Abstract:
A fiber placement system is provided. The fiber placement system provides a plurality of working zones relative to a common gantry system. Such a configuration permits for the use of one working zone while another working zone is loaded/unloaded with parts. Also provided is a method for manufacturing composite parts using a fiber placement system having a plurality of working zones arranged relative to a common gantry.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 62/126,828, filed Mar. 2, 2015, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention generally relates to manufacturing equipment, and more specifically to fiber placement machinery. 
       BACKGROUND OF THE INVENTION 
       [0003]    Automated fiber placement machines are nowadays widely used to manufacture parts, components, and structures from composite materials. These systems typically comprise a fiber placement head carried out in space by a multi-axis positioner, with the head responsible for laying up carbon fiber composite onto a stationary mold. 
         [0004]    The materials used in automated fiber placement heads are typically composed of unidirectional carbon fibers pre-impregnated into a resin that appears as tapes, or thin strips, commonly known as “tows.” 
         [0005]    Each head is usually capable of laying and compacting a plurality of tows of a determined dimension (such as ⅛″, ⅜″, ½″, etc.) arranged side-by-side to form a “ply” or “course” over and onto a tool. The head usually has all means to lay-up the tows/tape automatically such as a compaction roller, means to individually cut or add each tow whenever required, as well as means to heat up the tows/tape and/or the substrate zone to ensure sufficient tack for tow/tape adhesion. The head is also automatically fed by an integrated tow magazine (referred to as a “creel”) which supplies the tow/tape in an organized array and with a correct tension. 
         [0006]    In order to achieve flexibility, usually a CNC controlled positioner is capable of selectively and automatically picking up a desired head—creel assembly from a magazine and under instructions provided by suitable control means is capable of following a desired multiple-pass lay-up path onto a stationary or rotating mold duly anchored to ground. 
         [0007]    One of the most common positioner arrangements adopted is a gantry-type of machine travelling above a single working envelope located within the gantry travelling columns and extending longitudinally along the X-axis of the machine. 
         [0008]    One restricted portion of the positioner working area is usually used by the positioner to access to the heads&#39; magazine. Such a configuration, while recognized as allowing for the manufacture of parts within the working envelope, is limited to that single envelope. As a result, as parts are loaded and unloaded from the working envelope, the machine is idle. Unfortunately, this machine down time has led to inefficiencies, especially considering the growing demand for the rapid production of composite parts. As such, there is a need in the art for a fiber placement system with greater efficiency. 
         [0009]    The invention provides such a fiber placement system and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    In one aspect, embodiments of the invention provide a fiber placement system that utilizes a plurality of working zones relative to a common gantry. 
         [0011]    In another aspect, embodiments of the invention provide a method for manufacturing composite parts using a fiber placement system having a plurality of working zones arranged relative to a common gantry. 
         [0012]    Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0014]      FIG. 1  shows a tridimensional view of an exemplary embodiment of an Automatic Fiber Placement System (“AFPS”) according to the present invention with the head ready to operate in working zone I; 
           [0015]      FIG. 2  shows a tridimensional view of the AFPS of  FIG. 1  with the head ready to operate in working zone II; and 
           [0016]      FIG. 3  shows a tridimensional view of the AFPS of  FIG. 1  according to an alternative embodiment of  FIG. 1 , featuring a third working zone III, and a fourth working zone IV. 
           [0017]    While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Various embodiments of an automatic fiber placement system (“AFPS”) having a gantry-type positioner capable of operating in multiple working zones are provided. The AFPS is thus able to operate at a higher level of flexibility and efficiency. However, as will be recognized by those skilled in the art from the following description, such embodiments are provided by way of example only, not by way of limitation, and that all alternative embodiments are reserved herein. 
         [0019]    An embodiment of an AFPS  10  is provided in  FIG. 1 . The AFPS  10  features a gantry-type positioner  11 . The gantry-type positioner  11  generally includes two columns  12   a ,  12   b  supporting a cross-rail  14 . The columns  12   a ,  12   b  travel along tracks  16   a ,  16   b . The tracks  16   a ,  16   b  defines a linear axis of travel X for the gantry-type positioner  11 . Disposed on the linear axis X is a first working zone I. As depicted in  FIG. 1 , the working zone I includes a planar mold  18 . 
         [0020]    A vertical ram  20  is provided on the cross-rail  14 . The ram  20  travels along a track  22  that extends along a substantial portion of the cross-rail  14 . In embodiments, the track  22  extends beyond the cross-rail  14  as shown in  FIGS. 1-3 . The track  22 , thus, defines a second linear axis of travel Y for the ram  20 . As shown in  FIG. 1 , the cross-rail  14  extends past column  12   b  to position the ram  20  in a second working zone H. 
         [0021]    The ram  20  provides vertical movement for a fiber placement head  24  along a third linear axis of travel Z. Additionally, a machine wrist  25  operably coupled to the ram  20  provides a first rotational axis A that is perpendicular to the third linear axis Z. The machine wrist  25  also provides rotation about the third linear axis Z as shown by curved path C. 
