Methods, nuts, screw connections and bolts for reusable, positive-locking screw connection locking

Abstract

A threaded bolt (2), nuts (1), a screw connection, and a method for positively securing a nut (1) on a threaded bolt (2) are proposed. The method comprises the following steps: introducing a first part of a bolt (3), the second part of which engages in a first cavity (4) in the nut (1), into a second cavity (5) in the threaded bolt (2) that is open at the end, and fixing the bolt (3) to the nut (1) by means of a fixing means.

Description

The present invention relates to a method, nuts, a threaded connection and bolts. In particular, the present invention relates to easily usable, reusable, positive-locking screw connection securing means.In order to prevent an undesired loosening of a screw connection, different methods are known in the prior art. For example, self-locking nuts are used which have a polymer ring in the threaded region. The polymer ring cuts into the bolt and thus increases the frictional forces as the nut rotates on the bolt. On the one hand, such a self-locking nut is not temperature-stable as desired, and on the other hand, an increase in the relative frictional engagement is not a guarantee for preventing an undesired loosening of the screw connection. Moreover, self-locking nuts are disposable products, since the locking effect decreases with each reuse.Furthermore, crown nuts are known which have grooves open at the end face. A channel in a threaded bolt oriented transversely to the screw axis can now be penetrated by a wire or a similar structure and prevent the workpiece-side nut from being released from the threaded bolt. However, inserting a bolt into the bore in the threaded bolt requires manual skill and is time-consuming. In particular, it is difficult to automate such a screw securing means and to monitor it automatically.Proceeding from the aforementioned prior art, it is an object of the present invention to provide a screw connection securing means which is positive-locking and reusable. In particular, UV- and temperature-stable screw connection securing means are to be made possible.The aforementioned object is achieved according to the invention by a method having the features according to claim 1, a screw connection having the features according to claim 2, a nut having the features according to claim 8, a nut having the features according to claim 10 and a threaded bolt having the features according to claim 11. The dependent claims show preferred developments of the invention.The present invention is based on the core idea that a slot in the threaded bolt which is open at the end face makes possible a much simpler, possibly even automatable, but in any case more economical securing of a nut on the threaded bolt. According to the method according to the invention for positively securing a nut on a threaded bolt, therefore, in a first step, at least a part of a bolt is introduced into a cavity in the threaded bolt which is open at the end face. A second part of the bolt is arranged in a cavity in the nut or engages in this cavity. The bolt has the task of causing a spatial fixing of the threaded bolt or the nut in such a way that it engages both in the cavity in the threaded bolt and in the cavity in the nut. In other words, a rotation of the nut relative to the threaded bolt is now no longer possible due to the presence of the bolt. The latch can be understood as a mechanical solid-state structure. In particular, the latch has a metallic structure or is produced from a metallic structure. The latch can be configured, for example, as a wire, pin, bolt, sheet metal or the like or can have the aforementioned structures. The bolt can elastically, in particular spring-elastically, strut into the cavity in the bolt and / or even into a predefined, space-gripping shape. In order to prevent the bolt from being released from the cavity in the nut and / or the cavity of the threaded bolt in an undesired manner, the bolt is fastened to the nut by means of a fixing means. The fixing means thus ensures the permanent positioning of the bolt while the bolt is in engagement with the cavity in the nut and the cavity in the threaded bolt. For this purpose, the fixing means can engage the nut and / or engage in the nut and / or be provided by a structure of the nut itself. For example, the fixing means can engage in a cavity in the nut and / or engage behind or undercut a undercutting structure of the screw connection (in particular on the workpiece side). This engagement / engagement can take place in particular elastically, so that a predefined force is required in order to release the engagement / engagement. The fixing means can be a component of the bolt or can engage directly on the bolt. In particular, the two parts of the latch can be arranged between components of the fixing means. Most preferably, both parts of the latch can be arranged jointly and directly adjacent to one another and can be arranged jointly between two components or sections of the fixing means. The fixing means can have a different orientation and / or a different shape and / or shape than the bolt or the two parts of the bolt. The two parts of the bolt can have in particular a common, in particular identical, linear alignment / orientation. In this way, the cavities are aligned with one another at least in a relative rotational position of the nut on the threaded bolt in such a way that the bolt can engage simultaneously in the cavity in the nut and in the cavity in the threaded bolt. In this way, the bolt can be introduced in the direction of the screw axis and used to secure the screw connection.The