Aircraft of molded fiber construction and related methods

Abstract

An aircraft includes a molded fiber fuselage and molded fiber wings extending outward from the fuselage. The fuselage, wings, or another component of the aircraft can be made by a method that includes: (a) dipping a forming tool in a pulp slurry tank to deposit a fiber mat on an inner surface of the forming tool, the fiber mat including at least one article region shaped to form the aircraft component; (b) pressing the at least one article region of the fiber mat between the forming tool and a transfer tool to produce a wet-pressed article; and (c) pressing the wet- pressed article between opposed dies of a hot press tool to produce a molded article corresponding to the aircraft component.

Description

AIRCRAFT OF MOLDED FIBER CONSTRUCTION AND RELATED METHODS FIELD

[0001] The teaching disclosed herein relates generally to an aircraft constructed of molded fiber components, and methods for making aircraft components out of molded fiber materials.INTRODUCTION

[0002] SYPAQ Systems Pty Ltd. of Australia sells an unmanned aircraft system under the name “Corvo Precision Payload Delivery System” which is described as a flat packed, easy to assemble and operate, low cost, expendable drone, made from sturdy wax-covered cardboard for protection from rain. These can be used for “last mile” delivery of humanitarian supplies like ration packs and blood bags in a compartment about the size of a shoebox.

[0003] The website at https: / / www.instructables.com / Cardboard-RC-Airplane- Full-Guide / teaches “how to build and fly an RC airplane made from cardboard.” The steps include cutting and folding cardboard to make wings and the fuselage of the airplane.SUMMARY

[0004] The following summary is intended to introduce the reader to various aspects of the applicant’s teaching, but not to define any invention.

[0005] According to one aspect of the teaching disclosed herein, an aircraft includes a molded fiber fuselage and molded fiber wings extending outward from the fuselage.

[0006] In some examples, the molded fiber fuselage is impregnated with resin for increased strength.

[0007] In some examples, the molded fiber fuselage is impregnated with resin for increased water resistance.

[0008] In some examples, the molded fiber wings are impregnated with resin for increased strength.

[0009] In some examples, the molded fiber wings are impregnated with resin for increased water resistance.

[0010] In some examples, the molded fiber fuselage has a wall thickness in a range from about 1 mm to about 4mm.

[0011] In some examples, the molded fiber fuselage has integrally molded interior support features for securing operational equipment including at least one of a battery, a motor, and a wireless communication device.

[0012] In some examples, the aircraft is formed of two halves including an upper half and a lower half, wherein the two halves are separate molded fiber articles.

[0013] In some examples, the lower half comprises a fuselage lower portion of the molded fiber fuselage, and the upper half comprises a fuselage upper portion of the molded fiber fuselage.

[0014] In some examples, the upper half comprises at least one of wing lower portions and wing upper portions of the molded fiber wings.

[0015] In some examples, the molded fiber fuselage includes a wing mount surface integrally molded in the fuselage, the wing mount surface receiving a portion of the molded fiber wings for attachment thereof to the molded fiber fuselage.

[0016] In some examples, the aircraft is an unmanned aircraft.

[0017] According to some aspects, a kit for assembling an aircraft includes a first molded fiber article defining at least in part a fuselage lower portion of an aircraft fuselage; and a second molded fiber article defining at least in part a fuselage upper portion of the aircraft fuselage, the second molded fiber article securable the first molded fiber article to provide the aircraft fuselage.

[0018] In some examples, the kit further includes at least one wing member securable to the fuselage to provide wings of the aircraft. In some examples, the at least one wing member comprises a third molded fiber article and a fourth molded fiber article securable to the third molded article to provide respective lower and upper wing surfaces of at least a portion of the wings. In some examples, the first, second, third, and fourth molded fiber articles are separate from one another.

