Abstract:
The invention relates to a shaped seal for sealing a power-operated closing device comprising a jam-protection zone, which has at least two electrically conductive areas, situated at a distance from each other. According to the invention, to save space and reduce weight and cost, the carrier is used as a metallic conductor for the conductive area so as to reduce volume resistance. Alternatively or in addition thereto, a frame can be used to which the shaped seal can be fixed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 09/937,083 filed Aug. 29, 2002, now abandoned as the National Stage of International Application No. PCT/EP00/02501, filed Mar. 21, 2000, which application is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a shaped seal or sealing profile for weathersealing a powered closing device, including an anti-trap guard comprising at least two electrically conductive portions spaced away from each other, whose contact triggers a switching action for activating the drive assembly of the closing device in which at least one of these portions is electrically conductive connected to a metallic conductor to reduce the volume resistivity. 
     2. Description of Related Art 
     A generic sealing profile is known from DE 197 20 713 C1 originated to the same Applicant. This known sealing profile comprises two electrically conductive portions spaced away from each other, in each of which a metallic conductor is embedded to reduce the volume resistivity. The disadvantage in making use of these two metallic conductors is that they take up a lot of room, relatively, and add to the price and weight of the sealing profile whilst complicating production since both metallic conductors need to be coextruded. 
     Furthermore, FR 1.549.640 A discloses an anti-trap guard for a powered window wherein a sealing profile is incorporated in a frame. This sealing profile comprises an electrically conductive insert, which contacts the frame configured as an electrical conductor in a trapped situation so as to trigger a switching action. In the trapped situation the insert, together with the sealing profile, is shifted relative  to the frame, wherein flexible tongues on the sealing profile ensure that the sealing profile returns to its original position. Actual practice has shown such a configuration to be unsatisfactory. 
     It is thus the objective of the present invention to sophisticate a generic sealing profile to achieve cost-effective production for a low price, weight and space requirement. 
     BRIEF SUMMARY OF THE INVENTION 
     The sealing profile in accordance with the invention now makes it possible to totally eliminate a metallic conductor as needed hitherto. Instead of this, recourse is made to the carrier of the sealing profile existing in many cases. This carrier is, as a rule, made of a light metal and is thus electrically conductive. As an alternative, or in addition thereto, a flange or frame may be used to which the sealing profile is securable. This flange or frame is already available, especially in automotive applications, and is made of an electrically conductive metal. Due to totally eliminating one of the metallic conductors as needed hitherto, the production of the sealing profile in accordance with the invention is substantially simplified, with a further reduction in price and weight, as well as reducing the space requirement. 
     Advantageous aspects and further embodiments read from the dependent claims. 
     In a first advantageous aspect the carrier contacts the electrically conductive portion. In this case the electrically conductive portion is arranged only on one side of the carrier in thus simplifying production. 
     In a second advantageous aspect the carrier is partly or totally surrounded by the electrically conductive portion in thus enlarging the contact surface area between the electrically conductive portion and the carrier so that the volume resistivity can be further reduced. 
     In accordance with one further embodiment the carrier is provided with recesses. These recesses reduce the weight of the carrier and permit flexing of  the sealing profile. In addition, the recesses permit, for a carrier surrounded partly or fully by the electrically conductive portion, a direct electrically conductive connection from one side of the carrier to the other. 
     This is of advantage when a carrier of an electrically non-conductive material, or a carrier insulated from the electrically conductive portion, is used. The recesses also make it possible in these cases to produce an electrically conductive connection from one side of the carrier to the other. 
     Advantageously the electrically conductive portion extends up to the outer side of the sealing profile to thus produce an electrical contact with the flange or frame to which the sealing profile can be secured without an additional electrical conductor needing to be provided, i.e. the sealing profile merely requiring to be secured, as usual, to the flange or frame. 
     In another advantageous aspect, the electrically conductive portion comprises lips or tabs for securing the sealing profile to the flange or frame. These lips or tabs are pressed into contact with the flange or frame to produce a good electrical contact so that the volume resistivity of the sealing profile can be reliably diminished. 
     In another advantageous further embodiment the anti-trap guard portion comprises a hollow chamber in which at least one of the electrically conductive portions is arranged. Advantageously, one of the electrically conductive portions is arranged at the inner side of the hollow chamber whilst the other protrudes into the hollow chamber to thus achieve a reliable contact between the electrically conductive portions, irrespective of the anti-trap guard. 
     In yet another advantageous aspect the hollow chamber serves to weatherseal the powered closing device. The anti-trap guard portion of the sealing profile in accordance with the invention then satisfies a dual function whilst eliminating the need for additional elements for weather-sealing the closing device in thus further reducing the space requirement and weight as well as the price of the sealing profile in accordance with the invention.  
     Advantageously the electrically conductive portion, provided separate from the carrier, flange or frame, comprises a metallic conductor, as a result of which the volume resistivity in this portion too is considerably reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       The invention will now be detailed by way of example embodiments as shown in the drawing diagrammatically in which: 
         FIG. 1  is a cross-section through a first embodiment of the sealing profile in accordance with the invention; 
         FIG. 2  is a cross-section through a second embodiment of the sealing profile in accordance with the invention; 
         FIG. 3  is a cross-section through a third embodiment of the sealing profile in accordance with the invention; 
         FIG. 4  is a cross-section through a fourth embodiment of the sealing profile in accordance with the invention; and 
         FIG. 5  is a system diagram of the principle involved. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1  there is illustrated a first embodiment of a sealing profile  10  in accordance with the invention. The sealing profile  10  comprises a clamping portion  11  as well as a sealing portion  12 . Further provided is a cover  13  with which components (not shown) are covered after the sealing profile  10  has been secured in place. For securing it in place, the clamping portion  11  comprises a recess  14  into which several lips  15  and protuberances  16  protrude. The recess  14  is clasped by a carrier  17  having a U-shaped cross-section. For securing it in place, the recess  14  of the clamping portion  11  is mounted on a flange as evident from  FIG. 5 . In this arrangement the lips  15  and protuberances  16  are firmly pressed against the flange in preventing release of the sealing profile  10 .  
