Patent Publication Number: US-2005115688-A1

Title: Rollup door with rollable door leaf

Description:
FIELD OF THE INVENTION  
      The present invention relates to a rollup industrial door that can operate at high speed and low noise level. More specifically, the invention relates to a rollup door comprising a door leaf or blade of increasing width from top to bottom and having flexibility in the rolling direction, channels for guiding the door, two modules for rolling and unrolling the door leaf so that a number of leaf layers do not come in contact, wherein the modules are situated on each side of the door, have the same center axes and are successively radially enlarged so that on opening and closing of the door, the narrower and wider parts of the leaf engage the smaller and larger parts respectively of the modules.  
     BACKGROUND OF THE INVENTION  
      Since the 1970&#39;s there has been a great need to use rapidly moving doors in buildings for industrial use. This applies to openings indoors as well as in external walls, where the door provides shielding between different activities or prevents drafts and heat losses. Presently, rolling doors with flexible door leaves are used for this purpose, but also more rigid constructions like slatted doors with polymeric or metallic lamellae are used. These doors are rolled up on an overhead drive cylinder and can be provided with additional elements like a weight balance system, tensioning system, windows or the like. For safety reasons, rolling doors can be provided with safety edge protection, failsafe devices, drop protection, etc.  
      As understood from the above, rollup doors are available in different styles and materials. In one traditional design the door leaf is rolled up on a shaft directly upon itself. The drawback with this construction for more rigid doors is that wear soon causes visible marks on the lamella surface, which is regarded as a negative factor. In addition the lamellae are rolled on each other without any padding, which causes noise. These doors are normally run at low opening and closing speed in order to overcome this.  
      A flexible door leaf with, for example, sensitive material such as PVC, can also suffer from these wear problems. U.S. Pat. No. 5,307,859 discloses that this can be overcome by applying additional flexible strips extending perpendicular to the driving shaft. When the curtain is rolled or folded in its retracted position, the separation strip rolls or folds on itself to hold the layers of the curtain apart from one another.  
      U.S. Pat. No. 5,484,007 describes a slatted door comprising two guide tracks situated on opposite sides of the door opening. The guide tracks extend vertically over approximately the height of the door opening, and then merge at the entrance of the door into an inwardly positional spiral, so that the slats of the door run essentially free of each other, thereby providing a high speed door. This design requires guiding channels approximately twice as long as the door height. The lamellae, rolls, and guiding system are in motion during the complete opening/closure operation, which causes increased wear and noise.  
      A related door construction is disclosed in WO 01/69032 which overcomes the above-described disadvantages by providing a chain of support bodies screwed onto the side of the lamellae. These links are thicker than the lamellae. During the roll up operation, these support bodies roll upon each other and create a distance between the lamellae. In order to create an even roll, the links are curved according to an average roll up diameter. Still, this door design has a disadvantage in that the rolled up layers are in direct contact with each other, which causes noise. Also, an increased diameter is necessitated. The support bodies are rolled upon each other on an irregular surface, which is only partly compensated by the arched geometry. This top-on-top rolling leads to the support bodies suffering from both tension and pressure, and both outer surfaces incur wear and tear.  
      U.S. Pat. No. 5,682,937 describes a closure comprising a deformable rolling blind or shade and a drum formed by two parallel shafts, which are situated transversely in the upper position substantially superposed to the axis of the blind or shade. The upper edge of the blind or shaft is joined to the first shaft. The second shaft is joined to the first shaft and free to rotate, when the first shaft is driven by a drive mechanism and is free to rotate, at a slightly different speed than the first shaft. This provides a winding mechanism in which successive layers or turns of the shade or blind do not come into contact to each other avoiding an erratic unwinding of the shade or blind. The patent also describes a shade or blind in which the separation of the successive layers or turns is achieved by having stepped pulleys mounted on each end of the shafts having cheeks of different diameters to selectively form bearings with the ends of the slats of the shade or blind. The separation may also be achieved by the cheeks of the two superimposed shafts forming a bearing with end pieces attached to the slats of the shade or blind and extending at different lengths from the slats. The separation of the slats of the shade or blind may be obtained by rollers of different diameter attached to the ends of the slats, co-operating in reverse with independent tracks having the same diameter borne by the ends of the superimposed shafts. The disadvantages with this winding principle are the need for multiple shafts, and a low winding speed, as the shade or blind has to pass around the several shafts.  
