Patent Description:
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Composite materials are used in aircraft to decrease the weight of the aircraft. This decreased weight improves performance features such as payload capacity and fuel efficiency. Further, composite materials provide longer service life for various components in an aircraft. Composite materials are tough, light-weight materials created by combining two or more functional components such as reinforcing fibers bound in a polymer resin matrix. The fibers may be unidirectional or may take the form of a woven cloth or fabric. The fibers and resins may be arranged and cured to form a composite structure.

Using composite materials to create aerospace composite structures can allow for portions of an aircraft to be manufactured in larger pieces or sections. For example, a fuselage in an aircraft can be created in cylindrical, half, or quarter sections that are assembled to form the fuselage of the aircraft. Other examples include, without limitation, wing sections joined to form a wing or stabilizer sections joined to form a stabilizer.

In manufacturing composite structures, layers of composite material can be laid up on a tool. The layers of composite material may be comprised of fibers in sheets. These sheets may take the form of, for example, fabrics, tape, tows, or other suitable configurations for the sheets. In some cases, a resin may be infused or pre-impregnated into the sheets. These types of sheets are commonly referred to as prepreg.

The different layers of prepreg can be laid up in different orientations and different numbers of layers can be used depending on the desired thickness of the composite structure being manufactured.

The layup of different layers forms an uncured composite structure. These layers can be consolidated and cured upon exposure to temperature and pressure, thus forming the final composite structure. The consolidation and curing can be performed using tools such as elastomeric bag and caul systems. These systems use disposable bagging materials covering a caul. The disposable bagging materials are secured using a sealant tape. Other components including an edge breather, release film, and flash breaker tape are also used in these systems. Current elastomeric bag and caul systems provide desired results but are often more time consuming to setup and expensive than desired. For example, it would be desirable to have a method and apparatus that overcome a technical problem with the set-up time and expense of current elastomeric bag and caul systems.

<CIT>, according to its abstract, states a method for manufacturing pieces of composite material by vacuum-bagging, wherein a laminate of uncured plies of composite material is layered up on a molding surface, and the upper surface of the laminate is then covered with one or more caul plates. Local vacuum bags are provided in the form of elongated strips or bands to locally seal the edges of the caul plates, such that the area of the local vacuum bags is smaller than the area of any of the caul plates.

<CIT>, according to its abstract, states fluid transfer and evacuation structures formed in a vacuum bag operable for use in vacuum-assisted resin transfer molding, debulking, compaction, or similar processes. A reusable vacuum bag can be provided including an elastomeric membrane having a preform-contact surface and at least one textured surface formed in the elastomeric membrane. The textured surface can define a fluid transfer channel. At least one fluid extraction port can be provided in communication with the fluid transfer channel, the fluid extraction port being adapted for engagement to a vacuum pump to remove fluids from the fluid transfer channel. The textured surface defining the fluid transfer channel can be adapted to permit the flow of fluids between the elastomeric membrane and a base mold in communication with the elastomeric membrane when the fluid extraction port is engaged to a vacuum pump.

An embodiment of the present disclosure provides a method for applying a vacuum-based pressure on an uncured composite structure. Membranes are bonded to a boundary of a caul. The membranes include positive features that define vacuum channels. The membranes are spliced to each other. The positive features that define the vacuum channels in the membranes are aligned to each other during splicing of the membranes. The membranes spliced to each other and bonded to the caul to form an integrated caul. The integrated caul applies a pressure on the uncured composite structure during operation of the integrated caul.

Another embodiment of the present disclosure provides a vacuum pressure system comprising a caul and membranes located on a boundary of the caul. The membranes are connected to the caul and have positive features defining vacuum channels. The caul and the membranes connected to the boundary of the caul form an integrated caul. The membranes are spliced together such that the vacuum channels are continuous through the membranes.

An example of the present disclosure provides a method for curing an uncured composite structure. An integrated caul is placed on the uncured composite structure. The integrated caul comprises membranes bonded to a caul in which the membranes include positive features that define vacuum channels and a filler in gaps between the membranes in which the filler has the positive features that form part of the vacuum channels that are continuous around a boundary of the caul. A vacuum is drawn in the vacuum channels such that the integrated caul applies a pressure on the uncured composite structure.

Another example of the present disclosure provides a product management system comprising a control system. The control system operates to place an integrated caul on an uncured composite structure. The integrated caul comprises membranes bonded to a caul in which the membranes include positive features that define vacuum channels and a filler in gaps between the membranes in which the filler has the positive features that form part of the vacuum channels that are continuous around a boundary of the caul. The control system operates to draw a vacuum in the vacuum channels such that the integrated caul applies a pressure on the uncured composite structure. The control system operates to cure the uncured composite structure while applying the pressure on the uncured composite structure using the integrated caul to form a composite structure.

The illustrative embodiments recognize and take into account one or more different considerations as described below. For example, the illustrative embodiments recognize and take into account that current bag and caul systems can take much more time than desired to set up for curing composite part. Example, with a section of the fuselage, the setup of the caul and elastomeric bag can take many hours. The elastomeric bag functions as a vacuum bag. Typically, a caul is applied with a consumable seal to the mandrel with the uncured composite structure laid up on the mandrel. This layup of the caul is followed by elastomeric bag and other components such as a release film, sealant tape, edge breathers, and other components. These components are used to draw a vacuum for consolidation and curing and can take <NUM> or more hours to put in place. The elastomeric bag, release film, sealant tape, edge breathers, and other components removed and discarded after curing.

