Patent Publication Number: US-9840869-B2

Title: Rolling gate having a door leaf in the form of a flexible curtain

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. nationalization under 35 U.S.C. §371 of International Application No. PCT/EP2013/067473, filed Aug. 22, 2013, which claims priority to German Patent Application No. 10 2012 111 611.3, filed Nov. 29, 2012. The disclosures set forth in the referenced applications are incorporated herein by reference in their entireties. 
     The invention relates to a rolling gate, in particular a high-speed rolling gate, comprising a door leaf in the form of a flexible curtain, lateral guides in which lateral edges of the door leaf are received, and a drive which generates a driving force for driving the door leaf, wherein the door leaf comprises an elastically designed terminating element on a forward edge which is tensioned between the lateral guides by means of laterally applied transverse force components. 
     Rolling gates with a flexible curtain of PVC or the like have been used in practice for a long time. They have proved of excellent value for producing a wind-tight closure, for instance, between individual rooms in larger halls or the like. As compared to gate arrangements with door leaves formed of slats or sections such rolling gates have the advantage of having lower weight. It is therefore possible to operate them at very high speeds. 
     Such rolling gates as a rule have a winding shaft on which the curtain is wound during opening. In this process, lateral edges of the curtain are guided in associated lateral guides to also produce a substantially wind-tight closure here. Since a curtain does not have inherent stiffness, conventional rolling gates are as a rule provided with a rigid end plate on the forward edge of the door leaf. It is usually designed as a metal profile and stiffens the curtain transversely to the direction of movement of the door leaf. Typically, this end plate reaches up to the region of the lateral guides and has a predetermined weight, so that the curtain is tensioned also in the direction of movement across its entire breadth between the terminating element, on the one hand, and the winding shaft, on the other hand. 
     Since such curtain is normally fastened directly to the winding shaft, the driving force for opening the rolling gate is applied directly from the winding shaft to the curtain. For the closing of such rolling gates the winding shaft is operated in the opposite direction such that it releases the curtain. Due to the inherent weight of the end plate the curtain winds off the winding shaft automatically and closes the door opening. 
     In order to enable reliable and quick closing of such rolling gates it is additionally known to promote the process by means of tension forces on the end plate. Examples of such rolling gates can be found in DE 34 11 664 A1 and in DE 43 24 641 A1. Here, traction ropes are provided which are pretensioned by means of spring force or weights and which act on both sides of the end plate and pretension it in the direction of the closing of the door. Apart from promoting closing process it is further achieved that the curtain is tensioned even better in the direction of movement of the rolling gate. It is then less susceptible to bulging under wind load or the like. Thus, a reliable closing of the door opening is achieved. With such systems it is moreover possible to better prevent disturbances such as, for instance, canting of the door leaf in the course of the closing process. 
     Since door openings provided with such rolling gates are as a rule frequented many times, and in the light of the definitely substantial speeds of movement of such door leaves, there is, however, considerable risk of collisions, e.g. with persons or fork lifts passing the door opening, etc. In order to counteract this it is, for instance, known to install optical signaling systems on such rolling gates. Door light grid systems have proved to be of particular value for this purpose. The installing of such systems is, however, associated with effort. Moreover, these systems are as a rule only suited to detect obstacles which are already present in the plane of movement of the door leaf. Fork lifts approaching from the side or the like which are on a collision course are, however, not detected or only detected by means of additional signaling systems in adjacent regions of the door opening. Such collisions in practice often result in substantial damage both to the door leaf, i.e. the curtain and the end plate, and to the object hit. Therefore, systems have been developed which enable a deflecting of the end plate from the plane of the door leaf in cases of collision. 
     An example of this can be found in EP 0 675 261 A1 and/or in DE 44 14 524 A1. Here, the end plate is guided at both sides by means of carriages in the lateral guides such that it is trapped in the direction of movement of the door leaf, but is capable of swiveling transversely thereto. Moreover, the end plate is connected on both sides with tensioning ropes such that a tensile connection between the gate drive and the end shield is maintained even if the end shield deflects. The tensioning ropes are elastically pretensioned, so that a corresponding movement path is enabled. They support a resetting of the end plate to its normal position. To the extent that no case of collision exists, these tensioning ropes serve, like in the constructions already explained, the tensioning of the curtain in the direction of movement of the door leaf. In cases of collision it is, in view of the mass of the rigid end plate, however still possible with the rolling gate according to EP 0 675 261 A1 that a substantial damage of the end plate and/or of the person involved or the object hit takes place. 
     An alternative design of a deflectable end plate is known from DE 295 01048 U1. This document discloses a rolling gate with a flexible curtain and a rigid end plate in the form of a lower beam. A respective guide element which is adapted to be folded away laterally is coupled to the lateral ends of the end plate. This enables the exiting of the guide element from the lateral guides and accordingly the swiveling out of the end plate from the plane of the door leaf. 