cavity in the nut can be open at the end face. In other words, in particular the end face of the nut facing away from the workpiece is provided with the cavity. The end face of the nut does not have to coincide with the beginning of a thread or a chamfer thereof, but can protrude several millimeters or even centimeters with respect to the thread, as is the case, for example, with a crown nut. The same applies to the end face of the threaded bolt which has the cavity. The cavity in the nut is also referred to as "first cavity" within the scope of the present disclosure, while the cavity in the screw bolt is also referred to as "second cavity". The cavity in the threaded bolt and / or the nut can be designed as a slot or groove or trench or groove. It can have a longitudinal extension direction which extends substantially in the radial direction with respect to the screw axis of the screw connection. In this case, the shape of the slot can intersect the screw axis. This has the advantage that correspondence of the two cavities is re-established after 180-degree rotation between nut and threaded bolt if the cavities pass or pass through the respective end sides in a substantially symmetrical manner (completely).All properties of the cavity of the threaded bolt can apply in a corresponding manner to the cavity / the slot in the nut.The strength of the nut is less weakened if the cavity is provided only on one side in the end face.The cavities can have a substantially rectangular, in particular prismatic, cross section. A trapezoidal cross section with a undercut has the advantage here that a bolt in the cavity always braces in the direction of the groove base when the nut is rotated with respect to the threaded bolt. The fixing means therefore has to exert particularly low forces. In particular, when the nut is rotated with respect to the threaded bolt on account of an undercut in the form of one of the two cavities, the bolt is secured, so to speak, automatically in the screw connection (or the cavities thereof).Particularly preferably, the bolt is dimensioned with respect to the cavities in such a way that it or its cross section can be accommodated completely in the cavity in the nut and / or in the cavity in the threaded bolt. In other words, the latch does not protrude at least at the end face out of the cavities after it has been positioned as intended for securing the screw connection.According to a second aspect of the present invention, a screw connection with a positive locking is proposed, which has a nut, a threaded bolt, a bolt and a fixing means. The nut has a first cavity, while the threaded bolt has a second cavity open at the end face. In the case of the screw connection secured in a positive-locking manner, the bolt is in engagement both with the first cavity and with the second cavity open at the end face and is fixed in this position by means of the fixing means. The fixing means is in particular configured to fix the bolt to the nut. For this purpose, the fixing means can engage around / undercut a structure of the nut in a frictional and / or positive-locking manner or be arranged in a cavity of the nut. The two cavities are fixed relative to one another by the latch in such a way that their volumes merge into one another behind the end face or opening cross sections correspond at least partially to one another. The fixing means can be designed, for example, in the manner of a protective cap, which are known for covering nuts. These may be made of plastic and either have a rotationally symmetrical outer shape or have a hexagonal structure in order to be able to transmit torques to the nut to a certain extent. The protective cap or protective nut can be penetrated by the bolt in a substantially radial direction or in a direction otherwise corresponding to the cavities and can be placed on the nut corresponding to the cavities at least in a rotational position. In summary, it can be stated that the screw connection with positive locking can be produced by a method according to the first aspect of the invention, so that the features, combinations of features and advantages mentioned there result in a corresponding manner.Preferably, the cross sections of the bolt and of the cavity in the nut and / or of the cavity in the threaded bolt can be matched to one another. For example, an undercut cross-sectional shape can advantageously be provided independently of one another both for the cavities and for the latch. In particular, the cavity narrows in the direction of the end face of the nut and of the threaded bolt. The cavity in the threaded bolt and / or in the nut can be dimensioned at least as deep as long. In particular, it may be twice or three times as deep as long. Alternatively or additionally, the respective cavity can be dimensioned as deep as wide, in particular twice as deep as wide, preferably three times as deep as wide. For example, the cavity can have a depth of at least one. 1 mm, preferably of mind. 2 mm, most preferably 3 mm, while the width of the cavity is likewise dimensioned in the range from 1 mm to 3 mm, preferably 1.5 mm to 2.5 mm. The length of the cavity depends in particular on how the radial extent of the threaded bolt or of the nut is dimensioned. This usually depends on the diameter of the (preferred metric) screw connection.The cavities can be taken into account in a casting mold or can be produced by machining production methods. Other production methods (laser cutting, plasma cutting or the like) are also possible.The fixing means can have a clamp for (in particular elastic) undercutting a structure of the nut. For example, it can be a metal bracket or a spring