Patent Description:
Vehicle frames, storage racks, solar panel sub-structures, aircraft parts, and other structures can include numerous mechanical fasteners. For example, a threaded fastener (e.g., a threaded bolt, a threaded structural fastener) can be installed in a threaded bore of a structural component and secure parts together. Properly installing a fastener into a threaded bore presents challenges.

<CIT> discloses a blind rivet subassembly provided with a rivet body and a mandrel.

According to one aspect of the present disclosure, a blind fastener is provided. The blind fastener comprises a sleeve and a mandrel. The sleeve is adapted for installation into a threaded bore in a structure. The sleeve comprises a head portion, a first sleeve end, a second sleeve end, an elongate portion extending intermediate the first sleeve end and the second sleeve end, and a cavity extending from the first sleeve end to the second sleeve end. The mandrel is at least partially disposed through the cavity of the sleeve. The mandrel comprises a first mandrel end disposed adjacent to the first sleeve end. The first mandrel end comprises an enlarged portion having a diameter greater than a diameter of the cavity. The elongate portion is configured to at least partially deform into threads of the threaded bore responsive to forcible contact between the enlarged portion and the sleeve.

According to another aspect of the present disclosure, a blind fastener is provided. The blind fastener comprises a sleeve and a mandrel. The sleeve is adapted for installation into a threaded bore in a structure. The sleeve comprises a head portion, a first sleeve end, a second sleeve end, an elongate portion extending intermediate the first sleeve end and the second sleeve end, and a cavity extending from the first sleeve end to the second sleeve end. The mandrel is at least partially disposed through the cavity of the sleeve. The mandrel comprises a first mandrel end disposed adjacent to the first sleeve end. The first mandrel end comprises an enlarged portion having a diameter greater than a diameter of the cavity. The elongate portion is configured to at least partially deform into threads of the threaded bore responsive to forcible contact between the enlarged portion and the sleeve.

According to yet another aspect of the present disclosure, a method for fastening is provided. The method comprises inserting a first sleeve end of a sleeve of a blind fastener into a threaded bore in a structure. The blind fastener comprises the sleeve and a mandrel. The sleeve comprises a head portion configured to receive a torque, the first sleeve end, a second sleeve end, an elongate portion extending intermediate the first sleeve end and the second sleeve end, and a cavity extending from the first sleeve end to the second sleeve end. The mandrel is at least partially disposed through the cavity of the sleeve. The mandrel comprises a first mandrel end disposed adjacent to the first sleeve end. The first mandrel end comprises an enlarged portion having a diameter greater than a diameter of the cavity. The elongate portion is configured to at least partially deform into threads of the threaded bore responsive to forcible contact between the enlarged portion and the sleeve. The elongate portion is deformed onto threads of the threaded bore, thereby securing at least a portion of the blind fastener into the structure.

It will be understood that the invention disclosed and described in this specification is 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.

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:.

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

Various examples are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed fastener and methods. The various examples described and illustrated herein are non-limiting and non-exhaustive. Thus, an 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.

Any references herein to "various embodiments," "some embodiments," "one embodiment," "an 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," 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.

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.

Also, any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of "<NUM> to <NUM>" includes all sub-ranges between (and including) the recited minimum value of <NUM> and the recited maximum value of <NUM>, that is, having a minimum value equal to or greater than <NUM> and a maximum value equal to or less than <NUM>. 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.

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.

Securing a threaded fastener into a threaded bore can require a selection of a type of threaded fastener. For example, <NUM>/<NUM>-<NUM>, M6 Coarse, and M6 Fine can install into a similar bore size but require a different thread pattern. Additionally, installation of a threaded fastener can require alignment of the threads on the threaded fastener and the threads in the threaded bore. An improper thread pattern or improper alignment of the threads can lead to an undesired installation of the threaded fastener (e.g., cross-threading). Moreover, a torque gauge may be needed to ensure the threaded fastener is properly inserted to the desired torque. Improper torque can result in damage to the threaded fastener and/or threaded bore and/or a securing force between the threaded fastener and structure that is less than desired. These additional steps can be time consuming, and if not properly followed, the threaded fastener may not be properly installed into the threaded bore, which can lead to failure of the structural joint. Thus, blind fasteners and methods of fastening are provided that can increase the speed of installation of a blind fastener and increase the reliability of a structural joint.

