Patent Description:
Composite layup involves forming layers of polymer-embedded fiber material into a specified shape to form an object. The polymer-embedded fiber material can be positioned manually or can be positioned automatically using an automated fiber placement machine. An automated fiber placement machine usually places the polymer-embedded fiber material as strips of material referred to as tows or fiber tows. A roller of the automated fiber placement machine rolls over each tow to compact the tow onto a mandrel or a previously placed layer to form the specified shape.

After one or more layers of the polymer-embedded fiber material are positioned as desired, a polymer of the polymer-embedded fiber material is hardened to secure the polymer-embedded fiber material in position. When the polymer includes a thermoset polymer, the polymer is usually cured by application of heat or ultraviolet light. If the polymer includes a thermoplastic polymer, the polymer is usually softened using heat and hardened by removing heat. High temperatures used to soften thermoplastic polymers can degrade polymer-based rollers. Degrading polymer-based rollers can leave residue on a surface of the polymer-embedded fiber material, which can cause delamination of one or more tows and a need to rework the object.

<CIT> describes, in accordance with its abstract, a fiber application head for a fiber application machine for the production of parts made of composite materials, comprising a compacting roller, said compacting roller comprising several independent roller segments mounted side by side on an axial rod. Each roller segment comprises a tubular central portion through which said segment is mounted on the axial rod, a tubular peripheral portion having a cylindrical outer surface and one or more curved spring plate arranged between the outer surface of the central portion and the inner surface of the peripheral portion.

<CIT> describes, in accordance with its abstract, a fiber application machine for the production of parts made of composite materials comprising a compacting roller for applying on an application surface a band formed of at least a resin pre-impregnated flat fiber, and a heating system able to emit a heat radiation towards the band. The compacting roller comprises a rigid central tube provided with radial holes, and a cylinder made of an elastically deformable, flexible material, assembled on the central tube, and having a fluid communication assembly that brings the radial holes into fluid communication with the external surface of the cylinder. The machine includes a thermal regulation system that injects a thermal regulation fluid in the central tube internal passage.

The invention to which this European patent relates is defined in the appended claims.

In a particular implementation, an automated fiber placement roller includes a flexible rim member arranged about a central axis. The flexible rim member has an inner side and an outer side, and the central axis is closer to the inner side than to the outer side. The automated fiber placement roller also includes a hub member arranged substantially concentric with the flexible rim member about the central axis. The hub member defines an opening to receive a shaft of an automated fiber placement machine. The automated fiber placement roller further includes a plurality of curved interconnect members extending between the hub member and the flexible rim member. Each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the flexible rim member. The automated fiber placement roller also includes one or more roller skin layers coupled to the outer side of the flexible rim member.

In another particular implementation, an automated fiber placement machine includes a fiber placement head including a roller and a shaft extending through a central opening of the roller. The roller is rotatable about the shaft and includes a flexible rim member arranged about the central axis. The flexible rim member has an inner side and an outer side, and the central axis is closer to the inner side than to the outer side. The roller also includes a hub member arranged substantially concentric with the flexible rim member about the central axis. The hub member defines the central opening. The roller further includes a plurality of curved interconnect members extending between the hub member and the flexible rim member. Each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the flexible rim member. The roller also includes one or more roller skin layers coupled to the outer side of the flexible rim member. The automated fiber placement machine also includes one or more actuators configured to adjust a relative position of the roller and a workpiece during addition of one or more fiber tows to the workpiece by the fiber placement head.

In a particular implementation, an automated fiber placement roller includes a cylindrical core having an outer side arranged about a central axis, a first edge, and a second edge. The cylindrical core defines a plurality of openings that extend between the first edge and the second edge. The outer side is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis. The automated fiber placement roller also includes a compliant layer including a first material coupled to the outer side of the cylindrical core. The automated fiber placement roller further includes an outer layer including a second material coupled to the compliant layer.

In another particular implementation, an automated fiber placement machine includes a fiber placement head including a roller and a shaft extending through a central opening of the roller. The roller is rotatable about the shaft and includes a cylindrical core having an outer side arranged about a central axis, a first edge, and a second edge. The cylindrical core defines a plurality of openings that extend between the first edge and the second edge. The outer side is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis. The roller also includes a compliant layer including a first material coupled to the outer side of the cylindrical core. The roller further includes an outer layer including a second material coupled to the compliant layer. The automated fiber placement machine also includes one or more actuators configured to adjust a relative position of the roller and a workpiece during addition of one or more fiber tows to the workpiece by the fiber placement head.

Particular implementations are described herein with reference to the drawings. In the description, common features are designated by common reference numbers throughout the drawings. In some drawings, multiple instances of a particular type of feature are used. Although these features are physically and/or logically distinct, the same reference number is used for each, and the different instances are distinguished by addition of a letter to the reference number. When the features as a group or a type are referred to herein (e.g., when no particular one of the features is being referenced), the reference number is used without a distinguishing letter. However, when one particular feature of multiple features of the same type is referred to herein, the reference number is used with the distinguishing letter. For example, referring to <FIG>, multiple actuators 116A and 116B are shown. When referring to a particular one of these actuators, such as the actuator 116A, the distinguishing letter "A" is used. However, when referring to any arbitrary one of these actuators or to these actuators as a group, the reference number <NUM> is used without a distinguishing letter.

As used herein, various terminology is used for the purpose of describing particular implementations only and is not intended to be limiting. For example, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the terms "comprise," "comprises," and "comprising" may be used interchangeably with "include," "includes," or "including. " Additionally, it will be understood that the term "wherein" may be used interchangeably with "where. " As used herein, "exemplary" may indicate an example, an implementation, and/or an aspect, and should not be construed as limiting or as indicating a preference or a preferred implementation. As used herein, an ordinal term (e.g., "first," "second," "third," etc.) used to modify an element, such as a structure, a component, an operation, etc., does not by itself indicate any priority, order, or position of the element with respect to another element, but rather merely distinguishes the element from another element having a same name (but for use of the ordinal term). As used herein, the term "set" refers to a grouping of one or more elements, and the term "plurality" refers to multiple elements.

In the present disclosure, terms such as "determining", "calculating", "generating", "adjusting", "modifying", etc. may be used to describe how one or more operations are performed. It should be noted that such terms are not to be construed as limiting and other techniques may be utilized to perform similar operations. Additionally, as referred to herein, "generating", "calculating", "using", "selecting", "accessing", and "determining" may be used interchangeably. For example, "generating", "calculating", or "determining" a parameter (or a signal) may refer to actively generating, calculating, or determining the parameter (or the signal) or may refer to using, selecting, or accessing the parameter (or signal) that is already generated, such as by another component or device. Additionally, "adjusting" and "modifying" may be used interchangeably. For example, "adjusting" or "modifying" a parameter may refer to changing the parameter from a first value to a second value (a "modified value" or an "adjusted value"). As used herein, "coupled" may include "communicatively coupled," "electrically coupled," or "physically coupled," and may also (or alternatively) include any combinations thereof. Two devices (or components) may be coupled (e.g., communicatively coupled, electrically coupled, or physically coupled) directly or indirectly via one or more other devices, components, wires, buses, networks (e.g., a wired network, a wireless network, or a combination thereof), etc. Two devices (or components) that are electrically coupled may be included in the same device or in different devices and may be connected via electronics, one or more connectors, or inductive coupling, as illustrative, non-limiting examples. In some implementations, two devices (or components) that are communicatively coupled, such as in electrical communication, may send and receive electrical signals (digital signals or analog signals) directly or indirectly, such as via one or more wires, buses, networks, etc. As used herein, "directly coupled" may include two devices that are coupled (e.g., communicatively coupled, electrically coupled, or physically coupled) without intervening components.

