FASTENING COLLARS, MULTI-PIECE FASTENERS, AND METHODS FOR FASTENING

The present disclosure relates to fastening collars, multi-piece fasteners, and methods for fastening. A fastening collar comprises a first collar end, a second collar end, and an elongate portion intermediate the first collar end and the second collar end and defining a longitudinal axis of the fastening collar. The elongate portion comprises a first region adjacent the first collar end, extending a first distance along the longitudinal axis; a second region adjacent to the second collar end, extending a second distance along the longitudinal axis, and comprising a flange; and an inner collar surface defining collar cavity extending through the elongate portion from the first collar end to the second collar end. The second collar end extends away from the longitudinal axis of the elongate portion at a first angle offset from an angle perpendicular to the longitudinal axis of the elongate portion.

FIELD OF USE

The present disclosure relates to fastening collars, multi-piece fasteners, and methods for fastening.

BACKGROUND

Vehicle frames, storage racks, solar panel sub-structures, aircraft parts, and other structures can include numerous mechanical fasteners. For example, a mechanical fastener can be installed in a bore of a structural component to secure parts together. Properly installing a mechanical fastener into a bore presents challenges.

SUMMARY

According to one non-limiting aspect of the present disclosure, a fastening collar is provided. The fastening collar comprises a first collar end, a second collar end, and an elongate portion intermediate the first collar end and the second collar end. The elongate portion defines a longitudinal axis of the fastening collar. The elongate portion comprises a first region, a second region, and an inner collar surface. The first region is adjacent to the first collar end and extends a first distance along the longitudinal axis. In certain non-limiting embodiments, the first distance is at least 5% of the total length of the fastening collar, as measured along the longitudinal axis. In various non-limiting embodiments, the first region comprises one or both of a taper and a portion defining a concave radius. In certain non-limiting embodiments, the first region comprises a portion of the elongate portion defining a concave radius of the elongate portion and the concave radius is at least 0.060 inches. The second region is adjacent to the second collar end, extends a second distance along the longitudinal axis, and comprises a flange. In various non-limiting embodiments, the second distance is at least 2% of the total length of the fastening collar, as measured along the longitudinal axis. The inner collar surface defines a collar cavity extending through the elongate portion from the first collar end to the second collar end. The second collar end extends away from the longitudinal axis of the elongate portion at a first angle offset from an angle perpendicular to the longitudinal axis of the elongate portion. In various non-limiting embodiments, the first angle is at least 1 degree offset from the angle perpendicular to the longitudinal axis of the elongate portion, at least 5 degrees offset from perpendicular to the longitudinal axis of the elongate portion, and/or in a range of 1 degree to 30 degrees offset from the angle perpendicular to the longitudinal axis of the elongate portion. In various non-limiting embodiments, the fastening collar comprises at least one of a metal, a metal alloy, and a composite.

According to another non-limiting aspect of the present disclosure, a fastening collar is provided. The fastening collar comprises a first collar end, a second collar end, and an elongate portion intermediate the first collar end and the second collar end. The elongate portion defines a longitudinal axis of the fastening collar. The elongate portion comprises a first region, a second region, and an inner collar surface. The first region is adjacent to the first collar end, extends a first distance along the longitudinal axis, and comprises one or both of a taper and a portion defining a concave radius. In certain non-limiting embodiments, the first distance is at least 5% of the total length of the fastening collar, as measured along the longitudinal axis. In certain non-limiting embodiments, the first region comprises a portion defining a concave radius and the concave radius is at least 0.060 inches. The second region is adjacent to the second collar end and extends a second distance along the longitudinal axis. In various non-limiting embodiments, the second distance is at least 2% of the total length of the fastening collar, as measured along the longitudinal axis. The inner collar surface defines a collar cavity extending through the elongate portion from the first collar end to the second collar end. In certain non-limiting embodiments, the second collar end comprises a flange and extends away from the longitudinal axis of the elongate portion at a first angle offset from an angle perpendicular to the longitudinal axis of the elongate portion. In various non-limiting embodiments, the first angle is at least 1 degree offset from the angle perpendicular to the longitudinal axis of the elongate portion, at least 5 degrees offset from the angle perpendicular to the longitudinal axis of the elongate portion, and/or in a range of 1 degree to 30 degrees offset from the angle perpendicular to the longitudinal axis of the elongate portion. In various non-limiting embodiments, the fastening collar comprises at least one of a metal, a metal alloy, and a composite.

