Abstract:
A seat assembly includes a seat element constituting a component of the seat structure of a motor vehicle seat, a tubular drive element connected pivotably around its longitudinal axis to the seat element that constitutes a component of a displacement arrangement for an adjustable seat part, for example, for a height adjustable seat cushion, as well as a preferably electrically operated weight sensor for the detection of seat occupancy using the weight of a person sitting in the corresponding motor vehicle seat. Through the detection of seat occupancy, it is possible to control various functional groups of a motor vehicle as a function of seat occupancy, such as, for example, automatic occupancy- and/or weight-dependent adjustment of certain seat components as well as the occupancy- and/or weight-dependent deployment of an airbag module.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
   This application claims priority of German Patent Application Number 103 06 541.5, filed on Feb. 13, 2003, and German Patent Application Number 10 2004 006 051.7, filed on Jan. 30, 2004. 
   BACKGROUND OF THE INVENTION 
   A seat assembly for a motor vehicle seat comprises a seat element constituting a component of a seat structure of a motor vehicle seat, a tubular drive element (drive tube) connected pivotably (around its longitudinal axis) to the seat element constituting a component of a displacement arrangement for an adjustable seat part (such as a height adjustable seat cushion), as well as a weight sensor (which in an exemplary embodiment is electrically operated) for the detection of seat occupancy using the weight of a person sitting in the corresponding motor vehicle seat. Through the detection of seat occupancy, it is possible to control various functional groups of a motor vehicle as a function of that seat occupancy such as for example, automatic occupancy- and/or weight-dependent adjustment of certain seat components as well as the occupancy- and/or weight-dependent deployment of an airbag module. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to specify a new, advantageous arrangement of a weight sensor on a seat structure. 
   Accordingly, the tubular drive element pivotably connected with a seat element is mounted on the seat element via the weight sensor. 
   The solution according to the invention has the advantage that a protected arrangement of the weight sensor between the tubular drive element and the associated seat element is possible in which the sensor can extend into the tubular drive element. The solution according to the invention further enables the integration of the weight sensor into a preassembled modular unit. This results in simple assembly and ease of assembly of the seat assembly as a whole. 
   The term weight sensor here means any sensor that generates sensor signals as a function of the force of the weight occurring when the seat is occupied. 
   The seat structure comprises all structural elements of a motor vehicle seat including its subassembly, which may in some embodiments include telescoping guide rails. 
   In one embodiment of the invention, the tubular drive element is pivotably mounted on a mounting section of the weight sensor which extends axially into the inside of the tubular drive element or into a mounting element forming an adapter (tube adapter) nonpivotably connected to the tubular drive element. The weight sensor can be adapted to tubular drive elements of different diameters using an adapter which in a particular embodiment takes the form of an adapter bushing. 
   In an exemplary embodiment of the present invention, the pivotable mounting of the tubular drive element on the weight sensor occurs via a mounting element arranged on the tubular drive element which can be screwed on the inside or outside wall of the tubular drive element via suitable threads. The mounting element can also be attached thereto via any integral connection (such as that produced by welding), via a frictional connection (produced by application of pressure) or a formfitting connection. Furthermore, an integral attachment of a mounting element (serving as a tube adapter) on the tubular drive element can also occur using an adhesive, for example, by gluing the mounting element against the inside wall of the tubular drive element. The adhesive also serves to compensate or reconcile tolerances and holds the mounting element rattle-flee in the tubular drive element. 
   In a further embodiment, the gluing of the mounting element into the tubular drive element occurs after making a preassembled assembly from the weight sensor and the mounting element pivotably mounted thereon. To this end, the mounting element is axially retained on the mounting section of the weight sensor. For this, known locking elements such as nuts can be used. Along one direction, the axial retention can even be implemented by the main body of the weight sensor itself. 
   In yet another embodiment, the mounting element is designed having multiple parts wherein one part of the mounting element has a bearing area for pivotable mounting on the mounting section of the weight sensor and the other part of the mounting element has an attachment area for nonpivotable connection to the tubular drive element. The two parts of the mounting element can be nonpivotably connected to each other via a screw connection; in an exemplary embodiment the two parts of the mounting element are each designed as threaded bushings, of which one has on its inside the bearing area and on its outside a thread and the other has on its inside a thread and on its outside the attachment area for the connection to the tubular drive element. This can also be designed as a bearing bushing with the use of a one-piece mounting element. 
