Lock nut

Abstract

The present invention provides a lock nut comprising a nut body including a threaded portion having an internal thread, an adjacent peripheral shoulder, and a collar surrounding the shoulder, and a metal annular washer, the annular washer being placed on the shoulder within the collar and the collar being bent inward to form an annular groove between the bent collar and the shoulder in which the annular washer is housed. The annular washer has internal threads on its inner periphery that correspond to the internal threads of the threaded portion of the nut body, and the internal threads of the annular washer are axially offset by a certain distance relative to the internal threads of the nut body. To better secure the annular washer in the annular groove, a series of protrusions or recesses are formed on the shoulder or the annular washer where the annular washer and shoulder overlap, protruding axially and distributed circumferentially around the shoulder or the annular washer. The protrusions form a support surface, line, or point against the annular washer on the shoulder when the annular washer is placed inside the collar on the shoulder of the nut body. As the collar deforms to form the annular groove, an axial force is applied to the annular washer, partially deforming and / or partially pressing the protrusion or indentation into the opposite surface of the annular washer or shoulder, resulting in the annular washer being retained in the annular groove by pressure engagement and positive fit.

Description

[Technical field]

[0001] The invention relates to a locking nut according to the preamble of claim 1. [Background technology]

[0002] Such locking nuts are known, for example, from DE 2638560 C, DE 4313809 C1, DE 4313845 C1 and WO 2011 / 000393 A1.

[0003] A locking nut is a reusable one-piece metal nut, in particular a nut integrally formed from steel having a metal nut body provided with an internal thread and an adjacent collar that is deformed into an annular groove to hold a metal locking washer therein. The locking nut is manufactured by placing an annular washer inside the collar on the nut body, crimping the collar to hold the annular washer in the annular groove thus formed, and then cutting an internal thread simultaneously in the nut body and the annular washer. As a result, the thread corresponds to the thread of the nut on the inner peripheral edge of the locking annular washer. The annular washer and the thread of the washer are axially offset by a small distance with respect to the thread of the nut, for example a distance corresponding to about 5-30%, preferably 10-20%, of the thread pitch of the thread of the nut, to adjust the tightening effect of the locking nut. The locking annular washer has a certain elasticity in the axial direction, whereby the clamping force of the locking nut can be adjusted by the offset of the inner thread of the annular washer, and the locking nut maintains this adjusted clamping force for many screwing operations.

[0004] This type of locking nut provides an effective and simple means of securing a screw so that the threaded connection does not loosen. No further fasteners or machine elements or further machining of the screw shank, thread end or bolt are required to secure the screw. The locking washer constitutes a fastening part that can be elastically deformed when the screw or bolt is screwed in. As a result, it provides radial and axial holding forces that can be adjusted by the offset of the locking annular washer. The locking nut ensures a permanent connection even under large temperature fluctuations and vibrations.

[0005] This known locking nut has established itself on the market due to its excellent locking properties. To increase the elasticity of the locking annular washer, which may be desirable for example for certain nut sizes or extreme temperature loads, the above mentioned documents suggest providing an annular washer with a segmented peripheral recess on the outer periphery and / or with additional notches on the outer periphery and with a variable thickness in the radial direction. This makes it possible to manufacture the annular washer from a hard elastic material, such as spring steel, and still achieve the elasticity required for the desired axial deflection, while keeping the elastic restoring force of the annular washer high enough to achieve a high retention force. Since the annular washer is made from a material at least as hard as the material of the nut body, the thread of the annular washer is not damaged even after many screwing operations, so that the locking nut can be loosened and retightened several times without a noticeable change in the tightening force in the locked position. Materials that can withstand very high temperatures can be used, which is very important, for example, when used in automobiles.

[0006] The above mentioned documents suggest viable solutions for optimizing the elasticity of the retaining annular washer, however, practice has shown that the fixing of the retaining annular washer in the annular groove can still be improved.

[0007] The prior art also knows locking nuts with a plastic retaining and sealing ring, which is held in a collar of the nut body in a manner similar to that of a common locking nut. Such locking nuts are described, for example, in EP 0047061 A1, DE 1815585 A, DE 3640225 C2, DE 8424281 U1, US 4,019,550 A, US 3,275,054 A, US 3,316,338 A, US 2,450,694 A, US 5,454,675 A. However, these locking nuts are based on a different principle of operation. The initially unthreaded part of the plastic retaining and sealing ring connects directly to the internal thread of the nut and projects slightly beyond it. When the bolt is screwed in, it cuts into the inner periphery of the retaining sealing washer. Most of the above-mentioned documents deal with the absorption of the receding plastic material when the bolt is screwed in.

[0008] The teachings of this prior art, with regard to the adjustment of the elasticity and retention force of the locking annular washer, are not transferable to locking nuts made integrally from metal, because, among other reasons, plastic annular washers behave differently from metallic annular washers with regard to their elasticity, and because this prior art does not provide for an axial offset of the annular washer and the internal thread of the nut body. The retention force of these locking nuts is based on a different operating principle. It is the object of the present invention to further optimize the reliability of locking nuts made integrally from metal.

