or a sealed gas CO2 type laser. The laser includes a variable power output. The laser output includes a visible beam, such as a red laser for example, that is used for positioning of the object within the cutting path. The laser also includes a cutting laser beam that is non-visible or invisible. The non-visible laser beam is positioned with the visible beam. 
         [0036]    A cable  260  is routed from the laser unit  240 , through the support column  120 , through the radial arm  130 , and into the laser head  140 . In one embodiment, the cable  260  includes two fiber-optics and two copper wires. The cable  260  is secured within the cabinet enclosure  110  via a series of pulleys  270  and springs  280  that provide tension to prevent the cable from crimping and such like when the height of the radial arm  130  is adjusted. The cable then extends through the support column  120  to the radial arm  130 . 
         [0037]    The radial arm  130  is attached at one end to the support column  120 . A radial arm cover  132  is positioned to cover the radial arm  130  at the end that connects with the support column. A lever  134  extends from the support column  120  for adjusting the height of the radial arm  130 . Additionally, the radial arm  130  pivots around the support column to provide for adjusting the position of the laser head within the available cutting area of the laser woodworking machine  100 . 
         [0038]      FIG. 3  illustrates a top view of the table surface  114  of the laser woodworking machine  100 . The support column  120  is located at the rear of the machine  100  beyond the fence  116 .  FIG. 4  is a front view of the support column  120  within the cabinet enclosure  110 . The base of the support column  120  rests upon the enclosure shelf  220 . Three brackets or stiffeners  410   a,    410   b,    410   c  at approximately 90° angles from each other secure the support column  120  to the enclosure shelf  220 . In one embodiment, the stiffeners  410  are situated toward the front and to either side of the cabinet enclosure. No stiffener  410  or bracket is necessary at the rear of the cabinet enclosure  110  since the rear of the support column  120  is adjacent to the rear of the cabinet enclosure  110 . 
         [0039]    In the illustrated embodiment, four support channels  210  (or struts) provide support for the enclosure shelf  210 . Those of skill in the art will appreciate that the number of support channels  210  and their spacing may be varied according to the strength necessary for the enclosure shelf  220  to support the support column  120 , the laser unit  240 , as well as any additional items that may optionally be placed on the enclosure shelf  220 . 
         [0040]      FIG. 5  is a top view of the support column  120  that extends from the interior of the cabinet enclosure  110  to the radial arm  130 .  FIG. 6  is a front view of a cable slot of the support column  120  and looking in toward the point where  FIG. 5  is looking down the support column  120 . 
         [0041]    As noted above, one end of the radial arm  130  is attached to the support column  120 . The support column  120  includes an inner portion  510  and a sleeve  512  adjacent to the inner portion  510 . Within the inner portion  510  are a threaded rod  520 , a tube  540 , a shield plate  550 , and stabilizers  552   a,    552   b.  In one embodiment, the stabilizers  552  are welded to both the shield plate  550  and to the tube  540  to provide for maximum stability of the tube  540 . One or more cables pass through the tube  540 . In one embodiment, a single cable  260  that includes both fiber-optics and copper wire provides for delivery to the laser head and to the control panel. 
         [0042]    The lever  134  attaches to the threaded rod  520  that extends downward through the support column to a base (see  FIG. 7 ). The lever provides for turning the rod  520  to adjust the height of the radial arm  130 , and thus the height of the laser head  140 , above the table surface  114 . A tube  540  within the support column  120  provides a passageway for the cable  260  that passes from the laser unit  240  to the radial arm  130 . 
         [0043]    Two radial supports  530   a,    530   b  extend from opposite sides of the column support  120  and through the radial arm  130 . The radial supports  530  provide the structural support for the weight of the radial arm  130 , and also for the laser head  140 . In one embodiment, the radial supports  530  are steel pipes of a sufficient size and strength to support the combined weight of the radial arm  130  and the laser head  140 . In another embodiment, the radial supports  530  are rods of sufficient size and strength to support the combined weight of the radial arm  130  and the laser head  140 , as above. In one embodiment, one end of each radial support  530  is welded to the support column  120  on opposite sides of the outer sleeve  512 . 
         [0044]    An elongated slot  514  in the support column  120  adjacent the end of the radial arm  130  provides an opening to the tube  540  through which the cable  260  passes. The cable  260  passes through the tube  540 , out a cable opening  610  and through the slot  514  into the radial arm  130 . The slot  514  allows for the up and down movement of the support column  120 . 
