Thread forming and thread locking fasteners

Abstract

To provide a fastener equipped with a side locking mechanism. [Solution] A fastener combining thread formation and thread locking is disclosed. The fastener comprises three sections. The first thread section utilizes a first thread formation thread shape having an increasing outer diameter. The second thread section extends from the end of the first section utilizing the first thread formation thread shape and continues with a constant diameter. The third thread section utilizes a thread locking thread shape that continues along substantially the rest of the shaft of the fastener.

Description

[Technical Field]

[0001] The present invention relates to threaded fasteners. [Background Art]

[0002] Background Information Conventional threaded fasteners (e.g., screws or bolts) can be designed to have a self-tapping thread forming action. An example of such a self-tapping fastener is described in U.S. Patent No. 9,404,524 to Alan Pritchard, entitled "High Performance Thread Rolling Screw / Bolt For Use in An Unthreaded Nut Anchor", the contents of which are incorporated herein by reference.

[0003] Other conventional fasteners can include a thread locking mechanism, which can be achieved for example by mechanical interference between the fastener and a nut member. An exemplary thread locking fastener is described in U.S. Patent No. 7,722,304 to Alan Pritchard, entitled "Fastener and Fastener Assembly", the contents of which are incorporated herein by reference.

[0004] A notable drawback of prior art fasteners is that they are optimized for either thread forming or thread locking, but not both. This requires a user to determine which characteristic is more important for a particular application, which can result in a sub-optimal application of such fasteners. [Summary of the Invention] [Means for Solving the Problems]

[0005] Summary The shortcomings of the prior art are overcome by providing exemplary fasteners optimized for both thread formation and thread locking. The fastener includes two distinct thread shapes divided into, for example, three sections along the shaft of the fastener. The first section utilizing the thread-forming thread shape is located immediately adjacent to the entry point of the fastener. Along the first section, the outer diameter of the thread shape increases along a first (e.g., 1-5) pitch. The second section transitions from the first section and utilizes the same thread-forming thread shape as the first section, but maintains a constant thread outer diameter. The second section extends beyond the first section, for example, over 1-3 pitches. The third section utilizing the thread shape for thread locking also maintains a constant outer diameter. It should be noted that in alternative embodiments of the present invention, the fastener may have only two sections, such as the second and third sections. Therefore, it should be noted that the description of three sections should be interpreted as merely illustrative.

[0006] According to exemplary embodiments of the present invention, the first and second thread shapes may be selected to complement each other in order to achieve a desired level of mechanical interference (i.e., thread lock). Furthermore, by utilizing the present invention, the second thread shape (thread lock) may be optimized to cooperate with the thread created by the first thread shape (thread formation). This can result in an optimized thread lock mechanism. As the fastener forms or reforms its own threads on the nut member, tolerance variations between the thread shape of the thread lock and the thread shape of the nut member are reduced. This allows for better fit and more precise locking action than using a conventional thread lock thread shape on a pre-formed nut member.

[0007] According to exemplary embodiments of the present invention, the thread shape of the thread lock may be designed to achieve a locking action by causing mechanical interference at the tip of the thread shape. In alternative embodiments of the present invention, the thread shape of the thread lock may be designed to achieve a locking action by causing mechanical interference along the side of the thread shape (i.e., side locking). Since the fastener forms or reforms the threads of the nut member, a very tight match between the thread shape of the thread lock and the threads of the nut member is possible. By varying the height and width of the thread shape, it is possible to create fasteners with a strong locking action or fasteners with a weak locking action depending on the specific application.

