WO2014094906A1

WO2014094906A1 - Height adjustment apparatus

Info

Publication number: WO2014094906A1
Application number: PCT/EP2012/076799
Authority: WO
Inventors: Paul FRAZER; Lynsey BOWMAN; Andrew JESS
Original assignee: Short Brothers Plc
Priority date: 2012-12-21
Filing date: 2012-12-21
Publication date: 2014-06-26

Abstract

A height adjustment apparatus (10) for an attractor (14) includes a frame (34), a motor (38) disposed on the frame, a spool (42) connected operably to the motor, and a cable (16) connected to the spool. The cable connects to the spool at a first end and to the attractor at a second end. Operation of the motor rotates the spool, thereby taking up or playing out the cable connected to the spool, permitting adjustment of a height of the attractor in at least a vertical direction.

Description

Height Adjustment Apparatus

Field of the Invention

[001] The present invention concerns the construction and operation of an apparatus designed to adjust the height of an associated fabric attractor, such as a fabric lifting suction cup. More specifically, the present invention concerns a device intended to assist with the lifting, manipulation, and transfer fabric from a transfer station to a mold. Even more specifically, the apparatus of the present invention is designed to assist with the lifting, manipulation, and transfer fabrics used to manufacture components made from composite materials, such as those employed for the construction of aircraft.

Description of the Related Art

[002] The prior art includes examples of several devices that may be employed to handle fabric materials. This includes woven and non-woven fabric such as flexible carbon fabric.

[003] By way of background, as should be apparent to those skilled in the art, for large, low volume composite components, hand lay-up remains the most common method for molding such composite components, which include items such as aircraft components, aircraft wings, aircraft fairings, boat hulls, wind turbines blades, and the like.

[004] The assembly of certain aircraft components, such as aircraft wings, involves the formation of complex, three dimensional geometries with multiple curvatures. To create these geometries, large pieces of carbon fiber fabric are employed together with stiffeners (also called stringers in aircraft) that are integrated into the wing skin. For a conventional hand layup, it is estimated that about an hour is required to handle about 15 kg (38.1 lb) of fabric material. Production time is therefore an issue.

[005] As should be apparent to those skilled in the art, manual processes are prone to error and may, in some instances, lack precise reproducibility. [006] It is known, for example, that manual handling of fabric materials may result in stretching or creasing of the fabric material. In addition, if gripping tools are used, the gripping tools may damage the fabric during handling, especially at the locations where the gripper tools are used. These deformations may adversely affect the ability to produce a composite component by increasing production times, especially if damaged fabric plies need to be removed and replaced prior to final formation of the composite component.

[007] By way of background, some prior art references describe the formation of composite structures relying on plies of carbon fiber fabric. Other prior art references rely on tapes (i.e., narrow strips) of composite materials that are applied in an overlapping pattern. It is the first of these two techniques that presents particular challenges to the manufacturer of composite components.

[008] U.S. Patent No. 6,343,639 (hereinafter "the '639 Patent") describes a machine for laying up fabric to produce a laminate. The machine includes a table 18 with a perforated upper surface 19. (The '639 Patent at col. 2, lines 59- 64.) Fabric is deposited onto the table 18 from a roll of fabric 30. (The '639 Patent at col. 3, lines 5-10.) A roller 48 is provided to pick up the fabric element, after being cut into the appropriate shape, using vacuum pressure. (The '639 Patent at col. 4, lines 28-37.) The shaped material is then transferred to a layup station 40, 42 where it is deposited. (The '639 Patent at col. 4, lines 38-46.)

[009] U.S. Patent Application Publication No. 2007/0187026 (hereinafter

"the '026 Application") describes a fabric handling apparatus and a method of composite manufacture. Here, the fabric is cut and shaped on a cutting table 1 10. (The '026 Application at paragraph [0023] .) The cut fabric may then be transferred from the cutting table 1 10 to a mold table 170 after being rolled up onto a vacuum actuated take up drum 130. (The '026 Application at paragraphs [0024] - [0025].)

[0010] U.S. Patent Application Publication No. 2011/0240213 (hereinafter

"the '213 Application") describes a method and device for laying and draping portions of reinforcing fiber structure to produce a profiled preform. The '213 Application relies on opposed roller conveyors 21, 22 to deposit fabric onto a core 19. (The '213 Application at paragraph [0053].)