     Another example of a deflectable end plate is given in DE 43 24 641 A1 which has already been mentioned above. The rigid end plate which exists here and which is nevertheless elastically deformable to a certain extent is connected with a respective guide arm in the region of the lateral guides. For this purpose an attachment at the respective guide arm is inserted loosely into a recess on the associated lateral end of the end plate. The guide arm is engaged by the traction rope for tensioning the curtain in the closing direction, on the one hand, and by a band which is available to be flush in the same operational axis as the traction rope, but is of opposite orientation and is pretensioned, on the other hand. By means of this the guide arm is moved similar to the curtain. For this purpose the band is also wound on the winding shaft. In the case of collision the restrictedly possible elastic deformation of the otherwise rigid end plate is sufficient for the attachments to be able to exit from the recesses on the end plate. The curtain can then swivel out from the plane of the door leaf together with the end plate. However, due to the intrinsically rigid design of the end plate there is still substantial risk of damage for the end plate and for people concerned, etc. Moreover, the loose plug connection of this known door arrangement is an uncertain system, which is a problem in particular in the case of a high-speed operation. It cannot be excluded here that the connection is released due to wobble movements, etc. 
     Another systematic approach for a collision protection device on a rolling gate has become known from EP 2 402 543 A2. This rolling gate whose curtain is conventionally wound on and/or wound off in a motor-driven manner on a winding shaft does not comprise any end plate of a rigid metal profile or the like, but a terminating element which is intrinsically elastic and thus designed to be deformable in the plane of the curtain and transversely thereto. It is thus capable of evading obstacles and thus avoiding damage. For this purpose, the terminating element comprises a hinge body and/or a chain which may additionally be pretensioned by an elastic traction means. The hinge body and/or the chain comprise a certain inherent weight, so that the terminating element automatically assumes a stretched position under the influence of gravity. A traction means such as a rubber cord or a rubber band is used here as an additional element for the tensioning of the terminating element, so that the gate curtain is simultaneously also tensioned in the direction of movement of the door leaf. When the rolling gate is closed, the inherent weight of the hinge body and/or of the chain on the terminating element has a supporting effect caused by gravity. The two elastic traction means arranged on both sides also promote the closing process. 
     One of the traction means serves simultaneously also as an indicator of the existence of a collision case in that it cooperates with a sensor detecting the position of the traction means in the region of the terminating element. If a collision case exists, the orientation of the traction means changes, so that the sensor may output an appropriate signal. 
     A disadvantage of the rolling gate pursuant to EP 2 402 543 A2 is, however, that the hinge body and/or the chain must have a definitely substantial weight to be able to fulfil the desired function of tensioning the curtain and/or of promoting the closing movement of the same. Due to the mass thus existing, these elements continue to represent a danger for persons or objects hit by the forward edge of the rolling gate, so that injuries or damages may still occur here. Since the terminating element is not of rigid design there is additionally increased danger that canting occurs in the course of the closing process of the door leaf. 
     DE 698 31 080 T2 finally discloses a further design of a rolling gate with an elastically designed terminating element. In order to provide a reliable closure of the door opening when the rolling gate is closed, this terminating element is coupled with carriages on the sides which are guided in lateral guides. Moreover, a tensioning strap is provided within the terminating element. In this manner, the terminating element is tensioned in transverse direction by appropriate transverse force components. 
     In the case of collision a detachment of the terminating element from the lateral carriage arrangements is possible since these elements are kept to each other by magnetic force only. The terminating element and partial areas of the curtain may then deflect from the plane of the door leaf, adapt themselves to obstacles they hit and/or deform around them elastically. In this manner damage of the terminating element and of the object concerned, etc. is avoided to a certain scope. 
     However, a high degree of precision is required for adjusting the intensity of the magnetic force such that a sufficiently stable connection exists, on the one hand, so that the coherence of the components required for the opening and the closing is ensured and such that, on the other hand, the terminating element detaches in time from the lateral carriage arrangements before damage occurs. 
     This known rolling gate is driven in a per se conventional manner by the actuation of the winding shaft on which the curtain is wound during the opening of the rolling gate. In order to promote the closing process of the curtain, a ballast tube is moreover arranged at the foremost end of the forward edge, said ballast tube being filled with a deformable material such as sand. This ballast tube provides a weight at the underside of the lifting gate illustrated, which does not just support the closing process as such, but also tensions the curtain in the vertical direction. This additional weight, however, restricts the opening speed. 
     Since the ballast tube pursuant to DE 698 31 080 T2 thus must have considerable weight, the mass associated therewith represents, similar to a conventional end profile, a risk for the object hit, etc. Here, too injuries of persons or damage to fork lifts, products, etc. are still possible. 
     It is therefore an object of the invention to improve a generic rolling gate such that it has high operational reliability and represents less danger to people or objects in cases of collision. 
     This object is solved by a rolling gate with the features of claim  1 . It is characterized in particular in that the driving force of the drive engages on the terminating element of the door leaf and thus provides the laterally applied transverse force components for the tensioning of the terminating element of the door leaf and a tension force component directed substantially in the direction of movement of the door leaf for closing the door leaf. 
