Lockbolt fasteners and methods for fastening

Abstract

Lockbolt fasteners and methods for fastening are provided. The lockbolt fastener comprises a pin and a fastening collar. The pin comprises a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end. The second pin end comprises a head having a first diameter. The shank defines a longitudinal axis. The shank comprises a pull-region having a second diameter, a lock region having a third diameter, and a grounding region having a fourth diameter. The pull-region is intermediate the lock region and the first pin end. The grounding region is intermediate the lock region and the second pin end. The grounding region comprises at least two splines substantially aligned with the longitudinal axis, each spline having a crest. The crests define a fourth diameter greater than the second diameter and the third diameter, and less than the first diameter.

Description

TITLELOCKBOLT FASTENERS AND METHODS FOR FASTENINGCROSS-REFERENCE

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 708,967, which was filed on October 18, 2024. The contents of which is hereby incorporated by reference into this specification.FIELD OF USE

[0002] The present disclosure relates to lockbolt fasteners and methods for fastening.BACKGROUND

[0003] 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 provide a grounding lug. Properly installing a mechanical fastener into a bore for electrical grounding presents challenges.SUMMARY

[0004] According to non-limiting aspects of the present disclosure, a lockbolt fastener comprises a pin and a fastening collar. The pin comprises a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end. The second pin end comprises a head having a first diameter. The shank defines a longitudinal axis. The shank comprises a pull-region having a second diameter, a lock region having a third diameter, and a grounding region having a fourth diameter. The pull-region is intermediate the lock region and the first pin end. The grounding region is intermediate the lock region and the second pin end. The grounding region comprises at least two splines substantially aligned with the longitudinal axis, each spline comprising a crest. The crests define a fourth diameter greater than the second diameter, greater than the third diameter, and less than the first diameter. The collar is capable to be deformed onto the lock region of the shank. 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 collar cavity capable to receive the first pin end.1#321397500.6

[0005] According to other non-limiting aspects of the present disclosure, a method for fastening comprises inserting a first pin end of a pin of a lockbolt fastener into a bore defined by an inner surface of a structure. The method comprises forcibly contacting a pull-region of a shank with a collet of an installation apparatus, and applying a direct tension load to the pull-region of the shank with the collet of the installation apparatus, thereby cutting the inner surface of the structure with the grounding region and enabling electrical communication between the lockbolt fastener and the structure. The method comprises inserting the first pin end of the pin into the collar cavity of the fastening collar of the lockbolt fastener. The method comprises moving the fastening collar distal from the pull-region. The method comprises forcibly contacting the fastening collar of the lockbolt fastener with an anvil of the installation apparatus and deforming the fastening collar onto the lock region of the shank of the pin, thereby securing at least a portion of the lockbolt fastener in the structure.

[0006] 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.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The features and advantages of the examples, and the manner of attaining them, will become more apparent, and the examples will be better understood, by reference to the following description taken in conjunction with the accompanying drawings, wherein:

[0008] FIG. l is a cross-sectional side view of a non-limiting embodiment of a lockbolt fastener according to the present disclosure;

[0009] FIG. 2 is a detailed view of the area 2 in FIG. 1;

[0010] FIG. 3 is a perspective view of a non-limiting embodiment of a pin of a non-limiting embodiment of a lockbolt fastener according to the present disclosure;

[0011] FIG. 4 is a cross-sectional view of the pin of FIG. 3 taken along line 4-4;

[0012] FIG. 5 is a top view of the pin of FIG. 3;

[0013] FIG. 6 is a cross-sectional side view of a non-limiting embodiment of a lockbolt fastener according to the present disclosure and a structure in a first configuration;

[0014] FIG. 7 is a cross-sectional side view of the lockbolt fastener of FIG. 6 shown partially inserted into a bore in a structure and with a pull-region of the pin of the lockbolt fastener contacted with a collet of an installation tool;

[0015] FIG. 8 is a cross-sectional side view of the lockbolt fastener according of FIG. 7 shown after a direct tension load has been applied to the pull-region of the lockbolt fastener and a grounding region of the lockbolt fastener has cut into an inner surface of the structure;

[0016] FIG. 9 is a cross-sectional side view of the lockbolt fastener according to FIG. 8 shown with the first pin end inserted through a collar cavity of a collar;

[0017] FIG. 10 is a cross-sectional side view of a lockbolt fastener according to FIG. 9 shown with the collar deformed onto the pin of the lockbolt fastener; and

[0018] FIG. 11 is a cross-sectional side view of the lockbolt fastener of FIG. 10 shown with a threaded nut securing a device to the lockbolt fastener.

[0019] 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

[0020] Various examples are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed fasteners 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, thisspecification. 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.

[0021] As used herein, “intermediate” means that the referenced element is between two elements but is not necessarily in contact with either of 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 element and / or the second element, and other elements may be between the intermediate element and the first element and / or the second element.