<FIG> illustrates an embodiment of a blind fastener <NUM> according to the present disclosure. The blind fastener <NUM> can be adapted to be installed in a bore in a structure (e.g., as illustrated in <FIG>, discussed below). The blind fastener <NUM> can include a sleeve <NUM> and a mandrel <NUM>. In various embodiments, the sleeve <NUM> is generally cylindrical. For example, the sleeve <NUM> can be free of threads, grooves, or an annular shoulder.

<FIG> shows a portion of the sleeve <NUM> removed, exposing the mandrel <NUM> therein. The sleeve <NUM> can comprise a first sleeve end <NUM>, a second sleeve end <NUM>, an elongate portion <NUM> disposed intermediate the first sleeve end <NUM> and the second sleeve end <NUM>, and a cavity <NUM> extending from the first sleeve end <NUM> to the second sleeve end <NUM>.

The cavity <NUM> of the sleeve <NUM> can comprise a diameter, d<NUM>, and be configured to at least partially receive the mandrel <NUM> therein. For example, the mandrel <NUM> can comprise a shape suitable to be received by the cavity <NUM>, such as, for example, a generally cylindrical shape. The mandrel <NUM> can comprise a first mandrel end <NUM>, a second mandrel end <NUM>, and a shank region <NUM>. The shank region <NUM> can extend intermediate the first mandrel end <NUM> and the second mandrel end <NUM> and can be at least partially disposed through the cavity <NUM>. When the mandrel <NUM> is inserted in the cavity <NUM>, the first mandrel end <NUM> can be disposed adjacent to the first sleeve end <NUM>, and the second mandrel end <NUM> can be disposed adjacent to the second sleeve end <NUM>.

The first mandrel end <NUM> can comprise an enlarged portion <NUM> comprising a diameter, d<NUM>, which can be greater than the diameter, d<NUM>, of the cavity <NUM>. The enlarged portion <NUM> can engage the sleeve <NUM>. For example, the enlarged portion <NUM> can engage the first sleeve end <NUM> and the elongate portion <NUM>. The enlarged portion <NUM> can apply a force to the sleeve <NUM> and can deform the first sleeve end <NUM> and elongate portion <NUM> during installation of the blind fastener <NUM>. For example, the first sleeve end <NUM> and/or elongate portion <NUM> can be deformed into threads of a threaded bore responsive to forcible contact between the enlarged portion <NUM> and the sleeve <NUM>. The deformation can comprise expansion of the first sleeve end <NUM> and/or the elongate portion <NUM>. The elongate portion <NUM> can be configured to form external threads corresponding to the threads of the threaded bore responsive to the forcible contact. For example, an outer surface 128a of the elongate portion <NUM> can deform into the threads of a threaded bore <NUM> as shown in <FIG> below. The outer surface 128a can change shape corresponding to the threads of the threaded bore (e.g., threads can be cut into the outer surface 128a).

Upon forcible contact between the first sleeve end <NUM> and the enlarged portion <NUM>, the enlarged portion <NUM> can deform in order to be received by the cavity <NUM>. For example, the enlarged portion <NUM> can lengthen and/or reduce in diameter, d<NUM>, in order to be received by the cavity <NUM>. The enlarged portion <NUM> can be hollow as illustrated in <FIG>, of axially split into or more portions.

The second mandrel end <NUM> can comprise a pull region <NUM> configured to be engaged by an installation tool (e.g., installation tool <NUM>, as illustrated in <FIG> and discussed below). The pull region <NUM> can comprise an axial length and may not comprise a taper. In other embodiments, the pull region <NUM> can comprise a taper or a reverse taper. For example, as one moves along the pull region <NUM> away from the shank region <NUM> along a longitudinal axis of the blind fastener <NUM>, the diameter of the pull region <NUM> can decrease. In certain other embodiments, the pull region <NUM> can comprise a reverse taper where, as one moves along the pull region <NUM> away from the shank region <NUM> along the longitudinal axis of the blind fastener <NUM>, the diameter of the pull region <NUM> increases. In various embodiments, the pull region <NUM> can be generally conical.

The pull region <NUM> can comprise at least one of a generally smooth region, an annular shoulder, a groove, and a bore or can comprise another feature configured to be engaged by an installation tool. For example, the pull region <NUM> can comprise grooves <NUM>, as illustrated in <FIG> that can be engaged by an installation tool.

