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FIELD OF THE DISCLOSURE 
       [0001]    This patent generally pertains to a horizontal side-moving door and, more specifically, to an upper seal for such a door. 
       BACKGROUND 
       [0002]    Typical horizontal side-moving doors include either a rigid or semi-rigid planar door panel that translates horizontally in front of a doorway or a flexible door panel that coils about a roller as a leading edge of the flexible panel translates horizontally in front of the doorway. Horizontal side-moving doors with a flexible panel and a roller can be referred to as horizontal side-rolling doors. 
         [0003]    Horizontal side-rolling doors, such as the one disclosed in U.S. Pat. No. 4,096,902, include one or two vertical rollers at either one or both lateral edges of the doorway. Some horizontal side-rolling doors have a single roller at one side of the doorway with a single curtain that extends and retracts across the full width of the doorway. 
         [0004]    In some cases, the “single curtain” is actually comprised of two layers, each having its own vertical take-up roller. In such cases, the two rollers are right next to each other at one lateral edge of the doorway. As the door opens, the two layers of the curtain separate at the edge of the doorway and wrap upon their respective rollers. 
         [0005]    Other horizontal side-rolling doors include two individual curtains, each supported by its own roller at opposite lateral edges of the doorway. For such doors, the leading edges of the two separate curtains meet at the center of the doorway as the door closes. To open the door, the two curtains move apart from each other and wrap upon their own roller (or set of rollers if each curtain has two layers). 
         [0006]    The leading edges of side-rolling curtains and planar door panels are often reinforced by a relatively rigid, vertically elongate member that can be susceptible to being accidentally struck by a forklift passing through the doorway. To prevent permanent damage to the door in the event of a collision, the door panel or curtain is often made to restorably break away. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a front view of one example of a horizontal side-moving door shown in a closed position. 
           [0008]      FIG. 2  is a front view of the door of  FIG. 1  but showing the door partially open. 
           [0009]      FIG. 3  is a front view of the door of  FIG. 1  but showing the door fully open. 
           [0010]      FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 2 . 
           [0011]      FIG. 5  is a cross-sectional view similar to  FIG. 4  but showing air pressure deflecting the curtain&#39;s upper edge. 
           [0012]      FIG. 6  is a cross-sectional view similar to  FIG. 5  but showing air pressure deflecting the curtain&#39;s upper edge in an opposite direction. 
           [0013]      FIG. 7  is a cross-sectional view similar to  FIG. 4  but showing the seal guide deflecting upward in reaction to a vertically elongate member being forced in one direction. 
           [0014]      FIG. 8  is a cross-sectional view similar to  FIG. 7  but showing the curtain&#39;s upper edge deflecting in reaction to the vertically elongate member being forced in an opposite direction. 
           [0015]      FIG. 9  is a partial front view similar to  FIG. 2 , wherein the door is about to be struck. 
           [0016]      FIG. 10  is a partial front view similar to  FIG. 9  but showing a portion of the curtain&#39;s upper edge being dislodged by an impact. 
           [0017]      FIG. 11  is a partial front view similar to  FIG. 10  but showing the door in its fully open position. 
           [0018]      FIG. 12  is a partial front view similar to  FIG. 11  but showing the door closing as a means to restore the upper seal to its normal operating condition. 
           [0019]      FIG. 13  is a cross-section view similar to  FIG. 4  but showing another example of a seal guide. 
           [0020]      FIG. 14  is a cross-sectional view similar to  FIGS. 4 and 13  but showing another example of a seal guide. 
           [0021]      FIG. 15  is a cross-sectional view similar to  FIG. 7  but showing the example of  FIG. 14 . 
           [0022]      FIG. 16  is a cross-sectional view similar to  FIG. 15  but showing the elongate member more tilted. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify the same or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, several examples have been described throughout this specification. Any features from any examples may be included with, a replacement for, or otherwise combined with other features from other examples. 
         [0024]    The leading edges of some side-rolling curtains and planar door panels are often reinforced by a relatively rigid, vertically elongate member that can be susceptible to being accidentally struck by a forklift passing through the doorway. The need for the vertically elongate member, either with or without such a breakaway feature, however, can make it difficult to design an effective seal at the upper edge of the door. 
         [0025]      FIGS. 1-12  show a horizontal side-moving door or door  10  with at least one flexible curtain  12  that moves horizontally across a doorway  14  in a wall  15  to open and close the door  10 . To seal an upper edge  16  of curtain  12 , upper edge  16  slides within a seal groove  18  ( FIG. 4 ) of a seal member  20 . In some examples, upper edge  16  and curtain  12  may be a unitary piece. In this particular example, door  10  includes two similar curtains  12  supported by spring-loaded rollers  22  installed in proximity with lateral edges  14   a  of doorway  14 . A preloaded torsion spring  24  urges each of the spring-loaded rollers  22  to rotate in a direction that tends to draw in and wrap its respective curtain  12  onto itself. 