According to yet another non-limiting aspect of the present disclosure, a multi-piece fastener is provided. The multi-piece fastener comprises a fastening collar according to the present disclosure and a pin configured to be at least partially received within a collar cavity of the fastening collar. In certain non-limiting embodiments, the pin comprises a shank comprising at least one of an annular shoulder, a groove, a threaded region, and a substantially smooth region. In various non-limiting embodiments, the shank comprises a shank diameter in a range of 0.06 inch to 4 inches. In various non-limiting embodiments, the multi-piece fastener is configured to be installed in a bore in a structure configured as at least one of an aerospace part or component, an automotive part or component, a transportation part or component, and a building and construction part or component.

According to a further non-limiting aspect of the present disclosure, a method for fastening is provided. The method comprises inserting a first pin end of a pin of a multi-piece fastener according to the present disclosure into a bore of a structure. The method further comprises forcibly contacting the elongate portion of the fastening collar with a contact surface of an installation tool, thereby forcibly contacting the structure with the second collar end of the fastening collar and deforming the elongate portion onto the shank of the pin. A force required during forcibly contacting the elongate portion to deform the elongate portion onto the shank of the pin is reduced compared to a force required to forcibly contact and deform onto the pin a comparative elongate portion that does not comprise a second collar end extending away from a longitudinal axis of the elongate portion at the first angle offset from the angle perpendicular to the longitudinal axis.

It will be understood that the inventions disclosed and described in this specification are not limited to the aspects summarized in this Summary. The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of various non-limiting and non-exhaustive aspects according to this specification.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain non-limiting embodiments, in one form, and such exemplifications are not to be construed as limiting the scope of the appended claims in any manner.

DETAILED DESCRIPTION OF NON-LIMITING EMBODIMENTS

Various examples are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed fastening collars, multi-piece fasteners, pins, and methods of fastening. The various examples described and illustrated herein are non-limiting and non-exhaustive. Thus, the invention is not limited by the description of the various non-limiting and non-exhaustive examples disclosed herein. Rather, the invention is defined solely by the claims. The features and characteristics illustrated and/or described in connection with various examples may be combined with the features and characteristics of other examples. Such modifications and variations are intended to be included within the scope of this specification. As such, the claims may be amended to recite any features or characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Further, Applicant reserves the right to amend the claims to affirmatively disclaim features or characteristics that may be present in the prior art. The various embodiments disclosed and described in this specification can comprise, consist of, or consist essentially of the features and characteristics as variously described herein.

As used herein, “intermediate” means that the referenced element is disposed between two elements but is not necessarily in contact with those elements. Accordingly, unless stated otherwise herein, an element that is “intermediate” a first element and a second element may or may not be adjacent to or in contact with the first and/or second elements, and other elements may be disposed between the intermediate element and the first and/or second elements.

Referring toFIG.1, a conventional fastening collar102has a first collar end104and a second collar end106. The first collar end104can be configured to engage an installation tool140. The conventional fastening collar102has a constant wall thickness and a region defining a convex radius, r1, of curvature on the first collar end104.

A drawback of the conventional fastening collar102can be the limited contact surface area between the installation tool140and the conventional fastening collar102during the installation process due to the convex radius, r1, which can create a significantly high bearing stress during the installation process. Therefore, for example, a coating on the first collar end104of the conventional fastening collar102can be damaged during installation, resulting in uncoated regions which can affect the life of the part. Fastening collars, multi-piece fasteners, and methods for fastening are provided herein that can reduce bearing stress during the installation process and/or reduce damage to a coating on the fastening collars.

