GB2552524A

GB2552524A - Fastener system and assembly

Info

Publication number: GB2552524A
Application number: GB1613030.4A
Authority: GB
Inventors: Cresswell Philip; Stuckey John
Original assignee: Airbus Operations Ltd
Current assignee: Airbus Operations Ltd
Priority date: 2016-07-28
Filing date: 2016-07-28
Publication date: 2018-01-31
Also published as: GB201613030D0

Abstract

A fastener (15) comprises an outer member (29) having a longitudinal axis (35), an inner volume (37) and at least one radial opening (39). An inner member (31) is configured to be longitudinally movable within the inner volume (37) of the outer member (29) between a locking position and an opening position. A resilient member (33) is located within the inner volume (37) of the outer member (29), wherein the resilient member (33) comprises a locking portion (47) that extends substantially radially with respect to the longitudinal axis (35) of the outer member (29). The locking portion (47) of the resilient member (33) is positioned within the inner volume (37) of the outer member (29) when the inner member (31) is in the opening position. The locking portion (47) of the resilient member (33) is positioned to extend through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29) when the inner member (31) is in the locking position.

Description

(54) Title of the Invention: Fastener system and assembly Abstract Title: Fastener (57) A fastener (15) comprises an outer member (29) having a longitudinal axis (35), an inner volume (37) and at least one radial opening (39). An inner member (31) is configured to be longitudinally movable within the inner volume (37) of the outer member (29) between a locking position and an opening position. A resilient member (33) is located within the inner volume (37) of the outer member (29), wherein the resilient member (33) comprises a locking portion (47) that extends substantially radially with respect to the longitudinal axis (35) of the outer member (29). The locking portion (47) of the resilient member (33) is positioned within the inner volume (37) of the outer member (29) when the inner member (31) is in the opening position. The locking portion (47) of the resilient member (33) is positioned to extend through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29) when the inner member (31) is in the locking position.

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FASTENER SYSTEM AND ASSEMBLY

TECHNICAL FIELD [0001] The present invention relates to a fastener system and an assembly. The assembly can be used on an aircraft, the assembly comprising a first aircraft structure held to a second aircraft structure by the fastener system.

BACKGROUND [0002] Fastening aircraft structures together may require the use of so-called blind fasteners. Blind fasteners are used to attach a first structural component to a second structural component, wherein these components are only easily accessible from one side. Often, there is a need to be able to quickly release blind fasteners if needed.

[0003] US 6,261,042 BI describes a quick release fastener comprising a stud assembly and a receptacle assembly. That fastener comprises many parts and has a complex setup.

SUMMARY [0004] It is therefore an object of the present invention to provide a less complex fastener system which is able to be used as a quickly releasable blind fastener.

[0005] In accordance with a first aspect of the present invention, there is provided a fastener comprising an outer member having a longitudinal axis, an inner volume and at least one radial opening, an inner member configured to be longitudinally movable within the inner volume of the outer member between a locking position and an opening position, a resilient member located within the inner volume of the outer member, wherein the resilient member comprises a locking portion that extends substantially radially with respect to the longitudinal axis of the outer member, wherein the locking portion of the resilient member is positioned within the inner volume of the outer member when the inner member is in the opening position, and wherein the locking portion of the resilient member is positioned to extend through the at least one radial opening of the outer member outside of the inner volume of the outer member when the inner member is in the locking position.

[0006] This fastener has a simpler setup. It allows fastening two structural components together from one side without the need to attach any fastener part from the other side. It is even possible to bore through the two structural components from one side when the other side is inaccessible, and use the fastener described herein to fasten them together immediately after boring.

[0007] Optionally, the resilient member is resiliently deformable against a resilient force, and the inner member is configured to deform the resilient member against the resilient force when the inner member is moved from the opening position to the locking position causing the locking portion of the resilient member to move upon such deformation through the at least one radial opening of the outer member outside of the inner volume of the outer member.

[0008] The resilient member may, for instance, essentially have an Ω-shape, wherein the locking portions are the spreading legs of the Ω. The resilient member may comprise any spring material like steel, plastic, aluminium, or any other suitable metal providing an adequate resilient force to be deformable when the inner member is moved from the opening position to the locking position and to self-retract when the inner member is moved from the locking position to the opening position.

[0009] Optionally, the outer member has at least two radial openings including a first radial opening and a second radial opening, wherein the second radial opening is located opposite to the first radial opening. Correspondingly, the resilient member may be designed as a single member with two legs as locking portions, e.g. as Ω-shape. Optionally, the resilient member comprises at least two locking portions including a first locking portion and a second locking portion, wherein the locking portions extends in opposite directions substantially radially with respect to the longitudinal axis of the outer member, wherein the first locking portion of the resilient member is positioned to extend through the first radial opening of the outer member outside of the inner volume of the outer member when the inner member is in the locking position, and wherein the second locking portion of the resilient member is positioned to extend through the second radial opening of the outer member outside of the inner volume of the outer member when the inner member is in the locking position.

