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CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a divisional of co-pending U.S. application Ser. No. 10/931,561, filed Aug. 31, 2004, which claims priority to European patent application No. 03077819.5, filed Sep. 8, 2003, which are both hereby incorporated by reference as if fully disclosed herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a covering for an architectural opening, such as a roller shade for a window, having one or more, vertically-extending parallel layers of shade material. This invention especially relates to a roller shade, to which front and rear layers of a shade material are attached, so that the layers can be moved parallel to one another to open and close the shade to light. 
         [0004]    2. Description of the Relevant Art 
         [0005]    Architectural coverings are known with two vertically-extending parallel sheet layers, which are disposed one in front of the other and each of which has an array of elongated, longitudinally-extending, vertically-alternating transparent and opaque stripes. When the transparent stripes of one layer have been in vertical alignment with the transparent stripes of the other layer, light has been transmitted through the coverings, but when the opaque stripes of one layer have been vertically aligned with the transparent stripes of the other layer, these coverings have blocked light. See GB 926 663, GB 1 227 619, U.S. Pat. No. 2,029,675, FR 1 366 224, DE 2 326 438, NL 7209084 and U.S. Pat. No. 6,189,592. 
         [0006]    The two vertically-extending layers of such coverings have been made of fabric, plastic or the like and have been connected at their top and/or bottom ends by top and/or bottom bars. A special fabric, very suitable for such coverings, has been described in EP 1 088 920 and EP 1 241 318. This fabric is a two layer woven fabric having one or more binder threads connecting the layers, so that one layer could slide along the binder threads and along the other layer. 
         [0007]    Such double layer architectural coverings have been made as roller shades, having a roller to which the layers of shade materials have been attached at radially different locations of the roller, so that partial rotation of the roller has displaced the layers relative to each other and continued rotation has wound the layers about the roller. The layers of shade materials of roller shades have generally been attached to their rollers by folding each layer over an attachment member or rod and then sliding or pushing the attachment member with the layer folded over it into a groove or slit of the roller. See GB 19 449 and DE 25 19 365. 
         [0008]    However, the use of an attachment member has proven unsatisfactory for attaching a layer of a shade material to a roller. If the shade material has not been well aligned with the roller when folded over its attachment member, the shade has not hung straight down from the roller and has not operated well. Also, the layer folded over the attachment member has sometimes tended to get out of alignment during assembly of the roller shade which has been hard to correct afterwards. With two layer roller shades, it has been particularly difficult to align the complementary patterns, typically stripes of the front and rear layers, using such attachment members. Also, the layers have tended to become skewed, relative to one another, when wound about the roller if both layers have not been perfectly aligned with the roller. When the layers have not been perfectly aligned, light has shone through gaps between the stripes, and the patterns have no longer appeared to be complimentary. 
       SUMMARY OF THE INVENTION 
       [0009]    In accordance with this invention, an architectural covering, such as a roller shade, is provided which includes a vertically-extending layer of a shade material between an elongated longitudinally-extending roller and an elongated longitudinally-extending bar; an elongated groove extending longitudinally along the length of the outer surface of the roller; a top portion of the layer of shade material being attached to an elongated longitudinally-extending top attachment member in the groove; the layer of shade material extending longitudinally along the roller, so that partial rotation of the roller causes the layer to move vertically and continued rotation of the roller winds the layer around the roller, and wherein:
       the outer surface of the top attachment member has at least two peaks along its length such that when the upper portion of the layer of the shade material is attached to the attachment member, the peaks extend through the upper portion of the layer, preferably through an open structured section of the top portion of the layer.
 
Advantageously, the shade material comprises a plurality of vertically-extending layers, especially front and rear layers, the outer surface of the roller comprises a plurality of radially spaced apart grooves, and a top portion of each layer is attached to a different attachment member in a different groove, especially front or rear groove. Also advantageously, a bottom portion of each layer of the shade material is also attached to an elongated longitudinally-extending bottom attachment member in an elongated longitudinally-extending slit in the bar; the outer surface of the bottom attachment member having at least two peaks along its length such that when the bottom portion of the layer of shade material is attached to the bottom attachment member, the peaks extend through the bottom portion of the layer, preferably through an open structured section of the bottom portion of the layer. It is particularly advantageous that the shade material comprises front and rear layers, each with an array of elongated, longitudinally-extending, vertically-alternating transparent and opaque stripes.
