Patent Publication Number: US-7222656-B2

Title: Method of making a window covering

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. patent application Ser. No. 10/378,829, filed Mar. 5, 2003 now U.S. Pat. No. 6,854,504, and published on Jun. 3, 2004, as US 2004/0103994 A) and U.S. patent application Ser. No. 10/460,478, filed Jun. 13, 2003 now U.S. Pat. No. 7,195,050. 

   BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The invention relates to methods of making window coverings of the type having a plurality of spaced apart slats, as in a venetian blind. 
   2. Description of the Related Art 
   Venetian type blinds are well-known and popular window coverings in which a plurality of slats are hung on ladders that extend between the headrail and a bottomrail. The ladders have two parallel rails connected by a series of equally spaced rungs on which the slats rest. The slats usually are metal, wood or plastic, but fabric slats have also been used. The rungs of the ladders in conventional venetian type blinds are not readily seen when the slats are in a horizontal open position. However, when the slats are tilted the rungs may be visible from one side or the other of the blind depending upon how the slats were tilted and whether or not they are obscured by the rails of the ladder. 
   U.S. Pat. No. 2,374,591 to Dunn discloses a venetian blind having metal slats. The longitudinal edges of the slats are rolled to form a U-shape. Notches are cut in the rolled edge to receive T-shaped clips crimped to tilt cords. 
   Sugiura in U.S. Pat. No. 1,851,782 discloses a venetian blind in which the slats are tubes of fabric stretched between two parallel rods. Spaced apart strips of material or tapes are secured to the longitudinal edges of the fabric slat. From the figures it appears that the tapes are sewn or glued to the slats. Movement of the tapes tilts the slats. 
   U.S. Pat. No. 6,105,657 to Zorbas discloses a fabric blind slat and a fabric Venetian blind assembly. The fabric blind slat includes an elongated strip of fabric. The strip of fabric has at least one longitudinally extending pocket on a longitudinal edge into which a relatively rigid support member is insertable. This design of fabric blind slat has drawbacks. Tilting the fabric blind slat moves the fabric body of the fabric blind slat in a manner that causes the upper part of the fabric blind slat to compress the lower part of the fabric blind slat, resulting in a wrinkle. In other words, supporting or stretching means must be provided so that the fabric body of the fabric blind slat can be maintained smooth under any operation status. 
   Another type of venetian type blind has a fabric sheet or fringe attached to one edge of each slat. This sheet or fringe extends to or below the adjacent slat. An example of this type of blind is disclosed in U.S. Pat. No. 3,388,490 to Kandel. In these blinds, the slats are supported on conventional ladders having parallel rails connected by a series of rungs of which the slats rest. 
   In United States published application US 2004/0103994 A1, I disclose a venetian type blind having fabric slats that does not utilize conventional ladders with rungs. Instead, I provide braided cords with spaced apart loops or clips that engage rods within the longitudinal pocket along opposite edges of each fabric slat. Consequently, the blind has no ladder rungs. Another advantage of this type of blind is that the blind can be readily assembled in accordance with the method here disclosed. That method can be used for blinds containing slats having pockets along opposite longitudinal edges, as well as blinds having such slats, and a screening flap attached to one or both longitudinal edges. 
   SUMMARY OF THE INVENTION 
   In a method of making a window covering material a plurality of slats preferably made of fabric or plastic film, are provided. Each slat has opposite longitudinal edges and each longitudinal edge has a pocket with at least one transverse slot. There is one rail for each transverse slot in any selected slat. Each rail has a loop extending from the rail which loop is sized to fit within a selected transverse slot in a slat pocket. The loop may be woven into the rail or clip affixed to the rail. The fabric slats and the rails are positioned so that ultimately there is one loop in each transverse slot. A rod is inserted into each pocket of the fabric slat so that the rod passes through the loop in each transverse slot of that pocket. If desired, one may attach a light screening flap to one or both longitudinal edges of the slats. 
   The rails extend between a headrail and a bottomrail. One end of the rails is connected to a tilt mechanism in the headrail or the bottomrail. The rails may be attached to the headrail and bottomrail before or after being connected to the slats. 
   Other objects and advantages of the present method will become apparent from a description of the present preferred embodiments thereof as illustrated in the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a blind that can be made using a first preferred embodiment of the method for making a window covering. 
       FIG. 2  is an exploded view of a portion of the blind shown in  FIG. 1  from which the first preferred embodiment of the method can be best understood. 