[0009] This problem is solved by a locking nut according to the respective independent claims. The respective dependent claims define embodiments. Summary of the Invention

[0010] The present invention provides a locking nut comprising a nut body including a threaded portion having an internal thread, a peripheral shoulder adjacent to the threaded portion, and a collar surrounding the shoulder, and a metallic annular washer, the annular washer being placed on the inner shoulder of the collar, the collar being bent inwardly to form an annular groove between the bent collar in which the annular washer is housed and the shoulder. An internal thread corresponding to the internal thread of the threaded portion of the nut body is formed on the inner peripheral edge of the annular washer, the internal thread of the annular washer being axially offset by a distance with respect to the internal thread of the nut body. To better secure the annular washer in the annular groove, a series of projections or recesses are formed on the shoulder or the annular washer where the annular washer and the shoulder overlap, the projections or recesses projecting in the axial direction and distributed around the periphery of the shoulder or the annular washer. The projections or recesses form a support surface, line or point for the annular washer on the shoulder when the annular washer is placed inside the collar on the shoulder of the nut body. By deforming the collar to form the annular groove, an axial force is applied to the annular washer, partially deforming the projection or recess, or the remaining material between the recesses, and / or partially pressing it into the opposing surface, annular washer, or shoulder. As a result, the annular washer is forcefully and conformally clamped into the annular groove. The projection formed on the annular washer or material between the shoulder, or recess, penetrates to some extent into the opposing surface of the annular washer or shoulder when the collar is deformed to secure the annular washer against rotation within the annular groove. Furthermore, the projection or recess allows the axial offset of the annular washer to be more precisely adjusted, since it can conform better than a shoulder or a continuous or stepped surface of the annular washer.

[0011] In various embodiments, the projections or recesses are radially aligned and evenly distributed around the circumference of the shoulder or annular washer, which provides good alignment of the annular washer perpendicular to the axis of the nut body.

[0012] Depending on the size of the locking nut, a different number of projections or recesses may be selected in the radial direction, with at least 16 projections or recesses being provided in various embodiments. For example, at least 24 or 40 projections or recesses may be provided in the axial direction.

[0013] The protrusions or remaining material between the depressions can have various shapes. In various embodiments, the protrusions or remaining material have a shape of convex curvature, in particular a circular or elliptical dome or a lying semi-cylinder, or an angular or pointed shape, in particular a lying triangular prism or tetrahedron, or approximately such a shape. Particularly good results have been obtained with protrusions or remaining material between the depressions in the shape of an irregular tetrahedron.

[0014] When a protrusion or recess is formed in the shoulder, for example, a first face of a tetrahedron may abut the collar and a second face of the tetrahedron may abut the shoulder such that the height of the tetrahedron decreases radially from the collar towards the inner periphery of the shoulder. The protrusion or remaining material between the recesses, for example, a tetrahedron, may extend radially across all or only a portion of the shoulder, for example, 1 / 2 to 4 / 5 of the radial extension of the shoulder from the collar.

[0015] When the protrusions or recesses are formed in the annular washer, for example, a first surface of a tetrahedron may be aligned with the outer peripheral edge of the annular washer and a second surface of the tetrahedron may abut the annular washer such that the height of the tetrahedron decreases radially from the outer peripheral edge of the annular washer to the inner peripheral edge of the annular washer. The protrusions or remaining material between the recesses, for example, are tetrahedrons, but may extend radially across all or only a portion of the annular washer, for example, from the outer peripheral edge of the annular washer to 1 / 2 to 4 / 5 of the radial extension of the annular washer.

[0016] In various embodiments, the shoulder has a shoulder surface that is inclined to the radial plane of the locking nut by an angle α_s, where α_s is in the range of about 0°-15° or about 5° or 10°, and the protrusion or remaining material between the recesses may have an apex line that is inclined to the radial plane of the locking nut by an angle α_v, where α_v>α_s and α_v is, for example, in the range of 30°-60° or about 40°, 45°, or 50°.

[0017] In various embodiments, the width B of the projections or recesses relative to the center-to-center distance A of the projections when they abut the collar is equal to or approximately equal to B=b*A, where b is in the range of 0.2 to 1, more particularly 0.5 to 1, or approximately 1 or 0.5. The maximum height of the projections or remaining material between the recesses may be approximately equal to the width of these projections or remaining material, or may range from half the width to twice the width. The maximum height of the projections 40 and / or remaining material between the recesses may be determined by the thickness of the fixed annular washer 22, e.g., 0.25 times the thickness of the washer to 1 times the thickness of the washer. The width of the projections and / or the height of the projections and / or remaining material between the recesses may decrease radially inward.

[0018] In a further embodiment, circumferentially aligned projections are formed on the shoulder of the nut body. The projections may be formed, for example, by forming recesses in the interior by receiving the annular washer in an annular groove, and forming circumferentially extending one-piece or multi-piece ribs on the shoulder of the nut body, which recesses reshape the ribs into a plurality of circumferentially aligned projections. For example, the one-piece ribs can be formed by forming frontal recesses on the shoulder adjacent to the collar, for example, by turning the nut body. If the annular washer has tabs or other extensions on its periphery, these can penetrate the ribs when the collar of the nut body is flanged and, as a result, can be placed in the recesses formed in the ribs. This secures the annular washer to the nut body against rotation.

[0019] In a further embodiment, circumferentially aligned projections are formed on the surface of the annular washer facing the shoulder of the nut body. The projections may be formed, for example, by forming a circumferentially extending one-piece or multi-piece rib on the surface of the annular washer, inside which recesses are formed that reshape the rib into a plurality of circumferentially aligned projections when the annular washer is received in the annular groove. For example, the one-piece rib may be formed by forming a frontal recess on the surface of the annular washer, for example by turning the annular washer. If the shoulder of the nut body has tabs or other extensions on its periphery, these tabs or extensions can penetrate the ribs when the collar of the nut body is flanged and, as a result, can be placed in the recesses formed in the ribs. This secures the annular washer to the nut body against rotation.

[0020] In various embodiments, the annular washer may have a constant thickness, or the thickness of the annular washer at its inner diameter may be greater than the thickness of the annular washer at its outer diameter.

