Patent Publication Number: US-2010122604-A1

Title: Detachable steering wheel connection structure

Description:
PRIORITY INFORMATION 
     This application claims priority to European Application No. EP08169164.4 filed on Nov. 14, 2008, and incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to a detachable steering wheel connection structure for connecting and disconnecting a steering wheel to/from a steering wheel hub. 
     BACKGROUND OF THE INVENTION 
     Steering wheels are commonly used in vehicles, e.g. cars, and vessels, e.g. boats. Unfortunately, such vehicles and vessels are attractive for thieves. To prevent theft, various kinds of anti-theft devices are known, e.g. electronic alarms and steering wheel locks. 
     However, with these conventional anti-theft devices, once a thief has broken the lock or shut off the alarm, the thief can steal the vehicle or vessel and drive away. In order to make theft more difficult, it is known9 to use removable steering wheels. Hence, the steering wheel may be removed by the proper user/owner when leaving the vehicle or vessel. Without a steering wheel, it will be difficult for a thief to drive away. 
     GB 298, 047 discloses an anti-theft device of the type in which the steering wheel can be coupled or uncoupled with the steering column. The steering wheel may take up two positions, in the lower of which it engages the steering column, while in the upper it rotates idly thereon. The hub of the wheel is formed with internal teeth, which, in the lower position engage external teeth on a flange secured to the column. The wheel is locked in one position or the other by means of a toothed ring operated by a key k through toothed wheels. 
     With this kind of anti-theft devices preventing operation of the steering wheel, the purpose is to render it difficult for the thief to steal the vehicle or vessel. At the same time it should be convenient for the proper user/owner of the vehicle or vessel to couple or uncouple the steering wheel. It is preferred that the uncoupling of the steering wheel is quick and easy, so that the anti-theft function is actually used. If it is too complicated to perform the detachment, some persons would not use the anti-theft device, although it is already installed in their vehicle or vessel. Especially, it is preferred that no extra tool or key is needed for detachment and re-connection. For convenience, as few grips as possible should be needed to uncouple the steering wheel. Preferably it should be possible without shifting the grip. Yet it should be a safe construction so that the steering wheel is not uncoupled unintentionally. 
     Conventional detachable steering wheel connection structures are often locked and unlocked by a key in a lock. In that case, there is always a risk of losing the key. There is also a risk that the thief actually breaks the lock and manages to drive away the vehicle or vessel anyway. 
     There is therefore a need for an improved detachable steering wheel connection structure. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 
     Preferably, a detachable steering wheel connection structure is provided which needs as few grips as possible for uncoupling. 
     Advantageously, a detachable steering wheel connection structure is provided which is handled without the need of a lock and corresponding key. 
     The object above may be achieved by the invention according to claim  1 . 
     In a first aspect of the present invention there is provided a detachable steering wheel connection structure intended to be located between a removable steering wheel and a steering wheel hub. 
     The structure comprises a first and a second connection part. One of the first and second connection parts is adapted to be rigidly connected to the steering wheel, while the other is adapted to be rigidly connected to the steering wheel hub. One of the connection parts comprises a release means, which is axially movable between a first and a second position. In the first position the release means prevents relative movement between the first and second connection parts, thereby keeping them in an interconnected state. In the second position the release means allows for relative rotational movement between the first and second connection parts, thereby allowing them to be moved to a rotational position, wherein they are detachable from each other by movement in an axial direction. 
     The steering wheel connection structure according to the present invention may be operated without the use of a key. In the normal case, the whole steering wheel is removed after having detached the steering wheel connection structure. A possible thief just finds a “naked” steering wheel hub and cannot drive away. There is therefore no need for a key-operated lock. 
     Another advantage of the suggested the steering wheel connection structure is that it is possible to operate with only one grip. The person wanting to detach the structure, may place his hands close to the hub of the steering wheel, move the release means from the first to the second position, rotate the first and second connection parts relative to each other and detach them. All these operations could be done without shifting grip, providing a one-grip solution, which is very convenient. 