       FIG. 3  is an enlarged view of the portion of the blind that is within circle A in  FIG. 1 . 
       FIG. 4  is a side view of the blind shown in  FIG. 1  with the blind in a fully lowered, open position. 
       FIG. 5  is a side view similar to  FIG. 4  with the blind in a fully lowered, partially closed position. 
       FIG. 6  is a perspective view of a second blind that can be made in accordance with the present method. 
       FIG. 7  is an enlarged exploded view similar to  FIG. 2  of a portion of the blind shown in  FIG. 6 . 
       FIG. 8  is an exploded view of a third window covering that can be made with the present method. 
       FIG. 9  is a perspective assembly view of the third window covering shown in  FIG. 8 . 
       FIG. 10  is a side view of the window covering shown in  FIGS. 8 and 9  in a fully lowered open position. 
       FIG. 11  is a side view similar to  FIG. 10  showing the blind in a partially closed position. 
       FIG. 12  is a side view of the blind shown in  FIGS. 8 through 11  in a fully raised position. 
       FIG. 13  is an exploded assembly view of a fourth window blind that can be made using the present method. 
       FIG. 14  is a side view of the blind shown in  FIG. 13  in a fully lowered, open position.  4 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 through 5 , a first venetian type blind assembly  100  having window covering material made in accordance with the present invention has a headrail  111  and a bottomrail  112  between which the window covering material is attached. The window covering material is comprised of a plurality of equally spaced fabric blind slats  114  which are held by rails  113 . Each fabric blind slat  114  includes an elongated strip of fabric  141  and two rod members  142 . The strip of fabric  141  is a piece of fabric capable of diffusing or reflecting light. The fabric may be opaque material or material having a weave through which light may pass. Each slat has two pockets  143  longitudinally extended along two opposite long sides thereof. The pockets  143  can be formed by folding the edges of the strip of fabric  141  and securing the fold by stitching, adhesive bonding or welding. Each pocket  143  has transversely extended slots  144 . The rod members  142  are rigid or semirigid metal or plastic members, having an outer diameter smaller than the inner diameter of the pockets  143 . The length of the rod members  142  is substantially equal to the longitudinal depth of the pockets  143 . When inserted into the pockets  143 , the rod members  142  can be slightly rotated in the pockets  143 . 
   As can be seen most clearly in  FIGS. 2 and 3 , each rail  113  has a plurality of spaced apart loops  131  which fit into a transverse slot  144  in the longitudinal pocket  143  of a fabric slat, the loop may be rigid plastic or metal structure attached to the rail. However, in a preferred rail  223 , shown in  FIG. 7 , the loop  231  is a thread or threads, the loops  231  being formed on the rail  223  as the rail is braided or otherwise manufactured. 
   To make the window covering shown in  FIGS. 1  though  5  one obtains or makes a plurality of fabric slats  141  having longitudinal pockets  143 . In this blind assembly two transverse cuts or slots  144  are provided in each of the longitudinal pockets  143  such that for each slot in one pocket there is an aligned slot in the opposite pocket as shown in  FIGS. 2 and 3 . Next one positions the rails  113  so that there is one loop  131  from one of the rails  113  in each slot  144 . When the loops are so positioned a rod is inserted into each pocket  143  so as to pass through the loops that are in the slots of that pocket. If a pocket has more than one slot one could place a loop in the first slot, advance the rod through the pocket and loop, insert a second loop in the second slot, advance the rod through that loop and continue the process until the rod is fully within the pocket. If desired one could first attach a rail or rails to one longitudinal edge of several slats and then connect the rails to the second longitudinal edge of the same slats. Alternatively, one could attach all the rails to one slat, then attach all the rails to the next slat and continue slat by slat until the window covering is complete. Other variations in the order of attaching rails to slats could be followed without departing from the present method. As another example, one could attach rails to the top slat and the bottom slat and then attach the intermediate slats. At some point one end of each rail is attached to the bottomrail  112  and the opposite end is attached to the headrail  111 . Typically, one end of each rail would be connected to tilt mechanism within the headrail or the bottomrail as shown in  FIGS. 4 and 5 . The order of attachment is not critical. Moreover, one could attach the rails to the bottomrail and headrail before or after attaching the fabric slats to those rails. 
   After the window covering material has been assembled the rod members  142  support the fabric blind slats  114  in a longitudinal direction, prohibiting the strip of fabric  141  of each fabric blind slat  114  from curving downwards and the braided rails  113  support the fabric slats  114  in transverse direction, keeping the fabric blind slats  114  smooth. 