[0010] Optionally, the inner member comprises an outer thread configured to be screwed into the inner volume of the outer member. Alternatively, the inner member may be a bolt without an outer thread, so that the bolt is simply pushed longitudinally from the opening position into the locking position. In both cases there is an option that the fastener comprises a locking feature to prevent the inner member from leaving the locking position upon vibrations or other non-intended influence. The locking feature may prevent unintended rotation of the threaded inner member in form of loctite® or a similar means to increase the thread friction.

If the inner member is a thread-less bolt, the locking feature may be a lateral indentation into which the resilient member can slightly retract when the inner member is in the locking position. In this configuration, the inner member must not only overcome a resilient force to deform the resilient member to reach the locking position, but also a resilient force to deform the resilient member to leave the locking position.

[0011] Optionally, the outer member comprises a head portion, a tip portion, and a tubular portion extending from the head portion to the tip portion, wherein the head portion extends radially further than the tubular portion and an inner surface of the tip portion is configured to be biased against by the resilient member when the inner member is moved from the opening position to the locking position. For instance, the head portion may comprise a countersink. The resilient member may be held in place by its locking portion(s) resting in the radial opening of the outer member both when the inner member is in the locking position and when the inner member is in the opening position.

[0012] Upon assembly of the fastener, the resilient member can be inserted into the tip portion of the outer member until it clicks with its locking portions into the radial openings. An additional sleeve may be inserted or screwed into the tubular portion of the outer member to define a narrower path for the inner member and to prevent the resilient member from leaving the tip portion of the outer member.

[0013] Optionally, the inner member is configured to bias the resilient member against an inner surface of the tip portion of the outer member when the inner member is moved from the opening position to the locking position causing the resilient member to deform and the locking portion of the resilient member to move upon such deformation through the at least one radial opening of the outer member outside of the inner volume of the outer member.

[0014] Optionally, the resilient member comprises two parts, wherein each part essentially has an Ω-shape, the parts being arranged in a crossed configuration to each other such that four locking portions extend substantially radially with respect to the longitudinal axis of the outer member, and wherein the outer member comprises four corresponding radial openings. This configuration may increase the overall locking surface by applying the same fastening principle twice in essentially orthogonal directions.

[0015] In accordance with a second aspect of the present invention, there is provided an assembly comprising a first structure having a first surface portion at a first side of the assembly, a second structure having a second surface portion at a second side of the assembly, a fastener configured to hold the first structure and the second structure together, the fastener comprising an outer member having a longitudinal axis, an inner volume and at least one radial opening, wherein the outer member is configured to fit in a hole through the first structure and the second structure, an inner member configured to be longitudinally movable within the inner volume of the outer member between a locking position and an opening position, wherein the inner member is accessible from the first side of the assembly, a resilient member located within the inner volume of the outer member, wherein the resilient member comprises a locking portion that extends substantially radially with respect to the longitudinal axis of the outer member, wherein the locking portion of the resilient member is positioned within the inner volume of the outer member when the inner member is in the opening position, and wherein the locking portion of the resilient member is positioned to extend through the at least one radial opening of the outer member outside of the inner volume of the outer member engaging with the second surface portion when the inner member is in the locking position.

[0016] In this assembly the two structures are held together by a fastener with a simpler setup. The two structures can be fastened together from one side without the need to attach any fastener part from the other side. It is even possible to bore through the two structures from one side when the other side is inaccessible, and use the fastener described herein to fasten them together immediately after boring.

[0017] Optionally, the outer member of the fastener comprises a head portion, a tip portion, and a tubular portion extending from the head portion to the tip portion, wherein the head portion is configured to engage with the first surface portion. For instance, the head portion may comprise a countersink, wherein the first surface portion may comprise a corresponding chamfer to receive the countersink.

[0018] Optionally, the assembly may at least partially define a volume at the second side of the assembly, wherein the second side of the assembly is less accessible than the first side of the assembly. In this configuration, the fastener of the assembly may act as quickly releasable blind fastener.

[0019] The first structure and/or the second structure may comprise composite material. The fastener system does not laterally expand into the structure and is therefore particularly suited to fasten structures comprising composite material.

