Patent Abstract:
A door seal for a doorway in a vehicle for public passenger transportation has at least one reinforcing element coated with an elastomer, the reinforcing element having a lesser elasticity in the longitudinal direction of the seal than in the transverse direction.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of European Patent Application No. EP 13 002 883.0, filed Jun. 5, 2013, the content of which is incorporated herein in its entirety. 
     FIELD OF THE INVENTION 
     The invention relates to a seal profile, having a hollow space, of a door seal of a doorway in a vehicle for public passenger transportation, more specifically of a high-speed train, the seal profile having at least one connecting member to be received by the coachwork and/or the door of the vehicle. 
     BACKGROUND OF THE INVENTION 
     A door seal for a high-speed rail vehicle is sufficiently known from the prior art. Such seals are highly stressed when used in doors of high-speed trains because the doors move with a considerable force against the seals in the door opening, thus subjecting the seals to a strong deformation. This is necessary to prevent the pressure surges, which occur when the high-speed train is moving and which act against the outer shell of the train, e.g. when two trains meet or when a train enters a tunnel, from entering into the interior of the vehicle. 
     US2009/243142 A1 discloses a seal with a connecting member, the connecting member serving for example for fixation on the coachwork of a vehicle. The connecting member has a support made of metal with a U-shaped cross-section, the support having several slots disposed in a row transversely to the longitudinal axis. The support is coated with an elastomer. The slots in the support serve to adapt the connecting member to the shape of the coachwork. The seal, which is disposed on the connecting member, has a hollow space and consists apparently of an elastomer. 
     Up to now seals with a complex cross-section were manufactured by vulcanisation in a mould. This is extremely complicated, particularly considering that a multitude of doors of different sizes must be equipped with such seals, wherein at least one moulding tool needs to be provided for each seal profile of each door type. This means that the expense required for providing the appropriate moulding tools, but also the manufacturing effort itself, are enormous as a consequence of job production in a mould. 
     SUMMARY OF THE INVENTION 
     The problem underlying the invention therefore consists in solving this problem. The problem more specifically consists in being able to manufacture door seals, including with a complex cross-section, at a lower cost. In order to be able to manufacture such a seal of the type mentioned in the introduction at a lower cost, the invention provides that the seal has at least one reinforcing element coated with an elastomer, the reinforcing element having a lesser elasticity in the longitudinal direction of the seal than in the transverse direction. Thereby, it is achieved that such a seal with such a reinforcing element can be manufactured by extrusion. Up to now, it was assumed that seals with complex cross-sections with reinforcements were not producible by extrusion. The reason for this is that the reinforcing element folds during the extrusion in the extrusion tool. Since the reinforcing element is now more rigid in the longitudinal direction of the seal, i.e. in the extrusion direction, than in the transverse direction, the formation of such folds during the extrusion is avoided. 
     It has already been pointed out that the object of the invention is seals, more specifically with a complex form or contour. Such a complex seal is characterized in that the wall of the seal has a drawn-in area in the area of the sealing lip. In the drawn-in or vaulted state of the seal, the wall of the seal has a contour with a U-shaped cross-section in the area of the sealing lip. 
     Furthermore, it is more specifically provided that the reinforcing element has a plurality of more specifically oval or diamond-shaped openings extending in the longitudinal direction of the sealing profile. Regarding the arrangement of the oval or diamond-shaped openings, it is provided that several rows of such openings are provided, the openings of the individual rows being staggered relative to each other. More specifically thanks to these openings extending in the longitudinal direction of the profile, and here more specifically very narrow oval openings, a high stability of the reinforcement in the longitudinal direction, i.e. in the direction of extrusion, is achieved. In the transverse direction however, the reinforcing element is highly flexible, which entails another advantage, which is that by inflating such a seal in the mounted state, in order to increase the sealing force between the door on the one hand and the frame of the vehicle on the other hand, or also between two doors, the seal can go through a great volume change, which increases the seal effect. Stated another way, the reinforcing element allows the seal to inflate from a non-inflated to an inflated state and expand in the transverse direction thereby sealing while being stable and not expanding in the longitudinal direction. The consequence of this is that the seal no longer has to be squeezed as much as in the prior art, the consequence being that the seal is subjected to less wear. 
     In this respect, according to another feature of the invention, means for inflating the seal are provided on the seal, the means for inflating the seal being more specifically a valve. 
     The seal has at least one connecting member to be received by the coachwork or the door of the vehicle. It has already been pointed out that the seal can be disposed on the front side of the door as well as on the front side of the frame of the coachwork of the vehicle. According to another feature of the invention, the connecting member is designed in the manner of a rail and is preferably made of an elastomer, so that the seal can be extruded in one piece together with the connecting member. The connecting member itself has grooves extending in the longitudinal direction of the seal, in order to be able to insert this seal into the front side of the door and/or the front side of the frame on the coachwork side by clipping it in. 
     According to another feature, the seal has a sealing lip, which preferably protrudes outward on the front side, i.e. is oriented toward the front side of the door or the front side of the frame on the coachwork side, depending on the installation. 
     The sealing lip, which is preferably also made of an elastomer, is disposed preferably in the middle of the seal in a parallel direction to the door surface. The arrangement of the sealing lip as well as the arrangement of the connecting member on the seal is such that the reinforcing element protrudes at least into the sealing lip or the connecting member, in order to effect a stable connection between the reinforcing element coated with an elastomer and the sealing lip or the connecting member. From this it is clear that the seal consists of four elements, namely two lateral parts or two sidewalls, comprising the reinforcing element coated with an elastomer and the connecting member on the one front side of the seal profile and, on the opposite side, the sealing lip, which is also connected to the sidewalls of the seal. 
     When manufacturing a seal of the type described above by extrusion, it has turned out to be particularly advantageous, if a silicone rubber is used as an elastomer. The reason for this is that silicone has excellent sliding properties for extrusion, which makes it possible to maintain a low friction resistance during passage through the extrusion tool, the consequence being that the formation of folds in the reinforcing element is also substantially avoided. 
     In the following, the invention is exemplarily described in more detail based on the drawings. In the drawings: 
    