     As the release means is moved axially and the connection parts are rotated, there are two different directions of movement involved, occurring one after the other. Thereby the risk of unintentional detachment of the connection structure is diminished. Another advantage of having different movements is that, in the event of unexpected external forces e.g. in a crash situation, these forces will work in mainly one direction and thus not detach the steering wheel unintentionally. 
     The detachable steering wheel connection structure can be arranged so that the release means is only movable in the axial direction between the first and second position. 
     The release means may be connected to either the first or second connection part. Thereby it cannot fall off and disappear. If the connection part whereto the release means is connected is rotated as described above, the release means will rotate together with that connection part, but no movement between the first and second position of the release means is occurring. 
     The detachable steering wheel connection structure may be arranged to be operable with only one grip, wherein the grip enables axial movement of the release means from the first to the second position, rotating of the first and second connection parts relative to each other and their detachment from each other without need to shift grip. 
     The release means may be arranged to be accessible from the peripheral surface of said structure. This facilitates the connecting or detachment operation using only one grip. 
     The detachable steering wheel connection structure may be arranged so that the first connection part is adapted to be rigidly connected to the steering wheel hub and the second connection part is adapted to be rigidly connected to the steering wheel. 
     The first and second connection parts may be arranged so that there during the rotational movement is at least one detachable position, wherein the connection parts are detachable from each other by axial movement, and at least one non-detachable position, wherein they are only movable relative to each other by the rotation. This arrangement helps to keep the rotational movement separate from the axial movement of detachment. 
     In one embodiment, the first and second connection parts are hindered from moving relative to each other by a protrusion from the release means engaging with at least one of the connection parts, when the connection parts are in the interconnected state and the release means is in the first position. The protrusion helps to prevent unintentional detachment. Such a protrusion could for example be useful in making the connection structure stable in case of a crash. 
     In one embodiment, the first connection part comprises a first part and a first lock means with the first lock means being rigidly connected to the first part. The second connection part comprises a second part and a second lock means, with the second lock means being rigidly connected to the second part. The first and the second lock means engage with each other when being in the at least one non-detachable position and disengage with each other in the at least one detachable position. This arrangement facilitates an efficient manufacturing of the steering wheel connection structure. 
     The first and second lock means may be annular rings having teeth and recesses. One of them has teeth and recesses around its inner diameter and the other around its outer diameter. The teeth and recesses correspond to each other, such that they can pass through each other in the at least one detachable position and such that they engage with each other in the at least one non-detachable position. The teeth and recess arrangement keeps the lock means and thereby the connection parts well attached to each other, especially if the teeth are distributed around the whole perimeter. In the non-detachable position; there may be a tooth under every recess. This would give a stable connection, which is good to withstand external forces, for example in the event of a crash. 
     The release means may have the form of an annular ring. A circular form is suitable since the steering wheel hub usually is round. It is also easy to move an annular ring between the first and second position of the release means. 
     The release means may be biased towards the first position, e.g. by a compressible or extendible resilient means. Thereby the release means will strive to be in the first position, so that when the release means is released from the second position, it will automatically return to the first position. The release means will then only be in the second position, when it is actively moved there, which diminishes the risk of unintentional detachment of the connection structure. 
     In an embodiment, the detachable steering wheel connection structure further comprises at least one first guiding means, the first guiding means being attached to one of the connection parts and the release means having a corresponding receiving slot, wherein the first guiding means is adapted to be received by the slot, when the two connection parts are mounted to each other. The slot allows for rotation of the first and second connection parts relative to each other when the release means is in its second position. The function of the first guiding means is to facilitate finding the correct position, of the first and second connection parts relative to each other when connecting the structure. During rotation the first guiding means moves within the slot. Therefore, preferably one end of the slot corresponds to reaching the end position of the rotation. The detachable steering wheel connection structure may further comprise at least one second guiding means, the second guiding means being attached to one of the connection parts and having a height allowing for rotation of the first and second connection parts relative to each other when the release means is in its second position. The release means has a corresponding receiving hole or cavity, the second guiding means being received by the hole or cavity, when the release means is in its first position. Therefore, the user knows that, when the second guiding means can enter the receiving hole or cavity, the first and second connection parts are in a correct interconnected state. During the movement of the release means to its first position preventing rotation, the second guiding means enters the hole or cavity. 