A particular aspect of the disclosure relates to a roller for automated fiber placement. The roller has one or more roller skin layers around a flexible core. For example, the roller skin layer(s) may include one or more polymer layers. The flexible core has airflow channels to facilitate removal of heat from the roller skin layer(s) of the roller. The roller is designed to withstand high temperatures and is flexible enough to be used to manufacture contoured parts.

In some implementations, the core is designed to enable low cost manufacturing of the core such as via injection molding, compression molding, or additive manufacturing processes (e.g., three-dimensional (3D) printing). For example, in implementation designed for additive manufacturing, various feature of the core are shaped and sized to be additively manufactured without the use of support structures that are subsequently removed. As another example, in implementations designed for compression molding or injection molding, internal voids may be omitted to enable use of simpler molds. Such implementations, limit post fabrication processing that would otherwise be needed, such as cleanup of support structures used in 3D printing. In some implementations, the core is a single unitary body formed of metal or one or more polymers.

In a particular implementation, the core is cylindrical with an outer side arranged about a central axis. The outer side is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis. The automated fiber placement roller according to the invention includes a flexible rim member, a hub member, and a plurality of curved interconnect members (also referred to herein as "interconnect members" for ease of reference) extending between the flexible hub member and the rim member. The interconnect members are configured to elastically deform responsive to force applied to the flexible rim member. The interconnect members also act as heat sinks to remove heat from the metallic rim member. To illustrate, the interconnect members define a plurality of openings that extend between a first end and a second end of the core. The openings between the interconnect members facilitate heat dissipation into the ambient surroundings or into a cooling medium (e.g., cooling air) blown through the openings.

The inner side of the flexible rim member includes a plurality of grooves to improve the flexibility of the flexible rim member (e.g., to reduce force required to elastically deform the flexible rim member). For example, the grooves can include axial grooves, circumferential grooves, or both. In some implementations, the flexible rim member and the interconnect members deform elastically responsive to forces up to <NUM> pounds of force applied to the outer side. In a particular implementation, the flexible rim member and the interconnect members deform elastically responsive to forces up to <NUM> pounds of force applied to the outer side.

One or more roller skin layers are coupled to the outer side of the flexible rim member. For example, the one or more roller skin layers include a compliant layer to improve compliance of the roller. To illustrate, the compliant layer may be designed to give the roller a specified Shore hardness (e.g., in a range between <NUM> and <NUM>). The one or more roller skin layers also include an outer layer coupled to the compliant layer. The outer layer has a high degradation temperature to resist degradation due to temperatures used to soften thermoplastic polymers during automated fiber placement. In some implementations, the roller skin layers also include a wear layer between the outer layer and the compliant layer to improve the durability of the compliant layer. In some implementations, an insulation layer is disposed between the roller skin layers and the flexible rim member.

In some implementations, the roller is able to withstand high temperature operation without degradation. For example, the roller does not soften or off-gas at temperatures consistent with softening of thermoplastic polymers, such as temperatures greater than <NUM> degrees Celsius (°C). In some implementations, materials used to form the roller are stable (e.g., are not damaged by) exposure to temperatures of at least <NUM> to <NUM>. Thus, in addition to being readily manufactured using molding or additive manufacturing techniques, the roller disclosed herein is not damaged by operating conditions that damage polymer-based rollers.

<FIG> is a diagram that illustrates an example of a system <NUM> for automated fiber placement according to a particular implementation. The system <NUM> includes an automated fiber placement machine <NUM> and a tooling surface <NUM>. The tooling surface <NUM> is a surface of a mold or mandrel upon which a workpiece <NUM> is fabricated using multiple layers of composite material. The composite material includes one or more fiber tows <NUM> applied to the tooling surface <NUM> by the automated fiber placement machine <NUM>. In some implementations, the fiber tows <NUM> are applied to form several layers (e.g., plies) of fibers to build up the workpiece <NUM> on the tooling surface <NUM>.

The automated fiber placement machine <NUM> includes one or more fiber placement heads <NUM>, one or more tow dispensers <NUM>, one or more actuators <NUM>, and one or more heat sources <NUM>. Each tow dispenser <NUM> is configured to provide fiber tows <NUM> to the fiber placement head(s) <NUM>. In a particular implementation, each tow dispenser <NUM> includes a reel of fiber tow material (e.g., fiber tape) and passively dispenses the fiber tow material. For example, the fiber placement head(s) <NUM> pull the fiber tow material from the reel as the fiber placement head <NUM> applies the fiber tows <NUM> to the workpiece <NUM>.

The one or more actuators <NUM> include one or more rotary actuators, one or more linear actuators, or combinations thereof, to move the fiber placement head <NUM> relative to the workpiece <NUM>, to move the workpiece <NUM> relative to the fiber placement head <NUM>, or both. The relative movement of the workpiece <NUM> and the fiber placement head <NUM> allows the fiber placement head <NUM> to apply the fiber tows <NUM> continuously over the tooling surface <NUM> or to particular target portions of the tooling surface <NUM> to build (or build up) the workpiece <NUM>.

The heat source(s) <NUM> are configured to direct heat <NUM> at one or more targeted portions <NUM> of the workpiece <NUM> or of the tooling surface <NUM>. In the specific implementation illustrated in <FIG>, the fiber tows <NUM> include a plurality of fibers coupled to or embedded within a thermoplastic polymer, and the heat source(s) <NUM> applies the heat <NUM> to the portion(s) <NUM> to soften the thermoplastic polymer to facilitate adhesion between the fiber tows <NUM> in different layers of the workpiece <NUM>. In some implementations, the heat source(s) <NUM> are configured to, during a fiber placement operation, heat portions of the workpiece <NUM> to a local temperature greater than <NUM>. For example, as the actuator(s) <NUM> move the fiber placement head <NUM> along a direction of travel <NUM> relative to the workpiece <NUM>, the heat source(s) <NUM> heat the portion(s) <NUM> ahead of one or more rollers <NUM> of the fiber placement head <NUM>. The roller(s) <NUM> apply the fiber tow(s) <NUM> to the workpiece <NUM> and apply a force <NUM> to consolidate layers of the workpiece <NUM>. In some implementations, the rate of relative motion between the workpiece <NUM> and the fiber placement head <NUM> can be controlled to cause the heat source(s) <NUM> to heat the portion <NUM> of the workpiece <NUM> to a working temperature that is greater than a glass transition temperature of a thermoplastic polymer of the fiber tows <NUM>. In some implementations, a power output of the heat source(s) <NUM>, an orientation of the heat source(s) <NUM>, or both, is controlled to cause the heat source(s) <NUM> to heat the portion <NUM> of the workpiece <NUM> to a working temperature that is greater than a glass transition temperature of the thermoplastic polymer.

