Abstract:
A distance device bridges a free space between a carrier part and a roof body for fastening a roof luggage rack, such as a roof rail, a roof strip or the like, on a vehicle roof by a threaded screw, with a support part and a counter support part. The support part and counter support part are held together by a threaded connection and can be adjusted relative to each other in order to set a bridging length. The support part or counter support part is carried along by a rotationally engaging connection with the threaded screw when it is screwed into a counter thread of the roof luggage rack or carrier part as far as a contact position with the carrier part or the roof body. The rotationally engaging connection has a plastic carrier into which the thread of the threaded screw is/has been screwed for carrying along with frictional resistance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 371 U.S. National Stage of International Application No. PCT/EP2009/008539, filed Dec. 1, 2009. This application claims priority to German Patent Application No. DE 10 2008062894.8, filed Dec. 12, 2008. The disclosures of the above applications are incorporated herein by reference. 
     FIELD 
     The invention relates to a distance device for bridging a free space between a carrier part and a roof body for fastening a roof luggage rack, such as a roof rail, a roof strip or the like, on a vehicle roof by means of a threaded screw, with a support part and a counter support part, wherein support part and counter support part are held together by a threaded connection and can be adjusted relative to each other in order to set the bridging length in that the support part or counter support part is carried along by a rotationally engaging connection with the threaded screw when it is screwed into a counter thread of the roof luggage rack or carrier part as far as a contact position with the carrier part or the roof body. 
     BACKGROUND 
     Roof luggage racks, such as roof rails, roof strips and the like are mounted on the vehicle roof of a vehicle, wherein they are not supported on the roof body which consists of thin sheet metal but are connected to a carrier part of the roof of the vehicle by means of a distance device. The carrier part can absorb forces which are present with heavy roof loads. The carrier part is invisible from the outside, as it lies below the sheet metal of the roof body. The carrier part is also invisible from the interior of the vehicle, as it is covered by the internal cladding (roof lining). A free space, which is variable in size due to manufacturing tolerances, is formed between the underside of the roof body and the top of the carrier part. When the roof luggage rack is fitted, it must be ensured that there is a secure connection to the carrier part, but at the same time no pressure is exerted on the roof body which would lead to deformation of the sheet metal and be perceived as annoying distortion. 
     Distance devices which require elaborate fitting have been disclosed. For example, it is possible to use distance pieces of different lengths, wherein the fitter chooses the appropriate distance piece for the size of the free space available in each case. Furthermore, it has been disclosed that the distance piece has two parts which are held together by a threaded connection and which are adjusted for bridging the free space in that there is a rotational engagement with a threaded screw which is provided for fastening the roof luggage rack so that, when it is screwed in, the threaded screw displaces the two parts by means of the threaded connection by carrying them along to such an extent that the free space is bridged. A spring element, which is provided with leaf spring sections and which both enables the threaded screw to be pushed in, that is to say enables an axial movement thereof, and guarantees that a clamping force is exerted on the screw in such a way as to enable the above-mentioned rotational engagement with the threaded screw for setting the bridging length of the free space, is provided to enable the threaded screw to perform the carrying-along action. The spring element which is provided with leaf spring sections leads to a complex design. 
     SUMMARY 
     The invention is based on the object of specifying a simple distance device which is easy to fit. 
     Taking into account the characteristics mentioned in the introduction, this object is achieved in that the rotationally engaging connection has a plastic carrier into which the thread of the threaded screw is/has been screwed for carrying along with frictional resistance. The embodiment in the form of a plastic carrier guarantees a simple frictional carrying-along due to the relatively soft plastic material compared with the metal of the threaded screw which, after completion of the carrying-along process, allows the threaded screw to be turned further without any problems in order to fasten the roof luggage rack. The use according to the invention of a simple plastic carrier allows known distance devices which work on a principle which differs from that of the invention also to be used in accordance with the invention in that they can be easily fitted with the plastic carrier. This can be inserted without difficulty into the receptacle for the threaded screw. 