[0011] U.S. Patent No. 8,088,236 (hereinafter "the '236 Patent") describes an apparatus and method for producing a large area fiber composite structural component. The apparatus includes a shaping element 1 onto which a nonwoven carpet 15 is deposited from nonwoven rolls 2, 3. (The '236 Patent at col. 6, lines 4-13.)

[0012] U.S. Patent No. 7,228,611 (hereinafter "the '611 Patent") describes a method of transferring a large uncured composite laminate from a male layup mandrel tool to a female cure tool. (The '611 Patent at the Abstract.)

[0013] U.S. Patent No 8,1 14,241 (hereinafter "the '241 Patent") describes a method for applying a vacuum bag around a fuselage barrel made of material to be polymerized. The sheet of bag material 30 is applied to the mandrel 10 as the mandrel rotates about a rotational axis. (The '241 Patent at col. 4, lines 1-6.)

[0014] U.S. Patent No. 7,611,601 (hereinafter "the '601 Patent") describes an automated layup system and method that relies on the application of multiple strips of fabric onto a layup mold or tool. (The '601 Patent at col. 4, lines 40-64.)

[0015] U.S. Patent No. 7,137,182 (hereinafter "the Ί82 Patent") describes an apparatus for forming a composite structure that relies on a plurality of material dispensers, arranged side-by-side, to deposit strips of material 62 onto a mold. (The ' 182 Patent at col. 4, lines 8-35.) The mold is positioned on a rotary turntable 80. (The Ί82 Patent at col. 3, lines 39-47.)

[0016] U.S. Patent Application Publication No. 2007/0277919 (hereinafter

"the '919 Application") describes a system and method for automatic monitoring of a composite manufacturing process. The process relies on laser light to assist with detection of edges, overlaps, gaps, wrinkles, and foreign object debris that may impact upon the manufacturing process. (The '919 Application at the Abstract.)

[0017] While each of the methods and apparatuses described above provide at least some solutions for automating the manufacture of fabric components, a desire remains for mechanical devices that automate the layup and handling of large plies of fabric materials.

[0018] Additionally, there is a desire for a mechanical device that may help to improve the reliability, accuracy, and repeatability of layup processes associated with the manufacture of components, such as aircraft components, from composite fabric materials.

[0019] In summary, there remains a need for a device that handles fabric materials, such as fabrics used in the manufacture of composite components, without crimping, folding, stretching, or otherwise changing the shape of the fabric material as it is being handled.

Summary of the Invention

[0020] The present invention addresses one or more deficiencies associated with the prior art.

[0021] In one contemplated embodiment, the present invention provides a height adjustment apparatus for an attractor that includes a frame, a motor disposed on the frame, a spool connected operably to the motor, and a cable connected to the spool. The cable connects to the spool at a first end and to the attractor at a second end. Operation of the motor rotates the spool, thereby taking up or playing out the cable connected to the spool, permitting adjustment of a height of the attractor in at least a vertical direction.

[0022] In a further embodiment, wherein the motor is a bidirectional, rotating motor.

[0023] The motor may be disposed on the frame such that an axis of rotation is substantially parallel to the vertical direction.

[0024] In another contemplated embodiment, the motor is a linear actuator.

[0025] It is contemplated that the frame may include a guide that directs the cable from a substantially horizontal disposition adjacent to the spool to a substantially vertical disposition adjacent to the attractor. [0026] It is also contemplated that the spool may be a worm gear, connected to the motor, permitting rotation of the worm gear.

[0027] Alternatively, the height adjustment apparatus of the present invention may include a spool housing encasing the worm gear. If so, the worm gear is contemplated to be disposed internally to the spool housing.

[0028] It is also contemplated that the apparatus of the present invention will include a conduit extending from a position adjacent to the frame to the attractor. If so, the attractor may be a suction cup, the height adjustment apparatus may include a suction source, and the conduit may connect the suction cup to the suction source.

[0029] In one embodiment, it is contemplated that the conduit may define a plurality of grooves on an exterior surface thereof. If so, at least one switch may be provided to generate signals indicative of the height of the attractor. Specifically, the switch may generate the signals at least partially due to interaction between the switch and the grooves on the exterior of the conduit.