[0019] According to some aspects, a method of making an aircraft component includes: (a) dipping a forming tool in a pulp slurry tank to deposit a fiber mat on an inner surface of the forming tool, the fiber mat including at least one article region shaped to form the aircraft component; (b) pressing the at least one article region of the fiber mat between the forming tool and a transfer tool to produce a wet -pressed article; and (c) pressing the wet-pressed article between opposed dies of a hot press tool to produce a molded article corresponding to the aircraft component.

[0020] In some examples, the aircraft component comprises at least a portion of one of a fuselage and a wing. In some examples, the method includes mixing carbon fibers in the pulp slurry before said dipping the forming tool. In some examples, the method includes impregnating the molded article with resin.

[0021] Other aspects and features of the teachings disclosed herein will become apparent to those ordinarily skilled in the art, upon review of the following description of the specific examples of the present disclosure.DRAWINGS

[0022] For a better understanding of the described examples and to show more clearly how they may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

[0023] Figure 1 is a perspective view of a molded fiber aircraft, according to an embodiment;

[0024] Figure 2 is a perspective view of the lower half of the aircraft of Figure 1 ;

[0025] Figure 3 is a perspective view of the upper half of the aircraft of Figures 1 and 2;

[0026] Figure 4 is a plan view of the lower half of the aircraft of Figures 1 -3;

[0027] Figure 5 is a perspective view of a molded fiber aircraft, with the wings separated, according to an embodiment;

[0028] Figure 6 is a perspective view of the wings of the aircraft of Figure 5 in isolation;

[0029] Figure 7A is a cross-sectional view of a molded fiber aircraft wing, according to an embodiment; and

[0030] Figure 7B is a cross-sectional view of a molded fiber aircraft wing, according to another embodiment.

[0031] The drawings included herewith are for illustrating various examples of apparatuses and methods of the teaching of the present specification and are not intended to limit the scope of what is taught in any way.DESCRIPTION OF VARIOUS EXAMPLES

[0032] Various apparatuses or processes will be described below to provide an example of each claimed invention. No example described below limits any claimed invention and any claimed invention may cover processes or apparatuses that differ from those described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an example of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors, or owners do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document.

[0033] The system and methods herein describe an aircraft comprising structural components constructed using pulp fiber molding methods. The components may be manufactured using a pulp fiber molding method including a number of sequential processing operations configured to produce components of the aircraft having, among other features, a high degree of dimensional accuracy, low weight, high strength, improved performance, and low production cost. The aircraft components made according to the teaching disclosed herein may further facilitate ease of assembly with one another and with other modules or parts of the aircraft, further contributing to reduction in cost of the final aircraft product.

[0034] Some of the processing operations can include a wet press operation and a subsequent dry press operation, as described further herein. The processes can produce components having a desired surface finish, which can, for example, improve performance in flight.

[0035] Additionally, the molded fiber structural components may be impregnated, coated or treated with additional materials, such as resins, to improve water resistance, and / or structural strength.

[0036] In some examples, the fiber pulp material from which the aircraft components are molded includes reinforcement materials such as, for example, carbon fibers.

[0037] By constructing aircraft using molded fiber structural components, aircraft production costs may be decreased, and assembly time and cost may be decreased.

[0038] Referring first to Figure 1 , pictured therein is a perspective view of an aircraft 100 constructed from molded fiber structural components. In the example illustrated, the aircraft 100 is an unmanned aircraft, and may be referred to herein as a UAV or drone. In other examples, the aircraft may be a manned aircraft.

[0039] The aircraft 100 comprises a fuselage 108. In the example illustrated, the fuselage 108 comprises a generally hollow tubular form, extending along a longitudinal axis from nose to tail. Two wings 106 are coupled to the fuselage, the two wings 106 extending laterally outward from the fuselage 108. Furthermore, in the example illustrated, the aircraft 100 comprises a vertical stabilizer (or tail) 110 coupled to the fuselage 108.

