Abstract:
A composites lamination system uses a six-axis positioner and multiple removable heads for applying composite material to a tool. The six-axis positioner has a gantry and a wrist. The gantry has two spaced uprights that support a crossbeam that is movable in the X-axis. A workzone containing a tool is positioned between the two spaced uprights. A movable column is supported on the crossbeam, and is movable relative to the crossbeam in the Y-axis and the Z-axis. A wrist mounted on the column rotates around an I-axis parallel to the X-axis, around a J-axis parallel to the Y-axis, and around a K-axis parallel to the Z-axis. A replaceable head is mounted on the wrist so that the gantry and the wrist provide six axis of motion for the replaceable head, and removal of the head from the wrist allows the six axis of motion to remain with the positioner.

Description:
FIELD 
       [0001]    The invention relates to a 6-axis gantry composites lamination system having the ability to quickly change heads to lay composite contour tape layer grade tape or fiber towpreg, or to trim or ink mark composite material, or to perform other functions. 
       BACKGROUND 
       [0002]    Composites lamination systems are used to manufacture aircraft and aerospace components, wind turbine components, and other articles where high strength and light weight are primary objectives. Composite contour tape layer (CTL) grade tape and fiber towpreg are both widely used; each system has its advantages and limitations. 
         [0003]    A fiber placement head provides independent control over material feed via the clamp, cut and re-start mechanism for up to 16 individual tows of composite prepreg slit tape (towpreg), allowing automated “on-the-fly” adjustment of the fiber band width, controlled placement of fibers around changing contours, and precise configuration of openings. The fiber placement head allows wrinkle-free, near-net-shape lay-up of enclosed and deeply contoured structures and concave/convex surfaces. The fiber placement head is ideal for precision production of fuselage sections, outer mold line and inner mold line panels, cowls, ducts and nozzle cones for commercial, military and space vehicles, including parts that make use of lightweight honeycomb core materials. 
         [0004]    A tape laying head deposits carbon/epoxy CTL grade tape at speeds up to 60 m/min (2400 inches per minute) using 75, 150 or 300 mm (3, 6 or 12 in) carbon/epoxy tape at any orientation and number of plies, ensuring consistent quality, part shape, thickness and strength. 
         [0005]    The same application head cannot be used to lay up both tape and fiber towpreg, and as a result, laying up CTL grade tape and then switching to fiber towpreg requires moving the article being laid up from a first machine to a second machine. Because the article being laid up is usually large, relocating a half laid up article from a tape laying machine to a fiber placement machine or vice-versa is a cumbersome, time consuming task and reduces accuracy of ply-to-ply placement. 
         [0006]    Certain prior art systems with removable and interchangeable heads have one or more major machine axes that stay with the head and dock away from the machine when the heads are switched due to their concept configuration or the legacy design from which they are derived. This makes the cost of each individual head more expensive since duplicate axis hardware is built into each head. Other head designs incorporate an integral wrist and creel that stays with the head and detaches from the remainder of the machine when one head is swapped for another, thus adding even more cost for the redundant mechanism that is designed into a multi-head system. 
       OBJECTS 
       [0007]    Accordingly it would be desirable to design a composites lamination system that would be able to lay up both composite CTL grade tape and composite fiber towpreg. 
         [0008]    It would further be desirable to design a composites lamination system that would be able to quickly and efficiently change heads from one that lays up tape to one that lays up fiber. 
         [0009]    It would further be desirable to design a composites lamination system that employs multiple replaceable heads in which none of the six motion axis of the system resides with the head. 
         [0010]    It would further be desirable to have a composites lamination system with a six-axis gantry positioner with live docking stations to support a fiber placement head and CTL tape head in a docking zone within the reach and travel of the positioner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a gantry lamination system. 
           [0012]      FIG. 2  is a detail view of the wrist mechanism that joins a composite placement head to the end of a gantry column. 
           [0013]      FIG. 3  is a detail view of a head docking station designated by the section line  3  in  FIG. 1 . 
           [0014]      FIG. 4  is a detail view showing motion of the gantry column to dock a head at a first docking station. 
           [0015]      FIG. 5  is a detail view showing motion of the gantry mechanism along the Z and X-axis to a second docking station in the docking zone. 
           [0016]      FIG. 6  is a detail view showing motion of the gantry column in the X and Z-axis to retrieve a head at a second docking station. 
           [0017]      FIG. 7  is a detail view showing a utilities arm and an attached maintenance plate in a standby position in a docking station. 
           [0018]      FIG. 8  is a detail view showing the motion of a live utilities arm and the attached maintenance plate coupling with the lower coupling plate on a composite head. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]      FIG. 1  shows a gantry type composite placement machine  10  comprising a six-axis positioner  12  and a head  14 . The head  14  may comprise an integrated head and creel so that the head carries with it the composite material that will be laid on the tool  16  in the workzone  15 . The integrated head  14  applies composite material to a tool  16 . The head  14  is provided with six motion axes by the six-axis positioner  12 . 
