Patent ID: 12196241

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

FIG.1Ais a cross-sectional view of an exemplary thread forming and thread locking fastener100in accordance with an illustrative embodiment of the present invention. The fastener100includes an entry point105and a head110with a shaft115extending therebetween. Illustratively, entry point105is illustrated as having a substantially flat end. However, it should be noted that in alternative embodiments of the present invention, the fastener100may have an entry point105that is rounded, pointed, etc. As such, the description of entry point105being substantially flat should be taken as exemplary only. Head110is illustratively shown as having a hexagonal shape for use with a driving apparatus for insertion. Head110extends for some length120in the same axis of the shaft115to enable a driver, e.g., a wrench, etc. to engage the head110to exert torque on the fastener for insertion of the fastener into a nut member (not shown). Head110includes a substantially flat bottom125that is designed to rest flush with a nut member (not shown) when the fastener is fully inserted. As will be appreciated by those skilled in the art, head110may have a plurality of differing shapes based on the desired driving apparatus. Therefore, the description of head110having a hexagonal shape should be taken as exemplary only.

The body or shaft115of the fastener100includes a plurality of zones of threads including, for example, a first zone130, a second zone135, and a third zone140. Illustratively, the three zones are utilized to both perform a thread forming function as well as a thread locking function once the fastener has been inserted into a nut member. The first zone130is illustratively approximately 1-5 pitches long of an exemplary first thread profile angling outward from the core with an increasing diameter as the zone moves away from the entry point105of the fastener. That is, the outer diameter of the first zone130is smallest at entry point105and enlarges as the threads move towards head110along the shaft115. The second zone135illustratively comprises an additional 1-3 pitches of the first (thread forming) thread profile but with a substantially constant outer diameter. As is illustrated inFIG.1A, the first thread profile illustratively comprises a substantially 60° angled thread profile cross section. In exemplary embodiments, the first thread profile may comprise that described in the above-incorporated U.S. Pat. No. 9,404,524. It should be noted that while a particular thread forming thread profile is shown and described, the principles of the present invention may utilize any thread forming thread profile in alternative embodiments of the present invention. Therefore, the particular thread forming thread profile shown and described herein should be taken as exemplary only.

The third zone140utilizes a second thread profile, which is illustratively a thread locking thread profile. As is illustrated inFIG.1A, the exemplary second thread profile comprises a 60° angled thread at the base of the thread that transitions to a 30° angled thread at the tip. An exemplary thread locking thread profile is described in the above-incorporated U.S. Pat. No. 7,722,304. It should be noted that while a particular thread locking profile is shown and described, the principles of the present invention may utilize any thread locking thread profile in alternative embodiments of the present invention. Therefore, the particular thread locking thread profile shown and described herein should be taken as exemplary only.

Thus, in operation, when a fastener100in accordance with an illustrative embodiment of the present invention is inserted into a nut member, the threads of the first zone engage the nut member as the fastener is initially inserted. The first and second zone threads deform the nut member to create threads. Upon continued insertion of the fastener into the nut member, the threads of the third zone engage the newly created threads to induce mechanical interference, which causes a locking mechanism to occur. Illustratively, the second thread profile is chosen to compliment the first thread profile. In accordance with alternative embodiments of the present invention, the two thread profiles may be selected so that the thread locking profile (the second thread profile) is designed with the a priori knowledge of the dimensions of the threads created in a nut member by the thread forming profile (the first thread profile). As the fastener is creating the internal threads in an unthreaded nut member, the thread locking profile threads may be configured for optimized performance with the internal threads. Examples of variations are described below in relation toFIGS.4A, B, C and5A, B, C.

Further, in accordance with illustrative embodiments of the present invention, the thread forming and thread locking thread profiles may be designed to create a specified amount of thread locking. This may be desirous for a number of reasons. For example, a particular user of the fastener may desire that the fastener may be able to be removed and reinserted into the nut member a specified number of times, e.g., at least 10, while maintaining at least a minimum prevailing torque. In such a scenario, a fastener with reduced locking action may be desirous. Conversely, a fastener for use in an apparatus where there is a need for a high prevailing torque may be designed to have a higher locking action. Exemplary techniques for varying the amount of thread locking are shown and described below in relation toFIGS.25-26.