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
         FIG. 1  is a schematic of a vehicle for public passenger transportation with a door; 
         FIG. 2  is a cross-sectional view taken along line II-II in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along line in  FIG. 2 ; and 
         FIG. 4  is a detailed lateral view of a seal according to  FIG. 2 , wherein the door receiving the seal profile has been left out. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The vehicle  1  has a door opening  3  with the door  5  in its coachwork  2 . The door  5  can be designed as a sliding plug door or as a pivoting door, for example. 
     The design of the seal can be gathered in detail by looking at  FIGS. 2 to 4 .  FIG. 2  shows the seal  10  in a sectional representation, the seal being received by the door  5 . It is noticeable that the seal  10  has a reinforcing element  14  in the area of both walls  12 , which is coated with an elastomer layer  15 , e.g. a silicone rubber. The elastomer coating can be carried out on both sides of the reinforcing element  14  or only on one side. On each side, the wall  12  ends in the sealing lip  16  and in the connecting member  18 , the connecting member  18  having grooves  20  on both sides in the area of the transition to the wall  12  extending in the longitudinal direction, which allows for a clip-on arrangement on the front side  6  of the door  5  or the coachwork  2 . An essential part of the design of the seal  10  is that the respective reinforcing element  14  in the area of the wall  12  protrudes on the one hand into the connecting member  18  and on the other hand into the sealing lip  16 , in order to effect a stable connection of the reinforcing element and thereby of the flanks on the connecting member  18  on the one hand and on the sealing lip  16  on the other hand. The reinforcing element itself, which is formed by a woven fabric or a warp-knitted fabric or a weft-knitted fabric for example, is advantageously equipped with the elastomer layer  15  on both sides. The configuration of the reinforcing element  14  can be seen in detail in  FIG. 4 . The reinforcing element  14  has several superimposed rows of slim oval openings  24  that are elongated in the longitudinal direction of the seal, which cause the reinforcing element  14  to be substantially non-elastic in the longitudinal direction (arrow  30 ) but extremely elastic in the transverse direction (arrow  35 ). This is explained by the fact that the openings  24  with a slim oval form, which are shown in  FIG. 4 , are able to bulge in the direction of the arrow  35  when a tension is exerted in that direction, in order to be able to provide the desired elasticity in that direction when the seal is inflated. The same correspondingly applies to diamond-shaped openings. 
     The design of the reinforcing element can also be such that a foil made of a plastic, e.g. a polyethylene or polypropylene is equipped with the slim oval openings described above e.g. by die cutting or punching. 
     The seal with a complex cross-sectional design according to  FIG. 2  has a drawn-in area  17  in the area of the sealing lip  16 . This means that the area  17   a  of the wall  12 , which receives the sealing lip  16 , is vaulted toward the area  17   b  facing the wall  12  with the connecting member  18 , the hollow space of the seal profile being downsized in the process. This means that the profile has a contour with a U-shaped cross-section. It has already been pointed out that seals, more specifically with a complex shape or contour, are the object of the invention. To sum up, such a complex seal is characterized in that the wall of the seal has a drawn-in area in the area of the sealing lip. In this respect, the seal as a whole, in its drawn-in or vaulted state, has a contour with a U-shaped cross-section ( FIG. 2 ). 
     In this regard, in  FIG. 4 , a schematic of a valve  26  is visible, by means of which the seal profile can be inflated. When the seal profile is inflated, the seal takes up a rectangular shape, wherein the sealing lip protrudes outwards. This means that due to the internal pressure, the seal  10  will be deformed in the direction of the orientation of the sealing lip  16 , i.e. in the direction of the arrow  40 . Thereby, the individual openings  24  in the reinforcing element  14  of the flanks  12 , which at first have a longitudinally extending oval shape, then more specifically take up a more round shape. In contrast, by creating a negative pressure, the profile can be contracted, i.e. brought into the shape according to  FIG. 2 . Since the sealing lip does not protrude from the seal, there is no risk of damaging the sealing lip when the door is brought into its closed position. 
     LIST OF REFERENCE NUMBERS 
     
         
         
           
               1  vehicle 
               2  coachwork 
               3  doorway 
               5  door 
               6  front side of the door or the coachwork 
               10  seal 
               12  wall of the seal 
               14  reinforcing element 
               15  elastomer layer 
               16  sealing lip 
               17  drawn-in area 
               17   a  area of the wall with the sealing lip 
               17   b  area of the wall with the connecting member 
               18  connecting member 
               20  grooves on the connecting member 
               24  oval openings 
               26  valve in the seal profile 
               30  arrow 
               35  arrow 
               40  arrow

Technology Classification (CPC): 1