         [0022]    The fiber placement head  24  is provided with fiber from a creel  26 . The creel  26  can be a climate controlled environment in certain embodiments, and the creel  26  stores a plurality of spools of fiber tow. Within the creel  26  are further components that assist in dispensing and directing the fiber tows to the fiber placement head  24 . The fiber tows have a width of, for example, ¼ inch to ⅜ inch, although any tow size is entirely possible. In an embodiment, the fiber placement head  24  and the creel  26  are part of a single modular assembly  27  such that the fiber tows can be quickly and easily replenished or exchanged during operation. 
         [0023]    The fiber placement head  24  performs the necessary operations to the fiber tows or mold to layup (also referred to as lay down) the fiber tows onto the mold (such as the planar mold  18 ). The fiber placement head  24  typically includes a compaction roller and other components used for fiber lay-up which may include heaters for heating the tows or the mold, visual inspection devices, tow cutters, etc. These additional components need not necessarily be part of the fiber placement head  24  and could be included as part of other structures, for instance, adjacent to the fiber placement head  24  or creel  26 . 
         [0024]    The gantry-type positioner  11  moves along the first linear axis X and the ram  20  moves along the second linear axis Y to position the fiber placement head  24  over the mold  18  in the first working zone I. The ram  20  moves the fiber placement head  24  along the third linear axis Z to layup the fiber tows on the mold  18 . During fiber layup, movement of the wrist  25  to provide rotation about the first rotational axis A and/or about the linear axis Z along path C may also be required such as for curved molds or for diagonal placement of the fiber on a mold. The fiber placement head  24  is manipulated in this way until the molded composite structure is complete. 
         [0025]    Conventionally, once the molded composite structure is complete, the gantry-type positioner would be idle while the working zone I is prepared for a new molded composite structure. However, using the present AFPS  10 , the ram  20  can be moved along the second linear axis Y parallel to the cross-rail  14  to the region outside the column  12   b  to the second working zone II as shown in  FIG. 2 . 
         [0026]    In  FIG. 2 , the second working zone II is a rotating mandrel  28  with a layup surface  30 . The rotating mandrel  28  has a headstock region  32  that provides rotation about a second rotational axis C 1  that is parallel to the first linear axis X As can be seen in  FIG. 2 , the fiber placement head  24  has been rotated via the machine wrist  25  about the first rotational axis A to apply fiber tows  33  to the layup surface  30 . The rotating mandrel  28  can be used to produce large composite parts such as, for instance, for a fuselage. As with the first working zone I, the rotating mandrel  28  can be loaded and unloaded while the fiber placement head  24  is operating in the first working zone I. Thus, providing just these two working zones I, II increases manufacturing flexibility of the AFPS  10  having a single gantry-type positioner  10 . 
         [0027]    However, further enhancements to manufacturing efficiency and flexibility can be achieved by adding additional working zones. As shown in  FIGS. 1 and 2 , a third working zone III is provided along the first linear axis X spatially disposed from the first working zone I. As depicted, the third working zone III provides multiple storage cradles  34  for additional modular assemblies  27  and/or other tools. Referring to  FIG. 1 , each modular assembly  27  has a clamping flange  36  that engages a clamping plate  38  on the machine wrist  25 . In this way, the modular assemblies  27  can be easily exchanged to replenish or replace the fiber tows, or the modular assembly  27  can be replaced with a different tool, such as a finishing tool, router, etc., to perform a different function on the composite material. 
         [0028]    The fiber tows in the additional modular assemblies  27  of the storage cradle  34  can be the same or different than the fiber tows in the in-use modular assembly  27 . The fiber tows can be different in size, thickness, or composition. For instance, the modular assemblies  27  in the storage cradle  34  can be thicker or thinner in width and/or thickness than the in-use modular assembly  27 . Further, the additional modular assemblies  27  can have fibers tows containing fibers of different sizes or containing resins of different types. Moreover, the creel  26  of the modular assembly  27  can provide different climate controlled environments for the fiber tows. Accordingly, the geometry and structure of the fiber placement head  24  can also vary by modular assembly so as to provide a variety of heaters for heating the tows or the mold, visual inspection devices, tow cutters, and the like. 
         [0029]    In a further embodiment depicted in  FIG. 3 , a fourth working zone IV is provided outside of the column  12   a  such that the cross rail  14  extends past both columns  12   a ,  12   b  along the second linear axis Y. Dashed lines are used in  FIG. 3  to depict a the region of the cross rail  14  extending beyond the column  12   a . The fourth working zone IV can provide any of a variety of suitable mold surfaces such as a horizontally or vertically arranged planar mold, a rotating mandrel, a concave or convex curved surface, etc. 
         [0030]    Also, as shown in each of  FIGS. 1-3 , an operator platform  40  is provided to control the movement of the gantry-type positioner  11  between the working zones I, II, III, and IV. 
         [0031]    All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0032]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0033]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.