For example, referring toFIGS.2A-2B, a non-limiting embodiment of a fastening collar202according to the present disclosure can comprise a first collar end204, a second collar end206, an elongate portion208intermediate the first collar end204and the second collar end206, an inner collar surface216, and an external collar surface218. The elongate portion208can define a longitudinal axis, Al, of the fastening collar202. The inner collar surface216extends from the first collar end204to the second collar end206. The inner collar surface216can define a cavity210that extends through the elongate portion208from the first collar end204to the second collar end206.

The elongate portion208can comprise a first region208aadjacent to the first collar end204and a second region208badjacent to the second collar end206. The first region208aextends a first distance, d1, along the elongate portion208, and comprises at least one of a taper, and a region defining a concave radius. The first region208acan be configured to conform to a contact surface on a multi-piece fastener installation tool (e.g., multi-piece fastener installation tool440as described with respect toFIGS.4A-4B) such that a contact surface area between the multi-piece fastener installation tool and the fastening collar202can be increased during installation to reduce bearing stress. The first distance, d1, can be at least 5% of the total length, dt, of the fastening collar202a measured along the longitudinal axis, Al, such as, for example, at least 10%, or at least 20% of the total length, dt, of the fastening collar202. In various non-limiting embodiments, the first distance, d1, can be in a range of 0.020 inches to 0.350 inches. As used herein, “concave” and “convex” of a region of the elongate portion208are determined relative to the external collar surface218.

Reducing bearing stress can improve the operational life of the fastening collar202and/or a multi-piece fastener installation tool. For example, the fastening collar202can be more resistant to the formation of one or more of bare spots, flaking, blisters, coating separations, runs, sags, corrosion, and electromagnetic effects than the conventional fastening collar102illustrated inFIG.1. Referring toFIGS.2A and2B, the first region208aand/or the second region208bcan reduce the force required to initiate the installation of a multi-piece fastener (e.g., multi-piece fastener300) comprising the fastening collar202.

In various non-limiting embodiments, referring toFIG.2B, the first region208acan comprise a radius, r2, of curvature that can be at least 0.060 inches, such as, for example, at least 0.1 inches, or at least 0.2 inches. In certain non-limiting embodiments, the radius, r2, of curvature can be in a range of 0.060 inches to 0.600 inches. The radius, r2, can be concave relative to the external collar surface218. In various non-limiting embodiments, referring toFIG.2C, the first region208acomprises a taper213such that an exterior surface of the first region208acomprises a frusto-conical shape. In various non-limiting embodiments, the taper213can comprise an angle, β, of at least 3 degrees relative to the longitudinal axis, Al, such as, for example, at least 5 degrees, or at least 10 degrees, all relative to the longitudinal axis, Al. In certain non-limiting embodiments, the angle, β, is in a range of 3 degrees to 70 degrees relative to the longitudinal axis, Al, such as, for example, 3 degrees to 60 degrees, 3 degrees to 45 degrees, or 3 degrees to 25 degrees, all relative to the longitudinal axis, Al.

Referring toFIGS.2B and2C, the first region208acan comprise a reduced outer diameter, ϕ1, (measured at an end thereof), relative to a diameter, ϕ2, of the elongate portion208between the first region208aand the second region208b. For example, the outer diameter, ϕ1, of the first region208acan be at least 2% less than the diameter, ϕ2, such as, for example, at least 5% less, or at least 10% less than the diameter, ϕ2.

The second region208bextends a second distance, d2, along the elongate portion208, and can comprise a radially projecting flange214. The second region208bcan be configured to conform to a surface of a structure (e.g., first side458of structure444as described with respect toFIGS.4A-4B) such that a contact surface area between the structure and the fastening collar202can be increased during installation of a multi-piece fastener including the fastening collar202to reduce bearing stress during installation. The second distance, d2, can be at least 2% of the total length, dt, of the fastening collar202, as measured along the longitudinal axis, Al, such as, for example, at least 5%, or at least 10% of the total length, dt, of the fastening collar202.

