Abstract:
In a tachograph ( 1 ) for a motor vehicle, a drawer ( 10 ) can be extended through an opening ( 8 ) in a front panel frame ( 2 ). When the drawer ( 10 ) is in the closed state, a recording disc ( 9 ) in the drawer ( 10 ) is situated in the opening ( 8 ) in the front panel frame ( 2 ) and holds a circumferential sealing lip ( 14 ). A second sealing lip ( 16 ) seals off the recording disc ( 9 ) from a drawer panel ( 3 ). When the drawer ( 10 ) is in the closed state, the sealing lip ( 14 ) sealing off the recording disc ( 9 ) abuts an inwardly pointing edge ( 15 ) of the opening ( 8 ) in the front panel frame ( 2 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. national stage application of International Application No. PCT/EP2006/067821 filed Oct. 26, 2006, which designates the United States of America, and claims priority to German application number 10 2005 056 605.7 filed Nov. 28, 2005, the contents of which are hereby incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a tachograph for a motor vehicle having a housing, having an electric device which is arranged in the housing, having an opening in the housing and a drawer which is inserted into the opening, having a receiving plate of the drawer, having a drawer panel for covering the receiving plate and having a sealing lip which seals off the opening from a front panel frame of the housing. 
       BACKGROUND 
       [0003]    Such tachographs are, in particular, frequently used in industrially used motor vehicles nowadays and are known from practice. The tachograph generally has a printer and has, in the drawer, a magazine for holding a paper supply for the printer. For use in contemporary motor vehicles they have provision for the drawer to be reliably protected from deposition of dust and penetrating spray water. In the tachograph which is known from practice, the receiving plate is a sheet-metal part to which the drawer panel is attached. The drawer panel secures the sealing lip which, in the closed state, is pressed against the front panel frame. In this context, the sealing lip is deformed and seals the opening for the drawer. 
         [0004]    A disadvantage of the known tachograph is, however, that the sealing lip can buckle laterally when the drawer closes. In addition, when the drawer is opened and closed repeatedly, the sealing lip is permanently deformed. For this reason, permanent tightness cannot be reliably ensured. Furthermore, tolerances in the attachment of the drawer panel to the receiving plate bring about a change in the prestress of the sealing lip, which also adversely affects the tightness of the tachograph. 
       SUMMARY 
       [0005]    A tachograph of the type mentioned at the beginning can be developed in such a way that the seal of the drawer in the housing is reliably ensured. According to an embodiment, a tachograph for a motor vehicle may comprise a housing in which an electric device is arranged, an opening in the housing and a drawer which is inserted into the opening, a receiving plate of the drawer, a drawer panel for covering the receiving plate, and a sealing lip which seals off the opening from a front panel frame of the housing, wherein the sealing lip is arranged on the receiving plate and bears radially on the inside of an edge, bounding the opening, of the front panel frame. 
         [0006]    According to a further embodiment, the sealing lip may point away from the drawer and in the opened state of the drawer the sealing lip protrudes beyond the outer edge of the receiving plate. According to a further embodiment, the receiving plate may have at least a second sealing lip, and the second sealing lip may bear against the drawer panel. According to a further embodiment, the sealing lip which seals off the receiving plate from the front panel frame and the second sealing lip can be fabricated in one piece. According to a further embodiment, at least one of the sealing lips may be fabricated from plastic using an injection molding method. According to a further embodiment, at least one of the sealing lips may be connected in a materially joined fashion to the receiving plate. According to a further embodiment, the receiving plate and the drawer panel can be connected to one another by means of a latched connection. According to a further embodiment, the latched connection can be configured in an annular shape. According to a further embodiment, the receiving plate can be fabricated from plastic. According to a further embodiment, at least one duct can be arranged between the receiving plate and the drawer panel, and the duct is opened toward the underside of the drawer. According to a further embodiment, a plurality of ducts can be made to extend close to various latched connections. According to a further embodiment, the drawer panel may cover the opening in the front panel frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0007]    The invention permits numerous embodiments. In order to clarify its basic principle further, one of these embodiments is illustrated in the drawing and will be described below. In said drawing: 
           [0008]      FIG. 1  is a front view of a tachograph according to an embodiment, 
           [0009]      FIG. 2  is a sectional illustration through the tachograph from  FIG. 1  along the line II-II, 
           [0010]      FIG. 3  is a sectional illustration through the tachograph from  FIG. 1  along the line III-III, 
           [0011]      FIG. 4  is a sectional illustration through a receiving plate with a drawer panel of the tachograph from  FIG. 1 , 
           [0012]      FIG. 5  is a highly enlarged view of a sealing lip which is attached to the receiving plate, with the joining areas of the receiving plate and the drawer panel, and 
           [0013]      FIG. 6  is a perspective view of the receiving plate and the drawer panel before assembly. 