   According to one embodiment of the invention, the mounting section of the weight sensor serves as a radial bearing for the tubular drive element and has an additional support element to axially retain the tubular drive element in one direction. The support element can be attached as a separate element on the mounting section or can be formed in one piece thereon. Along the opposing axial direction, the tubular drive element can be secured against axial displacement by the main body of the weight sensor. 
   In a further embodiment of the invention, the mounting section of the drive weight sensor serves for both the radial and axial mounting of the tubular drive element. The mounting of the tubular drive element on the mounting section of the weight sensor can in this case be implemented using meshing threaded areas. 
   In an exemplary embodiment, the weight sensor is an electrically operated sensor. Using this sensor, the bending strain acting on the tubular drive element is detected upon loading of the motor vehicle seat with a motor vehicle passenger positioned thereon. The exemplary embodiment enables an arrangement of the weight sensor such that the transverse forces causing bending strain are supported under defined, reproducible conditions. To this end, the weight sensor is arranged nonpivotably (for example by means of a lock nut) on the seat element serving for the mounting of the tubular drive element. 
   According to an alternative embodiment, the weight sensor includes two sensor parts nonpivotably connected to each other, one of which serves to pivotably mount the tubular drive element and the other to produce a nonpivotable connection with the associated seat element. This alternative embodiment of the invention enables a particularly advantageous integration of the weight sensor into the seat assembly between the tubular drive element and the associated seat element in which flexible conditions are produced for the creation of preassembled modular units including the weight sensor. 
   The tubular drive element can be a drive tube for seat height displacement which is rotated adjust the seat height and which runs from one seat side to the other seat side as a transverse tube at a right angle to the longitudinal seat direction. 
   The seat element serving to mount the drive tube can be a seat side part or a guide rail for longitudinal displacement of the seat or a mounting angle attached thereon. 
   Additional characteristics and advantages of the invention will become clear with the following description of exemplary embodiments with reference to the figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1   a  shows a first exemplary embodiment of a weight sensor preassembled on a drive tube, through which weight sensor the drive tube can be pivotably mounted on a seat part; 
       FIG. 1   b  shows an alternative to the embodiment of  FIG. 1   a  concerning the axial retention of the drive tube relative to the weight sensor; 
       FIG. 1   c  shows another alternative to the embodiment of  FIG. 1   a  concerning the axial retention of the drive tube relative to the weight sensor; 
       FIG. 2   a  shows an alternative to the embodiment of  FIG. 1   a  concerning the pivotable mounting of the drive tube on the weight sensor; 
       FIG. 2   b  shows an alternative to the embodiment of  FIG. 2   a  concerning the axial retention of the drive tube relative to the weight sensor; 
       FIG. 2   c  shows another alternative to the embodiment of  FIG. 2   a  concerning the axial retention of the drive tube relative to the weight sensor; 
       FIG. 3  shows the embodiment of  FIG. 2   c  together with a seat element, on which the drive tube is pivotably mounted via the weight sensor; 
       FIG. 4  shows an alternative to the embodiment of  FIGS. 1   a  and  2   a  concerning the pivotable mounting of the drive tube on the weight sensor and the axial retention of the drive tube relative to the weight sensor; 
       FIG. 5   a  shows a drive tube pivotably mounted on a side part of a seat via a two-part weight sensor; 
       FIG. 5   b  shows an alternative to the embodiment of  FIG. 5   a  concerning the attachment of the weight sensor on the side part of the seat; 
       FIG. 6  shows an alternative to the exemplary embodiment of  FIG. 5   b  concerning the pivotable mounting of the drive tube on the weight sensor; 
       FIG. 7  shows the embodiment of  FIG. 5   a  together with additional seat components; 
       FIG. 8  shows another exemplary embodiment of a weight sensor assembled on a drive tube, through which weight sensor the drive tube can be pivotably mounted on a seat part; 
       FIG. 9  shows a schematic side view of a motor vehicle seat. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 9  schematically depicts a motor vehicle seat, the seat structure of which comprises two seat side parts S arranged on the two longitudinal sides of the motor vehicle seat S (only one of which is discernible in the side view according to  FIG. 9 ).  FIG. 9  also depicts a seat back R tiltably connected to the two seat side parts S. The seat side parts S serve to accommodate a seat bucket, on which a seat cushion providing a seating surface for a motor vehicle passenger is arranged. The seat side parts S are each hingedly connected via front and rear adjusting levers V with a longitudinal seat guide that comprises a first guide rail, subrail U fixedly arranged on a car body as well as a seat side guide rail displaceable relative to the rail fixed to the car body, upper rail O. 