     The sealing portion  12  comprises a hollow chamber  18  which at its side facing a window pane  25  is provided with a friction-reducing coating  23 , more particularly a flake coating. The windowpane  25  is movable in the direction of the arrows  24 . When the windowpane  25  is closed the hollow chamber  18  is deformed so that the desired weatherseal is furnished. 
     The sealing profile  10  comprises further an anti-trap guard portion  32 . The anti-trap guard portion  32  includes two electrically conductive portions  19 ,  20  spaced away from each other by an interspace  21 . As soon as an object is trapped on closing of the windowpane  25 , the portion  19  is moved in the direction of the portion  20 . Contact of the two portions  19 ,  20  triggers a switching action for activating the drive assembly of the windowpane  25 . This switching action can either halt or reverse the movement of the windowpane  25 . 
     The portions  19 ,  20  are made to advantage by adding an electrically conductive material to the base material of the sealing profile  10  by means of coextrusion. To reduce the volume resistivity the portions  19  comprises a metallic conductor  22 . The portion  20  partly surrounds the carrier  17  configured as a metallic conductor, as a result of which the volume resistivity of the electrically conductive portion  20  is likewise diminished. No additional metallic conductor is needed for the portion  20 . 
     In the embodiment as shown in  FIG. 1  all electrically conductive components  17 ,  22  and portions  19 ,  20  are surrounded by the electrically non-conductive material of the sealing profile  10 . The sealing profile  10  is thus electrically neutral as regards its surroundings. 
     Three further embodiments of a sealing profile  30 ,  40 ,  50  in accordance with the invention are shown in  FIGS. 2 to 4 , whereby like or functionally identical components are identified by the same reference numerals as in  FIG. 1 , for the description of which, reference is made to the above comments to avoid tedious repetition. 
     Referring now to  FIG. 2  there is illustrated how the sealing profile  30  comprises a carrier  27 , which is totally surrounded by the electrically conductive  portion  20 . The carrier  27  is provided with recesses  28  through which the material of the electrically conductive portion  20  penetrates. The contact surface area between the electrically conductive portion  20  and the carrier  27  is substantially increased by the recesses  28 . Furthermore, any potential difference can be conducted from one side of the carrier  27  through the recesses  28  to the other side of the carrier  27  solely through the portion  20 . Even when not using a non-conductive carrier  27  the inner side and outer side of the carrier  27  are electrically interconnected by the recesses  28 . 
     The electrically conductive portion  20  extends up to the outer side of the sealing profile  30 . As soon as the sealing profile  30  is secured to a flange or frame, the lips  15  and protuberances  16  of the clamping portion  11  come into electrically conductive contact with the flange or frame to thus substantially reduce the volume resistivity of the electrically conductive portion  20 , this further making it possible to use a carrier  27  of a non-conductive material, such as plastics, for example. 
     Referring now to  FIG. 3  there is illustrated how the sealing profile  40  comprises a hollow chamber  18  in the anti-trap guard portion  32 . Arranged in the hollow chamber  18  are the electrically conductive portions  19 ,  20 , the portion  20  contacting the carrier  17 . Deformation of the hollow chamber  18  brings the portions  19 ,  20  into contact with each other in triggering the switching action as described above. 
     At the same time the hollow chamber  18  of the anti-trap guard portion  32  serves to seal off a powered closing device (not shown in  FIG. 3 ). More particularly the sealing profile  40  as shown in  FIG. 3  can be put to use to weatherseal an automotive sunroof. 
     Referring now to  FIG. 4  there is illustrated a sealing profile  50  in accordance with the invention, which is inserted into a substantially U-shaped frame  51  made of an electrically conductive material. The sealing profile  50  comprises a series of lips  52  having a friction-reducing coating  23  for sealing contact with the windowpane  25 . Tabs  53 ,  54  serve to secure the sealing profile  50 . The  electrically conductive portion  20  of the anti-trap guard portion  32  clasps the frame  51  in part and extends up to the outer side of the sealing profile  50 . 
     The sealing profiles  10 ,  30 ,  50  as shown in  FIGS. 1 ,  2  and  4  are particularly suitable for weathersealing automotive side windows. Referring now to  FIG. 5  there is illustrated a system diagram of the sealing profile  30  in the fitted condition. The sealing profile  30  is mounted on a flange  26  by its clamping portion  11 . The flange  26  is thus in electrically conductive contact with the electrically conductive portion  20  via the lips  15  and protuberances  16 . As is usual in automotive applications, the flange  26  is grounded, whilst the electrically conductive portions  19  of the sealing profile  30  is connected to the anode of a voltage source (not shown). As soon as the windowpane  25  is lifted and the anti-trap guard portion  32  deformed, the two portions  19 ,  20  come into contact with each other, resulting in a switching action, which is signaled to a controller  31 . The controller  31  correspondingly controls a motor  29  to move the windowpane  25 , which halts or reverses the movement of the windowpane  25 . 
     The sealing profile  10 ,  30 ,  40 ,  50  in accordance with the invention permits total elimination of one of the metallic conductors hitherto required, without having a detrimental effect on the anti-trap guard and sealing function. Instead, the space requirement, weight, costs and complications in production are all substantially reduced, as compared to known sealing profiles.