Patent Publication Number: US-2009236051-A1

Title: Bottom seals for a horizontal side-rolling door curtain

Description:
FIELD OF THE DISCLOSURE 
     The subject disclosure relates generally to a horizontal side-rolling fabric door and more specifically to a bottom seal for such a door. 
     BACKGROUND 
     Basically, there are two types of fabric rollup doors, those that have a curtain that rolls up vertically and those that roll up sideways. For vertically operating rollup doors, a horizontal drum or roller above the doorway takes up or pays out a fabric curtain to respectively open or close the door. An example of a vertically operating rollup door is shown in U. S. Pat. No. 7,151,450. 
     Side-rolling or horizontal side-rolling fabric doors, such as the one disclosed in U.S. Pat. No. 4,096,902; includes one or two vertical rollers at either one or both lateral edges of the doorway. Some 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. 
     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. 
     Other side-rolling doors include two individual curtains, each supported by their own roller at opposite lateral edges of the doorway. For such doors, 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). 
     Side-rolling doors, particularly those with two curtains, provide an almost instant field of view through the doorway as the door begins to open, whereas vertically operating doors generally need to open much farther in order for a person on one side of the doorway to see what is at the other side of the door. An instant field of view can provide an early warning of a potential collision at the doorway. 
     With side-rolling doors, however, it can be difficult to seal the lower edge of the curtain adjacent the floor. Since the lower edge of the curtain itself tends to wear prematurely due to repeated rubbing against the floor and, thus, eventually the entire curtain might need replacing to maintain an adequate seal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view a horizontal side-rolling door shown in a closed position. 
         FIG. 2  is a front view of the door of  FIG. 1  but showing the door open. 
         FIG. 3  is a closer view of the lower right corner of the door shown in  FIG. 2 . 
         FIG. 4  is a front view of another horizontal side-rolling door shown in a closed position. 
         FIG. 5  is a front view of the door of  FIG. 4  but showing the door open. 
     
    
    