[0022] Prior art grounding fasteners create a connection to a base material through an interference fit and / or a weld (e.g., a weld stud). Welding can produce heat affected zones, which can cause insufficient electrical conductivity. Conventional press-in fasteners often require backing support in the hole of the base material, as the thickness of the material is typically insufficient for maintaining the interference fit and, thus, conductivity between the fastener and base material can be reduced. Conventional press-in fasteners may not obtain enough surface contact with a surface of the base material to enable sufficient conductivity between the fastener and the base material. Conventional threaded fasteners can loosen under transverse vibrations, which can reduce conductivity between the fastener and the base material. Installing a fastener with a torque (e.g., rotating the pin and / or the nut) can reduce the surface contact between the fastener and the inner surface of the hole, which can reduce conductivity between the fastener and the base material.

[0023] Thus, the present disclosure provides a lockbolt fastener and methods of installation of a lockbolt fastener that can provide an enhanced electrical conductivity between the fastener and the base material, enhanced resistance to loosening, enhanced vibration resistance, and / or consistent sustained clamp force. For example, a non-limiting embodiment of a lockbolt fastener 100 according to the present disclosure is illustrated in FIGs. 1 and 3. As illustrated, the lockbolt fastener 100 comprises a fastening collar 102 and a pin 110. The lockbolt fastener 100 can be a two-piece fastener. The collar 102 can be swaged onto the pin 110, thereby forming a clamp force to hold assembled parts together and / or securing at least a portion of the lockbolt fastener 100 in a structure.

[0024] The pin 110 comprises a first pin end 112, a second pin end 114, and a shank 116 extending intermediate the first pin end 112 and the second pin end 114. The pin 110 can be shaped / configured to engage an installation apparatus and / or be received by the collar 102.

[0025] The second pin end 114 can comprise a head portion 118. The head portion 118 can inhibit the second pin end 112 from traversing into a bore of a structure, as described with respect to FIGs. 6-11 below. The head portion 118 can be adjacent to and / or abutting the shank 116. In various non-limiting embodiments, the head portion 118 can comprise a substantially cylindrical shape. For example, a first diameter, (|)i, of the head portion 118 can be substantially uniform along the longitudinal axis, Ai.

[0026] In various non-limiting embodiments, the first diameter, (|)i, can be in a range of 0.1 inches (2.54 mm) to 5 inches (127 mm), such as, for example, 0.25 inches (6.35 mm) to 2 inches (50.8 mm), 0.5 inches (12.7 mm) to 1.5 inches (38.1 mm), or 0.5 inches (12.7 mm) to 1 inches (25.4 mm).

[0027] The shank 116 can define the longitudinal axis, Ai, of the fastener 100. The shank 116 can comprise a pull-region 120, a lock region 122, and a grounding region 124, each extending a distance along the longitudinal axis, Ai. The lock region 122 can be intermediate the pull-region 120 and the grounding region 124. In various non-limiting embodiments, the pull-region 120 can be adjacent to and / or abutting the first pin end 112. In certain nonlimiting embodiments, the grounding region 124 can be adjacent to and / or abutting the second pin end 114 and / or the head portion 118.

[0028] The shank 116 can extend an axial distance, di, along the longitudinal axis, Ai. For example, the shank 116 can extend an axial distance, di, of at least 1 times a third diameter, (|)i, of the lock region 122, such as, for example, at least 1.1 times, at least 1.5 times, at least 2 times, at least 3 times, or at least 4 times the third diameter, (|)i, of the lock region 122.

[0029] The pull-region 120 can be intermediate the lock region 122 and the first pin end 112. The pull-region 120 can be capable to be engaged by a collet of an installation apparatus. For example, the pull-region 120 can comprise one or more of a substantially smooth region, an annular shoulder, a groove (e.g., a single groove, at least two grooves), and a threaded region. In various non-limiting embodiments, the pull-region 120 can comprise a groove. In certain non-limiting embodiments, a groove can have a groove diameter that is smaller than diameters on immediately adjacent portions of the shank 116 that the groove is positionedbetween. In various non-limiting embodiments, a shoulder can have a shoulder diameter equal to or smaller than a diameter on one immediately adjacent portion of the shank 116 and bigger than another immediately adjacent portion of the shank that the shoulder is positioned between.

[0030] The pull-region 120 has a second diameter, (|)2. For example, the second diameter, (|>2, can be defined by an external diameter of a substantially smooth region, a crest height of an annular shoulder, a crest height of a groove, and / or a crest height of a thread. The second diameter, (|)2, can be no greater than the third diameter, (|)3, of the lock region 122. For example, the second diameter, (|)2, can be less than the third diameter, (|)3, of the lock region 122, at least 10% less than the third diameter, (|)3, at least 20% less than the third diameter, (|)3, at least 25% less than the third diameter, (|)3, or at least 30% less than the third diameter, 4>3,of the lock region 122.