In various non-limiting embodiments, the second collar end206includes a region that extends away from the longitudinal axis, Al, of the elongate portion208at a first angle, δ, that is offset from an angle perpendicular to the longitudinal axis, Al, of the elongate portion208. For example, and without limitation, the first angle, δ, can be offset at least 1 degree from the angle perpendicular to the longitudinal axis, Al, such as, for example, at least 2 degrees, at least 5 degrees, at least 10 degrees, or at least 15 degrees offset from the angle perpendicular longitudinal axis, Al. For example, and without limitation the first angle, δ, can be in a range of 1 degree to 30 degrees offset from the angle perpendicular longitudinal axis, Al, such as, for example, 10 degrees to 20 degrees, or 14 degrees to 16 degrees offset from the angle perpendicular longitudinal axis, Al. Providing the first angle, δ, can reduce the likelihood or degree of splaying of the second collar end206during installation. For example, an outer surface206aof the second collar end206can be the surface of the fastening collar202that initially contacts a structure during installation of the fastening collar202. When the installation force continues to be applied to the fastening collar202, the first angle, δ, can be reduced and the contact surface area between the fastening collar202and the structure can be increased.

In various non-limiting embodiments, the first angle, δ, at which a region of the second collar end206extends away from the longitudinal axis of the elongate portion208can reduce the force spike during installation due to splaying, which can modulate the preload force so that the retained preload (e.g., steady state) can be at a desirable level. The resilience of the flange214as a result of providing the first angle, δ, at which the second collar end206extends away from the longitudinal axis, Al, of the elongate portion208can reduce shock during installation and thereby help prevent damage to the structure in which the fastener is installed.

The cavity210of the elongate portion208can be configured to at least partially receive a pin of a multi-piece fastener, such as pin320of the multi-piece fastener300shown inFIG.3. In other non-limiting embodiments (not shown), a multi-piece fastener according to the present disclosure can comprise three or more components. In various non-limiting embodiments, referring toFIG.3, the multi-piece fastener300can consist of a two-piece assembly including, for example, the fastening collar202and the pin320. In certain non-limiting embodiments, the multi-piece fastener300can comprise a lockbolt. In certain non-limiting embodiments of the multi-piece fastener300including a lockbolt, the lockbolt can be a structural lockbolt fastener, such as, for example, a structural rivet, a structural bolt, or a structural stud.

The pin320can comprise a first pin end328, a second pin end330, and a shank322. The shank322can comprise a shape suitable to be received within the cavity210of the fastening collar202. In various non-limiting embodiments, the shank322has a generally cylindrical shape. The shank322can be intermediate the first pin end328and the second pin end330and can be dimensioned so that the shank322can be inserted and extend at least partially into the cavity210. When the shank322is inserted in the cavity210, the first pin end328can be disposed adjacent to the first collar end204, and a head portion336of the second pin end330can be disposed adjacent to the second collar end206.

The cavity210of the fastening collar202can be configured to at least partially receive the shank322of the pin320therein. For example, the cavity210can comprise a shape suitable to receive the shank322of the pin320. The fastening collar202, including the inner collar surface216, can be configured to be at least partially deformed onto the shank322. For example, during and/or after introduction of the shank322into the cavity210, the elongate portion208, including at least a portion of the inner collar surface216, can be at least partially deformed (e.g., swaged) onto the shank322responsive to forcible contact between the fastening collar202and a multi-piece fastener installation tool. Deformation of the elongate portion208can secure the fastening collar202to the shank322of the pin320, securing the multi-piece fastener300within a bore in a structure.

In various non-limiting embodiments, the pin320may comprise a breakneck groove (not shown) configured to fracture to separate all or a portion of a pull region324from the pin320upon installation of the multi-piece fastener300in a bore in a structure. In certain other non-limiting embodiments, the pin320does not comprise a breakneck groove but is configured to include one or more other features so that the pull region324of the pin320fractures during installation of the multi-piece fastener300. In various non-limiting embodiments of the multi-piece fastener300, the pin320does not comprise a breakneck groove or other feature configured to fracture upon installation of the multi-piece fastener300, and the pull region324remains intact after installation. Thus, various non-limiting embodiments of multi-piece fasteners according to the present disclosure may be installed in a structure without fracturing of a breakneck groove or other feature or, alternatively, the fasteners may include a breakneck groove or other feature that fractures upon installation of the multi-piece fastener into the structure.

