High retention force fastener

A high retention force fastener for fixing at least two panels together is disclosed. The fastener includes two components. One component is a metal clip and the other is a plastic insert that can be substantially inserted into the metal clip. The metal clip includes a body having opposed panel engagement features extending therefrom, an insertion stop plate spaced apart from the engagement features and plastic insert locking tabs extending from the stop plate. The metal clip is preferably U-shaped and includes two sides joined by a connector. Each of the sides includes a pair of the panel engagement features. The plastic insert includes a head and a leg for insertion into the metal clip. The leg extends from the head. The plastic insert additionally includes metal tab engagement arms extending from and integrally formed with the head for engaging the plastic insert locking tabs of the metal clip.

TECHNICAL FIELD

The disclosed inventive concept relates generally to fasteners for attaching two or more substrates together. More particularly, the disclosed inventive concept relates to a high force retention fastener that is relatively easy to install into a hole of at least one of the substrates and is relatively difficult to extract. The hole may be of any shape, including, but not limited to, round, square or rectangular. The high force retention fastener includes a first part in the form of a metal clip and a second part in the form of a plastic insert. The metal clip is provided for initial insertion into the holes of the substrates. The plastic insert includes a leg which is then inserted into the metal clip, thereby causing the metal clip to expand against and engage the underside of the lower substrate. Once the plastic insert is installed into the metal clip, the two or more substrates are secured together.

BACKGROUND OF THE INVENTION

In many industries it is necessary to assemble two components together in an easy and efficient manner. Examples of such requirements are the need to attach one vehicle component to another, such as the attachment of an inner fender liner to a fender or the attachment of one interior component to another.

Conventional metal fasteners used for such applications rely on square or slotted holes. This is the result of manufacturers matching the straight bends of the fastener to the edges of the hole for improved fastener retention. However, square or slotted holes are not preferred among panel manufacturers due to the relatively high cost and complexity of the necessary punches. Another undesirable feature of the square or slotted holes is that the four corners of the hole concentrate panel stress and thus may induce component failure.

Thus an alternative approach to the shape of both the metal fastener and the holes for the fastener are desired. For example, it is desirable to provide a high performance metal fastener that can engage holes formed in two or more substrates such as panels. It is further desired to provide such a metal fastener that is capable of engaging holes in substrates that requires a relatively low insertion effort but that has a high resistance to being extracted from the components.

Accordingly, and as is the case in many industries, known approaches to fastening two or more components together using known fasteners are often undesirable and impractical. An improved fastener arrangement for attaching two components together remains wanting.

SUMMARY OF THE INVENTION

The disclosed inventive concept overcomes the problems associated with known fasteners and fastening arrangements for attaching two or more substrates such as vehicle interior or exterior panels. The fastening system of the disclosed inventive concept comprises a high retention force fastener that can be used to attach two or more substrates. The high retention force fastener includes two components. One component is a metal clip and the other is a plastic insert that can be substantially inserted into the metal clip.

The metal clip comprises a body having opposed panel engagement features extending therefrom, an insertion stop plate spaced apart from the engagement features and plastic insert locking tabs extending from the stop plate. The metal clip is preferably U-shaped and comprises two sides joined by a connector. Each of the sides includes a pair of the panel engagement features.

Preferably, but not absolutely, the each of the panel engagement features is curved. Each pair of panel engagement features includes a first curved engagement feature and a second curved engagement feature. The first and second curved engagement features curve toward one another. Each of the curved engagement features includes an upper edge for engaging one of the substrates. Each of the sides includes a stop plate.

The plastic insert comprises a head and a leg for insertion into the metal clip. The leg extends from the head. The plastic insert additionally includes metal tab engagement arms extending from and integrally formed with the head for engaging the plastic insert locking tabs of the metal clip.

The plastic insert further includes a pair of opposed flexible arms for interference with the insert locking tabs of the metal clip when the plastic insert is inserted into the metal clip. The plastic insert further includes a pair of opposed pre-engagement fasteners. Each of the pre-engagement fasteners extends outward from the leg. The plastic insert additionally includes a latching mechanism hole. The latching mechanism is positionable in the latching mechanism hole to retain the plastic insert in its pre-locking position within the metal clip.

In use, the metal clip of the high retention force fastener is inserted into the holes formed in the two or more panels to be joined. The holes may be of any shape, including, but not limited to, round, square or rectangular. The shapes of the holes may be the same or may be different. Once fully inserted, the curved engagement features and the stop plates preliminarily capture the panels therebetween. The plastic insert is then pushed into the metal clip, thereby expanding the metal clip fully into the holes. The metal tab engagement arms of the head of the plastic insert are locked to the plastic insert locking tabs of the stop plates.

