The present invention refers to a fastening device comprising at least two parts, and particular to a bolt and a nut arranged to be engaged with each other, in a rapid way by engaging flanges with projections.

Background

Traditional fastening devices 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 upwards 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 takes 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.

One of the major problems with traditionally used fastening means is that both the screw as well as the bolt and nut are subjected to loosening over time. Vibration, stress and dilation will also cause the fastening device to loosen over time. This problem has previously been solved for example by using various locking mechanisms. For example one could use adhesives, safety pins or lockwire, nylon inserts or slightly oval-shaped threads. It is also possible to achieve a better locking if one would use two nuts threaded onto the bolt after each other. The bottom nut would then prevent unthreading of the top nut from the bolt. Longer periods of vibration or stress would however unthread the nuts anyway or the lower nut would break from stress.

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 longitudinal 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 rota- tion.

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. The use of the boss and recess is more complicated to manufacture.

The present invention solves these and other problems.

Hence, one aspect of the present invention is a fastening device which in one embodiment comprises at least two connecting parts, one stem part and one locking part arranged to engage with each other by connecting the locking part onto the stem part along a main longitudinal direction of the stem part from a distal end towards an proximate end along a main axis, wherein the first part, being one of the at least two connecting parts is in circumferential direction provided with at least one axial segment with slightly curved flanges and at least one axial segment with substantially flat surface, and the second part, being the other of said at least two parts, in circumferential direction being provided with at least one axial segment with projections and at least one axial segment with substantially flat surface, and at least one of said two connecting parts is rotatable in relation to the other to bring the slightly curved flange and the projection in and out of engagement with each other.

In another aspect of the invention, the fastening device further comprises a resilient third part arranged to apply a spring force against the stem part along said main axis towards the distal end. The third part can either be attached to the stem part or the locking part or be a separate part.

In a further aspect of the invention, the fastening device comprises a first part being the stem part and the second part being the locking device, wherein the projections are provided on the locking part and a distance from the upper end of the locking part to the projections is different from the distance from the second end of the locking part to the projections.

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. 1 shows a perspective view of the fastening device

Fig. 2A shows a perspective side view of the stem part

Fig. 2B shows perspective front view of the stem part

Fig. 3 shows a perspective view of the flanges Fig. 4 shows a magnified view of a part of the flanges

Fig. 5A shows a perspective view of the locking part as a hexagonal nut

Fig. 5B shows a perspective view of the locking part as a wing nut.

Fig. 6 shows a cross-sectional view of the locking part

For the purpose of this description and claims the main axis is defined as the vertical axis going through the center of the stem part as oriented in Fig. 1. The terms "upwards", "downwards", "vertical" and any derivatives thereof relates to the invention as oriented in Fig. 1. Furthermore, a bolt is defined to be a fastening means comprising a long pin and a head, wherein the pin is connected to a nut, used to fasten things together. Further a flat surface is defined to be a radially curved surface without any projections or flanges. The flanges are curved radially along the axial direction of the stem part or locking part.

Referring to Fig. 1-6 a fastening device in accordance with the present invention suitably comprises at least two connecting parts, a stem part 1 and a locking part 2, arranged to connect and engage with each other into a locked state in which said stem part 1 and locking part 2 together form said fastening device for the purpose of securing an article (not shown) between the stem part and the locking part.

One of the said at least two connecting parts is provided with at least one axial segment with slightly curved flanges 4 and at least one axial segment with substantially flat surfaces 5, and the other of said at least two connecting parts is, in circumferential direction, provided with at least one axial segment with projections 11 and at least one axial segment with substantially flat surface 12, and at least one of said two connecting parts is rotatable in relation to the other to bring the slightly curved flange and the projection in and out of engagement with each other. The term slightly curved is to be interpreted as that the overall impression when the flange is seen from the front is that they appear to be slightly curved upwards in the edges.

Fig. 1 shows a fastening device comprising a stem part 1, in the shape of a bolt and a locking part 2, in the shape of a nut, wherein the bolt comprises flanges 4 and at least one axial segment with substantially flat surface 5. The locking part 2 comprises projections 11 and at least one axial segment with substantially flat surface 12. The flanges 4 on the stem part 1 are arranged to engage and connect to the projections on the locking part 2. Fig. 1 further shows a resilient third part 3 arranged between the proximate end of the stem part 1 and the locking part 2. The resilient third part 3 is defined by having a hole therein to allow the third part 3 to be connected onto the stem part 1 from the distal end towards the proximate end. The flanges 4 on the stem part 1 form a locking feature together with the projections (11) on the locking part, by connecting the stem part 1 and the locking part 2 and rotating at least one of the two connecting parts so that the projections 11 and the flanges 4 engage with each other. It is to be noted that the flanges 4 can also be arranged on the stem part 1 and the projections 11 will in that case be arranged on the locking part 2.