   For adjustment of the seat height (which comprises in the embodiment shown the vertical distance of the seating surface from the longitudinal seat guide), the two adjusting levers V are hinged. One of the adjusting levers is associated with an adjustment drive and the other adjusting lever is a passive adjustment lever which merely reproduces the hinged movement induced by the first adjusting lever. 
   In the exemplary embodiment of a seat structure depicted in  FIG. 9 , a drive tube  2  associated with the rear adjusting lever V forms the lower axis about which the adjusting lever V is rotatably hinged to the upper rail O of the longitudinal seat guide. The drive tube  2  is a transverse tube that runs from the rear adjusting lever V on one longitudinal side of the motor vehicle seat at a right angle to the longitudinal seat direction x to the corresponding rear adjusting lever of the seat side part arranged on the other longitudinal side of the motor vehicle seat. In alternative embodiments, the seat direction x comprises either the longitudinal axis of the vehicle, or longitudinal direction of the rails. 
   Weight sensors are known that detect the occupancy of a known motor vehicle seat by a motor vehicle passenger. The sensors operate by using the difference in weight between an occupied and an unoccupied seat and, optionally, the weight of the user of the seat as well as by determining the position and size of the user of the seat by determining a fictitious center of gravity. As a function of the occupancy of the seat, it is possible, for example, to control the longitudinal displacement of the seat by means of guide rails O, U or an air bag module associated with the motor vehicle seat. 
     FIG. 1   a  depicts a first exemplary embodiment the invention having a weight sensor  3  in a motor vehicle seat of the type depicted in  FIG. 9 . Accordingly, the weight sensor  3  constitutes an assembly that can be preassembled together with the drive tube  2  and in which the drive tube  2  is pivotably mounted on the weight sensor  3 . The weight sensor  3  is an electrically operated sensor the function of which will be presented in greater detail below with reference to  FIG. 3 . The weight sensor  3  has a main body  30  provided with an external thread  33 . The sensor components necessary to generate a weight-dependent sensor signal as well as a journal  35  spaced at a distance from the main body  30  in the axial direction A (longitudinal direction of the drive tube  2 ) are arranged in the main body  30 . The journal  35  extends into the inside of the drive tube  2 . 
   A mounting element  4  in the form of a bearing bushing with a thread  41  is screwed on the threaded exterior of the wall  20  of the drive tube  2 . This mounting element  4  has a mounting section  44  running from the end of the drive tube  2  facing the sensor  3  all the way to the journal  35  of the weight sensor  3 , spaced at a distance from its main body  40  such that the drive tube  2  is mounted radially via the mounting element  4  pivotably on the journal  35  of the weight sensor  3 . 
   The main body  30  of the sensor  3  (which is arranged in front of one end of the drive tube  2  outside the drive tube) serves to axially retain the drive tube  3  on the journal  35  of the weight sensor  3 , as does an axial locking element  36  arranged on the journal  35  (for example in the form of a clamping ring). Thus, the mounting section  44  of the mounting element  4  attached to the drive tube  2  is fixed axially and substantially immobile between the main body  30  and the axial locking element  36  of the weight sensor  3 . 
   Thus, the weight sensor  3  and the drive tube  2  constitute an assembly that can be preassembled and which features a simple construction as well as an ease of installation on a corresponding seat element. In comparison, consider the discussion regarding  FIG. 3  below. 
     FIG. 1   b  depicts an alternative embodiment to that shown in  FIG. 1   a , in which the journal  35  of the weight sensor  3  has an external thread  35   a  on which a nut is screwed as an axial locking element  37 . This is provided as an alternative to the clamping ring  36  of  FIG. 1   a.    
   In the exemplary embodiment depicted in  FIG. 1   c , an adapter in the form of an adapter bushing  38  is screwed onto the external thread  35   a  of the journal  35  of the weight sensor  3 . The adapter forms a radial bearing for the drive tube  2  by defining together with the mounting element  4  of the drive tube  2  a radial bearing  45 . The adapter also serves (together with the main body  30  of the weight sensor  3 ) to axially retain the drive tube  2  relative to weight sensor  3 . 