       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Further aspects of the invention will be apparent from the detailed description below of particular embodiments and the drawings thereof, in which: 
           [0012]      FIG. 1  is a schematic perspective view of a roller shade with a double layer shade material extending between an elongated roller and an elongated bottom bar; 
           [0013]      FIG. 2  is a cross-section of the shade of  FIG. 1 , showing the attachment of the shade material to the roller and bottom bar; 
           [0014]      FIG. 3A-3D  is a schematic representation of the attachment of a first embodiment of an elongated attachment member to one of the layers of a woven fabric shade material and the subsequent attachment of the attachment member to an elongated groove in the roller; 
           [0015]      FIGS. 4A-4C  is a schematic representation of the attachment of two layers of the woven fabric shade material together to the first embodiment of the attachment member prior to attaching the attachment member to the bottom bar; 
           [0016]      FIGS. 5A-5E  are schematic perspective views of alternative embodiments of the attachment members; and 
           [0017]      FIGS. 6A-6C  are schematic perspective views, like  FIGS. 3A-3C , of the attachment of the attachment member of  FIG. 5D  to a non-woven shade material. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]      FIGS. 1 and 2  show a roller shade or blind  1  of the invention having an elongated longitudinally-extending roller  3  at its top, a two-layer vertically-extending shade material or covering  5 , an elongated longitudinally-extending bar or rail  7  at its bottom and means  9  for rotating the roller  3  to raise and lower the shade material and the bar to open and close the shade (e.g., a conventional manually operated ball-chain or endless cord). The roller  3  is preferably a conventional hollow tube-like profile extending between a left end  11  and a right end  13 . The outer surface  3 A of the roller has and an elongated longitudinally-extending front groove  15  and an elongated longitudinally-extending rear groove  17 . The front and rear grooves  15 ,  17  are radially spaced apart along the outer surface  3 A of the roller and are preferably undercut grooves. In this regard, each groove  15 ,  17  has a longitudinally-extending top slit  19 ,  21  in communication with a laterally larger, interior top pocket  19 A,  21 A. The top pocket  19 A,  21 A of each groove  15 ,  17  can hold an elongate, longitudinally-extending top attachment member  23 ,  25 , so that the top attachment members cannot fall out through the top slits  19 ,  21  while the shade material  5 , attached to the top attachment members, extends downwards from the grooves. 
         [0019]    The shade material  5  includes a vertically-extending front layer  27  and a vertically-extending rear layer  29 . When the shade material  5  is assembled to the roller  3 , the front layer  27  extends downwardly from the slit  19  of the front groove  15 , and the rear layer  29  extends downwardly from the slit  21  of the rear groove  17 . The front layer  27  has a plurality of elongate longitudinally-extending parallel rectangular stripes  31 ,  33 . Relatively opaque stripes  31  alternate with relative translucent stripes  33 . The rear layer  29  also has a plurality of elongate longitudinally-extending parallel rectangular stripes  35 ,  37  which are alternating relatively opaque stripes  35  and relatively translucent stripes  37 . The rear layer  29  can be moved vertically relative to the front layer  27 , so that the opaque stripes  31 ,  35  of both layers can be aligned with each other or with the translucent stripes  33 ,  37  of the opposite layer. Such movement of one layer relative to the other can be used to control and vary the light-transmitting properties of the shade  1 . 
         [0020]    The top portions  39 ,  41  of the front and rear layer  27 ,  29  of the shade material  5  are attached to the front and rear top grooves  15 ,  17  of the roller  3 , using the front and rear, top attachment members  23 ,  25 . The manner of attaching the layers to the top attachment members is described below in relation to  FIGS. 3 and 4 . 
         [0021]    The bar  7  is preferably a generally U-shaped profile extending between a left end  43  and a right end  45 . The bar ( 7 ) has a front wall  47 , a rear wall  49  and a bottom wall  51  with an upwardly open, elongate, longitudinally-extending bottom slit  53  that opens into an interior space  55  in the bar. The bottom slit  53  extends along the entire length of the bar  7 , and the shade material  5  is attached to the bar  7  and extends upwardly from the bottom slit  53  towards the roller  3 . At the top of the front wall  47  of the bar  7  is an elongate longitudinally-extending interior undercut bottom pocket  57 , adjacent the bottom slit  53 . The bottom pocket  57  has a downwardly open, elongate, longitudinally-extending mouth  59  which is laterally smaller than the bottom pocket. Preferably, the bottom pocket  57  is integrally formed with the front wall  47  of the bar  7 . The layers  27 ,  29  of the shade material  5 , mounted on the bar  7 , extend downwardly from the mouth  59  of the bottom pocket  57  into the interior space  55  of the bar and then upwardly through the bottom slit  53  towards the roller  3 . 