In order to attach the locking part 2 to the stem part 1 the locking part 2 has to be positioned so that the at least one substantially flat surface 12 align with the at least one axial segment comprising flanges on the stem part 1. Upon aligning of the substantially flat surface 12 with the segment comprising flanges 4, the locking part 2 can be connected to and translated along the main axis from a distal end towards a proximate end of the stem part 1, until a desired position is achieved. To engage the stem part 1 and the locking part 2, at least one of the said connecting parts is rotated a quarter of a rotation of an axis so that the flanges 4 on the stem part 1 align with the projections 11 on the locking part 2. The projections 11 will be lead upwards, towards the proximate end of the stem part 1, and over one of the upwards projecting edges 6 on the flanges 4 to a countersunk section 7.

An advantage of the use of the fastening device according to the invention is a rapid and tight locking mechanism without the need to follow-up draft of the locking part.

To separate the locking part 2 from the stem part 1, the second part 2 must again be rotated so that the at least one axial segment of projections 11 align with the at least one axial segment of substantially flat surface 5 on the stem part 1. The resilient part 3 is provided with a hole to connect the resilient pa rt 3 to the stem part 1. The resilient part can be added from the bottom of the body of the stem part 1 and upwards towards the head to the stem part 1. The function of the stem part 1 is to give a resilient function which will give a tighter fit between the locking part and the article to be fastened through which the locking part is added When the projections 11 on the locking part 2 are to be engaged with the flanges 4 on the stem part 1, the resilient part 3 will make it easier to push the projections 11 over the top of the flanges 4.

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

The resilient third part 3 can either be a separate part or attached to the stem part 1 or attached to the locking part 2. 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 third part 3 is exchangeable/replaceable so that the stiffness can be adapted to the specific use.

Fig. 2A shows the stem part 1 of the locking device in a side view and Fig. 2B shows the stem part 1 of the locking device in a side view. In Fig. 2B the resilient part 3 is also shown. The stem part comprises a head and a body extending from the head. The body of the stem part 1 is provided with at least one axial segment with flanges 4 and at least one axial segment of substantially flat surface 5. The flanges 4 are designed to achieve a tight and locked engagement with projections 11 on the locking part 2 (not shown in Fig. 2). The flanges will be described more in detail with reference to Figs. 3 and 4.

The stem part 1 is preferably provided with at least two axial segments with flanges 4 and at least two axial segments of substantially flat surfaces 5. It will however be understood by a person skilled in the art that it could be provided with less or more segments with flanges and substantially flat surfaces, respectively. The number of axial segments with flanges and substantially flat surfaces, respectively, can be adapted to the size of the stem part or to the intended use of the fastening means.

In this application the stem part 1 is shown as a hexagon-headed bolt with flanges on only a lower part of the length of the stem part body. It is also possible to have flanges along the entire length of the screw body. It could however also be any other type of bolt, screw or fastening means provided with flanges 4.

The stem part 1 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 screw.

Fig. 3 shows an axial segment of flanges 4. The flanges 4 comprise two upwards projecting edges 6 at either end of a countersunk section 7. The flanges can be arranged either on the stem part 1 or the locking part 2.

The vertical distance between the lower end of one flange and the upwards projecting edges 6 on the next underlying flange is at least of the same height as that of one projection, to assure that the projection 11 can be brought into the countersunk section 7 of the flange 4.

To accomplish the insertion of the stem part 1 into the locking part 2, the width of an axial segment of flanges 4 is somewhat narrower than the width of an axial segment with substantially flat surface. This will assure that it possible to move the locking part 2 upwards and downwards on the stem part 1 rapidly without engaging the flanges and projections.

As mentioned above, the flanges could be provided either on the stem part or the locking part, depending on the intended use of the fastening device.

Fig. 4 shows a magnified view of a part of a flange 4 showing one upwards projecting edge 6 and a part of the countersunk section 7. The upwards projecting edge 4 comprises a sloping outer wall 8, a top 9 and an inner wall 10. The lower part 8A of the sloping outer wall 8 is in principal perpendicular to the bottom part of the flange and changes into a sloping part 8B. The top of the upwards projecting edges is preferably rounded, but could also have other shapes. The top continues into an inner wall, where the upper part 10A of the inner wall is a sloping wall and the lower part 10B of the inner wall is either a sloping wall or perpendicular to the countersunk section 7. The sloping of the outer wall is necessary to make the projections 11 slide up against the upwards projecting edges and over the top 9 into the countersunk section 7. At least one of the two the inner walls 10B of each flange 4 has an angle towards the bottom of the countersunk section 7 that is essentially 90 degrees, in order to assure a locked state where the projections 11 stays in an engaged mode with the flanges. The angle could however differ between 85-95 degrees.

Each flange are provided with an upwards projecting edge in each end. And the projecting edges can be made different in the two ends. As well as the inner and outer walls of the flanges can be different.

If needed a tool can be used to connect the locking part to the stem part. This can be useful if the locking is very tight and it is hard to rotate the locking part or stem part by hand. Any tool that can be used to hold and rotate either the stem part or the locking part, or both, can be used for this purpose.