The shank region <NUM> can define the longitudinal axis of the blind fastener <NUM>. The shank region <NUM> can comprise at least one of a generally smooth region, a threaded region, an annular shoulder, and a groove. The threaded region, annular shoulder, and/or the groove can be external relative to the mandrel <NUM>. In various embodiments, all or a portion of the shank region <NUM> includes grooves. For example, as shown in <FIG>, the shank region <NUM> of the blind fastener <NUM> includes grooves <NUM>. In other embodiments, all or a portion of the shank region <NUM> lacks grooves. In various embodiments, all or a portion of the shank region <NUM> includes an annular shoulder. In other embodiments, the shank region <NUM> lacks an annular shoulder. In various embodiments, all or a portion of the shank region <NUM> includes a threaded portion. In other embodiments, the shank region <NUM> lacks a threaded portion.

In various embodiments, the blind fastener <NUM> may comprise a breakneck groove <NUM> or other feature configured to fracture upon installation of the blind fastener <NUM>, or the mandrel <NUM> may not comprise a breakneck groove or other feature configured to fracture upon installation of the blind fastener <NUM>. The blind fastener <NUM> may be installed into a structure without fracturing of the breakneck groove <NUM> or other feature, or the breakneck groove <NUM> or other feature may facture upon installation into the structure.

In various embodiments, the blind fastener <NUM> can comprise a single assembly of the sleeve <NUM> and the mandrel <NUM>. In certain embodiments, the blind fastener <NUM> can consist of the sleeve <NUM> and the mandrel <NUM>. In some embodiments, the blind fastener <NUM> can be a structural blind fastener, such as, for example, a structural blind rivet, a structural blind bolt, or a structural blind stud.

The blind fastener <NUM> can comprise at least one of a metal, a metal alloy, a composite material, and other material. For example, in various embodiments the blind fastener <NUM> can comprise at least one of aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, iron, an iron alloy, a carbon fiber composite material.

The sleeve <NUM> can comprise a head portion <NUM> positioned adjacent to the second sleeve end <NUM>. The head portion <NUM> can be configured to be engaged by an installation tool (e.g., installation tool <NUM> illustrated in <FIG>) in order to facilitate installation of the blind fastener <NUM>. The sleeve <NUM> can be configured to deform into threads of the threaded bore and swage onto the shank region <NUM> on an entrance side of a structure. For example, the first sleeve end <NUM> and/or elongate portion <NUM> can be deformed and the head portion <NUM> can be at least partially swaged onto the shank portion <NUM>, as illustrated in <FIG>.

The head portion <NUM> can be configured to receive a torque. For example, the head portion <NUM> can comprise at least one of a substantially flat side, a rib, a spline, an indent, a knurl, a lobe, a bore, and a tab. For example, the head portion <NUM> can be at least one of a square head portion, a hex head portion, a knurled head portion, and a splined head portion. In various other embodiments, the head portion <NUM> can be generally cylindrical. In various embodiments, a flange <NUM> is disposed adjacent to the head portion <NUM>.

In various embodiments, the mandrel <NUM> and sleeve <NUM> can comprise a stepped lock region. The stepped lock region can comprise two or more progressive counterbores in the sleeve <NUM> with stepped diameters matched to grooves on the mandrel <NUM>. The grooves on the mandrel <NUM> can be configured to receive deformed sleeve material from the progressive counterbores to form a mechanical lock between the mandrel <NUM> and the sleeve <NUM>.

As illustrated in <FIG>, the blind fastener <NUM> can be installed into a threaded bore <NUM> in a structure <NUM>. The threaded bore <NUM> can be at least partially threaded. For example, the threaded bore <NUM> can be completely threaded or the threaded bore <NUM> can comprise a section of threads and a generally smooth section. As illustrated, the threaded bore <NUM> may not extend through the structure <NUM> (e.g., a blind hole). The structure <NUM> can comprise, for example, at least one of a metal, a metal alloy, a composite material, and other material. For example, in certain embodiments, the structure <NUM> can 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.

In various embodiments, the structure <NUM> into which the blind fastener <NUM> is assembled comprises aluminum and/or an aluminum alloy such as, for example, <NUM> aluminum. With reference to the accompanying figures, the structure <NUM> 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, and other structure. The structure <NUM> can comprise a single layer of material or at least two layers of material. For example, as illustrated in <FIG>, the structure <NUM> can comprise a first layer <NUM> and a second layer <NUM>. Upon installation into the threaded bore <NUM>, the blind fastener <NUM> can secure the first layer <NUM> and the second layer <NUM> together, as illustrated in <FIG>.