[0021] In various embodiments, the annular washer is displaced relative to the nut body such that the internal threads of the annular washer are axially offset relative to the internal threads of the nut body by a distance that is approximately 5-30%, particularly 10-20% of the thread pitch of the internal threads. For example, the internal threads of the annular washer are axially offset from the internal threads of the nut body by a distance that is approximately 10% or 20% of the thread pitch. The offset of the annular washer and its internal threads can be used to adjust the clamping force of the locking nut.

[0022] In various embodiments, the thickness of the annular washer at its inner diameter is equal to or approximately equal to the thread pitch of the internal threads, or is between 1 times the thread pitch and 1.5 times the thread pitch.

[0023] In various embodiments, the annular washer is convexly curved toward the front of the locking nut.

[0024] In various embodiments, the outer periphery of the annular washer is formed with a number of cutouts and / or tabs distributed around the circumference of the annular washer.

[0025] The annular washer is made from a metal, in particular from spring steel, and the nut body is also made from a metal, in particular from steel.

[0026] The invention also provides a method for manufacturing a lock nut of the above type. A washer is placed inside a collar at the shoulder of the nut body, which is not yet threaded. A first force is applied axially to the collar to deform the collar inwardly, also called "flanging", to form an annular groove between the flanged collar and the shoulder, against which the annular washer is axially clamped. By applying the first force, the projections or remaining material between the recesses deform a first distance and penetrate slightly into the opposite surface. Then, in a single operation, an internal thread is formed in the nut body and the annular washer, which is fixed against rotation in the annular groove by the projections. Then, a second force is applied axially to the collar and the annular groove against which the annular washer is clamped, to displace the annular washer axially. By applying the second force, the projections or remaining material between the recesses deform a second distance. The projections or remaining material between the recesses allow the washer to be lowered axially precisely and uniformly, so that the offset of the threads can be precisely adjusted. Furthermore, the protrusions or remaining material between the recesses not only forcefully secure the annular washer in the annular groove, but also provide a form match between the annular washer and the nut body, thus fixing the annular washer against rotation in the annular groove, which is particularly advantageous when cutting threads, since the annular washer cannot be rotated during the cutting process.

[0027] In another embodiment, a method of manufacturing a locking nut includes forming a peripheral rib on a shoulder of a nut body by frontally penetrating the shoulder adjacent a collar, after which an annular washer is placed inside the collar with the as yet unthreaded shoulder of the nut body, and a first force is applied axially to the collar to flange the collar inwardly and form an annular groove between the axially tightened flanged collar and the shoulder, where application of the first force causes detents formed on an outer periphery of the annular washer to penetrate the peripheral rib and rest in recesses thereby formed in the rib.

[0028] Subsequently, in a single operation, internal threads can be formed in the nut body and the annular washer, after which a second force is applied axially to the collar and annular groove which tightens the annular washer displaces the annular washer axially, where application of the second force causes the claws to penetrate the ribs an additional distance.

[0029] Conversely, a peripheral rib can also be formed on the surface of the annular washer facing the shoulder, and a corresponding projection or detent can be peripherally aligned at the shoulder of the nut body such that the projection or detent penetrates into the rib on the annular washer when the flange mounting operation is performed on the collar.

[0030] The interaction between the ribs and the pawls allows for precise and uniform lowering of the washer in the axial direction, allowing for precise adjustment of the thread offset. Furthermore, the projections and recesses formed in the process provide a form fitting connection between the washer and the nut body in addition to frictionally fixing the washer in the annular groove, thus fixing the washer against rotation in the annular groove. This is particularly advantageous when forming threads, since the washer cannot be rotated during the cutting process.

[0031] In various embodiments, the annular washer is manufactured with a convex curvature in a pre-machining step and placed on the shoulder of the nut body such that the annular washer is convexly curved toward the front side of the locking nut, whereby the convex curvature of the annular washer is maintained or substantially maintained upon deformation.

[0032] The invention will be explained in more detail below by means of embodiments with reference to the drawings, in which: [Brief description of the drawings]

[0033] [Figure 1] FIG. 13 is a perspective view of a nut body of a locking nut from above, prior to insertion of a locking washer, according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a nut body of a lock nut from below according to an embodiment. [Diagram 3] FIG. 2 is a vertical sectional view of the nut body of FIG. [Figure 4] FIG. 7 is a top view of a lock nut for explaining the cross sections of FIGS. 5 and 6. [Diagram 5] FIG. 14 is a side cross-sectional view of a locking nut having a nut body and a secured locking washer taken along section line AA of FIGS. 4 and 13, according to an embodiment. [Figure 6] FIG. 14 is a side cross-sectional view of a locking nut having a nut body and a secured locking washer taken along section line BB of FIGS. 4 and 13, according to an embodiment. [Figure 7] FIG. 6 is an enlarged perspective view of section Y of FIG. 5. [Figure 8] FIG. 7 is an enlarged perspective view of section X in FIG. 6. [Figure 9] FIG. 9 is a vertical sectional perspective view of the lock nut of FIGS. [Figure 10] FIG. 13 is a perspective view of a lock nut from above with a lock washer tightened into place, according to an embodiment. [Figure 11] FIG. 11 is a view similar to FIG. 10, but without showing the locking annular washer. [Figure 12] FIG. 2 is a perspective view of a retaining annular washer according to an embodiment; [Figure 13] FIG. 2 is a top view of a lock washer according to an embodiment before it is inserted into a lock nut. [Figure 14] FIG. 14 is a view similar to FIG. 13 showing the retaining annular washer removed from the completed locking nut. [Figure 15] FIG. 13 is a top view of a retaining annular washer according to another embodiment. [Figure 16] FIG. 16 is a cross-sectional view of the fixed annular washer taken along line AA in FIG. 15. [Figure 17] FIG. 13 is a top view of a retaining annular washer according to another embodiment. [Figure 18] FIG. 18 is a cross-sectional view of the fixed annular washer taken along line BB in FIG. 17. [Figure 19] 22 is a vertical cross-sectional view of a nut body of a lock nut according to another embodiment taken along section line AA of FIG. [Figure 20] FIG. 20 is an enlarged perspective view of section B of FIG. 19. [Figure 21] FIG. 20 is a top view of the nut body according to the embodiment of FIG. 19. [Figure 22] FIG. 20 is a perspective view of the nut body according to the embodiment of FIG. 19 before the annular washer is inserted. [Diagram 23] 20 is a cross-sectional view similar to FIG. 19 of the nut body after an annular washer has been inserted and then removed again to illustrate the embodiment. [Figure 24] FIG. 24 is a perspective view of the mother body of FIG. 23. [Diagram 25] FIG. 24 is a top view of the nut body of FIG. 23. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The figures show example embodiments, whereby modifications may be made, such as, for example, to the embodiments described above. For clarity, not every feature is labeled in every figure. However, one skilled in the art will recognize that each figure shows a corresponding feature of the locking nut.

