Abstract:
Apparatus and method for carving a uniformly carved portion and a variably carved portion in a workpiece in a single pass. The apparatus consists of a uniform carving head fixed relative to the workpiece and a variable carving head that is movable simultaneously in two directions substantially perpendicular to the motion of the workpiece. A control system, which may include a programmable computer, controls the motion of the variable carving head.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a carving machine for flat material, such as wood mouldings, that combines in one machine a traditional carving head and a multi-axis carving head, so that the workpiece can be carved by both heads in one pass, to produce a variety of interesting and intricate designs in the workpiece.  
           [0002]    Flat material, such as wooden mouldings, can traditionally be carved automatically by a machine that feeds the workpiece under a spinning carving head that has affixed to it one or more blades. As the spinning blades contact the workpiece, a straight, uniform channel is produced in the workpiece. In the traditional carving machine, the carving head is fixed in place and does not change position either vertically or horizontally with respect to the workpiece.  
           [0003]    In some limited applications, it is known to move the carving head vertically with respect to the workpiece, in order to either maintain an even depth of cut when the surface of the workpiece varies (as in U.S. Pat. No. 3,891,015) or to produce ornamental patterns by vibrating the cutter structure and oscillating it orbitally (as in U.S. Pat. No. 3,882,911).  
           [0004]    Russian Federation Patent No. RU- 2094238, of which one of the present inventors is the inventor, discloses a multi-axis carving machine that can, under program control, move a cutting head parallel to and perpendicular to the surface of the workpiece as the workpiece is moved under the cutting head.  
           [0005]    However, the inventors do not know of any carving machine that combines the traditional flat material carving machine with a multi-axis carving machine to produce both types of carvings in a single pass through the machine.  
         SUMMARY OF THE INVENTION  
         [0006]    Apparatus and method for carving a uniformly carved portion and a variably carved portion in a workpiece in a single pass. The apparatus consists of a uniform carving head fixed relative to the workpiece and a variable carving head that is movable simultaneously in two directions substantially perpendicular to the motion of the workpiece. A control system, which may include a programmable computer, controls the motion of the variable carving head.  
           [0007]    A principle object and advantage of the present invention is that it can carve both a uniformly carved portion and a variably carved portion into the workpiece in a single pass.  
           [0008]    A second principle object and advantage of the present invention is that it can carve either uniformly or variably or both.  
           [0009]    Another principle object and advantage of the present invention is that it may include a control system to control the speed of movement of the workpiece past the carving heads and to control the motion of the variable carving head.  
           [0010]    A feature of the invention is that it may include side carving heads to cut the width of the workpiece for the exact size required.  
           [0011]    Another feature of the invention is self-adjusting feed rollers which can take variation of the material thickness into account without causing any damage to the workpiece or to the machine.  
           [0012]    Another feature of the invention is a self-adjusting hold-down mechanism which can hold the workpiece down on the machine for continuous accurate carving of the workpiece. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a schematic perspective view of the combination machine of the present invention.  
         [0014]    [0014]FIG. 2 is a top plan view of the combination machine of the present invention.  
         [0015]    [0015]FIG. 3 is a side elevational view of the combination machine of the present invention.  
         [0016]    [0016]FIG. 4 is a top plan view of the multi-axis carving machine of the present invention.  
         [0017]    [0017]FIG. 5 is a side elevational view of the multi-axis carving machine of the present invention.  
         [0018]    [0018]FIG. 6 is a schematic side elevational view of the multi-axis carving machine of the present invention.  
         [0019]    [0019]FIGS. 7 a - 7   d  are schematic elevational views of a variety of blades for shaping the edges of a workpiece. FIG. 7 e  is a schematic view of a workpiece with edges shaped by one of the blades of FIGS. 7 a - 7   d.    
         [0020]    [0020]FIG. 8 shows two samples of blades for use with the multi-axial carving machine of the present invention.  
         [0021]    [0021]FIG. 9 shows a blade holding mechanism with changeable carving blades for use with the multi-axial carving machine of the present invention.  
