Patent Description:
At least some systems for pressure forming structures (e.g., compaction systems or applicator systems) are used in the manufacture and construction of laminated composite structures, such as in the aerospace industry for the construction of composite airframes and airframe structural members. Such structures are typically constructed from a plurality of layers of material, or "plies," which are placed over a form and compacted under pressure.

Many known compaction systems include a tool, such as a mandrel or form, over which a structure is placed for compaction. A vacuum bag may be placed over the structure and sealed upon the form under pressure to compress the structure. Other known applicator systems include a shaped metallic compaction tool configured to press the structure into a desired shape on the tool. Such systems typically fail to account for variability in material thickness of the structure and/or apply insufficient pressure during compression of the structure. <CIT> relates to a forming device for thermoforming a thermoplastically deformable, preferably plate-like workpiece in particular made of fiber-reinforced plastic, comprising: at least one heating device for heating the workpiece, a molding tool for molding the heated workpiece forming a three-dimensional targe shape of the workpiece, wherein the molding tool comprises a plurality of shaping elements which are movable independently of each other in respective target positions to form the target shape, and a pressure generating device for pressing the heated workpiece against the mold during the molding of the workpiece.

In one aspect, an applicator assembly for applying pressure to a composite structure is provided according to claim <NUM>. The applicator assembly includes an external frame, an applicator casing disposed substantially within the external frame, and an applicator disposed substantially within the applicator casing. The applicator casing includes a first membrane, and a first jamming material disposed within the first membrane. The applicator includes a second membrane, and a second jamming material disposed within the second membrane.

In another aspect, an applicator system for applying pressure to a composite structure is provided according to claim <NUM>. The applicator system includes a forming tool having a receiving surface for receiving a composite structure, an air pump, and an applicator assembly coupled to the air pump and configured to press the composite structure on the receiving surface. The applicator assembly includes an external frame, an applicator casing disposed substantially within the external frame, and an applicator disposed substantially within the applicator casing. The applicator casing includes a first membrane, and a first jamming material disposed within the first membrane. The applicator includes a second membrane, and a second jamming material disposed within the second membrane.

In yet another non-claimed aspect, an applicator assembly for applying pressure to a composite structure is provided. The applicator assembly includes an external frame and an applicator disposed substantially within the external frame. The applicator includes a membrane and a jamming material disposed within the membrane. The applicator is configured to be jammed under vacuum and unjammed under positive pressure to compress a composite structure on a receiving surface of a tool disposed in opposition to the applicator.

Accordingly, a value modified by a term or terms, such as "about" and "substantially", are not to be limited to the precise value specified.

Embodiments of the present disclosure relate to applicator systems for applying pressure to a structure. More particularly, embodiments of the present disclosure relate to applicator systems that include an applicator that is jammed under vacuum and/or unjammed under positive pressure, such that the applicator is, in an unjammed configuration, deformable about a receiving surface of a forming tool and, in a jammed configuration, holds the shape of the forming tool for forming a structure on the forming tool. The structure is placed on the forming tool and a loading force is applied through the applicator assembly to the structure to press the structure on the forming tool. In addition, in some embodiments, the applicator is pressurized to apply additional pressure on the structure over the forming tool.

With respect to the embodiments described below, and in any of the embodiments, heat may be applied to the structure. For example, heat may be applied to the structure by an applicator, an applicator frame, or both. In addition, heat may be circulated through the jamming material disposed within an applicator or applicator frame, such as by one or more electrical heating element disposed within the applicator or applicator casing. In addition, in some embodiments, one or more membranes (e.g., a membrane of an applicator and/or a membrane of an applicator casing) may include one or more electrical heating elements, which may be configured to heat the membrane. Heat circulated through the jamming material and/or through the one or more membranes may be sufficient to make a structure being formed, such as a laminate composite structure, plaint or deformable.

