The present invention refers to a locking device comprising at least two parts, and particular to a nut to be engaged with a bolt in a rapid way with desired clamping force.

Background

Traditional fastening devices can comprise a screw or a bolt with external threads and a nut with internal threads, where the nut is threaded on to the bolt and screwed onwards until a desired attachment is achieved. A screw is mostly used to secure or fasten things or to attach an object to for example a wall, where the screw is attached directly into the material/article. A bolt and a nut is most often used to fasten a stack of parts together, where the bolt is brought through a hole in the article and the nut is thereafter threaded onto the body of the bolt to secure the article between the bolt head and the nut. The bolt and the nut are kept together by a combination of their threads friction, a slight stretch of the bolt and compression of the parts.

The traditionally used screws as well as bolts and nuts have a number of potential problems. For example, if the bolt is long it can take a long time to thread the nut from the bottom of the bolt towards the head of the bolt to fasten the article. It can also be hard to thread the nut onto the bolt if the space where the bolt and nut is to be used is limited. Furthermore, the nut has a tendency to unthread when it is exposed to stress or vibrations or the bolt can break. Temperature differences can possibly also affect the threading.

The problem that it takes a long time to thread a nut onto a long bolt has for example been addressed by WO2014/088600. WO2014/088600 describes a rapid-engaging, positive locking machine screw mechanism comprising a screw, wherein the body of the screw comprises male threads and at least one longitudinal segment devoid of threads. The application further describes a work piece which defines a hole having female threads for receiving the screw and at least one longitudinal segment devoid of threads. The longitudi- nal screw segment devoid of male threads and the longitudinal hole segment devoid of female threads are arranged such that the screw body is longitudinally received in the hole without engagement of the male screw threads with the female work piece threads. The male and female threads engage upon rotation of the screw with respect to the mating threaded work piece. The screw and the work piece are also provided with a locking feature and a mating locking feature, respectively. The locking feature comprises a boss and the mating locking feature comprises a recess to receive the boss. The locking features limit the rotation of the threaded sections to a maximum of one-half of a rotation.

Problems still arising with the screw mechanism according to WO2014/088600 is that it has threads and it requires a boss and a recess to receive the boss. Threads are subjected to loosening over time, which WO2014/088600 has solved by using a boss and a recess. However, the use of the boss and recess is more complicated to manufacture.

Another solution to the problem that it takes a long time to thread a nut onto a long bolt, and also addressing the problem of loosening over time, has been described in

WO/2016/080888. WO/2016/080888describes a fastening device comprising a stem part and a locking part both provided with segments with substantially flat surfaces, making it possible to move the locking part along the axis of the stem part without having to screw any of the parts. To avoid problems with unthreading and loss due to vibration, one of the parts are provided with an axial segment of flanges and the other with axial segments of projections. At least one of the parts is rotatable in relation to the other to bring the flanges and projections in and out of engagement with each other.

Problems still arising with the mechanism according to WO/2016/080888 are that it is not possible to keep turning one of the parts to achieve a required torque and/or clamping effect.

US 1,391,633 also describes a screwing mechanism wherein the two engaging members are provided with threads and axial grooves so that one part can be slid axially along the other part and then screwed. One of the engaging members is provided with a spring controlled bolt and a slot with a recess wherein the bolt fits to limit the relative rotation. This is a complicated solution and requires a lot of different parts to be put together, which in turn gives a higher risk for the nut to break or not function at all times. It will also be harder to remove the nut in narrower spaces.

Another solution to the problem that it takes a long time to thread a nut onto a long bolt is a SN Series Nut, provided by Pentair pic. The SN Series Nut is a three part nut which can be positioned on a threaded rod on any location and save time by not having to screw it along the whole rod. The nut can be opened by twisting the nut half a rotation of an axle.

Problems still arising with the mechanism according to the SN Series Nut is that it is not possible to easy adjust the position of the nut when it has been positioned, since the user would either have to keep screwing until the desired position has been reached or twist and open the nut to move it to another location and then twist to fasten it again.

The present invention solves these problems.

