Patent Description:
Tightening members used for different purposes in connection with vehicle accessories are known from the prior art. For example, tightening members are used for tightening different members or units of load carrying equipment to a supporting structure. It is known to use specific tightening members for attaching accessories to crossbars of a load carrier system, for example a load carrier system in which the crossbars are mounted on the roof of a vehicle. Accessories may include roof boxes or other objects to be fixed on the crossbars such as roof tents.

One drawback of known tightening members is that they are often provided integrally with a member to be operated by the same. For example, it is known to use tightening members for operating clamp mechanisms of a roof box system. The tightening members are an integral part of such clamp mechanisms and remain on the clamp mechanisms even if the tightening process is completed. Accordingly, such tightening members take up room within a roof box which is then not available for stowing goods to be transported. Furthermore, such tightening members are exposed and therefore prone to damages which may result from forces acting on the tightening member applied on the same by a good transported within the roof box, for example during abrupt deceleration.

Another drawback of known tightening members is that the use of the same is often cumbersome. For example, if such a tightening member is used for mounting an accessory on the crossbar, situations occur in which a clamp for mounting the accessory, such as a roof tent, needs to be mounted to the crossbar by use of a bracket enclosing a lower portion of the crossbars. Such a bracket needs to be tightened and mounted from below. A space between crossbars mounted on the roof of a vehicle and an upper surface of the roof of the vehicle is, however, very limited. Therefore, it is difficult for a user to carry out a tightening action in such limited space. <CIT>, <CIT>, <CIT> and <CIT> disclose wrenches.

A further drawback resides in the fact that tightening members are often used at positions that are not visible to a user. Accordingly, in such situations, the user has to carefully approach the member to be tightened and to couple the tightening member to the member to be tightened without having eyes on the position. Coupling the tightening member to the member to be tightened may thus be very cumbersome for the user and may include situations in which the user abuts portions other than the portion to which it is to be coupled. This may lead to damages on the tightening member and/or on portions of the accessory.

In order to overcome at least one of the above drawbacks, the tightening member may be configured detachable. In order to overcome at least one of the above drawbacks, the tightening member may be configured very compact in size. Furthermore, in order to overcome another of the above drawbacks, the tightening member may be configured to guide the user holding the tightening member towards a coupling position. Furthermore, a clamping device may be provided which allows for an improved coupling of a tightening member to the same.

It is the object of the invention to provide an improved tightening member.

The object is solved by a tightening member according to claim <NUM>. Advantageous further developments are subject of the dependent claims.

According to a first aspect, a tightening member for tightening a clamping device for fixing an accessory to a crossbar is disclosed. The accessory may be implemented by a load carrier, for example a roof box, or may be implemented by other systems to be supported on a load carrier frame such as crossbars, for example a roof tent.

The tightening member comprises a coupling portion for detachably coupling the tightening member to a coupling section of a clamping device. The coupling portion is configured engageable with the coupling section in a torque transferable manner.

The tightening member further comprises an operating portion configured to be grasped and rotated by a user. The operating portion is operatively coupled to the coupling portion. Accordingly, when a user grasps the operating portion and rotates the same, a rotation of the operating portion is transferred to the coupling portion. In particular, a rotation of the operating portion is transferred into a rotation of the coupling portion. The operating portion may be operatively coupled to the coupling portion such that a rotation of the operating portion is directly transferred into a rotation of the coupling portion.

The coupling portion comprises an accommodating portion for at least partially receiving a force receiving portion, for example a protrusion, of the coupling section therein.

According to an embodiment, the engaging portion comprises a resilient engaging member. The resilient engaging member can comprise a hook like protrusion. The hook like protrusion can comprise a barb. The resilient engaging member may be configured to automatically establish locking with the coupling section. In particular, the resilient engaging member may be configured to snap into the engaging section, for example upon inserting the tightening member on the force receiving portion, for example the protrusion.

The tightening member in addition comprises a torque limiting mechanism operatively coupling the coupling portion with the operating portion.

According to an embodiment, the torque limiting mechanism comprises a first toothed portion operatively coupled to the operating portion and the second toothed portion operatively coupled to the coupling portion. Furthermore, the torque limiting mechanism may comprise an urging member for urging the first toothed portion and the second toothed portion towards each other with a predetermined urging force. The predetermined urging force and a configuration of the first and second toothed portions may define a maximum transferable torque.

The tightening member comprises a ratchet mechanism. The ratchet mechanism may be a one-way ratchet mechanism and is configured to allow a pumping-like tightening operation by providing a one-way torque transmission. In other words, the ratchet mechanism comprises a one way torque transmitting capability. The direction of the torque transmitting capability may be reversable. For that, a reversing mechanism may be provided.

The ratchet mechanism may be configured similar to the above mentioned torque limiting mechanism, in other words with toothed portions normally forcedly engaged with each other by application of an urging force by an urging member. The tooth geometry is, however, different in order to provide maximum force transmission in one direction and to provide substantially no force transmission in opposite rotation direction. A single urging member is provided which acts in both the torque limiting mechanism and the ratchet mechanism.

According to an embodiment, the torque limiting mechanism and the ratchet mechanism may be provided in this order in a force transfer path from the operating portion to the accommodating portion. In this way, the ratchet mechanism may only transfer an already limited maximum torque to the accommodating portion, as received from and limited by the torque limiting mechanism.

The ratchet mechanism may comprise a third toothed portion and a fourth toothed portion. The third toothed portion and the fourth toothed portion are configured to provide a freewheel like configuration in which a rotational force may only be transferred in one direction. The third toothed portion may be operatively coupled to the operating portion and the fourth toothed portion may be operatively coupled to the coupling portion. Furthermore, an urging member, for example a disc spring or a wave spring, may be provided for urging the third toothed portion and the fourth toothed portion towards each other. The third and fourth toothed portions may comprise a tooth configuration such that in tightening direction, teeth of the driving toothed portion lock with teeth of the driven toothed portion, and in the other direction teeth of the driving toothed portion slip over teeth of the driven toothed portion.