[0035] In the various figures, a locking nut 10 is shown having a nut body 12 and a locking annular washer 22. The locking nut 10 is made from steel, for example as a hexagonal nut, i.e. in the embodiment, the nut body and the annular washer are made from steel. In the embodiment shown, the nut body 12 has a concentric collar 14 on one end face and a core bore 16, the diameter of which depends on the size of the nut and the internal diameter of the thread to be formed. In the figures, only the core bore 16 is shown, the internal thread cutting into this bore when the locking nut is completed, hereinafter also referred to as the "nut thread". An inner edge or periphery 18 of the collar 14 is offset outwardly with respect to the diameter of the core bore of the locking nut 10, forming a shoulder 20 between the core bore 16 and the collar 14 for receiving a locking washer 22.

[0036] Collar inner diameter D K is about 1.2 to 1.5 times the core hole diameter D, D K = 1.2*D to 1.5*D, for example, about 1.3 times the core hole diameter D. The height of the collar 14 is determined by the thickness of the locking annular washer 22, and may be, for example, about twice the thickness of the locking annular washer 22, where the thickness of the locking annular washer 22 is approximately between 1 and 1.5 times the thread pitch of the locking nut 10. The height of the collar 14 is such that the locking annular washer 22 can be securely tightened when the collar is flanged (crimped), as described below. The collar 14 has a generally conical shape, and its thickness (measured radially) increases axially from the face of the locking nut. The thickness of the collar can be used to adjust the tightening and retention force after flanging, as described below.

[0037] The locking annular washer 22, hereinafter also referred to as annular washer for short, is made from metal, preferably a resilient metal such as spring steel or spring strip steel.

[0038] A series of projections 40 are formed in the shoulder 20, projecting axially and adjacent to the inner wall 18 of the collar 14 and distributed around the circumference of the shoulder. The following examples relate to embodiments in which projections 40 are formed in the shoulder 20. In another embodiment, projections or recesses may instead be formed in the side of the annular washer that faces the shoulder 20 when the annular washer is inserted into the nut body, achieving the same or substantially the same effect as described with reference to Figures 5-9. In yet another embodiment, recesses are formed in the shoulder in a similar manner to those shown with reference to the annular washer in Figures 16 and 17, with the remaining material between the recesses having a similar function as the projections described above.

[0039] 1-16, projections 40 are in the shape of irregular tetrahedrons with one face of each tetrahedron adjacent collar inner wall 18, the adjacent face adjacent shoulder 20, and the other two sides of the tetrahedron encircling a wedge shape. The face adjacent shoulder 20 forms the base of projection 40, and the apex line of wedge-shaped projection 40 is inclined relative to the surface of shoulder 20 such that the height of projection 40 from shoulder 20 decreases in the direction from inner wall 18 of collar 14 to the axis of the locking nut.

[0040] In an embodiment, the projections 40 form a uniform row of teeth, and the projections 40 are arranged radially and evenly distributed around the circumference of the shoulder or annular washer. In various embodiments, at least 12, 16, 24 or at least 40 projections may be provided depending on the size and application of the locking nut. For example, a locking nut of size M8 may have at least 16, e.g., 20 projections, a locking nut of size M12 may have at least 20 projections, and a locking nut of size M16 may have at least 40 projections. The number of projections may be determined by the circumference of the core bore 16 or inner wall 18 of the collar 14. The height of the projections 40 measured from the shoulder 20 may be about one third the height of the collar 14 in one embodiment. The height of the projections 40 may also be determined by the thickness of the fixed annular washer 22, e.g., 0.25 times the thickness of the washer to 1 times the thickness of the washer.

[0041] For example, in an embodiment of a lock nut sized M12, the inner diameter of the collar 14 may be about 12-15 mm. The height of the collar 14, measured from the line of contact of the collar with the shoulder 20, may be about 3.5 mm. If 24 projections are provided in this embodiment, these projections have a center-to-center spacing of about 2 mm or 15°. The projections may have a maximum width of 2 mm at their widest point, at their base. The width of the projections at their base, at their widest point, may be, for example, about 1.8 mm, about 1.5 mm or about 1 mm. The height of the projections from the shoulder, at their highest point, may be, for example, about 0.5 mm to about 2 mm, for example, about 1 mm. The thickness of the annular washer 22 may be in the range of about 1.5 mm to 2.5 mm.