Hence, one aspect of the present invention is a locking device which in one embodiment comprises at least two relative each other turnable parts comprising cylindrical axial ex- tending holes, each part in circumferential direction being provided with at least one internal axial segment comprising at least one thread and at least one internal axial segment having a substantially flat surface, wherein the at least two parts are limited turnable in relation to each other, whereby in a first relative end position for each of the two turnable parts the at least one thread of the first part and the at least one thread of the second part are axially aligned above each other and the segments with substantially flat surfaces are axially aligned above each other and in a second relative end position for each of the two turnable parts the at least one thread of the first part and the at least one thread of the second part together form an all-around thread, and wherein said relative turnable parts comprise cooperating limitation means, limiting the relative turning of the two parts, wherein one of the said at least two relative turnable parts are provided with at least one indentation (6) and the other of the at least two relative turnable parts are provided with at least one shoulder, or both the first part and the second part are provided with at least one indentation and at least one shoulder, whereby said at least one indentation and said at least one shoulder are arranged to engage with each other to connect the two turnable parts to each other.

In a further aspect of the invention, the first part and second part are identical to each other.

Another aspect of the invention is a fastening device comprising at least two connecting parts, one stem part and one locking device, wherein the stem part is in circumferential direction provided with at least one axial segment comprising threads and at least one axial segment with substantially flat surface, wherein the stem part and the locking device are arranged to engage with each other by connecting the locking device onto the stem part along a main longitudinal direction of the stem part from a distal end towards an proximate end.

Described are also the use of a fastening device for assembling of pipe ends and for rapid engaging and locking of a bottle cap to a bottle or a jar.

In the following, the invention will be described in detail, with reference to exemplifying embodiments of the invention and to the enclosed drawings, in which:

Fig. 1A shows a perspective side view of the locking device in a first relative end position for each of the two turnable parts

Fig. IB shows a perspective side view of the locking device in a second relative end position for each of the two turnable parts

Fig. 2A shows a perspective view from below of the locking device in a first relative end position for each of the two turnable parts

Fig. 2B shows a perspective view from below of the locking device in a second relative end position for each of the two turnable parts

Fig. 3A shows a perspective side view of the first part

Fig. 3B shows a perspective view from the top of the first part

Fig. 3C shows a perspective view of the first part

Fig. 3D shows a perspective view of an alternative embodiment of the first part Fig. 4A shows a perspective side view of the second part

Fig. 4B shows a perspective view from the top of the second part

Fig. 4C shows a perspective view of the second part

Fig. 5A shows a perspective view of an alternative an alternative embodiment of the first part

Fig. 5B shows a cross-sectional view of the outside of an alternative an alternative embod iment of the first part

Fig. 5C shows a cross-sectional view of the inside of an alternative an alternative embodiment of the first part

Fig. 6A shows a perspective view of an alternative an alternative embodiment of the second part

Fig. 6B shows a cross-sectional view of the outside of an alternative embodiment of the second part

Fig. 6C shows a cross-sectional view of the inside of an alternative an alternative embodiment of the second part

Fig. 7A shows a perspective view of the fastening device

Fig. 7B shows a perspective view of an alternative embodiment of the fastening device Fig. 8A shows a perspective side view of an alternative embodiment of the locking device in a first relative end position for each of the two turnable parts

Fig. 8B shows a perspective exploded side view of the alternative embodiment of the first and second part

Fig. 9A and 9B shows perspective views of an alternative embodiment of the fastening device

Fig.lOA, 10B and IOC shows a perspective view of alternative designs of an alternative em bodiment of the locking device

For the purpose of this description and claims the main axis is defined as the vertical axis going through the center of the locking device as oriented in Fig. 1A and B. The terms "upwards", "downwards", "vertical" and any derivatives thereof relate to the invention as ori ented in Fig. 1A and B. Furthermore, a substantially flat surface is defined to be either a radially curved surface or a flat surface without any threads, such surfaces can for exampl be seen in Figs. 3C, 4C, 5C, 6C and 7A and B. The threads are curved radially along the axial direction of the stem part and the first and second parts.

Referring to Figs. 1-6 a locking device in accordance with the present invention suitably comprises at least two relative each other turnable parts, a first part 1 and a second part 2. The first part 1 and the second part 2 can be connected to each other, for example with a shoulder 5 on one of said two parts 1,2 that fits into an indentation 6 on the other of said two parts 1,2. When the two parts 1,2 are connected they can engage with each other to connect the turnable parts 1,2 to each other into a screw connecting state, forming a locking device. The locking device can in turn be connected to and engage with a stem part 100 and together form a fastening device, shown in Fig. 7A and B, for the purpose of securing an article (not shown) between the stem part and the locking device, or between the locking device and any other part or device that can be used on the stem part.