     In accordance with the invention it was thus recognized for the first time that it is possible to let the driving force for the closing of the door opening of such a rolling gate, although it is designed with a flexible curtain with a curtain section and an elastic, i.e. intrinsically freely elastically deformable terminating element, also have an effect on the terminating element. It is thus advantageously possible now to do without components with a large mass in the terminating element. This reduces the danger of injury for persons possibly hit by the terminating element quite substantially. Likewise, the danger of damage to goods and/or work tools in the case of collision is reduced. Moreover, the terminating element itself is then also less susceptible to damage. 
     This is also supported by the fact that the terminating element, due to its elastic design, is designed to be deformable without damage in the plane of the curtain and also transversely thereto and can therefore adapt itself flexibly to obstacles and/or deform around same. This is not achieved with a conventional end plate even if it should be deflectable to a certain degree. Moreover, by means of the transverse force components applied, the terminating element of the rolling gate according to the invention is capable of returning to its stretched normal position without damage after the obstacle has been removed, etc., i.e. there are no permanent changes in shape. 
     At the same time, however, it is also achieved that the closing process of the rolling gate can take place in a particularly reliable manner. The tension force component for the closing of the door leaf provided at the rolling gate in accordance with the invention thus constitutes an active drive by means of which this movement can be controlled more exactly than by means of the passively acting systems with the weight in prior art. 
     Moreover, the rolling gate according to the invention is independent of a concrete orientation, so that it need not necessarily be arranged as a lifting gate with upright orientation as in prior art, but enables, for instance, also an oblique or horizontal closure between rooms or different areas. 
     Furthermore, a reliable tensioning of the elastically designed terminating element is, however, also achieved. In the normal case it is thus, with respect to the stabilization of the forward edge of the curtain, functionally quasi equivalent to a rigid end plate of a metal profile without, however, comprising its disadvantages with respect to the weight and with respect to the danger of injury or damage. 
     Another advantage of the rolling gate in accordance with the invention is that it can be used with high functional reliability and is characterized by a long life. 
     The rolling gate according to the invention thus provides for the first time that the driving force of the drive is used simultaneously for the driving and tensioning of the curtain in the direction of movement and for the tensioning transversely thereto in the region of the forward edge. The rolling gate according to the invention may have a surprisingly simple construction. It is thus hardly failure-prone and can additionally be provided in a cost-efficient manner. In many applications it is moreover possible to do without additional signaling systems such as door light grid systems or the like. 
     Advantageous further developments of the rolling gate according to the invention are the subject matters of the dependent claims. 
     Thus, the drive of the rolling gate may comprise a respective traction element in the region of the lateral guides which transfers the driving force to the terminating element of the door leaf. This enables a particularly simple constructional design of the drive system and is characterized by high reliability. Such traction elements have been used with rolling gates for a long time and have proved to be of great value. 
     It is further of advantage if the traction element is designed in two-part form with a driving part and a tension force transferring part, wherein the driving part is designed as an endless element for transferring the driving force, and wherein the tension force transferring part transfers the driving force transferred with the driving part to the terminating element of the door leaf. The course of movement of the rolling gate according to the invention can thus be controlled even more exactly. Moreover, an even more precise adjustment of the transverse force component and/or of the tension force component is possible. Furthermore, it is possible to use identical components for rolling gates with different dimensions to a high degree in this manner. 
     The driving part of the traction element may be formed as a toothed belt, a chain or the like at least in a partial section. With such elements it is possible to provide a positive locking for the traction element, so that a particularly reliable operation of the rolling gate is enabled. 
     Moreover it is possible that the tension force transferring part of the traction element is designed as a traction rope. Thus, a permanent transfer of the tension forces can be achieved in an approved manner. 
     If the drive comprises a weight balancing means with a tension spring and/or a weight, the construction of the rolling gate according to the invention is further simplified. It is then possible to do without a separately designed weight counterbalance independently of the drive. Moreover, the rolling gate according to the invention is then given a particularly compact and simple construction. 
     In this respect it is a further advantage if the drive comprises a pulley arrangement over which the traction element is guided. It is thus possible to advantageously control the drive arrangement such that a particular door leaf movement can be achieved with a short movement path at the drive element, for instance, a pinion at the motor. Moreover, it is also possible to adjust the acting forces in an advantageous manner. 
     According to a further advantageous design it is possible that the terminating element of the door leaf is coupled on both sides with a carriage moving in a guided manner along with the terminating element in the lateral guides and carrying a deflecting means by which the traction element is deflectable from the region of the lateral guides to the terminating element. Thus, the traction element is oriented with respect to the terminating element such that it provides a particularly suitable division of the driving force into the transverse force component and/or the tension force component. It is of particular advantage that, due to the carriage moved along with the terminating element, the angle at which the traction element engages on the terminating element is always the same, irrespective of the closure state of the door leaf. Thus, the same tension force component is accordingly applied on the terminating element of the door leaf during the entire closure process. Likewise, the same transverse force component for tensioning the terminating element is provided in each intermediate level in the course of the closure process. This enables an even more reliable operation of the rolling gate according to the invention. 