As used herein, a structure, such as an applicator or applicator casing, is "jammed" when air is withdrawn from the applicator or applicator casing, such as under vacuum or partial vacuum, to force particles of a jamming material within the applicator or applicator casing into a rigid or semi-rigid configuration.

As used herein, a structure, such as an applicator or applicator casing, is "pressurized" when air is pumped into the applicator or applicator casing. During pressurization, the applicator or applicator casing becomes rigid or semi-rigid.

As used herein, a structure, such as an applicator or applicator casing, is "unjammed" or "relaxed" when a small amount of air or no air is pumped into applicator or applicator casing, or when air is released from an applicator or applicator casing, such that particles of a jamming material within the applicator or applicator casing are flowable or semi-flowable, and such that the applicator or applicator casing is flexible or deformable.

Although various applicator systems are described below with reference to the figures, it will be understood that these systems are merely exemplary and that other applicator systems capable of jamming and pressurization operations are also contemplated. For example, the specific jamming and unjamming operations described in connection with each applicator system below may vary based upon one or more factors, such as the jamming material used in each applicator system and the structure to be formed.

<FIG> is a cross-sectional view of an exemplary applicator system <NUM> for applying pressure to a structure <NUM>, such as, and without limitation, a composite laminate structure. Applicator system <NUM> includes an applicator assembly <NUM>, a forming tool <NUM>, an air pump <NUM>, and a movement mechanism <NUM>. Movement mechanism <NUM> may translate about an axis or system of axes which are used to control the movement of the applicator assembly <NUM>. In various embodiments, movement mechanism <NUM> is an actuator, such as a linear actuator or a robotic arm. In some embodiments, applicator system <NUM> includes an air filter (not shown) disposed in fluid communication with air pump <NUM> and configured to filter air entering and/or exiting air pump <NUM>.

In the exemplary embodiment, forming tool <NUM> is a rigid structure configured to receive structure <NUM> for forming on forming tool <NUM>. Forming tool <NUM> thus includes a receiving surface <NUM> that is shaped to receive structure <NUM> and on which structure <NUM> is pressed into a desired shape or form.

Applicator assembly <NUM> includes an applicator <NUM> and an external frame <NUM>. Applicator <NUM> includes a membrane <NUM> and a jamming material <NUM>. Membrane <NUM> is flexible and is made from any suitable flexible material, such as an elastomer, a rubber compound, or any other suitable material that is substantially gas impermeable and flexible. Membrane <NUM> also includes an outer surface <NUM> that is configured to make contact with receiving surface <NUM> of forming tool <NUM>.

Membrane <NUM> is filled with jamming material <NUM>. More particularly, a cavity <NUM> is defined within membrane <NUM>, and cavity <NUM> is filled with jamming material <NUM>.

Jamming material <NUM> is a granular media in which forces (such as normal forces, friction forces, Van der Wall forces) acting between particles of jamming material <NUM> can be varied to create a network of granular particles having a variable or adjustable rigidity. In various embodiments, jamming material <NUM> includes particles such as sand, glass beads, different organic particles (e.g., coffee grounds, tree nut shells), or any other granular media within which forces acting between the particles can be varied to influence the rigidity of the network or system of particles as a whole.

External frame <NUM> is a rigid support member to which membrane <NUM> is coupled and/or sealed. External frame <NUM> also includes a vacuum port <NUM> that is coupled to air pump <NUM>. Movement mechanism <NUM> is mechanically coupled to external frame <NUM> and configured to apply a loading force to external frame <NUM>.

<FIG> are a series of cross-sectional views of applicator system <NUM>, illustrating operation of applicator system <NUM>. Accordingly, with attention to <FIG>, during operation, a small amount of air is pumped into cavity <NUM> of applicator <NUM> to reduce the forces acting between particles of jamming material <NUM>, such that jamming material <NUM> is able to shift and flow within cavity <NUM>. Membrane <NUM> is thus compliant about jamming material <NUM>, and the shape of applicator <NUM> is adjustable or deformable. In some embodiments, no air is pumped into cavity <NUM> and/or air is released, which leaves jamming material <NUM> in a relaxed state, such that jamming material <NUM> is able to shift and flow within cavity <NUM>.