         [0022]    [0022]FIG. 10 is a block diagram of a control system for use with the combination machine of the present invention.  
         [0023]    [0023]FIG. 11 is a schematic of a computer implementing the control system shown in FIG. 10.  
         [0024]    [0024]FIG. 12 shows samples of workpieces carved by the combination machine of the present invention.  
         [0025]    [0025]FIG. 13 a is a side elevational view of adjustable rollers for use in the present invention. FIG. 13 b  is a front elevational view of the adjustable rollers.  
         [0026]    [0026]FIG. 14 is a side elevational view of a second embodiment of the multi-axis carving machine of the present invention for carving spindle carving.  
         [0027]    [0027]FIG. 14 a  shows various cross-sections of spindles that may be carved with the second embodiment.  
         [0028]    [0028]FIG. 15 is a top plan view of a second embodiment of the multi-axis carving machine of the present invention for carving spindle carving.  
         [0029]    [0029]FIG. 16 is a block diagram of a control system for use with the second embodiment of the present invention for spindle carving.  
         [0030]    [0030]FIG. 17 is a top plan view of a third embodiment of the multi-axis carving machine of the present invention for circular carving.  
         [0031]    [0031]FIG. 18 is a side elevational view of a third embodiment of the multi-axis carving machine of the present invention for circular carving.  
         [0032]    [0032]FIG. 19 is a schematic side elevational view of a fourth embodiment of the multi-axis carving machine of the present invention for picture carving.  
         [0033]    [0033]FIG. 20 is a side elevational view of a fourth embodiment of the multi-axis carving machine of the present invention for picture carving.  
         [0034]    [0034]FIG. 21 is a top plan view of a fourth embodiment of the multi-axis carving machine of the present invention for picture carving. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]    The combination traditional and multi-axis flat material carving machine of the present invention is generally shown in the Figures as reference numeral  10 .  
         [0036]    As initially seen in FIG. 1, the present invention comprises a carving machine  10  for carving a workpiece W. The carving machine  10  further comprises a traditional carving head  12  and a multi-axis carving head  14 .  
         [0037]    The traditional carving head  12  further comprises a substantially cylindrical member  12   a  with an axis A 1  substantially parallel to the top surface T of the workpiece W. Affixed to the cylindrical member  12   a  is at least one blade  12   b . The cylindrical member  12   a  is driven to rotate about the axis A 1  by a motor. The carving head  12  is fixed in place and does not move either vertically or horizontally with respect to the workpiece W. The workpiece W is driven along direction Z by rollers (not shown in this Figure). As the workpiece W moves under the spinning carving head  12 , the blade  12   b  produces a straight, uniform cut that does not vary in depth (direction Y) or width (direction X) along the workpiece W.  
         [0038]    In a first embodiment, the multi-axis carving head  14  further comprises a substantially cylindrical member  14   a  with an axis A 2  substantially parallel to the top surface T of the workpiece W. Affixed to the cylindrical member  14   a  is at least one blade  14   b . The cylindrical member  14   a  is driven to rotate about axis A 2  by a motor. The carving head  14  can be moved either vertically (direction Y) or horizontally (direction X) or both vertically and horizontally simultaneously with respect to the workpiece W. As the workpiece W moves under the spinning carving head  14 , the blade  14   b  produces patterns that vary in depth (direction Y), width (direction X) or both along the workpiece W. The multi-axis carving head  14  also has horizontal driving means  14   c  and vertical driving means  14   d , which move the cylindrical member  14   a  respectively horizontally and vertically with respect to the workpiece W. Horizontal driving means  14   c  and vertical driving means  14   d  have control connections  14   e  to a control system.  
         [0039]    The multi-axis carving head  14  may also preferably comprise a tilting assembly  15 . The tilting assembly  15  has an axis  15   a  which is substantially along the direction Z (the direction along which the workpiece W is moved). The tilting assembly  15  may rotate about axis  15   a , as shown by the arrow) in order to tilt the carving head  14  at various angles relative to the top surface T of the workpiece W. Typically, the operator manually tilts the head  14  to the desired angle before beginning the carving operation.  