As illustrated in <FIG>, in a first configuration of the blind fastener <NUM> and the structure <NUM>, the first mandrel end <NUM> of the blind fastener <NUM> can be positioned in alignment with the threaded bore <NUM>. To facilitate alignment of the blind fastener <NUM> with the threaded bore <NUM>, the threaded bore <NUM> can have a diameter, db, (e.g., internal diameter of the threads) that is greater than the diameter, d<NUM>, of the enlarged portion <NUM> of the first mandrel end <NUM>, thereby allowing the mandrel <NUM> to readily move into and through the threaded bore <NUM> when passing from a first configuration of the blind fastener <NUM> and the structure <NUM>, illustrated in <FIG>, to a second configuration, illustrated in <FIG>. In various embodiments, the diameter, db, of the threaded bore <NUM> can be less than the diameter, d<NUM>, of the enlarged portion <NUM> and/or a diameter of the sleeve <NUM> to allow the sleeve <NUM> to readily pass into the threaded bore <NUM>.

A diameter of the head portion <NUM> and/or flange <NUM> can be greater than the diameter, db, of the threaded bore <NUM> in order to inhibit the sleeve <NUM> from further traversal into the threaded bore <NUM>. In the second configuration, shown in <FIG>, the first mandrel end <NUM> has passed into the threaded bore <NUM> and the head portion <NUM> of the sleeve <NUM> or the flange <NUM> can be in forcible contact with the structure <NUM> at an entrance side 232a (<FIG>) of the structure <NUM>. The forcible contact between the head portion <NUM> or flange <NUM> and the structure <NUM> can limit further axial movement of the sleeve <NUM> into the threaded bore <NUM>.

Before or after insertion, a collet <NUM> of the installation tool <NUM> can engage the pull region <NUM> of the blind fastener <NUM>. For example, the collet <NUM> can be configured to forcibly contact an anvil <NUM> of the installation tool <NUM>. The forcible contact can close the collet <NUM> around the pull region <NUM> where the collet <NUM> forcibly contacts the pull region <NUM>. Upon engagement, the collet <NUM> can apply a force to the pull region <NUM> of the mandrel <NUM>.

The collet <NUM> can move the mandrel <NUM> independently of the sleeve <NUM>. For example, the collet <NUM> can retract within the installation tool <NUM> and move the mandrel <NUM> as the collet <NUM> retracts due to the contact between the pull region <NUM> and the collet <NUM>. Upon the collet <NUM> reaching a predetermined retraction distance into the installation tool <NUM>, the anvil <NUM> can forcibly contact the second sleeve end <NUM> (e.g., head portion <NUM>). The forcible contact between the second sleeve end <NUM> and the anvil <NUM> can move the second mandrel end <NUM> in a vector different than a vector of a force applied to the second sleeve end <NUM>. For example, the installation tool <NUM> can move the pull region <NUM> distal from the head portion <NUM> utilizing the collet <NUM> of the installation tool <NUM>.

In a third configuration of the blind fastener <NUM> and the structure <NUM> illustrated in <FIG>, the first sleeve end <NUM> and/or the elongate portion <NUM> can be deformed responsive to forcible contact from mandrel <NUM>. For example, the first sleeve end <NUM> and/or elongate portion <NUM> can be deformed into threads of the threaded bore <NUM> responsive to forcible contact between the enlarged portion <NUM> and the sleeve <NUM>. The first sleeve end <NUM> and elongate portion <NUM> can be expanded and form external threads corresponding to the threads of the threaded bore <NUM> responsive to the forcible contact.

Upon forcible contact between the first sleeve end <NUM> and the enlarged portion <NUM>, the enlarged portion <NUM> can be deformed in order to be received by the cavity <NUM>. For example, the enlarged portion <NUM> can be received by the cavity <NUM> of the sleeve <NUM> by reducing the diameter, d<NUM>, of the enlarged portion <NUM>.