steel, which is fastened to the latch. The structure of the nut can be, for example, the front rounding, which is usually provided in the case of nuts. These rounded portions lead the end face into the flanks of the outer hexagonal shape. An even larger undercut is known in self-locking nuts, the polymer ring of which is inserted into a rotationally symmetrical structure which is tapered with respect to the external hexagonal shape. The undercut can, however, also be formed by a washer which is provided on the workpiece side on the nut, but which has a smaller diameter than the hexagonal outer shape of the nut. In this way, a circumferential groove is formed between the workpiece and the nut, in which the fixing means can engage. The fixing means can also have a plastic ring which encloses, for example, the hexagonal outer shape and / or a undercutting structure of the nut. This plastic ring can be designed as a collar or jacket, as is known from plastic protective caps for nuts. The interior of the ring can have the bolt, which engages in the cavities of the screw connection when the plastic ring is applied. A structure protruding beyond the nut in the radial direction can be provided from the plastic ring or other fixing means, by means of which structure the bolt or the fixing means can be engaged behind, so that a predefined force required in the direction of the end face of the nut (direction facing away from the workpiece) can be applied for releasing the bolt from the cavities. For example, the user can use a tool pushed between the workpiece and the structure protruding in the radial direction in order to lever and / or lift the bolt and / or the fixing means from the screw connection.An example of such a structure is a wire pin which penetrates the fixing means in the radial direction, represents the latch in a central region and represents the radial structure for handling the fixing means or the latch in one or both distal regions. The structure protrudes, so to speak, in the radial direction and enables the attachment of a tool and / or a lever.A particularly compact configuration of a screw connection according to the invention results if the bolt protrudes from the cavity in the nut in the radial direction and forms a respective retaining structure at its distal ends. The holding structure can be designed as hooks, latching noses or the like. In the nut, cavities can be provided on the outer surface (hexagonal structure) as predefined retaining cavities, into which the retaining structure is configured to engage. The latch (in particular together with retaining structures) can be designed as a predefined space-gripping 2D or 3D structure, in particular prefabricated. The retaining structure may also engage around the entire nut and / or (as described above) at least the hex outer surface of the nut to secure the latch in place. In particular, for this purpose, the holding structure has a region running in the screw axis direction, on the distal end of which a undercutting structure oriented in the direction of smaller radii is arranged. In particular in the case of an elastic retaining structure, the undercutting structure can hereby engage in the predefined retaining cavity of the nut or engage around the nut (partially or completely).The fixing means and / or the bolt can have a shaped structure and / or a space-gripping structure and / or a spring steel. They can be configured integrally (inextricable, in particular in one piece or in multiple pieces). Both can be components of a prefabricated assembly and / or can be brought into their intended position (inserted into one another) at different times in order to secure a screw connection according to the invention. Depending on the application, a holding force suitable for the specific requirements for securing the screw connection can be provided by the design of the fixing means and / or the nut and / or the bolt.The cavity in the nut and / or the cavity in the screw bolt can have an identical cross section that remains the same over their respective entire length. Such a structure can be provided in particular by machining or by consideration in the casting tool. A forged configuration of the cavities can also be provided in order to enable a particularly cost-effective provision of a screw connection according to the invention. In particular in the radial direction, the cavity in the nut and / or in the threaded bolt can have a substantially linear shape. The cavities can intersect the screw axis in order to be enclosed on both sides by as much material as possible and on the other hand to have free cross sections corresponding to one another at as many relative screw positions as possible. A cross section (undercut) decreasing in the direction of the end face can be achieved, for example, by a relative tilting or two relative tilting of the tool with respect to the threaded bolt / nut during a machining step.According to a third aspect of the present invention, a nut for producing a screw connection with a positive locking in connection with a threaded bolt is proposed, wherein the threaded bolt has a cavity open at the end face. The cavity open on the end face can be configured as a slot, the longitudinal extent of which extends parallel to the screw axis through a threaded region or in a substantially axial direction transversely to the screw axis. The nut has a cavity which, in particular in the manner of a crown nut, has grooves, grooves, grooves, trenches or the like, which are oriented substantially in the radial direction, in an end face. If the threaded bolt to be used with the nut according to the invention has a cavity running parallel