         [0026]    In order to open and close door  10 , a leading edge  26  of curtains  12  are attached to relatively rigid elongate members  28  that are coupled to a drive unit  30 . Elongate members  28  can be made of rectangular steel tubing or of some other suitable material and shape that renders elongate members  28  stiffer than curtains  12 . For the illustrated example, drive unit  30  comprises two track followers  32  and  34  that are mounted for horizontal translation along an overhead track  36  that is installed in proximity with an upper edge  14   b  of doorway  14 . Elongate member  28  extends downward from track follower  32 , and the other elongate member  28  extends downward from track follower  34 . A chain  38  and/or cogged belt powered by a motor-driven wheel  40  and an idler wheel  41  is coupled to track followers  32  and  34 . Track follower  32  connects to an upper section  38   a  of chain  38 , and track follower  34  connects to a lower section  38   b  of chain  38  so that depending on the rotational direction of motor-driven wheel  40 , drive unit  30  either moves elongate members  28  apart or together to respectively open or close the door  10 .  FIG. 1  shows door  10  in a closed position with the curtains&#39;  12  leading edges  26  abutting each other near the center of doorway  14 ,  FIG. 3  shows door  10  in an open position with most of the curtain  12  wrapped around spring-loaded rollers  22 , and  FIG. 2  shows door  10  partially open. 
         [0027]    It should be noted that the actual structure of track  36  and track followers  32  and  34  could vary widely and still be within the scope of this disclosure. For the illustrated example, track follower  32  includes several rollers  42  for weight support and for limiting the tipping of track follower  32 . An extension arm  44  can enhance the track follower&#39;s  32  ability to resist tipping. Additional rollers  46  can further resist tipping and help guide the track follower  32  along the length of track  36 . In some cases, extension arm  44  on track follower  32  and a similar extension arm  44 ′ on track follower  34  can pass by each other in an overlapping relationship, as shown in  FIG. 1 . Although chain  38  is shown coupled to extension arms  44  and  44 ′, this was illustrated in this manner to clearly show the functional relationship between chain  38  and track followers  32  and  34 . Chain  38  can be connected to other points on track followers  32  and  34 . 
         [0028]    To hold elongate members  28  substantially vertical to facilitate operation and proper-closed alignment of elongate members  28  yet still make the door  10  able to remain operational and/or functional in the event of an accidental impact with a forklift or some other collision, elongate members  28  are each supported by a brace  48  ( FIG. 4 ) that includes a yieldable member  50  (e.g., a shear pin), as shown in  FIG. 4 .  FIGS. 4-6  show brace  48  in its usual configuration with elongate member  28  and door  10  being in a normally operative position.  FIG. 7  shows a force  52  of impact forcing elongate member  28  to one dislodged position, and  FIG. 8  shows another impact force  54  in an opposite direction forcing elongate member  28  to another dislodged position. 
         [0029]    In the operative position of  FIGS. 4-6 , a conventional fastener  56  pivotally connects an upper end  58  of brace  48  to a lug  60  on track follower  32 , and yieldable member  50  connects a lower end  61  of brace  48  to a lug  62  extending from elongate member  28 . In this case, yieldable member  50  is in the form of a steel shear pin extending through lower end  61  and lug  62 ; however, yieldable member  50  could be of various other designs and could be installed as any breakable or otherwise yieldable link between track follower  32  and elongate member  28 . The location of yieldable member  50  and fastener  56 , for instance, could be interchanged. 
         [0030]    If force  52  or  54  is excessive, yieldable member  50  shears or breaks to protectively release elongate member  28  from brace  48 . After a breakaway incident, yieldable member  50  can be replaced by an unbroken one. Until such a repair can be done, a pivotal coupling  64  between elongate member  28  and track follower  32  enables elongate member  28  to hang generally vertical so that door  10  can still be open and closed while brace  48  is disconnected. 
         [0031]    Pivotal coupling  64  can be a sleeve  66  journalled to a generally horizontal shaft  68 , wherein shaft  68  is attached to track follower  32 , and sleeve  66  is attached to the upper end  58  of elongate member  28 . Such a coupling permits pivotal motion in the same general direction that forklifts pass through doorway  14 , thus, elongate member  28  can “break away” or swing in a direction that elongate member  28  is mostly likely to be struck, i.e., in a direction generally perpendicular to the plane of doorway  14 . 
