Patent Publication Number: US-2003233790-A1

Title: Device for detecting an obstacle in the opening range of a powered closure element for a motor vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001] This application claims priority to German Patent Application Number 102 20 187.0 filed May 6, 2002.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002] Not applicable  
       REFERENCE TO A “SEQUENCE LISTING” 
       [0003] Not applicable.  
       BACKGROUND OF THE INVENTION  
       [0004] 1. Field of the Invention  
       [0005] The invention relates to a device for detecting an obstacle in the opening range of an automotive closure element movable between an open position and a closed position, more particularly an electrically powered window pane or sunroof. The device is provided with an elastomeric sealing profile sealing the closure element and secured to a frame of the motor vehicle. In addition, the device is provided with a sensor for detecting an obstacle in the opening range of the closure element comprising at least one electrical conductor generating an electrical field in the opening range of the closure element.  
       [0006] 2. Background Art  
       [0007] Devices of this kind are guards serving to prevent part of the human body being trapped between the closure element and at least some part of the edge surrounding the closure element. For this purpose known devices feature a sensor which detects the presence of an obstacle in the opening range of the closure element and furnishes a signal controlling the motor powering the closure element. As regards the function of the sensor a distinction is made between guards requiring physical contact with the obstacle and guards working by proximity (non-contact) detecting.  
       [0008] One such guard belonging to the first group is described, for example, in DE 199 13 105 A1. This known device comprises a sealing profile sealing a closure element and is engineered with two electrically conductive portions spaced away from each other. When physical contact occurs with an obstacle in the opening range of the closure element the electrically conductive portions are pressed together, resulting in a switching contact which triggers an electrical control signal.  
       [0009] Known from EP 1 154 110 A2 is a proximity or non-contact type guard. The way in which this guard works is based on a change in capacitance of an electrical field generated between two electrical conductors prompted by an obstacle in the opening range of a closure element. One of the conductors, the sensor electrode, is integrated in a sealing profile sealing the closure element, whereas the other conductor, the basic electrode is formed, for example, by an automotive frame to which the sealing profile is secured. To also detect non-conductive materials, such as, for example, wood or plastics, prompting no, or only a minor, change in the capacitance of the electric field, the portion of the sealing profile accommodating the sensor electrode is deformable. This makes sure that at least when an obstacle comes into physical contact with the sealing profile there is a change in the position of the sensor electrode which triggers a change in the capacitance.  
       [0010] All of these known devices have the disadvantage that an electrical conductor necessary for detecting the obstacle is connected to a sealing profile sealing the closure element. In this arrangement the conductor is configured for example, as a conductive portion of the sealing profile or a wire integrated in the sealing profile by coextrusion. This results in the production costs of sealing profile being relatively high. In addition to this, experience has shown that integrating the electrical conductor in the sealing profile is a drawback in assembly, it being especially in curved portions such as, for example, in the transition from the A pillar to the roof of a motor vehicle that the sealing profile is squeezed to such an extent that there is a risk of the electrical conductor being damaged.  
       [0011] Apart from this, integrating the electrical conductor in the sealing profile involves relatively complicated logistics as regards the remaining components of the sensor which as a rule are fabricated together with the sealing profile. Last but not least, integrating the electrical conductor in the sealing profile hampers trouble-shooting a defective guard.  
       BRIEF SUMMARY OF THE INVENTION  
       [0012] The invention is based on the objective of sophisticating a device of the aforementioned kind such that as compared to prior art lower production costs as well as simplified assembly and maintenance are now achieved.  
       [0013] To achieve this objective it is provided for in a device having the aforementioned features as it reads from claim 1 that the conductor is arranged on trim covering the frame and/or sealing profile at least in part and stationary secured to the motor vehicle.  
       [0014] The device in accordance with the invention is based on having discovered the advantages of configuring the sealing profile and the electrical conductor necessary for detecting an obstacle in the opening range of the closure element as separately components, this now making it possible to reduce the production costs of the sealing profile whilst facilitating assembly and maintenance. The reason for this is primarily due to decoupling the functions of the sealing profile and electrical conductor. Now, unlike prior art, the conductor is mounted on trim covering the frame and/or sealing profile at least in part. In this arrangement the device in accordance with the invention makes use of the fact that such trim, for example, in the form of a molding is employed in any case for visual appeal on the majority of conventional closure elements such as, for instance, a window pane. Accordingly, no additional work is involved in production and assembly.  