         [0022]    As best shown in  FIG. 2 , the top portion  39  of the front layer  27  of the shade material  5  is held by the front top attachment member  23  in the top pocket  19 A of the front top groove  15  of the roller  3 , and the top portion  41  of the rear layer  29  of the shade material is held by the rear top attachment member  25  in the top pocket  21 A of the rear top groove  17  of the roller. Also, front and rear bottom portions  61 ,  63  of the front and rear layers  27 ,  29  of the shade material  5  are attached to a bottom attachment member  65  in the bottom pocket  57  in the bar  7 . Preferably, the rear layer  29  of the shade material is longer than the front layer  27 , and when the bottom portions  61 ,  63  of the two layers are mounted in the bottom pocket  57 , a loop  67  is formed in the rear layer  29  in the interior space  55  of the bar to serve as a hammock for a ballast rod  69 . The ballast rod  69  serves to pull the shade material taut and to help keep its layers aligned during operation of the shade  1 . 
         [0023]    The top and bottom attachment members  21 ,  23 ,  65  with the shade material  5  attached to them are preferably slid into the top and bottom pockets pockets  19 A,  21 A,  57  from the right or left ends  11 ,  13 ,  43 ,  45  of the roller  3  and bar  7 . The left and right ends of the roller and bar can then be closed by a suitable end cap (not shown). 
         [0024]    Partial clockwise rotation of the roller  3 , as shown in  FIG. 2 , by the operating means  9 , will move the front and rear layers  27 ,  29  relative to each other, for example, to align either the opaque stripes of both layers, or the opaque stripes of each layer with the translucent stripes of the opposite layer. The front and rear top grooves  15 ,  17  will move clockwise, and the rear layer  29  will be lifted a small distance, causing the loop  67  in the rear layer to move upwards within interior space  55  of bar  7  with ballast rod  69 . The small distance can be the vertical height of a stripe  35 ,  37  of the rear layer  29 , thereby causing the opaque stripes  31 ,  35  of both layers  27 ,  29  to align or the opaque stripes  35  of the rear layer  29  to align with the translucent stripes  33  of the front layer. Continued clockwise rotation of the roller  3  will further lift the loop  67  and ballast rod  69  into abutment with the front and rear walls  47 ,  49  of the bar  7 , near the bottom slit  53 . If such clockwise rotation is continued, the front and rear layers  27 ,  29  of the shade material  5  will be wound about the roller  3 , thereby lifting the bar  7  upwardly. Thereafter, counter clock wise rotation will move the front and rear top grooves counter clockwise, causing the shade material to be unwound and the bar to be lowered. When the shade material is unwound and the counter clockwise rotation continues, the rear layer  29  will move again relative to the front layer  27 . Continued counter clockwise rotation after the ballast rod  69  has reached its lowest point will again cause the shade material to be wound around the roller and the bar to be lifted. 
         [0025]    The depth of the interior space  55  of the bar  7  is preferably at least twice the height of a stripe  31 ,  33 ,  35 ,  37  of the shade material  5 . This ensures that there is enough space for the rear layer  29  to move relative to the front layer  27  between the closed position of the shade  1  when the opaque stripes  31 ,  35  of one layer are aligned with the translucent stripes  33 ,  37  of the opposite layer and the open position of the shade when the opaque stripes of both layers are aligned. 
         [0026]      FIGS. 3A-3D  show the assembly of the top portion  39 ,  41  of either the front or rear layer  27 ,  29  of a woven shade material  5  to the front or rear, top attachment member  23 ,  25  and then to the front or rear top groove  15 ,  17  of the roller  3 . The assembly will be explained using the front layer  27  and the front top attachment member  23  as an example, but it is identical for the rear layer  29 . In  FIG. 3A  the front layer  27  and front top attachment member are ready to be assembled, in  FIG. 3B  they are in a first stage of assembly, in  FIG. 3C  they are completely assembled and ready for insertion into the front to groove  15 , and in  FIG. 3D  the front top attachment member  23  with the front layer  27  are in the front top groove  15 . 