     If the carriages are guided in the lateral guides by means of rolls it is possible to guide them almost frictionless, and therefore they have a long lifespan. Moreover, the reliability of the rolling gate according to the invention is further increased. 
     It is of further advantage if the terminating element of the door leaf is detachably coupled on both sides with the respective carriage such that it is deflectable from the plane of the door leaf in the case of collision. Then, the rolling gate according to the invention also provides a kind of active collision protection device and does not only provide a passive protection device by the elastically designed terminating element. The danger of damage to the rolling gate according to the invention or to objects concerned, etc. in the course of a collision can be reduced distinctly by that. Since the traction elements on both sides are, however, still connected with the terminating element of the door leaf, it is not released completely and is moreover resettable to its normal position by means of the traction elements. 
     In this respect it is of advantage if the carriages are each connected with lateral edge elements of the terminating element by means of a snapping connection. Such snapping connection can be released non-destructively in the case of collision and subsequently be established anew. The danger of damage to the terminating element in the case of collision is thus further reduced. Moreover, it is possible with simple means to reset the rolling gate into its operating state. Furthermore, such snapping connection constitutes a reliable coupling manner which permanently enables a trouble-free normal operation of the rolling gate according to the invention. 
     In this respect it has further turned out to be advantageous if the snapping connection is designed such that the lateral edge elements of the terminating element, if the terminating element is deflected, automatically snap into the carriages in the course of a closing movement of the door leaf. Thus, a resetting to the normal state of the rolling gate according to the invention is possible after a case of collision in very short time and with little effort. In the scope of the invention it is in particular provided for the first time that this resetting to the normal position is not performed in the course of an opening movement of the door leaf, but of a closing movement. This leads to the further advantage that, in unfavorable cases, a manual interference is possible without problems if required so as to reestablish the snapping connection between the terminating element and the lateral carriages since the resetting process takes place in an area good to access, as a rule on the bottom side. 
     It is of further advantage if a sensor device is arranged on at least one carriage, said sensor device detecting the coupling state between the carriage and the terminating element. In this manner it is possible to detect a case of collision in a particularly reliable way. It is irrelevant whether the coupling state was released by the lateral exiting of the terminating element from the plane of the door leaf or by an elastic deformation of the terminating element in the plane of the door leaf. By means of the sensor device an appropriate failure routine can be initiated immediately and reliably. It consists as a rule at least in that the rolling gate opens and thus provides a larger clearance height in the door opening. 
    
    
     
       The invention will be explained in more detail in the following in embodiments by means of the Figures of the drawing. There show: 
         FIG. 1  a section from a schematic front view of a rolling gate according to the invention in accordance with a first embodiment, wherein the frame housing of the lateral guide has been omitted for illustration purposes; 
         FIG. 2  a sectional plan view of a lateral edge region of the rolling gate pursuant to  FIG. 1 ; 
         FIG. 3  a perspective detailed view of a drive system of the rolling gate according to the first embodiment; 
         FIG. 4  a detailed view in the bottom-side end region on the rolling gate according to the first embodiment; 
         FIG. 5 a    a perspective view of a rolling gate according to a second embodiment in an open state, wherein frame parts have been omitted for illustration purposes; 
         FIG. 5 b    a perspective slanted view from above of the rolling gate according to the second embodiment in the open state; 
         FIG. 6 a    a perspective view of the rolling gate according to the second embodiment in the closed state; 
         FIG. 6 b    a perspective slanted view from above of the rolling gate according to the second embodiment in the closed state; 
         FIG. 7  a sectional plan view of a lateral edge region of the rolling gate according to the second embodiment; 
         FIG. 8  a section through the lateral edge region of the rolling gate according to the second embodiment with a closed rolling gate at the lower end of the lateral frame; 
         FIG. 9  a perspective view of the rolling gate according to the second embodiment with a deflected terminating element; 
         FIG. 10  a perspective view similar to  FIG. 9  in the course of a resetting of the deflected terminating element to the normal operating state; and 
         FIG. 11  a perspective view similar to  FIGS. 9 and 10 , wherein the terminating element has been reset to its normal position. 
     
    
    
       FIGS. 1 to 4  illustrate a first embodiment of a rolling gate  100 . 
     It comprises a door leaf  110  consisting substantially of a flexible curtain with a curtain section  111  and a terminating element  112  arranged at the forward edge thereof. The forward edge is the edge region and/or the edge at the curtain section  111  which is positioned in front in the direction of movement during the closing of the door leaf  110 . 
     The rolling gate  100  which is designed as a lifting gate in the instant case further comprises a winding shaft  120  on which the door leaf  110  is wound during the opening of the rolling gate  100 . Moreover, the rolling gate  100  comprises lateral guides  130  one of which is shown in  FIG. 2  and which receive lateral edges of the door leaf  110 . Finally, the rolling gate  100  comprises a drive  140  which generates a driving force for driving the door leaf  110 . 