         [0040]    Additionally, the present invention may comprise a bottom carving spindle  16  and side carving spindles  18 , also acting on the moving workpiece W.  
         [0041]    More details of the invention can be seen in FIGS. 2 and 3. A materials driving mechanism  20  such as a motor  22 , drive chain  24 , and rollers  26 , is used to move the workpiece W in the Z direction, as shown by the arrows. The materials driving mechanism may have feed rollers  26  (shown in FIG. 13) that produce a steady force against the workpiece even if the workpiece has variable thickness. Springs  26   a  hold the rollers  26  against the workpiece W. The rollers are adjustable for material thickness by the use of adjustment slots  26   b  and bolts  26   c . A hold-down mechanism  28  keeps the workpiece from moving in the vertical (Y) direction. The hold-down mechanism  28  may be self-adjusting to hold the workpiece down for continuous accurate carving. For example, the hold-down mechanism  28  may include a weight plate  28   a , arm  28   b , adjustable pivot shaft  28   c , and hold-down roller  28   d.    
         [0042]    Turning to FIG. 2, details of the horizontal driving means  14   c  may be appreciated. The horizontal driving means may be any appropriate mechanism for moving the carving head  14  in the horizontal (X) direction. Suitably, the horizontal driving means  14   c  may further comprise a motor  30 , ball gear  32 , and ball joint connecting rod  34 . As the motor  30  is energized by the control system, the motor drives ball gear  32 , which in turn drives the connecting rod  34  toward or away from the workpiece W. The connecting rod  34  engages the cutting head  14  at a first ball joint  36 . As best seen in FIG. 4, this produces rotation about a first pivot point  38  (which may be a ball joint), so that the cutter  14   a  moves in an arc with radius m (shown by dotted lines) along the direction X.  
         [0043]    Turning to FIG. 3, details of the vertical driving means  14   d  may be appreciated. The vertical driving means may be any appropriate mechanism for moving the carving head  14  in the vertical (Y) direction. Suitably, the vertical driving means  14 d may further comprise a motor  30 , ball gear  32 , and ball joint connecting rod  34 . As the motor  30  is energized by the control system, the motor drives ball gear  32 , which in turn drives the connecting rod  34  toward or away from the workpiece W. The connecting rod  34  engages the cutting head  14  at a second ball joint  40 . As best seen in FIG. 5, this produces rotation about a second pivot point  42  (which may be a ball joint), so that the cutter  14   a  moves in an arc a with radius n (shown by dotted lines) along the direction Y.  
         [0044]    Details of the multi-axial cutter  14  may also be appreciated from FIGS. 4 and 5. The multi-axial cutter  14  further comprises a chassis  50  pivoting about the second pivot point  42 . A motor  52  is mounted on the chassis  50  and drives the cutter head  14   a  by a belt  54  or other suitable mechanism.  
         [0045]    [0045]FIG. 6 shows that for optimal operation, the moment Ml between the cutter  14   a  and the second pivot point  42  should equal the moment M 2  between the second pivot point  42  and the motor  52 , so that there is little force exerted by the cutter  14   a  against the workpiece W.  
         [0046]    [0046]FIG. 7 shows that a variety of blades (FIGS. 7 a - 7   d ) may be attached to the side cutters  18 . FIG. 7 e  shows a scalloped pattern that may be produced in a workpiece W by the use of one of the blades.  
         [0047]    [0047]FIG. 8 shows examples of blades  14   b  that may be attached to the cutter  14   a  of the multi-axis cutter  14 . The type of cut produced will vary depending upon the blade configuration.  
         [0048]    [0048]FIG. 9 shows that several blades A-F may be attached to the cutter  14   a  in any combination to produce varying cuts.  