Each fiber placement head <NUM> includes one or more shafts <NUM>. One or more rollers <NUM> are coupled to each shaft <NUM>. The roller(s) <NUM> are configured to press one or more fiber tows <NUM> onto the tooling surface <NUM> or onto a previously applied layer of the workpiece <NUM>. Each roller <NUM> includes a core <NUM> (e.g., a cylindrical core) that includes a flexible rim member <NUM>, a hub member <NUM>, multiple curved interconnect members <NUM> ("interconnect members") extending between the flexible rim member <NUM> and the hub member <NUM>. The roller(s) <NUM> also include one or more roller skin layers <NUM> coupled to the flexible rim member <NUM>. <FIG>, <FIG>, <FIG>, <FIG> illustrate examples of implementations of the roller(s) <NUM>.

The core <NUM> is cylindrical, and the hub member <NUM> includes a central opening <NUM> to receive the shaft <NUM> of the fiber placement head <NUM>. In some implementations, the roller <NUM> is freely rotatable about the shaft <NUM>. In some such implementations, the shaft <NUM> and the central opening <NUM> have a round cross-section, and a set of bearings are disposed between the shaft <NUM> and the hub member <NUM>. In other implementations, the roller <NUM> rotates with the shaft <NUM>. For example, the central opening <NUM> has a cross-section that is not round (e.g., keyed or square), and the shaft <NUM> has a corresponding shape to retain the roller <NUM>. In this example, the shaft <NUM> includes bearings, or the shaft <NUM> is driven to cause rotation of the roller <NUM> during operation.

The interconnect members <NUM> are curved to facilitate flexing (e.g., elastic deformation) along a length of each interconnect members <NUM> between the hub member <NUM> and the flexible rim member <NUM>. In a particular implementation, each of the interconnect members <NUM> defines an S-shaped curve in a radial direction (e.g., extending along a direction corresponding to a radius of the roller <NUM>). The roller <NUM> includes at least two interconnect members <NUM>, and generally includes eight or more interconnect members <NUM>. The interconnect members <NUM> are substantially evenly spaced apart circumferentially (e.g., in a direction corresponding to or along a circumference of the roller <NUM>). Spaces between the interconnect members <NUM> facilitate cooling of the roller <NUM>. For example, a coolant, such as air of an airflow <NUM>, can flow between and over the interconnect members <NUM> to remove heat from the roller <NUM>. In some implementations, such as illustrated in <FIG>, the hub member <NUM> includes an inner hub member and an outer hub member, and a plurality of openings are defined between the inner hub member and the outer hub member. In such implementations, a portion of the airflow <NUM> passes between the inner hub member and the outer hub member.

In some implementations, each of the interconnect members <NUM> includes a plurality of relief openings <NUM>. The relief openings <NUM> improve heat removal by increasing a surface area for contact with the airflow <NUM>. The relief opening <NUM> are also sized and shaped to adjust (e.g., tune) elastic deformation characteristics (e.g., stiffness) of the curved interconnect members <NUM>. For example, an interconnect member <NUM> can include many relatively small relief openings <NUM> along an interface with the flexible rim member <NUM> to facilitate small deformations due to local variations in force applied to the flexible rim member <NUM> (e.g., due to bumps in the surface of the workpiece <NUM>). In this example, the interconnect member <NUM> can also include a smaller number of relatively large relief openings <NUM> closer to the hub member <NUM> to adjust overall deformation characteristics of the interconnect member <NUM>.

The flexible rim member <NUM> includes an inner side <NUM> and an outer side <NUM>, where a central axis of the roller <NUM> is closer to the inner side <NUM> than to the outer side <NUM>. The roller skin layer(s) <NUM> are coupled to the outer side <NUM>. In some implementations, the flexible rim member <NUM> includes a plurality of grooves <NUM> to make the flexible rim member <NUM> more flexible (less stiff). In the example illustrated in <FIG>, the grooves <NUM> are formed on the inner side <NUM> of the flexible rim member <NUM>. In other examples, the grooves <NUM> are formed on the outer side <NUM> of the flexible rim member <NUM>. Having the grooves <NUM> on the outer side <NUM> of the flexible rim can facilitate adhesion of the roller skin layer(s) <NUM> to the outer side <NUM>. In still other examples, the grooves <NUM> are formed on both the inner side <NUM> and the outer side <NUM>.

Due to the flexibility of the core <NUM> and compliance of the roller skin layer(s) <NUM>, the flexible rim member <NUM> is able to flex to maintain contact between the fiber tows <NUM> and the workpiece <NUM> over curves of the workpiece <NUM>. In some implementations, the grooves <NUM> enable the flexible rim member <NUM> to flex in multiple directions. For example, the flexible rim member <NUM> is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis. The grooves <NUM> can include axial grooves <NUM>, circumferential grooves <NUM>, or both. In this context, "axial" means oriented in a direction that is parallel to or along a central axis of the roller <NUM>, and "circumferential" means oriented in a direction that is similar to (e.g., concentric with) a circumference of the roller <NUM>.

In the example illustrated in <FIG>, the roller skin layer(s) <NUM> include an outer layer <NUM>, a wear layer <NUM>, and a compliant layer <NUM>. An insulation layer <NUM> is disposed between the core <NUM> and the roller skin layer(s) <NUM>. In some implementations, the roller skin layer(s) <NUM> include polymeric materials, or a combination of polymeric and non-polymeric materials (e.g., non-polymeric materials in a polymer matrix). To illustrate, the compliant layer <NUM> may include glass fibers in a polymer aerogel matrix. Additionally, or alternatively, one or more of the roller skin layer(s) <NUM> may include a non-polymeric material. To illustrate, the outer layer <NUM> may include a release layer that is sprayed onto the wear layer <NUM> (or on the compliant layer <NUM> if the wear layer <NUM> is omitted).

The material of the compliant layer <NUM> and thickness of the compliant layer <NUM> are selected to give the roller <NUM> required compliance and degradation temperature for a particular application. Compliance of the roller <NUM> facilitates compaction of fiber tows in regions with surface irregularities, edges, valleys, or hills. In particular implementations, the material and thickness of the compliant layer <NUM> is selected to give the roller <NUM> a Shore A hardness of between <NUM> and <NUM>. Examples of materials that have sufficiently high degradation temperatures and appropriate hardness to form the compliant layer <NUM> include a high-temperature silicone polymer material or a fluoroelastomer polymer material. In a particular implementation, the compliant layer <NUM> includes fiberglass in an amorphous silica, methylsilylated silica aerogel matrix, such as a Pyrogel® XTF material, a Pyrogel® XTE material, or a Pyrogel® HPS material (Pyrogel is a registered trademark of Aspen Aerogels, Inc. of Northborough, Massachusetts, USA). In another particular implementation, the compliant layer <NUM> includes a silicone coated fiberglass material, such as a HI TEMP Welding Blanket available from W. Grainger, Inc. of Lake Forest, Illinois, USA. In another particular implementation, the compliant layer <NUM> includes a flexible, epoxy-based resin foam including graphene (e.g., graphene strips, platelets, or powder), such as a high heat tolerant graphene resin blend available from Ressinea of Houston, Texas, USA.