[0008] The above-mentioned advantages and further advantages of the embodiments of the present invention can be understood in relation to the accompanying drawings, in which similar reference numerals indicate the same or functionally the same elements. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a side view of an exemplary fastener according to an exemplary embodiment of the present invention. [Figure 1B] This is a diagram of the head of an exemplary fastener as seen along its long axis, according to an exemplary embodiment of the present invention. [Figure 1C] This is a diagram showing an exemplary entry point of an exemplary fastener viewed along its long axis, according to an exemplary embodiment of the present invention. [Figure 2] This is an enlarged view of the entry point end of an exemplary fastener according to an exemplary embodiment of the present invention. [Figure 3] This is an example diagram of an exemplary blank (material piece) for use in forming a fastener, according to an exemplary embodiment of the present invention. [Figure 4A] This is a cross-sectional view of an exemplary screw thread shape according to an exemplary embodiment of the present invention. [Figure 4B] This is a cross-sectional view of an exemplary screw thread shape according to an exemplary embodiment of the present invention. [Figure 4C]This is a cross-sectional view of an exemplary screw thread shape according to an exemplary embodiment of the present invention. [Figure 5A] This is a cross-sectional view showing interference between the threads of a nut member and the threads of a fastener, according to an exemplary embodiment of the present invention. [Figure 5B] This is a cross-sectional view showing interference between the threads of a nut member and the threads of a fastener, according to an exemplary embodiment of the present invention. [Figure 5C] This is a cross-sectional view showing interference between the threads of a nut member and the threads of a fastener, according to an exemplary embodiment of the present invention. [Figure 6] This is a cross-sectional view showing the insertion of an exemplary fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 7] This is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 8] This is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 9] This is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 10] This is a cross-sectional view showing the insertion of a fastener into an unthreaded nut member according to an exemplary embodiment of the present invention. [Figure 11] This is a cross-sectional view showing the insertion of a fastener into an unthreaded nut member according to an exemplary embodiment of the present invention. [Figure 12] This is a cross-sectional view showing the insertion of a fastener into an unthreaded nut member according to an exemplary embodiment of the present invention. [Figure 13] This is a cross-sectional view showing the insertion of a fastener into an unthreaded nut member according to an exemplary embodiment of the present invention. [Figure 14] This is an enlarged view of the entry point end of an exemplary fastener according to an exemplary embodiment of the present invention. [Figure 15] This is a cross-sectional view showing the insertion of an exemplary fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 16] It is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 17] It is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 18] It is a cross-sectional view showing the insertion of a fastener into a threaded nut member according to an exemplary embodiment of the present invention. [Figure 19] It is a cross-sectional view showing the insertion of a fastener into a non-threaded nut member according to an exemplary embodiment of the present invention. [Figure 20] It is a cross-sectional view showing the insertion of a fastener into a non-threaded nut member according to an exemplary embodiment of the present invention. [Figure 21] It is a cross-sectional view showing the insertion of a fastener into a non-threaded nut member according to an exemplary embodiment of the present invention. [Figure 22] It is a cross-sectional view showing the insertion of a fastener into a non-threaded nut member according to an exemplary embodiment of the present invention. [Figure 23A] It is a cross-sectional view showing the maximum state of a nut member according to an exemplary embodiment of the present invention. [Figure 23B] It is a cross-sectional view showing the minimum state of a nut member according to an exemplary embodiment of the present invention. [Figure 24A] It is a cross-sectional view showing the maximum state of a nut member according to an exemplary embodiment of the present invention. [Figure 24B] It is a cross-sectional view showing the minimum state of a nut member according to an exemplary embodiment of the present invention. [Figure 25] It is a cross-sectional view of an exemplary thread-locking fastener showing variability in the amount of locking according to an exemplary embodiment of the present invention. [Figure 26] It is a cross-sectional view of an exemplary side-locking fastener showing variability in the amount of locking according to an exemplary embodiment of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0010] Detailed Description of Exemplary Embodiments Figure 1A is a cross-sectional view of an exemplary thread-forming and thread-locking fastener 100 according to an exemplary embodiment of the present invention. The fastener 100 includes an entry point 105 and a head 110, with a shaft 115 extending between them. In practice, the entry point 105 is shown to have a substantially flat end. However, it should be noted that in alternative embodiments of the present invention, the fastener 100 may have an entry point 105 that is rounded or pointed, etc. Therefore, the description of a substantially flat entry point 105 should be interpreted as merely illustrative. The head 110 is exemplaryly shown to have a hexagonal shape for use with an insertion drive mechanism. The head 110 extends over a certain length 120 on the same axis of the shaft 115 to allow a driver (e.g., a wrench (spanner)) to engage with the head 110 in order to apply torque to the fastener for insertion into a nut member (not shown). The head 110 includes a substantially flat bottom 125 designed to abut coplanar with a nut member (not shown) when the fastener is fully inserted. As will be understood by those skilled in the art, the head 110 can have several different shapes based on the desired drive mechanism. Accordingly, the description of the head 110 having a hexagonal shape should be interpreted as merely illustrative.