As result, these components are consumables which are not reusable, increasing the cost. Thus, when another uncured composite structure is to be consolidated and cured, the caul is used with another elastomeric bag, and other components.

It is desirable to have a tooling system in which consolidation and curing of composite materials can be performed in less time. It is also desirable to reduce the number of components needed such as sealant tape, and elastomeric bag, release film, edge breather, and other components that may be considered to be consumables. As used herein, a "number of" when used with reference to items means one or more items. For example, a number of components is one or more components.

Thus, illustrative examples take into account one or more of the considerations discussed above as well as other considerations and provide a method, apparatus, and system for applying a vacuum-based pressure on uncured composite structure. This vacuum-based pressure can be used to perform consolidation and curing of the uncured composite structure. In the illustrative examples, an integrated caul is used in place of an elastomeric bag and caul system. The integrated caul comprises a caul and membranes. These membranes can be segments of elastomeric material around the boundary of the caul. These membranes are spliced together to form the integrated caul. The splicing can be performed using a filler that can be an uncured elastomer that joins the ends of a pair of membranes to each other. In these illustrative examples, the membrane includes channels that function as vacuum channels. When spliced using the filler, a continuous channel can be present around the boundary of the caul through which a vacuum can be drawn.

The integrated caul can be placed on a tool with an uncured composite structure in less time as compared to current elastomeric bag and caul systems. The use of an elastomeric bag is unnecessary. Further, the use of other components such as at least one of sealant tape, release film, edge breathers, or other components are unnecessary or can be reduced. This integrated caul is reusable for use in curing other uncured composite structures without needing another elastomeric bag with a consumable seal.

With reference now to the figures in particular with reference to <FIG>, a pictorial illustration of an integrated caul system placed on an uncured fuselage section laid up on a tool is depicted in accordance with an illustrative embodiment. In this illustrative example, integrated caul <NUM> is placed on an uncured fuselage section (not shown) laid up on tool <NUM>.

Integrated caul <NUM> comprises caul <NUM> and membranes <NUM>. In this example, membranes <NUM> are attached to boundary <NUM> of caul <NUM>. As seen in this view, membranes <NUM> comprises corner membrane <NUM>, end membrane <NUM>, end membrane <NUM>, corner membrane <NUM>, side membrane <NUM>, side membrane <NUM>, side membrane <NUM>, corner membrane <NUM>, end membrane <NUM>, and end membrane <NUM>. In this example, another corner membrane and two side membranes are also part of membranes <NUM> but not seen in this view.

As depicted, integrated caul <NUM> can be placed on the uncured composite structure laid up on tool <NUM> without performing operations such as placing nylon bag, sealant tape, release film, edge breathers, or other consumable components. As result, the amount of time is reduced as compared to current systems. Further, removal of these components is unnecessary since they are not used as part of integrated caul <NUM> for placement for curing the uncured composite structure. Additionally, the removal of integrated caul <NUM> is less complicated and takes less time as compared to current elastomeric bag and caul systems.

Moreover, integrated caul <NUM> is reusable without needing consumable components to cure another uncured composite structure. Additionally, where damage occurs to a membrane in membranes <NUM>, that membrane can be replaced, and the replacement membrane can be re-spliced with the other membranes and membranes <NUM>.

Turning next to <FIG>, an illustration of a block diagram of a composite manufacturing environment is depicted in accordance with an illustrative embodiment. In this illustrative example, integrated caul <NUM> in <FIG> is an example of a tool that can be used in composite manufacturing environment <NUM>.

As depicted, uncured composite structure <NUM> is comprised of uncured composite materials <NUM> laid up on tool <NUM>. In this illustrative example, uncured composite structure <NUM> can take a number of different forms. For example, uncured composite structure <NUM> can be selected from one of a full barrel fuselage section, half barrel fuselage section, quarter fuselage section, a skin panel, a door, a stringer, a stabilizer section, a fairing, or other suitable structure.

In this illustrative example, uncured composite materials <NUM> can take a number of different forms. For example, uncured composite materials <NUM> can be selected from at least one of fibers in a sheet, a fabric, a tape, a tow, a prepreg, or other suitable material. In this example, resin can be infused or pre-impregnated and is referred to as a prepreg.

In this illustrative example, uncured composite structure <NUM> laid up on tool <NUM> can be cured to form composite structure <NUM>. The process of curing uncured composite structure <NUM> can involve applying vacuum based pressure <NUM> on uncured composite structure <NUM>. The application of vacuum based pressure <NUM> can occur during at least one of consolidation or curing of uncured composite structure <NUM>.

As depicted, vacuum based pressure <NUM> can be applied to uncured composite structure <NUM> using vacuum pressure system <NUM>. In this illustrative example, vacuum pressure system <NUM> comprises integrated caul <NUM> and vacuum source <NUM>. Integrated caul <NUM> in <FIG> is an example of one implementation for integrated caul <NUM>.

Integrated caul <NUM> can be placed on uncured composite structure <NUM> laid up on tool <NUM>. In this illustrative example, integrated caul <NUM> comprises membranes <NUM> and caul <NUM>. In this illustrative example, membranes <NUM> are located on boundary <NUM> of caul <NUM>.

In this illustrative example, membranes <NUM> are comprised of at least one of silicon, a synthetic rubber and fluoropolymer elastomer, a fluoroelastomer, or other suitable material. In one example, a membrane can be comprised of more than one material. For example, membrane can be comprised of a silicon layer and a fluoroelastomer layer. For example, the fluoroelastomer layer can be used with a silicon layer to reduce diffusion of nitrogen. Further, this layer can be selected for compatibility with chromate or sealant tape.