       FIG. 2  is a sectional plan view of one of the lateral guides  130 . As may be gathered therefrom, it comprises a frame box  131  forming a feed hopper  132  in the region of the associated lateral edge of the door leaf  110 , said feed hopper  132  opening into a guide slot  133 . In the illustrated embodiment the feed hopper  132  has an opening angle of approximately 100°. The guide slot  133  has been chosen such that the door leaf  110  can be guided therein with clearance. 
     In accordance with the illustration in  FIG. 3  the drive  140  comprises a motor  141  which is coupled with the winding shaft  120  via a transmission gearing  142 . The winding shaft  120  is rotated by the motor  141 . Depending on the direction of rotation the door leaf  110  is wound on the winding shaft  120  or wound off the winding shaft  120 . 
     A drive pinion  143  driving a traction element  144  is further arranged on the winding shaft  120  laterally outside of the winding area for the curtain section  111 . This traction element  144  serves to apply a driving force for the closing of the door leaf  110  on the terminating element  112 . Simultaneously, a transverse force component is applied on the terminating element  112  by means of which it is tensioned in transverse direction between the two lateral guides  130 . 
     The terminating element  112  is not designed as a rigid component, but is designed elastically. It is thus intrinsically freely deformable both in the plane of the curtain and transversely thereto and can accordingly adapt itself to obstacles and/or deform elastically around them without damage to or permanent changes of shape of the terminating element  112  occurring. In the illustrated example the terminating element  112  is formed by a bag of flexible material, such as the curtain material, which is formed at the forward edge and into which a slight, flexible and dampening body such as, for instance, foam material or the like, is inserted. Without the transverse force components applied on both sides thereof by the traction element  144  the terminating element  112  would be flexible and/or deformable with low lateral forces already and would not be able to produce a reliable closure in the bottom-side area. 
     For the transferring of the driving force the traction element  144  comprises a toothed belt  145  which cooperates in a positive locking manner with the drive pinion  143 . Moreover, the traction element  144  comprises a traction rope  146  absorbing the driving force of the toothed belt  145  and transferring it further. A weight  147  is provided which has the toothed belt  145  fastened on one side thereof and the traction rope  146  fastened on the other side thereof. The drive  140  further comprises a tension spring  148  which is fixed on the bottom side and cooperates with the traction rope  146 . 
     Furthermore, the drive  140  comprises a buffer container  149  for the toothed belt  145 . The toothed belt  145  is fastened in this buffer container  149  with a spring arrangement (not shown) connected therebetween. The buffer container  149  is moreover suited to receive a backlash of the toothed belt  145  during the closing of the door leaf  110  in a certain scope. In the case of a greater length of the tension-free end of the toothed belt  145  the excess length will simply hang over laterally. 
     If, however, the door leaf  110  is opened, the toothed belt  145  runs over the drive pinion  143  until the door leaf  110  has reached its opened position. In order to mitigate the stopping of the door leaf  110  at the top end of the door opening, the mentioned, non-illustrated spring in the buffer container  149  dampens the last section of the movement path of the toothed belt  145 . 
     The end of the traction rope  146  which is not connected with the weight  147  engages on a lateral edge element  113  of the terminating element  112  and is fastened there, as may in particular be seen in  FIG. 4 . 
     The drive  140  further comprises a pulley arrangement  150  over which the traction rope  146  runs. For this purpose, the traction rope  146  is first of all guided over a deflection roll  151  at the free end of the tension spring  148 , as may in particular be seen in  FIG. 1 . Then the traction rope  146  is guided over a further deflection roll  152  at the weight  147 . Finally, the traction rope  146  runs over a deflection roll  153  fixed on the bottom side to the associated lateral edge element  113  of the terminating element  112 . 
     In the following, the operating mode of the rolling gate  100  will be explained in more detail. 
     For the closing of the rolling gate the motor  141  is actuated such that it drives the winding shaft  120  for winding off the door leaf  110 . Thus, the door leaf  110  is released from the winding shaft  120 . 
     By the toothed belt  145  the weight  147  is pulled upward in the direction of the winding shaft  120 . At the other side of the drive pinion  143  the backlash at the toothed belt  145  is then moved into the buffer container  149  or hangs over laterally, respectively. 
     By the movement of the weight  147  the traction rope  146  is tensioned. It then runs off over the deflection rolls  151 ,  152  and  153  such that it tensions the tension spring  148 , on the one hand, and applies, with the door leaf-side end, a tension force component on the terminating element  112  for the closing of the door leaf  110 , on the other hand. In this manner the closing movement of the door leaf  110  is promoted, i.e. the door leaf  110  is pulled off the winding shaft  120 . 
     As the closing movement of the door leaf  110  continues the door leaf-side end of the traction rope  146  engages on the terminating element  112  at an ever diminishing angle relative to the contact area of the rolling gate  100 , as may in particular be seen from  FIG. 4 . Accordingly, an ever increasing transverse force component engages on the lateral edge elements  113  of the terminating element  112 . When the rolling gate  100  is closed, the traction rope  146  is positioned approximately at an angle of 40° to 50° to the associated lateral edge element  113  at the terminating element  112 . The transverse force component existing thereby is sufficient to tension the terminating element  112  expediently in transverse direction between the lateral guides  130 . 