[0030] Separately, the switch may operate independently of the grooves on the exterior of the conduit. Relying on an operation that should be understood by those skilled in the art, it is contemplated that the apparatus of the switch will be configured to generate one or more signals indicative of the height of the attractor by detecting one or more parameters associated with the height of the attractor.

[0031] In one contemplated embodiment, the switch may encompass a first switch and a second switch. If so, the first switch is contemplated to stop upward motion of the attractor when the attractor reaches near to a maximum height of the attractor. The second switch is contemplated to cooperate with the cable to stop downward motion of the attractor near to a minimum height of the attractor. In this arrangement, the first switch may be disposed on the frame and stops upward motion of the attractor when detecting the presence of the attractor adjacent thereto. The second switch may be disposed on the frame and stops downward motion of the attractor when detecting a slack condition of the cable. [0032] In a further contemplated embodiment of the present invention, the cable may be made from stranded fibers. The cable may be metal. Still further, the cable may be made from iron, alloys of iron, steel, copper, alloys of copper, aluminum, alloys of aluminum, natural fibers, aramid fibers, carbon fibers, cotton, silk, nylon, polyester, plastic, polypropylene, and polyethylene.

[0033] The apparatus of the present invention may rely for its operation on a suction source that establishes a vacuum. Alternatively, the suction source may provide a pressurized gas that is converted to suction for use by the attractor.

[0034] Still further features of the present invention should be appreciated from the drawings appended hereto and from the discussion herein.

Brief Description of the Drawings

[0035] The present invention will now be described in connection with the drawings appended hereto, in which:

[0036] Fig. 1 is a perspective illustration of a portion of a fabric handling array with which the height adjustment apparatus of the present invention is intended to operate;

[0037] Fig. 2 is a side view of five of the attractors illustrated in connection with the fabric handling array shown in Fig. 1, where the five attractors are aligned along a horizontal plane;

[0038] Fig. 3 is a side view of the five attractors that are illustrated in Fig.

2, where the respective heights of several of the attractors has been altered so that the attractors follow the surface features of a mold;

[0039] Fig. 4 is a perspective illustration of the height adjustment device of the present invention; and

[0040] Fig. 5 is a perspective illustration of a portion of the height adjustment device of the present invention.

Detailed Description of Embodiment(s) of the Invention

[0041] The present invention will now be described in connection with one or more embodiments. Discussion of any one particular embodiment is intended to be illustrative of the breadth and scope of the invention. In other words, while attention is focused on specific embodiments, those embodiments are not intended to be limiting of the scope of the present invention. To the contrary, after appreciating the discussion and drawings presented herein, those skilled in the art will readily appreciate one or more variations and equivalents of the embodiments described and illustrated. Those variations and equivalents are intended to be encompassed by the present invention as though they were described herein.

[0042] The modern manufacture of aircraft has recently departed from traditional reliance upon aluminum and aluminum alloys for the external components of the aircraft and moved to a greater reliance on composite materials. It is anticipated that future aircraft will rely even more heavily on components made from composite materials. The reason for this is simple: as a general rule, composite materials are stronger and lighter than their metallic counterparts and, at least for this reason, present engineering and design advantages over metals and their alloys.

[0043] Manufacture of components from composite materials, however, is not without its engineering challenges.

[0044] As should be apparent to those skilled in the art, and by way of background to the discussion that follows, the term "composite material" encompasses a broad category of different substances. In the context of aircraft manufacture, composite materials are understood to refer to fabrics made primarily from carbon fibers and resins. While the present invention is contemplated to encompass carbon fiber fabrics, the present invention is not intended to be limited thereto. Other fabrics used in the manufacture of composite components are also intended to be encompassed by the scope of the present invention. For example, the present invention includes, but is not limited to, materials incorporating aramid fibers, ceramics, glass, and related compounds, either now known or developed in the future. Moreover, fabrics that combine different compounds and materials together also are intended to be encompassed by the present invention. [0045] As a general rule, fabrics fall into one of two categories. The first category is woven fabrics. Woven fabrics encompass those that are made from threads of composite materials. Woven fabrics have a weft and weave, as should be apparent to those skilled in the art. These materials are similar to cloth made from other fibrous materials, such as cotton. The second category is non-woven fabrics. Non-woven fabrics encompass those that are not made from threads woven together. Typically, non-woven fabrics combine a plurality of fibers that are randomly intertwined to form a batt or alternatively, aligned in a particular direction. These materials are sometimes known as having uni- directional or uni- axial fibers.