to the screw axis, the nut must have a cavity which cooperates (corresponds) with the cavity in the intended screw position. For example, this means that a cavity extends through a section of the thread parallel to the main screw axis. The nut can furthermore have a holding cavity, in particular two holding cavities in a (respective) side surface (lateral surface or hexagonal outer surface), in which holding structures for fixing a bolt can engage. For example, one of the six otherwise planar surfaces can have a bore and / or an elongated slot as retaining cavities, in which retaining structures for fixing the bolt can engage. The retaining cavities can have an increasing depth in the direction of the workpiece. The depth may increase continuously or stepwise. In this way, the latch likewise braces in the direction of the groove base / the base of the cavity or is prevented from bracing in a direction facing away from the workpiece after introduction. In particular, a side surface of the nut can have a blind hole slot which extends from an end face facing away from the workpiece as far as the retaining cavity, which has a greater depth than the blind hole slot. After positioning the nut, a user can now insert a clamp into the blind hole slot and, until the retaining structures thereof engage in the retaining cavities, push the bolt into the cavity open on the end face in the threaded bolt (optionally also into a cavity open on the end face corresponding thereto in the nut).In order to keep the screw position of the nut or of the threaded bolt flexible, the nut can have a plurality, in particular a plurality, of cavities at different positions of an end face in the circumferential direction. In particular, in the region of each partial surface of the hexagonal structure, a cavity can be provided on the end face and / or on the jacket side (in the second case configured as a retaining cavity and / or blind hole slot). A single cavity open at the end in the form of a slot in the threaded bolt can now be used after a rotation of 60 degrees in each case with one of the cavities in the nut in order to secure the screw connection according to the invention. An example of a nut according to the invention can be based on a crown nut which is configured in a manner according to the invention by retaining cavities on the lateral surface side to fix a bolt in a cavity of a threaded bolt which is open on the end face.According to a fourth aspect of the present invention, a nut is proposed which comprises a bolt, a guide and restoring means. The guide can be designed as a slot which simultaneously secures the bolt as a cavity against rotation about the screw axis. This nut offers a particularly comfortable and compact possibility for producing a screw connection according to the invention, since it can be used directly and easily with a threaded bolt which has a front-side cavity. The bolt is arranged in a volume of the nut and preferably protrudes at least partially through that free volume within the nut which is surrounded by the thread of the nut. In the case of a cap nut, the bolt is located at least in its intended end position in the securing position within the free volume of the cap nut. The guide guides the bolt movably guided in the nut. In particular, the latch is movably guided in a direction of a screw axis. The bolt can thus, with the nut held in place, strut in the direction of the screw bolt or be removed from the screw bolt. The restoring means is configured to let the bolt strut in the direction of the threaded bolt. Pressed differently, the restoring means biases the bolt in the direction of that opening of the nut at which the threaded bolt is placed on the nut. In an assembly state (initial state), a splint or spacer may prevent the latch from bracing towards the opening. For this purpose, the splint or spacer can be arranged within the guide between the bolt and the opening / the region of the nut that is not slotted by the guide and can be arranged to absorb the forces of the restoring means. Alternatively or additionally, the bolt can be tilted about an axis oriented transversely to the screw axis in order to release a positive connection of its distal ends and / or of another structure with the guide and / or the nut. For example, in a secured position, the distal ends of the bolt can engage behind a structure of the nut, in particular in the hat region, or lie on the hat of the nut, so that they counteract the restoring force of the restoring means. If the bolt or the distal structures are tilted in such a way that they can likewise enter the guide, the bolt can be lowered in the direction of the screw bolt.The restoring means can be a constituent part of the fixing means according to the above explanations and above exemplary embodiments. The guide can also be understood as a component of the fixing means. The bolt can be fixed in the nut according to the invention in such a way that it cannot be removed from the nut in the radial direction without overcoming a frictional and / or positive fit. For example, the bolt can have a cavity facing the restoring means or a notch, in which the restoring means engages (within the nut). During the prestress of the bolt, the restoring means (or an element provided between the bolt and the restoring means, for example a disk, preferably made of a metal sheet, that is to say similar to a washer) now brings about a positive fit of the bolt within the nut. In other words, the restoring means must be compressed with the bolt held in place until the form fit with the bolt is released, after which the bolt can be removed from the nut in the radial direction. The