Membranes <NUM> can be connected to caul <NUM> by bonding material <NUM>. Bonding material <NUM> can be selected from at least one of an adhesive, a glue, a resin, or other suitable material that can create a bond between membranes <NUM> and caul <NUM>.

Membranes <NUM> can be bonded to caul <NUM> prior to splicing membranes <NUM> to each other. In another implementation, membranes <NUM> can be bonded to caul <NUM> after to splicing membranes <NUM> to each other.

In this illustrative example, membranes <NUM> have features <NUM> that include positive features <NUM>. Positive features <NUM> are features that can define other features in feature <NUM> such as vacuum channels <NUM>. In this illustrative example, membranes <NUM> can be spliced together such that that vacuum channels <NUM> are continuous through membranes <NUM>.

In the illustrative example, vacuum channels <NUM> for membranes <NUM> means that each membrane in membranes <NUM> can have a set of vacuum channels <NUM>. For example, a membrane can have one vacuum channel or to two channels depending on the particular implementation. Each vacuum channel or back to channels in a membrane are collectively referred to as vacuum channels <NUM>.

A set of ports <NUM> are also present in membranes <NUM>. In this illustrative example, the set of ports <NUM> can be connected to vacuum source <NUM>.

As used herein, a "set of" when used with reference items means one or more items. For example, a set of ports <NUM> is one or more ports.

In this example, the set of ports <NUM> can be a single port or multiple ports in membranes <NUM>. A port is not required in every membrane in membranes <NUM>.

With this connection, vacuum source <NUM> can draw vacuum <NUM> to cause integrated caul <NUM> to apply pressure <NUM>. Pressure <NUM> is applied on uncured composite structure <NUM> on which integrated caul is placed during the curing process to cure uncured composite structure <NUM> to form composite structure <NUM>. In this example, pressure <NUM> is vacuum based pressure <NUM>. Turning next to <FIG>, an illustration of a block diagram for splicing membranes is depicted in accordance with an illustrative embodiment. In the illustrative examples, the same reference numeral may be used in more than one figure. This reuse of a reference numeral in different figures represents the same element in the different figures.

As depicted, membranes <NUM> can be aligned such that positive features <NUM> that define vacuum channels <NUM> are aligned to each other. In this example, gaps <NUM> are present between membranes <NUM> aligned to each other.

In the illustrative example, filler <NUM> is added between gaps <NUM> to join membranes <NUM> aligned to each other. In this illustrative example, filler <NUM> comprises positive features <NUM> and connects vacuum channels <NUM> in membranes <NUM> to each other. Filler <NUM> can be a material that is cured in gaps <NUM> in a shape has positive features <NUM>. In the illustrative examples, the width of gaps can be selected based on the particular filler used. The selection of the gap can be based on enabling the filler to be pushed into the gap to provide a seal and form corresponding features to the membranes. A gap can be, for example, <NUM> to <NUM> inches wide.

In this illustrative example, filler <NUM> can take a number of different forms. For example, filler <NUM> can be selected from at least one of a silicon, a room temperature vulcanizing silicon, a rubber polymer, a siloxane polymer, a polyurethane, or some other suitable material.

For example, a pair of membranes <NUM> can have ends that are aligned to each other such that positive features <NUM> that define vacuum channels <NUM> in the pair of membranes <NUM> are aligned to each other. The connection of vacuum channels <NUM> to each other can form one or more continuous vacuum channels <NUM> through membranes <NUM>.

In this illustrative example, filler <NUM> can be added between gaps <NUM> to join membranes <NUM> aligned to each other. In this illustrative example, filler <NUM> comprises positive features <NUM> and connects vacuum channels <NUM> in membranes <NUM> to each other. As result, vacuum channels <NUM> can be continuous.

This alignment can be made using support tool <NUM>. In this example, support tool <NUM> has mirror image features <NUM>. These mirror image features are a mirror image of features <NUM>, including positive features <NUM> in feature <NUM>. For example, a pair of membranes <NUM> can be aligned with each other such that positive features <NUM> that define vacuum channels <NUM> in the pair of membranes <NUM> are aligned to each other using support tool <NUM>. Support tool <NUM> has mirror image features <NUM> that hold and align features <NUM> including positive features <NUM> between the pair of membranes <NUM>.

Filler <NUM> can be added between a gap between the pair of membranes <NUM> held by support tool <NUM>. In this example, filler <NUM> has features <NUM> when cured on support tool <NUM> with mirror image features <NUM>. Thus, filler <NUM> has features <NUM>, including positive features <NUM> that define other features such as vacuum channels <NUM> in filler <NUM>.

Thus, vacuum pressure system <NUM> can apply pressure <NUM> to uncured composite materials <NUM> in uncured composite structure <NUM> during the manufacturing of composite structure <NUM>. This pressure can be applied to consolidate uncured composite materials <NUM> in uncured composite structure <NUM>. Further, pressure <NUM> can be applied during the curing of uncured composite materials <NUM> in uncured composite structure <NUM> to form composite structure <NUM>.

