US20150164184A1

US20150164184A1 - Fastener for operatively coupling matable components

Info

Publication number: US20150164184A1
Application number: US14/109,296
Authority: US
Inventors: Steven E. Morris; Jennifer P. Lawall
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2013-12-17
Filing date: 2013-12-17
Publication date: 2015-06-18
Also published as: DE102014118724A1; CN104712629A

Abstract

A fastener for operatively coupling matable components is provided. The fastener includes a base portion. The fastener also includes a protrusion extending from the base portion, wherein the protrusion is formed of an elastically deformable material and configured to elastically deform upon insertion through a first aperture of a first matable component and a second aperture of a second matable component, wherein the first aperture and the second aperture are aligned.

Description

FIELD OF THE INVENTION

The invention relates to a mechanical fastener, and more particularly to an elastically deformable fastener for coupling matable components.

BACKGROUND

Currently, components which are to be mated together in a manufacturing process are subject to positional variation based on the mating arrangements between the components. One common arrangement includes components mutually located with respect to each other by 2-way and/or 4-way male alignment features; typically undersized structures which are received into corresponding oversized female alignment features such as apertures in the form of openings and/or slots. Alternatively, double-sided tape, adhesives or welding processes may be employed to mate parts. Irrespective of the precise mating arrangement, there is a clearance between at least a portion of the alignment features which is predetermined to match anticipated size and positional variation tolerances of the mating features as a result of manufacturing (or fabrication) variances. As a result, occurrence of significant positional variations between the mated components is possible, which may contribute to the presence of undesirably large and varying gaps and otherwise poor fit. The clearance between the aligning and attaching features may lead to relative motion between mated components, which contribute to poor perceived quality. Additional undesirable effects may include squeaking and rattling of the mated components, for example.

SUMMARY OF THE INVENTION

In one exemplary embodiment, a fastener for operatively coupling matable components is provided. The fastener includes a base portion. The fastener also includes a protrusion extending from the base portion, wherein the protrusion is formed of an elastically deformable material and is configured to elastically deform upon insertion through a first aperture of a first matable component and a second aperture of a second matable component, wherein the first aperture and the second aperture are aligned, and wherein the first matable component and the second matable component are retained to each other upon insertion of the protrusion through the first aperture and the second aperture.
In another exemplary embodiment, a fastener for operatively coupling matable components is provided. The fastener includes a base portion having a first side and a second side. The fastener also includes a first protrusion extending from the first side of the base portion, wherein the first protrusion is formed of an elastically deformable material and is configured to elastically deform upon insertion through a first aperture of a first matable component. The fastener further includes a second protrusion extending from the second side of the base portion, wherein the second protrusion is formed of an elastically deformable material and is configured to elastically deform upon insertion through a second aperture of a second matable component, wherein the first protrusion and the second protrusion are each configured to provide at least one of retention and alignment of the first matable component and the second matable component.
In yet another exemplary embodiment, an elastic retaining assembly for matable components includes a first component having a first aperture. Also included is a second component having a second aperture, wherein the second component is configured to be mated with the first component. Further included is an elastically deformable fastener configured to operatively couple the first component to the second component, the elastically deformable fastener having a base portion and at least one protrusion extending away from the base portion, wherein the at least one protrusion is formed of an elastically deformable material and is configured to elastically deform upon insertion with at least one of the first aperture and the second aperture, and wherein the first matable component and the second matable component are retained to each other upon insertion of the protrusion through the first aperture and the second aperture.
The above features and advantages and other features and advantages of the invention are readily apparent from the following detailed description of the invention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, advantages and details appear, by way of example only, in the following detailed description of embodiments, the detailed description referring to the drawings in which:

FIG. 1 is a side, elevational view of an elastically deformable fastener according to a first embodiment;

FIG. 2 is a perspective view of the elastically deformable fastener according to a second embodiment;

FIG. 3 is a perspective view of a first component and a second component to be coupled by the elastically deformable fastener;

FIG. 4 is a side, cross-sectional view of the first component and the second component in a pre-coupled condition;

FIG. 5 is a side, cross-sectional view of the first component and the second component in a partially coupled condition;

FIG. 6 is a side, cross-sectional view of the first component and the second component in a fully coupled condition;

FIG. 7 is a perspective view of the elastically deformable fastener according to a third embodiment;

FIG. 8 is a side, elevational view of the elastically deformable fastener according to a fourth embodiment;

FIG. 9 is a perspective view of the first component; and

FIG. 10 is a perspective view shown partly in phantom of the first component engaged with the elastically deformable fastener of FIG. 7.

