Abstract:
A winding device for a roller blind arrangement, in particular for a vehicle, which has a winding element having a longitudinal axis. The winding element is constructed to be rotatably supported about the longitudinal axis on a vehicle and to wind and unwind a roller blind web. The winding device further has a coil spring having an axially extending hollow space, wherein the winding element is connected to the vehicle by means of the coil spring and the coil spring enables a rotational movement of the winding element relative to the vehicle. In addition, the winding device has a rod element which is arranged in the hollow space of the coil spring for guiding the coil spring, wherein the rod element is constructed in such a manner that the rod element radially tensions the coil spring.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. national phase application filed under 35 U.S.C. §371 of International Application No. PCT/EP2014/068091, filed Aug. 26, 2014, designating the United States, which claims priority from German Patent Application No. 10 2013 109 708.1, filed Sep. 5, 2013, which are hereby incorporated herein by reference in their entirety for all purposes. 
     FIELD 
     The invention relates to a winding device for a roller blind arrangement, in particular for a vehicle, which has a winding element. Furthermore, the invention relates to a roller blind arrangement having such a winding device and a roof arrangement having such a roller blind arrangement. 
     BACKGROUND 
     There are known from the prior art roller blind arrangements which are arranged in a vehicle and in which a roller blind web is wound up to form a roller blind winding. To this end, the roller blind arrangements generally have a winding device which is constructed to wind up and unwind the roller blind web. 
     An object of the invention is to provide a winding device for a roller blind arrangement, a roller blind arrangement and a roof arrangement which enable a simple construction together with low costs and which are distinguished by a high level of mechanical stability. 
     SUMMARY 
     According to a first aspect of the invention, there is described a winding device for a roller blind arrangement, in particular for a vehicle, which has a winding element having a longitudinal axis. The winding element is designed to be rotatably supported about the longitudinal axis on a vehicle and to wind and unwind a roller blind web. The winding device further has a coil spring having an axially extending hollow space, wherein the winding element is connected to the vehicle by means of the coil spring and the coil spring enables a rotational movement of the winding element relative to the vehicle. In addition, the winding device has a rod element which is arranged in the hollow space of the coil spring for guiding the coil spring, wherein the rod element is constructed in such a manner that the rod element radially tensions the coil spring. 
     The winding device according to the first aspect makes provision for a rod element to be arranged in the hollow space of the coil spring. The rod element has, on the one hand, the function of guiding the coil spring so that the coil spring is mechanically stabilized by the internal rod element in all operating states of the winding device. On the other hand, the rod element has the function of radially tensioning the coil spring. 
     With respect to a rod element which is arranged in a loose or relaxed manner in the coil spring, for example, a rod element which is displaceably and/or rotatably arranged inside the hollow space of the coil spring, the rod element according to the first aspect affords the advantage that, substantially in all operating states of the winding device, a negative noise development, for example, a rattling of the winding device, is reduced. This is a result of the fact that the rod element in the coil spring is arranged in a substantially secure and non-positive-locking manner. That is to say, the rod element expands against it in the hollow space of the coil spring. In particular at very high speeds of the vehicle, for example, up to 250 km/h, but also with powerful vehicle excitation, such as, for example, when driving on a poor road or with unfavorable natural frequency, a disruptive noise development can thus be prevented. Furthermore, the winding device is constructed in a mechanically very simple manner. In addition, the winding device affords the advantage that a simple assembly of the winding device is possible since, for example, the rod element can be inserted in the hollow space in a simple manner and no additional connections are required with respect to the winding element or a vehicle. Consequently, any costs for the winding device itself and for the assembly thereof can be achieved. 
     According to an embodiment, the rod element has (distributed over a longitudinal rod axis) a plurality of contact locations with the coil spring. This has the advantage that the rod element tensions the coil spring over the plurality of the contact locations. Preferably, the boundary points have different peripheral angles with respect to the longitudinal rod axis so that the radial tensioning is achieved in different spatial directions starting from the longitudinal rod axis. 
     In another embodiment, the contact locations of the rod element, in a state in which the rod element is not arranged in the hollow space of the coil spring, has with respect to the longitudinal rod axis a radial spacing which is greater than half a diameter of a geometric cross-section of the hollow space of the coil spring. The state can also be referred to as a non-assembled state. The hollow space of the coil spring substantially has a circular geometric cross-section. The rod element in contrast has with respect to the longitudinal rod axis the contact locations which have different radial spacings with respect to the longitudinal rod axis, wherein the radial spacings are greater than half a diameter or a radius of the geometric cross-section of the hollow space. It is thereby possible to radially tension the coil spring. 