     In order to obstruct theft, the connection structure may further comprise at least one first identity means, being attached to one of the connection parts. In this case the release means may have a corresponding receiving identity slot. The first identity means is then received by the identity slot, when the two connection parts are mounted to each other. 
     The detachable steering wheel connection structure may further, or as an alternative, comprise a second identity means, the second identity means being attached to one of the connection parts and having a height allowing for rotation of the first and second connection parts relative to each other when the release means is in its second position. The release means then has a corresponding receiving hole or cavity, with the second identity means being adapted to be received by the hole or cavity, when the release means is in its first position. During the movement of the release means to its first position, preventing rotation, the second identity means enters the hole or cavity. 
     In one embodiment, the first and/or second identity means has a predetermined location, such that a certain first connection part only is connectable to a mating second connection part of the same connection structure. 
     Moreover, the slot and/or the receiving identity slot may have a second end arranged so that it provides an end position of the rotational movement. 
     The first and/or second guiding means are provided to facilitate for the user of the detachable steering wheel connection structure finding the correct position of the first and second connection parts relative to each other when connecting the structure. The guiding means may have the same position/s for a whole batch of detachable steering wheel connection structures. 
     The first and/or second identity means is used to individualize the connection structure, so that a possible thief cannot take any loose steering wheel comprising a connection part and put it on a steering wheel hub with the steering wheel removed. The purpose is to make sure that only the mating connection part fits, so that only the correct connection part of the correct steering wheel can be used. Moreover, an identity means may also be used as a guiding means, for example by providing an end of the rotational movement. 
     In a second aspect of the present invention, there is provided a steering wheel comprising a detachable steering wheel connection structure as described above. 
     In a third aspect of the present invention there is provided a method of detaching a detachable steering wheel connection structure comprising the steps of:
         moving a release means axially from a first to a second position,   rotating first and second connection parts relative to each other,   separating the first and second connection parts from each other by axial movement,
 
wherein the connection parts and release means are as described above.
       

     Since the detachment involves three different movements, the risk of unintentional detachment is diminished. At the same time the detachment movements are easy to perform. They are convenient, since they could be made without shifting grip. Also, detachment may be made quickly. Yet, at the same time, unintentional detachment is prevented. 
     In a fourth aspect of the present invention, there is provided a method of connecting a detachable steering wheel connection structure comprising the steps of:
         placing the first and second connection parts in contact to each other in the at least one detachable position, thereby moving a release means to a second position, which allows for relative rotational movement between the first and second connection parts,   rotating the first and second connection parts relative to each other until they reach the at least one non-detachable position,
 
wherein the connection parts and release means are as described above.
       

     By means of placing the two connection parts on top of each other, the release means is moved to its second position, which allows relative rotational movement. If the release means is biased towards the first position, as in one of the embodiments described above, it will return to the first position automatically, otherwise it may be moved back manually. 
     The connection could be performed quick and easy, without the use of keys or tools, yet a stable connection is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be explained in greater detail by means of non-limiting examples and with reference to the appended drawings in which: 
         FIG. 1  is a schematic side view of a detachable steering wheel connection structure according to a first embodiment of the invention; 
         FIG. 2  is a top view of the detachable steering wheel connection structure of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view from the side of the detachable steering wheel connection structure of  FIG. 1 ; 
         FIG. 4   a - c  is a bottom, top and cross-sectional side view of a bottom part; 
         FIG. 5   a - b  is a top and cross-sectional view of a first lock means; 
         FIG. 6   a - c  is a top, bottom and cross-sectional side view of a top part; 
         FIG. 7   a - b  is a top and cross-sectional view of a second lock means; 
         FIG. 8   a - c  is a top, bottom and cross-sectional side view of a release means; 
         FIG. 9  is a schematic perspective view of a first connection part of a detachable steering wheel connection structure according to a second embodiment of the invention; 
         FIG. 10  is a schematic perspective view of a second connection part of a detachable steering wheel connection structure, according to a second embodiment of the invention; 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention will, in the following, be exemplified by embodiments. It is to be understood, however, that the embodiments are included in order to explain principles of the invention and not to limit the scope of the invention, defined by the appended claims. The directions downwards and upwards, as well as the words top and bottom, relate to when the connection structure is mounted to the steering wheel hub. 