BRIEF DESCRIPTION OF THE DRAWINGS [0020] Embodiments will now be described by way of example only with reference to the following figures of which:

Figure lisa schematic top view on an aircraft comprising one or more assemblies as an exemplary embodiment;

Figure 2 is a cross-sectional view of an assembly as an exemplary embodiment, wherein an inner member of a fastener is in an opening position;

Figure 3 is a cross-sectional view of an assembly as an exemplary embodiment, wherein an inner member of a fastener is in a locking position;

Figure 4 is a perspective view on a fastener as an exemplary embodiment, wherein an inner member of the fastener is in an opening position;

Figure 5 is a perspective view on a fastener as an exemplary embodiment, wherein an inner member of the fastener is in an locking position;

Figure 6 is a perspective view on a resilient member of a fastener as an exemplary embodiment;

Figure 7 is a perspective view on a resilient member of a fastener as an exemplary embodiment, wherein the resilient member comprises two parts being arranged in a crossed configuration.

DETAILED DESCRIPTION [0021] Fig. 1 shows a commercial passenger aircraft 1 with a fuselage 3, fixed wings 5 and aircraft engines 7. The aircraft 1 may comprise assembled structures requiring less tooling space with an easily removable and re-usable fastener system. The assembled structures may need to be quickly disassembled for repair, inspection or installation purposes. The assembled structures may define an inaccessible volume requiring the use of blind fasteners which can be installed from one side of the assembled structures only.

[0022] Fig. 2 shows an assembly 9 with a first structure 11 and second structure 13 to be held together by a fastener 15. The first structure 11 has a first surface portion 17 at a first side 19 of the assembly 9 and the second structure 13 has a second surface portion 21 at a second side 23 of the assembly 9. The fastener 15 is positioned in a hole 25, e.g. a bore, in the first structure 11 and second structure 13. The second side 23 of the assembly is less accessible than the first side 19 of the assembly 9, such that the fastener 15 is inserted into the hole 25 from the first side 19. The hole 25 has a chamfer at the first side 19 to receive a corresponding countersink head portion 27 of the fastener 15.

[0023] The fastener 15 has an outer member 29, an inner member 31 and a resilient member

33. The outer member 29 defines a longitudinal axis 35 and an inner volume 37 and at least one radial opening 39. The fastener of Fig. 2 has two opposite radial openings 39 which open laterally into the less accessible space at the second side 23 of the assembly 9 adjacent to the second surface portion 21. The outer member 29 comprises the countersink head portion 27, a tip portion 41, and a tubular portion 43 extending from the head portion 27 to the tip portion

41. The resilient member 33 rests within the tip portion 41 of the outer member 29.

[0024] The inner member 31 of the fastener 15 is configured to be longitudinally movable within the inner volume 37 of the outer member between a locking position and an opening position. Fig. 2 shows the inner member 31 in the opening position, wherein the inner member 31 is accessible from the first side 19 of the assembly 9. The inner member 31 is laterally stabilised by a sleeve 45 located within the tubular portion 43 of the outer member 29, wherein the sleeve 45 defines a narrower path for the inner member 31 within the outer member 29 and prevents the resilient member 33 from leaving the tip portion 41 of the outer member 29.

[0025] The resilient member 33 has essentially an Ω-shape with two locking portions 47 extending substantially radially with respect to the longitudinal axis 35 of the outer member

29. In the opening position of the inner member 31 as shown in Fig. 2, the locking portions 47 of the resilient member 33 are positioned within the inner volume 37 of the outer member

29. The tips of the locking portions 47 may already be clicked into the radial openings 39 of the outer member 29, such that the resilient member 33 held in position and cannot rotate around the longitudinal axis 35. However, in the opening position of the inner member 31 as shown in Fig. 2, the locking portions 47 should not protrude through the radial openings 39 of the outer member 29 to allow a quick release of the fastener 15.

[0026] The locking portions 47 of the resilient member 33 are positioned to extend through the radial openings 39 of the outer member 29 outside of the inner volume 37 of the outer member 29 engaging with the second surface portion 23 when the inner member 31 is in the locking position as shown in Fig. 3. The inner member 31 may comprise a tapered tip 49 to facilitate spreading the legs of the Ω-shaped resilient member 33 and to push the locking portions 47 out of the radial openings 39 when the inner member 31 is moved from the opening position (Fig. 2) into the locking position (Fig. 3).

