Abstract:
The present invention discloses an apparatus and a method using a multipurpose flexible CNC machine that is able to perform a variety of machining operations on all parts of a product. Specific operations include carving, boring, cutting, grooving, molding, shaping, routing, mortising, edge working, sawing, planing, squaring, sanding, drilling and dovetailing. The CNC control integrates machining instructions, operator: instructions and sequence of operations into a coherent package.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to a Computer Numerical Control (CNC) machine. More particularly, the present invention uses multi-media to coordinate production arrangements between a CNC machine and its operator.  
         BACKGROUND OF THE INVENTION  
         [0002]    The machining industry is one of the most fundamental industries of industrial and developing countries. It is an industry that has a direct impact on almost all manufactured goods. The technological advancement of the machining industry, from a short-term impact perspective, has a direct bearing on the quality of goods, the durability of goods, the production capability of goods, and the desirability of goods. From a long-term impact perspective, the technological advancement of the machining industry has a direct impact on the competitiveness of a country&#39;s product in the world market. The present invention is a major breakthrough in the concept and methodology of the machining industry that will revolutionize the manufacturing base of U.S. industries.  
           [0003]    Ever since the industrial revolution, many manufacturing bases of U.S. industry embraced manufacturing cost savings based on the economy of scales. Depending upon the state of technology at any moment in time, many manufacturing bases of U.S. industries established manufacturing plants that are optimized based on mass production only to be limited by the technology of the day. From this background, the conventional concept and methodology of manufacturing have been established. With the advancement of computer technology, the conventional concept and methodology of manufacturing a-e becoming more outdated with each passing day.  
           [0004]    Take the furniture manufacturing industry for example, the conventional concept and methodology teach batch and specialized productions, where each production line manufactures only one of many parts that are required for a desired piece of furniture. This concept and methodology is anchored upon amortizing machine setup times over a long period of time. The advantages of this concept and methodology are increased production efficiency, low per part cost, and simplicity of manufacturing on each production line. The disadvantages of this concept and methodology of manufacturing are high initial investment cost, large warehouse storage requirements, heavy transportation cost, high man-hour labor requirement, and complex record keeping. This conventional concept and methodology of manufacturing is only viable when the demand for goods require mass production. Should the demand for goods be less than the scale of manufacturing, the per-part cost increases substantially.  
           [0005]    Based on the unprecedented advancement of computer technology, Thermwood Corporation of Dale, Indiana has implemented a new concept and methodology of manufacturing in the present invention. The present invention substantially overcomes the disadvantages stated above yet yields a return that substantially conforms to that of a mass production.  
         SUMMARY OF THE INVENTION  
         [0006]    One object of the present invention is to implement a new manufacturing process.  
           [0007]    A second object of the present invention is to produce a plurality of parts from a series of work zones on a single worktable.  
           [0008]    A third object of the present invention is to conveniently provide manufacturing instructions to an operator.  
           [0009]    A fourth object of the present invention is to provide an efficient method of producing complex parts of a piece of furniture.  
           [0010]    A fifth object of the present invention is to provide manufacturing instructions through a display and a speaker.  
           [0011]    A sixth object of the present invention is to reduce the cost of small order productions.  
           [0012]    A seventh object of the present invention is to incorporate all the required skills into a CNC machine thus relieving dependency upon a highly skilled machine operator.  
           [0013]    An eighth object of the present invention is to minimize the chances of operator error in a production. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0014]    [0014]FIG. 1 is a perspective view of a computer controlled router machine.  
         [0015]    [0015]FIG. 2 is a perspective view of a tool changer capable of holding 50 tool bits.  
         [0016]    [0016]FIG. 3 is another perspective view of a computer-controlled router with a turret machine tool system.  
         [0017]    [0017]FIG. 4 is a perspective view of a machine vertical side table.  
         [0018]    [0018]FIG. 5 is a perspective view of a machine table attached with fences and pop-up pins.  
         [0019]    [0019]FIG. 6 is a logic diagram illustrating the operation of the present invention.  
         [0020]    [0020]FIG. 7 is a perspective view of a desk representative of an end product that can be manufactured by the present invention.  
         [0021]    [0021]FIG. 8 is an exploded view of the desk of FIG. 7.  
         [0022]    [0022]FIG. 9 is a perspective view of wood stock of various sizes. 
     
    
     DETAILED DESCRIPTION  
       [0023]    The present invention implements a concept and methodology of manufacturing that is based on an assumption of near zero setup time for short run productions. Unlike batch productions that require multiple machines each producing a large quantity of the same part, the present invention uses a single multi-purpose flexible work center to manufacture all parts of a product.  
         [0024]    For example, due to the large quantity of different parts in a piece of furniture, it is very difficult if not impossible for an operator to remember the configurations and dimensions of each component and correctly machine them. Therefore, the present invention incorporates machining operations, part placement instructions, and sequence of operations into one single package. This way, it is the controller that keeps track of configurations and dimensions of parts. All that the operator has to do is to follow the part placement instructions and implement them correctly. As the parts are being machined, an operator can concurrently perform assembly work. This concept and methodology of furniture production not only overcome all the above-mentioned disadvantages, but also produce better quality furniture.  