guide can therefore be designed, for example, as a central through slot in the cap region of a cap nut. In this case, the cap nut is divided into two only in part and remains completely intact in the opening region facing the threaded bolt. A restoring means is now introduced into the cap nut, which can be designed as a spring means or spring spring. The restoring means is now compressed with a tool in such a way that the bolt can be inserted into the guide or the slot in the radial direction. The bolt can hereby completely project through the free cross section inside the nut. It now comes to lie between the intact opening region, on the one hand, the flanks of the slot as guide means, on the other hand, and to a good extent between the compressed spring means. When the spring means is now expanded, it clamps the latch between the intact edge and the flanks of the guide. The bolt now tends towards the opening of the nut from which the threaded bolt is screwed. After a plurality of revolutions, the bolt tends, due to the contact with the end face of the threaded bolt, in the direction of the restoring means, which is compressed by the screwing process. If the threaded bolt (as described above) has a cavity open at the end face, to which the bolt corresponds, the bolt automatically latches into the cavity. The screw connection can be further closed if the bolt is initially fixed (by muscle force or by a temporary splint or by a undercut in the guide or outside the nut or the like) in a region facing the hat of the hat nut, whereby the restoring means is also compressed more strongly than in a target position. If the restoring means is now relaxed or the splint is removed, the bolt braces by the restoring means in the direction of the end face of the threaded bolt and, in the case of a predefined relative rotational position between nut and threaded bolt, will automatically latch into the cavity of the threaded bolt which is open at the end face. Additional handling of the fixing means according to the above embodiments is not required. In order to further simplify the handling of the bolt or the nut, the bolt can protrude from the nut in the radial direction. These protruding structures can be used for compressing the restoring means or for handling the bolt, for example, if the screw connection secured according to the invention is to be released. The term "cap nut" is used broadly within the scope of the present disclosure and does not have to meet a predefined standard. The hat or the one-sided cover can provide more or less space for a thread, a threaded bolt and / or a guide and / or a bolt / reset means compared to standardized hat nuts. The guide can in particular completely divide the cap region, while at least a plurality of threads in the region of the opening of the cap nut are embodied intact in accordance with a normal nut. In order to enable a particularly long stroke of the bolt, the hat can be replaced or extended by a cavity in the manner of a tube or a lattice frame. In this way, a long spring or other return means can be used.This screw connection can be further advantageously improved by a threaded bolt which has a cavity open at the end face for receiving a bolt. However, the cavity does not have flanks steep on all sides, but rather has at least one ramp which has a slope in the closing rotational direction of less than 80 degrees, in particular less than 70 degrees, preferably less than 60 degrees, with respect to a circular cross-sectional surface of the threaded bolt. This ramp is configured in this way to automatically lift the prestressed bolt of the nut when the screw connection is closed and in the process to compress the restoring means of the nut. When the screw connection is closed, the bolt is thus not positively fixed in the cavity open at the end, but rather can automatically leave the cavity and is raised up to the end face of the threaded bolt until it engages again in the cavity open at the end. Conversely, such a ramp is not provided in the opening rotation direction. Rather, the cavity open at the end has a flank slope which does not allow automatic lifting of the bolt in the direction of the end face of the threaded bolt. In other words, the flank slope is dimensioned such that the latch collides with the flank in the opening rotational direction and prevents a further opening of the screw connection. The pitch of the flank or flanks in the opening rotation direction is therefore, for example, at least 80 degrees, in particular 90 degrees or greater compared to a circular cross-sectional surface of the threaded bolt. By means of such a threaded bolt, a screw connection secured in a positively locking manner can be easily tightened, for example with a simple wrench, if the screwed elements have, for example, decayed over time.In the context of the present disclosure, a "slot" is understood to mean a cavity which is at least twice as long, preferably three times as long as wide. In particular, the cavity is twice, preferably three times as deep as wide.All elements of the present invention may be made of or coated with metal, especially stainless steel.Brief Description of the FiguresFurther details, advantages and features of the present invention are evident from the following description of exemplary embodiments with reference to the drawing. The following are shown: FIG. 1 shows a perspective basic illustration of a screw connection according to the invention (fixing means according to the invention not illustrated); FIG. 2 shows a perspective illustration of a second exemplary embodiment of a screw connection according to the invention, comprising an exemplary embodiment