DESCRIPTION OF THE EMBODIMENTS

The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Referring to FIG. 1, a fastener 10 is illustrated according to a first embodiment. The fastener 10 is at least partially formed of an elastically deformable material, as will be described in detail below. The fastener 10 includes a base portion 12 having a first side 14 and a second side 16. In the illustrated embodiment, the base portion 12 is a substantially planar member, with both the first side 14 and the second side 16 comprising relatively flat surfaces. However, it is to be appreciated that non-planar geometries are contemplated and would be suitable for certain applications. The fastener 10 also includes a protrusion 18 extending from the first side 14 of the base portion 12. The protrusion 18 is a relatively spherical, solid member. Typically, the fastener 10 is a single, integrally formed component, such as a molded component, but it is contemplated that the protrusion 18 and the base portion 12 may be operatively coupled to each other.
Referring to FIG. 2, a second embodiment of the fastener 10 is illustrated to emphasize that numerous other geometries and configurations may be employed to construct the fastener 10. In the illustrated embodiment, a standoff 17 in the form of a non-planar member is shown. The standoff 17 is disposed between the base portion 12 and the protrusion 18. The standoff 17 is formed in a relatively trapezoidal manner, but alternative geometries may be suitable. Extending therefrom is the protrusion 18 comprising a relatively cylindrical member. It is to be understood that several other protrusion geometries may be employed, such as a “teardrop,” a pin, a multi-lobular member (i.e., multiple lobes of the structure), etc. Furthermore, as exemplified by the illustrated and herein-described embodiments, the protrusion 18 may be hollow or solid. The standoff 17 spaces the protrusion 18 from the base portion 12 to account for relatively thick mating components that the fastener 10 is used with.
Any suitable elastically deformable material may be used for the protrusion 18 and possibly the base portion 12 and/or the standoff 17 of the fastener 10. The term “elastically deformable” refers to components, or portions of components, including component features, comprising materials having a generally elastic deformation characteristic, wherein the material is configured to undergo a resiliently reversible change in its shape, size, or both, in response to application of a force. The force causing the resiliently reversible or elastic deformation of the material may include a tensile, compressive, shear, bending or torsional force, or various combinations of these forces. The elastically deformable materials may exhibit linear elastic deformation, for example that described according to Hooke's law, or non-linear elastic deformation.
Numerous examples of materials that may at least partially form the components include various metals, polymers, ceramics, inorganic materials or glasses, or composites of any of the aforementioned materials, or any other combinations thereof. Many composite materials are envisioned, including various filled polymers, including glass, ceramic, metal and inorganic material filled polymers, particularly glass, metal, ceramic, inorganic or carbon fiber filled polymers. Any suitable filler morphology may be employed, including all shapes and sizes of particulates or fibers. More particularly any suitable type of fiber may be used, including continuous and discontinuous fibers, woven and unwoven cloths, felts or tows, or a combination thereof. Any suitable metal may be used, including various grades and alloys of steel, cast iron, aluminum, magnesium or titanium, or composites thereof, or any other combinations thereof. Polymers may include both thermoplastic polymers or thermoset polymers, or composites thereof, or any other combinations thereof, including a wide variety of co-polymers and polymer blends. An example of a suitable polymer includes acetal (e.g., POM). In one embodiment, a preferred plastic material is one having elastic properties so as to deform elastically without fracture, as for example, a material comprising an acrylonitrile butadiene styrene (ABS) polymer, and more particularly a polycarbonate ABS polymer blend (PC/ABS), such as an ABS acrylic. The material may be in any form and formed or manufactured by any suitable process, including stamped or formed metal, composite or other sheets, forgings, extruded parts, pressed parts, castings, or molded parts and the like, to include the deformable features described herein. The material, or materials, may be selected to provide a predetermined elastic response characteristic of the fastener 10. The predetermined elastic response characteristic may include, for example, a predetermined elastic modulus and/or coefficient of friction.
Referring to FIG. 3, irrespective of the precise geometric configuration of the fastener 10, the fastener 10 is configured to operatively couple and retain matable components, such as a first component 20 and a second component 22 that are configured to be mated and aligned with respect to each other. In one embodiment, the first and second components 20, 22 are employed in a vehicle application. However, it is to be understood that the components may be associated with numerous other applications and industries, such as home appliance and aerospace applications, for example. In an exemplary embodiment, such as the aforementioned vehicle application, the first component 20 and/or the second component 22 may be blow molded components, such as a HVAC duct, for example. Many alternative components may benefit from use of the fastener 10 for alignment and retention purposes. In one embodiment, the first component 20 may be an instrument panel, while the second component 22 is a HVAC duct.