[0040] The aircraft further comprises a propulsion system for powering flight. In the example illustrated, the propulsion system includes a propeller 132 driven by a motor 114. In the example illustrated, the propeller is mounted at a nose of the fuselage, and the motor 114 is housed within the fuselage, behind the propeller 132. Furthermore, in the example illustrated, an antenna 116 is coupled to a rear of the aircraft 100, for transmitting and receiving control signals and other signals (e.g.receiving image signals from onboard imaging equipment in some examples) to and from the aircraft 100.

[0041] The fuselage 108 is of molded fiber construction. In the example illustrated, the fuselage 108 comprises pressed pulp fiber, and is produced using a pulp fiber molding process, including a wet press operation and a dry press operation. In the example illustrated, the fuselage 108 comprises a wall thickness ranging from about 1 mm to about 4mm.

[0042] In the example illustrated, the pulp fiber comprises wood pulp fiber. In other examples, other pulp fibers may be used. In some examples, the pulp fiber can further include reinforcing fibers. In some examples reinforcing fibers can comprise carbon fibers or glass fibers.

[0043] With reference also to Figures 2 and 3, in the example illustrated, the fuselage 108 is substantially formed of two halves, a fuselage upper half 102 and a fuselage lower half 104. The fuselage lower half 104 has an upper peripheral edge 122 (Figure 2), and the fuselage upper half 102 has a lower peripheral edge 124 (Figure 3), which when joined together, form a fuselage interface 120 (Figure 1 ).

[0044] Referring now to Figure 3, the fuselage upper half 102 has a lower peripheral edge 124 for adjoined assembly with the upper peripheral edge 122 of the fuselage lower half 104. In the example illustrated, the wings 106 are affixed to outer surfaces of the fuselage upper half 102, proximate a front end of the fuselage. The tail 110 is, in the example illustrated, affixed to an outer surface of the fuselage upper half, proximate a rear end of the fuselage 108.

[0045] The fuselage upper half 102 and the fuselage lower half 104 are, in the example illustrated, separately produced molded fiber components, in a fiber molding process that includes a wet press operation and a dry press operation. The separately formed upper and lower halves 102, 104 can be subsequently joined using adhesive, tape or other suitable assembly techniques, to form the assembled fuselage 108.

[0046] When assembling together the fuselage upper half 102 and the fuselage lower half 104, the upper peripheral edge 122 and the lower peripheral edge 124 maybe mated before fusing the halves 102, 104 together with adhesive. In some examples, each edge 122, 124 may comprise geometric features (such as, for example, alignment tabs) to assist in aligning the upper edge 124 and the lower edge 122 precisely with one another when fusing the upper half 102 and the lower half 104 with adhesive. Such features or tabs may also promote structural strength at the interface 120 of the aircraft 100.

[0047] In the example illustrated, the wings 106 are also of molded fiber. More particularly, the wings 106 comprise pressed pulp fiber, and are produced using a pulp fiber molding process, In the example illustrated, the molded fiber wings 106 and the molded fiber fuselage 108 are impregnated with resin for increased strength. In the example illustrated, the molded fiber wings 106 and the molded fiber fuselage 108 are impregnated with resin for increased water resistance. In some examples, the wings 106 and the fuselage 108 are impregnated with resin by a spraying operation. In other examples, the wings 106 and the fuselage 108 are impregnated with resin by a dipping operation.

[0048] In the example illustrated, the pulp fiber comprises wood pulp fiber. In other examples, other pulp fibers may be used. In some examples, the pulp fiber can further include reinforcing fibers. In some examples reinforcing fibers can comprise carbon fibers or glass fibers.

[0049] In the example illustrated, each wing 106 includes a wing body and a wing control surface (e.g. in the form of a flap) 118 movably coupled to the wing body. The wing flaps 118 are, in the example illustrated, individually moveable for altering the airflow path above and below the wing, thereby adjusting the aerodynamic character of each wing 106 to control flight of the aircraft. In the example illustrated, a flap actuator is coupled to each wing flap 118 for controlling the position of each wing flap 118.

