Patent Description:
Forming large composite parts (also referred to as working components), such as composite aircraft parts (e.g., wings, fuselage sections, etc.) can require large tools. Such tools include draping tools, support tools, layup surface tools (commonly referred to as molds or mandrels), etc. These tools are used in a variety of composite part formation processes, such as hand layup, automated layup, draping, hot draping, automated fiber placement, automated tape laying, curing, and trimming. These tools include surfaces (e.g., a layup surface) that are used to form or support formation of the composite parts. The layup surface may include shapes, contours, and/or geometries that conform to design specifications and are complementary to the composite parts being formed.

Such tools are commonly made of metal and are monolithic pieces (i.e., a single structure composed of multiple permanently joined pieces, such as by welded or bonded joints). Additionally, these tools have precise contoured surfaces (e.g., within allowable tolerances) and must be able to withstand the weight of the composite part and rigors of forming the composite part. For example, a particular tool may be subjected to vacuum conditions (e.g., vacuum pressure) and high temperature conditions during composite formation and curing. If a tool deforms to become out of tolerance from prior use, is unable to maintain a vacuum condition, or is unable to maintain tolerances upon heating, weight, or vacuum conditions, the tool is unable to create parts and a new tool must be created. Production of the part may be halted until a new tool is available. Also, some times during a design process, multiple tool designs (e.g., prototype tools or iterations of tools) are generated to improve the formation process of the part. As such, current tools can have high fabrication costs and/or have long fabrication cycle times.

<CIT>, in accordance with its abstract, relates to a method and apparatus for reworking a composite structure. A fastener is cooled from a first temperature to a second temperature at which a diameter of a post of the fastener is reduced by a desired amount. The post of the fastener is placed into a channel in a bushing such that a desired interference fit occurs when the fastener is at the first temperature. The bushing with the fastener is positioned in a hole in the composite structure. A gap is present between an outer surface of the bushing and an inner surface of the hole. A gap is also present between an end of the bushing and a second structure.

<CIT>, in accordance with its abstract, relates to a method and system for installing a fastener. A fastener installation system comprises a fastener, a cooling system, and a tool. The fastener has a top portion including a dielectric material. The cooling system is configured to cool the top portion of the fastener to stiffen the top portion. The tool is configured to install the fastener in a structure after cooling.

<CIT>, in accordance with its abstract, relates to an apparatus and methods for manufacturing a flanged component from a composite lay-up. The apparatus includes a support structure coupled to the composite lay-up and a mold ring coupled to the support structure. The mold ring includes a ring guide surface and a radial contact surface that is configured to couple to the composite lay-up. The apparatus further includes a mold plate coupled to the mold ring. The mold plate includes a recessed surface and a plate guide surface, where the recessed surface is configured to couple to the composite lay-up and the plate guide surface is configured to couple to the ring guide surface. The apparatus also includes an autoclave that applies pressure to the mold ring and the mold plate to move the plate guide surface along the ring guide surface to apply pressure to the composite lay-up.

Described herein is a tool assembly comprising: a first piece having a first joint portion including a top surface and at least a first interlock surface; a second piece having a second joint portion configured to interlock with the first joint portion, the second joint portion including a top surface and at least a second interlock surface that is complementary to the first interlock surface; and a fastener extending through the first and second joint portions. The first interlock surface and the top surface of the first joint portion form an obtuse angle corner and the second interlock surface, and the top surface of the second joint portion form an acute angle corner. The first interlock surface is configured to contact the second interlock surface to inhibit relative movement between the first piece and the second piece along a longitudinal axis of the tool assembly. The first piece further comprises a third interlock surface and a first intermediate surface, and the first intermediate surface and the first interlock surface form an obtuse angle corner. The first intermediate surface and the third interlock surface form an obtuse angle corner.

In a particular implementation, a tool assembly includes a first piece having a first joint portion including a top surface and at least a first interlock surface. The tool assembly also includes a second piece having a second joint portion configured to interlock with the first joint portion, the second joint portion including a top surface and at least a second interlock surface that is complementary to the first interlock surface. The tool assembly further includes a fastener extending through the first and second joint portions. The first interlock surface and the top surface of the first joint portion form an obtuse angle corner and the second interlock surface and the top surface of the second joint portion form an acute angle corner. The first interlock surface is configured to contact the second interlock surface to inhibit relative movement between the first piece and the second piece along a longitudinal axis of the tool assembly.

In another particular implementation, a tool assembly includes a first piece having a top surface and a first joint portion including at least a first interlock surface. The tool assembly also includes a second piece having a second joint portion configured to interlock with the first joint portion, the second joint portion including a top surface and at least a second interlock surface that is complementary to the first interlock surface. The tool assembly further includes a fastener extending through the first and second joint portions. The first interlock surface and the top surface of the first piece form an obtuse angle corner and the second interlock surface and the top surface of the second joint portion form an acute angle corner. The first interlock surface is configured to contact the second interlock surface to inhibit relative movement between the first piece and the second piece along a longitudinal axis of the tool assembly.

In a particular implementation, a method of heating a tool assembly includes joining a first piece of the tool assembly with a second piece of the tool assembly via a first joint portion and a second joint portion. The method also includes inserting a fastener through the first and second joint portions of the tool assembly. The method further includes applying heat to the tool assembly, where upon heating, interlock surfaces of the first and second joint portions tighten.

In another particular implementation, a method of applying composite material to a tool assembly includes joining a first piece of the tool assembly with a second piece of the tool assembly via a first joint portion and a second joint portion, where the tool assembly includes a layup surface. The method further includes applying the composite material onto the layup surface. The layup surface is configured to support formation of a composite part and has a shape that is complementary to a shape of the composite part.

In yet another particular implementation, a method of making a tool assembly includes forming a first joint portion of a first piece of the tool assembly using an additive manufacturing process. The first joint portion includes a top surface and at least a first interlock surface. The method further includes forming a second joint portion of a second piece of the tool assembly using the additive manufacturing process. The second joint portion includes a top surface and at least a second interlock surface that is complementary to the first interlock surface.

By utilizing a tool assembly (e.g., a multi-piece tool), composite parts can be formed more quickly and with reduced costs as compared to one piece tools. Additionally, by utilizing a tool assembly with joint portions and interlock surfaces, the tool assembly can be fabricated to support formation of large composite pieces, such as aircraft wings and fuselage sections.

Implementations disclosed herein enable formation of a composite part (e.g., curing a large composite part) using a tool assembly (i.e., a multi-piece tool). Examples of large composite parts in the context of an aircraft are wing components, such as the leading edge, the flaps, or other parts of the wing, and fuselage components of the aircraft. Other examples of large composite parts include rocket fuselages and stabilizers and ship hulls or skins. The pieces of the tool assembly are joined together by joint portions to form joints. The joint portions include one or more interlock surfaces that self-interlock and are able to withstand thermal expansion upon heating and maintain a vacuum seal and vacuum integrity. For example, thermal expansion of the pieces of the tool assembly tighten the vacuum seal between interlock surfaces. The joint portions interlock such that a layup surface of the tool assembly is within design tolerance (i.e., does not deform to a shape that is out of the designed or desired tolerance). Additionally, the joint portions are strong enough to enable handling of the tool assembly. In some implementations, the tool assembly includes one or more fasteners to enable thermal expansion and increase joint strength to enable tool handling and/or adhesive material (e.g., adhesive films or pastes) to further secure the tool assembly and maintain a vacuum seal and the vacuum integrity. While "adhesive material" is described herein, any suitable type of material that adheres or bonds components together, permanently or temporarily, can be used.

In some implementations, the tool assembly includes one or more additively manufactured pieces, such as pieces made by fused filament fabrication (FFF), such as fused deposition modeling (FDM), plastic jet printing (PJP), three-dimensional (<NUM>-D) printing, powder bed processing, selective heat sintering (SHS), stereolithography (SLA), selective laser melting (SLM), selective laser sintering (SLS), and the like. Additively manufactured tool pieces of tool assemblies are usually made from materials that are generally chemically inert, and thus bonded joints or bonded butt joints between additively manufactured tool pieces may be difficult to form. Additionally, additively manufactured tool pieces of tool assemblies are usually made from materials where the coefficient of thermal expansion is anisotropic (i.e., the tool piece expands differently in different directions). This anisotropic thermal expansion can decrease the ability of a tool assembly to maintain vacuum integrity in a heated tool usage environment (e.g., fabrication of composite parts). By using the joint portions with interlock surfaces described herein, tool assemblies can include one or more additively manufactured pieces and can support formation of large composite parts.

Multi-piece tool assemblies, such as the tool assemblies described herein, can have lower costs and reduced tool fabrication cycle time, as compared to monolithic metal tools. Additionally, as compared to monolithic metal tools or metal tool assemblies, multi-piece tool assemblies having additively manufactured pieces can have lower costs and reduced tool fabrication cycle time. The lower costs and reduced fabrication cycle time of tool assemblies having additively manufactured pieces can reduce costs and fabrication cycle time associated with manufacturing composite parts (e.g., large composite parts) and the systems which include the composite parts.

<FIG> illustrates an example of a composite part manufacturing system <NUM> that includes a tool assembly <NUM>, a layup device <NUM>, a vacuum system <NUM>, a curing device <NUM>, and a controller <NUM>. The composite part manufacturing system <NUM> enables formation of composite parts, such as a composite part <NUM>. The composite part manufacturing system <NUM> may include or correspond to a hand layup manufacturing system, an automated layup manufacturing system, a draping system, a hot draping system, an automated fiber placement system, an automated tape laying system, a composite part trimming system, or a combination thereof.