[0042] For example, in an embodiment of a lock nut sized M20, the inner diameter of the collar 14 may be about 20-25 mm. The height of the collar 14, measured from the line of contact with the shoulder 20, may be about 5 mm. Thirty-two projections, if provided in this embodiment, have a center-to-center spacing of about 2 mm or 11.25°. The projections may have a maximum width of 2 mm at their base and at their widest point. The width of the projections at their base may be, for example, about 1.8 mm, about 1.5 mm or about 1 mm at their widest point. The height of the projections from the shoulder may be, for example, in the range of about 0.5 mm to about 3 mm, such as about 0.6, 1.5 or 2.5 mm, at their highest point. The thickness of the annular washer 22 may be in the range of about 1.5 mm to 4 mm, more particularly in the range of 2.5 mm to 3.75 mm.

[0043] The projections may be essentially adjacent to one another at their base, widest point, or may be spaced apart by small distances, for example 0.5mm to 2mm, or up to 5mm or even 1cm, in the case of very large locking nuts.

[0044] While in the illustrated embodiment the projections are wedge-shaped and have an inclined apex line, the projections may have other shapes, for example a shape of convex curvature, in particular a circular or elliptical dome or a reclining semi-cylinder, or other angular shapes, in particular a reclining triangular prism, a gabled roof, a non-inclined wedge or other tetrahedral or polyhedral shapes. Variations of such shapes, for example rounded or truncated corners, are also within the scope of the invention. With regard to the width, height and spacing of the projections the above applies in principle.

[0045] The shoulder 20 may be aligned with the radial plane of the lock nut 10, thereby perpendicular to the inner surface 18 of the collar 14, or may be slightly inclined with respect to the radial plane, inclining radially inwardly away from the collar 14. For example, the shoulder 20 may be inclined with respect to the radial plane by an angle α_s of, for example, up to 20°, e.g., about 10°. The apex line of the projection may have an inclination angle α_v of, for example, about 45°, e.g., between 30° and 60°, e.g., with respect to the same radial plane. These angles are shown in FIG. 7, where the inclination of the shoulder and the inclination of the projection are best seen.

[0046] An embodiment of the annular washer 22 is shown in Figures 12 to 14. The washer has a core hole diameter D equal to or slightly smaller than the core hole diameter D of the nut body 12. R 12-14, the annular washer 22 has three cutouts 24 that are not circular segments on the outer periphery of the annular washer 22. A pair of detents 26 is formed between each of the three cutouts 24 on the periphery of the annular washer 22. The annular washer 22 is secured to the nut body 12 in the region of each pair of detents 26 between the circular segment shaped cutouts 24 by flange mounting the collar 14, as described below.

[0047] The annular washer 22 may have a uniform thickness, or the thickness of the annular washer 22 may be greater at its inner diameter than at its outer diameter. By varying the thickness of the locking annular washer 22 with diameter, the resilience of the annular washer, and therefore the retention force of the locking nut, may be adjusted. For example, the thickness of the annular washer 22 at the outer diameter may be less than or equal to the height of the thread pitch of the nut thread, such as between one-half and one time the thread pitch. For example, the thickness at the outer diameter may be about three-quarters of the thread pitch. The thickness of the annular washer 22 at the inner diameter may be greater than or equal to the thread pitch, but less than or equal to 2.5 times the thread pitch. For example, the thickness at the inner diameter may be between one and two times the thread pitch, such as about 1.5 times the thread pitch. In practice, if the thickness of the annular washer at its inner diameter is greater than twice the thread pitch, excessive braking torque of the locking nut will be generated when threading the bolt in most applications, whereby the braking torque and holding force will also depend on the overall dimensions of the locking nut and nut threads and the magnitude of the axial offset of the threads of the annular washer 22 relative to the nut threads.

[0048] When the locking nut is manufactured, the annular washer 22 is initially placed on the shoulder 20 surrounded by the collar 14. In this pre-assembled state, the annular washer 22 may have a convex curvature towards the front side of the locking nut, as can be seen particularly well in Figures 5 and 6.

[0049] 5-9, the collar 14 is then deformed and drawn at its upper end by a pressure punch or the like, by means of a flanged mounting process, thereby forming an annular groove 28 in which the annular washer 22 is held against axial movement. The flanged collar 14' is attached. To flange the collar 14, a first pressing force is applied which is sufficient to deform the collar and to press the annular washer 22 against the projections 40 so that, upon deformation, the projections penetrate into the material of the annular washer 22 by a small distance. For example, the pressing force can be adjusted so that the projections 40 penetrate into the material of the annular washer 22 by up to one-third of their height. In this way, the annular washer 22 is not only axially fixed in the annular groove 28, but also fixed against rotation. This state is shown in FIGS. 5-9, where FIGS. 5 and 7 show cross-sectional views of the sections AA and BB shown relative to the orientation of the fixed annular washer 22 in FIGS. 4 and 13. 5 intersects one of the cutouts 24 and the opposing space between a pair of detents 26 so that the annular washer 22 does not abut the inner wall 18 of the collar 14 at these locations. Cut plane BB intersects two opposing detents 26 such that the annular washer 22 abuts the inner wall 18 of the collar 14 at these locations.

[0050] After securing the annular washer 22 in the annular groove 28, a cutting tool is used to simultaneously cut the internal threads in the nut body 12 and the annular washer 22 so that they have identical, continuous threads (not shown). The projections 40 are pressed partially into the material of the annular washer 22 so that the annular washer 22 is secured against rotation while forming the threads. The detents 26 provide additional anti-rotation protection.