[0050] In the example illustrated, the wing body of each wing 106 is formed of an upper body portion and a lower body portion separately attached to the lower body portion. The upper body portions of the wing bodies are, in the example illustrated, integrally formed with the upper fuselage half 102, and the lower body portions of thewing bodies are separately attached to the respective upper body portions. The lower portions of the wings 106 may be molded separately, and attached to the upper half 102 of the aircraft 100, using, for example, adhesive or tape. In other examples, other portions of the wing bodies, or an entirety of the wing bodies, or no portion of the wing bodies, may be integrally formed with the upper fuselage half.

[0051] In the example illustrated, the tail 110 includes a tail body and a vertical control surface (e.g. rudder) 112 movable relative to the tail body. The rudder 112 is, in the illustrated example, movable relative to the tail body for altering the airflow path along the left and right sides of the tail 110. In the example illustrated, a rudder actuator is coupled to the rudder 112 for controlling the position of the rudder 112. In the example illustrated, the tail body is integrally formed with the fuselage upper half 102. In other examples, the tail body may be separately formed and separately attached to the fuselage 108.

[0052] Referring now to Figure 4, the interior 126 of the fuselage 108 is configured to house various operational equipment of the aircraft 100. The operational equipment includes, in the example illustrated, a wireless communication device 128, a battery 130, and the motor 114. In the example illustrated, the battery 130 is electrically coupled to the motor 114 and the wireless communication device 128, and the wireless communication device 128 is coupled to the antenna 116.

[0053] In the example illustrated, interior support features 134 are provided in the interior 126 of the fuselage 108 of the aircraft 100, integrally formed with, and protruding inwardly from inner surfaces of, the fuselage 108. The interior support features 134 are positioned and shaped to retain operational equipment of the aircraft (e.g. the battery 130, motor 114, and wireless communication device 128). The interior support features 134 additionally identify where the internal components are to be inserted, thereby facilitating assembly thereof.

[0054] Referring again to Figure 4, the interior support features 134 can each be shaped and positioned according to the internal components they are supporting. For example, four interior support features 134 are present around the battery 130, while only two interior support features 134 are present around the wirelesscommunication device 128, as the battery 130 comprises a mass greater than the wireless communication device 128, and accordingly requires greater amount of mechanical support.

[0055] The presence of the interior support features 134 simplifies assembly of the aircraft 100. Components may be placed and retained within the interior support features 134 and, if necessary, further secured in place with, for example, an adhesive. The support features can help to speed assembly of the components, and ensure reliable and accurate placement of the components within the fuselage, thereby avoiding potential performance problems due to, for example, improper weight distribution of the components relative to the fuselage.

[0056] While the interior support features 134 are depicted as structures which retain the corners of components within the interior 126 of the aircraft 100, in other examples, the interior support features 134 may comprise different geometry.

[0057] Referring now to Figures 5 and 6, another example of an aircraft 1100 is similar to the aircraft 100, with like features identified by like reference characters, incremented by 1000.

[0058] The aircraft 1100 is generally constructed from molded fiber structural components. The aircraft 1100 comprises a fuselage 1108 and a wing assembly 1106 coupled to the fuselage, with left and right wings extending outward from the fuselage 1108. Each of the wing assembly 1106 and the fuselage 1108 are of molded fiber construction, using a fiber molding process including a wet press operation and a subsequent dry press operation.

[0059] In the example illustrated, the fuselage 1108 is, like the fuselage 108, of two-piece construction, with an upper fuselage half joined to a lower fuselage half along a fuselage interface 1120 (Fig. 5). The left and right wings are, in the example illustrated, formed integrally with the wing assembly 1106, and formed separately from the fuselage 1108 (Fig. 6).

[0060] In the example illustrated, the fuselage 1108 includes a wing mount surface 1136 (Fig. 6) integrally molded in the fuselage 1 108. The wing mount surface1136 is, in the example illustrated, provided along an upper surface of the fuselage upper half of the fuselage 1108. The wing mount surface 1136 is configured to receive a portion of the wing assembly 1106 for attachment thereof to the fuselage 1108.

