Patent Publication Number: US-2009236050-A1

Title: Window covering

Description:
FIELD OF THE INVENTION 
     The invention relates to window coverings. More specifically, the invention relates to adjustable window coverings having sheets with different light transmitting properties. 
     BACKGROUND OF THE INVENTION 
     There exist many types of window coverings. Window coverings are used for a variety of purposes, such as privacy or shade. One known type of window covering is a roller blind which typically includes an opaque or translucent flexible sheet of material. Such roller blinds only permit the user to permit all the light to pass through (by raising the blind) or to cover the window with the flexible sheet, thereby reducing or eliminating the transmission of light through the window. 
     SUMMARY OF THE INVENTION 
     The embodiments described herein provide in one aspect a window covering for a window having a frame. The window covering comprises: 
     a first roller and a spaced-apart second roller, where the first and second rollers are rotatably mounted to the frame; 
     a first sheet connected to the first roller and a second sheet connected to the second roller, where each of the first and second sheets comprises a pair of opposing side edges, a trailing edge and a leading edge; the trailing edge being secured to the corresponding roller; 
     wherein first and second sheets are each movable between a stowed position and a deployed position, wherein the first and second sheets are coiled around the corresponding roller in the stowed position, wherein the leading edge is extended away from the corresponding roller in the deployed position; 
     wherein the first and second rollers are each adapted to bias the corresponding sheet in the stowed position; 
     wherein the leading edge of the first sheet and the leading edge of the second sheet are adapted to make a removable connection therebetween to maintain the first and second sheets in the deployed position; 
     wherein at least a portion of the first sheet is adapted to permit more light to pass therethrough than the second sheet. 
     Further aspects and advantages of the embodiments described herein will appear from the following description taken together with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the embodiments described herein and to show more clearly how they may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings which show at least one exemplary embodiment, and in which: 
         FIG. 1  is an exploded perspective view of a first embodiment of a window covering according to the present invention; 
         FIG. 2  is an exploded perspective view of a second embodiment of a window covering according to the present invention; 
         FIG. 3 . is a perspective view of the second embodiment showing two different types of flexible sheets; 
         FIG. 4 . is a perspective view of the second embodiment showing one of the sheets covering the entire window; and 
         FIG. 5 . is a perspective view of the second embodiment showing yet another different set of two sheets. 
     
    
    
     It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION OF THE INVENTION 
     It will be appreciated that numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Furthermore, this description is not to be considered as limiting the scope of the embodiments described herein in any way, but rather as merely describing the implementation of the various embodiments described herein. 
       FIG. 1  shows a window covering  10  according to an embodiment of the present invention. The window covering  10  includes a first preferably flexible sheet  30 , rolled onto a first roller  34  that is mounted to a window frame  20  (shown in  FIG. 3 ) by mounts  80 ,  90  connected to opposing ends of the first roller  34 . The first roller  34  is adapted to bias the first flexible sheet  30  into a stowed position where the first flexible sheet  30  is coiled around the first roller  34 . The leading edge  36  of the first flexible sheet  30  may be extended away from the first roller  34  to bring the first flexible sheet  30  into a deployed position. A second preferably flexible sheet  50  is likewise connected to a second roller  54  that is also mounted to the frame (not shown) using mounts  81 ,  91  (preferably identical to mounts  80 ,  90 ). The second roller  54  is mounted in the window at a distance spaced apart from the first roller  34 . Preferably, the first and second rollers  34 ,  54  are located at opposing ends of the window. 
     The second roller  54  is adapted to bias the second flexible sheet  50  into a stowed position where the second flexible sheet  50  is coiled around the second roller  54 . Likewise, the leading edge  56  of the second flexible sheet  50  may be extended away from the second roller  54  to bring the second flexible sheet  50  into a deployed position. Further, the leading edge  36  of the first flexible sheet  30  and the leading edge  56  of the second flexible sheet  50  are adapted to make a removable connection therebetween, holding the first flexible sheet  30  and the second flexible sheet  50  in the deployed position. 