         [0025]    It is well known in the furniture manufacturing industry that wood is not a very stable material. Depending upon the moisture content within a piece of wood, the shape of the piece of wood changes within days. Therefore, in a batch production, a manufacturer must provide humidity-controlled environments to store cut pieces, escalating the overall cost of manufacturing. The present invention overcomes this problem by cutting all required parts at the same run and assemble all the parts on the same day they are cut. Details of the present invention will become apparent in view of the following explanations. A book titled “Furniture Manufacturing in the New Millennium” written by the Kenneth J. Susnjara is incorporated herein by reference.  
         [0026]    [0026]FIG. 1 illustrates a router machine  10  and a machine controller  11 . They are operatively connected for displacing a router bit of the machine along a longitudinal line of travel or along an x-axis, a transverse line of travel or along a y-axis and a vertical line of travel or along a z-axis in accordance with a program executed by the controller for performing a work function on one or more workpieces positioned on the machine. Preferably, the controller will have multi-tasking capabilities such as that of the Thermwood 91000 SuperControl, available from the Thermwood Corporation, Dale, Ind. In the Thermwood SuperControl, the “front end” of the machine controller is a Pentium-based personal computer (PC) shown generally as  54  in FIG. 1, which computer includes a video monitor  56  and a speaker  64 . The PC processor provides the control and communication functions for the PC compatible peripheral devices including display  56 .  
         [0027]    Generally, the machine includes a base member  12 , a bridge member  13 , a tool head support assembly  14  and a tool head assembly  15 . The base member is provided with a work table  17  rigidly mounted on the base member and a pair of trackways  18  mounted on the sides of the base member and disposed parallel to the x-axis of the machine. Worktable  17  supports one or more workpieces to be machined. Such workpieces are positioned by positioning pins or other means and secured in position by clamps, a vacuum hold-down system or any other means.  
         [0028]    The bridge member includes a transversely disposed beam section  19  spaced above and spanning the base member, and a pair of transversely spaced, depending leg sections  20  and  21  straddling the sides of the base member and mounted on trackways  18  for displacement relative to the base member along the x-axis. The bridge member is displaced relative to the base member along the x-axis by means of a pair of drive screw assemblies  22  operatively interconnecting the side portions of the base member and inner side portions of leg sections  20  and  21 .  
         [0029]    Tool head support assembly  14  is supported on and guided along a pair of transversely disposed, vertically spaced trackways  23  and  24  provided on a front face of transverse beam section  19 , and is displaceable along the y-axis by a drive screw assembly operatively interconnecting the bridge member and the tool head support assembly. Each of the tool head assemblies is supported and displaceable along transversely spaced, vertically disposed trackways mounted on support assembly  14 , and is adapted to be displaced by a drive screw assembly operatively interconnecting the support assembly and a tool head assembly. Each of the tool head assemblies further is provided with a router bit  25  adapted to be displaced along the x, y and z axes to provide a cutting pattern.  
         [0030]    [0030]FIG. 2 shows a tool changer designed to work cooperatively with the router of FIG. 1. This tool changer contains up to 50 different tool bits for a variety of machine operations. If more tool bits are required, multiple tool changers can be installed for a single CNC machine. Each tool bit is assigned to a location with a specific address. This information is available to either computer  54  or machine controller  11 . Whenever a particular tool bit is called for in a program, toolhead assembly  15  would automatically return any mounted tool bit to its assigned address and automatically go to a predetermined address to acquire the required tool bit. This cycle only takes about thirty seconds.  
         [0031]    [0031]FIG. 3 illustrates another embodiment of the present invention. This embodiment includes a base member  70 , a worktable  72 , a gantry  32 , a toolhead support assembly  33  and a toolhead assembly  74 . The base member is formed of steel sections welded together to provide a rigid end stable foundation. Worktable  72  is mounted horizontally on the base member and is adapted to be displaced longitudinally relative to the base member or along a y-axis. Gantry  74  includes a pair of leg members  80  and  82  rigidly secured at their lower ends to the base member, and a transversely disposed section  84  supported on the leg sections and spanning above the worktable. The front face of transverse section  84  is provided with a pair of vertically spaced, transversely disposed rails  86  and  88  on which toolhead support assembly  76  is mounted and displaceable transversely or along an x-axis. Toolhead assembly  78  is mounted on he toolhead support assembly adapted to be displaced vertically or along a z-axis. Each of worktable  72 , toolhead support assembly  76  and toolhead assembly  78  is displaceable along its respective axis by a feedscrew arrangement driven by an AC servomotor. The operation of such servomotors is controlled by a Computer Numerical Control (CNC) to provide for the movement of a tool mounted on the toolhead assembly along a motion path to perform a work function such as routing, soaping, drilling, sanding and the like on a workpiece mounted on the worktable. Instead of the worktable being displaceable and the gantry being stationary as described, the worktable can be stationary and the gantry may be displaceable along the y-axis to provide the displacement between the gantry and the worktable.  