[0046] As should be apparent to those skilled in the art, when constructing an aircraft component, after multiple layers of fabric are layered onto one another in a predetermined orientation, a resin or other type of matrix material is used to bind the fabric layers to one another. Matrix materials include, but are not limited to, resins, epoxy materials, nylon, polyester, polypropylene, ceramics, and the like.

[0047] In the art, it is known that the fabric may be pre-impregnated with a matrix material, such as resin. Such fabrics are often referred to as "prepreg" fabrics. Alternatively, the fabric may be a "dry" fabric, meaning that the fabric is not pre-impregnated with the matrix material, such as resin.

[0048] In either case, it is generally recognized that the matrix material will be introduced into the fabric and cured, typically using pressure and heat to create the composite material component. Once cured into a hardened component, the hardened component may be further machined to fabricate the aircraft part.

[0049] One process employed for manufacturing and curing a composite fabric structure is known to those skilled in the art as "Resin Transfer Infusion" or "RTL" Other processes also are known in the art, and the present invention is not intended to be limited to RTL

[0050] As also should be apparent to those skilled in the art, regardless of the type of fabric employed for the construction of an aircraft component (i.e., a prepreg or a dry fabric), construction techniques using those fabrics tend to fall within two general categories. A first approach to the manufacture of aircraft parts relies on the repetitive application of layers of fabric strips, including what is commonly referred to as "strips" or "tow." In this method of manufacture, the strips are applied to the surface of a mold, following a predetermined pattern. In a second approach to the manufacture of aircraft components, sheets of fabric, cut into predetermined shapes, are laid over one another in a predetermined pattern and arrangement. In either technique, the orientations of the fibers in the layers typically are altered from layer to layer. With each layer having a slightly different orientation, the strength of the aircraft component is maximized in many directions.

[0051] With respect to the manufacturing method that relies on the use of fabric strips, the strips are usually dispensed from a roll. In particular, as the roll of strips passes over the surface of the mold, a single layer of the fabric strips are dispensed onto the mold in parallel lines. The orientation of the roll may be altered for each successive application of the strips to vary the directional orientation of the composite fibers.

[0052] The second manufacturing method relies primarily on human manipulation of the fabric. Specifically, individual pieces of material are first shaped by means of a cutting machine or other method and then positioned on the mold in the correct orientation. It is, of course, possible to employ one or more mechanical devices to position pieces of pre-cut fabric in a suitable orientation for formation of the aircraft component. It is with this second manufacturing method, in particular an automated process therefor (or at least partially automated), that the present invention concerns itself.

[0053] When mechanical devices pickup and carry a piece of fabric to lay the fabric on a mold in a predetermined orientation, it is preferred for the fabric to be deposited on the mold so that the fabric is positioned properly and so that the fabric is not deformed, folded, or otherwise distorted. As should be apparent, when the fabric is deposited so that the fabric is in the correct orientation and without distortions, the layers of fabric will properly form the final composite structure after introduction and/or hardening of the matrix material.

[0054] As should be apparent from the discussion of the related art, many automated devices rely on vacuum rolls to pick up and transfer composite fabric from one location to another.

[0055] The present invention provides a height adjustment device 10 that is intended to cooperate with a fabric handling array 12 for the pickup of composite fabrics from a first location (such as a layup table, where cutting may or may not occur) with the purpose of transferring the fabric to a second location (such as a mold). Before describing the details of the height adjustment device 10, a discussion of the fabric handling array 12 is provided.

[0056] The fabric handling array 12 includes a plurality of fabric attractors

14 that are arranged in a grid pattern as illustrated in Fig. 1. The attractors 14 are arranged along an x-y plane 18, at least in an inactive state or an initial position.

[0057] The attractors 14 are contemplated to be suction cups or any other form of gripping media that are suspended from the height adjustment devices 10 via cables 16. Gravity g acts upon the attractors 14, which causes the attractors 14 to hang from their respective height adjustment devices 10. The height adjustment devices 10 act upon the cables 16 to change the height of the attractors 14 along the z-axis. The z-axis is parallel to (or at least substantially parallel to) the force of gravity g.