[0011] The main body or shaft 115 of the fastener 100 includes multiple threaded sections, for example, a first section 130, a second section 135, and a third section 140. In practice, the three sections are used to perform both thread-forming and thread-locking functions once the fastener is inserted into the nut member. The first section 130 is approximately 1 to 5 pitches long, representing an exemplary first thread shape that is angled outward from the core, with its diameter increasing as the section moves away from the entry point 105 of the fastener. That is, the outer diameter of the first section 130 is smallest at the entry point 105 and increases as the thread moves along the shaft 115 toward the head 110. The second section 135 is, in practice, the first (thread-forming) thread shape, but includes an additional 1 to 3 pitches with a substantially constant outer diameter. As shown in Figure 1A, the first thread shape includes, in example, a cross-section of a thread shape formed at a substantially 60° angle. In exemplary embodiments, the first thread shape may include those described in U.S. Patent No. 9,404,524, which are incorporated above. It should be noted that while specific thread-forming thread shapes are illustrated and described, the principles of the present invention can utilize any thread-forming thread shape in alternative embodiments of the invention. Therefore, the specific thread-forming thread shapes illustrated and described herein should be construed as merely illustrative.

[0012] The third section 140 utilizes a second thread shape, which is a thread-locking thread shape as an example. As shown in Figure 1A, the exemplary second thread shape includes a thread that transitions from a thread formed at a 60° angle at the base (base, bottom) of the thread to a thread formed at a 30° angle at the tip. The exemplary thread-locking thread shape is described in U.S. Patent No. 7,722,304, which is incorporated above. It should be noted that while specific thread-locking thread shapes are illustrated and described, the principle of the present invention can utilize any thread-locking thread shape in alternative embodiments of the present invention. Therefore, the specific thread-locking thread shapes illustrated and described herein should be construed as merely illustrative.

[0013] Thus, when the fastener 100 according to an exemplary embodiment of the present invention is inserted into a nut member during operation, the threads in the first area engage with the nut member when the fastener is first inserted. The threads in the first and second areas deform the nut member to create a thread. As insertion of the fastener into the nut member continues, the threads in the third area engage with the newly created thread, causing mechanical interference and thereby creating a locking mechanism. In practice, the second thread shape is selected to complement the first thread shape. According to an alternative embodiment of the present invention, the two thread shapes may be selected such that the thread-locking shape (second thread shape) is designed with deductive knowledge of the dimensions of the thread created in the nut member by the thread-forming shape (first thread shape). Since the fastener creates a female thread (internal thread) in an unthreaded nut member, the threads of the thread-locking shape may be configured for optimized performance with the female thread. Examples of deformed objects will be described later in relation to Figures 4A, 4B, 4C, 5A, 5B, and 5C.

[0014] Furthermore, according to exemplary embodiments of the present invention, the thread shape of the thread formation and thread lock can be designed to form a specified amount of thread lock. This may be desirable for several reasons. For example, a particular user of a fastener may want the fastener to be able to be removed and reinserted into a nut member a specified number of times, e.g., at least 10 times, while maintaining at least a minimum prevailing torque. In such situations, a fastener with a small locking action may be desired. Conversely, a fastener for use in a device requiring a high prevailing torque can be designed to have a large locking action. Exemplary techniques for varying the amount of thread lock are shown and described below in reference to Figures 25-26.

[0015] Figure 1B is an exemplary diagram of the head 110 of fastener 100 as seen along the long axis of the fastener, according to an exemplary embodiment of the present invention. As stated above, the illustration and description of the exemplary head having a hexagonal shape should be interpreted as merely illustrative. Figure 1C is a diagram of fastener 100 from the entry point 105 along the long axis of the fastener, according to an exemplary embodiment of the present invention. As can be understood from Figure 1C, the shaft 115 of the fastener is shaped, in example, to have multiple (e.g., three) lobes (rounded projections) in cross-section. It should be noted that the use of a multi-lobed shaft is merely illustrative, and the principle of the present invention can be used with fasteners having a substantially circular shaft. As will be understood by those skilled in the art, various types of fastener shaft cross-sections can be used to achieve desired properties of the fastener. More specifically, it is particularly intended that shafts having more than three lobes may be used, according to alternative embodiments of the present invention. Furthermore, in alternative embodiments, the shaft may have a varied cross-section. For example, a shaft may have a substantially circular cross-sectional region near the entry point, but transition to a non-circular cross-sectional region along the length of the shaft. An exemplary non-circular cross-sectional region is, for example, a cross-sectional region having three lobes. However, according to alternative embodiments of the present invention, other shapes in the substantially non-circular cross-sectional region may be utilized, and this is particularly intended. The principle of the present invention can be utilized with a wide range of cross-sectional shapes of the fastener shaft 115 to achieve desired functionality.