The torque limiting mechanism and the ratchet mechanism may be configured to share certain members and/or portions, for example the urging member and/or at least one force transfer member, for example an annular force transfer member, carrying toothed portions on opposite sides, wherein one of the toothed portions is associated with the ratchet mechanism and the other toothed portion is associated with the torque limiting mechanism.

The torque limiting mechanism and the ratchet mechanism may be provided by a single pair of toothed portions, for example in the first toothed portion and the second toothed portion or in the third toothed portion and the fourth toothed portion as mentioned above. Each toothed portion of the pair of toothed portions may comprise dual-action teeth allowing to transfer torque up to a predetermined first threshold limit in tightening direction and allowing slipping between the toothed portions in opposite rotating direction. In addition or alternatively, at least one toothed portion may be provided on a disc member prebiased towards engagement with the other toothed portion, for example by an urging member as described before. In addition or alternatively, at least the torque limiting mechanism and the ratchet mechanism may be fully accommodated in a common cylindrical housing portion. In addition or alternatively, the toothed portion of the torque transfer mechanism and/or of the ratchet mechanism, which is last in said force transfer path between the operating portion and the coupling portion, may be provided on a force transfer member having, on an opposite side to a side on which the toothed portion is provided, a force transfer portion engaged with the coupling portion such that a rotational force is transferable to the coupling portion while the force transfer member is held axially movable relative to the coupling portion.

According to an embodiment, the tightening member comprises a torque-limiting-free coupling portion. Such a coupling portion may be provided for untightening purposes or other situations in which a limitation of the transferable torque is undesired.

Further disclosed and not being part of the invention is a clamping device for fixing an accessory to a crossbar. The clamping device is configured to be operated by a detachable tightening member, for example a tightening member as described before in connection with the first aspect.

The clamping device comprises a base portion configured to be supported on an accessory to be mounted on the crossbar.

The clamping device further comprises at least one movable clamping member which is movable with respect to the base portion between a clamping position in which the clamping member at least partially embraces the lower portion of the crossbar and an opened position in which the clamping device is insertable on or removable from the crossbar. The movable clamping member may be a pivotable clamping member. Furthermore, in the clamping position, the clamping member may be configured to apply a clamping force on the lower portion of the crossbar.

The clamping device further comprises a rotatable force receiving portion operatively coupled to the at least one movable clamping member such that a rotation of the rotatable force receiving portion is transferred into a movement of the movable clamping member. Furthermore, the rotatable force receiving portion is configured to be to detachably couplable to a coupling portion of a tightening member in a torque transferable manner.

The rotatable force receiving portion at least comprises a torque transmitting profile defined by a wall portion. The wall portion at least partially extends about an axis of rotation of the force receiving portion. The torque transmitting profile may be provided on a radially outer surface of the wall portion.

The wall portion may comprise an engaging section on a radially inner surface. The engaging section may preferably comprise a recess at least partially extending about the axis of rotation.

The coupling section may be integrally formed with a tightening bolt and/or the coupling section is made of metal.

The base portion may comprise an opening. The opening may be a circular opening. The force receiving portion can be received in the opening such that its radially outer surface is arranged at a distance from a wall defining the opening such that a receiving space is provided between the wall and the outer surface. The receiving space may be configured for receiving an edge portion of the coupling portion of a tightening member.

The clamping device may further comprise a supporting surface for slidably supporting a lower supporting surface of the tightening member. The supporting surface may extend in a direction perpendicular to the axis of rotation of the coupling section. According to an embodiment, the coupling section comprises a hexalobular or Torx profile.

According to a further aspect, a clamping assembly comprising at least one tightening member as described above and at least one clamping device as described above in combination, is disclosed. The tightening member may be releasably attachable to the clamping device for tightening and releasing purposes and may be stowable in a detached state in a space-saving manner.

Additional features and advantages may be gleaned by the person skilled in the art from the following description of exemplary embodiments, and the attached drawings.

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the art to make and use the embodiments.

The features and advantages of the embodiments will become more apparent from the detailed description as given below when taken in conjunction with the drawings, in which like reference signs identify corresponding elements throughout. In the drawings like reference numbers generally indicate identical, functionally similar and/or structurally similar elements.

Embodiments and modifications will be described in the following with reference to the drawings.

<FIG> shows a perspective view of a clamping assembly <NUM> according to an example not covered by the invention.

The clamping assembly <NUM> comprises a clamping device <NUM> according to an example not covered by the invention.

A sectional view of the clamping device <NUM> revealing optional additional features of the clamping device <NUM>, is shown in <FIG>.

The clamping device <NUM> comprises two clamping members <NUM>. It is noted that the clamping device <NUM> may comprise a different number of clamping members.

According to a modification, the clamping device <NUM> comprises only a single clamping member. Each clamping member <NUM> is held movable between a clamping position in which the clamping member <NUM> can embrace a lower portion of a crossbar and an opened position in which the clamping device <NUM> is insertable on or removable from the crossbar. For that, each clamping member <NUM> is movably mounted on a base portion <NUM> of the clamping device <NUM>. With such a configuration, at least a free end portion of each clamping member <NUM> is movable towards and away from a supporting plane which is defined by a lower supporting surface <NUM> provided on a lower portion of the base portion <NUM>. In use, a crossbar may be clamped between each clamping member, for example a free end portion of the clamping member <NUM>, and a portion of the lower supporting surface <NUM>. In <FIG>, the clamping device <NUM> is shown in a state in which the clamping members <NUM> are positioned in the clamping position.

The clamping device <NUM> comprises a coupling section <NUM>. The coupling section <NUM> comprises a force receiving portion <NUM> which is rotatable about a rotation axis A. The rotation axis A may extend perpendicular to a plane in which a rotation axis B of a clamping member <NUM> extends. For example, the rotation axis A may extend skew to the rotation axis B so that both axes extend at an angle of <NUM> degrees and offset with respect to each other. The force receiving portion <NUM> is operatively coupled to each movable clamping member <NUM>. Accordingly, a rotation of the force receiving portion <NUM> is transferred into a rotating movement of each clamping member <NUM>. It is noted that according to a modification, a movable clamping member may be provided which is translatory movable. In such a configuration, the force receiving portion <NUM> is operatively coupled to each clamping member <NUM> such that a rotational movement of the force receiving portion is transferred into a translatory movement of the clamping member.