of a nut according to the invention; FIG. 3 shows a perspective illustration of a third exemplary embodiment of a screw connection according to the invention with an exemplary embodiment of a nut according to the invention; FIG. 4 shows a perspective illustration of a further exemplary embodiment of a nut according to the invention; FIG. 5 shows a perspective exploded view of an exemplary embodiment of a screw connection according to the invention with a protective cap made of plastic; FIG. 6 shows a perspective illustration of an exemplary embodiment of a screw connection according to the invention with an axially parallel slot as cavity; FIG. 7 shows a perspective illustration of an exemplary embodiment of a nut which can be used according to the invention and has a cavity which has a undercutting cross-sectional shape; FIG. 8 shows a perspective illustration of an exemplary embodiment of a screw bolt which can be used according to the invention and has a cavity which is open at the end side and has a undercutting cross-sectional shape; FIG. 9 is a perspective view of a spring plate latch according to the invention; FIG. 10 is a perspective view of a screw connection according to the invention, which is secured by the spring plate shown in FIG. 9 ; FIG. 11 is a partially cut side view of an embodiment of a nut according to the invention with elastic restoring means for a bolt; FIG. 12 shows a perspective basic illustration of an exemplary embodiment of a threaded bolt according to the invention with end-face ramps; and FIG. 13 shows a flow chart illustrating steps of an exemplary embodiment of a method according to the invention for positively securing a nut on a threaded bolt.Embodiments of the InventionFIG. 1 shows a perspective view of a screw connection in which a nut 1 is secured on a threaded bolt 2 by a linear, approximately radially oriented bolt 3. The bolt 3 engages in a first cavity 4 provided on one side in the nut 1 and in a second cavity 5 provided on one side in the threaded bolt 2. The bolt 3 shown in dashed lines is thus located partially behind an end face 7 of the nut 1 and partially behind an end face 8 of the threaded bolt 2. The latch 3 is not fixed in the position shown. According to the invention, the bolt 3 would have to be inserted, for example, into a protective cap 12 (see also FIG. 5 in this respect) which is plugged onto the nut 1.FIG. 2 shows an alternative exemplary embodiment of a screw connection according to the invention with positive locking, in which both the screw bolt 2 and the nut 1 have cavities 4, 5 which are oriented longitudinally in the radial direction and which correspond to one another in the position shown in such a way that they form a through slot. The likewise linear bolt 3 is arranged therein and thus prevents a rotation of the nut 1 with respect to the threaded bolt 2. the bolt 3 is fixed via a fixing means 6 in retaining cavities 10 of the nut 1, which as groove portions connect the six side surfaces of the nut 1 to one another. The structure of the latch 3 and of the fixing means 6 can be designed as an elastic round wire or spring steel (see FIG. 9 ).FIG. 3 shows an alternative embodiment of a nut 1 according to the invention, which has a blind bore as a retaining cavity 10 in the side face 13 corresponding to the cavity 4. For this purpose, the bolt 3 has a retaining structure at its ends 3 a, which points in each case in the radial direction with respect to the threaded bolt 2. The cross sections of the latch 3 and its ends 3a are identical, so that a wire structure can be bent to the 2D-shaped elastic clip shown.FIG. 4 shows a modification of the nut 1 shown in FIG. 3 in that the retaining cavity 10 is arranged in the side surface 13 of the nut 1 at a distal end of a guide structure 14 in the manner of a blind hole slot structure, which extends as far as the end face 7 of the nut 1. A user can insert the bolt 3 or its ends 3 ainto the blind hole slot structure with reduced force exertion and insert the holding structure of the ends 3 ainto the holding cavities 10 in order to arrange the bolt 3 in the front-side cavity 4. As a result of the guide structure 14, the introduction of the latch 3 not only becomes simpler, but the ends 3 acan even disappear in an envelope of the side surfaces 13.In this way, a wrench or nut can also be used to screw the illustrated nut 1. Moreover, FIG. 4 shows a undercutting structure 11 in the form of roundings of the end face 7. This undercut structure 11 can be used, for example, to fix the latch 3 shown in FIG. 9 via two clamps 6 a, 6 bof the fixing means 6.FIG. 5 shows a perspective illustration of a screw connection according to the invention for fixing a workpiece 29, the nut 1 being screwed onto a threaded bolt 2 provided with a slot at the end face, the cavities 4, 5 corresponding to one another. A protective cap 12 made of plastic is provided as a fixing means for fixing a bolt as a latch 3 in the cavities 4, 5. The ends 3 aof the bolt protrude laterally from the protective cap 12 and thereby enable, on the one hand, an optical orientation with respect to the position of the bolt 3 and, on the other hand, a rear engagement for releasing the protective cap 12 from the nut 1. However, it can also be supplemented by undercutting structures (not shown), which engage around undercutting structures 11 of nut 1 (shown in FIG. 4 ) and thus ensure a positive fit. It is also possible to see that a single end 3 acan protrude from the protective cap 12 in order to save material and to reduce the dimensions of the screw connection.FIG. 6 shows an arrangement modified from FIG. 5 to the effect that the cavities 4, 5 are