     According to another embodiment, the rod element is constructed in a coil and/or spiral manner. That is to say, the rod element has a curved and/or wound path with respect to the longitudinal rod axis. In particular, a center line of a geometric cross-section of the rod element is curved or not straight. It is thereby possible for the rod element to have different contact locations or abutment locations with the coil spring and to radially tension it. That is to say, the rod element has, in the non-assembled state, in a plurality of portions an expansion in a radial direction with respect to a longitudinal rod axis which is greater than half a diameter of the geometric cross-section of the hollow space of the coil spring. In this instance, it is possible for a geometric cross-section of the rod element to be smaller than the geometric cross-section of the hollow space of the coil spring. 
     According to another embodiment, the rod element is constructed in an undulating manner. 
     According to another embodiment, the rod element has thickened portions and/or projections. The thickened portions or projections produce the contact with the coil spring and radially tension it. 
     Such embodiments of the rod element enable the above advantages. 
     According to another embodiment, the winding element is a pipe element having a hollow space and the coil spring is arranged in the hollow space of the winding element. This affords the advantage that the tubular winding element forms an outer protection, for example, against wear, for the coil spring. 
     According to another embodiment, the winding device further has a bearing element, which can be securely connected to the vehicle, wherein the winding element is rotatably supported on the bearing element and is connected to the bearing element by means of the coil spring. It is thereby possible for the winding element to be able to be rotatably supported on the vehicle in a mechanically secure manner by means of the bearing element. As a result of the fact that the winding element is additionally connected to the bearing element by means of the coil spring, the coil spring can be pretensioned during a rotational winding or unwinding movement of the winding element. 
     According to a second aspect of the invention, there is described a roller blind arrangement which has a winding device according to the first aspect. The roller blind arrangement further has a roller blind web which is connected to the winding element in a mechanically secure manner. 
     The roller blind arrangement according to the second aspect substantially enables the above-mentioned advantages. 
     According to a third aspect of the invention, there is described a roof arrangement for a vehicle which has a transparent roof panel and which has a roller blind arrangement according to the second aspect of the invention, wherein the roller blind arrangement is arranged in the region of the roof panel in order to at least partially cover the roof panel. 
     The roof arrangement according to the third aspect of the invention substantially enables the above-mentioned advantages. 
     Other advantageous embodiments of the invention are explained in the following description of an embodiment. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       The invention is described in detail below with reference to the embodiment using the appended Figures. 
       In the Figures: 
         FIG. 1  is a perspective view of a roof arrangement of a vehicle, 
         FIG. 2  is a longitudinal section of the winding device, 
         FIG. 3  is a detailed view of the longitudinal section, 
         FIG. 4  is a cross-section through the detailed view according to  FIG. 3 , 
         FIG. 5  is a perspective view of a winding device for the roof arrangement, and 
         FIG. 6  is a perspective view of a rod element of the winding device. 
     
    
    
     Elements with the same construction or function are indicated with the same reference numerals in all the Figures. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a vehicle  10  with a roof arrangement which has a vehicle roof  12  which is provided with a roof opening  14 . The roof opening  14  is either closed or at least partially able to be released by means of a displaceable sliding roof cover, for example, a transparent roof panel. Alternatively, the roof opening  14  can also be closed by means of a fixedly arranged, that is to say, non-displaceable, transparent roof panel. The roof opening  14  is delimited by means of a roof opening frame  16  which is constructed on the vehicle roof  12 . The roof opening frame  16  preferably has guide rails  18  which are arranged at both sides and in which a roller blind arrangement  20  is arranged below the displaceable sliding roof cover. 
     The roller blind arrangement  20  has a roller blind web  22  which, with respect to the vehicle  10 , can be displaced forward in an unwinding direction and backward in a direction counter to the unwinding direction. If the roller blind web  22  is pushed completely backward, the roof opening  14  or the sliding roof cover or the roof panel is completely released. In a completely released state, sunlight and/or ambient air can be introduced into the inner space of the vehicle in an unimpeded manner via the roof opening  14 . However, if the roller blind web  22  is pushed completely forward, the roof opening  14  is covered by the roller blind web so that direct sunlight and/or ambient air can only partially reach the inner space of the vehicle. 
     At an end of the roller blind web  22  which is the rear end of the roller blind web  22  with respect to the longitudinal direction of the vehicle, the roller blind web  22  may be completely wound up. At another end  24  of the roller blind web, which is the front end of the roller blind web with respect to the longitudinal direction of the vehicle, there is arranged a curved pulling member  26  which a vehicle occupant can manually or electrically activate in order to thus push or pull the roller blind web  22  forward or backward, respectively. 