[0051] Thereafter, a second pressing force is applied to the flanged collar 14' by the same or another pressing die, which causes the annular washer 22 to be slightly displaced in the axial direction of the nut thread, so that the nut thread and the internal thread of the annular washer 22 are axially offset from each other. The axial offset of the annular washer 22 may be about 5-30%, preferably 10-20%, of the thread pitch, so that the offset of the two threads from each other is between one-quarter and one-half of the thread pitch. The second pressing force may be approximately equal to the first pressing force and is adjusted to achieve the desired offset of the threads of the nut body 12 and the annular washer 22. Such a desired offset may be adjusted, for example, depending on the desired holding torque of the locking nut. The locking annular washer does not lie flat on the shoulder 20, but on the projection 40, so that the axial offset of the locking annular washer 22 can be adjusted evenly and precisely. In this process, the projection 40 can deform and / or penetrate further into the material of the annular washer 22.

[0052] 13 and 14 show an embodiment of the retaining annular washer 22' before and after completion of the locking nut, with the recess 30 formed by the penetration of the projection 40 shown in FIG. 14. The recess 30 is located in the area of ​​the retaining annular washer 22' clamped between the projection 40 and the flange-mounted machined collar 14'.

[0053] Figures 15 and 16 show another embodiment of an annular washer 42 having protrusions 44 formed on its surface. The geometric configuration of the annular washer 42 can be essentially the same as or similar to that described with reference to Figures 12-14, except for the formation of the protrusions 44. Please refer to the above description of Figures 12-14.

[0054] In the embodiment of Figures 15 and 16, there are six groups of three projections 44 on each of the detents 46 distributed around the periphery of the annular washer 42. This is by way of example only, and a different number of projections may be provided and may be arranged, grouped or evenly distributed differently than shown in Figures 15 and 16. In the embodiment of Figures 15 and 16, the projections 44 may be similar in shape to the projections 40 on the shoulder 20 of the locking nut. This applies in particular to the shape, size and relative arrangement of the projections 44. See above for explanation.

[0055] The annular washer 42 of Figures 15 and 16 may have a smooth surface so that it can be mated with a locking nut which does not need to have a projection or depression formed in the shoulder. The completed locking nut may in principle be manufactured as described with reference to Figures 5 to 9, although in the embodiment of Figures 15 and 16 it is the projection 44 of the annular washer 42 which deforms rather than the projection on the shoulder. See above description of Figures 5 to 9.

[0056] Figures 17 and 18 show yet another embodiment of an annular washer 52 having depressions 54 formed in its surface. The geometric configuration of the annular washer 52 can be essentially the same as or similar to that described with reference to Figures 12-14, except for the formation of the depressions 54. Please refer to the above description of Figures 12-14.

[0057] In the embodiment shown in Figures 17 and 18, three groups of eleven recesses 54 are formed around the circumference of the annular washer 52, with each recess located on a detent 56 and between the detents. This is, of course, only one example, and a different number of recesses may be provided, and may be arranged, grouped, and shaped differently than shown in Figures 17 and 18. In the embodiment of Figures 17 and 18, the material remaining between the recesses 54 results in tooth- or rib-like structures 58, which may be similar in design to the projections 40 on the shoulder 20 of the locking nut 10, particularly with regard to the shape, dimensions, and relative placement of the tooth- or rib-like structures 58. See the above description of the projections.

[0058] The annular washer 52 of Figures 17 and 18 may be mated with a locking nut 10 and its shoulder may have a smooth surface as no projections or recesses need be formed. The locking nut may in principle be manufactured as described with reference to Figures 5 to 9, but in the embodiment of Figures 17 and 18 the tooth or rib-like structure 58 of the annular washer 52 is deformed rather than a projection of the shoulder. See above description of Figures 5 to 9.

[0059] In a further embodiment, not shown, recesses may be formed in shoulder 20 of locking nut 10 instead of projections 40, and between the recesses tooth or rib-like structures are formed from the material remaining between the recesses, which structures may be similar to those shown in Figures 17 and 18. Again, the locking nut is essentially manufactured as described with reference to Figures 5-9, but again, it is the tooth or rib-like structures 58 that are deformed at the shoulder, rather than the projections.

[0060] A further embodiment of the locking nut is shown in Figures 19 to 25. The locking nut is essentially constructed with a nut body 12 and a locking annular washer 22 as described above with reference to Figures 1 to 18, so reference is made to the above description. In particular, the annular washer 22 may be as described with reference to Figures 12 and 13. Only the differences are described below. The same reference signs as in the previous figures are used to indicate identical or corresponding features. Unless otherwise stated, the above remarks regarding the locking nut apply mutatis mutandis.

[0061] 19-25, a peripheral rib 60 is first formed on shoulder 14. This may be formed, for example, by machining a circumferential groove 62 adjacent collar 14 by turning nut body 12. Optionally, additional material may be removed from the surface of shoulder 20 on the side of rib 60 facing away from circumferential groove 62, i.e., radially inward, to define rib 60 of a desired width and height. The width and height of rib 60 may be essentially similar to the width and height of protrusion 40 described in the previous embodiment.

[0062] For example, the rib 60 may have a maximum width of 3 mm, preferably 1-2 mm, at its base, at its widest point. The height of the rib from the shoulder may be, for example, in the range of about 0.5 mm to 2 mm, e.g., about 1 mm, at its highest point. These values ​​are, of course, only examples and are variable depending on the size of the locknut, the thread, the material used, the retention force to be achieved, and other factors. The rib may, for example, have an essentially approximately triangular or trapezoidal cross section, or a semicircular, semi-elliptical, or parabolic cross section.