FIG.1Bis an exemplary view of the head110of the fastener100viewed along the long axis of the fastener in accordance with an illustrative embodiment of the present invention. As noted above, the illustration and description of exemplary head having a hexagonal shape should be taken as exemplary only.FIG.1Cis a view of the fastener100from the entry point105along the long axis of the fastener in accordance with an illustrative embodiment of the present invention. As can be appreciated fromFIG.1C, the shaft115of the fastener is illustratively shaped having a plurality, e.g., three lobes, in cross section. It should be noted that the use of a multi-lobed shaft is exemplary only and the principles of the present invention may be utilized with fasteners having shafts that are substantially circular. As will be appreciated by those skilled in the art, various types of fastener shaft cross sections may be utilized to achieve desired properties of the fastener. More particularly, it is expressly contemplated that shafts having more than three lobes may be utilized in accordance with alternative embodiments of the present invention. Further, in alternative embodiments, the shaft may have a varying cross section. For example, the shaft may have a substantially circular cross-sectional area close to the entry point, but transition to a non-circular cross-sectional area along the length of the shaft. An exemplary non-circular cross-sectional area would be, e.g., a three-lobed cross-sectional area. However, it is expressly contemplated that other forms on substantially non-circular cross-sectional areas may be utilized in accordance with alternative embodiments of the present invention. The principles of the present invention is may be utilized with a wide range of fastener shaft115cross sectional shapes in order to achieve desired functionality.

FIG.2is an enlarged view of the entry point end of a fastener100in accordance with an illustrative embodiment of the present invention. As can be seen fromFIG.2, the first zone130increases in outer diameter as it moves from the entry point105. The first zone utilizes a first thread profile, which is illustratively a thread forming thread profile. The second zone135continues the use of the thread forming threads, but at an overall diameter that is substantially constant, unlike the first zone130which has an increasing overall thread diameter. The third zone140then utilizes a second thread profile, e.g., a thread locking thread profile, for the remainder of the fastener100.

FIG.3is an exemplary view of a headed blank300for use in forming a fastener100in accordance with an illustrative embodiment of the present invention. Illustratively, the blank300comprises a single diameter blank, which eases manufacturing difficulty. However, it is expressly contemplated that the principles of the present invention may be utilized with more sophisticated blanks.

FIGS.4A, B, C illustrate illustrative thread profiles that may be utilized in alternative embodiments of the present invention. It should be noted that each thread profile has the same cross-sectional area.FIG.4Ais representative of an illustrative 60° thread profile, such as that shown inFIG.1.FIG.4Bis representative of an exemplary radius thread profile.FIG.4Cis representative of an exemplary angular thread form with a 60°/30° thread profile. It should be noted that in alternative embodiments of the present invention, differing thread profiles may be utilized. Therefore, it is expressly contemplated that the thread profiles shown inFIGS.4A, B, C are exemplary only.

FIGS.5A, B, C illustrate exemplary ranges of potential mechanical interference that may be obtained by utilizing differing thread profiles for nut members and fasteners in accordance with exemplary design choices in accordance with illustrative embodiments of the present invention. The various figures show combinations of thread profiles described above in relation toFIGS.4A,B, C. As can be seen fromFIGS.5A, B, and C, by varying the internal and external thread profiles, varying degrees of mechanical interference can be achieved. In alternative embodiments, by selecting various combination of thread profiles, a desired amount of mechanical interference may be achieved.

FIG.6is a cross-sectional view600of the insertion of a fastener100into a threaded nut member605in accordance with an illustrative embodiment of the present invention. The threaded nut member605illustratively includes a set of preformed threads610. View600is of the fastener100and nut605immediately prior to insertion of the end105of the fastener100into the threaded nut member605. The view along section A-A illustrates an exemplary cross section615of fastener100and the threaded nut member.

FIG.7is a cross-sectional view700of the insertion of a fastener100into a threaded nut member605in accordance with an illustrative embodiment of the present invention. In view700, the first130and second135zones of the fastener100have been inserted into the threaded nut member605. As can be seen in the enlarged view, space is left between the first130and second zone135threads and the internal threads610of the threaded nut member605.

FIG.8is a cross-sectional view800of the insertion of a fastener100into an unthreaded nut member in accordance with an illustrative embodiment of the present invention. In view800, the first zone threads130have nearly passed through the threaded nut member605, while the second zone threads135are completely contained within the nut member605. As can be seen, the third zone threads140have generated tip penetration at points805within the nut member.

FIG.9is a cross-sectional view900of the insertion of a fastener100into a threaded nut member605in accordance with an illustrative embodiment of the present invention. In view900, the first130and second zone threads135have passed completely through the nut member605and for each internal thread605, there are tip penetration points905of the third zone threads140. With the faster100inserted as shown inFIG.9, the points of tip penetration905generate a mechanical locking mechanism, thereby working to secure the fastener in the threaded nut member.