In various non-limiting embodiments, the second pin end330can further comprise the head portion336configured to inhibit the pin320from traversing into a bore in a structure beyond a predetermined distance. The shank322can comprise at least one of a generally smooth region, an annular shoulder, a groove, a thread, and/or can comprise one or more other features configured to engage the inner collar surface216of the fastening collar202.

In various non-limiting embodiments, the shank322can comprise the pull region324configured to be engaged by a multi-piece fastener installation tool (not shown) when installing the multi-piece fastener300in a bore in a structure. The pull region324can comprise an axial length, and in various non-limiting embodiments the pull region324can comprise a taper. In various non-limiting embodiments, the pull region324can comprise at least one of a generally smooth region, an annular shoulder, a groove, a thread, and/or can comprise one or more other features configured to be engaged by a multi-piece fastener installation tool. For example, and without limitation, the pull region324can comprise grooves348, as illustrated inFIG.3, that can be engaged by a multi-piece fastener installation tool. In certain non-limiting embodiments, the multi-piece fastener installation tool can be a puller tool or a squeezer tool.

The fastening collar202and/or the pin320can be sized as appropriate for the intended application. For example, the shank322can comprise a shank diameter in a range of 0.06 inch to 4 inches, and the fastening collar202can be size to receive the shank322.

The fastening collar202can comprise any suitable material, such as, for example, a metal, a metal alloy, a polymer, or another suitable material. For example, in various non-limiting embodiments, the multi-piece fastener100can comprise at least one of aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, iron, an iron alloy, and a carbon fiber composite material.

As illustrated in the non-limiting embodiments shown inFIGS.4A-4B, the multi-piece fastener300can be installed into a bore446in a structure444. As illustrated, the bore446can extend through the structure444from a first side458to a second side460of the structure444. The structure444can comprise, for example, at least one of a metal, a metal alloy, a composite material, or another suitable material. For example, in certain non-limiting embodiments, the structure444can comprise one or more of aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, iron, an iron alloy, and a carbon fiber composite material. In various non-limiting embodiments, the structure444in which the multi-piece fastener300is installed comprises aluminum and/or an aluminum alloy, such as, for example, a 7075 aluminum alloy. In various non-limiting embodiments, the structure444into which a multi-piece fastener300can be installed can be configured as at least one of an aerospace component or structure, an automotive component or structure, a transportation component or structure, a building and construction component or structure, or another component or structure.

The structure444can comprise a single layer of material or two or more layers of material. For example, as illustrated inFIGS.4A-4B, the structure444can comprise a first layer444aand a second layer444b, which may be the same material or different materials. The first layer444acan be positioned intermediate the second layer444band the fastening collar202when the multi-piece fastener300is installed. In various non-limiting embodiments, the first layer444ais adjacent to or contacts the fastening collar202.

Additionally, in various non-limiting embodiments, the first pin end328can be sized and configured to facilitate alignment of the pin320with the bore446, thereby allowing the first pin end328to readily move into and through the bore446. In various non-limiting embodiments, the head portion336can be sized and configured to inhibit the pin320from traversing into the bore446beyond a predetermined distance.

As illustrated inFIG.4A, the first pin end328of the pin320was positioned in alignment with the second side460of the bore446and inserted through the bore446. The fastening collar202was positioned over the first pin end328, and the first pin end328has been inserted into the cavity310of the fastening collar302. In the arrangement shown inFIG.4Athe fastening collar202has not yet been deformed about the pin320.