       FIG. 1-8  illustrate a detachable steering wheel connection structure  2  according to a first embodiment of the invention.  FIG. 1  shows a side view of the connection structure  2 . It comprises a first connection part  4  and a second connection part  6 . In this example, the first connection part  4  is intended to be rigidly connected to the steering wheel hub  8  and the second connection part to the steering wheel  10 , but the connection structure  2  may also be mounted upside down with the first connection part  4  connected to the steering wheel  10  and the second connection part  6  to the steering wheel hub  8 . The steering wheel hub  8  has an axial direction A. 
     A release means  12  is connected to the second connection part  6  in such a way that it is movable in the axial direction A of the steering wheel hub between a first and a second position. 
       FIG. 2  displays the connection structure  2  from above. In this example the second connection part  6  has a number of cavities  14  intended to receive fastening means, e.g. screws, connecting the second connection part  6  to the steering wheel  10 . The release means  12  surrounds the second connection part  6 . 
       FIG. 3  illustrates a cross-section of the connection structure  2 . The first connection part  4  comprises a bottom part  16  and a first lock means  18 . The second connection part  6  comprises a top part  20  and a second lock means  22 . The release means  12  is connected to the second connection part  6 , in such a way that the release means  12  is axially movable relative to the second connection part  6  as described above. The release means  12  is biased towards the first connection part  4  by means of a resilient structure  24 . The individual parts will be more detailedly described with the help of  FIG. 4-8 . 
       FIG. 4   a - c  shows the bottom part  16  from below, above and as cross-section from the side. Cavities  26  are intended to receive screws (not shown) for fastening the first connection part  4  to the steering wheel hub  8 . In the centre of the bottom part  16 , a projection  28  extends in the axial direction A. In the illustrated example, there is an extra cavity  30 , intended to receive a first identity means  32 . The cross-section in  FIG. 4   c  is along the dashed line of  FIG. 4   b , so that both the cavity  26  and extra cavity  30  can be seen. The first identity means  32  can be seen in  FIG. 3 . The identity means is an optional solution which makes it possible to individualize a connection structure by choosing the location of the identity means. The identity means could e.g. be a pin. There is a corresponding identity slot  56  in the release means which is intended to receive the first identity means  32 , which will be further explained below. The identity means  32  is used to prevent that a steering wheel with a first connection part  4  fits to any second connection part  6 . With the identity means it is made sure that the first connection part  4  and the second connection part  6  come from the same connection structure  2 . 
     The first lock means  18  is shown in  FIG. 5   a - b . The holes  34  correspond to the cavities  26  of the bottom part  16 . There is an extra hole  36  corresponding to the extra cavity  30 . Along its inner perimeter the first lock means  18  is provided with a contour having alternatively teeth  38  and recesses  40 . It is preferred that first lock means  18  is rotational-symmetric, but it is not necessary. The same screws (not shown) which fasten the bottom part  16  to the steering wheel hub  8  may also be used to fasten the first lock means  18  to the bottom part  16 .  FIG. 6   a - c  illustrates the top part  20  as seen from above, below and in cross-section from the side. A number of cavities  14  are intended to receive the fastening means for the steering wheel  10 . There are also a number of spring cavities  41 , in the example three, intended to receive the resilient means, here in the form of springs. Another set of cavities  42  are intended for fastening means, e.g. screws, connecting the second lock means  22  to the top part  20 . There is further a large cavity  44  intended to receive the projection  28  of the bottom part  16 . Along the rim, there are projections  46 , in this case three, extending downwards towards the first connection part  4 . The cross-section in  FIG. 6   c  is done, so that both a cavity  14  for fastening means and a spring cavity  41  can be seen. 