       [0015] Furthermore, the device in accordance with the invention reduces the logistical complications since, now, all components relating to the sensor can be made and furnished separately as outsourced items. In conclusion, the configuration in accordance with the invention ensures fitting the electrical conductor as is favorable for detecting an obstacle in the opening range of a closure element without influencing the arrangement of the sealing profile. This now makes it possible to take into account the special requirements of certain closure elements such as, for instance, doors, hatchback, trunk lid of a motor vehicle characterized by a relatively large spacing between sealing profile and a potential trapping zone.  
       [0016] Thus, in effectively configuring an electrical field by the electrical conductor it is of advantage to make the trim for electrically insulating the conductor of a dielectric material, preferably plastics material. A dielectric material in this sense is understood to be an insulant which ensures propagation of the electrical field without any significant increase in the capacitance.  
       [0017] It is in addition particularly of advantage to embed the conductor as an alternative or in addition thereto in a sheathing made of an elastomeric dielectric material secured to the trim. The sheathing protecting the electrical conductor from the environment may consist of an insulating rubber, for example, sponge rubber so that the conductor can be embedded in the sheathing by coextrusion cost effectively. In addition to this, such an aspect permits making the trim from metal, for example, aluminum.  
       [0018] Advantageously, the conductor is configured stranded or as a band to facilitate production. To make for simply assembly it is in addition of advantage to secure the conductor by a materially positive connection or positive or non-positive locking. Supplementing for instance a positive or non-positive connection by a material positive connection, for example, by bonding is particularly favorable for reliably and durably securing the conductor.  
       [0019] Connecting the conductor to the trim by positive locking and, where necessary, also by non-positive locking is achievable in one advantageous aspect of the device in accordance with the invention by locating the conductor between at least two webs configured on the trim. To facilitate speedy assembly the conductor may be clamped in place as an alternative also by a protuberance formed on the trim.  
       [0020] In another preferred aspect of the device in accordance with the invention the conductor may be located in a gap configured in the trim. In this case, it has proven to be expedient when the trim is flexible at least in the region of the gap in opening up the gap for simple insertion of the conductor. In addition this enables the gap to be configured in the form of a relief so that the conductor inserted in the gap is held in place both by positive locking and where necessary also by non-positive locking.  
       [0021] Preferably the trim is connected to the sealing profile by positive locking to achieve reliable fastening of the trim to the motor vehicle.  
       [0022] In conclusion, it is proposed in another preferred embodiment of the device in accordance with the invention to configure the trim as a molding extending along the sealing profile to make for added visual appeal.  
     
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
     [0023] The device in accordance with the invention and its further advantages will now be detained by way of describing preferred example embodiments with respect to the drawings illustrated therein merely diagrammatically in which:  
     [0024]FIG. 1 is a side view of a motor vehicle;  
     [0025]FIG. 2 is a sectional view taken along the line II in FIG. 1 showing a first embodiment of the present invention;  
     [0026]FIG. 3 a  is a view as shown in FIG. 2 but in a second embodiment of the present invention;  
     [0027]FIG. 3 b  is a view as shown in FIG. 3 a  but in a third embodiment of the present invention;  
     [0028]FIG. 3 c  is a view as shown in FIG. 3 a  but in a fourth embodiment of the present invention;  
     [0029]FIG. 3 d  is a view as shown in FIG. 3 a  but in a fifth embodiment of the present invention;  
     [0030]FIG. 4 a  is a sectional view taken along the line II in FIG. 1 showing a sixth embodiment of the present invention;  
     [0031]FIG. 4 b  is a view as shown in FIG. 4 a  showing an expanded sealing profile;  
     [0032]FIG. 5 a  is a cross-section through a trim in the opened up condition;  
     [0033]FIG. 5 b  is a cross-section through the trim as shown in FIG. 5 a  but in the closed condition;  
     [0034]FIG. 5 c  is a view as shown in FIG. 5 b  showing how the trim is secured to a frame; and  
     [0035]FIG. 6 is a sectional view taken along the line II in FIG. 1 showing a seventh embodiment of the present invention.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0036] Referring now to FIG. 1 there is illustrated a motor vehicle  10  provided in the region of a front door  11  with a window pane  20  powered by an electric motor  21 . The window pane  20  representing a closure element is powered in the direction y of the electric motor  21  between an open position and its closed position.  