     If the door leaf  110  is completely closed, the weight  147  reaches its highest position above the contact area of the rolling gate  100 . Furthermore, the tension spring  148  is also tensioned maximally in this state. It is thus achieved that the door leaf  110  opens automatically in an emergency case, for instance, in the case of a power failure. The weight  147  and the tension spring  148  thus constitute a weight balancing means which actively supports an opening movement of the door leaf  110 . 
     For the opening of the door leaf  110  the motor  141  is driven in the opposite direction, so that the curtain section  111  is wound on the winding shaft  112 . Simultaneously, the forward edge of the door leaf  110  is released gradually by the toothed belt  145  and the traction rope  146 , so that a controlled opening movement of the door leaf  110  and a crease-free winding of the same on the winding shaft  120  is enabled. As was already explained above, the backlash in the toothed belt  145  is pulled out of the buffer container  149  until its elastic fastening in the buffer container  149 . This spring force prohibits hard stopping of the door leaf  110  in the course of the winding process. It is thus possible to reliably prevent damages to the door leaf  110 . The weight  147  is then positioned in its lowermost position closest to the contact area and the tension spring  148  is also largely relieved. 
     The door leaf  110  of the rolling gate  100  is thus pulled actively to its closed position by the traction effect on the traction rope  146  of the traction element  144 , wherein the traction rope  146  provides a tension force component which is substantially directed in the direction of movement of the door leaf. Simultaneously, however, the traction rope  146  also provides a transverse force component to the terminating element  112  by means of which it is tensioned in transverse direction between the lateral guides  130 . 
     In cases of collision the elastically designed terminating element  112  is, despite the tensioning by the transverse force components, however capable of deforming and of thus avoiding damages to the terminating element  112  or the object hitting. In this case the tension spring  148  releases a certain length of traction rope  146  in a predetermined manner in correspondence with the force acting, so that the terminating element  112  may perform an appropriate deformation. The force acting on the terminating element  112  in the case of such a collision is thus assumed elastically by the tension spring  148  through the pulley arrangement. 
     Moreover, in the course of the opening or closing movement the tension spring  148  also has a balancing effect with respect to the forces applied on the door leaf  110  by the winding shaft  120 , on the one hand, and by the traction element  144 , on the other hand. Excessive wear of the components of the drive  140  and of the door leaf  110  is thus prevented. 
     For the sake of completeness it has to be noted that the foregoing explanation has merely considered one side of the rolling gate  100 . The opposite lateral edge region is substantially designed in mirror image, except for the motor  141  and the transmission gearing  142  which are provided on one side of the rolling gate  100  only. 
       FIGS. 5 to 11  illustrate a second embodiment of the invention by means of a rolling gate  200 . 
     In  FIGS. 5 a  and 5 b    the rolling gate  200  is illustrated in an open state while it is illustrated in a closed state in  FIGS. 6 a    and  6   b.    
     As may be gathered from these Figures, the rolling gate  200  also comprises a door leaf  210  which is formed substantially of a flexible curtain with a curtain section  211  and an elastically designed terminating element  212 . Furthermore, the rolling gate  200  comprises a winding shaft  220  and lateral guides  230 , only one of which is illustrated in the Figures for illustration purposes. Finally, the rolling gate  200  also comprises a drive  240  for providing the driving force for the operation of the door leaf  210 . 
     As may in particular be seen from  FIG. 7 , each of the lateral guides  230  comprises a frame box  231 . This frame box  231  contains a feed hopper  232  opening into a guide slit  233  in which the door leaf  210  is received with clearance. 
     The drive  240  comprises a motor  241  and a transmission gearing  242 , as may in particular be seen in  FIGS. 5 b  and 6 b   . They drive the winding shaft  220 . A drive pinion  243  cooperating with a traction element  244  is moreover arranged on the winding shaft  220 . The traction element  244  is designed to have several parts in this embodiment and comprises a driving part and a tension force transferring part. The driving part comprises a toothed belt  245  and a drive traction rope  246   a . They are designed as endless elements in this embodiment, i.e. are arranged relative to each other such that they are capable of circulatingly transferring a tension force. The tension force transferring part comprises a traction rope  246  which finally transfers the tension force to lateral edge elements  213  of the terminating element  212 . 
     Similar to the first embodiment, a weight  247  and a tension force  248  are also arranged at the rolling gate  200 . The weight  247  is received between one end of the toothed belt  245  and of the drive traction rope  246   a . The drive traction rope  246   a  is finally deflected over a deflection roll  254  fastened on the bottom side and is guided to a stop  255 . The other end of the toothed belt  245  is fastened to this stop  255 . 
     During operation of the drive pinion  243  the toothed belt  245  is thus moved circulatingly along a predetermined movement path together with the weight  247 , the drive traction rope  246   a  and the stop  255 . 