[0027] The inner member 31 may comprise an outer thread (not shown) configured to be screwed into the inner volume 27 of the outer member 29. The outer thread may engage with an inner thread of the sleeve 45. Alternatively, the inner member 31 may be a bolt without an outer thread, so that the bolt is simply pushed longitudinally from the opening position into the locking position. In both cases there is an option that the fastener comprises a locking feature to prevent the inner member 31 from leaving the locking position upon vibrations or other non-intended influence. The locking feature may prevent unintended rotation of the threaded inner member 31 in form of loctite® or a similar means to increase the thread friction. If the inner member is a thread-less bolt, the locking feature may be a lateral indentation 51 into which the resilient member 33 can slightly retract when the inner member 31 is in the locking position as shown in Fig. 3. In this configuration, the inner member 31 must not only overcome a resilient force to deform the resilient member 33 to reach the locking position, but also a resilient force to deform the resilient member 33 to leave the locking position.

[0028] The indentation 51 can be circumferential or comprised of two or more laterally opposite indentations. If the indentation 51 is circumferential, a longitudinal pull force is needed to overcome the resilient force to deform the resilient member 33 for the inner member 31 to leave the locking position. If the indentation 51 is comprised of laterally opposite indentations, the inner member 31 may be rotated by 90° to overcome the resilient force to deform the resilient member 33 for the inner member 31 and pulled without resistance out of the locking position into the opening position. The indentation 51 may comprise helix-shaped surfaces (not shown) acting as a thread to push the inner member 31 out into the opening position upon rotation by 90°.

[0029] Fig. 3 shows the fastener 15 with the inner member 31 in the locking position in which the locking portions 47 of the resilient member 33 are pushed through the two radial openings 39 of the outer member 29 outside of the inner volume 37 of the outer member 29, wherein the locking portions 47 engage with the second surface portion 21 to hold the first structure 11 and the second structure 13 together. An engaging surface section 53 of the locking portions 47 may form an acute angle a with the second surface portion 21 to avoid clogging against the hole 25 and to gradually increase the frictional force between the engaging surface section 53 and the second surface portion 21 when the locking portions 47 are pushed out.

[0030] Fig. 4 and Fig. 5 show the fastener 15 in isolation to further illustrate its functionality with the inner member being in the opening position (Fig. 4) and in the locking position (Fig. 5). The inner member 31 has a slit 55 at its end face to receive a tool like a screw driver for rotating and pulling out the inner member 31. In the locking position (Fig. 5), the locking portion 47 of the resilient member 33 protrudes through the radial opening 39 of the outer member 29.

[0031] Fig. 6 and 7 show the resilient member 33 in isolation. The resilient member 33 in Fig. 6 is one integral spring with a Ω-shape with two spreadable legs each having a radially extending foot as a locking portion 47. The resilient member 33 in Fig. 7 has two parts, wherein each part essentially has a Ω-shape, the parts being arranged in a crossed configuration to each other such that four locking portions extend substantially radially. In the configuration of Fig. 7, the outer member 29 may comprise four corresponding radial openings 39 and the inner member may comprise four corresponding lateral indentations 51. A 45° rotation of the inner member 31 with four identations 51 may release the inner member 31 to be easily pulled out of the locking position into the opening position for a quick release of the fastener 15.

[0032] Where, in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as optional, preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims.

[0033] The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. While at least one exemplary embodiment has been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art and may be changed without departing from the scope of the subject matter described herein, and this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0034] In addition, comprising does not exclude other elements or steps, and a or one does not exclude a plural number. Furthermore, characteristics or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other characteristics or steps of other exemplary embodiments described above. It should be understood that there should be embodied within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of the contribution to the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims and their legal equivalents.

REFERENCE NUMERALS

I Aircraft

Fuselage

Fixed wings

Engines

Assembly

II First structure

Second structure

Fastener

First surface portion

First side

Second surface portion

Second side

Hole

Head portion of the inner member

Outer member

Inner member

Resilient member

Longitudinal axis

Inner volume of the outer member

Radial opening

Tip portion of the outer member

Tubular portion of the outer member

Sleeve

Locking portion of the resilient member

Tip of the inner member

Indentation

Engaging surface section of the locking portion of the resilient member 55 Slit in the end face of the inner member oc Acute angle

Claims

1. A fastener (15) comprising an outer member (29) having a longitudinal axis (35), an inner volume (37) and at least one radial opening (39), an inner member (31) configured to be longitudinally movable within the inner volume (37) of the outer member (29) between a locking position and an opening position, a resilient member (33) located within the inner volume (37) of the outer member (29), wherein the resilient member (33) comprises a locking portion (47) that extends substantially radially with respect to the longitudinal axis (35) of the outer member (29), wherein the locking portion (47) of the resilient member (33) is positioned within the inner volume (37) of the outer member (29) when the inner member (31) is in the opening position, and wherein the locking portion (47) of the resilient member (33) is positioned to extend through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29) when the inner member (31) is in the locking position.