In the example, the force receiving portion <NUM> may be coupled to or may be integrally formed with a threaded rod <NUM>. The threaded rod <NUM> is held in the base portion <NUM> rotatably about the rotation axis A but stationary fixed in a longitudinal extension direction of the threaded rod <NUM>. In other words, the threaded rod <NUM> cannot be moved other than in a rotating manner. A force transfer member <NUM> is threadedly engaged with the threaded rod <NUM> such that a rotation of the threaded rod <NUM> leads to a displacement of the force transfer member <NUM> along the rotation axis A. The force transfer member <NUM> comprises a contact portion <NUM> configured to contact a force receiving portion 94a of the clamping member <NUM> and to apply a force on the clamping member <NUM> moving the same towards a closed position. The clamping member <NUM> is pivotably held on the base portion <NUM> by means of a pivot pin 94b. An urging member 94c is provided for urging the clamping member <NUM> towards the opened position. Accordingly, displacing the force transfer member along the rotation axis A moves the clamping member <NUM> between the open position and the closed position.

The force receiving portion <NUM> comprises a profile that allows to detachably couple a tightening member thereto. In particular, the force receiving portion <NUM> and the tightening member can be configured to be coupled to each other in a shaft and hub connection like manner.

According to the example not covered by the invention as shown in <FIG> and <FIG>, the force receiving portion <NUM> is configured as a protrusion. The force receiving portion <NUM> comprises a cylindrical portion. In the embodiment, the cylindrical portion is a hollow cylindrical portion with an inner space <NUM>. However, modifications in which the cylindrical portion is a solid cylinder are also possible.

According to the example not covered by the invention of <FIG> and <FIG>, the cylindrical portion comprises a non-round outer profile defined by a radially outer surface <NUM> and a circular inner profile defined by a radially inner surface <NUM>. According to a modification, an inverse arrangement is also possible. The non-round outer profile may comprise a polygonal shape or may comprise a hexalobular or Torx profile as shown in <FIG>. Accordingly, the force receiving portion <NUM> may be defined as a sleeve portion with a radially inner surface and a radially outer surface. In the example not covered by the invention as shown in.

<FIG> and <FIG>, an engaging section <NUM> is provided on the force receiving portion <NUM>. The engaging section <NUM> provides a portion for a positive connection with the force receiving portion. In the embodiment, the engaging section <NUM> comprises a recess which is formed in the radially inner surface of the force receiving portion <NUM>. The recess may be configured to fully extend about the rotation axis of the force receiving portion <NUM>. Hence, in the example not covered by the invention, the recess is an annular recess provided in the inner surface of the force receiving portion <NUM>. Instead of a continuous recess extending fully about the rotation axis, one or more recesses may be provided on the radially inner surface.

The force receiving portion <NUM> is rotatably accommodated in an opening <NUM> defined in the base portion <NUM>. According to the embodiment, the force receiving portion <NUM> is arranged such that its radially outer surface is supported at a distance from an inner wall <NUM> or surface of the opening <NUM>. For that, the force receiving portion <NUM> may be supported on the base portion via a flange portion <NUM> protruding radially outward from the outer surface of the receiving portion <NUM> and slidably accommodated in a recess provided on the base portion <NUM>. In this way, a space <NUM> is provided between the outer surface of the force receiving portion <NUM> and the inner wall <NUM>. This space <NUM> is suitable for receiving a guiding portion, for example an edge portion <NUM>, <NUM>, <NUM> of a coupling portion <NUM>, <NUM>, <NUM> of a tightening member <NUM>, <NUM>, <NUM>. The edge portion of the coupling portion may be slidingly supported on the inner wall <NUM> thereby providing a correct positioning of a tightening member about the rotational axis of the force receiving portion <NUM>. Such a configuration supports the tightening member in radial direction and therefore prevents a transfer of forces in radial direction on the force receiving portion.

The coupling section <NUM> further comprises an upper supporting surface <NUM>. The upper supporting surface <NUM> may be integrally formed with the base portion <NUM>. The upper supporting surface <NUM> may extend in a plane which is perpendicular to the rotation axis A of the force receiving portion <NUM>. The supporting surface <NUM> may serve as a sliding surface for supporting a tightening member detachably couplable to the coupling section <NUM>. Such a configuration provides increased stability of the tightening member due to an increased supporting surface on the clamping device. Furthermore, the supporting surface <NUM> prevents an application of a bending moment on the coupling section <NUM> as it secures a correct position of the tightening member on the coupling section. In this way, only a rotational force is transferred from the tightening member to the coupling section and tilting of the tightening member with respect to the rotational axis A of the force receiving portion <NUM> is prevented.

The clamping device <NUM> is operable by a suitable tightening member. Different tightening members <NUM>, <NUM>, <NUM>, <NUM> are available for such purpose.

In <FIG>, two possible configurations of tightening members <NUM>, <NUM> not covered by the invention are shown.

Further features of these tightening members <NUM>, <NUM> and their possible configurations will be described in greater detail with reference to <FIG>. Further tightening members for operating the clamping device <NUM> will be described later with reference to <FIG> and <FIG>. A possible application of the clamping assembly <NUM> will also be described later with reference to <FIG>.