   The adapter bushing  38  enables adaptation of the journal  35  to drive tubes  2  of different diameters or to differently designed mounting elements  4 . 
     FIG. 2   a  shows an alternative to the embodiment of  FIG. 1   a  regarding the attachment of the mounting element  4 ′ in the form of a bearing bushing on the drive tube  2 . According to  FIG. 2   a , the bearing bushing  4 ′ having an external thread  42  is screwed into the inside wall  22  of the drive tube  2  which is provided with an internal thread. The mounting section  44  of the bearing bushing  4 ′ is thus formed by the main body  40  provided with the thread  42 . An axial locking element  36  in the form of a clamping ring serves here, as in the exemplary embodiment of  FIG. 1   a , to axially retain the drive tube  2  mounted on the journal  35  of the weight sensor  3  via the radial bearing  45 . 
     FIG. 2   b  depicts a variant of the arrangement of  FIG. 2   a , in which the axial locking element  37  is formed by a nut screwed onto an external thread  35   a  of the journal  35 . 
     FIG. 2   c  depicts an alternative to the embodiment shown in  FIG. 2   a  in which a weight sensor  3  having an adapter bushing  39  screwed onto the external thread  35   a  of the journal  35 . The journal  35  forms (according to the embodiment shown in  FIG. 1   e ) a radial bearing  45  together with the bearing bushing  4 ′ and serves to axially retain the drive tube  2  relative to the weight sensor  3 . 
   The screwing of a bearing bushing  4 ′ with a thread into the inside wall  22  of the drive tube  2  depicted in  FIGS. 2   a  through  2   c  is particularly suited for drive tubes with large diameters, or for those applications in which no space is available for attachment of the mounting element on the outside wall  21  of the drive tube  2 . 
     FIG. 3  depicts a preassembled modular unit having the drive tube  2  and the weight sensor  3  shown after incorporation into a motor vehicle seat accomplished by attachment on a mounting angle  1  of the corresponding seat structure. The weight sensor  3  penetrates with its main body through an opening  10  of the mounting angle  1  substantially without play and is attached on the mounting angle  1  by means of a nut  51  as well as an associated lock nut  52 . The nut  51  and associated lock nut  52  are screwed on the two sides of the mounting angle  2  on the external thread  33  of the main body  30  of the weight sensor  3 . 
   In this case, the weight sensor  3  is nonpivotably attached on the mounting angle  1  and also serves to pivotably mount the drive tube  2  on the journal  35 . Accordingly, the drive tube  2  is pivotably connected via the weight sensor  3  to the seat element  1  in the form of a mounting angle. The weight sensor  3  additionally assumes the necessary function pivotably mounting the drive tube  2  on the mounting angle  1 . In addition to enabling preassembly of the weight sensor  3  with the drive tube  2  (with the main body  30  of the weight sensor  3  provided with an external thread  33  forming a defined interface with the associated seat element (mounting angle  1 )) as well as the simple structure of the overall arrangement, the protected mounting of the weight sensor  3 —partially in the inside of the drive tube  2  and partially surrounded by the mounting angle  1  as well as the associated lock nut  51 ,  52 —is, above all, advantageous. 
   In addition, this arrangement ensures that the forces of weight occurring with occupancy of the corresponding motor vehicle seat, which act as transverse forces F on the drive tube  2 , are always detected in the same manner by the sensor  3 . This is attributed to the defined support of the sensor  3  with its main body  30  against the edge of the opening  10  of the mounting angle I damped between the two nuts  51  and  52 . Thus, a bending of the drive tube  2  resulting from the transverse forces F generated by seat occupancy that is detected by the sensor  3  via the journal  35  extending into the drive tube can be reproducibly determined and evaluated, such that erroneous deployments are reliably avoided. 