         [0020]    The positioner  12  comprises a horizontal beam  18  that is supported above the factory floor  19  by a pair of spaced upright support members  21  that are mounted on rails  22  on the factory floor. The space between the rails  22  is called the workzone  15 . The form or tool  16  is positioned in the workzone  15 . A vertical Z-axis column  23  is supported on the horizontal beam  18 . The positioner  12  is able to move horizontally in the X-axis along the rails  22 , the column  23  is able to move horizontally in the Y-axis across the gantry beam  18 , and the column  23  is able to move vertically in the Z-axis, thus giving the head  14  motion in the X, Y, and Z-axes. The horizontal beam  18  extends beyond at least one of the spaced upright support members  21  so that the vertical column  23  can be positioned over a docking zone  25 , outside of the workzone  15 . One or more docking stations  26  are located in the docking zone  25 . Each docking station  26  has assigned to it a head  14 . Each of the heads  14  may be capable of performing different functions relating to a composite placement process. Docking stations  34  may also be located at one or both ends of the workzone  15 . 
         [0021]      FIG. 2  shows that the head  14  is mounted on a wrist  30  that is supported on the lower end of the Z-axis column  23 . The wrist comprises an I-axis turntable  31  that is coupled to the lower end of the column  23 , a J-axis yoke  32  that is coupled to the I-axis turntable  31 , and a K-axis yoke  33  that is supported by the J-axis yoke  32 . The I-axis turntable  31  allows the head  14  to pivot about an I-axis that is parallel to the X-axis of the machine, the J-axis yoke  32  allows the head  14  to pivot about a J-axis that is parallel to the Y-axis of the machine, and the K-axis yoke  33  allows the head  14  to pivot about a K-axis that is parallel to the Z-axis of the machine. The wrist  30  contains the necessary motors, gears, and drives to rotate the wrist about the I, J, and K axes. The linear motion of the gantry in the X, Y, and Z-axis, and the rotary motion of the wrist around the I, J, and K axis provide the positioner with six axes of motion. The motion of the gantry  12  and the head  14  may be controlled by an operator at a control panel  35 , or by CNC located in the control panel  35 . 
         [0022]    The head  14  can take several forms; a head that applies wide composite tape reeled with backing paper to a tool  16 , a head that applies composite fiber towpreg (⅛″, ¼″, ½″) to a tool, an ink jet marking head for ply placement checking and referencing, a ply perimeter trimming head comprising an ultrasonic or other type of ply cutter, a head with suction cups or other ply engaging device for ply placement onto a tool, a ply filler head for small precut pieces placement that are reeled with backing film, and other types of heads which may be required in for composite material lay-up. The head  14  shown in  FIG. 2  is a tape laying head that carries a supply of tape  40  on one or more reels on the head. 
         [0023]    An upper coupling plate  36  is mounted after the sixth primary axis (the K-axis) of the six-axis positioner on the lower end of the K-axis yoke  33 . A lower coupling plate  37  is mounted on the upper frame  38  of the head  14 , and the upper and lower coupling plates  36 , 37  couple together by means of mechanical clamps (not shown) to mount the head  14  to the wrist  30 . The upper and lower coupling plates  36 , 37  are a type of quick release clamping ring, and together form a docking point where a head  14  may be quickly detached from the positioner  12 . The upper and lower coupling plates  36 , 37  have separable connectors  39  for utilities and signal connections so that electrical power, pneumatic power, and signals from the wrist  30  can be coupled to the head  14  when the head is mounted on the end of the wrist. The lower coupling plates  37  for all of the heads are the same, allowing all of the heads to be coupled to the end of the wrist  30  without changing coupling hardware. 
         [0024]      FIG. 3  shows a head  14  positioned in a docking station  63 . The docking station is live meaning that is able to connect electrical power, pneumatic power, and signals to the head  14  as explained more fully below. The docking station comprises four legs  41  which form a base that rests on the floor  19 , and the base supports two shoulder portions  42 . A support bar  43  is mounted on each shoulder portion  42 . Two sides of the lower coupling plate  37  that is mounted on the head  14  have support flanges  44  that extend outward from the lower coupling plate  37 . The support flanges  44  on the lower coupling plate  37  rest on the support bars  43  so that the head can be suspended from the shoulders  42  of the docking station  63 . A utilities arm  46  with a maintenance plate  47  is mounted on the top of the docking station  63 . The utilities arm  46  contains electrical power, pneumatic power, and signal conductors that are connected to the maintenance plate  47 . The head  14  shown in  FIG. 3  is a fiber placement head that carries spools of fiber  45  on one or more spindles on the head. 