     The first flexible sheet  30  and second flexible sheet  50  have different light transmitting properties. The first flexible sheet  30  and the second flexible sheet  50  may each be composed of a plastic material or fabric and may exhibit any combination of transparency and translucency, from completely transparent and translucent to completely opaque. The first flexible sheet  30  and the second flexible sheet  50  may each comprise more than one type of material with more than one set of light transmitting properties. 
     As used in this application, translucency refers to the amount of light allowed to pass through so that a high degree of translucency refers to allowing a large fraction of incoming light to pass through the flexible sheet. As used in this application, transparency refers to the amount of distortion of light as it passes through a flexible sheet so that a high degree of transparency refers to a low degree of distortion: i.e. the user can see clearly through the sheet. 
     For example, as shown in  FIG. 3 , the first sheet  30  may be composed of an opaque material, such as fabric, which blocks light and provides privacy. The second sheet  50  is composed of alternating horizontal strips of an opaque material  150  (preferably identical to the material in the first sheet  30 ), and a transparent plastic material  152 . This configuration of second sheet  50  reduces the light passing through the window and provides some privacy while permitting the user to see out the window. 
     In addition, the first roller  34 , the first sheet  30 , the second roller  54  and the second flexible sheet  50  may be dimensioned so that when the leading edge  36  of the first sheet  30  is connected to the leading edge  56  of the second flexible sheet  50 , substantially all of the window between the first roller  34  and the second roller  54  is covered. 
     Further, the first roller  34  and the first sheet  30  may be dimensioned so that the first sheet  30 , when fully unrolled, is capable of covering substantially the entirety of the window. The second roller  54  and the second sheet  50  may be dimensioned so that the second flexible sheet  50 , when fully unrolled, is capable of covering substantially the entirety of the window. Alternatively, the first roller  34 , the first sheet  30 , the second roller  54  and the second sheet  50  may be dimensioned so that both the first sheet  30  and the second sheet  50  are capable of covering substantially the entirety of the window alone. In this embodiment, the leading edge  36  of the first sheet  30  and the leading edge  56  of the second sheet  50  may be drawn together and connected so that the first sheet  30  together with the second sheet  50  covers substantially all of the window between the first roller  34  and the second roller  54 . Additionally, when both the first sheet  30  and the second sheet  50  are capable of covering substantially all of the window between the rollers alone, the user may position the connecting point anywhere between the first roller  34  and the second roller  54  so as to permit the user to set the proportion of the window between the rollers being covered by the first sheet  30  and the second sheet  50 . 
     Referring again to  FIG. 1 , the first roller  34  and the second roller  54  are rotatably mounted to the frame  20 . The operation of the first roller  34  will now be described. Preferably, the configuration of the second roller  54  is identical to the first roller  34 . Specifically, parts  80 ,  82 ,  84 ,  90 ,  92 ,  94 ,  96 ,  98  and  100  associated with the first roller  34  are equivalent to parts  81 ,  83 ,  85 ,  91 ,  93 ,  95 ,  97 ,  99  and  101  associated with the second roller  54 . 
     First mount  80  is secured to the window frame  20  in any suitable fashion. Mount  80  includes a first spindle  82  projecting downwardly. Collar  84  fits over first spindle  82  and is free to rotate about first spindle  82 . A first end  33  of first roller  34  fits snuggly over collar  84 . Second mount  90  is secured to the frame  20  and includes a second spindle  92  projecting upwardly. Collar  94  fits over second spindle  92  and is free to rotate about spindle  92 . A second end of first roller  34  fits snuggly over collar  94 . 
     The first roller  34  is adapted to bias the first flexible  30  into the stowed position where the first sheet  30  is coiled around the first roller  34 . The second roller  54  is adapted to bias the second sheet  50  into the stowed position where the second sheet  50  is coiled around the second roller  54 . Preferably, both rollers  34 ,  54  use a spring  96  to bias the first and second sheets  34 ,  50  into the stowed position. 