provided as axially parallel slots in the threaded region of the nut 1 on the one hand and of the bolt 2 on the other hand. The latch 3 is therefore likewise arranged axially parallel and is let into a protective cap 12 made of plastic at its end 3 a. In this way, the bolt prevents a rotation of the nut 1 with respect to the threaded bolt 2, and the bolt 3 is arranged in a bore 18 in the protective cap 12 and can optionally be longitudinally guided in the bore 18. In this way, for example, the protective cap 12 can first be placed on the nut 1 and then the end 3 aof the bolt 3 can be driven through the bore 18 into the cavities 4, 5.FIG. 7 shows a perspective illustration of a nut 1 which can be used according to the invention and which has a slot which is open on the end face as cavity 4. The base 15 of the slot has a width that is increased compared to its width in the end face region, so that a undercutting structure results. The inclined flanks of the cavity 4 thus lead to the locking bolt tending towards the base 15 when the nut 1 is rotated on a threaded bolt 2 which is likewise slotted on the end face, as a result of which accidental release of the positive connection between the locking bolt 3 and the cavity 4 is prevented in a simple manner.FIG. 8 shows a screw bolt 2 which can be used according to the invention and whose thread 17 can engage in the thread 17 of the element shown in FIG. 7. The base 16 of the cavity 5 open at the end also has a greater width than the end region of the cavity 5.FIG. 9 shows a latch 3 made from a spring sheet with fixing means 6, which ends at the end in clamps 6 a, 6 b. By means of the clamps 6 a, 6 b, the fixing means 6 can engage behind a hexagonal nut, a self-locking nut or a nut 1 according to the invention shown in FIG. 2.FIG. 10 shows a perspective view of the bolt 3 shown in FIG. 9 in engagement with a self-locking nut 1. the clamps 6 a, 6 breceive the tapered securing metal region as a undercutting structure 11 of the nut 1. The end 3 aof the latch 3 protrudes out of the plane of the end face 13, whereby the securing means can be easily removed by the latch 3 being lifted upward out of the cavity 4 by means of the end 3 a.FIG. 11 shows a partially cut-away representation of an embodiment of a nut 1 according to the invention with a head-side slot as guide 21, in which a bolt 3, 3' is movably guided in the vertical direction (corresponding to the screw axis), as shown by a double arrow P. A return means 20 in the form of a spring is shown between the cap 19 and the latch 3, 3' (in the compressed configuration reference numeral 20, in the relaxed position reference numeral 20'). The ends 3a of the latch 3, 3' are arranged in a respective cavity 22 of the hat 19 in order to compress the restoring means 20. If the bolt 3, 3' is tilted, the ends 3a lose the form fit with the cavity 22, and the bolt 3, 3' moves downward (in the direction of the opening for the threaded bolt (not shown)). The guide 21 can be provided by a partial slot on both sides or by an upper division of the hat 19. A notch 30 in the latch 3, 3', shown by dashed lines, can cause a positive connection between the restoring means 20 and the latch 3, 3', whereby the latch 3, 3' can no longer be removed from the slot or the guide 21 in the horizontal direction, even if its ends 3a were linear with the latch 3, 3'. The function of the elastically mounted latch 3 is explained by way of example in connection with FIG. 12.FIG. 12 shows a threaded bolt 2 which has a slot as cavity 5 on the end face. The slot extends as a through slot and crosses the screw axis 23. ramps 24 are provided in the opening direction (arrow 25), which raise the bolt 3 shown in FIG. 11 in the direction of the end face 8 when the nut 1 is rotated in the clockwise direction. The screw connection can be easily closed in this way. However, when the nut is rotated in the opening rotation direction (arrow 28), the latch 3 collides with the substantially vertical flanks 27. in other words, the latch 3 prevents the screw connection from being automatically loosened by colliding with the flanks 27. In order to release the screw connection, the latch 3 must be raised manually at least at the height of the end face 8 in order to release the form fit with the cavity 5. The required angle of the flanks 24 with respect to the indicated circular cross-sectional surface 26 can be determined by tests. It would likewise be possible to provide a plurality of through slots as cavities 5 (for example at 0° and 90°), wherein a ramp 24 would then have to lead out of each cavity 5 in the closing rotational direction 25 and at least one or more steep flanks 27 would have to prevent the screw connection from being loosened.FIG. 13 shows steps of an exemplary embodiment of a method according to the invention for positively securing a nut on a threaded bolt. In step 100, a first part of a bolt, of which a second part engages in a first cavity in the nut, is introduced into a second cavity in the threaded bolt, which cavity is open at the end face. In other words, a bolt which blocks a cavity in the nut and a cavity in the threaded bolt into one another is provided and fixed to the nut by means of a fixing means in step 200. The fixing means can also be a guide, a cavity or a slot structure, in particular in the nut. The fixing means can also comprise a recess in the bolt and / or a restoring means for producing a defined position of the bolt relative to the nut.List of reference numbers:1 Nut 2 Threaded bolt 3 Bolt 3 aEnd of the bolt 3' Bolt in lowered position 4 Cavity in the nut 5 Cavity in the threaded bolt 6 Fixing means 6 a, 6 b Klammern of the fixing means 7 End side of the nut 8 End side of the threaded bolt 10 Retaining cavity in the nut 11 Undercut structure 12 Protective cap 13 Side surface of the nut 14 Guide structure 15 Base 16 Base 17 Thread 18 Bore 19 Cap 20 Restoring means 20' Restoring means in expanded configuration 21 Guide 22 Cavity in the cap 23 Screw axis 24 Ramp 25 Closing rotation direction 26 Cross-sectional area perpendicular to the screw axis 27 Flank 28 Opening rotation direction 29 Workpiece 30 Disengagement in the bolt 100, 200 Method steps