[0058] The cable 16 is contemplated to be made from a light-weight material such as an aramid fiber, carbon fiber, or any suitable equivalent. Alternatively, the cable 16 may be made from a metal, such as iron, alloys of iron, steel, copper, alloys of copper, aluminum, and alloys of aluminum, among many possible alternative materials. In a further alternative, the cable 16 may be made from a natural material, such as silk or cotton, to name a few natural fibers typically manufactured into threads, strings, and cables. Still further, the cable 16 may be made from any of a number of manmade materials such as nylon, plastic, polypropylene, and polyester. [0059] With respect to the illustrated embodiment, it is contemplated that the cable 16 will have a stranded construction. In other words, it is contemplated that the cable 16 will include a number of separate filaments (or threads) that are stranded together. Of course, it is also possible that the cable 16 may be made from a single filament of a selected material without departing from the scope of the present invention.

[0060] Since gravity g pulls the attractors 14 downward toward the ground, the weight of each of the attractors 14 pulls the associated cable 16 taut.

[0061] As noted, the attractors 14 are contemplated to be suction cups. However, the attractors 14 may be electrostatic devices or any other suitable equivalent. Mechanically operated attractors 14 also may be employed to handle the composite fabric 20. Regardless of the type of attractor 14 employed, the attractors 14 are contemplated to grip onto the composite fabric 20 without damaging or otherwise distorting the composite fabric 20.

[0062] Fig. 2 is a graphical, side view of five of the attractors 14 that are part of the fabric handling array illustrated in Fig. 1. To facilitate discussion of individuals ones of the attractors 14, the attractors are labeled 14A - 14E in this illustration. The five attractors 14A - 14E are aligned with respect to the x-y plane 18, which is shown by the line 18. Since the attractors 14A - 14E are aligned with respect to the x-y plane 18, the fabric 20 attached to the attractors 14 also is held in a planar configuration parallel to the x-y plane 18.

[0063] Fig. 3 is a graphical, side view of the five attractors 14A - 14E that are illustrated in Fig. 2. Here, the heights of the attractors 14A, 14B, 14D, and 14E have been adjusted to that the attractors 14A - 14E are disposed along an arcuate (or curved ) plane 22, which is shown by the line 22. Since the attractors are disposed along an arcuate (or curved) plane 22, the fabric 20 assumes the same arcuate (or curved) shape.

[0064] It is noted that the x-y plane 18 is flat (i.e., has no curvature), which is consistent with the surface of a layup table (where cutting may or may not occur) onto which the fabric 20 may be placed prior to being transferred to a mold (not shown). The fabric 20 may be a sheet having any predetermined shape and size.

[0065] Since the arcuate plane 22 has a curved surface configuration, the heights 24 A, 24E of the attractors 14A, 14E are lower than the heights 24B, 24D of the attractors 14B, 14D. Similarly, the height 24C of the attractor 14C is higher than the heights 24 A, 24B, 24D, 24E of each of the remaining attractors 14 A, 14B, 14D, 14E. For simplicity, the heights 24A - 24E of the attractors 14A - 14E is measured by comparison with the x-y plane 18, which is considered the initial state for the actuators 14A - 14E.

[0066] As should be apparent, the arcuate plane 22 represents one possible surface feature that may be presented to the attractors 14 by the surface of the mold. As should be apparent to those skilled in the art, a mold for an aircraft wing, for example, will present a complex set of different surface configurations or contours to which the plurality of attractors 14 are required to adapt before depositing the fabric 20 thereon.

[0067] With continued reference to Figs. 2 and 3, it is noted that adjacent ones of the attractors 14 are connected to one another via connectors 26. The connectors 26 maintain the attractors 14 in relation to one another in the x-y plane 18 or in the arcuate plane 22. The connectors 26 limit a differential in the height 24 between adjacent ones of the attractors 14 to within a predetermined range. This prevents the height 24 of any one attractor 14 from departing radically from the height 24 of any adjacent attractor 14. The connectors 26 assure a smooth transition from one attractor 14 to the next and, accordingly, assure a smooth contouring of the fabric handling array 12 across the surface of the mold.