With the use of integrated caul <NUM>, less time is needed to set up vacuum pressure system <NUM> for curing of uncured composite structure <NUM> as compared to current elastomeric bag and caul systems. Further, with the use of integrated caul <NUM>, the use of consumable items is reduced. For example, the use of a nylon bag, release film, sealant tape, edge breathers, and other consumable components can be reduced will become unnecessary. As result, the amount of time and expense needed to manufacture composite structures and the expense can be reduced. Turning to <FIG>, an illustration of a block diagram of features in a membrane is depicted in accordance with an illustrative embodiment. In this illustrative example, membrane <NUM> is an example of a membrane in membranes <NUM>. Membrane <NUM> can have a cross-section <NUM> with features <NUM>. Features <NUM> are examples of features <NUM> in <FIG>. In this illustrative example, features <NUM> comprises membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM>.

As depicted, resin dam <NUM>, inner seal <NUM>, and outer seal <NUM> are positive features in features <NUM>. Inner seal <NUM> and outer seal <NUM> define a width of outer vacuum channel <NUM>.

In this example, resin dam <NUM> can function as a seal with inner seal <NUM> to define a width of inner vacuum channel <NUM>. Resin dam <NUM> can also reduce or prevent the flow of resin from uncured composite materials <NUM> into inner vacuum channel <NUM> or other features in features <NUM> for membrane <NUM> during the curing of uncured composite materials <NUM>.

The illustration of composite manufacturing environment <NUM> in <FIG> is not meant to imply physical or architectural limitations to the manner in which an illustrative embodiment may be implemented. Other components in addition to or in place of the ones illustrated may be used. Some components may be unnecessary. Also, the blocks are presented to illustrate some functional components. One or more of these blocks may be combined, divided, or combined and divided into different blocks when implemented in an illustrative embodiment.

For example, membranes <NUM> are not required to be continuous all the way around boundary <NUM>. In another illustrative example, integrated caul <NUM> can be placed on uncured composite structure <NUM> with adhesive or some other compound that connects integrated caul <NUM> to uncured composite structure <NUM> for curing of uncured composite structure <NUM>. In another illustrative example, one or more vacuum sources can be present within vacuum pressure system <NUM> in addition to vacuum source <NUM>. These vacuum sources can be connected to integrated caul <NUM> to draw a desired level of vacuum.

Turning now to <FIG>, an illustration of an isometric top view of a membrane is depicted in accordance with an illustrative embodiment. As depicted, membrane <NUM> is an example of an implementation for a membrane in membranes <NUM> in <FIG> and membranes <NUM> in <FIG>. As depicted, membrane <NUM> has features such as outer surface <NUM>, inner surface <NUM>, inner edge <NUM>, and outer edge <NUM>. In this illustrative example, inner surface <NUM> of inner edge <NUM> can be connected to a caul when forming an integrated caul. Membrane <NUM> can have different dimensions depending on the particular implementation. For example, membrane <NUM> can be <NUM> inches in length and have a width of <NUM> inches in one implementation.

Next in <FIG>, an illustration of an isometric bottom view of a membrane is depicted in accordance with an illustrative embodiment. As depicted in this view of membrane <NUM>, features including positive features can be seen section <NUM> on inner surface <NUM> at end <NUM> of membrane <NUM>.

Turning to <FIG>, a more detailed illustration of positive features is depicted in accordance with an illustrative embodiment. In this figure, a more detailed view of section <NUM> in <FIG> is shown. As depicted, features such as membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM> are shown.

In this illustrative example, the positive features comprise resin dam <NUM>, inner seal <NUM>, and outer seal <NUM>. Resin dam <NUM> and inner seal <NUM> are features that define a feature in the form of inner vacuum channel <NUM>. Inner seal <NUM> and outer seal <NUM> define another feature in the form of outer vacuum channel <NUM>.

Membrane overlap <NUM> is a feature of membrane <NUM> that can be bonded to a boundary of a caul. Resin dam <NUM> performs additional functions in addition to being a seal for defining inner vacuum channel <NUM>. Resin dam <NUM> can also function to reduce or prevent resin in the uncured composite structure from flowing into inner vacuum channel <NUM> for outer vacuum channel <NUM>. Turning next to <FIG>, an illustration of an isometric bottom view of a curved membrane is depicted in accordance with an illustrative embodiment. In this illustrative example, curved membrane <NUM> is an example of an implementation for a membrane in membranes <NUM>. This curved membrane can be used to implement corner membrane <NUM>, corner membrane <NUM>, and corner membrane <NUM> in <FIG>.

In this bottom view, curved membrane <NUM> has outer surface <NUM> and inner surface <NUM>. As depicted, curved membrane <NUM> has inner edge <NUM> and outer edge <NUM>. Inner surface <NUM> of inner edge <NUM> can be bonded to a caul with other membranes as part of forming an integrated caul.

Turning next to <FIG>, an illustration of an isometric view of a support tool is depicted in accordance with an illustrative embodiment. In this illustrative example, support tool <NUM> is an example of an implementation for support tool <NUM> in <FIG>. As depicted, support tool <NUM> has mirror image features <NUM> to the features for membranes such as those show in <FIG>. In this example, the mirror image features <NUM> comprise membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM>.

These mirror image features are a mirror image for corresponding features in a membrane such as a membrane overlap, a resin dam, an inner vacuum channel, an inner seal, an outer vacuum channel, and an outer seal. As a result, these mirror image features can hold features in a membrane to align the membrane with another membrane also placed on support tool <NUM>.

Turning next to <FIG>, an illustration of a side view of the support tool is depicted in accordance with an illustrative embodiment. In this side view of support tool <NUM>, features such as membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM> are mirror image of features in corresponding features for the membranes that are placed onto support tool <NUM>.