[0016] Figure 2 is an enlarged view of the entry point end of the fastener 100 according to an exemplary embodiment of the present invention. As can be seen from Figure 2, the first region 130 increases in outer diameter as it moves from the entry point 105. The first region utilizes a first thread shape, which is, in practice, a thread-forming thread shape. The second region 135 continues to use the thread-forming thread shape, but unlike the first region 130 which has an increasing thread diameter, it has a substantially constant overall diameter. The third region 140 then utilizes a second thread shape (e.g., a thread-locking thread shape) with respect to the rest of the fastener 100.

[0017] Figure 3 is an example diagram of a headed blank 300 for use in forming a fastener 100, according to an exemplary embodiment of the present invention. In practice, the blank 300 consists of a single-diameter blank to reduce manufacturing difficulty. However, the principle of the present invention is particularly intended to be used with more elaborate blanks.

[0018] Figures 4A, 4B, and 4C show exemplary thread shapes that may be used in alternative embodiments of the present invention. It should be noted that each thread shape has the same cross-sectional area. Figure 4A is a representative example of an exemplary 60° thread shape, as shown in Figure 1. Figure 4B is a representative example of an exemplary rounded thread shape. Figure 4C is a representative example of an exemplary triangular thread shape having a 60° / 30° thread configuration. It should be noted that different thread shapes may be used in alternative embodiments of the present invention. Therefore, it is particularly intended that the thread shapes shown in Figures 4A, 4B, and 4C are merely illustrative.

[0019] Figures 5A, 5B, and 5C illustrate an exemplary range of potential mechanical interference that can be achieved by utilizing different thread shapes of the nut member and fastener, according to exemplary design selections in exemplary embodiments of the present invention. Various figures illustrate combinations of thread shapes described above in relation to Figures 4A, 4B, and 4C. As can be seen from Figures 5A, 5B, and 5C, various degrees of mechanical interference can be achieved by changing the shapes of the female (internal) and male (external) threads. In alternative embodiments, a desired amount of mechanical interference can be achieved by selecting various combinations of thread shapes.

[0020] Figure 6 is a cross-sectional view 600 showing the insertion of a fastener 100 into a threaded nut member 605 according to an exemplary embodiment of the present invention. The threaded nut member 605 includes, in example, a set of pre-formed threads 610. Figure 600 shows the fastener 100 and nut 605 immediately before insertion of the end 105 of the fastener 100 into the threaded nut member 605. The view along section AA shows an exemplary cross-section 615 of the fastener 100 and the threaded nut member.

[0021] Figure 7 is a cross-sectional view 700 showing the insertion of a fastener 100 into a threaded nut member 605 according to an exemplary embodiment of the present invention. In Figure 700, the first area 130 and the second area 135 of the fastener 100 are inserted into the threaded nut member 605. As can be seen in the enlarged view, a space remains between the threads of the first area 130 and the second area 135 and the female thread 610 of the threaded nut member 605.

[0022] Figure 8 is a cross-sectional view 800 showing the insertion of a fastener 100 into a threaded nut member according to an exemplary embodiment of the present invention. In Figure 800, the threads of the first area 130 almost pass through the threaded nut member 605, but the threads of the second area 135 are completely inside the nut member 605. As can be seen, the threads of the third area 140 are biting into the nut member at location 805.

[0023] Figure 9 is a cross-sectional view 900 showing the insertion of a fastener 100 into a threaded nut member 605 according to an exemplary embodiment of the present invention. In Figure 900, the threads of the first area 130 and the second area 135 completely pass through the nut member 605, and for each female thread 605, there is a tip-entry point 905 of the threads of the third area 140. With the fastener 100 inserted as shown in Figure 9, the tip-entry point 905 generates a mechanical locking mechanism, thereby acting to fix the fastener in the threaded nut member.

[0024] In exemplary embodiments of the present invention, the thread-forming shape of the threads in the first and second regions is designed to slightly enlarge the diameter of the threads of the threaded nut member. This resizing allows the fastener to be configured to have optimized interference between the resized threads and the thread-locking threads of the third region. By selecting the thread shape and size for the threads in the first and second regions, a desired amount of mechanical interference with the threads of the third region can be achieved. However, it should be noted that in alternative embodiments of the present invention, pre-formed female threads are not engaged by the threads in the first and second regions. Therefore, the description that the female threads are enlarged should be interpreted as merely illustrative. Furthermore, the action of the thread-forming shape reduces or removes foreign matter from thread formation. This reduces waste, which is very important in certain working environments.