         [0025]      FIG. 4  shows motion of the gantry column  23  beyond one of the spaced upright support members  21  so that the gantry column  23  is positioned over the docking zone  25 . In  FIGS. 4-6 , the docking stations have been assigned reference numbers  61 - 64 , and the heads that are supported by the docking stations  61 - 64  have been assigned reference numbers  51 - 54 , respectively. Arrows show the motion of the gantry to position a first head  51  so that it can be docked at the first docking station  61 . Once the head  51  is vertically aligned with a space between the first docking station  61  and an adjacent docking station, the column lowers along the Z-axis until lower coupling plate  37  on the first head  51  is slightly above the height of the support bars at the first docking station, and the head then is moved horizontally into the space between the two shoulders  42  of the first docking station. The column  23  then lowers until the lower coupling plate  37  on the first head  51  is resting on the support bars  43  on the first docking station  61 . The clamps on the upper and lower coupling plates  36  and  37  release so that the column  23  can be raised, leaving the first head  51  in the first docking station  61 . In another embodiment of the invention, the head  51  is vertically aligned over the docking station  61  and the column  23  then lowers the head into docking station  61  without a second horizontal move. In this embodiment, the head must be dimensioned to fit between the shoulders  42  of the docking station so that it can be lowered directly into the docking station. 
         [0026]      FIG. 5  shows motion of the gantry mechanism  12  along the X-axis to a third docking station  63  in the docking zone  25 . The gantry travels along the X-axis until the upper coupling plate  36  is aligned with a third head  53  in the third docking station  63 . The column  23  then lowers so that the upper coupling plate  36  on the lower end of the K-axis of the wrist  30  contacts the lower coupling plate  37  on the third head  53 . The clamps on the upper and lower coupling plates are activated and the third head  53  becomes attached to the wrist  30 . The lower coupling plate  37  for each head is the same so that each head can mate to the same upper coupling plate mounted on the lower end of the K-axis. 
         [0027]      FIG. 6  is a detail view showing motion of the gantry column to remove the third head  53  from the third docking station  63 . The column  23  raises slightly to lift the head off of the support bars  43  on the docking station, and the gantry  12  with the column moves in the X-axis to move the head horizontally until the head  53  can be raised without interference from the structure of the docking station  63 . The gantry  12  then moves the head into the workzone  15  to continue with the composite manufacturing process. 
         [0028]      FIG. 7  is a detail view showing the utilities arm  46  and maintenance plate  47  in a standby position. From this position, the utilities arm  46  can be swung to a position so that the maintenance plate is in vertical alignment with the lower coupling plate  37  that is mounted on the head  14 . The maintenance plate  47  and then lowered from the end of the utilities arm until it contacts the lower coupling plate  37  as shown in  FIG. 8 . 
         [0029]      FIG. 8  shows the maintenance plate  47  mated to the lower coupling plate  37 . In this position, the separable connectors  39  around the perimeter of the maintenance plate  47  and the lower coupling plate  37  mate with one another. The maintenance plate  47  couples utilities and signals from the control panel  35  to the lower coupling plate  37  so that the head  14  can be powered up and run for testing or maintenance purposes. When it is desired to remove a head  14  from a docking station  26  to mount the head on the six-axis positioner  12 , or for any other purpose, the maintenance plate  47  is raised out of contact with the lower coupling plate  37  and swung to the side of the lower coupling plate as shown in  FIG. 7 . 
         [0030]    In operation, the head  14  is able to separate from the wrist  30  and be docked for maintenance and repair purposes at a docking station  26  that is located within the reach and travel of the gantry manipulator. Once a first head is removed from the machine and docked, it can be replaced with a second head so that the gantry machine can quickly switch between tape laying and fiber placement lamination process, or other material lamination processes that are supported by the several forms of the head. The docking point formed by the upper and lower coupling plates  36 ,  37  where the heads  14  quickly detach from the machine is after the sixth primary axis of the gantry manipulator  12 . The heads have none of the six primary machine axes built into them, thus reducing detached head cost and complexity. All the drive components necessary for the six gantry axes remain with the gantry when any of the heads are removed and stored in a docking station. The live docking stations support the detached heads while the six-axis gantry is laying the composite material or performing some other function relating to the lay-up process with the attached head, increasing the efficiency and throughput of the system. The live docking stations allow access to the heads for material replenishment and maintenance. 
         [0031]    The composites system described above saves considerable cost in equipment, infrastructure and labor cost traditionally needed for two separate tape and fiber systems, making it ideal for suppliers and manufacturers who require cost economy and flexible capabilities. The system makes it possible for fabricators to consider combining composite CTL grade tape and fiber towpreg in the same part. 
         [0032]    Having thus described the device, various modifications and alterations will be apparent to those skilled in the art, which modifications and alterations are within the scope of the device as defined by the appended claims.