The tool assembly <NUM> includes two or more pieces <NUM>, <NUM>. As illustrated in the implementation illustrated in <FIG>, the tool assembly includes a first piece <NUM> and a second piece <NUM>. In some implementations, the first piece <NUM> and the second piece <NUM> are joined together, such as by interlocking, to form a layup surface <NUM>. In other implementations, a particular piece of the two or more pieces <NUM>, <NUM> includes the layup surface <NUM> or a subset of pieces of the two or more pieces <NUM>, <NUM> of the tool assembly <NUM> includes the layup surface <NUM>. The two or more pieces <NUM>, <NUM> of the tool assembly <NUM> each include one or more joint portions <NUM>, <NUM>. As illustrated in the implementation illustrated in <FIG>, the first piece <NUM> includes a first joint portion <NUM> and the second piece <NUM> includes a second joint portion <NUM>. The second joint portion <NUM> is configured to interlock with the first joint portion <NUM>. Each joint portion <NUM>, <NUM> includes one or more interlock surfaces <NUM>, <NUM>. As illustrated in the implementation illustrated in <FIG>, the first joint portion <NUM> includes a first interlock surface <NUM> and the second joint portion <NUM> includes a second interlock surface <NUM>. Additionally, each joint portion <NUM>, <NUM> includes a corresponding top surface <NUM>. Specific joints and interlock surface arrangements (e.g., two interlock surfaces that are configured to be interlocked) are described further with reference to <FIG> and <FIG>.

The first and second interlock surfaces <NUM>, <NUM> are complementary interlock surfaces or interlocking surfaces. For example, the first and second interlock surfaces <NUM>, <NUM> are positioned at complementary angles relative to a particular reference plane or surface. The first and second interlock surfaces <NUM>, <NUM> are configured to interlock with each other and form a vacuum seal or maintain vacuum integrity. To illustrate, the first interlock surface <NUM> is configured to contact the second interlock surface <NUM> to inhibit relative movement between the first piece <NUM> and the second piece <NUM>. The interlock surfaces <NUM>, <NUM> may inhibit relative movement between the first piece <NUM> and the second piece <NUM> along a particular direction or axis or within a particular plane. As illustrated in <FIG>, the interlock surfaces <NUM>, <NUM> inhibit relative movement between the first piece <NUM> and the second piece <NUM> along a longitudinal axis <NUM>. In other implementations, the interlock surfaces <NUM>, <NUM> inhibit relative movement between the first piece <NUM> and the second piece <NUM> along a transverse axis <NUM> of <FIG>.

The first and second interlock surfaces <NUM>, <NUM> are also configured to relieve stress and strain from thermal expansion and handling. In some implementations, the first and second interlock surfaces <NUM>, <NUM> are configured to "tighten" (e.g., form a tighter seal by pushing against other and/or by being forced toward each other) under high temperature conditions and/or vacuum conditions. For example, increasing the temperature of the joint portions <NUM>, <NUM> can cause the joint portions <NUM>, <NUM> to experience thermal expansion, which increases force and pressure on the first and second interlock surfaces <NUM>, <NUM> such that the first and second interlock surfaces <NUM>, <NUM> deform on a microscopic level to engage each other to a greater degree (e.g., a larger portion of the first and second interlock surfaces <NUM>, <NUM> contact each other on a microscopic level as compared to the contact between the interlock surfaces <NUM>, <NUM> prior to thermal expansion). This deformation may enable a more airtight seal and/or generate more friction (i.e., more resistance to movement).

The layup surface <NUM> is defined by one or more surfaces (e.g., the top surfaces <NUM>) of the pieces <NUM>, <NUM> of the tool assembly <NUM> when joined together. In certain examples, any surface of the pieces <NUM>, <NUM> can be or define the layup surface <NUM>. The layup surface <NUM> is configured to support formation of the composite part <NUM>. For example, the layup surface <NUM> acts as a form, mold, or mandrel for the layup device <NUM> and composite material <NUM>. To illustrate, a shape of the layup surface <NUM> of the tool assembly <NUM> is similar to or complementary to a shape of the composite part <NUM>. The composite material <NUM> (e.g., plies of fibrous material embedded in a resin matrix) conform to the shape of the layup surface <NUM> of the tool assembly <NUM> under heat and/or pressure to form the composite part <NUM>.

The layup device <NUM> is configured to position or deposit the composite material <NUM> on the layup surface <NUM> of the tool assembly <NUM>. The layup device <NUM> includes or corresponds to an automated layup machine, an automated tape laying machine, or an automated fiber placement machine. The composite material <NUM> may be in the form of tows, tape, plies, etc. The composite material <NUM> is two or more constituent materials combined to create a material with material properties different then the individual material characteristic, such as honeycomb panels, fiber and resin, etc. In some examples, the tool assembly <NUM> described herein can be used to make parts from a composite material <NUM> that is a combination of a fabric or fiber (fiberglass, carbon, metallic carbon fiber, KEVLAR®, aramid, aluminized fiberglass, etc.) and a resin (epoxy, bis-Maleimide (BMI), vinyl ester, polyester, etc.).

In other implementations, the composite part manufacturing system <NUM> does not include the layup device <NUM>. In such implementations, the layup device <NUM> is separate from the composite part manufacturing system <NUM> or the layup is done manually by hand.

The vacuum system <NUM> includes one or more components configured to generate and maintain vacuum conditions (e.g., vacuum pressure, which is a pressure less than an ambient pressure, or a vacuum seal). For example, the vacuum system <NUM> includes a pump <NUM>, a vacuum plate <NUM>, and a bladder <NUM> configured to generate and maintain vacuum conditions between or around the composite material <NUM> and the tool assembly <NUM>. As another example, the vacuum system <NUM> includes the pump <NUM> and a vacuum bag <NUM>. The vacuum system <NUM> generates and maintains the vacuum conditions during at least a portion of the fabrication process of the composite part <NUM>.

The curing device <NUM> is configured to cure the composite material <NUM> to form the composite part <NUM>. The curing device <NUM> can include a heating device <NUM>, a lighting device <NUM>, or a combination thereof. For example, the curing device <NUM> may include or correspond to a heater, a laser, an oven, an autoclave, etc. Additionally or alternatively, the curing device <NUM> includes or corresponds to an ultraviolet light source.

The controller <NUM> includes a processor <NUM> and a memory <NUM>. The memory <NUM> stores computer-executable instructions (e.g., a program of one or more instructions). The processor <NUM> is configured to execute the computer-executable instructions stored in the memory <NUM>. The instructions, when executed, cause one or more components of the composite manufacturing system, to perform one or more operations of the methods described with reference to <FIG> and <FIG>.

The controller <NUM> is configured to control one or more components of the composite part manufacturing system <NUM>. For example, the controller <NUM> may control or coordinate operation of the layup device <NUM>, the vacuum system <NUM>, the curing device <NUM>, or a combination thereof. To illustrate, the controller <NUM> generates and transmits one or more commands to the one or more components of the composite part manufacturing system <NUM>.

Prior to operation of the composite part manufacturing system <NUM>, the tool assembly <NUM> is assembled. For example, the first joint portion <NUM> of the first piece <NUM> is mated with the second joint portion <NUM> of the second piece <NUM> to form the tool assembly <NUM> and the layup surface <NUM> thereof. As the first and second pieces <NUM>, <NUM> may be large pieces (e.g., <NUM> feet by <NUM> feet or <NUM> feet by <NUM> feet sections), machinery (e.g., a forklift, a power jack, etc.) may be used to move and manipulate the first and second pieces <NUM>, <NUM>.

During operation of the composite part manufacturing system <NUM>, the layup device <NUM> applies or deposits the composite material <NUM> onto the layup surface <NUM> of the tool assembly <NUM> responsive to receiving commands from the controller <NUM>. The vacuum system <NUM> generates and maintains vacuum conditions (e.g., vacuum pressure or vacuum seal) and the curing device <NUM> applies heat, light, or both, to cure the composite material <NUM> responsive to receiving commands from the controller <NUM>. The composite material <NUM> undergoes chemical reactions and/or deforms to form the composite part <NUM> during application of the heat, the light, or both. The formed composite part <NUM> has a contoured surface that matches a contoured surface (e.g., the layup surface <NUM>) of the tool assembly.

In other implementations, a working part <NUM> is placed upon the layup surface <NUM> of the tool assembly <NUM> by the layup device <NUM>, machinery, or by hand. The working part <NUM> is then trimmed (e.g., cut, machined, bent, etc.) into the composite part <NUM>. The working part <NUM> may be formed by one or more steps of the process described above in creating the composite part <NUM>.

In some implementations, the pieces <NUM>, <NUM> of the tool assembly <NUM> are manufactured from a thermoplastic polymer material (e.g., Acrylonitrile-Butadiene-Styrene (ABS) material or carbon filled ABS material), a thermoset polymer material, or another polymer material. The pieces <NUM>, <NUM> of the tool assembly <NUM> may be built-up using an additive manufacturing process, such as fused filament fabrication, fused deposition modeling, plastic jet printing, <NUM>-D printing, powder bed processing, selective heat sintering, stereolithography, selective laser melting, selective laser sintering, and the like.

In some such implementations, the pieces <NUM>, <NUM> of the tool assembly <NUM> are joined with one or more fasteners <NUM>, adhesives, or a combination thereof, as described with reference to <FIG>. The adhesives are configured to help maintain vacuum integrity, and the fasteners <NUM> are configured to support movement of the tool assembly <NUM> thermal expansion of the tool assembly <NUM> and/or setting of the adhesive material. As some examples, the tool assembly <NUM> includes a fastener <NUM> extending through the first and second joint portions <NUM>, <NUM>.

Thus, the composite part manufacturing system <NUM> may enable fabrication of large composite parts <NUM> using the tool assembly <NUM>. Particularly, the composite part manufacturing system <NUM> may enable fabrication of large composite parts <NUM> using the tool assembly <NUM>, which is formed from pieces <NUM>, <NUM> that have been additively manufactured. Because the tool assembly <NUM> has reduced costs and fabrication time, fabrication of the composite parts has reduced costs and design time, as compared to metal one piece tools. Additionally, by using the tool assembly <NUM>, including the joint portions <NUM>, <NUM>, the composite part manufacturing system <NUM> can form larger composite parts as compared to using smaller tool assemblies joined by butt joints to form smaller composite parts.