         [0045]      FIG. 7  is a side view of the threaded rod  520  within the support column  120 . The threaded rod  520  is used to move the support column  120  up or down to adjust the height of the radial arm  130 . The threaded rod  520  is received by a threaded rod base  710 . The threaded rod base  710  is of sufficient height to allow the rod  520  to be withdrawn sufficient distance to increase the height of the radial arm  130  above the table surface  114  without the threaded rod  520  becoming unstable. 
         [0046]      FIG. 8  is a top view of a glider carriage  810  for a support yoke and a laser head  140 . The glider carriage  810  is supported by and secured to the radial supports  530   a,    530   b  for movement of the laser head  140  along the radial arm  130 . The glider carriage  810  includes stop levers  820   a,    820   b  one of which includes a handle for securing the glider carriage  810  in place and releasing it for movement along the radial supports  530   a,    530   b.  Each stop lever  820  includes wheels  822  and cams  824 . The wheels  822   a,    822   b,    822   c,    822   d  operate upon blocks  830   a,    830   b.  The blocks  830  include friction elements to hold the wheels in place when the glider carriage  810  is tightened against the radial supports  530   a,    530   b.  In one embodiment, the blocks  830  include teeth such that the teeth press against the wheels  822  to prevent motion. 
         [0047]    The glider carriage  810  is secured in place against the radial supports  530  via turning the handle attached to one of the stop levers  820 . In the illustrated embodiment, the stop lever  820   a  serves as the handle. It should be readily appreciated that either stop lever  820   a,    820   b  could be the handle. Upon turning the handle, the cams  824   a,    824   b,    824   c,    824   d  are rotated in so that the longer portion of each cam  824  pushes down to tighten the glider carriage  810  against the radial supports  530   a,    530   b.    
         [0048]    The glider carriage  810  also includes a carriage opening  840  through which a cable passes for connection to the laser head  140  and the control panel  150 . 
         [0049]      FIG. 9-A  is a front view of the laser head  140  attached to the support yoke  930  and the glider carriage  810 .  FIG. 9-B  is side view of the laser head  140  as attached to the support yoke  930  and the glider carriage  810 . A housing  910  is affixed to the upper portion of the glider carriage  810 . The support yoke  930  is attached to a turntable  932  on the underside of the glider carriage  810 . Nylon sleeves  920   a,    920   b,    920   c,    920   d  are affixed between the glider carriage  810  and the radial supports  530   a,    530   b  on the upper and lower sides of each radial support  530 . When the cams  824  are disengaged, the nylon sleeves facilitate the ease of movement for the glider carriage  810 . 
         [0050]    The cable  260  passes through the radial arm  130  and connects to the housing  910 . The cable  260  exits the underside of the housing  910  through the carriage opening  840  ( FIG. 8 ) and extends to the laser head  140 . 
         [0051]    The front view of the glider carriage  810  illustrates how the cams  824  cause the upper and lower portions of the glider carriage  810   a,    810   b  to compress as the cams  824  push against each portion. As each cam  824  applies pressure to the glider carriage  810   a,    810   b,  the nylon sleeves  920  press against the radial supports  530  to hold the glider carriage  810  in place. 
         [0052]    In one embodiment, the laser head  140   a,    140   b  has two sections made from a suitable composite material. In one such embodiment, assembly is via machine screw or similar fastening and securing mechanisms. It will be readily appreciated by those of skill in the art that deformations to the laser head  140  are typically necessary to house the beam combiner and focusing lenses. In one embodiment, screw type threads are formed into the laser head  140  for initial lens adjustment, after which the threads are intentionally burred to prevent movement of the lenses within the laser head  140 . 
         [0053]    The laser head  140  also includes deformations for the mounting of sensors that can detect when skin is in the path of the cutting laser beam. 
         [0054]    The top portion of the laser head  140  is mounted in a support yoke  930 . Fine adjustment of cutting angle is provided for with a turntable  930  that includes stops at 30°, 45°, and 60°. The support yoke  920  and turntable  930  are attached to the glider carriage  810  on the radial arm  130 . 
         [0055]      FIG. 10-A  is an end view of one embodiment of an adjustable fence assembly  116  with a spring attachment  1010 .  FIG. 10-B  shows an illustration of the fence  116  in an open position.  FIG. 10-C  is an illustration of the fence  116  in operation. As noted above, the fence  116  is located at the rear of the table surface  114 . The fence  116  is adjustable to lower the fence  116  so that the table surface  114  is substantially smooth. 
         [0056]    The spring mechanism  1010  is held in place inside the cabinet enclosure  110  via a fastener  1020 , such as a screw, for example. The fence handle  1030  is operable to increase and decrease the tension on the spring  1010  to open or close the fence assembly. 