[0063] Figure 22 shows how the annular washer 22 is mounted on the nut body 12. After inserting the annular washer 22, the collar 14 is also flanged in this embodiment to secure the annular washer 22 in the annular groove 28 against rotation, as described above with reference to Figures 6 to 9. In the embodiment of Figures 19 to 25, an annular washer 22 is used having radially outwardly protruding extensions, e.g., claws 26, as described with reference to Figures 12 and 13. The connection between the annular washer and the nut body, the formation of the threads and the deformation of the annular washer can essentially be performed as described with reference to Figures 1 to 18.

[0064] Figures 23-25 ​​show different views of the nut body after an annular washer as shown in Figure 22 has been inserted and removed again. Removal of the annular washer is not intended when the lock nut is used as intended. However, to verify deformation of the rib 60, the flanged machined portion of the collar 14 can be, for example, milled, so that the collar stub 14' shown in Figure 23 remains.

[0065] As shown in Figures 23-25, the detents 26 are pressed into the ribs 60 and deform the ribs 60 to define circumferentially aligned projections 60' separated by indentations 60" in the ribs 60 corresponding to the detents. The indentations 60" may completely or partially displace the material of the ribs 60 in a radial direction, with the remaining material of the ribs 60 forming separate projections 60' or a circumferentially continuous projection. In either case, the annular washer 22 is placed with the detents 26 in the indentations 60" and is rotationally secured thereto.

[0066] In an alternative embodiment, a peripheral rib may be formed on the surface of the annular washer and a corresponding projection or tab may be disposed on the shoulder of the nut body in the peripheral direction such that the projection or tab penetrates into the rib on the annular washer when the collar is flanged. The effect achieved is the same as that described above in connection with Figures 19-25.

[0067] In the described embodiment, the locking annular washer 22 in the preassembled state has a convex curvature in the direction of the front side of the nut body 12, i.e. a curvature pointing away from the nut thread. When forming the axial offset of the thread, this convex curvature can be somewhat reduced, but is not compensated for or even reversed. The pre-curvature of the locking annular washer 22 in the ready-assembled state can ensure a more defined deformation behavior when forming the axial offset, so that a more accurate setting of the axial offset and the resulting holding force of the locking nut can be achieved.

[0068] Although not shown, the threaded bolt screwed into the nut is clamped on all sides by the annular washer 22, whereby the axial spring force of the annular washer and the axial offset of the threads are decisive for the clamping force. The spring force of the annular washer 22 is determined to a large extent by its elasticity. Furthermore, the clamping force of the lock nut can be adjusted by the thickness of the collar 14. A thinner collar, especially a thinner front edge of the collar, can give the collar a certain elasticity so that it can yield somewhat when the bolt is screwed in.

[0069] The features disclosed in the above description, in the drawings and in the claims may be important both individually and in any combination for realizing the invention in its various embodiments.

Claims

1. A lock nut comprising a nut body (12) including a threaded portion having an internal thread (16), a peripheral shoulder (20) adjacent the threaded portion, and a collar surrounding the shoulder, and a metal annular washer (22, 22'), the collar is bent inwardly such that an annular groove (28) is formed between the bent collar and the shoulder, and the annular washer is received in the annular groove; an inner peripheral edge of the annular washer (22) is formed with an internal thread (16') corresponding to the internal thread (16) of the threaded portion, and the internal thread (16') of the annular washer (22) is axially offset by a certain distance with respect to the internal thread (16) of the nut body (12); a series of projections (40) or recesses are formed in the shoulder where the annular washer and the shoulder overlap, and a series of recesses (30) are formed in the annular washer into which the projections or recesses penetrate, the projections or recesses being axially protruding or recessed and distributed around the shoulder; The protrusion or remainder is formed with an apex line that is inclined to a radial plane of the locking nut by an angle α_v, the angle α_v being in the range of 30° to 60°.

2. 2. The locking nut of claim 1, wherein the shoulder comprises a shoulder surface that is inclined relative to a radial plane of the locking nut toward a thread axis by an angle α_s, the angle α_s being in the range of 0° to 15°.

3. 3. A lock nut as claimed in claim 1 or 2, wherein the projection or recess is moulded or formed in the shoulder.

4. The lock nut of claim 3 , wherein the projection or recess is adjacent the collar.

5. A locking nut according to claim 3 or 4, wherein the projection or recess extends radially from the collar to a portion of the shoulder, in particular 1 / 2 to 4 / 5 of the radial extension of the shoulder.

6. 6. A lock nut according to claim 3, wherein the width B of the projection or depression relative to the center distance A of the projection or depression facing the collar is equal to B=b*A, where b is in the range of 0.2 to 1.

7. A locking nut according to any one of claims 1 to 6, wherein the projections or recesses are radially aligned and / or evenly distributed around the shoulder.

8. 8. The lock nut of claim 7, wherein at least twelve projections or recesses are provided.

9. 3. A lock nut as claimed in claim 1 or 2, wherein the protrusion or depression is formed or moulded on a surface of the annular washer facing the nut body.

10. 10. A locking nut according to any one of claims 1 to 9, wherein the projection is formed with the convex curvature of a circular or elliptical dome or a lying semi-cylinder, or has the shape of an angled projection, a lying triangular prism or a tetrahedron, or approximately has said shape.

11. A locking nut according to any one of the preceding claims, wherein the width of the projection or recess and / or the height of the projection or the depth of the recess decreases radially inwards.