         [0027]    As shown in  FIG. 3A , it is preferred that the top-most translucent stripe  33 A in the top portion  39  of the front layer  27  is an open-structured stripe  71  which includes top and bottom, continuous, longitudinally-extending border lines  73 ,  75  along neighboring top and bottom opaque stripes  31 A,  31  B with the border lines being perpendicular to open slots in the open structured stripe  71 . The top attachment member  23  has a left end  77 , a right end  79  and main body  81  in between. The main body  81  includes a plurality of alternating generally outwardly- or upwardly-extending peaks or protuberances  83  and generally inwardly-or downwardly-extending valleys or depressions  85  along its length. When the open-structured stripe  71  of the front layer  27  is lowered onto the top attachment member  23 , the peaks  83  extend through the open-structure of the stripe  71  and outwardly of the front layer. This is shown in  FIG. 3B . The front layer is then folded around the top attachment member to keep the peaks  83  extending through, and outwardly away, from the front layer. This is shown in  FIG. 3C . Thereby, the attachment member  23  can move within the slot of the open structured stripe  71  and abut against the top border line  73  of the open-structured stripe  71 , adjacent to the top opaque stripe  31 A. Since the top attachment member  23  abuts against the top opaque stripe  31 A, there is an automatic horizontal alignment of the front layer  27 . If necessary, the top border line  73  can be pulled into abutment with the top attachment member after the front layer  27 , with front top attachment member  23  is inserted into the front groove  15  of the roller  3  as shown in  FIG. 3D . Once the shade  1  is completely assembled and ballast rod  69  is inserted in hammock-like loop  67  of the rear layer  29  as shown in  FIG. 2 , the weight of the ballast rod will ensure alignment of the front and rear layers. 
         [0028]      FIG. 4A-4C  show the attachment of the front and rear layers  27 ,  29  of the shade material  5  to the bottom attachment member  65 . The bottom attachment member  65  is preferably identical to the front and rear top attachment members  23 ,  25 . Preferably, the bottom-most translucent stripes  33 B,  37 B of the bottom sections  61 ,  63  of the front and rear layers  27  and  29  are open-structured stripes  71 ″ and  71 ′″, respectively. As described above, each open structured stripe  71 ″,  71 ′″ includes top and bottom, continuous, longitudinally-extending border lines  73 ″,  75 ″ and  73 ′″,  75 ′″ along neighboring top and bottom opaque stripes  31 C,  31 D and  35 C,  35 D of the front and rear layers. The bottom attachment member  65  has a left end  77 ″, a right end  79 ″ and a main body  81 ″. The main body  81 ″ includes a plurality of alternating generally upwardly-extending peaks  83 ″ and downwardly-extending valleys  85 ″ along its length. Preferably, the bottom open-structured stripes  71 ″,  71 ′″ of the front and rear layers  27 ,  29  are aligned one on top of the other when they are lowered onto the bottom attachment member  65 . The peaks  83 ″ of the bottom attachment member  65  will then extend through the open-structured stripes  71 ″,  71 ′″ of both layers. This is shown in  FIG. 4B . The two layers can then be folded around the bottom attachment member  65  to keep the peaks  83 ″ of the bottom attachment member extending outwardly of the layers and extending away from the front layer  27  as shown in  FIG. 4C . The attachment member then abuts against the bottom closed border lines  75 ″,  75 ′″ of the open structured stripes  71 ″ and  71 ′″. 
         [0029]    The attachment members  23 ,  25 ,  65  are preferably in the shape of helically wound wires, such as helical springs (e.g., steel springs). Such helical windings can provide the needed peaks and valleys to the attachment members. However, other forms of attachment member can be used, so long as they have a plurality of alternating peaks and valleys along the length of the attachment member. 
         [0030]      FIG. 5  shows five alternative embodiments  123 ,  223 ,  323 ,  423 ,  523  of attachment members which are similar to the attachment member  23  of  FIGS. 3 and 4  and for which corresponding reference numerals (greater by 100, 200 or 300) are used below for describing the same parts or corresponding parts. 
         [0000]    In  FIG. 5A , an attachment member  123  is an elongated rod-like structure  181 , along the axis of which, wheel-like portions or peaks  183  of greater radius alternate with wheel-like portions or valleys  185  of smaller radius. In  FIGS. 5B and 5C , comb-like attachment members  223 ,  323  each have an elongated body  281 ,  381  with teeth or peaks  283 ,  383  alternating with openings or valleys  285 ,  385 . In  FIGS. 5D and 5E , comb-like attachment members  423 ,  523  each have an elongated body  481 ,  581  with a pair of teeth or peaks  483 ,  583  alternating with openings or valleys  485 ,  585 . In  FIG. 5D , each peak  483  is a substantially round disk, and in  FIG. 5E , each peak  583  is wedge-shaped. 