With reference toFIG.4A, and as will be understood by those having ordinary skill in the multi-piece fastener art considering the present disclosure, jaws of the collet442of a multi-piece fastener installation tool440can close around and forcibly engage the pull region324of pin320. Upon engagement, the jaws of the collet442can apply an axial force to the pull region324of the pin320. The jaws of the collet442can retract into a housing450of the multi-piece fastener installation tool440, and the pin320can also move as the jaws of the collet442retract due to the engagement between the pull region324and the jaws of the collet442. As the pin320moves in this way, an anvil448of the multi-piece fastener installation tool440can forcibly contact the fastening collar202with an axial force and urge the fastening collar202along the pin320in a direction away from the first pin end328. The movement of the fastening collar202can decrease the width of a gap, if present, between the first layer444aand the second layer444bof the structure444and forcibly contact the fastening collar202with the structure444.

As illustrated inFIG.4A, the anvil448has engaged the first region208aof the elongate portion208and the outer surface206aof the second collar end206of the fastening collar202has engaged the first side458of the structure444, while an inner surface206bof the second collar end206has not engaged the structure444. In various non-limiting embodiments, the first region208ais shaped to conform to the anvil448of the multi-piece fastener installation tool440such that a contact surface area between the multi-piece fastener installation tool440and the fastening collar202can be increased during installation to reduce bearing stress on the fastening collar202.

Referring toFIG.4B, when the anvil448of the multi-piece fastener installation tool440imparts a sufficient force to the fastening collar202, the elongate portion208is at least partially deformed (e.g., swaged) onto the pin320. For example, the inner collar surface216can be deformed onto the shank322of the pin320intermediate the first layer444aand the first pin end328. During deformation, the first angle, δ, shown inFIG.4Acan be reduced to a first angle, δ′, shown inFIG.4B, such that a larger surface area region of the second collar end206is touching the first side458of the structure444in the configuration shown inFIG.4Bthan shown inFIG.4A. For example, the inner surface206bof the second collar end206is shown engaging the first side458of the structure444inFIG.4B. Because the area of contact between the second collar end206and the first side458of the structure444is initially minimal and gradually increases as the installation forced is applied, shock during installation can be reduced to help prevent damage to the structure444while maintaining a desirable preload force.

The deformation of the elongate portion208can secure the fastening collar202to the pin320and thereby secure the multi-piece fastener300to at least a portion of the structure444. In that way, for example, the first layer444aand second layer444bof the structure444are secured together. After installation of the multi-piece fastener300into the structure444, the fastening collar202and the head portion336of the pin320are applying a clamping force to the structure444.

As illustrated inFIG.4B, the pin320may not fracture after installation into the structure444. Alternatively, the pin320may fracture (not shown) after installation into the structure444as a result of force applied to the pin320by the multi-piece fastener installation tool440. For example, the pin320may fracture along a breakneck groove, if present, after installation into the structure444.

Embodiments of multi-piece fasteners according to the present disclosure can be used in a method for fastening a structure.FIG.5illustrates steps of a non-limiting embodiment of such a method. The method illustrated inFIG.5can comprise inserting the first pin end328of a multi-piece fastener300according to the present disclosure into a bore446in a structure444(at step502). After inserting the first pin end328into the structure444, the first pin end328can be inserted into the cavity210of the fastening collar202(at step504). Subsequent to inserting the first pin end328into the cavity210, in certain non-limiting embodiments, the fastening collar202can be forcibly contacted with an anvil448of a multi-piece fastener installation tool440, urging the fastening collar202to move along the pin320in a direction away from the first pin end328(at step506). In various non-limiting embodiments, the pull region324of the pin320can be forcibly contacted with jaws of the collet442of the multi-piece fastener installation tool440(at step508). In various non-limiting embodiments, steps506and508can occur simultaneously. The inner collar surface216of the fastening collar202can be deformed onto the shank322of the pin320, thereby securing the pin320to the fastening collar202and retaining at least a portion of the multi-piece fastener300in the structure444(at step510). A force spike during installation due to splaying of the second collar end206can be modulated so that the retained preload (e.g., steady state) can be at a desirable level and shock during installation is reduced to help prevent damage to the structure444due to the configuration of the second collar end206of the fastening collar and/or the configuration of the first region208aof the fastening collar202.