     SUMMARY OF THE INVENTION  
      To avoid the disadvantages of the closures of the art as stated herein above, the present invention provides an industrial rollup door comprising a door leaf curtain covering the door opening. The leaf is at least flexible in the rollup direction and may comprise a flexible sheet material, or substantially rigid lamellae or slats, or a combination thereof including sections for windows, etc. The leaf is guided at the edges and can be rolled up in several layers. In most door applications the door is operating vertically, but also horizontal or angled operation are possible.  
      In order to minimize the noise and wear and facilitate the rapid opening/closing of the door, it is important that the leaf is rolled up on specially designed pair of conical modules and thereby avoids direct contact with the other parts of the door leaf. The object of the present invention is to decrease the noise level and facilitate higher opening and closing speeds and to improve the safe operation of such types of rollup door. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of the spiral solid module (left side) according to a first embodiment of the present invention;  
       FIG. 2  is an internal view of the open door (to the left of  FIG. 2 ) and the closed door (to the right of  FIG. 2 );  
       FIG. 3  is a view from inside the door to the right, closed position;  
       FIG. 4  is a view from inside the door to the left, open approximately two thirds;  
       FIG. 5  is an internal view of the open door (to the left of  FIG. 5 ) and the closed door (to the right of  FIG. 5 ) according to a second embodiment;  
       FIG. 6  is a view from inside the door to the right, closed position;  
       FIG. 7  is a view from inside the door to the left, open approximately two thirds;  
       FIG. 8  is a cross section of two adjacent slats and a sealing strip;  
       FIG. 9A  is a front view of a slat with belt attached;  
       FIG. 9B  is a view of  FIG. 9A  from below;  
       FIG. 9C  is a rear view of a slat with inserted end piece, and a belt attached to the end piece; and  
       FIG. 9D  is a view of  FIG. 9C  from below further including a wind anchor. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      A first embodiment of the rollup door according to the present invention will now be described with reference to  FIGS. 1-4 .  FIG. 1  is a perspective view of a module  10  mounted on a shaft  12  and used in rolling and unrolling the door. Alternatively, the shaft  12  itself could have the shape of a module (not shown). In the present embodiment, the module  10  has an outer shape of a conical spiral with a solid continuous surface  14 . Advantageously, module  10  is successively radially enlarged, and includes smaller and larger parts of increasing diameter. The module  10  will be further described in reference to  FIG. 2 .  
       FIG. 2  is an internal view of the door in the closed position (see right portion of  FIG. 2 ), and in the open position (see left portion of  FIG. 2 ). The right portion of  FIG. 2  shows a door blade, or door leaf  16 , in a closed position covering a door opening. In most door applications the door is operated vertically as shown in  FIG. 2 , but horizontal or angled operation of the door is also contemplated. The door leaf  16  has a conical or trapezoidal shape of continuously increasing width from top to bottom. However this width increase may also be stepwise, as later shown and described. The door leaf  16  is flexible in at least the rolling direction and may comprise a flexible sheet material such as polyvinyl chloride (PVC), Rolltex® (a product offered by Albany International Corp.) or other kind of rollable door material suitable for the purpose. The door material may also be of laminate, reinforced or film-like construction. The door leaf  16  may further include sections with properties other than those of its main section, such as window sections.  
      According to the present embodiment shown in  FIG. 2 , the door leaf  16  comprises a series of connected substantially rigid lamellae, or slats  18 , which give the door flexibility in the rolling direction. The slats  18  may be of metal or polymeric composition, or a combination thereof, or of any other material suitable for the purpose, and may further comprise reinforced components (not shown). Note that the slats  18  may be colored or transparent, or may have various surface textures. With the present embodiment, the slats  18  are of continuously increasing width from top to bottom, as  FIG. 2  well illustrates. However this width increase may instead be stepwise, as later described in connection with a different embodiment. The door leaf  16  may also include edge portions (not shown) which correspond to the width increase of the door from top to bottom. Finally, note that the door leaf  16  is guided along its edges  20  which extend into vertical channels, as later shown in other figures.  