         [0057]      FIG. 11  is one embodiment of a control panel  150  for use with the laser woodworking machine  100 . In the illustrated embodiment, the control panel  150  is located at the end of the radial arm  130 . In the illustrated embodiment, the control panel  150  is a solid-state device that is preprogrammed for controlling the woodworking machine  100 . In one embodiment, the control panel  150  includes an industrial film type sealed keypad. The control panel  150  includes a key for PWR ON  1110 , a key for CUT ON  1120 , and a key for STOP  1130 . The PWR ON key  1110  is operable to provide power to the guide (aiming) laser. The CUT ON key  1120  provides power to the cutting laser or the laser head  140 . The STOP key  1130  removes or turns off all power to the laser woodworking machine  100 . 
         [0058]    As noted above, an emergency shutoff switch  250  is mounted on the front of the cabinet enclosure  110  for quick removal of the power. The control panel  150  also has capability for removing power from the machine  100  via the STOP key  1130   
         [0059]    During operation, the control panel is operable to select the cutting depth via the FT key  1160 , or the MM key  1170 , depending on the desired measuring system. In one embodiment, the control panel provides capability for measuring the cutting depth from 1/128 inch through 9 inches via increments of 1/128 inch. The control panel  150  varies the power output of the cutting laser to achieve the specific cutting depth that is chosen via the controls. That is, the operating power range of the cutting laser is varied to achieve the desired depth of cut. Those of skill in the art will readily appreciate that the precision and depth of the cut is merely a matter of the desired pre-programming of the control unit and of the capability of the instruments. The “Step Units” key  1140  is operable to select the unit size for adjustment. In this way, the adjustments to the desired cut can be made in larger or smaller increments at a time. That is, the power adjustment has a course and a fine adjustment for quicker setup. 
         [0060]    The control panel  150  is programmed to determine the measured cutting depth via sensors that are utilize sensing beams for measuring the distance of the laser head  140  above the table surface  114 . 
         [0061]    The display  1150  indicates the present cut setting via the value and also the units. Of course, other information can also be displayed according to need. 
         [0062]      FIG. 12-A  and  FIG. 12-B  are respective views of the inside of a laser cutting head or laser head  140 .  FIG. 13  is one embodiment of an aiming bracket  1230  for the laser cutting head  140 . The laser head  140  includes optical fiber  1210   a,    1210   b,  a sensing beam  1220 , a light beam  1230 , an aiming bracket  1240 , a beam combiner  1250 , spreaders  12601 ,  1260   b,  and focusing lenses  1270 . 
         [0063]    In one embodiment, the laser head  140   a,    140   b  has two sections made from a suitable composite material. In one such embodiment, assembly is via machine screw or similar fastening and securing mechanisms. It will be readily appreciated by those of skill in the art that deformations to the laser head  140  are typically necessary to house the beam combiner and focusing lenses. In one embodiment, screw type threads are formed into the laser head  140  for initial lens adjustment, after which the threads are intentionally burred to prevent movement of the lenses within the laser head  140 . 
         [0064]    The beam combiner  1240  is fixed within the laser head  140 , and not adjustable. In one embodiment, the beam combiner  1240  is located in-line with the fiber and is within the cabinet enclosure  110 . 
         [0065]    The fiber weld joints of the fiber slots are angle cut to merge the beams within the aiming bracket  1240 . The aiming bracket  1240  directs the fiber so that the laser beams are properly delivered to the polarization beam chamber  1250 . 
         [0066]    The laser head  140  is assembled in a manner that provides for movement by hand directly to the laser head  140  or via a handle attached to the laser head  140 . 
         [0067]    The laser head  140  also includes sensors for detecting human flesh. Four proximity switches detect whether human flesh is within the proximity of the laser cutting beam. The proximity switches turn the laser power beam off upon detection of flesh. The switches respond to frequencies that are not reflected by flesh only. That is when a frequency appears that is reflected by flesh, the proximity switches remove power from the laser cutting beam. The proximity switches operate when the cutting beam has power. 
         [0068]      FIG. 14  is an illustration of a fiber cable connector  1400 . The fiber cable connector  1400   a,    1400   b  is used for connecting the fiber from the laser unit  240  to the laser head  140 . In the illustrated embodiment, the fiber cable connector  1400   a  includes a laser cutting beam fiber  1410 , a visible beam fiber  1420 , and two sensing beam fibers  1430   a,    1430   b.  Those of skill in the art will readily appreciate that more or less fibers may be used for delivery to the laser head  140 , as well as optionally providing the control signals to and from the control panel  150 . 
         [0069]    While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.