The wear layer <NUM> is coupled to the compliant layer <NUM> to reduce the direct heat exposure of the compliant layer <NUM>, to protect the workpiece <NUM> from byproducts of degradation of the compliant layer <NUM>, to reduce adhesion between the workpiece <NUM> and the roller <NUM>, or a combination thereof. For example, in a particular implementation, the wear layer <NUM> has a degradation temperature greater than or equal to <NUM> degrees Celsius. The wear layer <NUM> may include, for example, a fluorinated ethylene propylene polymer material, a perfluoroalkoxy alkane polymer material, or a graphene resin material.

In some implementations, the outer layer <NUM> corresponds to or includes a release layer to reduce adhesion between the workpiece <NUM> and the roller <NUM>. The outer layer <NUM> has a degradation temperature greater than or equal to <NUM> degrees Celsius. For example, the outer layer <NUM> may include a polybenzimidazole material or a high-temperature silicone polymer material. In some implementations, the outer layer <NUM> includes a thin sheet of the Pyrogel® XTF material, a Pyrogel® XTE material, or a Pyrogel® HPS material. When configured as a release layer, the outer layer <NUM> is relatively thin in comparison to the compliant layer <NUM>. For example, in some implementations, the outer layer <NUM> is applied on the roller <NUM> as a thin sheet, a spray, or a liquid.

Although <FIG> and <FIG> illustrate the roller skin layer(s) <NUM> as including three distinct layers, in other implementations, the roller skin layer(s) <NUM> include more, fewer, or different layers. For example, in some implementations, the wear layer <NUM> is omitted. Additionally or alternatively, the insulation layer <NUM>, the outer layer <NUM>, or both, may be omitted. In some implementations, the outer layer <NUM> and the compliant layer <NUM> are the same (e.g. one material is used for both layers). The specific arrangement of and materials of the roller skin layer(s) <NUM> are selected to ensure that the degradation temperature of the roller skin layer(s) <NUM> is compatible with process conditions present during application of fiber tow(s) <NUM> of the workpiece <NUM> and to ensure chemical compatibility between the portions of the roller skin layer(s) <NUM> that contact the workpiece <NUM> and materials of the workpiece <NUM>. In this context, chemical compatibility includes the roller skin layer(s) <NUM> not leaving chemical residue on the workpiece that degrades the durability of the finished workpiece <NUM>, causes rework of the inprocess workpiece <NUM>, or both. For example, the outer layer <NUM> may be omitted if the wear layer <NUM> and/or compliant layer <NUM> are sufficiently heat tolerant and not prone to leave significant chemical residue under process conditions. However, many materials that have the flexibility and durability to be used as the compliant layer <NUM> have relatively low degradation temperatures or tend to leave contaminants on the surface of the workpiece <NUM> during processing. Accordingly, the wear layer <NUM>, the outer layer <NUM>, or both, are used when the compliant layer <NUM> is formed of such materials. Additional considerations may also drive the selection of material used for the various roller skin layer(s) <NUM>, such as per-unit cost, surface reflectivity (e.g., when a laser is used at the heat source <NUM>), surface smoothness or release characteristics, tiered thermal limits, ease of repair and reusability of the roller(s) <NUM>, etc..

If present, the insulation layer <NUM> is disposed between the core <NUM> (e.g., between the outer side <NUM> of the flexible rim member <NUM>) and the compliant layer <NUM>. The insulation layer <NUM> reduces heat flow between the roller skin layer(s) <NUM> and the core <NUM>. For example, the insulation layer <NUM> may be used when the core <NUM> is formed of a polymer with a lower degradation temperature that the degradation temperature(s) of the roller skin layer(s) <NUM>. As another example, the insulation layer <NUM> may be used to limit heat removed via the airflow <NUM> in order to regulate a temperature of the roller <NUM>. To illustrate, while the fiber tows <NUM> are being applied by the roller <NUM>, a surface of the roller <NUM> that contacts the fiber tows <NUM> may be maintained at or above a processing temperature associated with the fiber tows <NUM>, such as great than or equal to a glass transition temperature of a polymer of the fiber tows <NUM>. The insulation layer <NUM> includes, for example, semi-crystalline polymers, carbon felt blankets or wraps, or fiberglass materials. Examples of materials that may be used for the insulation layer <NUM> include Dragon Sleeve® material, Dragon Blanket® material, and Volcano® Wrap material (Dragon Sleeved , Dragon Blanket®, and Volcano® are registered trademarks of Techflex, Inc. of Sparta, New Jersey).

In a particular implementation, the core <NUM> is a single unitary (e.g., monolithic) body that includes the flexible rim member <NUM>, the hub member <NUM>, and the interconnect members <NUM>. Additionally, in some implementations, respective edges of the flexible rim member <NUM>, the hub member <NUM>, and the interconnect members <NUM> are coplanar. For example, the flexible rim member <NUM> includes a first edge <NUM> and a second edge <NUM>, the hub member <NUM> includes a first edge <NUM> and a second edge <NUM>, and each of the interconnect members <NUM> includes a first edge <NUM> and a second edge <NUM>. In this example, the first edges <NUM>, <NUM>, <NUM> are aligned (e.g., coplanar) with one another. To illustrate, the roller <NUM> can be manufactured using an additive manufacturing process to build the roller <NUM> on a build platform. In this illustrative example, the first edges <NUM>, <NUM>, <NUM> can correspond to portions of the roller <NUM> that contact the build platform during the additive manufacturing process and are therefore coplanar with one another. In some implementations, the second edges <NUM>, <NUM>, <NUM> are also aligned (e.g., coplanar) with one another.

During operation of the system <NUM>, the heat source(s) <NUM> apply heat <NUM> to a portion <NUM> of the workpiece <NUM>, the tooling surface <NUM>, or both. The heat <NUM> is sufficient to soften a thermoplastic polymer of the fiber tows <NUM>. For example, the portion <NUM> may be heated to a temperature that is greater than or equal to a glass transition temperature of the thermoplastic polymer.

Concurrently with or after the heat source(s) <NUM> heat the portion <NUM>, the actuator(s) <NUM> move the fiber placement head <NUM> over the workpiece <NUM> or the tooling surface <NUM>. The actuator(s) <NUM> also apply a force to the fiber placement head <NUM> to press the roller(s) <NUM> into contact with the workpiece <NUM>. The roller(s) <NUM> press the fiber tow(s) <NUM> into contact with a surface of the workpiece <NUM>. While the roller(s) <NUM> are in contact with or sufficiently near the heated portion <NUM> of the workpiece <NUM>, the roller(s) <NUM> conduct heat away from the heated portion <NUM> to increase adhesion of the fiber tow(s) <NUM> to the heated portion <NUM>. Heat removed from the heated portion <NUM> by the roller(s) <NUM> can be removed from the roller(s) <NUM> by a coolant (e.g., air of the airflow <NUM>) flowing between the interconnect members <NUM>. Removing heat from the fiber tow(s) <NUM> using the roller(s) <NUM> can reduce subsequent processing. For example, a next layer of fiber tow(s) <NUM> can be added without delay (or with less delay) to allow for consolidation of the layers of the workpiece <NUM> (e.g., allowing the thermoplastic polymer to cool and harden).