<FIG> is a diagram that illustrates an isometric view of an example of a tool assembly <NUM>. The diagram of <FIG> illustrates the tool assembly <NUM> in a vertical axis <NUM>, a longitudinal axis <NUM>, and a transverse axis <NUM>. As illustrated in <FIG>, the tool assembly <NUM> includes the first piece <NUM>, the second piece <NUM>, and a third piece <NUM>. <FIG> illustrates a diagram of a longitudinally aligned tool assembly <NUM>, in which the pieces <NUM>, <NUM>, <NUM> are arranged in the longitudinal axis <NUM>. In other implementations, the tool assembly <NUM> may be circumferentially aligned, such as aligned about a center of a circle along at least a portion of a circumference of the circle. In a particular implementation, the tool assembly <NUM> includes one or more circumferentially aligned pieces, one or more longitudinally aligned pieces, or a combination thereof.

As illustrated in <FIG>, the layup surface <NUM> is formed by, or corresponds to, the top surfaces <NUM> of the pieces <NUM>, <NUM>, <NUM>. In other implementations, the layup surface <NUM> includes one or more other surfaces of the pieces <NUM>, <NUM>, <NUM>, such as side surfaces, bottom surfaces, cutout surfaces (e.g., surfaces of cutouts <NUM>), or a combination thereof.

In some implementations, one or more of the pieces <NUM>, <NUM>, <NUM> include the cutouts <NUM>. The cutouts <NUM> are configured to reduce a weight and a volume of the tool assembly <NUM>, to provide a portion of the layup surface <NUM>, to trim the composite part <NUM>, or a combination thereof. Additionally, the cutouts <NUM> may enable transportation of the tool assembly <NUM> and the pieces <NUM>, <NUM>, <NUM> thereof. For example, forklift forks can be inserted through one or more of the cutouts <NUM> to lift, move, manipulate, and assemble the tool assembly <NUM>. Additionally or alternatively, one or more pieces <NUM>, <NUM>, <NUM> of the tool assembly <NUM> include ribs or supports (not shown) to enable moving or manipulating the tool assembly <NUM> or the pieces <NUM>, <NUM>, <NUM> thereof. For example, the ribs or supports may form channels or guides for the forks of the forklift or lifting means of another moving apparatus.

The pieces <NUM>, <NUM>, <NUM> are joined by joint portions, such as the joint portions <NUM>, <NUM> of <FIG>, as described and illustrated with reference to <FIG>. <FIG> also depicts cross-section line A-A oriented along the longitudinal axis <NUM> passing through the pieces <NUM>, <NUM>, <NUM>. <FIG> further illustrate and describe other examples of joint portions, such as the joint portions <NUM>, <NUM> of <FIG>, of the pieces <NUM>, <NUM>, <NUM>.

<FIG> is a diagram that illustrates an isometric view of a cross-section line A-A of the tool assembly <NUM> of <FIG> depicting joints <NUM>, <NUM> thereof. <FIG> illustrates an example joint scheme of the tool assembly <NUM>. As illustrated in <FIG>, the tool assembly <NUM> includes the first piece <NUM> having a female joint portion, a second piece <NUM> having two male joint portions, and a third piece <NUM> having a female joint portion. In other implementations, the tool assembly <NUM> may include one or more pieces having one male joint portion, one female joint portion, two male joint portions, two female joint portions, one male and female joint portion, or a combination thereof. A first joint <NUM> is formed by the first and second pieces <NUM>, <NUM>, and a second joint <NUM> is formed by the second and third pieces <NUM>, <NUM>, as illustrated and described further with reference to <FIG>.

In some implementations, the joints <NUM>, <NUM> extend in the transverse axis <NUM> along the width of the pieces <NUM>, <NUM>, <NUM>. In other implementations, the pieces <NUM>, <NUM>, <NUM> include one or more sections of joints <NUM>, <NUM> along the transverse axis <NUM>. For example, the pieces <NUM>, <NUM>, <NUM> are joined by one or more sections of joints <NUM>, <NUM> and by sections of one or more other joints (e.g., butt joints) positioned between the sections of joints <NUM>, <NUM> along the transverse axis <NUM>.

<FIG> is another diagram that illustrates an expanded isometric view of the cross-section of the tool assembly <NUM> of <FIG> depicting the joints <NUM>, <NUM> thereof. As illustrated in <FIG>, the second piece <NUM> includes a third joint portion <NUM> and the third piece <NUM> includes a fourth joint portion <NUM>. The third joint portion <NUM> of the second piece <NUM> is configured to join with the fourth joint portion <NUM> of the third piece <NUM> of the tool assembly <NUM>. Thus, <FIG> depicts the first joint <NUM> formed by the first and second joint portions <NUM>, <NUM> of the first and second pieces <NUM>, <NUM>, and the second joint <NUM> formed by the third and fourth joint portions <NUM>, <NUM> of the second and third pieces <NUM>, <NUM>.

In some implementations, the third joint portion <NUM> has a shape similar to the first joint portion <NUM> or the second joint portion <NUM>. As illustrated in the implementation shown in <FIG>, the third joint portion <NUM> has a shape (e.g., a male joint portion shape) that is similar to a shape of the second joint portion <NUM> and the fourth joint portion <NUM> has a shape (e.g., female joint portion shape) that is similar to a shape of the first joint portion <NUM>.

As illustrated in <FIG>, the male joint portions, i.e., the second and third joint portions <NUM>, <NUM>, include tabs <NUM> (e.g., protrusions) which fit into recesses of the female joint portions, the first and fourth joint portions <NUM>, <NUM>. The surfaces of the joint portions <NUM>, <NUM>, <NUM>, <NUM> may include angled surfaces (e.g., the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> of <FIG>) as illustrated in <FIG> and <FIG>. The angled surfaces (e.g., the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> of <FIG>) may help the joints <NUM>, <NUM> accommodate thermal expansion of the pieces <NUM>, <NUM>, <NUM> better than horizontal or vertical surfaces.

Thermal expansion of a component is based on or governed by a few properties of the component, such as material composition, arrangement (e.g., micro arrangement such as wood grain or fiber arrangement), and size. For linear thermal expansion (e.g., thermal expansion along a particular axis), thermal expansion of a component is dependent on a length of the component in the particular axis and a particular coefficient of thermal expansion along the particular axis, which is dependent based on the material and the arrangement. To illustrate, for the first piece <NUM>, thermal expansion along the longitudinal axis <NUM> is much greater (e.g., <NUM> times greater) than thermal expansion along the vertical axis <NUM> because the length of the first piece <NUM> in the longitudinal axis <NUM> is greater than the thickness the first piece <NUM> in the vertical axis <NUM> and because the coefficient of the thermal expansion along the longitudinal axis <NUM> is greater than the coefficient of the thermal expansion along the vertical axis <NUM>. In a particular implementation, the material of the first piece <NUM> has a <NUM> times greater coefficient of thermal expansion in the longitudinal axis <NUM>, as compared to the vertical axis <NUM>, because fibers of the material are oriented with the longitudinal axis <NUM>. Thermal expansion along the transverse axis <NUM> is substantially parallel to an orientation of the joints <NUM>, <NUM> and thus, thermal expansion along the transverse axis <NUM> affects the joints <NUM>, <NUM> to a lesser amount than thermal expansion along the vertical or longitudinal axes <NUM>, <NUM>.

For conventional joints, such a difference in thermal expansion between the axes <NUM>, <NUM> may cause the layup surface <NUM> of <FIG> to deform. For example, joint portions <NUM>, <NUM> may deflect along the vertical axis <NUM> (e.g., upwards as illustrated in <FIG>) and deform a layup surface. In the implementation illustrated in <FIG>, the geometry of the tab <NUM> causes the tab <NUM> to remain in place or deflect downwards as illustrated in <FIG>, and thus the layup surface <NUM> is preserved. Additionally, fasteners or adhesives can be added to cause the tab <NUM> to remain in place or resist deflection in the vertical axis <NUM>, which preserves the geometry of layup surface <NUM>.

<FIG> is a diagram that illustrates an exploded view of joint portions <NUM>, <NUM> of first and second pieces <NUM>, <NUM> of the tool assembly <NUM> of <FIG>. The exploded view is of cross-sections of the first and second joint portions <NUM>, <NUM>.

The first joint portion <NUM> of the first piece <NUM> includes a top surface 136a, intermediate surfaces <NUM>, <NUM>, a vertical edge surface <NUM>, a bottom surface <NUM>, the first interlock surface <NUM>, and a third interlock surface <NUM>. As illustrated in <FIG>, the top surface 136a of the first piece <NUM> is also part of the layup surface <NUM>. In some implementations, the vertical edge surface <NUM> include a notch <NUM>. In some such implementations, a portion of the vertical edge surface <NUM> contacts the second joint portion <NUM>, such as the portion of the vertical edge surface <NUM> below the notch <NUM> as illustrated in <FIG>.

The top surface 136a and the first interlock surface <NUM> form an obtuse angle corner <NUM> (e.g., an obtuse angle edge). The first interlock surface <NUM> and a first intermediate surface <NUM> form an obtuse angle corner <NUM>. The first intermediate surface <NUM> and the third interlock surface <NUM> form an obtuse angle corner <NUM>. The third interlock surface <NUM> and the second intermediate surface <NUM> form another obtuse angle corner <NUM>. The second intermediate surface <NUM> and the vertical edge surface <NUM> form a substantially right angle corner <NUM>. The vertical edge surface <NUM> and the bottom surface <NUM> form a substantially right angle corner.

The second joint portion <NUM> of the second piece <NUM> includes a top surface 136b, intermediate surfaces <NUM>, <NUM>, vertical edge surface <NUM>, a bottom surface <NUM>, the second interlock surface <NUM>, and a fourth interlock surface <NUM>. As illustrated in <FIG>, the top surface 136b of the second piece <NUM> is also part of the layup surface <NUM>.