Fig. 8A-B shows an alternative embodiment of the locking device, wherein the first part 1 and second part 2 are identical to each other. Fig. 9A-B shows the locking device shown in Fig.8A-B attached on a stem part.

Fig. 1A shows a locking device, in the form of a nut, comprising two relative each other turnable parts, being a first part 1 and a second part 2, in a first relative end position. In the first end position the first part 1 and the second part 2 is aligned so that an at least one internal thread 3' of the first part 1 and an at least one internal thread 3" of the second part 2 are axially aligned above each other and an internal segment with substantially flat surfaces 4' of the first part and an internal segment with substantially flat surface of the second part 4" are axially aligned above each other. In this end position, the locking device can be connected to and translated along a main axis from a distal end towards a proximate end of a stem part 100, which stem part 100 is also provided with at least one external segment comprising a substantially flat surface 104 and at least one external segment comprising threads 103, until a desired position is achieved. To engage the first part 1 and the second part 2, one of the said first and second parts is rotated a quarter of a rotation of an axis so that the at least one thread 3' on the first part

1 and the at least one thread 3" on the second part 2 together form an all-around thread 3. The locking device can then be rotated until a required torque and/or clamping effect has been achieved.

An advantage of the use of a locking device according to the invention is a rapid locking mechanism with the additional feature that the torque and/or clamping effect can be adjusted by a user.

In fig.lA the first part 1 and the second part 2 have been connected to each other with a shoulder 5 on the first part 1 and an indentation 6 on the second part 2. It is to be noted that the shoulder 5 can also be arranged on the second part 2 and the indentation 6 will in that case be arranged on the first part 1, which can be seen in Figs. 3A-D and 4A-C. It is a further possibility to have a first part 1 with at least one shoulder and at least one indentation, and a second part that also have at least one shoulder and at least one indentation, as shown in Fig. 8A-B. It is further to be noticed that it is possible to achieve the connection between said first part 1 and said second part 2 in other ways, as long as one of said two parts show a higher friction against the stem part 100 than to the other of said two parts. It is also possible to have more than one indentation 6 and more than one shoulder 5.

Fig. 1A further shows limiting means on the first part 7' and on the second part 7" limiting the relative turning of the two parts that ensures that the first part 1 and the second part

2 are not rotated past the second end position.

Fig IB shows the same locking device as in Fig.lA, but in a second relative end position. At least one of said parts 1, 2 has been rotated a quarter of a rotation in relation to the other part, bringing the locking device into a state where the threads inside of the parts together form an all-around thread. As can be seen from Fig. IB the external surface of the locking device preferably has an essentially continuous surface, especially it can have a shape of a hexagonal nut, this has the advantage that any tool adapted to be used with hexagonal surfaces can be used to further rotate the locking device, when connected on a stem part 100, to further adapt the torque and/or clamping effect.

To bring the first part 1 and the second part 2 out of engagement with each other, one of the parts must again be rotated in relation to the other, so that the at least one axial segment of substantially flat surface 4' of the first part 1 corresponds with the at least one axial segment of substantially flat surface 4" on the second part 2. In this first relative end position, as shown in Fig. 1A, it is possible for the parts to be detached from each other.

The shape of the first part 1 and the second part 2, when rotated as shown in Fig. IB, facilitates the use of tightening tools.

Fig. 2A shows the locking device as shown from the above in the position shown in Fig. 1A, where the first part 1 and the second part 2 are connected to each other in a first relative end position. In this first relative end position the threads 3' align with the threads 3" (cannot be seen in Fig. 2A) and the substantially flat surface 4' align with the substantially flat surface 4" (cannot be seen in Fig. 2A), whereby it is possible to connect the locking device onto a stem part 100 and move the locking device along the axis of the stem part, without the need for rotating the locking device.

Fig. 2B shows the locking device as shown from the above in the position shown in Fig. IB, where the first part 1 and the second part 2 are connected to each other in a second relative end position, whereby the threads 3' on the first part 1 and the threads 3" on the second part 2 together form an all-around thread 3.

To accomplish the insertion of a stem part 100 into the locking device, the width of an axial segment of threads is somewhat narrower that the width of an axial segment with substantially flat surface. This will assure that it is possible to move the locking device upwards and downwards on the stem part 100 rapidly without engaging the internal threads on the locking device with the external threads on the stem part.