A first example of a tightening member <NUM> not covered by the invention is shown in <FIG> and <FIG>. The tightening member <NUM> is a knob graspable by a user and detachably mountable to the above mentioned coupling section <NUM> of the clamping device <NUM>. The tightening member <NUM> comprises a coupling portion <NUM>. The coupling portion <NUM> is adapted to the configuration of the coupling section <NUM> to which it is detachably mountable. The tightening member <NUM> comprises an operating portion <NUM> graspable by a user. The operating portion <NUM> and the coupling portion <NUM> may be integrally formed, for example from plastics material. The operating portion <NUM> is provided on an outer circumferential surface of the tightening member <NUM>. An outer circumferential diameter of the tightening member is larger than a dimension of the tightening member in axial extension direction. This renders the tightening member flat and disc-like. The coupling portion <NUM> comprises an accommodating member in the form of a recess <NUM> for receiving a force receiving portion <NUM> of a clamping device <NUM>. The recess <NUM> is defined by an inner surface <NUM> which is shaped corresponding to an outer wall or radially outer surface <NUM> of the force receiving portion <NUM>. The inner surface <NUM> may define a cylindrical shape or a conical shape. In other words, the inner surface <NUM> may define a lateral surface of the recess <NUM>. The cross section of the inner surface <NUM> is configured non-round. In the example, a profile provided by the inner surface <NUM> is hexalobular and, thus, suitable for transferring a rotational force to the force receiving portion <NUM>. On the other hand, the inner surface <NUM> is configured so as to allow an insertion and detachment of the tightening member <NUM> on the receiving portion <NUM> in axial direction.

The above features would already be enough to provide a suitable tightening member for operating the clamp mechanism <NUM>. Therefore, according to an example, a tightening member with a recess <NUM> configured matingly with the receiving portion <NUM> and configured detachably couplable to the receiving portion is provided. In the example, however, optional further features are shown which may be provided in addition. For example, the tightening member <NUM> may comprise an engaging portion <NUM> which is configured to engage with a mating engaging section <NUM> of a force receiving portion <NUM>. The engaging portion <NUM> comprises a resilient engaging member <NUM> in the form of a hook like protrusion <NUM>. The protrusion extends from a base portion <NUM> limiting the recess <NUM> in axial direction. The base portion <NUM> may also be referred to as bottom portion of the recess <NUM>.

A receiving space <NUM> is formed between the protrusion and the inner surface <NUM>. On a free end portion of the protrusion <NUM>, a projection <NUM> projecting in radial direction towards the inner surface <NUM> is provided. The projection <NUM> is configured to engage with an engaging section <NUM> provided on the force receiving portion <NUM> of a clamping device <NUM>, for example a clamping device <NUM> as described before. The resilient engaging member <NUM> may be configured to snap into the engaging section <NUM> upon inserting the tightening member <NUM> on the clamping device <NUM>. In this way, a positive coupling is established between the tightening member <NUM> and the clamping device <NUM> which may prevent or at least make it more difficult for the tightening member to come off of the force receiving portion <NUM> during a tightening action. The tightening member <NUM> may further comprise an edge portion <NUM> configured to be received in the above-mentioned receiving space <NUM> defined between the inner wall <NUM> and the force receiving portion <NUM>.

A first example not covered by the invention of a tightening member is shown in <FIG> and <FIG> and will be described with reference to these drawings in the following. The tightening member <NUM> is again a knob graspable by a user and detachably mountable to the above mentioned coupling section <NUM> of the clamping device <NUM>. The tightening member <NUM> comprises a coupling portion <NUM>. Similar as in the tightening member <NUM> according to the first example, the coupling portion <NUM> is adapted to the configuration of the coupling section <NUM> to which it is detachably mountable.

The tightening member <NUM> comprises an operating portion <NUM> graspable by a user.

The operating portion <NUM> is provided by an outer circumferential surface of the tightening member <NUM>. The coupling portion <NUM> comprises a recess <NUM> for receiving a force receiving portion <NUM> of a clamping device <NUM>.

The tightening member <NUM> also comprises a securing mechanism <NUM> for temporarily fixedly coupling the coupling portion <NUM> to the coupling section <NUM> such that the tightening member is prevented from coming off of the coupling section <NUM>. A difference compared to the coupling portion <NUM> of the tightening member <NUM> according to the first example is that the securing mechanism <NUM> is configured to be releasable only by way of an active deactivation of the same by a user.

The securing mechanism <NUM> comprises an engaging portion <NUM> which is configured to engage with a mating engaging section <NUM> of a force receiving portion <NUM>. The engaging portion <NUM> comprises one or more resilient engaging members <NUM> that may be in the form of a hook-like protrusion such as a barb. The one or more engaging members <NUM>, for example protrusions, may extend from a base portion <NUM> which is received on a support portion <NUM>. The base portion <NUM> and the one or more resilient engaging members <NUM> are integrally formed, for example from a bent sheet metal. The one or more resilient engaging members <NUM> comprise a flexing section <NUM> extending along the support portion <NUM> and along a middle axis of the tightening member <NUM>. At a free end of each flexing section <NUM>, an engaging portion is formed. The engaging portion may be formed by bending a free end portion of the flexing section <NUM> such that an angle of <NUM> degrees or less is formed between the bent portion and an adjacent portion of the flexing section <NUM>. In the embodiment, the bent portion and the adjacent portion form a V-shape. The engaging portion may therefore also be referred to as barb.

The flexing section <NUM> may be arranged such that the same extends at an angle with respect to the guiding portion and/or middle axis in an unloaded condition. Accordingly, in a state in which no load is applied on the flexing section, the engaging portion is positioned radially offset from the support portion <NUM> and the middle axis of the tightening member <NUM>. Due to its resilient nature, the flexing section <NUM> tends to move the engaging portion towards this unloaded position.

A release mechanism <NUM> is provided and configured to move each engaging portion radially inwardly upon operating the same. Accordingly, the release mechanism <NUM> may be configured to elastically bend the flexing sections <NUM> for radially displacing each engaging portion inwardly towards the middle axis of the tightening member <NUM>. In the embodiment, the release mechanism <NUM> is provided for such purpose. The release mechanism <NUM> is configured for releasing a locking which is established by the resilient engaging member <NUM> when the tightening member <NUM> is inserted on a clamping device. The release mechanism <NUM> comprises an operating portion <NUM>. The operating portion <NUM> is configured as a push button. An engagement is releasable by pushing the operating portion <NUM>.