The top surface 136b and the second interlock surface <NUM> form an obtuse angle corner <NUM>. The second interlock surface <NUM> and a first intermediate surface <NUM> form an obtuse angle corner <NUM>. A second intermediate surface <NUM> and the fourth interlock surface <NUM> form an obtuse angle corner <NUM>. The fourth interlock surface <NUM> and the second intermediate surface <NUM> form an obtuse angle corner <NUM>. The second intermediate surface <NUM> and the vertical edge surface <NUM> form a substantially right angle corner <NUM>. The vertical edge surface <NUM> and the bottom surface <NUM> form another substantially right angle corner.

In some implementations, the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> are oriented at a <NUM> degree angle relative to the longitudinal axis <NUM> of <FIG>. By orienting the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> as opposing surfaces at a <NUM> degree angle or a <NUM> degree angle, the joint <NUM> becomes self-locking. These <NUM> degree or <NUM> degree angle opposing surfaces help mitigate cracks in a bond (e.g., a bond line) of the joint <NUM> which occur from the thermal stresses the tool assembly <NUM> encounters during curing. By mitigating these cracks in the bond line, the tool assembly <NUM> is able to maintain vacuum integrity (e.g., maintain vacuum pressure applied) during fabrication of the composite part <NUM> of <FIG>.

In some implementations, one or more of the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM>, the top surfaces 136a, 136b, the intermediate surfaces <NUM>, <NUM>, <NUM>, <NUM>, or the vertical edge surfaces <NUM>, <NUM> of the joint portions <NUM>, <NUM> form filleted (e.g., rounded) or chamfered corners <NUM>. Thus, one of more of the acute angle corner <NUM>, or the obtuse angle corners <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are filleted or chamfered corners <NUM>. As illustrated in <FIG>, the obtuse angle corners <NUM>, <NUM>, <NUM>, <NUM> are filleted (e.g., rounded) corners <NUM>. Such filleted or chamfered corners <NUM> can reduce localized stress and strain maximums and, therefore, breaking or cracking of the joint portions <NUM>, <NUM>. For example, as compared to sharp angled (e.g., acute corners and/or non-filleted or chamfered corner) or right angled edges and corners, filleted (e.g., rounded) or chamfered corners and edges are less likely to cause localized stress and strain maximums and, therefore, breaking or cracking.

The first and second joint portions <NUM>, <NUM> further include tangs <NUM>, <NUM> respectively. The tangs <NUM>, <NUM> are configured to contact each other to form a joint. For example, the tangs <NUM>, <NUM> contact each other via the vertical edge surfaces <NUM>, <NUM> below the notch <NUM>. The tangs <NUM>, <NUM> form a trapezoidal shape when joined, as illustrated in <FIG>. In some implementations, the tangs <NUM>, <NUM> provide a space for fasteners, as described with reference to <FIG> and <FIG>.

<FIG> is a diagram that illustrates a front view of the cross-section of the tool assembly <NUM> of <FIG> depicting joints thereof. <FIG> illustrates gaps <NUM>-<NUM> formed by mating the joint portions <NUM>, <NUM> of the first and second pieces <NUM>, <NUM>. As illustrated in <FIG>, the interlock surfaces <NUM>, <NUM> and the interlock surfaces <NUM>, <NUM> are in contact and are interlocked.

As illustrated in <FIG>, when the first and second joint portions <NUM>, <NUM> are joined (e.g., mated), a first gap <NUM> is formed by (e.g., positioned between and defined by) the surfaces <NUM>, <NUM> of <FIG>, a second gap <NUM> is formed by (e.g., positioned between and defined by) the surfaces <NUM>, <NUM> of <FIG>, and a third gap <NUM> is formed by (e.g., positioned between and defined by) the vertical edge surfaces <NUM>, <NUM> of <FIG>. As illustrated in <FIG>, the third gap <NUM> ends at the notch <NUM>. The end of the gap <NUM> and the notch <NUM> may define an upper portion of the tangs <NUM>, <NUM>, as illustrated in <FIG> by a dashed rectangle.

In <FIG>, the second gap <NUM> and the third gap <NUM> are connected. In other implementations or under certain conditions, such as thermal expansion, the second gap <NUM> and the third gap <NUM> are not connected. For example, a portion of one or more of the surfaces <NUM>, <NUM>, <NUM>, <NUM> of <FIG> near the corners <NUM>, <NUM> of <FIG> is in contact with a portion of another of the surfaces <NUM>, <NUM>, <NUM>, <NUM> of <FIG>. <FIG> also depicts a cross-section line B-B passing through the first gap <NUM>.

In some implementations, the joint <NUM> includes adhesive material <NUM> configured to form a bond (e.g., a bond line) between surfaces of the joint <NUM>. In certain implementations, the adhesive material <NUM> is applied to at least a portion of one of the first or second joint portions <NUM>, <NUM>. For example, the adhesive material <NUM> is applied to particular portions of the first and second joint portions <NUM>, <NUM>, such as to surfaces of the first and second joint portions <NUM>, <NUM> corresponding to the gaps <NUM>-<NUM>. In such implementations, the gaps <NUM>-<NUM> define bond lines which are areas where the surfaces of the first and second joint portions <NUM>, <NUM> are bonded by the adhesive material <NUM>. The bond line helps enable the joint <NUM> to maintain vacuum integrity. For example, the gaps <NUM>-<NUM> in the joint <NUM> provide space for the adhesive material <NUM> and inhibit movement of the adhesive material <NUM> to maintain the vacuum integrity of the joint <NUM>. Additionally, the gaps <NUM>-<NUM> provide space for thermal expansion of the material of the tool assembly <NUM>.

The adhesive materials <NUM> may include thermoset polyimides, benzoxazine resins, bismaleimides, thermoset polyurethanes, epoxies, phenolics, or vinyl esters. The adhesive material <NUM> may include or correspond to an adhesive paste or an adhesive film. An adhesive film may have a higher heat resistance (e.g., capable of withstanding high temperatures without deforming or reducing adhesion strength) as compared to adhesive pastes, but may be harder to assemble.

<FIG> is a diagram that illustrates a cross-section of another example of a tool assembly <NUM> including a first example of the fastener <NUM> of <FIG>. More specifically, the first example of the fastener <NUM> is a fastener assembly <NUM>. As illustrated in <FIG>, the fastener assembly <NUM> includes a bolt <NUM>, a washer <NUM>, a spring <NUM>, and a nut <NUM>. In other implementations, the spring <NUM> may be replaced by other biasing members, such as a spring washer, a Belleview washer, etc..

The fastener assembly <NUM> is positioned at least partially in a clearance hole (not shown) that passes through the tangs <NUM>, <NUM> of the first and second joint portions <NUM>, <NUM>. As illustrated in <FIG>, the fastener assembly <NUM> is oriented substantially parallel to the layup surface <NUM> and the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. In <FIG>, the fastener assembly <NUM> is positioned at least partially in a counter bore hole (e.g., recess). As illustrated in <FIG>, the fastener assembly <NUM> extends through the tangs <NUM>, <NUM> of the first and second joint portions <NUM>, <NUM>. In some implementations, multiple fastener assemblies <NUM> are placed through the tangs <NUM>, <NUM> of <FIG> along the transverse axis <NUM> of <FIG> to join the first and second pieces <NUM>, <NUM>.

When in a high temperature environment, such as when curing composite parts, or upon heating, the spring <NUM> enables the fastener assembly <NUM> to maintain a retention force joining the first and second pieces <NUM>, <NUM> while allowing for thermal expansion of the first and second pieces <NUM>, <NUM>. Specifically, the spring <NUM> can deform (e.g., extend and compress) such that the fastener assembly <NUM> provides the retention force at varying lengths or stages of thermal expansion. Additionally, the fastener assembly <NUM> is configured to relieve stress and strain on the tool assembly <NUM> when the tool assembly <NUM> is moved or handled. Furthermore, the fastener assembly <NUM> helps maintain the vacuum integrity of the tool assembly <NUM>.

<FIG> is a diagram that illustrates a cross-section of the tool assembly <NUM> of <FIG> including a second example of the fastener <NUM> of <FIG>. More specifically, the second example of the fastener <NUM> is a second fastener assembly <NUM>. As illustrated in <FIG>, the second fastener assembly <NUM> includes a screw <NUM>, the washer <NUM>, and the spring <NUM>. In other implementations, the second fastener assembly <NUM> includes a different biasing member in place of the spring <NUM>. Alternatively, the second fastener assembly <NUM> includes or corresponds to a blind fastener. In such implementations, the second piece <NUM> include a threaded section or a blind nut.

The second fastener assembly <NUM> is configured to join the first and second pieces <NUM>, <NUM>. As illustrated in <FIG>, the first piece <NUM> include a counter bore hole <NUM>, and the second fastener assembly <NUM> is inserted into the counter bore hole <NUM>. A shank of the screw <NUM> passes through a clearance hole <NUM> of the first piece <NUM> where threads <NUM> of the screw <NUM> do not engage with (i.e., contact) the first piece <NUM>. The threads <NUM> of a distal end of the screw <NUM> opposite the washer <NUM> and a screw head engage (i.e., contact) the second piece <NUM> in a pilot hole <NUM> thereof. Although the screw <NUM> is illustrated as fully threaded in <FIG>, in other implementations, a portion of the shank of the screw <NUM> is unthreaded (e.g., a partially threaded screw <NUM> or shank). In other implementations, the first piece <NUM> includes a counter sink hole or a recess in the alternative to the counter bore hole <NUM>.

Because the screw <NUM> of the second fastener assembly <NUM> drives into the second piece <NUM> (e.g., the top piece of the joint <NUM>), the second fastener assembly <NUM> secures (e.g., pulls) the pieces <NUM>, <NUM> together, which stabilizes the joint <NUM>. Because the threads <NUM> of the screw <NUM> pass through the clearance hole <NUM> of the first piece <NUM>, the second fastener assembly <NUM> enables the material of the tool assembly <NUM> to expand in a high temperature environment (e.g., enables the first piece <NUM>, the second piece <NUM>, and/or the gap <NUM> to expand and contract). The spring <NUM> enables thermal expansion of the tool assembly <NUM> and can inhibit transferring stress and strain causes by thermal expansion of the tool assembly <NUM> into the screw <NUM> itself. The second fastener assembly <NUM> helps maintain the vacuum integrity of the tool assembly <NUM>. In some implementations, multiple second fastener assemblies <NUM> are placed along a centerline of the joint <NUM> (e.g., along the transverse axis <NUM> of <FIG> between the first and second pieces <NUM>, <NUM>).