         [0032]    As it has been shown that the toolhead assembly  34  is a turret system comprising of 8 tool bits. This machine is more suitable for machining operations requiring less tool bits. Due to its rotary design, all the right tool bits are at most simply one revolution away, further curtailing the need to mount or dismount tool bits.  
         [0033]    [0033]FIG. 4 shows a vertical side table of the present invention. This vertical arrangement is especially useful for edge working such as dovetailing and edge boring. In operation, the wood panels are affixed to the vertical side table. The toolhead assembly then travels along x, y, and z-axes axes to perform the desired wood work.  
         [0034]    [0034]FIG. 5 shows a possible worktable arrangement for the present invention. This worktable can be used for the embodiment in either FIG. 1 or  3 . Mounted on this worktable is a plurality of pop-up pins. A plurality of fences  100  and  101  can be placed in lieu of these pop-up pins. These pop-up pins and fences are locating pins and locating fences, even though they can be used in conjunction to allow the fences lean securely against the pop-up pins. Adjacent to these fences is a plurality of work zones  104 ,  106 ,  108 ,  110  and  112 .  
         [0035]    Any workpieces can be placed in these work zones. In addition to the option of securing workpieces by the pop-up pins and fences, each work area comprises of a plurality of vacuum holes and rubber seals to hold the workpiece by air suction. The number of rubber seals in each work area and the configurations of each rubber seal depend on the specifications of the parts to be machined. What is important is that there must be vacuum holes within the enclosure of the rubber seal. Reference numerals  120 ,  122 ,  124 ,  126 ,  128  and  130  in FIG. 5 illustrate some representative configurations and arrangements. For most operations, the suctioning effect would be sufficient to hold a workpiece without the assistance of pop-up pins and fences. In fact, most of the time, the fences and pop-up pins are merely used for referencing purposes. The sized of the fences and work zones can be altered to suit the characteristic of the wood dimensions and machining requirements.  
         [0036]    Reference numeral  114  shows an enlarged view of fences  100  and  101 . It is shown that both segments of the L-shape fences also contain a ruler that can be used to measure the dimensions of a workpiece. There is also a gap between both segments of the L-shaped fences. This is for the purpose of removing wood dust from the machining area.  
         [0037]    [0037]FIG. 6 shows a flow chart diagram depicting the logic of the present invention. At the very initial stage, a designer must design and program all the machine instructions, layouts and operator instructions pertaining to a particular production. For example, assuming the product is a desk as shown in FIG. 7. This desk is a composite of numerous parts as shown in an exploded view of the desk in FIG. 8. A designer must identify each part as shown. The designer must then determine the appropriate machining processes to be performed on different wood-stocks as shown by example in FIG. 9 to arrive at the desired parts. The designer then must write a program providing the machining instructions and operator instructions.  
         [0038]    Upon a production run, there is a master program allowing selection of a particular production among various available productions as shown in step  200 . Upon receiving a selection, the computer retrieves the machine macros related to the selected product, as shown in step  202 . The computer then provides instructions regarding worktable layouts and machine setup requirements to the operator via monitor  56  and speaker  64 , as shown in step  204 . Once the worktable layouts and machine setup requirements are determined to be satisfied in step  206 , the manufacturing process is initiated, as shown in step  208 . The steps from  208  to  222  are actual subroutines called by the master program. This subroutine actually contains the specific computer instructions and operator instructions. The computer would inform the operator the work zones and their respective instructions through monitor  56  and speaker  64 , as shown in step  212 . Since the operator will be moving about the worktable instead of being stationary in front of the monitor, it is preferable for the instructions to be given through speaker  64 , so that the operator does not need to read from the monitor for each instruction.  
         [0039]    For example, the instruction may be “putting a 2″×4″×24″ board on work area  104  aligning the 24″ length with the x-axis of the fence.” Hearing this instruction, the operator would place wood stock  300  in work area  104  as instructed. The operator can quickly check whether the right wood stock is placed by checking the wood stock dimensions through the rulers on the fences. Once instructions are given for each work area and they are implemented by the operator at step  216 , the operator can inform the computer the status through either a start switch, a keyboard, a mouse, a remote control button, etc. The machine would then perform the programmed machining processes in all work zones as shown in step  218 . At the end of this process cycle, if there are more instructions, steps  212 ,  214 ,  216  and  218  will be repeated for the next set of instructions. During the machining time, the operator is free to assembly the machined parts.  
         [0040]    If all instructions are completed, the subroutine will return to the master program. At the master program, another product selection can be made in step  224 . If another selection is made, then a new subroutine will be called to repeat steps  208  to  222 . If no more selection is made, the master program comes to a complete halt in step  226 .  
         [0041]    The present invention has been described in terms of one preferred embodiment. Numerous variations and changes will become apparent to those having ordinary skill in the art. It is intended that all such variations and changes being within the scope of the present invention as limited solely by the following claims.