The support portion <NUM> slidably supports the operating portion <NUM> of the release mechanism <NUM> for releasing a locking established by the resilient engaging member <NUM> when the tightening member <NUM> is inserted on a clamping device. The operating portion <NUM> comprises a sleeve portion <NUM>. The base portion <NUM> and at least a portion of the flexing section <NUM> are accommodatable in the sleeve portion <NUM> by moving the sleeve portion in axial direction. The inner diameter of the sleeve portion <NUM> is smaller than a radial outer dimension of the flexing sections <NUM> so that moving the sleeve portion <NUM> on the flexing sections <NUM> along the middle axis results in a bending movement of the same and, thus, to a radially inward movement of their free end portions comprising the engaging portions. Accordingly, a mechanism is provided in which a translatory movement of the operating portion <NUM> along the middle axis is transferred into a movement of the engaging portions in radial direction for disengaging the engaging portions.

A further difference is that the tightening member <NUM> according to the first example not covered by the invention may in addition or alternatively comprise a torque limiting mechanism <NUM>. The torque limiting mechanism <NUM> is provided in a force transfer path between the operating portion <NUM> and the coupling portion <NUM>. Accordingly, the torque transferable from the operating portion <NUM> to the coupling portion <NUM> is limited to a predetermined torque.

The torque limiting mechanism <NUM> comprises a first toothed portion <NUM> operatively coupled to the operating portion <NUM> and a second toothed portion <NUM> operatively coupled to the coupling portion <NUM>. In the example the first toothed portion <NUM> and the second toothed portion <NUM> are provided on disc like portions. The second toothed portion <NUM> may be integrally formed with other portions or elements of the coupling portion <NUM>. The coupling portion <NUM> with the second toothed portion <NUM> is accommodated and held in the operating portion <NUM> such that a relative rotation between both portions is possible if the torque limiting mechanism <NUM> is in a release state. The first toothed portion <NUM> is coupled to the operating portion <NUM> so as to be integrally rotatable therewith. As long as the teeth of both portions are engaged, a torque is transmitted via the toothed engagement. The first toothed portion <NUM> is held movable along the middle axis and is prebiased towards the second toothed portion <NUM> by means of one or more urging members <NUM> applying an urging force in a direction parallel with the middle axis. The torque limiting mechanism <NUM> is configured such that the first toothed portion <NUM> is normally engaged with the second toothed portion <NUM>. The urging members <NUM> determine the force by which the first toothed portion and the second toothed portion are pressed against each other. Therefore, the one or more urging members as well as the teeth geometry of the toothed portions determine the maximum transferable torque. If a predetermined torque is exceeded, the toothed portions slip and are pushed away from each other against the urging force applied by the urging members <NUM> so that the teeth are disengaged and may pass each other without transferring any torque.

In addition or alternatively, the securing mechanism <NUM> may comprise a magnet <NUM>.

The magnet <NUM> may be provided in the center of the tightening member <NUM> in the coupling portion <NUM>. The magnet <NUM> generates an attraction force towards the coupling section <NUM>. For that, the coupling section <NUM> can comprise a portion made of metal. In particular, a portion of the force receiving portion <NUM> may be made from metal. The magnet <NUM> may be configured to provide an attraction force which is high enough for suitable holding the tightening member <NUM> on the coupling section <NUM> and the force receiving portion <NUM>. Such an attraction force may not only be suitable for holding the tightening member <NUM> on the coupling section <NUM> but may also assist a user in finding the correct coupling position when the user approaches the tightening member <NUM> towards the force receiving portion <NUM>. In other words, the magnet may be configured to attract the force receiving portion <NUM> into the coupling portion <NUM>.

The tightening member <NUM> may further comprise a lower supporting surface <NUM> configured to be supported on the upper supporting surface <NUM> of the clamping device <NUM> in a sliding manner.

A tightening member <NUM> according to a second example not covered by the invention will be described with reference to <FIG>. The tightening member <NUM> is similar to the tightening member <NUM> according to the first example not covered by the invention with the difference that the tightening member <NUM> does not comprise a securing mechanism <NUM>. The tightening member <NUM> may thus be seen as a more simplified solution compared the tightening member <NUM> but comprising a torque limiting function. Same reference signs identify same or functionally similar elements. Again, the tightening member <NUM> comprises a coupling portion <NUM> corresponding to the above mentioned coupling portion <NUM>. Furthermore, the tightening member <NUM> comprises the torque limiting mechanism <NUM> which corresponds to the torque limiting mechanism <NUM> described above. The operating portion <NUM> is operatively coupled to the coupling portion <NUM> via the torque limiting mechanism <NUM>. The torque limiting mechanism <NUM> comprises a first toothed portion <NUM> operatively coupled to the operating portion <NUM> and a second toothed portion <NUM> operatively coupled to the coupling portion <NUM>. As long as the teeth of both portions are engaged, a torque is transmitted via the toothed engagement. The function of the torque limiting mechanism <NUM> corresponds to the function of the above mentioned torque limiting mechanism <NUM>.

<FIG> shows a roof box <NUM> which is fixable to a load carrier system by means of clamping devices as described before. The load carrier system may comprise a crossbar <NUM> and may be configured like the load carrier <NUM> as will be described later with reference to <FIG>. The roof box <NUM> comprises a base <NUM> configured to support goods to be transported and an openable and closeable lid <NUM> hingedly coupled to the base <NUM> and lockable to the base <NUM> by means of locking devices <NUM>. On its bottom portion, the base <NUM> comprises mounting sections <NUM> for accommodating a portion of the crossbar <NUM> therein. The base <NUM> comprises a trough shape. An opening in the form of a longitudinal slot <NUM> is provided on the bottom portion. The opening <NUM> is configured to partially receive the before mentioned clamping device <NUM>, at least such that the clamping members <NUM> are passed through the opening <NUM> and protrude from an outer side of the bottom portion so as to be engageable with the crossbar <NUM>. The lower support surface <NUM> of the clamping device <NUM> may be supported on an edge portion limiting the opening <NUM> on opposite lateral sides. The clamping device <NUM> may be slidable in longitudinal direction of the slot so as to allow a correct positioning of the same with respect to the crossbar <NUM>.