As will be apparent from the description herein, the elastically deformable nature of the fastener 10, in combination with the particular orientations described, facilitates precise alignment and retention of the first component 20 relative to the second component 22 by accounting for positional variation of the retaining and/or locating features of the components that are inherently present due to manufacturing processes. The self-aligning benefits associated with use of the fastener 10 will be described in detail below.
The first component 20 includes a first aperture 24 and the second component 22 includes a second aperture 26 that is to be aligned with the first aperture 24 upon mating of the components.
Reference is now made to FIGS. 4-6, which depict detail of the fastener 10 in various stages of insertion for mating the first and second components 20, 22 (FIG. 4, pre-assembled; FIG. 5, partially assembled; and, FIG. 6, assembled).
At the pre-assembly stage, as depicted in FIG. 4, it can be seen that an embodiment includes an arrangement where a first surface 50 of the second component 22 interacts with a distal end 52 of the elastically deformable protrusion 18. In particular, the protrusion 18 engages the second component 22 proximate the aperture wall 32 of the aperture 26. A lead-in region (i.e., angled region) (not shown) may be included along a portion of the aperture walls 32 to facilitate insertion of the protrusion 18, with the lead-in region providing sufficient biasing force to elastically deform the protrusion 18 upon entry into the aperture 26.
At the partially assembled stage, as depicted in FIG. 5, the fastener 10, and more particularly the protrusion 18, is inserted into the first and second apertures 24, 26. The protrusion 18 includes a protrusion width 28 that is greater than an aperture width 30 of the first and second apertures 24, 26, thereby ensuring deformation of the protrusion 18 upon passing through the first and second apertures 24, 26. The larger prortrusion width 28, relative to the aperture width 30, causes an interference condition during assembly that is overcome through elastic deformation as described herein.
At the assembled stage, as depicted in FIG. 6, further insertion of the fastener 10, and more specifically the protrusion 18, into the first and second apertures 24, 26 ultimately leads to a fully engaged position of the fastener 10. In the fully engaged position, a tight, fitted engagement between the fastener 10 and the first and second apertures 24, 26 is achieved by contact interface between at least a portion of the perimeter of the protrusion 18 and respective aperture walls 32 defining the first and second apertures 24, 26, thereby providing a retention force on the mated components. The interference between the protrusion 18 and the aperture walls 32 causes elastic deformation proximate the perimeter of the protrusion 18. The malleability of the materials reduces issues associated with positional variance. More particularly, in contrast to a rigid insert that typically results in gaps between the insert and receiving structure at portions around the perimeter of the insert, the protrusion 18 advantageously deforms to maintain alignment of the first component 20 and the second component 22, while also reducing or eliminating gaps associated with manufacturing challenges. The assembly also advantageously reduces the number of mechanical fasteners, such as threaded fasteners required for attachment of the components, thereby reducing cost and component degradation.
As shown, the first component 20 and the second component 22 may include a plurality of apertures 24, 26 configured to receive a plurality of protrusions of a plurality of fasteners. Each of the plurality of apertures are positioned to correspondingly receive respective protrusions in a manner described in detail above. The elastic deformation of the plurality of elastically deformable protrusions elastically averages any positional errors of the first component 20 and the second component 22. In other words, gaps that would otherwise be present due to positional errors associated with portions or segments of the first component 20 and the second component 22, particularly locating and retaining features, are eliminated by offsetting the gaps with an over-constrained condition of other elastically deformable protrusions. Specifically, the positional variance of each protrusion and/or aperture is offset by the remaining protrusions to average in aggregate the positional variance of each protrusion. Elastic averaging provides elastic deformation of the interface(s) between mated components, wherein the average deformation provides a precise alignment, the manufacturing positional variance being minimized to X_min, defined by X_min=X/√N, wherein X is the manufacturing positional variance of the locating features of the mated components and N is the number of features inserted. To obtain elastic averaging, an elastically deformable component is configured to have at least one feature and its contact surface(s) that is over-constrained and provides an interference fit with a mating feature of another component and its contact surface(s). The over-constrained condition and interference fit resiliently reversibly (elastically) deforms at least one