     FIG. 4  depicts an alternative to the embodiments of the preassembled modular units depicted in  FIGS. 1   a  through  1   c  and  2   a  through  2   c  concerning the attachment of the mounting element  4 ″ on the drive tube  2 . According to  FIG. 4 , the mounting element  4 ″ is attached on one end of the drive tube  2  (by welding in an exemplary embodiment). The radial bearing  45 , through which the drive tube  2  is mounted on the journal  35  of the weight sensor  3  lies outside the interior of the actual drive tube  2 . To axially retain the drive tube  2  relative to weight sensor  3 , a locking element in the form of a wedge  36 ′ is pressed into a radial bore of the journal  35  extending into the inside of the drive tube  2 . For this, a corresponding assembly opening M is provided in the wall  20  of the drive tube  2 . 
   In the modular unit depicted in  FIG. 5   a , the weight sensor  3  is made up of two sensor parts  31  and  32  nonpivotably connected to each other, of which the sensor part  31  serves to nonpivotably connect the weight sensor  3  to a mounting angle  1  of the seat structure and the sensor part  32  serves to pivotably mount the drive tube  2  on the weight sensor  3 . 
   The first sensor part  31  penetrates an opening  10  of the mounting angle  1  and lies against the edge of the opening with an angled protrusion  31   a . On the other side of the opening  10 , a lock nut  51  is screwed onto an external thread  33  of the first sensor part  31  such that the mounting angle  1  is firmly clamped between the radially outward projecting protrusion  31   a  of the first sensor part  31  and the lock nut  51 . Thus, the first sensor part  31  is fixed nonpivotably on the mounting angle  1 . An electronic assembly  6 , as well as an electric plug connector  60  of the weight sensor  3  are further arranged on the first sensor part  31 , such that the sensor  3  is supplied with electrical energy via the first sensor part  31  and can output sensor signals through it. 
   The second sensor part  32  has a journal  35  extending into the inside of the drive tube  2  which, with a mounting element  4 ′″ nonpivotably arranged on the inside wall of the drive tube  2 , forms a radial bearing  45  for the pivotable mounting of the drive tube  2  on the weight sensor  3 . To axially retain the drive tube  2  relative to the weight sensor  3 , the mounting element  4 ′″ is supported on the main body of the second sensor part  32  as well as (in the interior of the drive tube  2 ) on a locking element  37  in the form of a nut screwed onto an external thread  35   a  of the journal  35 . 
   To prevent excess rigidity in the mounting of the drive tube  2  via the mounting element  4 ′″ on the journal  35   a , the mounting element  4 ′″ and the journal  35  are spaced at a distance from each other in the radial direction outside the radial bearing  45 . A gap Z is thus present in each case in the radial direction to provide bearing clearance. 
     FIG. 5   b  depicts an alternative embodiment to that shown in  FIG. 5   a , in which the first sensor part  31  is supported on a radially outward projecting protrusion  31   a  on the end of the edge of the opening  10  in the mounting angle  1  facing the drive tube  2 , and the associated lock nut  52  is located on the end of the edge of the opening  10  facing away from the drive tube  2 . The arrangement of the radial protrusion  31   a  and the associated lock nut is thus precisely reversed relative to the exemplary embodiment depicted in  FIG. 5   a . This enables complete preassembly of the assembly including the drive tube  2  and the two sensor parts  31  and  32 . The assembly is then introduced into the opening  10  of the mounting element  1  such that the first sensor part  31  with its section having an external thread  33  penetrates the opening  10  and lies with its radially projecting protrusion  31   a  against the edge of the opening. The position of the weight sensor  3  is then secured by screwing the lock nut  52  on the external thread  33  of the first sensor part  31 . 
     FIG. 6  depicts an alternative to the embodiments shown in  FIGS. 5   a  and  5   b  in which coordinated threaded areas  35   a  and  46  of the journal  35  and the mounting elements  4 ′″, respectively, serve to mount the mounting element  4 ′″ molded with the drive tube  2  on the journal  35  of the second sensor part  32 . Thus, the bearing itself directly takes over the necessary axial retention of the drive tube relative to weight sensor  3  without the need for additional, separate axial locking elements. 
   However, forming the bearing by meshing threaded areas  47  by rotation of the drive tube  2  results in a relative movement of drive tube  2  and thread weight sensor  3  along the tube axis A (corresponding to the transverse axis of the vehicle y). The extent of this movement depends on the pitch of the meshing threads  35   a  and  46 . This movement can be compensated for by play provided in the arrangement as well as the ever-present elasticities. 