A tightening member <NUM> according to the invention will now be described with reference to <FIG>. As shown in <FIG>, the tightening member <NUM> comprises a coupling portion <NUM> and an operating portion <NUM>. The coupling portion <NUM> and the operating portion <NUM> are operatively coupled. Accordingly, a movement of the operating portion <NUM> is transferred to the coupling portion <NUM>. The operating portion <NUM> comprises a gripping handle <NUM> which may be grasped by a user. The operating portion <NUM> is coupled to the coupling portion at a first end portion thereof which may also be referred to as coupling section <NUM>. On an opposite end portion of the operating portion <NUM>, a torque limiting free coupling portion <NUM> may be provided. The torque limiting free coupling portion <NUM> comprises an opening <NUM> with an inner profile configured to be engaged with a force receiving section of a clamping device, for example with force receiving section <NUM> of the clamping device <NUM> as described before, or with a force receiving section <NUM> of a clamping device <NUM> that will be described later in greater detail with reference to <FIG>. The torque limiting free coupling portion <NUM> is in particular useful for untightening a clamping device since a force applied may be transferred without any torque limitation. Therefore, a user may apply high forces on the force receiving sections for untightening the clamping members.

The coupling portion <NUM> comprises an accommodating portion <NUM> which in the shown embodiment is provided as a through opening. The accommodating portion <NUM> comprises an inner profile which allows to transfer a rotational force on a correspondingly shaped force receiving section. The force receiving section may be one of the before mentioned force receiving sections <NUM> and <NUM>. The force receiving section may be a bolt head or a nut, for instance. In the embodiment, a torque limiting function and a ratchet function are combined in the tightening member <NUM> in order to increase the usability for a user. For that, a torque limiting mechanism <NUM> and a ratchet mechanism <NUM> are provided. The ratchet mechanism <NUM> allows a user to apply a tightening force on the coupling sections by means of a pumping action. The torque limiting mechanism <NUM> is provided to limit a torque transferable on a coupling section. According to the embodiment, the torque limiting mechanism <NUM> and the ratchet mechanism <NUM> are provided in this order in the force transfer path from the operating portion <NUM> to the accommodating portion <NUM>. In this way, the ratchet mechanism <NUM> only transfers an already limited maximum torque to the accommodating portion <NUM>, as received from and limited by the torque limiting mechanism <NUM>.

A possible configuration of the tightening member <NUM> is shown in <FIG> and <FIG>. The coupling section <NUM> may comprise a housing portion <NUM> which is integrally formed with the operating portion <NUM>. The housing portion <NUM> comprises a cylindrical wall portion <NUM> and a bottom portion <NUM>. The cylindrical wall portion <NUM> and the bottom portion <NUM> are integrally formed. The cylindrical wall portion <NUM> extends in a direction substantially perpendicular to a main extension direction of the gripping handle <NUM>. The cylindrical wall portion <NUM> is a hollow cylindrical portion defining an interior space therein in which parts and members of the torque limiting mechanism <NUM> and the ratchet mechanism <NUM> are accommodated. The cylindrical wall portion <NUM> is an annular portion that extends about and along a middle axis C. The bottom portion <NUM> is provided at a lower axial end portion of the cylindrical wall portion <NUM> and is configured as flange <NUM> protruding or extending radially inwardly from the cylindrical wall portion <NUM>. The bottom portion <NUM> comprises an outer wall portion facing away from an interior space defined by the cylindrical wall portion <NUM> and an inner wall portion facing towards and limiting the interior space defined by the cylindrical wall portion <NUM> in axial direction. On the inner wall portion, a first toothed portion <NUM> is provided. The first toothed portion <NUM> is provided for transmitting a rotational force about the middle axis C. Furthermore, an annular recess <NUM> is provided in the cylindrical wall portion <NUM> at an upper axial end portion of the cylindrical wall portion <NUM>. The annular recess <NUM> is configured to rotatably receive the coupling portion <NUM> and to limit a movement of the coupling portion <NUM> in a direction along the middle axis C. In particular, the annular recess <NUM> is provided such that the coupling portion <NUM> may be engaged with the cylindrical wall portion <NUM> in a snap fit like manner. An opening <NUM> extending in axial direction is provided in the flange <NUM>.

The opening <NUM> is configured to rotatably support a hollow cylindrical portion <NUM> of the coupling portion <NUM>. Besides the hollow cylindrical portion <NUM>, the coupling portion <NUM> comprises a flange portion <NUM> extending radially inwardly from an upper portion of the hollow cylindrical portion <NUM>. The flange portion <NUM> defines an upper end of the coupling portion <NUM> and comprises at least a portion of the accommodating portion <NUM>, more precisely an opening granting access to the interior space of the hollow cylindrical portion <NUM>. On a radially outer edge portion of the flange portion <NUM>, force receiving portions <NUM> are provided. The force receiving portions <NUM> are provided as protrusions extending from the flange portion <NUM> substantially in parallel with an outer surface of the hollow cylindrical portion <NUM>. The force receiving portions <NUM> are arranged at a distance with respect to each other and may be arranged equidistantly along the outer edge portion of the flange portion <NUM>. In this way, accommodating spaces for receiving force transfer portions <NUM> of a second force transfer member <NUM> are provided. Free end portions of the force receiving portions <NUM> comprise engaging portions <NUM> that are configured to be engaged with the annular recess <NUM>. Radially outer surfaces of the force receiving portions <NUM> are configured to get in sliding contact with an inner surface of the cylindrical wall portion <NUM>. Accordingly, a coupling portion <NUM> as described before is held rotatable about the middle axis C and axially immovable when correctly inserted into the housing portion <NUM>. A surface of the flange portion <NUM> facing in opposite direction of the extension direction of the hollow cylindrical portion <NUM> may be configured as supporting surface that may be brought in sliding contact with a suitable support surface on a clamping device, for example an upper supporting surface <NUM> of the clamping device <NUM>.