<FIG> are each a diagram that illustrates an example of joint portions of other joints for tool assemblies <NUM>. <FIG> illustrate cross-section views of the joints. <FIG> illustrate examples of a lap joint (e.g., a half lap splice joint). <FIG> illustrates an example cross-section of a half lap splice joint <NUM> including a third example of the fastener <NUM> of <FIG>, i.e., a third fastener assembly <NUM>. As illustrated in <FIG>, the third fastener assembly <NUM> includes a bolt <NUM>, two washers <NUM>, and a nut <NUM>. <FIG> illustrates another example cross-section of a half lap splice joint <NUM> including a fourth example of the fastener <NUM> of <FIG>, i.e., a fourth fastener <NUM>. As illustrated in <FIG>, the fourth fastener <NUM> includes or corresponds to a screw, such as the screw <NUM> of <FIG>.

<FIG> illustrate examples of a tongue and groove joint <NUM>. As compared the lap joints <NUM> of <FIG>, the tongue and groove joints <NUM> of <FIG> have inserts or tongues <NUM> that are positioned between the layup surface <NUM> of <FIG> and top surfaces 136a, 136b of <FIG> or bottom surfaces <NUM>, <NUM> of <FIG> of the joint portions <NUM>, <NUM>. As illustrated in <FIG>, the tongues <NUM> are positioned below or beneath the layup surface <NUM> of <FIG> and the top surfaces 136a, 136b of the first and second pieces in the vertical axis <NUM> of <FIG>.

<FIG> illustrate examples of scarf joints <NUM> (e.g., nibbed scarf joints). The scarf joints <NUM> of <FIG> include the interlock surfaces <NUM>, <NUM> and a nib <NUM> (e.g., a blunt portion or feature that engages a matching shoulder in the mating piece). The interlock surfaces <NUM>, <NUM> are angled relative to the top surfaces 136a, 136b.

<FIG> illustrate examples of a nibbed scarf joint <NUM> with the third fastener assembly <NUM>. As compared to the nib <NUM> of <FIG>, the nib 934a of <FIG> is larger or deeper in the vertical axis <NUM> of <FIG>. <FIG> illustrate examples of nibbed scarf joints <NUM> with the fourth fastener <NUM>. As compared to the nibs <NUM>, 934a of <FIG> which have substantially vertical surfaces, the nibs 934b corresponding to the top surfaces 136a, 136b of <FIG> (e.g., upper nibs 934b as illustrated in <FIG>) have angled surfaces <NUM> and form an obtuse angled corner <NUM> or outside edge <NUM> with the angled surface <NUM>.

<FIG> illustrates an example of a beveled lap joint <NUM> (e.g., a beveled lap splice joint). As compared to the half lap splice joint <NUM> of <FIG>, the beveled lap splice joint <NUM> has an angled intermediate surface <NUM>. The angled intermediate surface <NUM> includes a pair of complementary intermediate surfaces that are positioned at an angle relative to the layup surface <NUM>.

<FIG> illustrates an example of a combination joint <NUM> (e.g., a beveled lap and scarf joint). The combination joint <NUM> includes a scarf joint <NUM> where the nib <NUM> is a beveled lap joint <NUM>. As illustrated in <FIG>, the scarf joint <NUM> starts from one end of a beveled lap joint <NUM>. As compared the beveled lap joint <NUM> of <FIG>, the combination joint <NUM> of <FIG> includes an angled scarf portion <NUM>, which includes the interlock surfaces <NUM>, <NUM>. As illustrated in <FIG>, the combination joint <NUM> includes the fourth fastener <NUM> inserted into the counter bore hole <NUM> of the second joint portion <NUM> of the second piece <NUM>. In some implementations, the second joint portion <NUM> includes the clearance hole <NUM> and the threads <NUM> of the third fastener assembly <NUM> do not contact the second joint portion <NUM> in the clearance hole <NUM>. As illustrated in <FIG>, the fourth fastener <NUM> is oriented at an angle relative to the layup surface <NUM> and the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. The fourth fastener <NUM> is oriented substantially orthogonal to the angled scarf portion <NUM> and passes through tangs <NUM>, <NUM> of the first and second joint portions <NUM>, <NUM>.

<FIG> illustrates an example of an angled tabled splice joint <NUM> (a. , a hooked scarf joint). As illustrated in <FIG>, the angled tabled splice joint <NUM> includes the fourth fastener <NUM> inserted into the counter bore hole <NUM> of the first joint portion <NUM>. In some implementations, the first joint portion <NUM> includes the clearance hole <NUM> and the threads <NUM> of the screw <NUM> do not contact the first joint portion <NUM> in the clearance hole <NUM>.

As illustrated in <FIG>, the fourth fastener <NUM> and the counter bore hole <NUM> are oriented substantially orthogonal to the angled intermediate surface <NUM> and are angled relative to the layup surface <NUM> of <FIG> and to the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. Additionally or alternatively, the fourth fastener <NUM> and/or one or more additional fasteners, such as one of the fasteners <NUM>, <NUM> or one of the fastener assemblies <NUM>, <NUM>, <NUM> may be arranged along the vertical axis <NUM> of <FIG> and substantially orthogonal to the layup surface <NUM> of <FIG> and the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. As compared to the joint <NUM> of <FIG> and <FIG>, which has the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> positioned at an angle relative to the layup surface <NUM> and the intermediate surfaces <NUM>, <NUM> that are substantially parallel to the layup surface <NUM>, the angled tabled splice joint <NUM> of <FIG> includes vertical interlock surfaces <NUM>, <NUM> and the angled intermediate surfaces <NUM>, <NUM>. The vertical interlock surfaces <NUM>, <NUM> each include a pair of complementary interlock surfaces (e.g., such as the interlock surfaces <NUM>, <NUM>) that are substantially orthogonal to the layup surface <NUM>.

<FIG> illustrates an example of an angled tabled splice joint <NUM> with the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM> positioned at an angle relative to the layup surface <NUM>. As illustrated in <FIG>, the first joint portion <NUM> of the angled tabled splice joint <NUM> includes the counter bore hole <NUM> and the clearance hole <NUM>, and the second joint portion <NUM> includes the pilot hole <NUM> for receiving a fastener, such as the fourth fastener <NUM>. Alternatively, the pilot hole <NUM> can be replaced with or configured to receive a threaded portion (e.g., a blind nut) of a blind fastener such that that first and second joint portions <NUM>, <NUM> can be joined with the blind fastener. As illustrated in <FIG>, the holes <NUM>-<NUM> are arranged along the vertical axis <NUM> of <FIG> and substantially orthogonal to the layup surface <NUM> of <FIG> and the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. Additionally or alternatively, a fastener, such as one of the fasteners <NUM>, <NUM> or one of the fastener assemblies <NUM>, <NUM>, <NUM> may be oriented substantially orthogonal to a second angled intermediate surface <NUM> and angled relative to the layup surface <NUM> of <FIG> and the top surfaces 136a, 136b of the first and second pieces <NUM>, <NUM>. As compared to the joint <NUM> of <FIG> and <FIG>, the angled tabled splice joint <NUM> of <FIG> includes the angled intermediate surfaces <NUM>, <NUM>.

In some implementations, the angled tabled splice joint <NUM> includes gaps <NUM>-<NUM>, as illustrated in <FIG>. The gaps <NUM>-<NUM> may be configured to receive adhesive materials <NUM>, keys, or wedges. For example, the gaps <NUM>, <NUM> may include key holes and be configured to receive a key or wedge. Insertion of the key or wedge tightens the angled tabled splice joint <NUM>.

<FIG> are depicted with a particular type of fastener, such as one of the third fastener assemblies <NUM> or the fourth fasteners <NUM>. In other implementations, other types of fasteners may be used with the examples depicted in <FIG>, such as one or more of the fasteners <NUM>, <NUM> or one or more of the fastener assemblies <NUM>, <NUM>, <NUM>. In some implementations, the joints <NUM>-<NUM> of <FIG> include or more additional fasteners. For example, the example joints may include multiple fasteners of the some type as illustrated and/or one or more additional fasteners of another type. Additionally or alternatively, the joints <NUM>-<NUM> of <FIG> further include the adhesive material <NUM> of <FIG>. In some implementations, the corners or edges of the joints of <FIG> are filleted corners or chamfered corners.

<FIG> is a diagram that illustrates an example of a piece, such as the first piece <NUM>, of the tool assembly <NUM> including an annular ring seal <NUM> (e.g., a tubular seal or an O-ring seal). In some examples, the annular ring seal <NUM> is cylindrical with an inlet and an opposing outlet. The annular ring seal <NUM> is positioned between the first interlock surface <NUM> and the second interlock surface <NUM> (not shown in <FIG>). The annular ring seal <NUM> is configured to create or maintain an air-tight seal between the interlock surfaces <NUM>, <NUM>. For example, joining of the first and second pieces <NUM>, <NUM> (e.g., joint portions <NUM>, <NUM> thereof) compresses the annular ring seal <NUM> and creates or maintains the vacuum sealing. As illustrated in <FIG>, the annular ring seal <NUM> is positioned in the middle of the first interlock surface <NUM> and extends along the first interlock surface <NUM> in the transverse axis <NUM>. In other implementations, the annular ring seal <NUM> may be placed on the first interlock surface <NUM> closer to or further from the top of the tool assembly <NUM> (e.g., the layup surface <NUM>).