   As in a conventional venetian blind movement of the rails will cause the fabric slats to move from an open position shown in  FIG. 4  to a partially closed position shown in  FIG. 5 , or fully closed position (not shown). Because the rod members  142  can be rotated relative to the loops  131  of the rails  113 , rotating the headrail  111  to tilt the fabric blind slats  114  causes the loops  131  to be turned relative to the rod members  142 , thereby preventing uneven tension between the rails  113  and the fabric blind slats  114 . 
   A second window blind that can be made with the present method is shown in  FIGS. 6 and 7 . That blind  200  has a headrail  221 , bottomrail  222  and a plurality of fabric blind slats  224  carried on three rails  223 . Each of the rails  223  has a plurality of equally vertically spaced loops  231  for fastening the rails  223  to the fabric blind slats  224 . 
   Each fabric blind slat  224  is composed of an elongated strip of fabric  241  and two rods  242 . The strip of fabric  241  has two pockets  243  longitudinally extended along two opposite long sides thereof. One of the two pocket  243  of each fabric blind slat  24  is provided with two transversely extended slots  244 , and the other pocket  243  of each fabric blind slat  24  is provided with one transversely extended slot  244 . The rod members  242  are inserted into the pockets  243 . Before insertion of the rods  242  into the pockets  243 , the loops  231  of the rails  223  are respectively inserted into the slots  244  of the pockets  243  of the fabric blind slats  224 , and then the rods  242  are respectively inserted into the pockets  243  and the loops  231 , enabling the rods  242  to be respectively secured with the pockets  243 . The rails  233  are attached to a headrail and bottomrail. Again, the order of attachment is not critical. 
   Referring to  FIGS. 8 through 11  a third window covering  10  which can be made in accordance with the present method is comprised of a headrail  12 , a bottomrail  14 , sets  16  of rails  17 ,  18 , a plurality of flexible slats  22 , a plurality of flexible light screening flaps  26 , two lift cords  32 , and a control unit  34 . The headrail  12  is a hollow frame bar transversely (horizontally) affixed to the top side of a window (not shown). The bottomrail  14  is a hollow frame bar arranged in parallel to and suspended from the headrail  12 . 
   Each set  16  is comprised of a front rail  17  and a rear rail  18  similar to rail  113  shown in  FIG. 2  or rail  223  shown in  FIG. 7 . The rails  17  and  18  each have a top end respectively inserted into the headrail  12  and a bottom end fixedly connected to the bottomrail  14 . According to this embodiment, the rails  17  and  18  are symmetrically provided at two sides. Depending upon the transverse width of the window, the combination window covering can be equipped with more sets of rails. The rails could be offset from one another as in the window covering of  FIG. 6 . 
   The slats  22  are narrow, elongated, rectangular members made of fabric of low penetrability to light, and arranged in parallel between the headrail  12  and the bottomrail  14  within the space defined between the front rails  17  and the rear rails  18 . Each slat  22  has two sleeves or pockets  23  respectively extended along the respective two opposite long sides. Two plastic ribs  24  are respectively inserted into the sleeves  23  and respectively connected to the front rails  17  and the rear rails  18 . The slats have two holes  25  for the passing of the lift cords  32 . The plastic ribs  24  support the flexible slat  22  to maintain its shape. As in the previous embodiment, the sleeves or pockets  23  have slots so that the respective loops of the rails  17  and  18  can encircle the plastic ribs  24 . 
   The flexible light screening flaps  26  of the slat units are rectangular pieces of thin layer of meshed fabric or film equal to the length and number of the flexible slats  22 , and preferably have a permeability to light relatively higher than the light permeability of the slats  22 . Each flap has one long side stitched to one long side of one flexible slat  22  and the other long side provided with a sleeve or pocket  27  and a rib  28  in the sleeve  27 . As illustrated in  FIG. 10 , the flexible light screening flaps  26  are respectively vertically suspended from the slats  22 . The width D 1  of the flexible light screening flaps  26  is slightly greater than the distance or pitch D 2  between two adjacent slats  22  (which corresponds to the distance between each two vertically spaced adjacent loops of each of the front and rear rails.) Therefore, when the flexible light screening flaps  26  are suspended from the slats  22 , the bottom side edges of each flexible light screening flap  26  is lower than the elevation of the front long side of the respective slat  22  below, i.e., the bottom side edge of each flexible light screening flap  26  covers the front edge of the next slat  22 . Therefore, the flexible light screening flaps  26  form a light screening face  29  on one side of the combination window covering  10 , as shown in  FIG. 9 . In the same way, flexible light screening flaps may be respectively fastened to the other long side of each of the flexible slats. Then there would be a light screening face on both sides of the combination window covering. 