[0061] In the example illustrated, the wing assembly 1106 comprises a fuselage mount surface 1138 integrally molded with the wing assembly 1106. In the example illustrated, the fuselage mount surface 1138 is located on an underside portion of an intermediate connecting segment disposed between, and connected on either side to, the left and right wings of the wing assembly 1106. The fuselage mount surface 1138 is, in the illustrated example, configured to bear in flush engagement against with the wing mount surface 1136 of the fuselage 1108.

[0062] When producing the aircraft 1 100, the fuselage 1108 and the wing assembly 1106 are manufactured separately, using a fiber molding process, and subsequently assembled, using adhesive, tape or other methods of assembly, as described previously above in reference to aircraft 100.

[0063] As with aircraft 100, the left and right wings (of the wing assembly 1106) and the fuselage 1108 are impregnated with resin to improve strength and / or water resistance. In other examples, the wings 1106 and fuselage 1108 may not be impregnated with resin.

[0064] In some examples, the aircraft 1100 may be provided as a kit for assembly. The kit may comprise a molded fiber fuselage 1108 and a molded fiber wing assembly 1106 for attachment to the fuselage 1108. In some examples, the kit for assembly can be suitable for assembly in remote locations with limited access to tools.

[0065] The left and right wings of the wing assembly 1106 each include wing flaps 1118. The wing flaps 1118 are individually moveable for altering the airflow path above and below the wing, thereby adjusting the aerodynamic character of each wing to control flight of the aircraft. In the example illustrated, a flap actuator is coupled to each wing flap 1118 for controlling the position of each wing flap 1118.

[0066] In the example illustrated, the tail 1110 includes a tail body and a vertical control surface (e.g. rudder) 1112 movable relative to the tail body. The rudder 1112 is, in the illustrated example, movable relative to the tail body for altering the airflow path along the left and right sides of the tail 1110. In the example illustrated, a rudder actuator is coupled to the rudder 1112 for controlling the position of the rudder 1112.

[0067] The aircraft 1100 further comprises a propulsion system for powering flight. In the example illustrated, the propulsion system includes a propeller 1132 driven by a motor 1114. In the example illustrated, the propeller 1132 is mounted at a nose of the fuselage, and the motor 1114 is housed within the fuselage, behind the propeller 1132. Furthermore, in the example illustrated, an antenna 1116 is coupled to a rear of the aircraft 1100 for facilitating wireless communication within, and / or remotely with, the aircraft 1100.

[0068] In some examples, the aircraft can comprise an aircraft having a delta wing configuration, which can help to provide desired flight performance of the aircraft.

[0069] Referring now to Figures 7A and 7B, pictured therein are cross sectional views of two alternate embodiments of an aircraft wing for an aircraft constructed from molded fiber components.

[0070] The wing 3008 of Figure 7A is constructed from two molded fiber halves, an upper wing 3040 and a lower wing 3042. The upper wing 3040 and lower wing 3042 are molded as separate, discrete components and joined at a wing interface 3044. The upper wing 3040 and the lower wing 3042 may be joined with adhesives in some examples.

[0071] The wing 4008 of Figure 7B is similar to the wing 3008 of Figure 7A. The wing 4008 of Figure 7B is constructed from two molded fiber halves, an upper wing 4040 and a lower wing 4042. The upper wing 4040 and lower wing 4042 are molded as separate, discrete components and joined at a wing interface 3044.

[0072] The wing 4008 differs in that coupled to the leading edge of the wing 4008 is a leading-edge reinforcement 4046. The leading-edge reinforcement 4046 is positioned on the wing interface 4044, to promote wing strength and reduce theaerodynamic impact of the wing interface 4044 on the leading edge of the wing 4008. The leading-edge reinforcement 4046 extends along the length of the wing 4008. In the example illustrated, the leading-edge reinforcement is constructed from a polymer tape and attached to the wing 4008 with adhesive.