     According to an improvement of the invention, it is provided that the plastic carrier has an undersized internal thread for the threaded screw, an undersized screw channel and/or a receiving channel for self-cutting insertion of the thread of the threaded screw. If the undersized internal thread is provided, then the threaded screw can only be screwed into the undersized internal thread with appropriate frictional resistance, as a result of which the rotationally engaging connection is realized. If an undersized screw channel is provided, then the undersized screw channel binds on the spiral roof of the thread of the threaded screw, as a result of which the rotational carrying-along is likewise ensured. At the same time, with this embodiment, the threaded screw can also be moved axially in the undersized threaded channel with appropriate axial force. Furthermore, it is possible to use a receiving channel for self-cutting insertion of the thread of the threaded screw. The cutting of the thread of the threaded screw ensures a frictional connection which guarantees a rotational engagement. With the undersized internal thread and with the receiving channel, damage can occur to the thread due to a milling action of the screw thread if the threaded screw is screwed in further after the bridging dimension of the distance device has been set. Any combinations of the above-mentioned solutions are of course possible. 
     According to an improvement of the invention, it is provided that the plastic carrier is designed in the form of a carrier sleeve which has an internal channel for the threaded screw. The internal channel can in particular be the undersized internal thread, the undersized screw channel or the receiving channel for self-cutting. 
     It is advantageous when the carrier sleeve is fixed in the support part or counter support part or forms the support part or counter support part. In the first case, the carrier sleeve forms an insert part. In the second case, the whole support part or counter support part is designed in one piece and in doing so simultaneously realizes the carrier sleeve. 
     An improvement of the invention provides the creation of a rotational locking device between carrier sleeve and support part or counter support part, wherein the rotational locking device is designed in the form of an out-of-round external cross section of the carrier sleeve and a correspondingly shape-matched internal cross section of a cutout of the support part or counter support part. This guarantees that the carrier sleeve, which is set into rotation due to the engaging connection, turns the support part or counter support part with it in order to set the length of the distance device. 
     It is advantageous to provide a holder which can be or is fastened to the support part or counter support part in order to fix the support part or counter support part to the carrier part or to the roof structure. As a result of this measure, one part of the parts which are held together by the threaded connection is held stationary and consequently is unable to turn when the other part is turned. The holder also simplifies fitting, as the distance device does not leave its fitting position unintentionally. This also applies in pre-assembly when the bridging length has not yet been set. 
     Preferably, the holder can be fastened to the support part or counter support part by means of a clip fastener. The clip fastener holds the holder on the support part or counter support part so that it cannot turn. Alternatively, it is also possible for the holder to be designed in one piece with the support part or counter support part. 
     According to an improvement of the invention, it is provided that the holder has supporting and rear-engaging elements for fastening to the carrier part or to the roof body. Preferably, the holder is fastened to an edge region of a through-opening of the carrier part or roof body. The supporting elements are supported on the edge region of the through-opening, for example on the underside of the roof body, and the rear-engaging elements rest on the edge region of the through-opening on the top of the roof body so that a secure fixing to the carrier part or the roof body is guaranteed by the support and the rear engagement. The supporting and/or rear-engaging elements can be made from elastic material so that, for fastening, they can be moved and subsequently moved back again, as a result of which the support and/or rear engagement can be realized. 
     The holder is preferably designed in the form of an annular holder which encompasses the support part or counter support part. Consequently, it is pushed over the support part or counter support part like a ring and then preferably secured by means of the clip fastener. 
     An improvement of the invention provides that the support part is designed as an outer sleeve with an internal thread. Preferably, it is provided that the counter support part is designed as an inner sleeve which is provided with an external thread. The external thread of the inner sleeve is screwed into the internal thread of the outer sleeve, as a result of which the above-mentioned threaded connection between support part and counter support part for setting the bridging length is realized. 
     Furthermore, it is advantageous when the supporting and rear-engaging elements of the holder are designed to fix to the edge region of a through-opening of the roof body. This has already been discussed in detail above. Furthermore, it has been mentioned that the supporting and/or rear-engaging elements can be made of elastic material; preferably it is provided that they are formed by or have elastic retaining arms. 