[0068] As should be apparent, the connectors 26 ensure that the three- dimensional distance between adjacent attractors 14 remains substantially constant. In other words, the connectors 26 establish a substantially constant positional relationship between the attractors 14. In this regard, the connectors 26 are considered to exhibit substantially no elongation or compression properties. If the connectors 26 were permitted to stretch or compress, a substantially three- dimensional distance between adjacent attractors 14 would be more difficult to maintain.

[0069] In the embodiment illustrated in Figs. 1 and 2, the connectors 26 are contemplated to be rigid rods 28 that are connected to the attractors 14 via ball joints 30. In the embodiment illustrated in Fig. 3, the connectors 26 are considered to be flexible rods 32 that flex with the adjustment of the fabric handling array 12. As in the prior embodiment, the flexible rods 32 are substantially incompressible and/or substantially inelastic. As a result, the length of the flexible rods 32 remains substantially constant (i.e., no elongation or compression), thereby maintaining a substantially constant three-dimensional distance (or spacing) between adjacent ones of the attractors 14. It is noted that the exact construction and connection of the connectors 26 is not critical to the present invention.

[0070] In this regard, while the connectors 26 are illustrated as rod-like structures that connect the attractors 14 to one another, the connectors 26 may be part of a mat that connects the attractors 14 to one another. Specifically, the attractors 14 may be incorporated into a two-dimensional plane of flexible material. The continuous mat would then form connectors between individual attractors 14 that are planar in nature. As before, the mat is contemplated to be substantially incompressible or substantially inelastic to discourage lateral movement of the attractors 14 with respect to one another. Still further, the mat may define regions (as in the case of a plurality of electrostatic attractors) that define individual ones of the attractors 14. In other words, the attractors 14 need not be components that are separable from the mat.

[0071] The height adjustment device 10 (or height adjuster 10) of the present invention will now be described in connection with Figs. 4 and 5.

[0072] Fig. 4 is a perspective illustration of one contemplated embodiment of the height adjuster 10 according to the present invention. As illustrated in Fig. 4, the height adjuster 10 includes a frame 34 to which a motor housing 36 is connected. The frame 34 is contemplated to attach to a frame (not shown) from which the fabric handling array 12 is suspended. [0073] The motor housing 36 includes at least one motor 38. The motor

38 is connected to and rotates a spool 42. In the current embodiment, the spool 42 is a worm gear. It should be apparent, however, that the spool 42 may be any element on which wire can be wound or unwound for distribution or use.

[0074] The motor 38 is contemplated to be a two-way motor (or bidirectional motor), permitting rotation in either direction around a motor axis. As should be apparent from Figs. 4 and 5, the motor axis is aligned vertically. This means that the motor axis is parallel to the direction of the force of gravity. It is noted, however, that the motor axis may be disposed horizontally without departing from the scope of the present invention. Still further, the motor axis may be disposed at an angle with respect to vertical, if required or desired. Therefore, while the motor axis is vertically disposed in the illustrated embodiment, the motor axis may deviate from vertical without departing from the scope of the present invention.

[0075] A worm gear or spool 42 is disposed within a spool housing 40.

An enlarged detail of the worm gear or spool 42 is provided in the insert in Fig. 4. As illustrated, the cable 16 wraps around the spool 42 within (i.e., inside of) the housing 40.

[0076] A conduit carrying a tube 44 or other suction power source delivery element extends between the frame 34 and the attractor 14. The cable 16 extends from the spool 42, makes a ninety degree turn through a guide 46, and connects to the attractor 14. A switch 48 also is disposed on the frame 34. In the illustrated embodiment, the switch 48 is designed, in a first instance, to make contact with the top surface of the attractor. In a second instance, the switch 48, which is positioned adjacent to the cable, is actuated when the cable 16 becomes slack. In other words, the switch 48 is activated by two events. When the attractor 14 come into contact with the switch 48 at the top end of the attractor' s travel distance, the switch 48 is activated and the motor 38 is stopped. At the other extreme, when the attractor 14 comes into contact with the surface of the mold and the cable 16 becomes slack, the switch 48 detects the slack condition of the cable 16 and stops the motor 38. [0077] As should be apparent, the switch 48 need not be a single switch.