The roller(s) <NUM> disclosed herein are able to withstand repeated use at high temperatures and with application of significant force <NUM> without degradation. For example, the roller skin layer(s) <NUM> have a degradation temperature that is greater than the temperature of the heated portion <NUM>. In this context, "degradation temperature" refers to a charring temperature, a glass transition temperature, a melting temperature, or another temperature at which one or more of the roller skin layer(s) <NUM> undergoes a phase change or a chemical reaction (e.g., oxidation) when exposed to conditions present during operation of the system <NUM>.

Further, in some implementations, the roller(s) <NUM> disclosed herein do not off-gas at high temperatures. In addition, the openings of the core <NUM> enable greater heat removal than can be achieved by solid core rollers. As such, using the roller(s) <NUM> can improve the fiber placement operation by removing some of the heat <NUM> as the roller(s) <NUM> press the fiber tows <NUM> to the workpiece <NUM>, which allows the thermoplastic polymer of the fiber tows <NUM> to cool and adhere to underlying layers of the workpiece <NUM> thereby reducing subsequent processing, such as consolidation and curing operations.

<FIG> is a diagram that illustrates an example of the system <NUM> for automated fiber placement of <FIG>. In <FIG>, a portion of the automated fiber placement machine <NUM> is shown as a robotic arm including a plurality of actuators <NUM>, including a first actuator 116A and a second actuator 116B. The fiber placement head <NUM> is coupled to an end of the automated fiber placement machine <NUM>. The fiber placement head <NUM> includes a roller <NUM>, a tow dispenser <NUM>, and a heat source <NUM>. In <FIG>, the heat source <NUM> includes a laser which directs the heat <NUM> toward the portion <NUM> of the workpiece <NUM> as a beam of light.

After the portion <NUM> of the workpiece <NUM> is heated by the heat source <NUM>, the automated fiber placement machine <NUM> moves the fiber placement head <NUM> along the direction of travel <NUM> and presses the roller <NUM> toward the workpiece <NUM>. The roller <NUM> presses a fiber tow <NUM> into contact with the workpiece <NUM> to form a layer on the workpiece <NUM>. The heat supplied by the heat source <NUM> softens a thermoplastic polymer of the fiber tow <NUM> as the fiber tow <NUM> is applied to the workpiece <NUM> and the roller <NUM> removes heat from the fiber tow <NUM> to harden the thermoplastic polymer to cause the fiber tow <NUM> to adhere to the workpiece <NUM>.

Although <FIG> illustrates the automated fiber placement machine <NUM> as a robotic arm, in other implementations, the automated fiber placement machine <NUM> is arranged in a different configuration. For example, the fiber placement head <NUM> can be mounted on a gantry system that includes the actuators <NUM>. Also, although <FIG> shows the fiber placement head <NUM> including a single roller <NUM>, in some implementations, the fiber placement head <NUM> includes more than one roller <NUM>. In such implementations, the rollers <NUM> can operation concurrently to apply multiple fiber tows <NUM> to the workpiece <NUM> at the same time. Further, although <FIG> and <FIG> show the fiber tows <NUM> being applied to the workpiece <NUM>, it should be understood that initial layers to form the workpiece <NUM> are applied to the tooling surface <NUM>. During formation of the initial layer(s) on the tooling surface <NUM>, the heat source <NUM> may heat a portion of the tooling surface <NUM> in front of the roller <NUM> along the direction of travel <NUM>. Alternatively, the tooling surface <NUM> can include a second heat source (not shown) that heats the tooling surface <NUM> before or during application of fiber tows <NUM> to the tooling surface <NUM>.

<FIG>, <FIG> are diagrams illustrating various views of an example of an automated fiber placement roller <NUM> according to a particular implementation. <FIG> shows a view along a central axis <NUM> of an example of the roller <NUM> according to a particular implementation. <FIG> shows a cross-sectional view taken substantially along cutting line 3B-3B of <FIG>. <FIG> shows a perspective view of the roller <NUM> of <FIG>. <FIG> shows a more detailed perspective view of the inner side <NUM> and several interconnect members <NUM> of the roller <NUM> of <FIG>.

<FIG>, <FIG> illustrate the core <NUM>, which includes the flexible rim member <NUM>, the hub member <NUM>, and a plurality of curved interconnect members <NUM> ("interconnect members") extending between the flexible rim member <NUM> and the hub member <NUM>. The hub member <NUM> defines a central opening <NUM> around the central axis <NUM>. In the example illustrated in <FIG>, the flexible rim member <NUM> is concentric with the hub member <NUM> about the central axis <NUM>. A plurality of gaps <NUM> are defined between the interconnect members <NUM> to facilitate heat removal and to provide space for flexing (e.g., elastic deformation) of the interconnect members <NUM>. In <FIG>, each of the interconnect members <NUM> defines an S-shaped curve, in other implementations, the interconnect members <NUM> define a different curve shape, such as a C-shaped curve.

The flexible rim member <NUM> includes an outer side <NUM> and an inner side <NUM> as shown in <FIG>, where the central axis <NUM> is closer to the inner side <NUM> than to the outer side <NUM>. The roller skin layer(s) <NUM> are coupled to the core <NUM> (e.g., to the outer side <NUM> of the flexible rim member <NUM>). In <FIG>, <FIG>, the roller skin layer(s) <NUM> include the compliant layer <NUM>, the wear layer <NUM>, and the outer layer <NUM>. In some implementations, the roller <NUM> also includes the insulation layer <NUM> between the roller skin layer(s) <NUM> and the core <NUM>.

As best seen in <FIG>, the flexible rim member <NUM> defines a plurality of grooves <NUM> that increase the flexibility of the flexible rim member <NUM> relative to an implementation of the flexible rim member <NUM> without the grooves. In <FIG>, the grooves <NUM> are illustrated on the inner side <NUM> of the flexible rim member <NUM>; however, in other implementations, grooves <NUM> are defined on the outer side <NUM> of the flexible rim member <NUM>, or on both the inner side <NUM> and the outer side <NUM>. In <FIG>, the grooves <NUM> include multiple axial grooves <NUM> and multiple circumferential grooves <NUM> arranged in a grid. In the example illustrated, multiple axial grooves <NUM> are disposed between each pair of adjacent interconnect members <NUM>. In other implementations, the grooves <NUM> include only the axial grooves <NUM> or only the circumferential grooves <NUM>. In yet another implementation, the grooves <NUM> are arranged in a different manner, such as in a spiral arrangement along the inner side <NUM>.

As best seen in <FIG>, one or more of the interconnect members <NUM> includes relief openings <NUM> which are sized and shaped to tune the elastic deformation characteristics (e.g., stiffness) of the interconnect members <NUM>. In the example illustrated in <FIG>, the relief openings <NUM> include first relief openings 146A at a first end (proximate to the inner side <NUM>) of the one or more interconnect members <NUM> and second relief openings 146B at a second end (proximate to the hub member <NUM>) of the one or more interconnect members <NUM>. In the example illustrated, each of the first relief openings 146A is aligned with a respective one of the circumferential grooves <NUM>.