With reference to <FIG>, an illustration of a support tool located under a membrane is depicted in accordance with an illustrative embodiment. In this illustrative example, end <NUM> of membrane <NUM> is located on support tool <NUM>. In this illustrative example, membrane <NUM> is an example of an implementation for a membrane in membranes <NUM> in <FIG>.

End <NUM> of membrane <NUM> is held in place by mirror image features <NUM> on support tool <NUM>. As depicted, membrane <NUM> has features <NUM> on inner surface <NUM> that are a mirror image to mirror image features <NUM> on support tool <NUM>.

For example, features <NUM> for membrane <NUM> comprises membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM>.

In this example, these features are held and aligned by corresponding mirror image features for support tool <NUM> that are mirror images or symmetrical to features on inner surface <NUM> of membrane <NUM>.

For example, membrane overlap <NUM> for support tool <NUM> is a mirror image of membrane overlap <NUM> for membrane <NUM>. Resin dam <NUM> for support tool <NUM> is a mirror image of resin dam <NUM> for membrane <NUM>, and inner vacuum channel <NUM> for support tool <NUM> is a mirror image of inner vacuum channel <NUM> for membrane <NUM>. As another example, inner seal <NUM> for support tool <NUM> is a mirror image of inner seal <NUM> for membrane <NUM>, and outer vacuum channel <NUM> for support tool <NUM> is a mirror image of outer vacuum channel <NUM> for membrane <NUM>. Outer seal <NUM> for support tool <NUM> is a mirror image of outer seal <NUM> for membrane <NUM>.

Thus, with mirror image features <NUM> for support tool <NUM> that correspond to features <NUM> for membrane <NUM>, membrane <NUM> can be held in place for alignment when, membrane <NUM> is placed on support tool <NUM>.

With reference to <FIG>, an illustration of a pair membranes on a support tool is depicted in accordance with an illustrative embodiment. In this illustrative example, a pair of membranes, membrane <NUM> and membrane <NUM>, located on support tool <NUM>. As depicted, membrane <NUM> and membrane <NUM> are examples of membranes <NUM> in <FIG>, and support tool <NUM> is an example of an implementation for support tool <NUM> in <FIG>.

As depicted, membrane <NUM> and membrane <NUM> are each comprised of two layers. As depicted, membrane <NUM> is comprised of silicon layer <NUM> and fluoroelastomer layer <NUM>. Membrane <NUM> is comprised of silicon layer <NUM> and fluoroelastomer layer <NUM>. In this illustrative example, fluoroelastomer layer <NUM> and fluoroelastomer layer <NUM> can be used to reduce diffusion of nitrogen and increase compatibility with chromate or sealant tape.

The placement of membrane <NUM> and membrane <NUM> can be such that features for membrane <NUM> and membrane <NUM> mesh or fits with corresponding mirror image features on support tool <NUM>. These corresponding mirror image features are mirror images or symmetrical to features on membrane <NUM> and membrane <NUM>.

As depicted, gap <NUM> is present between membrane <NUM> and membrane <NUM>. Gap <NUM> is a location where a filler can be added to connect membrane <NUM> and membrane <NUM> together. With reference to <FIG>, an illustration of a cross-sectional view of a pair of membranes on the support tool is depicted in accordance with an illustrative embodiment. This cross-sectional view of membrane <NUM> and membrane <NUM> on support tool <NUM> is taken along lines <NUM> - <NUM> in <FIG>. As illustrated in this cross-sectional view, end <NUM> of membrane <NUM> is on support tool <NUM>. In a similar fashion, end <NUM> of membrane <NUM> is on support tool <NUM>.

Turning to <FIG>, an illustration of a cross-sectional view of a pair of membranes on the support tool is depicted in accordance with an illustrative embodiment. This cross-sectional view, filler <NUM> has been placed into gap <NUM>. In this illustrative example, filler <NUM> is an example of an implementation for filler <NUM> shown in <FIG>.

Filler <NUM> can be cured to connect end <NUM> of membrane <NUM> and end <NUM> of membrane <NUM>. This connection occurs to splice the two membranes to each other.

Turning next to <FIG>, an illustration of a cross-sectional view of a filler on a support tool is depicted in accordance with an illustrative embodiment. In this figure, a cross-sectional view of support tool <NUM> taken along lines <NUM>-<NUM> in <FIG> is depicted.

In this cross-sectional view, filler <NUM> has been added and cured on support tool <NUM>. As illustrated, filler <NUM> has features <NUM> on inner surface <NUM> of filler <NUM>.

These features are aligned with the features in membrane <NUM> and membrane <NUM>. For example, filler <NUM> has membrane overlap <NUM>, resin dam <NUM>, inner vacuum channel <NUM>, inner seal <NUM>, outer vacuum channel <NUM>, and outer seal <NUM>. These features connect to the corresponding features in membrane <NUM> and membrane <NUM>. As depicted, support tool <NUM> provides a mechanism for enabling the alignment and connection of corresponding features between filler <NUM> and membrane <NUM> and corresponding features between filler <NUM> and membrane <NUM>.

Turning next to <FIG>, an illustration of a top view of a portion of an integrated caul is depicted in accordance with an illustrative embodiment. As depicted, integrated caul <NUM> is comprised of caul <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, and membrane <NUM>. Membrane <NUM> and membrane <NUM> are corner membranes in membranes in integrated caul <NUM>.

In this illustrative example, membrane <NUM> and membrane <NUM> include breathing pathways <NUM>, which are an optional feature. Breathing pathways <NUM> are comprised of path <NUM>, path <NUM>, path <NUM>, path <NUM>, path <NUM>, and path <NUM>. These paths are channels connected to inner vacuum channel <NUM> extending through membrane <NUM>, membrane <NUM>, membrane <NUM>, and membrane <NUM>.