     [0037] As evident from FIG. 2 the front door  11  comprises a metal frame  12  to which a sealing profile  30  seals the window pane  20 . The sealing profile  30  made of an electrically non-conducting elastomeric material comprises a fastening portion  32  extending along a channel  13  in the frame  12  and provided with retaining lips  33  for locating the sealing profile  30 . In addition, the sealing profile  30  is provided with a cavity  34  and sealing lips  35  for guiding and sealing the window pane  20 . Furthermore the sealing profile  30  comprises a recess  31  for positive connection of a molding  50 . The molding  50  serves to finish the sealing profile  30  and frame  12  at least in part in adding to the visual appeal. The molding  50  made of plastics material and arranged stationary is provided with an electrical conductor  40 . The electrical conductor  40  represents a sensor electrode as described in EP 1 154 110 A2 and serves to generate an electrical field. In this arrangement the grounded frame  12  forms the opposing electrode needed to maintain the electrical field. An analyzer (not shown) detects the change in the capacitance caused by an obstacle in the opening range of the  20  and furnishes as a function of the change a signal for controlling the electric motor  21  which halts the electric motor  21 , when necessary. Depending on the particularly application the molding  50  may be configured pliable so that on physical contact with an obstacle the molding  50  is deformed, prompting a change in the capacitance of the electrical field for evaluation as a control signal. To ensure adequate deformability the molding  50  is spaced away from  30  at least in the region of the electrical conductor  40  so that the molding  50  forms a so-called softspot in the region of the electrical conductor  40 .  
     [0038] Referring now to FIGS. 3 a  to  3   d  there are illustrated alternative embodiments of how the electrical conductor  40  is configured and arranged. Common to all embodiments is that the electrical conductor  40  is arranged at the side of the molding  50  facing the sealing profile  30  in thus being concealed from view without so that the electrical conductor  40  does not spoil the visual appeal of the finish afforded by the molding  50 .  
     [0039] Referring now to FIG. 3 a  there is illustrated an embodiment of the electrical conductor configured stranded, surrounded by a protective sheathing  41 . The sheathing  41  is made of a non-conducting elastomeric material, for example, sponge rubber fabricated by coextrusion. The sheathing  41  is bonded to the molding  50  for a materially positive connection.  
     [0040] Referring now to FIG. 3 b  there is illustrated an embodiment of the electrical conductor  40  configured likewise as a thin wire or stranded. Unlike the embodiment as shown in FIG. 2 the electrical conductor  40  is not integrated in the molding  50 , for example, by injection molded, it instead being located between two webs  51  configured on the molding  50 . In this arrangement, these webs  51  may form a continuous channel or a line of fingers. Providing the webs  51  permits outsourcing production of the molding  50  and electrical conductor  40  separately whilst ensuring facilitated, speedy assembly.  
     [0041] Referring now to FIG. 3 c  there is illustrated an embodiment of the electrical conductor  40  configured as a strip clamped in place by a protuberance  52  formed on the molding  50 . In this case too, electrical conductor  40  and molding  50  can be outsourced in separate production for facilitated, speedy connecting together.  
     [0042] Referring now to FIG. 3 d  there is illustrated an embodiment of the molding  50  featuring a gap  53  in which the electrical conductor  40  is located. The gap  53  is configured in the form of a relief positively preventing the electrical conductor  40  from breaking out of place. To insert the electrical conductor  40  into the gap  53  it is necessary to bend the molding  50  in the direction indicated in FIG. 3 d  by “w”, as a result of which the gap  53  is opened up. Depending on the dimensioning of the gap  53  this also makes it possible to clamp in place the electrical conductor  40  in the gap  53  by non-positive locking.  
     [0043] The embodiments as described above for a device for detecting an obstacle in the opening range of the window pane  20  excel over conventional guards by being relatively cheap in production whilst featuring relatively simple assembly and maintenance. The main reason for this is that the electrical conductor  40  is arranged on the molding  50  providing finishing concealment of the frame  12  and sealing profile  30  at least in part. It is in this way that for both production as well as for assembly and maintenance that the electrical conductor  40  permitting detecting an obstacle in the opening range of the window pane  20  is now decoupled from the sealing profile  30 . This decoupling effect not only simplifies production, it also enables the electrical conductor  40  to be arranged at a location best suited for detecting an obstacle. For, unlike the sealing profile  30  which as a rule has the task of providing a reliable seal whilst guiding the powered window pane  20 , arranging the molding  50 , mainly subject to the requirements of visual appeal, can now be varied to a greater degree.  