To the contrary, the switch 48 may include two switches, one to detect the uppermost position of the attractor 14 and the other to detect the lowermost position of the attractor 14. In a further contemplated embodiment, the switch 48 may include more than two switches, as required or as desired.

[0078] As illustrated in Fig. 4, the conduit 44 is connected to a suction (or vacuum) source 52. In this embodiment the conduit houses an air delivery pipe. Via the conduit 44, a power source (in this case compressed air) is applied to the attractor 14, in the form of a suction cup, at the bottom end of the conduit 44.

[0079] In the illustrated embodiment, the suction cup 14 converts a compressed air source into a vacuum. In other words, a pressurized gas, such as air, is converted to suction via a suitable device, such as a Coanda bellows or other suitable component. As should be apparent, however, the suction cup 14 may be connected directly to a vacuum source.

[0080] Fig. 5 is an enlarged detail of the frame 34, motor housing 36, spool housing 40, and worm gear 42 that are illustrated in Fig. 4. As in Fig. 4, the worm gear 42 is shown exterior to the spool housing 40 for clarification. In addition, a portion of the spool housing 40 is shown as having been removed to illustrate the worm gear 42 therein.

[0081] The operation of the height adjuster 10 will now be described.

[0082] It is noted that each height adjuster 10 is contemplated to operate independently from each other height adjuster 10. This permits the height adjusters 10, when connected to the fabric handling array 12, to establish any suitable configuration for the attractors 14 making up the fabric handling array 12. As a result, it is possible to conform the fabric handling array 12 to any mold shape, permitting the deposition of the fabric 20 thereon without any folds, creases, or other distortions that might interfere with the formation of the composite aircraft component.

[0083] As should be apparent from the foregoing, to adjust the height 24 of one or more of the attractors 14, the motor 38 is activated to rotate the worm gear 42 in one of two directions. In a first rotation direction, the worm gear 42 takes up the cable 16, thereby shortening the cable 16 and increasing the height 24 of the attractor 14 with respect to a reference plane, such as the x-y plane 18. In a second rotation direction, the worm gear 42 plays out the cable 16, thereby lengthening the cable 16 and decreasing the height 24 of the attractor 14. In this embodiment the computer-controlled stepper motor 38 is used to provide accurate and repeatable positioning for the attractor 14.The conduit containing the air (or vacuum) tube 44, which is connected to the frame 34 (or adjacent to the frame 34) at its top end and to the attractor 14 at its bottom end, moves together with the attractor 14. The switch 48, which is positioned to be in contact with the top surface of the attractor 14, generates a signal based on contact of the attractor with the switch 48. When the attractor 14 reaches its topmost position, the switch 48 generates a signal that is indicative of the attractor 14 reaching a fully retracted or home position. The switch48 (or a second switch 48) is positioned to contact the cable 16. The switch 48 is activated when the cable 16 becomes slack thereby generating a signal when the attractor 14 comes in contact with a surface such as the mold or pick up table.

[0084] As should be apparent, there are a number of variations that are contemplated for the various components described above.

[0085] For example, a worm gear 42 is not required for the height adjuster 10 of the present invention. Any other suitable motive component may be employed without departing from the scope of the present invention. A worm gear 42 has been selected for the illustrated embodiment because worm gears 42 permit small adjustments when connected to the motor 38. As a result, it is contemplated that a worm gear 42 will enhance the operation of the fabric handling array 12 by providing fine adjustment of the positions of the attractors 14.

[0086] In addition, the motor 38, which is contemplated to be a rotating motor, may be replaced by a suitable linear actuator without departing from the scope of the present invention. As should be apparent, the exact construction and operation of the motor 38 is not critical to the operation of the height adjuster of the present invention. In a further embodiment a linear actuator that is free running may be employed, thereby allowing the attractors 14 to naturally comply with the surface curvature of the mold or flat surface of the pick up table.

[0087] Next, it is noted that, while the spool housing 40 is provided to encase the worm gear 42 and, thereby, cooperate with the worm gear 42 motor 38 to take up and play out the cable 16, a spool housing 40 is not required for the present invention. Any suitable alternative may be employed without departing from the scope of the present invention. Moreover, where the height adjuster 10 incorporates a linear actuator, a worm gear 42 may not be needed at all. For purposes of the present invention, a linear actuator is considered a motor, as should be apparent to those skilled in the art. In other words, the term "motor" is not intended to refer solely to a rotary motor, such as the motor 38.