     Referring to  FIG. 1 , the spring  96  is connected in any suitable fashion to the spindle  92  in such a way so as not to interfere with the rotation of collar  94  about the spindle  92 . For example, the spindle  92  may be constructed so as to extend through the collar  94  so that the spring  96  may be connected, using for example a press fit, to the extended portion of the spindle  92 . 
     The spring  96  extends into the first roller  34  and is connected to the inside surface of the first roller in any suitable fashion. For example, a plug  98  may be provided that fits snuggly inside the first roller  34  while the spring  96  is connected to the plug  98 , for example using a press fit. As an alternative example, the plug  98  may interface with a groove or ridge on the inside of the first roller  34 . As the first sheet  30  is drawn out into the deployed position, the tension in the spring  96  increases and imparts a rotational force on the first roller  34  such that it pulls the first sheet  30  toward the stowed position. Optionally, the spring  96  may be pre-tensioned in order to increase the force on the first sheet  30 . In addition, a spring tube  100 , of nominally greater diameter than the spring  96 , may also be provided in order to prevent the spring from flexing in a radial direction. 
     The first roller  34  may be contained within a first cassette  32  and the second roller  54  may be contained within a second cassette  52 . The first cassette  32  and the second cassette  52  preferably serve to provide a clean and finished appearance to the window covering  10  according to the first embodiment. The cassettes may also include slits  37  to prevent the first flexible sheet  30  and the second flexible sheet  50  from being completely pulled into the stowed position, thus keeping the leading edges  36 ,  56  accessible for the user&#39;s grasp. 
     The leading edge  36  of the first sheet  30  and the leading edge  56  of the second sheet  50  are adapted to make a removable connection therebetween, holding the first flexible sheet  30  and the second flexible sheet  50  in the deployed position. Any suitable manner of making a removable connection may be used, such as for example, buttons, snaps, laces, clamps, hook and loop fasteners or magnets. 
     Preferably, a first header  38  connected to the leading edge  36  of the first sheet  30  and a second header  58  connected to the leading edge  56  of the second sheet  50  are provided. Preferably, each header includes a magnetic strip  70  of opposing polarity (or one magnetic strip and another metal strip which is attracted to a magnet) so that the headers are attracted to each other. This permits a removable connection to be formed between the first header  38  and the second header  58  when they are brought in close proximity. In the embodiment shown in  FIG. 1 , the magnetic strips  70  fit into a slot  72  on the ends of the headers. End caps  74  may be mounted on the ends of the headers  38 ,  58  to keep the magnetic strip in place and protect the user from rough edges. A handle  76  is connected to each header  38 ,  58  to allow the user to more easily grasp the headers  38 ,  58 . 
       FIG. 2  shows a second embodiment  11  of the window covering. Similar parts to those shown in  FIG. 1  are assigned similar part numbers and will not be further described. This embodiment further comprises upper and lower guide rails  110 ,  112 , wheels  114 , a lock  120  and decelerators  130 . The guide rails  110 ,  112  guide the flexible sheets  30 ,  50 . The wheels  114  allow the first header  38  to move more easily in the guide rails. The lock  120  locks the flexible sheets into a desired configuration. The decelerators  130  attenuate the force of the springs  96 ,  97 . 
     The upper and lower guide rails  110 ,  112  guide the first flexible sheet  30  and the second flexible sheet  50  in transitioning from the stowed position to the deployed position. The guide rails also guide the first header  38  and the second header  58  when being connected. The guide rails  110 ,  112  may have a substantially U-shaped cross-section which receives the headers  38 ,  58  and the flexible sheets  30 ,  50 . The guide rails  110 ,  112  may be secured to the mounts  80 ,  81 ,  90 ,  91  or may be mounted directly to the frame  20  in any suitable fashion, such as using fasteners. 