         [0032]    To enable leading edge seals  70  of curtains  12  come together in sealingly tight engagement when door  10  closes, elongate members  28  preferably hang generally parallel and vertical as viewed in  FIG. 1 . To accomplish this, an adjustment screw  72  ( FIG. 4 ) between one end of shaft  68  and a lug  74  extending from track follower  32  can be tightened or loosened to level shaft  68 . To enable leading edge seals  70  to be substantially coplanar, the length of brace  48  can be made adjustable. In a currently preferred example, a threaded shank  76  of brace  48  can be screwed farther in or out of ends  58  and/or  61  to adjust the brace&#39;s  48  overall length, which in turn adjusts the angle between elongate members  28  and the plane of doorway  14 . 
         [0033]    As for sealing the upper edge of door  10 , a preferred example includes a seal guide or seal member  20  in the form of a plastic extrusion mounted to a front cover  78  and extending the width of doorway  14 . A seal is created between curtain  12  and seal member  20  by virtue of upper edge  16 , which can be an integral extension of curtain  12  and/or an added strip of material extending into and moving along seal groove  18 . The penetration of upper edge  16  into seal groove  18  enables both faces of upper edge  16  to have sealing contact with seal groove  18 . 
         [0034]    Upper edge  16  may be sufficiently flexible to deflect in a way that maintains an effective seal whether there is a positive or negative pressure differential across door  10 . In  FIG. 5 , for instance, air pressure  80  from one side of door  10  deflects flexible upper edge  16  in one direction against seal member  20 , and  FIG. 6  shows air pressure  82  from the other side of door  10  deflecting upper edge  16  in an opposite direction against seal member  20 . 
         [0035]    Even if upper edge  16  is not sufficiently flexible to react in this way to such pressure differentials, the structure of seal member  20  enhances the sealing function. Because seal member  20  defines seal groove  18  into which upper edge  16  extends, a tortuous air path is created for air moving from one side of the door  10  to the other, because the air turns several corners going up, over, and back down relative to upper edge  16 . This tortuous path itself creates a pressure differential across upper edge  16 , which impedes the free flow of air, thus, enhancing sealing. 
         [0036]    Since seal member  20  extends over upper edge  16  with both sides of upper edge  16  being enveloped within seal groove  18 , seal member  20  and the upper edge  16  of elongate member  28  are in laterally spaced relation to avoid interference between seal member  20  and elongate member  28  as elongate member  28  translates along its path of travel. This is particularly true because elongate member  28  is hanging generally pendant from an elevated support point (shaft  68 ), and seal member  20  is below that support point yet is above upper edge  16 . 
         [0037]    Upper edge  16  and/or seal member  20  are also responsive to a breakaway condition, as shown in  FIGS. 7 and 8 .  FIG. 7  shows seal member  20  having sufficient flexibility to bend upward in reaction to elongate member  28  being forced against seal member  20 , and  FIG. 8  shows upper edge  16  having sufficient flexibility to deflect in response to excessive movement in elongate member  28 . 
         [0038]    Under certain breakaway conditions, a breakaway portion  16   a  ( FIGS. 10 and 11 ) of the curtain&#39;s upper edge  16  may get pulled out from within seal groove  18  of seal member  20  and, thus, in some examples, the breakaway portion  16   a  is free to escape from within the seal groove  18 . Such a condition causing a breakaway and an operational sequence to restore door  10  to it normal operation is illustrated in  FIGS. 9-12 .  FIG. 9  shows door  10  partially open and prior to being struck, thus, breakaway portion  16   a  is still properly engaged within seal groove  18 . 
         [0039]      FIG. 10  shows door  10  having been struck with sufficient force to pull breakaway portion  16   a  of the curtain&#39;s upper edge  16  out from within seal groove  18 . It should be noted, however, that a leading end  16   b  of upper edge  16  still remains within seal groove  18 . This is because leading end  16   b  is immediately adjacent to elongate member  28  and is thus supported by elongate member  28 , whereas breakaway portion  16   a  of upper edge  16  is relatively free and unsupported. To reinsert breakaway portion  16   a  in seal groove  18 , door  10  first is moved to its open position as indicated by arrow  84  of  FIG. 10 . 
         [0040]    Once door  10  is in its fully open position, as shown in  FIG. 11 , breakaway portion  16   a  of upper edge  16  is positioned at the seal guide&#39;s  20  entrance or a lead-in opening  18   a  that guides breakaway portion  16   a  of upper edge  16  back into seal groove  18 . Lead-in opening  18   a  can simply be where seal groove  18  is open at the distal ends of seal member  20 , thus, lead-in opening  18   a  has a profile equal to or greater than that of seal groove  18  as shown in  FIGS. 4-8 . Lead-in opening  18   a  may include edges with smoothly tapered guide-in surfaces or the edges could be squared corners. 
         [0041]    After door  10  is in the open position of  FIG. 11 , door  10  can be closed by track follower  32  moving elongate member  28  and curtain  12  in the direction indicated by arrow  86  of  FIG. 12 . Such movement automatically draws the curtain&#39;s breakaway portion  16   a,  including breakaway portion  16   a,  back into seal groove  18 . Although  FIGS. 10 and 11  show significant slack in the curtain&#39;s upper edge  16 , such slack can actually be taken up by spring-loaded roller  22  exerting tension on curtain  12 . 