2. The fastener (15) according to claim 1, wherein the resilient member (33) is resiliently deformable against a resilient force, and wherein the inner member (31) is configured to deform the resilient member (33) against the resilient force when the inner member (31) is moved from the opening position to the locking position causing the locking portion (47) of the resilient member (33) to move upon such deformation through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29).

3. The fastener (15) according to claim 1 or 2, wherein the outer member (29) has at least two radial openings (39) including a first radial opening and a second radial opening, wherein the second radial opening is located opposite to the first radial opening.

4. The fastener (15) according to claim 3, wherein the resilient member (33) comprises at least two locking portions (47) including a first locking portion and a second locking portion, wherein the locking portions (47) extend in opposite directions substantially radially with respect to the longitudinal axis (35) of the outer member (29), wherein the first locking portion (47) of the resilient member (33) is positioned to extend through the first radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (33) when the inner member (31) is in the locking position, and wherein the second locking portion (47) of the resilient member (33) is positioned to extend through the second radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29) when the inner member (31) is in the locking position.

5. The fastener (15) according to any preceding claim, wherein the inner member (31) comprises an outer thread configured to be screwed into the inner volume (37) of the outer member (29).

6. The fastener (15) according to any preceding claim, wherein the outer member (29) comprises a head portion (27), a tip portion (41), and a tubular portion (43) extending from the head portion (27) to the tip portion (41), wherein the head portion (27) extends radially further than the tubular portion (43) and an inner surface of the tip portion (41) is configured to be biased against by the resilient member (33) when the inner member (31) is moved from the opening position to the locking position.

7. The fastener (15) according to claim 6, wherein the inner member (31) is configured to bias the resilient member (33) against an inner surface of the tip portion (41) of the outer member (29) when the inner member (31) is moved from the opening position to the locking position causing the resilient member (33) to deform and the locking portion (47) of the resilient member (33) to move upon such deformation through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29).

8. The fastener (15) according to any preceding claim, wherein the fastener (15) comprises a locking feature (51) to prevent the inner member (31) from leaving the locking position upon vibrations or other non-intended influence.

9. The fastener (15) according to any preceding claim, wherein the resilient member (33) essentially has a Ω-shape.

10. The fastener (15) according to any preceding claim, wherein the resilient member (33) comprises two parts, wherein each part essentially has an Ω-shape, the parts being arranged in a crossed configuration to each other such that four locking portions (47) extend substantially radially with respect to the longitudinal axis (35) of the outer member (29), and wherein the outer member (29) comprises four corresponding radial openings (39).

11. An assembly (9) comprising a first structure (11) having a first surface portion (17) at a first side (19) of the assembly (9), a second structure (13) having a second surface portion (21) at a second side (23) of the assembly (9), a fastener (15) configured to hold the first structure (11) and the second structure (13) together, the fastener (15) comprising an outer member (29) having a longitudinal axis (35), an inner volume (37) and at least one radial opening (39), wherein the outer member (29) is configured to fit in a hole (25) through the first structure (11) and the second structure (13), an inner member (31) configured to be longitudinally movable within the inner volume (37) of the outer member (29) between a locking position and an opening position, wherein the inner member (31) is accessible from the first side (19) of the assembly (9), a resilient member (33) located within the inner volume (37) of the outer member (29), wherein the resilient member (33) comprises a locking portion (47) that extends substantially radially with respect to the longitudinal axis (35) of the outer member (29), wherein the locking portion (47) of the resilient member (33) is positioned within the inner volume (37) of the outer member (29) when the inner member (31) is in the opening position, and wherein the locking portion (47) of the resilient member (33) is positioned to extend through the at least one radial opening (39) of the outer member (29) outside of the inner volume (37) of the outer member (29) engaging with the second surface portion (21) when the inner member (31) is in the locking position.

12. The assembly (9) according to claim 11, wherein the outer member (29) of the fastener (15) comprises a head portion (27), a tip portion (41), and a tubular portion (43) extending from the head portion (27) to the tip portion (41), wherein the head portion (19) is configured to engage with the first surface portion (17).

13. The assembly (9) according to claim 12, wherein the head portion (27) comprises a countersink configured to fit into a corresponding chamfer in the first surface portion (17).

14. The assembly (9) according to any of the claims 11 to 13, wherein the assembly (9) at least partially defines a volume at the second side (23) of the assembly (9), wherein the second side (23) of the assembly (9) is less accessible than the first side (19) of the assembly (9).

15. The assembly (9) according to any of the claims 11 to 14, wherein the assembly (9) comprises a fastener (15) according to any of the claims 1 to 10.

Intellectual

Property

Office

Application No: GB 1613030.4