[0088] With respect to the worm gear 42, it is noted that any suitable alternative to the worm gear 42 may be employed without departing from the scope of the invention. Since the worm gear 42 acts as a spool to take up and let out the cable 16, the worm gear 42 is referred to generically as a spool 42 for purposes of the present invention.

[0089] As noted above, the present invention is described in connection with one or more embodiments thereof. The embodiments are intended to be illustrative of the breadth of the present invention. Focus on any one particular embodiment is not intended to be limiting thereof. The present invention, therefore, is intended to encompass variations and equivalents, as would be a p p r e c i a t e d b y t h o s e s k i l l e d i n t h e a r t .

Claims

What is claimed is:

1. A height adjustment apparatus for an attractor, comprising:

a frame;

a motor disposed on the frame;

a spool connected operably to the motor; and

a cable connected to the spool;

wherein the cable connects to the spool at a first end and to the attractor at a second end, and

wherein operation of the motor rotates the spool, thereby taking up or playing out the cable connected to the spool, permitting adjustment of a height of the attractor in at least a vertical direction.

2. The height adjustment apparatus of claim 1, wherein the motor is a bidirectional, rotating motor.

3. The height adjustment apparatus of claim 2, wherein the motor is disposed on the frame such that an axis of rotation is substantially parallel to the vertical direction.

4. The height adjustment apparatus of claim 1, wherein the motor is a linear actuator.

5. The height adjustment apparatus of claim 1, wherein the frame comprises a guide that directs the cable from a substantially horizontal disposition adjacent to the spool to a substantially vertical disposition adjacent to the attractor.

6. The height adjustment apparatus, wherein the spool comprises a worm gear, connected to the motor, permitting rotation of the worm gear.

7. The height adjustment apparatus of claim 6, further comprising:

a spool housing encasing the worm gear,

wherein the worm gear is disposed internally to the spool housing.

8. The height adjustment apparatus of claim 1, further comprising:

a conduit extending from a position adjacent to the frame to the attractor.

9. The height adjustment apparatus of claim 8, wherein:

the attractor is a suction cup,

the height adjustment apparatus further comprises a suction source, and the conduit connects the suction cup to the suction source.

10. The height adjustment apparatus of claim 8, wherein the conduit defines a plurality of grooves on an exterior surface thereof.

11. The height adjustment apparatus of claim 10, further comprising:

at least one switch to generate signals indicative of the height of the attractor,

wherein the at least one switch generates the signals at least partially due to interaction between the switch and the grooves on the exterior of the conduit.

12. The height adjustment apparatus of claim 1, wherein the cable comprises stranded fibers.

13. The height adjustment apparatus of claim 12, wherein the cable comprises metal.

14. The height adjustment apparatus of claim 12, wherein the cable comprises at least one selected from a group comprising iron, alloys of iron, steel, copper, alloys of copper, aluminum, alloys of aluminum, natural fibers, aramid fibers, carbon fibers, cotton, silk, nylon, polyester, plastic, polypropylene, and polyethylene.

15. The height adjustment apparatus of claim 1, further comprising:

at least one switch to generate signals indicative of the height of the attractor.

16. The height adjustment apparatus of claim 15, wherein the at least one switch comprises:

a first switch; and

a second switch,

wherein the first switch stops upward motion of the attractor when the attractor reaches near to a maximum height of the attractor; and

wherein the second switch cooperates with the cable to stop downward motion of the attractor near to a minimum height of the attractor.

17. The height adjustment apparatus of claim 16, wherein the first switch is disposed on the frame and stops upward motion of the attractor when detecting the presence of the attractor adjacent thereto.

18. The height adjustment apparatus of claim 16, wherein the second switch is disposed on the frame and stops downward motion of the attractor when detecting a slack condition of the cable.

19. The height adjustment apparatus of claim 8, wherein the suction source is a source establishing a vacuum.

20. The height adjustment apparatus of claim 9, wherein the suction source provides a gas that is converted to suction for use by the attractor.