In some implementations, one or both of the interlock surfaces <NUM>, <NUM> include a recess to accommodate the annular ring seal <NUM>. The recess is configured to enable insertion or placement of the annular ring seal <NUM> when the tool assembly <NUM> is disassembled and retention of the annular ring seal <NUM> when the tool assembly <NUM> is assembled.

In some implementations, the annular ring seal <NUM> is used in the alternative to the adhesive material <NUM> of <FIG>. For example, when the tool assembly <NUM> is not exposed to significant handling (e.g., handling conditions that cause loads which create deflections which are greater than the adhesive material <NUM> or an adhesive bond formed therefrom can withstand).

In other implementations, the annular ring seal <NUM> is used in conjunction with the adhesive material <NUM> of <FIG>. For example, the annular ring seal <NUM> provides additional sealing or backup sealing such that cracks in the adhesive bond formed by the adhesive material <NUM> do not lead to leaks or loss of vacuum integrity. Such cracks in the adhesive bond may occur in large tools from handling or exposure to repeated curing processes.

<FIG> illustrates a plurality of fastener assemblies <NUM> to couple the first piece <NUM> to the second piece <NUM>. Although the example of the tool assembly <NUM> illustrated in <FIG> does not illustrate fasteners extending through the first and second pieces <NUM>, <NUM> in the vertical axis <NUM>, such as the second fastener assembly <NUM> of <FIG>, in other implementations the tool assembly <NUM> includes one or more fasteners extending through the first and second pieces <NUM>, <NUM> in the vertical axis <NUM>, as described with reference to <FIG>. Additionally, the pieces <NUM>, <NUM>, <NUM> of the tool assembly <NUM> of <FIG> may have joint portions (e.g., the joint portions <NUM>, <NUM>) that extend along only a portion of a width of the tool assembly <NUM> in the transverse axis <NUM>, as illustrated in <FIG>.

<FIG> is a diagram that illustrates an example of a tool assembly <NUM> including the annular ring seal <NUM> (e.g., a tubular seal or O-ring seal) and a support plate <NUM>. The support plate <NUM> is configured to secure two adjoining pieces (e.g., the first and second pieces <NUM>, <NUM>) and is fastened to a side surface <NUM> using one or more fasteners, such as the fastener <NUM> of <FIG>. As illustrated in <FIG>, the support plate <NUM> is coupled to the tool assembly <NUM> using two screws <NUM>, one for each piece <NUM>, <NUM>. In some implementations, as shown in <FIG>, the support plate <NUM> covers or protects the annular ring seal <NUM>. To illustrate, the support plate <NUM> covers and protects an inlet, an outlet, both, (i.e., "ends") of the annular ring seal <NUM>. In such implementations, the support plate <NUM> creates or maintains the vacuum seal in conjunction with the annular ring seal <NUM>. In certain implementations, the annular ring seal <NUM> extends past the side surface <NUM> of the tool assembly <NUM> such that fastening the support plate <NUM> to the pieces <NUM>, <NUM> compresses the annular ring seal <NUM> and creates or maintains the vacuum sealing.

<FIG> is a diagram that illustrates a particular example of a piece of a tool assembly <NUM> including the annular ring seal <NUM> and tape <NUM>. In the example illustrated in <FIG>, the annular ring seal <NUM> extends in the transverse axis <NUM> to the side surface <NUM> of the first piece <NUM>.

The tape <NUM> (e.g., bag tape) is configured to secure a vacuum bag to the tool assembly <NUM> during curing and create a seal between the tool assembly <NUM> and the vacuum bag. The vacuum bag (not shown) is wrapped around the tool assembly <NUM> and includes a port from which air is removed to generate the vacuum pressure.

<FIG> is a diagram that illustrates another example of a piece, such as the first piece <NUM>, of a tool assembly <NUM> including the annular ring seal <NUM> and the tape <NUM>. In the example illustrated in <FIG>, the annular ring seal <NUM> extends to the top surface 136a (e.g., the layup surface <NUM>) of the first piece <NUM> underneath the tape <NUM> (e.g., between the tape <NUM> and the top surface 136a). For example, the inlet or the outlet of the annular ring seal <NUM> is positioned toward the top surface 136a. In the implementation illustrated in <FIG>, the annular ring seal <NUM> extends in the vertical and longitudinal axes <NUM>, <NUM> near the side surface <NUM>. In other implementations, the annular ring seal <NUM> extends to the top surface 136a without extending in the longitudinal axis <NUM>. For example, in tool assemblies <NUM> where the joint portions do not extend the entire width of the tool assembly <NUM> along the transverse axis <NUM>, as illustrated in <FIG>, the annular ring seal <NUM> curves upwards in the vertical and transverse axes <NUM>, <NUM> towards the ends of the tool assembly <NUM>. As another example, the annular ring seal <NUM> has a <NUM> degree curve and extends upwards in the vertical axis <NUM> near the ends of the tool assembly <NUM>.

As compared to the configuration illustrated in <FIG>, the configuration illustrated in <FIG> reduces vacuum losses from an area between the tape <NUM> and the annular ring seal <NUM>. Alternatively, the configuration in FIG. <NUM> reduces vacuum losses from the edges of the annular ring seal (e.g., reduces vacuum leaks near the ends the annular ring seal <NUM>).

In some implementations, the tool assembly <NUM> of <FIG> and <FIG> further includes a support plate, such as the support plate <NUM> of <FIG>. In certain implementations, the support plate <NUM> is coupled to the side surface <NUM>, and the annular ring seal <NUM> extends to the top surface 136a and the tape <NUM> (i.e., does not extend to the support plate <NUM>). In other implementations, the support plate <NUM> is coupled to the top surface 136a, and the annular ring seal <NUM> extends to the support plate <NUM>.

<FIG> illustrates a particular example of a method <NUM> of heating a tool assembly, such as the tool assembly <NUM>. The method <NUM> may be performed by the composite part manufacturing system <NUM>, the layup device, <NUM>, the curing device <NUM> of <FIG>, or a combination thereof, as illustrative, non-limiting examples. The tool assembly <NUM> may include one or more joints as described with reference to <FIG> and <FIG>. In <FIG>, optional steps of the method <NUM> are illustrated as dashed boxes.

In some implementations, the method <NUM> includes, at <NUM>, forming a first piece of a tool assembly, a second piece of the tool assembly, or both by additive manufacturing. For example, the tool assembly may include or correspond to the tool assembly <NUM> of <FIG>. The first and second pieces may each include or correspond to the first piece <NUM>, the second piece <NUM> of <FIG>, or the third piece <NUM> of <FIG>. To illustrate, the first piece <NUM>, the second piece <NUM>, or the third piece <NUM> of the tool assembly <NUM> may be formed or fabricated by an additive manufacturing process, as described with reference to <FIG>. Exemplary additive manufacturing process include fused filament fabrication, such as fused deposition modeling, plastic jet printing, <NUM>-D printing, powder bed processing, selective heat sintering, stereolithography, selective laser melting, selective laser sintering, and the like.

The method <NUM> includes, at <NUM>, joining a first piece of the tool assembly with a second piece of the tool assembly via a first joint portion and a second joint portion. The first and second joint portions may each include or correspond to the first joint portion <NUM> or the second joint portion <NUM> of <FIG>. The first and second joint portions <NUM>, <NUM> may be joined <NUM> by hand or by machinery. As another example, the joint portions may corresponds to joint portions of <FIG> and <FIG>.

The method <NUM> includes, at <NUM>, inserting a fastener through the first and second joint portions of the tool assembly. For example, the fastener may include or correspond to the fastener <NUM> of <FIG>, the fastener assembly <NUM> of <FIG>, the second fastener assembly <NUM> of <FIG>, the third fastener assembly <NUM> of <FIG>, or the fourth fastener <NUM> of <FIG>. Inserting the fastener <NUM>, <NUM> or the fastener assemblies <NUM>, <NUM>, <NUM> through the first and second joint portions <NUM>, <NUM> can secure the first and second joint potions <NUM>, <NUM> together such that first and second pieces <NUM>, <NUM> may be moved as a single tool assembly <NUM>, to form the layup surface <NUM>, or both. Additionally, the first and second joint portions may be joined <NUM> by hand or by machinery and may be secured, or further secured, by inserting <NUM> additional fasteners of a same or different type, applying adhesive material <NUM>, or both, as described with reference to <FIG>.

In some implementations, the method <NUM> further includes, at <NUM>, applying composite material onto a layup surface of the tool assembly. The layup surface is configured to support formation of a composite part and has a shape that is complementary to a shape of the composite part. For example, the layup device <NUM> applies <NUM> the composite material <NUM> onto the layup surface <NUM> of the tool assembly <NUM> responsive to receiving commands from the controller <NUM>, as described with reference to <FIG>. To illustrate, the composite material <NUM> may be applied <NUM> onto the layup surface <NUM> using any suitable method for positioning the composite material <NUM> on the tool assembly <NUM>. For example, the composite material <NUM> can be applied <NUM> by: (a) hand layup which includes manually placing the composite material <NUM> on the layup surface <NUM> by an individual, (b) robotically placed (e.g., pick-n-place) using a robot having a vacuum assist end effector as the layup device <NUM> to place the composite material <NUM> on to the layup surface <NUM>, (c) via Automated Fiber Placement (AFP) in which a machine, acting as the layup device <NUM>, places the composite material <NUM> on the layup surface <NUM>, especially for composite materials having a width within a range of predetermined widths, (d) via Automated Tap Laying (ATL) which is similar to AFP but used when the composite material <NUM> is a tape material, or (e) any combination of two or more of the (a)-(d).