[0025] Figure 10 is a cross-sectional view 1000 showing the insertion of a fastener 100 into an unthreaded nut member 1005 according to an exemplary embodiment of the present invention. In Figure 1000, the fastener 100 is about to be inserted into a nut member 1005 having an unthreaded opening or hole 1010.

[0026] Figure 11 is a cross-sectional view 1100 showing the insertion of the fastener 100 into an unthreaded nut member 1005 according to an exemplary embodiment of the present invention. Figure 1100 shows the first and second threads fully inserted into the unthreaded nut member.

[0027] Figure 12 is a cross-sectional view 1200 showing the insertion of the fastener 100 into an unthreaded nut member 1005 according to an exemplary embodiment of the present invention. At this point, the threads of the third area 140 have entered the previously formed threads, resulting in tip engagement at location 1205.

[0028] Figure 13 is a cross-sectional view 1300 showing the insertion of a fastener 100 into an unthreaded nut member according to an exemplary embodiment of the present invention. In Figure 1300, the threads in the first and second areas pass through the nut member 1005, and the multiple threads in the third area engage with the nut member 1005 at multiple tip-bite locations 1305.

[0029] As described above in relation to Figures 6 to 9, in exemplary embodiments of the present invention, the threads in the first and second areas can be sized to create threads of an optimal size to achieve desired mechanical interference with the threads in the third area.

[0030] The thread locking action described above utilizes mechanical interference at the tip of the thread shape in the third region to produce the locking action. These embodiments work well with nut members made from steel or other hard metals. However, with softer materials such as aluminum or soft cast alloys, the desired results may not be obtained. In another embodiment of the present invention, a novel fastener is designed to produce a locking action by using mechanical interference along the side of the thread. This side locking action has been shown to work well even with materials where the tip locking action described above does not work.

[0031] Figure 14 is an enlarged view of the entry point end of an exemplary fastener according to an exemplary embodiment of the present invention. Figure 14 shows a first area 130, a second area 135, and a third area 140, similar to Figure 2 described above. The first area utilizes a thread-forming thread shape designed to form side-lock threads on a nut member (not shown), for example. The second and third areas utilize thread-locking thread shapes designed to cause side-locking mechanical interference to the threads formed by the thread-forming thread shape, for example.

[0032] In alternative embodiments of the present invention, the first region 130 may not be utilized. In such alternative embodiments, the fastener includes a second region 135 (thread-forming thread shape) and a third region 140 (thread-locking thread shape).

[0033] Figures 15 to 22 are similar to Figures 6 to 13, but show the insertion of fasteners that utilize thread-forming and thread-locking thread shapes that cause side-lock mechanical interference.

[0034] Figure 15 is a cross-sectional view 1500 showing the insertion of a fastener 100 into a threaded nut member 1505 according to an exemplary embodiment of the present invention. The threaded nut member 1505 includes, for example, a pre-formed set of threads 1510. Figure 1500 shows the fastener 100 and nut member 1505 immediately before the end 105 of the fastener 100 is inserted into the threaded nut member 1505. The view along section AA shows an exemplary cross-section 1515 of the fastener 100 and the threaded nut member.

[0035] Figure 16 is a cross-sectional view 1600 showing the insertion of a fastener 100 into a threaded nut member 1505 according to an exemplary embodiment of the present invention. In Figure 1600, the first section 130 and the second section 135 of the fastener 100 are inserted into the threaded nut member 1505. As can be seen in the enlarged view, a space remains between the threads of the first section 130 and the second section 135 and the female thread 1510 of the threaded nut member 1505.

[0036] Figure 17 is a cross-sectional view 1700 showing the insertion of the fastener 100 into an unthreaded nut member according to an exemplary embodiment of the present invention. In Figure 800, the threads of the first area 130 almost pass through the threaded nut member 1505, and the threads of the second area 135 are completely housed within the nut member 1505. As can be seen, the threads of the third area 140 cause mechanical interference along the side surface of the threads at point 1705 within the nut member.