       
    
    
     DETAILED DESCRIPTION  
       [0014]    According to various embodiments, the sealing lip can be arranged on the receiving plate and may bear radially on the inside of an edge, bounding the opening, of the front panel frame. 
         [0015]    As a result of this embodiment, tolerances between the receiving plate and the drawer panel no longer bring about a change in the prestress of the sealing lip against the front panel frame. Thus compression of the sealing lip can be avoided, resulting in particularly low deformation forces of the sealing lip. In addition, lateral and vertical tolerances of the printer drawer with respect to the front panel frame are easily compensated by the sealing lip. The tachograph according to various embodiments therefore has a particularly reliable seal preventing the ingress of spray water. 
         [0016]    According to another embodiment, particularly low loading of the sealing lip when the drawer is closed can be easily achieved if the sealing lip points away from the drawer and, in the opened state, protrudes beyond the outer edge of the receiving plate. This embodiment ensures that when the drawer closes the sealing lip fits snugly against the inside of the edge of the opening of the front panel frame and in doing so is deformed only to a small degree. This brings about the low loading and therefore leads to a long service life of the sealing lip. The tightness of the seal of the receiving plate with respect to the front panel frame is therefore reliably ensured. A further advantage of this embodiment is that possible clamping of the drawer as a result of large deformation forces of the sealing lip is reliably avoided. 
         [0017]    According to another embodiment, the seal of the drawer panel with respect to the receiving plate is structurally particularly simple if the receiving plate has at least a second sealing lip and if the second sealing lip bears against the drawer panel. 
         [0018]    It helps to reduce the fabrication costs of the tachograph according to an embodiment if the sealing lip which seals the receiving plate against the front panel frame and the second sealing lip are fabricated in one piece. 
         [0019]    It helps to reduce the fabrication costs of the tachograph according to an embodiment further if at least one of the sealing lips is fabricated from plastic using an injection molding method. 
         [0020]    A reliable seal of the sealing lips with respect to the receiving plate can be reliably ensured according to another embodiment if at least one of the sealing lips is connected in a materially joined fashion to the receiving plate. This also contributes to further reducing the fabrication costs of the tachograph according to an embodiment. The materially joined connection of the sealing lip to the receiving plate is advantageously produced by virtue of the fact that the sealing lip is integrally injection molded onto the receiving plate during the injection molding method. 
         [0021]    The tachograph according to an embodiment is particularly easy to assemble if the receiving plate and the drawer panel are connected to one another by means of a latched connection. 
         [0022]    Reliable orientation of the drawer panel with respect to the receiving plate can be easily achieved according to another embodiment if the latched connection is embodied in an annular shape. A further advantage of this embodiment is that as a result the receiving plate and the drawer panel have a particularly high degree of rigidity while a small amount of material is used. The small amount of material used for the drawer panel also avoids what are referred to as collapsing points, and therefore produces a uniform surface on the visible areas of the drawer panel. 
         [0023]    According to another embodiment, the receiving plate can be particularly easily fabricated and particularly easily fabricated in one piece with a plurality of stiffening means and parts of the latched connection if the receiving plate is fabricated from plastic. Furthermore, the sealing lip can, as a result, easily be integrally injection molded and the materially joined connection of the sealing lip to the receiving plate can therefore be produced. 
         [0024]    According to another embodiment, the drawer panel can be particularly easily removed if at least one duct is arranged between the receiving plate and the drawer panel and if the duct is opened toward the underside of the drawer. By virtue of this embodiment it is easy to insert a simple tool, for example a screwdriver, into the duct and force open the latched connection. 
         [0025]    Damage to the drawer panel can be reliably avoided during its removal according to another embodiment if a plurality of ducts are made to extend close to various latched connections. 
         [0026]    According to another embodiment, the sealing lip is reliably protected against dirt and/or mechanical loads if the drawer panel covers the opening in the front panel frame. 