12. A lock nut comprising a nut body (12) including a threaded portion having an internal thread (16), a peripheral shoulder (20) adjacent the threaded portion, and a collar surrounding the shoulder, and a metal annular washer (22, 22'), the collar is bent inwardly such that an annular groove (28) is formed between the bent collar and the shoulder, and the annular washer is received in the annular groove; an inner peripheral edge of the annular washer (22) is formed with an internal thread (16') corresponding to the internal thread (16) of the threaded portion, and the internal thread (16') of the annular washer (22) is axially offset by a certain distance with respect to the internal thread (16) of the nut body (12); a series of projections (60') and recesses (60") are formed in said shoulder where said annular washer and said shoulder overlap, said projections or recesses being axially protruding or recessed and distributed about said shoulder; The recess defines a rib-like structure.

13. A lock nut comprising a nut body (12) including a threaded portion having an internal thread (16), a peripheral shoulder (20) adjacent the threaded portion, and a collar surrounding the shoulder, and a metal annular washer (22, 22'), the collar is bent inwardly such that an annular groove (28) is formed between the bent collar and the shoulder, and the annular washer is received in the annular groove; an inner peripheral edge of the annular washer (22) is formed with an internal thread (16') corresponding to the internal thread (16) of the threaded portion, and the internal thread (16') of the annular washer (22) is axially offset by a certain distance with respect to the internal thread (16) of the nut body (12); a series of projections (60') and recesses (60") are formed in said shoulder where said annular washer and said shoulder overlap, said projections or recesses being axially protruding or recessed and distributed about said shoulder; A locking nut, comprising: a single or multi-part circumferentially extending rib formed on the shoulder of the nut body; and an annular groove configured to receive the annular washer and form recesses in the rib, the recesses reshaping the rib into a plurality of protrusions aligned in the circumferential direction.

14. 14. The lock nut of claim 13, wherein said circumferential rib is continuous before said annular washer is received in said annular groove and is formed by machining a circumferential groove in said shoulder adjacent said collar.

15. A lock nut comprising a nut body (12) including a threaded portion having an internal thread (16), a peripheral shoulder (20) adjacent the threaded portion, and a collar surrounding the shoulder, and a metal annular washer (22, 22'), the collar is bent inwardly such that an annular groove (28) is formed between the bent collar and the shoulder, and the annular washer is received in the annular groove; an inner peripheral edge of the annular washer (22) is formed with an internal thread (16') corresponding to the internal thread (16) of the threaded portion, and the internal thread (16') of the annular washer (22) is axially offset by a certain distance with respect to the internal thread (16) of the nut body (12); a series of projections (60') and recesses (60") are formed in the annular washer where the annular washer and shoulder overlap, the projections and recesses being axially protruding or recessed and distributed around the circumference of the annular washer; A locking nut wherein circumferentially aligned projections are formed on a surface of the annular washer facing the shoulder of the nut body.

16. 16. The lock nut of claim 15, wherein a single or multi-part circumferentially extending rib is formed on a surface of the annular washer, and receipt of the annular washer in the annular groove forms recesses in the rib, the recesses reshaping the rib into a plurality of protrusions disposed in the circumferential direction.

17. 17. The lock nut of claim 16, wherein the circumferential rib is continuous and formed by a circumferential groove on a surface of the annular washer before the annular washer is received in the annular groove.

18. 18. A lock nut according to any one of claims 1 to 17, wherein the annular washer is retained in the annular groove by pressure engagement and positive fit.

19. 19. A lock nut according to any one of claims 1 to 18, wherein the annular washer (22) has a constant thickness or the thickness of the inner diameter of the annular washer (22) is greater than the thickness of the outer diameter of the annular washer (22).

20. 20. The lock nut according to any one of claims 1 to 19, wherein the internal threads (16') of the annular washer (22) are axially offset from the internal threads (16) of the nut body (12) by a distance of approximately 3 to 30% of the thread pitch.

21. 21. A lock nut according to any one of claims 1 to 20, wherein the thickness of the annular washer (22) at the inner diameter is equal to the thread pitch of the internal thread (16) or is between 1 and 2 times the thread pitch.

22. A lock nut according to any one of claims 1 to 21, wherein the annular washer (22, 22') is convexly curved towards an end face of the lock nut.

23. 23. A lock nut as claimed in any one of claims 1 to 22, wherein one or more cutouts distributed around the periphery of the annular washer (22) are formed in the outer periphery of the annular washer, the cutouts defining one or more extensions of detents (26) around the periphery of the annular washer.

24. 24. A lock nut according to any one of claims 1 to 23, wherein the surface of the annular washer (22) has one or more protrusions distributed around the periphery of the annular washer.

25. 14. A method of manufacturing a lock nut according to claim 13, comprising the steps of: A circumferential rib (60) is formed on the shoulder of the nut body by a circumferential groove adjacent to the collar; the annular washer (22) has one or more cutouts distributed about its periphery, the cutouts defining one or more tabs (26); The annular washer (22) is disposed inside the collar on the shoulder of the as yet unthreaded nut body (12); a first force is applied axially to the collar to bend the collar inwardly to form an annular groove (28) between the collar and the shoulder in which the annular washer is axially clamped, the application of the first force causes the pawls (26) to deform the circumferential rib (60) a first distance; Then, the nut body (12) and the annular washer (22) are formed with internal threads (16, 16') in a single operation. A second force is then applied axially to the collar and the annular groove (28) in which the annular washer is clamped to axially displace the annular washer, causing the circumferential rib to deform a second distance and the pawls (26) to seat in recesses (60") formed in the circumferential rib, which reshape the circumferential rib (60) into a plurality of protrusions (60').

26. 26. The method of claim 25, wherein the annular washer (22, 22') is manufactured with a pre-convex curvature and is placed on the shoulder of the nut body (12) such that the annular washer (22, 22') is convex toward an end face of the lock nut, and the convex curvature of the annular washer is maintained or substantially maintained upon deformation.

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