The method <NUM> further includes, at <NUM>, applying heat to the tool assembly, where upon heating, interlock surfaces of the first and second joint portions tighten against each other. For example, the curing device <NUM> applies <NUM> heat to the tool assembly <NUM> to further contact each other or interlock to tighten the interlock surfaces <NUM>, <NUM> against each other, as described with reference to <FIG>. Preferably, the composite material <NUM> is applied <NUM> onto the layup surface <NUM> prior to applying <NUM> the heat to the tool assembly <NUM>. The tool assembly <NUM> in the heated condition maintains vacuum integrity and can be used to cure large composite parts, such as the composite part <NUM>, as described with reference to <FIG>. In certain implementations, upon or after applying <NUM> the heat, the tool assembly <NUM> expands longitudinally in the longitudinal axis <NUM> of <FIG> and the tab <NUM> deflects in the vertical axis <NUM> towards the bottom surface <NUM> (e.g., downwards).

In some implementations, the method <NUM> includes, at <NUM>, generating vacuum pressure between the composite material and the layup surface. For example, the vacuum system <NUM> generates vacuum pressure or vacuum conditions between the composite material <NUM> and the layup surface <NUM> of the tool assembly <NUM> responsive to receiving commands from the controller <NUM>, as described with reference to <FIG>. As illustrated in <FIG>, vacuum pressure is generated <NUM> after the heat is applied at <NUM>. In other implementations, vacuum pressure is generated <NUM> prior to the heat being applied to tool assembly at <NUM> or at least partially concurrently with the heat being applied to tool assembly at <NUM>.

In some implementations, the fastener <NUM> inserted at <NUM> includes or corresponds to a fastener device. The fastener device extends through tangs of the first and second joint portions, and the fastener device is configured to enable the tool assembly <NUM> to undergo thermal expansion and still maintain vacuum integrity. For example, the fastener device includes or corresponds to fastener assembly <NUM> of <FIG> or the second fastener assembly <NUM> of <FIG>. To illustrate, the fastener assembly <NUM> extends through the tangs <NUM>, <NUM> of <FIG> along the longitudinal axis <NUM> of <FIG>, as described with reference to <FIG>. In certain implementations, the fastener <NUM> is substantially parallel to the layup surface <NUM> for longitudinally aligned arrangements or is substantially parallel to a local tangent of the layup surface <NUM> for circumferentially aligned arrangements. In other implementations, the fastener <NUM> is substantially orthogonal to the layup surface <NUM> for longitudinally aligned arrangements or is substantially orthogonal to a local tangent of the layup surface <NUM> for circumferentially aligned arrangements. Alternatively, the fastener <NUM> is substantially orthogonal to a particular interlock surface <NUM>, <NUM> or an intermediate surface <NUM>, <NUM> of the tool assembly <NUM>.

In some implementations, a joint formed by the first and second joint portions includes one or more gaps defined by surfaces of the first and second joint portions. For example, the joint <NUM>, <NUM> include the gaps <NUM>-<NUM>, as described with reference to <FIG>. In some such implementations, the joint includes adhesive material positioned in the one or more gaps in between surfaces the first and second joint portions. The adhesive material is configured to maintain vacuum integrity of the joint. For example, one or more of the gaps <NUM>-<NUM> of the joint <NUM>, <NUM> include the adhesive material <NUM> on at least a portion of one of the surfaces thereof, as described with reference to <FIG>.

In some implementations, prior to joining the first piece and the second piece, the method <NUM> further includes applying an adhesive paste or an adhesive film to at least a portion of the first joint portion of the first piece. For example, the adhesive material <NUM> of <FIG> may be applied to surfaces corresponding to the gaps <NUM>-<NUM> of the joint portions <NUM>, <NUM> as a paste or a film, as described with reference to <FIG> and <FIG>.

In certain implementations, the fastener does not pass through interlock surfaces or angled interlock surfaces. For example, the fastener assembly <NUM> of <FIG> and the second fastener assembly <NUM> of <FIG> do not extend through any of the interlock surfaces <NUM>, <NUM>, <NUM>, <NUM>, as described with reference to <FIG> and <FIG>.

In some implementations, the tool assembly further includes one or more second fasteners configured to couple the first piece to the second piece. For example, a particular tool assembly <NUM> includes the fastener assembly <NUM> and one or more second fastener assemblies <NUM>, as described with reference to <FIG>. In some such implementations, the fastener, the one or more second fasteners, or a combination thereof, include or correspond to a spring-loaded device or a blind fastener configured to allow thermal expansion of the tool assembly. For example, the fastener includes or corresponds to the fastener assembly <NUM> of <FIG> and the second fastener assembly <NUM> of <FIG> including the spring <NUM> or a biasing member. In certain implementations, the one or more second fasteners are substantially orthogonal to the fastener. For example, the fastener assembly <NUM> is oriented with or parallel to the longitudinal axis <NUM> and the one or more second fasteners are oriented with or parallel the vertical axis <NUM>, as described with reference to <FIG> and <FIG>.

In some implementations where the joint portions <NUM>, <NUM> correspond to the joint portions of <FIG> and include the obtuse angle corners <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the acute angle corner <NUM>, the obtuse angle corners are at approximately <NUM> degrees and the acute angle corner is at approximately <NUM> degrees. For example, the angles are manufactured within design tolerances or plus or minus <NUM> degrees. In such implementations, the angle of the corners reduces normal and shear stresses on the joints <NUM>, <NUM>. In some implementations, the corners include or correspond to filleted corners, chamfered corners, or a combination thereof. Such corners reduce normal and shear stresses (e.g., prevent or reduce local maximums of stresses) on the joints <NUM>, <NUM>.

In some implementations, the first piece includes a material that has an anisotropic coefficient of thermal expansion. For example, the first piece <NUM> may have a <NUM> times greater coefficient of thermal expansion in one axis (e.g., the longitudinal axis <NUM>) than another axis (e.g., the vertical axis <NUM>). In some such implementations, the first pieces includes a thermoplastic polymer material (e.g., ABS material or carbon filled ABS material), a thermoset polymer material, or another polymer material.

In some implementations, the first joint portion of the first piece further includes a third interlock surface, a first intermediate surface, and a second intermediate surface. The first intermediate surface and each of the first and second interlock surfaces form obtuse angle corners. The second intermediate surface and the second interlock surface forms another obtuse angle corner. For example, the first intermediate surface <NUM> and each of the first and third interlock surfaces <NUM>, <NUM> form obtuse angle corners <NUM>, <NUM>, and the second intermediate surface <NUM> and the third interlock surface <NUM> form another obtuse angle corner <NUM>, as described with reference to <FIG>. In certain implementations, the second intermediate surface and a vertical edge surface form a substantially right angle corner. For example, the second intermediate surface <NUM> and the vertical edge surface <NUM> form a substantially right angle corner <NUM>, as described with reference to <FIG>. Additionally or alternatively, the second joint portion of the second piece further includes a fourth interlock surface, a first intermediate surface, and a second intermediate surface. The first intermediate surface and each of the first and second interlock surfaces form obtuse angle corners. The second intermediate surface and the second interlock surface form another obtuse angle corner. For example, the first intermediate surface <NUM> and each of the second and fourth interlock surfaces <NUM>, <NUM> form obtuse angle corners <NUM>, <NUM>, and the second intermediate surface <NUM> and the fourth interlock surface <NUM> form another obtuse angle corner <NUM>, as described with reference to <FIG>.

In some implementations, the second piece further includes a third joint portion. The third joint portion having a shape similar to the first joint portion or the second joint portion and configured to join with a fourth joint portion of a third piece of the tool assembly. For example, the second piece <NUM> includes a third joint portion <NUM> that interlocks with the fourth joint portion <NUM> of the third piece <NUM>, as described with reference to <FIG> and <FIG>.

<FIG> illustrates a particular example of a method <NUM> of applying composite material to a tool assembly, such as the tool assembly <NUM>. The method <NUM> may be performed by the composite part manufacturing system <NUM>, the layup device, <NUM>, the curing device <NUM> of <FIG>, or a combination thereof, as illustrative, non-limiting examples. The tool assembly <NUM> may include one or more joints as described with reference to <FIG> and <FIG>. In <FIG>, optional steps of the method <NUM> are illustrated as dashed boxes.

In some implementations, the method <NUM> includes, at <NUM>, forming a first piece <NUM> of a tool assembly <NUM>, a second piece <NUM> of the tool assembly <NUM>, or both by additive manufacturing, as described with reference to <FIG>. In certain implementations, forming <NUM> includes forming a first joint portion <NUM> of the first piece <NUM> of the tool assembly <NUM> using an additive manufacturing process. The first joint portion <NUM> includes a top surface 136a and at least a first interlock surface <NUM>. Forming <NUM> further includes forming the second joint portion <NUM> of a second piece <NUM> of the tool assembly <NUM> using the additive manufacturing process. The second joint portion <NUM> includes a top surface 136b and at least a second interlock surface <NUM> that is complementary to the first interlock surface <NUM>.

In some implementations, forming <NUM> the first joint portion <NUM> includes forming an obtuse angle corner <NUM> between the first interlock surface <NUM> and the top surface <NUM> of the first joint portion <NUM> using the additive manufacturing process. Additionally, forming the second joint portion <NUM> includes forming an acute angle corner <NUM> between the second interlock surface <NUM> and the top surface 136b of the second joint portion <NUM> using the additive manufacturing process.

In some implementations, forming <NUM> further includes forming tangs <NUM>, <NUM> of the first and second joint portions using the additive manufacturing process. In some implementations, forming <NUM> the first and second joint portions <NUM>, <NUM> using the additive manufacturing process includes forming the first and second pieces using at least one of a fused filament fabrication process, a plastic jet printing process, a three-dimensional printing process, a powder bed processing process, a selective heat sintering process, a fused deposition modeling process, a stereolithography process, a selective laser sintering process, or a selective laser melting process.

The method <NUM> includes, at <NUM>, joining the first piece <NUM> of the tool assembly <NUM> with the second piece <NUM> of the tool assembly <NUM> via a first joint portion <NUM> and a second joint portion <NUM>, where the tool assembly <NUM> includes a layup surface <NUM>. The first and second joint portions may be joined <NUM> by hand or by machinery and may be joined <NUM> using the joint portions along with applying fasteners, adhesives, or both, as described with reference to <FIG>. As another example, the joint portions may correspond to joint portions of <FIG>.