As shown with reference to <FIG>, applicator assembly <NUM> is lowered over or otherwise moved into contact with receiving surface <NUM> of forming tool <NUM>. In some embodiments, movement mechanism <NUM> moves applicator assembly <NUM> into and out of contact with forming tool <NUM>. As applicator assembly <NUM> makes contact with forming tool <NUM>, jamming material <NUM> flows or shifts within membrane <NUM>, such that applicator <NUM> takes the shape of receiving surface <NUM> of forming tool <NUM>.

With reference to <FIG>, air is pumped out of cavity <NUM> of applicator <NUM>, causing jamming material <NUM> to become rigid, or jam, within applicator <NUM>. Applicator <NUM> is thus jammed in the shape of receiving surface <NUM> of forming tool <NUM>. This may happen progressively and at any stage during the movement of applicator assembly <NUM> towards the surface of forming tool <NUM>.

As shown with reference to <FIG>, an external force is also applied, such as by movement mechanism <NUM>, such that structure <NUM> is pressed and compacted between applicator <NUM> and forming tool <NUM>. The external force applied is sufficient to smoothly and suitably compact structure <NUM> as well as to give structure <NUM> the desired shape against forming tool <NUM>. In addition, in some embodiments, applicator <NUM> is pressurized under positive pressure, such that applicator <NUM> applies an additional loading force or pressure against structure <NUM> on forming tool <NUM>.

<FIG> is a cross-sectional view of an applicator system <NUM> for applying pressure to a structure <NUM>. Applicator system <NUM> includes an applicator assembly <NUM>, a forming tool <NUM>, an air pump <NUM>, and a movement mechanism <NUM>. Movement mechanism <NUM> may translate about an axis or system of axes which are used to control the movement of the applicator assembly <NUM>. In various embodiments, movement mechanism <NUM> is an actuator, such as a linear actuator or a robotic arm. In some embodiments, applicator system <NUM> includes an air filter (not shown) disposed in fluid communication with air pump <NUM> and configured to filter air entering and/or exiting air pump <NUM>.

In the exemplary embodiment, forming tool <NUM> is substantially similar to forming tool <NUM>. For example, forming tool <NUM> is a rigid structure configured to receive structure <NUM>, such as a composite laminate structure, for forming on forming tool <NUM>. Forming tool <NUM> thus includes a receiving surface <NUM> that is shaped to receive structure <NUM> and on which structure <NUM> is pressed into a desired shape or form.

Applicator assembly <NUM> includes an applicator casing <NUM>, an applicator <NUM>, and an external frame <NUM>. Applicator casing <NUM> includes a first membrane <NUM> and a first jamming material <NUM>. First membrane <NUM> is flexible and is made from any suitable flexible material, such as an elastomer, a rubber compound, or any other suitable material that is substantially gas impermeable and flexible.

First membrane <NUM> is filled with first jamming material <NUM>. More particularly, a cavity <NUM> is defined within first membrane <NUM>, and first jamming material <NUM> fills cavity <NUM>. First jamming material <NUM> is the same as jamming material <NUM>.

Applicator <NUM> includes a second membrane <NUM> and a second jamming material <NUM>. Second membrane <NUM> is flexible and is made from any suitable flexible material, such as an elastomer, a rubber compound, or any other suitable material that is substantially gas impermeable and flexible. Second membrane <NUM> includes a contact surface <NUM> that is configured to make contact with structure <NUM>.

Second membrane <NUM> is filled with second jamming material <NUM>. For example, a cavity <NUM> is defined within second membrane <NUM>, and second jamming material <NUM> fills cavity <NUM>. In the exemplary embodiment, second jamming material <NUM> is the same as first jamming material <NUM>. However, in various embodiments, second jamming material is different from first jamming material <NUM>. In other words, in some embodiments, first membrane <NUM> is filled with one type of jamming material (e.g., sand), while second membrane <NUM> is filled with another type of jamming material (e.g., tree nut shells).