Fig. 5A shows a perspective view of a locking part 2, shown as a hexagonal nut. The locking part 2 is provided with at least one axial segment with projections 11 and at least one axial segment of substantially flat surface 12. The projections are designed to achieve a tight and locked engagement with the flanges 4 on the stem part 1 (not shown in Fig. 5).

The width of an axial segment of projections 11 is somewhat narrower than the width of an axial segment with substantially flat surface 5 on the stem part 1 in order to make it possible to move the locking part 2 upwards and downwards on the stem part 1. The locking part is preferably provided with at least two axial segments with projections 11 and at least two axial segments of substantially flat surface s 12, but could however be provided with less or more segments with projections 11 and substantially flat surfaces 12, respectively.

In this application the locking part 2 is shown in the shape of a hexagonal nut. It could however also be a wing nut (as shown in Fig. 5B), a captive nut, a threaded sleeve or any other type of nut/sleeve which has the ability to engage with the stem part 1. The locking part 2 could also be a general piece of structure into which the stem part 1 is to be received, provided that the locking part can be provided with the projections 11. The locking part 2 could for example be integrated in a cap, a pipe or any other application. The function of the locking part can be migrated into a welded nut or in any other parts in a manufacturing line.

The width of the projections 11 is adapted to fit within the flanges 4 and can hence not be wider than the width of the countersunk section 7 on the flanges 4.

The locking part can further comprises a marking 13 to show the placement of projections 11 or the axial segments of substantially flat surface 12 to facilitate correct placement of the locking part 2 in relation to the flanges 4 on the stem part 1 during connection of the locking part 2 and stem part 1 to each other.

Fig. 6 shows a cross-sectional view of the locking part 2. In this embodiment of the application, the distance LI from the top of the locking part (as shown in Fig. 6) to the top of the first projection differs from the distance L2 from the bottom of the nut to the bottom of the last projection. The distance LI is preferably twice the corresponding distance on L2. This feature makes it possible to turn the locking part upside down if the fastening device is not locked tight enough against the article and will then have a tighter fit when it engages with the stem part 1. In the same way is it possible to have a looser fit if the fastening device is turns out to be locked to tight against the article, or if it is not possible to rotate the stem part or locking part into engagement with each other. Above, an exemplifying preferred embodiment has been described. However, it is realized that the invention can be varied without departing from the basic idea of the invention.

The invention as it has been described can for example be used on skateboards. Fastening means on skate boards are exposed to a lot of vibrations and it is hard to find fastening means where no retightening needed. A lost fastening means during use of a skate-board could mean that the person using the skateboard is hurt. The fastening means described in this application will make sure that the wheels are securely fastened to the skateboard.

The invention can further be used in different types of stairs, for example fire escapes and industrial stairs where a lot of movement occurs and the vibrations and stress affects the fastening means. The fastening means according to the invention will be advantageous since there is no need for retightening the locking part. The fastening means according to the invention will also save time during installation, because of the rapid locking due to the use of axial segments without flanges 4 and projections 11, respectively.

Another advantageous use is in ladder scaffolding, where the scaffolding is to be mounted and dismantled over and over again. It will not only be more time efficient compared to regular fastening devices it will also be safer and have greater structural strength since the flanges will stay inside the protrusions until a tool or a person actively rotates at least one of the connecting parts.

Furthermore the invention as it has been described can be used in applications where there is little space for mounting, in motor vehicles, lawn mowers, furniture production etc. The screws/bolts are often located in areas that are difficult or not possible to access for follow-up draft/retightening. The axial segment with substantially flat surface will make it easier to mount the fastening device in areas with limited space as compared to a regular bolt and nut where one would need to rotate the nut and/or bolt upwards until a locked state is achieved. The easier mounting is due to the fact that the locking part can pushed upwards along the stem parts main axis until a desired locking is accomplished and then one of the two connecting parts is rotated into a locked state where the projections fit within the countersunk part of the flanges. The locking mechanism provided with the present invention do not need any follow-up draft or retightening.

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. The neck of a bottle is provided with the at least one axial segment of flanges 4 and at least one axial segment of substantially flat surface for rapid engagement and fast locking as has been described above. The bottle cap is provided with at least one axial segment of projections and at least one axial segment of substantially flat surface. At least one of said two parts 1, 2 is rotatable in relation to the other to bring the slightly curved flanges 4 and the projections 11 in and out of engagement with each other.

It is to be noted that the flanges could also be provided on the locking part and in that case the projections will be provided on the stem part.

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 with 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.

In another application of the present invention, the fastening device is utilized for assembling pipe ends, wherein the stem part 1 is arranged in or on one pipe and the locking part 2 is arranged in a second pipe, wherein at least one of said two parts is rotatable in relation to the other to bring the axial segment of slightly curved flanges 4 and the axial segment of projections 11 in and out of engagement with each other and thereby assembling the two pipes together, in the same way as has been described with reference to Figs. 1 and 3. The flanges on the stem part 1 can either be attached inside one of the pipe ends or the flanges can be attached to the outside of one of the pipe ends. The pipe containing the locking part 2 will surround the pipe containing the stem part when they are brought into engagement with each other.

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.