     The second lock means  22  is shown in  FIG. 7   a - b . It has holes  48  corresponding to the cavities  42  of the top part  20 . On its outer rim it is provided with a contour having alternatively teeth  50  and recesses  52 . The first  18  and second  22  lock means match each other, so that the teeth  38  of the first lock means  18  fit the recesses  52  of the second lock means  22 , and the recesses  40  of the first lock means  18  fit the teeth  50  of the second lock means  22 . In the detachable position the second lock means  22  is able to pass through the first lock means  18  in the axial direction. The first  4  and second  6  connection parts are thus detachable from each other. By a relative rotational movement, rotation around the axis A, the first  18  and second lock means  22  move to the non-detachable position, wherein the first  4  and second  6  connection parts cannot be detached from each other. The second lock means  22  then prevent the first lock means  18  from moving in the axial direction. The non-detachable position is reached when the teeth  38  of the first lock means  18  is just above the teeth  50  of the second lock means  22 . With the illustrated geometry this is achieved by 60° rotation, but depending on the number and shape of the teeth any predetermined angle could be chosen. In the intermediate positions between the detachable and non-detachable position, the first  18  and second  22  lock means have partly overlapping teeth thereby blocking each other from axial movement, but it is only in the non-detachable position that they can be locked by the protrusions  58  of the release means  12 , as described below. 
     The release means  12  as illustrated in  FIG. 8   a - c  has a number of slots  54  intended to receive the projections  46  of the top part  20 . The slots  54  make it possible for the release means  12  to move in an axial direction relative to the top part  20 , but prevent rotational movement between the release means  12  and the top part  20 . There is also provided an identity slot  56  intended to receive the first identity means  32 . The arc length of the identity slot  56  corresponds to the rotation needed to move between the detachable and non-detachable positions of the lock means  18 ,  22  mentioned above, in this case 60°. The release means  12  further comprises protrusions  58 . The protrusions  58  have a shape that fits into the recesses  40  of the first lock means  18 . 
     Going back again to  FIG. 3 , it is illustrated that the first and second lock means are in a non-detachable position. On the left-hand side of the connection structure, it can be seen that the teeth of the first lock means  18  overlap the teeth of the second lock means  22 . The release means  12  is in its first position preventing relative movement. It can be seen that the protrusions  58  of the release means  12  fit into the recesses  52  of the second lock means  22 . When the release means  12  is in its first position, these protrusions  58  are located in the recesses  40  of the first lock means  18 , thereby preventing relative movement between the first  4  and second  6  connection parts. 
     When the release means  12  is moved to its second position, in this example by moving the release means  12  upwards against the force of the resilient means  24 , the protrusions  58  are lifted out of the recesses  40  of the first lock means. With the protrusions  58  free from the recesses  40 , the first connection part  4  is allowed to move relative to the second connection part  6  with rotational movement around the axis A. The connection parts  4 ,  6  can then be rotated the predetermined angle mentioned above, in this case 60°, so that they reach the detachable position, wherein the connection parts  4 ,  6  are detachable from each other and the steering wheel can be disconnected from the steering wheel hub  8 . 
     The invention has been described above by way of example only and the skilled person will appreciate that many modifications of the above-described embodiments are conceivable within the scope of the appended claims. 
     The used 60° geometry is just an example. The teeth  38 ,  50  and recesses  40 ,  52  could have any arc length or shape as long as the first lock means  18  can pass through the second lock means  22 , in the detachable position, and then be moved to the non-detachable position, wherein the connection parts  4 ,  6  are locked by each other. It is usually preferred to let the teeth and recesses have the same arc length. The teeth  38 ,  50  could have another geometry than the recesses  40 ,  52 , e.g. have a longer or shorter arc length. The example shows three teeth, but instead another number of teeth could be used. For example using four teeth and recesses with the same arc length, each tooth could be 45° and the predetermined rotation angle also 45°. In the same way, using two teeth would correspond to 90°. Using only one tooth is less preferred, since the connection between the two connection parts  4 ,  6  would be unbalanced with the whole connection in one half of the connection parts. On the other hand, using too many teeth is not good either, since the predetermined angle to rotate becomes small, increasing the risk of unintentional detachment. 