Fig. 3A shows the first part 1 in a side view, Fig. 3B shows the first part from the top and Fig. 3C shows a perspective view of the first part and Fig. 3D shows a perspective view of a different embodiment of the first part.

The first part 1 is in circumferential direction provided with at least one internal axial seg- ment comprising at least one thread 3'and at least one internal axial segment having a substantially flat surface 4'.

The first part 1 is preferably provided with at least two axial segments with threads 3' and at least two axial segments of substantially flat surfaces 4'. It will however be understood by a person skilled in the art that it could be provided with less or more segments with threads and substantially flat surfaces, respectively. The number of axial segments with threads and substantially flat surfaces, respectively, can be adapted to the size of the stem part 100 or to the intended use of the locking device. The first part 1 can be provided with an indentation 6, adapted to be able to receive and connect with a shoulder 5 on the second part 2. The indentation 6 extends along a part of the surface of the first part 1 and can have a slope, which can be seen in Fig. 3A, to reduce tension between the first and second part when they are rotated into the second end position. It is however also possible to have an indentation 6 without a slope, as shown in Fig. 3D.

The first part 1 can further be provided with at least one stop lug 7'. The stop lug 7' functions as a limitation means to limit the relative turning of the first and second parts when connected to each other. The limitation means has the function of ensuring that the first and second part will not detach, but will move as one unit, a locking part, along the stem.

The axial slots that can be seen in Fig. 3D are described further in relation to Figs. 6A-C.

Fig. 4A shows the second part 2 in a side view, Fig. 4B shows the second part from the top and Fig. 4C shows a perspective view of the second part. The second part 2 is in circumferential direction provided with at least one internal axial segment comprising at least one thread 3" and at least one internal axial segment having a substantially flat surface 4". The second part 2 is preferably provided with at least two axial segments with threads 3" and at least two axial segments of substantially flat surfaces 4". It will however be understood by a person skilled in the art that it could be provided with less or more segments with threads and substantially flat surfaces, respectively. The number of axial segments with threads and substantially flat surfaces, respectively, can be adapted to the size of the stem part 100 or to the intended use of the locking device.

The second part 2 can be provided with a shoulder 5, adapted to be able to fit in and connect with an indentation 6 on the first part 1. The shoulder extends along the internal side of a stop lug 7" of the second part 2, which can be seen in Figs. 3A and 3C. The stop lug 7" has a further function as a limitation means to limit the relative turning of the first and second part when connected to each other.

Fig. 5A shows a perspective view of an alternative embodiment of a first part 11, Fig. 5B shows a cross-sectional view of the outside of a n alternative embodiment of a first part 11, and Fig. 5C shows a cross-sectional view of the inside of an alternative embodiment of a first part 11.

The first part 11 is an alternative embodiment to the first part 1 as shown I Figs. 1-4. The first part 11 is in circumferential direction provided with at least one axial segment comprising at least one thread 3' and at least one axial segment having a substantially flat sur- face 4'. It is further in circumferential direction provided with a shoulder 5, adapted to fit in an indentation on the second part 21. The shoulder extends along a segment of the inside of the first part 11, as shown in Fig. 5A and SC. In the same way as the first part 1, the number of segments with threads and substantially flat surface, respectively, can be adapted for an intended use or to the design of the stem part 100.

The shoulder 5 in the first part 11 can function as a limitation means together with an in- dentation 6 in the second part 21.

The functions and details of the first part 1 and the first part 11 are essentially similar and therefore these details are not further described in relation to the embodiment shown in Fig. 5A-C.

Fig. 6A shows a perspective view of an alternative embodiment of a second part 21, Fig. 6B shows a cross-sectional view of the outside of an alternative embodiment of a second part 21, and Fig. 6C shows a cross-sectional view of the inside of an alternative embodiment of a second part 21. The embodiment shown in Fig. 6A-C also comprises axial slots 28. The axial slots can be varied in appearance and are used to make it easier to press the first 1,11 and second part 2,21 together. The second part 21 is an alternative embodiment to the second part 2 as shown I Figs. 1-4. The second part 21 is in circumferential direction provided with at least one axial segment comprising at least one thread 3' and at least one axial segment having a substantially flat surface 4'. It is further in circumferential direction provided with an indentation 6, adapted to receive and connect with a shoulder 5 on the first part 11. The indentation 6 extends along a segment of the surface of the second part 21 and has a slope, as shown in Fig. 5A and 5C, to reduce tension between the first and second part when they are rotated into the second end position.