     The invention further relates to a fastening arrangement having a vehicle roof which has at least one carrier part and one roof body, a roof luggage rack and a distance device, in particular according to one or more of the above-mentioned embodiments, for fastening the roof luggage rack, such as a roof rail, a roof strip or the like, on the vehicle roof, wherein the roof body has a through-opening, to the edge region of which the distance device can be fastened, and wherein the distance device protrudes through the through-opening towards the roof luggage rack to rest thereon. This protrusion takes place by means of a support part or counter support part of the distance device without contact with the through-opening so that no deforming forces act on the roof body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the invention with reference to an exemplary embodiment, namely: 
         FIG. 1  shows a schematic section view through a fastening arrangement with a distance device, 
         FIG. 2  shows the distance device in perspective view at an angle from below, 
         FIG. 3  shows an exploded view of the distance device, 
         FIG. 4  shows a perspective view of the distance device at an angle from above with threaded screw, 
         FIG. 5  shows a view on the distance device and a roof body of a vehicle from above, and 
         FIG. 6  shows of view on the arrangement of  FIG. 5  from below. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a section of a fastening arrangement  1  having a vehicle roof  2 , of which a region of a carrier part  3  and a region of a roof body  4  is shown. The roof body is a roof panel of the vehicle, in particular a motor vehicle, which is visible from the outside; the carrier part  3  is a stable component of the vehicle roof  2  which is not visible either from the outside or from the interior of the vehicle and is capable of absorbing high forces. Between carrier part  3  and roof body  4  is located a distance device  5  with which is associated a threaded screw  6  by means of which a roof luggage rack  7  is retained outside on the roof of the vehicle, wherein only a small section of the roof luggage rack  7  is shown. 
     It is clear from  FIG. 1  that a head  8  of the threaded screw is clamped against the underside  9  of the carrier part  3 , that because of the clamping force applied to the roof luggage rack  7  by the threaded screw  6  the underside of the distance device  5  is supported on the top  11  of the carrier part  3 , and that the top  12  of the distance device  5  is supported on the underside  13  of the roof luggage rack  7  so that the roof luggage rack  7  is securely clamped to the carrier part  3  without forces which could lead to a deformation of the roof body  4  acting on the roof body  4 . The roof body  4  has a through-opening  14  for the threaded screw  6  and the distance device  5  to protrude through. A threaded shaft  15  of the threaded screw  6  is screwed into a threaded hole  16  (counter thread) on the underside  13  of the roof luggage rack  7  to achieve the mentioned clamping. The roof luggage rack  7  can be designed as a roof strip, for example. From all this, it is clear that the distance device  5  spans a free space  17  with a bridging length A, wherein—depending on manufacturing tolerances—the bridging length A can vary in individual vehicles and/or is of a different magnitude in different vehicle types, so that the distance device  5  must be capable of compensating for these differences when fitted. The design of the distance device  5  will therefore be discussed in detail below. 
     According to  FIGS. 1 to 4 , the distance device  5  has a support part  18  and a counter support part  19 . The support part  18  is designed as an outer sleeve with an internal thread  20  and the counter support part  19  as an inner sleeve with an external thread  22 . Support part  18  and counter support part  19  are connected to one another by means of the internal thread  20  and the external thread  22 , that is to say these two parts are screwed together. The further the inner sleeve  19  is screwed out of the outer sleeve  18 , the longer the distance device  5  and therefore the bridging length A becomes. In the not yet fitted state, the inner sleeve  19  is screwed into the outer sleeve  18  to such an extent as to provide a total length of the distance device  5  which is less than the bridging length A. Internal thread  20  and external thread  22  form a threaded connection  24  between support part  18  and counter support part  19 . 
     The counter support part  19  has a cutout  25  which—particularly according to FIGS.  2  and  3 —can have an octagonal internal cross section. A rotationally engaging connection in the form of a plastic carrier  28  is arranged, in particular axially inserted, in the cutout  25 , wherein the plastic carrier  28  is preferably designed as a carrier sleeve. The carrier sleeve  28  has an external cross section, which is shape-matched to the internal cross section of the control  25  and which consequently can also be designed octagonally. Other out-of-round, that is to say non-circular, cross sections, which lead to a rotational locking arrangement being formed between counter support part  19  and plastic carrier  28 , can be used in place of the octagonality. 
     The plastic carrier  28  has an internal channel  32  for accommodating the threaded shaft  15  of the threaded screw  6 , wherein, in the present exemplary embodiment, the internal channel  32  is designed as an undersized screw channel, i.e. the threaded shaft  15  has no play in the undersized screw channel  32 , but the smooth channel walls of the undersized screw channel  32  exert a radial force on the threaded shaft  15 , which however is not so great that the threaded screw  6  can no longer turn relative to the plastic carrier  28 , but the parts can turn relative to one another above a certain specifiable torque. Furthermore, it is possible to move the threaded shaft  15  axially within the undersized screw channel  32 , which however likewise requires an appropriate movement force due to the clamping effect of the plastic carrier  28  on the threaded shaft. 