      To minimize noise and wear and facilitate the safe and rapid opening/closing of the door shown in  FIG. 2 , the door leaf  16  is rolled up on a pair of conical modules  10 ,  22  so that the slats  18  do not to come in contact during rollup or unrolling. Advantageously, the aforementioned winding principle permits rapid door speeds of up to, for example, 3 meters per second. Note further that the modules  10 ,  22  are connected by a shaft  12  rotated by a drive unit  24 , which may be a motor or the like. As  FIG. 2  indicates, the modules  10 ,  22  are situated on respective sides of the shaft  12 , and have the same center axes. Importantly, the modules  10 ,  22  are successive radially enlarged so that on opening and closing of the door, the narrower and wider parts respectively of the door leaf  16  engage the smaller and larger parts respectively of the modules  10 ,  22 . In this regard, the door leaf edges  20  are shaped to fit the continuous spiral contour of the modules  10 ,  22 . Dampening material  26  may be provided on the surface of the modules  10 ,  22  or directly on the door leaf  16  to reduce noise and wear, increase the grip when winding up, and prevent the slats  18  from sliding.  
      In  FIG. 2 , the door leaf  16  is attached to each of the modules  10 ,  22  via a vertical hoisting belt  28  on each side of the door. However the door leaf  16  may instead be attached directly to the modules  10 ,  22  without a belt, instead using other means suitable for the purpose. That is, the principal function of the present invention also works for pin jointed lamellae or other conventionally hinged door with slats.  
      In the embodiment of the present invention illustrated in  FIG. 2 , the hoisting belt  28  is attached along the entire door leaf  16 ; that is, belt  28  connects to the end of each slat  18  via screws  30  or other suitable attachment means. Thus, with this embodiment, there is no need for the conventional hinge-lock between slats, as the hoisting belt  28  takes up the main vertical forces between each slat  18 . Instead, connection between the slats  18  may be of a flexible material to make the closure tight, as later described. Alternatively, the belt  28  may be divided along the edges of the door and overlapping sideways (not shown). Note that the door may include additional features such as belts and springs  32  for counterbalancing shown in  FIG. 2 , and a tensioning system, safety edges or sensors (not shown).  
       FIG. 3  is a view, from inside the door to the right, of the door in the closed position. The stepwise increments  34  of the spiral module  22  are shown. Note that the slats  18  are attached to the module  22  at a fixing point  36  and guided in internal and external vertical guiding elements  38  and  38 A respectively. The guides  38 ,  38 A may be enlarged to conceal the non-square shape of the door. Further, the space between the guides  38 ,  38 A may be adapted to the slat caliper and guides  38 ,  38 A may be lined with wear-resistant material (not shown).  FIG. 4  is a view, from inside the door to the left, of the door open approximately two thirds. The slats  18  of continuously increasing width are shown wound around the successive radially enlarged module  10  without contacting (overlapping).  
      A second embodiment of the invention is now described with reference to  FIGS. 5-7 .  FIG. 5  is an internal view of the door in the closed position (see right portion of  FIG. 5 ), and in the open position (see left portion of  FIG. 5 ). According to the present embodiment, door leaf  40  comprises layers  42 ,  44 ,  46  of stepwise increasing width from top to bottom. Note that each layer comprises slats of equal width. Also with this embodiment, each of the two modules is a package of thin-walled parallel disks. For simplicity, the disk package comprising disks  50 ,  52 ,  54  on the right side of the door will be described. Distance elements  56  are provided, for example, to stiffen up the disc package. The distance element  56  between the smallest and middle disks  50 ,  52  may also serve as a fixing point  64  for the attachment of the hoisting belt  66 . In addition, the distance elements  56  also facilitate guiding the door leaf  40 .  