     The window covering  11  according to the second embodiment may include wheels  114  connected to both ends of the headers  38 ,  58 . The wheels  114  engage with the guide rails  110 ,  112  in any suitable manner in order to ease the movement of the first header  38 , the first flexible sheet  30 , the second header  58  and the second sheet  50  while transitioning from the stowed position to the deployed position. 
     The window covering  11  may also comprise a lock  120 , connected to the first header  38 , for locking the first flexible sheet  30  into place. Preferably, the lock  120  includes an actuator, such as button  122 , which when operated by a user, causes a rod  124  to project vertically through a hole  126  in the end cap  74  to engage with a stop  128  that is secured to the upper guide rail  110 . The stop engages with the rod  124  to lock the first sheet  30  into place. The second sheet  50  may also be locked into place simultaneously when it is secured to the first flexible sheet  30  in the manner described above. 
     In an alternative embodiment (not shown), the lock  120  may further comprise a second rod extending vertically downward through a hole in the end cap  74  to engage with a stop that is secured to the bottom guide rail  112 . The second rod may be extended using the same button  122  as the rod  124  or using a different actuator. 
     In another alternative embodiment (not shown), the window covering  11  may further comprise a second lock connected to the second header  58  for locking the second sheet  50  into place. In this embodiment, both sheets may be locked into place independently, possibly leaving a gap of uncovered window between the leading edge  36  of the first flexible sheet  30  and the leading edge  56  of the second sheet  50 . 
     Referring again to  FIG. 2 , the window covering  11  according to the second embodiment may also comprise decelerators  130  coupled to the first roller and the second roller  34 ,  54 . The decelerator  130  is used to attenuate the force applied to each of the rollers  34 ,  54  by the spring  96  so as to reduce the acceleration of the sheets  30 ,  50  from the deployed position back to the stowed position. The further the leading edge of the each sheet is drawn from the corresponding roller, the greater the return force applied by the spring  96 . This force can be significant. If a user accidentally releases the sheet when it is in the deployed position, the sheet may snap back with a force that could create a risk of injury or at least startle the user. The decelerator  130  attenuates the force applied to each roller in order to slow the return of each sheet to the stowed position. 
     One end of the decelerator  130  is connected to the spindle  82  so as not to interfere with the collar&#39;s  84  rotation about the spindle  82 , for example by extending the spindle  82  through the collar  84 . The other end of the decelerator  130  fits snuggly inside the first roller  34 , for example using a press fit. Alternatively, the decelerator  130  may interface with a groove or ridge on the inside of each roller. 
       FIG. 3  shows the window covering  11  according to the embodiment of  FIG. 2  in a deployed position inside the frame  20 , where the first sheet  30  and the second sheet  50  each cover substantially half of the window. 
       FIG. 4  shows the window covering  11  according to the embodiment of  FIG. 2  inside a frame  20  in a deployed position, where the first sheet  30  covers substantially the entirety of the window. 
       FIG. 5  shows the window covering  11  according to the embodiment of  FIG. 2  inside a frame  20  in the deployed position, where the first sheet  30  covers about 25% of the window and the second sheet  50  covers about 75% of the window. The first sheet  30  shown in  FIG. 5  includes alternating vertical strips of an opaque material  160  and a transparent material  162 . The second sheet  50  shown in  FIG. 5  is an opaque material. 
     As will be apparent to one skilled in the art, the proportion of the window that is covered by either the first sheet  30  or the second sheet  50  is arbitrary and may be adjusted by the user to suit his/her desires. Since both flexible sheets are dimensioned so that they are capable of covering the entire window alone, any proportional coverage desired is achievable: ranging from substantially complete coverage by the first sheet  30  to substantially complete coverage by the flexible sheet  50  and any combination therebetween. 
     In yet another alternative embodiment, the window covering  10  according to the embodiment of  FIG. 1  or the window covering  11  according to the embodiment of  FIG. 2  may be oriented vertically in the window such that the first and second sheets  30 ,  50  are unrolled from the top and bottom sides of the window, respectively. Otherwise, the window covering according to this embodiment operates in the same manner as described above. 
     While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.