The number, shape, dimensions, and placement of the first relief openings 146A and the second relief openings 146B are selected in part to provide target elastic deformation characteristics to the roller <NUM> or the core <NUM>. By omitting material that would be present if the interconnect members <NUM> did not have relief openings <NUM>, the flexibility of each interconnect member <NUM> is increased and the stiffness is decreased. Larger relief openings <NUM> increase the flexibility more than the same number of smaller relief openings <NUM> because the larger relief openings leave less material of the interconnect member <NUM> to resist deformation. For similar reasons, more relief openings <NUM> of a particular size and shape increase the flexibility of the interconnect member <NUM> more than fewer relief openings <NUM> of the same size and shape. A relief opening <NUM> is more effective at increasing flexibility of the interconnect member <NUM> when the relief opening <NUM> is positioned near a bend of the interconnect member <NUM> since the bend provides a natural focus of bending motion of the interconnect member <NUM>.

In some implementations, one or more of the relief openings <NUM> is shaped to enable additive manufacturing of the interconnect members <NUM> without use of temporary support structures. For example, an angle formed by edges of a relief opening <NUM> may be selected, in part, to enable building the interconnect member <NUM> in a layer-by-layer additive process without the need for temporary support structures to fill in and support portions of the interconnect member <NUM> that form the edges of the relief opening <NUM>. The specific angle to avoid use of temporary support structures depends on the additive manufacturing process used. In some implementations, the grooves <NUM> are also shaped to enable additive manufacturing of the flexible rim member <NUM> without use of temporary support structures.

In some implementations, each of the interconnect members <NUM> includes a different number of the first relief openings 146A than of the second relief openings 146B. For example, each of the interconnect members <NUM> defines a first number of the first relief openings 146A and defines a second number of the second relief openings 146B, and the first number is different from the second number. In the example illustrated in <FIG>, the first number is greater than the second number; however in other implementations, the second number is greater than the first number.

In some implementations, the first relief openings 146A have a different size than the second relief openings 146B. For example, each of the first relief openings 146A defines a corresponding first opening volume, each of the second relief openings 146B defines a corresponding second opening volume, and the first opening volume is different from the second opening volume. In the example illustrated in <FIG>, the first opening volume is less than the second opening volume; however in other implementations, the second opening volume is less than the first opening volume.

<FIG> shows the first edge <NUM> of the flexible rim member <NUM> (e.g., a surface between the inner side <NUM> and the outer side <NUM>) and the second edge <NUM> of the flexible rim member <NUM> (e.g., a surface between the inner side <NUM> and the outer side <NUM> on a side opposite the first edge <NUM>). <FIG> also shows respective the first and second edges <NUM>, <NUM> of the hub member <NUM>, and the first and second edges <NUM>, <NUM> of the interconnect members <NUM>. In the example illustrated, the first edges <NUM>, <NUM>, <NUM> are substantially coplanar with one another to facilitate fabrication via additive manufacturing (e.g., on a base plate or other support structure). In some implementations, the second edges <NUM>, <NUM>, <NUM> are also substantially coplanar with one another.

<FIG>, <FIG> are diagrams illustrating various views of an example of an automated fiber placement roller <NUM> according to a particular implementation. <FIG> shows a view along a central axis <NUM> of an example of the roller <NUM> according to a particular implementation. <FIG> shows a perspective view of the roller <NUM> of <FIG>. <FIG> shows more detailed perspective view of the inner side <NUM> of the roller <NUM> of <FIG>. <FIG> shows more detailed perspective view of several interconnect members <NUM> of the roller <NUM> of <FIG>.

In <FIG>, <FIG>, the roller includes the core <NUM> and the roller skin layers <NUM>. The roller skin layers <NUM> in <FIG> are the same as the roller skin layers <NUM> of <FIG> and function as described above. For example, the roller skin layers <NUM> of <FIG> include one or more of the compliant layer <NUM>, the wear layer <NUM>, and the outer layer <NUM>. In some implementations, the roller <NUM> also includes the insulation layer <NUM> between the roller skin layers <NUM> and the core <NUM>.

The core <NUM> of <FIG> includes the flexible rim member <NUM>, the hub member <NUM>, and a plurality of interconnect members <NUM> extending between the flexible rim member <NUM> and the hub member <NUM>. A plurality of gaps <NUM> (also referred to herein as openings) are defined between the interconnect members <NUM> to facilitate heat removal and to provide space for flexing (e.g., elastic deformation) of the interconnect members <NUM>. In <FIG>, each of the interconnect members <NUM> defines an S-shaped curve, in other implementations, the interconnect members <NUM> define a different curve shape, such as a C-shaped curve.

The hub member <NUM> of <FIG> defines the central opening <NUM> about the central axis <NUM>. The hub member <NUM> of <FIG> includes an inner hub member <NUM>, an outer hub member <NUM>, and one or more spacers <NUM> between the inner hub member <NUM> and the outer hub member <NUM>. A plurality of openings <NUM> are defined in the hub member <NUM> between the inner hub member <NUM>, the outer hub member <NUM>, and the spacers <NUM>. The openings <NUM> facilitate additional airflow (e.g., airflow in addition to airflow through the gaps <NUM>) to improve a rate of heat removal from the core <NUM> during use.

As best seen in <FIG>, the flexible rim member <NUM> defines the plurality of grooves <NUM> of <FIG>, including axial grooves <NUM> and circumferential grooves <NUM>. The grooves <NUM>, <NUM> increase the flexibility of the flexible rim member <NUM> relative to an implementation of the flexible rim member <NUM> without the grooves. In <FIG>, the grooves <NUM>, <NUM> are illustrated on the inner side <NUM> of the flexible rim member <NUM>; however, in other implementations, grooves <NUM>, <NUM> are defined on the outer side <NUM> of the flexible rim member <NUM>, or on both the inner side <NUM> and the outer side <NUM>. In some implementations, only the axial grooves <NUM> or only the circumferential grooves <NUM> are present. In other implementation, the grooves are arranged in a different manner, such as in a spiral arrangement along the inner side <NUM>.

As best seen in <FIG>, one or more of the interconnect members <NUM> includes relief openings <NUM>. In the example illustrated in <FIG>, the relief openings <NUM> include first relief openings 146A at a first end (proximate to the inner side <NUM>) of the one or more interconnect members <NUM> and interior relief openings 146C through a body of each interconnect member <NUM>. In the example illustrated, each of the first relief openings 146A is aligned with a respective one of the circumferential grooves <NUM>. The interior relief openings 146C, the first relief openings 146A, or both, are sized and shaped to tune the elastic deformation characteristics (e.g., stiffness) of the interconnect members <NUM>. Additionally, the interior relief openings 146C enable additional airflow (e.g., airflow in addition to airflow through the openings <NUM>) to improve a rate of heat removal from the core <NUM> during use.

The shape, dimensions, and placement of the interior relief openings 146C, the first relief openings 146A, or both, are selected in part to provide target elastic deformation characteristics to the roller <NUM> or the core <NUM>. For example, a large interior relief opening 146C in each interconnect members <NUM> result in great flexibility of the core <NUM> than does a smaller interior relief opening 146C in each interconnect members <NUM>. The shape and position within each interconnect member <NUM> of the interior relief openings 146C can be modified to provide specific deformation characteristics, such as increased or decreased stiffness at ends (e.g., edges <NUM>, <NUM>) of the flexible rim member <NUM>.