     In a region of the rear end of the roof opening  14 , there is arranged a winding device  30  which is described in detail below in  FIGS. 2 to 6 . 
       FIG. 2  shows a longitudinal section through the winding device  30 . The winding device  30  has a winding element  32  with a longitudinal axis L. The winding element  32  is preferably constructed as a tubular element with a hollow space  34 . Preferably, the roller blind web  22  can be wound up and unwound on the tubular winding element  32 . In a wound state, the roller blind web  22  forms a roller blind winding. 
     The winding device  30  further has a bearing bush  36  which is arranged at an axial end of the tubular winding element  32  and which is securely connected to the winding element  32 . 
     The winding device  30  further has at least one bearing element  38  which is, for example, securely connected to the roof opening frame  16  of the vehicle  10 . The bearing element  38  may also be secured to another portion of the vehicle  10 , for example, to a window frame or a door frame or to the edge of an opening of another component of the vehicle  10 . The winding element  32  is rotatably supported on the bearing element  38  with respect to the longitudinal axis L by means of the bearing bush  36 . 
     The winding device  30  has a coil spring  40 . The coil spring  40  has a large number of windings  41 . The coil spring  40  is arranged in the hollow space  34  of the tubular winding element  32 . The coil spring  40  has a hollow space  42  and a first spring end portion  44  and a second spring end portion  46 . The first spring end portion  44  and the second spring end portion  46  are arranged at two axially opposing ends of the coil spring  40 . The first spring end portion  44  is securely connected to the bearing element  38 . The second spring end portion  46  is preferably constructed in a rectangular manner (see  FIG. 3 ). The second spring end portion  46  may also be constructed separately from the remaining portions of the coil spring  40 . This would have the advantage that the sequence in the assembly of the winding device  30  could be changed, if necessary. In particular, the spring end portion  46 , which is constructed as a rectangular frame, is arranged in the region of the longitudinal axis L of the winding element  32 . 
     As illustrated with reference to  FIG. 4 , there are arranged in the winding element  32  recesses  48  which are preferably constructed in the manner of a groove. The recesses  48  of the winding element  32  are preferably separated from each other by means of webs  49 . The second spring end portion  46  is arranged in the hollow space  34  of the winding element  32  in such a manner that two lateral portions of the rectangular second spring end portion  46  engage in two groove-like recesses  48  of the winding element  32 . Consequently, the rectangular second spring end portion  46  is connected to the winding element  32  in such a manner that, when the winding element  32  is rotated about the longitudinal axis L, in particular by winding up or unwinding the roller blind web  22 , the second spring end portion  46  of the coil spring  40  can be caused to rotate by the winding element  32 . Consequently, in the event of a rotation movement of the winding element  32  about the longitudinal axis L, a tensioning or relaxing of the coil spring  40  can be enabled. 
     A damping element  50  is arranged radially between the coil spring  40  and the tubular winding element  32 . The damping element  50  preferably completely or partially comprises a plastics material, in particular an elastomer material. By means of the damping element  50 , direct contact between the coil spring and the winding element  32  in the region of the windings  41  can be prevented. Consequently, the damping element  50  may provide an effective contribution to noise damping of the winding device  30 . 
     A rod element  52  is arranged in the hollow space  42  of the coil spring  40 . The rod element is preferably arranged over a significant portion of the axial length of the coil spring  40  in the region of the windings  41  so that the rod element  52  can guide the coil spring  40  in a particularly effective manner. The rod element  52  has a first rod end portion  54  and a second rod end portion  56  which are arranged at two axial, opposing ends of the rod element  52 . The first rod end portion  54  abuts the bearing element  38 . The second rod end portion  58  abuts the frame-like second spring end portion  46  of the coil spring  40 , as illustrated with reference to  FIGS. 2 and 3 . As a result of the abutment of the rod element  52  in the region of the rod end portions  54 ,  56  with the bearing element  38  and the second spring end portion  56 , it becomes possible for the movement of the rod element  52  to be limited in the direction of the longitudinal axis L. It can thereby be ensured that the rod element  52  substantially always remains in an identical axial position with respect to the coil spring  50 . It can consequently be ensured that the rod element  52  can guide the coil spring  40 . 
       FIG. 5  is a partial exploded view of the winding device  30 . In this instance, it can clearly be seen that the winding element  32  surrounds the damping element  50 . The coil spring  40  and the rod element  52  are arranged within the damping element  50 . In this instance, the second spring end portion  46  is also shown. 