In an illustrative embodiment of the present invention, the thread forming thread profile of the first and second zone threads are designed so as to slightly enlarge the diameter of the threads of the threaded nut member. This resizing enables the fastener to be constructed so that there is an optimized interference between the resized threads and the thread locking threads of the third zone threads. By selecting the thread profile and size for the first and second zone threads, the desired amount of mechanical interference with the third zone threads may be achieved. However, it should be noted that in alternative embodiments of the present invention, the preformed internal threads are not enlarged by the first and second zone threads. Therefore, the description of the internal threads being enlarged should be taken as exemplary only. Further, the action of the thread forming thread profile reduces or eliminates debris from the formation of the threads. This reduces waste and is critical in certain operational environments.

FIG.10is a cross-sectional view1000of the insertion of a fastener100into an un-threaded nut member1005in accordance with an illustrative embodiment of the present invention. In view1000, the fastener100is that about to be inserted into a nut member1005, which has an un-threaded aperture or hole1010.

FIG.11is a cross-sectional view1100of the insertion of a fastener100into an unthreaded nut member1005in accordance with an illustrative embodiment of the present invention. View1100shows when the first and second zone threads have been inserted into the unthreaded nut member completely.

FIG.12is a cross-sectional view1200of the insertion of a fastener100into an unthreaded nut member1005in accordance with an illustrative embodiment of the present invention. The third zone threads140have now entered the previously formed threads and have generated tip penetrations at points1205.

FIG.13is a cross-sectional view1300of the insertion of a fastener100into an unthreaded nut member in accordance with an illustrative embodiment of the present invention. In view1300, the first and third zone threads have passed through the nut member1005, a plurality of third zone threads are engaging the nut member1005at a plurality of tip penetration points1305.

As noted above, in relation toFIGS.6-9, in illustrative embodiments of the present invention, the first and second zone threads may be sized to create an optimally sized thread to achieve a desired mechanical interference with the third zone threads.

The thread locking action described above utilizes mechanical interference at the tips of the third zone thread profile to create a locking action. These embodiments work well in nut members made from steel or other hard metals. However, in softer materials, such as aluminum, or soft cast alloys, the desired outcome may not be achieved. In another embodiment of the present invention, the novel fastener is designed to create a locking action by the use of mechanical interference along the flanks of the thread. This flank locking action has been found to work well with materials where the previously described tip locking action does not.

FIG.14is an enlarged view of the entry point end of an exemplary fastener in accordance with an illustrative embodiment of the present invention.FIG.14, similar toFIG.2described above, illustrates a first zone130, a second zone135, and a third zone140. The first zone illustratively utilizes a thread forming thread profile that is designed to form a flank locking thread in the nut member (not shown). The second and third zones illustratively utilize a thread locking thread profile that is designed to induce flank locking mechanical interference with the threads formed by the thread forming thread profile.

In alternative embodiments of the present invention, the first zone130may not be utilized. In such alternative embodiments, the fastener comprises the second zone135(thread forming thread profile) and third zone140(thread locking thread profile).

FIGS.15-22are similar toFIGS.6-13but illustrate the insertion of a fastener that utilizes a thread forming thread profile and a thread locking thread profile that causes flank locking mechanical interference.

FIG.15is a cross-sectional view1500of the insertion of a fastener100into a threaded nut member1505in accordance with an illustrative embodiment of the present invention. The threaded nut member1505illustratively includes a set of preformed threads1510. View1500is of the fastener100and nut member1505immediately prior to insertion of the end105of the fastener100into the threaded nut member1505. The view along section A-A illustrates an exemplary cross section1515of fastener100and the threaded nut member.

FIG.16is a cross-sectional view1600of the insertion of a fastener100into a threaded nut member1505in accordance with an illustrative embodiment of the present invention. In view1600, the first130and second135zones of the fastener100have been inserted into the threaded nut member1505. As can be seen in the enlarged view, space is left between the first130and second zone135threads and the internal threads1510of the threaded nut member1505.

FIG.17is a cross-sectional view1700of the insertion of a fastener100into an unthreaded nut member in accordance with an illustrative embodiment of the present invention. In view800, the first zone threads130have nearly passed through the threaded nut member1505, while the second zone threads135are completely contained within the nut member1505. As can be seen, the third zone threads140have generated mechanical interference along the flanks of the threads at points1705within the nut member.

FIG.18is a cross-sectional view1800of the insertion of a fastener100into a threaded nut member1505in accordance with an illustrative embodiment of the present invention. In view1800, the first130and second zone threads135have passed completely through the nut member1505and for each internal thread1510, there are flank mechanical interference points1705with each of the third zone threads140. With the faster100inserted as shown inFIG.18, the flank locking mechanical interference points1705generate a mechanical locking mechanism, thereby working to secure the fastener in the threaded nut member.