Breathing pathways <NUM> locally bypass resin dam <NUM> from an uncured composite structure (not shown) under caul <NUM> to inner vacuum channel <NUM>. These breathing pathways enable the uncured composite structure to expel volatile gases during the curing process and can also prevent or reduce porosity in the composite structure after curing. These breathing channels can be implemented as structures formed in the membranes or by using strips of peel ply cloth under the membranes to define breathing pathways <NUM>.

Turning to <FIG>, an illustration of an integrated caul is depicted in accordance with an illustrative embodiment. In this illustrative example, integrated caul <NUM> is comprised of caul <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, membrane <NUM>, and membrane <NUM>. As depicted, the membranes are bonded to caul <NUM> and are spliced together.

Integrated caul <NUM> can be placed on uncured composite structure. A vacuum can be drawn to apply pressure on the uncured composite structure during the curing process. Integrated caul <NUM> can be reused without using consumables or a reduced amount of consumables as compared to current elastomeric bag and caul systems. Further, this configuration also reduces the amount of setup time needed for curing an uncured composite structure.

The illustration of integrated cauls, membranes, support tools, and the different components in <FIG> are shown for purposes of illustrating example implementations and not meant to limit the manner in which other illustrative examples can be implemented. For example, an integrated caul can have shapes other than the rectangular shape shown in <FIG>. For example, an integrated caul can have shapes selected from one of a rectangle, an oval, a circle, a pentagon, an irregular shape, or some other suitable shape. As another example, membranes can include extensions or features for the use of bladders with an integrated caul.

Turning next to <FIG>, an illustration of a flowchart of a process for forming an integrated caul to apply a vacuum-based pressure on an uncured composite structure is depicted in accordance with an illustrative embodiment. The process in <FIG> can be implemented in hardware, software, or both to control manufacturing equipment to apply pressure on uncured composite structure. When implemented in software, the process can take the form of program code that is run by one of more processor units located in one or more hardware devices in one or more computer systems. One or more operations can also be performed by human operators in addition to or in place of a computer implemented process.

The process begins by bonding membranes to a boundary of a caul (operation <NUM>). In operation <NUM>, the membranes include positive features that define vacuum channels.

The process splices the membranes to each other (operation <NUM>). The process terminates thereafter. In operation <NUM>, the positive features that define the vacuum channels in the membranes are aligned to each other during splicing of the membranes. Also, the membranes spliced to each other and bonded to the caul form an integrated caul. The integrated caul applies a pressure on the uncured composite structure during operation of the integrated caul.

In <FIG>, the operations are not necessarily performed in the order shown. For example, the membranes can be bonded to the caul prior to or after splicing the membranes to each other. Turning next to <FIG>, an illustration of a flowchart of process for splicing membranes is depicted in accordance with an illustrative embodiment. The process illustrated in <FIG> is an example of one implementation for operation <NUM> in <FIG>.

The process begins by aligning the membranes to each other such that the positive features that define the vacuum channels in the membranes are aligned (operation <NUM>). In this operation, gaps are present between the membranes aligned to each other.

The process adds a filler between the gaps to join the membranes aligned to each other (operation <NUM>). The process terminates thereafter. In operation <NUM>, the filler comprises the positive features and connects the vacuum channels in the membranes to each other. In other words, the filler also includes portions of the vacuum channels that connect to the vacuum channels in the membranes to form a continuous vacuum channel between membranes.

With reference to <FIG>, an illustration of a flowchart of a process for aligning membranes to each other is depicted in accordance with an illustrative embodiment. The process illustrated in <FIG> is an example of an implementation for operation <NUM> in <FIG>.

The process aligns a pair of the membranes to each other such that the positive features that define the vacuum channels in the pair of the membranes are aligned to each other using a support tool that has mirror image features that hold and align the features between the pair of membranes (operation <NUM>). The process terminates thereafter. This process can be performed between pairs of membranes in the membranes for the integrated caul.

In <FIG>, an illustration of a flowchart of a process for adding filler to a gap is depicted in accordance with an illustrative embodiment. The process illustrated in <FIG> is an example of an implementation for operation <NUM> in <FIG>.

The process adds the filler between a gap between the pair of the membranes held by the support tool wherein the filler has the positive features when formed on the support tool with the mirror image features (operation <NUM>). The process terminates thereafter.

With reference to <FIG>, an illustration of a flowchart of a process for curing an uncured composite structure is depicted in accordance with an illustrative embodiment. In this illustrative example, the process can cure uncured composite structure using vacuum pressure system <NUM> in <FIG>.

The process begins by placing the integrated caul on the uncured composite structure (operation <NUM>). In operation <NUM>, the integrated caul comprises membranes bonded to a caul in which the membranes include positive features that define vacuum channels and a filler in gaps between the membranes in which the filler has the positive features that form part of the vacuum channels that are continuous around a boundary of the caul.

The process draws a vacuum in the vacuum channels such that the integrated caul applies the pressure on the uncured composite structure (operation <NUM>). The process cures the uncured composite structure while applying the pressure on the uncured composite structure using the integrated caul to form a composite structure (operation <NUM>). The process terminates thereafter. In <FIG>, an illustration a flowchart of a process for reusing an integrated caul is depicted in accordance with an illustrative embodiment. In this illustrative example, the process reuses the integrated caul to cure another cure uncured composite structure.