     The traction rope  246  is also fastened to the weight  247 . It is further guided over a pulley arrangement  250  to the lateral edge element  213  at the terminating element  212 . For this purpose, the pulley arrangement  250  comprises a deflection roll  251  at the tension spring  248  and a further deflection roll  252  at the weight  247 , similar to the configuration of the first embodiment. The traction rope  246  is then deflected over a deflection roll  253  fastened on the bottom side such that it can finally act on the lateral edge elements  213  of the terminating element  212 . 
     Other than in the first embodiment, however, the traction rope  246  here runs on both sides over a carriage  260  which is guided in the area of the associated lateral guide  230 . For this purpose the carriage  260  comprises rolls  261  by means of which it props adjacently to the guide slit  233  within the frame box  231  and is moved to roll. The carriage  260  further comprises a deflection section  262 , here in the form of a roll, by means of which the traction rope  246  is deflected such that it engages on the lateral edge element  213  of the terminating element  212  at a particular angle which is the same in all closing positions of the door leaf  210 . For this purpose the carriage  260  is moved together with the terminating element  212  when the door leaf  210  is moved. 
     The carriage  260  is connected with the terminating element  212 . In accordance with the illustration in  FIG. 8  each lateral edge element  213  of the terminating element  212  comprises an engagement hook  214  engaging in a form-locking manner into a snap-in nose  263  on the sledge  260 . This connection is releasable in the case of collision. 
     In order that an unlocking of the terminating element  212  from a carriage  260  can be detected, a sensor element  265  is further arranged on the carriage  260 . It cooperates with a sensor part  215  on a lateral edge element  213 . If the relative position of the sensor part  215  with respect to the sensor element  265  changes, a swiveling out of the terminating element  212  from the plane of the door leaf and/or a deformation of the terminating element  212  in the plane of the door leaf can be detected and a failure routine or the like can be initiated. The sensor consisting of the sensor element  265  and the sensor part  215  is here designed as a magnetic switch. 
     The functioning of the rolling gate  200  is in principle similar to that of the rolling gate  100  according to the first embodiment. For the closing of the door leaf  210  here, too, a driving force is exerted by the motor  241  via the transmission gearing  242  on the drive pinion  243  such that the toothed belt  245  pulls the weight  247  in the direction of the winding shaft  220 . Thus, the drive traction rope  246   a  is also pulled and in turn pulls the stop  255  downward and thus, due to the circulating configuration with the toothed belt  245 , keeps the same under tension. At the same time the door leaf  210  is released from the winding shaft  220 . 
     With the shifting of the weight  247  the traction rope  246  is also pulled. The tension spring  248  is tensioned via the pulley arrangement  250  and the tension force of the traction rope  246  is further transferred via the carriage  260  to the terminating element  212 . Thus, a tension force component is applied thereon for the closing of the door leaf  210 . 
     For the opening of the door leaf  210  the motor  241  is driven in the opposite direction, so that the door leaf  210  is wound on the winding shaft  220 . At the same time the toothed belt  245  is driven in a direction in which the weight  247  can be lowered in the direction of the contact area of the rolling gate  200 . Accordingly the tension spring  248  releases and, via the pulley arrangement  250 , the traction rope  246  is given a backlash such that it enables the lifting of the forward edge of the door leaf  210 . Once the door leaf  210  has reached its upper position, i.e. the completely opened position, the stop  255  hits a corresponding counterpart on the frame side and thus prevents the winding of the door leaf  210  beyond a predetermined point. The stop  255  is elastically pretensioned, so that abrupt stopping of the door leaf does not occur. 
     As was already explained above, the deflection section  262  at the respective carriage  260  has the effect that the traction rope  246  engages always at the same angle on the lateral edge element  213  of the terminating element  212 . The relation of the magnitude of the transverse force component to the tension force component therefore remains the same in all closing positions of the door leaf  210 . The magnitudes of the transverse force component and of the tension force component increase with the continuing approach to the closed position of the door leaf  210  due to the increasing pretension of the tension spring  248 . The forward edge of the door leaf  210  with the terminating element  212  arranged thereon is, however, tensioned in any position of the door leaf  210 . 
     Like in the first embodiment, the configuration of the rolling gate  200  also allows an emergency opening if for instance, the power supply fails. Then, the door leaf  210  opens automatically due to the mass of the weight  247  and the pretension of the tension spring  248 . 
     While it was possible for the door leaf in the first embodiment to exit from the lateral guides in the case of collision, the rolling gate  200  enables a swiveling out of a middle section of the terminating element  212  from the plane of the door leaf in the case of collision. Then, the snapping connection between the lateral edge elements  213  and the respectively associated carriage  260  illustrated in  FIG. 8  is released. In this process, the engagement hook  214  is disengaged from the snap-in nose  263 . This state is illustrated in  FIG. 9 . At the same time, however, the connection of the traction rope  246  with the terminating element  212  is maintained. This facilitates the reestablishment of the snapping connection between the terminating element  212  and the carriage  260 . In the case of the rolling gate  200  this is performed in the course of the closing of the door leaf  210 . 