[0031] In various non-limiting embodiments, the pull-region 120 can be substantially cylindrical. For example, the second diameter, (|>2, of the pull-region 120 can be substantially uniform along the longitudinal axis, Ai. In certain non-limiting embodiments, the pull-region 120 can be tapered.

[0032] The lock region 122 can be capable to receive the deformed collar 102 and engage with the deformed collar 102 to secure the collar 102 to the pin 110. For example, the lock region 122 can comprise one or more of an annular shoulder, a groove, and a threaded region. In various non-limiting embodiments, the lock region 122 can comprise a groove.

[0033] The lock region 122 has a third diameter, (|)3. For example, the third diameter, (|>3, can be defined by a crest height of an annular shoulder, a crest height of a groove, and / or a crest height of a thread. In various non-limiting embodiments, the third diameter, (|)3, can be in a range of 0.06 inches (1.52 mm) to 4 inches (101.6 mm), such as, for example, 0.1875 inch (4.76 mm) to 2 inches (50.8 mm) or 0.25 inches (6.35 mm) to 1 inch (25.4 mm). In certain non-limiting embodiments, the third diameter, (|)3, can be indicative of the nominal size of the lockbolt fastener 100. In various non-limiting embodiments, the third diameter, (|)3, can be the same as or greater than the second diameter, (|)2.

[0034] In various non-limiting embodiments, the lock region 122 can be substantially cylindrical. For example, the third diameter, (|)3, of the lock region 122 can be substantiallyuniform along the longitudinal axis, Ai. In certain non-limiting embodiments, the lock region 122 can be tapered.

[0035] The grounding region 124 can be intermediate the lock region 122 and the second pin end 114. The grounding region 124 may be abutting the head portion 118. The grounding region 124 can be capable to facilitate electrical communication between the lockbolt fastener 100 and a structure into which the lockbolt fastener 100 is installed. For example, the grounding region 124 can enhance direct surface area contact between the fastener 100 and the structure such that electrical conductivity between the fastener 100 and the structure is enhanced.

[0036] Referring to FIGs. 2 and 4, the grounding region 124 can comprise a structural feature configured to cut into a structure in which the lockbolt fastener 100 is installed and enhance electrical conductivity between the fastener 100 and the structure. The structural feature can be capable to inhibit the fastener 100 from rotating about the longitudinal axis, Ai. For example, the grounding region 124 can comprise at least two splines 126, which may be substantially aligned with the longitudinal axis, Ai. In various non-limiting embodiments, the grounding region 124 can comprise at least 4 splines, at least 8 splines, at least 10 splines, at least 14 splines, at least 20 splines, or at least 25 splines.

[0037] In various non-limiting embodiments, the splines 126 may be helical.

[0038] As used herein, a spline refers to any structure or feature on the grounding region 124 of the shank 116 of the pin 110 and which is capable of cutting into an inner surface of a bore in a structure, thereby increasing a contact area between the pin 110 and the structure and / or inhibiting rotation of the pin 110 relative to the structure subsequent to installation of the fastener in the structure. A spline comprises an aspect ratio of a width, w, to length, 1, (as measured along the longitudinal axis, Ai; distance, 2) of less than 1. For example, the aspect ratio of a spline can be 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.25 or less, or 0.2 or less.

[0039] The splines 126 can extend radially from the grounding region 124 relative to the longitudinal axis, Ai and can be positioned around a circumference of the grounding region 124. For example, the splines 126 can be unevenly positioned or evenly positioned around a circumference of the grounding region 124. The splines 126 can cut into the structure and inhibit the fastener 100 from rotating about the longitudinal axis, Ai. In certain non-limitingembodiments, the splines 126 can be deformed by the structure and can create intimate contact (e.g., friction contact) to inhibit the fastener 100 from rotating about the longitudinal axis, Ai.

[0040] The splines 126 can extend a distance, d2, relative to the longitudinal axis, Ai, that may be at least 0.125 inch (3.175 mm), such as, for example, at least 0.25 inch (6.25 mm), at least 0.375 inch (9.53 mm), or at least 0.5 inch (12.7 mm). For example, the distance, d2, may be in a range of 0.125 inch (3.175 mm) to 3 inches (76.2 mm). The distance, d2, can be configured to enable suitable surface contact with a structure.

[0041] In the non-limiting embodiment shown in FIGs. 2-4, each spline 126 can have a crest 126c and a root 126r. For example, each spline 126 can extend from the root 126r to the crest 126c. The splines 126 can define gaps 126b between each of splines 126. The gaps 126b can be capable to receive material cut from a structure by the splines 126, thereby enabling the splines 126 to continue to cut into the structure.