The method <NUM> includes, at <NUM>, applying composite material <NUM> onto the layup surface <NUM>. The layup surface <NUM> is configured to support formation of a composite part <NUM> and has a shape that is complementary to a shape of the composite part <NUM>. In some implementations, applying composite material <NUM> onto the layup surface <NUM> includes depositing or placing the composite material <NUM> manually or by an automated device. For example, the composite material <NUM> may be deposited or placed by the layup device <NUM> to form the composite part <NUM>, as described with reference to <FIG>. Alternatively, the composite material <NUM> deposited or placed onto the layup surface <NUM> defines or corresponds to a working part (e.g., a not yet completed composite part), such as the working part <NUM> of <FIG>. In such implementations, the method <NUM> further includes, at 1136a, trimming the working part <NUM> to generate the composite part <NUM>, as described with reference to <FIG>.

In some implementations, the method <NUM> further includes, at <NUM>, generating vacuum pressure between the composite material <NUM> and the layup surface <NUM>. For example, the vacuum system <NUM> generates vacuum pressure or vacuum conditions between the composite material <NUM> and the layup surface <NUM> of the tool assembly <NUM> responsive to receiving commands from the controller <NUM>, as described with reference to <FIG>.

In some implementations, the method <NUM> further includes, at 1410a, applying heat and/or light to cure the composite material <NUM> and form the composite part <NUM>. For example, the curing device <NUM> applies 1410a heat and/or light to the composite material <NUM> to cure the composite material <NUM> and form the composite part <NUM>, as described with reference to <FIG>. As illustrated in <FIG>, heat may be applied 1410a to the tool assembly <NUM> after the vacuum pressure is optionally generated at <NUM>. In other implementations, the heat and/or light is applied 1410a to the tool assembly without generating the vacuum pressure at <NUM>, prior to the vacuum pressure being generated at <NUM>, or at least partially concurrently with the vacuum pressure being generated at <NUM>.

In some implementations, the tool assembly <NUM> further includes adhesive material <NUM> adhering the first piece to the second piece. For example, adhesive paste or adhesive film is applied to the intermediate surfaces <NUM>, <NUM> of the tool assembly <NUM>, as described with reference to <FIG>.

In some implementations, the tool assembly <NUM> of the method <NUM> or <NUM> is an additively manufactured tool assembly, e.g., one or more of the pieces <NUM>, <NUM>, <NUM> thereof are made by an additive manufacturing process, such as fused filament fabrication, such as fused deposition modeling, plastic jet printing, <NUM>-D printing, powder bed processing, selective heat sintering, selective laser sintering, stereolithography, selective laser melting, and the like. Because the tool assembly <NUM> has reduced costs and fabrication time, using the tool assembly <NUM> to fabricate the composite parts <NUM> has reduced costs and fabrication time, as compared to using metal tools and tool assemblies. Additionally, by using the tool assembly <NUM> including one or more of the joints described herein, the composite part manufacturing system <NUM> of <FIG> can form larger composite parts as compared to using smaller tool assemblies joined by butt joints to form smaller composite parts.

The method <NUM> of <FIG> and/or the method <NUM> of <FIG> may be initiated or controlled by an application-specific integrated circuit (ASIC), a processing unit, such as a central processing unit (CPU), a controller, another hardware device, a firmware device, a field-programmable gate array (FPGA) device, or any combination thereof. As an example, the method <NUM> of <FIG> and/or the method <NUM> of <FIG> can be initiated or controlled by one or more processors, such as one or more processors included in or coupled to the controller <NUM> of the composite part manufacturing system <NUM>. In some implementations, one or more operations of one of the methods <FIG> or <FIG> may be combined with one or more operations of the other of the methods of <FIG> or <FIG>. Additionally, one or more operations described with reference to the methods of <FIG> or <FIG> may be optional, may be performed in a different order than shown or described, or both. Additionally, two or more operations described with reference to the methods of <FIG> or <FIG> may be performed at least partially concurrently.

Referring to <FIG> and <FIG>, examples of the disclosure are described in the context of a vehicle manufacturing and service method <NUM> as illustrated by the flow chart of <FIG> and a vehicle <NUM> as illustrated by the block diagram of <FIG>. A vehicle produced by the vehicle manufacturing and service method <NUM> of <FIG>, such as the vehicle <NUM> of <FIG>, may include an aircraft, an airship, a rocket, a satellite, a submarine, a ship, an automobile, or another vehicle, as illustrative, non-limiting examples. The vehicle <NUM> may be manned or unmanned (e.g., a drone or an unmanned aerial vehicle (UAV)).

Referring to <FIG>, a flowchart of an illustrative example of a method of composite part manufacturing and service is shown and designated <NUM>. During pre-production, the exemplary method <NUM> includes, at <NUM>, specification and design of a vehicle, such as a vehicle <NUM> described with reference to <FIG>. During the specification and design of the vehicle <NUM>, the method <NUM> may include specifying a design of a composite part, such as a composite part <NUM> of <FIG>. At <NUM>, the method <NUM> includes material procurement. For example, the method <NUM> may include procuring materials (e.g., design and fabrication of the tool assembly <NUM> of <FIG>) for the vehicle <NUM>.

During production, the method <NUM> includes, at <NUM>, component and subassembly manufacturing and, at <NUM>, system integration of the vehicle <NUM>. The method <NUM> may include component and subassembly manufacturing (e.g., manufacturing the composite part <NUM> of <FIG>) of the vehicle <NUM> and system integration (e.g., coupling the composite part <NUM> of <FIG> to one or more components of the vehicle <NUM>). For example, at <NUM>, the system <NUM> of <FIG> can implement method <NUM> of <FIG> and/or method <NUM> of <FIG> to manufacture the composite part <NUM> that is then assembled at <NUM> to manufacture the vehicle <NUM>.

At <NUM>, the method <NUM> includes certification and delivery of the vehicle <NUM> and, at <NUM>, placing the vehicle <NUM> in service. Certification and delivery may include certifying the composite part <NUM> of <FIG> by inspection or non-destructive testing. While in service by a customer, the vehicle <NUM> may be scheduled for routine maintenance and service, which may also include modification, reconfiguration, refurbishment, and so on. At <NUM>, the method <NUM> includes performing maintenance and service on the vehicle <NUM>. The method <NUM> may include performing maintenance and service of the composite part <NUM>. For example, maintenance and service of the communications system may include replacing the composite part <NUM> or repairing a surface of the composite part <NUM>.

Each of the processes of the method <NUM> may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of vehicle manufacturers and major-system subcontractors; a third party may include without limitation any number of venders, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.

Referring to <FIG>, a block diagram of an illustrative implementation of the vehicle <NUM> that includes a composite part formed using a tool assembly, such as the tool assembly <NUM> of <FIG>. To illustrate, the vehicle <NUM> may include an aircraft, as an illustrative, non-limiting example. The vehicle <NUM> may have been produced by at least a portion of the method <NUM> of <FIG>. As shown in <FIG>, the vehicle <NUM> (e.g., an aircraft) may include an airframe <NUM>, an interior <NUM>, the composite part <NUM>, and a plurality of systems <NUM>. In other implementations, the airframe <NUM> includes or corresponds to the composite part <NUM>. For example, the composite part <NUM> may include or correspond to a wing, a section of the wing, a section of a fuselage, or other airframe <NUM> components. The plurality of systems <NUM> may include one or more of a propulsion system <NUM>, an electrical system <NUM>, an environmental system <NUM>, a hydraulic system <NUM> or a communication system <NUM>. The composite part <NUM> is formed or manufactured using the tool assembly <NUM>. The composite part <NUM> may be manufactured by the composite part manufacturing system <NUM> of <FIG>. For example the composite part <NUM> may be manufactured by one or more steps of the methods <NUM> and <NUM> of <FIG> and <FIG> and/or as described with reference to <FIG>.

Apparatus and methods included herein may be employed during any one or more of the stages of the method <NUM> of <FIG>. For example, components or subassemblies corresponding to production process <NUM> may be fabricated or manufactured in a manner similar to components or subassemblies produced while the vehicle <NUM> is in service, at <NUM> for example and without limitation. Also, one or more apparatus implementations, method implementations, or a combination thereof may be utilized during the production stages (e.g., stages <NUM>-<NUM> of the method <NUM>), for example, by substantially expediting assembly of or reducing the cost of the vehicle <NUM>. Similarly, one or more of apparatus implementations, method implementations, or a combination thereof, may be utilized while the vehicle <NUM> is in service, at <NUM> for example and without limitation, to maintenance and service, at <NUM>.

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.

Claim 1:
A tool assembly (<NUM>) comprising:
a first piece (<NUM>) having a first joint portion (<NUM>) including a top surface (136a) and at least a first interlock surface (<NUM>);
a second piece (<NUM>) having a second joint portion (<NUM>) configured to interlock with the first joint portion (<NUM>), the second joint portion (<NUM>) including a top surface (136b) and at least a second interlock surface (<NUM>) that is complementary to the first interlock surface (<NUM>); and
a fastener (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) extending through the first joint portion (<NUM>) and the second joint portion (<NUM>),
wherein the first interlock surface (<NUM>) and the top surface (136a) of the first joint portion (<NUM>) form an obtuse angle corner (<NUM>) and the second interlock surface (<NUM>) and the top surface (136b) of the second joint portion (<NUM>) form an acute angle corner (<NUM>),
wherein the first interlock surface (<NUM>) is configured to contact the second interlock surface (<NUM>) to inhibit relative movement between the first piece (<NUM>) and the second piece (<NUM>) along a longitudinal axis (<NUM>) of the tool assembly (<NUM>), and
wherein the first piece (<NUM>) further comprises a third interlock surface (<NUM>) and a first intermediate surface (<NUM>), and the first intermediate surface (<NUM>) and the first interlock surface (<NUM>) form an obtuse angle corner (<NUM>), and wherein the first intermediate surface (<NUM>) and the third interlock surface (<NUM>) form an obtuse angle corner (<NUM>).