[0037] Figure 18 is a cross-sectional view 1800 showing the insertion of a fastener 100 into a threaded nut member 1505 according to an exemplary embodiment of the present invention. In Figure 1800, the threads of the first area 130 and the second area 135 completely pass through the nut member 1505, and with respect to each female thread 1510, there is a lateral mechanical interference point 1705 between each of the threads of the third area 140. With the fastener 100 inserted as shown in Figure 18, the lateral locking mechanical interference point 1705 generates a mechanical locking mechanism, which in turn works to fix the fastener within the threaded nut member.

[0038] In exemplary embodiments of the present invention, the thread-forming shapes of the first and second regions are designed to slightly enlarge the diameter of the threads of the threaded nut member. This resizing allows the fastener to be configured such that interference between the resized threads and the thread-locking threads of the third region is optimized. By selecting the thread shapes and sizes of the first and second regions, a desired amount of mechanical interference with the third region's threads can be achieved. However, it should be noted that in alternative embodiments of the present invention, the pre-formed female threads are not enlarged by the threads of the first and second regions. Therefore, the description of female thread enlargement should be considered illustrative only.

[0039] Figure 19 is a cross-sectional view 1900 showing the insertion of a fastener 100 into an unthreaded nut member 1005 according to an exemplary embodiment of the present invention. In Figure 1900, the fastener 100 is about to be inserted into a nut member 1005 having an unthreaded opening or hole 1010.

[0040] Figure 20 is a cross-sectional view 1100 showing the insertion of the fastener 100 into an unthreaded nut member 2005 according to an exemplary embodiment of the present invention. Figure 1100 shows the state in which the threads of the first area 130 and the second area 135 are fully inserted into the unthreaded nut member. The thread-forming shape of the second area 135 is beginning to form an internal thread on the inside of the opening 1010 of the unthreaded nut member 1005.

[0041] Figure 21 is a cross-sectional view 1200 showing the insertion of a fastener 100 into an unthreaded nut member 2005 according to an exemplary embodiment of the present invention. At this point, the threads of the third area 140 are engaged with the previously formed threads, causing lateral locking mechanical interference at point 2105.

[0042] Figure 22 is a cross-sectional view 2200 showing the insertion of the fastener 100 into an unthreaded nut member 2005 according to an exemplary embodiment of the present invention. In Figure 2200, the threads of the first area 130 and the second area 135 pass through the nut member 1005, and the multiple threads of the third area engage with the nut member 1005 at multiple side-locking mechanical interference points 2105.

[0043] Figure 23A is a cross-sectional view 2300A showing the maximum state of the nut member according to an exemplary embodiment of the present invention.

[0044] Figure 23B is a cross-sectional view 2300B showing the minimum state of the nut member according to an exemplary embodiment of the present invention.

[0045] Figure 24A is a cross-sectional view 2400A showing the maximum state of the nut member according to an exemplary embodiment of the present invention.

[0046] Figure 24B is a cross-sectional view 2400B showing the minimum state of the nut member according to an exemplary embodiment of the present invention.

[0047] Figure 25 is a cross-sectional view 2500 showing an exemplary screw-lock fastener demonstrating variable locking amount according to an exemplary embodiment of the present invention. The exemplary cross-sectional view 2500 is of a fastener 100 that utilizes a thread-forming screw shape designed to produce mechanical interference at the tip, as shown and described above in relation to Figures 6 to 13. In Figure 2500, X represents the length of the individual threads of the screw-lock screw shape, and Y represents the height of the threads of the screw-lock screw shape. To produce a fastener with a greater locking action, X is increased and Y is decreased. Conversely, to reduce the magnitude of the locking action produced by a particular fastener, X is decreased and Y is increased.

[0048] Figure 26 is a cross-sectional view showing an exemplary side-locking fastener demonstrating variable locking amount according to an exemplary embodiment of the present invention. Exemplary Figure 2600 shows a fastener 100 that utilizes a thread-forming thread shape designed to cause mechanical interference on the side of the thread, as shown and described above in relation to Figures 14 to 22. In Figure 2600, X represents the length of an individual thread of the thread-locking thread shape, and Y represents the height of the thread of the thread-locking thread shape. To produce a fastener with a greater locking action, X is decreased and Y is increased. Conversely, to reduce the magnitude of the locking action produced by a particular fastener, X is increased and Y is decreased.

[0049] Thus, fasteners can be designed to generate the desired amount of locking force for a specific application. Furthermore, the magnitude of the locking force (prevailing torque) can be maintained through multiple insertions and removals. Because the fasteners of the present invention generate little to no foreign matter from the thread-forming action, the nut member can remain in a state suitable for additional insertion of the fastener.