In the same way as the second part 2, the number of segments with threads and substantially flat surface, respectively, can be adapted for an intended use or to the design of the stem part 100. The indentation 6 in the second part 21 can function as a limitation means together with a shoulder 6 on the first part 11.

The functions and details of the second part 2 and the second part 21 are essentially similar and therefore these details are not further described in relation to the embodiment shown in Fig. 6A-C.

Fig. 7A shows a fastening device comprising a stem part 100 and a locking device comprising a first part 11 and a second part 21. Fig. 7B shows a fastening device comprising another embodiment of a stem part 100 and a locking device comprising a first part 1 and a second part 2.

The stem part 100 comprises a head and a body extending from the head. The body of the stem part 100 is in circumferential direction provided with at least one axial segment comprising threads 103 and at least one axial segment of substantially flat surface 104.

The segment of substantially flat surface on the stem part 100 can also be helically wound around the axis of the stem part 100.

The stem part 100 is preferably provided with at least two axial segments with threads 103 and at least two axial segments of substantial flat surfaces 104. It will however be understood by a person skilled in the art that it could be provided with less or more segments with threads and substantially flat surfaces, respectively. The number of axial segments with threads and flat surfaces, respectively, can be adapted to the size of the stem part or to the intended use of the fastening device.

The stem part 100 and the locking device 1,2;11,21 are arranged to engage with each other by connecting the locking device onto the stem part 100 along a main longitudinal direction of the stem part 100 from a distal end towards a proximate end. In order to attach the locking device 1,2;11,21 to the stem part 100 the locking device 1,2;11,21 should be positioned so that the at least one substantially flat surface 4',4" align with the at least one axial segment comprising threads 103 on the stem part 100. Upon aligning of the substantially flat surface 4', 4" with the segment comprising threads 103, the locking device can be connected to and translated along the main axis from a distal end towards a proximate end of the stem part 100, until a desired position is achieved. When a desired position is achieved, one of the two parts of the locking device 1,2;11,21 can be rotated so that the threads 3' of the first part 1, 11 and the threads of the second part 2, 21 together form an all-around thread 3 whereby the torque and/or clamping effect can be adjusted by further rotating the locking device 1,2;11,21 until a desired torque and/or clamping effect are achieved.

The locking device can be connected to the stem part 100 in either direction, i.e. either with the first part first or the second part first.

To separate the locking device from the stem part 100, the first part 1, 11 and the second part 2, 21 has to be rotated into a second end position so that the segment having substantially flats surface of the first part 4' align with the surface having substantially flat surface on the second part 4", the locking device thereafter has to be rotated so that the at least one axial segment of threads 103 align with the at least one axial segment of substantially flat surface 4',4" on the locking device.

If needed a tool can be used to rotate the locking device on the stem part 100. Any tool that can be used to hold and rotate either the stem part or the locking device can be used for this purpose, for example a wrench.

It is a further advantage that the locking device according to the present invention is not dependent on an unbroken thread on the stem part 100. During cutting of the threaded rod, it is quite common that the threads are, at least partially, damaged. Since the locking device according to the present invention can be attached to the rod at any distance from any of the ends of the rod and is therefore not dependent on an unbroken thread.

According to an especially preferred embodiment, the first part 1 and the second part 2 are essentially identical but being located turned to each other when on a stem part, as shown in Fig.8A-B. Fig. 8A shows a perspective view of the alternative embodiment where the essential identical parts 1,2 are in a connected state in one end position, i.e. the parts has been connected to each other and at least one of the parts has been rotated around its axis until a locking state is achieved.

In this case where the first part 1 and the second part 2 are identical, both parts are provided with at least one internal axial segment comprising at least one thread 3', 3" and at least one internal axial segment having a substantially flat surface 4',4". Both parts are further provided with at least one indentation 6 and at least one shoulder 5, so that the parts can be easily attached and removed from each other by rotating at least one of the parts, as has been described above for other embodiments. The rotation around the axis is limited by limitation means 7', 7", as shown in Fig. 8B and as has been described above for other embodiments of the present invention.

This embodiment is preferred since only one part needs to be manufactured. It will save costs but it will also make it easier for the user, since there is no possibility to have the wrong part, as the case might be when you have a first part 1 with one design and a second part 2 with another design. Fig. 8B clearly shows a perspective exploded side view of the alternative embodiment of the first and second part, wherein the first part 1 and second part 2 are identical to each other.