         [0049]    [0049]FIG. 10 illustrates schematically a control system  60  for the invention, consisting of a computer  62 , motion controller  64 , amplifier  66 , and actuators  68 . The machine  10  is guided by the computer  62  through the motion controller  64  and work in automatic as well as manual mode. A working program developed on the computer  62  with 3-D graphics may be downloaded to the motion controller  64 , which drives the three actuators  68  and receives back signals from encoders and sensors. The motion controller  64  may perform checking of end point sensors, zero sensors, and an emergency stop button. In case of an emergency, the controller  64  can stop all motion and send a signal to the computer  62 . According to the program, the controller  64  can turn on and off the various motors and verify the on/off status.  
         [0050]    The control system may work in two motion modes. In a master/slave mode, the movement of the workpiece W is used as a master and the motions in various axes are slaved, resulting in a surface that depends on the coordinates along the workpiece. In the second mode, each axis of motion can work independently and the surface can vary from point to point.  
         [0051]    The computer program may work in two modes: manual or automatic. In manual mode, the operator can adjust the machine, modify its speed, modify intervals of axial motion, and save parameters in a library or change these parameters. In automatic mode, the program works with parameters chosen from the library.  
         [0052]    [0052]FIG. 11 illustrates schematically a computer on which the control system  60  may be implemented.  
         [0053]    [0053]FIG. 12 illustrates the types of carvings that may be produced by the machine  10 . The portions  70  of the workpiece W are carved by the traditional carving head  12 , while the portions  80  are simultaneously carved by the multi-axis carving head  14 .  
         [0054]    A second embodiment of the apparatus of the present invention is shown in FIGS.  14 - 16 .  
         [0055]    The second embodiment is similar to the first embodiment, except the workpiece W is a spindle W 1  which is rotated about an axis A 3  by a motor  72 . The spindle is centered and held in place by centering and holding mechanism  74 . The motor, spindle, and centering and holding mechanism are mounted on a movable plate  76 , which is moved along the direction Z by materials driving mechanism  20 , as shown by the arrow in FIG. 14. FIG. 14 a  shows various spindle cross-sections which may be used with this embodiment.  
         [0056]    As in the first embodiment, the second embodiment may be moved in the direction X by the horizontal driving means  14 c and in the direction Y by the vertical driving means  14   d .  
         [0057]    In addition, the second embodiment may pivot about a vertical axis V, as shown by the phantom lines in FIG. 15 To accomplish this result, the apparatus  10  further comprises a V-axis driving means  14   f , which may comprise a motor  30 , ball gear  32 , and ball joint connecting rod  34 .  
         [0058]    As shown in FIG. 16, the control system  60  is modified by adding an additional actuator to control motion about the V-axis.  
         [0059]    A third embodiment of the apparatus of the present invention is shown in FIGS.  17 - 18 .  
         [0060]    The third embodiment is similar to the first embodiment, except the workpiece W is a flat disk W 2  which is rotated about an axis A 4  by a materials driving mechanism  20 , which is a motor  82 , as shown by the arrow in FIG. 17.  
         [0061]    As in the first embodiment, in the third embodiment the head  14  may be moved in the direction X by the horizontal driving means  14   c  and in the direction Y by the vertical driving means  14   d.    
         [0062]    Simultaneously, the traditional carving head  12  may produce straight, uniform cuts as previously described.  
         [0063]    A fourth embodiment of the apparatus of the present invention is shown in FIGS.  19 - 21 .  
         [0064]    In the fourth embodiment, the multi-axis carving head  14  is modified to be a member  90  having an axis A 5  that is substantially perpendicular to the top surface T of the workpiece W. Preferably, the member  90  is a router  92 . However, another tool such as a laser burning head could also be used.  
         [0065]    Substantially in the same way as the first embodiment, in the fourth embodiment the head  14  may be moved in the direction X by the horizontal driving means  14   c  (FIG. 21) and in the direction Y by the vertical driving means  14   d  (FIG. 20)  
         [0066]    As the workpiece W is moved in the direction Z, as shown by the arrow, motion of the head  14  causes the router to carve the workpiece W. This may be used to produce pictures in the top surface T of the workpiece W.  
         [0067]    Simultaneously, the traditional carving head  12  may produce straight, uniform cuts as previously described.  
         [0068]    The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.