Removal of the high retention force fastener is accomplished by using a removal tool such as the flat end of a screwdriver to pry the plastic insert from the metal clip.

The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce alternative embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

The figures illustrate a high retention force fastener for fastening one object to another and, in particular, provides a system for attaching an upper substrate to a lower substrate. The upper and lower substrates may be selected from any component needing to be attached to another component. The high retention force fastener of the disclosed inventive concept is particularly useful for a broad variety of applications in that it may be used to attach substrates at least one of which has a fastener hole. For example, and without limiting the scope of the disclosed inventive concept, the high retention force fastener of the disclosed inventive concept may be used to attach the plastic liner of a vehicle wheel well which may have a fastener-passing hole to the metal fender which may alternatively or additionally have a fastener-passing hole. The hole may be of any shape, including, but not limited to, round, square or rectangular Having disclosed such an application, it is nonetheless to be understood that the high retention force fastener of the disclosed inventive concept may be used for virtually any other application in which a practical and easy-to-use approach to fastening two components together is needed.

In general, the high retention force fastener of the disclosed inventive concept includes a first part in the form of a metal clip and a second part in the form of a plastic insert. To assemble the two or more substrates together, the metal clip is initially inserted into the fastener-passing hole of the upper substrate and passes therethrough into the fastener-passing hole of the lower substrate.

The plastic insert includes a leg. The leg of the plastic insert is then inserted into the metal clip, thereby causing the metal clip to expand against and engage the underside of the lower substrate. Once the plastic insert is installed into the metal clip, the two or more substrates are secured together. Removal is possible using a tool such as, for example, a flat-ended screwdriver.

The high retention force fastener of the disclosed inventive concept and its two components are illustrated in combination inFIGS. 1 through 5. The metal clip is shown in isolation inFIGS. 6 through 12. The high retention force fastener of the disclosed inventive concept is illustrated relative to two substrates inFIGS. 13 through 17.

Referring toFIGS. 1 through 5, a high retention force fastener according to the disclosed inventive concept is generally illustrated as10. The high retention force fastener10includes a metal clip12and a plastic insert14. The plastic insert14is illustrated as being partially inserted into the metal clip12. In this position, the high retention force fastener10is ready for installation into the fastener holes of substrates to be attached. The metal clip12is illustrated in isolation in various views inFIGS. 6 through 10. The plastic insert14may be formed from any polymerized material suitable for the purpose.

The metal clip12is preferably but not exclusively formed from stamped steel, thus providing expandable characteristics. A variety of spring steel metals may be used for the metal clip12. Non-limiting examples of the metal for use in the metal clip12are SAE 1050 carbon steel through SAE 1065 carbon steel.

The metal clip12includes a U-shaped body16. The body16includes a first spring or primary retention arm18and a second spring or primary retention arm18′. The primary retention arms18and18′ are joined by a connector20. The primary retention arms18and18′ are angled inward to aid in gripping the plastic insert14.

A pair of spaced apart, wing-like rigid panel engagement features22and22′ extend from the first primary retention arm18. The wing-like rigid panel engagement feature22includes an upper edge23and the wing-like rigid panel engagement feature22′ includes an upper edge23′. A pair of spaced apart, wing-like rigid panel engagement features24and24′ extend from the second primary retention arm18′. The wing-like rigid panel engagement feature24includes an upper edge25and the wing-like rigid panel engagement feature24′ includes an upper edge25′. The upper edges23,23′,25, and25′ engage the underside of the lower substrate upon insertion of the metal clip12into the substrate holes as will be described below. Each of the upper edges23,23′,25, and25′ includes a corner tip for providing secure engagement with the underside of the lower substrate. The upper edge23includes a corner tip21, the upper edge23′ includes a corner tip21′, the upper edge25includes a corner tip27, and the upper edge25′ includes a corner tip27′. Each of the corner tips21,21′,27, and27′ grip or bite into the underside of the lower substrate when the high retention force fastener10is in its secured or engaging position (illustrated inFIGS. 13 and 14and discussed in relation thereto).

At the end of the first primary retention arm18opposite the connector20is provided an insertion stop plate26. Extending from the ends of the stop plate26is a pair of locking tabs28and28′. The locking tab28includes a hooked end29and the locking tab28′ includes a hooked end29′. At the end of the second primary retention arm18′ opposite the connector20is provided an insertion stop plate30. The stop plate26is connected to the first primary retention arm18by a shoulder31. The stop plate30is connected to the secondary primary retention arm18′ by a shoulder31′. Extending from the ends of the stop plate30is a pair of locking tabs32and32′. The locking tab32includes a hooked end33and the locking tab32′ includes a hooked end33′.