All features that has been described earlier in this description are also applicable for the embodiment shown in Fig. 8A-B. The reference numbers used in the description above, Fig.9A and 9B shows the locking device described above and shown in Fig.8A-B attached to a stem part 100 in a connected state.

Fig. lOA-C shows alternative designs for the locking device as described above with reference to the alternative embodiment shown in Fig. 8A-B. It is also possible to have other designs of the outside of the locking part, as the person skilled in the art will understand.

It is also possible to attach the first part 1 and second part 2 to the stem part 100 and at the same time to each other. The locking device is in this split vertically and can be clamped around a stem part. It is hence not necessary to first attach the first part 1 to the second part 2 and then slide the locking device on to the stem part. In some cases, it would be easier and more beneficial to attach the first part 1 and the second part 2 to each other further into the stem part 100.

The locking device can further comprise a marking to show the placement of threads or axial segments of substantially flat surfaces to facilitate correct placement of the locking device in relation to the threads on the stem part during connection of the locking device and the stem part to each other.

The fastening device can further comprise a third part, for example a resilient part (not shown) arranged between the proximate end of the stem part 100 and the locking device.

The resilient part is provided with a hole to connect the resilient part to the stem part 100. The resilient part can be added from the bottom of the body of the stem part 100 and upwards towards the head to the stem part 100. The function of the resilient part is to give a resilient function which will give a tighter fit between the locking device and the article to be fastened through which the locking device is added.

The resilient third part is arranged to apply a spring force against the stem part 100 along the main longitudinal direction of the stem part 100 towards the distal end and against and/or to apply a spring force against the locking device along said main longitudinal direction.

The resilient part can either be a separate part or attached to the stem part 100 or attached to the locking device 1,2;11,21. The resilient third part can for example be a rubber packing, an elastic washer or the like. It could also be for example a cylinder head gasket for an engine. The resilient part is exchangeable/replaceable so that the stiffness can be adapted to the specific use.

Above, an exemplified preferred embodiment has been described. However, it is realized that the invention can be varied without departing from the basic idea of the invention. In the preferred embodiment described above, it has been described that at least one of the parts 1,2;11,21 is rotated a quarter of a rotation to bring the locking device from a first end position to a second end position. It would also be possible to rotate one of the parts 1,2;11,21 three quarter of a rotation to bring the locking device into the same position, given that there are only one limitation means. It is however possible to have other embodiments where the rotation is shorter or longer, depending on the amount of segments comprising threads and substantially flat surfaces, respectively.

The locking device is preferably a nut, wherein it is preferable that at least one of the first and second parts has the shape of a hexagonal nut. It is however possible to have other outer shapes of the nut as well, such as a wing nut, a captive nut, a threaded sleeve or any other type of nut/sleeve which has the ability to engage with the stem part 100, provided that the locking device can be provided with segments comprising threads and segments comprising substantially flat surfaces. The locking device could for example be integrated in a cap, a pipe or any other application. The function of the locking device can be migrated into a welded nut or in any other parts in a manufacturing line.

In this application, the stem part 100 is either shown as a hexagon-headed bolt with threads on only a lower part of the stem part body (Fig. 7A) or as a threaded rod (Fig. 7B, 9A-B). It is also possible to have threads along the entire length of the stem part body of a bolt. It could also be any other type of bolt, screw, rebar or fastening means provided with threads.

The stem part 100 can further be integrated in for example a sheet metal, a pipe, a plastic cap or any other type of material suitable for integration with a bolt or a screw.

In the preferred embodiments described above, the first part 1, is provided with an indentation 6, the second part 2 is provided with a shoulder 5, the first part 11 is provided with a shoulder 5 and the second part 21 is provided with an indentation 6. It is also possible that the first part 1 is provided with a shoulder 5, the second part 21 can be provided with an indentation 6, the first part 11 can be provided with an indentation 6 and the second part 21 can be provided with a shoulder 5. As has been described above, it is also possible to hold the first and second part together using other means.

A further advantage with the locking device according to the invention is that up to 30% of the material can be saved during production compared to a normal screw and bolt.