A first force transfer member <NUM> is provided in the cylindrical wall portion <NUM> adjacent to the bottom portion <NUM>. The first force transfer member <NUM> is an annular member and may be configured in a disk like manner. The first force transfer member <NUM> comprises an annular base portion <NUM> comprising an outer diameter which is slightly smaller than the inner diameter of the cylindrical wall portion <NUM>. Accordingly, the first force transfer member <NUM> is arranged such that a radially outer surface of the same is in sliding contact with the radially inner wall of the cylindrical wall portion <NUM>. The base portion <NUM> comprises a central opening <NUM> having a diameter allowing to slidably receive the hollow cylindrical portion <NUM> of the coupling portion <NUM>. The base portion <NUM> comprises a first portion facing towards the bottom portion <NUM> and a second portion facing in opposite direction. A second toothed portion <NUM> is provided on the first portion and a third toothed portion <NUM> is provided on the second portion. The second toothed portion <NUM> is configured matingly with the first toothed portion <NUM> provided in the housing portion <NUM>. If the second toothed portion <NUM> is in engagement with the first toothed portion <NUM>, a rotational force can be transferred from the housing portion to the first force transfer member <NUM>. The first toothed portion <NUM> and the second toothed portion <NUM> form part of the torque limiting mechanism <NUM>. The third toothed portion <NUM> is configured corresponding to a fourth toothed portion <NUM> provided on a force receiving portion <NUM> of a second force transfer member <NUM>.

The second force transfer member <NUM> comprises an annular and disk like base member having a central opening <NUM> limited by an inner circumferential surface configured to get in sliding contact with an outer surface of the hollow cylindrical portion <NUM>, and a radially outer surface configured to get in sliding contact with the inner surface of the cylindrical wall portion <NUM>. The force receiving portion <NUM> is provided on an axial side of the second force transfer member <NUM>, which faces the first force transfer member <NUM>. On an opposite side of the second force transfer member <NUM>, a force transfer portion <NUM> is provided and configured to be engaged with the coupling portion <NUM>. The third toothed portion <NUM> and the fourth toothed portion <NUM> both form part of the ratchet mechanism <NUM>. The third toothed portion and the fourth toothed portion are configured to provide a freewheel like configuration in which a rotational force may only be transferred in one direction.

The force transfer portion <NUM> comprises protrusions <NUM>. The protrusions <NUM> extend in a direction substantially in parallel with the middle axis C and at a radial distance from the middle axis C at which the force receiving portions <NUM> of the coupling portion <NUM> are provided. In a mounted condition of the tightening member <NUM>, the protrusions <NUM> extend into the spaces provided between the force receiving portions <NUM>. Accordingly, a rotational force may be transferred through an engagement between the latter members. The protrusions <NUM> and the force receiving portions <NUM> partially overlap each other in axial direction. The protrusions <NUM> are axially movable with respect to the force receiving portions <NUM>. An outer surface of the protrusions <NUM> is configured to be slidable on an inner surface of the cylindrical wall portion <NUM>.

An urging member <NUM> is arranged between the coupling portion <NUM> and the second force transfer member <NUM> such that the second force transfer member <NUM> is urged away from the flange portion <NUM> along the middle axis C. The urging member <NUM> may comprise a spring <NUM>, for example a wave spring and/or one or more disk springs stacked upon each other. The urging member <NUM> comprises an opening <NUM> through which the hollow cylindrical portion <NUM> of the coupling portion <NUM> extends in a mounted condition of the tightening member <NUM>. With this configuration, the second force transfer member <NUM> is pushed on the first force transfer member <NUM> which is in turn pushed against the engaging portion <NUM> of the housing portion <NUM>. The combination of a predefined urging force exerted by the urging member <NUM> with specific shapes of the toothed portions results in a mechanism in which a ratchet mechanism <NUM> and a torque limiting mechanism <NUM> are combined leading to a space-saving and enhanced tightening member. The configuration is particular space-saving since parts <NUM>, <NUM> forming the ratchet mechanism and the torque limiting mechanism are configured as members arranged upon each other in axial direction and engaging with each other in axial direction. In this way, the dimension in axial direction of the accommodating portion <NUM> can be reduced. The force transfer members <NUM>, <NUM>, the urging member <NUM> and at least sections of the coupling portion <NUM>, preferably the entire coupling portion <NUM>, are accommodated in the housing portion <NUM>. The housing may comprise a dimension in axial direction of the middle axis C which is at most three times of the dimension of the gripping handle in this direction.

Although a ratchet mechanism is only described in connection with the invention, it is noted that such a ratchet mechanism may also be applied in the other examples of tightening members not covered by the invention in a similar way.

Although not shown in the embodiments, it is possible to provide a locking mechanism for suppressing or bypassing the torque limiting function and/or the ratchet function. In this way, the tightening members may be configured to be also used for untightening purposes that need higher torques, so that a torque-limiting-free coupling portion <NUM> as mentioned above could be omitted.

In some embodiments of the tightening members <NUM>, <NUM> and <NUM>, the parts and members of the different portions and mechanisms are substantially fully accommodated within the operating portions <NUM>, <NUM> and <NUM>. In some examples or embodiments the coupling portion does in axial direction not protrude from the operating portions or knob more than <NUM> percent of the dimension of the operating portion in this direction.

According to a modification, a torque-limiting-free coupling portion may in axial direction be provided on one side of the operating portion and a torque-limiting coupling portion may be provided on the opposite side, so that coupling portions are provided on opposite sides of the tightening member. For example, a torque-limiting-free coupling portion may be provided in an upper portion or surface of the tightening member <NUM>.

Furthermore, according to a modification, the coupling portion may comprise a protrusion instead of an accommodating portion, recess or opening, and the force receiving portion of the clamping device may comprise an accommodating portion, recess or opening instead of a protruding portion accommodatable in the tightening member. In such an inverse arrangement, other features like the torque limiting mechanism, ratchet mechanism and/or securing mechanism may be provided and suitably combined in the manners described above.