Various aspects of non-limiting embodiments of inventions according to the present disclosure include, but are not limited to, the aspects listed in the following numbered clauses.

Clause 1. A fastening collar comprising a first collar end, a second collar end, and an elongate portion intermediate the first collar end and the second collar end and defining a longitudinal axis of the fastening collar, and wherein the elongate portion comprises: a first region adjacent the first collar end, extending a first distance along the longitudinal axis; a second region adjacent to the second collar end, extending a second distance along the longitudinal axis and comprising a flange; and an inner collar surface defining a collar cavity extending through the elongate portion from the first collar end to the second collar end and wherein the second collar end extends away from the longitudinal axis of the elongate portion at a first angle offset from the angle perpendicular to the longitudinal axis of the elongate portion.

Clause 2. The fastening collar of clause 1, wherein the first angle is at least 1 degree offset from the angle perpendicular to the longitudinal axis of the elongate portion.

Clause 3. The fastening collar of clause 1, wherein the first angle is at least 5 degrees offset from the angle perpendicular to the longitudinal axis of the elongate portion.

Clause 4. The fastening collar of clause 1, wherein the first angle is in a range of 1 degree to 30 degrees offset from the angle perpendicular to the longitudinal axis of the elongate portion.

Clause 5. The fastening collar of any of clauses 1-4, wherein the first region comprises at least one of a taper and a region defining a concave radius.

Clause 6. The fastening collar of any of clauses 1-5, wherein the first region comprises a region defining a concave radius is at least 0.060 inches, and/or the first region comprises the taper and the taper comprises a second angle in a range of 3 degrees to 70 degrees relative to the longitudinal axis.

Clause 7. The fastening collar of any of clauses 5-6, wherein the first distance is at least 5% of the total length of the fastening collar and the second distance is at least 2% of the total length of the fastening collar.

Clause 8. The fastening collar of any of clauses 1-7, wherein the fastening collar comprises at least one of a metal, a metal alloy, and a composite

Clause 9. A multi-piece fastener comprising:the fastening collar of any of clauses 1-8; anda pin configured to be at least partially received in the cavity of the fastening collar.

Clause 10. The multi-piece fastener of clause 9, wherein the pin comprises a shank comprising at least one of an annular shoulder, a groove, a threaded region, and a substantially smooth region.

Clause 11. The multi-piece fastener of any of clauses 9-10, wherein the multi-piece fastener is configured to be installed in a bore in a structure configured as at least one of an aerospace part or component, an automotive part or component, a transportation part or component, and a building and construction part or component.

Clause 12. The multi-piece fastener of any of clauses 9-11, wherein the pin comprises a shank comprising a shank diameter in a range of 0.06 inch to 4 inches.

Clause 13. A method for fastening, the method comprising:providing a multi-piece fastener comprising:(a) a fastening collar comprisinga first collar end,a second collar end, andan elongate portion intermediate the first collar end and the second collar end and defining a longitudinal axis of the fastening collar,wherein the elongate portion comprises a first region adjacent the first collar end, extending a first distance along the longitudinal axis, and a second region adjacent to the second collar end, extending a second distance along the longitudinal axis, and comprising a flange, andan inner collar surface defining a collar cavity extending through the elongate portion from the first collar end to the second collar end,wherein the second collar end extends away from the longitudinal axis of the elongate portion at a first angle offset from an angle perpendicular to the longitudinal axis of the elongate portion; and(b) a pin configured to be at least partially received by the collar cavity, the pin comprisinga first pin end,a second pin end, anda shank extending intermediate the first pin end and the second pin end,inserting the first ping end of the pin into a bore of a structure; andforcibly contacting the elongate portion of the fastening collar with a contact surface of an installation tool, thereby forcibly contacting the structure with the second collar end of the fastening collar and deforming the elongate portion onto the shank of the pin, wherein a force required during forcibly contacting the elongate portion to deform the elongate portion onto the shank of the pin is reduced compared to a force required to forcibly contact and deform onto the pin a comparative elongate portion that does not comprise a second collar end extending away from a longitudinal axis of the elongate portion at the first angle offset from the angle perpendicular to the longitudinal axis.