      As the door is raised, each respective layer  42 ,  44 ,  46  is rolled up on the respective disks  50 ,  52 ,  54  so as to avoid direct contact with the other layers. Advantageously, the disks  50 ,  52 ,  54  are successive radially enlarged, so that on opening and closing of the door, the narrower and wider layers  42 ,  44 ,  46  respectively engage the smaller and larger disks  50 ,  52 ,  54  respectively. In this connection, the door leaf edge  58  is shaped to fit the stepped contour of the disk package.  
      The other elements of the present embodiment shown in  FIG. 5  are similar to those previously detailed with respect to the first embodiment shown in  FIG. 2 . For example, provided are a shaft  70  connecting the respective left and right side disk packages. Alternatively, the shaft  70  could accommodate an additional disk (not shown) at its midpoint, used for example to support the first turn of the door leaf  16 . Also provided is a counterbalance mechanism  60 . Note also that the layers  42 ,  44 ,  46  are attached to each of the disk packages at each fixing point  64  via a hoisting belt  66  on each side, and that a respective belt  66  is screw  68  or other means connected to each slat.  
      Noise reduction members or dampeners  62  are provided tangentially around the circumference of each disk. In the case where a respective disk is made thin, for example, the dampener  62  can be made wide so as to even cover both sides at the edge of the disk. This dampener  62  is mainly dampening noise coming from direct mechanical contact of the various moving parts of the door assembly.  
       FIG. 6  is a view, from inside the door to the right, of the door in the closed position. According to the winding principle of the present embodiment, the top slat is fixed to the disk package via the hoisting belt  66  as previously described, and the slats  72  guided in internal and external guides  74 ,  74 A are rolled over the disks  50 ,  52 ,  54  without sliding. As a result, wear on the slats and disks, along with noise, sliding/friction, and energy losses, are all low. Also, for each disk, the difference between its smallest radius “S” and its largest radius “L” is a distance “D”, which is equal to the slat thickness plus a distance for operating space. Generally, the number of steps, layers and disks and their respective dimensions are determined according to the height of the door leaf. For example, a door leaf of 3 meters height having 1 step and thus 2 layers, will roll onto 2 disks each having a circumference of approximately 1.5 meters.  
       FIG. 7  is a view, from inside the door to the left, of the door open approximately two thirds, so that the narrowest and middle layers  42 ,  44  are wound onto the smallest and middle disks  80 ,  82  without contacting (overlapping). Note that the largest radius “R” of any disk is the same as the smallest radius “R” of the next larger disk in the transfer section “T”. (The transfer section is where a slat is partly rolled up on one disk and partly on the next disk). As a result, the slats are wound up in a continuously increasing radius. This gives a desirably even power/torque and smooth transfer between the disks  80 ,  82 ,  84 . Also, by fixing the top slat  86  to the smallest disk  80  via the hoisting belt  66 , safe operation of the door is ensured. This is because the kinetic energy of the door leaf  40  in either the open or closed position is favorably low with respect to the forces and angles in the upper portions of internal and external guides  74 ,  74 A. Further, since only tension forces are affecting the hoisting belt  66 , the large disk radius does not cause bending forces in the door leaf  40 , and minimal friction occurs.  
       FIG. 8  is a cross section of a sealing strip  90  of flexible or rigid material connecting two adjacent slats  96  to make the closure therebetween tight and weather resistant. The strip  90  is easily inserted between the slats  96  from the side or pressed in from the front of the door, and also includes fastening elements  92 . The strip  90  also includes a central portion  94  for dampening noise between swinging slats  96  during the opening and closing of the door.  
       FIGS. 9A and 9B  show a typical slat  100  connected directly to the hoisting belt  102 .  FIGS. 9C and 9D  show an alternative embodiment wherein a respective slat  100  includes an endpiece  104  inserted therein. The endpiece  104  is connected to the hoisting belt  102 . In this way, the door may comprise slats of equal width but having respective endpieces  104  of increasing width from top to bottom of the door. Note that the endpiece  104  is easily maintained or replaced from the front or side of the door, and may further include a wind resistant hook, or wind anchor  106  to assist in guiding the slats  100 .  
      As understood from the forgoing description, modifications to the industrial rollup door would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the appended claims.