According to a modification, the ratchet mechanism and the torque limiting mechanism may be integrally combined by use of a specific force transfer member <NUM> as shown in <FIG>. Force transfer member <NUM> is configured similar to the above described second force transfer member <NUM>. Force transfer member <NUM> also comprises the force transfer portion <NUM> which is provided and configured to be engaged with the coupling portion <NUM>. It differs, however, in that its force receiving portion <NUM> differs from the force receiving portion <NUM>. More precisely, the force receiving portions <NUM>, <NUM> differ in their toothed portions.

In the configuration as shown in <FIG>, the ratchet mechanism <NUM> is provided by a pair of toothed portions, namely the third toothed portion <NUM> and the fourth toothed portion <NUM>. These toothed portions <NUM>, <NUM> each comprise teeth. Each tooth comprises a first tooth flank that extends in radial direction from the middle axis C and in a direction substantially parallel to the middle axis C. Each tooth comprises a second tooth flank that extends in radial direction and about the middle axis C at an angle with respect to the first tooth flank. With this configuration, a rotational force about the middle axis C may be transferred via the tooth flanks which extend in parallel to the extension direction of the middle axis C when moving the operating portion <NUM> in tightening direction. On the other hand, the other tooth flanks are only slightly inclined with respect to a plane extending perpendicular to the middle axis C so that a rotation of the operating portion <NUM> in opposite direction leads to a sliding movement between the tooth flanks. A sliding movement of one of the toothed portions relative to the other one urges the toothed portions away from each other. A grip between the toothed portions is thus lost leading to a relative movement of the toothed portions.

The torque limiting mechanism <NUM> is provided by an interaction between the first toothed portion <NUM> and the second toothed portion <NUM>. The first toothed portion <NUM> comprises teeth extending along the middle axis C and each having an angled surface. The second toothed portion <NUM> also comprises teeth extending along the middle axis C and each having an angled surface. The teeth of the first toothed portion <NUM> are adapted to interact with the teeth on the second toothed portion <NUM> so as to transfer torque imparted by a user therebetween. The second toothed portion <NUM> and the first toothed portion are biased against each other by means of the urging member <NUM>. If a predetermined threshold value of torque is reached, the teeth will start to slip and eventually loose grip with each other. As the grip is lost, the first toothed portion <NUM> will rotate relative to the second toothed portion <NUM>. A torque transfer exceeding the threshold torque is thus prevented. The threshold torque may be set depending on the strength of the urging member and/or the angle/inclination of tooth flanks contacting each other for torque transfer.

The embodiment as shown in <FIG> comprises two separate toothed portions embodied as discs for ratchet and torque function and, hence, an additional member compared to the modification. The engagements between the toothed portions are configured such that the ratchet mechanism transfers full torque in tightening direction and allows relative movement between the toothed portions in opposite direction. The torque limiting mechanism is configured to transfer a predetermined threshold torque in tightening direction. In opposite direction, the torque limiting mechanism transfers a torque which is higher than the torque transferable in the ratchet mechanism.

According to the modification as shown in <FIG>, the force receiving portion <NUM> comprises a dual-action toothed portion <NUM>, for providing both ratchet and torque limiting function. Teeth provided on the toothed portion <NUM> comprise different angles and/or slopes with respect to a plane extending parallel with middle axis C. None of the tooth flanks extends in a plane extending along the middle axis C. The teeth may thus act in both tightening and in opposite rotational direction and may comprises different slopes or inclinations for different functions, for example torque limiting in one rotational direction and ratchet in the opposite rotational direction. Such configuration allows the teeth to slip on each other if a predetermined threshold torque is exceeded. In tightening direction, the threshold torque is considerably higher than in the opposite rotational direction.

<FIG> shows a state in which the first toothed portion <NUM> is in engagement with the toothed portion <NUM>. The force transfer member <NUM> is biased against the flange <NUM> so that both toothed portions are normally engaged. <FIG> shows a state in which a torque exceeding a ratchet threshold value is applied in untightening direction. The first toothed portion <NUM> already moved relative to the toothed portion <NUM> as indicated by the arrow. Due to the small inclination between the cooperating tooth flanks, the toothed portion <NUM> is translated against the urging force of the urging member <NUM> under application of a relatively small rotational force by a user. <FIG> shows a state in which a torque exceeding a tightening torque threshold value is applied in tightening direction as indicated by the arrow. The first toothed portion <NUM> already moved relative to the toothed portion <NUM>. Due to the steeper inclination between the cooperating tooth flanks, higher torque is necessary for creating slipping between the tooth flanks.

Claim 1:
Tightening member (<NUM>) for tightening a clamping device (<NUM>) for fixing a roof tent to a crossbar (<NUM>), said tightening member (<NUM>) comprising
a coupling portion (<NUM>) for detachably coupling said tightening member (<NUM>) to a coupling section of said clamping device (<NUM>), said coupling portion (<NUM>) being configured engageable with said coupling section in a torque transferable manner,
an operating portion (<NUM>) configured to be grasped and rotated by a user, said operating portion (<NUM>) being operatively coupled to said coupling portion (<NUM>),
a torque limiting mechanism (<NUM>) operatively coupling said coupling portion (<NUM>) with said operating portion (<NUM>), and
a ratchet mechanism (<NUM>) configured to allow a pumping-like tightening operation by providing a one way torque transmission, said ratchet mechanism (<NUM>) comprising a third toothed portion (<NUM>) operatively coupled to said operating portion (<NUM>), and a fourth toothed (<NUM>) portion operatively coupled to said coupling portion (<NUM>),
a single urging member (<NUM>) which acts in both said torque limiting mechanism (<NUM>) and said ratchet mechanism (<NUM>),
wherein said coupling portion (<NUM>) comprises an accommodating portion (<NUM>) for at least partially receiving a force receiving portion (<NUM>) of said coupling section therein,
characterized in that
said urging member (<NUM>) urges said third toothed portion (<NUM>) and said fourth toothed portion (<NUM>) towards each other.