Clause 14. A fastening collar comprising:a first collar end;a second collar end; andan elongate portion intermediate the first collar end and the second collar end and defining a longitudinal axis of the fastening collar, wherein the elongate portion comprisesa first region adjacent the first collar end, extending a first distance along the longitudinal axis, wherein the first region comprises at least one of a taper and a region defining a concave radius,a second region adjacent to the second collar end, extending a second distance along the longitudinal axis, and comprising a flange, andan inner collar surface defining a collar cavity extending through the elongate portion from the first collar end to the second collar end.

Clause 15. The fastening collar of clause 14, wherein the first region comprises the region defining the concave radius and the concave radius is at least 0.060 inches, and/or the first region comprises the taper and the taper comprises an angle in a range of 3 degrees to 70 degrees relative to the longitudinal axis.

Clause 16. The fastening collar of any one of clauses 14-15, wherein the first distance is at least 5% of the total length of the fastening collar.

Clause 17. A multi-piece fastener comprising:the fastening collar any of clauses 14-16; anda pin configured to be at least partially received in the cavity of the fastening collar.

Clause 18. The multi-piece fastener of clause 17, wherein the pin comprises a shank and the shank comprises at least one of an annular shoulder, a groove, a threaded region, and substantially smooth region.

Clause 19. The multi-piece fastener of any of clauses 17-18, wherein the multi-piece fastener is configured to be installed in a bore in a structure configured as at least one of an aerospace part or component, an automotive part or component, a transportation part or component, and a building and construction part or component.

Clause 20. A method for fastening, the method comprising:inserting a pin end of the pin of the multi-piece fastener of any of clauses 17-20 into a bore of a structure; andforcibly contacting the elongate portion of the fastening collar with a contact surface of an installation tool, thereby forcibly contacting the structure with the second collar end of the fastening collar and deforming the elongate portion onto the pin, wherein a preload force required during forcibly contacting the elongate portion to deform the elongate portion onto the shank of the pin is reduced compared to a preload force required to forcibly contact and deform onto the pin a comparative elongate portion that does not comprise a second collar end extending away from a longitudinal axis of the elongate portion at the first angle offset from the angle perpendicular to the longitudinal axis.

One skilled in the art will recognize that the fastening collars, multi-piece fasteners, structures, methods, operations/actions, and objects described herein, and the accompanying discussion, are non-limiting examples presented for the sake of conceptual clarity and that various modifications to the disclosed configurations are contemplated. Consequently, as used herein, the specific examples/embodiments set forth, and the accompanying discussion, are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class and the non-inclusion of specific components, devices, apparatus, operations/actions, and objects should not be taken as limiting. While the present disclosure provides descriptions of various specific aspects for the purpose of illustrating various aspects of the present disclosure and/or its potential applications, it is understood that variations and modifications will occur to those skilled in the art. Accordingly, the invention or inventions described herein should be understood to be at least as broad as they are claimed and not as more narrowly defined by particular illustrative aspects provided herein.

Any references herein to “various embodiments”, “some embodiments”, “one embodiment”, “an embodiment”, a “non-limiting embodiment”, or like phrases mean that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments”, “in some embodiments”, “in one embodiment”, “in an embodiment”, “in a non-limiting embodiment”, or like phrases in the specification do not necessarily refer to the same embodiment. Furthermore, the particular described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present embodiments.

Also, any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of “1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification.

The grammatical articles “a”, “an”, and “the”, as used herein, are intended to include “at least one” or “one or more”, unless otherwise indicated, even if “at least one” or “one or more” is expressly used in certain instances. Thus, the foregoing grammatical articles are used herein to refer to one or more than one (i.e., to “at least one”) of the particular identified elements. Further, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of the usage requires otherwise.