External frame <NUM> is a rigid support member to which applicator casing <NUM> is coupled and/or sealed. External frame <NUM> includes a vacuum port <NUM> that is coupled to air pump <NUM>. Movement mechanism <NUM> is also mechanically coupled to external frame <NUM> and configured to apply a loading force to external frame <NUM>.

In the exemplary embodiment, applicator casing <NUM> is substantially n-shaped and first membrane <NUM> of applicator casing <NUM> defines a pocket <NUM> that is configured to receive or house applicator <NUM>. Thus, applicator <NUM> is disposed at least partially within pocket <NUM> of applicator casing <NUM>. Applicator <NUM> is coupled within applicator casing <NUM>, such as by one or more fasteners, an adhesive, heat bonding, and the like.

Vacuum port <NUM> is in fluid communication with applicator casing <NUM>, such that air pump <NUM> is able to withdraw air from applicator casing <NUM> to jam applicator casing <NUM> and to pump air into applicator casing <NUM> to pressurize applicator casing <NUM>. Similarly, vacuum port <NUM> is in fluid communication with applicator <NUM>, such that air pump <NUM> is able to withdraw air from applicator <NUM> to jam applicator <NUM> and to pump air into applicator <NUM> to pressurize applicator <NUM>. In some embodiments, a selectively configurable valve (not shown) is included in vacuum port <NUM> to selectively control jamming and unjamming operations for each of applicator casing <NUM> and applicator <NUM>. In other embodiments, applicator casing <NUM> and applicator <NUM> are coupled to independent vacuum ports (not shown), such that one or more air pumps can be operated to independently jam and unjam applicator casing <NUM> and applicator <NUM>.

In addition, applicator casing <NUM> includes a first contact surface <NUM> and a second contact surface <NUM>, each of which is configured to make contact with receiving surface <NUM> of forming tool <NUM>. First contact surface <NUM> and second contact surface <NUM> are flexible and configured to conform to receiving surface <NUM> of forming tool <NUM>. In the exemplary embodiment, first contact surface <NUM> and second contact surface <NUM> are configured to form a seal with receiving surface <NUM> of forming tool <NUM>, such that, when applicator <NUM> is pressurized within applicator casing <NUM>, second membrane <NUM> of applicator <NUM> does not burst under pressure.

<FIG> are a series of cross-sectional views of applicator system <NUM>, illustrating a first exemplary operation of applicator system <NUM>. Accordingly, with attention to <FIG>, during operation, applicator assembly <NUM> is lowered or otherwise placed in contact with structure <NUM> on forming tool <NUM>, such as by movement mechanism <NUM>. In this example, both of applicator casing <NUM> and applicator <NUM> begin operation in an unjammed or relaxed configuration.

With reference to <FIG>, once applicator <NUM> is in contact with structure <NUM> of forming tool <NUM>, applicator <NUM> may be jammed, and/or applicator casing <NUM> may be jammed. In addition, as shown, first contact surface <NUM> and second contact surface <NUM> of applicator casing <NUM> make contact against receiving surface <NUM> of forming tool <NUM>, which is irregularly shaped, such that receiving surface <NUM> is non-planar or includes at least one non-planar feature. In some embodiments, first contact surface <NUM> and second contact surface <NUM> form at least a partial seal against receiving surface <NUM>.