The plastic insert14may be made from any of several materials, such as but not limited to nylon or acrylonitrile butadiene styrene (ABS). The flexible nature of plastic as a choice of material for forming the plastic insert14is advantageous over other material in that this material is more customizable, engages with the metal clip12more easily, and takes up any looseness in the holes of the substrate. The plastic insert14may be sized so that it can be adapted for universal fit in a broad variety of metal clips12.

The plastic insert14includes head40from which extends an engagement leg42. A pair of reinforcing ribs43,43′ are formed under the head40. The reinforcing ribs43,43′ provide rigidity and function in part to reduce flexibility of the head40in relation to the engagement leg42, thereby operating to help prevent the plastic insert14from coming out of the metal clip12. The shapes of the reinforcing ribs43,43′ can be adapted as needed for tuning and may be either solid or slotted. A pair of opposed integral flexible struts44,44′ extend from each side of the engagement leg42. The integral flexible integral flexible struts44,44′ function as pre-engagement fasteners for initial retention within the holes of the substrates being fastened while the high retention force fastener10is in its pre-engagement condition as illustrated inFIGS. 1 through 5. Should-receiving recessed areas45,45′ (shown inFIGS. 11 and 12) are formed on opposite sides of the plastic insert14. When the high retention force fastener10is its pre-insertion condition, the shoulder31rests in the recessed area45and the shoulder31′ rests in the recessed area45′. The recessed area45includes a ramp47and the recessed area45′ includes a ramp47′. The ramps47and47′ operate to separate and drive apart the primary retention arms18and18′ while bending the connector20as the operator presses the plastic insert14from its pre-insertion position to its locking position. While the ramps47and47′ are illustrated as being planar, it is to be understood that the ramps47and47′ may also be curved.

At opposite ends of the head40and integrally molded therewith are provided a pair of opposed metal tab engagement features46and46′. Owing to the plastic material from which the plastic insert14is formed, the metal tab engagement features46and46′ have a degree of flexibility. This flexibility is a feature that allows the metal tab engagement features46and46′ to respectively engage the locking tabs of the metal clip12when the plastic insert14is inserted into the metal clip12to engage the substrates as will be discussed below.

Beneath the head40of the plastic insert14and integrally molded therewith is a pair of opposed flexible arms48and48′. The opposed flexible arms48and48′ provide interference between the plastic insert14and the metal clip12when the plastic insert14is inserted into the metal clip12to engage the substrates as will also be discussed below. The flexible arms48and48′ also press against the upper substrate and create tension therewith to minimize vibrations that could cause the high retention force fastener10to become loose.

Extending outward from opposed sides of the engagement leg42is a pair of opposed soft latching mechanisms of which one, soft latching mechanisms49, is illustrated. On partial insertion of the plastic insert14into the metal clip12to form the high retention force fastener10before it is attached to the substrates, the soft latching mechanisms49engages an engagement hole50formed in the primary retention arm18and an opposite soft latching mechanism engages an engagement hole50′ formed in the primary retention arm18′. This arrangement assures that the plastic insert14and the metal clip12will not become separated before insertion into the substrates.

The high retention force fastener10is illustrated in its pre-insertion condition inFIGS. 1 through 5and the metal clip12is illustrated in isolation inFIGS. 6 through 12. The high retention force fastener10is illustrated in various stages of insertion inFIGS. 13 through 16relative to an upper substrate S1and a lower substrate S2. It is to be understood that while only two substrate layers are illustrated, more than two layers may be attached by the high retention force fastener10. It is also to be understood that the illustrated layers of substrate material may be of any type or any combination of types of virtually any thickness.FIG. 17illustrates the high retention force fastener10shown in its separate components of the metal clip12and the plastic insert14relative to the substrates S1and S2. The substrate S1includes a hole H1and the substrate S2includes a hole H2. The high retention force fastener10of the disclosed inventive concept has particular but not exclusive utility in attaching substrates having round holes, square holes, rectangular holes, or any combination thereof.

For attaching two or more panels, the high retention force fastener10of the disclosed inventive concept is moved from the pre-installation position illustrated inFIG. 2through an intermediate position illustrated inFIG. 11, to a locked position illustrated inFIG. 12. More particularly and as illustrated inFIG. 2, the plastic insert14is only partially inserted into the metal clip12. The pair of opposed integral flexible struts44,44′ retain the primary retention arms18and18′. In this resting position, the shoulder31rests in the recessed area45and the shoulder31′ rests in the recessed area45′. In this position, the high retention force fastener10is ready for installation into the fastener holes of substrates to be attached.