<FIG> is a diagram that illustrates another example of an automated fiber placement roller <NUM> according to a particular implementation. The automated fiber placement roller <NUM> illustrated in <FIG> is similar to the automated fiber placement roller <NUM> illustrated in <FIG> except that the flexible rim member <NUM> does not include the grooves <NUM> and the interconnect members <NUM> include the relief opening 146C but not the relief opening 146A. Omission of the grooves <NUM> and the relief openings 146A simplifies production of the core <NUM> using some manufacturing processes. For example, while very complex molds or post-casting operations may be used to form the relief opening 146A of the core <NUM> of <FIG>, simpler molds with fewer or no post-casting operations can be used to form the core <NUM> of <FIG>.

<FIG> is a diagram that illustrates a cross-sectional view (along the central axis <NUM>) of an example of the automated fiber placement roller <NUM>. <FIG> is a diagram that illustrates a cross-sectional view (along the central axis <NUM>) of another example of the automated fiber placement roller <NUM>. The rollers <NUM> of each of <FIG> include the roller skin layers <NUM> around the core <NUM>. For example, the rollers <NUM> of each of <FIG> include the compliant layer <NUM>, the wear layer <NUM>, and the outer layer <NUM>. The rollers <NUM> of each of <FIG> include the insulation layer <NUM> between the core <NUM> and the roller skin layers <NUM>.

In <FIG>, each core <NUM> includes a flexible rim member <NUM>, a hub member <NUM>, and a plurality of interconnect members <NUM> between the flexible rim member <NUM> and the hub member <NUM>. The hub member <NUM> in each of <FIG> includes an inner hub member <NUM>, an outer hub member <NUM>, and one or more openings <NUM> disposed between the inner hub member <NUM> and the outer hub member <NUM>.

In <FIG>, the interconnect members <NUM> include the relief openings 146A and the relief openings 146C. Additionally, the flexible rim member <NUM> of <FIG> includes at least the circumferential grooves <NUM>. The flexible rim member <NUM> of <FIG> may also include axial grooves <NUM>, which are not visible in the view illustrated in <FIG>.

The relief openings 146A and the relief openings 146C of <FIG> are shaped and sized to facilitate additive manufacturing of the interconnect members <NUM> without use of temporary support structures. For example, angles formed by edges of the relief openings 146A and the relief openings 146C may be selected, in part, to enable building the interconnect member <NUM> in a layer-by-layer additive process without the need for temporary support structures to fill in and support portions of the interconnect member <NUM> that form the edges of the relief opening <NUM>. The specific angle to avoid use of temporary support structures depends on the additive manufacturing process used. In some implementations, the grooves <NUM> are also shaped to enable additive manufacturing of the flexible rim member <NUM> without use of temporary support structures.

The roller <NUM> of <FIG> is similar to the roller <NUM> of <FIG>. However, in contrast with <FIG>, the interconnect members <NUM> of <FIG> do not include relief openings <NUM>. Additionally, in <FIG>, the flexible rim member <NUM> does not include grooves <NUM>. Omission of the relief openings <NUM>, the grooves <NUM>, or both, simplifies production of the core <NUM> using some manufacturing processes. For example, the core <NUM> of <FIG> can be cast using common techniques, such as injection molding or compression molding, and using relatively simple molds.

<FIG> is a flow chart of an example of a method <NUM> of automated composite layup. The method <NUM> includes, at <NUM>, applying heat to a portion of a workpiece using a heat source coupled to a fiber placement head of an automated fiber placement machine. For example, the heat source <NUM> directs the heat <NUM> toward the portion <NUM> of the workpiece <NUM> (or of the tooling surface <NUM>). In a particular implementation, the heat source <NUM> includes a laser source that generates the heat <NUM> via a beam of light.

The method <NUM> includes, at <NUM>, after applying the heat to the portion of the workpiece, moving a roller of the fiber placement head over the portion of the workpiece while the roller presses one or more tows into contact with the portion of the workpiece. For example, the roller <NUM> of <FIG> is used to press the fiber tows <NUM> into contact with the workpiece <NUM> or the tooling surface <NUM>. In some implementations, the heat source <NUM> is controlled to heat the portion <NUM> of the workpiece <NUM> sufficiently to soften a thermoplastic polymer of the fiber tows <NUM>. For example, the relative motion of the workpiece <NUM> and the fiber placement head <NUM> can be controlled to cause the heat source <NUM> to heat the portion <NUM> of the workpiece <NUM> to a working temperature that is greater than a glass transition temperature of the thermoplastic polymer. To illustrate, the heat source <NUM> can output heat at a relatively constant rate and the relative motion of the workpiece <NUM> and the fiber placement head <NUM> is controlled to control the working temperature of the portion <NUM>. In another example, a power output of the heat source <NUM>, an orientation of the heat source <NUM>, or both, are controlled to cause the heat source <NUM> to heat the portion <NUM> of the workpiece <NUM> to a working temperature that is greater than a glass transition temperature of the thermoplastic polymer. To illustrate, the heat output of the heat source <NUM> can be pulsed or redirected (e.g., scanned) to control the working temperature.

The method <NUM> also includes, at <NUM>, while moving the roller over the portion of the workpiece, cooling the roller to dissipate at least a portion of the heat. In a particular example, the roller is cooled by airflow through openings between a rim member of the roller, a hub member of the roller, and a plurality of curved interconnect members of the roller. For example, the heat can be conductively transferred from the workpiece <NUM> to the flexible rim member <NUM>. The rate of heat transfer may be limited, in some implementations, by thermal properties of the roller skin layers <NUM> and/or the insulation layer <NUM>. The flexible rim member <NUM> conducts the heat to the interconnect members <NUM>, and the interconnect members <NUM> transfer to the heat to the airflow <NUM> (or another coolant) flowing between the openings <NUM> between the interconnect members <NUM>. In some implementations, the airflow is unidirectional (e.g., from the first edge <NUM> of the flexible rim member <NUM> toward the second edge <NUM> of the flexible rim member <NUM>) to improve heat removal. In some implementations, the roller <NUM> may also be cooled by additional airflow through openings <NUM> between an inner hub member <NUM> and an outer hub member <NUM>.

Although one or more of <FIG> may illustrate systems, apparatuses, and/or methods according to the teachings of the disclosure, the disclosure is not limited to these illustrated systems, apparatuses, and/or methods. One or more functions or components of any of <FIG> as illustrated or described herein may be combined with one or more other portions of another of <FIG>. Accordingly, no single implementation described herein should be construed as limiting and implementations of the disclosure may be suitably combined without departing form the teachings of the disclosure. As an example, one or more operations described with reference to <FIG> may be optional, may be performed at least partially concurrently, and/or may be performed in a different order than shown or described.

The illustrations of the examples described herein are intended to provide a general understanding of the structure of the various implementations. Many other implementations may be apparent to those of skill in the art upon reviewing the disclosure. Other implementations may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. For example, method operations may be performed in a different order than shown in the figures or one or more method operations may be omitted. Moreover, although specific examples have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar results may be substituted for the specific implementations shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various implementations. Combinations of the above implementations, and other implementations not specifically described herein, will be apparent to those of skill in the art upon reviewing the description.

Also disclosed herein is an automated fiber placement roller. The roller comprises: an elastically deformable rim member arranged about a central axis and having an inner side and an outer side, wherein the central axis is closer to the inner side than to the outer side; a hub member arranged substantially concentric with the rim member about the central axis, wherein the hub member defines an opening to receive a shaft of an automated fiber placement machine; a plurality of curved interconnect members extending between the hub member and the rim member, wherein each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the flexible rim member; and one or more roller skin layers coupled to the outer side of the flexible rim member.