[0073] A method of making an aircraft component, for example, components of the aircraft 100 or aircraft 1000, comprises dipping a forming tool in a pulp slurry tank to deposit a fiber mat on an inner surface of the forming tool, the fiber mat including at least one article region shaped to form the aircraft component. The method further includes pressing the at least one article region of the fiber mat between the forming tool and a transfer tool to produce a wet-pressed article. The method further includes pressing the wet-pressed article between opposed dies of a hot press tool to produce a molded article corresponding to the aircraft component.

[0074] In some examples, the aircraft component comprises at least a portion of one of a fuselage and a wing. In some examples, the method further includes mixing carbon fibers in the pulp slurry before said dipping the forming tool. In some examples, the method further includes impregnating the molded article with resin.

[0075] What has been described above is intended to be illustrative of examples of the teaching disclosed herein, without limiting the scope of patent claims granted herefrom. The scope of such claims should be given the broadest interpretation consistent with the description as a whole.

Claims

CLAIMS:1 . An aircraft, comprising: a) a molded fiber fuselage; and b) molded fiber wings extending outward from the fuselage.

2. The aircraft of claim 1 , wherein the molded fiber fuselage is impregnated with resin for providing at least one of increased strength and moisture resistance.

3. The aircraft of claim 1 or 2, wherein the molded fiber wings are impregnated with resin for providing at least one of increased strength and moisture resistance.

4. The aircraft of any one of claims 1 to 3, wherein the molded fiber fuselage has a wall thickness in a range from about 1 mm to about 4mm.

5. The aircraft of any one of claims 1 to 4, wherein the molded fiber fuselage has integrally molded interior support features for securing operational equipment including at least one of a battery, a motor, and a wireless communication device.

6. The aircraft of any one of claims 1 to 5, wherein the aircraft is substantially constructed in two halves including an upper half and a lower half, wherein the two halves are separate molded fiber articles.

7. The aircraft of claim 6, wherein the lower half comprises a fuselage lower portion of the molded fiber fuselage, and the upper half comprises a fuselage upper portion of the molded fiber fuselage.

8. The aircraft of claim 7, wherein the upper half comprises at least one of wing lower portions and wing upper portions of the molded fiber wings.

9. The aircraft of claim 1 to 8, wherein the molded fiber fuselage includes a wing mount surface integrally molded in the fuselage, the wing mount surface receiving a portion of the molded fiber wings for attachment thereof to the molded fiber fuselage.

10. The aircraft of any one of claims 1 to 9, wherein the aircraft is an unmanned aircraft.

11. A kit for assembling an aircraft, the kit comprising: a) a first molded fiber article defining at least in part a fuselage lower portion of an aircraft fuselage; and b) a second molded fiber article defining at least in part a fuselage upper portion of the aircraft fuselage, the second molded fiber article securable the first molded fiber article to provide the aircraft fuselage.

12. The kit of claim 11 , further comprising at least one wing member securable to the fuselage to provide wings of the aircraft.

13. The kit of claim 12, wherein the at least one wing member comprises a third molded fiber article and a fourth molded fiber article securable to the third molded article to provide respective lower and upper wing surfaces of at least a portion of the wings.

14. The kit of claim 13, wherein first, second, third, and fourth molded fiber articles are separate from one another.

15. A method of making an aircraft component, comprising: a) dipping a forming tool in a pulp slurry tank to deposit a fiber mat on an inner surface of the forming tool, the fiber mat including at least one article region shaped to form the aircraft component; b) pressing the at least one article region of the fiber mat between the forming tool and a transfer tool to produce a wet-pressed article; and c) pressing the wet-pressed article between opposed dies of a hot press tool to produce a molded article corresponding to the aircraft component.

16. The method of claim 15, wherein the aircraft component comprises at least a portion of one of a fuselage and a wing.

17. The method of claim 15, further comprising mixing carbon fibers in the pulp slurry before said dipping the forming tool.

18. The method of claim 15, further comprising impregnating the molded article with resin.

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