[0042] The crests 126c can define a fourth diameter, (|)4. The fourth diameter, (|)4, can be greater than the second diameter, (|)2, and the third diameter, (|)3. The fourth diameter, (|)4, can be less than the first diameter, (|)i. The first diameter, (|)i, can be greater than the fourth diameter, (|)4, such as, for example, at least 10% greater, at least 20% greater, at least 30% greater, at least 40% greater, at least 50% greater, at least 75% greater, at least 100% greater, at least 125% greater, or at least 150% greater, than the fourth diameter, (|)4.

[0043] The roots 126r can define a fifth diameter, (|)5, that can be greater than the second diameter, (|)2, and the third diameter, (|)3. In various non-limiting embodiments, the fourth diameter, (|)4, can be at least 0.1% greater than the fifth diameter, (|)5, such as, for example, at least 1%, at least 2%, at least 3%, at least 5%, at least 7%, at least 10%, or at least 11%, greater than the fifth diameter, (|)5. In various non-limiting embodiments, the fifth diameter, (|)5, can be smaller than a diameter of a bore in a structure that the fastener 100 will be installed into.

[0044] Referring to FIG. 4, the splines 126 can comprise an included angle, a, of at least 45 degrees, such as, for example, at least 50 degrees, or at least 55 degrees. The splines 126 can comprise an included angle, a, of no greater than 80 degrees, such as, for example, no greater than 75 degrees, or no greater than 70 degrees. In various non-limiting embodiments, thesplines 126 can comprise an included angle, a, in a range of 45 degrees to 80 degrees, such as, for example, 50 degrees to 70 degrees. In certain non-limiting embodiments, the splines 126 can comprise a triangular cross-sectional shape. In certain non-limiting embodiments, the splines 126 can comprise rounded or curved edges.

[0045] In certain non-limiting embodiments, the grounding region 124 can comprise a tapered lead-in region 132 intermediate the splines 126 and the lock region 122. The tapered lead-in region 132 can increase in diameter from the lock region 122 towards the second pin end 114. In various non-limiting embodiments, the tapered lead-in region 132 at least partially overlaps with the splines 126 such that each spline 126 comprises a tapered end 126e that increases in diameter from the lock region 122 to the respective crest 126c of the respective spline 126.

[0046] The tapered lead-in region 132 can comprise an angle relative to the longitudinal axis, Ai, in a range of 0 to 45, such as, for example, 1 degree to 45 degrees, 5 degrees to 45 degrees, 10 degrees to 45 degrees, or 15 degrees to 45 degrees.

[0047] The tapered lead-in region 132 can extend a distance, ds, relative to the longitudinal axis, Ai, in a range of 0 to 0.25 in (6.35 mm), such as, for example, 0.05 in (1.27 mm) to 0.25 in (6.35 mm), or 0.1 in (2.54 mm) to 0.25 in (6.35 mm).

[0048] In various non-limiting embodiments, the pin 110 can comprise, intermediate the lock region 122 and the pull-region 120, a breakneck groove and / or other feature configured to fracture upon installation of the fastener 100, and the pull-region 120 may detach after installation. In certain non-limiting embodiments, the pin 110 may not comprise a breakneck groove or other feature configured to fracture upon installation of the fastener 100, and the pull-region 120 may stay intact after installation.

[0049] The collar 102 can be capable to be deformed onto the lock region 122 of the shank 116. For example, an anvil of an installation apparatus can deform the collar 102 into the grooves, shoulders, and / or other feature of the lock region 122 in order to inhibit movement of the collar 102 along the longitudinal axis, Ai. In various non-limiting embodiments, the collar 102 can be capable to enable deformation, such as, for example, the collar 102 can comprise a suitable wall thickness, hardness, material, and / or other property such that the collar 102 can be deformed by the installation apparatus and retain a desired clamp / tensile strength with the pin 110 after deformation. For example, the collar 102 can be deformedinwardly towards the longitudinal axis, Ai, and engage the lock region 122. The engagement may be contact between an inner surface 128 of an elongate portion 108 of the collar 102 and a substantially smooth region of the lock region 122, annular shoulders of the lock region 122, a groove of the lock region 122, and / or a thread of the lock region 122. In various nonlimiting embodiments, the collar 102 can be sized and / or configured to deform to secure the collar 102 to the pin 110 at a load less than a strip strength of the pull-region 120.

[0050] The collar 102 can comprise a first collar end 104, a second collar end 106, and the elongate portion 108 intermediate the first collar end 104 and the second collar end 106. The elongate portion 108 can comprise the inner surface 128 that can define a collar cavity 130 capable to receive the first pin end 112.

[0051] To install the fastener 100, an installation apparatus can grip the pin 110 and then pull the pin 110 into a structure and / or urge the pin 110 into the collar 102. Next, the installation apparatus can be forced along the collar 102 to progressively squeeze (e.g., swage) the collar 102 onto the pin 110. The direct contact of the collar 102 swaged onto the pin 110 can reduce loosening effects of transverse vibration.