     DETAILED DESCRIPTION 
     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 common 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 example may be included with, a replacement for, or otherwise combined with other features from other examples. 
       FIGS. 1-3  show a horizontal side-rolling door  10  with at least one curtain  12  that moves horizontally across a doorway  14  to open and close the door  10 . In this particular example, door  10  includes two curtains  12  supported by spring-loaded rollers  16  installed in proximity with lateral edges  18  of doorway  14 . A preloaded torsion spring  20  urges each roller  16  to rotate in a direction that tends to draw in and wrap the respective curtain  12  onto itself. An overhead track  22  and drive unit  24  coupled to the leading edges of curtains  16  are used for opening and closing the door  10 .  FIG. 1  shows door  10  closed with leading edges of curtains  12  abutting each other near the center of doorway  14 , and  FIGS. 2 and 3  show door  10  open with most of the curtains  12  wrapped around rollers  16 . 
     To provide a means for replacing a worn bottom edge of curtain  12  and/or to seal a gap that might exist between curtain  12  and floor  26 , each curtain  12  includes a replaceable bottom seal  28 . Seal  28  is replaceable by virtue of a separable joint  30 , such as, for example, a zipper, hook-and-loop connector, snaps, lace, or some other reconnectable means. As bottom seal  28  becomes worn, joint  30  allows seal  28  to be readily replaced without having to replace the entire curtain. 
     If a replaceable seal were simply added to the lower edge of an ordinary horizontal side-rolling door, the seal and/or the joint that connects the seal to the curtain would likely be thicker than the curtain material itself, and that could cause some problems. As the door opens and the curtain wraps around the roller, a relatively thick seal and joint could build up on the roller, which could create a substantial bulge at the lower end of the roller. The bulging area might press against the floor or other adjacent surfaces and interfere with the roller being able to smoothly take up the curtain. The bulging section might also twist and strain adjacent areas of the curtain. 
     To avoid such problems, even though joint  30  might be thicker than curtain  12 , joint  30  preferably lies at an incline so that as curtain  12  wraps around roller  16 , joint  30  is broadly distributed in an approximate helical pattern  32  as shown in  FIG. 3 . The terms, “incline” and “inclined” mean being angularly displaced relative to a horizontal plane. The incline or slope of joint  30  can be positive or negative, thus joint  30  could wrap helically upward or downward as the door opens. 
     The various components of door  10  may vary. Curtain  12 , for instance, can be comprised of a pliable sheet, fabric, or any continuous or segmented panel with sufficient flexibility to wrap around roller  16 . Referring to  FIG. 3 , each roller  16  can be comprised of a rotatable outer drum  34  journaled about a stationary central shaft  36 . Opposite ends of spring  20  ( FIG. 1 ) are connected to drum  34  and shaft  36  so that preloaded spring  20  urges drum  34  to rotate about shaft  36 , thereby pulling curtain  12  taut and providing impetus for curtain  12  to wrap around roller  16 . 
     Drive unit  24  can be comprised of a chain  38  or cogged belt driven between a motor-driven sprocket  40  and an idler sprocket  42  or may comprise any other suitable components. Track followers  44  and  46 , rolling or sliding along track  22 , couple the leading edges of curtains  12  to chain  38 . Track follower  44  connects one curtain  12  to an upper part of chain  38 , and track follower  46  connects the other curtain  12  to the lower section of chain  38  so that drive unit  24  can move track followers  44  and  46  and their respective curtains  12  in opposite directions to selectively open or close the door. 
     To simplify manufacturing, seal  28  can be made as part of a generally rectangular seal assembly  48 , wherein the assembly comprises an upper piece  50  and bottom seal  28 . Assembly  48  can be sewn, bonded, welded or otherwise attached to create a generally horizontal seam  52  that connects assembly  48  to a lower portion of curtain  12 . Once connected by seam  52 , upper piece  50  of seal assembly  48  now becomes an extension of curtain  12  itself, in which case an inclined lower edge  54  of curtain  12  is where bottom seal  28  is removably connected via separable joint  30 . Since seam  52  is generally horizontal and joint  30  is inclined, seam  52  and joint  30  are displaced out of co-parallel alignment with each other. Lower edge  54  can be any edge near the bottom of curtain  12  and is not necessarily the lowermost edge of the curtain. Seam  52  preferably, but not necessarily, provides a more permanent connection than does separable joint  30 . 
     Although bottom seal  28  can be any lower piece or segment in proximity with floor  26 , seal  28  does not necessarily have to be touching floor  26  in order to be considered a bottom seal. Nonetheless, bottom seal  28  preferably engages floor  26 . To ensure such engagement, bottom seal  28  can be comprised of a loop  56  ( FIG. 3 ) of flexible material with a flexible but somewhat stiffer or heavier elongate insert  58 . The weight and/or relative stiffness of insert  58  helps hold loop  56  of seal  28  down against floor  26 . 
     Loop  56  and insert  58  can add bulk and thickness to bottom seal  28 . To prevent such thickness from creating a bulge at the lower end of roller  16  as door  10  opens, seal  28  preferably extends below a major outer periphery  60  of drum  34 , as shown in  FIG. 3 . This allows loop  56  and insert  58 , if the curtain includes such a loop and insert, to coil about itself in a more open area  62  that is underneath the larger diameter part of drum  34 . The bottom end of drum  34  could be even higher to allow additional room for the coiling of a horizontal or inclined joint  30  in the same way, or the drum could have multiple stepped diameters to accommodate a curtain having multiple areas of different thickness. The expression, “major outer periphery” of a roller refers to the maximum outer surface about which the curtain is wrapped. In the case of a cylindrical roller (as opposed to an octagonal or multifaceted one), the major outer periphery is the roller&#39;s maximum outer diameter. 
     Although seal assembly  48  might simplify manufacturing,  FIGS. 4 and 5  show a horizontal side-rolling door  10 ′ where bottom seal  28  is attached directly to a curtain  12 ′ without using upper piece  50  and seam  30 . Other than the omission of upper piece  50  and seam  30 , door  10 ′ is structurally and functionally the same as door  10 , with  FIGS. 4 and 5  corresponding to  FIGS. 1 and 2  respectively. Reference numbers in  FIGS. 4 and 5  that are the same as those used in  FIGS. 1 and 2  correspond to structures that are similar or identical to those described in connection with  FIGS. 2 and 3 . 
     At least some of the aforementioned examples include one or more features and/or benefits including, but not limited to, the following: 
     In some examples, a horizontal side-rolling door includes a replaceable bottom seal. 
     In some examples, a horizontal side-rolling door includes an inclined disconnectable joint that connects a bottom seal to the door&#39;s curtain. 
     In some examples, a horizontal side-rolling door includes an inclined zipperjoint that connects a bottom seal to the door&#39;s curtain. 
     In some examples, a horizontal side-rolling door includes a roller with extra space below the roller to provide roll-up room for a relatively thick bottom seal. 
     In some examples, a horizontal side-rolling door includes a roller with extra space below the roller to provide roll-up room for a bottom seal that comprises a loop of material containing a weighted and/or stiffening element. 
     In some examples, a horizontal side-rolling door includes a disconnectable joint that connects a bottom seal to the door&#39;s curtain, wherein the joint wraps upon a roller in an approximate helical pattern. 
     In some examples curtains  12  could be comprised of a series of rigid vertical slats that are pivotally interconnected side-by-side, thereby providing a flexible curtain assembly. Such an assembled curtain could coil about relatively short upper and lower rollers rather than wrapping around one long continuous roller. 
     Furthermore, although certain example methods, apparatus and articles of manufacture have been described herein, the scope of 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.