In an illustrative embodiment of the present invention, the thread forming thread profile of the first and second zone threads are designed so as to slightly enlarge the diameter of the threads of the threaded nut member. This resizing enables the fastener to be constructed so that there is an optimized interference between the resized threads and the thread locking threads of the third zone threads. By selecting the thread profile and size for the first and second zone threads, the desired amount of mechanical interference with the third zone threads may be achieved. However, it should be noted that in alternative embodiments of the present invention, the preformed internal threads are not enlarged by the first and second zone threads. Therefore, the description of the internal threads being enlarged should be taken as exemplary only.

FIG.19is a cross-sectional view1900of the insertion of a fastener100into an un-threaded nut member100in accordance with an illustrative embodiment of the present invention. In view1900, the fastener100is that about to be inserted into a nut member1005, which has an un-threaded aperture or hole1010.

FIG.20is a cross-sectional view1100of the insertion of a fastener100into an unthreaded nut member2005in accordance with an illustrative embodiment of the present invention. View1100shows when the first130and second zone135threads have been inserted into the unthreaded nut member completely. The thread forming thread profile of the second zone135has begun to form the unthreaded nut member1005to create internal threads within the inside of the aperture1010.

FIG.21is a cross-sectional view1200of the insertion of a fastener100into an unthreaded nut member2005in accordance with an illustrative embodiment of the present invention. The third zone threads140have now entered the previously formed threads and have generated flank locking mechanical interference at points2105.

FIG.22is a cross-sectional view2200of the insertion of a fastener100into an unthreaded nut member2005in accordance with an illustrative embodiment of the present invention. In view2200, the first130and second135zone threads have passed through the nut member1005, a plurality of third zone threads are engaging the nut member1005at a plurality of flank locking mechanical interference points2105.

FIG.23Ais a cross sectional view2300A illustrating a maximum condition for a nut member in accordance with an illustrative embodiment of the present invention.

FIG.23Bis a cross sectional view2300B illustrating a minimum condition for a nut member in accordance with an illustrative embodiment of the present invention.

FIG.24Ais a cross sectional view2400A illustrating a maximum condition for a nut member in accordance with an illustrative embodiment of the present invention.

FIG.24Bis a cross sectional view2400B illustrating a minimum condition for a nut member in accordance with an illustrative embodiment of the present invention.

FIG.25is a cross-sectional view2500of an illustrative thread locking fastener illustrating variability of the amount of locking in accordance with an illustrative embodiment of the present invention. Exemplary view2500is of a fastener100that utilizes a thread forming thread profile that is designed to create mechanical interferences at the tips, such as that shown and described above in relation toFIGS.6-13. In view2500X represents a length of an individual thread of the thread locking thread profile and Y represents a height of a thread of the thread locking thread profile. In order to generate a fastener with more locking action, X is increased, and Y is decreased. Conversely, to reduce the amount of locking action generated by a particular fastener, X is reduced, and Y is increased.

FIG.26is a cross-sectional view of an illustrative flank locking fastener illustrating variability of the amount of locking in accordance with an illustrative embodiment of the present invention. Exemplary view2600is of a fastener100that utilizes a thread forming thread profile that is designed to create mechanical interferences at the flanks of the threads, such as that shown and described above in relation toFIGS.14-22. In view2600, X represents a length of an individual thread of the thread locking thread profile and Y represents a height of a thread of the thread locking thread profile. In order to generate a fastener with more locking action, X is decreased, and Y is increased. Conversely, to reduce the amount of locking action generated by a particular fastener, X is increased, and Y is decreased.

In this manner, a fastener may be designed to generate an amount of locking action that is desired for a particular application. The amount of locking action (prevailing torque) may also be maintained through a plurality of insertions and removals. As a fastener of the present invention produces little or no debris from the thread forming action, the nut member may remain suitable for additional insertions of the fastener.

It should be noted that while the present invention has been described in relation to particular thread profiles, the principles of the present invention may be utilized with a variety of thread forming and/or thread locking thread profiles. As such, the specific descriptions of particular thread profiles contained herein should be viewed as exemplary only. Furthermore, while various descriptions of number of pitch threads in the various zones has been given, as will be appreciated by those skilled in the art, the number of pitches in the various zones may vary depending on intended uses. As such, the description of particular numbers of pitches in the various zones should be taken as exemplary.

The present description is written in terms of various illustrative embodiments of the present invention. As will be appreciated by those skilled in the art, various modifications may be made to the embodiments described herein without departing from the spirit or scope of the invention. As such, the described embodiments should be taken as illustrative only.