     The first identity means  32  is an option, which secures that the first and second connection parts belong to the same connection structure. By choosing the location of the first identity means  32 , it is possible to individualize a connection structure. As an alternative two, three, four or more identity means may be used. 
     Suitable materials for the connection structure are metals and alloys, for example aluminum, stainless steel and alloys comprising aluminum, copper, zinc and/or iron. A good choice is aluminum alloy, which is suitable from a manufacturing point of view. 
     In the illustrated example the connection parts  4 ,  6  comprise more than one individual part. This is useful from a manufacturing point of view, but it would also be possible to make the first  4  and second  6  connection parts as integrated units, manufactured in one piece. 
     The exemplary parts in  FIGS. 4 to 8  are all rotational-symmetric. This is rather natural considering the application in a steering system, but it is not a must. One or more of the parts could for example be polygonal, e.g. square, hexagonal or octagonal. If desired, the number of teeth could be matched to the number of sides in the polygon. 
     The purpose of the release means  12  is on one hand, being in the fist position, to prevent relative movement of the first  4  and second  6  connection part, and on the other hand, being in the second position, to allow relative rotational movement of the first  4  and second  6  connection parts. In the second position, the first  18  and second locking means  22  are prevented from uncoupling. In this particular illustrated case, relative movement is prevented by locating protrusions  58  in the recesses  40 . This locking effect could also be achieved in other ways, e.g. by letting a protrusion or a pin attached to the release means  12  fit into a receiving cavity in the first connection part. 
     The exemplary release means  12  has the form of an annular ring surrounding the axis A. The diameter is somewhat larger than that of the first and second connection part to facilitate the movement between the first and second position. However, the release means  12  could instead for example comprise a lever or a grip protruding from the connection structure. The lever/grip would then be used for enabling the movement between the first and second position. The lever/grip could be done as an integral part of the release means, but it could also be manufactured of another material and attached to the release means. 
     A procedure for detaching the connection structure  2  of  FIG. 1-8  comprises the steps of: 
     (a) moving the release means  12  axially from the first to the second position,
 
(b) rotating the connection parts  4 ,  6  relative to each other,
 
(c) separating the first and second connection parts from each other by axial movement.
 
Since the procedure involves three distinct steps, which are carried out in a certain order, it is highly unlikely that they would occur unintentionally.
 
     A procedure for connecting the connection structure  2  of  FIG. 1-8  comprises the steps of: 
     (a) placing the first and second connection parts  4 ,  6  in contact to each other in the at least one detachable position,
 
(b) rotating the first and second connection parts  4 ,  6  relative to each other until they reach the at least one non-detachable position.
 
     The release means is moved to the second position when placing the connection parts  4 ,  6  in contact to each other, step (a). The release means  12  may be biased, e.g. by a resilient means  24  as in  FIG. 1-8 . In that case, the release means  12  is moved to the second position against the force of the resilient means  24  when placing the connection parts  4 ,  6  in contact to each other, step (a). After rotation to the at least one non-detachable position, step (b), the release means  12  automatically returns to the first position when released. If not biased, it might be moved back manually. 
     In  FIG. 1-8  the connection structure is operated by moving the release means axially and rotating the locking means. The reverse would also possible, moving the locking means axially in and out of a matched position, and letting the release means rotate between the first and second position. Even if it would be possible that the release and the locking means either both rotate or both move axially, it is preferred that they have different movements, since that diminishes the risk of unintentional detachment of the connection structure. 
     Another advantage of having different movements is, is in the event of unexpected external forces, e.g. in a crash situation. These forces will work in mainly one direction and thus not detach the steering wheel unintentionally. 