     If the snapping connection between the carriage  260  and the terminating element  212  is released, the carriage  260  does no longer move together with the door leaf  210 . It thus rests substantially at the lower end of the associated lateral guide  230 . If the somewhat opened door leaf  210  is closed and thus lowered to the carriages  260 , the engagement hooks  214  on both sides of the terminating element  212  get into contact with a respective guiding chamfer  264  on the carriage  260  and slide down thereon until they snap again into the snap-in noses  263 . These processes are illustrated in  FIGS. 10 and 11 . Thus, the snapping connection between the carriage  260  and the terminating element  212  has been reestablished. 
     It has to be added that the angle of attack of the traction rope  246  at the lateral edge element  213  is different in the released snapping connection than in the normal operating condition. Then, the traction rope  246  engages on the lateral edge element  213  at a larger angle to the contact area of the rolling gate  200 , so that increased tension force in the door closing direction is provided. This facilitates the process of reestablishment of the snapping connection between the lateral edge element  213  and the respective carriage  260 . 
     In cases of collision it is, due to the elastic properties of the terminating element  212  and of the tension spring  248 , also possible here to produce a backlash at the traction rope  246 , so that, on the one hand, the terminating element  212  can swivel out of the plane of the door leaf and, on the other hand, an elastic deformation of the terminating element  212  in the plane of the door leaf and also transversely thereto is also enabled. Thus, damage to the terminating element  212  can be avoided in a particularly reliable manner. Moreover, the danger of damage to hitting objects and the danger of injury for persons participating in such a collision are also reduced. 
     As may in particular be seen from  FIG. 7 , the snap-in nose  263  on the carriage  260  has a shape which is complementary to the feed hopper  232  of the lateral guides  230 . Thus, the carriage  260  can be guided particularly well on the associated frame box  231 . The engagement hook  214  at the lateral edge element  213  also comprises a corresponding configuration matching with the feed hopper  232  at the side facing thereto, so that the engaging of the terminating element  212  in the case of collision is facilitated. In other words, the feed hopper  232  guides the engagement hook  214  laterally during reengaging in the snap-in nose  263  such that the reestablishment of this snapping connection is possible in a particularly reliable manner. A quick resetting of the rolling gate  200  in its normal operating condition is thus possible after a case of collision. 
     Like in the first embodiment the rolling gate  200  is explained in detail in the Figures only by means of one lateral edge region. It is to be understood that the configuration in the region of the other lateral guide is of substantially mirror image design. 
     In addition to the embodiments explained the invention allows for further design approaches. 
     Thus, it is possible to do without the weight  147  and/or  247  in some applications. This is in particular the case if the tension spring  148  and/or  248  provides sufficient reset force for an emergency opening of the rolling gate  100  and/or  200 , or if such an emergency opening function is not necessary. 
     On the other hand it is, however, also possible to do without the tension spring  148  and/or  248  in particular applications. Then, a corresponding pretensioning effect can be achieved due to the influence of gravity on the weight  147  and/or  247 , or such a function is renounced. 
     Furthermore, it is not stringently necessary to provide a pulley arrangement  150  and/or  250 . Basically it would also be possible to establish a direct operative connection between the drive pinion via the toothed belt and the traction rope to the terminating element  112  and/or  212 . Expediently, an elastic length compensation for the traction element could be provided for this purpose at a suitable place in this traction connection. 
     The traction element  144  and/or  244  may, instead of a toothed belt or a chain, also comprise a traction band which is wound, for instance, in the region of the winding shaft  120  and/or  220 . 
     As may be gathered from the embodiments explained, the terminating element of the door leaf may on both sides also be detachably coupled with the respective carriage such that it exits from this connection in the case of collision without leaving the plane of the door leaf. This is, for instance, the case if the door leaf is lowered to an obstacle during closing. Due to the deformation of the terminating element in the plane of the door leaf which is produced in this process the connection to the respective carriage will then be released. 
     The connection between the carriage  260  and the terminating element  212  may also be performed in a manner different from a snapping connection. Thus, coherence by magnetic forces may, for instance, be established. Alternatively it is also possible to establish a connection by means of shearing pins or the like, wherein the releasability of this connection has been predetermined appropriately. 
     The reestablishment of the connection between the terminating element  212  and the associated carriage in the case of a swiveled terminating element  212  may also be performed in another manner and in another position in the movement path of the door leaf  210 . For instance, this is also possible at the upper end of the lateral guides  230  which is adjacent to the winding shaft. 
     Furthermore, the sensor device with the sensor element  265  and the sensor part  215  may be renounced if such automatic detection of a case of collision is deemed not to be required. 
     Instead of the magnetic switch described, any other kind of sensor for detecting a case of collision may also be used. 
     The deflection section  262  may also be designed in the form of a sliding guide or the like instead of the roll explained. 
     The two embodiments explained each show rolling gates in the form of lifting gates. Other orientations of the door leaf such as inclined or horizontally oriented door leaves are, however, also possible.