[0052] The pin 110 can comprise a second shank 134 extending from the second pin end 112 along the longitudinal axis, Ai. The second shank 134 can be, for example, a grounding stud and can be capable to be in electrical communication with a structure contacting the grounding region 124 and / or head portion 118. In various non-limiting embodiments, the second shank 134 can comprise threads suitable to engage with a nut to urge a device in direct contact with the head portion 118 and / or a structure.

[0053] The second shank 134 can extend an axial distance, ds, along the longitudinal axis, Ai. For example, the second shank 134 can extend an axial distance, ds, of at least 1 times a sixth diameter, (|>6, of the second shank 134, such as, for example, at least 1.1 times, at least 1.5 times, at least 2 times, at least 3 times, or at least 4 times the sixth diameter, (|>6, of the second shank 134.

[0054] In various non-limiting embodiments, the sixth diameter, (|>6, can be in a range of 0.06 inches (1.52 mm) to 4 inches (101.6 mm), such as, for example, 0.1875 inch (4.76 mm) to 2 inches (50.8 mm) or 0.25 inches (6.35 mm) to 1 inch (25.4 mm).

[0055] The fastener 100 can comprise at least one of a metal, a metal alloy, a composite material, and another suitable material. For example, in various embodiments, the fastener 100 can comprise at least one of aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, iron, an iron alloy (e.g., steel), and a carbon fiber composite material.

[0056] The present disclosure also provides methods for fastening a fastener into a structure. The methods can provide an enhanced electrical conductivity between the fastener and the structure, enhanced resistance to loosening, enhanced vibration resistance, and / or consistent sustained clamp force.

[0057] As illustrated in FIGs. 6-11, the fastener 100 can be installed into a bore 646 in a structure 644 and the fastener 100 can be attached to a device 1180 for electrical grounding. The bore 646 can be defined by an inner surface 644a of the structure 644. As illustrated, the bore 646 can extend through the structure 644 from a first side 658 to a second side 660. In various embodiments, the bore 646 may comprise threads, while in other non-limiting embodiments the bore 646 does not comprise threads.

[0058] The structure 644 can comprise, for example, at least one of a metal, a metal alloy, a polymer, wood, concrete, a composite material, or another suitable material. For example, in certain embodiments, the structure 644 can comprise at least one of aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, iron, an iron alloy (e.g., steel), and a carbon fiber composite material. In various embodiments, the structure 644 comprises aluminum and / or an aluminum alloy, such as, for example, 7075 aluminum alloy. With reference to the accompanying figures, in various non-limiting embodiments the structure 644 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.

[0059] The structure 644 can comprise a single layer of material or at least two (i.e., two or more) layers of material. For example, as illustrated in FIGs. 6-11, the structure 644 can comprise a single layer.

[0060] To facilitate alignment of the fastener 100 and the bore 646, a size and / or shape of the first pin end 112 can be configured to readily enter into and move through the bore 646. In various non-limiting embodiments, the third diameter, <J>3, and the fourth diameter, <J>4, can be less than a diameter, (jib, of the bore 646 in order to enable the pin 110 to enter into and movethrough the bore 646. As illustrated in FIG. 6, the first pin end 112 of the pin 110 was positioned in alignment with the second side 660 of the bore 646 before being inserted through the bore 646.

[0061] Referring to FIG. 7, the first pin end 112 was partially inserted into the bore 646 by moving the pin 110 along the longitudinal axis, Ai. The pin 110 can be partially inserted manually (e.g., by the hand of an operator) and / or with an installation apparatus 700. In various non-limiting embodiments, the first diameter, (jn, of the head portion 118 can be greater than a diameter, (jib, of the bore 646 in order to inhibit the pin 110 from further advancing into the bore 646.

[0062] The installation apparatus 770 can comprise a housing 776, anvil 774 positioned within the housing 776, and collet 772 positioned within the housing 776. The anvil 774 can be capable to selectively forcibly contact at least a portion of the collar 102 of the fastener 100. The collet 772 can comprise jaws 772a capable to forcibly contact at least a portion of the pull-region 120 of the pin 110.

[0063] The pull-region 120 can be forcibly contacted with the collet 772 of the installation apparatus 770. A direct tension load (e.g., an axial force along the longitudinal axis, Ai) can be applied to the pull-region 120 with the collet 772 of the installation apparatus 770. For example, the collet 772 can grip the pull-region 120 with jaws 772a, and the collet 772 can retract within the installation apparatus 770 and away from the second pin end 114 and the structure 644. The collet 772 can move along the longitudinal axis, Ai, and may not substantially rotate the fastener 100 about the longitudinal axis, Ai. In various non-limiting embodiments, the fastener 100 may be moved (e.g., pulled) through the bore 646 along the longitudinal axis, Ai, while not rotating the fastener 100 more than a quarter turn after the grounding region 124 initiates contact with the structure 644 or not rotating the fastener 100 at all.