of the at least one feature or the mating feature, or both features. The resiliently reversible nature of these features of the components allows repeatable insertion and withdrawal of the components that facilitates their assembly and disassembly. In some embodiments, the elastically deformable component configured to have the at least one feature and associated mating feature disclosed herein may require more than one of such features, depending on the requirements of a particular embodiment. Positional variance of the components may result in varying forces being applied over regions of the contact surfaces that are over-constrained and engaged during insertion of the component in an interference condition. It is to be appreciated that a single inserted component may be elastically averaged with respect to a length of the perimeter of the component. The principles of elastic averaging are described in detail in commonly owned, co-pending U.S. patent application Ser. No. 13/187,675, now U.S. Publication No. U.S. 2013-0019455, the disclosure of which is incorporated by reference herein in its entirety. The embodiments disclosed above provide the ability to convert an existing component that is not compatible with the above-described elastic averaging principles, or that would be further aided with the inclusion of an elastically averaged alignment and retention system as herein disclosed, to an assembly that does facilitate elastic averaging and the benefits associated therewith.
Referring to FIGS. 7 and 8, a third and fourth embodiment, respectively, of the fastener 10 are illustrated in detail. In the illustrated embodiments, the fastener 10 includes a base portion 12 having a first and second side 14, 16, as described in detail above. Rather than having a single protrusion extending from one of the first and second side 14, 16, the illustrated embodiments include a first protrusion 40 and a second protrusion 42. The first protrusion 40 extends from the first side 14 of the base portion 12 and the second protrusion 42 extends from the second side 16 of the base portion 12. Instead of mating components that are positioned on one side of the base portion 12, the illustrated embodiments operatively couple components disposed on opposite sides of the base portion 12. Specifically, the first protrusion 40 is configured to engage the first component 20 by inserting through the first aperture 24, while the second protrusion 42 is configured to engage the second component 22 by inserting through the second aperture 26. Only a single component to be mated is illustrated for clarity (FIGS. 9 and 10). In particular, the protrusion 42 engages the second component 22 proximate the aperture wall 32 of the apertures 26. A lead-in region (i.e., angled region) (not shown) may be included along a portion of the aperture walls 32 to facilitate insertion of the protrusion 42, with the lead-in region providing sufficient biasing force to elastically deform the protrusion 42 upon entry into the apertures 26.
As described above in relation to other embodiments, at the partially assembled stage, the fastener 10, and more particularly the protrusion 42, is inserted into the apertures 26. The protrusion 42 includes a protrusion width that is greater than an aperture width of the apertures 26, thereby ensuring deformation of the protrusion 42 upon passing through the apertures 26. The larger protrusion width, relative to the aperture width, causes an interference condition during assembly that is overcome through elastic deformation as described herein.
At the assembled stage, further insertion of the fastener 10, and more specifically the protrusion 42, into the apertures 26 ultimately leads to a fully engaged position of the fastener 10. In the fully engaged position, a tight, fitted engagement between the fastener 10 and the apertures 26 is achieved by contact interface between at least a portion of the perimeter of the protrusion 42 and respective aperture walls 32 defining the apertures 26, thereby providing a retention force on the mated components. The interference between the protrusion 42 and the aperture walls 32 causes elastic deformation proximate the perimeter of the protrusion 42.
FIG. 7 illustrates an embodiment configured to provide both retention and alignment with both protrusions 40, 42, while FIG. 8 illustrates an embodiment configured to provide retention on at least one side with the first protrusion 40. The second protrusion 42 provides alignment and/or retention. Although illustrated as a substantially cylindrical member, the second protrusion 42 may be shaped in alternative configurations.
It is to be appreciated that numerous configurations of the fastener 10 may be employed, particularly with respect to the first protrusion 40 and the second protrusion 42. Specifically, any of the above-noted geometries may be used. Furthermore, any combination of such geometries may be employed. The illustrated embodiments of sphere-sphere (FIG. 7) and sphere-tube (FIG. 8) are merely examples of combinations that may be used.
The above-described embodiments advantageously enable two or more parts with aligned apertures to be mated with one or more elastically deformable fasteners in a manner that provides a tight fit and enhanced alignment, thereby improving overall consumer satisfaction. The embodiments of the fastener 10 described herein may be used to replace damaged push type fasteners, for example, which are often referred to in the industry as “Christmas tree” fasteners.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the application.