Once the high retention force fastener10is inserted into two aligned holes formed in two side-by-side substrates (illustrated inFIGS. 13 through 17and discussed in relation thereto), the installer presses against the head40to move the plastic insert14into the metal clip12through an intermediate position such as that illustrated inFIG. 11in which the31from which extends an engagement leg42. This motion causes the shoulder31to be moved out of the recessed area45, the shoulder31′ to be moved out of the recessed area45′, and the retention arms18and18′ to be spread apart as the shoulders31and31′ ride respectively along the ramps47and47′.

To complete the locking engagement of the high retention force fastener10in the holes of the substrate and thereby locking the substrates against one another, the operator pushes the head40of the plastic insert14until it bottoms out in the metal clip12. In this position, the locking tab28′ engages the metal tab engagement feature46and the locking tab28′ engages the metal tab engagement feature46′ thereby locking the plastic insert14against movement out of the metal clip12.

Referring toFIG. 13, a side view of the high retention force fastener10in position relative to the upper substrate S1and the lower substrate S2is shown. However, upon being initially inserted into the holes of the substrates S1and S2but before the high retention force fastener10is fully inserted into the holes as illustrated inFIG. 14, the opposed integral flexible struts44,44′ function as pre-engagement fasteners for initial retention of the high retention force fastener10in the within the holes of the substrates S1and S2. Once fully inserted and in this pre-locking position, the U-shaped body16of the metal clip12has been inserted by an installer into two coaxial holes formed in the substrates. Insertion depth of the metal clip12into the holes is limited by the insertion stop plates26and30.

Upon insertion of the high retention force fastener10into the holes of the substrates, the wing-like rigid panel engagement features22and22′ of the first primary retention arm18and the pair of wing-like rigid panel engagement features24and24′ of the second primary retention arm18′ are slightly bent inward toward the U-shaped body16of the metal clip12, thereby allowing passage through the holes. Once through the holes, the wing-like rigid panel engagement features22,22′,24, and24′ spring back partially to their original shape and the upper edges23and23′ of the wing-like rigid panel engagement features22and22′ respectively and the upper edges25and25′ of the wing-like rigid panel engagement features24and24′ engage the underside of the lower substrate S2, thereby preventing withdrawal of the metal clip12from the holes of the substrates S1and S2.

After the high retention force fastener10is initially inserted into the holes of the substrates S1and S2, the installer then presses the plastic insert14into the metal clip12until the plastic insert14can be inserted no further. The soft latching mechanisms, of which one, mechanism49is shown, are released from their engagement holes50and50′.

Three mechanical events occur virtually simultaneously upon complete insertion of the plastic insert14into the metal clip12. One event, the initial event, is that the flexible arm48provided below the head40contacts the upper surfaces of the locking tabs28and32′ and the flexible arm48′, also provided below the head40, contacts the upper surfaces of the locking tabs28′ and32, thereby providing a limited but specific degree of interference between the plastic insert14and the metal clip12.

An event that immediately follows the initial event involving the flexible arms48and48′ described above is the locking of the head40to the metal clip12. Specifically, the metal tab engagement feature46engages both the hooked end29of the locking tab28and the hooked end33′ of the locking tab32′ while the metal tab engagement feature46′ engages both the hooked end29′ of the locking tab28′ and the hooked end33of the locking tab32.

Insertion of the plastic insert14into the metal clip12simultaneously causes the U-shaped body16of the metal clip12to fully expand within the holes H1and H2of the substrates S1and S2respectively. At this point and upon full insertion of the plastic insert into the metal clip12, the corner tips21,21′,27, and27′ bite into and lock against the underside of the substrate S2.

Once the high retention force fastener10is locked into position in the substrates, a relatively high degree of force is required for its removal (at least about 4 kN), particularly as compared with the degree of force needed for its insertion (less than 45N). However, if removal of the high retention force fastener10from the substrates S1and S2is desired, a tool suitable for the purpose, such as a flat tool (a screwdriver is a non-limiting example) is inserted into a slot54illustrated inFIG. 15. The plastic insert14is pried from the metal clip12by rotation of the head of the screwdriver. As the plastic insert14is removed, the metal clip12collapses and is then removed from the substrates S1and S2. If a remover attempts to lift the metal clip12from the substrates S1and S2, the upper edges23and23′ of the wing-like rigid panel engagement features22and22′ respectively and the upper edges25and25′ of the wing-like rigid panel engagement features24and24′ will be forced to spread apart.

One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.