The process begins by removing the integrated caul from the composite structure (operation <NUM>). In operation <NUM>, the process can reuse the integrated caul after curing an uncured composite structure to form the composite structure. This reuse can be performed without needing additional consumables such as an elastomeric vacuum bag. The process places the integrated caul on a second uncured composite structure (operation <NUM>).

The process cures the second uncured composite structure while applying the pressure on the second uncured composite structure using the integrated caul to form a second composite structure (operation <NUM>). The process terminates thereafter.

The flowcharts and block diagrams in the different depicted embodiments illustrate the architecture, functionality, and operation of some possible implementations of apparatuses and methods in an illustrative embodiment. In this regard, each block in the flowcharts or block diagrams can represent at least one of a module, a segment, a function, or a portion of an operation or step.

In some alternative implementations of an illustrative embodiment, the function or functions noted in the blocks may occur out of the order noted in the figures. For example, in some cases, two blocks shown in succession may be performed substantially concurrently, or the blocks may sometimes be performed in the reverse order, depending upon the functionality involved. Also, other blocks may be added in addition to the illustrated blocks in a flowchart or block diagram. Illustrative embodiments of the disclosure may be described in the context of aircraft manufacturing and service method <NUM> as shown in <FIG> and aircraft <NUM> as shown in <FIG>. Turning first to <FIG>, an illustration of an aircraft manufacturing and service method is depicted in accordance with an illustrative embodiment. During pre-production, aircraft manufacturing and service method <NUM> may include specification and design <NUM> of aircraft <NUM> in <FIG> and material procurement <NUM>.

During production, component and subassembly manufacturing <NUM> and system integration <NUM> of aircraft <NUM> in <FIG> takes place. Thereafter, aircraft <NUM> in <FIG> can go through certification and delivery <NUM> in order to be placed in service <NUM>. While in service <NUM> by a customer, aircraft <NUM> in <FIG> is scheduled for routine maintenance and service <NUM>, which may include modification, reconfiguration, refurbishment, and other maintenance or service.

Each of the processes of aircraft manufacturing and service method <NUM> may be performed or carried out by a system integrator, a third party, an operator, or some combination thereof.

With reference now to <FIG>, an illustration of an aircraft is depicted in which an illustrative embodiment may be implemented. In this example, aircraft <NUM> is produced by aircraft manufacturing and service method <NUM> in <FIG> and may include airframe <NUM> with plurality of systems <NUM> and interior <NUM>. Examples of systems <NUM> include one or more of propulsion system <NUM>, electrical system <NUM>, hydraulic system <NUM>, and environmental system <NUM>. Any number of other systems may be included. Although an aerospace example is shown, different illustrative embodiments may be applied to other industries, such as the automotive industry.

Apparatuses and methods embodied herein may be employed during at least one of the stages of aircraft manufacturing and service method <NUM> in <FIG>.

In one illustrative example, components or subassemblies produced in component and subassembly manufacturing <NUM> in <FIG> can be fabricated or manufactured in a manner similar to components or subassemblies produced while aircraft <NUM> is in service <NUM> in <FIG>. As yet another example, one or more apparatus embodiments, method embodiments, or a combination thereof can be utilized during production stages, such as component and subassembly manufacturing <NUM> and system integration <NUM> in <FIG>. One or more apparatus embodiments, method embodiments, or a combination thereof may be utilized while aircraft <NUM> is in service <NUM>, during maintenance and service <NUM> in <FIG>, or both. The use of a number of the different illustrative embodiments may substantially expedite the assembly of aircraft <NUM>, reduce the cost of aircraft <NUM>, or both expedite the assembly of aircraft <NUM> and reduce the cost of aircraft <NUM>.

For example, with the use of integrated caul <NUM> as described in <FIG>, the amount of time needed to manufacture composite structures during component and subassembly manufacturing <NUM> can be reduced. With the use of an integrated caul, the time needed to install components such as an elastomeric bag, release film, sealant tape, edge breathers, and other components can be eliminated. Further, a reduction in costs can also occur through reducing the need for consumables such as an elastomeric bag, release film, sealant tape, edge breathers, and other components used in current elastomeric bag and caul systems.

Turning now to <FIG>, an illustration of a block diagram of a product management system is depicted in accordance with an illustrative embodiment. Product management system <NUM> is a physical hardware system. In this illustrative example, product management system <NUM> includes at least one of manufacturing system <NUM> or maintenance system <NUM>.

Manufacturing system <NUM> is configured to manufacture products, such as aircraft <NUM> in <FIG>. As depicted, manufacturing system <NUM> includes manufacturing equipment <NUM>.

Manufacturing equipment <NUM> includes at least one of fabrication equipment <NUM> or assembly equipment <NUM>.

Fabrication equipment <NUM> is equipment that used to fabricate components for parts used to form aircraft <NUM> in <FIG>. For example, fabrication equipment <NUM> can include machines and tools. These machines and tools can be at least one of a drill, a hydraulic press, a furnace, an autoclave, a mold, a composite tape laying machine, an automated fibre placement (AFP) machine, a vacuum system, a robotic pick and place system, a flatbed cutting machine, a laser cutter, a computer numerical control (CNC) cutting machine, a lathe, or other suitable types of equipment. Fabrication equipment <NUM> can be used to fabricate at least one of metal parts, composite parts, semiconductors, circuits, fasteners, ribs, skin panels, spars, antennas, or other suitable types of parts. In this illustrative example, fabrication equipment <NUM> also includes vacuum pressure system <NUM> with integrated caul <NUM> in <FIG>. Integrated caul <NUM> can be used in curing uncured composite to form composite structures for a product such as aircraft <NUM>. Assembly equipment <NUM> is equipment used to assemble parts to form aircraft <NUM> in <FIG>. In particular, assembly equipment <NUM> is used to assemble components and parts to form aircraft <NUM> in <FIG>. Assembly equipment <NUM> also can include machines and tools. These machines and tools may be at least one of a robotic arm, a crawler, a faster installation system, a rail-based drilling system, or a robot. Assembly equipment <NUM> can be used to assemble parts such as seats, horizontal stabilizers, wings, engines, engine housings, landing gear systems, and other parts for aircraft <NUM> in <FIG>.