Claims

What is claimed is:

1. A fastener for operatively coupling matable components, the fastener comprising:

a base portion; and

a protrusion extending from the base portion, wherein the protrusion is formed of an elastically deformable material and configured to elastically deform upon insertion through a first aperture of a first matable component and a second aperture of a second matable component, wherein the first aperture and the second aperture are aligned, and wherein the first matable component and the second matable component are retained to each other upon insertion of the protrusion through the first aperture and the second aperture.

2. The fastener of claim 1, wherein the protrusion comprises a protrusion width greater than an aperture width of the first aperture and the second aperture.

3. The fastener of claim 1, wherein the protrusion comprises a spherical member.

4. The fastener of claim 1, wherein the protrusion comprises a tubular member configured to align the first aperture and the second aperture.

5. The fastener of claim 1, wherein the protrusion comprises a multi-lobular member.

6. The fastener of claim 1, wherein the first aperture is defined by a first aperture wall and the second aperture is defined by a second aperture wall, wherein at least one of the first aperture wall and the second aperture wall includes an angled portion for facilitating insertion of the protrusion.

7. The fastener of claim 1, wherein the base portion comprises a substantially planar member.

8. A fastener for operatively coupling matable components, the fastener comprising:

a base portion having a first side and a second side; and

a first protrusion extending from the first side of the base portion, wherein the first protrusion is formed of an elastically deformable material and configured to elastically deform upon insertion through a first aperture of a first matable component; and

a second protrusion extending from the second side of the base portion, wherein the second protrusion is formed of an elastically deformable material and configured to elastically deform upon insertion through a second aperture of a second matable component, wherein the first protrusion and the second protrusion are each configured to provide at least one of retention and alignment of the first matable component and the second matable component.

9. The fastener of claim 8, wherein the first protrusion comprises a first protrusion width greater than a first aperture width of the first aperture.

10. The fastener of claim 8, wherein the second protrusion comprises a second protrusion width greater than a second aperture width of the second aperture.

11. The fastener of claim 8, wherein at least one of the first protrusion and the second protrusion comprises a spherical member.

12. The fastener of claim 8, wherein at least one of the first protrusion and the second protrusion comprises a tubular member.

13. The fastener of claim 8, further comprising a fully engaged position of first protrusion and the second protrusion, wherein the fully engaged position comprises contact interference between a protrusion surface of each of the protrusions and the apertures, wherein an amount of deformation of the first protrusion and the second protrusion is averaged in aggregate in the fully engaged position.

14. The fastener of claim 8, wherein the first aperture is defined by a first aperture wall and the second aperture is defined by a second aperture wall, wherein the first aperture wall and the second aperture wall each include an angled portion for facilitating insertion of the first protrusion and the second protrusion.

15. The fastener of claim 8, wherein the base portion comprises a substantially planar member.

16. An elastic retaining assembly disposable between matable components comprising:

a first component having a first aperture;

a second component having a second aperture, wherein the second component is configured to be mated with the first component;

an elastically deformable fastener configured to operatively couple the first component to the second component, the elastically deformable fastener having a base portion and at least one protrusion extending away from the base portion, wherein the at least one protrusion is formed of an elastically deformable material and configured to elastically deform upon insertion with at least one of the first aperture and the second aperture, and wherein the first matable component and the second matable component are retained to each other upon insertion of the protrusion through the first aperture and the second aperture.

17. The elastic retaining assembly of claim 16, further comprising:

a plurality of elastically deformable fasteners; and

a plurality of apertures of the first component configured to receive the plurality of elastically deformable fasteners.

18. The elastic retaining assembly of claim 17, further comprising a fully engaged position of each of the elastically deformable fasteners, wherein the fully engaged position comprises contact interference between a protrusion surface of each of the plurality of elastically deformable fasteners and the plurality of apertures, wherein an amount of deformation of the plurality of elastically deformable fasteners is averaged in aggregate.

19. The elastic retaining assembly of claim 16, wherein the first component and the second component each comprise automotive components.

20. The elastic retaining assembly of claim 19, wherein at least one of the first component and the second component comprise blow molded components.