A plurality of grooves are defined in the rim member to reduce force required to elastically deform the rim member.

The plurality of grooves may include multiple circumferential grooves.

The plurality of grooves may include multiple axial grooves.

Each of the plurality of curved interconnect members may define an S-shaped curve in a plane orthogonal to the central axis.

Each of the plurality of curved interconnect members may define a relief opening therethrough.

The hub member may comprise an inner hub member and an outer hub member, wherein the central axis is closer to the inner hub member than to the outer hub member, and wherein a plurality of openings are defined between the inner hub member and the outer hub member.

The one or more roller skin layers may comprise a compliant layer and an outer layer, wherein the central axis is closer to the compliant layer than to the outer layer, wherein the outer layer has a degradation temperature greater than or equal to <NUM> degrees Celsius, and wherein the compliant layer has a Shore A hardness of between <NUM> and <NUM>.

An insulation layer may be provided between the one or more roller skin layers and the rim member.

The rim member, the hub member, and the plurality of curved interconnect members may be metallic.

The rim member, the hub member, and the plurality of curved interconnect members may be polymeric.

The rim member may have a first rim edge corresponding to a surface between the inner side and the outer side, wherein the hub member has a first hub edge, wherein each of the plurality of curved interconnect members has a respective first interconnect edge, and wherein the first rim edge, the first hub edge, and each of the first interconnect edges are substantially coplanar.

The rim member has a second rim edge opposite the first rim edge, wherein the hub member may have a second hub edge opposite the first hub edge, wherein each of the plurality of curved interconnect members has a respective second interconnect edge opposite a corresponding first interconnect edge, and wherein the second rim edge, the second hub edge, and each of the second interconnect edges are substantially coplanar.

The rim member, the hub member, and the plurality of curved interconnect members together may be a single monolithic body.

Also disclosed is a further automated fiber placement machine. It comprises: a fiber placement head comprising a roller and a shaft extending through an opening (e.g. a central opening) of the roller, wherein the roller is rotatable about the shaft and comprises: a flexible rim member arranged about a central axis and having an inner side and an outer side, wherein the central axis is closer to the inner side than to the outer side; a hub member arranged substantially concentric with the flexible rim member about the central axis, wherein the hub member defines the central opening; a plurality of curved interconnect members extending between the hub member and the flexible rim member, wherein each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the flexible rim member; and one or more roller skin layers coupled to the outer side of the flexible rim member; and one or more actuators configured to adjust a relative position of the roller and a workpiece during addition of one or more fiber tows to the workpiece by the fiber placement head.

Also disclosed is a further automated fiber placement machine. It comprises: a fiber placement head comprising an automated fiber roller according to any of the above examples, and a shaft extending through the opening of the roller; the automated fiber placement machine further comprising one or more actuators configured to adjust a relative position of the roller and a workpiece during addition of one or more fiber tows to the workpiece by the fiber placement head. The opening may be a central opening.

A heat source may also be provided and configured to, during a fiber placement operation, direct heat toward a portion of the workpiece ahead of the roller along a direction of travel of the roller relative to the workpiece, wherein openings are defined between the plurality of curved interconnect members, the hub member, and the flexible rim member to enable airflow therebetween to remove heat from the roller.

A heat source may be configured to, during a fiber placement operation, heat a portion of the workpiece to a local temperature greater than <NUM> degrees Celsius, and wherein materials of the one or more roller skin layers have degradation temperatures greater than <NUM> degrees Celsius.

Also disclosed herein is an automated fiber placement roller. It comprises: a cylindrical core having an outer side arranged about a central axis, a first edge, and a second edge, wherein the cylindrical core defines a plurality of openings that extend between the first edge and the second edge, and wherein the outer side is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis; a compliant layer comprising a first material coupled to the outer side of the cylindrical core; and an outer layer comprising a second material coupled to the compliant layer.

The cylindrical core may comprise: a flexible rim member arranged about the central axis; a hub member arranged substantially concentric with the flexible rim member about the central axis, the hub member defining an opening to receive a shaft of an automated fiber placement machine; and a plurality of curved interconnect members extending between the hub member and the flexible rim member, wherein each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the flexible rim member.

The cylindrical core may be a single monolithic, unitary body.

The outer layer may comprise a release layer with a degradation temperature greater than or equal to <NUM> degrees Celsius.

The second material may comprise a polybenzimidazole polymer material or high-temperature silicone polymer material.

The first material may comprise a polymer with a Shore A hardness of between <NUM> and <NUM>.

The first material may comprise a high-temperature silicone polymer material, a fluoroelastomer polymer material, or a silica aerogel material.

A wear layer may be provided between the compliant layer and the outer layer, wherein the wear layer comprises a third material.

The third material may comprise a fluorinated ethylene propylene polymer material or a perfluoroalkoxy alkane polymer material.

One or more insulating layers may be disposed between the compliant layer and the cylindrical core.

The plurality of openings may extend between the first edge and the second edge of the cylindrical core enable unidirectional airflow between the first edge and the second edge through the cylindrical core.

Also disclosed here is a further automated fiber placement machine. It may comprise: a fiber placement head comprising a roller and a shaft extending through a central opening of the roller, wherein the roller is rotatable about the shaft and comprises: a cylindrical core having an outer side arranged about a central axis, a first edge, and a second edge, wherein the cylindrical core defines a plurality of openings that extend between the first edge and the second edge, and wherein the outer side is flexible in a direction parallel to the central axis and is flexible radially relative to the central axis; a compliant layer comprising a first material coupled to the outer side of the cylindrical core; and an outer layer comprising a second material coupled to the compliant layer; and one or more actuators configured to adjust a relative position of the roller and a workpiece during addition of one or more fiber tows to the workpiece by the fiber placement head.

A heat source may be configured to, during a fiber placement operation, direct heat toward a portion of the workpiece ahead of the roller along a direction of travel of the roller relative to the workpiece, wherein the plurality of openings that extend between the first edge and the second edge enable airflow therebetween to remove heat from the roller.

A heat source may be configured to, during a fiber placement operation, heat a portion of the workpiece to a local temperature greater than <NUM> degrees Celsius, and wherein the second material has a degradation temperature greater than <NUM> degrees Celsius.

Examples described above illustrate but do not limit the disclosure.

Claim 1:
An automated fiber placement roller (<NUM>) comprising:
an elastically deformable rim member (<NUM>) arranged about a central axis (<NUM>) and having an inner side (<NUM>) and an outer side (<NUM>), wherein the central axis is closer to the inner side than to the outer side;
a hub member (<NUM>) arranged substantially concentric with the rim member about the central axis, wherein the hub member defines an opening (<NUM>) to receive a shaft (<NUM>) of an automated fiber placement machine (<NUM>);
a plurality of curved interconnect members (<NUM>) extending between the hub member and the rim member, wherein each of the plurality of curved interconnect members is elastically deformable to accommodate deformation of the rim member; and
one or more roller skin layers (<NUM>) coupled to the outer side of the rim member;
wherein a plurality of grooves (<NUM>) are defined in the rim member to reduce a force required to elastically deform the rim member.