     A holder  34 , which is releasably fastened to the support part  18 , is provided in order to be able to hold the distance device  5  stationary, and in particular so that it cannot turn, when it is fitted to the roof body  4 . The holder  34  is designed as an annular holder. It has a ring  36  which is pushed axially onto the support part  18  to such an extent that a clip fastener  37  engages with the support part  18 . The clip fastener  37  has two diametrically opposed latching hooks  38  which engage radially in axial recesses  39  of the support part  18  which are open at the edge. At the same time, a ring face surface  40  of the ring  36  abuts a ring step  41  of the support part  18  so that no axial movement of the holder  34  is possible on the support part  18 . The latching hooks  38  which engage in the recesses  39  prevent a relative rotation of holder  34  and support part  18 . Supporting elements  42  and rear-engaging elements  43  are formed preferably in one piece on the outer surface of the ring  36  of the holder  34 , wherein preferably three supporting elements  42  with equal angular spacing and three rear-engaging elements  43  with equal angular spacing are provided. Supporting elements  42  and rear-engaging elements  43  are designed in the form of arms, that is to say they are able to spring radially on account of the flexibility of the material, in particular of plastic material. The rear-engaging elements  43  have rear-engaging tongues  44  which point radially outwards. If—according to FIGS.  5  and  6 —the distance device  5  is to be fastened in the through-opening  14  of the roof body  4 , then the distance device  5  is inserted in the through-opening  14  from the outside, that is to say from outside the vehicle, in such a way that the supporting elements  42 , which run substantially at an angle to the longitudinal extension of the distance device, spring radially inwards. As soon as the rear-engaging tongues  44  rest on the top of the roof body  4 , the supporting elements  42  snap elastically radially outwards by leaving the edge of the through-opening  14  and in this way are supported on the underside of the roof body  4 . As a result, the distance device  5  is securely clipped in the through-opening  14 , wherein—according to FIGS.  5  and  6 —protection against turning is also provided due to the out-of-round cross section of the through-opening  14  and the likewise out-of-round structure of the distance device  5 . Furthermore, it can be seen from  FIGS. 5 and 6  that the diameter of the support part  18  is smaller than the smallest diameter of the through-opening  14  so that—according to FIG.  1 —there is no contact between roof body  4  and support part  18  and, furthermore, the support part  18  protrudes outwards from the through-opening  14  to such an extent that a roof luggage rack  7  which is fastened here is supported on the support part  18  and not on the roof body  4 . 
     The functionality is as follows: To fit the roof luggage rack  7  on the vehicle roof  2 , a distance device  5 , in which the support part  18  and counter support part  19  are screwed together to a small bridging distance, is initially clipped from the outside—as described above—into the through-opening  14  of the roof body  4 . With the roof lining not yet fitted or with the roof lining removed, the threaded screw  6  is then fed through a through-hole  45  of the carrier part  3  and pressed into the undersized screw channel  32  from the interior of the vehicle. Due to the undersize, this requires an appropriate force and can only be carried out in an axial direction until the free end of the threaded shaft  15  of the threaded screw  6  comes into contact with the threaded hole  16  of the roof luggage rack  7  which is placed on the vehicle roof  2  from the outside. The threaded screw  6  is now screwed into the threaded hole  16  with a suitable tool. As the carrier sleeve  28  is carried along at the same time by the turning of the threaded screw  6  due to a frictional resistance, the counter support part  19  is screwed axially out of the support part  18  until the underside  10  of the counter support part  19  comes into contact with the top  11  of the carrier part  3 . In this situation, the threaded screw  6  is not yet completely screwed into the threaded hole  16 . If the threaded screw  16  is now turned further, then the frictional resistance between the plastic carrier  28  and the threaded screw is overcome. The screw  6  is turned until the roof luggage rack  7  is secure. In doing so, it is supported by its underside  13  on the top  12  of the support part  18 , the underside  10  of the counter support part  19  is supported on the top  11  of the carrier part  3  and the head  8  of the threaded screw  6  rests on the underside  9  of the carrier part  3 . The top  46  of the roof body  4  is at a distance S from the underside  13  of the roof luggage rack  7  which is greater than the thickness of the rear-engaging tongues  44  so that these are not crushed. The roof luggage rack  7  is therefore firmly and securely connected to the carrier part  3  of the vehicle roof  2  without inadmissible forces being exerted on the roof body  4 . 
     Naturally, a plurality of fastening arrangements  1  is preferably provided over the longitudinal extension of the roof luggage rack  7 .