In this illustrative example, maintenance system <NUM> includes maintenance equipment <NUM>. Maintenance equipment <NUM> can include any equipment needed to perform maintenance on aircraft <NUM> in <FIG>. Maintenance equipment <NUM> may include tools for performing different operations on parts on aircraft <NUM> in <FIG>. These operations can include at least one of disassembling parts, refurbishing parts, inspecting parts, reworking parts, manufacturing replacement parts, or other operations for performing maintenance on aircraft <NUM> in <FIG>. These operations can be for routine maintenance, inspections, upgrades, refurbishment, or other types of maintenance operations.

In the illustrative example, maintenance equipment <NUM> may include ultrasonic inspection devices, x-ray imaging systems, vision systems, drills, crawlers, and other suitable devices. In some cases, maintenance equipment <NUM> can include fabrication equipment <NUM>, assembly equipment <NUM>, or both to produce and assemble parts that needed for maintenance.

Product management system <NUM> also includes control system <NUM>. Control system <NUM> is a hardware system and may also include software or other types of components. Control system <NUM> is configured to control the operation of at least one of manufacturing system <NUM> or maintenance system <NUM>. In particular, control system <NUM> can control the operation of at least one of fabrication equipment <NUM>, assembly equipment <NUM>, or maintenance equipment <NUM>. The hardware in control system <NUM> can be implemented using hardware that may include computers, circuits, networks, and other types of equipment. The control may take the form of direct control of manufacturing equipment <NUM>. For example, robots, computer-controlled machines, and other equipment can be controlled by control system <NUM>. In other illustrative examples, control system <NUM> can manage operations performed by human operators <NUM> in manufacturing or performing maintenance on aircraft <NUM>. For example, control system <NUM> can assign tasks, provide instructions, display models, or perform other operations to manage operations performed by human operators <NUM>. In these illustrative examples.

In the different illustrative examples, human operators <NUM> can operate or interact with at least one of manufacturing equipment <NUM>, maintenance equipment <NUM>, or control system <NUM>. This interaction can occur to manufacture aircraft <NUM> in <FIG>.

Of course, product management system <NUM> may be configured to manage other products other than aircraft <NUM> in <FIG>. Although product management system <NUM> has been described with respect to manufacturing in the aerospace industry, product management system <NUM> can be configured to manage products for other industries. For example, product management system <NUM> can be configured to manufacture products for the automotive industry as well as any other suitable industries.

Thus, the illustrative examples provide a method, apparatus, system for applying pressure on uncured composite structure as part of the curing process to manufacture a composite structure. The illustrative examples employ an integrated caul comprising a caul and membranes attached to the boundary of the caul. As depicted, these membranes are spliced together to each other such that corresponding features in the different membranes are aligned to each other.

The use of the integrated caul in the different examples can reduce the amount of time needed cure uncured composite structure to form a composite structure. For example, time needed to install components such as nylon bag, sealant tape, an edge breather, release film, flash breaker tape and other components are unnecessary or can be reduced. Further, the use of disposable or consumable components is reduced or avoided by using the integrated caul. Further, integrated caul is reusable to cure other uncured composite structures.

The description of the different illustrative embodiments has been presented for purposes of illustration and description and is not intended to be exhaustive or limited to the embodiments in the form disclosed. The different illustrative examples describe components that perform actions or operations. In an illustrative embodiment, a component can be configured to perform the action or operation described. For example, the component can have a configuration or design for a structure that provides the component an ability to perform the action or operation that is described in the illustrative examples as being performed by the component. Further, To the extent that terms "includes", "including", "has", "contains", and variants thereof are used herein, such terms are intended to be inclusive in a manner similar to the term "comprises" as an open transition word without precluding any additional or other elements.

Claim 1:
A method for applying a vacuum based pressure (<NUM>) on an uncured composite structure (<NUM>), the method comprising:
bonding (<NUM>) membranes (<NUM>, <NUM>) to a boundary (<NUM>, <NUM>) of a caul (<NUM>, <NUM>, <NUM>, <NUM>), wherein the membranes (<NUM>, <NUM>) include positive features (<NUM>) that define vacuum channels (<NUM>); and
splicing (<NUM>) the membranes (<NUM>, <NUM>) to each other, wherein the positive features (<NUM>) that define the vacuum channels (<NUM>) in the membranes (<NUM>, <NUM>) are aligned to each other during splicing of the membranes (<NUM>, <NUM>), the membranes (<NUM>, <NUM>) spliced to each other and bonded to the caul (<NUM>, <NUM>, <NUM>, <NUM>) to form an integrated caul (<NUM>, <NUM>, <NUM>, <NUM>), and the integrated caul (<NUM>, <NUM>, <NUM>, <NUM>) applies a pressure (<NUM>) on the uncured composite structure (<NUM>) during operation of the integrated caul (<NUM>, <NUM>, <NUM>, <NUM>).