         [0031]    The top and bottom open-structured stripes  71 ,  71 ″ and  71 ′″ of the front and rear layers  27 ,  29  of the sheet material  5  can be any type of open-structured material. It is preferred that each stripe  71 ,  71 ″ and  71 ′″ includes a plurality of vertically-extending bridging members  87  between its top and bottom border lines  73 ,  73 ″,  73 ′″,  75 ,  75 ″,  75 ′″. These bridging members  87  are preferably distributed along the longitudinal length of each open-structured stripe. The bridging members can be formed by cutting away material from the front and rear layers  27 ,  29  in their top-most and bottom-most translucent stripes. When the front and rear layers are assembled with the attachment members  23 ,  25 ,  65 ,  123 ,  223 ,  323 ,  423 ,  523  each peak  83 ,  183 ,  283 ,  383 ,  483 ,  583  of an attachment member extends through an open-structured stripe  71 ,  71 ″,  71 ′″ between, and outwardly of, a pair of adjacent bridging members  87  of the layers. Preferably, the double-layer fabric shade material  5  is woven with its open-structured stripes being formed by omitting warp or weft threads of the fabric, thereby forming the bridging members  87  as weft or warp threads. 
         [0032]    It is not necessary that the number of peaks  83 ,  183 ,  283 ,  383 ,  483 ,  583  on the attachment members  23 ,  25 ,  65 ,  123 ,  223 ,  383 ,  483 ,  583  and the number of bridging members  87  in the open-structured stripes  71 ,  71 ″ and  71 ′″ are equal. For a minimal alignment of the shade material  5  with the roller  3 , only about two peaks on each attachment member are needed. See  FIGS. 5D and 5E . The longitudinal spacing between adjacent bridging members  87  is not considered critical, so long as at least two peaks extend between adjacent pairs of bridging members. 
         [0033]      FIG. 6  shows an alternative embodiment of a layer  627  of a two-layer shade material  605  of the invention which is similar to the front layer  27  of the shade material  5   FIGS. 3 and 4  and for which corresponding reference numerals (greater by  600 ) are used below for describing the same parts or corresponding parts. 
         [0034]    Shown in  FIGS. 6A-6C , the layer  627  of the two-layer shade material  605  is a non-woven material. Which can be a non-woven fabric but can also be a plastic sheet material or the like. A plurality of longitudinally-adjacent open-structured stripes  671  are cut into the top-most translucent stripe  633 A in the top portion  639  of the layer  627  and bridging members  687  are left between the open-structured stripes  671 . Each open-structured stripe  671  includes top and bottom, closed longitudinally-extending border lines  673 ,  675  along neighboring top and bottom opaque stripes  631 A,  631 B.  FIG. 6A  shows the layer  627  and a front attachment member  423  of  FIG. 5D  prior to being assembled.  FIG. 6B  shows the layer  627  positioned over the front attachment member  423  with its peaks  483  directly underneath the open-structured stripes  671  of the layer.  FIG. 6C  shows the peaks  483  of the front attachment member  423  inserted into the open-structured stripes  671  of the layer  627 , between its bridging members  687  and the layer then folded around the attachment member, with the peaks  483  outside of, and extending away from the layer, so that the attachment member can then be inserted into the front groove  15  of the roller  3  of the shade  1 . 
         [0035]    In  FIG. 6 , the bridging member  687  are shown as relatively wide, and the spacings between them are relatively narrow. However, this is not necessary. Likewise, the attachment member  423  is shown with two peaks  483 , but it could have more peaks. 
         [0036]    This invention is, of course, not limited to the above-described embodiments which may be modified without departing from the scope of the invention or sacrificing all of its advantages. In this regard, the terms in the foregoing description and the following claims, such as “longitudinal”, “vertical”, “horizontal”, “top”, “bottom”, “radial”, “clockwise”, “counter-clockwise”, “right” and “left”, have been used only as relative terms to describe the relationships of the various elements of this invention for architectural coverings. 
         [0037]    For example, the layers of the shade material  5  of the roller shade  1  can be fabric, preferably a woven or knit fabric (as shown in  FIGS. 3 and 4 ), or a non-woven fabric or perforated plastic sheet (as shown in  FIG. 6 ). However, with a non-woven fabric, separate border lines  673 ,  675  are preferably provided, for example by providing a line of adhesive or an adhesively attached reinforcing strip along the top and bottom borders of the open-structured stripes  671 . 
         [0038]    Moreover, the roller  3  can be at the bottom of the shade  1  and the bar  7  can be at the top of the shade.

Summary:
A system for attaching a shade material to a roller having recesses in its surface includes inserting portions of the shade material into an associated elongated recess and retaining the material in the recess with an attachment member having peaks and valleys along its length for intermittent engagement with the material within the recess.