         [0042]    Referring to  FIG. 13 , sealing between a seal guide  20 ′ and the curtain&#39;s upper edge  16  can be enhanced by installing separate contacting seal members (e.g., a brush seal  88 , flexible lip, resilient foam strip, bulb seal, etc.) that contact one or both sides (faces  92  and  94 ) of upper edge  16 . For sake of example,  FIG. 13  shows the contacting seal members as being brush seals  88  installed within a groove  18 ′ of seal guide  20 ′. Brush seals  88  preferably extend the full length of seal guide  20 ′. In this particular example, each brush seal  88  is inserted into a brush groove  90  in seal guide  20 ′; however, brush seal  88  or an equivalent thereof (e.g., flexible lip, resilient foam strip, bulb seal, etc) could be attached to a seal member by various other conceivable means. 
         [0043]      FIGS. 14-16  show an alternate seal guide  20 ″ with a mounting arrangement that enables seal guide  20 ″ to move out of the way in reaction to being forced over by an elongate member  28 ′. Depending on the severity of the breakaway, seal guide  20 ″ can move as shown in  FIG. 15  or  16 . 
         [0044]    For a milder breakaway, as shown in  FIG. 15 , elongate member  28 ′ can push seal guide  20 ″ aside by virtue of a movable connection  96  that couples seal guide  20 ″ to a distal end  98  of a support arm  100 . In this example, an anchored end  102  of support arm  100  remains substantially stationary, while a fastener  104  extending through a slot  106  in seal guide  20 ″ or in distal end  98  enables relative movement between seal guide  20 ″ and distal end  98 . To urge seal guide  20 ″ back to its normal operating position of  FIG. 14 , a resilient member  108  can be installed somewhere between distal end  98  and seal guide  20 ″. Resilient member  108  is schematically illustrated to represent anything capable of urging seal guide  20 ″ toward elongate member  28 ′. Examples of resilient member  108  include, but are not limited to, a compression spring, a piece of spring steel or leaf spring, torsion spring, resiliently compressible foam, etc. 
         [0045]    In addition to resilient member  108 , or as an alternative to it, support arm  100  itself can be resiliently flexible to accommodate breakaways, as shown in  FIG. 16 . In this example, the elongate member  28 ′ pushing seal guide  20 ″ even farther over causes support arm  100  to resiliently deflect, which may force the curtain&#39;s upper edge  16  out from within a groove  18 ″. After the breakaway, elongate member  28 ′ naturally swings back down and can be reconnected to brace  48 . The curtain&#39;s upper edge  16  can be reinserted in groove  18 ″ by simply opening and closing the door (e.g., door  10 ), as shown in  FIGS. 10-12 . 
         [0046]    Although seal guide  20 ″ is shown to include two contacting brush seals  88  that contact both side faces  92  and  94  of the curtain&#39;s upper edge  16 , seal guide  20 ″ could alternatively include just one brush seal  88  or none. 
         [0047]    At least some of the aforementioned examples include one or more features and/or benefits including, but not limited to, the following: 
         [0048]    In some examples, a horizontal side-moving door includes an upper seal that includes an integral extension of the door&#39;s curtain received within a groove formed in a seal guide disposed adjacent the door. 
         [0049]    In some examples, a horizontal side-moving door includes an upper seal guide that can resiliently deflect in reaction to being struck by a relatively stiff, vertically elongate member that serves as a curtain&#39;s leading edge. 
         [0050]    In some examples, a horizontal side-moving door includes an upper seal with an upper edge that is an integral extension of the door&#39;s curtain, wherein a leading end of the upper edge remains within a groove of a seal guide even though other portions of the upper edge might become dislodged out from within the groove. 
         [0051]    In some examples, a horizontal side-moving door includes an upper seal that restorably breaks away in reaction to an impact and then automatically feeds back into position by simply opening and closing the door. 
         [0052]    Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of the coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Summary:
An example of a horizontal side-moving door with a side-winding or horizontally translating curtain includes an upper seal comprising an upper edge of the curtain sliding within a groove of a seal guide. To protect the door in the event of an impact, at least a portion of the curtain&#39;s upper edge can restorably pull out from within the groove. To avoid damage in certain situations, the seal guide might resiliently deflect as well. After an impact, the curtain&#39;s upper edge is automatically fed back into the groove by simply opening and closing the door. During normal operation, the curtain&#39;s upper edge advantageously deflects in response to air pressure against either side of the door. In some examples, the seal guide is of a uniform cross-section, which makes the seal guide easy to manufacture by way of a conventional plastic extrusion process.