     It would also be possible to replace the movements of at least one of the steps (a) to (c) of the detachment method, or at least one of the steps (a) to (b) of the connection method with a translational movement perpendicular to the axis A. 
       FIG. 9-10  illustrate a detachable steering wheel connection structure  2  according to a second embodiment of the invention. Since most details are similar to as for the first embodiment, only the differences will be pointed out. For details that are similar in the first and second embodiment, the reference numbers from the first embodiment are used. 
       FIG. 9  shows the first connection part  4 , which comprises a bottom part  16  and a first lock means  18 . The first lock means is provided with a second identity means  60 , a first guiding means  62  and a second guiding means  64 . The second identity means  60  and the second guiding means  64  are somewhat lower than the first guiding means  62 . 
       FIG. 10  shows the second connection part  6  comprising a top part  20  and a second lock means  22 . The release means  12  is connected to the second connection part  6  and can be moved axially between the first and second position as explained above for the first embodiment. In the perspective view, it can be seen that the projections  46  of the top part  20  are located in the slots  54 , just as for the first embodiment. 
     The release means  12  comprises a receiving hole or cavity  66  adapted to receive the second identity means  60 , a slot  68  adapted to receive the first guiding means  62  and a receiving hole or cavity  70  adapted to receive the second guiding means  64 . 
     As can be seen in  FIG. 9 , the second identity means  60  and the second guiding means  64  are somewhat lower than the first guiding means  62 . This difference in height makes it possible, with the release means  12  being in its second position allowing rotational movement, to rotate the release means  12  without engaging with the corresponding receiving holes or cavities  66 ,  70 . The first guiding means  62  is on the other hand somewhat higher and will move within the slot  68 . The arc length of the slot  68  should preferably have a length corresponding to the rotation needed to move between the detachable and non-detachable positions of the lock means  18 ,  22 , in this case 60°. It would also work with longer slots  68 , but the release means would be unnecessarily weakened. 
     In the illustrated embodiment, the slot  68  is located, so that a first end  72  corresponds to the position of the first guiding means  62  when placing the first  4  and second connection parts  6  in contact to each other in the at least one detachable position. When the first  4  and second connection parts  6  thereafter are rotated relative to each other, the first guiding means  62  will move within the slot  68  until it reaches the second end  74 . This provides an end of the rotation. In this position, the first  18  and second lock means  22  are locking by substantially complete overlap. Further, the release means has thereby been rotated to a position, wherein the second identity means  60  is situated directly below the corresponding hole  66  and the second guiding means  64  directly below the holes  70 . When the release means  12  thereafter is axially moved to the first position preventing rotation, either manually or since it is biased by means of a resilient structure  24  as in the first embodiment, the second identity means  60  and the second guiding means  64  will enter their respective holes  66 ,  70 . As can be seen the second guiding means  64  has a frustoconical shape, which will facilitate entering the holes  70 . Alternatively they may also be cylindrical or have any other shape suitable to be received in a corresponding cavity, such as having a square, hexagonal or octagonal cross section. Also the first  32  and second  60  identity means, as well as the first guiding means  62 , may be frustoconical or have a square, hexagonal or octagonal cross section. 
     The second identity means  60  is an option, which secures that the first  4  and second connection parts  6  belong to the same connection structure  2 . By choosing the location of the second identity means  60 , it is possible to individualize a connection structure. The second identity means is used to prevent that a steering wheel with a first connection part  4  fits to any second connection part  6 . With the identity means it is made sure that the first connection part  4  and the second connection part  6  come from the same connection structure  2 . As an alternative two, three, four or more second identity means may be used. Further, it is also possible to combine first identity means  32  and second identity means  60  within the same embodiment (not illustrated). 
       FIG. 9-10  disclose one first guiding means  62  and two second guiding means  64 . However, the number of the guiding means may be varied, for example by using one, two, three or more guiding means of the respective type. 
     Further modifications of the invention within the scope of the appended claims are feasible. As such, the present invention should not be considered as limited by the embodiments and figures described herein. Rather, the full scope of the invention should be determined by the appended claims, with reference to the description and drawings.