     The rod element  52  preferably comprises polyoxymethylene or has polyoxymethylene. Polyoxymethylene is a mechanically very stable material and has a high breaking resistance. 
     As illustrated with reference to  FIG. 6 , the rod element  52  is constructed in a helical manner. This means that the rod element  52  has, at outer sides with respect to a longitudinal rod axis  58  which connects central locations of geometric cross-sections of the first rod end portion  54  and the second rod end portion  56 , different spacings with respect to the longitudinal rod axis  58 . That is to say, the rod element  52  has a central line  59  of a cross-section extent with respect to the longitudinal rod axis  58  which is curved and which does not coincide with the longitudinal rod axis  58 . The geometric cross-section of the rod element  58  is substantially identical with respect to a length of the rod element  52  and circular. As a result of the helical shape, the rod element  52  expands against the coil spring  40  and tensions the winding device  30  per se. As a result of the helical configuration of the rod element  52 , a three-dimensional abutment of the rod element  52  within the coil spring  40  is achieved so that the coil spring  40  is radially tensioned. Consequently, a rattling of the winding device  30 , in particular at high speeds of up to 250 km/h, is prevented. It is consequently practically impossible for disruptive noise to be produced. 
     As a result of the helical configuration of the rod element  52 , the rod element  52  has a plurality of contact locations  60  with the coil spring  40 , as shown with reference to  FIGS. 2 and 6 . In a non-assembled state of the rod element  52 , that is to say, when the rod element  52  is not inserted or introduced into the hollow space  42  of the coil spring  40 , the contact locations  60  have with respect to the longitudinal rod axis  58  a larger radial spacing than half a diameter or a radius of the hollow space  42  of the coil spring. With respect to the longitudinal axis L of the winding element  32 , the contact locations  60  consequently have a larger radial spacing with respect to the longitudinal axis L than half a diameter of the hollow space  42  of the coil spring  40 . The contact locations  60  have, with respect to the longitudinal rod axis  58  or the longitudinal axis L of the winding element  32 , different peripheral angles so that the expansion or the tensioning is carried out in different spatial directions. 
     When the rod element  52  is introduced into the hollow space  42  of the coil spring  40 , the application of a force is consequently required for assembly. This is a result of the fact that the rod element  52  radially tensions the coil spring  40  and during the assembly a friction force thus has to be overcome. In the assembled state, the rod element  52  expands the coil spring  40  radially outward and consequently tensions it. 
     Alternatively, the rod element  52  may also be constructed in an undulating or helix-like manner. Alternatively or additionally, the rod element  52  may also have projections or formations which also ensure the radial tensioning of the coil spring  40 . 
     Depending on a tension state of the coil spring  40 , both the length of the coil spring  40  in the direction of the longitudinal axis L and the diameter thereof change. Consequently, with a completely deployed roller blind web  22 , that is to say, which is unwound from the winding device  30 , the length of the coil spring  40  is at a maximum and the diameter of the coil spring  40  is at a minimum. With a roller blind web  22  which is completely wound up, however, the length of the coil spring  40  is at a minimum and the diameter of the coil spring  40  is at a maximum. The rod element  52  is preferably sized in such a manner that the coil spring  40 , even at the maximum length of the coil spring  40 , can be safely guided and stabilized by the rod element  52 . The rod element  52  is further preferably sized in such a manner that the radial spacing of the contact locations  60  in the non-assembled state described above is always greater than half the diameter of the hollow space  42  of the coil spring  40  in the non-assembled state. Consequently, in the event of a change of the diameter of the coil spring  40 , the rod element  52  is intended to be prevented from being loosely received in the coil spring  40 , which would lead to rattling and negative noise developments. 
     The winding device  30  described with reference to the embodiment can, in addition to the roof arrangement for a vehicle, also be provided in other arrangements. Such other arrangements are, for example, roller blind arrangements for glass roofs in buildings, in particular in conservatories or on house roofs. The roller blind webs further do not necessarily have to act as sun protection, but can also, for example, be used as mosquito protection grids. 
     The invention is not limited to the embodiment set out. In particular, it is possible to combine the features differently with each other so that such arrangements of the invention are also included. It is particularly decisive for the rod element  58  to be used in the described embodiments so that the radial tensioning of the coil spring  40  is achieved. The structural configuration of the winding device  30 , which is described with reference to  FIGS. 2 to 6 , can be seen only by way of example and may have other structural configurations and arrangements.