     [0044] Apart from this, arranging the electrical conductor  40  on the molding  50  has the advantage that the sealing profile  30  can now be configured independently of the electrical conductor  40  as regards shape and material. On top of this, due to the stationary arrangement of the molding  50  the electrical conductor  40  is now subject to no, or at the most low, dynamic stress in thus ensuring it being clamped in place with low wear and thus durably. Last but not least, the pliancy of the molding  50  can be adapted to the particular application by suitably selecting material and dimensioning to thus take into account the softspot requirements as mentioned above.  
     [0045] Referring now to FIGS. 4 a  and  4   b  there is illustrated a further embodiment of how the electrical conductor  40  is arranged in a recess  61  of a trim  60  made of an elastomeric material. The trim  60  may be, for example, fabricated in coextrusion with the sealing profile  30  and unlike an electrically conducting portion  36  of the sealing profile  30  made of a non-conducting rubber. The recess  61  joins a gap  62  extending through the sealing profile  30  and porting the side of the sealing profile  30  facing the frame  12 . As evident from FIG. 4 b  the electrical conductor  40  can be easily inserted into the recess  61  by bending the  30  in the direction as indicated by “w” when non-assembled, as a result of which the gap  62  is opened up, whereas when the sealing profile  30  is assembled the gap  62  is closed to thus positively retain the electrical conductor  40  in the recess  61 , as evident from FIG. 4 a.    
     [0046] Referring now to FIGS. 5 a  to  5   c  there is illustrated a similar aspect for securing the electrical conductor  40 . A trim  70  of U-shaped cross-section has legs  71 ,  72  and a base  73 . Provided in the base  73  of the trim  70  made for example, of a plastics material is a recess  74  in which the electrical conductor  40  is arranged. Interposed between the outer surface of the base  73  and the recess  74  is a relatively thin web  75  acting like a live hinge to permit hinging the leg  72  relative to leg  71 . As evident from FIG. 5 a  the electrical conductor  40  can be inserted with no problem into the recess  74  with the leg  72  hinged open, whereas in the closed condition the electrical conductor  40  is positively held in the recess  74  as shown in FIG. 5 b . Hinging open the legs  71 ,  72  is prevented in the assembled condition of the trim  70  by adhesive  76  which joins the inner surfaces of the legs  71 ,  72  to the opposite surfaces of the frame  12  as evident from FIG. 5 c.    
     [0047] Both the aspect as shown in FIGS. 4 a  and  4   b  as well as the aspect as shown in FIGS. 5 a  to  5   c  are characterized by facilitated, reliable location of the electrical conductor  40  in the trim  60 ,  70 . In both cases the electrical conductor is inserted into the recess  61 ,  74  from the frame side with the advantage that, for one thing, once fitted, the trim  60 ,  70  of the electrical conductor  40  is non-releasably located in the recess  61 ,  74 , and, for another, the visual appeal of the exposed outer surface of the trim  60 ,  70  is not detrimented.  
     [0048] Referring now to FIG. 6 there is illustrated a further embodiment which unlike that as shown in FIG. 2 shows how the sealing profile  30  in this case is secured to the frame  12  by means of a clip fastener  37 . The clip fastener  37  connected to the sealing profile  30  penetrates for this purpose a hole  14  drilled in the frame  12  to clasp a surface area  15  of the frame  12  facing away from the sealing profile  30 . The electrical conductor  40  is arranged on a trim  54  finishing the frame  12 . In this arrangement, the electrical conductor  40  can be joined to the trim  54  the same as shown in FIGS. 2 and 3 a  to  3   d.    
     [0049] The device for detecting an obstacle as described above may find application not only as a guard for the window pane  20  but also for other closure elements of the motor vehicle  10  such as a sun-roof, a hatchback or a trunk lid. The important thing is that a molding  50  or some other kind of trim for securing the electrical conductor  40  can be provided.