[0064] In certain non- limiting embodiments comprising splines 126 that are helical, the fastener 100 may be pulled through the bore 646 along the longitudinal axis, Ai, while rotating the fastener 100 after the grounding region 124 initiates contact with the structure 644. The rotation may be more than a quarter turn.

[0065] The anvil 774 can move independently of the collet 772. Referring to FIG. 8, the anvil 774 can be moved to contact the structure 644 in order to provide a reaction force for the direct tension load applied by the collet 772.

[0066] Referring to FIG. 8, the direct tension load applied to the pull-region 120 can cut the inner surface 644a of the structure 644 with the grounding region 124 and enable or enhance electrical communication (i.e., conductivity) between the fastener 100 and the structure 644. For example, the splines 126 of the grounding region 124 can cut into the inner surface 644a of the structure 644, and the gaps 126b can be capable to receive material cut from the structure 644 by the splines 126. Substantially no rotation force about the longitudinal axis, Ai, may be applied, which can inhibit rotation of the fastener 100 about the longitudinal axis, Ai. Inhibiting, if not preventing, rotation of the fastener 100 about the longitudinal axis, Ai, can maintain a desirable surface area contact between the fastener 100 and the inner surface 644a of the structure 644, thereby enhancing electrical conductivity between the fastener 100 and the structure 644. Rotation of the fastener 100 can undesirably deform the splines 126 and / or increase play / slop between the fastener 100 and the inner surface 644a of the structure 644 and degrade electrical conductivity between the fastener and the structure 644.

[0067] Referring to FIG. 9, the first pin end 112 can be inserted into the collar cavity 130 of the collar 102. The collar 102 can be urged towards the structure 644 and distal from the pull-region 120. The collar 102 can be moved towards the second pin end 114 and the second collar end 106 of the collar 102 can be in contact with the structure 644. In various non- limiting embodiments in which the pin 110 and the collar 102 comprise threads, inserting the first pin end 112 into the cavity 130 of the collar 102 may require rotation of the collar 102. The rotation of the collar 102 may not substantially apply a torque to the pin 110 to minimize rotation of the pin 110.

[0068] The collar 102 can be in forcible contact with the structure 644. The forcible contact between the collar 102 and the structure 644 can limit further axial movement of the collar 102 relative to the pin 110 along the longitudinal axis, Ai, of the fastener 100.

[0069] Referring to FIG. 10, the pull-region 120 can be forcibly contacted with the collet 772 of the installation apparatus 770 and the collar 102 of the fastener 100 can be forcibly contacted with the anvil 774 of the installation apparatus 770. The collar 102 can be at least partially deformed (e.g., swaged) onto the lock region 124, thereby securing at least a portionof the fastener 100 in the structure 644. For example, the force applied by the anvil 774 may compress the collar 102 and the force may not cause the fastener 100 to substantially rotate about the longitudinal axis, Ai. A direct tension load can be applied to the pull-region 120 with the collet 772 of the installation apparatus 770, and the anvil 774 can move along the longitudinal axis, Ai.

[0070] For example, the collet 772 can retract within the installation apparatus 770. As the collet 772 retracts, the anvil 774 can forcibly contact the collar 102. After a predetermined force is achieved, the elongate portion 108 of the collar 102 can be at least partially deformed as a result of the forcible contact between the anvil 774 and the collar 102. For example, the elongate portion 108 can be at least partially swaged onto at least a portion of the lock region 122.

[0071] The fastener 100 can be installed and provide enhanced electrical conductivity between the fastener 100 and the structure 644 without using a weld. In various non-limiting embodiments, referring to FIG. 11, a device 1180 can be placed around the second shank 134 and in direct contact with the second shank 134, head portion 118, and / or the structure 644. The device 1180 can be secured to the fastener 100 by, for example, threading a nut 1182 onto the second shank 134. The device 1180 can enable electrical communication between the fastener 100 and a secondary object. For example, the device 1180 can provide grounding for the secondary object.

[0072] The secondary object may be a structural component (e.g., frame) of a vehicle. The vehicle may be an aerospace vehicle or an automotive vehicle. For example, the secondary object may be a light duty, medium duty, or heavy duty truck frame.

[0073] After installation of the fastener 100 into the structure 644, the collar 102 and the head portion 118 of the pin 110 can apply a clamping force to the structure 644, thereby securing the fastener 100 to at least a portion of the structure 644. In that way, for example, the fastener 100 can be secured to the structure 644 and, optionally, if the structure comprises at least two layers, the at least two layers of the structure can be secured together by the fastener 100.