Claims

Method for positively securing a nut (1) on a threaded bolt (2), comprising the steps: - introducing (100) a first part of a bolt (3), a second part of which engages in a first cavity (4) in the nut (1), into a second cavity (5) in the threaded bolt (2), which cavity is open at the end face, and - fixing (200) the bolt (3) to the nut (1) by means of a fixing means (6).Screw connection with positive locking comprising - a nut (1), - a threaded bolt (2), - a bolt (3) and - a fixing means (6), wherein the nut (1) has a first cavity (4), the threaded bolt (2) has a second cavity (5) open at the end face, the bolt (3) is in engagement both with the first cavity (4) and with the second cavity (5) open at the end face and is fixed to the nut (1) by means of the fixing means (6).Method according to claim 1 or screw connection according to claim 2, wherein the first cavity (4) and / or the second cavity (5) - penetrates or penetrates an entire end face (7) of the nut (1) or of the threaded bolt (2) or penetrates or penetrates only partially and / or - has or have an undercut cross section, and / or - is or are at least twice, in particular at least three times as deep as wide, and / or - has or have a depth of at least 1 mm, in particular of at least 2 mm, preferably of at least 3 mm, and / or - align with one another at least in a relative position of the nut (1) and of the threaded bolt (2).Method according to one of the preceding claims 1 or 3 or the screw connection according to one of the preceding claims 2 or 3, wherein the fixing means (6) comprises - a clamp for undercutting a structure of the nut (1) and / or - a plastic ring for enclosing the nut (1), into which the bolt (3) is inserted and from which the bolt (3) projects, preferably laterally at least on one side, in particular, and / or - a structure (8) engaging behind the nut (1) or engaging laterally into the nut (1).Method according to any one of the preceding claims 1, 3 or 4 or a screw connection according to any one of the preceding claims 2 to 4, wherein the bolt (3) protrudes laterally from the first cavity (4) and forms at its ends (3a) a respective retaining structure which engages in a predefined retaining cavity (10) of the nut (1) or is configured to engage around a undercutting structure (11) of the nut (1).Method according to one of the preceding claims 1 or 3 to 5 or a screw connection according to one of the preceding claims 2 to 5, - wherein the fixing means (6) and / or the bolt (3) - has a predefined, space-gripping shaped structure and / or a spring steel and / or - are part of a prefabricated assembly and / or - wherein the fixing means (6) comprises a ring and / or a protective cap (12) made of plastic for a nut (1) and in particular has a structure which is configured to engage behind a nut (1) or into a retaining cavity (10) in a side face (13) of the nut (1).Method according to one of the preceding claims 1 or 3 to 6 or a screw connection according to one of the preceding claims 2 to 6, wherein - the first cavity (4) and / or - the second front-side cavity (5) has a cross section identical over the length and / or - has a linear shape and / or - has a decreasing width in the direction of a front surface (7, 8).Nut (1) for producing a screw connection with a positive locking in connection with a threaded bolt (2) which has a second cavity (5) open at the end face, comprising - a first cavity (4) and - a retaining cavity (10), in particular two retaining cavities (10), in a side face (13) or two side faces (13) which are arranged in particular at circumferential positions corresponding to the first cavity (4) and are configured to be engaged by a fixing means (6) which is configured to fix a bolt (3) in the first cavity (4).Method according to one of the preceding claims 1 or 3 to 7 or a screw connection according to one of the preceding claims 2 to 7 or a nut according to claim 8, wherein the nut (1) - has a plurality of first cavities (4) at different positions of an end face (7) which in particular intersect a screw axis (23) and / or - is a crown nut.Nut (1), in particular cap nut, comprising - a bolt (3), - a guide (21), and - a restoring means (20), wherein the bolt (3) - is arranged in a volume of the nut (1) and - is guided movably through the guide (21) in the direction of a screw axis (23), and wherein the restoring means (20) is configured to pretension the bolt (3) in the direction of a threaded bolt (2) onto which the nut (1) is configured to be screwed.Threaded bolt (2) comprising a cavity (5) open at the end face, - which has at least one ramp (24), preferably two ramps (24), which has a pitch in the closing rotation direction (25) of less than 80°, in particular less than 70°, preferably less than 60°, with respect to a circular cross-sectional surface (26) by the threaded bolt (2), and - which has at least one flank (27), preferably two flanks (27), which has a pitch in the opening rotation direction (28) of at least 80°, in particular equal to or greater than 90° with respect to a circular cross-sectional surface (26) by the threaded bolt (2).

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