The second sleeve end <NUM> can be swaged onto the shank region <NUM> on the entrance side 232a of the structure <NUM> responsive to forcible contact from the anvil <NUM>. For example, the head portion <NUM> can be swaged onto the shank region <NUM>. The swaging of the second sleeve end <NUM> and/or deformation of the first sleeve end <NUM> and/or elongate portion <NUM> can secure at least a portion of the blind fastener <NUM> in the structure <NUM>. In that way, for example, the first layer <NUM> and second layer <NUM> of the structure <NUM> are secured together.

As illustrated in <FIG>, the mandrel <NUM> may not fracture after installation into the structure <NUM>, or as shown in <FIG>, the mandrel <NUM> may fracture along breakneck groove <NUM> after installation into the structure <NUM> in a fourth configuration of the blind fastener <NUM> and the structure <NUM>.

The blind fastener <NUM> can be removed from the threaded bore <NUM> by rotating the blind fastener <NUM>. For example, a torque can be applied to the head portion <NUM> of the blind fastener <NUM>. In embodiments where the threads in the threaded bore <NUM> are right-handed threads, the blind fastener can be removed by rotating the blind fastener <NUM> in a counterclockwise direction (when viewing from the second sleeve end <NUM> of the sleeve <NUM> to the first sleeve end <NUM> of the sleeve <NUM>). In embodiments where the threads in the threaded bore <NUM> are left-handed threads, the blind fastener <NUM> can be removed by rotating the blind fastener <NUM> in a clockwise direction (when viewing from the second sleeve end <NUM> of the sleeve <NUM> to the first sleeve end <NUM> of the sleeve <NUM>).

In a fifth configuration of the blind fastener <NUM> and the structure <NUM> illustrated in <FIG>, the blind fastener <NUM> can be at least partially removed from the threaded bore <NUM>. For example, the blind fastener <NUM> can be completely removed from the threaded bore <NUM> by rotating the blind fastener <NUM>. In that way, for example, the first layer <NUM> and second layer <NUM> of the structure <NUM> may be unsecured.

In various embodiments, the blind fastener <NUM> can be used in a method for fastening the structure <NUM>. The method can comprise inserting the first sleeve end <NUM> into the threaded bore <NUM> in the structure <NUM>. The collet <NUM> of the installation tool <NUM> can engage with the pull region <NUM> of the blind fastener <NUM>. After inserting the blind fastener <NUM> into the threaded bore <NUM>, the second sleeve end <NUM> of the blind fastener <NUM> can contact the anvil <NUM> of the installation tool <NUM>. The pull region <NUM> can be moved distal from the head portion <NUM> utilizing the collet <NUM> of the installation tool <NUM>. In various embodiments, the pull region <NUM> can be moved distal from the head portion <NUM> utilizing the collet <NUM> of the installation tool until the mandrel <NUM> fractures (e.g., at the breakneck groove <NUM> or other feature configured to fracture).

The sleeve <NUM> can be deformed onto the threads of the threaded bore <NUM>, thereby securing at least a portion of the blind fastener <NUM> in the structure <NUM>. Deforming the sleeve <NUM> can comprise forming external threads on the elongate portion <NUM>, wherein the external threads correspond to the threads of the threaded bore <NUM>. The second sleeve end <NUM> can be swaged onto the shank region <NUM> of the mandrel <NUM> on the entrance side 232a of the structure <NUM>.

Claim 1:
A blind fastener (<NUM>) comprising:
a sleeve (<NUM>) adapted for installation into a threaded bore in a structure, the sleeve comprising
a head portion (<NUM>) comprising at least one feature configured to receive a torque, the feature selected from at least one of a substantially flat side, a rib, a spline, an indent, a knurl, a lobe, a bore, and a tab,
a first sleeve end (<NUM>),
a second sleeve end (<NUM>),
an elongate portion (<NUM>) extending intermediate the first sleeve end and the second sleeve end, and
a cavity (<NUM>) extending from the first sleeve end to the second sleeve end;
and
a mandrel (<NUM>) at least partially disposed through the cavity of the sleeve, the mandrel comprising
a first mandrel end (<NUM>) disposed adjacent to the first sleeve end and comprising an enlarged portion (<NUM>) having a diameter greater than a diameter of the cavity, wherein the enlarged portion is substantially hollow or axially split;
wherein the elongate portion is configured to at least partially deform into threads of the threaded bore and the diameter of the enlarged portion is configured to be at least partially reduced responsive to forcible contact between the enlarged portion and the sleeve.