As shown with reference to <FIG>, once applicator casing <NUM> is in contact with and/or sealed on receiving surface <NUM> of forming tool <NUM>, air is pumped into applicator <NUM> to pressurize applicator <NUM>. As applicator <NUM> is pressurized, second membrane <NUM> of applicator <NUM> exerts pressure against first membrane <NUM> of applicator casing <NUM>. In this configuration, applicator <NUM> is contained within applicator casing <NUM>, which is jammed, such that applicator <NUM> is supported within jammed applicator casing <NUM> and does not burst under pressure. In addition, the pressure exerted by second membrane <NUM> of applicator <NUM> acts to press structure <NUM> onto receiving surface <NUM> of forming tool <NUM> and compresses or compacts structure <NUM> on receiving surface <NUM>. In some embodiments, movement mechanism <NUM> also applies a loading force to external frame <NUM> to press structure <NUM> between applicator assembly <NUM> and receiving surface <NUM> of forming tool <NUM>.

<FIG> are a series of cross-sectional views of applicator system <NUM> (shown in <FIG>), illustrating a second exemplary operation of applicator system <NUM>. The second exemplary operation is substantially similar to the first exemplary operation described above with reference to <FIG>, except that applicator casing <NUM> and applicator <NUM> begin in jammed configurations. Thus, in the second exemplary operation, applicator <NUM> is brought into contact with structure <NUM> on receiving surface <NUM> of forming tool <NUM> already jammed and partially surrounded by jammed applicator casing <NUM>.

<FIG> are a series of cross-sectional views of applicator system <NUM> (shown in <FIG>), illustrating a third exemplary operation of applicator system <NUM>. The third exemplary operation is substantially similar to the second exemplary operation described above with reference to <FIG>, in that applicator casing <NUM> and applicator <NUM> begin operation in a jammed configuration. However, as shown at <FIG>, applicator casing <NUM> is pressurized over jammed applicator <NUM> to bring first contact surface <NUM> and second contact surface <NUM> of applicator casing <NUM> into pressurized contact with receiving surface <NUM> of forming tool <NUM>. In addition, as shown with respect to <FIG>, applicator <NUM> is pressurized within pressurized applicator casing <NUM> to exert additional pressure and compression force against structure <NUM> on receiving surface <NUM> of forming tool <NUM>.

<FIG> is a cross-sectional view of an alternative non-claimed applicator system <NUM> for applying pressure to a structure <NUM>. Applicator system <NUM> is substantially similar to applicator system <NUM>, except that applicator system <NUM> does not include applicator casing <NUM>. Accordingly, as shown, applicator system <NUM> includes an applicator assembly <NUM>, a forming tool <NUM>, an air pump <NUM>, and a movement mechanism <NUM>. Forming tool <NUM>, air pump <NUM>, and movement mechanism <NUM> are substantially similar to forming tool <NUM>, air pump <NUM>, and movement mechanism <NUM>, respectively. Movement mechanism <NUM> may translate about an axis or system of axes which are used to control the movement of applicator assembly <NUM>. In various embodiments, movement mechanism <NUM> is an actuator, such as a linear actuator or a robotic arm. In some embodiments, applicator system <NUM> includes an air filter (not shown) disposed in fluid communication with air pump <NUM> and configured to filter air entering and/or exiting air pump <NUM>.

In the exemplary embodiment, applicator assembly <NUM> includes an applicator <NUM> and an external frame <NUM>. Applicator <NUM> includes a membrane <NUM> and a jamming material <NUM>. Membrane <NUM> is flexible and is made from any suitable flexible material, such as an elastomer, a rubber compound, or any other suitable material that is substantially gas impermeable and flexible. Membrane <NUM> includes a contact surface <NUM> that is configured to make contact with structure <NUM>.

Membrane <NUM> is filled within jamming material <NUM>. For example, a cavity <NUM> is defined within membrane <NUM>, and jamming material <NUM> fills cavity <NUM>. In the exemplary embodiment, jamming material <NUM> is the same as jamming material <NUM>.

External frame <NUM> is a rigid support member to which applicator <NUM> is coupled and/or sealed. External frame <NUM> includes a vacuum port <NUM> that is coupled to air pump <NUM>. Vacuum port <NUM> is in fluid communication with applicator <NUM>, such that air pump <NUM> is able to withdraw air from applicator <NUM> to jam applicator <NUM> and to pump air into applicator <NUM> to pressurize applicator <NUM>. Movement mechanism <NUM> is mechanically coupled to external frame <NUM> and configured to apply a loading force to external frame <NUM>.