         [0027]      FIG. 1  shows a tachograph  1  with a front panel frame  2  and a drawer panel  3 . A gap  4  for a paper feed  5  for a printer  6  which is illustrated in  FIG. 2  is arranged between the drawer panel  3  and the front panel frame  2 . The drawer panel  3  has a tear-off strip  7  for paper of the printer  6 .  FIG. 2  shows the tachograph  1  from  FIG. 1  in a sectional illustration along the line II-II. The drawer panel  3  covers an opening  8  in the front panel frame  2  and is mounted on a receiving plate  9  of a drawer  10 . The receiving plate  9  is attached to the drawer  10  by means of screws  11  which are concealed by the drawer panel  3 . A printer roller  12  of the printer  6  is arranged directly behind the paper guide  5 . The drawer  10  also has a receiving chamber  13  for a magazine (not illustrated in more detail) of a paper supply. The paper supply is, for example, a paper roll.  FIG. 3  shows the tachograph  1  from  FIG. 1  in a sectional illustration along the line III-III. Consideration of  FIGS. 2 and 3  together makes it clear that the receiving plate  9  has a circumferential sealing lip  14  which seals the receiving plate  9  with respect to the opening  8  in the front panel frame  2 . The sealing lip  14  bears against an edge  15  which bounds the opening  8  toward the inside. Furthermore, the sealing lip  14  is fabricated in one piece with a second sealing lip  16  which seals the receiving plate  9  with respect to the drawer panel  3 . The tachograph  1  has an opening key  17  for opening the drawer  10  and an operator control element  18  for operating the tachograph  1 . 
         [0028]      FIG. 4  shows, for the sake of clarification, the receiving plate  9  with the sealing lips  14 ,  16  and adjoining areas of the drawer panel  3  in a sectional illustration. It is apparent here that the sealing lip  14  which seals the receiving plate  9  with respect to the front panel frame  2  points away from the receiving plate  9 , and in the opened state of the drawer  10  it protrudes beyond the outer periphery of the receiving plate  9 . When the drawer  10  closes, the sealing lip  14  moves against the edge  15  of the opening  8  (illustrated in  FIG. 1 ) of the front panel frame  2  and in the process is compressed slightly in the radial direction with respect to the opening  8 . As a result, the sealing lip  14  fits snugly against the edge  15 . Furthermore,  FIG. 5  illustrates the sealing lip  14  which seals the receiving plate  9  with respect to the front panel frame  2 , and  FIG. 5  shows the configuration of said sealing lip  14  in one piece with the second sealing lip  16  which seals the receiving plate  9  with respect to the drawer panel  3 . 
         [0029]      FIG. 5  shows in the highly enlarged form a sectional illustration of the receiving plate  9  in the region of a connection to the drawer panel  3 . The connection of the drawer panel  3  to the receiving plate  9  has a latched connection  19  with an annular latching element  20  which is arranged on the drawer panel  3 , and a second latching element  21  which is also arranged in an annular shape on the receiving plate  9 . The latching elements  20 ,  21  can be pressed one into the other and connect the receiving plate  9  to the drawer panel  3  in a positively locking fashion. 
         [0030]    In order to release the latched connection  19  illustrated in  FIG. 5 , a tool (not illustrated), for example a screwdriver, is inserted into a duct  22  (illustrated in  FIG. 4 ) between the receiving plate  9  and the drawer panel  3 , and the drawer panel  3  is forced away from the receiving plate  9  by means of levers. In the process, the latched connection  19  is released. The duct  22  is essentially located in the receiving plate  9 , while the webs  23  for supporting the tool are arranged on the drawer panel  3 . 
         [0031]      FIG. 6  shows the receiving plate  9  and the front panel  3  before assembly. The receiving plate  9  has a plurality of recesses  24  for the insertion of the screws  11  (illustrated in  FIG. 2 ) for the connection to the drawer  10 . Furthermore, a plurality of latching elements  20 ,  21 , which each produce a latched connection  19  (illustrated by way of example in  FIG. 5 ), are arranged on the receiving plate  9  and the drawer panel  3 . In total, two ducts  22  and the webs  23  for a tool to be fitted against are arranged on the side of the receiving plate  9  and of the front panel  3  which forms the underside of the drawer  10 . Furthermore,  FIG. 6  shows that the second sealing lip  16  for sealing the receiving plate  9  to the drawer panel  3  branches into recesses  25 ,  26  for the operator control element  18  (illustrated in  FIG. 1 ) and the opening key  17 , and is made to extend around the circumference of the receiving plate  9 .