[0074] In various non-limiting embodiments, the installation tool can be a puller tool or a squeezer tool. For example, as is known in the art, a squeezer tool can simultaneously apply a compressive force to the collar 102 and the second pin end 114 of the pin 110. Thecompressive force can deform the collar 102 onto the shank 116 of the pin 110, thereby securing the collar 102 onto the pin 110.

[0075] Various aspects of embodiments according to the present disclosure include, but are not limited to, the aspects listed in the following numbered clauses.

[0076] Clause 1. A lockbolt fastener comprising: a pin comprising a first pin end, a second pin end comprising a head portion having a first diameter, and a shank extending intermediate the first pin end and the second pin end and defining a longitudinal axis, the shank comprising a pull-region having a second diameter, a lock region having a third diameter, wherein the pull-region is intermediate the lock region and the first pin end, and a grounding region, wherein the grounding region is intermediate the lock region and the second pin end, the grounding region comprising at least two splines, each spine having a crest, where the crests define a fourth diameter greater than the second diameter and the third diameter, and less than the first diameter; and a fastening collar capable to be deformed onto the lock region of the shank, the 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 collar cavity capable to receive the first pin end.

[0077] Clause 2. The lockbolt fastener of clause 1, wherein the splines comprise an included angle of at least 45 degrees.

[0078] Clause 3. The lockbolt fastener of any of clauses 1-2, wherein the grounding region further comprises a tapered lead-in intermediate each spline and the lock region.

[0079] Clause 4. The lockbolt fastener of any of clauses 1-3, wherein a root of the splines defines a fifth diameter greater than the second diameter and the third diameter, and wherein the splines define gaps between each spline capable to receive material cut from a structure by the splines.

[0080] Clause 5. The lockbolt fastener of clause 4, wherein the fourth diameter is at least 0.1% greater than the fifth diameter.

[0081] Clause 6. The lockbolt fastener of any of clauses 1-5, wherein the lock region comprises at least one of an annular shoulder, a groove, and a threaded region.

[0082] Clause 7. The lockbolt fastener of any of clauses 1-6, wherein the pull-region comprises at least one of a substantially smooth region, an annular shoulder, a groove, and a threaded region.

[0083] Clause 8. The lockbolt fastener of any of clauses 1-7, wherein the at least two splines are capable to cut into a structure and engage with the structure.

[0084] Clause 9. The lockbolt fastener of any of clauses 1-8, wherein the third diameter is defined by a crest height of a groove.

[0085] Clause 10. The lockbolt fastener of any of clauses 1-9, wherein the grounding region comprises at least 10 splines.

[0086] Clause 11. The lockbolt fastener of any of clauses 1-10, wherein the splines are capable to inhibit the lockbolt fastener from rotating about the longitudinal axis after being installed into a structure.

[0087] Clause 12. The lockbolt fastener of any of clauses 1-11, wherein the splines extend a distance relative to the longitudinal axis in a range of 0.125 inch to 3 inches.

[0088] Clause 13. The lockbolt fastener of any of clauses 1-12, wherein the splines are positioned around a circumference of the grounding region.

[0089] Clause 14. The lockbolt of any of clauses 1-13, wherein the grounding region is capable of facilitating electrical contact between the lockbolt and a structure.

[0090] Clause 15. The lockbolt of any of clauses 1-14, wherein the shank is a first shank and further comprising a second shank extending from the second pin end along the longitudinal axis, wherein the second shank is capable to be in electrical communication with a structure through the grounding region.

[0091] Clause 16. The lockbolt of any of clauses 1-15, wherein the splines are substantially aligned with the longitudinal axis.

[0092] Clause 17. The lockbolt of any of clauses 1-15, wherein the splines are helical.

[0093] Clause 18. A method for fastening, the method comprising: inserting the first pin end of the pin of the lockbolt fastener of any of clauses 1-17 into a bore defined by an innersurface of a structure; forcibly contacting the pull-region of the shank with a collet of an installation apparatus; applying a direct tension load to the pull-region of the shank with the collet of the installation apparatus, thereby cutting the inner surface of the structure with the grounding region and enabling electrical communication between the lockbolt fastener and the structure; inserting the first pin end of the pin into the collar cavity of the fastening collar of the lockbolt fastener; moving the fastening collar along the longitudinal axis towards the second pin end; and forcibly contacting the fastening collar of the lockbolt fastener with an anvil of the installation apparatus and deforming the fastening collar onto the lock region of the shank of the pin, thereby securing at least a portion of the lockbolt fastener in the structure.

[0094] Clause 19. The method of clause 18, wherein during application of the direct tension load to the pull-region of the shank with the collet of the installation apparatus, the fastener is not rotated more than a quarter turn after the grounding region initiates contact with the structure and wherein forcibly contacting the fastening collar of the lockbolt fastener with the anvil of the installation apparatus does not cause the fastener to substantially rotate about the longitudinal axis.