External frame <NUM> is substantially n-shaped and defines a recess <NUM> that is configured to receive and/or house applicator <NUM>. Thus, applicator <NUM> is disposed at least partially within recess <NUM> of external frame <NUM>. In the exemplary embodiment, applicator <NUM> is coupled within recess <NUM>, such as by one or more fasteners, an adhesive, heat bonding, and the like.

<FIG> are a series of cross-sectional views of applicator system <NUM>, illustrating a first exemplary operation of applicator system <NUM>. Accordingly, with attention to <FIG> and <FIG>, during operation, applicator assembly <NUM> is lowered or otherwise placed in contact with structure <NUM> on forming tool <NUM>, such as by movement mechanism <NUM>. In this example, applicator <NUM> is positioned over structure <NUM> in an unjammed or relaxed configuration. With reference to <FIG>, applicator <NUM> is subsequently pressurized to exert a compressive force over structure <NUM>, such that structure <NUM> is pressed, as described herein, onto forming tool <NUM>.

<FIG> are a series of cross-sectional views of applicator system <NUM>, illustrating a second exemplary operation of applicator system <NUM>. Accordingly, with attention to <FIG>, during operation, applicator assembly <NUM> is lowered or otherwise placed in contact with structure <NUM> on forming tool <NUM>, such as by movement mechanism <NUM>. In this example, applicator <NUM> is positioned over structure <NUM> in jammed configuration. In addition, and with reference to <FIG>, applicator <NUM> is subsequently pressurized to exert a compressive force over structure <NUM>, such that structure <NUM> is pressed, as described herein, onto forming tool <NUM>.

Embodiments of the applicator systems, as described above, facilitate the application of pressure to a structure. More particularly, embodiments of the present disclosure relate to applicator systems that include, at least, an applicator that is jammed under vacuum and/or unjammed under positive pressure, such that the applicator is, in an unjammed configuration, deformable about a receiving surface of a forming tool and, in a jammed configuration, holds the shape of the forming tool for forming a structure on the forming tool. The structure is placed on the forming tool and a loading force is applied through the applicator assembly to the structure to press the structure on the forming tool. In addition, in some embodiments, the applicator is pressurized to apply additional pressure on the structure over the forming tool.

Exemplary technical effects of the applicator systems described herein include, for example: (a) forming a structure between a jammed applicator and a forming tool; (b) forming a structure between a pressurized applicator and a forming tool; (c) forming a structure between a jammed and/or pressurized applicator and a forming tool, in which the applicator is at least partially surrounded by an unjammed and/or pressurized applicator casing; and (d) forming a structure between a jammed and/or pressurized applicator and a forming tool, in which the applicator is at least partially surrounded by a rigid external frame.

Exemplary embodiments of applicator systems and related components are described above in detail. The systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the configuration of components described herein may also be used in combination with other processes, and is not limited to practice with the systems and related methods as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many applications where pressure forming a structure is desired.

Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

Claim 1:
An applicator assembly (<NUM>) for applying pressure to a composite structure (<NUM>), said applicator assembly (<NUM>) comprising:
an external frame (<NUM>);
an applicator casing (<NUM>) disposed substantially within said external frame (<NUM>), said applicator casing (<NUM>) comprising:
a first membrane (<NUM>); and
a first jamming material (<NUM>) disposed within said first membrane (<NUM>); and
an applicator (<NUM>) disposed substantially within said applicator casing (<NUM>), said applicator (<NUM>) comprising:
a second membrane (<NUM>); and
a second jamming material (<NUM>) disposed within said second membrane (<NUM>),
wherein the first jamming material (<NUM>) and the second jamming material (<NUM>) each comprise respective granular particles in which forces acting between the respective granular particles are variable such that the respective granular particles have a variable or adjustable rigidity.