[0050] It should be noted that although the present invention has been described in relation to a specific thread shape, the principles of the present invention can be used with a variety of thread shapes for thread formation and / or thread locking. Therefore, any specific descriptions of a particular thread shape included herein should be considered merely illustrative. Furthermore, although various descriptions of the number of thread pitches are given in different areas, as will be understood by those skilled in the art, the number of pitches in different areas may vary depending on the intended application. Therefore, any descriptions of a specific number of pitches in different areas should be interpreted as illustrative.

[0051] This description relates to various exemplary embodiments of the present invention. As will be understood by those skilled in the art, various modifications can be made to the embodiments described herein without departing from the spirit or scope of the invention. Therefore, the embodiments described should be construed as merely illustrative.

[0052] Exemplary embodiments of the present invention are listed below. 1. Fasteners, It includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, and the cross-sectional shape has three or more lobes. The shaft has a first thread shape engraved in a first area and a second area, and the first thread shape is a thread-forming thread shape that is shaped to generate an internal thread of a predetermined size in the nut member. The first area begins at the entrance point and extends along the shaft over approximately a first predetermined number of thread pitches, the diameter of the first area increasing from the entrance point to the second area, The second area has a constant outer diameter and extends over approximately a second predetermined number of screw thread pitches, The third area has a second thread shape different from the first thread shape, which extends from the transition point from the second area toward the bottom of the head along a substantial portion of the remaining part of the shaft. A fastener wherein the second thread shape is a thread-locking thread shape, and the second thread shape has a predetermined size such that, based on the predetermined size information of the internal thread, it causes a desired amount of mechanical interference between one or more sides of one or more threads of the second thread shape of the nut member and the internal thread formed by the first thread shape. 2. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to claim 1, wherein the magnitude of the prevailing torque is increased by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 3. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to claim 1, wherein the magnitude of the prevailing torque is reduced by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 4. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to claim 1, wherein the magnitude of the prevailing torque is increased by reducing the height of the threads of the thread-locking thread shape and increasing the width of the threads of the thread-locking thread shape. 5. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to claim 1, wherein the magnitude of the prevailing torque of the thread-locking thread shape is increased by reducing the height of the threads and increasing the width of the threads. 6. Fasteners, The present invention includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, wherein the cross-sectional shape of the shaft transitions from a substantially circular cross-section to a substantially non-circular cross-section. The shaft has a first thread shape engraved in a first area and a second area, and the first thread shape is a thread-forming thread shape that is shaped to generate an internal thread of a predetermined size in the nut member. The first area begins at the entrance point and extends along the shaft over approximately a first predetermined number of thread pitches, the diameter of the first area increasing from the entrance point to the second area, The second area has a constant outer diameter and extends over approximately a second predetermined number of screw thread pitches, The third area has a second thread shape different from the first thread shape, which extends from the transition point from the second area toward the bottom of the head along a substantial portion of the remaining part of the shaft. A fastener wherein the second thread shape is a thread-locking thread shape, and the second thread shape has a predetermined size such that, based on the predetermined size information of the internal thread, it causes a desired amount of mechanical interference between one or more sides of one or more threads of the second thread shape of the nut member and the internal thread formed by the first thread shape. 7. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 6, wherein the magnitude of the prevailing torque is increased by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 8. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 6, wherein the magnitude of the prevailing torque is reduced by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 9. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 6, wherein the magnitude of the prevailing torque is increased by reducing the height of the threads of the thread-locking thread shape and increasing the width of the threads of the thread-locking thread shape. 10. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to claim 6, wherein the magnitude of the prevailing torque of the thread-locking thread shape is increased by reducing the height of the threads and increasing the width of the threads. 11. Fasteners, The present invention includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, wherein the cross-sectional shape of the shaft transitions from a substantially non-circular cross-section to a substantially circular cross-section. The shaft has a first thread shape engraved in a first area and a second area, and the first thread shape is a thread-forming thread shape that is shaped to generate an internal thread of a predetermined size in the nut member. The first area begins at the entrance point and extends along the shaft over approximately a first predetermined number of thread pitches, the diameter of the first area increasing from the entrance point to the second area, The second area has a constant outer diameter and extends over approximately a second predetermined number of screw thread pitches, The third area has a second thread shape different from the first thread shape, which extends from the transition point from the second area toward the bottom of the head along a substantial portion of the remaining part of the shaft. A fastener wherein the second thread shape is a thread-locking thread shape, and the second thread shape has a predetermined size such that, based on the predetermined size information of the internal thread, it causes a desired amount of mechanical interference between one or more sides of one or more threads of the second thread shape of the nut member and the internal thread formed by the first thread shape. 12. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 11, wherein the magnitude of the prevailing torque is increased by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 13. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 11, wherein the magnitude of the prevailing torque is reduced by increasing the height of the threads of the thread-locking thread shape and narrowing the width of the threads of the thread-locking thread shape. 14. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 11, wherein the magnitude of the prevailing torque is increased by reducing the height of the threads of the thread-locking thread shape and increasing the width of the threads of the thread-locking thread shape. 15. Mechanical interference of a desired magnitude generates a connection between the fastener and the nut member having a predetermined prevailing torque. The fastener according to 11, wherein the magnitude of the prevailing torque of the thread-locking thread shape is increased by reducing the height of the threads and increasing the width of the threads. 16. Fasteners, It includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, and the cross-sectional shape has three or more lobes. The shaft has a first thread shape engraved in a first area, the first area starting from the entry point and extending along the shaft over approximately a first predetermined number of thread pitches, The second area has a second thread shape that extends from the transition point from the first area toward the bottom of the head along a substantial portion of the remaining part of the shaft, The first thread shape is a thread-forming thread shape that is shaped to generate an internal thread in the nut member, A fastener wherein the second thread shape is a thread-locking thread shape formed to produce a desired size of mechanical interference between the nut member and the internal thread. 17. The fastener according to 16, wherein the mechanical interference occurs on one or more sides of one or more threads in the second area. 18. The fastener according to 16, wherein the mechanical interference occurs at one or more tips of one or more threads in the second area. 19. Fasteners, The present invention includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, wherein the cross-sectional shape of the shaft transitions from a substantially circular cross-section to a substantially non-circular cross-section. The shaft has a first thread shape engraved in a first area, the first area starting from the entry point and extending along the shaft over approximately a first predetermined number of thread pitches, The second area has a second thread shape that extends from the transition point from the first area toward the bottom of the head along a substantial portion of the remaining part of the shaft, The first thread shape is a thread-forming thread shape that is shaped to generate an internal thread in the nut member, A fastener wherein the second thread shape is a thread-locking thread shape formed to produce a desired size of mechanical interference between the nut member and the internal thread. 20. The fastener according to 19, wherein the mechanical interference occurs on one or more sides of one or more threads in the second area. 21. The fastener according to 19, wherein the mechanical interference occurs at one or more tips of one or more threads in the second area. 22. Fasteners, The present invention includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, wherein the cross-sectional shape of the shaft transitions from a substantially non-circular cross-section to a substantially circular cross-section. The shaft has a first thread shape engraved in a first area, the first area starting from the entry point and extending along the shaft over approximately a first predetermined number of thread pitches, The second area has a second thread shape that extends from the transition point from the first area toward the bottom of the head along a substantial portion of the remaining part of the shaft, The first thread shape is a thread-forming thread shape that is shaped to generate an internal thread in the nut member, A fastener wherein the second thread shape is a thread-locking thread shape formed to produce a desired size of mechanical interference between the nut member and the internal thread. 23. The fastener according to 22, wherein the mechanical interference occurs on one or more sides of one or more threads in the second area. 24. The fastener according to 22, wherein the mechanical interference occurs at one or more tips of one or more threads in the second area.

Claims

[Claim 1] A fastener, It includes a shaft having a cross-sectional shape, an entrance point at a first end, and a head at a second end, and the cross-sectional shape has three or more lobes. The shaft has a first thread shape engraved in a first area and a second area, and the first thread shape is a thread-forming thread shape that is shaped to generate an internal thread of a predetermined size in the nut member. The first area begins at the entrance point and extends along the shaft over approximately a first predetermined number of thread pitches, the diameter of the first area increasing from the entrance point to the second area, The second area has a constant outer diameter and extends approximately over a second predetermined number of screw thread pitches, The third area has a second thread shape different from the first thread shape, which extends from the transition point from the second area toward the bottom of the head along a substantial portion of the remaining part of the shaft. A fastener wherein the second thread shape is a thread-locking thread shape, and the second thread shape has a predetermined size such that, based on the predetermined size information of the internal thread, it causes a desired amount of mechanical interference between one or more sides of one or more threads of the second thread shape of the nut member and the internal thread formed by the first thread shape.

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