     FIG. 7  depicts the embodiment shown in  FIG. 5   a  together with additional seat structure components, namely a subrail U fixed on the motor vehicle floor B, as well as an upper rail O guided and longitudinally displaceable on the subrail U. The upper rail O is attached on the mounting angle  1  that serves as the pivotable mounting of the drive tube  2  via the weight sensor  3 . In  FIG. 7 , an adjusting lever V (cf.  FIG. 9 ) is shown nonpivotably connected to the drive tube  2 . The adjusting lever V serves to adjust the seat height. 
   With reference to  FIG. 7  the weight sensor  3  is shown positioned partially inside the drive tube  2  as well as partially covered by the mounting angle  1  and protected laterally by the guides O and U. 
   In the particularly easy to assemble exemplary embodiment depicted in  FIG. 8 , the main body  30  of the weight sensor  3  is attached to a mounting angle  1  which can serve to secure the weight sensor on a guide rail of a longitudinal seat guide of a motor vehicle seat. The main body  30  of the weight sensor extends substantially without play into an opening  10  of the mounting angle  1  and is fixed thereon by means of at least one nut  53  screwed onto an external thread  33  of the main body  30  of the weight sensor  3 . 
   The weight sensor  3  has a mounting section  35   a  stepped in one piece from the main body  30 , which forms two circumferential bearing surfaces  350  and  351  oriented at right angles to each other and connecting directly with each other, and on which a bearing bushing  4   a  provided with an external thread  452  is pivotably mounted by means of corresponding circumferential bearing surfaces  450  and  451  oriented at right angles to each other. 
   The bearing bushing  4   a  is secured on the mounting section  35  of the weight sensor  3  in the axial direction. It is supported axially via its angled bearing surface  451  against the associated angled bearing surface  351  of the weight sensor  3 . It is secured in the opposite direction against axial slippage by means of a lock nut  37  screwed on to an external thread  352  of the weight sensor  3 . 
   The bearing surfaces  350 ,  351 ,  450  and  451 , as well as the axial retention or mounting of the bearing bushing  4   a  by means of the associated lock nut  37 , can optionally be supplemented and improved in their efficiency by additional plain bearings and/or axial disks. Furthermore, the bearing areas can be designed with angular movement to keep disrupting influences (such as for example tolerances or angular movements of the structure) away from the weight sensor  3 . To set a predefined axial play between weight sensor  3  and bearing bushing  4   a , the lock nut  37  is firmly screwed onto the weight sensor  3  up to a defined axial stop. For production engineering reasons, it may be necessary to use a spacing element  370  to bridge the thread runout in the lock nut  37 . 
   Because of the axial retention of the bearing bushing  4   a  provided with an external thread  452  on the mounting section  35  of the weight sensor  30  between its angled bearing surface  351  and the lock nut  37 , the weight sensor  3  can be combined with the bearing bushing  4   a  into a preassembled assembly onto which the drive tube  2  (in the form of a transverse shaft) is subsequently attached. 
   For this combination, a threaded bushing  4   b  is attached (for example by welding) in the region of the front end of the main body  20  of the drive tube  2 , and provided with an internal thread  453  running along the end facing the weight sensor  3  with an attachment section  455  as well as along a part of the outside wall  21  of the drive tube  2 . By screwing this threaded bushing  4   b  with its internal thread  453  onto the external thread  452  of the bearing bushing  4   a , a nonpivotable connection is produced between drive tube  2  and bearing bushing  4   a . The drive tube  2  is mounted via the threaded bushing  4   b  and the bearing bushing  4   a  is pivotably mounted on the bearing surfaces  350  and  351  of the mounting section  35  of the weight sensor  3 . 
   In an exemplary embodiment, the drive tube  2  and the threaded bushing  4   b  can be designed in one piece with a thread  453  cut directly into the drive tube  2 . 
   In an embodiment alternative to the above-described welded connections between the drive tube  2  and a respective mounting element via which the drive tube  2  is mounted on the mounting section  35  of the weight sensor  3 , a mounting element (which can be optionally preassembled on the mounting section  35  of the weight sensor  3 ) can also be attached by gluing on the drive tube  2 . In a further embodiment, the mounting element can be attached by an adhesive connection with the inside wall  22  of the drive tube  2 . The adhesive also serves to compensate or reconcile tolerances on the inside of the drive tube  2  and holds the mounting element serving as an adapter rattle-free in the drive tube  2 .