The term "thread" or "threads" as used in this document are meant to mean any kind of three-dimensional helical structure intended to transform a rotating movement to a linear movement. The threads can for example be metrical threads, English threads, pipe threads, trapezoidal threads or any other type of threads. The type of threads are preferably adapted to the intended use of the locking device 1,2;11,21 and the stem part 100, respectively. It is also possible that the locking device 1,2;11,21 is provided with one type of threads and the stem part 100 is provided with another type of threads.

The pitch, i.e. the threads per axial distance, can have the same or different values for the locking device 1,2;11,21 and the stem part 100. The stem part 100 can for example be provided with threads 103 with a larger pitch (fewer threads per axial distance) and the locking device 1,2;11,21 can be provided with threads 3', 3" with a smaller pitch (more threads per axial distance), or the stem part 100 can be provided with threads 103 having a smaller pitch and the locking device 1,2;11,21 can be provided with threads 3', 3" having a larger pitch.

In a preferred embodiment, the threads 3,3',3" of first part 1 has a pitch that is different from the pitch of the threads 3,3',3" on the second part 2. In another preferred embodiment, the threads on the inside of the first part 1 and the second part 2 have a pitch that differs from the pitch (or slope) for the indentation 6 and shoulder 5, which is used to attach the first part 1 and the second part 2 to each other into a connected state, i.e. a locking device. It has shown to be an advantage when the pitch of the threads differs, since that will give an extra moment of inertia when the locking device is rotated, which in turn will provide more friction and a safer locking (connection) of the first part 1 and second part 2 to each other. This will also have the effect that the locking part is easier to slide on to and on a stem part 100. If both of these embodiments are combined it will provide a locking that is almost entirely as a check-nut (or lock nut), but without the need for a secondary nut. This is for example preferred when reinforcement bars (or rebar) with a large die is used, since a different pitch could result in that the parts fit together badly.

It is further possible to, in the locking device, have a thread that has a pitch on a part of the continuous surface and that changes to an essentially flat appearance, i.e. thread with essentially no pitch, to then change again into a pitch, wherein that pitch can be the same or different from the first pitch. This will give a better locking of the parts to each other.

The first part 1, the second part 2 and the stem part 100 can be made of any type of metal, plastic, rubber or any other type of material suitable for production of screws and nuts, as well as combinations of different materials. The first part 1, the second part 2 and the stem part 100 can be made of the same or different material. It is also possible that for example the first part 1 and the stem part 100 are made of one material and the second part 2 is made of another material, or any other combination of the different parts.

In one application of the present invention, the fastening device is utilized for assembling pipe ends, wherein the stem part 100 is arranged in or on a first pipe and the locking device 1,2;11,21 is arranged in or on a second pipe, wherein the locking device 1,2;11,21 is connected onto the stem part 100 along a main longitudinal direction of the stem part 100 from a distal end towards an proximate end and the locking device 1,2;11,21 is then rotated around the axis of the stem part 100 and thereby engaging the threads 3, 103 and assembling the two pipes together, in the same way as has been described with reference to Figs. 7A and 7B. The pipe containing the locking device 1,2;11,21 will surround the pipe containing the stem part 100 when they are brought into engagement with each other. This way of assembling to ends can also be applied on any other products having two parts that are to be brought together.

In another application of the present invention, the fastening device according to the invention is utilized for rapid engaging and locking of a bottle cap to a bottle, wherein either the locking device 1,2;11,21 or the stem part 100 is formed upon a neck of a bottle or a jar, and the other of the locking device 1,2;11,21 and the stem part 100 is provided within a bottle cap or jar cap and at least one of said locking device 1,2;11,21 and stem part 100 is rotatable in relation to the other to bring the threads 3,103 in and out of engagement with each other.

The embodiment described above can also be applied to for example medicine jars or bottles or other types of jars and bottles with screw cap.

The use of the fastening device according to the invention incorporated into a medicine jar or bottle gives the advantage that it is easier to open for a person with reduced manual power or for persons experiencing problems with un-screwing and screwing caps onto bottles, jars and bottles. It could for example make it easier for elderly persons or persons with rheumatism to open bottles, jars and cans without the need of help from others.

The locking device according to the invention can be widely used in many other applications, especially where long threaded rods are used for example in the field of ventilation, or where little space is available for tightening and fastening of nuts, such as for example manhole covers. It is also useful in different sorts of building and tubing, and in electrical cabinets and service hatches.

Hence the invention is not to be considered limited to the above described embodiments, but may be varied within the scope of the enclosed claims.