[0095] Clause 20. The method of any of clauses 18-19, wherein the shank is a first shank and further comprising a second shank extending from the second pin end along the longitudinal axis, wherein the second shank is capable to be in electrical communication with a structure through the grounding region, and wherein the method further comprises securing a device to the fastener by threading a nut onto the second shank.

[0096] One skilled in the art will recognize that the fasteners, pins, fastening collars, 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 inthe 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.

[0097] 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.

[0098] In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term “about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0099] 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.

[0100] 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.

Claims

CLAIMSWhat is claimed is:

1. A lockbolt fastener comprising: a pin comprising a first pin end, a second pin end comprising a head portion having a first diameter, and a shank extending intermediate the first pin end and the second pin end and defining a longitudinal axis, the shank comprising a pull-region having a second diameter, a lock region having a third diameter, wherein the pull-region is intermediate the lock region and the first pin end, and a grounding region, wherein the grounding region is intermediate the lock region and the second pin end, the grounding region comprising at least two splines, each spine having a crest, where the crests define a fourth diameter greater than the second diameter and the third diameter, and less than the first diameter; and a fastening collar capable to be deformed onto the lock region of the shank, the 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 collar cavity capable to receive the first pin end.

2. The lockbolt fastener of claim 1, wherein the splines comprise an included angle of at least 45 degrees.

3. The lockbolt fastener of claim 1, wherein the grounding region further comprises a tapered lead-in intermediate each spline and the lock region.

4. The lockbolt fastener of claim 1, wherein a root of the splines defines a fifth diameter greater than the second diameter and the third diameter, and wherein the splines define gaps between each spline capable to receive material cut from a structure by the splines.

5. The lockbolt fastener of claim 4, wherein the fourth diameter is at least 0.1% greater than the fifth diameter.

6. The lockbolt fastener of claim 1, wherein the lock region comprises at least one of an annular shoulder, a groove, and a threaded region.

7. The lockbolt fastener of claim 1, wherein the pull-region comprises at least one of a substantially smooth region, an annular shoulder, a groove, and a threaded region.

8. The lockbolt fastener of claim 1, wherein the at least two splines are capable to cut into a structure and engage with the structure.

9. The lockbolt fastener of claim 1, wherein the third diameter is defined by a crest height of a groove.

10. The lockbolt fastener of claim 1, wherein the grounding region comprises at least 10 splines.

11. The lockbolt fastener of claim 1, wherein the splines are capable to inhibit the lockbolt fastener from rotating about the longitudinal axis after being installed into a structure.

12. The lockbolt fastener of claim 1, wherein the splines extend a distance relative to the longitudinal axis in a range of 0.125 inch to 3 inches.

13. The lockbolt fastener of claim 1, wherein the splines are positioned around a circumference of the grounding region.

14. The lockbolt of claim 1, wherein the grounding region is capable of facilitating electrical contact between the lockbolt and a structure.

15. The lockbolt of claim 1, wherein the shank is a first shank and further comprising a second shank extending from the second pin end along the longitudinal axis, wherein thesecond shank is capable to be in electrical communication with a structure through the grounding region.

16. The lockbolt of claim 1, wherein the splines are substantially aligned with the longitudinal axis.

17. The lockbolt of claim 1, wherein the splines are helical.

18. A method for fastening, the method comprising: inserting the first pin end of the pin of the lockbolt fastener of claim 1 into a bore defined by an inner surface of a structure; forcibly contacting the pull-region of the shank with a collet of an installation apparatus; applying a direct tension load to the pull-region of the shank with the collet of the installation apparatus, thereby cutting the inner surface of the structure with the grounding region and enabling electrical communication between the lockbolt fastener and the structure; inserting the first pin end of the pin into the collar cavity of the fastening collar of the lockbolt fastener; moving the fastening collar along the longitudinal axis towards the second pin end; and forcibly contacting the fastening collar of the lockbolt fastener with an anvil of the installation apparatus and deforming the fastening collar onto the lock region of the shank of the pin, thereby securing at least a portion of the lockbolt fastener in the structure.

19. The method of claim 18, wherein during application of the direct tension load to the pull-region of the shank with the collet of the installation apparatus, the fastener is not rotated more than a quarter turn after the grounding region initiates contact with the structure and wherein forcibly contacting the fastening collar of the lockbolt fastener with the anvil of the installation apparatus does not cause the fastener to substantially rotate about the longitudinal axis.

20. The method of claim 18, wherein the shank is a first shank and further comprising a second shank extending from the second pin end along the longitudinal axis, wherein thesecond shank is capable to be in electrical communication with a structure through the grounding region, and wherein the method further comprises securing a device to the fastener by threading a nut onto the second shank.

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