   The control unit  34  comprises a lift cord mechanism operated by cords  35  and a tilt control mechanism operated by cord loop  36 . The lift control mechanism is to be operated by the user to lift or lower the bottomrail  14 , so as to further stack or extend the slats  22 . The tilt mechanism is adapted to control relative movement of the front ladder rails  17  and the rear ladder rails  18  vertically in opposite directions, so as to tilt the slats  22 . The control unit  34  is of the known art and can comprise two rod members (not shown) fastened rotatably with the inside of the headrail  12 , a pair of reels (not shown) respectively mounted on one rod member, a barrel for each pair of rails mounted on the second rod member, a lift-control operation cord set  35  and a tilt-control operation chain  36  respectively coupled to the rod members for operation by the user to rotate the rod members respectively. The top ends of the lift cords  32  are respectively fastened to the two reels on the second rod member. The front rails  17  and rear rails  18  of the sets  16  are respectively coupled to opposite sides of the barrels on the first rod member. Because the control unit is of the known art and not within the scope of the claims of the present invention, no further detailed description in this regard is necessary. 
   When the aforesaid combination window covering  10  is assembled, the slats  22  block the light or the sight between the outside of the room and the inside of the room. By means of operating the tilt control cords  36  of the control unit  34  to move the front rails  17  and the rear rails  18  in opposite directions, the slats  22  are tilted to regulate the light, as shown in  FIGS. 10 and 11 . 
   The flexible light screening flaps  26  are vertically suspended from the slats  22  at the front side. The ribs  28  of the flexible light screening flaps  26  support the front long side of each flexible flap  26  to stabilize and smoothen the suspension of those flaps forming the aforesaid light screening face  29 . The light screening face  29  screens and softens the light, producing a soft and pleasant atmosphere in the room. 
   When operating the lift control cords  35  of the control unit  34  to roll up the lift cords  32 , the bottomrail  14  is lifted, and the slats  22  are stacked onto one another from the bottom side toward the top side to the fully raised position shown in  FIG. 12 . When the slats  22  are stacked together, the flexible light screening flaps  26  are overlapped on one another in order as shown in  FIG. 12 . 
   In comparison with other conventional products having similar functions, the window covering material  10  shown in  FIGS. 8 through 12  has a simple structure and is easy to manufacture using the method here disclosed. Further, it is practical to have the slats and the light screening flaps made of the same fabric material, i.e., each light screening flap and the corresponding slat can be formed of one single piece of fabric sewn to form a flexible slat and an integrated light screening flap light. The portion of the single piece of fabric forming the slat may be coated with a layer of film or color paint. 
   As indicated above, the slats, as well as the light screening flaps of the combination window covering shown in  FIGS. 8 through 12 , are preferably made of fabric instead of conventional plastic or wooden material. Therefore, the combination window covering softens the light, producing a pleasant atmosphere in the house. 
     FIGS. 13 and 14  show a fourth blind  40  that can be constructed according to the method here disclosed. This embodiment is similar to the aforesaid third window blind  10  shown in  FIGS. 8 through 12  with the exception of the arrangement of flexible light screening flaps. According to this embodiment, flexible light screening flaps  44  of the slat units are respectively provided at the front and rear long sides of the flexible slats  42  of the slat units, forming a respective light screening face  45  at the front and rear sides of the flexible slats  42 . 
   In the embodiments shown in  FIGS. 8 through 14 , the light screening flaps typically will be sewn into the fabric slats before the slats are connected to the rails. However, one could: connect the light screening flaps to the fabric slats after the slats have been connected to the rails. In that event, the flaps may be attached to the slats with Velcro hook and loop fasteners or adhesive tape rather than being sewn into the fabric slats. 
   Although all of the window blinds shown in the drawings have fabric slats, the present method could be used with plastic, plastic film, metal, metal foil or wood slats that have pockets with slots along their longitudinal edges. Similarly, the light screening flaps could be a film rather than a fabric. The rails could be plastic, metal or wood rather than braided cord, particularly if plastic, metal or wood slats are used. Such a window covering would be more like a shutter than a venetian blind. 
   Although I have shown and described certain preferred methods of making window coverings it is to be distinctly understood that the invention is not limited thereto, but may be variously embodied within the scope of the following claims.